xref: /linux/fs/ntfs/attrib.c (revision 0c0b282d502b1fc5a67740ea1d88b90c042d5727)

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * NTFS attribute operations.
 *
 * Copyright (c) 2001-2012 Anton Altaparmakov and Tuxera Inc.
 * Copyright (c) 2002 Richard Russon
 * Copyright (c) 2025 LG Electronics Co., Ltd.
 *
 * Part of this file is based on code from the NTFS-3G.
 * and is copyrighted by the respective authors below:
 * Copyright (c) 2000-2010 Anton Altaparmakov
 * Copyright (c) 2002-2005 Richard Russon
 * Copyright (c) 2002-2008 Szabolcs Szakacsits
 * Copyright (c) 2004-2007 Yura Pakhuchiy
 * Copyright (c) 2007-2021 Jean-Pierre Andre
 * Copyright (c) 2010 Erik Larsson
 */

#include <linux/writeback.h>
#include <linux/iomap.h>

#include "attrib.h"
#include "attrlist.h"
#include "lcnalloc.h"
#include "debug.h"
#include "mft.h"
#include "ntfs.h"
#include "iomap.h"

__le16 AT_UNNAMED[] = { cpu_to_le16('\0') };

/*
 * Maximum size allowed for reading attributes by ntfs_attr_readall().
 * Extended attribute, reparse point are not expected to be larger than this size.
 */

#define NTFS_ATTR_READALL_MAX_SIZE	(64 * 1024)

/*
 * ntfs_map_runlist_nolock - map (a part of) a runlist of an ntfs inode
 * @ni:		ntfs inode for which to map (part of) a runlist
 * @vcn:	map runlist part containing this vcn
 * @ctx:	active attribute search context if present or NULL if not
 *
 * Map the part of a runlist containing the @vcn of the ntfs inode @ni.
 *
 * If @ctx is specified, it is an active search context of @ni and its base mft
 * record.  This is needed when ntfs_map_runlist_nolock() encounters unmapped
 * runlist fragments and allows their mapping.  If you do not have the mft
 * record mapped, you can specify @ctx as NULL and ntfs_map_runlist_nolock()
 * will perform the necessary mapping and unmapping.
 *
 * Note, ntfs_map_runlist_nolock() saves the state of @ctx on entry and
 * restores it before returning.  Thus, @ctx will be left pointing to the same
 * attribute on return as on entry.  However, the actual pointers in @ctx may
 * point to different memory locations on return, so you must remember to reset
 * any cached pointers from the @ctx, i.e. after the call to
 * ntfs_map_runlist_nolock(), you will probably want to do:
 *	m = ctx->mrec;
 *	a = ctx->attr;
 * Assuming you cache ctx->attr in a variable @a of type struct attr_record *
 * and that you cache ctx->mrec in a variable @m of type struct mft_record *.
 *
 * Return 0 on success and -errno on error.  There is one special error code
 * which is not an error as such.  This is -ENOENT.  It means that @vcn is out
 * of bounds of the runlist.
 *
 * Note the runlist can be NULL after this function returns if @vcn is zero and
 * the attribute has zero allocated size, i.e. there simply is no runlist.
 *
 * WARNING: If @ctx is supplied, regardless of whether success or failure is
 *	    returned, you need to check IS_ERR(@ctx->mrec) and if 'true' the @ctx
 *	    is no longer valid, i.e. you need to either call
 *	    ntfs_attr_reinit_search_ctx() or ntfs_attr_put_search_ctx() on it.
 *	    In that case PTR_ERR(@ctx->mrec) will give you the error code for
 *	    why the mapping of the old inode failed.
 *
 * Locking: - The runlist described by @ni must be locked for writing on entry
 *	      and is locked on return.  Note the runlist will be modified.
 *	    - If @ctx is NULL, the base mft record of @ni must not be mapped on
 *	      entry and it will be left unmapped on return.
 *	    - If @ctx is not NULL, the base mft record must be mapped on entry
 *	      and it will be left mapped on return.
 */
int ntfs_map_runlist_nolock(struct ntfs_inode *ni, s64 vcn, struct ntfs_attr_search_ctx *ctx)
{
	s64 end_vcn;
	unsigned long flags;
	struct ntfs_inode *base_ni;
	struct mft_record *m;
	struct attr_record *a;
	struct runlist_element *rl;
	struct folio *put_this_folio = NULL;
	int err = 0;
	bool ctx_is_temporary = false, ctx_needs_reset = false;
	struct ntfs_attr_search_ctx old_ctx = { NULL, };
	size_t new_rl_count;

	ntfs_debug("Mapping runlist part containing vcn 0x%llx.",
			(unsigned long long)vcn);
	if (!NInoAttr(ni))
		base_ni = ni;
	else
		base_ni = ni->ext.base_ntfs_ino;
	if (!ctx) {
		ctx_is_temporary = ctx_needs_reset = true;
		m = map_mft_record(base_ni);
		if (IS_ERR(m))
			return PTR_ERR(m);
		ctx = ntfs_attr_get_search_ctx(base_ni, m);
		if (unlikely(!ctx)) {
			err = -ENOMEM;
			goto err_out;
		}
	} else {
		s64 allocated_size_vcn;

		WARN_ON(IS_ERR(ctx->mrec));
		a = ctx->attr;
		if (!a->non_resident) {
			err = -EIO;
			goto err_out;
		}
		end_vcn = le64_to_cpu(a->data.non_resident.highest_vcn);
		read_lock_irqsave(&ni->size_lock, flags);
		allocated_size_vcn =
			ntfs_bytes_to_cluster(ni->vol, ni->allocated_size);
		read_unlock_irqrestore(&ni->size_lock, flags);
		if (!a->data.non_resident.lowest_vcn && end_vcn <= 0)
			end_vcn = allocated_size_vcn - 1;
		/*
		 * If we already have the attribute extent containing @vcn in
		 * @ctx, no need to look it up again.  We slightly cheat in
		 * that if vcn exceeds the allocated size, we will refuse to
		 * map the runlist below, so there is definitely no need to get
		 * the right attribute extent.
		 */
		if (vcn >= allocated_size_vcn || (a->type == ni->type &&
				a->name_length == ni->name_len &&
				!memcmp((u8 *)a + le16_to_cpu(a->name_offset),
				ni->name, ni->name_len) &&
				le64_to_cpu(a->data.non_resident.lowest_vcn)
				<= vcn && end_vcn >= vcn))
			ctx_needs_reset = false;
		else {
			/* Save the old search context. */
			old_ctx = *ctx;
			/*
			 * If the currently mapped (extent) inode is not the
			 * base inode we will unmap it when we reinitialize the
			 * search context which means we need to get a
			 * reference to the page containing the mapped mft
			 * record so we do not accidentally drop changes to the
			 * mft record when it has not been marked dirty yet.
			 */
			if (old_ctx.base_ntfs_ino && old_ctx.ntfs_ino !=
					old_ctx.base_ntfs_ino) {
				put_this_folio = old_ctx.ntfs_ino->folio;
				folio_get(put_this_folio);
			}
			/*
			 * Reinitialize the search context so we can lookup the
			 * needed attribute extent.
			 */
			ntfs_attr_reinit_search_ctx(ctx);
			ctx_needs_reset = true;
		}
	}
	if (ctx_needs_reset) {
		err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
				CASE_SENSITIVE, vcn, NULL, 0, ctx);
		if (unlikely(err)) {
			if (err == -ENOENT)
				err = -EIO;
			goto err_out;
		}
		WARN_ON(!ctx->attr->non_resident);
	}
	a = ctx->attr;
	/*
	 * Only decompress the mapping pairs if @vcn is inside it.  Otherwise
	 * we get into problems when we try to map an out of bounds vcn because
	 * we then try to map the already mapped runlist fragment and
	 * ntfs_mapping_pairs_decompress() fails.
	 */
	end_vcn = le64_to_cpu(a->data.non_resident.highest_vcn) + 1;
	if (unlikely(vcn && vcn >= end_vcn)) {
		err = -ENOENT;
		goto err_out;
	}
	rl = ntfs_mapping_pairs_decompress(ni->vol, a, &ni->runlist, &new_rl_count);
	if (IS_ERR(rl))
		err = PTR_ERR(rl);
	else {
		ni->runlist.rl = rl;
		ni->runlist.count = new_rl_count;
	}
err_out:
	if (ctx_is_temporary) {
		if (likely(ctx))
			ntfs_attr_put_search_ctx(ctx);
		unmap_mft_record(base_ni);
	} else if (ctx_needs_reset) {
		/*
		 * If there is no attribute list, restoring the search context
		 * is accomplished simply by copying the saved context back over
		 * the caller supplied context.  If there is an attribute list,
		 * things are more complicated as we need to deal with mapping
		 * of mft records and resulting potential changes in pointers.
		 */
		if (NInoAttrList(base_ni)) {
			/*
			 * If the currently mapped (extent) inode is not the
			 * one we had before, we need to unmap it and map the
			 * old one.
			 */
			if (ctx->ntfs_ino != old_ctx.ntfs_ino) {
				/*
				 * If the currently mapped inode is not the
				 * base inode, unmap it.
				 */
				if (ctx->base_ntfs_ino && ctx->ntfs_ino !=
						ctx->base_ntfs_ino) {
					unmap_extent_mft_record(ctx->ntfs_ino);
					ctx->mrec = ctx->base_mrec;
					WARN_ON(!ctx->mrec);
				}
				/*
				 * If the old mapped inode is not the base
				 * inode, map it.
				 */
				if (old_ctx.base_ntfs_ino &&
				    old_ctx.ntfs_ino !=	old_ctx.base_ntfs_ino) {
retry_map:
					ctx->mrec = map_mft_record(old_ctx.ntfs_ino);
					/*
					 * Something bad has happened.  If out
					 * of memory retry till it succeeds.
					 * Any other errors are fatal and we
					 * return the error code in ctx->mrec.
					 * Let the caller deal with it...  We
					 * just need to fudge things so the
					 * caller can reinit and/or put the
					 * search context safely.
					 */
					if (IS_ERR(ctx->mrec)) {
						if (PTR_ERR(ctx->mrec) == -ENOMEM) {
							schedule();
							goto retry_map;
						} else
							old_ctx.ntfs_ino =
								old_ctx.base_ntfs_ino;
					}
				}
			}
			/* Update the changed pointers in the saved context. */
			if (ctx->mrec != old_ctx.mrec) {
				if (!IS_ERR(ctx->mrec))
					old_ctx.attr = (struct attr_record *)(
							(u8 *)ctx->mrec +
							((u8 *)old_ctx.attr -
							(u8 *)old_ctx.mrec));
				old_ctx.mrec = ctx->mrec;
			}
		}
		/* Restore the search context to the saved one. */
		*ctx = old_ctx;
		/*
		 * We drop the reference on the page we took earlier.  In the
		 * case that IS_ERR(ctx->mrec) is true this means we might lose
		 * some changes to the mft record that had been made between
		 * the last time it was marked dirty/written out and now.  This
		 * at this stage is not a problem as the mapping error is fatal
		 * enough that the mft record cannot be written out anyway and
		 * the caller is very likely to shutdown the whole inode
		 * immediately and mark the volume dirty for chkdsk to pick up
		 * the pieces anyway.
		 */
		if (put_this_folio)
			folio_put(put_this_folio);
	}
	return err;
}

/*
 * ntfs_map_runlist - map (a part of) a runlist of an ntfs inode
 * @ni:		ntfs inode for which to map (part of) a runlist
 * @vcn:	map runlist part containing this vcn
 *
 * Map the part of a runlist containing the @vcn of the ntfs inode @ni.
 *
 * Return 0 on success and -errno on error.  There is one special error code
 * which is not an error as such.  This is -ENOENT.  It means that @vcn is out
 * of bounds of the runlist.
 *
 * Locking: - The runlist must be unlocked on entry and is unlocked on return.
 *	    - This function takes the runlist lock for writing and may modify
 *	      the runlist.
 */
int ntfs_map_runlist(struct ntfs_inode *ni, s64 vcn)
{
	int err = 0;

	down_write(&ni->runlist.lock);
	/* Make sure someone else didn't do the work while we were sleeping. */
	if (likely(ntfs_rl_vcn_to_lcn(ni->runlist.rl, vcn) <=
			LCN_RL_NOT_MAPPED))
		err = ntfs_map_runlist_nolock(ni, vcn, NULL);
	up_write(&ni->runlist.lock);
	return err;
}

struct runlist_element *ntfs_attr_vcn_to_rl(struct ntfs_inode *ni, s64 vcn, s64 *lcn)
{
	struct runlist_element *rl = ni->runlist.rl;
	int err;
	bool is_retry = false;

	if (!rl) {
		err = ntfs_attr_map_whole_runlist(ni);
		if (err)
			return ERR_PTR(-ENOENT);
		rl = ni->runlist.rl;
	}

remap_rl:
	/* Seek to element containing target vcn. */
	while (rl->length && rl[1].vcn <= vcn)
		rl++;
	*lcn = ntfs_rl_vcn_to_lcn(rl, vcn);

	if (*lcn <= LCN_RL_NOT_MAPPED && is_retry == false) {
		is_retry = true;
		if (!ntfs_map_runlist_nolock(ni, vcn, NULL)) {
			rl = ni->runlist.rl;
			goto remap_rl;
		}
	}

	return rl;
}

/*
 * ntfs_attr_vcn_to_lcn_nolock - convert a vcn into a lcn given an ntfs inode
 * @ni:			ntfs inode of the attribute whose runlist to search
 * @vcn:		vcn to convert
 * @write_locked:	true if the runlist is locked for writing
 *
 * Find the virtual cluster number @vcn in the runlist of the ntfs attribute
 * described by the ntfs inode @ni and return the corresponding logical cluster
 * number (lcn).
 *
 * If the @vcn is not mapped yet, the attempt is made to map the attribute
 * extent containing the @vcn and the vcn to lcn conversion is retried.
 *
 * If @write_locked is true the caller has locked the runlist for writing and
 * if false for reading.
 *
 * Since lcns must be >= 0, we use negative return codes with special meaning:
 *
 * Return code	Meaning / Description
 * ==========================================
 *  LCN_HOLE	Hole / not allocated on disk.
 *  LCN_ENOENT	There is no such vcn in the runlist, i.e. @vcn is out of bounds.
 *  LCN_ENOMEM	Not enough memory to map runlist.
 *  LCN_EIO	Critical error (runlist/file is corrupt, i/o error, etc).
 *
 * Locking: - The runlist must be locked on entry and is left locked on return.
 *	    - If @write_locked is 'false', i.e. the runlist is locked for reading,
 *	      the lock may be dropped inside the function so you cannot rely on
 *	      the runlist still being the same when this function returns.
 */
s64 ntfs_attr_vcn_to_lcn_nolock(struct ntfs_inode *ni, const s64 vcn,
		const bool write_locked)
{
	s64 lcn;
	unsigned long flags;
	bool is_retry = false;

	ntfs_debug("Entering for i_ino 0x%llx, vcn 0x%llx, %s_locked.",
			ni->mft_no, (unsigned long long)vcn,
			write_locked ? "write" : "read");
	if (!ni->runlist.rl) {
		read_lock_irqsave(&ni->size_lock, flags);
		if (!ni->allocated_size) {
			read_unlock_irqrestore(&ni->size_lock, flags);
			return LCN_ENOENT;
		}
		read_unlock_irqrestore(&ni->size_lock, flags);
	}
retry_remap:
	/* Convert vcn to lcn.  If that fails map the runlist and retry once. */
	lcn = ntfs_rl_vcn_to_lcn(ni->runlist.rl, vcn);
	if (likely(lcn >= LCN_HOLE)) {
		ntfs_debug("Done, lcn 0x%llx.", (long long)lcn);
		return lcn;
	}
	if (lcn != LCN_RL_NOT_MAPPED) {
		if (lcn != LCN_ENOENT)
			lcn = LCN_EIO;
	} else if (!is_retry) {
		int err;

		if (!write_locked) {
			up_read(&ni->runlist.lock);
			down_write(&ni->runlist.lock);
			if (unlikely(ntfs_rl_vcn_to_lcn(ni->runlist.rl, vcn) !=
					LCN_RL_NOT_MAPPED)) {
				up_write(&ni->runlist.lock);
				down_read(&ni->runlist.lock);
				goto retry_remap;
			}
		}
		err = ntfs_map_runlist_nolock(ni, vcn, NULL);
		if (!write_locked) {
			up_write(&ni->runlist.lock);
			down_read(&ni->runlist.lock);
		}
		if (likely(!err)) {
			is_retry = true;
			goto retry_remap;
		}
		if (err == -ENOENT)
			lcn = LCN_ENOENT;
		else if (err == -ENOMEM)
			lcn = LCN_ENOMEM;
		else
			lcn = LCN_EIO;
	}
	if (lcn != LCN_ENOENT)
		ntfs_error(ni->vol->sb, "Failed with error code %lli.",
				(long long)lcn);
	return lcn;
}

struct runlist_element *__ntfs_attr_find_vcn_nolock(struct runlist *runlist, const s64 vcn)
{
	size_t lower_idx, upper_idx, idx;
	struct runlist_element *run;
	int rh = runlist->rl_hint;

	if (runlist->count <= 1)
		return ERR_PTR(-ENOENT);

	if (runlist->count - 1 > rh && runlist->rl[rh].vcn <= vcn) {
		if (vcn < runlist->rl[rh].vcn + runlist->rl[rh].length)
			return &runlist->rl[rh];
		if (runlist->count - 2 == rh)
			return ERR_PTR(-ENOENT);

		lower_idx = rh + 1;
	} else {
		run = &runlist->rl[0];
		if (vcn < run->vcn)
			return ERR_PTR(-ENOENT);
		else if (vcn < run->vcn + run->length) {
			runlist->rl_hint = 0;
			return run;
		}

		lower_idx = 1;
	}

	run = &runlist->rl[runlist->count - 2];
	if (vcn >= run->vcn && vcn < run->vcn + run->length) {
		runlist->rl_hint = runlist->count - 2;
		return run;
	}
	if (vcn >= run->vcn + run->length)
		return ERR_PTR(-ENOENT);

	upper_idx = runlist->count - 2;

	while (lower_idx <= upper_idx) {
		idx = (lower_idx + upper_idx) >> 1;
		run = &runlist->rl[idx];

		if (vcn < run->vcn)
			upper_idx = idx - 1;
		else if (vcn >= run->vcn + run->length)
			lower_idx = idx + 1;
		else {
			runlist->rl_hint = idx;
			return run;
		}
	}

	return ERR_PTR(-ENOENT);
}

/*
 * ntfs_attr_find_vcn_nolock - find a vcn in the runlist of an ntfs inode
 * @ni:		ntfs inode describing the runlist to search
 * @vcn:	vcn to find
 * @ctx:	active attribute search context if present or NULL if not
 *
 * Find the virtual cluster number @vcn in the runlist described by the ntfs
 * inode @ni and return the address of the runlist element containing the @vcn.
 *
 * If the @vcn is not mapped yet, the attempt is made to map the attribute
 * extent containing the @vcn and the vcn to lcn conversion is retried.
 *
 * If @ctx is specified, it is an active search context of @ni and its base mft
 * record.  This is needed when ntfs_attr_find_vcn_nolock() encounters unmapped
 * runlist fragments and allows their mapping.  If you do not have the mft
 * record mapped, you can specify @ctx as NULL and ntfs_attr_find_vcn_nolock()
 * will perform the necessary mapping and unmapping.
 *
 * Note, ntfs_attr_find_vcn_nolock() saves the state of @ctx on entry and
 * restores it before returning.  Thus, @ctx will be left pointing to the same
 * attribute on return as on entry.  However, the actual pointers in @ctx may
 * point to different memory locations on return, so you must remember to reset
 * any cached pointers from the @ctx, i.e. after the call to
 * ntfs_attr_find_vcn_nolock(), you will probably want to do:
 *	m = ctx->mrec;
 *	a = ctx->attr;
 * Assuming you cache ctx->attr in a variable @a of type attr_record * and that
 * you cache ctx->mrec in a variable @m of type struct mft_record *.
 * Note you need to distinguish between the lcn of the returned runlist element
 * being >= 0 and LCN_HOLE.  In the later case you have to return zeroes on
 * read and allocate clusters on write.
 */
struct runlist_element *ntfs_attr_find_vcn_nolock(struct ntfs_inode *ni, const s64 vcn,
		struct ntfs_attr_search_ctx *ctx)
{
	unsigned long flags;
	struct runlist_element *rl;
	int err = 0;
	bool is_retry = false;

	ntfs_debug("Entering for i_ino 0x%llx, vcn 0x%llx, with%s ctx.",
			ni->mft_no, (unsigned long long)vcn, ctx ? "" : "out");
	if (!ni->runlist.rl) {
		read_lock_irqsave(&ni->size_lock, flags);
		if (!ni->allocated_size) {
			read_unlock_irqrestore(&ni->size_lock, flags);
			return ERR_PTR(-ENOENT);
		}
		read_unlock_irqrestore(&ni->size_lock, flags);
	}

retry_remap:
	rl = ni->runlist.rl;
	if (likely(rl && vcn >= rl[0].vcn)) {
		rl = __ntfs_attr_find_vcn_nolock(&ni->runlist, vcn);
		if (IS_ERR(rl))
			err = PTR_ERR(rl);
		else if (rl->lcn >= LCN_HOLE)
			return rl;
		else if (rl->lcn <= LCN_ENOENT)
			err = -EIO;
	}
	if (!err && !is_retry) {
		/*
		 * If the search context is invalid we cannot map the unmapped
		 * region.
		 */
		if (ctx && IS_ERR(ctx->mrec))
			err = PTR_ERR(ctx->mrec);
		else {
			/*
			 * The @vcn is in an unmapped region, map the runlist
			 * and retry.
			 */
			err = ntfs_map_runlist_nolock(ni, vcn, ctx);
			if (likely(!err)) {
				is_retry = true;
				goto retry_remap;
			}
		}
		if (err == -EINVAL)
			err = -EIO;
	} else if (!err)
		err = -EIO;
	if (err != -ENOENT)
		ntfs_error(ni->vol->sb, "Failed with error code %i.", err);
	return ERR_PTR(err);
}

static u32 ntfs_resident_attr_min_value_length(const __le32 type)
{
	switch (type) {
	case AT_STANDARD_INFORMATION:
		return offsetof(struct standard_information, ver) +
		       sizeof(((struct standard_information *)0)->ver.v1.reserved12);
	case AT_FILE_NAME:
		return offsetof(struct file_name_attr, file_name) +
			sizeof(__le16) * 1;
	case AT_VOLUME_INFORMATION:
		return sizeof(struct volume_information);
	case AT_EA_INFORMATION:
		return sizeof(struct ea_information);
	default:
		return 0;
	}
}

/*
 * ntfs_attr_find - find (next) attribute in mft record
 * @type:	attribute type to find
 * @name:	attribute name to find (optional, i.e. NULL means don't care)
 * @name_len:	attribute name length (only needed if @name present)
 * @ic:		IGNORE_CASE or CASE_SENSITIVE (ignored if @name not present)
 * @val:	attribute value to find (optional, resident attributes only)
 * @val_len:	attribute value length
 * @ctx:	search context with mft record and attribute to search from
 *
 * You should not need to call this function directly.  Use ntfs_attr_lookup()
 * instead.
 *
 * ntfs_attr_find() takes a search context @ctx as parameter and searches the
 * mft record specified by @ctx->mrec, beginning at @ctx->attr, for an
 * attribute of @type, optionally @name and @val.
 *
 * If the attribute is found, ntfs_attr_find() returns 0 and @ctx->attr will
 * point to the found attribute.
 *
 * If the attribute is not found, ntfs_attr_find() returns -ENOENT and
 * @ctx->attr will point to the attribute before which the attribute being
 * searched for would need to be inserted if such an action were to be desired.
 *
 * On actual error, ntfs_attr_find() returns -EIO.  In this case @ctx->attr is
 * undefined and in particular do not rely on it not changing.
 *
 * If @ctx->is_first is 'true', the search begins with @ctx->attr itself.  If it
 * is 'false', the search begins after @ctx->attr.
 *
 * If @ic is IGNORE_CASE, the @name comparisson is not case sensitive and
 * @ctx->ntfs_ino must be set to the ntfs inode to which the mft record
 * @ctx->mrec belongs.  This is so we can get at the ntfs volume and hence at
 * the upcase table.  If @ic is CASE_SENSITIVE, the comparison is case
 * sensitive.  When @name is present, @name_len is the @name length in Unicode
 * characters.
 *
 * If @name is not present (NULL), we assume that the unnamed attribute is
 * being searched for.
 *
 * Finally, the resident attribute value @val is looked for, if present.  If
 * @val is not present (NULL), @val_len is ignored.
 *
 * ntfs_attr_find() only searches the specified mft record and it ignores the
 * presence of an attribute list attribute (unless it is the one being searched
 * for, obviously).  If you need to take attribute lists into consideration,
 * use ntfs_attr_lookup() instead (see below).  This also means that you cannot
 * use ntfs_attr_find() to search for extent records of non-resident
 * attributes, as extents with lowest_vcn != 0 are usually described by the
 * attribute list attribute only. - Note that it is possible that the first
 * extent is only in the attribute list while the last extent is in the base
 * mft record, so do not rely on being able to find the first extent in the
 * base mft record.
 *
 * Warning: Never use @val when looking for attribute types which can be
 *	    non-resident as this most likely will result in a crash!
 */
static int ntfs_attr_find(const __le32 type, const __le16 *name,
		const u32 name_len, const u32 ic,
		const u8 *val, const u32 val_len, struct ntfs_attr_search_ctx *ctx)
{
	struct attr_record *a;
	struct ntfs_volume *vol = ctx->ntfs_ino->vol;
	__le16 *upcase = vol->upcase;
	u32 upcase_len = vol->upcase_len;
	unsigned int space;
	u16 name_offset;
	u32 attr_len;
	u32 name_size;

