xref: /linux/fs/xfs/xfs_iops.c (revision d0efc9e4276cda07c2f76652d240b165c30b05b8)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2000-2005 Silicon Graphics, Inc.
4  * All Rights Reserved.
5  */
6 #include "xfs.h"
7 #include "xfs_fs.h"
8 #include "xfs_shared.h"
9 #include "xfs_format.h"
10 #include "xfs_log_format.h"
11 #include "xfs_trans_resv.h"
12 #include "xfs_mount.h"
13 #include "xfs_inode.h"
14 #include "xfs_acl.h"
15 #include "xfs_quota.h"
16 #include "xfs_da_format.h"
17 #include "xfs_da_btree.h"
18 #include "xfs_attr.h"
19 #include "xfs_trans.h"
20 #include "xfs_trans_space.h"
21 #include "xfs_bmap_btree.h"
22 #include "xfs_trace.h"
23 #include "xfs_icache.h"
24 #include "xfs_symlink.h"
25 #include "xfs_dir2.h"
26 #include "xfs_iomap.h"
27 #include "xfs_error.h"
28 #include "xfs_ioctl.h"
29 #include "xfs_xattr.h"
30 #include "xfs_file.h"
31 #include "xfs_bmap.h"
32 #include "xfs_zone_alloc.h"
33 
34 #include <linux/posix_acl.h>
35 #include <linux/security.h>
36 #include <linux/iversion.h>
37 #include <linux/fiemap.h>
38 
39 /*
40  * Directories have different lock order w.r.t. mmap_lock compared to regular
41  * files. This is due to readdir potentially triggering page faults on a user
42  * buffer inside filldir(), and this happens with the ilock on the directory
43  * held. For regular files, the lock order is the other way around - the
44  * mmap_lock is taken during the page fault, and then we lock the ilock to do
45  * block mapping. Hence we need a different class for the directory ilock so
46  * that lockdep can tell them apart.  Directories in the metadata directory
47  * tree get a separate class so that lockdep reports will warn us if someone
48  * ever tries to lock regular directories after locking metadata directories.
49  */
50 static struct lock_class_key xfs_nondir_ilock_class;
51 static struct lock_class_key xfs_dir_ilock_class;
52 
53 static int
xfs_initxattrs(struct inode * inode,const struct xattr * xattr_array,void * fs_info)54 xfs_initxattrs(
55 	struct inode		*inode,
56 	const struct xattr	*xattr_array,
57 	void			*fs_info)
58 {
59 	const struct xattr	*xattr;
60 	struct xfs_inode	*ip = XFS_I(inode);
61 	int			error = 0;
62 
63 	for (xattr = xattr_array; xattr->name != NULL; xattr++) {
64 		struct xfs_da_args	args = {
65 			.dp		= ip,
66 			.attr_filter	= XFS_ATTR_SECURE,
67 			.name		= xattr->name,
68 			.namelen	= strlen(xattr->name),
69 			.value		= xattr->value,
70 			.valuelen	= xattr->value_len,
71 		};
72 		error = xfs_attr_change(&args, XFS_ATTRUPDATE_UPSERT);
73 		if (error < 0)
74 			break;
75 	}
76 	return error;
77 }
78 
79 /*
80  * Hook in SELinux.  This is not quite correct yet, what we really need
81  * here (as we do for default ACLs) is a mechanism by which creation of
82  * these attrs can be journalled at inode creation time (along with the
83  * inode, of course, such that log replay can't cause these to be lost).
84  */
85 int
xfs_inode_init_security(struct inode * inode,struct inode * dir,const struct qstr * qstr)86 xfs_inode_init_security(
87 	struct inode	*inode,
88 	struct inode	*dir,
89 	const struct qstr *qstr)
90 {
91 	return security_inode_init_security(inode, dir, qstr,
92 					     &xfs_initxattrs, NULL);
93 }
94 
95 static void
xfs_dentry_to_name(struct xfs_name * namep,struct dentry * dentry)96 xfs_dentry_to_name(
97 	struct xfs_name	*namep,
98 	struct dentry	*dentry)
99 {
100 	namep->name = dentry->d_name.name;
101 	namep->len = dentry->d_name.len;
102 	namep->type = XFS_DIR3_FT_UNKNOWN;
103 }
104 
105 static int
xfs_dentry_mode_to_name(struct xfs_name * namep,struct dentry * dentry,int mode)106 xfs_dentry_mode_to_name(
107 	struct xfs_name	*namep,
108 	struct dentry	*dentry,
109 	int		mode)
110 {
111 	namep->name = dentry->d_name.name;
112 	namep->len = dentry->d_name.len;
113 	namep->type = xfs_mode_to_ftype(mode);
114 
115 	if (unlikely(namep->type == XFS_DIR3_FT_UNKNOWN))
116 		return -EFSCORRUPTED;
117 
118 	return 0;
119 }
120 
121 STATIC void
xfs_cleanup_inode(struct inode * dir,struct inode * inode,struct dentry * dentry)122 xfs_cleanup_inode(
123 	struct inode	*dir,
124 	struct inode	*inode,
125 	struct dentry	*dentry)
126 {
127 	struct xfs_name	teardown;
128 
129 	/* Oh, the horror.
130 	 * If we can't add the ACL or we fail in
131 	 * xfs_inode_init_security we must back out.
132 	 * ENOSPC can hit here, among other things.
133 	 */
134 	xfs_dentry_to_name(&teardown, dentry);
135 
136 	xfs_remove(XFS_I(dir), &teardown, XFS_I(inode));
137 }
138 
139 /*
140  * Check to see if we are likely to need an extended attribute to be added to
141  * the inode we are about to allocate. This allows the attribute fork to be
142  * created during the inode allocation, reducing the number of transactions we
143  * need to do in this fast path.
144  *
145  * The security checks are optimistic, but not guaranteed. The two LSMs that
146  * require xattrs to be added here (selinux and smack) are also the only two
147  * LSMs that add a sb->s_security structure to the superblock. Hence if security
148  * is enabled and sb->s_security is set, we have a pretty good idea that we are
149  * going to be asked to add a security xattr immediately after allocating the
150  * xfs inode and instantiating the VFS inode.
151  */
152 static inline bool
xfs_create_need_xattr(struct inode * dir,struct posix_acl * default_acl,struct posix_acl * acl)153 xfs_create_need_xattr(
154 	struct inode	*dir,
155 	struct posix_acl *default_acl,
156 	struct posix_acl *acl)
157 {
158 	if (acl)
159 		return true;
160 	if (default_acl)
161 		return true;
162 #if IS_ENABLED(CONFIG_SECURITY)
163 	if (dir->i_sb->s_security)
164 		return true;
165 #endif
166 	return false;
167 }
168 
169 
170 STATIC int
xfs_generic_create(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode,dev_t rdev,struct file * tmpfile)171 xfs_generic_create(
172 	struct mnt_idmap	*idmap,
173 	struct inode		*dir,
174 	struct dentry		*dentry,
175 	umode_t			mode,
176 	dev_t			rdev,
177 	struct file		*tmpfile)	/* unnamed file */
178 {
179 	struct xfs_icreate_args	args = {
180 		.idmap		= idmap,
181 		.pip		= XFS_I(dir),
182 		.rdev		= rdev,
183 		.mode		= mode,
184 	};
185 	struct inode		*inode;
186 	struct xfs_inode	*ip = NULL;
187 	struct posix_acl	*default_acl, *acl;
188 	struct xfs_name		name;
189 	int			error;
190 
191 	/*
192 	 * Irix uses Missed'em'V split, but doesn't want to see
193 	 * the upper 5 bits of (14bit) major.
