xref: /linux/fs/xfs/xfs_iops.c (revision a7f25dc23ff6d238ed70e8a3a8a3792cde3bcc68)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2000-2005 Silicon Graphics, Inc.
4  * All Rights Reserved.
5  */
6 #include "xfs_platform.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)292 xfs_vn_create(
293 	struct mnt_idmap	*idmap,
294 	struct inode		*dir,
295 	struct dentry		*dentry,
296 	umode_t			mode)
297 {
298 	return xfs_generic_create(idmap, dir, dentry, mode, 0, NULL);
299 }
300 
301 STATIC struct dentry *
xfs_vn_mkdir(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode)302 xfs_vn_mkdir(
303 	struct mnt_idmap	*idmap,
304 	struct inode		*dir,
305 	struct dentry		*dentry,
306 	umode_t			mode)
307 {
308 	return ERR_PTR(xfs_generic_create(idmap, dir, dentry, mode, 0, NULL));
309 }
310 
311 STATIC struct dentry *
xfs_vn_lookup(struct inode * dir,struct dentry * dentry,unsigned int flags)312 xfs_vn_lookup(
313 	struct inode	*dir,
314 	struct dentry	*dentry,
315 	unsigned int flags)
316 {
317 	struct inode *inode;
318 	struct xfs_inode *cip;
319 	struct xfs_name	name;
320 	int		error;
321 
322 	if (dentry->d_name.len >= MAXNAMELEN)
323 		return ERR_PTR(-ENAMETOOLONG);
324 
325 	xfs_dentry_to_name(&name, dentry);
326 	error = xfs_lookup(XFS_I(dir), &name, &cip, NULL);
327 	if (likely(!error))
328 		inode = VFS_I(cip);
329 	else if (likely(error == -ENOENT))
330 		inode = NULL;
331 	else
332 		inode = ERR_PTR(error);
333 	return d_splice_alias(inode, dentry);
334 }
335 
336 STATIC struct dentry *
xfs_vn_ci_lookup(struct inode * dir,struct dentry * dentry,unsigned int flags)337 xfs_vn_ci_lookup(
338 	struct inode	*dir,
339 	struct dentry	*dentry,
340 	unsigned int	flags)
341 {
342 	struct xfs_inode *ip;
343 	struct xfs_name	xname;
344 	struct xfs_name ci_name;
345 	struct qstr	dname;
346 	int		error;
347 
348 	if (dentry->d_name.len >= MAXNAMELEN)
349 		return ERR_PTR(-ENAMETOOLONG);
350 
351 	xfs_dentry_to_name(&xname, dentry);
352 	error = xfs_lookup(XFS_I(dir), &xname, &ip, &ci_name);
353 	if (unlikely(error)) {
354 		if (unlikely(error != -ENOENT))
355 			return ERR_PTR(error);
356 		/*
357 		 * call d_add(dentry, NULL) here when d_drop_negative_children
358 		 * is called in xfs_vn_mknod (ie. allow negative dentries
359 		 * with CI filesystems).
360 		 */
361 		return NULL;
362 	}
363 
364 	/* if exact match, just splice and exit */
365 	if (!ci_name.name)
366 		return d_splice_alias(VFS_I(ip), dentry);
367 
368 	/* else case-insensitive match... */
369 	dname.name = ci_name.name;
370 	dname.len = ci_name.len;
371 	dentry = d_add_ci(dentry, VFS_I(ip), &dname);
372 	kfree(ci_name.name);
373 	return dentry;
374 }
375 
376 STATIC int
xfs_vn_link(struct dentry * old_dentry,struct inode * dir,struct dentry * dentry)377 xfs_vn_link(
378 	struct dentry	*old_dentry,
379 	struct inode	*dir,
380 	struct dentry	*dentry)
381 {
382 	struct inode	*inode = d_inode(old_dentry);
383 	struct xfs_name	name;
384 	int		error;
385 
386 	error = xfs_dentry_mode_to_name(&name, dentry, inode->i_mode);
387 	if (unlikely(error))
388 		return error;
389 
390 	if (IS_PRIVATE(inode))
391 		return -EPERM;
392 
393 	error = xfs_link(XFS_I(dir), XFS_I(inode), &name);
394 	if (unlikely(error))
395 		return error;
396 
397 	ihold(inode);
398 	d_instantiate(dentry, inode);
399 	return 0;
400 }
401 
402 STATIC int
xfs_vn_unlink(struct inode * dir,struct dentry * dentry)403 xfs_vn_unlink(
404 	struct inode	*dir,
405 	struct dentry	*dentry)
406 {
407 	struct xfs_name	name;
408 	int		error;
409 
410 	xfs_dentry_to_name(&name, dentry);
411 
412 	error = xfs_remove(XFS_I(dir), &name, XFS_I(d_inode(dentry)));
413 	if (error)
414 		return error;
415 
416 	/*
417 	 * With unlink, the VFS makes the dentry "negative": no inode,
418 	 * but still hashed. This is incompatible with case-insensitive
419 	 * mode, so invalidate (unhash) the dentry in CI-mode.