	/*
	 * Iterate over attributes in mft record starting at @ctx->attr, or the
	 * attribute following that, if @ctx->is_first is 'true'.
	 */
	if (ctx->is_first) {
		a = ctx->attr;
		ctx->is_first = false;
	} else
		a = (struct attr_record *)((u8 *)ctx->attr +
				le32_to_cpu(ctx->attr->length));
	for (;;	a = (struct attr_record *)((u8 *)a + le32_to_cpu(a->length))) {
		if ((u8 *)a < (u8 *)ctx->mrec || (u8 *)a > (u8 *)ctx->mrec +
				le32_to_cpu(ctx->mrec->bytes_allocated))
			break;

		space = le32_to_cpu(ctx->mrec->bytes_in_use) - ((u8 *)a - (u8 *)ctx->mrec);
		if ((space < offsetof(struct attr_record, data.resident.reserved) + 1 ||
		      space < le32_to_cpu(a->length)) && (space < 4 || a->type != AT_END))
			break;

		ctx->attr = a;
		if (((type != AT_UNUSED) && (le32_to_cpu(a->type) > le32_to_cpu(type))) ||
				a->type == AT_END)
			return -ENOENT;
		if (unlikely(!a->length))
			break;
		if (a->name_length) {
			name_offset = le16_to_cpu(a->name_offset);
			attr_len = le32_to_cpu(a->length);
			name_size = a->name_length * sizeof(__le16);

			if (name_offset > attr_len ||
			    attr_len - name_offset < name_size) {
				ntfs_error(vol->sb,
					   "Corrupt attribute name in MFT record %llu\n",
					   ctx->ntfs_ino->mft_no);
				break;
			}
		}

		if (type == AT_UNUSED)
			return 0;
		if (a->type != type)
			continue;
		/*
		 * If @name is present, compare the two names.  If @name is
		 * missing, assume we want an unnamed attribute.
		 */
		if (!name || name == AT_UNNAMED) {
			/* The search failed if the found attribute is named. */
			if (a->name_length)
				return -ENOENT;
		} else {
			if (!ntfs_are_names_equal(name, name_len,
					(__le16 *)((u8 *)a + le16_to_cpu(a->name_offset)),
					a->name_length, ic, upcase, upcase_len)) {
				register int rc;

				rc = ntfs_collate_names(name, name_len,
						(__le16 *)((u8 *)a + le16_to_cpu(a->name_offset)),
						a->name_length, 1, IGNORE_CASE,
						upcase, upcase_len);
				/*
				 * If @name collates before a->name, there is no
				 * matching attribute.
				 */
				if (rc == -1)
					return -ENOENT;
				/* If the strings are not equal, continue search. */
				if (rc)
					continue;
				rc = ntfs_collate_names(name, name_len,
						(__le16 *)((u8 *)a + le16_to_cpu(a->name_offset)),
						a->name_length, 1, CASE_SENSITIVE,
						upcase, upcase_len);
				if (rc == -1)
					return -ENOENT;
				if (rc)
					continue;
			}
		}

		 /* Validate attribute's value offset/length */
		if (!a->non_resident) {
			u32 min_len;
			u32 value_length = le32_to_cpu(a->data.resident.value_length);
			u16 value_offset = le16_to_cpu(a->data.resident.value_offset);

			if (value_length > le32_to_cpu(a->length) ||
			    value_offset > le32_to_cpu(a->length) - value_length)
				break;

			min_len = ntfs_resident_attr_min_value_length(a->type);
			if (min_len && value_length < min_len) {
				ntfs_error(vol->sb,
					   "Too small %#x resident attribute value in MFT record %lld\n",
					   le32_to_cpu(a->type), (long long)ctx->ntfs_ino->mft_no);
				break;
			}
		} else {
			u32 min_len;
			u16 mp_offset;

			min_len = offsetof(struct attr_record, data.non_resident.initialized_size) +
				  sizeof(a->data.non_resident.initialized_size);
			if (le32_to_cpu(a->length) < min_len)
				break;

			mp_offset = le16_to_cpu(a->data.non_resident.mapping_pairs_offset);
			if (mp_offset < min_len ||
			    mp_offset > le32_to_cpu(a->length))
				break;
		}

		/*
		 * The names match or @name not present and attribute is
		 * unnamed.  If no @val specified, we have found the attribute
		 * and are done.
		 */
		if (!val || a->non_resident)
			return 0;
		/* @val is present; compare values. */
		else {
			u32 value_length = le32_to_cpu(a->data.resident.value_length);
			int rc;

			rc = memcmp(val, (u8 *)a + le16_to_cpu(
					a->data.resident.value_offset),
					min_t(u32, val_len, value_length));
			/*
			 * If @val collates before the current attribute's
			 * value, there is no matching attribute.
			 */
			if (!rc) {
				if (val_len == value_length)
					return 0;
				if (val_len < value_length)
					return -ENOENT;
			} else if (rc < 0)
				return -ENOENT;
		}
	}
	ntfs_error(vol->sb, "mft %#llx, type %#x is corrupt. Run chkdsk.",
		   (long long)ctx->ntfs_ino->mft_no, le32_to_cpu(type));
	NVolSetErrors(vol);
	return -EIO;
}

void ntfs_attr_name_free(unsigned char **name)
{
	if (*name) {
		kfree(*name);
		*name = NULL;
	}
}

char *ntfs_attr_name_get(const struct ntfs_volume *vol, const __le16 *uname,
		const int uname_len)
{
	unsigned char *name = NULL;
	int name_len;

	name_len = ntfs_ucstonls(vol, uname, uname_len, &name, 0);
	if (name_len < 0) {
		ntfs_error(vol->sb, "ntfs_ucstonls error");
		/* This function when returns -1, memory for name might
		 * be allocated. So lets free this memory.
		 */
		ntfs_attr_name_free(&name);
		return NULL;

	} else if (name_len > 0)
		return name;

	ntfs_attr_name_free(&name);
	return NULL;
}

int load_attribute_list(struct ntfs_inode *base_ni, u8 *al_start, const s64 size)
{
	struct inode *attr_vi = NULL;
	u8 *al;
	struct attr_list_entry *ale;

	if (!al_start || size <= 0)
		return -EINVAL;

	attr_vi = ntfs_attr_iget(VFS_I(base_ni), AT_ATTRIBUTE_LIST, AT_UNNAMED, 0);
	if (IS_ERR(attr_vi)) {
		ntfs_error(base_ni->vol->sb,
			   "Failed to open an inode for Attribute list, mft = %llu",
			   base_ni->mft_no);
		return PTR_ERR(attr_vi);
	}

	if (ntfs_inode_attr_pread(attr_vi, 0, size, al_start) != size) {
		iput(attr_vi);
		ntfs_error(base_ni->vol->sb,
			   "Failed to read attribute list, mft = %llu",
			   base_ni->mft_no);
		return -EIO;
	}
	iput(attr_vi);

	for (al = al_start; al < al_start + size; al += le16_to_cpu(ale->length)) {
		ale = (struct attr_list_entry *)al;
		if (ale->name_offset != sizeof(struct attr_list_entry))
			break;
		if (le16_to_cpu(ale->length) <= ale->name_offset + ale->name_length ||
		    al + le16_to_cpu(ale->length) > al_start + size)
			break;
		if (ale->type == AT_UNUSED)
			break;
		if (MSEQNO_LE(ale->mft_reference) == 0)
			break;
	}
	if (al != al_start + size) {
		ntfs_error(base_ni->vol->sb, "Corrupt attribute list, mft = %llu",
			   base_ni->mft_no);
		return -EIO;
	}
	return 0;
}

/*
 * ntfs_external_attr_find - find an attribute in the attribute list of an inode
 * @type:	attribute type to find
 * @name:	attribute name to find (optional, i.e. NULL means don't care)
 * @name_len:	attribute name length (only needed if @name present)
 * @ic:		IGNORE_CASE or CASE_SENSITIVE (ignored if @name not present)
 * @lowest_vcn:	lowest vcn to find (optional, non-resident attributes only)
 * @val:	attribute value to find (optional, resident attributes only)
 * @val_len:	attribute value length
 * @ctx:	search context with mft record and attribute to search from
 *
 * You should not need to call this function directly.  Use ntfs_attr_lookup()
 * instead.
 *
 * Find an attribute by searching the attribute list for the corresponding
 * attribute list entry.  Having found the entry, map the mft record if the
 * attribute is in a different mft record/inode, ntfs_attr_find() the attribute
 * in there and return it.
 *
 * On first search @ctx->ntfs_ino must be the base mft record and @ctx must
 * have been obtained from a call to ntfs_attr_get_search_ctx().  On subsequent
 * calls @ctx->ntfs_ino can be any extent inode, too (@ctx->base_ntfs_ino is
 * then the base inode).
 *
 * After finishing with the attribute/mft record you need to call
 * ntfs_attr_put_search_ctx() to cleanup the search context (unmapping any
 * mapped inodes, etc).
 *
 * If the attribute is found, ntfs_external_attr_find() returns 0 and
 * @ctx->attr will point to the found attribute.  @ctx->mrec will point to the
 * mft record in which @ctx->attr is located and @ctx->al_entry will point to
 * the attribute list entry for the attribute.
 *
 * If the attribute is not found, ntfs_external_attr_find() returns -ENOENT and
 * @ctx->attr will point to the attribute in the base mft record before which
 * the attribute being searched for would need to be inserted if such an action
 * were to be desired.  @ctx->mrec will point to the mft record in which
 * @ctx->attr is located and @ctx->al_entry will point to the attribute list
 * entry of the attribute before which the attribute being searched for would
 * need to be inserted if such an action were to be desired.
 *
 * Thus to insert the not found attribute, one wants to add the attribute to
 * @ctx->mrec (the base mft record) and if there is not enough space, the
 * attribute should be placed in a newly allocated extent mft record.  The
 * attribute list entry for the inserted attribute should be inserted in the
 * attribute list attribute at @ctx->al_entry.
 *
 * On actual error, ntfs_external_attr_find() returns -EIO.  In this case
 * @ctx->attr is undefined and in particular do not rely on it not changing.
 */
static int ntfs_external_attr_find(const __le32 type,
		const __le16 *name, const u32 name_len,
		const u32 ic, const s64 lowest_vcn,
		const u8 *val, const u32 val_len, struct ntfs_attr_search_ctx *ctx)
{
	struct ntfs_inode *base_ni = ctx->base_ntfs_ino, *ni = ctx->ntfs_ino;
	struct ntfs_volume *vol;
	struct attr_list_entry *al_entry, *next_al_entry;
	u8 *al_start, *al_end;
	struct attr_record *a;
	__le16 *al_name;
	u32 al_name_len;
	u32 attr_len, mft_free_len;
	bool is_first_search = false;
	int err = 0;
	static const char *es = " Unmount and run chkdsk.";

	ntfs_debug("Entering for inode 0x%llx, type 0x%x.", ni->mft_no, type);
	if (!base_ni) {
		/* First call happens with the base mft record. */
		base_ni = ctx->base_ntfs_ino = ctx->ntfs_ino;
		ctx->base_mrec = ctx->mrec;
		ctx->mapped_base_mrec = ctx->mapped_mrec;
	}
	if (ni == base_ni)
		ctx->base_attr = ctx->attr;
	if (type == AT_END)
		goto not_found;
	vol = base_ni->vol;
	al_start = base_ni->attr_list;
	al_end = al_start + base_ni->attr_list_size;
	if (!ctx->al_entry) {
		ctx->al_entry = (struct attr_list_entry *)al_start;
		is_first_search = true;
	}
	/*
	 * Iterate over entries in attribute list starting at @ctx->al_entry,
	 * or the entry following that, if @ctx->is_first is 'true'.
	 */
	if (ctx->is_first) {
		al_entry = ctx->al_entry;
		ctx->is_first = false;
		/*
		 * If an enumeration and the first attribute is higher than
		 * the attribute list itself, need to return the attribute list
		 * attribute.
		 */
		if ((type == AT_UNUSED) && is_first_search &&
				le32_to_cpu(al_entry->type) >
				le32_to_cpu(AT_ATTRIBUTE_LIST))
			goto find_attr_list_attr;
	} else {
		/* Check for small entry */
		if (((al_end - (u8 *)ctx->al_entry) <
		      (long)offsetof(struct attr_list_entry, name)) ||
		    (le16_to_cpu(ctx->al_entry->length) & 7) ||
		    (le16_to_cpu(ctx->al_entry->length) < offsetof(struct attr_list_entry, name)))
			goto corrupt;

		al_entry = (struct attr_list_entry *)((u8 *)ctx->al_entry +
				le16_to_cpu(ctx->al_entry->length));

		if ((u8 *)al_entry == al_end)
			goto not_found;

		/* Preliminary check for small entry */
		if ((al_end - (u8 *)al_entry) <
		    (long)offsetof(struct attr_list_entry, name))
			goto corrupt;

		/*
		 * If this is an enumeration and the attribute list attribute
		 * is the next one in the enumeration sequence, just return the
		 * attribute list attribute from the base mft record as it is
		 * not listed in the attribute list itself.
		 */
		if ((type == AT_UNUSED) && le32_to_cpu(ctx->al_entry->type) <
				le32_to_cpu(AT_ATTRIBUTE_LIST) &&
				le32_to_cpu(al_entry->type) >
				le32_to_cpu(AT_ATTRIBUTE_LIST)) {
find_attr_list_attr:

			/* Check for bogus calls. */
			if (name || name_len || val || val_len || lowest_vcn)
				return -EINVAL;

			/* We want the base record. */
			if (ctx->ntfs_ino != base_ni)
				unmap_mft_record(ctx->ntfs_ino);
			ctx->ntfs_ino = base_ni;
			ctx->mapped_mrec = ctx->mapped_base_mrec;
			ctx->mrec = ctx->base_mrec;
			ctx->is_first = true;

			/* Sanity checks are performed elsewhere. */
			ctx->attr = (struct attr_record *)((u8 *)ctx->mrec +
					le16_to_cpu(ctx->mrec->attrs_offset));

			/* Find the attribute list attribute. */
			err = ntfs_attr_find(AT_ATTRIBUTE_LIST, NULL, 0,
					IGNORE_CASE, NULL, 0, ctx);

			/*
			 * Setup the search context so the correct
			 * attribute is returned next time round.
			 */
			ctx->al_entry = al_entry;
			ctx->is_first = true;

			/* Got it. Done. */
			if (!err)
				return 0;

			/* Error! If other than not found return it. */
			if (err != -ENOENT)
				return err;

			/* Not found?!? Absurd! */
			ntfs_error(ctx->ntfs_ino->vol->sb, "Attribute list wasn't found");
			return -EIO;
		}
	}
	for (;; al_entry = next_al_entry) {
		/* Out of bounds check. */
		if ((u8 *)al_entry < base_ni->attr_list ||
				(u8 *)al_entry > al_end)
			break;	/* Inode is corrupt. */
		ctx->al_entry = al_entry;
		/* Catch the end of the attribute list. */
		if ((u8 *)al_entry == al_end)
			goto not_found;

		if ((((u8 *)al_entry + offsetof(struct attr_list_entry, name)) > al_end) ||
		    ((u8 *)al_entry + le16_to_cpu(al_entry->length) > al_end) ||
		    (le16_to_cpu(al_entry->length) & 7) ||
		    (le16_to_cpu(al_entry->length) <
		     offsetof(struct attr_list_entry, name_length)) ||
		    (al_entry->name_length && ((u8 *)al_entry + al_entry->name_offset +
					       al_entry->name_length * sizeof(__le16)) > al_end))
			break; /* corrupt */

		next_al_entry = (struct attr_list_entry *)((u8 *)al_entry +
				le16_to_cpu(al_entry->length));
		if (type != AT_UNUSED) {
			if (le32_to_cpu(al_entry->type) > le32_to_cpu(type))
				goto not_found;
			if (type != al_entry->type)
				continue;
		}
		/*
		 * If @name is present, compare the two names.  If @name is
		 * missing, assume we want an unnamed attribute.
		 */
		al_name_len = al_entry->name_length;
		al_name = (__le16 *)((u8 *)al_entry + al_entry->name_offset);

		/*
		 * If !@type we want the attribute represented by this
		 * attribute list entry.
		 */
		if (type == AT_UNUSED)
			goto is_enumeration;

		if (!name || name == AT_UNNAMED) {
			if (al_name_len)
				goto not_found;
		} else if (!ntfs_are_names_equal(al_name, al_name_len, name,
				name_len, ic, vol->upcase, vol->upcase_len)) {
			register int rc;

			rc = ntfs_collate_names(name, name_len, al_name,
					al_name_len, 1, IGNORE_CASE,
					vol->upcase, vol->upcase_len);
			/*
			 * If @name collates before al_name, there is no
			 * matching attribute.
			 */
			if (rc == -1)
				goto not_found;
			/* If the strings are not equal, continue search. */
			if (rc)
				continue;

			rc = ntfs_collate_names(name, name_len, al_name,
					al_name_len, 1, CASE_SENSITIVE,
					vol->upcase, vol->upcase_len);
			if (rc == -1)
				goto not_found;
			if (rc)
				continue;
		}
		/*
		 * The names match or @name not present and attribute is
		 * unnamed.  Now check @lowest_vcn.  Continue search if the
		 * next attribute list entry still fits @lowest_vcn.  Otherwise
		 * we have reached the right one or the search has failed.
		 */
		if (lowest_vcn && (u8 *)next_al_entry >= al_start &&
				(u8 *)next_al_entry + 6 < al_end &&
				(u8 *)next_al_entry + le16_to_cpu(
					next_al_entry->length) <= al_end &&
				le64_to_cpu(next_al_entry->lowest_vcn) <=
					lowest_vcn &&
				next_al_entry->type == al_entry->type &&
				next_al_entry->name_length == al_name_len &&
				ntfs_are_names_equal((__le16 *)((u8 *)
					next_al_entry +
					next_al_entry->name_offset),
					next_al_entry->name_length,
					al_name, al_name_len, CASE_SENSITIVE,
					vol->upcase, vol->upcase_len))
			continue;

is_enumeration:
		if (MREF_LE(al_entry->mft_reference) == ni->mft_no) {
			if (MSEQNO_LE(al_entry->mft_reference) != ni->seq_no) {
				ntfs_error(vol->sb,
					"Found stale mft reference in attribute list of base inode 0x%llx.%s",
					base_ni->mft_no, es);
				err = -EIO;
				break;
			}
		} else { /* Mft references do not match. */
			/* If there is a mapped record unmap it first. */
			if (ni != base_ni)
				unmap_extent_mft_record(ni);
			/* Do we want the base record back? */
			if (MREF_LE(al_entry->mft_reference) ==
					base_ni->mft_no) {
				ni = ctx->ntfs_ino = base_ni;
				ctx->mrec = ctx->base_mrec;
				ctx->mapped_mrec = ctx->mapped_base_mrec;
			} else {
				/* We want an extent record. */
				ctx->mrec = map_extent_mft_record(base_ni,
						le64_to_cpu(
						al_entry->mft_reference), &ni);
				if (IS_ERR(ctx->mrec)) {
					ntfs_error(vol->sb,
							"Failed to map extent mft record 0x%lx of base inode 0x%llx.%s",
							MREF_LE(al_entry->mft_reference),
							base_ni->mft_no, es);
					err = PTR_ERR(ctx->mrec);
					if (err == -ENOENT)
						err = -EIO;
					/* Cause @ctx to be sanitized below. */
					ni = NULL;
					break;
				}
				ctx->ntfs_ino = ni;
				ctx->mapped_mrec = true;

			}
		}
		a = ctx->attr = (struct attr_record *)((u8 *)ctx->mrec +
					le16_to_cpu(ctx->mrec->attrs_offset));
		/*
		 * ctx->vfs_ino, ctx->mrec, and ctx->attr now point to the
		 * mft record containing the attribute represented by the
		 * current al_entry.
		 */
		/*
		 * We could call into ntfs_attr_find() to find the right
		 * attribute in this mft record but this would be less
		 * efficient and not quite accurate as ntfs_attr_find() ignores
		 * the attribute instance numbers for example which become
		 * important when one plays with attribute lists.  Also,
		 * because a proper match has been found in the attribute list
		 * entry above, the comparison can now be optimized.  So it is
		 * worth re-implementing a simplified ntfs_attr_find() here.
		 */
		/*
		 * Use a manual loop so we can still use break and continue
		 * with the same meanings as above.
		 */
do_next_attr_loop:
		if ((u8 *)a < (u8 *)ctx->mrec ||
		    (u8 *)a >= (u8 *)ctx->mrec + le32_to_cpu(ctx->mrec->bytes_allocated) ||
		    (u8 *)a >= (u8 *)ctx->mrec + le32_to_cpu(ctx->mrec->bytes_in_use))
			break;

		mft_free_len = le32_to_cpu(ctx->mrec->bytes_in_use) -
			       ((u8 *)a - (u8 *)ctx->mrec);
		if (mft_free_len >= sizeof(a->type) && a->type == AT_END)
			continue;

		attr_len = le32_to_cpu(a->length);
		if (!attr_len ||
		    attr_len < offsetof(struct attr_record, data.resident.reserved) +
		    sizeof(a->data.resident.reserved) ||
		    attr_len > mft_free_len)
			break;

		if (al_entry->instance != a->instance)
			goto do_next_attr;
		/*
		 * If the type and/or the name are mismatched between the
		 * attribute list entry and the attribute record, there is
		 * corruption so we break and return error EIO.
		 */
		if (al_entry->type != a->type)
			break;
		if (a->name_length && ((le16_to_cpu(a->name_offset) +
			       a->name_length * sizeof(__le16)) > attr_len))
			break;
		if (!ntfs_are_names_equal((__le16 *)((u8 *)a +
				le16_to_cpu(a->name_offset)), a->name_length,
				al_name, al_name_len, CASE_SENSITIVE,
				vol->upcase, vol->upcase_len))
			break;

		ctx->attr = a;

		if (a->non_resident) {
			u32 min_len;
			u16 mp_offset;

			min_len = offsetof(struct attr_record,
					   data.non_resident.initialized_size) +
				  sizeof(a->data.non_resident.initialized_size);

			if (le32_to_cpu(a->length) < min_len)
				break;

			mp_offset =
				le16_to_cpu(a->data.non_resident.mapping_pairs_offset);
			if (mp_offset < min_len || mp_offset > attr_len)
				break;
		}

		/*
		 * If no @val specified or @val specified and it matches, we
		 * have found it!
		 */
		if ((type == AT_UNUSED) || !val)
			goto attr_found;
		if (!a->non_resident) {
			u32 value_length = le32_to_cpu(a->data.resident.value_length);
			u16 value_offset = le16_to_cpu(a->data.resident.value_offset);

			if (attr_len < offsetof(struct attr_record, data.resident.reserved) +
					sizeof(a->data.resident.reserved))
				break;
			if (value_length > attr_len || value_offset > attr_len - value_length)
				break;

			value_length = ntfs_resident_attr_min_value_length(a->type);
			if (value_length && le32_to_cpu(a->data.resident.value_length) <
			    value_length) {
				pr_err("Too small resident attribute value in MFT record %lld, type %#x\n",
				       (long long)ctx->ntfs_ino->mft_no, a->type);
				break;
			}
			if (value_length == val_len &&
			    !memcmp((u8 *)a + value_offset, val, val_len)) {
attr_found:
				ntfs_debug("Done, found.");
				return 0;
			}
		}
do_next_attr:
		/* Proceed to the next attribute in the current mft record. */
		a = (struct attr_record *)((u8 *)a + attr_len);
		goto do_next_attr_loop;
	}

corrupt:
	if (ni != base_ni) {
		if (ni)
			unmap_extent_mft_record(ni);
		ctx->ntfs_ino = base_ni;
		ctx->mrec = ctx->base_mrec;
		ctx->attr = ctx->base_attr;
		ctx->mapped_mrec = ctx->mapped_base_mrec;
	}

	if (!err) {
		u64 mft_no = ctx->al_entry ? MREF_LE(ctx->al_entry->mft_reference) : 0;
		u32 type = ctx->al_entry ? le32_to_cpu(ctx->al_entry->type) : 0;

		ntfs_error(vol->sb,
			"Base inode 0x%llx contains corrupt attribute, mft %#llx, type %#x. %s",
			(long long)base_ni->mft_no, (long long)mft_no, type,
			"Unmount and run chkdsk.");
		err = -EIO;
	}

	if (err != -ENOMEM)
		NVolSetErrors(vol);
	return err;
not_found:
	/*
	 * If we were looking for AT_END, we reset the search context @ctx and
	 * use ntfs_attr_find() to seek to the end of the base mft record.
	 */
	if (type == AT_UNUSED || type == AT_END) {
		ntfs_attr_reinit_search_ctx(ctx);
		return ntfs_attr_find(AT_END, name, name_len, ic, val, val_len,
				ctx);
	}
	/*
	 * The attribute was not found.  Before we return, we want to ensure
	 * @ctx->mrec and @ctx->attr indicate the position at which the
	 * attribute should be inserted in the base mft record.  Since we also
	 * want to preserve @ctx->al_entry we cannot reinitialize the search
	 * context using ntfs_attr_reinit_search_ctx() as this would set
	 * @ctx->al_entry to NULL.  Thus we do the necessary bits manually (see
	 * ntfs_attr_init_search_ctx() below).  Note, we _only_ preserve
	 * @ctx->al_entry as the remaining fields (base_*) are identical to
	 * their non base_ counterparts and we cannot set @ctx->base_attr
	 * correctly yet as we do not know what @ctx->attr will be set to by
	 * the call to ntfs_attr_find() below.
	 */
	if (ni != base_ni)
		unmap_extent_mft_record(ni);
	ctx->mrec = ctx->base_mrec;
	ctx->attr = (struct attr_record *)((u8 *)ctx->mrec +
			le16_to_cpu(ctx->mrec->attrs_offset));
	ctx->is_first = true;
	ctx->ntfs_ino = base_ni;
	ctx->base_ntfs_ino = NULL;
	ctx->base_mrec = NULL;
	ctx->base_attr = NULL;
	ctx->mapped_mrec = ctx->mapped_base_mrec;
	/*
	 * In case there are multiple matches in the base mft record, need to
	 * keep enumerating until we get an attribute not found response (or
	 * another error), otherwise we would keep returning the same attribute
	 * over and over again and all programs using us for enumeration would
	 * lock up in a tight loop.
	 */
	do {
		err = ntfs_attr_find(type, name, name_len, ic, val, val_len,
				ctx);
	} while (!err);
	ntfs_debug("Done, not found.");
	return err;
}