194 	 */
195 	if (S_ISCHR(args.mode) || S_ISBLK(args.mode)) {
196 		if (unlikely(!sysv_valid_dev(args.rdev) ||
197 			     MAJOR(args.rdev) & ~0x1ff))
198 			return -EINVAL;
199 	} else {
200 		args.rdev = 0;
201 	}
202 
203 	error = posix_acl_create(dir, &args.mode, &default_acl, &acl);
204 	if (error)
205 		return error;
206 
207 	/* Verify mode is valid also for tmpfile case */
208 	error = xfs_dentry_mode_to_name(&name, dentry, args.mode);
209 	if (unlikely(error))
210 		goto out_free_acl;
211 
212 	if (!tmpfile) {
213 		if (xfs_create_need_xattr(dir, default_acl, acl))
214 			args.flags |= XFS_ICREATE_INIT_XATTRS;
215 
216 		error = xfs_create(&args, &name, &ip);
217 	} else {
218 		args.flags |= XFS_ICREATE_TMPFILE;
219 
220 		/*
221 		 * If this temporary file will not be linkable, don't bother
222 		 * creating an attr fork to receive a parent pointer.
223 		 */
224 		if (tmpfile->f_flags & O_EXCL)
225 			args.flags |= XFS_ICREATE_UNLINKABLE;
226 
227 		error = xfs_create_tmpfile(&args, &ip);
228 	}
229 	if (unlikely(error))
230 		goto out_free_acl;
231 
232 	inode = VFS_I(ip);
233 
234 	error = xfs_inode_init_security(inode, dir, &dentry->d_name);
235 	if (unlikely(error))
236 		goto out_cleanup_inode;
237 
238 	if (default_acl) {
239 		error = __xfs_set_acl(inode, default_acl, ACL_TYPE_DEFAULT);
240 		if (error)
241 			goto out_cleanup_inode;
242 	}
243 	if (acl) {
244 		error = __xfs_set_acl(inode, acl, ACL_TYPE_ACCESS);
245 		if (error)
246 			goto out_cleanup_inode;
247 	}
248 
249 	xfs_setup_iops(ip);
250 
251 	if (tmpfile) {
252 		/*
253 		 * The VFS requires that any inode fed to d_tmpfile must have
254 		 * nlink == 1 so that it can decrement the nlink in d_tmpfile.
255 		 * However, we created the temp file with nlink == 0 because
256 		 * we're not allowed to put an inode with nlink > 0 on the
257 		 * unlinked list.  Therefore we have to set nlink to 1 so that
258 		 * d_tmpfile can immediately set it back to zero.
259 		 */
260 		set_nlink(inode, 1);
261 		d_tmpfile(tmpfile, inode);
262 	} else
263 		d_instantiate(dentry, inode);
264 
265 	xfs_finish_inode_setup(ip);
266 
267  out_free_acl:
268 	posix_acl_release(default_acl);
269 	posix_acl_release(acl);
270 	return error;
271 
272  out_cleanup_inode:
273 	xfs_finish_inode_setup(ip);
274 	if (!tmpfile)
275 		xfs_cleanup_inode(dir, inode, dentry);
276 	xfs_irele(ip);
277 	goto out_free_acl;
278 }
279 
280 STATIC int
xfs_vn_mknod(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode,dev_t rdev)281 xfs_vn_mknod(
282 	struct mnt_idmap	*idmap,
283 	struct inode		*dir,
284 	struct dentry		*dentry,
285 	umode_t			mode,
286 	dev_t			rdev)
287 {
288 	return xfs_generic_create(idmap, dir, dentry, mode, rdev, NULL);
289 }
290 
291 STATIC int
xfs_vn_create(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode,bool flags)292 xfs_vn_create(
293 	struct mnt_idmap	*idmap,
294 	struct inode		*dir,
295 	struct dentry		*dentry,
296 	umode_t			mode,
297 	bool			flags)
298 {
299 	return xfs_generic_create(idmap, dir, dentry, mode, 0, NULL);
300 }
301 
302 STATIC struct dentry *
xfs_vn_mkdir(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode)303 xfs_vn_mkdir(
304 	struct mnt_idmap	*idmap,
305 	struct inode		*dir,
306 	struct dentry		*dentry,
307 	umode_t			mode)
308 {
309 	return ERR_PTR(xfs_generic_create(idmap, dir, dentry, mode | S_IFDIR, 0, NULL));
310 }
311 
312 STATIC struct dentry *
xfs_vn_lookup(struct inode * dir,struct dentry * dentry,unsigned int flags)313 xfs_vn_lookup(
314 	struct inode	*dir,
315 	struct dentry	*dentry,
316 	unsigned int flags)
317 {
318 	struct inode *inode;
319 	struct xfs_inode *cip;
320 	struct xfs_name	name;
321 	int		error;
322 
323 	if (dentry->d_name.len >= MAXNAMELEN)
324 		return ERR_PTR(-ENAMETOOLONG);
325 
326 	xfs_dentry_to_name(&name, dentry);
327 	error = xfs_lookup(XFS_I(dir), &name, &cip, NULL);
328 	if (likely(!error))
329 		inode = VFS_I(cip);
330 	else if (likely(error == -ENOENT))
331 		inode = NULL;
332 	else
333 		inode = ERR_PTR(error);
334 	return d_splice_alias(inode, dentry);
335 }
336 
337 STATIC struct dentry *
xfs_vn_ci_lookup(struct inode * dir,struct dentry * dentry,unsigned int flags)338 xfs_vn_ci_lookup(
339 	struct inode	*dir,
340 	struct dentry	*dentry,
341 	unsigned int flags)
342 {
343 	struct xfs_inode *ip;
344 	struct xfs_name	xname;
345 	struct xfs_name ci_name;
346 	struct qstr	dname;
347 	int		error;
348 
349 	if (dentry->d_name.len >= MAXNAMELEN)
350 		return ERR_PTR(-ENAMETOOLONG);
351 
352 	xfs_dentry_to_name(&xname, dentry);
353 	error = xfs_lookup(XFS_I(dir), &xname, &ip, &ci_name);
354 	if (unlikely(error)) {
355 		if (unlikely(error != -ENOENT))
356 			return ERR_PTR(error);
357 		/*
358 		 * call d_add(dentry, NULL) here when d_drop_negative_children
359 		 * is called in xfs_vn_mknod (ie. allow negative dentries
360 		 * with CI filesystems).
361 		 */
362 		return NULL;
363 	}
364 
365 	/* if exact match, just splice and exit */
366 	if (!ci_name.name)
367 		return d_splice_alias(VFS_I(ip), dentry);
368 
369 	/* else case-insensitive match... */
370 	dname.name = ci_name.name;
371 	dname.len = ci_name.len;
372 	dentry = d_add_ci(dentry, VFS_I(ip), &dname);
373 	kfree(ci_name.name);
374 	return dentry;
375 }
376 
377 STATIC int
xfs_vn_link(struct dentry * old_dentry,struct inode * dir,struct dentry * dentry)378 xfs_vn_link(
379 	struct dentry	*old_dentry,
380 	struct inode	*dir,
381 	struct dentry	*dentry)
382 {
383 	struct inode	*inode = d_inode(old_dentry);
384 	struct xfs_name	name;
385 	int		error;
386 
387 	error = xfs_dentry_mode_to_name(&name, dentry, inode->i_mode);
388 	if (unlikely(error))
389 		return error;
390 
391 	if (IS_PRIVATE(inode))
392 		return -EPERM;
393 
394 	error = xfs_link(XFS_I(dir), XFS_I(inode), &name);
395 	if (unlikely(error))
396 		return error;
397 
398 	ihold(inode);
399 	d_instantiate(dentry, inode);
400 	return 0;
401 }
402 
403 STATIC int
xfs_vn_unlink(struct inode * dir,struct dentry * dentry)404 xfs_vn_unlink(
405 	struct inode	*dir,
406 	struct dentry	*dentry)
407 {
408 	struct xfs_name	name;
409 	int		error;
410 
411 	xfs_dentry_to_name(&name, dentry);
412 
413 	error = xfs_remove(XFS_I(dir), &name, XFS_I(d_inode(dentry)));
414 	if (error)
415 		return error;
416 
417 	/*
418 	 * With unlink, the VFS makes the dentry "negative": no inode,
419 	 * but still hashed. This is incompatible with case-insensitive
420 	 * mode, so invalidate (unhash) the dentry in CI-mode.
