xref: /openbmc/linux/fs/xfs/xfs_iops.c (revision 79f08d9e)
1 /*
2  * Copyright (c) 2000-2005 Silicon Graphics, Inc.
3  * All Rights Reserved.
4  *
5  * This program is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU General Public License as
7  * published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it would be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write the Free Software Foundation,
16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
17  */
18 #include "xfs.h"
19 #include "xfs_fs.h"
20 #include "xfs_shared.h"
21 #include "xfs_format.h"
22 #include "xfs_log_format.h"
23 #include "xfs_trans_resv.h"
24 #include "xfs_sb.h"
25 #include "xfs_ag.h"
26 #include "xfs_mount.h"
27 #include "xfs_da_format.h"
28 #include "xfs_inode.h"
29 #include "xfs_bmap.h"
30 #include "xfs_bmap_util.h"
31 #include "xfs_acl.h"
32 #include "xfs_quota.h"
33 #include "xfs_error.h"
34 #include "xfs_attr.h"
35 #include "xfs_trans.h"
36 #include "xfs_trace.h"
37 #include "xfs_icache.h"
38 #include "xfs_symlink.h"
39 #include "xfs_da_btree.h"
40 #include "xfs_dir2_priv.h"
41 #include "xfs_dinode.h"
42 
43 #include <linux/capability.h>
44 #include <linux/xattr.h>
45 #include <linux/namei.h>
46 #include <linux/posix_acl.h>
47 #include <linux/security.h>
48 #include <linux/fiemap.h>
49 #include <linux/slab.h>
50 
51 static int
52 xfs_initxattrs(
53 	struct inode		*inode,
54 	const struct xattr	*xattr_array,
55 	void			*fs_info)
56 {
57 	const struct xattr	*xattr;
58 	struct xfs_inode	*ip = XFS_I(inode);
59 	int			error = 0;
60 
61 	for (xattr = xattr_array; xattr->name != NULL; xattr++) {
62 		error = xfs_attr_set(ip, xattr->name, xattr->value,
63 				     xattr->value_len, ATTR_SECURE);
64 		if (error < 0)
65 			break;
66 	}
67 	return error;
68 }
69 
70 /*
71  * Hook in SELinux.  This is not quite correct yet, what we really need
72  * here (as we do for default ACLs) is a mechanism by which creation of
73  * these attrs can be journalled at inode creation time (along with the
74  * inode, of course, such that log replay can't cause these to be lost).
75  */
76 
77 STATIC int
78 xfs_init_security(
79 	struct inode	*inode,
80 	struct inode	*dir,
81 	const struct qstr *qstr)
82 {
83 	return security_inode_init_security(inode, dir, qstr,
84 					    &xfs_initxattrs, NULL);
85 }
86 
87 static void
88 xfs_dentry_to_name(
89 	struct xfs_name	*namep,
90 	struct dentry	*dentry,
91 	int		mode)
92 {
93 	namep->name = dentry->d_name.name;
94 	namep->len = dentry->d_name.len;
95 	namep->type = xfs_mode_to_ftype[(mode & S_IFMT) >> S_SHIFT];
96 }
97 
98 STATIC void
99 xfs_cleanup_inode(
100 	struct inode	*dir,
101 	struct inode	*inode,
102 	struct dentry	*dentry)
103 {
104 	struct xfs_name	teardown;
105 
106 	/* Oh, the horror.
107 	 * If we can't add the ACL or we fail in
108 	 * xfs_init_security we must back out.
109 	 * ENOSPC can hit here, among other things.
110 	 */
111 	xfs_dentry_to_name(&teardown, dentry, 0);
112 
113 	xfs_remove(XFS_I(dir), &teardown, XFS_I(inode));
114 	iput(inode);
115 }
116 
117 STATIC int
118 xfs_vn_mknod(
119 	struct inode	*dir,
120 	struct dentry	*dentry,
121 	umode_t		mode,
122 	dev_t		rdev)
123 {
124 	struct inode	*inode;
125 	struct xfs_inode *ip = NULL;
126 	struct posix_acl *default_acl = NULL;
127 	struct xfs_name	name;
128 	int		error;
129 
130 	/*
131 	 * Irix uses Missed'em'V split, but doesn't want to see
132 	 * the upper 5 bits of (14bit) major.
133 	 */
134 	if (S_ISCHR(mode) || S_ISBLK(mode)) {
135 		if (unlikely(!sysv_valid_dev(rdev) || MAJOR(rdev) & ~0x1ff))
136 			return -EINVAL;
137 		rdev = sysv_encode_dev(rdev);
138 	} else {
139 		rdev = 0;
140 	}
141 
142 	if (IS_POSIXACL(dir)) {
143 		default_acl = xfs_get_acl(dir, ACL_TYPE_DEFAULT);
144 		if (IS_ERR(default_acl))
145 			return PTR_ERR(default_acl);
146 
147 		if (!default_acl)
148 			mode &= ~current_umask();
149 	}
150 
151 	xfs_dentry_to_name(&name, dentry, mode);
152 	error = xfs_create(XFS_I(dir), &name, mode, rdev, &ip);
153 	if (unlikely(error))
154 		goto out_free_acl;
155 
156 	inode = VFS_I(ip);
157 
158 	error = xfs_init_security(inode, dir, &dentry->d_name);
159 	if (unlikely(error))
160 		goto out_cleanup_inode;
161 
162 	if (default_acl) {
163 		error = -xfs_inherit_acl(inode, default_acl);
164 		default_acl = NULL;
165 		if (unlikely(error))
166 			goto out_cleanup_inode;
167 	}
168 
169 
170 	d_instantiate(dentry, inode);
171 	return -error;
172 
173  out_cleanup_inode:
174 	xfs_cleanup_inode(dir, inode, dentry);
175  out_free_acl:
176 	posix_acl_release(default_acl);
177 	return -error;
178 }
179 
180 STATIC int
181 xfs_vn_create(
182 	struct inode	*dir,
