[XFS] wire up ->open for directories
[linux-2.6.git] / fs / xfs / xfs_vnodeops.c
1 /*
2  * Copyright (c) 2000-2006 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
19 #include "xfs.h"
20 #include "xfs_fs.h"
21 #include "xfs_types.h"
22 #include "xfs_bit.h"
23 #include "xfs_log.h"
24 #include "xfs_inum.h"
25 #include "xfs_trans.h"
26 #include "xfs_sb.h"
27 #include "xfs_ag.h"
28 #include "xfs_dir2.h"
29 #include "xfs_dmapi.h"
30 #include "xfs_mount.h"
31 #include "xfs_da_btree.h"
32 #include "xfs_bmap_btree.h"
33 #include "xfs_alloc_btree.h"
34 #include "xfs_ialloc_btree.h"
35 #include "xfs_dir2_sf.h"
36 #include "xfs_attr_sf.h"
37 #include "xfs_dinode.h"
38 #include "xfs_inode.h"
39 #include "xfs_inode_item.h"
40 #include "xfs_itable.h"
41 #include "xfs_btree.h"
42 #include "xfs_ialloc.h"
43 #include "xfs_alloc.h"
44 #include "xfs_bmap.h"
45 #include "xfs_attr.h"
46 #include "xfs_rw.h"
47 #include "xfs_error.h"
48 #include "xfs_quota.h"
49 #include "xfs_utils.h"
50 #include "xfs_rtalloc.h"
51 #include "xfs_trans_space.h"
52 #include "xfs_log_priv.h"
53 #include "xfs_filestream.h"
54 #include "xfs_vnodeops.h"
55
56 int
57 xfs_setattr(
58         struct xfs_inode        *ip,
59         struct iattr            *iattr,
60         int                     flags)
61 {
62         xfs_mount_t             *mp = ip->i_mount;
63         struct inode            *inode = VFS_I(ip);
64         int                     mask = iattr->ia_valid;
65         xfs_trans_t             *tp;
66         int                     code;
67         uint                    lock_flags;
68         uint                    commit_flags=0;
69         uid_t                   uid=0, iuid=0;
70         gid_t                   gid=0, igid=0;
71         int                     timeflags = 0;
72         struct xfs_dquot        *udqp, *gdqp, *olddquot1, *olddquot2;
73         int                     file_owner;
74         int                     need_iolock = 1;
75
76         xfs_itrace_entry(ip);
77
78         if (mp->m_flags & XFS_MOUNT_RDONLY)
79                 return XFS_ERROR(EROFS);
80
81         if (XFS_FORCED_SHUTDOWN(mp))
82                 return XFS_ERROR(EIO);
83
84         olddquot1 = olddquot2 = NULL;
85         udqp = gdqp = NULL;
86
87         /*
88          * If disk quotas is on, we make sure that the dquots do exist on disk,
89          * before we start any other transactions. Trying to do this later
90          * is messy. We don't care to take a readlock to look at the ids
91          * in inode here, because we can't hold it across the trans_reserve.
92          * If the IDs do change before we take the ilock, we're covered
93          * because the i_*dquot fields will get updated anyway.
94          */
95         if (XFS_IS_QUOTA_ON(mp) && (mask & (ATTR_UID|ATTR_GID))) {
96                 uint    qflags = 0;
97
98                 if ((mask & ATTR_UID) && XFS_IS_UQUOTA_ON(mp)) {
99                         uid = iattr->ia_uid;
100                         qflags |= XFS_QMOPT_UQUOTA;
101                 } else {
102                         uid = ip->i_d.di_uid;
103                 }
104                 if ((mask & ATTR_GID) && XFS_IS_GQUOTA_ON(mp)) {
105                         gid = iattr->ia_gid;
106                         qflags |= XFS_QMOPT_GQUOTA;
107                 }  else {
108                         gid = ip->i_d.di_gid;
109                 }
110
111                 /*
112                  * We take a reference when we initialize udqp and gdqp,
113                  * so it is important that we never blindly double trip on
114                  * the same variable. See xfs_create() for an example.
115                  */
116                 ASSERT(udqp == NULL);
117                 ASSERT(gdqp == NULL);
118                 code = XFS_QM_DQVOPALLOC(mp, ip, uid, gid, ip->i_d.di_projid,
119                                          qflags, &udqp, &gdqp);
120                 if (code)
121                         return code;
122         }
123
124         /*
125          * For the other attributes, we acquire the inode lock and
126          * first do an error checking pass.
127          */
128         tp = NULL;
129         lock_flags = XFS_ILOCK_EXCL;
130         if (flags & XFS_ATTR_NOLOCK)
131                 need_iolock = 0;
132         if (!(mask & ATTR_SIZE)) {
133                 if ((mask != (ATTR_CTIME|ATTR_ATIME|ATTR_MTIME)) ||
134                     (mp->m_flags & XFS_MOUNT_WSYNC)) {
135                         tp = xfs_trans_alloc(mp, XFS_TRANS_SETATTR_NOT_SIZE);
136                         commit_flags = 0;
137                         if ((code = xfs_trans_reserve(tp, 0,
138                                                      XFS_ICHANGE_LOG_RES(mp), 0,
139                                                      0, 0))) {
140                                 lock_flags = 0;
141                                 goto error_return;
142                         }
143                 }
144         } else {
145                 if (DM_EVENT_ENABLED(ip, DM_EVENT_TRUNCATE) &&
146                     !(flags & XFS_ATTR_DMI)) {
147                         int dmflags = AT_DELAY_FLAG(flags) | DM_SEM_FLAG_WR;
148                         code = XFS_SEND_DATA(mp, DM_EVENT_TRUNCATE, ip,
149                                 iattr->ia_size, 0, dmflags, NULL);
150                         if (code) {
151                                 lock_flags = 0;
152                                 goto error_return;
153                         }
154                 }
155                 if (need_iolock)
156                         lock_flags |= XFS_IOLOCK_EXCL;
157         }
158
159         xfs_ilock(ip, lock_flags);
160
161         /* boolean: are we the file owner? */
162         file_owner = (current_fsuid() == ip->i_d.di_uid);
163
164         /*
165          * Change various properties of a file.
166          * Only the owner or users with CAP_FOWNER
167          * capability may do these things.
168          */
169         if (mask & (ATTR_MODE|ATTR_UID|ATTR_GID)) {
170                 /*
171                  * CAP_FOWNER overrides the following restrictions:
172                  *
173                  * The user ID of the calling process must be equal
174                  * to the file owner ID, except in cases where the
175                  * CAP_FSETID capability is applicable.
176                  */
177                 if (!file_owner && !capable(CAP_FOWNER)) {
178                         code = XFS_ERROR(EPERM);
179                         goto error_return;
180                 }
181
182                 /*
183                  * CAP_FSETID overrides the following restrictions:
184                  *
185                  * The effective user ID of the calling process shall match
186                  * the file owner when setting the set-user-ID and
187                  * set-group-ID bits on that file.
188                  *
189                  * The effective group ID or one of the supplementary group
190                  * IDs of the calling process shall match the group owner of
191                  * the file when setting the set-group-ID bit on that file
192                  */
193                 if (mask & ATTR_MODE) {
194                         mode_t m = 0;
195
196                         if ((iattr->ia_mode & S_ISUID) && !file_owner)
197                                 m |= S_ISUID;
198                         if ((iattr->ia_mode & S_ISGID) &&
199                             !in_group_p((gid_t)ip->i_d.di_gid))
200                                 m |= S_ISGID;
201 #if 0
202                         /* Linux allows this, Irix doesn't. */
203                         if ((iattr->ia_mode & S_ISVTX) && !S_ISDIR(ip->i_d.di_mode))
204                                 m |= S_ISVTX;
205 #endif
206                         if (m && !capable(CAP_FSETID))
207                                 iattr->ia_mode &= ~m;
208                 }
209         }
210
211         /*
212          * Change file ownership.  Must be the owner or privileged.
213          */
214         if (mask & (ATTR_UID|ATTR_GID)) {
215                 /*
216                  * These IDs could have changed since we last looked at them.
217                  * But, we're assured that if the ownership did change
218                  * while we didn't have the inode locked, inode's dquot(s)
219                  * would have changed also.
220                  */
221                 iuid = ip->i_d.di_uid;
222                 igid = ip->i_d.di_gid;
223                 gid = (mask & ATTR_GID) ? iattr->ia_gid : igid;
224                 uid = (mask & ATTR_UID) ? iattr->ia_uid : iuid;
225
226                 /*
227                  * CAP_CHOWN overrides the following restrictions:
228                  *
229                  * If _POSIX_CHOWN_RESTRICTED is defined, this capability
230                  * shall override the restriction that a process cannot
231                  * change the user ID of a file it owns and the restriction
232                  * that the group ID supplied to the chown() function
233                  * shall be equal to either the group ID or one of the
234                  * supplementary group IDs of the calling process.
235                  */
236                 if ((iuid != uid ||
237                      (igid != gid && !in_group_p((gid_t)gid))) &&
238                     !capable(CAP_CHOWN)) {
239                         code = XFS_ERROR(EPERM);
240                         goto error_return;
241                 }
242                 /*
243                  * Do a quota reservation only if uid/gid is actually
244                  * going to change.
245                  */
246                 if ((XFS_IS_UQUOTA_ON(mp) && iuid != uid) ||
247                     (XFS_IS_GQUOTA_ON(mp) && igid != gid)) {
248                         ASSERT(tp);
249                         code = XFS_QM_DQVOPCHOWNRESV(mp, tp, ip, udqp, gdqp,
250                                                 capable(CAP_FOWNER) ?
251                                                 XFS_QMOPT_FORCE_RES : 0);
252                         if (code)       /* out of quota */
253                                 goto error_return;
254                 }
255         }
256
257         /*
258          * Truncate file.  Must have write permission and not be a directory.
259          */
260         if (mask & ATTR_SIZE) {
261                 /* Short circuit the truncate case for zero length files */
262                 if (iattr->ia_size == 0 &&
263                     ip->i_size == 0 && ip->i_d.di_nextents == 0) {
264                         xfs_iunlock(ip, XFS_ILOCK_EXCL);
265                         lock_flags &= ~XFS_ILOCK_EXCL;
266                         if (mask & ATTR_CTIME)
267                                 xfs_ichgtime(ip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
268                         code = 0;
269                         goto error_return;
270                 }
271
272                 if (S_ISDIR(ip->i_d.di_mode)) {
273                         code = XFS_ERROR(EISDIR);
274                         goto error_return;
275                 } else if (!S_ISREG(ip->i_d.di_mode)) {
276                         code = XFS_ERROR(EINVAL);
277                         goto error_return;
278                 }
279                 /*
280                  * Make sure that the dquots are attached to the inode.
281                  */
282                 if ((code = XFS_QM_DQATTACH(mp, ip, XFS_QMOPT_ILOCKED)))
283                         goto error_return;
284         }
285
286         /*
287          * Change file access or modified times.
288          */
289         if (mask & (ATTR_ATIME|ATTR_MTIME)) {
290                 if (!file_owner) {
291                         if ((mask & (ATTR_MTIME_SET|ATTR_ATIME_SET)) &&
292                             !capable(CAP_FOWNER)) {
293                                 code = XFS_ERROR(EPERM);
294                                 goto error_return;
295                         }
296                 }
297         }
298
299         /*
300          * Now we can make the changes.  Before we join the inode
301          * to the transaction, if ATTR_SIZE is set then take care of
302          * the part of the truncation that must be done without the
303          * inode lock.  This needs to be done before joining the inode
304          * to the transaction, because the inode cannot be unlocked
305          * once it is a part of the transaction.
306          */
307         if (mask & ATTR_SIZE) {
308                 code = 0;
309                 if (iattr->ia_size > ip->i_size) {
310                         /*
311                          * Do the first part of growing a file: zero any data
312                          * in the last block that is beyond the old EOF.  We
313                          * need to do this before the inode is joined to the
314                          * transaction to modify the i_size.
315                          */
316                         code = xfs_zero_eof(ip, iattr->ia_size, ip->i_size);
317                 }
318                 xfs_iunlock(ip, XFS_ILOCK_EXCL);
319
320                 /*
321                  * We are going to log the inode size change in this
322                  * transaction so any previous writes that are beyond the on
323                  * disk EOF and the new EOF that have not been written out need
324                  * to be written here. If we do not write the data out, we
325                  * expose ourselves to the null files problem.
326                  *
327                  * Only flush from the on disk size to the smaller of the in
328                  * memory file size or the new size as that's the range we
329                  * really care about here and prevents waiting for other data
330                  * not within the range we care about here.
331                  */
332                 if (!code &&
333                     ip->i_size != ip->i_d.di_size &&
334                     iattr->ia_size > ip->i_d.di_size) {
335                         code = xfs_flush_pages(ip,
336                                         ip->i_d.di_size, iattr->ia_size,
337                                         XFS_B_ASYNC, FI_NONE);
338                 }
339
340                 /* wait for all I/O to complete */
341                 vn_iowait(ip);
342
343                 if (!code)
344                         code = xfs_itruncate_data(ip, iattr->ia_size);
345                 if (code) {
346                         ASSERT(tp == NULL);
347                         lock_flags &= ~XFS_ILOCK_EXCL;
348                         ASSERT(lock_flags == XFS_IOLOCK_EXCL);
349                         goto error_return;
350                 }
351                 tp = xfs_trans_alloc(mp, XFS_TRANS_SETATTR_SIZE);
352                 if ((code = xfs_trans_reserve(tp, 0,
353                                              XFS_ITRUNCATE_LOG_RES(mp), 0,
354                                              XFS_TRANS_PERM_LOG_RES,
355                                              XFS_ITRUNCATE_LOG_COUNT))) {
356                         xfs_trans_cancel(tp, 0);
357                         if (need_iolock)
358                                 xfs_iunlock(ip, XFS_IOLOCK_EXCL);
359                         return code;
360                 }
361                 commit_flags = XFS_TRANS_RELEASE_LOG_RES;
362                 xfs_ilock(ip, XFS_ILOCK_EXCL);
363         }
364
365         if (tp) {
366                 xfs_trans_ijoin(tp, ip, lock_flags);
367                 xfs_trans_ihold(tp, ip);
368         }
369
370         /*
371          * Truncate file.  Must have write permission and not be a directory.
372          */
373         if (mask & ATTR_SIZE) {
374                 /*
375                  * Only change the c/mtime if we are changing the size
376                  * or we are explicitly asked to change it. This handles
377                  * the semantic difference between truncate() and ftruncate()
378                  * as implemented in the VFS.
379                  */
380                 if (iattr->ia_size != ip->i_size || (mask & ATTR_CTIME))
381                         timeflags |= XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG;
382
383                 if (iattr->ia_size > ip->i_size) {
384                         ip->i_d.di_size = iattr->ia_size;
385                         ip->i_size = iattr->ia_size;
386                         if (!(flags & XFS_ATTR_DMI))
387                                 xfs_ichgtime(ip, XFS_ICHGTIME_CHG);
388                         xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
389                 } else if (iattr->ia_size <= ip->i_size ||
390                            (iattr->ia_size == 0 && ip->i_d.di_nextents)) {
391                         /*
392                          * signal a sync transaction unless
393                          * we're truncating an already unlinked
394                          * file on a wsync filesystem
395                          */
396                         code = xfs_itruncate_finish(&tp, ip, iattr->ia_size,
397                                             XFS_DATA_FORK,
398                                             ((ip->i_d.di_nlink != 0 ||
399                                               !(mp->m_flags & XFS_MOUNT_WSYNC))
400                                              ? 1 : 0));
401                         if (code)
402                                 goto abort_return;
403                         /*
404                          * Truncated "down", so we're removing references
405                          * to old data here - if we now delay flushing for
406                          * a long time, we expose ourselves unduly to the
407                          * notorious NULL files problem.  So, we mark this
408                          * vnode and flush it when the file is closed, and
409                          * do not wait the usual (long) time for writeout.