421 	 */
422 	if (xfs_has_asciici(XFS_M(dir->i_sb)))
423 		d_invalidate(dentry);
424 	return 0;
425 }
426 
427 STATIC int
xfs_vn_symlink(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,const char * symname)428 xfs_vn_symlink(
429 	struct mnt_idmap	*idmap,
430 	struct inode		*dir,
431 	struct dentry		*dentry,
432 	const char		*symname)
433 {
434 	struct inode	*inode;
435 	struct xfs_inode *cip = NULL;
436 	struct xfs_name	name;
437 	int		error;
438 	umode_t		mode;
439 
440 	mode = S_IFLNK |
441 		(irix_symlink_mode ? 0777 & ~current_umask() : S_IRWXUGO);
442 	error = xfs_dentry_mode_to_name(&name, dentry, mode);
443 	if (unlikely(error))
444 		goto out;
445 
446 	error = xfs_symlink(idmap, XFS_I(dir), &name, symname, mode, &cip);
447 	if (unlikely(error))
448 		goto out;
449 
450 	inode = VFS_I(cip);
451 
452 	error = xfs_inode_init_security(inode, dir, &dentry->d_name);
453 	if (unlikely(error))
454 		goto out_cleanup_inode;
455 
456 	xfs_setup_iops(cip);
457 
458 	d_instantiate(dentry, inode);
459 	xfs_finish_inode_setup(cip);
460 	return 0;
461 
462  out_cleanup_inode:
463 	xfs_finish_inode_setup(cip);
464 	xfs_cleanup_inode(dir, inode, dentry);
465 	xfs_irele(cip);
466  out:
467 	return error;
468 }
469 
470 STATIC int
xfs_vn_rename(struct mnt_idmap * idmap,struct inode * odir,struct dentry * odentry,struct inode * ndir,struct dentry * ndentry,unsigned int flags)471 xfs_vn_rename(
472 	struct mnt_idmap	*idmap,
473 	struct inode		*odir,
474 	struct dentry		*odentry,
475 	struct inode		*ndir,
476 	struct dentry		*ndentry,
477 	unsigned int		flags)
478 {
479 	struct inode	*new_inode = d_inode(ndentry);
480 	int		omode = 0;
481 	int		error;
482 	struct xfs_name	oname;
483 	struct xfs_name	nname;
484 
485 	if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
486 		return -EINVAL;
487 
488 	/* if we are exchanging files, we need to set i_mode of both files */
489 	if (flags & RENAME_EXCHANGE)
490 		omode = d_inode(ndentry)->i_mode;
491 
492 	error = xfs_dentry_mode_to_name(&oname, odentry, omode);
493 	if (omode && unlikely(error))
494 		return error;
495 
496 	error = xfs_dentry_mode_to_name(&nname, ndentry,
497 					d_inode(odentry)->i_mode);
498 	if (unlikely(error))
499 		return error;
500 
501 	return xfs_rename(idmap, XFS_I(odir), &oname,
502 			  XFS_I(d_inode(odentry)), XFS_I(ndir), &nname,
503 			  new_inode ? XFS_I(new_inode) : NULL, flags);
504 }
505 
506 /*
507  * careful here - this function can get called recursively, so
508  * we need to be very careful about how much stack we use.
509  * uio is kmalloced for this reason...
510  */
511 STATIC const char *
xfs_vn_get_link(struct dentry * dentry,struct inode * inode,struct delayed_call * done)512 xfs_vn_get_link(
513 	struct dentry		*dentry,
514 	struct inode		*inode,
515 	struct delayed_call	*done)
516 {
517 	char			*link;
518 	int			error = -ENOMEM;
519 
520 	if (!dentry)
521 		return ERR_PTR(-ECHILD);
522 
523 	link = kmalloc(XFS_SYMLINK_MAXLEN+1, GFP_KERNEL);
524 	if (!link)
525 		goto out_err;
526 
527 	error = xfs_readlink(XFS_I(d_inode(dentry)), link);
528 	if (unlikely(error))
529 		goto out_kfree;
530 
531 	set_delayed_call(done, kfree_link, link);
532 	return link;
533 
534  out_kfree:
535 	kfree(link);
536  out_err:
537 	return ERR_PTR(error);
538 }
539 
540 static uint32_t
xfs_stat_blksize(struct xfs_inode * ip)541 xfs_stat_blksize(
542 	struct xfs_inode	*ip)
543 {
544 	struct xfs_mount	*mp = ip->i_mount;
545 
546 	/*
547 	 * If the file blocks are being allocated from a realtime volume, then
548 	 * always return the realtime extent size.
549 	 */
550 	if (XFS_IS_REALTIME_INODE(ip))
551 		return XFS_FSB_TO_B(mp, xfs_get_extsz_hint(ip) ? : 1);
552 
553 	/*
554 	 * Allow large block sizes to be reported to userspace programs if the
555 	 * "largeio" mount option is used.
556 	 *
557 	 * If compatibility mode is specified, simply return the basic unit of
558 	 * caching so that we don't get inefficient read/modify/write I/O from
559 	 * user apps. Otherwise....
560 	 *
561 	 * If the underlying volume is a stripe, then return the stripe width in
562 	 * bytes as the recommended I/O size. It is not a stripe and we've set a
563 	 * default buffered I/O size, return that, otherwise return the compat
564 	 * default.
565 	 */
566 	if (xfs_has_large_iosize(mp)) {
567 		if (mp->m_swidth)
568 			return XFS_FSB_TO_B(mp, mp->m_swidth);
569 		if (xfs_has_allocsize(mp))
570 			return 1U << mp->m_allocsize_log;
571 	}
572 
573 	return max_t(uint32_t, PAGE_SIZE, mp->m_sb.sb_blocksize);
574 }
575 
576 static void
xfs_report_dioalign(struct xfs_inode * ip,struct kstat * stat)577 xfs_report_dioalign(
578 	struct xfs_inode	*ip,
579 	struct kstat		*stat)
580 {
581 	struct xfs_buftarg	*target = xfs_inode_buftarg(ip);
582 	struct block_device	*bdev = target->bt_bdev;
583 
584 	stat->result_mask |= STATX_DIOALIGN | STATX_DIO_READ_ALIGN;
585 	stat->dio_mem_align = bdev_dma_alignment(bdev) + 1;
586 
587 	/*
588 	 * For COW inodes, we can only perform out of place writes of entire
589 	 * allocation units (blocks or RT extents).
590 	 * For writes smaller than the allocation unit, we must fall back to
591 	 * buffered I/O to perform read-modify-write cycles.  At best this is
592 	 * highly inefficient; at worst it leads to page cache invalidation
593 	 * races.  Tell applications to avoid this by reporting the larger write
594 	 * alignment in dio_offset_align, and the smaller read alignment in
595 	 * dio_read_offset_align.
596 	 */
597 	stat->dio_read_offset_align = bdev_logical_block_size(bdev);
598 	if (xfs_is_cow_inode(ip))
599 		stat->dio_offset_align = xfs_inode_alloc_unitsize(ip);
600 	else
601 		stat->dio_offset_align = stat->dio_read_offset_align;
602 }
603 
604 unsigned int
xfs_get_atomic_write_min(struct xfs_inode * ip)605 xfs_get_atomic_write_min(
606 	struct xfs_inode	*ip)
607 {
608 	struct xfs_mount	*mp = ip->i_mount;
609 
610 	/*
611 	 * If we can complete an atomic write via atomic out of place writes,
612 	 * then advertise a minimum size of one fsblock.  Without this
613 	 * mechanism, we can only guarantee atomic writes up to a single LBA.
