xref: /openbmc/linux/fs/xfs/xfs_iops.c (revision 600a711c)
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_acl.h"
21 #include "xfs_log.h"
22 #include "xfs_trans.h"
23 #include "xfs_sb.h"
24 #include "xfs_ag.h"
25 #include "xfs_alloc.h"
26 #include "xfs_quota.h"
27 #include "xfs_mount.h"
28 #include "xfs_bmap_btree.h"
29 #include "xfs_dinode.h"
30 #include "xfs_inode.h"
31 #include "xfs_bmap.h"
32 #include "xfs_rtalloc.h"
33 #include "xfs_error.h"
34 #include "xfs_itable.h"
35 #include "xfs_attr.h"
36 #include "xfs_buf_item.h"
37 #include "xfs_utils.h"
38 #include "xfs_vnodeops.h"
39 #include "xfs_inode_item.h"
40 #include "xfs_trace.h"
41 
42 #include <linux/capability.h>
43 #include <linux/xattr.h>
44 #include <linux/namei.h>
45 #include <linux/posix_acl.h>
46 #include <linux/security.h>
47 #include <linux/fiemap.h>
48 #include <linux/slab.h>
49 
50 static int
51 xfs_initxattrs(
52 	struct inode		*inode,
53 	const struct xattr	*xattr_array,
54 	void			*fs_info)
55 {
56 	const struct xattr	*xattr;
57 	struct xfs_inode	*ip = XFS_I(inode);
58 	int			error = 0;
59 
60 	for (xattr = xattr_array; xattr->name != NULL; xattr++) {
61 		error = xfs_attr_set(ip, xattr->name, xattr->value,
62 				     xattr->value_len, ATTR_SECURE);
63 		if (error < 0)
64 			break;
65 	}
66 	return error;
67 }
68 
69 /*
70  * Hook in SELinux.  This is not quite correct yet, what we really need
71  * here (as we do for default ACLs) is a mechanism by which creation of
72  * these attrs can be journalled at inode creation time (along with the
73  * inode, of course, such that log replay can't cause these to be lost).
74  */
75 
76 STATIC int
77 xfs_init_security(
78 	struct inode	*inode,
79 	struct inode	*dir,
80 	const struct qstr *qstr)
81 {
82 	return security_inode_init_security(inode, dir, qstr,
83 					    &xfs_initxattrs, NULL);
84 }
85 
86 static void
87 xfs_dentry_to_name(
88 	struct xfs_name	*namep,
89 	struct dentry	*dentry)
90 {
91 	namep->name = dentry->d_name.name;
92 	namep->len = dentry->d_name.len;
93 }
94 
95 STATIC void
96 xfs_cleanup_inode(
97 	struct inode	*dir,
98 	struct inode	*inode,
99 	struct dentry	*dentry)
100 {
101 	struct xfs_name	teardown;
102 
103 	/* Oh, the horror.
104 	 * If we can't add the ACL or we fail in
105 	 * xfs_init_security we must back out.
106 	 * ENOSPC can hit here, among other things.
107 	 */
108 	xfs_dentry_to_name(&teardown, dentry);
109 
110 	xfs_remove(XFS_I(dir), &teardown, XFS_I(inode));
111 	iput(inode);
112 }
113 
114 STATIC int
115 xfs_vn_mknod(
116 	struct inode	*dir,
117 	struct dentry	*dentry,
118 	umode_t		mode,
119 	dev_t		rdev)
120 {
121 	struct inode	*inode;
122 	struct xfs_inode *ip = NULL;
123 	struct posix_acl *default_acl = NULL;
124 	struct xfs_name	name;
125 	int		error;
126 
127 	/*
128 	 * Irix uses Missed'em'V split, but doesn't want to see
129 	 * the upper 5 bits of (14bit) major.
130 	 */
131 	if (S_ISCHR(mode) || S_ISBLK(mode)) {
132 		if (unlikely(!sysv_valid_dev(rdev) || MAJOR(rdev) & ~0x1ff))
133 			return -EINVAL;
134 		rdev = sysv_encode_dev(rdev);
135 	} else {
136 		rdev = 0;
137 	}
138 
139 	if (IS_POSIXACL(dir)) {
140 		default_acl = xfs_get_acl(dir, ACL_TYPE_DEFAULT);
141 		if (IS_ERR(default_acl))
142 			return PTR_ERR(default_acl);
143 
144 		if (!default_acl)
145 			mode &= ~current_umask();
146 	}
147 
148 	xfs_dentry_to_name(&name, dentry);
149 	error = xfs_create(XFS_I(dir), &name, mode, rdev, &ip);
150 	if (unlikely(error))
151 		goto out_free_acl;
152 
153 	inode = VFS_I(ip);
154 
155 	error = xfs_init_security(inode, dir, &dentry->d_name);
156 	if (unlikely(error))
157 		goto out_cleanup_inode;
158 
159 	if (default_acl) {
160 		error = -xfs_inherit_acl(inode, default_acl);
161 		default_acl = NULL;
162 		if (unlikely(error))
163 			goto out_cleanup_inode;
164 	}
165 
166 
167 	d_instantiate(dentry, inode);
168 	return -error;
169 
170  out_cleanup_inode:
171 	xfs_cleanup_inode(dir, inode, dentry);
172  out_free_acl:
173 	posix_acl_release(default_acl);
174 	return -error;
175 }
176 
177 STATIC int
178 xfs_vn_create(
179 	struct inode	*dir,
180 	struct dentry	*dentry,
181 	umode_t		mode,
182 	bool		flags)
183 {
184 	return xfs_vn_mknod(dir, dentry, mode, 0);
185 }
186 
187 STATIC int
188 xfs_vn_mkdir(
189 	struct inode	*dir,
190 	struct dentry	*dentry,
191 	umode_t		mode)
192 {