420 	 */
421 	if (xfs_has_asciici(XFS_M(dir->i_sb)))
422 		d_invalidate(dentry);
423 	return 0;
424 }
425 
426 STATIC int
xfs_vn_symlink(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,const char * symname)427 xfs_vn_symlink(
428 	struct mnt_idmap	*idmap,
429 	struct inode		*dir,
430 	struct dentry		*dentry,
431 	const char		*symname)
432 {
433 	struct inode		*inode;
434 	struct xfs_inode	*cip = NULL;
435 	struct xfs_name		name;
436 	int			error;
437 	umode_t			mode = S_IFLNK | S_IRWXUGO;
438 
439 	error = xfs_dentry_mode_to_name(&name, dentry, mode);
440 	if (unlikely(error))
441 		goto out;
442 
443 	error = xfs_symlink(idmap, XFS_I(dir), &name, symname, mode, &cip);
444 	if (unlikely(error))
445 		goto out;
446 
447 	inode = VFS_I(cip);
448 
449 	error = xfs_inode_init_security(inode, dir, &dentry->d_name);
450 	if (unlikely(error))
451 		goto out_cleanup_inode;
452 
453 	xfs_setup_iops(cip);
454 
455 	d_instantiate(dentry, inode);
456 	xfs_finish_inode_setup(cip);
457 	return 0;
458 
459  out_cleanup_inode:
460 	xfs_finish_inode_setup(cip);
461 	xfs_cleanup_inode(dir, inode, dentry);
462 	xfs_irele(cip);
463  out:
464 	return error;
465 }
466 
467 STATIC int
xfs_vn_rename(struct mnt_idmap * idmap,struct inode * odir,struct dentry * odentry,struct inode * ndir,struct dentry * ndentry,unsigned int flags)468 xfs_vn_rename(
469 	struct mnt_idmap	*idmap,
470 	struct inode		*odir,
471 	struct dentry		*odentry,
472 	struct inode		*ndir,
473 	struct dentry		*ndentry,
474 	unsigned int		flags)
475 {
476 	struct inode	*new_inode = d_inode(ndentry);
477 	int		omode = 0;
478 	int		error;
479 	struct xfs_name	oname;
480 	struct xfs_name	nname;
481 
482 	if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
483 		return -EINVAL;
484 
485 	/* if we are exchanging files, we need to set i_mode of both files */
486 	if (flags & RENAME_EXCHANGE)
487 		omode = d_inode(ndentry)->i_mode;
488 
489 	error = xfs_dentry_mode_to_name(&oname, odentry, omode);
490 	if (omode && unlikely(error))
491 		return error;
492 
493 	error = xfs_dentry_mode_to_name(&nname, ndentry,
494 					d_inode(odentry)->i_mode);
495 	if (unlikely(error))
496 		return error;
497 
498 	return xfs_rename(idmap, XFS_I(odir), &oname,
499 			  XFS_I(d_inode(odentry)), XFS_I(ndir), &nname,
500 			  new_inode ? XFS_I(new_inode) : NULL, flags);
501 }
502 
503 /*
504  * careful here - this function can get called recursively, so
505  * we need to be very careful about how much stack we use.
506  * uio is kmalloced for this reason...
507  */
508 STATIC const char *
xfs_vn_get_link(struct dentry * dentry,struct inode * inode,struct delayed_call * done)509 xfs_vn_get_link(
510 	struct dentry		*dentry,
511 	struct inode		*inode,
512 	struct delayed_call	*done)
513 {
514 	char			*link;
515 	int			error = -ENOMEM;
516 
517 	if (!dentry)
518 		return ERR_PTR(-ECHILD);
519 
520 	link = kmalloc(XFS_SYMLINK_MAXLEN+1, GFP_KERNEL);
521 	if (!link)
522 		goto out_err;
523 
524 	error = xfs_readlink(XFS_I(d_inode(dentry)), link);
525 	if (unlikely(error))
526 		goto out_kfree;
527 
528 	set_delayed_call(done, kfree_link, link);
529 	return link;
530 
531  out_kfree:
532 	kfree(link);
533  out_err:
534 	return ERR_PTR(error);
535 }
536 
537 static uint32_t
xfs_stat_blksize(struct xfs_inode * ip)538 xfs_stat_blksize(
539 	struct xfs_inode	*ip)
540 {
541 	struct xfs_mount	*mp = ip->i_mount;
542 
543 	/*
544 	 * If the file blocks are being allocated from a realtime volume, then
545 	 * always return the realtime extent size.
546 	 */
547 	if (XFS_IS_REALTIME_INODE(ip))
548 		return XFS_FSB_TO_B(mp, xfs_get_extsz_hint(ip) ? : 1);
549 
550 	/*
551 	 * Allow large block sizes to be reported to userspace programs if the
552 	 * "largeio" mount option is used.
553 	 *
554 	 * If compatibility mode is specified, simply return the basic unit of
555 	 * caching so that we don't get inefficient read/modify/write I/O from
556 	 * user apps. Otherwise....
557 	 *
558 	 * If the underlying volume is a stripe, then return the stripe width in
559 	 * bytes as the recommended I/O size. It is not a stripe and we've set a
560 	 * default buffered I/O size, return that, otherwise return the compat
561 	 * default.
562 	 */
563 	if (xfs_has_large_iosize(mp)) {
564 		if (mp->m_swidth)
565 			return XFS_FSB_TO_B(mp, mp->m_swidth);
566 		if (xfs_has_allocsize(mp))
567 			return 1U << mp->m_allocsize_log;
568 	}
569 
570 	return max_t(uint32_t, PAGE_SIZE, mp->m_sb.sb_blocksize);
571 }
572 
573 static void
xfs_report_dioalign(struct xfs_inode * ip,struct kstat * stat)574 xfs_report_dioalign(
575 	struct xfs_inode	*ip,
576 	struct kstat		*stat)
577 {
578 	struct xfs_buftarg	*target = xfs_inode_buftarg(ip);
579 	struct block_device	*bdev = target->bt_bdev;
580 
581 	stat->result_mask |= STATX_DIOALIGN | STATX_DIO_READ_ALIGN;
582 	stat->dio_mem_align = bdev_dma_alignment(bdev) + 1;
583 
584 	/*
585 	 * For COW inodes, we can only perform out of place writes of entire
586 	 * allocation units (blocks or RT extents).
587 	 * For writes smaller than the allocation unit, we must fall back to
588 	 * buffered I/O to perform read-modify-write cycles.  At best this is
589 	 * highly inefficient; at worst it leads to page cache invalidation
590 	 * races.  Tell applications to avoid this by reporting the larger write
591 	 * alignment in dio_offset_align, and the smaller read alignment in
592 	 * dio_read_offset_align.
593 	 */
594 	stat->dio_read_offset_align = bdev_logical_block_size(bdev);
595 	if (xfs_is_cow_inode(ip))
596 		stat->dio_offset_align = xfs_inode_alloc_unitsize(ip);
597 	else
598 		stat->dio_offset_align = stat->dio_read_offset_align;
599 }
600 
601 unsigned int
xfs_get_atomic_write_min(struct xfs_inode * ip)602 xfs_get_atomic_write_min(
603 	struct xfs_inode	*ip)
604 {
605 	struct xfs_mount	*mp = ip->i_mount;
606 
607 	/*
608 	 * If we can complete an atomic write via atomic out of place writes,
609 	 * then advertise a minimum size of one fsblock.  Without this
610 	 * mechanism, we can only guarantee atomic writes up to a single LBA.
611 	 *
612 	 * If out of place writes are not available, we can guarantee an atomic
613 	 * write of exactly one single fsblock if the bdev will make that
614 	 * guarantee for us.