/*
 * ntfs_attr_lookup - find an attribute in an ntfs inode
 * @type:	attribute type to find
 * @name:	attribute name to find (optional, i.e. NULL means don't care)
 * @name_len:	attribute name length (only needed if @name present)
 * @ic:		IGNORE_CASE or CASE_SENSITIVE (ignored if @name not present)
 * @lowest_vcn:	lowest vcn to find (optional, non-resident attributes only)
 * @val:	attribute value to find (optional, resident attributes only)
 * @val_len:	attribute value length
 * @ctx:	search context with mft record and attribute to search from
 *
 * Find an attribute in an ntfs inode.  On first search @ctx->ntfs_ino must
 * be the base mft record and @ctx must have been obtained from a call to
 * ntfs_attr_get_search_ctx().
 *
 * This function transparently handles attribute lists and @ctx is used to
 * continue searches where they were left off at.
 *
 * After finishing with the attribute/mft record you need to call
 * ntfs_attr_put_search_ctx() to cleanup the search context (unmapping any
 * mapped inodes, etc).
 *
 * Return 0 if the search was successful and -errno if not.
 *
 * When 0, @ctx->attr is the found attribute and it is in mft record
 * @ctx->mrec.  If an attribute list attribute is present, @ctx->al_entry is
 * the attribute list entry of the found attribute.
 *
 * When -ENOENT, @ctx->attr is the attribute which collates just after the
 * attribute being searched for, i.e. if one wants to add the attribute to the
 * mft record this is the correct place to insert it into.  If an attribute
 * list attribute is present, @ctx->al_entry is the attribute list entry which
 * collates just after the attribute list entry of the attribute being searched
 * for, i.e. if one wants to add the attribute to the mft record this is the
 * correct place to insert its attribute list entry into.
 */
int ntfs_attr_lookup(const __le32 type, const __le16 *name,
		const u32 name_len, const u32 ic,
		const s64 lowest_vcn, const u8 *val, const u32 val_len,
		struct ntfs_attr_search_ctx *ctx)
{
	struct ntfs_inode *base_ni;

	ntfs_debug("Entering.");
	if (ctx->base_ntfs_ino)
		base_ni = ctx->base_ntfs_ino;
	else
		base_ni = ctx->ntfs_ino;
	/* Sanity check, just for debugging really. */
	if (!base_ni || !NInoAttrList(base_ni) || type == AT_ATTRIBUTE_LIST)
		return ntfs_attr_find(type, name, name_len, ic, val, val_len,
				ctx);
	return ntfs_external_attr_find(type, name, name_len, ic, lowest_vcn,
			val, val_len, ctx);
}

/**
 * ntfs_attr_init_search_ctx - initialize an attribute search context
 * @ctx:        attribute search context to initialize
 * @ni:         ntfs inode with which to initialize the search context
 * @mrec:       mft record with which to initialize the search context
 *
 * Initialize the attribute search context @ctx with @ni and @mrec.
 */
static bool ntfs_attr_init_search_ctx(struct ntfs_attr_search_ctx *ctx,
		struct ntfs_inode *ni, struct mft_record *mrec)
{
	if (!mrec) {
		mrec = map_mft_record(ni);
		if (IS_ERR(mrec))
			return false;
		ctx->mapped_mrec = true;
	} else {
		ctx->mapped_mrec = false;
	}

	ctx->mrec = mrec;
	/* Sanity checks are performed elsewhere. */
	ctx->attr = (struct attr_record *)((u8 *)mrec + le16_to_cpu(mrec->attrs_offset));
	ctx->is_first = true;
	ctx->ntfs_ino = ni;
	ctx->al_entry = NULL;
	ctx->base_ntfs_ino = NULL;
	ctx->base_mrec = NULL;
	ctx->base_attr = NULL;
	ctx->mapped_base_mrec = false;
	return true;
}

/*
 * ntfs_attr_reinit_search_ctx - reinitialize an attribute search context
 * @ctx:	attribute search context to reinitialize
 *
 * Reinitialize the attribute search context @ctx, unmapping an associated
 * extent mft record if present, and initialize the search context again.
 *
 * This is used when a search for a new attribute is being started to reset
 * the search context to the beginning.
 */
void ntfs_attr_reinit_search_ctx(struct ntfs_attr_search_ctx *ctx)
{
	bool mapped_mrec;

	if (likely(!ctx->base_ntfs_ino)) {
		/* No attribute list. */
		ctx->is_first = true;
		/* Sanity checks are performed elsewhere. */
		ctx->attr = (struct attr_record *)((u8 *)ctx->mrec +
				le16_to_cpu(ctx->mrec->attrs_offset));
		/*
		 * This needs resetting due to ntfs_external_attr_find() which
		 * can leave it set despite having zeroed ctx->base_ntfs_ino.
		 */
		ctx->al_entry = NULL;
		return;
	} /* Attribute list. */
	if (ctx->ntfs_ino != ctx->base_ntfs_ino && ctx->ntfs_ino)
		unmap_extent_mft_record(ctx->ntfs_ino);

	mapped_mrec = ctx->mapped_base_mrec;
	ntfs_attr_init_search_ctx(ctx, ctx->base_ntfs_ino, ctx->base_mrec);
	ctx->mapped_mrec = mapped_mrec;
}

/*
 * ntfs_attr_get_search_ctx - allocate/initialize a new attribute search context
 * @ni:		ntfs inode with which to initialize the search context
 * @mrec:	mft record with which to initialize the search context
 *
 * Allocate a new attribute search context, initialize it with @ni and @mrec,
 * and return it. Return NULL if allocation failed.
 */
struct ntfs_attr_search_ctx *ntfs_attr_get_search_ctx(struct ntfs_inode *ni,
		struct mft_record *mrec)
{
	struct ntfs_attr_search_ctx *ctx;
	bool init;

	ctx = kmem_cache_alloc(ntfs_attr_ctx_cache, GFP_NOFS);
	if (ctx) {
		init = ntfs_attr_init_search_ctx(ctx, ni, mrec);
		if (init == false) {
			kmem_cache_free(ntfs_attr_ctx_cache, ctx);
			ctx = NULL;
		}
	}

	return ctx;
}

/*
 * ntfs_attr_put_search_ctx - release an attribute search context
 * @ctx:	attribute search context to free
 *
 * Release the attribute search context @ctx, unmapping an associated extent
 * mft record if present.
 */
void ntfs_attr_put_search_ctx(struct ntfs_attr_search_ctx *ctx)
{
	if (ctx->mapped_mrec)
		unmap_mft_record(ctx->ntfs_ino);

	if (ctx->mapped_base_mrec && ctx->base_ntfs_ino &&
	    ctx->ntfs_ino != ctx->base_ntfs_ino)
		unmap_extent_mft_record(ctx->base_ntfs_ino);
	kmem_cache_free(ntfs_attr_ctx_cache, ctx);
}

/*
 * ntfs_attr_find_in_attrdef - find an attribute in the $AttrDef system file
 * @vol:	ntfs volume to which the attribute belongs
 * @type:	attribute type which to find
 *
 * Search for the attribute definition record corresponding to the attribute
 * @type in the $AttrDef system file.
 *
 * Return the attribute type definition record if found and NULL if not found.
 */
static struct attr_def *ntfs_attr_find_in_attrdef(const struct ntfs_volume *vol,
		const __le32 type)
{
	struct attr_def *ad;

	WARN_ON(!type);
	for (ad = vol->attrdef; (u8 *)ad - (u8 *)vol->attrdef <
			vol->attrdef_size && ad->type; ++ad) {
		/* We have not found it yet, carry on searching. */
		if (likely(le32_to_cpu(ad->type) < le32_to_cpu(type)))
			continue;
		/* We found the attribute; return it. */
		if (likely(ad->type == type))
			return ad;
		/* We have gone too far already.  No point in continuing. */
		break;
	}
	/* Attribute not found. */
	ntfs_debug("Attribute type 0x%x not found in $AttrDef.",
			le32_to_cpu(type));
	return NULL;
}

/*
 * ntfs_attr_size_bounds_check - check a size of an attribute type for validity
 * @vol:	ntfs volume to which the attribute belongs
 * @type:	attribute type which to check
 * @size:	size which to check
 *
 * Check whether the @size in bytes is valid for an attribute of @type on the
 * ntfs volume @vol.  This information is obtained from $AttrDef system file.
 */
int ntfs_attr_size_bounds_check(const struct ntfs_volume *vol, const __le32 type,
		const s64 size)
{
	struct attr_def *ad;

	if (size < 0)
		return -EINVAL;

	/*
	 * $ATTRIBUTE_LIST has a maximum size of 256kiB, but this is not
	 * listed in $AttrDef.
	 */
	if (unlikely(type == AT_ATTRIBUTE_LIST && size > 256 * 1024))
		return -ERANGE;
	/* Get the $AttrDef entry for the attribute @type. */
	ad = ntfs_attr_find_in_attrdef(vol, type);
	if (unlikely(!ad))
		return -ENOENT;
	/* Do the bounds check. */
	if (((le64_to_cpu(ad->min_size) > 0) &&
			size < le64_to_cpu(ad->min_size)) ||
			((le64_to_cpu(ad->max_size) > 0) && size >
			le64_to_cpu(ad->max_size)))
		return -ERANGE;
	return 0;
}

/*
 * ntfs_attr_can_be_non_resident - check if an attribute can be non-resident
 * @vol:	ntfs volume to which the attribute belongs
 * @type:	attribute type which to check
 *
 * Check whether the attribute of @type on the ntfs volume @vol is allowed to
 * be non-resident.  This information is obtained from $AttrDef system file.
 */
static int ntfs_attr_can_be_non_resident(const struct ntfs_volume *vol,
		const __le32 type)
{
	struct attr_def *ad;

	/* Find the attribute definition record in $AttrDef. */
	ad = ntfs_attr_find_in_attrdef(vol, type);
	if (unlikely(!ad))
		return -ENOENT;
	/* Check the flags and return the result. */
	if (ad->flags & ATTR_DEF_RESIDENT)
		return -EPERM;
	return 0;
}

/*
 * ntfs_attr_can_be_resident - check if an attribute can be resident
 * @vol:	ntfs volume to which the attribute belongs
 * @type:	attribute type which to check
 *
 * Check whether the attribute of @type on the ntfs volume @vol is allowed to
 * be resident.  This information is derived from our ntfs knowledge and may
 * not be completely accurate, especially when user defined attributes are
 * present.  Basically we allow everything to be resident except for index
 * allocation and $EA attributes.
 *
 * Return 0 if the attribute is allowed to be non-resident and -EPERM if not.
 *
 * Warning: In the system file $MFT the attribute $Bitmap must be non-resident
 *	    otherwise windows will not boot (blue screen of death)!  We cannot
 *	    check for this here as we do not know which inode's $Bitmap is
 *	    being asked about so the caller needs to special case this.
 */
int ntfs_attr_can_be_resident(const struct ntfs_volume *vol, const __le32 type)
{
	if (type == AT_INDEX_ALLOCATION)
		return -EPERM;
	return 0;
}

/*
 * ntfs_attr_record_resize - resize an attribute record
 * @m:		mft record containing attribute record
 * @a:		attribute record to resize
 * @new_size:	new size in bytes to which to resize the attribute record @a
 *
 * Resize the attribute record @a, i.e. the resident part of the attribute, in
 * the mft record @m to @new_size bytes.
 */
int ntfs_attr_record_resize(struct mft_record *m, struct attr_record *a, u32 new_size)
{
	u32 old_size, alloc_size, attr_size;

	old_size   = le32_to_cpu(m->bytes_in_use);
	alloc_size = le32_to_cpu(m->bytes_allocated);
	attr_size  = le32_to_cpu(a->length);

	ntfs_debug("Sizes: old=%u alloc=%u attr=%u new=%u\n",
			(unsigned int)old_size, (unsigned int)alloc_size,
			(unsigned int)attr_size, (unsigned int)new_size);

	/* Align to 8 bytes if it is not already done. */
	if (new_size & 7)
		new_size = (new_size + 7) & ~7;
	/* If the actual attribute length has changed, move things around. */
	if (new_size != attr_size) {
		u32 new_muse = le32_to_cpu(m->bytes_in_use) -
				attr_size + new_size;
		/* Not enough space in this mft record. */
		if (new_muse > le32_to_cpu(m->bytes_allocated))
			return -ENOSPC;

		if (a->type == AT_INDEX_ROOT && new_size > attr_size &&
			new_muse + 120 > alloc_size && old_size + 120 <= alloc_size) {
			ntfs_debug("Too big struct index_root (%u > %u)\n",
					new_muse, alloc_size);
			return -ENOSPC;
		}

		/* Move attributes following @a to their new location. */
		memmove((u8 *)a + new_size, (u8 *)a + le32_to_cpu(a->length),
				le32_to_cpu(m->bytes_in_use) - ((u8 *)a -
				(u8 *)m) - attr_size);
		/* Adjust @m to reflect the change in used space. */
		m->bytes_in_use = cpu_to_le32(new_muse);
		/* Adjust @a to reflect the new size. */
		if (new_size >= offsetof(struct attr_record, length) + sizeof(a->length))
			a->length = cpu_to_le32(new_size);
	}
	return 0;
}

/*
 * ntfs_resident_attr_value_resize - resize the value of a resident attribute
 * @m:		mft record containing attribute record
 * @a:		attribute record whose value to resize
 * @new_size:	new size in bytes to which to resize the attribute value of @a
 *
 * Resize the value of the attribute @a in the mft record @m to @new_size bytes.
 * If the value is made bigger, the newly allocated space is cleared.
 */
int ntfs_resident_attr_value_resize(struct mft_record *m, struct attr_record *a,
		const u32 new_size)
{
	u32 old_size;

	/* Resize the resident part of the attribute record. */
	if (ntfs_attr_record_resize(m, a,
			le16_to_cpu(a->data.resident.value_offset) + new_size))
		return -ENOSPC;
	/*
	 * The resize succeeded!  If we made the attribute value bigger, clear
	 * the area between the old size and @new_size.
	 */
	old_size = le32_to_cpu(a->data.resident.value_length);
	if (new_size > old_size)
		memset((u8 *)a + le16_to_cpu(a->data.resident.value_offset) +
				old_size, 0, new_size - old_size);
	/* Finally update the length of the attribute value. */
	a->data.resident.value_length = cpu_to_le32(new_size);
	return 0;
}

/*
 * ntfs_attr_make_non_resident - convert a resident to a non-resident attribute
 * @ni:		ntfs inode describing the attribute to convert
 * @data_size:	size of the resident data to copy to the non-resident attribute
 *
 * Convert the resident ntfs attribute described by the ntfs inode @ni to a
 * non-resident one.
 *
 * @data_size must be equal to the attribute value size.  This is needed since
 * we need to know the size before we can map the mft record and our callers
 * always know it.  The reason we cannot simply read the size from the vfs
 * inode i_size is that this is not necessarily uptodate.  This happens when
 * ntfs_attr_make_non_resident() is called in the ->truncate call path(s).
 */
int ntfs_attr_make_non_resident(struct ntfs_inode *ni, const u32 data_size)
{
	s64 new_size;
	struct inode *vi = VFS_I(ni);
	struct ntfs_volume *vol = ni->vol;
	struct ntfs_inode *base_ni;
	struct mft_record *m;
	struct attr_record *a;
	struct ntfs_attr_search_ctx *ctx;
	struct folio *folio;
	struct runlist_element *rl;
	unsigned long flags;
	int mp_size, mp_ofs, name_ofs, arec_size, err, err2;
	u32 attr_size;
	u8 old_res_attr_flags;

	if (NInoNonResident(ni)) {
		ntfs_warning(vol->sb,
			"Trying to make non-resident attribute non-resident.  Aborting...\n");
		return -EINVAL;
	}

	/* Check that the attribute is allowed to be non-resident. */
	err = ntfs_attr_can_be_non_resident(vol, ni->type);
	if (unlikely(err)) {
		if (err == -EPERM)
			ntfs_debug("Attribute is not allowed to be non-resident.");
		else
			ntfs_debug("Attribute not defined on the NTFS volume!");
		return err;
	}

	if (NInoEncrypted(ni))
		return -EIO;

	if (!NInoAttr(ni))
		base_ni = ni;
	else
		base_ni = ni->ext.base_ntfs_ino;
	m = map_mft_record(base_ni);
	if (IS_ERR(m)) {
		err = PTR_ERR(m);
		m = NULL;
		ctx = NULL;
		goto err_out;
	}
	ctx = ntfs_attr_get_search_ctx(base_ni, m);
	if (unlikely(!ctx)) {
		err = -ENOMEM;
		goto err_out;
	}
	err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
			CASE_SENSITIVE, 0, NULL, 0, ctx);
	if (unlikely(err)) {
		if (err == -ENOENT)
			err = -EIO;
		goto err_out;
	}
	m = ctx->mrec;
	a = ctx->attr;

	/*
	 * The size needs to be aligned to a cluster boundary for allocation
	 * purposes.
	 */
	new_size = (data_size + vol->cluster_size - 1) &
			~(vol->cluster_size - 1);
	if (new_size > 0) {
		if ((a->flags & ATTR_COMPRESSION_MASK) == ATTR_IS_COMPRESSED) {
			/* must allocate full compression blocks */
			new_size =
				((new_size - 1) |
				 ((1L << (STANDARD_COMPRESSION_UNIT +
					  vol->cluster_size_bits)) - 1)) + 1;
		}

		/*
		 * Will need folio later and since folio lock nests
		 * outside all ntfs locks, we need to get the folio now.
		 */
		folio = __filemap_get_folio(vi->i_mapping, 0,
					    FGP_CREAT | FGP_LOCK,
					    mapping_gfp_mask(vi->i_mapping));
		if (IS_ERR(folio)) {
			err = -ENOMEM;
			goto err_out;
		}

		/* Start by allocating clusters to hold the attribute value. */
		rl = ntfs_cluster_alloc(vol, 0,
				ntfs_bytes_to_cluster(vol, new_size),
				-1, DATA_ZONE, true, false, false);
		if (IS_ERR(rl)) {
			err = PTR_ERR(rl);
			ntfs_debug("Failed to allocate cluster%s, error code %i.",
					ntfs_bytes_to_cluster(vol, new_size) > 1 ? "s" : "",
					err);
			goto folio_err_out;
		}
	} else {
		rl = NULL;
		folio = NULL;
	}

	down_write(&ni->runlist.lock);
	/* Determine the size of the mapping pairs array. */
	mp_size = ntfs_get_size_for_mapping_pairs(vol, rl, 0, -1, -1);
	if (unlikely(mp_size < 0)) {
		err = mp_size;
		ntfs_debug("Failed to get size for mapping pairs array, error code %i.\n", err);
		goto rl_err_out;
	}

	if (NInoNonResident(ni) || a->non_resident) {
		err = -EIO;
		goto rl_err_out;
	}

	/*
	 * Calculate new offsets for the name and the mapping pairs array.
	 */
	if (NInoSparse(ni) || NInoCompressed(ni))
		name_ofs = (offsetof(struct attr_record,
				data.non_resident.compressed_size) +
				sizeof(a->data.non_resident.compressed_size) +
				7) & ~7;
	else
		name_ofs = (offsetof(struct attr_record,
				data.non_resident.compressed_size) + 7) & ~7;
	mp_ofs = (name_ofs + a->name_length * sizeof(__le16) + 7) & ~7;
	/*
	 * Determine the size of the resident part of the now non-resident
	 * attribute record.
	 */
	arec_size = (mp_ofs + mp_size + 7) & ~7;
	/*
	 * If the folio is not uptodate bring it uptodate by copying from the
	 * attribute value.
	 */
	attr_size = le32_to_cpu(a->data.resident.value_length);
	WARN_ON(attr_size != data_size);
	if (folio && !folio_test_uptodate(folio)) {
		folio_fill_tail(folio, 0, (u8 *)a +
				le16_to_cpu(a->data.resident.value_offset),
				attr_size);
		folio_mark_uptodate(folio);
	}

	/* Backup the attribute flag. */
	old_res_attr_flags = a->data.resident.flags;
	/* Resize the resident part of the attribute record. */
	err = ntfs_attr_record_resize(m, a, arec_size);
	if (unlikely(err))
		goto rl_err_out;

	/*
	 * Convert the resident part of the attribute record to describe a
	 * non-resident attribute.
	 */
	a->non_resident = 1;
	/* Move the attribute name if it exists and update the offset. */
	if (a->name_length)
		memmove((u8 *)a + name_ofs, (u8 *)a + le16_to_cpu(a->name_offset),
				a->name_length * sizeof(__le16));
	a->name_offset = cpu_to_le16(name_ofs);
	/* Setup the fields specific to non-resident attributes. */
	a->data.non_resident.lowest_vcn = 0;
	a->data.non_resident.highest_vcn =
		cpu_to_le64(ntfs_bytes_to_cluster(vol, new_size - 1));
	a->data.non_resident.mapping_pairs_offset = cpu_to_le16(mp_ofs);
	memset(&a->data.non_resident.reserved, 0,
			sizeof(a->data.non_resident.reserved));
	a->data.non_resident.allocated_size = cpu_to_le64(new_size);
	a->data.non_resident.data_size =
			a->data.non_resident.initialized_size =
			cpu_to_le64(attr_size);
	if (NInoSparse(ni) || NInoCompressed(ni)) {
		a->data.non_resident.compression_unit = 0;
		if (NInoCompressed(ni) || vol->major_ver < 3)
			a->data.non_resident.compression_unit = 4;
		a->data.non_resident.compressed_size =
				a->data.non_resident.allocated_size;
	} else
		a->data.non_resident.compression_unit = 0;
	/* Generate the mapping pairs array into the attribute record. */
	err = ntfs_mapping_pairs_build(vol, (u8 *)a + mp_ofs,
			arec_size - mp_ofs, rl, 0, -1, NULL, NULL, NULL);
	if (unlikely(err)) {
		ntfs_error(vol->sb, "Failed to build mapping pairs, error code %i.",
				err);
		goto undo_err_out;
	}