410                          */
411                         xfs_iflags_set(ip, XFS_ITRUNCATED);
412                 }
413         }
414
415         /*
416          * Change file access modes.
417          */
418         if (mask & ATTR_MODE) {
419                 ip->i_d.di_mode &= S_IFMT;
420                 ip->i_d.di_mode |= iattr->ia_mode & ~S_IFMT;
421
422                 inode->i_mode &= S_IFMT;
423                 inode->i_mode |= iattr->ia_mode & ~S_IFMT;
424
425                 xfs_trans_log_inode (tp, ip, XFS_ILOG_CORE);
426                 timeflags |= XFS_ICHGTIME_CHG;
427         }
428
429         /*
430          * Change file ownership.  Must be the owner or privileged.
431          */
432         if (mask & (ATTR_UID|ATTR_GID)) {
433                 /*
434                  * CAP_FSETID overrides the following restrictions:
435                  *
436                  * The set-user-ID and set-group-ID bits of a file will be
437                  * cleared upon successful return from chown()
438                  */
439                 if ((ip->i_d.di_mode & (S_ISUID|S_ISGID)) &&
440                     !capable(CAP_FSETID)) {
441                         ip->i_d.di_mode &= ~(S_ISUID|S_ISGID);
442                 }
443
444                 /*
445                  * Change the ownerships and register quota modifications
446                  * in the transaction.
447                  */
448                 if (iuid != uid) {
449                         if (XFS_IS_UQUOTA_ON(mp)) {
450                                 ASSERT(mask & ATTR_UID);
451                                 ASSERT(udqp);
452                                 olddquot1 = XFS_QM_DQVOPCHOWN(mp, tp, ip,
453                                                         &ip->i_udquot, udqp);
454                         }
455                         ip->i_d.di_uid = uid;
456                         inode->i_uid = uid;
457                 }
458                 if (igid != gid) {
459                         if (XFS_IS_GQUOTA_ON(mp)) {
460                                 ASSERT(!XFS_IS_PQUOTA_ON(mp));
461                                 ASSERT(mask & ATTR_GID);
462                                 ASSERT(gdqp);
463                                 olddquot2 = XFS_QM_DQVOPCHOWN(mp, tp, ip,
464                                                         &ip->i_gdquot, gdqp);
465                         }
466                         ip->i_d.di_gid = gid;
467                         inode->i_gid = gid;
468                 }
469
470                 xfs_trans_log_inode (tp, ip, XFS_ILOG_CORE);
471                 timeflags |= XFS_ICHGTIME_CHG;
472         }
473
474
475         /*
476          * Change file access or modified times.
477          */
478         if (mask & (ATTR_ATIME|ATTR_MTIME)) {
479                 if (mask & ATTR_ATIME) {
480                         inode->i_atime = iattr->ia_atime;
481                         ip->i_d.di_atime.t_sec = iattr->ia_atime.tv_sec;
482                         ip->i_d.di_atime.t_nsec = iattr->ia_atime.tv_nsec;
483                         ip->i_update_core = 1;
484                 }
485                 if (mask & ATTR_MTIME) {
486                         inode->i_mtime = iattr->ia_mtime;
487                         ip->i_d.di_mtime.t_sec = iattr->ia_mtime.tv_sec;
488                         ip->i_d.di_mtime.t_nsec = iattr->ia_mtime.tv_nsec;
489                         timeflags &= ~XFS_ICHGTIME_MOD;
490                         timeflags |= XFS_ICHGTIME_CHG;
491                 }
492                 if (tp && (mask & (ATTR_MTIME_SET|ATTR_ATIME_SET)))
493                         xfs_trans_log_inode (tp, ip, XFS_ILOG_CORE);
494         }
495
496         /*
497          * Change file inode change time only if ATTR_CTIME set
498          * AND we have been called by a DMI function.
499          */
500
501         if ((flags & XFS_ATTR_DMI) && (mask & ATTR_CTIME)) {
502                 inode->i_ctime = iattr->ia_ctime;
503                 ip->i_d.di_ctime.t_sec = iattr->ia_ctime.tv_sec;
504                 ip->i_d.di_ctime.t_nsec = iattr->ia_ctime.tv_nsec;
505                 ip->i_update_core = 1;
506                 timeflags &= ~XFS_ICHGTIME_CHG;
507         }
508
509         /*
510          * Send out timestamp changes that need to be set to the
511          * current time.  Not done when called by a DMI function.
512          */
513         if (timeflags && !(flags & XFS_ATTR_DMI))
514                 xfs_ichgtime(ip, timeflags);
515
516         XFS_STATS_INC(xs_ig_attrchg);
517
518         /*
519          * If this is a synchronous mount, make sure that the
520          * transaction goes to disk before returning to the user.
521          * This is slightly sub-optimal in that truncates require
522          * two sync transactions instead of one for wsync filesystems.
523          * One for the truncate and one for the timestamps since we
524          * don't want to change the timestamps unless we're sure the
525          * truncate worked.  Truncates are less than 1% of the laddis
526          * mix so this probably isn't worth the trouble to optimize.
527          */
528         code = 0;
529         if (tp) {
530                 if (mp->m_flags & XFS_MOUNT_WSYNC)
531                         xfs_trans_set_sync(tp);
532
533                 code = xfs_trans_commit(tp, commit_flags);
534         }
535
536         xfs_iunlock(ip, lock_flags);
537
538         /*
539          * Release any dquot(s) the inode had kept before chown.
540          */
541         XFS_QM_DQRELE(mp, olddquot1);
542         XFS_QM_DQRELE(mp, olddquot2);
543         XFS_QM_DQRELE(mp, udqp);
544         XFS_QM_DQRELE(mp, gdqp);
545
546         if (code) {
547                 return code;
548         }
549
550         if (DM_EVENT_ENABLED(ip, DM_EVENT_ATTRIBUTE) &&
551             !(flags & XFS_ATTR_DMI)) {
552                 (void) XFS_SEND_NAMESP(mp, DM_EVENT_ATTRIBUTE, ip, DM_RIGHT_NULL,
553                                         NULL, DM_RIGHT_NULL, NULL, NULL,
554                                         0, 0, AT_DELAY_FLAG(flags));
555         }
556         return 0;
557
558  abort_return:
559         commit_flags |= XFS_TRANS_ABORT;
560         /* FALLTHROUGH */
561  error_return:
562         XFS_QM_DQRELE(mp, udqp);
563         XFS_QM_DQRELE(mp, gdqp);
564         if (tp) {
565                 xfs_trans_cancel(tp, commit_flags);
566         }
567         if (lock_flags != 0) {
568                 xfs_iunlock(ip, lock_flags);
569         }
570         return code;
571 }
572
573 /*
574  * The maximum pathlen is 1024 bytes. Since the minimum file system
575  * blocksize is 512 bytes, we can get a max of 2 extents back from
576  * bmapi.
577  */
578 #define SYMLINK_MAPS 2
579
580 STATIC int
581 xfs_readlink_bmap(
582         xfs_inode_t     *ip,
583         char            *link)
584 {
585         xfs_mount_t     *mp = ip->i_mount;
586         int             pathlen = ip->i_d.di_size;
587         int             nmaps = SYMLINK_MAPS;
588         xfs_bmbt_irec_t mval[SYMLINK_MAPS];
589         xfs_daddr_t     d;
590         int             byte_cnt;
591         int             n;
592         xfs_buf_t       *bp;
593         int             error = 0;
594
595         error = xfs_bmapi(NULL, ip, 0, XFS_B_TO_FSB(mp, pathlen), 0, NULL, 0,
596                         mval, &nmaps, NULL, NULL);
597         if (error)
598                 goto out;
599
600         for (n = 0; n < nmaps; n++) {
601                 d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock);
602                 byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount);
603
604                 bp = xfs_buf_read(mp->m_ddev_targp, d, BTOBB(byte_cnt), 0);
605                 error = XFS_BUF_GETERROR(bp);
606                 if (error) {
607                         xfs_ioerror_alert("xfs_readlink",
608                                   ip->i_mount, bp, XFS_BUF_ADDR(bp));
609                         xfs_buf_relse(bp);
610                         goto out;
611                 }
612                 if (pathlen < byte_cnt)
613                         byte_cnt = pathlen;
614                 pathlen -= byte_cnt;
615
616                 memcpy(link, XFS_BUF_PTR(bp), byte_cnt);
617                 xfs_buf_relse(bp);
618         }
619
620         link[ip->i_d.di_size] = '\0';
621         error = 0;
622
623  out:
624         return error;
625 }
626
627 int
628 xfs_readlink(
629         xfs_inode_t     *ip,
630         char            *link)
631 {
632         xfs_mount_t     *mp = ip->i_mount;
633         int             pathlen;
634         int             error = 0;
635
636         xfs_itrace_entry(ip);
637
638         if (XFS_FORCED_SHUTDOWN(mp))
639                 return XFS_ERROR(EIO);
640
641         xfs_ilock(ip, XFS_ILOCK_SHARED);
642
643         ASSERT((ip->i_d.di_mode & S_IFMT) == S_IFLNK);
644         ASSERT(ip->i_d.di_size <= MAXPATHLEN);
645
646         pathlen = ip->i_d.di_size;
647         if (!pathlen)
648                 goto out;
649
650         if (ip->i_df.if_flags & XFS_IFINLINE) {
651                 memcpy(link, ip->i_df.if_u1.if_data, pathlen);
652                 link[pathlen] = '\0';
653         } else {
654                 error = xfs_readlink_bmap(ip, link);
655         }
656
657  out:
658         xfs_iunlock(ip, XFS_ILOCK_SHARED);
659         return error;
660 }
661
662 /*
663  * xfs_fsync
664  *
665  * This is called to sync the inode and its data out to disk.  We need to hold
666  * the I/O lock while flushing the data, and the inode lock while flushing the
667  * inode.  The inode lock CANNOT be held while flushing the data, so acquire
668  * after we're done with that.
669  */
670 int
671 xfs_fsync(
672         xfs_inode_t     *ip)
673 {
674         xfs_trans_t     *tp;
675         int             error;
676         int             log_flushed = 0, changed = 1;
677
678         xfs_itrace_entry(ip);
679
680         if (XFS_FORCED_SHUTDOWN(ip->i_mount))
681                 return XFS_ERROR(EIO);
682
683         /* capture size updates in I/O completion before writing the inode. */
684         error = filemap_fdatawait(VFS_I(ip)->i_mapping);
685         if (error)
686                 return XFS_ERROR(error);
687
688         /*
689          * We always need to make sure that the required inode state is safe on
690          * disk.  The vnode might be clean but we still might need to force the
691          * log because of committed transactions that haven't hit the disk yet.
692          * Likewise, there could be unflushed non-transactional changes to the
693          * inode core that have to go to disk and this requires us to issue
694          * a synchronous transaction to capture these changes correctly.
695          *
696          * This code relies on the assumption that if the update_* fields
697          * of the inode are clear and the inode is unpinned then it is clean
698          * and no action is required.
699          */
700         xfs_ilock(ip, XFS_ILOCK_SHARED);
701
702         if (!(ip->i_update_size || ip->i_update_core)) {
703                 /*
704                  * Timestamps/size haven't changed since last inode flush or
705                  * inode transaction commit.  That means either nothing got
706                  * written or a transaction committed which caught the updates.
707                  * If the latter happened and the transaction hasn't hit the
708                  * disk yet, the inode will be still be pinned.  If it is,
709                  * force the log.
710                  */
711
712                 xfs_iunlock(ip, XFS_ILOCK_SHARED);
713
714                 if (xfs_ipincount(ip)) {
715                         error = _xfs_log_force(ip->i_mount, (xfs_lsn_t)0,
716                                       XFS_LOG_FORCE | XFS_LOG_SYNC,
717                                       &log_flushed);
718                 } else {
719                         /*
720                          * If the inode is not pinned and nothing has changed
721                          * we don't need to flush the cache.
722                          */
723                         changed = 0;
724                 }
725         } else  {
726                 /*
727                  * Kick off a transaction to log the inode core to get the
728                  * updates.  The sync transaction will also force the log.
729                  */
730                 xfs_iunlock(ip, XFS_ILOCK_SHARED);
731                 tp = xfs_trans_alloc(ip->i_mount, XFS_TRANS_FSYNC_TS);
732                 error = xfs_trans_reserve(tp, 0,
733                                 XFS_FSYNC_TS_LOG_RES(ip->i_mount), 0, 0, 0);
734                 if (error) {
735                         xfs_trans_cancel(tp, 0);
736                         return error;
737                 }
738                 xfs_ilock(ip, XFS_ILOCK_EXCL);
739
740                 /*
741                  * Note - it's possible that we might have pushed ourselves out
742                  * of the way during trans_reserve which would flush the inode.
743                  * But there's no guarantee that the inode buffer has actually
744                  * gone out yet (it's delwri).  Plus the buffer could be pinned
745                  * anyway if it's part of an inode in another recent
746                  * transaction.  So we play it safe and fire off the
747                  * transaction anyway.
748                  */
749                 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
750                 xfs_trans_ihold(tp, ip);
751                 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
752                 xfs_trans_set_sync(tp);
753                 error = _xfs_trans_commit(tp, 0, &log_flushed);
754
755                 xfs_iunlock(ip, XFS_ILOCK_EXCL);
756         }
757
758         if ((ip->i_mount->m_flags & XFS_MOUNT_BARRIER) && changed) {
759                 /*
760                  * If the log write didn't issue an ordered tag we need
761                  * to flush the disk cache for the data device now.
762                  */
763                 if (!log_flushed)
764                         xfs_blkdev_issue_flush(ip->i_mount->m_ddev_targp);
765
766                 /*
767                  * If this inode is on the RT dev we need to flush that
768                  * cache as well.
769                  */
770                 if (XFS_IS_REALTIME_INODE(ip))
771                         xfs_blkdev_issue_flush(ip->i_mount->m_rtdev_targp);
772         }
773
774         return error;
775 }
776
777 /*
778  * This is called by xfs_inactive to free any blocks beyond eof
779  * when the link count isn't zero and by xfs_dm_punch_hole() when
780  * punching a hole to EOF.
781  */
782 int
783 xfs_free_eofblocks(
784         xfs_mount_t     *mp,
785         xfs_inode_t     *ip,
786         int             flags)
787 {
788         xfs_trans_t     *tp;
789         int             error;
790         xfs_fileoff_t   end_fsb;
791         xfs_fileoff_t   last_fsb;
792         xfs_filblks_t   map_len;
793         int             nimaps;
794         xfs_bmbt_irec_t imap;
795         int             use_iolock = (flags & XFS_FREE_EOF_LOCK);
796
797         /*
798          * Figure out if there are any blocks beyond the end
799          * of the file.  If not, then there is nothing to do.
800          */
801         end_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)ip->i_size));
802         last_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_MAXIOFFSET(mp));
803         map_len = last_fsb - end_fsb;
804         if (map_len <= 0)
805                 return 0;
806
807         nimaps = 1;
808         xfs_ilock(ip, XFS_ILOCK_SHARED);
809         error = xfs_bmapi(NULL, ip, end_fsb, map_len, 0,
810                           NULL, 0, &imap, &nimaps, NULL, NULL);
811         xfs_iunlock(ip, XFS_ILOCK_SHARED);
812
813         if (!error && (nimaps != 0) &&
814             (imap.br_startblock != HOLESTARTBLOCK ||
815              ip->i_delayed_blks)) {
816                 /*
817                  * Attach the dquots to the inode up front.
818                  */
819                 if ((error = XFS_QM_DQATTACH(mp, ip, 0)))
820                         return error;
821
822                 /*
823                  * There are blocks after the end of file.
824                  * Free them up now by truncating the file to
825                  * its current size.
826                  */
827                 tp = xfs_trans_alloc(mp, XFS_TRANS_INACTIVE);
828
829                 /*
830                  * Do the xfs_itruncate_start() call before
831                  * reserving any log space because
832                  * itruncate_start will call into the buffer
833                  * cache and we can't
834                  * do that within a transaction.