614 	 *
615 	 * If out of place writes are not available, we can guarantee an atomic
616 	 * write of exactly one single fsblock if the bdev will make that
617 	 * guarantee for us.
618 	 */
619 	if (xfs_inode_can_hw_atomic_write(ip) ||
620 	    xfs_inode_can_sw_atomic_write(ip))
621 		return mp->m_sb.sb_blocksize;
622 
623 	return 0;
624 }
625 
626 unsigned int
xfs_get_atomic_write_max(struct xfs_inode * ip)627 xfs_get_atomic_write_max(
628 	struct xfs_inode	*ip)
629 {
630 	struct xfs_mount	*mp = ip->i_mount;
631 
632 	/*
633 	 * If out of place writes are not available, we can guarantee an atomic
634 	 * write of exactly one single fsblock if the bdev will make that
635 	 * guarantee for us.
636 	 */
637 	if (!xfs_inode_can_sw_atomic_write(ip)) {
638 		if (xfs_inode_can_hw_atomic_write(ip))
639 			return mp->m_sb.sb_blocksize;
640 		return 0;
641 	}
642 
643 	/*
644 	 * If we can complete an atomic write via atomic out of place writes,
645 	 * then advertise a maximum size of whatever we can complete through
646 	 * that means.  Hardware support is reported via max_opt, not here.
647 	 */
648 	if (XFS_IS_REALTIME_INODE(ip))
649 		return XFS_FSB_TO_B(mp, mp->m_groups[XG_TYPE_RTG].awu_max);
650 	return XFS_FSB_TO_B(mp, mp->m_groups[XG_TYPE_AG].awu_max);
651 }
652 
653 unsigned int
xfs_get_atomic_write_max_opt(struct xfs_inode * ip)654 xfs_get_atomic_write_max_opt(
655 	struct xfs_inode	*ip)
656 {
657 	unsigned int		awu_max = xfs_get_atomic_write_max(ip);
658 
659 	/* if the max is 1x block, then just keep behaviour that opt is 0 */
660 	if (awu_max <= ip->i_mount->m_sb.sb_blocksize)
661 		return 0;
662 
663 	/*
664 	 * Advertise the maximum size of an atomic write that we can tell the
665 	 * block device to perform for us.  In general the bdev limit will be
666 	 * less than our out of place write limit, but we don't want to exceed
667 	 * the awu_max.
668 	 */
669 	return min(awu_max, xfs_inode_buftarg(ip)->bt_awu_max);
670 }
671 
672 static void
xfs_report_atomic_write(struct xfs_inode * ip,struct kstat * stat)673 xfs_report_atomic_write(
674 	struct xfs_inode	*ip,
675 	struct kstat		*stat)
676 {
677 	generic_fill_statx_atomic_writes(stat,
678 			xfs_get_atomic_write_min(ip),
679 			xfs_get_atomic_write_max(ip),
680 			xfs_get_atomic_write_max_opt(ip));
681 }
682 
683 STATIC int
xfs_vn_getattr(struct mnt_idmap * idmap,const struct path * path,struct kstat * stat,u32 request_mask,unsigned int query_flags)684 xfs_vn_getattr(
685 	struct mnt_idmap	*idmap,
686 	const struct path	*path,
687 	struct kstat		*stat,
688 	u32			request_mask,
689 	unsigned int		query_flags)
690 {
691 	struct inode		*inode = d_inode(path->dentry);
692 	struct xfs_inode	*ip = XFS_I(inode);
693 	struct xfs_mount	*mp = ip->i_mount;
694 	vfsuid_t		vfsuid = i_uid_into_vfsuid(idmap, inode);
695 	vfsgid_t		vfsgid = i_gid_into_vfsgid(idmap, inode);
696 
697 	trace_xfs_getattr(ip);
698 
699 	if (xfs_is_shutdown(mp))
700 		return -EIO;
701 
702 	stat->size = XFS_ISIZE(ip);
703 	stat->dev = inode->i_sb->s_dev;
704 	stat->mode = inode->i_mode;
705 	stat->nlink = inode->i_nlink;
706 	stat->uid = vfsuid_into_kuid(vfsuid);
707 	stat->gid = vfsgid_into_kgid(vfsgid);
708 	stat->ino = ip->i_ino;
709 	stat->atime = inode_get_atime(inode);
710 
711 	fill_mg_cmtime(stat, request_mask, inode);
712 
713 	stat->blocks = XFS_FSB_TO_BB(mp, ip->i_nblocks + ip->i_delayed_blks);
714 
715 	if (xfs_has_v3inodes(mp)) {
716 		if (request_mask & STATX_BTIME) {
717 			stat->result_mask |= STATX_BTIME;
718 			stat->btime = ip->i_crtime;
719 		}
720 	}
721 
722 	/*
723 	 * Note: If you add another clause to set an attribute flag, please
724 	 * update attributes_mask below.
725 	 */
726 	if (ip->i_diflags & XFS_DIFLAG_IMMUTABLE)
727 		stat->attributes |= STATX_ATTR_IMMUTABLE;
728 	if (ip->i_diflags & XFS_DIFLAG_APPEND)
729 		stat->attributes |= STATX_ATTR_APPEND;
730 	if (ip->i_diflags & XFS_DIFLAG_NODUMP)
731 		stat->attributes |= STATX_ATTR_NODUMP;
732 
733 	stat->attributes_mask |= (STATX_ATTR_IMMUTABLE |
734 				  STATX_ATTR_APPEND |
735 				  STATX_ATTR_NODUMP);
736 
737 	switch (inode->i_mode & S_IFMT) {
738 	case S_IFBLK:
739 	case S_IFCHR:
740 		stat->blksize = BLKDEV_IOSIZE;
741 		stat->rdev = inode->i_rdev;
742 		break;
743 	case S_IFREG:
744 		if (request_mask & (STATX_DIOALIGN | STATX_DIO_READ_ALIGN))
745 			xfs_report_dioalign(ip, stat);
746 		if (request_mask & STATX_WRITE_ATOMIC)
747 			xfs_report_atomic_write(ip, stat);
748 		fallthrough;
749 	default:
750 		stat->blksize = xfs_stat_blksize(ip);
751 		stat->rdev = 0;
752 		break;
753 	}
754 
755 	return 0;
756 }
757 
758 static int
xfs_vn_change_ok(struct mnt_idmap * idmap,struct dentry * dentry,struct iattr * iattr)759 xfs_vn_change_ok(
760 	struct mnt_idmap	*idmap,
761 	struct dentry		*dentry,
762 	struct iattr		*iattr)
763 {
764 	struct xfs_mount	*mp = XFS_I(d_inode(dentry))->i_mount;
765 
766 	if (xfs_is_readonly(mp))
767 		return -EROFS;
768 
769 	if (xfs_is_shutdown(mp))
770 		return -EIO;
771 
772 	return setattr_prepare(idmap, dentry, iattr);
773 }
774 
775 /*
776  * Set non-size attributes of an inode.
777  *
778  * Caution: The caller of this function is responsible for calling
779  * setattr_prepare() or otherwise verifying the change is fine.