615 	 */
616 	if (xfs_inode_can_hw_atomic_write(ip) ||
617 	    xfs_inode_can_sw_atomic_write(ip))
618 		return mp->m_sb.sb_blocksize;
619 
620 	return 0;
621 }
622 
623 unsigned int
xfs_get_atomic_write_max(struct xfs_inode * ip)624 xfs_get_atomic_write_max(
625 	struct xfs_inode	*ip)
626 {
627 	struct xfs_mount	*mp = ip->i_mount;
628 
629 	/*
630 	 * If out of place writes are not available, we can guarantee an atomic
631 	 * write of exactly one single fsblock if the bdev will make that
632 	 * guarantee for us.
633 	 */
634 	if (!xfs_inode_can_sw_atomic_write(ip)) {
635 		if (xfs_inode_can_hw_atomic_write(ip))
636 			return mp->m_sb.sb_blocksize;
637 		return 0;
638 	}
639 
640 	/*
641 	 * If we can complete an atomic write via atomic out of place writes,
642 	 * then advertise a maximum size of whatever we can complete through
643 	 * that means.  Hardware support is reported via max_opt, not here.
644 	 */
645 	if (XFS_IS_REALTIME_INODE(ip))
646 		return XFS_FSB_TO_B(mp, mp->m_groups[XG_TYPE_RTG].awu_max);
647 	return XFS_FSB_TO_B(mp, mp->m_groups[XG_TYPE_AG].awu_max);
648 }
649 
650 unsigned int
xfs_get_atomic_write_max_opt(struct xfs_inode * ip)651 xfs_get_atomic_write_max_opt(
652 	struct xfs_inode	*ip)
653 {
654 	unsigned int		awu_max = xfs_get_atomic_write_max(ip);
655 
656 	/* if the max is 1x block, then just keep behaviour that opt is 0 */
657 	if (awu_max <= ip->i_mount->m_sb.sb_blocksize)
658 		return 0;
659 
660 	/*
661 	 * Advertise the maximum size of an atomic write that we can tell the
662 	 * block device to perform for us.  In general the bdev limit will be
663 	 * less than our out of place write limit, but we don't want to exceed
664 	 * the awu_max.
665 	 */
666 	return min(awu_max, xfs_inode_buftarg(ip)->bt_awu_max);
667 }
668 
669 static void
xfs_report_atomic_write(struct xfs_inode * ip,struct kstat * stat)670 xfs_report_atomic_write(
671 	struct xfs_inode	*ip,
672 	struct kstat		*stat)
673 {
674 	generic_fill_statx_atomic_writes(stat,
675 			xfs_get_atomic_write_min(ip),
676 			xfs_get_atomic_write_max(ip),
677 			xfs_get_atomic_write_max_opt(ip));
678 }
679 
680 STATIC int
xfs_vn_getattr(struct mnt_idmap * idmap,const struct path * path,struct kstat * stat,u32 request_mask,unsigned int query_flags)681 xfs_vn_getattr(
682 	struct mnt_idmap	*idmap,
683 	const struct path	*path,
684 	struct kstat		*stat,
685 	u32			request_mask,
686 	unsigned int		query_flags)
687 {
688 	struct inode		*inode = d_inode(path->dentry);
689 	struct xfs_inode	*ip = XFS_I(inode);
690 	struct xfs_mount	*mp = ip->i_mount;
691 	vfsuid_t		vfsuid = i_uid_into_vfsuid(idmap, inode);
692 	vfsgid_t		vfsgid = i_gid_into_vfsgid(idmap, inode);
693 
694 	trace_xfs_getattr(ip);
695 
696 	if (xfs_is_shutdown(mp))
697 		return -EIO;
698 
699 	stat->size = XFS_ISIZE(ip);
700 	stat->dev = inode->i_sb->s_dev;
701 	stat->mode = inode->i_mode;
702 	stat->nlink = inode->i_nlink;
703 	stat->uid = vfsuid_into_kuid(vfsuid);
704 	stat->gid = vfsgid_into_kgid(vfsgid);
705 	stat->ino = inode->i_ino;
706 	stat->atime = inode_get_atime(inode);
707 
708 	fill_mg_cmtime(stat, request_mask, inode);
709 
710 	stat->blocks = XFS_FSB_TO_BB(mp, ip->i_nblocks + ip->i_delayed_blks);
711 
712 	if (xfs_has_v3inodes(mp)) {
713 		if (request_mask & STATX_BTIME) {
714 			stat->result_mask |= STATX_BTIME;
715 			stat->btime = ip->i_crtime;
716 		}
717 	}
718 
719 	/*
720 	 * Note: If you add another clause to set an attribute flag, please
721 	 * update attributes_mask below.
722 	 */
723 	if (ip->i_diflags & XFS_DIFLAG_IMMUTABLE)
724 		stat->attributes |= STATX_ATTR_IMMUTABLE;
725 	if (ip->i_diflags & XFS_DIFLAG_APPEND)
726 		stat->attributes |= STATX_ATTR_APPEND;
727 	if (ip->i_diflags & XFS_DIFLAG_NODUMP)
728 		stat->attributes |= STATX_ATTR_NODUMP;
729 
730 	stat->attributes_mask |= (STATX_ATTR_IMMUTABLE |
731 				  STATX_ATTR_APPEND |
732 				  STATX_ATTR_NODUMP);
733 
734 	switch (inode->i_mode & S_IFMT) {
735 	case S_IFBLK:
736 	case S_IFCHR:
737 		stat->blksize = BLKDEV_IOSIZE;
738 		stat->rdev = inode->i_rdev;
739 		break;
740 	case S_IFREG:
741 		if (request_mask & (STATX_DIOALIGN | STATX_DIO_READ_ALIGN))
742 			xfs_report_dioalign(ip, stat);
743 		if (request_mask & STATX_WRITE_ATOMIC)
744 			xfs_report_atomic_write(ip, stat);
745 		fallthrough;
746 	default:
747 		stat->blksize = xfs_stat_blksize(ip);
748 		stat->rdev = 0;
749 		break;
750 	}
751 
752 	return 0;
753 }
754 
755 static int
xfs_vn_change_ok(struct mnt_idmap * idmap,struct dentry * dentry,struct iattr * iattr)756 xfs_vn_change_ok(
757 	struct mnt_idmap	*idmap,
758 	struct dentry		*dentry,
759 	struct iattr		*iattr)
760 {
761 	struct xfs_mount	*mp = XFS_I(d_inode(dentry))->i_mount;
762 
763 	if (xfs_is_readonly(mp))
764 		return -EROFS;
765 
766 	if (xfs_is_shutdown(mp))
767 		return -EIO;
768 
769 	return setattr_prepare(idmap, dentry, iattr);
770 }
771 
772 /*
773  * Set non-size attributes of an inode.