835                  */
836                 if (use_iolock)
837                         xfs_ilock(ip, XFS_IOLOCK_EXCL);
838                 error = xfs_itruncate_start(ip, XFS_ITRUNC_DEFINITE,
839                                     ip->i_size);
840                 if (error) {
841                         xfs_trans_cancel(tp, 0);
842                         if (use_iolock)
843                                 xfs_iunlock(ip, XFS_IOLOCK_EXCL);
844                         return error;
845                 }
846
847                 error = xfs_trans_reserve(tp, 0,
848                                           XFS_ITRUNCATE_LOG_RES(mp),
849                                           0, XFS_TRANS_PERM_LOG_RES,
850                                           XFS_ITRUNCATE_LOG_COUNT);
851                 if (error) {
852                         ASSERT(XFS_FORCED_SHUTDOWN(mp));
853                         xfs_trans_cancel(tp, 0);
854                         xfs_iunlock(ip, XFS_IOLOCK_EXCL);
855                         return error;
856                 }
857
858                 xfs_ilock(ip, XFS_ILOCK_EXCL);
859                 xfs_trans_ijoin(tp, ip,
860                                 XFS_IOLOCK_EXCL |
861                                 XFS_ILOCK_EXCL);
862                 xfs_trans_ihold(tp, ip);
863
864                 error = xfs_itruncate_finish(&tp, ip,
865                                              ip->i_size,
866                                              XFS_DATA_FORK,
867                                              0);
868                 /*
869                  * If we get an error at this point we
870                  * simply don't bother truncating the file.
871                  */
872                 if (error) {
873                         xfs_trans_cancel(tp,
874                                          (XFS_TRANS_RELEASE_LOG_RES |
875                                           XFS_TRANS_ABORT));
876                 } else {
877                         error = xfs_trans_commit(tp,
878                                                 XFS_TRANS_RELEASE_LOG_RES);
879                 }
880                 xfs_iunlock(ip, (use_iolock ? (XFS_IOLOCK_EXCL|XFS_ILOCK_EXCL)
881                                             : XFS_ILOCK_EXCL));
882         }
883         return error;
884 }
885
886 /*
887  * Free a symlink that has blocks associated with it.
888  */
889 STATIC int
890 xfs_inactive_symlink_rmt(
891         xfs_inode_t     *ip,
892         xfs_trans_t     **tpp)
893 {
894         xfs_buf_t       *bp;
895         int             committed;
896         int             done;
897         int             error;
898         xfs_fsblock_t   first_block;
899         xfs_bmap_free_t free_list;
900         int             i;
901         xfs_mount_t     *mp;
902         xfs_bmbt_irec_t mval[SYMLINK_MAPS];
903         int             nmaps;
904         xfs_trans_t     *ntp;
905         int             size;
906         xfs_trans_t     *tp;
907
908         tp = *tpp;
909         mp = ip->i_mount;
910         ASSERT(ip->i_d.di_size > XFS_IFORK_DSIZE(ip));
911         /*
912          * We're freeing a symlink that has some
913          * blocks allocated to it.  Free the
914          * blocks here.  We know that we've got
915          * either 1 or 2 extents and that we can
916          * free them all in one bunmapi call.
917          */
918         ASSERT(ip->i_d.di_nextents > 0 && ip->i_d.di_nextents <= 2);
919         if ((error = xfs_trans_reserve(tp, 0, XFS_ITRUNCATE_LOG_RES(mp), 0,
920                         XFS_TRANS_PERM_LOG_RES, XFS_ITRUNCATE_LOG_COUNT))) {
921                 ASSERT(XFS_FORCED_SHUTDOWN(mp));
922                 xfs_trans_cancel(tp, 0);
923                 *tpp = NULL;
924                 return error;
925         }
926         /*
927          * Lock the inode, fix the size, and join it to the transaction.
928          * Hold it so in the normal path, we still have it locked for
929          * the second transaction.  In the error paths we need it
930          * held so the cancel won't rele it, see below.
931          */
932         xfs_ilock(ip, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL);
933         size = (int)ip->i_d.di_size;
934         ip->i_d.di_size = 0;
935         xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
936         xfs_trans_ihold(tp, ip);
937         xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
938         /*
939          * Find the block(s) so we can inval and unmap them.
940          */
941         done = 0;
942         XFS_BMAP_INIT(&free_list, &first_block);
943         nmaps = ARRAY_SIZE(mval);
944         if ((error = xfs_bmapi(tp, ip, 0, XFS_B_TO_FSB(mp, size),
945                         XFS_BMAPI_METADATA, &first_block, 0, mval, &nmaps,
946                         &free_list, NULL)))
947                 goto error0;
948         /*
949          * Invalidate the block(s).
950          */
951         for (i = 0; i < nmaps; i++) {
952                 bp = xfs_trans_get_buf(tp, mp->m_ddev_targp,
953                         XFS_FSB_TO_DADDR(mp, mval[i].br_startblock),
954                         XFS_FSB_TO_BB(mp, mval[i].br_blockcount), 0);
955                 xfs_trans_binval(tp, bp);
956         }
957         /*
958          * Unmap the dead block(s) to the free_list.
959          */
960         if ((error = xfs_bunmapi(tp, ip, 0, size, XFS_BMAPI_METADATA, nmaps,
961                         &first_block, &free_list, NULL, &done)))
962                 goto error1;
963         ASSERT(done);
964         /*
965          * Commit the first transaction.  This logs the EFI and the inode.
966          */
967         if ((error = xfs_bmap_finish(&tp, &free_list, &committed)))
968                 goto error1;
969         /*
970          * The transaction must have been committed, since there were
971          * actually extents freed by xfs_bunmapi.  See xfs_bmap_finish.
972          * The new tp has the extent freeing and EFDs.
973          */
974         ASSERT(committed);
975         /*
976          * The first xact was committed, so add the inode to the new one.
977          * Mark it dirty so it will be logged and moved forward in the log as
978          * part of every commit.
979          */
980         xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
981         xfs_trans_ihold(tp, ip);
982         xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
983         /*
984          * Get a new, empty transaction to return to our caller.
985          */
986         ntp = xfs_trans_dup(tp);
987         /*
988          * Commit the transaction containing extent freeing and EFDs.
989          * If we get an error on the commit here or on the reserve below,
990          * we need to unlock the inode since the new transaction doesn't
991          * have the inode attached.
992          */
993         error = xfs_trans_commit(tp, 0);
994         tp = ntp;
995         if (error) {
996                 ASSERT(XFS_FORCED_SHUTDOWN(mp));
997                 goto error0;
998         }
999         /*
1000          * transaction commit worked ok so we can drop the extra ticket
1001          * reference that we gained in xfs_trans_dup()
1002          */
1003         xfs_log_ticket_put(tp->t_ticket);
1004
1005         /*
1006          * Remove the memory for extent descriptions (just bookkeeping).
1007          */
1008         if (ip->i_df.if_bytes)
1009                 xfs_idata_realloc(ip, -ip->i_df.if_bytes, XFS_DATA_FORK);
1010         ASSERT(ip->i_df.if_bytes == 0);
1011         /*
1012          * Put an itruncate log reservation in the new transaction
1013          * for our caller.
1014          */
1015         if ((error = xfs_trans_reserve(tp, 0, XFS_ITRUNCATE_LOG_RES(mp), 0,
1016                         XFS_TRANS_PERM_LOG_RES, XFS_ITRUNCATE_LOG_COUNT))) {
1017                 ASSERT(XFS_FORCED_SHUTDOWN(mp));
1018                 goto error0;
1019         }
1020         /*
1021          * Return with the inode locked but not joined to the transaction.
1022          */
1023         *tpp = tp;
1024         return 0;
1025
1026  error1:
1027         xfs_bmap_cancel(&free_list);
1028  error0:
1029         /*
1030          * Have to come here with the inode locked and either
1031          * (held and in the transaction) or (not in the transaction).
1032          * If the inode isn't held then cancel would iput it, but
1033          * that's wrong since this is inactive and the vnode ref
1034          * count is 0 already.
1035          * Cancel won't do anything to the inode if held, but it still
1036          * needs to be locked until the cancel is done, if it was
1037          * joined to the transaction.
1038          */
1039         xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
1040         xfs_iunlock(ip, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL);
1041         *tpp = NULL;
1042         return error;
1043
1044 }
1045
1046 STATIC int
1047 xfs_inactive_symlink_local(
1048         xfs_inode_t     *ip,
1049         xfs_trans_t     **tpp)
1050 {
1051         int             error;
1052
1053         ASSERT(ip->i_d.di_size <= XFS_IFORK_DSIZE(ip));
1054         /*
1055          * We're freeing a symlink which fit into
1056          * the inode.  Just free the memory used
1057          * to hold the old symlink.
1058          */
1059         error = xfs_trans_reserve(*tpp, 0,
1060                                   XFS_ITRUNCATE_LOG_RES(ip->i_mount),
1061                                   0, XFS_TRANS_PERM_LOG_RES,
1062                                   XFS_ITRUNCATE_LOG_COUNT);
1063
1064         if (error) {
1065                 xfs_trans_cancel(*tpp, 0);
1066                 *tpp = NULL;
1067                 return error;
1068         }
1069         xfs_ilock(ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
1070
1071         /*
1072          * Zero length symlinks _can_ exist.
1073          */
1074         if (ip->i_df.if_bytes > 0) {
1075                 xfs_idata_realloc(ip,
1076                                   -(ip->i_df.if_bytes),
1077                                   XFS_DATA_FORK);
1078                 ASSERT(ip->i_df.if_bytes == 0);
1079         }
1080         return 0;
1081 }
1082
1083 STATIC int
1084 xfs_inactive_attrs(
1085         xfs_inode_t     *ip,
1086         xfs_trans_t     **tpp)
1087 {
1088         xfs_trans_t     *tp;
1089         int             error;
1090         xfs_mount_t     *mp;
1091
1092         ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
1093         tp = *tpp;
1094         mp = ip->i_mount;
1095         ASSERT(ip->i_d.di_forkoff != 0);
1096         error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
1097         xfs_iunlock(ip, XFS_ILOCK_EXCL);
1098         if (error)
1099                 goto error_unlock;
1100
1101         error = xfs_attr_inactive(ip);
1102         if (error)
1103                 goto error_unlock;
1104
1105         tp = xfs_trans_alloc(mp, XFS_TRANS_INACTIVE);
1106         error = xfs_trans_reserve(tp, 0,
1107                                   XFS_IFREE_LOG_RES(mp),
1108                                   0, XFS_TRANS_PERM_LOG_RES,
1109                                   XFS_INACTIVE_LOG_COUNT);
1110         if (error)
1111                 goto error_cancel;
1112
1113         xfs_ilock(ip, XFS_ILOCK_EXCL);
1114         xfs_trans_ijoin(tp, ip, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL);
1115         xfs_trans_ihold(tp, ip);
1116         xfs_idestroy_fork(ip, XFS_ATTR_FORK);
1117
1118         ASSERT(ip->i_d.di_anextents == 0);
1119
1120         *tpp = tp;
1121         return 0;
1122
1123 error_cancel:
1124         ASSERT(XFS_FORCED_SHUTDOWN(mp));
1125         xfs_trans_cancel(tp, 0);
1126 error_unlock:
1127         *tpp = NULL;
1128         xfs_iunlock(ip, XFS_IOLOCK_EXCL);
1129         return error;
1130 }
1131
1132 int
1133 xfs_release(
1134         xfs_inode_t     *ip)
1135 {
1136         xfs_mount_t     *mp = ip->i_mount;
1137         int             error;
1138
1139         if (!S_ISREG(ip->i_d.di_mode) || (ip->i_d.di_mode == 0))
1140                 return 0;
1141
1142         /* If this is a read-only mount, don't do this (would generate I/O) */
1143         if (mp->m_flags & XFS_MOUNT_RDONLY)
1144                 return 0;
1145
1146         if (!XFS_FORCED_SHUTDOWN(mp)) {
1147                 int truncated;
1148
1149                 /*
1150                  * If we are using filestreams, and we have an unlinked
1151                  * file that we are processing the last close on, then nothing
1152                  * will be able to reopen and write to this file. Purge this
1153                  * inode from the filestreams cache so that it doesn't delay
1154                  * teardown of the inode.
1155                  */
1156                 if ((ip->i_d.di_nlink == 0) && xfs_inode_is_filestream(ip))
1157                         xfs_filestream_deassociate(ip);
1158
1159                 /*
1160                  * If we previously truncated this file and removed old data
1161                  * in the process, we want to initiate "early" writeout on
1162                  * the last close.  This is an attempt to combat the notorious
1163                  * NULL files problem which is particularly noticable from a
1164                  * truncate down, buffered (re-)write (delalloc), followed by
1165                  * a crash.  What we are effectively doing here is
1166                  * significantly reducing the time window where we'd otherwise
1167                  * be exposed to that problem.
1168                  */
1169                 truncated = xfs_iflags_test_and_clear(ip, XFS_ITRUNCATED);
1170                 if (truncated && VN_DIRTY(VFS_I(ip)) && ip->i_delayed_blks > 0)
1171                         xfs_flush_pages(ip, 0, -1, XFS_B_ASYNC, FI_NONE);
1172         }
1173
1174         if (ip->i_d.di_nlink != 0) {
1175                 if ((((ip->i_d.di_mode & S_IFMT) == S_IFREG) &&
1176                      ((ip->i_size > 0) || (VN_CACHED(VFS_I(ip)) > 0 ||
1177                        ip->i_delayed_blks > 0)) &&
1178                      (ip->i_df.if_flags & XFS_IFEXTENTS))  &&
1179                     (!(ip->i_d.di_flags &
1180                                 (XFS_DIFLAG_PREALLOC | XFS_DIFLAG_APPEND)))) {
1181                         error = xfs_free_eofblocks(mp, ip, XFS_FREE_EOF_LOCK);
1182                         if (error)
1183                                 return error;
1184                 }
1185         }
1186
1187         return 0;
1188 }
1189
1190 /*
1191  * xfs_inactive
1192  *
1193  * This is called when the vnode reference count for the vnode
1194  * goes to zero.  If the file has been unlinked, then it must
1195  * now be truncated.  Also, we clear all of the read-ahead state
1196  * kept for the inode here since the file is now closed.
1197  */
1198 int
1199 xfs_inactive(
1200         xfs_inode_t     *ip)
1201 {
1202         xfs_bmap_free_t free_list;
1203         xfs_fsblock_t   first_block;
1204         int             committed;
1205         xfs_trans_t     *tp;
1206         xfs_mount_t     *mp;
1207         int             error;
1208         int             truncate;
1209
1210         xfs_itrace_entry(ip);
1211
1212         /*
1213          * If the inode is already free, then there can be nothing
1214          * to clean up here.
1215          */
1216         if (ip->i_d.di_mode == 0 || VN_BAD(VFS_I(ip))) {
1217                 ASSERT(ip->i_df.if_real_bytes == 0);
1218                 ASSERT(ip->i_df.if_broot_bytes == 0);
1219                 return VN_INACTIVE_CACHE;
1220         }
1221
1222         /*
1223          * Only do a truncate if it's a regular file with
1224          * some actual space in it.  It's OK to look at the
1225          * inode's fields without the lock because we're the
1226          * only one with a reference to the inode.