	/* Setup the in-memory attribute structure to be non-resident. */
	ni->runlist.rl = rl;
	if (rl) {
		for (ni->runlist.count = 1; rl->length != 0; rl++)
			ni->runlist.count++;
	} else
		ni->runlist.count = 0;
	write_lock_irqsave(&ni->size_lock, flags);
	ni->allocated_size = new_size;
	if (NInoSparse(ni) || NInoCompressed(ni)) {
		ni->itype.compressed.size = ni->allocated_size;
		if (a->data.non_resident.compression_unit) {
			ni->itype.compressed.block_size = 1U <<
				(a->data.non_resident.compression_unit +
				 vol->cluster_size_bits);
			ni->itype.compressed.block_size_bits =
					ffs(ni->itype.compressed.block_size) -
					1;
			ni->itype.compressed.block_clusters = 1U <<
					a->data.non_resident.compression_unit;
		} else {
			ni->itype.compressed.block_size = 0;
			ni->itype.compressed.block_size_bits = 0;
			ni->itype.compressed.block_clusters = 0;
		}
		vi->i_blocks = ni->itype.compressed.size >> 9;
	} else
		vi->i_blocks = ni->allocated_size >> 9;
	write_unlock_irqrestore(&ni->size_lock, flags);
	/*
	 * This needs to be last since the address space operations ->read_folio
	 * and ->writepage can run concurrently with us as they are not
	 * serialized on i_mutex.  Note, we are not allowed to fail once we flip
	 * this switch, which is another reason to do this last.
	 */
	NInoSetNonResident(ni);
	NInoSetFullyMapped(ni);
	/* Mark the mft record dirty, so it gets written back. */
	mark_mft_record_dirty(ctx->ntfs_ino);
	ntfs_attr_put_search_ctx(ctx);
	unmap_mft_record(base_ni);
	up_write(&ni->runlist.lock);
	if (folio) {
		iomap_dirty_folio(vi->i_mapping, folio);
		folio_unlock(folio);
		folio_put(folio);
	}
	ntfs_debug("Done.");
	return 0;
undo_err_out:
	/* Convert the attribute back into a resident attribute. */
	a->non_resident = 0;
	/* Move the attribute name if it exists and update the offset. */
	name_ofs = (offsetof(struct attr_record, data.resident.reserved) +
			sizeof(a->data.resident.reserved) + 7) & ~7;
	if (a->name_length)
		memmove((u8 *)a + name_ofs, (u8 *)a + le16_to_cpu(a->name_offset),
				a->name_length * sizeof(__le16));
	mp_ofs = (name_ofs + a->name_length * sizeof(__le16) + 7) & ~7;
	a->name_offset = cpu_to_le16(name_ofs);
	arec_size = (mp_ofs + attr_size + 7) & ~7;
	/* Resize the resident part of the attribute record. */
	err2 = ntfs_attr_record_resize(m, a, arec_size);
	if (unlikely(err2)) {
		/*
		 * This cannot happen (well if memory corruption is at work it
		 * could happen in theory), but deal with it as well as we can.
		 * If the old size is too small, truncate the attribute,
		 * otherwise simply give it a larger allocated size.
		 */
		arec_size = le32_to_cpu(a->length);
		if ((mp_ofs + attr_size) > arec_size) {
			err2 = attr_size;
			attr_size = arec_size - mp_ofs;
			ntfs_error(vol->sb,
				"Failed to undo partial resident to non-resident attribute conversion.  Truncating inode 0x%llx, attribute type 0x%x from %i bytes to %i bytes to maintain metadata consistency.  THIS MEANS YOU ARE LOSING %i BYTES DATA FROM THIS %s.",
					ni->mft_no,
					(unsigned int)le32_to_cpu(ni->type),
					err2, attr_size, err2 - attr_size,
					((ni->type == AT_DATA) &&
					!ni->name_len) ? "FILE" : "ATTRIBUTE");
			write_lock_irqsave(&ni->size_lock, flags);
			ni->initialized_size = attr_size;
			i_size_write(vi, attr_size);
			write_unlock_irqrestore(&ni->size_lock, flags);
		}
	}
	/* Setup the fields specific to resident attributes. */
	a->data.resident.value_length = cpu_to_le32(attr_size);
	a->data.resident.value_offset = cpu_to_le16(mp_ofs);
	a->data.resident.flags = old_res_attr_flags;
	memset(&a->data.resident.reserved, 0,
			sizeof(a->data.resident.reserved));
	/* Copy the data from folio back to the attribute value. */
	if (folio)
		memcpy_from_folio((u8 *)a + mp_ofs, folio, 0, attr_size);
	/* Setup the allocated size in the ntfs inode in case it changed. */
	write_lock_irqsave(&ni->size_lock, flags);
	ni->allocated_size = arec_size - mp_ofs;
	write_unlock_irqrestore(&ni->size_lock, flags);
	/* Mark the mft record dirty, so it gets written back. */
	mark_mft_record_dirty(ctx->ntfs_ino);
rl_err_out:
	up_write(&ni->runlist.lock);
	if (rl) {
		if (ntfs_cluster_free_from_rl(vol, rl) < 0) {
			ntfs_error(vol->sb,
				"Failed to release allocated cluster(s) in error code path.  Run chkdsk to recover the lost cluster(s).");
			NVolSetErrors(vol);
		}
		kvfree(rl);
folio_err_out:
		folio_unlock(folio);
		folio_put(folio);
	}
err_out:
	if (ctx)
		ntfs_attr_put_search_ctx(ctx);
	if (m)
		unmap_mft_record(base_ni);
	ni->runlist.rl = NULL;

	if (err == -EINVAL)
		err = -EIO;
	return err;
}

/*
 * ntfs_attr_set - fill (a part of) an attribute with a byte
 * @ni:		ntfs inode describing the attribute to fill
 * @ofs:	offset inside the attribute at which to start to fill
 * @cnt:	number of bytes to fill
 * @val:	the unsigned 8-bit value with which to fill the attribute
 *
 * Fill @cnt bytes of the attribute described by the ntfs inode @ni starting at
 * byte offset @ofs inside the attribute with the constant byte @val.
 *
 * This function is effectively like memset() applied to an ntfs attribute.
 * Note thie function actually only operates on the page cache pages belonging
 * to the ntfs attribute and it marks them dirty after doing the memset().
 * Thus it relies on the vm dirty page write code paths to cause the modified
 * pages to be written to the mft record/disk.
 */
int ntfs_attr_set(struct ntfs_inode *ni, s64 ofs, s64 cnt, const u8 val)
{
	struct address_space *mapping = VFS_I(ni)->i_mapping;
	struct folio *folio;
	pgoff_t index;
	u8 *addr;
	unsigned long offset;
	size_t attr_len;
	int ret = 0;

	index = ofs >> PAGE_SHIFT;
	while (cnt) {
		folio = read_mapping_folio(mapping, index, NULL);
		if (IS_ERR(folio)) {
			ret = PTR_ERR(folio);
			ntfs_error(VFS_I(ni)->i_sb, "Failed to read a page %lu for attr %#x: %ld",
				   index, ni->type, PTR_ERR(folio));
			break;
		}

		offset = offset_in_folio(folio, ofs);
		attr_len = min_t(size_t, (size_t)cnt, folio_size(folio) - offset);

		folio_lock(folio);
		addr = kmap_local_folio(folio, offset);
		memset(addr, val, attr_len);
		kunmap_local(addr);

		folio_mark_dirty(folio);
		folio_unlock(folio);
		folio_put(folio);

		ofs += attr_len;
		cnt -= attr_len;
		index++;
		cond_resched();
	}

	return ret;
}

int ntfs_attr_set_initialized_size(struct ntfs_inode *ni, loff_t new_size)
{
	struct ntfs_attr_search_ctx *ctx;
	int err = 0;

	if (!NInoNonResident(ni))
		return -EINVAL;

	ctx = ntfs_attr_get_search_ctx(ni, NULL);
	if (!ctx)
		return -ENOMEM;

	err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
			       CASE_SENSITIVE, 0, NULL, 0, ctx);
	if (err)
		goto out_ctx;

	ctx->attr->data.non_resident.initialized_size = cpu_to_le64(new_size);
	ni->initialized_size = new_size;
	mark_mft_record_dirty(ctx->ntfs_ino);
out_ctx:
	ntfs_attr_put_search_ctx(ctx);
	return err;
}

/*
 * ntfs_make_room_for_attr - make room for an attribute inside an mft record
 * @m:		mft record
 * @pos:	position at which to make space
 * @size:	byte size to make available at this position
 *
 * @pos points to the attribute in front of which we want to make space.
 */
static int ntfs_make_room_for_attr(struct mft_record *m, u8 *pos, u32 size)
{
	u32 biu;

	ntfs_debug("Entering for pos 0x%x, size %u.\n",
			(int)(pos - (u8 *)m), (unsigned int) size);

	/* Make size 8-byte alignment. */
	size = (size + 7) & ~7;

	/* Rigorous consistency checks. */
	if (!m || !pos || pos < (u8 *)m) {
		pr_err("%s: pos=%p  m=%p\n", __func__, pos, m);
		return -EINVAL;
	}

	/* The -8 is for the attribute terminator. */
	if (pos - (u8 *)m > (int)le32_to_cpu(m->bytes_in_use) - 8)
		return -EINVAL;
	/* Nothing to do. */
	if (!size)
		return 0;

	biu = le32_to_cpu(m->bytes_in_use);
	/* Do we have enough space? */
	if (biu + size > le32_to_cpu(m->bytes_allocated) ||
	    pos + size > (u8 *)m + le32_to_cpu(m->bytes_allocated)) {
		ntfs_debug("No enough space in the MFT record\n");
		return -ENOSPC;
	}
	/* Move everything after pos to pos + size. */
	memmove(pos + size, pos, biu - (pos - (u8 *)m));
	/* Update mft record. */
	m->bytes_in_use = cpu_to_le32(biu + size);
	return 0;
}

/*
 * ntfs_resident_attr_record_add - add resident attribute to inode
 * @ni:		opened ntfs inode to which MFT record add attribute
 * @type:	type of the new attribute
 * @name:	name of the new attribute
 * @name_len:	name length of the new attribute
 * @val:	value of the new attribute
 * @size:	size of new attribute (length of @val, if @val != NULL)
 * @flags:	flags of the new attribute
 */
int ntfs_resident_attr_record_add(struct ntfs_inode *ni, __le32 type,
		__le16 *name, u8 name_len, u8 *val, u32 size,
		__le16 flags)
{
	struct ntfs_attr_search_ctx *ctx;
	u32 length;
	struct attr_record *a;
	struct mft_record *m;
	int err, offset;
	struct ntfs_inode *base_ni;

	if (!ni || (!name && name_len))
		return -EINVAL;

	ntfs_debug("Entering for inode 0x%llx, attr 0x%x, flags 0x%x.\n",
			(long long) ni->mft_no, (unsigned int) le32_to_cpu(type),
			(unsigned int) le16_to_cpu(flags));

	err = ntfs_attr_can_be_resident(ni->vol, type);
	if (err) {
		if (err == -EPERM)
			ntfs_debug("Attribute can't be resident.\n");
		else
			ntfs_debug("ntfs_attr_can_be_resident failed.\n");
		return err;
	}

	/* Locate place where record should be. */
	ctx = ntfs_attr_get_search_ctx(ni, NULL);
	if (!ctx) {
		ntfs_error(ni->vol->sb, "%s: Failed to get search context",
				__func__);
		return -ENOMEM;
	}
	/*
	 * Use ntfs_attr_find instead of ntfs_attr_lookup to find place for
	 * attribute in @ni->mrec, not any extent inode in case if @ni is base
	 * file record.
	 */
	err = ntfs_attr_find(type, name, name_len, CASE_SENSITIVE, val, size, ctx);
	if (!err) {
		err = -EEXIST;
		ntfs_debug("Attribute already present.\n");
		goto put_err_out;
	}
	if (err != -ENOENT) {
		err = -EIO;
		goto put_err_out;
	}
	a = ctx->attr;
	m = ctx->mrec;

	/* Make room for attribute. */
	length = offsetof(struct attr_record, data.resident.reserved) +
			  sizeof(a->data.resident.reserved) +
		((name_len * sizeof(__le16) + 7) & ~7) +
		((size + 7) & ~7);
	err = ntfs_make_room_for_attr(ctx->mrec, (u8 *) ctx->attr, length);
	if (err) {
		ntfs_debug("Failed to make room for attribute.\n");
		goto put_err_out;
	}

	/* Setup record fields. */
	offset = ((u8 *)a - (u8 *)m);
	a->type = type;
	a->length = cpu_to_le32(length);
	a->non_resident = 0;
	a->name_length = name_len;
	a->name_offset =
		name_len ? cpu_to_le16((offsetof(struct attr_record, data.resident.reserved) +
				sizeof(a->data.resident.reserved))) : cpu_to_le16(0);

	a->flags = flags;
	a->instance = m->next_attr_instance;
	a->data.resident.value_length = cpu_to_le32(size);
	a->data.resident.value_offset = cpu_to_le16(length - ((size + 7) & ~7));
	if (val)
		memcpy((u8 *)a + le16_to_cpu(a->data.resident.value_offset), val, size);
	else
		memset((u8 *)a + le16_to_cpu(a->data.resident.value_offset), 0, size);
	if (type == AT_FILE_NAME)
		a->data.resident.flags = RESIDENT_ATTR_IS_INDEXED;
	else
		a->data.resident.flags = 0;
	if (name_len)
		memcpy((u8 *)a + le16_to_cpu(a->name_offset),
				name, sizeof(__le16) * name_len);
	m->next_attr_instance =
		cpu_to_le16((le16_to_cpu(m->next_attr_instance) + 1) & 0xffff);
	if (ni->nr_extents == -1)
		base_ni = ni->ext.base_ntfs_ino;
	else
		base_ni = ni;
	if (type != AT_ATTRIBUTE_LIST && NInoAttrList(base_ni)) {
		err = ntfs_attrlist_entry_add(ni, a);
		if (err) {
			ntfs_attr_record_resize(m, a, 0);
			mark_mft_record_dirty(ctx->ntfs_ino);
			ntfs_debug("Failed add attribute entry to ATTRIBUTE_LIST.\n");
			goto put_err_out;
		}
	}
	mark_mft_record_dirty(ni);
	ntfs_attr_put_search_ctx(ctx);
	return offset;
put_err_out:
	ntfs_attr_put_search_ctx(ctx);
	return -EIO;
}

/*
 * ntfs_non_resident_attr_record_add - add extent of non-resident attribute
 * @ni:			opened ntfs inode to which MFT record add attribute
 * @type:		type of the new attribute extent
 * @name:		name of the new attribute extent
 * @name_len:		name length of the new attribute extent
 * @lowest_vcn:		lowest vcn of the new attribute extent
 * @dataruns_size:	dataruns size of the new attribute extent
 * @flags:		flags of the new attribute extent
 */
static int ntfs_non_resident_attr_record_add(struct ntfs_inode *ni, __le32 type,
		__le16 *name, u8 name_len, s64 lowest_vcn, int dataruns_size,
		__le16 flags)
{
	struct ntfs_attr_search_ctx *ctx;
	u32 length;
	struct attr_record *a;
	struct mft_record *m;
	struct ntfs_inode *base_ni;
	int err, offset;

	if (!ni || dataruns_size <= 0 || (!name && name_len))
		return -EINVAL;

	ntfs_debug("Entering for inode 0x%llx, attr 0x%x, lowest_vcn %lld, dataruns_size %d, flags 0x%x.\n",
			(long long) ni->mft_no, (unsigned int) le32_to_cpu(type),
			(long long) lowest_vcn, dataruns_size,
			(unsigned int) le16_to_cpu(flags));

	err = ntfs_attr_can_be_non_resident(ni->vol, type);
	if (err) {
		if (err == -EPERM)
			pr_err("Attribute can't be non resident\n");
		else
			pr_err("ntfs_attr_can_be_non_resident failed\n");
		return err;
	}

	/* Locate place where record should be. */
	ctx = ntfs_attr_get_search_ctx(ni, NULL);
	if (!ctx) {
		pr_err("%s: Failed to get search context\n", __func__);
		return -ENOMEM;
	}
	/*
	 * Use ntfs_attr_find instead of ntfs_attr_lookup to find place for
	 * attribute in @ni->mrec, not any extent inode in case if @ni is base
	 * file record.
	 */
	err = ntfs_attr_find(type, name, name_len, CASE_SENSITIVE, NULL, 0, ctx);
	if (!err) {
		err = -EEXIST;
		pr_err("Attribute 0x%x already present\n", type);
		goto put_err_out;
	}
	if (err != -ENOENT) {
		pr_err("ntfs_attr_find failed\n");
		err = -EIO;
		goto put_err_out;
	}
	a = ctx->attr;
	m = ctx->mrec;

	/* Make room for attribute. */
	dataruns_size = (dataruns_size + 7) & ~7;
	length = offsetof(struct attr_record, data.non_resident.compressed_size) +
		((sizeof(__le16) * name_len + 7) & ~7) + dataruns_size +
		((flags & (ATTR_IS_COMPRESSED | ATTR_IS_SPARSE)) ?
		 sizeof(a->data.non_resident.compressed_size) : 0);
	err = ntfs_make_room_for_attr(ctx->mrec, (u8 *) ctx->attr, length);
	if (err) {
		pr_err("Failed to make room for attribute\n");
		goto put_err_out;
	}

	/* Setup record fields. */
	a->type = type;
	a->length = cpu_to_le32(length);
	a->non_resident = 1;
	a->name_length = name_len;
	a->name_offset = cpu_to_le16(offsetof(struct attr_record,
					      data.non_resident.compressed_size) +
			((flags & (ATTR_IS_COMPRESSED | ATTR_IS_SPARSE)) ?
			 sizeof(a->data.non_resident.compressed_size) : 0));
	a->flags = flags;
	a->instance = m->next_attr_instance;
	a->data.non_resident.lowest_vcn = cpu_to_le64(lowest_vcn);
	a->data.non_resident.mapping_pairs_offset = cpu_to_le16(length - dataruns_size);
	a->data.non_resident.compression_unit =
		(flags & ATTR_IS_COMPRESSED) ? STANDARD_COMPRESSION_UNIT : 0;
	/* If @lowest_vcn == 0, than setup empty attribute. */
	if (!lowest_vcn) {
		a->data.non_resident.highest_vcn = cpu_to_le64(-1);
		a->data.non_resident.allocated_size = 0;
		a->data.non_resident.data_size = 0;
		a->data.non_resident.initialized_size = 0;
		/* Set empty mapping pairs. */
		*((u8 *)a + le16_to_cpu(a->data.non_resident.mapping_pairs_offset)) = 0;
	}
	if (name_len)
		memcpy((u8 *)a + le16_to_cpu(a->name_offset),
				name, sizeof(__le16) * name_len);
	m->next_attr_instance =
		cpu_to_le16((le16_to_cpu(m->next_attr_instance) + 1) & 0xffff);
	if (ni->nr_extents == -1)
		base_ni = ni->ext.base_ntfs_ino;
	else
		base_ni = ni;
	if (type != AT_ATTRIBUTE_LIST && NInoAttrList(base_ni)) {
		err = ntfs_attrlist_entry_add(ni, a);
		if (err) {
			pr_err("Failed add attr entry to attrlist\n");
			ntfs_attr_record_resize(m, a, 0);
			goto put_err_out;
		}
	}
	mark_mft_record_dirty(ni);
	/*
	 * Locate offset from start of the MFT record where new attribute is
	 * placed. We need relookup it, because record maybe moved during
	 * update of attribute list.
	 */
	ntfs_attr_reinit_search_ctx(ctx);
	err = ntfs_attr_lookup(type, name, name_len, CASE_SENSITIVE,
				lowest_vcn, NULL, 0, ctx);
	if (err) {
		pr_err("%s: attribute lookup failed\n", __func__);
		ntfs_attr_put_search_ctx(ctx);
		return err;

	}
	offset = (u8 *)ctx->attr - (u8 *)ctx->mrec;
	ntfs_attr_put_search_ctx(ctx);
	return offset;
put_err_out:
	ntfs_attr_put_search_ctx(ctx);
	return -1;
}

/*
 * ntfs_attr_record_rm - remove attribute extent
 * @ctx:	search context describing the attribute which should be removed
 *
 * If this function succeed, user should reinit search context if he/she wants
 * use it anymore.
 */
int ntfs_attr_record_rm(struct ntfs_attr_search_ctx *ctx)
{
	struct ntfs_inode *base_ni, *ni;
	__le32 type;
	int err;

	if (!ctx || !ctx->ntfs_ino || !ctx->mrec || !ctx->attr)
		return -EINVAL;

	ntfs_debug("Entering for inode 0x%llx, attr 0x%x.\n",
			(long long) ctx->ntfs_ino->mft_no,
			(unsigned int) le32_to_cpu(ctx->attr->type));
	type = ctx->attr->type;
	ni = ctx->ntfs_ino;
	if (ctx->base_ntfs_ino)
		base_ni = ctx->base_ntfs_ino;
	else
		base_ni = ctx->ntfs_ino;

	/* Remove attribute itself. */
	if (ntfs_attr_record_resize(ctx->mrec, ctx->attr, 0)) {
		ntfs_debug("Couldn't remove attribute record. Bug or damaged MFT record.\n");
		return -EIO;
	}
	mark_mft_record_dirty(ni);

	/*
	 * Remove record from $ATTRIBUTE_LIST if present and we don't want
	 * delete $ATTRIBUTE_LIST itself.
	 */
	if (NInoAttrList(base_ni) && type != AT_ATTRIBUTE_LIST) {
		err = ntfs_attrlist_entry_rm(ctx);
		if (err) {
			ntfs_debug("Couldn't delete record from $ATTRIBUTE_LIST.\n");
			return err;
		}
	}

	/* Post $ATTRIBUTE_LIST delete setup. */
	if (type == AT_ATTRIBUTE_LIST) {
		if (NInoAttrList(base_ni) && base_ni->attr_list)
			kvfree(base_ni->attr_list);
		base_ni->attr_list = NULL;
		NInoClearAttrList(base_ni);
	}

	/* Free MFT record, if it doesn't contain attributes. */
	if (le32_to_cpu(ctx->mrec->bytes_in_use) -
			le16_to_cpu(ctx->mrec->attrs_offset) == 8) {
		if (ntfs_mft_record_free(ni->vol, ni)) {
			ntfs_debug("Couldn't free MFT record.\n");
			return -EIO;
		}
		/* Remove done if we freed base inode. */
		if (ni == base_ni)
			return 0;
		ntfs_inode_close(ni);
		ctx->ntfs_ino = ni = NULL;
	}

	if (type == AT_ATTRIBUTE_LIST || !NInoAttrList(base_ni))
		return 0;

	/* Remove attribute list if we don't need it any more. */
	if (!ntfs_attrlist_need(base_ni)) {
		struct ntfs_attr na;
		struct inode *attr_vi;

		ntfs_attr_reinit_search_ctx(ctx);
		if (ntfs_attr_lookup(AT_ATTRIBUTE_LIST, NULL, 0, CASE_SENSITIVE,
					0, NULL, 0, ctx)) {
			ntfs_debug("Couldn't find attribute list. Succeed anyway.\n");
			return 0;
		}
		/* Deallocate clusters. */
		if (ctx->attr->non_resident) {
			struct runlist_element *al_rl;
			size_t new_rl_count;

			al_rl = ntfs_mapping_pairs_decompress(base_ni->vol,
					ctx->attr, NULL, &new_rl_count);
			if (IS_ERR(al_rl)) {
				ntfs_debug("Couldn't decompress attribute list runlist. Succeed anyway.\n");
				return 0;
			}
			if (ntfs_cluster_free_from_rl(base_ni->vol, al_rl))
				ntfs_debug("Leaking clusters! Run chkdsk. Couldn't free clusters from attribute list runlist.\n");
			kvfree(al_rl);
		}
		/* Remove attribute record itself. */
		if (ntfs_attr_record_rm(ctx)) {
			ntfs_debug("Couldn't remove attribute list. Succeed anyway.\n");
			return 0;
		}

		na.mft_no = VFS_I(base_ni)->i_ino;
		na.type = AT_ATTRIBUTE_LIST;
		na.name = NULL;
		na.name_len = 0;

		attr_vi = ilookup5(VFS_I(base_ni)->i_sb, VFS_I(base_ni)->i_ino,
				   ntfs_test_inode, &na);
		if (attr_vi) {
			clear_nlink(attr_vi);
			iput(attr_vi);
		}

	}
	return 0;
}

/*
 * ntfs_attr_add - add attribute to inode
 * @ni:		opened ntfs inode to which add attribute
 * @type:	type of the new attribute
 * @name:	name in unicode of the new attribute
 * @name_len:	name length in unicode characters of the new attribute
 * @val:	value of new attribute
 * @size:	size of the new attribute / length of @val (if specified)
 *
 * @val should always be specified for always resident attributes (eg. FILE_NAME
 * attribute), for attributes that can become non-resident @val can be NULL
 * (eg. DATA attribute). @size can be specified even if @val is NULL, in this
 * case data size will be equal to @size and initialized size will be equal
 * to 0.
 *
 * If inode haven't got enough space to add attribute, add attribute to one of
 * it extents, if no extents present or no one of them have enough space, than
 * allocate new extent and add attribute to it.
 *
 * If on one of this steps attribute list is needed but not present, than it is
 * added transparently to caller. So, this function should not be called with
 * @type == AT_ATTRIBUTE_LIST, if you really need to add attribute list call
 * ntfs_inode_add_attrlist instead.
 *
 * On success return 0. On error return -1 with errno set to the error code.
 */
int ntfs_attr_add(struct ntfs_inode *ni, __le32 type,
		__le16 *name, u8 name_len, u8 *val, s64 size)
{
	struct super_block *sb;
	u32 attr_rec_size;
	int err, i, offset;
	bool is_resident;
	bool can_be_non_resident = false;
	struct ntfs_inode *attr_ni;
	struct inode *attr_vi;
	struct mft_record *ni_mrec;

	if (!ni || size < 0 || type == AT_ATTRIBUTE_LIST)
		return -EINVAL;

	ntfs_debug("Entering for inode 0x%llx, attr %x, size %lld.\n",
			(long long) ni->mft_no, type, size);

	if (ni->nr_extents == -1)
		ni = ni->ext.base_ntfs_ino;

	/* Check the attribute type and the size. */
	err = ntfs_attr_size_bounds_check(ni->vol, type, size);
	if (err) {
		if (err == -ENOENT)
			err = -EIO;
		return err;
	}

	sb = ni->vol->sb;
	/* Sanity checks for always resident attributes. */
	err = ntfs_attr_can_be_non_resident(ni->vol, type);
	if (err) {
		if (err != -EPERM) {
			ntfs_error(sb, "ntfs_attr_can_be_non_resident failed");
			goto err_out;
		}
		/* @val is mandatory. */
		if (!val) {
			ntfs_error(sb,
				"val is mandatory for always resident attributes");
			return -EINVAL;
		}
		if (size > ni->vol->mft_record_size) {
			ntfs_error(sb, "Attribute is too big");
			return -ERANGE;
		}
	} else
		can_be_non_resident = true;

	/*
	 * Determine resident or not will be new attribute. We add 8 to size in
	 * non resident case for mapping pairs.
	 */
	err = ntfs_attr_can_be_resident(ni->vol, type);
	if (!err) {
		is_resident = true;
	} else {
		if (err != -EPERM) {
			ntfs_error(sb, "ntfs_attr_can_be_resident failed");
			goto err_out;
		}
		is_resident = false;
	}

	/* Calculate attribute record size. */
	if (is_resident)
		attr_rec_size = offsetof(struct attr_record, data.resident.reserved) +
			1 +
			((name_len * sizeof(__le16) + 7) & ~7) +
			((size + 7) & ~7);
	else
		attr_rec_size = offsetof(struct attr_record, data.non_resident.compressed_size) +
			((name_len * sizeof(__le16) + 7) & ~7) + 8;