774  *
775  * Caution: The caller of this function is responsible for calling
776  * setattr_prepare() or otherwise verifying the change is fine.
777  */
778 static int
xfs_setattr_nonsize(struct mnt_idmap * idmap,struct dentry * dentry,struct xfs_inode * ip,struct iattr * iattr)779 xfs_setattr_nonsize(
780 	struct mnt_idmap	*idmap,
781 	struct dentry		*dentry,
782 	struct xfs_inode	*ip,
783 	struct iattr		*iattr)
784 {
785 	xfs_mount_t		*mp = ip->i_mount;
786 	struct inode		*inode = VFS_I(ip);
787 	int			mask = iattr->ia_valid;
788 	xfs_trans_t		*tp;
789 	int			error;
790 	kuid_t			uid = GLOBAL_ROOT_UID;
791 	kgid_t			gid = GLOBAL_ROOT_GID;
792 	struct xfs_dquot	*udqp = NULL, *gdqp = NULL;
793 	struct xfs_dquot	*old_udqp = NULL, *old_gdqp = NULL;
794 
795 	ASSERT((mask & ATTR_SIZE) == 0);
796 
797 	/*
798 	 * If disk quotas is on, we make sure that the dquots do exist on disk,
799 	 * before we start any other transactions. Trying to do this later
800 	 * is messy. We don't care to take a readlock to look at the ids
801 	 * in inode here, because we can't hold it across the trans_reserve.
802 	 * If the IDs do change before we take the ilock, we're covered
803 	 * because the i_*dquot fields will get updated anyway.
804 	 */
805 	if (XFS_IS_QUOTA_ON(mp) && (mask & (ATTR_UID|ATTR_GID))) {
806 		uint	qflags = 0;
807 
808 		if ((mask & ATTR_UID) && XFS_IS_UQUOTA_ON(mp)) {
809 			uid = from_vfsuid(idmap, i_user_ns(inode),
810 					  iattr->ia_vfsuid);
811 			qflags |= XFS_QMOPT_UQUOTA;
812 		} else {
813 			uid = inode->i_uid;
814 		}
815 		if ((mask & ATTR_GID) && XFS_IS_GQUOTA_ON(mp)) {
816 			gid = from_vfsgid(idmap, i_user_ns(inode),
817 					  iattr->ia_vfsgid);
818 			qflags |= XFS_QMOPT_GQUOTA;
819 		}  else {
820 			gid = inode->i_gid;
821 		}
822 
823 		/*
824 		 * We take a reference when we initialize udqp and gdqp,
825 		 * so it is important that we never blindly double trip on
826 		 * the same variable. See xfs_create() for an example.
827 		 */
828 		ASSERT(udqp == NULL);
829 		ASSERT(gdqp == NULL);
830 		error = xfs_qm_vop_dqalloc(ip, uid, gid, ip->i_projid,
831 					   qflags, &udqp, &gdqp, NULL);
832 		if (error)
833 			return error;
834 	}
835 
836 	error = xfs_trans_alloc_ichange(ip, udqp, gdqp, NULL,
837 			capable_noaudit(CAP_FOWNER), &tp);
838 	if (error)
839 		goto out_dqrele;
840 
841 	/*
842 	 * Register quota modifications in the transaction.  Must be the owner
843 	 * or privileged.  These IDs could have changed since we last looked at
844 	 * them.  But, we're assured that if the ownership did change while we
845 	 * didn't have the inode locked, inode's dquot(s) would have changed
846 	 * also.
847 	 */
848 	if (XFS_IS_UQUOTA_ON(mp) &&
849 	    i_uid_needs_update(idmap, iattr, inode)) {
850 		ASSERT(udqp);
851 		old_udqp = xfs_qm_vop_chown(tp, ip, &ip->i_udquot, udqp);
852 	}
853 	if (XFS_IS_GQUOTA_ON(mp) &&
854 	    i_gid_needs_update(idmap, iattr, inode)) {
855 		ASSERT(xfs_has_pquotino(mp) || !XFS_IS_PQUOTA_ON(mp));
856 		ASSERT(gdqp);
857 		old_gdqp = xfs_qm_vop_chown(tp, ip, &ip->i_gdquot, gdqp);
858 	}
859 
860 	setattr_copy(idmap, inode, iattr);
861 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
862 
863 	XFS_STATS_INC(mp, xs_ig_attrchg);
864 
865 	if (xfs_has_wsync(mp))
866 		xfs_trans_set_sync(tp);
867 	error = xfs_trans_commit(tp);
868 
869 	/*
870 	 * Release any dquot(s) the inode had kept before chown.
871 	 */
872 	xfs_qm_dqrele(old_udqp);
873 	xfs_qm_dqrele(old_gdqp);
874 	xfs_qm_dqrele(udqp);
875 	xfs_qm_dqrele(gdqp);
876 
877 	if (error)
878 		return error;
879 
880 	/*
881 	 * XXX(hch): Updating the ACL entries is not atomic vs the i_mode
882 	 * 	     update.  We could avoid this with linked transactions
883 	 * 	     and passing down the transaction pointer all the way
884 	 *	     to attr_set.  No previous user of the generic
885 	 * 	     Posix ACL code seems to care about this issue either.
886 	 */
887 	if (mask & ATTR_MODE) {
888 		error = posix_acl_chmod(idmap, dentry, inode->i_mode);
889 		if (error)
890 			return error;
891 	}
892 
893 	return 0;
894 
895 out_dqrele:
896 	xfs_qm_dqrele(udqp);
897 	xfs_qm_dqrele(gdqp);
898 	return error;
899 }
900 
901 /*
902  * Truncate file.  Must have write permission and not be a directory.