183 	struct dentry	*dentry,
184 	umode_t		mode,
185 	bool		flags)
186 {
187 	return xfs_vn_mknod(dir, dentry, mode, 0);
188 }
189 
190 STATIC int
191 xfs_vn_mkdir(
192 	struct inode	*dir,
193 	struct dentry	*dentry,
194 	umode_t		mode)
195 {
196 	return xfs_vn_mknod(dir, dentry, mode|S_IFDIR, 0);
197 }
198 
199 STATIC struct dentry *
200 xfs_vn_lookup(
201 	struct inode	*dir,
202 	struct dentry	*dentry,
203 	unsigned int flags)
204 {
205 	struct xfs_inode *cip;
206 	struct xfs_name	name;
207 	int		error;
208 
209 	if (dentry->d_name.len >= MAXNAMELEN)
210 		return ERR_PTR(-ENAMETOOLONG);
211 
212 	xfs_dentry_to_name(&name, dentry, 0);
213 	error = xfs_lookup(XFS_I(dir), &name, &cip, NULL);
214 	if (unlikely(error)) {
215 		if (unlikely(error != ENOENT))
216 			return ERR_PTR(-error);
217 		d_add(dentry, NULL);
218 		return NULL;
219 	}
220 
221 	return d_splice_alias(VFS_I(cip), dentry);
222 }
223 
224 STATIC struct dentry *
225 xfs_vn_ci_lookup(
226 	struct inode	*dir,
227 	struct dentry	*dentry,
228 	unsigned int flags)
229 {
230 	struct xfs_inode *ip;
231 	struct xfs_name	xname;
232 	struct xfs_name ci_name;
233 	struct qstr	dname;
234 	int		error;
235 
236 	if (dentry->d_name.len >= MAXNAMELEN)
237 		return ERR_PTR(-ENAMETOOLONG);
238 
239 	xfs_dentry_to_name(&xname, dentry, 0);
240 	error = xfs_lookup(XFS_I(dir), &xname, &ip, &ci_name);
241 	if (unlikely(error)) {
242 		if (unlikely(error != ENOENT))
243 			return ERR_PTR(-error);
244 		/*
245 		 * call d_add(dentry, NULL) here when d_drop_negative_children
246 		 * is called in xfs_vn_mknod (ie. allow negative dentries
247 		 * with CI filesystems).
248 		 */
249 		return NULL;
250 	}
251 
252 	/* if exact match, just splice and exit */
253 	if (!ci_name.name)
254 		return d_splice_alias(VFS_I(ip), dentry);
255 
256 	/* else case-insensitive match... */
257 	dname.name = ci_name.name;
258 	dname.len = ci_name.len;
259 	dentry = d_add_ci(dentry, VFS_I(ip), &dname);
260 	kmem_free(ci_name.name);
261 	return dentry;
262 }
263 
264 STATIC int
265 xfs_vn_link(
266 	struct dentry	*old_dentry,
267 	struct inode	*dir,
268 	struct dentry	*dentry)
269 {
270 	struct inode	*inode = old_dentry->d_inode;
271 	struct xfs_name	name;
272 	int		error;
273 
274 	xfs_dentry_to_name(&name, dentry, inode->i_mode);
275 
276 	error = xfs_link(XFS_I(dir), XFS_I(inode), &name);
277 	if (unlikely(error))
278 		return -error;
279 
280 	ihold(inode);
281 	d_instantiate(dentry, inode);
282 	return 0;
283 }
284 
285 STATIC int
286 xfs_vn_unlink(
287 	struct inode	*dir,
288 	struct dentry	*dentry)
289 {
290 	struct xfs_name	name;
291 	int		error;
292 
293 	xfs_dentry_to_name(&name, dentry, 0);
294 
295 	error = -xfs_remove(XFS_I(dir), &name, XFS_I(dentry->d_inode));
296 	if (error)
297 		return error;
298 
299 	/*
300 	 * With unlink, the VFS makes the dentry "negative": no inode,
301 	 * but still hashed. This is incompatible with case-insensitive
302 	 * mode, so invalidate (unhash) the dentry in CI-mode.
303 	 */
304 	if (xfs_sb_version_hasasciici(&XFS_M(dir->i_sb)->m_sb))
305 		d_invalidate(dentry);
306 	return 0;
307 }
308 
309 STATIC int
310 xfs_vn_symlink(
311 	struct inode	*dir,
312 	struct dentry	*dentry,
313 	const char	*symname)
314 {
315 	struct inode	*inode;
316 	struct xfs_inode *cip = NULL;
317 	struct xfs_name	name;
318 	int		error;
319 	umode_t		mode;
320 
321 	mode = S_IFLNK |
322 		(irix_symlink_mode ? 0777 & ~current_umask() : S_IRWXUGO);
323 	xfs_dentry_to_name(&name, dentry, mode);
324 
325 	error = xfs_symlink(XFS_I(dir), &name, symname, mode, &cip);
326 	if (unlikely(error))
327 		goto out;
328 
329 	inode = VFS_I(cip);
330 
331 	error = xfs_init_security(inode, dir, &dentry->d_name);
332 	if (unlikely(error))
333 		goto out_cleanup_inode;
334 
335 	d_instantiate(dentry, inode);
336 	return 0;
337 
338  out_cleanup_inode:
339 	xfs_cleanup_inode(dir, inode, dentry);
340  out:
341 	return -error;
342 }
343 
344 STATIC int
345 xfs_vn_rename(
346 	struct inode	*odir,
347 	struct dentry	*odentry,
348 	struct inode	*ndir,
349 	struct dentry	*ndentry)
350 {
351 	struct inode	*new_inode = ndentry->d_inode;
352 	struct xfs_name	oname;
353 	struct xfs_name	nname;
354 
355 	xfs_dentry_to_name(&oname, odentry, 0);
356 	xfs_dentry_to_name(&nname, ndentry, odentry->d_inode->i_mode);
357 
358 	return -xfs_rename(XFS_I(odir), &oname, XFS_I(odentry->d_inode),
359 			   XFS_I(ndir), &nname, new_inode ?
360 						XFS_I(new_inode) : NULL);
361 }
362 
363 /*
364  * careful here - this function can get called recursively, so
365  * we need to be very careful about how much stack we use.
366  * uio is kmalloced for this reason...