1227          */
1228         truncate = ((ip->i_d.di_nlink == 0) &&
1229             ((ip->i_d.di_size != 0) || (ip->i_size != 0) ||
1230              (ip->i_d.di_nextents > 0) || (ip->i_delayed_blks > 0)) &&
1231             ((ip->i_d.di_mode & S_IFMT) == S_IFREG));
1232
1233         mp = ip->i_mount;
1234
1235         if (ip->i_d.di_nlink == 0 && DM_EVENT_ENABLED(ip, DM_EVENT_DESTROY))
1236                 XFS_SEND_DESTROY(mp, ip, DM_RIGHT_NULL);
1237
1238         error = 0;
1239
1240         /* If this is a read-only mount, don't do this (would generate I/O) */
1241         if (mp->m_flags & XFS_MOUNT_RDONLY)
1242                 goto out;
1243
1244         if (ip->i_d.di_nlink != 0) {
1245                 if ((((ip->i_d.di_mode & S_IFMT) == S_IFREG) &&
1246                      ((ip->i_size > 0) || (VN_CACHED(VFS_I(ip)) > 0 ||
1247                        ip->i_delayed_blks > 0)) &&
1248                       (ip->i_df.if_flags & XFS_IFEXTENTS) &&
1249                      (!(ip->i_d.di_flags &
1250                                 (XFS_DIFLAG_PREALLOC | XFS_DIFLAG_APPEND)) ||
1251                       (ip->i_delayed_blks != 0)))) {
1252                         error = xfs_free_eofblocks(mp, ip, XFS_FREE_EOF_LOCK);
1253                         if (error)
1254                                 return VN_INACTIVE_CACHE;
1255                 }
1256                 goto out;
1257         }
1258
1259         ASSERT(ip->i_d.di_nlink == 0);
1260
1261         if ((error = XFS_QM_DQATTACH(mp, ip, 0)))
1262                 return VN_INACTIVE_CACHE;
1263
1264         tp = xfs_trans_alloc(mp, XFS_TRANS_INACTIVE);
1265         if (truncate) {
1266                 /*
1267                  * Do the xfs_itruncate_start() call before
1268                  * reserving any log space because itruncate_start
1269                  * will call into the buffer cache and we can't
1270                  * do that within a transaction.
1271                  */
1272                 xfs_ilock(ip, XFS_IOLOCK_EXCL);
1273
1274                 error = xfs_itruncate_start(ip, XFS_ITRUNC_DEFINITE, 0);
1275                 if (error) {
1276                         xfs_trans_cancel(tp, 0);
1277                         xfs_iunlock(ip, XFS_IOLOCK_EXCL);
1278                         return VN_INACTIVE_CACHE;
1279                 }
1280
1281                 error = xfs_trans_reserve(tp, 0,
1282                                           XFS_ITRUNCATE_LOG_RES(mp),
1283                                           0, XFS_TRANS_PERM_LOG_RES,
1284                                           XFS_ITRUNCATE_LOG_COUNT);
1285                 if (error) {
1286                         /* Don't call itruncate_cleanup */
1287                         ASSERT(XFS_FORCED_SHUTDOWN(mp));
1288                         xfs_trans_cancel(tp, 0);
1289                         xfs_iunlock(ip, XFS_IOLOCK_EXCL);
1290                         return VN_INACTIVE_CACHE;
1291                 }
1292
1293                 xfs_ilock(ip, XFS_ILOCK_EXCL);
1294                 xfs_trans_ijoin(tp, ip, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL);
1295                 xfs_trans_ihold(tp, ip);
1296
1297                 /*
1298                  * normally, we have to run xfs_itruncate_finish sync.
1299                  * But if filesystem is wsync and we're in the inactive
1300                  * path, then we know that nlink == 0, and that the
1301                  * xaction that made nlink == 0 is permanently committed
1302                  * since xfs_remove runs as a synchronous transaction.
1303                  */
1304                 error = xfs_itruncate_finish(&tp, ip, 0, XFS_DATA_FORK,
1305                                 (!(mp->m_flags & XFS_MOUNT_WSYNC) ? 1 : 0));
1306
1307                 if (error) {
1308                         xfs_trans_cancel(tp,
1309                                 XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
1310                         xfs_iunlock(ip, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL);
1311                         return VN_INACTIVE_CACHE;
1312                 }
1313         } else if ((ip->i_d.di_mode & S_IFMT) == S_IFLNK) {
1314
1315                 /*
1316                  * If we get an error while cleaning up a
1317                  * symlink we bail out.
1318                  */
1319                 error = (ip->i_d.di_size > XFS_IFORK_DSIZE(ip)) ?
1320                         xfs_inactive_symlink_rmt(ip, &tp) :
1321                         xfs_inactive_symlink_local(ip, &tp);
1322
1323                 if (error) {
1324                         ASSERT(tp == NULL);
1325                         return VN_INACTIVE_CACHE;
1326                 }
1327
1328                 xfs_trans_ijoin(tp, ip, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL);
1329                 xfs_trans_ihold(tp, ip);
1330         } else {
1331                 error = xfs_trans_reserve(tp, 0,
1332                                           XFS_IFREE_LOG_RES(mp),
1333                                           0, XFS_TRANS_PERM_LOG_RES,
1334                                           XFS_INACTIVE_LOG_COUNT);
1335                 if (error) {
1336                         ASSERT(XFS_FORCED_SHUTDOWN(mp));
1337                         xfs_trans_cancel(tp, 0);
1338                         return VN_INACTIVE_CACHE;
1339                 }
1340
1341                 xfs_ilock(ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
1342                 xfs_trans_ijoin(tp, ip, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL);
1343                 xfs_trans_ihold(tp, ip);
1344         }
1345
1346         /*
1347          * If there are attributes associated with the file
1348          * then blow them away now.  The code calls a routine
1349          * that recursively deconstructs the attribute fork.
1350          * We need to just commit the current transaction
1351          * because we can't use it for xfs_attr_inactive().
1352          */
1353         if (ip->i_d.di_anextents > 0) {
1354                 error = xfs_inactive_attrs(ip, &tp);
1355                 /*
1356                  * If we got an error, the transaction is already
1357                  * cancelled, and the inode is unlocked. Just get out.
1358                  */
1359                  if (error)
1360                          return VN_INACTIVE_CACHE;
1361         } else if (ip->i_afp) {
1362                 xfs_idestroy_fork(ip, XFS_ATTR_FORK);
1363         }
1364
1365         /*
1366          * Free the inode.
1367          */
1368         XFS_BMAP_INIT(&free_list, &first_block);
1369         error = xfs_ifree(tp, ip, &free_list);
1370         if (error) {
1371                 /*
1372                  * If we fail to free the inode, shut down.  The cancel
1373                  * might do that, we need to make sure.  Otherwise the
1374                  * inode might be lost for a long time or forever.
1375                  */
1376                 if (!XFS_FORCED_SHUTDOWN(mp)) {
1377                         cmn_err(CE_NOTE,
1378                 "xfs_inactive:  xfs_ifree() returned an error = %d on %s",
1379                                 error, mp->m_fsname);
1380                         xfs_force_shutdown(mp, SHUTDOWN_META_IO_ERROR);
1381                 }
1382                 xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES|XFS_TRANS_ABORT);
1383         } else {
1384                 /*
1385                  * Credit the quota account(s). The inode is gone.
1386                  */
1387                 XFS_TRANS_MOD_DQUOT_BYINO(mp, tp, ip, XFS_TRANS_DQ_ICOUNT, -1);
1388
1389                 /*
1390                  * Just ignore errors at this point.  There is nothing we can
1391                  * do except to try to keep going. Make sure it's not a silent
1392                  * error.
1393                  */
1394                 error = xfs_bmap_finish(&tp,  &free_list, &committed);
1395                 if (error)
1396                         xfs_fs_cmn_err(CE_NOTE, mp, "xfs_inactive: "
1397                                 "xfs_bmap_finish() returned error %d", error);
1398                 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
1399                 if (error)
1400                         xfs_fs_cmn_err(CE_NOTE, mp, "xfs_inactive: "
1401                                 "xfs_trans_commit() returned error %d", error);
1402         }
1403         /*
1404          * Release the dquots held by inode, if any.
1405          */
1406         XFS_QM_DQDETACH(mp, ip);
1407
1408         xfs_iunlock(ip, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL);
1409
1410  out:
1411         return VN_INACTIVE_CACHE;
1412 }
1413
1414 /*
1415  * Lookups up an inode from "name". If ci_name is not NULL, then a CI match
1416  * is allowed, otherwise it has to be an exact match. If a CI match is found,
1417  * ci_name->name will point to a the actual name (caller must free) or
1418  * will be set to NULL if an exact match is found.
1419  */
1420 int
1421 xfs_lookup(
1422         xfs_inode_t             *dp,
1423         struct xfs_name         *name,
1424         xfs_inode_t             **ipp,
1425         struct xfs_name         *ci_name)
1426 {
1427         xfs_ino_t               inum;
1428         int                     error;
1429         uint                    lock_mode;
1430
1431         xfs_itrace_entry(dp);
1432
1433         if (XFS_FORCED_SHUTDOWN(dp->i_mount))
1434                 return XFS_ERROR(EIO);
1435
1436         lock_mode = xfs_ilock_map_shared(dp);
1437         error = xfs_dir_lookup(NULL, dp, name, &inum, ci_name);
1438         xfs_iunlock_map_shared(dp, lock_mode);
1439
1440         if (error)
1441                 goto out;
1442
1443         error = xfs_iget(dp->i_mount, NULL, inum, 0, 0, ipp, 0);
1444         if (error)
1445                 goto out_free_name;
1446
1447         xfs_itrace_ref(*ipp);
1448         return 0;
1449
1450 out_free_name:
1451         if (ci_name)
1452                 kmem_free(ci_name->name);
1453 out:
1454         *ipp = NULL;
1455         return error;
1456 }
1457
1458 int
1459 xfs_create(
1460         xfs_inode_t             *dp,
1461         struct xfs_name         *name,
1462         mode_t                  mode,
1463         xfs_dev_t               rdev,
1464         xfs_inode_t             **ipp,
1465         cred_t                  *credp)
1466 {
1467         xfs_mount_t             *mp = dp->i_mount;
1468         xfs_inode_t             *ip;
1469         xfs_trans_t             *tp;
1470         int                     error;
1471         xfs_bmap_free_t         free_list;
1472         xfs_fsblock_t           first_block;
1473         boolean_t               unlock_dp_on_error = B_FALSE;
1474         int                     dm_event_sent = 0;
1475         uint                    cancel_flags;
1476         int                     committed;
1477         xfs_prid_t              prid;
1478         struct xfs_dquot        *udqp, *gdqp;
1479         uint                    resblks;
1480
1481         ASSERT(!*ipp);
1482         xfs_itrace_entry(dp);
1483
1484         if (DM_EVENT_ENABLED(dp, DM_EVENT_CREATE)) {
1485                 error = XFS_SEND_NAMESP(mp, DM_EVENT_CREATE,
1486                                 dp, DM_RIGHT_NULL, NULL,
1487                                 DM_RIGHT_NULL, name->name, NULL,
1488                                 mode, 0, 0);
1489
1490                 if (error)
1491                         return error;
1492                 dm_event_sent = 1;
1493         }
1494
1495         if (XFS_FORCED_SHUTDOWN(mp))
1496                 return XFS_ERROR(EIO);
1497
1498         /* Return through std_return after this point. */
1499
1500         udqp = gdqp = NULL;
1501         if (dp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT)
1502                 prid = dp->i_d.di_projid;
1503         else
1504                 prid = (xfs_prid_t)dfltprid;
1505
1506         /*
1507          * Make sure that we have allocated dquot(s) on disk.
1508          */
1509         error = XFS_QM_DQVOPALLOC(mp, dp,
1510                         current_fsuid(), current_fsgid(), prid,
1511                         XFS_QMOPT_QUOTALL|XFS_QMOPT_INHERIT, &udqp, &gdqp);
1512         if (error)
1513                 goto std_return;
1514
1515         ip = NULL;
1516
1517         tp = xfs_trans_alloc(mp, XFS_TRANS_CREATE);
1518         cancel_flags = XFS_TRANS_RELEASE_LOG_RES;
1519         resblks = XFS_CREATE_SPACE_RES(mp, name->len);
1520         /*
1521          * Initially assume that the file does not exist and
1522          * reserve the resources for that case.  If that is not
1523          * the case we'll drop the one we have and get a more
1524          * appropriate transaction later.
1525          */
1526         error = xfs_trans_reserve(tp, resblks, XFS_CREATE_LOG_RES(mp), 0,
1527                         XFS_TRANS_PERM_LOG_RES, XFS_CREATE_LOG_COUNT);
1528         if (error == ENOSPC) {
1529                 resblks = 0;
1530                 error = xfs_trans_reserve(tp, 0, XFS_CREATE_LOG_RES(mp), 0,
1531                                 XFS_TRANS_PERM_LOG_RES, XFS_CREATE_LOG_COUNT);
1532         }
1533         if (error) {
1534                 cancel_flags = 0;
1535                 goto error_return;
1536         }
1537
1538         xfs_ilock(dp, XFS_ILOCK_EXCL | XFS_ILOCK_PARENT);
1539         unlock_dp_on_error = B_TRUE;
1540
1541         XFS_BMAP_INIT(&free_list, &first_block);
1542
1543         ASSERT(ip == NULL);
1544
1545         /*
1546          * Reserve disk quota and the inode.
1547          */
1548         error = XFS_TRANS_RESERVE_QUOTA(mp, tp, udqp, gdqp, resblks, 1, 0);
1549         if (error)
1550                 goto error_return;
1551
1552         error = xfs_dir_canenter(tp, dp, name, resblks);
1553         if (error)
1554                 goto error_return;
1555         error = xfs_dir_ialloc(&tp, dp, mode, 1,
1556                         rdev, credp, prid, resblks > 0,
1557                         &ip, &committed);
1558         if (error) {
1559                 if (error == ENOSPC)
1560                         goto error_return;
1561                 goto abort_return;
1562         }
1563         xfs_itrace_ref(ip);
1564
1565         /*
1566          * At this point, we've gotten a newly allocated inode.
1567          * It is locked (and joined to the transaction).
1568          */
1569
1570         ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
1571
1572         /*
1573          * Now we join the directory inode to the transaction.  We do not do it
1574          * earlier because xfs_dir_ialloc might commit the previous transaction
1575          * (and release all the locks).  An error from here on will result in
1576          * the transaction cancel unlocking dp so don't do it explicitly in the
1577          * error path.
1578          */
1579         IHOLD(dp);
1580         xfs_trans_ijoin(tp, dp, XFS_ILOCK_EXCL);
1581         unlock_dp_on_error = B_FALSE;
1582
1583         error = xfs_dir_createname(tp, dp, name, ip->i_ino,
1584                                         &first_block, &free_list, resblks ?
1585                                         resblks - XFS_IALLOC_SPACE_RES(mp) : 0);
1586         if (error) {
1587                 ASSERT(error != ENOSPC);
1588                 goto abort_return;
1589         }
1590         xfs_ichgtime(dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
1591         xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
1592
1593         /*
1594          * If this is a synchronous mount, make sure that the
1595          * create transaction goes to disk before returning to
1596          * the user.
1597          */
1598         if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC)) {
1599                 xfs_trans_set_sync(tp);
1600         }
1601
1602         dp->i_gen++;
1603
1604         /*
1605          * Attach the dquot(s) to the inodes and modify them incore.
1606          * These ids of the inode couldn't have changed since the new
1607          * inode has been locked ever since it was created.
1608          */
1609         XFS_QM_DQVOPCREATE(mp, tp, ip, udqp, gdqp);
1610
1611         /*
1612          * xfs_trans_commit normally decrements the vnode ref count
1613          * when it unlocks the inode. Since we want to return the
1614          * vnode to the caller, we bump the vnode ref count now.