780  */
781 static int
xfs_setattr_nonsize(struct mnt_idmap * idmap,struct dentry * dentry,struct xfs_inode * ip,struct iattr * iattr)782 xfs_setattr_nonsize(
783 	struct mnt_idmap	*idmap,
784 	struct dentry		*dentry,
785 	struct xfs_inode	*ip,
786 	struct iattr		*iattr)
787 {
788 	xfs_mount_t		*mp = ip->i_mount;
789 	struct inode		*inode = VFS_I(ip);
790 	int			mask = iattr->ia_valid;
791 	xfs_trans_t		*tp;
792 	int			error;
793 	kuid_t			uid = GLOBAL_ROOT_UID;
794 	kgid_t			gid = GLOBAL_ROOT_GID;
795 	struct xfs_dquot	*udqp = NULL, *gdqp = NULL;
796 	struct xfs_dquot	*old_udqp = NULL, *old_gdqp = NULL;
797 
798 	ASSERT((mask & ATTR_SIZE) == 0);
799 
800 	/*
801 	 * If disk quotas is on, we make sure that the dquots do exist on disk,
802 	 * before we start any other transactions. Trying to do this later
803 	 * is messy. We don't care to take a readlock to look at the ids
804 	 * in inode here, because we can't hold it across the trans_reserve.
805 	 * If the IDs do change before we take the ilock, we're covered
806 	 * because the i_*dquot fields will get updated anyway.
807 	 */
808 	if (XFS_IS_QUOTA_ON(mp) && (mask & (ATTR_UID|ATTR_GID))) {
809 		uint	qflags = 0;
810 
811 		if ((mask & ATTR_UID) && XFS_IS_UQUOTA_ON(mp)) {
812 			uid = from_vfsuid(idmap, i_user_ns(inode),
813 					  iattr->ia_vfsuid);
814 			qflags |= XFS_QMOPT_UQUOTA;
815 		} else {
816 			uid = inode->i_uid;
817 		}
818 		if ((mask & ATTR_GID) && XFS_IS_GQUOTA_ON(mp)) {
819 			gid = from_vfsgid(idmap, i_user_ns(inode),
820 					  iattr->ia_vfsgid);
821 			qflags |= XFS_QMOPT_GQUOTA;
822 		}  else {
823 			gid = inode->i_gid;
824 		}
825 
826 		/*
827 		 * We take a reference when we initialize udqp and gdqp,
828 		 * so it is important that we never blindly double trip on
829 		 * the same variable. See xfs_create() for an example.
830 		 */
831 		ASSERT(udqp == NULL);
832 		ASSERT(gdqp == NULL);
833 		error = xfs_qm_vop_dqalloc(ip, uid, gid, ip->i_projid,
834 					   qflags, &udqp, &gdqp, NULL);
835 		if (error)
836 			return error;
837 	}
838 
839 	error = xfs_trans_alloc_ichange(ip, udqp, gdqp, NULL,
840 			has_capability_noaudit(current, CAP_FOWNER), &tp);
841 	if (error)
842 		goto out_dqrele;
843 
844 	/*
845 	 * Register quota modifications in the transaction.  Must be the owner
846 	 * or privileged.  These IDs could have changed since we last looked at
847 	 * them.  But, we're assured that if the ownership did change while we
848 	 * didn't have the inode locked, inode's dquot(s) would have changed
849 	 * also.
850 	 */
851 	if (XFS_IS_UQUOTA_ON(mp) &&
852 	    i_uid_needs_update(idmap, iattr, inode)) {
853 		ASSERT(udqp);
854 		old_udqp = xfs_qm_vop_chown(tp, ip, &ip->i_udquot, udqp);
855 	}
856 	if (XFS_IS_GQUOTA_ON(mp) &&
857 	    i_gid_needs_update(idmap, iattr, inode)) {
858 		ASSERT(xfs_has_pquotino(mp) || !XFS_IS_PQUOTA_ON(mp));
859 		ASSERT(gdqp);
860 		old_gdqp = xfs_qm_vop_chown(tp, ip, &ip->i_gdquot, gdqp);
861 	}
862 
863 	setattr_copy(idmap, inode, iattr);
864 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
865 
866 	XFS_STATS_INC(mp, xs_ig_attrchg);
867 
868 	if (xfs_has_wsync(mp))
869 		xfs_trans_set_sync(tp);
870 	error = xfs_trans_commit(tp);
871 
872 	/*
873 	 * Release any dquot(s) the inode had kept before chown.
874 	 */
875 	xfs_qm_dqrele(old_udqp);
876 	xfs_qm_dqrele(old_gdqp);
877 	xfs_qm_dqrele(udqp);
878 	xfs_qm_dqrele(gdqp);
879 
880 	if (error)
881 		return error;
882 
883 	/*
884 	 * XXX(hch): Updating the ACL entries is not atomic vs the i_mode
885 	 * 	     update.  We could avoid this with linked transactions
886 	 * 	     and passing down the transaction pointer all the way
887 	 *	     to attr_set.  No previous user of the generic
888 	 * 	     Posix ACL code seems to care about this issue either.
889 	 */
890 	if (mask & ATTR_MODE) {
891 		error = posix_acl_chmod(idmap, dentry, inode->i_mode);
892 		if (error)
893 			return error;
894 	}
895 
896 	return 0;
897 
898 out_dqrele:
899 	xfs_qm_dqrele(udqp);
900 	xfs_qm_dqrele(gdqp);
901 	return error;
902 }
903 
904 /*
905  * Truncate file.  Must have write permission and not be a directory.
906  *
907  * Caution: The caller of this function is responsible for calling
908  * setattr_prepare() or otherwise verifying the change is fine.
909  */
910 STATIC int
xfs_setattr_size(struct mnt_idmap * idmap,struct dentry * dentry,struct xfs_inode * ip,struct iattr * iattr)911 xfs_setattr_size(
912 	struct mnt_idmap	*idmap,
913 	struct dentry		*dentry,
914 	struct xfs_inode	*ip,
915 	struct iattr		*iattr)
916 {
917 	struct xfs_mount	*mp = ip->i_mount;
918 	struct inode		*inode = VFS_I(ip);
919 	xfs_off_t		oldsize, newsize;
920 	struct xfs_trans	*tp;
921 	int			error;
922 	uint			lock_flags = 0;
923 	uint			resblks = 0;
924 	bool			did_zeroing = false;
925 	struct xfs_zone_alloc_ctx ac = { };
926 
927 	xfs_assert_ilocked(ip, XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL);
928 	ASSERT(S_ISREG(inode->i_mode));
929 	ASSERT((iattr->ia_valid & (ATTR_UID|ATTR_GID|ATTR_ATIME|ATTR_ATIME_SET|
930 		ATTR_MTIME_SET|ATTR_TIMES_SET)) == 0);
931 
932 	oldsize = inode->i_size;
933 	newsize = iattr->ia_size;
934 
935 	/*
936 	 * Short circuit the truncate case for zero length files.
937 	 */
938 	if (newsize == 0 && oldsize == 0 && ip->i_df.if_nextents == 0) {
939 		if (!(iattr->ia_valid & (ATTR_CTIME|ATTR_MTIME)))
940 			return 0;
941 
942 		/*
943 		 * Use the regular setattr path to update the timestamps.
944 		 */
945 		iattr->ia_valid &= ~ATTR_SIZE;
946 		return xfs_setattr_nonsize(idmap, dentry, ip, iattr);
947 	}
948 
949 	/*
950 	 * Make sure that the dquots are attached to the inode.
951 	 */
952 	error = xfs_qm_dqattach(ip);
953 	if (error)
954 		return error;
955 
956 	/*
957 	 * Wait for all direct I/O to complete.
958 	 */
959 	inode_dio_wait(inode);
960 
961 	/*
962 	 * Normally xfs_zoned_space_reserve is supposed to be called outside the
963 	 * IOLOCK.  For truncate we can't do that since ->setattr is called with
964 	 * it already held by the VFS.  So for now chicken out and try to
965 	 * allocate space under it.
966 	 *
967 	 * To avoid deadlocks this means we can't block waiting for space, which
968 	 * can lead to spurious -ENOSPC if there are no directly available
969 	 * blocks.  We mitigate this a bit by allowing zeroing to dip into the
970 	 * reserved pool, but eventually the VFS calling convention needs to
971 	 * change.