367  */
368 STATIC void *
369 xfs_vn_follow_link(
370 	struct dentry		*dentry,
371 	struct nameidata	*nd)
372 {
373 	char			*link;
374 	int			error = -ENOMEM;
375 
376 	link = kmalloc(MAXPATHLEN+1, GFP_KERNEL);
377 	if (!link)
378 		goto out_err;
379 
380 	error = -xfs_readlink(XFS_I(dentry->d_inode), link);
381 	if (unlikely(error))
382 		goto out_kfree;
383 
384 	nd_set_link(nd, link);
385 	return NULL;
386 
387  out_kfree:
388 	kfree(link);
389  out_err:
390 	nd_set_link(nd, ERR_PTR(error));
391 	return NULL;
392 }
393 
394 STATIC void
395 xfs_vn_put_link(
396 	struct dentry	*dentry,
397 	struct nameidata *nd,
398 	void		*p)
399 {
400 	char		*s = nd_get_link(nd);
401 
402 	if (!IS_ERR(s))
403 		kfree(s);
404 }
405 
406 STATIC int
407 xfs_vn_getattr(
408 	struct vfsmount		*mnt,
409 	struct dentry		*dentry,
410 	struct kstat		*stat)
411 {
412 	struct inode		*inode = dentry->d_inode;
413 	struct xfs_inode	*ip = XFS_I(inode);
414 	struct xfs_mount	*mp = ip->i_mount;
415 
416 	trace_xfs_getattr(ip);
417 
418 	if (XFS_FORCED_SHUTDOWN(mp))
419 		return -XFS_ERROR(EIO);
420 
421 	stat->size = XFS_ISIZE(ip);
422 	stat->dev = inode->i_sb->s_dev;
423 	stat->mode = ip->i_d.di_mode;
424 	stat->nlink = ip->i_d.di_nlink;
425 	stat->uid = inode->i_uid;
426 	stat->gid = inode->i_gid;
427 	stat->ino = ip->i_ino;
428 	stat->atime = inode->i_atime;
429 	stat->mtime = inode->i_mtime;
430 	stat->ctime = inode->i_ctime;
431 	stat->blocks =
432 		XFS_FSB_TO_BB(mp, ip->i_d.di_nblocks + ip->i_delayed_blks);
433 
434 
435 	switch (inode->i_mode & S_IFMT) {
436 	case S_IFBLK:
437 	case S_IFCHR:
438 		stat->blksize = BLKDEV_IOSIZE;
439 		stat->rdev = MKDEV(sysv_major(ip->i_df.if_u2.if_rdev) & 0x1ff,
440 				   sysv_minor(ip->i_df.if_u2.if_rdev));
441 		break;
442 	default:
443 		if (XFS_IS_REALTIME_INODE(ip)) {
444 			/*
445 			 * If the file blocks are being allocated from a
446 			 * realtime volume, then return the inode's realtime
447 			 * extent size or the realtime volume's extent size.
448 			 */
449 			stat->blksize =
450 				xfs_get_extsz_hint(ip) << mp->m_sb.sb_blocklog;
451 		} else
452 			stat->blksize = xfs_preferred_iosize(mp);
453 		stat->rdev = 0;
454 		break;
455 	}
456 
457 	return 0;
458 }
459 
460 static void
461 xfs_setattr_mode(
462 	struct xfs_trans	*tp,
463 	struct xfs_inode	*ip,
464 	struct iattr		*iattr)
465 {
466 	struct inode	*inode = VFS_I(ip);
467 	umode_t		mode = iattr->ia_mode;
468 
469 	ASSERT(tp);
470 	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
471 
472 	ip->i_d.di_mode &= S_IFMT;
473 	ip->i_d.di_mode |= mode & ~S_IFMT;
474 
475 	inode->i_mode &= S_IFMT;
476 	inode->i_mode |= mode & ~S_IFMT;
477 }
478 
479 int
480 xfs_setattr_nonsize(
481 	struct xfs_inode	*ip,
482 	struct iattr		*iattr,
483 	int			flags)
484 {
485 	xfs_mount_t		*mp = ip->i_mount;
486 	struct inode		*inode = VFS_I(ip);
487 	int			mask = iattr->ia_valid;
488 	xfs_trans_t		*tp;
489 	int			error;
490 	kuid_t			uid = GLOBAL_ROOT_UID, iuid = GLOBAL_ROOT_UID;
491 	kgid_t			gid = GLOBAL_ROOT_GID, igid = GLOBAL_ROOT_GID;
492 	struct xfs_dquot	*udqp = NULL, *gdqp = NULL;
493 	struct xfs_dquot	*olddquot1 = NULL, *olddquot2 = NULL;
494 
495 	trace_xfs_setattr(ip);
496 
497 	/* If acls are being inherited, we already have this checked */
498 	if (!(flags & XFS_ATTR_NOACL)) {
499 		if (mp->m_flags & XFS_MOUNT_RDONLY)
500 			return XFS_ERROR(EROFS);
501 
502 		if (XFS_FORCED_SHUTDOWN(mp))
503 			return XFS_ERROR(EIO);
504 
505 		error = -inode_change_ok(inode, iattr);
506 		if (error)
507 			return XFS_ERROR(error);
508 	}
509 
510 	ASSERT((mask & ATTR_SIZE) == 0);
511 
512 	/*
513 	 * If disk quotas is on, we make sure that the dquots do exist on disk,
514 	 * before we start any other transactions. Trying to do this later
515 	 * is messy. We don't care to take a readlock to look at the ids
516 	 * in inode here, because we can't hold it across the trans_reserve.
517 	 * If the IDs do change before we take the ilock, we're covered
518 	 * because the i_*dquot fields will get updated anyway.
519 	 */
520 	if (XFS_IS_QUOTA_ON(mp) && (mask & (ATTR_UID|ATTR_GID))) {
521 		uint	qflags = 0;
522 
523 		if ((mask & ATTR_UID) && XFS_IS_UQUOTA_ON(mp)) {
524 			uid = iattr->ia_uid;
525 			qflags |= XFS_QMOPT_UQUOTA;
526 		} else {
527 			uid = inode->i_uid;
528 		}
529 		if ((mask & ATTR_GID) && XFS_IS_GQUOTA_ON(mp)) {
530 			gid = iattr->ia_gid;
531 			qflags |= XFS_QMOPT_GQUOTA;
532 		}  else {
533 			gid = inode->i_gid;
534 		}
535 
536 		/*
537 		 * We take a reference when we initialize udqp and gdqp,
538 		 * so it is important that we never blindly double trip on
539 		 * the same variable. See xfs_create() for an example.