1615          */
1616         IHOLD(ip);
1617
1618         error = xfs_bmap_finish(&tp, &free_list, &committed);
1619         if (error) {
1620                 xfs_bmap_cancel(&free_list);
1621                 goto abort_rele;
1622         }
1623
1624         error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
1625         if (error) {
1626                 IRELE(ip);
1627                 tp = NULL;
1628                 goto error_return;
1629         }
1630
1631         XFS_QM_DQRELE(mp, udqp);
1632         XFS_QM_DQRELE(mp, gdqp);
1633
1634         *ipp = ip;
1635
1636         /* Fallthrough to std_return with error = 0  */
1637
1638 std_return:
1639         if ((*ipp || (error != 0 && dm_event_sent != 0)) &&
1640             DM_EVENT_ENABLED(dp, DM_EVENT_POSTCREATE)) {
1641                 (void) XFS_SEND_NAMESP(mp, DM_EVENT_POSTCREATE,
1642                         dp, DM_RIGHT_NULL,
1643                         *ipp ? ip : NULL,
1644                         DM_RIGHT_NULL, name->name, NULL,
1645                         mode, error, 0);
1646         }
1647         return error;
1648
1649  abort_return:
1650         cancel_flags |= XFS_TRANS_ABORT;
1651         /* FALLTHROUGH */
1652
1653  error_return:
1654         if (tp != NULL)
1655                 xfs_trans_cancel(tp, cancel_flags);
1656
1657         XFS_QM_DQRELE(mp, udqp);
1658         XFS_QM_DQRELE(mp, gdqp);
1659
1660         if (unlock_dp_on_error)
1661                 xfs_iunlock(dp, XFS_ILOCK_EXCL);
1662
1663         goto std_return;
1664
1665  abort_rele:
1666         /*
1667          * Wait until after the current transaction is aborted to
1668          * release the inode.  This prevents recursive transactions
1669          * and deadlocks from xfs_inactive.
1670          */
1671         cancel_flags |= XFS_TRANS_ABORT;
1672         xfs_trans_cancel(tp, cancel_flags);
1673         IRELE(ip);
1674
1675         XFS_QM_DQRELE(mp, udqp);
1676         XFS_QM_DQRELE(mp, gdqp);
1677
1678         goto std_return;
1679 }
1680
1681 #ifdef DEBUG
1682 int xfs_locked_n;
1683 int xfs_small_retries;
1684 int xfs_middle_retries;
1685 int xfs_lots_retries;
1686 int xfs_lock_delays;
1687 #endif
1688
1689 /*
1690  * Bump the subclass so xfs_lock_inodes() acquires each lock with
1691  * a different value
1692  */
1693 static inline int
1694 xfs_lock_inumorder(int lock_mode, int subclass)
1695 {
1696         if (lock_mode & (XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL))
1697                 lock_mode |= (subclass + XFS_LOCK_INUMORDER) << XFS_IOLOCK_SHIFT;
1698         if (lock_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL))
1699                 lock_mode |= (subclass + XFS_LOCK_INUMORDER) << XFS_ILOCK_SHIFT;
1700
1701         return lock_mode;
1702 }
1703
1704 /*
1705  * The following routine will lock n inodes in exclusive mode.
1706  * We assume the caller calls us with the inodes in i_ino order.
1707  *
1708  * We need to detect deadlock where an inode that we lock
1709  * is in the AIL and we start waiting for another inode that is locked
1710  * by a thread in a long running transaction (such as truncate). This can
1711  * result in deadlock since the long running trans might need to wait
1712  * for the inode we just locked in order to push the tail and free space
1713  * in the log.
1714  */
1715 void
1716 xfs_lock_inodes(
1717         xfs_inode_t     **ips,
1718         int             inodes,
1719         uint            lock_mode)
1720 {
1721         int             attempts = 0, i, j, try_lock;
1722         xfs_log_item_t  *lp;
1723
1724         ASSERT(ips && (inodes >= 2)); /* we need at least two */
1725
1726         try_lock = 0;
1727         i = 0;
1728
1729 again:
1730         for (; i < inodes; i++) {
1731                 ASSERT(ips[i]);
1732
1733                 if (i && (ips[i] == ips[i-1]))  /* Already locked */
1734                         continue;
1735
1736                 /*
1737                  * If try_lock is not set yet, make sure all locked inodes
1738                  * are not in the AIL.
1739                  * If any are, set try_lock to be used later.
1740                  */
1741
1742                 if (!try_lock) {
1743                         for (j = (i - 1); j >= 0 && !try_lock; j--) {
1744                                 lp = (xfs_log_item_t *)ips[j]->i_itemp;
1745                                 if (lp && (lp->li_flags & XFS_LI_IN_AIL)) {
1746                                         try_lock++;
1747                                 }
1748                         }
1749                 }
1750
1751                 /*
1752                  * If any of the previous locks we have locked is in the AIL,
1753                  * we must TRY to get the second and subsequent locks. If
1754                  * we can't get any, we must release all we have
1755                  * and try again.
1756                  */
1757
1758                 if (try_lock) {
1759                         /* try_lock must be 0 if i is 0. */
1760                         /*
1761                          * try_lock means we have an inode locked
1762                          * that is in the AIL.
1763                          */
1764                         ASSERT(i != 0);
1765                         if (!xfs_ilock_nowait(ips[i], xfs_lock_inumorder(lock_mode, i))) {
1766                                 attempts++;
1767
1768                                 /*
1769                                  * Unlock all previous guys and try again.
1770                                  * xfs_iunlock will try to push the tail
1771                                  * if the inode is in the AIL.
1772                                  */
1773
1774                                 for(j = i - 1; j >= 0; j--) {
1775
1776                                         /*
1777                                          * Check to see if we've already
1778                                          * unlocked this one.
1779                                          * Not the first one going back,
1780                                          * and the inode ptr is the same.
1781                                          */
1782                                         if ((j != (i - 1)) && ips[j] ==
1783                                                                 ips[j+1])
1784                                                 continue;
1785
1786                                         xfs_iunlock(ips[j], lock_mode);
1787                                 }
1788
1789                                 if ((attempts % 5) == 0) {
1790                                         delay(1); /* Don't just spin the CPU */
1791 #ifdef DEBUG
1792                                         xfs_lock_delays++;
1793 #endif
1794                                 }
1795                                 i = 0;
1796                                 try_lock = 0;
1797                                 goto again;
1798                         }
1799                 } else {
1800                         xfs_ilock(ips[i], xfs_lock_inumorder(lock_mode, i));
1801                 }
1802         }
1803
1804 #ifdef DEBUG
1805         if (attempts) {
1806                 if (attempts < 5) xfs_small_retries++;
1807                 else if (attempts < 100) xfs_middle_retries++;
1808                 else xfs_lots_retries++;
1809         } else {
1810                 xfs_locked_n++;
1811         }
1812 #endif
1813 }
1814
1815 /*
1816  * xfs_lock_two_inodes() can only be used to lock one type of lock
1817  * at a time - the iolock or the ilock, but not both at once. If
1818  * we lock both at once, lockdep will report false positives saying
1819  * we have violated locking orders.
1820  */
1821 void
1822 xfs_lock_two_inodes(
1823         xfs_inode_t             *ip0,
1824         xfs_inode_t             *ip1,
1825         uint                    lock_mode)
1826 {
1827         xfs_inode_t             *temp;
1828         int                     attempts = 0;
1829         xfs_log_item_t          *lp;
1830
1831         if (lock_mode & (XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL))
1832                 ASSERT((lock_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL)) == 0);
1833         ASSERT(ip0->i_ino != ip1->i_ino);
1834
1835         if (ip0->i_ino > ip1->i_ino) {
1836                 temp = ip0;
1837                 ip0 = ip1;
1838                 ip1 = temp;
1839         }
1840
1841  again:
1842         xfs_ilock(ip0, xfs_lock_inumorder(lock_mode, 0));
1843
1844         /*
1845          * If the first lock we have locked is in the AIL, we must TRY to get
1846          * the second lock. If we can't get it, we must release the first one
1847          * and try again.
1848          */
1849         lp = (xfs_log_item_t *)ip0->i_itemp;
1850         if (lp && (lp->li_flags & XFS_LI_IN_AIL)) {
1851                 if (!xfs_ilock_nowait(ip1, xfs_lock_inumorder(lock_mode, 1))) {
1852                         xfs_iunlock(ip0, lock_mode);
1853                         if ((++attempts % 5) == 0)
1854                                 delay(1); /* Don't just spin the CPU */
1855                         goto again;
1856                 }
1857         } else {
1858                 xfs_ilock(ip1, xfs_lock_inumorder(lock_mode, 1));
1859         }
1860 }
1861
1862 int
1863 xfs_remove(
1864         xfs_inode_t             *dp,
1865         struct xfs_name         *name,
1866         xfs_inode_t             *ip)
1867 {
1868         xfs_mount_t             *mp = dp->i_mount;
1869         xfs_trans_t             *tp = NULL;
1870         int                     is_dir = S_ISDIR(ip->i_d.di_mode);
1871         int                     error = 0;
1872         xfs_bmap_free_t         free_list;
1873         xfs_fsblock_t           first_block;
1874         int                     cancel_flags;
1875         int                     committed;
1876         int                     link_zero;
1877         uint                    resblks;
1878         uint                    log_count;
1879
1880         xfs_itrace_entry(dp);
1881         xfs_itrace_entry(ip);
1882
1883         if (XFS_FORCED_SHUTDOWN(mp))
1884                 return XFS_ERROR(EIO);
1885
1886         if (DM_EVENT_ENABLED(dp, DM_EVENT_REMOVE)) {
1887                 error = XFS_SEND_NAMESP(mp, DM_EVENT_REMOVE, dp, DM_RIGHT_NULL,
1888                                         NULL, DM_RIGHT_NULL, name->name, NULL,
1889                                         ip->i_d.di_mode, 0, 0);
1890                 if (error)
1891                         return error;
1892         }
1893
1894         error = XFS_QM_DQATTACH(mp, dp, 0);
1895         if (error)
1896                 goto std_return;
1897
1898         error = XFS_QM_DQATTACH(mp, ip, 0);
1899         if (error)
1900                 goto std_return;
1901
1902         if (is_dir) {
1903                 tp = xfs_trans_alloc(mp, XFS_TRANS_RMDIR);
1904                 log_count = XFS_DEFAULT_LOG_COUNT;
1905         } else {
1906                 tp = xfs_trans_alloc(mp, XFS_TRANS_REMOVE);
1907                 log_count = XFS_REMOVE_LOG_COUNT;
1908         }
1909         cancel_flags = XFS_TRANS_RELEASE_LOG_RES;
1910
1911         /*
1912          * We try to get the real space reservation first,
1913          * allowing for directory btree deletion(s) implying
1914          * possible bmap insert(s).  If we can't get the space
1915          * reservation then we use 0 instead, and avoid the bmap
1916          * btree insert(s) in the directory code by, if the bmap
1917          * insert tries to happen, instead trimming the LAST
1918          * block from the directory.
1919          */
1920         resblks = XFS_REMOVE_SPACE_RES(mp);
1921         error = xfs_trans_reserve(tp, resblks, XFS_REMOVE_LOG_RES(mp), 0,
1922                                   XFS_TRANS_PERM_LOG_RES, log_count);
1923         if (error == ENOSPC) {
1924                 resblks = 0;
1925                 error = xfs_trans_reserve(tp, 0, XFS_REMOVE_LOG_RES(mp), 0,
1926                                           XFS_TRANS_PERM_LOG_RES, log_count);
1927         }
1928         if (error) {
1929                 ASSERT(error != ENOSPC);
1930                 cancel_flags = 0;
1931                 goto out_trans_cancel;
1932         }
1933
1934         xfs_lock_two_inodes(dp, ip, XFS_ILOCK_EXCL);
1935
1936         /*
1937          * At this point, we've gotten both the directory and the entry
1938          * inodes locked.
1939          */
1940         IHOLD(ip);
1941         xfs_trans_ijoin(tp, dp, XFS_ILOCK_EXCL);
1942
1943         IHOLD(dp);
1944         xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
1945
1946         /*
1947          * If we're removing a directory perform some additional validation.
1948          */
1949         if (is_dir) {
1950                 ASSERT(ip->i_d.di_nlink >= 2);
1951                 if (ip->i_d.di_nlink != 2) {
1952                         error = XFS_ERROR(ENOTEMPTY);
1953                         goto out_trans_cancel;
1954                 }
1955                 if (!xfs_dir_isempty(ip)) {
1956                         error = XFS_ERROR(ENOTEMPTY);
1957                         goto out_trans_cancel;
1958                 }
1959         }
1960
1961         XFS_BMAP_INIT(&free_list, &first_block);
1962         error = xfs_dir_removename(tp, dp, name, ip->i_ino,
1963                                         &first_block, &free_list, resblks);
1964         if (error) {
1965                 ASSERT(error != ENOENT);
1966                 goto out_bmap_cancel;
1967         }
1968         xfs_ichgtime(dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
1969
1970         /*
1971          * Bump the in memory generation count on the parent
1972          * directory so that other can know that it has changed.
1973          */
1974         dp->i_gen++;
1975         xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
1976
1977         if (is_dir) {
1978                 /*
1979                  * Drop the link from ip's "..".
1980                  */
1981                 error = xfs_droplink(tp, dp);
1982                 if (error)
1983                         goto out_bmap_cancel;
1984
1985                 /*
1986                  * Drop the "." link from ip to self.
1987                  */
1988                 error = xfs_droplink(tp, ip);
1989                 if (error)
1990                         goto out_bmap_cancel;
1991         } else {
1992                 /*
1993                  * When removing a non-directory we need to log the parent
1994                  * inode here for the i_gen update.  For a directory this is
1995                  * done implicitly by the xfs_droplink call for the ".." entry.
1996                  */
1997                 xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
1998         }
1999
2000         /*
2001          * Drop the link from dp to ip.
2002          */
2003         error = xfs_droplink(tp, ip);
2004         if (error)
2005                 goto out_bmap_cancel;
2006
2007         /*
2008          * Determine if this is the last link while
2009          * we are in the transaction.
2010          */
2011         link_zero = (ip->i_d.di_nlink == 0);
2012
2013         /*
2014          * If this is a synchronous mount, make sure that the
2015          * remove transaction goes to disk before returning to
2016          * the user.
2017          */
2018         if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC))
2019                 xfs_trans_set_sync(tp);
2020
2021         error = xfs_bmap_finish(&tp, &free_list, &committed);
2022         if (error)
2023                 goto out_bmap_cancel;
2024
2025         error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
2026         if (error)
2027                 goto std_return;
2028
2029         /*
2030          * If we are using filestreams, kill the stream association.
2031          * If the file is still open it may get a new one but that
2032          * will get killed on last close in xfs_close() so we don't
2033          * have to worry about that.