193 	return xfs_vn_mknod(dir, dentry, mode|S_IFDIR, 0);
194 }
195 
196 STATIC struct dentry *
197 xfs_vn_lookup(
198 	struct inode	*dir,
199 	struct dentry	*dentry,
200 	unsigned int flags)
201 {
202 	struct xfs_inode *cip;
203 	struct xfs_name	name;
204 	int		error;
205 
206 	if (dentry->d_name.len >= MAXNAMELEN)
207 		return ERR_PTR(-ENAMETOOLONG);
208 
209 	xfs_dentry_to_name(&name, dentry);
210 	error = xfs_lookup(XFS_I(dir), &name, &cip, NULL);
211 	if (unlikely(error)) {
212 		if (unlikely(error != ENOENT))
213 			return ERR_PTR(-error);
214 		d_add(dentry, NULL);
215 		return NULL;
216 	}
217 
218 	return d_splice_alias(VFS_I(cip), dentry);
219 }
220 
221 STATIC struct dentry *
222 xfs_vn_ci_lookup(
223 	struct inode	*dir,
224 	struct dentry	*dentry,
225 	unsigned int flags)
226 {
227 	struct xfs_inode *ip;
228 	struct xfs_name	xname;
229 	struct xfs_name ci_name;
230 	struct qstr	dname;
231 	int		error;
232 
233 	if (dentry->d_name.len >= MAXNAMELEN)
234 		return ERR_PTR(-ENAMETOOLONG);
235 
236 	xfs_dentry_to_name(&xname, dentry);
237 	error = xfs_lookup(XFS_I(dir), &xname, &ip, &ci_name);
238 	if (unlikely(error)) {
239 		if (unlikely(error != ENOENT))
240 			return ERR_PTR(-error);
241 		/*
242 		 * call d_add(dentry, NULL) here when d_drop_negative_children
243 		 * is called in xfs_vn_mknod (ie. allow negative dentries
244 		 * with CI filesystems).
245 		 */
246 		return NULL;
247 	}
248 
249 	/* if exact match, just splice and exit */
250 	if (!ci_name.name)
251 		return d_splice_alias(VFS_I(ip), dentry);
252 
253 	/* else case-insensitive match... */
254 	dname.name = ci_name.name;
255 	dname.len = ci_name.len;
256 	dentry = d_add_ci(dentry, VFS_I(ip), &dname);
257 	kmem_free(ci_name.name);
258 	return dentry;
259 }
260 
261 STATIC int
262 xfs_vn_link(
263 	struct dentry	*old_dentry,
264 	struct inode	*dir,
265 	struct dentry	*dentry)
266 {
267 	struct inode	*inode = old_dentry->d_inode;
268 	struct xfs_name	name;
269 	int		error;
270 
271 	xfs_dentry_to_name(&name, dentry);
272 
273 	error = xfs_link(XFS_I(dir), XFS_I(inode), &name);
274 	if (unlikely(error))
275 		return -error;
276 
277 	ihold(inode);
278 	d_instantiate(dentry, inode);
279 	return 0;
280 }
281 
282 STATIC int
283 xfs_vn_unlink(
284 	struct inode	*dir,
285 	struct dentry	*dentry)
286 {
287 	struct xfs_name	name;
288 	int		error;
289 
290 	xfs_dentry_to_name(&name, dentry);
291 
292 	error = -xfs_remove(XFS_I(dir), &name, XFS_I(dentry->d_inode));
293 	if (error)
294 		return error;
295 
296 	/*
297 	 * With unlink, the VFS makes the dentry "negative": no inode,
298 	 * but still hashed. This is incompatible with case-insensitive
299 	 * mode, so invalidate (unhash) the dentry in CI-mode.
300 	 */
301 	if (xfs_sb_version_hasasciici(&XFS_M(dir->i_sb)->m_sb))
302 		d_invalidate(dentry);
303 	return 0;
304 }
305 
306 STATIC int
307 xfs_vn_symlink(
308 	struct inode	*dir,
309 	struct dentry	*dentry,
310 	const char	*symname)
311 {
312 	struct inode	*inode;
313 	struct xfs_inode *cip = NULL;
314 	struct xfs_name	name;
315 	int		error;
316 	umode_t		mode;
317 
318 	mode = S_IFLNK |
319 		(irix_symlink_mode ? 0777 & ~current_umask() : S_IRWXUGO);
320 	xfs_dentry_to_name(&name, dentry);
321 
322 	error = xfs_symlink(XFS_I(dir), &name, symname, mode, &cip);
323 	if (unlikely(error))
324 		goto out;
325 
326 	inode = VFS_I(cip);
327 
328 	error = xfs_init_security(inode, dir, &dentry->d_name);
329 	if (unlikely(error))
330 		goto out_cleanup_inode;
331 
332 	d_instantiate(dentry, inode);
333 	return 0;
334 
335  out_cleanup_inode:
336 	xfs_cleanup_inode(dir, inode, dentry);
337  out:
338 	return -error;
339 }
340 
341 STATIC int
342 xfs_vn_rename(
343 	struct inode	*odir,
344 	struct dentry	*odentry,
345 	struct inode	*ndir,
346 	struct dentry	*ndentry)
347 {
348 	struct inode	*new_inode = ndentry->d_inode;
349 	struct xfs_name	oname;
350 	struct xfs_name	nname;
351 
352 	xfs_dentry_to_name(&oname, odentry);
353 	xfs_dentry_to_name(&nname, ndentry);
354 
355 	return -xfs_rename(XFS_I(odir), &oname, XFS_I(odentry->d_inode),
356 			   XFS_I(ndir), &nname, new_inode ?
357 			   			XFS_I(new_inode) : NULL);
358 }
359 
360 /*
361  * careful here - this function can get called recursively, so
362  * we need to be very careful about how much stack we use.
363  * uio is kmalloced for this reason...