540 		 */
541 		ASSERT(udqp == NULL);
542 		ASSERT(gdqp == NULL);
543 		error = xfs_qm_vop_dqalloc(ip, xfs_kuid_to_uid(uid),
544 					   xfs_kgid_to_gid(gid),
545 					   xfs_get_projid(ip),
546 					   qflags, &udqp, &gdqp, NULL);
547 		if (error)
548 			return error;
549 	}
550 
551 	tp = xfs_trans_alloc(mp, XFS_TRANS_SETATTR_NOT_SIZE);
552 	error = xfs_trans_reserve(tp, &M_RES(mp)->tr_ichange, 0, 0);
553 	if (error)
554 		goto out_dqrele;
555 
556 	xfs_ilock(ip, XFS_ILOCK_EXCL);
557 
558 	/*
559 	 * Change file ownership.  Must be the owner or privileged.
560 	 */
561 	if (mask & (ATTR_UID|ATTR_GID)) {
562 		/*
563 		 * These IDs could have changed since we last looked at them.
564 		 * But, we're assured that if the ownership did change
565 		 * while we didn't have the inode locked, inode's dquot(s)
566 		 * would have changed also.
567 		 */
568 		iuid = inode->i_uid;
569 		igid = inode->i_gid;
570 		gid = (mask & ATTR_GID) ? iattr->ia_gid : igid;
571 		uid = (mask & ATTR_UID) ? iattr->ia_uid : iuid;
572 
573 		/*
574 		 * Do a quota reservation only if uid/gid is actually
575 		 * going to change.
576 		 */
577 		if (XFS_IS_QUOTA_RUNNING(mp) &&
578 		    ((XFS_IS_UQUOTA_ON(mp) && !uid_eq(iuid, uid)) ||
579 		     (XFS_IS_GQUOTA_ON(mp) && !gid_eq(igid, gid)))) {
580 			ASSERT(tp);
581 			error = xfs_qm_vop_chown_reserve(tp, ip, udqp, gdqp,
582 						NULL, capable(CAP_FOWNER) ?
583 						XFS_QMOPT_FORCE_RES : 0);
584 			if (error)	/* out of quota */
585 				goto out_trans_cancel;
586 		}
587 	}
588 
589 	xfs_trans_ijoin(tp, ip, 0);
590 
591 	/*
592 	 * Change file ownership.  Must be the owner or privileged.
593 	 */
594 	if (mask & (ATTR_UID|ATTR_GID)) {
595 		/*
596 		 * CAP_FSETID overrides the following restrictions:
597 		 *
598 		 * The set-user-ID and set-group-ID bits of a file will be
599 		 * cleared upon successful return from chown()
600 		 */
601 		if ((ip->i_d.di_mode & (S_ISUID|S_ISGID)) &&
602 		    !capable(CAP_FSETID))
603 			ip->i_d.di_mode &= ~(S_ISUID|S_ISGID);
604 
605 		/*
606 		 * Change the ownerships and register quota modifications
607 		 * in the transaction.
608 		 */
609 		if (!uid_eq(iuid, uid)) {
610 			if (XFS_IS_QUOTA_RUNNING(mp) && XFS_IS_UQUOTA_ON(mp)) {
611 				ASSERT(mask & ATTR_UID);
612 				ASSERT(udqp);
613 				olddquot1 = xfs_qm_vop_chown(tp, ip,
614 							&ip->i_udquot, udqp);
615 			}
616 			ip->i_d.di_uid = xfs_kuid_to_uid(uid);
617 			inode->i_uid = uid;
618 		}
619 		if (!gid_eq(igid, gid)) {
620 			if (XFS_IS_QUOTA_RUNNING(mp) && XFS_IS_GQUOTA_ON(mp)) {
621 				ASSERT(!XFS_IS_PQUOTA_ON(mp));
622 				ASSERT(mask & ATTR_GID);
623 				ASSERT(gdqp);
624 				olddquot2 = xfs_qm_vop_chown(tp, ip,
625 							&ip->i_gdquot, gdqp);
626 			}
627 			ip->i_d.di_gid = xfs_kgid_to_gid(gid);
628 			inode->i_gid = gid;
629 		}
630 	}
631 
632 	/*
633 	 * Change file access modes.
634 	 */
635 	if (mask & ATTR_MODE)
636 		xfs_setattr_mode(tp, ip, iattr);
637 
638 	/*
639 	 * Change file access or modified times.
640 	 */
641 	if (mask & ATTR_ATIME) {
642 		inode->i_atime = iattr->ia_atime;
643 		ip->i_d.di_atime.t_sec = iattr->ia_atime.tv_sec;
644 		ip->i_d.di_atime.t_nsec = iattr->ia_atime.tv_nsec;
645 	}
646 	if (mask & ATTR_CTIME) {
647 		inode->i_ctime = iattr->ia_ctime;
648 		ip->i_d.di_ctime.t_sec = iattr->ia_ctime.tv_sec;
649 		ip->i_d.di_ctime.t_nsec = iattr->ia_ctime.tv_nsec;
650 	}
651 	if (mask & ATTR_MTIME) {
652 		inode->i_mtime = iattr->ia_mtime;
653 		ip->i_d.di_mtime.t_sec = iattr->ia_mtime.tv_sec;
654 		ip->i_d.di_mtime.t_nsec = iattr->ia_mtime.tv_nsec;
655 	}
656 
657 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
658 
659 	XFS_STATS_INC(xs_ig_attrchg);
660 
661 	if (mp->m_flags & XFS_MOUNT_WSYNC)
662 		xfs_trans_set_sync(tp);
663 	error = xfs_trans_commit(tp, 0);
664 
665 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
666 
667 	/*
668 	 * Release any dquot(s) the inode had kept before chown.