903  */
904 int
xfs_vn_setattr_size(struct mnt_idmap * idmap,struct dentry * dentry,struct iattr * iattr)905 xfs_vn_setattr_size(
906 	struct mnt_idmap	*idmap,
907 	struct dentry		*dentry,
908 	struct iattr		*iattr)
909 {
910 	struct inode		*inode = d_inode(dentry);
911 	struct xfs_inode	*ip = XFS_I(inode);
912 	struct xfs_mount	*mp = ip->i_mount;
913 	xfs_off_t		oldsize = inode->i_size;
914 	xfs_off_t		newsize = iattr->ia_size;
915 	struct xfs_trans	*tp;
916 	int			error;
917 	uint			lock_flags = 0;
918 	uint			resblks = 0;
919 	bool			did_zeroing = false;
920 	struct xfs_zone_alloc_ctx ac = { };
921 
922 	xfs_assert_ilocked(ip, XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL);
923 	ASSERT(S_ISREG(inode->i_mode));
924 	ASSERT((iattr->ia_valid & (ATTR_UID|ATTR_GID|ATTR_ATIME|ATTR_ATIME_SET|
925 		ATTR_MTIME_SET|ATTR_TIMES_SET)) == 0);
926 
927 	trace_xfs_setattr(ip);
928 
929 	error = xfs_vn_change_ok(idmap, dentry, iattr);
930 	if (error)
931 		return error;
932 
933 	/*
934 	 * Short circuit the truncate case for zero length files.
935 	 */
936 	if (newsize == 0 && oldsize == 0 && ip->i_df.if_nextents == 0) {
937 		if (!(iattr->ia_valid & (ATTR_CTIME|ATTR_MTIME)))
938 			return 0;
939 
940 		/*
941 		 * Use the regular setattr path to update the timestamps.
942 		 */
943 		iattr->ia_valid &= ~ATTR_SIZE;
944 		return xfs_setattr_nonsize(idmap, dentry, ip, iattr);
945 	}
946 
947 	/*
948 	 * Make sure that the dquots are attached to the inode.
949 	 */
950 	error = xfs_qm_dqattach(ip);
951 	if (error)
952 		return error;
953 
954 	/*
955 	 * Wait for all direct I/O to complete.
956 	 */
957 	inode_dio_wait(inode);
958 
959 	/*
960 	 * Normally xfs_zoned_space_reserve is supposed to be called outside the
961 	 * IOLOCK.  For truncate we can't do that since ->setattr is called with
962 	 * it already held by the VFS.  So for now chicken out and try to
963 	 * allocate space under it.
964 	 *
965 	 * To avoid deadlocks this means we can't block waiting for space, which
966 	 * can lead to spurious -ENOSPC if there are no directly available
967 	 * blocks.  We mitigate this a bit by allowing zeroing to dip into the
968 	 * reserved pool, but eventually the VFS calling convention needs to
969 	 * change.
970 	 */
971 	if (xfs_is_zoned_inode(ip)) {
972 		error = xfs_zoned_space_reserve(mp, 1,
973 				XFS_ZR_NOWAIT | XFS_ZR_RESERVED, &ac);
974 		if (error) {
975 			if (error == -EAGAIN)
976 				return -ENOSPC;
977 			return error;
978 		}
979 	}
980 
981 	/*
982 	 * File data changes must be complete before we start the transaction to
983 	 * modify the inode.  This needs to be done before joining the inode to
984 	 * the transaction because the inode cannot be unlocked once it is a
985 	 * part of the transaction.
986 	 *
987 	 * Start with zeroing any data beyond EOF that we may expose on file
988 	 * extension, or zeroing out the rest of the block on a downward
989 	 * truncate.
990 	 */
991 	if (newsize > oldsize) {
992 		trace_xfs_zero_eof(ip, oldsize, newsize - oldsize);
993 		error = xfs_zero_range(ip, oldsize, newsize - oldsize,
994 				&ac, &did_zeroing);
995 	} else {
996 		error = xfs_truncate_page(ip, newsize, &ac, &did_zeroing);
997 	}
998 
999 	if (xfs_is_zoned_inode(ip))
1000 		xfs_zoned_space_unreserve(mp, &ac);
1001 
1002 	if (error)
1003 		return error;
1004 
1005 	/*
1006 	 * We've already locked out new page faults, so now we can safely remove
1007 	 * pages from the page cache knowing they won't get refaulted until we
1008 	 * drop the XFS_MMAP_EXCL lock after the extent manipulations are
1009 	 * complete. The truncate_setsize() call also cleans partial EOF page
1010 	 * PTEs on extending truncates and hence ensures sub-page block size
1011 	 * filesystems are correctly handled, too.
1012 	 *
1013 	 * We have to do all the page cache truncate work outside the
1014 	 * transaction context as the "lock" order is page lock->log space
1015 	 * reservation as defined by extent allocation in the writeback path.
1016 	 * Hence a truncate can fail with ENOMEM from xfs_trans_alloc(), but
1017 	 * having already truncated the in-memory version of the file (i.e. made
1018 	 * user visible changes). There's not much we can do about this, except
1019 	 * to hope that the caller sees ENOMEM and retries the truncate
1020 	 * operation.
1021 	 *
1022 	 * And we update in-core i_size and truncate page cache beyond newsize
1023 	 * before writeback the [i_disk_size, newsize] range, so we're
1024 	 * guaranteed not to write stale data past the new EOF on truncate down.
1025 	 */
1026 	truncate_setsize(inode, newsize);
1027 
1028 	/*
1029 	 * We are going to log the inode size change in this transaction so
1030 	 * any previous writes that are beyond the on disk EOF and the new
1031 	 * EOF that have not been written out need to be written here.  If we
1032 	 * do not write the data out, we expose ourselves to the null files
1033 	 * problem. Note that this includes any block zeroing we did above;
1034 	 * otherwise those blocks may not be zeroed after a crash.
1035 	 */
1036 	if (did_zeroing ||
1037 	    (newsize > ip->i_disk_size && oldsize != ip->i_disk_size)) {
1038 		error = filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
1039 						ip->i_disk_size, newsize - 1);
1040 		if (error)
1041 			return error;
1042 	}
1043 
1044 	/*
1045 	 * For realtime inode with more than one block rtextsize, we need the
1046 	 * block reservation for bmap btree block allocations/splits that can
1047 	 * happen since it could split the tail written extent and convert the
1048 	 * right beyond EOF one to unwritten.
1049 	 */
1050 	if (xfs_inode_has_bigrtalloc(ip))
1051 		resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
1052 
1053 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, resblks,
1054 				0, 0, &tp);
1055 	if (error)
1056 		return error;
1057 
1058 	lock_flags |= XFS_ILOCK_EXCL;
1059 	xfs_ilock(ip, XFS_ILOCK_EXCL);
1060 	xfs_trans_ijoin(tp, ip, 0);
1061 
1062 	/*
1063 	 * Only change the c/mtime if we are changing the size or we are
1064 	 * explicitly asked to change it.  This handles the semantic difference
1065 	 * between truncate() and ftruncate() as implemented in the VFS.