2034          */
2035         if (!is_dir && link_zero && xfs_inode_is_filestream(ip))
2036                 xfs_filestream_deassociate(ip);
2037
2038         xfs_itrace_exit(ip);
2039         xfs_itrace_exit(dp);
2040
2041  std_return:
2042         if (DM_EVENT_ENABLED(dp, DM_EVENT_POSTREMOVE)) {
2043                 XFS_SEND_NAMESP(mp, DM_EVENT_POSTREMOVE, dp, DM_RIGHT_NULL,
2044                                 NULL, DM_RIGHT_NULL, name->name, NULL,
2045                                 ip->i_d.di_mode, error, 0);
2046         }
2047
2048         return error;
2049
2050  out_bmap_cancel:
2051         xfs_bmap_cancel(&free_list);
2052         cancel_flags |= XFS_TRANS_ABORT;
2053  out_trans_cancel:
2054         xfs_trans_cancel(tp, cancel_flags);
2055         goto std_return;
2056 }
2057
2058 int
2059 xfs_link(
2060         xfs_inode_t             *tdp,
2061         xfs_inode_t             *sip,
2062         struct xfs_name         *target_name)
2063 {
2064         xfs_mount_t             *mp = tdp->i_mount;
2065         xfs_trans_t             *tp;
2066         int                     error;
2067         xfs_bmap_free_t         free_list;
2068         xfs_fsblock_t           first_block;
2069         int                     cancel_flags;
2070         int                     committed;
2071         int                     resblks;
2072
2073         xfs_itrace_entry(tdp);
2074         xfs_itrace_entry(sip);
2075
2076         ASSERT(!S_ISDIR(sip->i_d.di_mode));
2077
2078         if (XFS_FORCED_SHUTDOWN(mp))
2079                 return XFS_ERROR(EIO);
2080
2081         if (DM_EVENT_ENABLED(tdp, DM_EVENT_LINK)) {
2082                 error = XFS_SEND_NAMESP(mp, DM_EVENT_LINK,
2083                                         tdp, DM_RIGHT_NULL,
2084                                         sip, DM_RIGHT_NULL,
2085                                         target_name->name, NULL, 0, 0, 0);
2086                 if (error)
2087                         return error;
2088         }
2089
2090         /* Return through std_return after this point. */
2091
2092         error = XFS_QM_DQATTACH(mp, sip, 0);
2093         if (!error && sip != tdp)
2094                 error = XFS_QM_DQATTACH(mp, tdp, 0);
2095         if (error)
2096                 goto std_return;
2097
2098         tp = xfs_trans_alloc(mp, XFS_TRANS_LINK);
2099         cancel_flags = XFS_TRANS_RELEASE_LOG_RES;
2100         resblks = XFS_LINK_SPACE_RES(mp, target_name->len);
2101         error = xfs_trans_reserve(tp, resblks, XFS_LINK_LOG_RES(mp), 0,
2102                         XFS_TRANS_PERM_LOG_RES, XFS_LINK_LOG_COUNT);
2103         if (error == ENOSPC) {
2104                 resblks = 0;
2105                 error = xfs_trans_reserve(tp, 0, XFS_LINK_LOG_RES(mp), 0,
2106                                 XFS_TRANS_PERM_LOG_RES, XFS_LINK_LOG_COUNT);
2107         }
2108         if (error) {
2109                 cancel_flags = 0;
2110                 goto error_return;
2111         }
2112
2113         xfs_lock_two_inodes(sip, tdp, XFS_ILOCK_EXCL);
2114
2115         /*
2116          * Increment vnode ref counts since xfs_trans_commit &
2117          * xfs_trans_cancel will both unlock the inodes and
2118          * decrement the associated ref counts.
2119          */
2120         IHOLD(sip);
2121         IHOLD(tdp);
2122         xfs_trans_ijoin(tp, sip, XFS_ILOCK_EXCL);
2123         xfs_trans_ijoin(tp, tdp, XFS_ILOCK_EXCL);
2124
2125         /*
2126          * If the source has too many links, we can't make any more to it.
2127          */
2128         if (sip->i_d.di_nlink >= XFS_MAXLINK) {
2129                 error = XFS_ERROR(EMLINK);
2130                 goto error_return;
2131         }
2132
2133         /*
2134          * If we are using project inheritance, we only allow hard link
2135          * creation in our tree when the project IDs are the same; else
2136          * the tree quota mechanism could be circumvented.
2137          */
2138         if (unlikely((tdp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT) &&
2139                      (tdp->i_d.di_projid != sip->i_d.di_projid))) {
2140                 error = XFS_ERROR(EXDEV);
2141                 goto error_return;
2142         }
2143
2144         error = xfs_dir_canenter(tp, tdp, target_name, resblks);
2145         if (error)
2146                 goto error_return;
2147
2148         XFS_BMAP_INIT(&free_list, &first_block);
2149
2150         error = xfs_dir_createname(tp, tdp, target_name, sip->i_ino,
2151                                         &first_block, &free_list, resblks);
2152         if (error)
2153                 goto abort_return;
2154         xfs_ichgtime(tdp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
2155         tdp->i_gen++;
2156         xfs_trans_log_inode(tp, tdp, XFS_ILOG_CORE);
2157
2158         error = xfs_bumplink(tp, sip);
2159         if (error)
2160                 goto abort_return;
2161
2162         /*
2163          * If this is a synchronous mount, make sure that the
2164          * link transaction goes to disk before returning to
2165          * the user.
2166          */
2167         if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC)) {
2168                 xfs_trans_set_sync(tp);
2169         }
2170
2171         error = xfs_bmap_finish (&tp, &free_list, &committed);
2172         if (error) {
2173                 xfs_bmap_cancel(&free_list);
2174                 goto abort_return;
2175         }
2176
2177         error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
2178         if (error)
2179                 goto std_return;
2180
2181         /* Fall through to std_return with error = 0. */
2182 std_return:
2183         if (DM_EVENT_ENABLED(sip, DM_EVENT_POSTLINK)) {
2184                 (void) XFS_SEND_NAMESP(mp, DM_EVENT_POSTLINK,
2185                                 tdp, DM_RIGHT_NULL,
2186                                 sip, DM_RIGHT_NULL,
2187                                 target_name->name, NULL, 0, error, 0);
2188         }
2189         return error;
2190
2191  abort_return:
2192         cancel_flags |= XFS_TRANS_ABORT;
2193         /* FALLTHROUGH */
2194
2195  error_return:
2196         xfs_trans_cancel(tp, cancel_flags);
2197         goto std_return;
2198 }
2199
2200
2201 int
2202 xfs_mkdir(
2203         xfs_inode_t             *dp,
2204         struct xfs_name         *dir_name,
2205         mode_t                  mode,
2206         xfs_inode_t             **ipp,
2207         cred_t                  *credp)
2208 {
2209         xfs_mount_t             *mp = dp->i_mount;
2210         xfs_inode_t             *cdp;   /* inode of created dir */
2211         xfs_trans_t             *tp;
2212         int                     cancel_flags;
2213         int                     error;
2214         int                     committed;
2215         xfs_bmap_free_t         free_list;
2216         xfs_fsblock_t           first_block;
2217         boolean_t               unlock_dp_on_error = B_FALSE;
2218         boolean_t               created = B_FALSE;
2219         int                     dm_event_sent = 0;
2220         xfs_prid_t              prid;
2221         struct xfs_dquot        *udqp, *gdqp;
2222         uint                    resblks;
2223
2224         if (XFS_FORCED_SHUTDOWN(mp))
2225                 return XFS_ERROR(EIO);
2226
2227         tp = NULL;
2228
2229         if (DM_EVENT_ENABLED(dp, DM_EVENT_CREATE)) {
2230                 error = XFS_SEND_NAMESP(mp, DM_EVENT_CREATE,
2231                                         dp, DM_RIGHT_NULL, NULL,
2232                                         DM_RIGHT_NULL, dir_name->name, NULL,
2233                                         mode, 0, 0);
2234                 if (error)
2235                         return error;
2236                 dm_event_sent = 1;
2237         }
2238
2239         /* Return through std_return after this point. */
2240
2241         xfs_itrace_entry(dp);
2242
2243         mp = dp->i_mount;
2244         udqp = gdqp = NULL;
2245         if (dp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT)
2246                 prid = dp->i_d.di_projid;
2247         else
2248                 prid = (xfs_prid_t)dfltprid;
2249
2250         /*
2251          * Make sure that we have allocated dquot(s) on disk.
2252          */
2253         error = XFS_QM_DQVOPALLOC(mp, dp,
2254                         current_fsuid(), current_fsgid(), prid,
2255                         XFS_QMOPT_QUOTALL | XFS_QMOPT_INHERIT, &udqp, &gdqp);
2256         if (error)
2257                 goto std_return;
2258
2259         tp = xfs_trans_alloc(mp, XFS_TRANS_MKDIR);
2260         cancel_flags = XFS_TRANS_RELEASE_LOG_RES;
2261         resblks = XFS_MKDIR_SPACE_RES(mp, dir_name->len);
2262         error = xfs_trans_reserve(tp, resblks, XFS_MKDIR_LOG_RES(mp), 0,
2263                                   XFS_TRANS_PERM_LOG_RES, XFS_MKDIR_LOG_COUNT);
2264         if (error == ENOSPC) {
2265                 resblks = 0;
2266                 error = xfs_trans_reserve(tp, 0, XFS_MKDIR_LOG_RES(mp), 0,
2267                                           XFS_TRANS_PERM_LOG_RES,
2268                                           XFS_MKDIR_LOG_COUNT);
2269         }
2270         if (error) {
2271                 cancel_flags = 0;
2272                 goto error_return;
2273         }
2274
2275         xfs_ilock(dp, XFS_ILOCK_EXCL | XFS_ILOCK_PARENT);
2276         unlock_dp_on_error = B_TRUE;
2277
2278         /*
2279          * Check for directory link count overflow.
2280          */
2281         if (dp->i_d.di_nlink >= XFS_MAXLINK) {
2282                 error = XFS_ERROR(EMLINK);
2283                 goto error_return;
2284         }
2285
2286         /*
2287          * Reserve disk quota and the inode.
2288          */
2289         error = XFS_TRANS_RESERVE_QUOTA(mp, tp, udqp, gdqp, resblks, 1, 0);
2290         if (error)
2291                 goto error_return;
2292
2293         error = xfs_dir_canenter(tp, dp, dir_name, resblks);
2294         if (error)
2295                 goto error_return;
2296         /*
2297          * create the directory inode.
2298          */
2299         error = xfs_dir_ialloc(&tp, dp, mode, 2,
2300                         0, credp, prid, resblks > 0,
2301                 &cdp, NULL);
2302         if (error) {
2303                 if (error == ENOSPC)
2304                         goto error_return;
2305                 goto abort_return;
2306         }
2307         xfs_itrace_ref(cdp);
2308
2309         /*
2310          * Now we add the directory inode to the transaction.
2311          * We waited until now since xfs_dir_ialloc might start
2312          * a new transaction.  Had we joined the transaction
2313          * earlier, the locks might have gotten released. An error
2314          * from here on will result in the transaction cancel
2315          * unlocking dp so don't do it explicitly in the error path.
2316          */
2317         IHOLD(dp);
2318         xfs_trans_ijoin(tp, dp, XFS_ILOCK_EXCL);
2319         unlock_dp_on_error = B_FALSE;
2320
2321         XFS_BMAP_INIT(&free_list, &first_block);
2322
2323         error = xfs_dir_createname(tp, dp, dir_name, cdp->i_ino,
2324                                         &first_block, &free_list, resblks ?
2325                                         resblks - XFS_IALLOC_SPACE_RES(mp) : 0);
2326         if (error) {
2327                 ASSERT(error != ENOSPC);
2328                 goto error1;
2329         }
2330         xfs_ichgtime(dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
2331
2332         /*
2333          * Bump the in memory version number of the parent directory
2334          * so that other processes accessing it will recognize that
2335          * the directory has changed.
2336          */
2337         dp->i_gen++;
2338
2339         error = xfs_dir_init(tp, cdp, dp);
2340         if (error)
2341                 goto error2;
2342
2343         cdp->i_gen = 1;
2344         error = xfs_bumplink(tp, dp);
2345         if (error)
2346                 goto error2;
2347
2348         created = B_TRUE;
2349
2350         *ipp = cdp;
2351         IHOLD(cdp);
2352
2353         /*
2354          * Attach the dquots to the new inode and modify the icount incore.
2355          */
2356         XFS_QM_DQVOPCREATE(mp, tp, cdp, udqp, gdqp);
2357
2358         /*
2359          * If this is a synchronous mount, make sure that the
2360          * mkdir transaction goes to disk before returning to
2361          * the user.
2362          */
2363         if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC)) {
2364                 xfs_trans_set_sync(tp);
2365         }
2366
2367         error = xfs_bmap_finish(&tp, &free_list, &committed);
2368         if (error) {
2369                 IRELE(cdp);
2370                 goto error2;
2371         }
2372
2373         error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
2374         XFS_QM_DQRELE(mp, udqp);
2375         XFS_QM_DQRELE(mp, gdqp);
2376         if (error) {
2377                 IRELE(cdp);
2378         }
2379
2380         /* Fall through to std_return with error = 0 or errno from
2381          * xfs_trans_commit. */
2382
2383 std_return:
2384         if ((created || (error != 0 && dm_event_sent != 0)) &&
2385             DM_EVENT_ENABLED(dp, DM_EVENT_POSTCREATE)) {
2386                 (void) XFS_SEND_NAMESP(mp, DM_EVENT_POSTCREATE,
2387                                         dp, DM_RIGHT_NULL,
2388                                         created ? cdp : NULL,
2389                                         DM_RIGHT_NULL,
2390                                         dir_name->name, NULL,
2391                                         mode, error, 0);
2392         }
2393         return error;
2394
2395  error2:
2396  error1:
2397         xfs_bmap_cancel(&free_list);
2398  abort_return:
2399         cancel_flags |= XFS_TRANS_ABORT;
2400  error_return:
2401         xfs_trans_cancel(tp, cancel_flags);
2402         XFS_QM_DQRELE(mp, udqp);
2403         XFS_QM_DQRELE(mp, gdqp);
2404
2405         if (unlock_dp_on_error)
2406                 xfs_iunlock(dp, XFS_ILOCK_EXCL);
2407
2408         goto std_return;
2409 }
2410
2411 int
2412 xfs_symlink(
2413         xfs_inode_t             *dp,
2414         struct xfs_name         *link_name,
2415         const char              *target_path,
2416         mode_t                  mode,
2417         xfs_inode_t             **ipp,
2418         cred_t                  *credp)
2419 {
2420         xfs_mount_t             *mp = dp->i_mount;
2421         xfs_trans_t             *tp;
2422         xfs_inode_t             *ip;
2423         int                     error;
2424         int                     pathlen;
2425         xfs_bmap_free_t         free_list;
2426         xfs_fsblock_t           first_block;
2427         boolean_t               unlock_dp_on_error = B_FALSE;
2428         uint                    cancel_flags;
2429         int                     committed;
2430         xfs_fileoff_t           first_fsb;
2431         xfs_filblks_t           fs_blocks;
2432         int                     nmaps;
2433         xfs_bmbt_irec_t         mval[SYMLINK_MAPS];
2434         xfs_daddr_t             d;
2435         const char              *cur_chunk;
2436         int                     byte_cnt;
2437         int                     n;
2438         xfs_buf_t               *bp;
2439         xfs_prid_t              prid;
2440         struct xfs_dquot        *udqp, *gdqp;
2441         uint                    resblks;
2442
2443         *ipp = NULL;
2444         error = 0;
2445         ip = NULL;
2446         tp = NULL;
2447
2448         xfs_itrace_entry(dp);
2449
2450         if (XFS_FORCED_SHUTDOWN(mp))
2451                 return XFS_ERROR(EIO);
2452
2453         /*
2454          * Check component lengths of the target path name.
2455          */
2456         pathlen = strlen(target_path);
2457         if (pathlen >= MAXPATHLEN)      /* total string too long */
2458                 return XFS_ERROR(ENAMETOOLONG);
2459
2460         if (DM_EVENT_ENABLED(dp, DM_EVENT_SYMLINK)) {
2461                 error = XFS_SEND_NAMESP(mp, DM_EVENT_SYMLINK, dp,
2462                                         DM_RIGHT_NULL, NULL, DM_RIGHT_NULL,
2463                                         link_name->name, target_path, 0, 0, 0);
2464                 if (error)
2465                         return error;
2466         }
2467
2468         /* Return through std_return after this point. */
2469
2470         udqp = gdqp = NULL;
2471         if (dp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT)
2472                 prid = dp->i_d.di_projid;
2473         else
2474                 prid = (xfs_prid_t)dfltprid;
2475
2476         /*
2477          * Make sure that we have allocated dquot(s) on disk.
2478          */
2479         error = XFS_QM_DQVOPALLOC(mp, dp,
2480                         current_fsuid(), current_fsgid(), prid,
2481                         XFS_QMOPT_QUOTALL | XFS_QMOPT_INHERIT, &udqp, &gdqp);
2482         if (error)
2483                 goto std_return;
2484
2485         tp = xfs_trans_alloc(mp, XFS_TRANS_SYMLINK);
2486         cancel_flags = XFS_TRANS_RELEASE_LOG_RES;
2487         /*
2488          * The symlink will fit into the inode data fork?
2489          * There can't be any attributes so we get the whole variable part.