364  */
365 STATIC void *
366 xfs_vn_follow_link(
367 	struct dentry		*dentry,
368 	struct nameidata	*nd)
369 {
370 	char			*link;
371 	int			error = -ENOMEM;
372 
373 	link = kmalloc(MAXPATHLEN+1, GFP_KERNEL);
374 	if (!link)
375 		goto out_err;
376 
377 	error = -xfs_readlink(XFS_I(dentry->d_inode), link);
378 	if (unlikely(error))
379 		goto out_kfree;
380 
381 	nd_set_link(nd, link);
382 	return NULL;
383 
384  out_kfree:
385 	kfree(link);
386  out_err:
387 	nd_set_link(nd, ERR_PTR(error));
388 	return NULL;
389 }
390 
391 STATIC void
392 xfs_vn_put_link(
393 	struct dentry	*dentry,
394 	struct nameidata *nd,
395 	void		*p)
396 {
397 	char		*s = nd_get_link(nd);
398 
399 	if (!IS_ERR(s))
400 		kfree(s);
401 }
402 
403 STATIC int
404 xfs_vn_getattr(
405 	struct vfsmount		*mnt,
406 	struct dentry		*dentry,
407 	struct kstat		*stat)
408 {
409 	struct inode		*inode = dentry->d_inode;
410 	struct xfs_inode	*ip = XFS_I(inode);
411 	struct xfs_mount	*mp = ip->i_mount;
412 
413 	trace_xfs_getattr(ip);
414 
415 	if (XFS_FORCED_SHUTDOWN(mp))
416 		return -XFS_ERROR(EIO);
417 
418 	stat->size = XFS_ISIZE(ip);
419 	stat->dev = inode->i_sb->s_dev;
420 	stat->mode = ip->i_d.di_mode;
421 	stat->nlink = ip->i_d.di_nlink;
422 	stat->uid = ip->i_d.di_uid;
423 	stat->gid = ip->i_d.di_gid;
424 	stat->ino = ip->i_ino;
425 	stat->atime = inode->i_atime;
426 	stat->mtime = inode->i_mtime;
427 	stat->ctime = inode->i_ctime;
428 	stat->blocks =
429 		XFS_FSB_TO_BB(mp, ip->i_d.di_nblocks + ip->i_delayed_blks);
430 
431 
432 	switch (inode->i_mode & S_IFMT) {
433 	case S_IFBLK:
434 	case S_IFCHR:
435 		stat->blksize = BLKDEV_IOSIZE;
436 		stat->rdev = MKDEV(sysv_major(ip->i_df.if_u2.if_rdev) & 0x1ff,
437 				   sysv_minor(ip->i_df.if_u2.if_rdev));
438 		break;
439 	default:
440 		if (XFS_IS_REALTIME_INODE(ip)) {
441 			/*
442 			 * If the file blocks are being allocated from a
443 			 * realtime volume, then return the inode's realtime
444 			 * extent size or the realtime volume's extent size.
445 			 */
446 			stat->blksize =
447 				xfs_get_extsz_hint(ip) << mp->m_sb.sb_blocklog;
448 		} else
449 			stat->blksize = xfs_preferred_iosize(mp);
450 		stat->rdev = 0;
451 		break;
452 	}
453 
454 	return 0;
455 }
456 
457 int
458 xfs_setattr_nonsize(
459 	struct xfs_inode	*ip,
460 	struct iattr		*iattr,
461 	int			flags)
462 {
463 	xfs_mount_t		*mp = ip->i_mount;
464 	struct inode		*inode = VFS_I(ip);
465 	int			mask = iattr->ia_valid;
466 	xfs_trans_t		*tp;
467 	int			error;
468 	uid_t			uid = 0, iuid = 0;
469 	gid_t			gid = 0, igid = 0;
470 	struct xfs_dquot	*udqp = NULL, *gdqp = NULL;
471 	struct xfs_dquot	*olddquot1 = NULL, *olddquot2 = NULL;
472 
473 	trace_xfs_setattr(ip);
474 
475 	if (mp->m_flags & XFS_MOUNT_RDONLY)
476 		return XFS_ERROR(EROFS);
477 
478 	if (XFS_FORCED_SHUTDOWN(mp))
479 		return XFS_ERROR(EIO);
480 
481 	error = -inode_change_ok(inode, iattr);
482 	if (error)
483 		return XFS_ERROR(error);
484 
485 	ASSERT((mask & ATTR_SIZE) == 0);
486 
487 	/*
488 	 * If disk quotas is on, we make sure that the dquots do exist on disk,
489 	 * before we start any other transactions. Trying to do this later
490 	 * is messy. We don't care to take a readlock to look at the ids
491 	 * in inode here, because we can't hold it across the trans_reserve.
492 	 * If the IDs do change before we take the ilock, we're covered
493 	 * because the i_*dquot fields will get updated anyway.
494 	 */
495 	if (XFS_IS_QUOTA_ON(mp) && (mask & (ATTR_UID|ATTR_GID))) {
496 		uint	qflags = 0;
497 
498 		if ((mask & ATTR_UID) && XFS_IS_UQUOTA_ON(mp)) {
499 			uid = iattr->ia_uid;
500 			qflags |= XFS_QMOPT_UQUOTA;
501 		} else {
502 			uid = ip->i_d.di_uid;
503 		}
504 		if ((mask & ATTR_GID) && XFS_IS_GQUOTA_ON(mp)) {
505 			gid = iattr->ia_gid;
506 			qflags |= XFS_QMOPT_GQUOTA;
507 		}  else {
508 			gid = ip->i_d.di_gid;
509 		}
510 
511 		/*
512 		 * We take a reference when we initialize udqp and gdqp,
513 		 * so it is important that we never blindly double trip on
514 		 * the same variable. See xfs_create() for an example.