	/*
	 * If we have enough free space for the new attribute in the base MFT
	 * record, then add attribute to it.
	 */
retry:
	ni_mrec = map_mft_record(ni);
	if (IS_ERR(ni_mrec)) {
		err = -EIO;
		goto err_out;
	}

	if (le32_to_cpu(ni_mrec->bytes_allocated) -
			le32_to_cpu(ni_mrec->bytes_in_use) >= attr_rec_size) {
		attr_ni = ni;
		unmap_mft_record(ni);
		goto add_attr_record;
	}
	unmap_mft_record(ni);

	/* Try to add to extent inodes. */
	err = ntfs_inode_attach_all_extents(ni);
	if (err) {
		ntfs_error(sb, "Failed to attach all extents to inode");
		goto err_out;
	}

	for (i = 0; i < ni->nr_extents; i++) {
		attr_ni = ni->ext.extent_ntfs_inos[i];
		ni_mrec = map_mft_record(attr_ni);
		if (IS_ERR(ni_mrec)) {
			err = -EIO;
			goto err_out;
		}

		if (le32_to_cpu(ni_mrec->bytes_allocated) -
				le32_to_cpu(ni_mrec->bytes_in_use) >=
				attr_rec_size) {
			unmap_mft_record(attr_ni);
			goto add_attr_record;
		}
		unmap_mft_record(attr_ni);
	}

	/* There is no extent that contain enough space for new attribute. */
	if (!NInoAttrList(ni)) {
		/* Add attribute list not present, add it and retry. */
		err = ntfs_inode_add_attrlist(ni);
		if (err) {
			ntfs_error(sb, "Failed to add attribute list");
			goto err_out;
		}
		goto retry;
	}

	attr_ni = NULL;
	/* Allocate new extent. */
	err = ntfs_mft_record_alloc(ni->vol, 0, &attr_ni, ni, NULL);
	if (err) {
		ntfs_error(sb, "Failed to allocate extent record");
		goto err_out;
	}
	unmap_mft_record(attr_ni);

add_attr_record:
	if (is_resident) {
		/* Add resident attribute. */
		offset = ntfs_resident_attr_record_add(attr_ni, type, name,
				name_len, val, size, 0);
		if (offset < 0) {
			if (offset == -ENOSPC && can_be_non_resident)
				goto add_non_resident;
			err = offset;
			ntfs_error(sb, "Failed to add resident attribute");
			goto free_err_out;
		}
		return 0;
	}

add_non_resident:
	/* Add non resident attribute. */
	offset = ntfs_non_resident_attr_record_add(attr_ni, type, name,
			name_len, 0, 8, 0);
	if (offset < 0) {
		err = offset;
		ntfs_error(sb, "Failed to add non resident attribute");
		goto free_err_out;
	}

	/* If @size == 0, we are done. */
	if (!size)
		return 0;

	/* Open new attribute and resize it. */
	attr_vi = ntfs_attr_iget(VFS_I(ni), type, name, name_len);
	if (IS_ERR(attr_vi)) {
		err = PTR_ERR(attr_vi);
		ntfs_error(sb, "Failed to open just added attribute");
		goto rm_attr_err_out;
	}
	attr_ni = NTFS_I(attr_vi);

	/* Resize and set attribute value. */
	if (ntfs_attr_truncate(attr_ni, size) ||
		(val && (ntfs_inode_attr_pwrite(attr_vi, 0, size, val, false) != size))) {
		err = -EIO;
		ntfs_error(sb, "Failed to initialize just added attribute");
		if (ntfs_attr_rm(attr_ni))
			ntfs_error(sb, "Failed to remove just added attribute");
		iput(attr_vi);
		goto err_out;
	}
	iput(attr_vi);
	return 0;

rm_attr_err_out:
	/* Remove just added attribute. */
	ni_mrec = map_mft_record(attr_ni);
	if (!IS_ERR(ni_mrec)) {
		if (ntfs_attr_record_resize(ni_mrec,
					(struct attr_record *)((u8 *)ni_mrec + offset), 0))
			ntfs_error(sb, "Failed to remove just added attribute #2");
		unmap_mft_record(attr_ni);
	} else
		pr_err("EIO when try to remove new added attr\n");

free_err_out:
	/* Free MFT record, if it doesn't contain attributes. */
	ni_mrec = map_mft_record(attr_ni);
	if (!IS_ERR(ni_mrec)) {
		int attr_size;

		attr_size = le32_to_cpu(ni_mrec->bytes_in_use) -
			le16_to_cpu(ni_mrec->attrs_offset);
		unmap_mft_record(attr_ni);
		if (attr_size == 8) {
			if (ntfs_mft_record_free(attr_ni->vol, attr_ni))
				ntfs_error(sb, "Failed to free MFT record");
			if (attr_ni->nr_extents < 0)
				ntfs_inode_close(attr_ni);
		}
	} else
		pr_err("EIO when testing mft record is free-able\n");

err_out:
	return err;
}

/*
 * __ntfs_attr_init - primary initialization of an ntfs attribute structure
 * @ni:		ntfs attribute inode to initialize
 * @ni:		ntfs inode with which to initialize the ntfs attribute
 * @type:	attribute type
 * @name:	attribute name in little endian Unicode or NULL
 * @name_len:	length of attribute @name in Unicode characters (if @name given)
 *
 * Initialize the ntfs attribute @na with @ni, @type, @name, and @name_len.
 */
static void __ntfs_attr_init(struct ntfs_inode *ni,
		const __le32 type, __le16 *name, const u32 name_len)
{
	ni->runlist.rl = NULL;
	ni->type = type;
	ni->name = name;
	if (name)
		ni->name_len = name_len;
	else
		ni->name_len = 0;
}

/*
 * ntfs_attr_init - initialize an ntfs_attr with data sizes and status
 * @ni: ntfs inode to initialize
 * @non_resident: true if attribute is non-resident
 * @compressed: true if attribute is compressed
 * @encrypted: true if attribute is encrypted
 * @sparse: true if attribute is sparse
 * @allocated_size: allocated size of the attribute
 * @data_size: actual data size of the attribute
 * @initialized_size: initialized size of the attribute
 * @compressed_size: compressed size (if compressed or sparse)
 * @compression_unit: compression unit size (log2 of clusters)
 *
 * Final initialization for an ntfs attribute.
 */
static void ntfs_attr_init(struct ntfs_inode *ni, const bool non_resident,
		const bool compressed, const bool encrypted, const bool sparse,
		const s64 allocated_size, const s64 data_size,
		const s64 initialized_size, const s64 compressed_size,
		const u8 compression_unit)
{
	if (non_resident)
		NInoSetNonResident(ni);
	if (compressed) {
		NInoSetCompressed(ni);
		ni->flags |= FILE_ATTR_COMPRESSED;
	}
	if (encrypted) {
		NInoSetEncrypted(ni);
		ni->flags |= FILE_ATTR_ENCRYPTED;
	}
	if (sparse) {
		NInoSetSparse(ni);
		ni->flags |= FILE_ATTR_SPARSE_FILE;
	}
	ni->allocated_size = allocated_size;
	ni->data_size = data_size;
	ni->initialized_size = initialized_size;
	if (compressed || sparse) {
		struct ntfs_volume *vol = ni->vol;

		ni->itype.compressed.size = compressed_size;
		ni->itype.compressed.block_clusters = 1 << compression_unit;
		ni->itype.compressed.block_size = 1 << (compression_unit +
				vol->cluster_size_bits);
		ni->itype.compressed.block_size_bits = ffs(
				ni->itype.compressed.block_size) - 1;
	}
}

/*
 * ntfs_attr_open - open an ntfs attribute for access
 * @ni:		open ntfs inode in which the ntfs attribute resides
 * @type:	attribute type
 * @name:	attribute name in little endian Unicode or AT_UNNAMED or NULL
 * @name_len:	length of attribute @name in Unicode characters (if @name given)
 */
int ntfs_attr_open(struct ntfs_inode *ni, const __le32 type,
		__le16 *name, u32 name_len)
{
	struct ntfs_attr_search_ctx *ctx;
	__le16 *newname = NULL;
	struct attr_record *a;
	bool cs;
	struct ntfs_inode *base_ni;
	int err;

	if (!ni || !ni->vol)
		return -EINVAL;

	ntfs_debug("Entering for inode %lld, attr 0x%x.\n",
			ni->mft_no, type);

	if (NInoAttr(ni))
		base_ni = ni->ext.base_ntfs_ino;
	else
		base_ni = ni;

	if (name && name != AT_UNNAMED && name != I30) {
		name = ntfs_ucsndup(name, name_len);
		if (!name) {
			err = -ENOMEM;
			goto err_out;
		}
		newname = name;
	}

	ctx = ntfs_attr_get_search_ctx(base_ni, NULL);
	if (!ctx) {
		err = -ENOMEM;
		pr_err("%s: Failed to get search context\n", __func__);
		goto err_out;
	}

	err = ntfs_attr_lookup(type, name, name_len, 0, 0, NULL, 0, ctx);
	if (err)
		goto put_err_out;

	a = ctx->attr;

	if (!name) {
		if (a->name_length) {
			name = ntfs_ucsndup((__le16 *)((u8 *)a + le16_to_cpu(a->name_offset)),
					    a->name_length);
			if (!name)
				goto put_err_out;
			newname = name;
			name_len = a->name_length;
		} else {
			name = AT_UNNAMED;
			name_len = 0;
		}
	}

	__ntfs_attr_init(ni, type, name, name_len);

	/*
	 * Wipe the flags in case they are not zero for an attribute list
	 * attribute.  Windows does not complain about invalid flags and chkdsk
	 * does not detect or fix them so we need to cope with it, too.
	 */
	if (type == AT_ATTRIBUTE_LIST)
		a->flags = 0;

	if ((type == AT_DATA) &&
	    (a->non_resident ? !a->data.non_resident.initialized_size :
	     !a->data.resident.value_length)) {
		/*
		 * Define/redefine the compression state if stream is
		 * empty, based on the compression mark on parent
		 * directory (for unnamed data streams) or on current
		 * inode (for named data streams). The compression mark
		 * may change any time, the compression state can only
		 * change when stream is wiped out.
		 *
		 * Also prevent compression on NTFS version < 3.0
		 * or cluster size > 4K or compression is disabled
		 */
		a->flags &= ~ATTR_COMPRESSION_MASK;
		if (NInoCompressed(ni)
				&& (ni->vol->major_ver >= 3)
				&& NVolCompression(ni->vol)
				&& (ni->vol->cluster_size <= MAX_COMPRESSION_CLUSTER_SIZE))
			a->flags |= ATTR_IS_COMPRESSED;
	}

	cs = a->flags & (ATTR_IS_COMPRESSED | ATTR_IS_SPARSE);

	if (ni->type == AT_DATA && ni->name == AT_UNNAMED &&
	    ((!(a->flags & ATTR_IS_COMPRESSED) != !NInoCompressed(ni)) ||
	     (!(a->flags & ATTR_IS_SPARSE)     != !NInoSparse(ni)) ||
	     (!(a->flags & ATTR_IS_ENCRYPTED)  != !NInoEncrypted(ni)))) {
		err = -EIO;
		pr_err("Inode %lld has corrupt attribute flags (0x%x <> 0x%x)\n",
				(unsigned long long)ni->mft_no,
				a->flags, ni->flags);
		goto put_err_out;
	}

	if (a->non_resident) {
		if (((a->flags & ATTR_COMPRESSION_MASK) || a->data.non_resident.compression_unit) &&
				(ni->vol->major_ver < 3)) {
			err = -EIO;
			pr_err("Compressed inode %lld not allowed  on NTFS %d.%d\n",
					(unsigned long long)ni->mft_no,
					ni->vol->major_ver,
					ni->vol->major_ver);
			goto put_err_out;
		}

		if ((a->flags & ATTR_IS_COMPRESSED) && !a->data.non_resident.compression_unit) {
			err = -EIO;
			pr_err("Compressed inode %lld attr 0x%x has no compression unit\n",
					(unsigned long long)ni->mft_no, type);
			goto put_err_out;
		}
		if ((a->flags & ATTR_COMPRESSION_MASK) &&
		    (a->data.non_resident.compression_unit != STANDARD_COMPRESSION_UNIT)) {
			err = -EIO;
			pr_err("Compressed inode %lld attr 0x%lx has an unsupported compression unit %d\n",
					(unsigned long long)ni->mft_no,
					(long)le32_to_cpu(type),
					(int)a->data.non_resident.compression_unit);
			goto put_err_out;
		}
		ntfs_attr_init(ni, true, a->flags & ATTR_IS_COMPRESSED,
				a->flags & ATTR_IS_ENCRYPTED,
				a->flags & ATTR_IS_SPARSE,
				le64_to_cpu(a->data.non_resident.allocated_size),
				le64_to_cpu(a->data.non_resident.data_size),
				le64_to_cpu(a->data.non_resident.initialized_size),
				cs ? le64_to_cpu(a->data.non_resident.compressed_size) : 0,
				cs ? a->data.non_resident.compression_unit : 0);
	} else {
		s64 l = le32_to_cpu(a->data.resident.value_length);

		ntfs_attr_init(ni, false, a->flags & ATTR_IS_COMPRESSED,
				a->flags & ATTR_IS_ENCRYPTED,
				a->flags & ATTR_IS_SPARSE, (l + 7) & ~7, l, l,
				cs ? (l + 7) & ~7 : 0, 0);
	}
	ntfs_attr_put_search_ctx(ctx);
out:
	ntfs_debug("\n");
	return err;

put_err_out:
	ntfs_attr_put_search_ctx(ctx);
err_out:
	kfree(newname);
	goto out;
}

/*
 * ntfs_attr_close - free an ntfs attribute structure
 * @ni:		ntfs inode to free
 *
 * Release all memory associated with the ntfs attribute @na and then release
 * @na itself.
 */
void ntfs_attr_close(struct ntfs_inode *ni)
{
	if (NInoNonResident(ni) && ni->runlist.rl)
		kvfree(ni->runlist.rl);
	/* Don't release if using an internal constant. */
	if (ni->name != AT_UNNAMED && ni->name != I30)
		kfree(ni->name);
}

/*
 * ntfs_attr_map_whole_runlist - map the whole runlist of an ntfs attribute
 * @ni:		ntfs inode for which to map the runlist
 *
 * Map the whole runlist of the ntfs attribute @na.  For an attribute made up
 * of only one attribute extent this is the same as calling
 * ntfs_map_runlist(ni, 0) but for an attribute with multiple extents this
 * will map the runlist fragments from each of the extents thus giving access
 * to the entirety of the disk allocation of an attribute.
 */
int ntfs_attr_map_whole_runlist(struct ntfs_inode *ni)
{
	s64 next_vcn, last_vcn, highest_vcn;
	struct ntfs_attr_search_ctx *ctx;
	struct ntfs_volume *vol = ni->vol;
	struct super_block *sb = vol->sb;
	struct attr_record *a;
	int err;
	struct ntfs_inode *base_ni;
	int not_mapped;
	size_t new_rl_count;

	ntfs_debug("Entering for inode 0x%llx, attr 0x%x.\n",
			(unsigned long long)ni->mft_no, ni->type);

	if (NInoFullyMapped(ni) && ni->runlist.rl)
		return 0;

	if (NInoAttr(ni))
		base_ni = ni->ext.base_ntfs_ino;
	else
		base_ni = ni;

	ctx = ntfs_attr_get_search_ctx(base_ni, NULL);
	if (!ctx) {
		ntfs_error(sb, "%s: Failed to get search context", __func__);
		return -ENOMEM;
	}

	/* Map all attribute extents one by one. */
	next_vcn = last_vcn = highest_vcn = 0;
	a = NULL;
	while (1) {
		struct runlist_element *rl;

		not_mapped = 0;
		if (ntfs_rl_vcn_to_lcn(ni->runlist.rl, next_vcn) == LCN_RL_NOT_MAPPED)
			not_mapped = 1;

		err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
					CASE_SENSITIVE, next_vcn, NULL, 0, ctx);
		if (err)
			break;

		a = ctx->attr;

		if (not_mapped) {
			/* Decode the runlist. */
			rl = ntfs_mapping_pairs_decompress(ni->vol, a, &ni->runlist,
							   &new_rl_count);
			if (IS_ERR(rl)) {
				err = PTR_ERR(rl);
				goto err_out;
			}
			ni->runlist.rl = rl;
			ni->runlist.count = new_rl_count;
		}

		/* Are we in the first extent? */
		if (!next_vcn) {
			if (a->data.non_resident.lowest_vcn) {
				err = -EIO;
				ntfs_error(sb,
					"First extent of inode %llu attribute has non-zero lowest_vcn",
					(unsigned long long)ni->mft_no);
				goto err_out;
			}
			/* Get the last vcn in the attribute. */
			last_vcn = ntfs_bytes_to_cluster(vol,
					le64_to_cpu(a->data.non_resident.allocated_size));
		}

		/* Get the lowest vcn for the next extent. */
		highest_vcn = le64_to_cpu(a->data.non_resident.highest_vcn);
		next_vcn = highest_vcn + 1;

		/* Only one extent or error, which we catch below. */
		if (next_vcn <= 0) {
			err = -ENOENT;
			break;
		}

		/* Avoid endless loops due to corruption. */
		if (next_vcn < le64_to_cpu(a->data.non_resident.lowest_vcn)) {
			err = -EIO;
			ntfs_error(sb, "Inode %llu has corrupt attribute list",
					(unsigned long long)ni->mft_no);
			goto err_out;
		}
	}
	if (!a) {
		ntfs_error(sb, "Couldn't find attribute for runlist mapping");
		goto err_out;
	}
	if (not_mapped && highest_vcn && highest_vcn != last_vcn - 1) {
		err = -EIO;
		ntfs_error(sb,
			"Failed to load full runlist: inode: %llu highest_vcn: 0x%llx last_vcn: 0x%llx",
			(unsigned long long)ni->mft_no,
			(long long)highest_vcn, (long long)last_vcn);
		goto err_out;
	}
	ntfs_attr_put_search_ctx(ctx);
	if (err == -ENOENT) {
		NInoSetFullyMapped(ni);
		return 0;
	}

	return err;

err_out:
	ntfs_attr_put_search_ctx(ctx);
	return err;
}

/*
 * ntfs_attr_record_move_to - move attribute record to target inode
 * @ctx:	attribute search context describing the attribute record
 * @ni:		opened ntfs inode to which move attribute record
 */
int ntfs_attr_record_move_to(struct ntfs_attr_search_ctx *ctx, struct ntfs_inode *ni)
{
	struct ntfs_attr_search_ctx *nctx;
	struct attr_record *a;
	int err;
	struct mft_record *ni_mrec;
	struct super_block *sb;

	if (!ctx || !ctx->attr || !ctx->ntfs_ino || !ni) {
		ntfs_debug("Invalid arguments passed.\n");
		return -EINVAL;
	}

	sb = ni->vol->sb;
	ntfs_debug("Entering for ctx->attr->type 0x%x, ctx->ntfs_ino->mft_no 0x%llx, ni->mft_no 0x%llx.\n",
			(unsigned int) le32_to_cpu(ctx->attr->type),
			(long long) ctx->ntfs_ino->mft_no,
			(long long) ni->mft_no);

	if (ctx->ntfs_ino == ni)
		return 0;

	if (!ctx->al_entry) {
		ntfs_debug("Inode should contain attribute list to use this function.\n");
		return -EINVAL;
	}

	/* Find place in MFT record where attribute will be moved. */
	a = ctx->attr;
	nctx = ntfs_attr_get_search_ctx(ni, NULL);
	if (!nctx) {
		ntfs_error(sb, "%s: Failed to get search context", __func__);
		return -ENOMEM;
	}

	/*
	 * Use ntfs_attr_find instead of ntfs_attr_lookup to find place for
	 * attribute in @ni->mrec, not any extent inode in case if @ni is base
	 * file record.
	 */
	err = ntfs_attr_find(a->type, (__le16 *)((u8 *)a + le16_to_cpu(a->name_offset)),
				a->name_length, CASE_SENSITIVE, NULL,
				0, nctx);
	if (!err) {
		ntfs_debug("Attribute of such type, with same name already present in this MFT record.\n");
		err = -EEXIST;
		goto put_err_out;
	}
	if (err != -ENOENT) {
		ntfs_debug("Attribute lookup failed.\n");
		goto put_err_out;
	}

	/* Make space and move attribute. */
	ni_mrec = map_mft_record(ni);
	if (IS_ERR(ni_mrec)) {
		err = -EIO;
		goto put_err_out;
	}

	err = ntfs_make_room_for_attr(ni_mrec, (u8 *) nctx->attr,
				le32_to_cpu(a->length));
	if (err) {
		ntfs_debug("Couldn't make space for attribute.\n");
		unmap_mft_record(ni);
		goto put_err_out;
	}
	memcpy(nctx->attr, a, le32_to_cpu(a->length));
	nctx->attr->instance = nctx->mrec->next_attr_instance;
	nctx->mrec->next_attr_instance =
		cpu_to_le16((le16_to_cpu(nctx->mrec->next_attr_instance) + 1) & 0xffff);
	ntfs_attr_record_resize(ctx->mrec, a, 0);
	mark_mft_record_dirty(ctx->ntfs_ino);
	mark_mft_record_dirty(ni);

	/* Update attribute list. */
	ctx->al_entry->mft_reference =
		MK_LE_MREF(ni->mft_no, le16_to_cpu(ni_mrec->sequence_number));
	ctx->al_entry->instance = nctx->attr->instance;
	unmap_mft_record(ni);
put_err_out:
	ntfs_attr_put_search_ctx(nctx);
	return err;
}

/*
 * ntfs_attr_record_move_away - move away attribute record from it's mft record
 * @ctx:	attribute search context describing the attribute record
 * @extra:	minimum amount of free space in the new holder of record
 */
int ntfs_attr_record_move_away(struct ntfs_attr_search_ctx *ctx, int extra)
{
	struct ntfs_inode *base_ni, *ni = NULL;
	struct mft_record *m;
	int i, err;
	struct super_block *sb;

	if (!ctx || !ctx->attr || !ctx->ntfs_ino || extra < 0)
		return -EINVAL;

	ntfs_debug("Entering for attr 0x%x, inode %llu\n",
			(unsigned int) le32_to_cpu(ctx->attr->type),
			(unsigned long long)ctx->ntfs_ino->mft_no);

	if (ctx->ntfs_ino->nr_extents == -1)
		base_ni = ctx->base_ntfs_ino;
	else
		base_ni = ctx->ntfs_ino;

	sb = ctx->ntfs_ino->vol->sb;
	if (!NInoAttrList(base_ni)) {
		ntfs_error(sb, "Inode %llu has no attrlist",
				(unsigned long long)base_ni->mft_no);
		return -EINVAL;
	}

	err = ntfs_inode_attach_all_extents(ctx->ntfs_ino);
	if (err) {
		ntfs_error(sb, "Couldn't attach extents, inode=%llu",
			(unsigned long long)base_ni->mft_no);
		return err;
	}

	mutex_lock(&base_ni->extent_lock);
	/* Walk through all extents and try to move attribute to them. */
	for (i = 0; i < base_ni->nr_extents; i++) {
		ni = base_ni->ext.extent_ntfs_inos[i];

		if (ctx->ntfs_ino->mft_no == ni->mft_no)
			continue;
		m = map_mft_record(ni);
		if (IS_ERR(m)) {
			ntfs_error(sb, "Can not map mft record for mft_no %lld",
					(unsigned long long)ni->mft_no);
			mutex_unlock(&base_ni->extent_lock);
			return -EIO;
		}
		if (le32_to_cpu(m->bytes_allocated) -
		    le32_to_cpu(m->bytes_in_use) < le32_to_cpu(ctx->attr->length) + extra) {
			unmap_mft_record(ni);
			continue;
		}
		unmap_mft_record(ni);

		/*
		 * ntfs_attr_record_move_to can fail if extent with other lowest
		 * s64 already present in inode we trying move record to. So,
		 * do not return error.
		 */
		if (!ntfs_attr_record_move_to(ctx, ni)) {
			mutex_unlock(&base_ni->extent_lock);
			return 0;
		}
	}
	mutex_unlock(&base_ni->extent_lock);

	/*
	 * Failed to move attribute to one of the current extents, so allocate
	 * new extent and move attribute to it.
	 */
	ni = NULL;
	err = ntfs_mft_record_alloc(base_ni->vol, 0, &ni, base_ni, NULL);
	if (err) {
		ntfs_error(sb, "Couldn't allocate MFT record, err : %d", err);
		return err;
	}
	unmap_mft_record(ni);

	err = ntfs_attr_record_move_to(ctx, ni);
	if (err)
		ntfs_error(sb, "Couldn't move attribute to MFT record");

	return err;
}

/*
 * If we are in the first extent, then set/clean sparse bit,
 * update allocated and compressed size.
 */
static int ntfs_attr_update_meta(struct attr_record *a, struct ntfs_inode *ni,
		struct mft_record *m, struct ntfs_attr_search_ctx *ctx)
{
	int sparse, err = 0;
	struct ntfs_inode *base_ni;
	struct super_block *sb = ni->vol->sb;

	ntfs_debug("Entering for inode 0x%llx, attr 0x%x\n",
			(unsigned long long)ni->mft_no, ni->type);

	if (NInoAttr(ni))
		base_ni = ni->ext.base_ntfs_ino;
	else
		base_ni = ni;

	if (a->data.non_resident.lowest_vcn)
		goto out;

	a->data.non_resident.allocated_size = cpu_to_le64(ni->allocated_size);

	sparse = ntfs_rl_sparse(ni->runlist.rl);
	if (sparse < 0) {
		err = -EIO;
		goto out;
	}