669 	 */
670 	xfs_qm_dqrele(olddquot1);
671 	xfs_qm_dqrele(olddquot2);
672 	xfs_qm_dqrele(udqp);
673 	xfs_qm_dqrele(gdqp);
674 
675 	if (error)
676 		return XFS_ERROR(error);
677 
678 	/*
679 	 * XXX(hch): Updating the ACL entries is not atomic vs the i_mode
680 	 * 	     update.  We could avoid this with linked transactions
681 	 * 	     and passing down the transaction pointer all the way
682 	 *	     to attr_set.  No previous user of the generic
683 	 * 	     Posix ACL code seems to care about this issue either.
684 	 */
685 	if ((mask & ATTR_MODE) && !(flags & XFS_ATTR_NOACL)) {
686 		error = -xfs_acl_chmod(inode);
687 		if (error)
688 			return XFS_ERROR(error);
689 	}
690 
691 	return 0;
692 
693 out_trans_cancel:
694 	xfs_trans_cancel(tp, 0);
695 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
696 out_dqrele:
697 	xfs_qm_dqrele(udqp);
698 	xfs_qm_dqrele(gdqp);
699 	return error;
700 }
701 
702 /*
703  * Truncate file.  Must have write permission and not be a directory.
704  */
705 int
706 xfs_setattr_size(
707 	struct xfs_inode	*ip,
708 	struct iattr		*iattr)
709 {
710 	struct xfs_mount	*mp = ip->i_mount;
711 	struct inode		*inode = VFS_I(ip);
712 	int			mask = iattr->ia_valid;
713 	xfs_off_t		oldsize, newsize;
714 	struct xfs_trans	*tp;
715 	int			error;
716 	uint			lock_flags = 0;
717 	uint			commit_flags = 0;
718 
719 	trace_xfs_setattr(ip);
720 
721 	if (mp->m_flags & XFS_MOUNT_RDONLY)
722 		return XFS_ERROR(EROFS);
723 
724 	if (XFS_FORCED_SHUTDOWN(mp))
725 		return XFS_ERROR(EIO);
726 
727 	error = -inode_change_ok(inode, iattr);
728 	if (error)
729 		return XFS_ERROR(error);
730 
731 	ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
732 	ASSERT(S_ISREG(ip->i_d.di_mode));
733 	ASSERT((mask & (ATTR_UID|ATTR_GID|ATTR_ATIME|ATTR_ATIME_SET|
734 			ATTR_MTIME_SET|ATTR_KILL_PRIV|ATTR_TIMES_SET)) == 0);
735 
736 	oldsize = inode->i_size;
737 	newsize = iattr->ia_size;
738 
739 	/*
740 	 * Short circuit the truncate case for zero length files.
741 	 */
742 	if (newsize == 0 && oldsize == 0 && ip->i_d.di_nextents == 0) {
743 		if (!(mask & (ATTR_CTIME|ATTR_MTIME)))
744 			return 0;
745 
746 		/*
747 		 * Use the regular setattr path to update the timestamps.
748 		 */
749 		iattr->ia_valid &= ~ATTR_SIZE;
750 		return xfs_setattr_nonsize(ip, iattr, 0);
751 	}
752 
753 	/*
754 	 * Make sure that the dquots are attached to the inode.
755 	 */
756 	error = xfs_qm_dqattach(ip, 0);
757 	if (error)
758 		return error;
759 
760 	/*
761 	 * Now we can make the changes.  Before we join the inode to the
762 	 * transaction, take care of the part of the truncation that must be
763 	 * done without the inode lock.  This needs to be done before joining
764 	 * the inode to the transaction, because the inode cannot be unlocked
765 	 * once it is a part of the transaction.
766 	 */
767 	if (newsize > oldsize) {
768 		/*
769 		 * Do the first part of growing a file: zero any data in the
770 		 * last block that is beyond the old EOF.  We need to do this
771 		 * before the inode is joined to the transaction to modify
772 		 * i_size.
773 		 */
774 		error = xfs_zero_eof(ip, newsize, oldsize);
775 		if (error)
776 			return error;
777 	}
778 
779 	/*
780 	 * We are going to log the inode size change in this transaction so
781 	 * any previous writes that are beyond the on disk EOF and the new
782 	 * EOF that have not been written out need to be written here.  If we
783 	 * do not write the data out, we expose ourselves to the null files
784 	 * problem.
785 	 *
786 	 * Only flush from the on disk size to the smaller of the in memory
787 	 * file size or the new size as that's the range we really care about
788 	 * here and prevents waiting for other data not within the range we
789 	 * care about here.
790 	 */
791 	if (oldsize != ip->i_d.di_size && newsize > ip->i_d.di_size) {
792 		error = -filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
793 						      ip->i_d.di_size, newsize);
794 		if (error)
795 			return error;
796 	}
797 
798 	/*
799 	 * Wait for all direct I/O to complete.
800 	 */
801 	inode_dio_wait(inode);
802 
803 	error = -block_truncate_page(inode->i_mapping, newsize, xfs_get_blocks);
804 	if (error)
805 		return error;
806 
807 	tp = xfs_trans_alloc(mp, XFS_TRANS_SETATTR_SIZE);
808 	error = xfs_trans_reserve(tp, &M_RES(mp)->tr_itruncate, 0, 0);
809 	if (error)
810 		goto out_trans_cancel;
811 
812 	truncate_setsize(inode, newsize);
813 
814 	commit_flags = XFS_TRANS_RELEASE_LOG_RES;
815 	lock_flags |= XFS_ILOCK_EXCL;
816 
817 	xfs_ilock(ip, XFS_ILOCK_EXCL);
818 
819 	xfs_trans_ijoin(tp, ip, 0);
820 
821 	/*
822 	 * Only change the c/mtime if we are changing the size or we are
823 	 * explicitly asked to change it.  This handles the semantic difference
824 	 * between truncate() and ftruncate() as implemented in the VFS.
825 	 *
826 	 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
827 	 * special case where we need to update the times despite not having
828 	 * these flags set.  For all other operations the VFS set these flags
829 	 * explicitly if it wants a timestamp update.
830 	 */
831 	if (newsize != oldsize && (!(mask & (ATTR_CTIME | ATTR_MTIME)))) {
832 		iattr->ia_ctime = iattr->ia_mtime =
833 			current_fs_time(inode->i_sb);
834 		mask |= ATTR_CTIME | ATTR_MTIME;
835 	}
836 
837 	/*
838 	 * The first thing we do is set the size to new_size permanently on
839 	 * disk.  This way we don't have to worry about anyone ever being able
840 	 * to look at the data being freed even in the face of a crash.