1066 	 *
1067 	 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
1068 	 * special case where we need to update the times despite not having
1069 	 * these flags set.  For all other operations the VFS set these flags
1070 	 * explicitly if it wants a timestamp update.
1071 	 */
1072 	if (newsize != oldsize &&
1073 	    !(iattr->ia_valid & (ATTR_CTIME | ATTR_MTIME))) {
1074 		iattr->ia_ctime = iattr->ia_mtime =
1075 			current_time(inode);
1076 		iattr->ia_valid |= ATTR_CTIME | ATTR_MTIME;
1077 	}
1078 
1079 	/*
1080 	 * The first thing we do is set the size to new_size permanently on
1081 	 * disk.  This way we don't have to worry about anyone ever being able
1082 	 * to look at the data being freed even in the face of a crash.
1083 	 * What we're getting around here is the case where we free a block, it
1084 	 * is allocated to another file, it is written to, and then we crash.
1085 	 * If the new data gets written to the file but the log buffers
1086 	 * containing the free and reallocation don't, then we'd end up with
1087 	 * garbage in the blocks being freed.  As long as we make the new size
1088 	 * permanent before actually freeing any blocks it doesn't matter if
1089 	 * they get written to.
1090 	 */
1091 	ip->i_disk_size = newsize;
1092 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
1093 
1094 	if (newsize <= oldsize) {
1095 		error = xfs_itruncate_extents(&tp, ip, XFS_DATA_FORK, newsize);
1096 		if (error)
1097 			goto out_trans_cancel;
1098 
1099 		/*
1100 		 * Truncated "down", so we're removing references to old data
1101 		 * here - if we delay flushing for a long time, we expose
1102 		 * ourselves unduly to the notorious NULL files problem.  So,
1103 		 * we mark this inode and flush it when the file is closed,
1104 		 * and do not wait the usual (long) time for writeout.
1105 		 */
1106 		xfs_iflags_set(ip, XFS_ITRUNCATED);
1107 
1108 		/* A truncate down always removes post-EOF blocks. */
1109 		xfs_inode_clear_eofblocks_tag(ip);
1110 	}
1111 
1112 	setattr_copy(idmap, inode, iattr);
1113 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
1114 
1115 	XFS_STATS_INC(mp, xs_ig_attrchg);
1116 
1117 	if (xfs_has_wsync(mp))
1118 		xfs_trans_set_sync(tp);
1119 
1120 	error = xfs_trans_commit(tp);
1121 out_unlock:
1122 	if (lock_flags)
1123 		xfs_iunlock(ip, lock_flags);
1124 	return error;
1125 
1126 out_trans_cancel:
1127 	xfs_trans_cancel(tp);
1128 	goto out_unlock;
1129 }
1130 
1131 STATIC int
xfs_vn_setattr(struct mnt_idmap * idmap,struct dentry * dentry,struct iattr * iattr)1132 xfs_vn_setattr(
1133 	struct mnt_idmap	*idmap,
1134 	struct dentry		*dentry,
1135 	struct iattr		*iattr)
1136 {
1137 	struct inode		*inode = d_inode(dentry);
1138 	struct xfs_inode	*ip = XFS_I(inode);
1139 	int			error;
1140 
1141 	if (iattr->ia_valid & ATTR_SIZE) {
1142 		uint			iolock;
1143 
1144 		xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
1145 		iolock = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL;
1146 
1147 		error = xfs_break_layouts(inode, &iolock, BREAK_UNMAP);
1148 		if (error) {
1149 			xfs_iunlock(ip, XFS_MMAPLOCK_EXCL);
1150 			return error;
1151 		}
1152 
1153 		error = xfs_vn_setattr_size(idmap, dentry, iattr);
1154 		xfs_iunlock(ip, XFS_MMAPLOCK_EXCL);
1155 	} else {
1156 		trace_xfs_setattr(ip);
1157 
1158 		error = xfs_vn_change_ok(idmap, dentry, iattr);
1159 		if (!error)
1160 			error = xfs_setattr_nonsize(idmap, dentry, ip, iattr);
1161 	}
1162 
1163 	return error;
1164 }
1165 
1166 STATIC int
xfs_vn_update_time(struct inode * inode,enum fs_update_time type,unsigned int flags)1167 xfs_vn_update_time(
1168 	struct inode		*inode,
1169 	enum fs_update_time	type,
1170 	unsigned int		flags)
1171 {
1172 	struct xfs_inode	*ip = XFS_I(inode);
1173 	struct xfs_mount	*mp = ip->i_mount;
1174 	int			log_flags = XFS_ILOG_TIMESTAMP;
1175 	struct xfs_trans	*tp;
1176 	int			error;
1177 
1178 	trace_xfs_update_time(ip);
1179 
1180 	if (inode->i_sb->s_flags & SB_LAZYTIME) {
1181 		int dirty;
1182 
1183 		dirty = inode_update_time(inode, type, flags);
1184 		if (dirty <= 0)
1185 			return dirty;
1186 		if (dirty == I_DIRTY_TIME) {
1187 			__mark_inode_dirty(inode, I_DIRTY_TIME);
1188 			return 0;
1189 		}
1190 
1191 		/* Capture the iversion update that just occurred */
1192 		log_flags |= XFS_ILOG_CORE;
1193 	} else {
1194 		if (flags & IOCB_NOWAIT)
1195 			return -EAGAIN;
1196 	}
1197 
1198 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_fsyncts, 0, 0, 0, &tp);
1199 	if (error)
1200 		return error;
1201 
1202 	xfs_ilock(ip, XFS_ILOCK_EXCL);
1203 	if (type == FS_UPD_ATIME)
1204 		inode_set_atime_to_ts(inode, current_time(inode));
1205 	else
1206 		inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
1207 	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
1208 	xfs_trans_log_inode(tp, ip, log_flags);
1209 	return xfs_trans_commit(tp);
1210 }
1211 
1212 static void
xfs_vn_sync_lazytime(struct inode * inode)1213 xfs_vn_sync_lazytime(
1214 	struct inode		*inode)
1215 {
1216 	struct xfs_inode	*ip = XFS_I(inode);
1217 	struct xfs_mount	*mp = ip->i_mount;
1218 	struct xfs_trans	*tp;
1219 
1220 	if (xfs_trans_alloc(mp, &M_RES(mp)->tr_fsyncts, 0, 0, 0, &tp))
1221 		return;
1222 	xfs_ilock(ip, XFS_ILOCK_EXCL);
1223 	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
1224 	xfs_trans_log_inode(tp, ip, XFS_ILOG_TIMESTAMP);
1225 	xfs_trans_commit(tp);
1226 }
1227 
1228 STATIC int