	/* Attribute become sparse. */
	if (sparse && !(a->flags & (ATTR_IS_SPARSE | ATTR_IS_COMPRESSED))) {
		/*
		 * Move attribute to another mft record, if attribute is too
		 * small to add compressed_size field to it and we have no
		 * free space in the current mft record.
		 */
		if ((le32_to_cpu(a->length) -
		     le16_to_cpu(a->data.non_resident.mapping_pairs_offset) == 8) &&
		    !(le32_to_cpu(m->bytes_allocated) - le32_to_cpu(m->bytes_in_use))) {

			if (!NInoAttrList(base_ni)) {
				err = ntfs_inode_add_attrlist(base_ni);
				if (err)
					goto out;
				err = -EAGAIN;
				goto out;
			}
			err = ntfs_attr_record_move_away(ctx, 8);
			if (err) {
				ntfs_error(sb, "Failed to move attribute");
				goto out;
			}

			err = ntfs_attrlist_update(base_ni);
			if (err)
				goto out;
			err = -EAGAIN;
			goto out;
		}
		if (!(le32_to_cpu(a->length) -
		    le16_to_cpu(a->data.non_resident.mapping_pairs_offset))) {
			err = -EIO;
			ntfs_error(sb, "Mapping pairs space is 0");
			goto out;
		}

		NInoSetSparse(ni);
		ni->flags |= FILE_ATTR_SPARSE_FILE;
		a->flags |= ATTR_IS_SPARSE;
		a->data.non_resident.compression_unit = 0;

		memmove((u8 *)a + le16_to_cpu(a->name_offset) + 8,
				(u8 *)a + le16_to_cpu(a->name_offset),
				a->name_length * sizeof(__le16));

		a->name_offset = cpu_to_le16(le16_to_cpu(a->name_offset) + 8);

		a->data.non_resident.mapping_pairs_offset =
			cpu_to_le16(le16_to_cpu(a->data.non_resident.mapping_pairs_offset) + 8);
	}

	/* Attribute no longer sparse. */
	if (!sparse && (a->flags & ATTR_IS_SPARSE) &&
	    !(a->flags & ATTR_IS_COMPRESSED)) {
		NInoClearSparse(ni);
		ni->flags &= ~FILE_ATTR_SPARSE_FILE;
		a->flags &= ~ATTR_IS_SPARSE;
		a->data.non_resident.compression_unit = 0;

		memmove((u8 *)a + le16_to_cpu(a->name_offset) - 8,
				(u8 *)a + le16_to_cpu(a->name_offset),
				a->name_length * sizeof(__le16));

		if (le16_to_cpu(a->name_offset) >= 8)
			a->name_offset = cpu_to_le16(le16_to_cpu(a->name_offset) - 8);

		a->data.non_resident.mapping_pairs_offset =
			cpu_to_le16(le16_to_cpu(a->data.non_resident.mapping_pairs_offset) - 8);
	}

	/* Update compressed size if required. */
	if (NInoFullyMapped(ni) && (sparse || NInoCompressed(ni))) {
		s64 new_compr_size;

		new_compr_size = ntfs_rl_get_compressed_size(ni->vol, ni->runlist.rl);
		if (new_compr_size < 0) {
			err = new_compr_size;
			goto out;
		}

		ni->itype.compressed.size = new_compr_size;
		a->data.non_resident.compressed_size = cpu_to_le64(new_compr_size);
	}

	if (NInoSparse(ni) || NInoCompressed(ni))
		VFS_I(base_ni)->i_blocks = ni->itype.compressed.size >> 9;
	else
		VFS_I(base_ni)->i_blocks = ni->allocated_size >> 9;
	/*
	 * Set FILE_NAME dirty flag, to update sparse bit and
	 * allocated size in the index.
	 */
	if (ni->type == AT_DATA && ni->name == AT_UNNAMED)
		NInoSetFileNameDirty(ni);
out:
	return err;
}

#define NTFS_VCN_DELETE_MARK -2
/*
 * ntfs_attr_update_mapping_pairs - update mapping pairs for ntfs attribute
 * @ni:		non-resident ntfs inode for which we need update
 * @from_vcn:	update runlist starting this VCN
 *
 * Build mapping pairs from @na->rl and write them to the disk. Also, this
 * function updates sparse bit, allocated and compressed size (allocates/frees
 * space for this field if required).
 *
 * @na->allocated_size should be set to correct value for the new runlist before
 * call to this function. Vice-versa @na->compressed_size will be calculated and
 * set to correct value during this function.
 */
int ntfs_attr_update_mapping_pairs(struct ntfs_inode *ni, s64 from_vcn)
{
	struct ntfs_attr_search_ctx *ctx;
	struct ntfs_inode *base_ni;
	struct mft_record *m;
	struct attr_record *a;
	s64 stop_vcn;
	int err = 0, mp_size, cur_max_mp_size, exp_max_mp_size;
	bool finished_build;
	bool first_updated = false;
	struct super_block *sb;
	struct runlist_element *start_rl;
	unsigned int de_cluster_count = 0;

retry:
	if (!ni || !ni->runlist.rl)
		return -EINVAL;

	ntfs_debug("Entering for inode %llu, attr 0x%x\n",
			(unsigned long long)ni->mft_no, ni->type);

	sb = ni->vol->sb;
	if (!NInoNonResident(ni)) {
		ntfs_error(sb, "%s: resident attribute", __func__);
		return -EINVAL;
	}

	if (ni->nr_extents == -1)
		base_ni = ni->ext.base_ntfs_ino;
	else
		base_ni = ni;

	ctx = ntfs_attr_get_search_ctx(base_ni, NULL);
	if (!ctx) {
		ntfs_error(sb, "%s: Failed to get search context", __func__);
		return -ENOMEM;
	}

	/* Fill attribute records with new mapping pairs. */
	stop_vcn = 0;
	finished_build = false;
	start_rl = ni->runlist.rl;
	while (!(err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
				CASE_SENSITIVE, from_vcn, NULL, 0, ctx))) {
		unsigned int de_cnt = 0;

		a = ctx->attr;
		m = ctx->mrec;
		if (!a->data.non_resident.lowest_vcn)
			first_updated = true;

		/*
		 * If runlist is updating not from the beginning, then set
		 * @stop_vcn properly, i.e. to the lowest vcn of record that
		 * contain @from_vcn. Also we do not need @from_vcn anymore,
		 * set it to 0 to make ntfs_attr_lookup enumerate attributes.
		 */
		if (from_vcn) {
			s64 first_lcn;

			stop_vcn = le64_to_cpu(a->data.non_resident.lowest_vcn);
			from_vcn = 0;
			/*
			 * Check whether the first run we need to update is
			 * the last run in runlist, if so, then deallocate
			 * all attrubute extents starting this one.
			 */
			first_lcn = ntfs_rl_vcn_to_lcn(ni->runlist.rl, stop_vcn);
			if (first_lcn == LCN_EINVAL) {
				err = -EIO;
				ntfs_error(sb, "Bad runlist");
				goto put_err_out;
			}
			if (first_lcn == LCN_ENOENT ||
			    first_lcn == LCN_RL_NOT_MAPPED)
				finished_build = true;
		}

		/*
		 * Check whether we finished mapping pairs build, if so mark
		 * extent as need to delete (by setting highest vcn to
		 * NTFS_VCN_DELETE_MARK (-2), we shall check it later and
		 * delete extent) and continue search.
		 */
		if (finished_build) {
			ntfs_debug("Mark attr 0x%x for delete in inode 0x%llx.\n",
				(unsigned int)le32_to_cpu(a->type), ctx->ntfs_ino->mft_no);
			a->data.non_resident.highest_vcn = cpu_to_le64(NTFS_VCN_DELETE_MARK);
			mark_mft_record_dirty(ctx->ntfs_ino);
			continue;
		}

		err = ntfs_attr_update_meta(a, ni, m, ctx);
		if (err < 0) {
			if (err == -EAGAIN) {
				ntfs_attr_put_search_ctx(ctx);
				goto retry;
			}
			goto put_err_out;
		}

		/*
		 * Determine maximum possible length of mapping pairs,
		 * if we shall *not* expand space for mapping pairs.
		 */
		cur_max_mp_size = le32_to_cpu(a->length) -
			le16_to_cpu(a->data.non_resident.mapping_pairs_offset);
		/*
		 * Determine maximum possible length of mapping pairs in the
		 * current mft record, if we shall expand space for mapping
		 * pairs.
		 */
		exp_max_mp_size = le32_to_cpu(m->bytes_allocated) -
			le32_to_cpu(m->bytes_in_use) + cur_max_mp_size;

		/* Get the size for the rest of mapping pairs array. */
		mp_size = ntfs_get_size_for_mapping_pairs(ni->vol, start_rl,
				stop_vcn, -1, exp_max_mp_size);
		if (mp_size <= 0) {
			err = mp_size;
			ntfs_error(sb, "%s: get MP size failed", __func__);
			goto put_err_out;
		}
		/* Test mapping pairs for fitting in the current mft record. */
		if (mp_size > exp_max_mp_size) {
			/*
			 * Mapping pairs of $ATTRIBUTE_LIST attribute must fit
			 * in the base mft record. Try to move out other
			 * attributes and try again.
			 */
			if (ni->type == AT_ATTRIBUTE_LIST) {
				ntfs_attr_put_search_ctx(ctx);
				if (ntfs_inode_free_space(base_ni, mp_size -
							cur_max_mp_size)) {
					ntfs_debug("Attribute list is too big. Defragment the volume\n");
					return -ENOSPC;
				}
				if (ntfs_attrlist_update(base_ni))
					return -EIO;
				goto retry;
			}

			/* Add attribute list if it isn't present, and retry. */
			if (!NInoAttrList(base_ni)) {
				ntfs_attr_put_search_ctx(ctx);
				if (ntfs_inode_add_attrlist(base_ni)) {
					ntfs_error(sb, "Can not add attrlist");
					return -EIO;
				}
				goto retry;
			}

			/*
			 * Set mapping pairs size to maximum possible for this
			 * mft record. We shall write the rest of mapping pairs
			 * to another MFT records.
			 */
			mp_size = exp_max_mp_size;
		}

		/* Change space for mapping pairs if we need it. */
		if (((mp_size + 7) & ~7) != cur_max_mp_size) {
			if (ntfs_attr_record_resize(m, a,
					le16_to_cpu(a->data.non_resident.mapping_pairs_offset) +
						mp_size)) {
				err = -EIO;
				ntfs_error(sb, "Failed to resize attribute");
				goto put_err_out;
			}
		}

		/* Update lowest vcn. */
		a->data.non_resident.lowest_vcn = cpu_to_le64(stop_vcn);
		mark_mft_record_dirty(ctx->ntfs_ino);
		if ((ctx->ntfs_ino->nr_extents == -1 || NInoAttrList(ctx->ntfs_ino)) &&
		    ctx->attr->type != AT_ATTRIBUTE_LIST) {
			ctx->al_entry->lowest_vcn = cpu_to_le64(stop_vcn);
			err = ntfs_attrlist_update(base_ni);
			if (err)
				goto put_err_out;
		}

		/*
		 * Generate the new mapping pairs array directly into the
		 * correct destination, i.e. the attribute record itself.
		 */
		err = ntfs_mapping_pairs_build(ni->vol,
				(u8 *)a + le16_to_cpu(a->data.non_resident.mapping_pairs_offset),
				mp_size, start_rl, stop_vcn, -1, &stop_vcn, &start_rl, &de_cnt);
		if (!err)
			finished_build = true;
		if (!finished_build && err != -ENOSPC) {
			ntfs_error(sb, "Failed to build mapping pairs");
			goto put_err_out;
		}
		a->data.non_resident.highest_vcn = cpu_to_le64(stop_vcn - 1);
		mark_mft_record_dirty(ctx->ntfs_ino);
		de_cluster_count += de_cnt;
	}

	/* Check whether error occurred. */
	if (err && err != -ENOENT) {
		ntfs_error(sb, "%s: Attribute lookup failed", __func__);
		goto put_err_out;
	}

	/*
	 * If the base extent was skipped in the above process,
	 * we still may have to update the sizes.
	 */
	if (!first_updated) {
		ntfs_attr_reinit_search_ctx(ctx);
		err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
				CASE_SENSITIVE, 0, NULL, 0, ctx);
		if (!err) {
			a = ctx->attr;
			a->data.non_resident.allocated_size = cpu_to_le64(ni->allocated_size);
			if (NInoCompressed(ni) || NInoSparse(ni))
				a->data.non_resident.compressed_size =
					cpu_to_le64(ni->itype.compressed.size);
			/* Updating sizes taints the extent holding the attr */
			if (ni->type == AT_DATA && ni->name == AT_UNNAMED)
				NInoSetFileNameDirty(ni);
			mark_mft_record_dirty(ctx->ntfs_ino);
		} else {
			ntfs_error(sb, "Failed to update sizes in base extent\n");
			goto put_err_out;
		}
	}

	/* Deallocate not used attribute extents and return with success. */
	if (finished_build) {
		ntfs_attr_reinit_search_ctx(ctx);
		ntfs_debug("Deallocate marked extents.\n");
		while (!(err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
				CASE_SENSITIVE, 0, NULL, 0, ctx))) {
			if (le64_to_cpu(ctx->attr->data.non_resident.highest_vcn) !=
					NTFS_VCN_DELETE_MARK)
				continue;
			/* Remove unused attribute record. */
			err = ntfs_attr_record_rm(ctx);
			if (err) {
				ntfs_error(sb, "Could not remove unused attr");
				goto put_err_out;
			}
			ntfs_attr_reinit_search_ctx(ctx);
		}
		if (err && err != -ENOENT) {
			ntfs_error(sb, "%s: Attr lookup failed", __func__);
			goto put_err_out;
		}
		ntfs_debug("Deallocate done.\n");
		ntfs_attr_put_search_ctx(ctx);
		goto out;
	}
	ntfs_attr_put_search_ctx(ctx);
	ctx = NULL;

	/* Allocate new MFT records for the rest of mapping pairs. */
	while (1) {
		struct ntfs_inode *ext_ni = NULL;
		unsigned int de_cnt = 0;

		/* Allocate new mft record. */
		err = ntfs_mft_record_alloc(ni->vol, 0, &ext_ni, base_ni, NULL);
		if (err) {
			ntfs_error(sb, "Failed to allocate extent record");
			goto put_err_out;
		}
		unmap_mft_record(ext_ni);

		m = map_mft_record(ext_ni);
		if (IS_ERR(m)) {
			ntfs_error(sb, "Could not map new MFT record");
			if (ntfs_mft_record_free(ni->vol, ext_ni))
				ntfs_error(sb, "Could not free MFT record");
			ntfs_inode_close(ext_ni);
			err = -ENOMEM;
			ext_ni = NULL;
			goto put_err_out;
		}
		/*
		 * If mapping size exceed available space, set them to
		 * possible maximum.
		 */
		cur_max_mp_size = le32_to_cpu(m->bytes_allocated) -
			le32_to_cpu(m->bytes_in_use) -
			(sizeof(struct attr_record) +
			 ((NInoCompressed(ni) || NInoSparse(ni)) ?
			  sizeof(a->data.non_resident.compressed_size) : 0)) -
			((sizeof(__le16) * ni->name_len + 7) & ~7);

		/* Calculate size of rest mapping pairs. */
		mp_size = ntfs_get_size_for_mapping_pairs(ni->vol,
				start_rl, stop_vcn, -1, cur_max_mp_size);
		if (mp_size <= 0) {
			unmap_mft_record(ext_ni);
			ntfs_inode_close(ext_ni);
			err = mp_size;
			ntfs_error(sb, "%s: get mp size failed", __func__);
			goto put_err_out;
		}

		if (mp_size > cur_max_mp_size)
			mp_size = cur_max_mp_size;
		/* Add attribute extent to new record. */
		err = ntfs_non_resident_attr_record_add(ext_ni, ni->type,
				ni->name, ni->name_len, stop_vcn, mp_size, 0);
		if (err < 0) {
			ntfs_error(sb, "Could not add attribute extent");
			unmap_mft_record(ext_ni);
			if (ntfs_mft_record_free(ni->vol, ext_ni))
				ntfs_error(sb, "Could not free MFT record");
			ntfs_inode_close(ext_ni);
			goto put_err_out;
		}
		a = (struct attr_record *)((u8 *)m + err);

		err = ntfs_mapping_pairs_build(ni->vol, (u8 *)a +
				le16_to_cpu(a->data.non_resident.mapping_pairs_offset),
				mp_size, start_rl, stop_vcn, -1, &stop_vcn, &start_rl,
				&de_cnt);
		if (err < 0 && err != -ENOSPC) {
			ntfs_error(sb, "Failed to build MP");
			unmap_mft_record(ext_ni);
			if (ntfs_mft_record_free(ni->vol, ext_ni))
				ntfs_error(sb, "Couldn't free MFT record");
			goto put_err_out;
		}
		a->data.non_resident.highest_vcn = cpu_to_le64(stop_vcn - 1);
		mark_mft_record_dirty(ext_ni);
		unmap_mft_record(ext_ni);

		de_cluster_count += de_cnt;
		/* All mapping pairs has been written. */
		if (!err)
			break;
	}
out:
	if (from_vcn == 0)
		ni->i_dealloc_clusters = de_cluster_count;
	return 0;

put_err_out:
	if (ctx)
		ntfs_attr_put_search_ctx(ctx);
	return err;
}

/*
 * ntfs_attr_make_resident - convert a non-resident to a resident attribute
 * @ni:		open ntfs attribute to make resident
 * @ctx:	ntfs search context describing the attribute
 *
 * Convert a non-resident ntfs attribute to a resident one.
 */
static int ntfs_attr_make_resident(struct ntfs_inode *ni, struct ntfs_attr_search_ctx *ctx)
{
	struct ntfs_volume *vol = ni->vol;
	struct super_block *sb = vol->sb;
	struct attr_record *a = ctx->attr;
	int name_ofs, val_ofs, err;
	s64 arec_size;

	ntfs_debug("Entering for inode 0x%llx, attr 0x%x.\n",
			(unsigned long long)ni->mft_no, ni->type);

	/* Should be called for the first extent of the attribute. */
	if (le64_to_cpu(a->data.non_resident.lowest_vcn)) {
		ntfs_debug("Eeek!  Should be called for the first extent of the attribute.  Aborting...\n");
		return -EINVAL;
	}

	/* Some preliminary sanity checking. */
	if (!NInoNonResident(ni)) {
		ntfs_debug("Eeek!  Trying to make resident attribute resident. Aborting...\n");
		return -EINVAL;
	}

	/* Make sure this is not $MFT/$BITMAP or Windows will not boot! */
	if (ni->type == AT_BITMAP && ni->mft_no == FILE_MFT)
		return -EPERM;

	/* Check that the attribute is allowed to be resident. */
	err = ntfs_attr_can_be_resident(vol, ni->type);
	if (err)
		return err;

	if (NInoCompressed(ni) || NInoEncrypted(ni)) {
		ntfs_debug("Making compressed or encrypted files resident is not implemented yet.\n");
		return -EOPNOTSUPP;
	}

	/* Work out offsets into and size of the resident attribute. */
	name_ofs = 24; /* = sizeof(resident_struct attr_record); */
	val_ofs = (name_ofs + a->name_length * sizeof(__le16) + 7) & ~7;
	arec_size = (val_ofs + ni->data_size + 7) & ~7;

	/* Sanity check the size before we start modifying the attribute. */
	if (le32_to_cpu(ctx->mrec->bytes_in_use) - le32_to_cpu(a->length) +
	    arec_size > le32_to_cpu(ctx->mrec->bytes_allocated)) {
		ntfs_debug("Not enough space to make attribute resident\n");
		return -ENOSPC;
	}

	/* Read and cache the whole runlist if not already done. */
	err = ntfs_attr_map_whole_runlist(ni);
	if (err)
		return err;

	/* Move the attribute name if it exists and update the offset. */
	if (a->name_length) {
		memmove((u8 *)a + name_ofs, (u8 *)a + le16_to_cpu(a->name_offset),
				a->name_length * sizeof(__le16));
	}
	a->name_offset = cpu_to_le16(name_ofs);

	/* Resize the resident part of the attribute record. */
	if (ntfs_attr_record_resize(ctx->mrec, a, arec_size) < 0) {
		/*
		 * Bug, because ntfs_attr_record_resize should not fail (we
		 * already checked that attribute fits MFT record).
		 */
		ntfs_error(ctx->ntfs_ino->vol->sb, "BUG! Failed to resize attribute record. ");
		return -EIO;
	}

	/* Convert the attribute record to describe a resident attribute. */
	a->non_resident = 0;
	a->flags = 0;
	a->data.resident.value_length = cpu_to_le32(ni->data_size);
	a->data.resident.value_offset = cpu_to_le16(val_ofs);
	/*
	 * File names cannot be non-resident so we would never see this here
	 * but at least it serves as a reminder that there may be attributes
	 * for which we do need to set this flag. (AIA)
	 */
	if (a->type == AT_FILE_NAME)
		a->data.resident.flags = RESIDENT_ATTR_IS_INDEXED;
	else
		a->data.resident.flags = 0;
	a->data.resident.reserved = 0;

	/*
	 * Deallocate clusters from the runlist.
	 *
	 * NOTE: We can use ntfs_cluster_free() because we have already mapped
	 * the whole run list and thus it doesn't matter that the attribute
	 * record is in a transiently corrupted state at this moment in time.
	 */
	err = ntfs_cluster_free(ni, 0, -1, ctx);
	if (err) {
		ntfs_error(sb, "Eeek! Failed to release allocated clusters");
		ntfs_debug("Ignoring error and leaving behind wasted clusters.\n");
	}

	/* Throw away the now unused runlist. */
	kvfree(ni->runlist.rl);
	ni->runlist.rl = NULL;
	ni->runlist.count = 0;
	/* Update in-memory struct ntfs_attr. */
	NInoClearNonResident(ni);
	NInoClearCompressed(ni);
	ni->flags &= ~FILE_ATTR_COMPRESSED;
	NInoClearSparse(ni);
	ni->flags &= ~FILE_ATTR_SPARSE_FILE;
	NInoClearEncrypted(ni);
	ni->flags &= ~FILE_ATTR_ENCRYPTED;
	ni->initialized_size = ni->data_size;
	ni->allocated_size = ni->itype.compressed.size = (ni->data_size + 7) & ~7;
	ni->itype.compressed.block_size = 0;
	ni->itype.compressed.block_size_bits = ni->itype.compressed.block_clusters = 0;
	return 0;
}

/*
 * ntfs_non_resident_attr_shrink - shrink a non-resident, open ntfs attribute
 * @ni:		non-resident ntfs attribute to shrink
 * @newsize:	new size (in bytes) to which to shrink the attribute
 *
 * Reduce the size of a non-resident, open ntfs attribute @na to @newsize bytes.
 */
static int ntfs_non_resident_attr_shrink(struct ntfs_inode *ni, const s64 newsize)
{
	struct ntfs_volume *vol;
	struct ntfs_attr_search_ctx *ctx;
	s64 first_free_vcn;
	s64 nr_freed_clusters;
	int err;
	struct ntfs_inode *base_ni;

	ntfs_debug("Inode 0x%llx attr 0x%x new size %lld\n",
		(unsigned long long)ni->mft_no, ni->type, (long long)newsize);

	vol = ni->vol;

	if (NInoAttr(ni))
		base_ni = ni->ext.base_ntfs_ino;
	else
		base_ni = ni;

	/*
	 * Check the attribute type and the corresponding minimum size
	 * against @newsize and fail if @newsize is too small.
	 */
	err = ntfs_attr_size_bounds_check(vol, ni->type, newsize);
	if (err) {
		if (err == -ERANGE)
			ntfs_debug("Eeek! Size bounds check failed. Aborting...\n");
		else if (err == -ENOENT)
			err = -EIO;
		return err;
	}

	/* The first cluster outside the new allocation. */
	if (NInoCompressed(ni))
		/*
		 * For compressed files we must keep full compressions blocks,
		 * but currently we do not decompress/recompress the last
		 * block to truncate the data, so we may leave more allocated
		 * clusters than really needed.
		 */
		first_free_vcn = ntfs_bytes_to_cluster(vol,
				((newsize - 1) | (ni->itype.compressed.block_size - 1)) + 1);
	else
		first_free_vcn =
			ntfs_bytes_to_cluster(vol, newsize + vol->cluster_size - 1);

	if (first_free_vcn < 0)
		return -EINVAL;
	/*
	 * Compare the new allocation with the old one and only deallocate
	 * clusters if there is a change.
	 */
	if (ntfs_bytes_to_cluster(vol, ni->allocated_size) != first_free_vcn) {
		struct ntfs_attr_search_ctx *ctx;

		err = ntfs_attr_map_whole_runlist(ni);
		if (err) {
			ntfs_debug("Eeek! ntfs_attr_map_whole_runlist failed.\n");
			return err;
		}

		ctx = ntfs_attr_get_search_ctx(ni, NULL);
		if (!ctx) {
			ntfs_error(vol->sb, "%s: Failed to get search context", __func__);
			return -ENOMEM;
		}

		/* Deallocate all clusters starting with the first free one. */
		nr_freed_clusters = ntfs_cluster_free(ni, first_free_vcn, -1, ctx);
		if (nr_freed_clusters < 0) {
			ntfs_debug("Eeek! Freeing of clusters failed. Aborting...\n");
			ntfs_attr_put_search_ctx(ctx);
			return (int)nr_freed_clusters;
		}
		ntfs_attr_put_search_ctx(ctx);

		/* Truncate the runlist itself. */
		if (ntfs_rl_truncate_nolock(vol, &ni->runlist, first_free_vcn)) {
			/*
			 * Failed to truncate the runlist, so just throw it
			 * away, it will be mapped afresh on next use.
			 */
			kvfree(ni->runlist.rl);
			ni->runlist.rl = NULL;
			ntfs_error(vol->sb, "Eeek! Run list truncation failed.\n");
			return -EIO;
		}