515 		 */
516 		ASSERT(udqp == NULL);
517 		ASSERT(gdqp == NULL);
518 		error = xfs_qm_vop_dqalloc(ip, uid, gid, xfs_get_projid(ip),
519 					 qflags, &udqp, &gdqp);
520 		if (error)
521 			return error;
522 	}
523 
524 	tp = xfs_trans_alloc(mp, XFS_TRANS_SETATTR_NOT_SIZE);
525 	error = xfs_trans_reserve(tp, 0, XFS_ICHANGE_LOG_RES(mp), 0, 0, 0);
526 	if (error)
527 		goto out_dqrele;
528 
529 	xfs_ilock(ip, XFS_ILOCK_EXCL);
530 
531 	/*
532 	 * Change file ownership.  Must be the owner or privileged.
533 	 */
534 	if (mask & (ATTR_UID|ATTR_GID)) {
535 		/*
536 		 * These IDs could have changed since we last looked at them.
537 		 * But, we're assured that if the ownership did change
538 		 * while we didn't have the inode locked, inode's dquot(s)
539 		 * would have changed also.
540 		 */
541 		iuid = ip->i_d.di_uid;
542 		igid = ip->i_d.di_gid;
543 		gid = (mask & ATTR_GID) ? iattr->ia_gid : igid;
544 		uid = (mask & ATTR_UID) ? iattr->ia_uid : iuid;
545 
546 		/*
547 		 * Do a quota reservation only if uid/gid is actually
548 		 * going to change.
549 		 */
550 		if (XFS_IS_QUOTA_RUNNING(mp) &&
551 		    ((XFS_IS_UQUOTA_ON(mp) && iuid != uid) ||
552 		     (XFS_IS_GQUOTA_ON(mp) && igid != gid))) {
553 			ASSERT(tp);
554 			error = xfs_qm_vop_chown_reserve(tp, ip, udqp, gdqp,
555 						capable(CAP_FOWNER) ?
556 						XFS_QMOPT_FORCE_RES : 0);
557 			if (error)	/* out of quota */
558 				goto out_trans_cancel;
559 		}
560 	}
561 
562 	xfs_trans_ijoin(tp, ip, 0);
563 
564 	/*
565 	 * Change file ownership.  Must be the owner or privileged.
566 	 */
567 	if (mask & (ATTR_UID|ATTR_GID)) {
568 		/*
569 		 * CAP_FSETID overrides the following restrictions:
570 		 *
571 		 * The set-user-ID and set-group-ID bits of a file will be
572 		 * cleared upon successful return from chown()
573 		 */
574 		if ((ip->i_d.di_mode & (S_ISUID|S_ISGID)) &&
575 		    !capable(CAP_FSETID))
576 			ip->i_d.di_mode &= ~(S_ISUID|S_ISGID);
577 
578 		/*
579 		 * Change the ownerships and register quota modifications
580 		 * in the transaction.
581 		 */
582 		if (iuid != uid) {
583 			if (XFS_IS_QUOTA_RUNNING(mp) && XFS_IS_UQUOTA_ON(mp)) {
584 				ASSERT(mask & ATTR_UID);
585 				ASSERT(udqp);
586 				olddquot1 = xfs_qm_vop_chown(tp, ip,
587 							&ip->i_udquot, udqp);
588 			}
589 			ip->i_d.di_uid = uid;
590 			inode->i_uid = uid;
591 		}
592 		if (igid != gid) {
593 			if (XFS_IS_QUOTA_RUNNING(mp) && XFS_IS_GQUOTA_ON(mp)) {
594 				ASSERT(!XFS_IS_PQUOTA_ON(mp));
595 				ASSERT(mask & ATTR_GID);
596 				ASSERT(gdqp);
597 				olddquot2 = xfs_qm_vop_chown(tp, ip,
598 							&ip->i_gdquot, gdqp);
599 			}
600 			ip->i_d.di_gid = gid;
601 			inode->i_gid = gid;
602 		}
603 	}
604 
605 	/*
606 	 * Change file access modes.
607 	 */
608 	if (mask & ATTR_MODE) {
609 		umode_t mode = iattr->ia_mode;
610 
611 		if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
612 			mode &= ~S_ISGID;
613 
614 		ip->i_d.di_mode &= S_IFMT;
615 		ip->i_d.di_mode |= mode & ~S_IFMT;
616 
617 		inode->i_mode &= S_IFMT;
618 		inode->i_mode |= mode & ~S_IFMT;
619 	}
620 
621 	/*
622 	 * Change file access or modified times.
623 	 */
624 	if (mask & ATTR_ATIME) {
625 		inode->i_atime = iattr->ia_atime;
626 		ip->i_d.di_atime.t_sec = iattr->ia_atime.tv_sec;
627 		ip->i_d.di_atime.t_nsec = iattr->ia_atime.tv_nsec;
628 	}
629 	if (mask & ATTR_CTIME) {
630 		inode->i_ctime = iattr->ia_ctime;
631 		ip->i_d.di_ctime.t_sec = iattr->ia_ctime.tv_sec;
632 		ip->i_d.di_ctime.t_nsec = iattr->ia_ctime.tv_nsec;
633 	}
634 	if (mask & ATTR_MTIME) {
635 		inode->i_mtime = iattr->ia_mtime;
636 		ip->i_d.di_mtime.t_sec = iattr->ia_mtime.tv_sec;
637 		ip->i_d.di_mtime.t_nsec = iattr->ia_mtime.tv_nsec;
638 	}
639 
640 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
641 
642 	XFS_STATS_INC(xs_ig_attrchg);
643 
644 	if (mp->m_flags & XFS_MOUNT_WSYNC)
645 		xfs_trans_set_sync(tp);
646 	error = xfs_trans_commit(tp, 0);
647 
648 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
649 
650 	/*
651 	 * Release any dquot(s) the inode had kept before chown.