841 	 * What we're getting around here is the case where we free a block, it
842 	 * is allocated to another file, it is written to, and then we crash.
843 	 * If the new data gets written to the file but the log buffers
844 	 * containing the free and reallocation don't, then we'd end up with
845 	 * garbage in the blocks being freed.  As long as we make the new size
846 	 * permanent before actually freeing any blocks it doesn't matter if
847 	 * they get written to.
848 	 */
849 	ip->i_d.di_size = newsize;
850 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
851 
852 	if (newsize <= oldsize) {
853 		error = xfs_itruncate_extents(&tp, ip, XFS_DATA_FORK, newsize);
854 		if (error)
855 			goto out_trans_abort;
856 
857 		/*
858 		 * Truncated "down", so we're removing references to old data
859 		 * here - if we delay flushing for a long time, we expose
860 		 * ourselves unduly to the notorious NULL files problem.  So,
861 		 * we mark this inode and flush it when the file is closed,
862 		 * and do not wait the usual (long) time for writeout.
863 		 */
864 		xfs_iflags_set(ip, XFS_ITRUNCATED);
865 
866 		/* A truncate down always removes post-EOF blocks. */
867 		xfs_inode_clear_eofblocks_tag(ip);
868 	}
869 
870 	/*
871 	 * Change file access modes.
872 	 */
873 	if (mask & ATTR_MODE)
874 		xfs_setattr_mode(tp, ip, iattr);
875 
876 	if (mask & ATTR_CTIME) {
877 		inode->i_ctime = iattr->ia_ctime;
878 		ip->i_d.di_ctime.t_sec = iattr->ia_ctime.tv_sec;
879 		ip->i_d.di_ctime.t_nsec = iattr->ia_ctime.tv_nsec;
880 	}
881 	if (mask & ATTR_MTIME) {
882 		inode->i_mtime = iattr->ia_mtime;
883 		ip->i_d.di_mtime.t_sec = iattr->ia_mtime.tv_sec;
884 		ip->i_d.di_mtime.t_nsec = iattr->ia_mtime.tv_nsec;
885 	}
886 
887 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
888 
889 	XFS_STATS_INC(xs_ig_attrchg);
890 
891 	if (mp->m_flags & XFS_MOUNT_WSYNC)
892 		xfs_trans_set_sync(tp);
893 
894 	error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
895 out_unlock:
896 	if (lock_flags)
897 		xfs_iunlock(ip, lock_flags);
898 	return error;
899 
900 out_trans_abort:
901 	commit_flags |= XFS_TRANS_ABORT;
902 out_trans_cancel:
903 	xfs_trans_cancel(tp, commit_flags);
904 	goto out_unlock;
905 }
906 
907 STATIC int
908 xfs_vn_setattr(
909 	struct dentry		*dentry,
910 	struct iattr		*iattr)
911 {
912 	struct xfs_inode	*ip = XFS_I(dentry->d_inode);
913 	int			error;
914 
915 	if (iattr->ia_valid & ATTR_SIZE) {
916 		xfs_ilock(ip, XFS_IOLOCK_EXCL);
917 		error = xfs_setattr_size(ip, iattr);
918 		xfs_iunlock(ip, XFS_IOLOCK_EXCL);
919 	} else {
920 		error = xfs_setattr_nonsize(ip, iattr, 0);
921 	}
922 
923 	return -error;
924 }
925 
926 STATIC int
927 xfs_vn_update_time(
928 	struct inode		*inode,
929 	struct timespec		*now,
930 	int			flags)
931 {
932 	struct xfs_inode	*ip = XFS_I(inode);
933 	struct xfs_mount	*mp = ip->i_mount;
934 	struct xfs_trans	*tp;
935 	int			error;
936 
937 	trace_xfs_update_time(ip);
938 
939 	tp = xfs_trans_alloc(mp, XFS_TRANS_FSYNC_TS);
940 	error = xfs_trans_reserve(tp, &M_RES(mp)->tr_fsyncts, 0, 0);
941 	if (error) {
942 		xfs_trans_cancel(tp, 0);
943 		return -error;
944 	}
945 
946 	xfs_ilock(ip, XFS_ILOCK_EXCL);
947 	if (flags & S_CTIME) {
948 		inode->i_ctime = *now;
949 		ip->i_d.di_ctime.t_sec = (__int32_t)now->tv_sec;
950 		ip->i_d.di_ctime.t_nsec = (__int32_t)now->tv_nsec;
951 	}
952 	if (flags & S_MTIME) {
953 		inode->i_mtime = *now;
954 		ip->i_d.di_mtime.t_sec = (__int32_t)now->tv_sec;
955 		ip->i_d.di_mtime.t_nsec = (__int32_t)now->tv_nsec;
956 	}
957 	if (flags & S_ATIME) {
958 		inode->i_atime = *now;
959 		ip->i_d.di_atime.t_sec = (__int32_t)now->tv_sec;
960 		ip->i_d.di_atime.t_nsec = (__int32_t)now->tv_nsec;
961 	}
962 	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
963 	xfs_trans_log_inode(tp, ip, XFS_ILOG_TIMESTAMP);
964 	return -xfs_trans_commit(tp, 0);
965 }
966 
967 #define XFS_FIEMAP_FLAGS	(FIEMAP_FLAG_SYNC|FIEMAP_FLAG_XATTR)
968 
969 /*
970  * Call fiemap helper to fill in user data.
971  * Returns positive errors to xfs_getbmap.