		/* Prepare to mapping pairs update. */
		ni->allocated_size = ntfs_cluster_to_bytes(vol, first_free_vcn);

		if (NInoSparse(ni) || NInoCompressed(ni)) {
			if (nr_freed_clusters) {
				ni->itype.compressed.size -=
					ntfs_cluster_to_bytes(vol, nr_freed_clusters);
				VFS_I(base_ni)->i_blocks = ni->itype.compressed.size >> 9;
			}
		} else
			VFS_I(base_ni)->i_blocks = ni->allocated_size >> 9;

		/* Write mapping pairs for new runlist. */
		err = ntfs_attr_update_mapping_pairs(ni, 0 /*first_free_vcn*/);
		if (err) {
			ntfs_debug("Eeek! Mapping pairs update failed. Leaving inconstant metadata. Run chkdsk.\n");
			return err;
		}
	}

	/* Get the first attribute record. */
	ctx = ntfs_attr_get_search_ctx(base_ni, NULL);
	if (!ctx) {
		ntfs_error(vol->sb, "%s: Failed to get search context", __func__);
		return -ENOMEM;
	}

	err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len, CASE_SENSITIVE,
				0, NULL, 0, ctx);
	if (err) {
		if (err == -ENOENT)
			err = -EIO;
		ntfs_debug("Eeek! Lookup of first attribute extent failed. Leaving inconstant metadata.\n");
		goto put_err_out;
	}

	/* Update data and initialized size. */
	ni->data_size = newsize;
	ctx->attr->data.non_resident.data_size = cpu_to_le64(newsize);
	if (newsize < ni->initialized_size) {
		ni->initialized_size = newsize;
		ctx->attr->data.non_resident.initialized_size = cpu_to_le64(newsize);
	}
	/* Update data size in the index. */
	if (ni->type == AT_DATA && ni->name == AT_UNNAMED)
		NInoSetFileNameDirty(ni);

	/* If the attribute now has zero size, make it resident. */
	if (!newsize && !NInoEncrypted(ni) && !NInoCompressed(ni)) {
		err = ntfs_attr_make_resident(ni, ctx);
		if (err) {
			/* If couldn't make resident, just continue. */
			if (err != -EPERM)
				ntfs_error(ni->vol->sb,
					"Failed to make attribute resident. Leaving as is...\n");
		}
	}

	/* Set the inode dirty so it is written out later. */
	mark_mft_record_dirty(ctx->ntfs_ino);
	/* Done! */
	ntfs_attr_put_search_ctx(ctx);
	return 0;
put_err_out:
	ntfs_attr_put_search_ctx(ctx);
	return err;
}

/*
 * ntfs_non_resident_attr_expand - expand a non-resident, open ntfs attribute
 * @ni:			non-resident ntfs attribute to expand
 * @prealloc_size:	preallocation size (in bytes) to which to expand the attribute
 * @newsize:		new size (in bytes) to which to expand the attribute
 * @holes:		how to create a hole if expanding
 * @need_lock:		whether mrec lock is needed or not
 *
 * Expand the size of a non-resident, open ntfs attribute @na to @newsize bytes,
 * by allocating new clusters.
 */
static int ntfs_non_resident_attr_expand(struct ntfs_inode *ni, const s64 newsize,
		const s64 prealloc_size, unsigned int holes, bool need_lock)
{
	s64 lcn_seek_from;
	s64 first_free_vcn;
	struct ntfs_volume *vol;
	struct ntfs_attr_search_ctx *ctx = NULL;
	struct runlist_element *rl, *rln;
	s64 org_alloc_size, org_compressed_size;
	int err, err2;
	struct ntfs_inode *base_ni;
	struct super_block *sb = ni->vol->sb;
	size_t new_rl_count;

	ntfs_debug("Inode 0x%llx, attr 0x%x, new size %lld old size %lld\n",
			(unsigned long long)ni->mft_no, ni->type,
			(long long)newsize, (long long)ni->data_size);

	vol = ni->vol;

	if (NInoAttr(ni))
		base_ni = ni->ext.base_ntfs_ino;
	else
		base_ni = ni;

	/*
	 * Check the attribute type and the corresponding maximum size
	 * against @newsize and fail if @newsize is too big.
	 */
	err = ntfs_attr_size_bounds_check(vol, ni->type, newsize);
	if (err	< 0) {
		ntfs_error(sb, "%s: bounds check failed", __func__);
		return err;
	}

	/* Save for future use. */
	org_alloc_size = ni->allocated_size;
	org_compressed_size = ni->itype.compressed.size;

	/* The first cluster outside the new allocation. */
	if (prealloc_size)
		first_free_vcn =
			ntfs_bytes_to_cluster(vol, prealloc_size + vol->cluster_size - 1);
	else
		first_free_vcn =
			ntfs_bytes_to_cluster(vol, newsize + vol->cluster_size - 1);
	if (first_free_vcn < 0)
		return -EFBIG;

	/*
	 * Compare the new allocation with the old one and only allocate
	 * clusters if there is a change.
	 */
	if (ntfs_bytes_to_cluster(vol, ni->allocated_size) < first_free_vcn) {
		err = ntfs_attr_map_whole_runlist(ni);
		if (err) {
			ntfs_error(sb, "ntfs_attr_map_whole_runlist failed");
			return err;
		}

		/*
		 * If we extend $DATA attribute on NTFS 3+ volume, we can add
		 * sparse runs instead of real allocation of clusters.
		 */
		if ((ni->type == AT_DATA && (vol->major_ver >= 3 || !NInoSparseDisabled(ni))) &&
		    (holes != HOLES_NO)) {
			if (NInoCompressed(ni)) {
				int last = 0, i = 0;
				s64 alloc_size;
				u64 more_entries = round_up(first_free_vcn -
						 ntfs_bytes_to_cluster(vol, ni->allocated_size),
						 ni->itype.compressed.block_clusters);

				do_div(more_entries, ni->itype.compressed.block_clusters);

				while (ni->runlist.rl[last].length)
					last++;

				rl = ntfs_rl_realloc(ni->runlist.rl, last + 1,
						last + more_entries + 1);
				if (IS_ERR(rl)) {
					err = -ENOMEM;
					goto put_err_out;
				}

				alloc_size = ni->allocated_size;
				while (i++ < more_entries) {
					rl[last].vcn = ntfs_bytes_to_cluster(vol,
							round_up(alloc_size, vol->cluster_size));
					rl[last].length = ni->itype.compressed.block_clusters -
						(rl[last].vcn &
						 (ni->itype.compressed.block_clusters - 1));
					rl[last].lcn = LCN_HOLE;
					last++;
					alloc_size += ni->itype.compressed.block_size;
				}

				rl[last].vcn = first_free_vcn;
				rl[last].lcn = LCN_ENOENT;
				rl[last].length = 0;

				ni->runlist.rl = rl;
				ni->runlist.count += more_entries;
			} else {
				rl = kmalloc(sizeof(struct runlist_element) * 2, GFP_NOFS);
				if (!rl) {
					err = -ENOMEM;
					goto put_err_out;
				}

				rl[0].vcn = ntfs_bytes_to_cluster(vol, ni->allocated_size);
				rl[0].lcn = LCN_HOLE;
				rl[0].length = first_free_vcn -
					ntfs_bytes_to_cluster(vol, ni->allocated_size);
				rl[1].vcn = first_free_vcn;
				rl[1].lcn = LCN_ENOENT;
				rl[1].length = 0;
			}
		} else {
			/*
			 * Determine first after last LCN of attribute.
			 * We will start seek clusters from this LCN to avoid
			 * fragmentation.  If there are no valid LCNs in the
			 * attribute let the cluster allocator choose the
			 * starting LCN.
			 */
			lcn_seek_from = -1;
			if (ni->runlist.rl->length) {
				/* Seek to the last run list element. */
				for (rl = ni->runlist.rl; (rl + 1)->length; rl++)
					;
				/*
				 * If the last LCN is a hole or similar seek
				 * back to last valid LCN.
				 */
				while (rl->lcn < 0 && rl != ni->runlist.rl)
					rl--;
				/*
				 * Only set lcn_seek_from it the LCN is valid.
				 */
				if (rl->lcn >= 0)
					lcn_seek_from = rl->lcn + rl->length;
			}

			rl = ntfs_cluster_alloc(vol,
					ntfs_bytes_to_cluster(vol, ni->allocated_size),
					first_free_vcn -
					ntfs_bytes_to_cluster(vol, ni->allocated_size),
					lcn_seek_from, DATA_ZONE, false, false, false);
			if (IS_ERR(rl)) {
				ntfs_debug("Cluster allocation failed (%lld)",
						(long long)first_free_vcn -
						ntfs_bytes_to_cluster(vol, ni->allocated_size));
				return PTR_ERR(rl);
			}
		}

		if (!NInoCompressed(ni)) {
			/* Append new clusters to attribute runlist. */
			rln = ntfs_runlists_merge(&ni->runlist, rl, 0, &new_rl_count);
			if (IS_ERR(rln)) {
				/* Failed, free just allocated clusters. */
				ntfs_error(sb, "Run list merge failed");
				ntfs_cluster_free_from_rl(vol, rl);
				kvfree(rl);
				return -EIO;
			}
			ni->runlist.rl = rln;
			ni->runlist.count = new_rl_count;
		}

		/* Prepare to mapping pairs update. */
		ni->allocated_size = ntfs_cluster_to_bytes(vol, first_free_vcn);
		err = ntfs_attr_update_mapping_pairs(ni, 0);
		if (err) {
			ntfs_debug("Mapping pairs update failed");
			goto rollback;
		}
	}

	ctx = ntfs_attr_get_search_ctx(base_ni, NULL);
	if (!ctx) {
		err = -ENOMEM;
		if (ni->allocated_size == org_alloc_size)
			return err;
		goto rollback;
	}

	err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len, CASE_SENSITIVE,
			       0, NULL, 0, ctx);
	if (err) {
		if (err == -ENOENT)
			err = -EIO;
		if (ni->allocated_size != org_alloc_size)
			goto rollback;
		goto put_err_out;
	}

	/* Update data size. */
	ni->data_size = newsize;
	ctx->attr->data.non_resident.data_size = cpu_to_le64(newsize);
	/* Update data size in the index. */
	if (ni->type == AT_DATA && ni->name == AT_UNNAMED)
		NInoSetFileNameDirty(ni);
	/* Set the inode dirty so it is written out later. */
	mark_mft_record_dirty(ctx->ntfs_ino);
	/* Done! */
	ntfs_attr_put_search_ctx(ctx);
	return 0;
rollback:
	/* Free allocated clusters. */
	err2 = ntfs_cluster_free(ni, ntfs_bytes_to_cluster(vol, org_alloc_size),
				-1, ctx);
	if (err2)
		ntfs_debug("Leaking clusters");

	/* Now, truncate the runlist itself. */
	if (need_lock)
		down_write(&ni->runlist.lock);
	err2 = ntfs_rl_truncate_nolock(vol, &ni->runlist,
			ntfs_bytes_to_cluster(vol, org_alloc_size));
	if (need_lock)
		up_write(&ni->runlist.lock);
	if (err2) {
		/*
		 * Failed to truncate the runlist, so just throw it away, it
		 * will be mapped afresh on next use.
		 */
		kvfree(ni->runlist.rl);
		ni->runlist.rl = NULL;
		ntfs_error(sb, "Couldn't truncate runlist. Rollback failed");
	} else {
		/* Prepare to mapping pairs update. */
		ni->allocated_size = org_alloc_size;
		/* Restore mapping pairs. */
		if (need_lock)
			down_read(&ni->runlist.lock);
		if (ntfs_attr_update_mapping_pairs(ni, 0))
			ntfs_error(sb, "Failed to restore old mapping pairs");
		if (need_lock)
			up_read(&ni->runlist.lock);

		if (NInoSparse(ni) || NInoCompressed(ni)) {
			ni->itype.compressed.size =  org_compressed_size;
			VFS_I(base_ni)->i_blocks = ni->itype.compressed.size >> 9;
		} else
			VFS_I(base_ni)->i_blocks = ni->allocated_size >> 9;
	}
	if (ctx)
		ntfs_attr_put_search_ctx(ctx);
	return err;
put_err_out:
	if (ctx)
		ntfs_attr_put_search_ctx(ctx);
	return err;
}

/*
 * ntfs_resident_attr_resize - resize a resident, open ntfs attribute
 * @attr_ni:		resident ntfs inode to resize
 * @newsize:		new size (in bytes) to which to resize the attribute
 * @prealloc_size:	preallocation size (in bytes) to which to resize the attribute
 * @holes:		flags indicating how to handle holes
 *
 * Change the size of a resident, open ntfs attribute @na to @newsize bytes.
 */
static int ntfs_resident_attr_resize(struct ntfs_inode *attr_ni, const s64 newsize,
		const s64 prealloc_size, unsigned int holes)
{
	struct ntfs_attr_search_ctx *ctx;
	struct ntfs_volume *vol = attr_ni->vol;
	struct super_block *sb = vol->sb;
	int err = -EIO;
	struct ntfs_inode *base_ni, *ext_ni = NULL;

attr_resize_again:
	ntfs_debug("Inode 0x%llx attr 0x%x new size %lld\n",
			(unsigned long long)attr_ni->mft_no, attr_ni->type,
			(long long)newsize);

	if (NInoAttr(attr_ni))
		base_ni = attr_ni->ext.base_ntfs_ino;
	else
		base_ni = attr_ni;

	/* Get the attribute record that needs modification. */
	ctx = ntfs_attr_get_search_ctx(base_ni, NULL);
	if (!ctx) {
		ntfs_error(sb, "%s: Failed to get search context", __func__);
		return -ENOMEM;
	}

	err = ntfs_attr_lookup(attr_ni->type, attr_ni->name, attr_ni->name_len,
			0, 0, NULL, 0, ctx);
	if (err) {
		ntfs_error(sb, "ntfs_attr_lookup failed");
		goto put_err_out;
	}

	/*
	 * Check the attribute type and the corresponding minimum and maximum
	 * sizes against @newsize and fail if @newsize is out of bounds.
	 */
	err = ntfs_attr_size_bounds_check(vol, attr_ni->type, newsize);
	if (err) {
		if (err == -ENOENT)
			err = -EIO;
		ntfs_debug("%s: bounds check failed", __func__);
		goto put_err_out;
	}
	/*
	 * If @newsize is bigger than the mft record we need to make the
	 * attribute non-resident if the attribute type supports it. If it is
	 * smaller we can go ahead and attempt the resize.
	 */
	if (newsize < vol->mft_record_size) {
		/* Perform the resize of the attribute record. */
		err = ntfs_resident_attr_value_resize(ctx->mrec, ctx->attr,
					newsize);
		if (!err) {
			/* Update attribute size everywhere. */
			attr_ni->data_size = attr_ni->initialized_size = newsize;
			attr_ni->allocated_size = (newsize + 7) & ~7;
			if (NInoCompressed(attr_ni) || NInoSparse(attr_ni))
				attr_ni->itype.compressed.size = attr_ni->allocated_size;
			if (attr_ni->type == AT_DATA && attr_ni->name == AT_UNNAMED)
				NInoSetFileNameDirty(attr_ni);
			goto resize_done;
		}

		/* Prefer AT_INDEX_ALLOCATION instead of AT_ATTRIBUTE_LIST */
		if (err == -ENOSPC && ctx->attr->type == AT_INDEX_ROOT)
			goto put_err_out;

	}
	/* There is not enough space in the mft record to perform the resize. */

	/* Make the attribute non-resident if possible. */
	err = ntfs_attr_make_non_resident(attr_ni,
			le32_to_cpu(ctx->attr->data.resident.value_length));
	if (!err) {
		mark_mft_record_dirty(ctx->ntfs_ino);
		ntfs_attr_put_search_ctx(ctx);
		/* Resize non-resident attribute */
		return ntfs_non_resident_attr_expand(attr_ni, newsize, prealloc_size, holes, true);
	} else if (err != -ENOSPC && err != -EPERM) {
		ntfs_error(sb, "Failed to make attribute non-resident");
		goto put_err_out;
	}

	/* Try to make other attributes non-resident and retry each time. */
	ntfs_attr_reinit_search_ctx(ctx);
	while (!(err = ntfs_attr_lookup(AT_UNUSED, NULL, 0, 0, 0, NULL, 0, ctx))) {
		struct inode *tvi;
		struct attr_record *a;

		a = ctx->attr;
		if (a->non_resident || a->type == AT_ATTRIBUTE_LIST)
			continue;

		if (ntfs_attr_can_be_non_resident(vol, a->type))
			continue;

		/*
		 * Check out whether convert is reasonable. Assume that mapping
		 * pairs will take 8 bytes.
		 */
		if (le32_to_cpu(a->length) <= (sizeof(struct attr_record) - sizeof(s64)) +
				((a->name_length * sizeof(__le16) + 7) & ~7) + 8)
			continue;

		if (a->type == AT_DATA)
			tvi = ntfs_iget(sb, base_ni->mft_no);
		else
			tvi = ntfs_attr_iget(VFS_I(base_ni), a->type,
				(__le16 *)((u8 *)a + le16_to_cpu(a->name_offset)),
				a->name_length);
		if (IS_ERR(tvi)) {
			ntfs_error(sb, "Couldn't open attribute");
			continue;
		}

		if (ntfs_attr_make_non_resident(NTFS_I(tvi),
		    le32_to_cpu(ctx->attr->data.resident.value_length))) {
			iput(tvi);
			continue;
		}

		mark_mft_record_dirty(ctx->ntfs_ino);
		iput(tvi);
		ntfs_attr_put_search_ctx(ctx);
		goto attr_resize_again;
	}

	/* Check whether error occurred. */
	if (err != -ENOENT) {
		ntfs_error(sb, "%s: Attribute lookup failed 1", __func__);
		goto put_err_out;
	}

	/*
	 * The standard information and attribute list attributes can't be
	 * moved out from the base MFT record, so try to move out others.
	 */
	if (attr_ni->type == AT_STANDARD_INFORMATION ||
	    attr_ni->type == AT_ATTRIBUTE_LIST) {
		ntfs_attr_put_search_ctx(ctx);

		if (!NInoAttrList(base_ni)) {
			err = ntfs_inode_add_attrlist(base_ni);
			if (err)
				return err;
		}

		err = ntfs_inode_free_space(base_ni, sizeof(struct attr_record));
		if (err) {
			err = -ENOSPC;
			ntfs_error(sb,
				"Couldn't free space in the MFT record to make attribute list non resident");
			return err;
		}
		err = ntfs_attrlist_update(base_ni);
		if (err)
			return err;
		goto attr_resize_again;
	}

	/*
	 * Move the attribute to a new mft record, creating an attribute list
	 * attribute or modifying it if it is already present.
	 */

	/* Point search context back to attribute which we need resize. */
	ntfs_attr_reinit_search_ctx(ctx);
	err = ntfs_attr_lookup(attr_ni->type, attr_ni->name, attr_ni->name_len,
			CASE_SENSITIVE, 0, NULL, 0, ctx);
	if (err) {
		ntfs_error(sb, "%s: Attribute lookup failed 2", __func__);
		goto put_err_out;
	}

	/*
	 * Check whether attribute is already single in this MFT record.
	 * 8 added for the attribute terminator.
	 */
	if (le32_to_cpu(ctx->mrec->bytes_in_use) ==
	    le16_to_cpu(ctx->mrec->attrs_offset) + le32_to_cpu(ctx->attr->length) + 8) {
		err = -ENOSPC;
		ntfs_debug("MFT record is filled with one attribute\n");
		goto put_err_out;
	}

	/* Add attribute list if not present. */
	if (!NInoAttrList(base_ni)) {
		ntfs_attr_put_search_ctx(ctx);
		err = ntfs_inode_add_attrlist(base_ni);
		if (err)
			return err;
		goto attr_resize_again;
	}

	/* Allocate new mft record. */
	err = ntfs_mft_record_alloc(base_ni->vol, 0, &ext_ni, base_ni, NULL);
	if (err) {
		ntfs_error(sb, "Couldn't allocate MFT record");
		goto put_err_out;
	}
	unmap_mft_record(ext_ni);

	/* Move attribute to it. */
	err = ntfs_attr_record_move_to(ctx, ext_ni);
	if (err) {
		ntfs_error(sb, "Couldn't move attribute to new MFT record");
		err = -ENOMEM;
		goto put_err_out;
	}

	err = ntfs_attrlist_update(base_ni);
	if (err < 0)
		goto put_err_out;

	ntfs_attr_put_search_ctx(ctx);
	/* Try to perform resize once again. */
	goto attr_resize_again;

resize_done:
	/*
	 * Set the inode (and its base inode if it exists) dirty so it is
	 * written out later.
	 */
	mark_mft_record_dirty(ctx->ntfs_ino);
	ntfs_attr_put_search_ctx(ctx);
	return 0;

put_err_out:
	ntfs_attr_put_search_ctx(ctx);
	return err;
}

int __ntfs_attr_truncate_vfs(struct ntfs_inode *ni, const s64 newsize,
		const s64 i_size)
{
	int err = 0;

	if (newsize < 0 ||
	    (ni->mft_no == FILE_MFT && ni->type == AT_DATA)) {
		ntfs_debug("Invalid arguments passed.\n");
		return -EINVAL;
	}

	ntfs_debug("Entering for inode 0x%llx, attr 0x%x, size %lld\n",
			(unsigned long long)ni->mft_no, ni->type, newsize);

	if (NInoNonResident(ni)) {
		if (newsize > i_size) {
			down_write(&ni->runlist.lock);
			err = ntfs_non_resident_attr_expand(ni, newsize, 0,
							    NVolDisableSparse(ni->vol) ?
							    HOLES_NO : HOLES_OK,
							    false);
			up_write(&ni->runlist.lock);
		} else
			err = ntfs_non_resident_attr_shrink(ni, newsize);
	} else
		err = ntfs_resident_attr_resize(ni, newsize, 0,
						NVolDisableSparse(ni->vol) ?
						HOLES_NO : HOLES_OK);
	ntfs_debug("Return status %d\n", err);
	return err;
}

int ntfs_attr_expand(struct ntfs_inode *ni, const s64 newsize, const s64 prealloc_size)
{
	int err = 0;

	if (newsize < 0 ||
	    (ni->mft_no == FILE_MFT && ni->type == AT_DATA)) {
		ntfs_debug("Invalid arguments passed.\n");
		return -EINVAL;
	}

	ntfs_debug("Entering for inode 0x%llx, attr 0x%x, size %lld\n",
			(unsigned long long)ni->mft_no, ni->type, newsize);

	if (ni->data_size == newsize) {
		ntfs_debug("Size is already ok\n");
		return 0;
	}

	/*
	 * Encrypted attributes are not supported. We return access denied,
	 * which is what Windows NT4 does, too.
	 */
	if (NInoEncrypted(ni)) {
		pr_err("Failed to truncate encrypted attribute\n");
		return -EACCES;
	}

	if (NInoNonResident(ni)) {
		if (newsize > ni->data_size)
			err = ntfs_non_resident_attr_expand(ni, newsize, prealloc_size,
							    NVolDisableSparse(ni->vol) ?
							    HOLES_NO : HOLES_OK, true);
	} else
		err = ntfs_resident_attr_resize(ni, newsize, prealloc_size,
						NVolDisableSparse(ni->vol) ?
						HOLES_NO : HOLES_OK);
	if (!err)
		i_size_write(VFS_I(ni), newsize);
	ntfs_debug("Return status %d\n", err);
	return err;
}

/*
 * ntfs_attr_truncate_i - resize an ntfs attribute
 * @ni:		open ntfs inode to resize
 * @newsize:	new size (in bytes) to which to resize the attribute
 * @holes:	how to create a hole if expanding
 *
 * Change the size of an open ntfs attribute @na to @newsize bytes. If the
 * attribute is made bigger and the attribute is resident the newly
 * "allocated" space is cleared and if the attribute is non-resident the
 * newly allocated space is marked as not initialised and no real allocation
 * on disk is performed.
 */
int ntfs_attr_truncate_i(struct ntfs_inode *ni, const s64 newsize, unsigned int holes)
{
	int err;

	if (newsize < 0 ||
	    (ni->mft_no == FILE_MFT && ni->type == AT_DATA)) {
		ntfs_debug("Invalid arguments passed.\n");
		return -EINVAL;
	}

	ntfs_debug("Entering for inode 0x%llx, attr 0x%x, size %lld\n",
			(unsigned long long)ni->mft_no, ni->type, newsize);

	if (ni->data_size == newsize) {
		ntfs_debug("Size is already ok\n");
		return 0;
	}

	/*
	 * Encrypted attributes are not supported. We return access denied,
	 * which is what Windows NT4 does, too.
	 */
	if (NInoEncrypted(ni)) {
		pr_err("Failed to truncate encrypted attribute\n");
		return -EACCES;
	}

	if (NInoCompressed(ni)) {
		pr_err("Failed to truncate compressed attribute\n");
		return -EOPNOTSUPP;
	}

	if (NInoNonResident(ni)) {
		if (newsize > ni->data_size)
			err = ntfs_non_resident_attr_expand(ni, newsize, 0, holes, true);
		else
			err = ntfs_non_resident_attr_shrink(ni, newsize);
	} else
		err = ntfs_resident_attr_resize(ni, newsize, 0, holes);
	ntfs_debug("Return status %d\n", err);
	return err;
}