652 	 */
653 	xfs_qm_dqrele(olddquot1);
654 	xfs_qm_dqrele(olddquot2);
655 	xfs_qm_dqrele(udqp);
656 	xfs_qm_dqrele(gdqp);
657 
658 	if (error)
659 		return XFS_ERROR(error);
660 
661 	/*
662 	 * XXX(hch): Updating the ACL entries is not atomic vs the i_mode
663 	 * 	     update.  We could avoid this with linked transactions
664 	 * 	     and passing down the transaction pointer all the way
665 	 *	     to attr_set.  No previous user of the generic
666 	 * 	     Posix ACL code seems to care about this issue either.
667 	 */
668 	if ((mask & ATTR_MODE) && !(flags & XFS_ATTR_NOACL)) {
669 		error = -xfs_acl_chmod(inode);
670 		if (error)
671 			return XFS_ERROR(error);
672 	}
673 
674 	return 0;
675 
676 out_trans_cancel:
677 	xfs_trans_cancel(tp, 0);
678 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
679 out_dqrele:
680 	xfs_qm_dqrele(udqp);
681 	xfs_qm_dqrele(gdqp);
682 	return error;
683 }
684 
685 /*
686  * Truncate file.  Must have write permission and not be a directory.
687  */
688 int
689 xfs_setattr_size(
690 	struct xfs_inode	*ip,
691 	struct iattr		*iattr,
692 	int			flags)
693 {
694 	struct xfs_mount	*mp = ip->i_mount;
695 	struct inode		*inode = VFS_I(ip);
696 	int			mask = iattr->ia_valid;
697 	xfs_off_t		oldsize, newsize;
698 	struct xfs_trans	*tp;
699 	int			error;
700 	uint			lock_flags = 0;
701 	uint			commit_flags = 0;
702 
703 	trace_xfs_setattr(ip);
704 
705 	if (mp->m_flags & XFS_MOUNT_RDONLY)
706 		return XFS_ERROR(EROFS);
707 
708 	if (XFS_FORCED_SHUTDOWN(mp))
709 		return XFS_ERROR(EIO);
710 
711 	error = -inode_change_ok(inode, iattr);
712 	if (error)
713 		return XFS_ERROR(error);
714 
715 	ASSERT(S_ISREG(ip->i_d.di_mode));
716 	ASSERT((mask & (ATTR_MODE|ATTR_UID|ATTR_GID|ATTR_ATIME|ATTR_ATIME_SET|
717 			ATTR_MTIME_SET|ATTR_KILL_SUID|ATTR_KILL_SGID|
718 			ATTR_KILL_PRIV|ATTR_TIMES_SET)) == 0);
719 
720 	if (!(flags & XFS_ATTR_NOLOCK)) {
721 		lock_flags |= XFS_IOLOCK_EXCL;
722 		xfs_ilock(ip, lock_flags);
723 	}
724 
725 	oldsize = inode->i_size;
726 	newsize = iattr->ia_size;
727 
728 	/*
729 	 * Short circuit the truncate case for zero length files.
730 	 */
731 	if (newsize == 0 && oldsize == 0 && ip->i_d.di_nextents == 0) {
732 		if (!(mask & (ATTR_CTIME|ATTR_MTIME)))
733 			goto out_unlock;
734 
735 		/*
736 		 * Use the regular setattr path to update the timestamps.
737 		 */
738 		xfs_iunlock(ip, lock_flags);
739 		iattr->ia_valid &= ~ATTR_SIZE;
740 		return xfs_setattr_nonsize(ip, iattr, 0);
741 	}
742 
743 	/*
744 	 * Make sure that the dquots are attached to the inode.
745 	 */
746 	error = xfs_qm_dqattach(ip, 0);
747 	if (error)
748 		goto out_unlock;
749 
750 	/*
751 	 * Now we can make the changes.  Before we join the inode to the
752 	 * transaction, take care of the part of the truncation that must be
753 	 * done without the inode lock.  This needs to be done before joining
754 	 * the inode to the transaction, because the inode cannot be unlocked
755 	 * once it is a part of the transaction.
756 	 */
757 	if (newsize > oldsize) {
758 		/*
759 		 * Do the first part of growing a file: zero any data in the
760 		 * last block that is beyond the old EOF.  We need to do this
761 		 * before the inode is joined to the transaction to modify
762 		 * i_size.
763 		 */
764 		error = xfs_zero_eof(ip, newsize, oldsize);
765 		if (error)
766 			goto out_unlock;
767 	}
768 
769 	/*
770 	 * We are going to log the inode size change in this transaction so
771 	 * any previous writes that are beyond the on disk EOF and the new
772 	 * EOF that have not been written out need to be written here.  If we
773 	 * do not write the data out, we expose ourselves to the null files
774 	 * problem.
775 	 *
776 	 * Only flush from the on disk size to the smaller of the in memory
777 	 * file size or the new size as that's the range we really care about
778 	 * here and prevents waiting for other data not within the range we
779 	 * care about here.
780 	 */
781 	if (oldsize != ip->i_d.di_size && newsize > ip->i_d.di_size) {
782 		error = xfs_flush_pages(ip, ip->i_d.di_size, newsize, 0,
783 					FI_NONE);
784 		if (error)
785 			goto out_unlock;
786 	}
787 
788 	/*
789 	 * Wait for all direct I/O to complete.
790 	 */
791 	inode_dio_wait(inode);
792 
793 	error = -block_truncate_page(inode->i_mapping, newsize, xfs_get_blocks);
794 	if (error)
795 		goto out_unlock;
796 
797 	tp = xfs_trans_alloc(mp, XFS_TRANS_SETATTR_SIZE);
798 	error = xfs_trans_reserve(tp, 0, XFS_ITRUNCATE_LOG_RES(mp), 0,
799 				 XFS_TRANS_PERM_LOG_RES,
800 				 XFS_ITRUNCATE_LOG_COUNT);
801 	if (error)
802 		goto out_trans_cancel;
803 
804 	truncate_setsize(inode, newsize);
805 
806 	commit_flags = XFS_TRANS_RELEASE_LOG_RES;
807 	lock_flags |= XFS_ILOCK_EXCL;
808 
809 	xfs_ilock(ip, XFS_ILOCK_EXCL);
810 
811 	xfs_trans_ijoin(tp, ip, 0);
812 
813 	/*
814 	 * Only change the c/mtime if we are changing the size or we are
815 	 * explicitly asked to change it.  This handles the semantic difference
816 	 * between truncate() and ftruncate() as implemented in the VFS.