972 	 */
973 	if (xfs_is_zoned_inode(ip)) {
974 		error = xfs_zoned_space_reserve(mp, 1,
975 				XFS_ZR_NOWAIT | XFS_ZR_RESERVED, &ac);
976 		if (error) {
977 			if (error == -EAGAIN)
978 				return -ENOSPC;
979 			return error;
980 		}
981 	}
982 
983 	/*
984 	 * File data changes must be complete before we start the transaction to
985 	 * modify the inode.  This needs to be done before joining the inode to
986 	 * the transaction because the inode cannot be unlocked once it is a
987 	 * part of the transaction.
988 	 *
989 	 * Start with zeroing any data beyond EOF that we may expose on file
990 	 * extension, or zeroing out the rest of the block on a downward
991 	 * truncate.
992 	 */
993 	if (newsize > oldsize) {
994 		trace_xfs_zero_eof(ip, oldsize, newsize - oldsize);
995 		error = xfs_zero_range(ip, oldsize, newsize - oldsize,
996 				&ac, &did_zeroing);
997 	} else {
998 		error = xfs_truncate_page(ip, newsize, &ac, &did_zeroing);
999 	}
1000 
1001 	if (xfs_is_zoned_inode(ip))
1002 		xfs_zoned_space_unreserve(mp, &ac);
1003 
1004 	if (error)
1005 		return error;
1006 
1007 	/*
1008 	 * We've already locked out new page faults, so now we can safely remove
1009 	 * pages from the page cache knowing they won't get refaulted until we
1010 	 * drop the XFS_MMAP_EXCL lock after the extent manipulations are
1011 	 * complete. The truncate_setsize() call also cleans partial EOF page
1012 	 * PTEs on extending truncates and hence ensures sub-page block size
1013 	 * filesystems are correctly handled, too.
1014 	 *
1015 	 * We have to do all the page cache truncate work outside the
1016 	 * transaction context as the "lock" order is page lock->log space
1017 	 * reservation as defined by extent allocation in the writeback path.
1018 	 * Hence a truncate can fail with ENOMEM from xfs_trans_alloc(), but
1019 	 * having already truncated the in-memory version of the file (i.e. made
1020 	 * user visible changes). There's not much we can do about this, except
1021 	 * to hope that the caller sees ENOMEM and retries the truncate
1022 	 * operation.
1023 	 *
1024 	 * And we update in-core i_size and truncate page cache beyond newsize
1025 	 * before writeback the [i_disk_size, newsize] range, so we're
1026 	 * guaranteed not to write stale data past the new EOF on truncate down.
1027 	 */
1028 	truncate_setsize(inode, newsize);
1029 
1030 	/*
1031 	 * We are going to log the inode size change in this transaction so
1032 	 * any previous writes that are beyond the on disk EOF and the new
1033 	 * EOF that have not been written out need to be written here.  If we
1034 	 * do not write the data out, we expose ourselves to the null files
1035 	 * problem. Note that this includes any block zeroing we did above;
1036 	 * otherwise those blocks may not be zeroed after a crash.
1037 	 */
1038 	if (did_zeroing ||
1039 	    (newsize > ip->i_disk_size && oldsize != ip->i_disk_size)) {
1040 		error = filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
1041 						ip->i_disk_size, newsize - 1);
1042 		if (error)
1043 			return error;
1044 	}
1045 
1046 	/*
1047 	 * For realtime inode with more than one block rtextsize, we need the
1048 	 * block reservation for bmap btree block allocations/splits that can
1049 	 * happen since it could split the tail written extent and convert the
1050 	 * right beyond EOF one to unwritten.
1051 	 */
1052 	if (xfs_inode_has_bigrtalloc(ip))
1053 		resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
1054 
1055 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, resblks,
1056 				0, 0, &tp);
1057 	if (error)
1058 		return error;
1059 
1060 	lock_flags |= XFS_ILOCK_EXCL;
1061 	xfs_ilock(ip, XFS_ILOCK_EXCL);
1062 	xfs_trans_ijoin(tp, ip, 0);
1063 
1064 	/*
1065 	 * Only change the c/mtime if we are changing the size or we are
1066 	 * explicitly asked to change it.  This handles the semantic difference
1067 	 * between truncate() and ftruncate() as implemented in the VFS.
1068 	 *
1069 	 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
1070 	 * special case where we need to update the times despite not having
1071 	 * these flags set.  For all other operations the VFS set these flags
1072 	 * explicitly if it wants a timestamp update.
1073 	 */
1074 	if (newsize != oldsize &&
1075 	    !(iattr->ia_valid & (ATTR_CTIME | ATTR_MTIME))) {
1076 		iattr->ia_ctime = iattr->ia_mtime =
1077 			current_time(inode);
1078 		iattr->ia_valid |= ATTR_CTIME | ATTR_MTIME;
1079 	}
1080 
1081 	/*
1082 	 * The first thing we do is set the size to new_size permanently on
1083 	 * disk.  This way we don't have to worry about anyone ever being able
1084 	 * to look at the data being freed even in the face of a crash.
1085 	 * What we're getting around here is the case where we free a block, it
1086 	 * is allocated to another file, it is written to, and then we crash.
1087 	 * If the new data gets written to the file but the log buffers
1088 	 * containing the free and reallocation don't, then we'd end up with
1089 	 * garbage in the blocks being freed.  As long as we make the new size
1090 	 * permanent before actually freeing any blocks it doesn't matter if
1091 	 * they get written to.
1092 	 */
1093 	ip->i_disk_size = newsize;
1094 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
1095 
1096 	if (newsize <= oldsize) {
1097 		error = xfs_itruncate_extents(&tp, ip, XFS_DATA_FORK, newsize);
1098 		if (error)
1099 			goto out_trans_cancel;
1100 
1101 		/*
1102 		 * Truncated "down", so we're removing references to old data
1103 		 * here - if we delay flushing for a long time, we expose
1104 		 * ourselves unduly to the notorious NULL files problem.  So,
1105 		 * we mark this inode and flush it when the file is closed,
1106 		 * and do not wait the usual (long) time for writeout.