/*
 * Resize an attribute, creating a hole if relevant
 */
int ntfs_attr_truncate(struct ntfs_inode *ni, const s64 newsize)
{
	return ntfs_attr_truncate_i(ni, newsize,
				    NVolDisableSparse(ni->vol) ?
				    HOLES_NO : HOLES_OK);
}

int ntfs_attr_map_cluster(struct ntfs_inode *ni, s64 vcn_start, s64 *lcn_start,
		s64 *lcn_count, s64 max_clu_count, bool *balloc, bool update_mp,
		bool skip_holes)
{
	struct ntfs_volume *vol = ni->vol;
	struct ntfs_attr_search_ctx *ctx;
	struct runlist_element *rl, *rlc;
	s64 vcn = vcn_start, lcn, clu_count;
	s64 lcn_seek_from = -1;
	int err = 0;
	size_t new_rl_count;

	err = ntfs_attr_map_whole_runlist(ni);
	if (err)
		return err;

	if (NInoAttr(ni))
		ctx = ntfs_attr_get_search_ctx(ni->ext.base_ntfs_ino, NULL);
	else
		ctx = ntfs_attr_get_search_ctx(ni, NULL);
	if (!ctx) {
		ntfs_error(vol->sb, "%s: Failed to get search context", __func__);
		return -ENOMEM;
	}

	err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
			CASE_SENSITIVE, vcn, NULL, 0, ctx);
	if (err) {
		ntfs_error(vol->sb,
			   "ntfs_attr_lookup failed, ntfs inode(mft_no : %llu) type : 0x%x, err : %d",
			   ni->mft_no, ni->type, err);
		goto out;
	}

	rl = ntfs_attr_find_vcn_nolock(ni, vcn, ctx);
	if (IS_ERR(rl)) {
		ntfs_error(vol->sb, "Failed to find run after mapping runlist.");
		err = PTR_ERR(rl);
		goto out;
	}

	lcn = ntfs_rl_vcn_to_lcn(rl, vcn);
	clu_count = min(max_clu_count, rl->length - (vcn - rl->vcn));
	if (lcn >= LCN_HOLE) {
		if (lcn > LCN_DELALLOC ||
		    (lcn == LCN_HOLE && skip_holes)) {
			*lcn_start = lcn;
			*lcn_count = clu_count;
			*balloc = false;
			goto out;
		}
	} else {
		WARN_ON(lcn == LCN_RL_NOT_MAPPED);
		if (lcn == LCN_ENOENT)
			err = -ENOENT;
		else
			err = -EIO;
		goto out;
	}

	/* Search backwards to find the best lcn to start seek from. */
	rlc = rl;
	while (rlc->vcn) {
		rlc--;
		if (rlc->lcn >= 0) {
			/*
			 * avoid fragmenting a compressed file
			 * Windows does not do that, and that may
			 * not be desirable for files which can
			 * be updated
			 */
			if (NInoCompressed(ni))
				lcn_seek_from = rlc->lcn + rlc->length;
			else
				lcn_seek_from = rlc->lcn + (vcn - rlc->vcn);
			break;
		}
	}

	if (lcn_seek_from == -1) {
		/* Backwards search failed, search forwards. */
		rlc = rl;
		while (rlc->length) {
			rlc++;
			if (rlc->lcn >= 0) {
				lcn_seek_from = rlc->lcn - (rlc->vcn - vcn);
				if (lcn_seek_from < -1)
					lcn_seek_from = -1;
				break;
			}
		}
	}

	rlc = ntfs_cluster_alloc(vol, vcn, clu_count, lcn_seek_from, DATA_ZONE,
			false, true, true);
	if (IS_ERR(rlc)) {
		err = PTR_ERR(rlc);
		goto out;
	}

	WARN_ON(rlc->vcn != vcn);
	lcn = rlc->lcn;
	clu_count = rlc->length;

	rl = ntfs_runlists_merge(&ni->runlist, rlc, 0, &new_rl_count);
	if (IS_ERR(rl)) {
		ntfs_error(vol->sb, "Failed to merge runlists");
		err = PTR_ERR(rl);
		if (ntfs_cluster_free_from_rl(vol, rlc))
			ntfs_error(vol->sb, "Failed to free hot clusters.");
		kvfree(rlc);
		goto out;
	}
	ni->runlist.rl = rl;
	ni->runlist.count = new_rl_count;

	if (!update_mp) {
		u64 free = atomic64_read(&vol->free_clusters) * 100;

		do_div(free, vol->nr_clusters);
		if (free <= 5)
			update_mp = true;
	}

	if (update_mp) {
		ntfs_attr_reinit_search_ctx(ctx);
		err = ntfs_attr_update_mapping_pairs(ni, 0);
		if (err) {
			int err2;

			err2 = ntfs_cluster_free(ni, vcn, clu_count, ctx);
			if (err2 < 0)
				ntfs_error(vol->sb,
					   "Failed to free cluster allocation. Leaving inconstant metadata.\n");
			goto out;
		}
	} else {
		VFS_I(ni)->i_blocks += clu_count << (vol->cluster_size_bits - 9);
		NInoSetRunlistDirty(ni);
		mark_mft_record_dirty(ni);
	}

	*lcn_start = lcn;
	*lcn_count = clu_count;
	*balloc = true;
out:
	ntfs_attr_put_search_ctx(ctx);
	return err;
}

/*
 * ntfs_attr_rm - remove attribute from ntfs inode
 * @ni:		opened ntfs attribute to delete
 *
 * Remove attribute and all it's extents from ntfs inode. If attribute was non
 * resident also free all clusters allocated by attribute.
 */
int ntfs_attr_rm(struct ntfs_inode *ni)
{
	struct ntfs_attr_search_ctx *ctx;
	int err = 0, ret = 0;
	struct ntfs_inode *base_ni;
	struct super_block *sb = ni->vol->sb;

	if (NInoAttr(ni))
		base_ni = ni->ext.base_ntfs_ino;
	else
		base_ni = ni;

	ntfs_debug("Entering for inode 0x%llx, attr 0x%x.\n",
			(long long) ni->mft_no, ni->type);

	/* Free cluster allocation. */
	if (NInoNonResident(ni)) {
		struct ntfs_attr_search_ctx *ctx;

		err = ntfs_attr_map_whole_runlist(ni);
		if (err)
			return err;
		ctx = ntfs_attr_get_search_ctx(ni, NULL);
		if (!ctx) {
			ntfs_error(sb, "%s: Failed to get search context", __func__);
			return -ENOMEM;
		}

		ret = ntfs_cluster_free(ni, 0, -1, ctx);
		if (ret < 0)
			ntfs_error(sb,
				"Failed to free cluster allocation. Leaving inconstant metadata.\n");
		ntfs_attr_put_search_ctx(ctx);
	}

	/* Search for attribute extents and remove them all. */
	ctx = ntfs_attr_get_search_ctx(base_ni, NULL);
	if (!ctx) {
		ntfs_error(sb, "%s: Failed to get search context", __func__);
		return -ENOMEM;
	}
	while (!(err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
				CASE_SENSITIVE, 0, NULL, 0, ctx))) {
		err = ntfs_attr_record_rm(ctx);
		if (err) {
			ntfs_error(sb,
				"Failed to remove attribute extent. Leaving inconstant metadata.\n");
			ret = err;
		}
		ntfs_attr_reinit_search_ctx(ctx);
	}
	ntfs_attr_put_search_ctx(ctx);
	if (err != -ENOENT) {
		ntfs_error(sb, "Attribute lookup failed. Probably leaving inconstant metadata.\n");
		ret = err;
	}

	return ret;
}

int ntfs_attr_exist(struct ntfs_inode *ni, const __le32 type, __le16 *name,
		u32 name_len)
{
	struct ntfs_attr_search_ctx *ctx;
	int ret;

	ntfs_debug("Entering\n");

	ctx = ntfs_attr_get_search_ctx(ni, NULL);
	if (!ctx) {
		ntfs_error(ni->vol->sb, "%s: Failed to get search context",
				__func__);
		return 0;
	}

	ret = ntfs_attr_lookup(type, name, name_len, CASE_SENSITIVE,
			0, NULL, 0, ctx);
	ntfs_attr_put_search_ctx(ctx);

	return !ret;
}

int ntfs_attr_remove(struct ntfs_inode *ni, const __le32 type, __le16 *name,
		u32 name_len)
{
	int err;
	struct inode *attr_vi;
	struct ntfs_inode *attr_ni;

	ntfs_debug("Entering\n");

	if (!ni)
		return -EINVAL;

	attr_vi = ntfs_attr_iget(VFS_I(ni), type, name, name_len);
	if (IS_ERR(attr_vi)) {
		err = PTR_ERR(attr_vi);
		ntfs_error(ni->vol->sb, "Failed to open attribute 0x%02x of inode 0x%llx",
				type, (unsigned long long)ni->mft_no);
		return err;
	}
	attr_ni = NTFS_I(attr_vi);

	err = ntfs_attr_rm(attr_ni);
	if (err)
		ntfs_error(ni->vol->sb, "Failed to remove attribute 0x%02x of inode 0x%llx",
				type, (unsigned long long)ni->mft_no);
	iput(attr_vi);
	return err;
}

/*
 * ntfs_attr_readall - read the entire data from an ntfs attribute
 * @ni:		open ntfs inode in which the ntfs attribute resides
 * @type:	attribute type
 * @name:	attribute name in little endian Unicode or AT_UNNAMED or NULL
 * @name_len:	length of attribute @name in Unicode characters (if @name given)
 * @data_size:	if non-NULL then store here the data size
 *
 * This function will read the entire content of an ntfs attribute.
 * If @name is AT_UNNAMED then look specifically for an unnamed attribute.
 * If @name is NULL then the attribute could be either named or not.
 * In both those cases @name_len is not used at all.
 *
 * On success a buffer is allocated with the content of the attribute
 * and which needs to be freed when it's not needed anymore. If the
 * @data_size parameter is non-NULL then the data size is set there.
 */
void *ntfs_attr_readall(struct ntfs_inode *ni, const __le32 type,
		__le16 *name, u32 name_len, s64 *data_size)
{
	struct ntfs_inode *bmp_ni;
	struct inode *bmp_vi;
	void *data, *ret = NULL;
	s64 size;
	struct super_block *sb = ni->vol->sb;

	ntfs_debug("Entering\n");

	bmp_vi = ntfs_attr_iget(VFS_I(ni), type, name, name_len);
	if (IS_ERR(bmp_vi)) {
		ntfs_debug("ntfs_attr_iget failed");
		goto err_exit;
	}
	bmp_ni = NTFS_I(bmp_vi);

	if (bmp_ni->data_size > NTFS_ATTR_READALL_MAX_SIZE &&
		(bmp_ni->type != AT_BITMAP ||
		bmp_ni->data_size > ((ni->vol->nr_clusters + 7) >> 3))) {
		ntfs_error(sb, "Invalid attribute data size");
		goto out;
	}

	data = kvmalloc(bmp_ni->data_size, GFP_NOFS);
	if (!data)
		goto out;

	size = ntfs_inode_attr_pread(VFS_I(bmp_ni), 0, bmp_ni->data_size,
			(u8 *)data);
	if (size != bmp_ni->data_size) {
		ntfs_error(sb, "ntfs_attr_pread failed");
		kvfree(data);
		goto out;
	}
	ret = data;
	if (data_size)
		*data_size = size;
out:
	iput(bmp_vi);
err_exit:
	ntfs_debug("\n");
	return ret;
}

int ntfs_non_resident_attr_insert_range(struct ntfs_inode *ni, s64 start_vcn, s64 len)
{
	struct ntfs_volume *vol = ni->vol;
	struct runlist_element *hole_rl, *rl;
	struct ntfs_attr_search_ctx *ctx;
	int ret;
	size_t new_rl_count;

	if (NInoAttr(ni) || ni->type != AT_DATA)
		return -EOPNOTSUPP;
	if (start_vcn > ntfs_bytes_to_cluster(vol, ni->allocated_size))
		return -EINVAL;

	hole_rl = kmalloc(sizeof(*hole_rl) * 2, GFP_NOFS);
	if (!hole_rl)
		return -ENOMEM;
	hole_rl[0].vcn = start_vcn;
	hole_rl[0].lcn = LCN_HOLE;
	hole_rl[0].length = len;
	hole_rl[1].vcn = start_vcn + len;
	hole_rl[1].lcn = LCN_ENOENT;
	hole_rl[1].length = 0;

	down_write(&ni->runlist.lock);
	ret = ntfs_attr_map_whole_runlist(ni);
	if (ret) {
		up_write(&ni->runlist.lock);
		return ret;
	}

	rl = ntfs_rl_find_vcn_nolock(ni->runlist.rl, start_vcn);
	if (!rl) {
		up_write(&ni->runlist.lock);
		kfree(hole_rl);
		return -EIO;
	}

	rl = ntfs_rl_insert_range(ni->runlist.rl, (int)ni->runlist.count,
				  hole_rl, 1, &new_rl_count);
	if (IS_ERR(rl)) {
		up_write(&ni->runlist.lock);
		kfree(hole_rl);
		return PTR_ERR(rl);
	}
	ni->runlist.rl =  rl;
	ni->runlist.count = new_rl_count;

	ni->allocated_size += ntfs_cluster_to_bytes(vol, len);
	ni->data_size += ntfs_cluster_to_bytes(vol, len);
	if (ntfs_cluster_to_bytes(vol, start_vcn) < ni->initialized_size)
		ni->initialized_size += ntfs_cluster_to_bytes(vol, len);
	ret = ntfs_attr_update_mapping_pairs(ni, 0);
	up_write(&ni->runlist.lock);
	if (ret)
		return ret;

	ctx = ntfs_attr_get_search_ctx(ni, NULL);
	if (!ctx) {
		ret = -ENOMEM;
		return ret;
	}

	ret = ntfs_attr_lookup(ni->type, ni->name, ni->name_len, CASE_SENSITIVE,
			       0, NULL, 0, ctx);
	if (ret) {
		ntfs_attr_put_search_ctx(ctx);
		return ret;
	}

	ctx->attr->data.non_resident.data_size = cpu_to_le64(ni->data_size);
	ctx->attr->data.non_resident.initialized_size = cpu_to_le64(ni->initialized_size);
	if (ni->type == AT_DATA && ni->name == AT_UNNAMED)
		NInoSetFileNameDirty(ni);
	mark_mft_record_dirty(ctx->ntfs_ino);
	ntfs_attr_put_search_ctx(ctx);
	return ret;
}

int ntfs_non_resident_attr_collapse_range(struct ntfs_inode *ni, s64 start_vcn, s64 len)
{
	struct ntfs_volume *vol = ni->vol;
	struct runlist_element *punch_rl, *rl;
	struct ntfs_attr_search_ctx *ctx = NULL;
	s64 end_vcn;
	int dst_cnt;
	int ret;
	size_t new_rl_cnt;

	if (NInoAttr(ni) || ni->type != AT_DATA)
		return -EOPNOTSUPP;

	end_vcn = ntfs_bytes_to_cluster(vol, ni->allocated_size);
	if (start_vcn >= end_vcn)
		return -EINVAL;

	down_write(&ni->runlist.lock);
	ret = ntfs_attr_map_whole_runlist(ni);
	if (ret) {
		up_write(&ni->runlist.lock);
		return ret;
	}

	len = min(len, end_vcn - start_vcn);
	for (rl = ni->runlist.rl, dst_cnt = 0; rl && rl->length; rl++)
		dst_cnt++;
	rl = ntfs_rl_find_vcn_nolock(ni->runlist.rl, start_vcn);
	if (!rl) {
		up_write(&ni->runlist.lock);
		return -EIO;
	}

	rl = ntfs_rl_collapse_range(ni->runlist.rl, dst_cnt + 1,
				    start_vcn, len, &punch_rl, &new_rl_cnt);
	if (IS_ERR(rl)) {
		up_write(&ni->runlist.lock);
		return PTR_ERR(rl);
	}
	ni->runlist.rl = rl;
	ni->runlist.count = new_rl_cnt;

	ni->allocated_size -= ntfs_cluster_to_bytes(vol, len);
	if (ni->data_size > ntfs_cluster_to_bytes(vol, start_vcn)) {
		if (ni->data_size > ntfs_cluster_to_bytes(vol, (start_vcn + len)))
			ni->data_size -= ntfs_cluster_to_bytes(vol, len);
		else
			ni->data_size = ntfs_cluster_to_bytes(vol, start_vcn);
	}
	if (ni->initialized_size > ntfs_cluster_to_bytes(vol, start_vcn)) {
		if (ni->initialized_size >
		    ntfs_cluster_to_bytes(vol, start_vcn + len))
			ni->initialized_size -= ntfs_cluster_to_bytes(vol, len);
		else
			ni->initialized_size = ntfs_cluster_to_bytes(vol, start_vcn);
	}

	if (ni->allocated_size > 0) {
		ret = ntfs_attr_update_mapping_pairs(ni, 0);
		if (ret) {
			up_write(&ni->runlist.lock);
			goto out_rl;
		}
	}
	up_write(&ni->runlist.lock);

	ctx = ntfs_attr_get_search_ctx(ni, NULL);
	if (!ctx) {
		ret = -ENOMEM;
		goto out_rl;
	}

	ret = ntfs_attr_lookup(ni->type, ni->name, ni->name_len, CASE_SENSITIVE,
			       0, NULL, 0, ctx);
	if (ret)
		goto out_ctx;

	ctx->attr->data.non_resident.data_size = cpu_to_le64(ni->data_size);
	ctx->attr->data.non_resident.initialized_size = cpu_to_le64(ni->initialized_size);
	if (ni->allocated_size == 0)
		ntfs_attr_make_resident(ni, ctx);
	mark_mft_record_dirty(ctx->ntfs_ino);

	ret = ntfs_cluster_free_from_rl(vol, punch_rl);
	if (ret)
		ntfs_error(vol->sb, "Freeing of clusters failed");
out_ctx:
	if (ctx)
		ntfs_attr_put_search_ctx(ctx);
out_rl:
	kvfree(punch_rl);
	mark_mft_record_dirty(ni);
	return ret;
}

int ntfs_non_resident_attr_punch_hole(struct ntfs_inode *ni, s64 start_vcn, s64 len)
{
	struct ntfs_volume *vol = ni->vol;
	struct runlist_element *punch_rl, *rl;
	s64 end_vcn;
	int dst_cnt;
	int ret;
	size_t new_rl_count;

	if (NInoAttr(ni) || ni->type != AT_DATA)
		return -EOPNOTSUPP;

	end_vcn = ntfs_bytes_to_cluster(vol, ni->allocated_size);
	if (start_vcn >= end_vcn)
		return -EINVAL;

	down_write(&ni->runlist.lock);
	ret = ntfs_attr_map_whole_runlist(ni);
	if (ret) {
		up_write(&ni->runlist.lock);
		return ret;
	}

	len = min(len, end_vcn - start_vcn + 1);
	for (rl = ni->runlist.rl, dst_cnt = 0; rl && rl->length; rl++)
		dst_cnt++;
	rl = ntfs_rl_find_vcn_nolock(ni->runlist.rl, start_vcn);
	if (!rl) {
		up_write(&ni->runlist.lock);
		return -EIO;
	}

	rl = ntfs_rl_punch_hole(ni->runlist.rl, dst_cnt + 1,
				start_vcn, len, &punch_rl, &new_rl_count);
	if (IS_ERR(rl)) {
		up_write(&ni->runlist.lock);
		return PTR_ERR(rl);
	}
	ni->runlist.rl = rl;
	ni->runlist.count = new_rl_count;

	ret = ntfs_attr_update_mapping_pairs(ni, 0);
	up_write(&ni->runlist.lock);
	if (ret) {
		kvfree(punch_rl);
		return ret;
	}

	ret = ntfs_cluster_free_from_rl(vol, punch_rl);
	if (ret)
		ntfs_error(vol->sb, "Freeing of clusters failed");

	kvfree(punch_rl);
	mark_mft_record_dirty(ni);
	return ret;
}

int ntfs_attr_fallocate(struct ntfs_inode *ni, loff_t start, loff_t byte_len, bool keep_size)
{
	struct ntfs_volume *vol = ni->vol;
	struct mft_record *mrec;
	struct ntfs_attr_search_ctx *ctx;
	s64 old_data_size;
	s64 vcn_start, vcn_end, vcn_uninit, vcn, try_alloc_cnt;
	s64 lcn, alloc_cnt;
	int err = 0;
	struct runlist_element *rl;
	bool balloc;

	if (NInoAttr(ni) || ni->type != AT_DATA)
		return -EINVAL;

	if (NInoNonResident(ni) && !NInoFullyMapped(ni)) {
		down_write(&ni->runlist.lock);
		err = ntfs_attr_map_whole_runlist(ni);
		up_write(&ni->runlist.lock);
		if (err)
			return err;
	}

	mutex_lock_nested(&ni->mrec_lock, NTFS_INODE_MUTEX_NORMAL);
	mrec = map_mft_record(ni);
	if (IS_ERR(mrec)) {
		mutex_unlock(&ni->mrec_lock);
		return PTR_ERR(mrec);
	}

	ctx = ntfs_attr_get_search_ctx(ni, mrec);
	if (!ctx) {
		err = -ENOMEM;
		goto out_unmap;
	}

	err = ntfs_attr_lookup(AT_DATA, AT_UNNAMED, 0, 0, 0, NULL, 0, ctx);
	if (err) {
		err = -EIO;
		goto out_unmap;
	}

	old_data_size = ni->data_size;
	if (start + byte_len > ni->data_size) {
		err = ntfs_attr_truncate(ni, start + byte_len);
		if (err)
			goto out_unmap;
		if (keep_size) {
			ntfs_attr_reinit_search_ctx(ctx);
			err = ntfs_attr_lookup(AT_DATA, AT_UNNAMED, 0, 0, 0, NULL, 0, ctx);
			if (err) {
				err = -EIO;
				goto out_unmap;
			}
			ni->data_size = old_data_size;
			if (NInoNonResident(ni))
				ctx->attr->data.non_resident.data_size =
					cpu_to_le64(old_data_size);
			else
				ctx->attr->data.resident.value_length =
					cpu_to_le32((u32)old_data_size);
			mark_mft_record_dirty(ni);
		}
	}

	ntfs_attr_put_search_ctx(ctx);
	unmap_mft_record(ni);
	mutex_unlock(&ni->mrec_lock);

	if (!NInoNonResident(ni))
		goto out;

	vcn_start = (s64)ntfs_bytes_to_cluster(vol, start);
	vcn_end = (s64)ntfs_bytes_to_cluster(vol,
			round_up(start + byte_len, vol->cluster_size));
	vcn_uninit = (s64)ntfs_bytes_to_cluster(vol,
			round_up(ni->initialized_size, vol->cluster_size));
	vcn_uninit = min_t(s64, vcn_uninit, vcn_end);

	/*
	 * we have to allocate clusters for holes and delayed within initialized_size,
	 * and zero out the clusters only for the holes.
	 */
	vcn = vcn_start;
	while (vcn < vcn_uninit) {
		down_read(&ni->runlist.lock);
		rl = ntfs_attr_find_vcn_nolock(ni, vcn, NULL);
		up_read(&ni->runlist.lock);
		if (IS_ERR(rl)) {
			err = PTR_ERR(rl);
			goto out;
		}

		if (rl->lcn > 0) {
			vcn += rl->length - (vcn - rl->vcn);
		} else if (rl->lcn == LCN_DELALLOC || rl->lcn == LCN_HOLE) {
			try_alloc_cnt = min(rl->length - (vcn - rl->vcn),
					    vcn_uninit - vcn);

			if (rl->lcn == LCN_DELALLOC) {
				vcn += try_alloc_cnt;
				continue;
			}

			while (try_alloc_cnt > 0) {
				mutex_lock_nested(&ni->mrec_lock, NTFS_INODE_MUTEX_NORMAL);
				down_write(&ni->runlist.lock);
				err = ntfs_attr_map_cluster(ni, vcn, &lcn, &alloc_cnt,
							    try_alloc_cnt, &balloc, false, false);
				up_write(&ni->runlist.lock);
				mutex_unlock(&ni->mrec_lock);
				if (err)
					goto out;

				err = ntfs_dio_zero_range(VFS_I(ni),
							  lcn << vol->cluster_size_bits,
							  alloc_cnt << vol->cluster_size_bits);
				if (err > 0)
					goto out;

				if (signal_pending(current))
					goto out;

				vcn += alloc_cnt;
				try_alloc_cnt -= alloc_cnt;
			}
		} else {
			err = -EIO;
			goto out;
		}
	}

	/* allocate clusters outside of initialized_size */
	try_alloc_cnt = vcn_end - vcn;
	while (try_alloc_cnt > 0) {
		mutex_lock_nested(&ni->mrec_lock, NTFS_INODE_MUTEX_NORMAL);
		down_write(&ni->runlist.lock);
		err = ntfs_attr_map_cluster(ni, vcn, &lcn, &alloc_cnt,
					    try_alloc_cnt, &balloc, false, false);
		up_write(&ni->runlist.lock);
		mutex_unlock(&ni->mrec_lock);
		if (err || signal_pending(current))
			goto out;

		vcn += alloc_cnt;
		try_alloc_cnt -= alloc_cnt;
		cond_resched();
	}

	if (NInoRunlistDirty(ni)) {
		mutex_lock_nested(&ni->mrec_lock, NTFS_INODE_MUTEX_NORMAL);
		down_write(&ni->runlist.lock);
		err = ntfs_attr_update_mapping_pairs(ni, 0);
		if (err)
			ntfs_error(ni->vol->sb, "Updating mapping pairs failed");
		else
			NInoClearRunlistDirty(ni);
		up_write(&ni->runlist.lock);
		mutex_unlock(&ni->mrec_lock);
	}
	return err;
out_unmap:
	if (ctx)
		ntfs_attr_put_search_ctx(ctx);
	unmap_mft_record(ni);
	mutex_unlock(&ni->mrec_lock);
out:
	return err >= 0 ? 0 : err;
}