2490          */
2491         if (pathlen <= XFS_LITINO(mp))
2492                 fs_blocks = 0;
2493         else
2494                 fs_blocks = XFS_B_TO_FSB(mp, pathlen);
2495         resblks = XFS_SYMLINK_SPACE_RES(mp, link_name->len, fs_blocks);
2496         error = xfs_trans_reserve(tp, resblks, XFS_SYMLINK_LOG_RES(mp), 0,
2497                         XFS_TRANS_PERM_LOG_RES, XFS_SYMLINK_LOG_COUNT);
2498         if (error == ENOSPC && fs_blocks == 0) {
2499                 resblks = 0;
2500                 error = xfs_trans_reserve(tp, 0, XFS_SYMLINK_LOG_RES(mp), 0,
2501                                 XFS_TRANS_PERM_LOG_RES, XFS_SYMLINK_LOG_COUNT);
2502         }
2503         if (error) {
2504                 cancel_flags = 0;
2505                 goto error_return;
2506         }
2507
2508         xfs_ilock(dp, XFS_ILOCK_EXCL | XFS_ILOCK_PARENT);
2509         unlock_dp_on_error = B_TRUE;
2510
2511         /*
2512          * Check whether the directory allows new symlinks or not.
2513          */
2514         if (dp->i_d.di_flags & XFS_DIFLAG_NOSYMLINKS) {
2515                 error = XFS_ERROR(EPERM);
2516                 goto error_return;
2517         }
2518
2519         /*
2520          * Reserve disk quota : blocks and inode.
2521          */
2522         error = XFS_TRANS_RESERVE_QUOTA(mp, tp, udqp, gdqp, resblks, 1, 0);
2523         if (error)
2524                 goto error_return;
2525
2526         /*
2527          * Check for ability to enter directory entry, if no space reserved.
2528          */
2529         error = xfs_dir_canenter(tp, dp, link_name, resblks);
2530         if (error)
2531                 goto error_return;
2532         /*
2533          * Initialize the bmap freelist prior to calling either
2534          * bmapi or the directory create code.
2535          */
2536         XFS_BMAP_INIT(&free_list, &first_block);
2537
2538         /*
2539          * Allocate an inode for the symlink.
2540          */
2541         error = xfs_dir_ialloc(&tp, dp, S_IFLNK | (mode & ~S_IFMT),
2542                                1, 0, credp, prid, resblks > 0, &ip, NULL);
2543         if (error) {
2544                 if (error == ENOSPC)
2545                         goto error_return;
2546                 goto error1;
2547         }
2548         xfs_itrace_ref(ip);
2549
2550         /*
2551          * An error after we've joined dp to the transaction will result in the
2552          * transaction cancel unlocking dp so don't do it explicitly in the
2553          * error path.
2554          */
2555         IHOLD(dp);
2556         xfs_trans_ijoin(tp, dp, XFS_ILOCK_EXCL);
2557         unlock_dp_on_error = B_FALSE;
2558
2559         /*
2560          * Also attach the dquot(s) to it, if applicable.
2561          */
2562         XFS_QM_DQVOPCREATE(mp, tp, ip, udqp, gdqp);
2563
2564         if (resblks)
2565                 resblks -= XFS_IALLOC_SPACE_RES(mp);
2566         /*
2567          * If the symlink will fit into the inode, write it inline.
2568          */
2569         if (pathlen <= XFS_IFORK_DSIZE(ip)) {
2570                 xfs_idata_realloc(ip, pathlen, XFS_DATA_FORK);
2571                 memcpy(ip->i_df.if_u1.if_data, target_path, pathlen);
2572                 ip->i_d.di_size = pathlen;
2573
2574                 /*
2575                  * The inode was initially created in extent format.
2576                  */
2577                 ip->i_df.if_flags &= ~(XFS_IFEXTENTS | XFS_IFBROOT);
2578                 ip->i_df.if_flags |= XFS_IFINLINE;
2579
2580                 ip->i_d.di_format = XFS_DINODE_FMT_LOCAL;
2581                 xfs_trans_log_inode(tp, ip, XFS_ILOG_DDATA | XFS_ILOG_CORE);
2582
2583         } else {
2584                 first_fsb = 0;
2585                 nmaps = SYMLINK_MAPS;
2586
2587                 error = xfs_bmapi(tp, ip, first_fsb, fs_blocks,
2588                                   XFS_BMAPI_WRITE | XFS_BMAPI_METADATA,
2589                                   &first_block, resblks, mval, &nmaps,
2590                                   &free_list, NULL);
2591                 if (error) {
2592                         goto error1;
2593                 }
2594
2595                 if (resblks)
2596                         resblks -= fs_blocks;
2597                 ip->i_d.di_size = pathlen;
2598                 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
2599
2600                 cur_chunk = target_path;
2601                 for (n = 0; n < nmaps; n++) {
2602                         d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock);
2603                         byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount);
2604                         bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d,
2605                                                BTOBB(byte_cnt), 0);
2606                         ASSERT(bp && !XFS_BUF_GETERROR(bp));
2607                         if (pathlen < byte_cnt) {
2608                                 byte_cnt = pathlen;
2609                         }
2610                         pathlen -= byte_cnt;
2611
2612                         memcpy(XFS_BUF_PTR(bp), cur_chunk, byte_cnt);
2613                         cur_chunk += byte_cnt;
2614
2615                         xfs_trans_log_buf(tp, bp, 0, byte_cnt - 1);
2616                 }
2617         }
2618
2619         /*
2620          * Create the directory entry for the symlink.
2621          */
2622         error = xfs_dir_createname(tp, dp, link_name, ip->i_ino,
2623                                         &first_block, &free_list, resblks);
2624         if (error)
2625                 goto error1;
2626         xfs_ichgtime(dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
2627         xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
2628
2629         /*
2630          * Bump the in memory version number of the parent directory
2631          * so that other processes accessing it will recognize that
2632          * the directory has changed.
2633          */
2634         dp->i_gen++;
2635
2636         /*
2637          * If this is a synchronous mount, make sure that the
2638          * symlink transaction goes to disk before returning to
2639          * the user.
2640          */
2641         if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC)) {
2642                 xfs_trans_set_sync(tp);
2643         }
2644
2645         /*
2646          * xfs_trans_commit normally decrements the vnode ref count
2647          * when it unlocks the inode. Since we want to return the
2648          * vnode to the caller, we bump the vnode ref count now.
2649          */
2650         IHOLD(ip);
2651
2652         error = xfs_bmap_finish(&tp, &free_list, &committed);
2653         if (error) {
2654                 goto error2;
2655         }
2656         error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
2657         XFS_QM_DQRELE(mp, udqp);
2658         XFS_QM_DQRELE(mp, gdqp);
2659
2660         /* Fall through to std_return with error = 0 or errno from
2661          * xfs_trans_commit     */
2662 std_return:
2663         if (DM_EVENT_ENABLED(dp, DM_EVENT_POSTSYMLINK)) {
2664                 (void) XFS_SEND_NAMESP(mp, DM_EVENT_POSTSYMLINK,
2665                                         dp, DM_RIGHT_NULL,
2666                                         error ? NULL : ip,
2667                                         DM_RIGHT_NULL, link_name->name,
2668                                         target_path, 0, error, 0);
2669         }
2670
2671         if (!error)
2672                 *ipp = ip;
2673         return error;
2674
2675  error2:
2676         IRELE(ip);
2677  error1:
2678         xfs_bmap_cancel(&free_list);
2679         cancel_flags |= XFS_TRANS_ABORT;
2680  error_return:
2681         xfs_trans_cancel(tp, cancel_flags);
2682         XFS_QM_DQRELE(mp, udqp);
2683         XFS_QM_DQRELE(mp, gdqp);
2684
2685         if (unlock_dp_on_error)
2686                 xfs_iunlock(dp, XFS_ILOCK_EXCL);
2687
2688         goto std_return;
2689 }
2690
2691 int
2692 xfs_inode_flush(
2693         xfs_inode_t     *ip,
2694         int             flags)
2695 {
2696         xfs_mount_t     *mp = ip->i_mount;
2697         int             error = 0;
2698
2699         if (XFS_FORCED_SHUTDOWN(mp))
2700                 return XFS_ERROR(EIO);
2701
2702         /*
2703          * Bypass inodes which have already been cleaned by
2704          * the inode flush clustering code inside xfs_iflush
2705          */
2706         if (xfs_inode_clean(ip))
2707                 return 0;
2708
2709         /*
2710          * We make this non-blocking if the inode is contended,
2711          * return EAGAIN to indicate to the caller that they
2712          * did not succeed. This prevents the flush path from
2713          * blocking on inodes inside another operation right
2714          * now, they get caught later by xfs_sync.
2715          */
2716         if (flags & FLUSH_SYNC) {
2717                 xfs_ilock(ip, XFS_ILOCK_SHARED);
2718                 xfs_iflock(ip);
2719         } else if (xfs_ilock_nowait(ip, XFS_ILOCK_SHARED)) {
2720                 if (xfs_ipincount(ip) || !xfs_iflock_nowait(ip)) {
2721                         xfs_iunlock(ip, XFS_ILOCK_SHARED);
2722                         return EAGAIN;
2723                 }
2724         } else {
2725                 return EAGAIN;
2726         }
2727
2728         error = xfs_iflush(ip, (flags & FLUSH_SYNC) ? XFS_IFLUSH_SYNC
2729                                                     : XFS_IFLUSH_ASYNC_NOBLOCK);
2730         xfs_iunlock(ip, XFS_ILOCK_SHARED);
2731
2732         return error;
2733 }
2734
2735
2736 int
2737 xfs_set_dmattrs(
2738         xfs_inode_t     *ip,
2739         u_int           evmask,
2740         u_int16_t       state)
2741 {
2742         xfs_mount_t     *mp = ip->i_mount;
2743         xfs_trans_t     *tp;
2744         int             error;
2745
2746         if (!capable(CAP_SYS_ADMIN))
2747                 return XFS_ERROR(EPERM);
2748
2749         if (XFS_FORCED_SHUTDOWN(mp))
2750                 return XFS_ERROR(EIO);
2751
2752         tp = xfs_trans_alloc(mp, XFS_TRANS_SET_DMATTRS);
2753         error = xfs_trans_reserve(tp, 0, XFS_ICHANGE_LOG_RES (mp), 0, 0, 0);
2754         if (error) {
2755                 xfs_trans_cancel(tp, 0);
2756                 return error;
2757         }
2758         xfs_ilock(ip, XFS_ILOCK_EXCL);
2759         xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
2760
2761         ip->i_d.di_dmevmask = evmask;
2762         ip->i_d.di_dmstate  = state;
2763
2764         xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
2765         IHOLD(ip);
2766         error = xfs_trans_commit(tp, 0);
2767
2768         return error;
2769 }
2770
2771 int
2772 xfs_reclaim(
2773         xfs_inode_t     *ip)
2774 {
2775
2776         xfs_itrace_entry(ip);
2777
2778         ASSERT(!VN_MAPPED(VFS_I(ip)));
2779
2780         /* bad inode, get out here ASAP */
2781         if (VN_BAD(VFS_I(ip))) {
2782                 xfs_ireclaim(ip);
2783                 return 0;
2784         }
2785
2786         vn_iowait(ip);
2787
2788         ASSERT(XFS_FORCED_SHUTDOWN(ip->i_mount) || ip->i_delayed_blks == 0);
2789
2790         /*
2791          * Make sure the atime in the XFS inode is correct before freeing the
2792          * Linux inode.
2793          */
2794         xfs_synchronize_atime(ip);
2795
2796         /*
2797          * If we have nothing to flush with this inode then complete the
2798          * teardown now, otherwise break the link between the xfs inode and the
2799          * linux inode and clean up the xfs inode later. This avoids flushing
2800          * the inode to disk during the delete operation itself.
2801          *
2802          * When breaking the link, we need to set the XFS_IRECLAIMABLE flag
2803          * first to ensure that xfs_iunpin() will never see an xfs inode
2804          * that has a linux inode being reclaimed. Synchronisation is provided
2805          * by the i_flags_lock.
2806          */
2807         if (!ip->i_update_core && (ip->i_itemp == NULL)) {
2808                 xfs_ilock(ip, XFS_ILOCK_EXCL);
2809                 xfs_iflock(ip);
2810                 xfs_iflags_set(ip, XFS_IRECLAIMABLE);
2811                 return xfs_reclaim_inode(ip, 1, XFS_IFLUSH_DELWRI_ELSE_SYNC);
2812         }
2813         xfs_inode_set_reclaim_tag(ip);
2814         return 0;
2815 }
2816
2817 /*
2818  * xfs_alloc_file_space()
2819  *      This routine allocates disk space for the given file.
2820  *
2821  *      If alloc_type == 0, this request is for an ALLOCSP type
2822  *      request which will change the file size.  In this case, no
2823  *      DMAPI event will be generated by the call.  A TRUNCATE event
2824  *      will be generated later by xfs_setattr.
2825  *
2826  *      If alloc_type != 0, this request is for a RESVSP type
2827  *      request, and a DMAPI DM_EVENT_WRITE will be generated if the
2828  *      lower block boundary byte address is less than the file's
2829  *      length.
2830  *
2831  * RETURNS:
2832  *       0 on success
2833  *      errno on error
2834  *
2835  */
2836 STATIC int
2837 xfs_alloc_file_space(
2838         xfs_inode_t             *ip,
2839         xfs_off_t               offset,
2840         xfs_off_t               len,
2841         int                     alloc_type,
2842         int                     attr_flags)
2843 {
2844         xfs_mount_t             *mp = ip->i_mount;
2845         xfs_off_t               count;
2846         xfs_filblks_t           allocated_fsb;
2847         xfs_filblks_t           allocatesize_fsb;
2848         xfs_extlen_t            extsz, temp;
2849         xfs_fileoff_t           startoffset_fsb;
2850         xfs_fsblock_t           firstfsb;
2851         int                     nimaps;
2852         int                     bmapi_flag;
2853         int                     quota_flag;
2854         int                     rt;
2855         xfs_trans_t             *tp;
2856         xfs_bmbt_irec_t         imaps[1], *imapp;
2857         xfs_bmap_free_t         free_list;
2858         uint                    qblocks, resblks, resrtextents;
2859         int                     committed;
2860         int                     error;
2861
2862         xfs_itrace_entry(ip);
2863
2864         if (XFS_FORCED_SHUTDOWN(mp))
2865                 return XFS_ERROR(EIO);
2866
2867         if ((error = XFS_QM_DQATTACH(mp, ip, 0)))
2868                 return error;
2869
2870         if (len <= 0)
2871                 return XFS_ERROR(EINVAL);
2872
2873         rt = XFS_IS_REALTIME_INODE(ip);
2874         extsz = xfs_get_extsz_hint(ip);
2875
2876         count = len;
2877         imapp = &imaps[0];
2878         nimaps = 1;
2879         bmapi_flag = XFS_BMAPI_WRITE | (alloc_type ? XFS_BMAPI_PREALLOC : 0);
2880         startoffset_fsb = XFS_B_TO_FSBT(mp, offset);
2881         allocatesize_fsb = XFS_B_TO_FSB(mp, count);
2882
2883         /*      Generate a DMAPI event if needed.       */
2884         if (alloc_type != 0 && offset < ip->i_size &&
2885                         (attr_flags & XFS_ATTR_DMI) == 0  &&
2886                         DM_EVENT_ENABLED(ip, DM_EVENT_WRITE)) {
2887                 xfs_off_t           end_dmi_offset;
2888
2889                 end_dmi_offset = offset+len;
2890                 if (end_dmi_offset > ip->i_size)
2891                         end_dmi_offset = ip->i_size;
2892                 error = XFS_SEND_DATA(mp, DM_EVENT_WRITE, ip, offset,
2893                                       end_dmi_offset - offset, 0, NULL);
2894                 if (error)
2895                         return error;
2896         }
2897
2898         /*
2899          * Allocate file space until done or until there is an error
2900          */
2901 retry:
2902         while (allocatesize_fsb && !error) {
2903                 xfs_fileoff_t   s, e;
2904
2905                 /*
2906                  * Determine space reservations for data/realtime.