1107 		 */
1108 		xfs_iflags_set(ip, XFS_ITRUNCATED);
1109 
1110 		/* A truncate down always removes post-EOF blocks. */
1111 		xfs_inode_clear_eofblocks_tag(ip);
1112 	}
1113 
1114 	ASSERT(!(iattr->ia_valid & (ATTR_UID | ATTR_GID)));
1115 	setattr_copy(idmap, inode, iattr);
1116 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
1117 
1118 	XFS_STATS_INC(mp, xs_ig_attrchg);
1119 
1120 	if (xfs_has_wsync(mp))
1121 		xfs_trans_set_sync(tp);
1122 
1123 	error = xfs_trans_commit(tp);
1124 out_unlock:
1125 	if (lock_flags)
1126 		xfs_iunlock(ip, lock_flags);
1127 	return error;
1128 
1129 out_trans_cancel:
1130 	xfs_trans_cancel(tp);
1131 	goto out_unlock;
1132 }
1133 
1134 int
xfs_vn_setattr_size(struct mnt_idmap * idmap,struct dentry * dentry,struct iattr * iattr)1135 xfs_vn_setattr_size(
1136 	struct mnt_idmap	*idmap,
1137 	struct dentry		*dentry,
1138 	struct iattr		*iattr)
1139 {
1140 	struct xfs_inode	*ip = XFS_I(d_inode(dentry));
1141 	int error;
1142 
1143 	trace_xfs_setattr(ip);
1144 
1145 	error = xfs_vn_change_ok(idmap, dentry, iattr);
1146 	if (error)
1147 		return error;
1148 	return xfs_setattr_size(idmap, dentry, ip, iattr);
1149 }
1150 
1151 STATIC int
xfs_vn_setattr(struct mnt_idmap * idmap,struct dentry * dentry,struct iattr * iattr)1152 xfs_vn_setattr(
1153 	struct mnt_idmap	*idmap,
1154 	struct dentry		*dentry,
1155 	struct iattr		*iattr)
1156 {
1157 	struct inode		*inode = d_inode(dentry);
1158 	struct xfs_inode	*ip = XFS_I(inode);
1159 	int			error;
1160 
1161 	if (iattr->ia_valid & ATTR_SIZE) {
1162 		uint			iolock;
1163 
1164 		xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
1165 		iolock = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL;
1166 
1167 		error = xfs_break_layouts(inode, &iolock, BREAK_UNMAP);
1168 		if (error) {
1169 			xfs_iunlock(ip, XFS_MMAPLOCK_EXCL);
1170 			return error;
1171 		}
1172 
1173 		error = xfs_vn_setattr_size(idmap, dentry, iattr);
1174 		xfs_iunlock(ip, XFS_MMAPLOCK_EXCL);
1175 	} else {
1176 		trace_xfs_setattr(ip);
1177 
1178 		error = xfs_vn_change_ok(idmap, dentry, iattr);
1179 		if (!error)
1180 			error = xfs_setattr_nonsize(idmap, dentry, ip, iattr);
1181 	}
1182 
1183 	return error;
1184 }
1185 
1186 STATIC int
xfs_vn_update_time(struct inode * inode,int flags)1187 xfs_vn_update_time(
1188 	struct inode		*inode,
1189 	int			flags)
1190 {
1191 	struct xfs_inode	*ip = XFS_I(inode);
1192 	struct xfs_mount	*mp = ip->i_mount;
1193 	int			log_flags = XFS_ILOG_TIMESTAMP;
1194 	struct xfs_trans	*tp;
1195 	int			error;
1196 	struct timespec64	now;
1197 
1198 	trace_xfs_update_time(ip);
1199 
1200 	if (inode->i_sb->s_flags & SB_LAZYTIME) {
1201 		if (!((flags & S_VERSION) &&
1202 		      inode_maybe_inc_iversion(inode, false))) {
1203 			generic_update_time(inode, flags);
1204 			return 0;
1205 		}
1206 
1207 		/* Capture the iversion update that just occurred */
1208 		log_flags |= XFS_ILOG_CORE;
1209 	}
1210 
1211 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_fsyncts, 0, 0, 0, &tp);
1212 	if (error)
1213 		return error;
1214 
1215 	xfs_ilock(ip, XFS_ILOCK_EXCL);
1216 	if (flags & (S_CTIME|S_MTIME))
1217 		now = inode_set_ctime_current(inode);
1218 	else
1219 		now = current_time(inode);
1220 
1221 	if (flags & S_MTIME)
1222 		inode_set_mtime_to_ts(inode, now);
1223 	if (flags & S_ATIME)
1224 		inode_set_atime_to_ts(inode, now);
1225 
1226 	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
1227 	xfs_trans_log_inode(tp, ip, log_flags);
1228 	return xfs_trans_commit(tp);
1229 }
1230 
1231 STATIC int
xfs_vn_fiemap(struct inode * inode,struct fiemap_extent_info * fieinfo,u64 start,u64 length)1232 xfs_vn_fiemap(
1233 	struct inode		*inode,
1234 	struct fiemap_extent_info *fieinfo,
1235 	u64			start,
1236 	u64			length)
1237 {
1238 	int			error;
1239 
1240 	xfs_ilock(XFS_I(inode), XFS_IOLOCK_SHARED);
1241 	if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
1242 		fieinfo->fi_flags &= ~FIEMAP_FLAG_XATTR;
1243 		error = iomap_fiemap(inode, fieinfo, start, length,
1244 				&xfs_xattr_iomap_ops);
1245 	} else {
1246 		error = iomap_fiemap(inode, fieinfo, start, length,
1247 				&xfs_read_iomap_ops);
1248 	}
1249 	xfs_iunlock(XFS_I(inode), XFS_IOLOCK_SHARED);
1250 
1251 	return error;
1252 }
1253 
1254 STATIC int
xfs_vn_tmpfile(struct mnt_idmap * idmap,struct inode * dir,struct file * file,umode_t mode)1255 xfs_vn_tmpfile(
1256 	struct mnt_idmap	*idmap,
1257 	struct inode		*dir,
1258 	struct file		*file,
1259 	umode_t			mode)
1260 {
1261 	int err = xfs_generic_create(idmap, dir, file->f_path.dentry, mode, 0, file);
1262 
1263 	return finish_open_simple(file, err);
1264 }
1265 
1266 static const struct inode_operations xfs_inode_operations = {
1267 	.get_inode_acl		= xfs_get_acl,
1268 	.set_acl		= xfs_set_acl,
1269 	.getattr		= xfs_vn_getattr,
1270 	.setattr		= xfs_vn_setattr,
1271 	.listxattr		= xfs_vn_listxattr,
1272 	.fiemap			= xfs_vn_fiemap,
1273 	.update_time		= xfs_vn_update_time,
1274 	.fileattr_get		= xfs_fileattr_get,
1275 	.fileattr_set		= xfs_fileattr_set,
1276 };
1277 
1278 static const struct inode_operations xfs_dir_inode_operations = {
1279 	.create			= xfs_vn_create,
1280 	.lookup			= xfs_vn_lookup,
1281 	.link			= xfs_vn_link,
1282 	.unlink			= xfs_vn_unlink,
1283 	.symlink		= xfs_vn_symlink,
1284 	.mkdir			= xfs_vn_mkdir,
1285 	/*
1286 	 * Yes, XFS uses the same method for rmdir and unlink.
1287 	 *
1288 	 * There are some subtile differences deeper in the code,
1289 	 * but we use S_ISDIR to check for those.
1290 	 */
1291 	.rmdir			= xfs_vn_unlink,
1292 	.mknod			= xfs_vn_mknod,
1293 	.rename			= xfs_vn_rename,
1294 	.get_inode_acl		= xfs_get_acl,
1295 	.set_acl		= xfs_set_acl,
1296 	.getattr		= xfs_vn_getattr,
1297 	.setattr		= xfs_vn_setattr,
1298 	.listxattr		= xfs_vn_listxattr,
1299 	.update_time		= xfs_vn_update_time,
1300 	.tmpfile		= xfs_vn_tmpfile,
1301 	.fileattr_get		= xfs_fileattr_get,
1302 	.fileattr_set		= xfs_fileattr_set,
1303 };
1304 
1305 static const struct inode_operations xfs_dir_ci_inode_operations = {
1306 	.create			= xfs_vn_create,
1307 	.lookup			= xfs_vn_ci_lookup,
1308 	.link			= xfs_vn_link,
1309 	.unlink			= xfs_vn_unlink,
1310 	.symlink		= xfs_vn_symlink,
1311 	.mkdir			= xfs_vn_mkdir,
1312 	/*
1313 	 * Yes, XFS uses the same method for rmdir and unlink.
1314 	 *
1315 	 * There are some subtile differences deeper in the code,
1316 	 * but we use S_ISDIR to check for those.