972  */
973 STATIC int
974 xfs_fiemap_format(
975 	void			**arg,
976 	struct getbmapx		*bmv,
977 	int			*full)
978 {
979 	int			error;
980 	struct fiemap_extent_info *fieinfo = *arg;
981 	u32			fiemap_flags = 0;
982 	u64			logical, physical, length;
983 
984 	/* Do nothing for a hole */
985 	if (bmv->bmv_block == -1LL)
986 		return 0;
987 
988 	logical = BBTOB(bmv->bmv_offset);
989 	physical = BBTOB(bmv->bmv_block);
990 	length = BBTOB(bmv->bmv_length);
991 
992 	if (bmv->bmv_oflags & BMV_OF_PREALLOC)
993 		fiemap_flags |= FIEMAP_EXTENT_UNWRITTEN;
994 	else if (bmv->bmv_oflags & BMV_OF_DELALLOC) {
995 		fiemap_flags |= (FIEMAP_EXTENT_DELALLOC |
996 				 FIEMAP_EXTENT_UNKNOWN);
997 		physical = 0;   /* no block yet */
998 	}
999 	if (bmv->bmv_oflags & BMV_OF_LAST)
1000 		fiemap_flags |= FIEMAP_EXTENT_LAST;
1001 
1002 	error = fiemap_fill_next_extent(fieinfo, logical, physical,
1003 					length, fiemap_flags);
1004 	if (error > 0) {
1005 		error = 0;
1006 		*full = 1;	/* user array now full */
1007 	}
1008 
1009 	return -error;
1010 }
1011 
1012 STATIC int
1013 xfs_vn_fiemap(
1014 	struct inode		*inode,
1015 	struct fiemap_extent_info *fieinfo,
1016 	u64			start,
1017 	u64			length)
1018 {
1019 	xfs_inode_t		*ip = XFS_I(inode);
1020 	struct getbmapx		bm;
1021 	int			error;
1022 
1023 	error = fiemap_check_flags(fieinfo, XFS_FIEMAP_FLAGS);
1024 	if (error)
1025 		return error;
1026 
1027 	/* Set up bmap header for xfs internal routine */
1028 	bm.bmv_offset = BTOBB(start);
1029 	/* Special case for whole file */
1030 	if (length == FIEMAP_MAX_OFFSET)
1031 		bm.bmv_length = -1LL;
1032 	else
1033 		bm.bmv_length = BTOBB(length);
1034 
1035 	/* We add one because in getbmap world count includes the header */
1036 	bm.bmv_count = !fieinfo->fi_extents_max ? MAXEXTNUM :
1037 					fieinfo->fi_extents_max + 1;
1038 	bm.bmv_count = min_t(__s32, bm.bmv_count,
1039 			     (PAGE_SIZE * 16 / sizeof(struct getbmapx)));
1040 	bm.bmv_iflags = BMV_IF_PREALLOC | BMV_IF_NO_HOLES;
1041 	if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR)
1042 		bm.bmv_iflags |= BMV_IF_ATTRFORK;
1043 	if (!(fieinfo->fi_flags & FIEMAP_FLAG_SYNC))
1044 		bm.bmv_iflags |= BMV_IF_DELALLOC;
1045 
1046 	error = xfs_getbmap(ip, &bm, xfs_fiemap_format, fieinfo);
1047 	if (error)
1048 		return -error;
1049 
1050 	return 0;
1051 }
1052 
1053 static const struct inode_operations xfs_inode_operations = {
1054 	.get_acl		= xfs_get_acl,
1055 	.getattr		= xfs_vn_getattr,
1056 	.setattr		= xfs_vn_setattr,
1057 	.setxattr		= generic_setxattr,
1058 	.getxattr		= generic_getxattr,
1059 	.removexattr		= generic_removexattr,
1060 	.listxattr		= xfs_vn_listxattr,
1061 	.fiemap			= xfs_vn_fiemap,
1062 	.update_time		= xfs_vn_update_time,
1063 };
1064 
1065 static const struct inode_operations xfs_dir_inode_operations = {
1066 	.create			= xfs_vn_create,
1067 	.lookup			= xfs_vn_lookup,
1068 	.link			= xfs_vn_link,
1069 	.unlink			= xfs_vn_unlink,
1070 	.symlink		= xfs_vn_symlink,
1071 	.mkdir			= xfs_vn_mkdir,
1072 	/*
1073 	 * Yes, XFS uses the same method for rmdir and unlink.
1074 	 *
1075 	 * There are some subtile differences deeper in the code,
1076 	 * but we use S_ISDIR to check for those.
1077 	 */
1078 	.rmdir			= xfs_vn_unlink,
1079 	.mknod			= xfs_vn_mknod,
1080 	.rename			= xfs_vn_rename,
1081 	.get_acl		= xfs_get_acl,
1082 	.getattr		= xfs_vn_getattr,
1083 	.setattr		= xfs_vn_setattr,
1084 	.setxattr		= generic_setxattr,
1085 	.getxattr		= generic_getxattr,
1086 	.removexattr		= generic_removexattr,
1087 	.listxattr		= xfs_vn_listxattr,
1088 	.update_time		= xfs_vn_update_time,
1089 };
1090 
1091 static const struct inode_operations xfs_dir_ci_inode_operations = {
1092 	.create			= xfs_vn_create,
1093 	.lookup			= xfs_vn_ci_lookup,
1094 	.link			= xfs_vn_link,
1095 	.unlink			= xfs_vn_unlink,
1096 	.symlink		= xfs_vn_symlink,
1097 	.mkdir			= xfs_vn_mkdir,
1098 	/*
1099 	 * Yes, XFS uses the same method for rmdir and unlink.
1100 	 *
1101 	 * There are some subtile differences deeper in the code,
1102 	 * but we use S_ISDIR to check for those.