817 	 *
818 	 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
819 	 * special case where we need to update the times despite not having
820 	 * these flags set.  For all other operations the VFS set these flags
821 	 * explicitly if it wants a timestamp update.
822 	 */
823 	if (newsize != oldsize && (!(mask & (ATTR_CTIME | ATTR_MTIME)))) {
824 		iattr->ia_ctime = iattr->ia_mtime =
825 			current_fs_time(inode->i_sb);
826 		mask |= ATTR_CTIME | ATTR_MTIME;
827 	}
828 
829 	/*
830 	 * The first thing we do is set the size to new_size permanently on
831 	 * disk.  This way we don't have to worry about anyone ever being able
832 	 * to look at the data being freed even in the face of a crash.
833 	 * What we're getting around here is the case where we free a block, it
834 	 * is allocated to another file, it is written to, and then we crash.
835 	 * If the new data gets written to the file but the log buffers
836 	 * containing the free and reallocation don't, then we'd end up with
837 	 * garbage in the blocks being freed.  As long as we make the new size
838 	 * permanent before actually freeing any blocks it doesn't matter if
839 	 * they get written to.
840 	 */
841 	ip->i_d.di_size = newsize;
842 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
843 
844 	if (newsize <= oldsize) {
845 		error = xfs_itruncate_extents(&tp, ip, XFS_DATA_FORK, newsize);
846 		if (error)
847 			goto out_trans_abort;
848 
849 		/*
850 		 * Truncated "down", so we're removing references to old data
851 		 * here - if we delay flushing for a long time, we expose
852 		 * ourselves unduly to the notorious NULL files problem.  So,
853 		 * we mark this inode and flush it when the file is closed,
854 		 * and do not wait the usual (long) time for writeout.
855 		 */
856 		xfs_iflags_set(ip, XFS_ITRUNCATED);
857 	}
858 
859 	if (mask & ATTR_CTIME) {
860 		inode->i_ctime = iattr->ia_ctime;
861 		ip->i_d.di_ctime.t_sec = iattr->ia_ctime.tv_sec;
862 		ip->i_d.di_ctime.t_nsec = iattr->ia_ctime.tv_nsec;
863 	}
864 	if (mask & ATTR_MTIME) {
865 		inode->i_mtime = iattr->ia_mtime;
866 		ip->i_d.di_mtime.t_sec = iattr->ia_mtime.tv_sec;
867 		ip->i_d.di_mtime.t_nsec = iattr->ia_mtime.tv_nsec;
868 	}
869 
870 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
871 
872 	XFS_STATS_INC(xs_ig_attrchg);
873 
874 	if (mp->m_flags & XFS_MOUNT_WSYNC)
875 		xfs_trans_set_sync(tp);
876 
877 	error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
878 out_unlock:
879 	if (lock_flags)
880 		xfs_iunlock(ip, lock_flags);
881 	return error;
882 
883 out_trans_abort:
884 	commit_flags |= XFS_TRANS_ABORT;
885 out_trans_cancel:
886 	xfs_trans_cancel(tp, commit_flags);
887 	goto out_unlock;
888 }
889 
890 STATIC int
891 xfs_vn_setattr(
892 	struct dentry	*dentry,
893 	struct iattr	*iattr)
894 {
895 	if (iattr->ia_valid & ATTR_SIZE)
896 		return -xfs_setattr_size(XFS_I(dentry->d_inode), iattr, 0);
897 	return -xfs_setattr_nonsize(XFS_I(dentry->d_inode), iattr, 0);
898 }
899 
900 STATIC int
901 xfs_vn_update_time(
902 	struct inode		*inode,
903 	struct timespec		*now,
904 	int			flags)
905 {
906 	struct xfs_inode	*ip = XFS_I(inode);
907 	struct xfs_mount	*mp = ip->i_mount;
908 	struct xfs_trans	*tp;
909 	int			error;
910 
911 	trace_xfs_update_time(ip);
912 
913 	tp = xfs_trans_alloc(mp, XFS_TRANS_FSYNC_TS);
914 	error = xfs_trans_reserve(tp, 0, XFS_FSYNC_TS_LOG_RES(mp), 0, 0, 0);
915 	if (error) {
916 		xfs_trans_cancel(tp, 0);
917 		return -error;
918 	}
919 
920 	xfs_ilock(ip, XFS_ILOCK_EXCL);
921 	if (flags & S_CTIME) {
922 		inode->i_ctime = *now;
923 		ip->i_d.di_ctime.t_sec = (__int32_t)now->tv_sec;
924 		ip->i_d.di_ctime.t_nsec = (__int32_t)now->tv_nsec;
925 	}
926 	if (flags & S_MTIME) {
927 		inode->i_mtime = *now;
928 		ip->i_d.di_mtime.t_sec = (__int32_t)now->tv_sec;
929 		ip->i_d.di_mtime.t_nsec = (__int32_t)now->tv_nsec;
930 	}
931 	if (flags & S_ATIME) {
932 		inode->i_atime = *now;
933 		ip->i_d.di_atime.t_sec = (__int32_t)now->tv_sec;
934 		ip->i_d.di_atime.t_nsec = (__int32_t)now->tv_nsec;
935 	}
936 	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
937 	xfs_trans_log_inode(tp, ip, XFS_ILOG_TIMESTAMP);
938 	return -xfs_trans_commit(tp, 0);
939 }
940 
941 #define XFS_FIEMAP_FLAGS	(FIEMAP_FLAG_SYNC|FIEMAP_FLAG_XATTR)
942 
943 /*
944  * Call fiemap helper to fill in user data.