1317 	 */
1318 	.rmdir			= xfs_vn_unlink,
1319 	.mknod			= xfs_vn_mknod,
1320 	.rename			= xfs_vn_rename,
1321 	.get_inode_acl		= xfs_get_acl,
1322 	.set_acl		= xfs_set_acl,
1323 	.getattr		= xfs_vn_getattr,
1324 	.setattr		= xfs_vn_setattr,
1325 	.listxattr		= xfs_vn_listxattr,
1326 	.update_time		= xfs_vn_update_time,
1327 	.tmpfile		= xfs_vn_tmpfile,
1328 	.fileattr_get		= xfs_fileattr_get,
1329 	.fileattr_set		= xfs_fileattr_set,
1330 };
1331 
1332 static const struct inode_operations xfs_symlink_inode_operations = {
1333 	.get_link		= xfs_vn_get_link,
1334 	.getattr		= xfs_vn_getattr,
1335 	.setattr		= xfs_vn_setattr,
1336 	.listxattr		= xfs_vn_listxattr,
1337 	.update_time		= xfs_vn_update_time,
1338 };
1339 
1340 /* Figure out if this file actually supports DAX. */
1341 static bool
xfs_inode_supports_dax(struct xfs_inode * ip)1342 xfs_inode_supports_dax(
1343 	struct xfs_inode	*ip)
1344 {
1345 	struct xfs_mount	*mp = ip->i_mount;
1346 
1347 	/* Only supported on regular files. */
1348 	if (!S_ISREG(VFS_I(ip)->i_mode))
1349 		return false;
1350 
1351 	/* Block size must match page size */
1352 	if (mp->m_sb.sb_blocksize != PAGE_SIZE)
1353 		return false;
1354 
1355 	/* Device has to support DAX too. */
1356 	return xfs_inode_buftarg(ip)->bt_daxdev != NULL;
1357 }
1358 
1359 static bool
xfs_inode_should_enable_dax(struct xfs_inode * ip)1360 xfs_inode_should_enable_dax(
1361 	struct xfs_inode *ip)
1362 {
1363 	if (!IS_ENABLED(CONFIG_FS_DAX))
1364 		return false;
1365 	if (xfs_has_dax_never(ip->i_mount))
1366 		return false;
1367 	if (!xfs_inode_supports_dax(ip))
1368 		return false;
1369 	if (xfs_has_dax_always(ip->i_mount))
1370 		return true;
1371 	if (ip->i_diflags2 & XFS_DIFLAG2_DAX)
1372 		return true;
1373 	return false;
1374 }
1375 
1376 void
xfs_diflags_to_iflags(struct xfs_inode * ip,bool init)1377 xfs_diflags_to_iflags(
1378 	struct xfs_inode	*ip,
1379 	bool init)
1380 {
1381 	struct inode            *inode = VFS_I(ip);
1382 	unsigned int            xflags = xfs_ip2xflags(ip);
1383 	unsigned int            flags = 0;
1384 
1385 	ASSERT(!(IS_DAX(inode) && init));
1386 
1387 	if (xflags & FS_XFLAG_IMMUTABLE)
1388 		flags |= S_IMMUTABLE;
1389 	if (xflags & FS_XFLAG_APPEND)
1390 		flags |= S_APPEND;
1391 	if (xflags & FS_XFLAG_SYNC)
1392 		flags |= S_SYNC;
1393 	if (xflags & FS_XFLAG_NOATIME)
1394 		flags |= S_NOATIME;
1395 	if (init && xfs_inode_should_enable_dax(ip))
1396 		flags |= S_DAX;
1397 
1398 	/*
1399 	 * S_DAX can only be set during inode initialization and is never set by
1400 	 * the VFS, so we cannot mask off S_DAX in i_flags.
1401 	 */
1402 	inode->i_flags &= ~(S_IMMUTABLE | S_APPEND | S_SYNC | S_NOATIME);
1403 	inode->i_flags |= flags;
1404 }
1405 
1406 /*
1407  * Initialize the Linux inode.
1408  *
1409  * When reading existing inodes from disk this is called directly from xfs_iget,
1410  * when creating a new inode it is called from xfs_init_new_inode after setting
1411  * up the inode. These callers have different criteria for clearing XFS_INEW, so
1412  * leave it up to the caller to deal with unlocking the inode appropriately.
1413  */
1414 void
xfs_setup_inode(struct xfs_inode * ip)1415 xfs_setup_inode(
1416 	struct xfs_inode	*ip)
1417 {
1418 	struct inode		*inode = &ip->i_vnode;
1419 	gfp_t			gfp_mask;
1420 	bool			is_meta = xfs_is_internal_inode(ip);
1421 
1422 	inode->i_ino = ip->i_ino;
1423 	inode->i_state |= I_NEW;
1424 
1425 	inode_sb_list_add(inode);
1426 	/* make the inode look hashed for the writeback code */
1427 	inode_fake_hash(inode);
1428 
1429 	i_size_write(inode, ip->i_disk_size);
1430 	xfs_diflags_to_iflags(ip, true);
1431 
1432 	/*
1433 	 * Mark our metadata files as private so that LSMs and the ACL code
1434 	 * don't try to add their own metadata or reason about these files,
1435 	 * and users cannot ever obtain file handles to them.
1436 	 */
1437 	if (is_meta) {
1438 		inode->i_flags |= S_PRIVATE;
1439 		inode->i_opflags &= ~IOP_XATTR;
1440 	}
1441 
1442 	if (S_ISDIR(inode->i_mode)) {
1443 		/*
1444 		 * We set the i_rwsem class here to avoid potential races with
1445 		 * lockdep_annotate_inode_mutex_key() reinitialising the lock
1446 		 * after a filehandle lookup has already found the inode in
1447 		 * cache before it has been unlocked via unlock_new_inode().
1448 		 */
1449 		lockdep_set_class(&inode->i_rwsem,
1450 				  &inode->i_sb->s_type->i_mutex_dir_key);
1451 		lockdep_set_class(&ip->i_lock, &xfs_dir_ilock_class);
1452 	} else {
1453 		lockdep_set_class(&ip->i_lock, &xfs_nondir_ilock_class);
1454 	}
1455 
1456 	/*
1457 	 * Ensure all page cache allocations are done from GFP_NOFS context to
1458 	 * prevent direct reclaim recursion back into the filesystem and blowing
1459 	 * stacks or deadlocking.
1460 	 */
1461 	gfp_mask = mapping_gfp_mask(inode->i_mapping);
1462 	mapping_set_gfp_mask(inode->i_mapping, (gfp_mask & ~(__GFP_FS)));
1463 
1464 	/*
1465 	 * For real-time inodes update the stable write flags to that of the RT
1466 	 * device instead of the data device.
1467 	 */
1468 	if (S_ISREG(inode->i_mode) && XFS_IS_REALTIME_INODE(ip))
1469 		xfs_update_stable_writes(ip);
1470 
1471 	/*
1472 	 * If there is no attribute fork no ACL can exist on this inode,
1473 	 * and it can't have any file capabilities attached to it either.
1474 	 */
1475 	if (!xfs_inode_has_attr_fork(ip)) {
1476 		inode_has_no_xattr(inode);
1477 		cache_no_acl(inode);
1478 	}
1479 }
1480 
1481 void
xfs_setup_iops(struct xfs_inode * ip)1482 xfs_setup_iops(
1483 	struct xfs_inode	*ip)
1484 {
1485 	struct inode		*inode = &ip->i_vnode;
1486 
1487 	switch (inode->i_mode & S_IFMT) {
1488 	case S_IFREG:
1489 		inode->i_op = &xfs_inode_operations;
1490 		inode->i_fop = &xfs_file_operations;
1491 		if (IS_DAX(inode))
1492 			inode->i_mapping->a_ops = &xfs_dax_aops;
1493 		else
1494 			inode->i_mapping->a_ops = &xfs_address_space_operations;
1495 		break;
1496 	case S_IFDIR:
1497 		if (xfs_has_asciici(XFS_M(inode->i_sb)))
1498 			inode->i_op = &xfs_dir_ci_inode_operations;
1499 		else
1500 			inode->i_op = &xfs_dir_inode_operations;
1501 		inode->i_fop = &xfs_dir_file_operations;
1502 		break;
1503 	case S_IFLNK:
1504 		inode->i_op = &xfs_symlink_inode_operations;
1505 		break;
1506 	default:
1507 		inode->i_op = &xfs_inode_operations;
1508 		init_special_inode(inode, inode->i_mode, inode->i_rdev);
1509 		break;
1510 	}
1511 }
1512