1103 	 */
1104 	.rmdir			= xfs_vn_unlink,
1105 	.mknod			= xfs_vn_mknod,
1106 	.rename			= xfs_vn_rename,
1107 	.get_acl		= xfs_get_acl,
1108 	.getattr		= xfs_vn_getattr,
1109 	.setattr		= xfs_vn_setattr,
1110 	.setxattr		= generic_setxattr,
1111 	.getxattr		= generic_getxattr,
1112 	.removexattr		= generic_removexattr,
1113 	.listxattr		= xfs_vn_listxattr,
1114 	.update_time		= xfs_vn_update_time,
1115 };
1116 
1117 static const struct inode_operations xfs_symlink_inode_operations = {
1118 	.readlink		= generic_readlink,
1119 	.follow_link		= xfs_vn_follow_link,
1120 	.put_link		= xfs_vn_put_link,
1121 	.get_acl		= xfs_get_acl,
1122 	.getattr		= xfs_vn_getattr,
1123 	.setattr		= xfs_vn_setattr,
1124 	.setxattr		= generic_setxattr,
1125 	.getxattr		= generic_getxattr,
1126 	.removexattr		= generic_removexattr,
1127 	.listxattr		= xfs_vn_listxattr,
1128 	.update_time		= xfs_vn_update_time,
1129 };
1130 
1131 STATIC void
1132 xfs_diflags_to_iflags(
1133 	struct inode		*inode,
1134 	struct xfs_inode	*ip)
1135 {
1136 	if (ip->i_d.di_flags & XFS_DIFLAG_IMMUTABLE)
1137 		inode->i_flags |= S_IMMUTABLE;
1138 	else
1139 		inode->i_flags &= ~S_IMMUTABLE;
1140 	if (ip->i_d.di_flags & XFS_DIFLAG_APPEND)
1141 		inode->i_flags |= S_APPEND;
1142 	else
1143 		inode->i_flags &= ~S_APPEND;
1144 	if (ip->i_d.di_flags & XFS_DIFLAG_SYNC)
1145 		inode->i_flags |= S_SYNC;
1146 	else
1147 		inode->i_flags &= ~S_SYNC;
1148 	if (ip->i_d.di_flags & XFS_DIFLAG_NOATIME)
1149 		inode->i_flags |= S_NOATIME;
1150 	else
1151 		inode->i_flags &= ~S_NOATIME;
1152 }
1153 
1154 /*
1155  * Initialize the Linux inode, set up the operation vectors and
1156  * unlock the inode.
1157  *
1158  * When reading existing inodes from disk this is called directly
1159  * from xfs_iget, when creating a new inode it is called from
1160  * xfs_ialloc after setting up the inode.
1161  *
1162  * We are always called with an uninitialised linux inode here.
1163  * We need to initialise the necessary fields and take a reference
1164  * on it.
1165  */
1166 void
1167 xfs_setup_inode(
1168 	struct xfs_inode	*ip)
1169 {
1170 	struct inode		*inode = &ip->i_vnode;
1171 	gfp_t			gfp_mask;
1172 
1173 	inode->i_ino = ip->i_ino;
1174 	inode->i_state = I_NEW;
1175 
1176 	inode_sb_list_add(inode);
1177 	/* make the inode look hashed for the writeback code */
1178 	hlist_add_fake(&inode->i_hash);
1179 
1180 	inode->i_mode	= ip->i_d.di_mode;
1181 	set_nlink(inode, ip->i_d.di_nlink);
1182 	inode->i_uid    = xfs_uid_to_kuid(ip->i_d.di_uid);
1183 	inode->i_gid    = xfs_gid_to_kgid(ip->i_d.di_gid);
1184 
1185 	switch (inode->i_mode & S_IFMT) {
1186 	case S_IFBLK:
1187 	case S_IFCHR:
1188 		inode->i_rdev =
1189 			MKDEV(sysv_major(ip->i_df.if_u2.if_rdev) & 0x1ff,
1190 			      sysv_minor(ip->i_df.if_u2.if_rdev));
1191 		break;
1192 	default:
1193 		inode->i_rdev = 0;
1194 		break;
1195 	}
1196 
1197 	inode->i_generation = ip->i_d.di_gen;
1198 	i_size_write(inode, ip->i_d.di_size);
1199 	inode->i_atime.tv_sec	= ip->i_d.di_atime.t_sec;
1200 	inode->i_atime.tv_nsec	= ip->i_d.di_atime.t_nsec;
1201 	inode->i_mtime.tv_sec	= ip->i_d.di_mtime.t_sec;
1202 	inode->i_mtime.tv_nsec	= ip->i_d.di_mtime.t_nsec;
1203 	inode->i_ctime.tv_sec	= ip->i_d.di_ctime.t_sec;
1204 	inode->i_ctime.tv_nsec	= ip->i_d.di_ctime.t_nsec;
1205 	xfs_diflags_to_iflags(inode, ip);
1206 
1207 	ip->d_ops = ip->i_mount->m_nondir_inode_ops;
1208 	switch (inode->i_mode & S_IFMT) {
1209 	case S_IFREG:
1210 		inode->i_op = &xfs_inode_operations;
1211 		inode->i_fop = &xfs_file_operations;
1212 		inode->i_mapping->a_ops = &xfs_address_space_operations;
1213 		break;
1214 	case S_IFDIR:
1215 		if (xfs_sb_version_hasasciici(&XFS_M(inode->i_sb)->m_sb))
1216 			inode->i_op = &xfs_dir_ci_inode_operations;
1217 		else
1218 			inode->i_op = &xfs_dir_inode_operations;
1219 		inode->i_fop = &xfs_dir_file_operations;
1220 		ip->d_ops = ip->i_mount->m_dir_inode_ops;
1221 		break;
1222 	case S_IFLNK:
1223 		inode->i_op = &xfs_symlink_inode_operations;
1224 		if (!(ip->i_df.if_flags & XFS_IFINLINE))
1225 			inode->i_mapping->a_ops = &xfs_address_space_operations;
1226 		break;
1227 	default:
1228 		inode->i_op = &xfs_inode_operations;
1229 		init_special_inode(inode, inode->i_mode, inode->i_rdev);
1230 		break;
1231 	}
1232 
1233 	/*
1234 	 * Ensure all page cache allocations are done from GFP_NOFS context to
1235 	 * prevent direct reclaim recursion back into the filesystem and blowing
1236 	 * stacks or deadlocking.
1237 	 */
1238 	gfp_mask = mapping_gfp_mask(inode->i_mapping);
1239 	mapping_set_gfp_mask(inode->i_mapping, (gfp_mask & ~(__GFP_FS)));
1240 
1241 	/*
1242 	 * If there is no attribute fork no ACL can exist on this inode,
1243 	 * and it can't have any file capabilities attached to it either.
1244 	 */
1245 	if (!XFS_IFORK_Q(ip)) {
1246 		inode_has_no_xattr(inode);
1247 		cache_no_acl(inode);
1248 	}
1249 
1250 	xfs_iflags_clear(ip, XFS_INEW);
1251 	barrier();
1252 
1253 	unlock_new_inode(inode);
1254 }
1255