945  * Returns positive errors to xfs_getbmap.
946  */
947 STATIC int
948 xfs_fiemap_format(
949 	void			**arg,
950 	struct getbmapx		*bmv,
951 	int			*full)
952 {
953 	int			error;
954 	struct fiemap_extent_info *fieinfo = *arg;
955 	u32			fiemap_flags = 0;
956 	u64			logical, physical, length;
957 
958 	/* Do nothing for a hole */
959 	if (bmv->bmv_block == -1LL)
960 		return 0;
961 
962 	logical = BBTOB(bmv->bmv_offset);
963 	physical = BBTOB(bmv->bmv_block);
964 	length = BBTOB(bmv->bmv_length);
965 
966 	if (bmv->bmv_oflags & BMV_OF_PREALLOC)
967 		fiemap_flags |= FIEMAP_EXTENT_UNWRITTEN;
968 	else if (bmv->bmv_oflags & BMV_OF_DELALLOC) {
969 		fiemap_flags |= FIEMAP_EXTENT_DELALLOC;
970 		physical = 0;   /* no block yet */
971 	}
972 	if (bmv->bmv_oflags & BMV_OF_LAST)
973 		fiemap_flags |= FIEMAP_EXTENT_LAST;
974 
975 	error = fiemap_fill_next_extent(fieinfo, logical, physical,
976 					length, fiemap_flags);
977 	if (error > 0) {
978 		error = 0;
979 		*full = 1;	/* user array now full */
980 	}
981 
982 	return -error;
983 }
984 
985 STATIC int
986 xfs_vn_fiemap(
987 	struct inode		*inode,
988 	struct fiemap_extent_info *fieinfo,
989 	u64			start,
990 	u64			length)
991 {
992 	xfs_inode_t		*ip = XFS_I(inode);
993 	struct getbmapx		bm;
994 	int			error;
995 
996 	error = fiemap_check_flags(fieinfo, XFS_FIEMAP_FLAGS);
997 	if (error)
998 		return error;
999 
1000 	/* Set up bmap header for xfs internal routine */
1001 	bm.bmv_offset = BTOBB(start);
1002 	/* Special case for whole file */
1003 	if (length == FIEMAP_MAX_OFFSET)
1004 		bm.bmv_length = -1LL;
1005 	else
1006 		bm.bmv_length = BTOBB(length);
1007 
1008 	/* We add one because in getbmap world count includes the header */
1009 	bm.bmv_count = !fieinfo->fi_extents_max ? MAXEXTNUM :
1010 					fieinfo->fi_extents_max + 1;
1011 	bm.bmv_count = min_t(__s32, bm.bmv_count,
1012 			     (PAGE_SIZE * 16 / sizeof(struct getbmapx)));
1013 	bm.bmv_iflags = BMV_IF_PREALLOC | BMV_IF_NO_HOLES;
1014 	if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR)
1015 		bm.bmv_iflags |= BMV_IF_ATTRFORK;
1016 	if (!(fieinfo->fi_flags & FIEMAP_FLAG_SYNC))
1017 		bm.bmv_iflags |= BMV_IF_DELALLOC;
1018 
1019 	error = xfs_getbmap(ip, &bm, xfs_fiemap_format, fieinfo);
1020 	if (error)
1021 		return -error;
1022 
1023 	return 0;
1024 }
1025 
1026 static const struct inode_operations xfs_inode_operations = {
1027 	.get_acl		= xfs_get_acl,
1028 	.getattr		= xfs_vn_getattr,
1029 	.setattr		= xfs_vn_setattr,
1030 	.setxattr		= generic_setxattr,
1031 	.getxattr		= generic_getxattr,
1032 	.removexattr		= generic_removexattr,
1033 	.listxattr		= xfs_vn_listxattr,
1034 	.fiemap			= xfs_vn_fiemap,
1035 	.update_time		= xfs_vn_update_time,
1036 };
1037 
1038 static const struct inode_operations xfs_dir_inode_operations = {
1039 	.create			= xfs_vn_create,
1040 	.lookup			= xfs_vn_lookup,
1041 	.link			= xfs_vn_link,
1042 	.unlink			= xfs_vn_unlink,
1043 	.symlink		= xfs_vn_symlink,
1044 	.mkdir			= xfs_vn_mkdir,
1045 	/*
1046 	 * Yes, XFS uses the same method for rmdir and unlink.
1047 	 *
1048 	 * There are some subtile differences deeper in the code,
1049 	 * but we use S_ISDIR to check for those.
1050 	 */
1051 	.rmdir			= xfs_vn_unlink,
1052 	.mknod			= xfs_vn_mknod,
1053 	.rename			= xfs_vn_rename,
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 	.update_time		= xfs_vn_update_time,
1062 };
1063 
1064 static const struct inode_operations xfs_dir_ci_inode_operations = {
1065 	.create			= xfs_vn_create,
1066 	.lookup			= xfs_vn_ci_lookup,
1067 	.link			= xfs_vn_link,
1068 	.unlink			= xfs_vn_unlink,
1069 	.symlink		= xfs_vn_symlink,
1070 	.mkdir			= xfs_vn_mkdir,
1071 	/*
1072 	 * Yes, XFS uses the same method for rmdir and unlink.
1073 	 *
1074 	 * There are some subtile differences deeper in the code,
1075 	 * but we use S_ISDIR to check for those.