xfs_vn_fiemap(struct inode * inode,struct fiemap_extent_info * fieinfo,u64 start,u64 length)1229 xfs_vn_fiemap(
1230 	struct inode		*inode,
1231 	struct fiemap_extent_info *fieinfo,
1232 	u64			start,
1233 	u64			length)
1234 {
1235 	int			error;
1236 
1237 	xfs_ilock(XFS_I(inode), XFS_IOLOCK_SHARED);
1238 	if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
1239 		fieinfo->fi_flags &= ~FIEMAP_FLAG_XATTR;
1240 		error = iomap_fiemap(inode, fieinfo, start, length,
1241 				&xfs_xattr_iomap_ops);
1242 	} else {
1243 		error = iomap_fiemap(inode, fieinfo, start, length,
1244 				&xfs_read_iomap_ops);
1245 	}
1246 	xfs_iunlock(XFS_I(inode), XFS_IOLOCK_SHARED);
1247 
1248 	return error;
1249 }
1250 
1251 STATIC int
xfs_vn_tmpfile(struct mnt_idmap * idmap,struct inode * dir,struct file * file,umode_t mode)1252 xfs_vn_tmpfile(
1253 	struct mnt_idmap	*idmap,
1254 	struct inode		*dir,
1255 	struct file		*file,
1256 	umode_t			mode)
1257 {
1258 	int err = xfs_generic_create(idmap, dir, file->f_path.dentry, mode, 0, file);
1259 
1260 	return finish_open_simple(file, err);
1261 }
1262 
1263 static const struct inode_operations xfs_inode_operations = {
1264 	.get_inode_acl		= xfs_get_acl,
1265 	.set_acl		= xfs_set_acl,
1266 	.getattr		= xfs_vn_getattr,
1267 	.setattr		= xfs_vn_setattr,
1268 	.listxattr		= xfs_vn_listxattr,
1269 	.fiemap			= xfs_vn_fiemap,
1270 	.update_time		= xfs_vn_update_time,
1271 	.sync_lazytime		= xfs_vn_sync_lazytime,
1272 	.fileattr_get		= xfs_fileattr_get,
1273 	.fileattr_set		= xfs_fileattr_set,
1274 };
1275 
1276 static const struct inode_operations xfs_dir_inode_operations = {
1277 	.create			= xfs_vn_create,
1278 	.lookup			= xfs_vn_lookup,
1279 	.link			= xfs_vn_link,
1280 	.unlink			= xfs_vn_unlink,
1281 	.symlink		= xfs_vn_symlink,
1282 	.mkdir			= xfs_vn_mkdir,
1283 	/*
1284 	 * Yes, XFS uses the same method for rmdir and unlink.
1285 	 *
1286 	 * There are some subtile differences deeper in the code,
1287 	 * but we use S_ISDIR to check for those.
1288 	 */
1289 	.rmdir			= xfs_vn_unlink,
1290 	.mknod			= xfs_vn_mknod,
1291 	.rename			= xfs_vn_rename,
1292 	.get_inode_acl		= xfs_get_acl,
1293 	.set_acl		= xfs_set_acl,
1294 	.getattr		= xfs_vn_getattr,
1295 	.setattr		= xfs_vn_setattr,
1296 	.listxattr		= xfs_vn_listxattr,
1297 	.update_time		= xfs_vn_update_time,
1298 	.sync_lazytime		= xfs_vn_sync_lazytime,
1299 	.tmpfile		= xfs_vn_tmpfile,
1300 	.fileattr_get		= xfs_fileattr_get,
1301 	.fileattr_set		= xfs_fileattr_set,
1302 };
1303 
1304 static const struct inode_operations xfs_dir_ci_inode_operations = {
1305 	.create			= xfs_vn_create,
1306 	.lookup			= xfs_vn_ci_lookup,
1307 	.link			= xfs_vn_link,
1308 	.unlink			= xfs_vn_unlink,
1309 	.symlink		= xfs_vn_symlink,
1310 	.mkdir			= xfs_vn_mkdir,
1311 	/*
1312 	 * Yes, XFS uses the same method for rmdir and unlink.
1313 	 *
1314 	 * There are some subtile differences deeper in the code,
1315 	 * but we use S_ISDIR to check for those.
1316 	 */
1317 	.rmdir			= xfs_vn_unlink,
1318 	.mknod			= xfs_vn_mknod,
1319 	.rename			= xfs_vn_rename,
1320 	.get_inode_acl		= xfs_get_acl,
1321 	.set_acl		= xfs_set_acl,
1322 	.getattr		= xfs_vn_getattr,
1323 	.setattr		= xfs_vn_setattr,
1324 	.listxattr		= xfs_vn_listxattr,
1325 	.update_time		= xfs_vn_update_time,
1326 	.sync_lazytime		= xfs_vn_sync_lazytime,
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 	.sync_lazytime		= xfs_vn_sync_lazytime,
1339 	.fileattr_get		= xfs_fileattr_get,
1340 	.fileattr_set		= xfs_fileattr_set,
1341 };
1342 
1343 /* Figure out if this file actually supports DAX. */
1344 static bool
xfs_inode_supports_dax(struct xfs_inode * ip)1345 xfs_inode_supports_dax(
1346 	struct xfs_inode	*ip)
1347 {
1348 	struct xfs_mount	*mp = ip->i_mount;
1349 
1350 	/* Only supported on regular files. */
1351 	if (!S_ISREG(VFS_I(ip)->i_mode))
1352 		return false;
1353 
1354 	/* Block size must match page size */
1355 	if (mp->m_sb.sb_blocksize != PAGE_SIZE)
1356 		return false;
1357 
1358 	/* Device has to support DAX too. */
1359 	return xfs_inode_buftarg(ip)->bt_daxdev != NULL;
1360 }
1361 
1362 static bool
xfs_inode_should_enable_dax(struct xfs_inode * ip)1363 xfs_inode_should_enable_dax(
1364 	struct xfs_inode *ip)
1365 {
1366 	if (!IS_ENABLED(CONFIG_FS_DAX))
1367 		return false;
1368 	if (xfs_has_dax_never(ip->i_mount))
1369 		return false;
1370 	if (!xfs_inode_supports_dax(ip))
1371 		return false;
1372 	if (xfs_has_dax_always(ip->i_mount))
1373 		return true;
1374 	if (ip->i_diflags2 & XFS_DIFLAG2_DAX)
1375 		return true;
1376 	return false;
1377 }
1378 
1379 void
xfs_diflags_to_iflags(struct xfs_inode * ip,bool init)1380 xfs_diflags_to_iflags(
1381 	struct xfs_inode	*ip,
1382 	bool init)
1383 {
1384 	struct inode            *inode = VFS_I(ip);
1385 	unsigned int            xflags = xfs_ip2xflags(ip);
1386 	unsigned int            flags = 0;
1387 
1388 	ASSERT(!(IS_DAX(inode) && init));
1389 
1390 	if (xflags & FS_XFLAG_IMMUTABLE)
1391 		flags |= S_IMMUTABLE;
1392 	if (xflags & FS_XFLAG_APPEND)
1393 		flags |= S_APPEND;
1394 	if (xflags & FS_XFLAG_SYNC)
1395 		flags |= S_SYNC;
1396 	if (xflags & FS_XFLAG_NOATIME)
1397 		flags |= S_NOATIME;
1398 	if (init && xfs_inode_should_enable_dax(ip))
1399 		flags |= S_DAX;
1400 
1401 	/*
1402 	 * S_DAX can only be set during inode initialization and is never set by
1403 	 * the VFS, so we cannot mask off S_DAX in i_flags.
1404 	 */
1405 	inode->i_flags &= ~(S_IMMUTABLE | S_APPEND | S_SYNC | S_NOATIME);
1406 	inode->i_flags |= flags;
1407 }
1408 
1409 /*
1410  * Initialize the Linux inode.
1411  *
1412  * When reading existing inodes from disk this is called directly from xfs_iget,
1413  * when creating a new inode it is called from xfs_init_new_inode after setting
1414  * up the inode. These callers have different criteria for clearing XFS_INEW, so
1415  * leave it up to the caller to deal with unlocking the inode appropriately.
1416  */
1417 void
xfs_setup_inode(struct xfs_inode * ip)1418 xfs_setup_inode(
1419 	struct xfs_inode	*ip)
1420 {
1421 	struct inode		*inode = &ip->i_vnode;
1422 	gfp_t			gfp_mask;
1423 	bool			is_meta = xfs_is_internal_inode(ip);
1424 
1425 	inode_state_set_raw(inode, I_NEW);
1426 
1427 	inode_sb_list_add(inode);
1428 	/* make the inode look hashed for the writeback code */
1429 	inode_fake_hash(inode);
1430 
1431 	i_size_write(inode, ip->i_disk_size);
1432 	xfs_diflags_to_iflags(ip, true);
1433 
1434 	/*
1435 	 * Mark our metadata files as private so that LSMs and the ACL code
1436 	 * don't try to add their own metadata or reason about these files,
1437 	 * and users cannot ever obtain file handles to them.
1438 	 */
1439 	if (is_meta) {
1440 		inode->i_flags |= S_PRIVATE;
1441 		inode->i_opflags &= ~IOP_XATTR;
1442 	}
1443 
1444 	if (S_ISDIR(inode->i_mode)) {
1445 		/*
1446 		 * We set the i_rwsem class here to avoid potential races with
1447 		 * lockdep_annotate_inode_mutex_key() reinitialising the lock
1448 		 * after a filehandle lookup has already found the inode in
1449 		 * cache before it has been unlocked via unlock_new_inode().
1450 		 */
1451 		lockdep_set_class(&inode->i_rwsem,
1452 				  &inode->i_sb->s_type->i_mutex_dir_key);
1453 		lockdep_set_class(&ip->i_lock, &xfs_dir_ilock_class);
1454 	} else {
1455 		lockdep_set_class(&ip->i_lock, &xfs_nondir_ilock_class);
1456 	}
1457 
1458 	/*
1459 	 * Ensure all page cache allocations are done from GFP_NOFS context to
1460 	 * prevent direct reclaim recursion back into the filesystem and blowing
1461 	 * stacks or deadlocking.
1462 	 */
1463 	gfp_mask = mapping_gfp_mask(inode->i_mapping);
1464 	mapping_set_gfp_mask(inode->i_mapping, (gfp_mask & ~(__GFP_FS)));
1465 
1466 	/*
1467 	 * For real-time inodes update the stable write flags to that of the RT
1468 	 * device instead of the data device.
1469 	 */
1470 	if (S_ISREG(inode->i_mode) && XFS_IS_REALTIME_INODE(ip))
1471 		xfs_update_stable_writes(ip);
1472 
1473 	/*
1474 	 * If there is no attribute fork no ACL can exist on this inode,
1475 	 * and it can't have any file capabilities attached to it either.
1476 	 */
1477 	if (!xfs_inode_has_attr_fork(ip)) {
1478 		inode_has_no_xattr(inode);
1479 		cache_no_acl(inode);
1480 	}
1481 }
1482 
1483 void
xfs_setup_iops(struct xfs_inode * ip)1484 xfs_setup_iops(
1485 	struct xfs_inode	*ip)
1486 {
1487 	struct inode		*inode = &ip->i_vnode;
1488 
1489 	switch (inode->i_mode & S_IFMT) {
1490 	case S_IFREG:
1491 		inode->i_op = &xfs_inode_operations;
1492 		inode->i_fop = &xfs_file_operations;
1493 		if (IS_DAX(inode))
1494 			inode->i_mapping->a_ops = &xfs_dax_aops;
1495 		else
1496 			inode->i_mapping->a_ops = &xfs_address_space_operations;
1497 		break;
1498 	case S_IFDIR:
1499 		if (xfs_has_asciici(XFS_M(inode->i_sb)))
1500 			inode->i_op = &xfs_dir_ci_inode_operations;
1501 		else
1502 			inode->i_op = &xfs_dir_inode_operations;
1503 		inode->i_fop = &xfs_dir_file_operations;
1504 		break;
1505 	case S_IFLNK:
1506 		inode->i_op = &xfs_symlink_inode_operations;
1507 		break;
1508 	default:
1509 		inode->i_op = &xfs_inode_operations;
1510 		init_special_inode(inode, inode->i_mode, inode->i_rdev);
1511 		break;
1512 	}
1513 }
1514