1076 	 */
1077 	.rmdir			= xfs_vn_unlink,
1078 	.mknod			= xfs_vn_mknod,
1079 	.rename			= xfs_vn_rename,
1080 	.get_acl		= xfs_get_acl,
1081 	.getattr		= xfs_vn_getattr,
1082 	.setattr		= xfs_vn_setattr,
1083 	.setxattr		= generic_setxattr,
1084 	.getxattr		= generic_getxattr,
1085 	.removexattr		= generic_removexattr,
1086 	.listxattr		= xfs_vn_listxattr,
1087 	.update_time		= xfs_vn_update_time,
1088 };
1089 
1090 static const struct inode_operations xfs_symlink_inode_operations = {
1091 	.readlink		= generic_readlink,
1092 	.follow_link		= xfs_vn_follow_link,
1093 	.put_link		= xfs_vn_put_link,
1094 	.get_acl		= xfs_get_acl,
1095 	.getattr		= xfs_vn_getattr,
1096 	.setattr		= xfs_vn_setattr,
1097 	.setxattr		= generic_setxattr,
1098 	.getxattr		= generic_getxattr,
1099 	.removexattr		= generic_removexattr,
1100 	.listxattr		= xfs_vn_listxattr,
1101 	.update_time		= xfs_vn_update_time,
1102 };
1103 
1104 STATIC void
1105 xfs_diflags_to_iflags(
1106 	struct inode		*inode,
1107 	struct xfs_inode	*ip)
1108 {
1109 	if (ip->i_d.di_flags & XFS_DIFLAG_IMMUTABLE)
1110 		inode->i_flags |= S_IMMUTABLE;
1111 	else
1112 		inode->i_flags &= ~S_IMMUTABLE;
1113 	if (ip->i_d.di_flags & XFS_DIFLAG_APPEND)
1114 		inode->i_flags |= S_APPEND;
1115 	else
1116 		inode->i_flags &= ~S_APPEND;
1117 	if (ip->i_d.di_flags & XFS_DIFLAG_SYNC)
1118 		inode->i_flags |= S_SYNC;
1119 	else
1120 		inode->i_flags &= ~S_SYNC;
1121 	if (ip->i_d.di_flags & XFS_DIFLAG_NOATIME)
1122 		inode->i_flags |= S_NOATIME;
1123 	else
1124 		inode->i_flags &= ~S_NOATIME;
1125 }
1126 
1127 /*
1128  * Initialize the Linux inode, set up the operation vectors and
1129  * unlock the inode.
1130  *
1131  * When reading existing inodes from disk this is called directly
1132  * from xfs_iget, when creating a new inode it is called from
1133  * xfs_ialloc after setting up the inode.
1134  *
1135  * We are always called with an uninitialised linux inode here.
1136  * We need to initialise the necessary fields and take a reference
1137  * on it.
1138  */
1139 void
1140 xfs_setup_inode(
1141 	struct xfs_inode	*ip)
1142 {
1143 	struct inode		*inode = &ip->i_vnode;
1144 
1145 	inode->i_ino = ip->i_ino;
1146 	inode->i_state = I_NEW;
1147 
1148 	inode_sb_list_add(inode);
1149 	/* make the inode look hashed for the writeback code */
1150 	hlist_add_fake(&inode->i_hash);
1151 
1152 	inode->i_mode	= ip->i_d.di_mode;
1153 	set_nlink(inode, ip->i_d.di_nlink);
1154 	inode->i_uid	= ip->i_d.di_uid;
1155 	inode->i_gid	= ip->i_d.di_gid;
1156 
1157 	switch (inode->i_mode & S_IFMT) {
1158 	case S_IFBLK:
1159 	case S_IFCHR:
1160 		inode->i_rdev =
1161 			MKDEV(sysv_major(ip->i_df.if_u2.if_rdev) & 0x1ff,
1162 			      sysv_minor(ip->i_df.if_u2.if_rdev));
1163 		break;
1164 	default:
1165 		inode->i_rdev = 0;
1166 		break;
1167 	}
1168 
1169 	inode->i_generation = ip->i_d.di_gen;
1170 	i_size_write(inode, ip->i_d.di_size);
1171 	inode->i_atime.tv_sec	= ip->i_d.di_atime.t_sec;
1172 	inode->i_atime.tv_nsec	= ip->i_d.di_atime.t_nsec;
1173 	inode->i_mtime.tv_sec	= ip->i_d.di_mtime.t_sec;
1174 	inode->i_mtime.tv_nsec	= ip->i_d.di_mtime.t_nsec;
1175 	inode->i_ctime.tv_sec	= ip->i_d.di_ctime.t_sec;
1176 	inode->i_ctime.tv_nsec	= ip->i_d.di_ctime.t_nsec;
1177 	xfs_diflags_to_iflags(inode, ip);
1178 
1179 	switch (inode->i_mode & S_IFMT) {
1180 	case S_IFREG:
1181 		inode->i_op = &xfs_inode_operations;
1182 		inode->i_fop = &xfs_file_operations;
1183 		inode->i_mapping->a_ops = &xfs_address_space_operations;
1184 		break;
1185 	case S_IFDIR:
1186 		if (xfs_sb_version_hasasciici(&XFS_M(inode->i_sb)->m_sb))
1187 			inode->i_op = &xfs_dir_ci_inode_operations;
1188 		else
1189 			inode->i_op = &xfs_dir_inode_operations;
1190 		inode->i_fop = &xfs_dir_file_operations;
1191 		break;
1192 	case S_IFLNK:
1193 		inode->i_op = &xfs_symlink_inode_operations;
1194 		if (!(ip->i_df.if_flags & XFS_IFINLINE))
1195 			inode->i_mapping->a_ops = &xfs_address_space_operations;
1196 		break;
1197 	default:
1198 		inode->i_op = &xfs_inode_operations;
1199 		init_special_inode(inode, inode->i_mode, inode->i_rdev);
1200 		break;
1201 	}
1202 
1203 	/*
1204 	 * If there is no attribute fork no ACL can exist on this inode,
1205 	 * and it can't have any file capabilities attached to it either.
1206 	 */
1207 	if (!XFS_IFORK_Q(ip)) {
1208 		inode_has_no_xattr(inode);
1209 		cache_no_acl(inode);
1210 	}
1211 
1212 	xfs_iflags_clear(ip, XFS_INEW);
1213 	barrier();
1214 
1215 	unlock_new_inode(inode);
1216 }
1217