2907                  */
2908                 if (unlikely(extsz)) {
2909                         s = startoffset_fsb;
2910                         do_div(s, extsz);
2911                         s *= extsz;
2912                         e = startoffset_fsb + allocatesize_fsb;
2913                         if ((temp = do_mod(startoffset_fsb, extsz)))
2914                                 e += temp;
2915                         if ((temp = do_mod(e, extsz)))
2916                                 e += extsz - temp;
2917                 } else {
2918                         s = 0;
2919                         e = allocatesize_fsb;
2920                 }
2921
2922                 if (unlikely(rt)) {
2923                         resrtextents = qblocks = (uint)(e - s);
2924                         resrtextents /= mp->m_sb.sb_rextsize;
2925                         resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
2926                         quota_flag = XFS_QMOPT_RES_RTBLKS;
2927                 } else {
2928                         resrtextents = 0;
2929                         resblks = qblocks = \
2930                                 XFS_DIOSTRAT_SPACE_RES(mp, (uint)(e - s));
2931                         quota_flag = XFS_QMOPT_RES_REGBLKS;
2932                 }
2933
2934                 /*
2935                  * Allocate and setup the transaction.
2936                  */
2937                 tp = xfs_trans_alloc(mp, XFS_TRANS_DIOSTRAT);
2938                 error = xfs_trans_reserve(tp, resblks,
2939                                           XFS_WRITE_LOG_RES(mp), resrtextents,
2940                                           XFS_TRANS_PERM_LOG_RES,
2941                                           XFS_WRITE_LOG_COUNT);
2942                 /*
2943                  * Check for running out of space
2944                  */
2945                 if (error) {
2946                         /*
2947                          * Free the transaction structure.
2948                          */
2949                         ASSERT(error == ENOSPC || XFS_FORCED_SHUTDOWN(mp));
2950                         xfs_trans_cancel(tp, 0);
2951                         break;
2952                 }
2953                 xfs_ilock(ip, XFS_ILOCK_EXCL);
2954                 error = XFS_TRANS_RESERVE_QUOTA_NBLKS(mp, tp, ip,
2955                                                       qblocks, 0, quota_flag);
2956                 if (error)
2957                         goto error1;
2958
2959                 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
2960                 xfs_trans_ihold(tp, ip);
2961
2962                 /*
2963                  * Issue the xfs_bmapi() call to allocate the blocks
2964                  */
2965                 XFS_BMAP_INIT(&free_list, &firstfsb);
2966                 error = xfs_bmapi(tp, ip, startoffset_fsb,
2967                                   allocatesize_fsb, bmapi_flag,
2968                                   &firstfsb, 0, imapp, &nimaps,
2969                                   &free_list, NULL);
2970                 if (error) {
2971                         goto error0;
2972                 }
2973
2974                 /*
2975                  * Complete the transaction
2976                  */
2977                 error = xfs_bmap_finish(&tp, &free_list, &committed);
2978                 if (error) {
2979                         goto error0;
2980                 }
2981
2982                 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
2983                 xfs_iunlock(ip, XFS_ILOCK_EXCL);
2984                 if (error) {
2985                         break;
2986                 }
2987
2988                 allocated_fsb = imapp->br_blockcount;
2989
2990                 if (nimaps == 0) {
2991                         error = XFS_ERROR(ENOSPC);
2992                         break;
2993                 }
2994
2995                 startoffset_fsb += allocated_fsb;
2996                 allocatesize_fsb -= allocated_fsb;
2997         }
2998 dmapi_enospc_check:
2999         if (error == ENOSPC && (attr_flags & XFS_ATTR_DMI) == 0 &&
3000             DM_EVENT_ENABLED(ip, DM_EVENT_NOSPACE)) {
3001                 error = XFS_SEND_NAMESP(mp, DM_EVENT_NOSPACE,
3002                                 ip, DM_RIGHT_NULL,
3003                                 ip, DM_RIGHT_NULL,
3004                                 NULL, NULL, 0, 0, 0); /* Delay flag intentionally unused */
3005                 if (error == 0)
3006                         goto retry;     /* Maybe DMAPI app. has made space */
3007                 /* else fall through with error from XFS_SEND_DATA */
3008         }
3009
3010         return error;
3011
3012 error0: /* Cancel bmap, unlock inode, unreserve quota blocks, cancel trans */
3013         xfs_bmap_cancel(&free_list);
3014         XFS_TRANS_UNRESERVE_QUOTA_NBLKS(mp, tp, ip, qblocks, 0, quota_flag);
3015
3016 error1: /* Just cancel transaction */
3017         xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
3018         xfs_iunlock(ip, XFS_ILOCK_EXCL);
3019         goto dmapi_enospc_check;
3020 }
3021
3022 /*
3023  * Zero file bytes between startoff and endoff inclusive.
3024  * The iolock is held exclusive and no blocks are buffered.
3025  *
3026  * This function is used by xfs_free_file_space() to zero
3027  * partial blocks when the range to free is not block aligned.
3028  * When unreserving space with boundaries that are not block
3029  * aligned we round up the start and round down the end
3030  * boundaries and then use this function to zero the parts of
3031  * the blocks that got dropped during the rounding.
3032  */
3033 STATIC int
3034 xfs_zero_remaining_bytes(
3035         xfs_inode_t             *ip,
3036         xfs_off_t               startoff,
3037         xfs_off_t               endoff)
3038 {
3039         xfs_bmbt_irec_t         imap;
3040         xfs_fileoff_t           offset_fsb;
3041         xfs_off_t               lastoffset;
3042         xfs_off_t               offset;
3043         xfs_buf_t               *bp;
3044         xfs_mount_t             *mp = ip->i_mount;
3045         int                     nimap;
3046         int                     error = 0;
3047
3048         /*
3049          * Avoid doing I/O beyond eof - it's not necessary
3050          * since nothing can read beyond eof.  The space will
3051          * be zeroed when the file is extended anyway.
3052          */
3053         if (startoff >= ip->i_size)
3054                 return 0;
3055
3056         if (endoff > ip->i_size)
3057                 endoff = ip->i_size;
3058
3059         bp = xfs_buf_get_noaddr(mp->m_sb.sb_blocksize,
3060                                 XFS_IS_REALTIME_INODE(ip) ?
3061                                 mp->m_rtdev_targp : mp->m_ddev_targp);
3062
3063         for (offset = startoff; offset <= endoff; offset = lastoffset + 1) {
3064                 offset_fsb = XFS_B_TO_FSBT(mp, offset);
3065                 nimap = 1;
3066                 error = xfs_bmapi(NULL, ip, offset_fsb, 1, 0,
3067                         NULL, 0, &imap, &nimap, NULL, NULL);
3068                 if (error || nimap < 1)
3069                         break;
3070                 ASSERT(imap.br_blockcount >= 1);
3071                 ASSERT(imap.br_startoff == offset_fsb);
3072                 lastoffset = XFS_FSB_TO_B(mp, imap.br_startoff + 1) - 1;
3073                 if (lastoffset > endoff)
3074                         lastoffset = endoff;
3075                 if (imap.br_startblock == HOLESTARTBLOCK)
3076                         continue;
3077                 ASSERT(imap.br_startblock != DELAYSTARTBLOCK);
3078                 if (imap.br_state == XFS_EXT_UNWRITTEN)
3079                         continue;
3080                 XFS_BUF_UNDONE(bp);
3081                 XFS_BUF_UNWRITE(bp);
3082                 XFS_BUF_READ(bp);
3083                 XFS_BUF_SET_ADDR(bp, XFS_FSB_TO_DB(ip, imap.br_startblock));
3084                 xfsbdstrat(mp, bp);
3085                 error = xfs_iowait(bp);
3086                 if (error) {
3087                         xfs_ioerror_alert("xfs_zero_remaining_bytes(read)",
3088                                           mp, bp, XFS_BUF_ADDR(bp));
3089                         break;
3090                 }
3091                 memset(XFS_BUF_PTR(bp) +
3092                         (offset - XFS_FSB_TO_B(mp, imap.br_startoff)),
3093                       0, lastoffset - offset + 1);
3094                 XFS_BUF_UNDONE(bp);
3095                 XFS_BUF_UNREAD(bp);
3096                 XFS_BUF_WRITE(bp);
3097                 xfsbdstrat(mp, bp);
3098                 error = xfs_iowait(bp);
3099                 if (error) {
3100                         xfs_ioerror_alert("xfs_zero_remaining_bytes(write)",
3101                                           mp, bp, XFS_BUF_ADDR(bp));
3102                         break;
3103                 }
3104         }
3105         xfs_buf_free(bp);
3106         return error;
3107 }
3108
3109 /*
3110  * xfs_free_file_space()
3111  *      This routine frees disk space for the given file.
3112  *
3113  *      This routine is only called by xfs_change_file_space
3114  *      for an UNRESVSP type call.
3115  *
3116  * RETURNS:
3117  *       0 on success
3118  *      errno on error
3119  *
3120  */
3121 STATIC int
3122 xfs_free_file_space(
3123         xfs_inode_t             *ip,
3124         xfs_off_t               offset,
3125         xfs_off_t               len,
3126         int                     attr_flags)
3127 {
3128         int                     committed;
3129         int                     done;
3130         xfs_off_t               end_dmi_offset;
3131         xfs_fileoff_t           endoffset_fsb;
3132         int                     error;
3133         xfs_fsblock_t           firstfsb;
3134         xfs_bmap_free_t         free_list;
3135         xfs_bmbt_irec_t         imap;
3136         xfs_off_t               ioffset;
3137         xfs_extlen_t            mod=0;
3138         xfs_mount_t             *mp;
3139         int                     nimap;
3140         uint                    resblks;
3141         uint                    rounding;
3142         int                     rt;
3143         xfs_fileoff_t           startoffset_fsb;
3144         xfs_trans_t             *tp;
3145         int                     need_iolock = 1;
3146
3147         mp = ip->i_mount;
3148
3149         xfs_itrace_entry(ip);
3150
3151         if ((error = XFS_QM_DQATTACH(mp, ip, 0)))
3152                 return error;
3153
3154         error = 0;
3155         if (len <= 0)   /* if nothing being freed */
3156                 return error;
3157         rt = XFS_IS_REALTIME_INODE(ip);
3158         startoffset_fsb = XFS_B_TO_FSB(mp, offset);
3159         end_dmi_offset = offset + len;
3160         endoffset_fsb = XFS_B_TO_FSBT(mp, end_dmi_offset);
3161
3162         if (offset < ip->i_size && (attr_flags & XFS_ATTR_DMI) == 0 &&
3163             DM_EVENT_ENABLED(ip, DM_EVENT_WRITE)) {
3164                 if (end_dmi_offset > ip->i_size)
3165                         end_dmi_offset = ip->i_size;
3166                 error = XFS_SEND_DATA(mp, DM_EVENT_WRITE, ip,
3167                                 offset, end_dmi_offset - offset,
3168                                 AT_DELAY_FLAG(attr_flags), NULL);
3169                 if (error)
3170                         return error;
3171         }
3172
3173         if (attr_flags & XFS_ATTR_NOLOCK)
3174                 need_iolock = 0;
3175         if (need_iolock) {
3176                 xfs_ilock(ip, XFS_IOLOCK_EXCL);
3177                 vn_iowait(ip);  /* wait for the completion of any pending DIOs */
3178         }
3179
3180         rounding = max_t(uint, 1 << mp->m_sb.sb_blocklog, PAGE_CACHE_SIZE);
3181         ioffset = offset & ~(rounding - 1);
3182
3183         if (VN_CACHED(VFS_I(ip)) != 0) {
3184                 xfs_inval_cached_trace(ip, ioffset, -1, ioffset, -1);
3185                 error = xfs_flushinval_pages(ip, ioffset, -1, FI_REMAPF_LOCKED);
3186                 if (error)
3187                         goto out_unlock_iolock;
3188         }
3189
3190         /*
3191          * Need to zero the stuff we're not freeing, on disk.
3192          * If its a realtime file & can't use unwritten extents then we
3193          * actually need to zero the extent edges.  Otherwise xfs_bunmapi
3194          * will take care of it for us.
3195          */
3196         if (rt && !xfs_sb_version_hasextflgbit(&mp->m_sb)) {
3197                 nimap = 1;
3198                 error = xfs_bmapi(NULL, ip, startoffset_fsb,
3199                         1, 0, NULL, 0, &imap, &nimap, NULL, NULL);
3200                 if (error)
3201                         goto out_unlock_iolock;
3202                 ASSERT(nimap == 0 || nimap == 1);
3203                 if (nimap && imap.br_startblock != HOLESTARTBLOCK) {
3204                         xfs_daddr_t     block;
3205
3206                         ASSERT(imap.br_startblock != DELAYSTARTBLOCK);
3207                         block = imap.br_startblock;
3208                         mod = do_div(block, mp->m_sb.sb_rextsize);
3209                         if (mod)
3210                                 startoffset_fsb += mp->m_sb.sb_rextsize - mod;
3211                 }
3212                 nimap = 1;
3213                 error = xfs_bmapi(NULL, ip, endoffset_fsb - 1,
3214                         1, 0, NULL, 0, &imap, &nimap, NULL, NULL);
3215                 if (error)
3216                         goto out_unlock_iolock;
3217                 ASSERT(nimap == 0 || nimap == 1);
3218                 if (nimap && imap.br_startblock != HOLESTARTBLOCK) {
3219                         ASSERT(imap.br_startblock != DELAYSTARTBLOCK);
3220                         mod++;
3221                         if (mod && (mod != mp->m_sb.sb_rextsize))
3222                                 endoffset_fsb -= mod;
3223                 }
3224         }
3225         if ((done = (endoffset_fsb <= startoffset_fsb)))
3226                 /*
3227                  * One contiguous piece to clear
3228                  */
3229                 error = xfs_zero_remaining_bytes(ip, offset, offset + len - 1);
3230         else {
3231                 /*
3232                  * Some full blocks, possibly two pieces to clear
3233                  */
3234                 if (offset < XFS_FSB_TO_B(mp, startoffset_fsb))
3235                         error = xfs_zero_remaining_bytes(ip, offset,
3236                                 XFS_FSB_TO_B(mp, startoffset_fsb) - 1);
3237                 if (!error &&
3238                     XFS_FSB_TO_B(mp, endoffset_fsb) < offset + len)
3239                         error = xfs_zero_remaining_bytes(ip,
3240                                 XFS_FSB_TO_B(mp, endoffset_fsb),
3241                                 offset + len - 1);
3242         }
3243
3244         /*
3245          * free file space until done or until there is an error
3246          */
3247         resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
3248         while (!error && !done) {
3249
3250                 /*
3251                  * allocate and setup the transaction. Allow this
3252                  * transaction to dip into the reserve blocks to ensure
3253                  * the freeing of the space succeeds at ENOSPC.
3254                  */
3255                 tp = xfs_trans_alloc(mp, XFS_TRANS_DIOSTRAT);
3256                 tp->t_flags |= XFS_TRANS_RESERVE;
3257                 error = xfs_trans_reserve(tp,
3258                                           resblks,
3259                                           XFS_WRITE_LOG_RES(mp),
3260                                           0,
3261                                           XFS_TRANS_PERM_LOG_RES,
3262                                           XFS_WRITE_LOG_COUNT);
3263
3264                 /*
3265                  * check for running out of space
3266                  */
3267                 if (error) {
3268                         /*
3269                          * Free the transaction structure.
3270                          */
3271                         ASSERT(error == ENOSPC || XFS_FORCED_SHUTDOWN(mp));
3272                         xfs_trans_cancel(tp, 0);
3273                         break;
3274                 }
3275                 xfs_ilock(ip, XFS_ILOCK_EXCL);
3276                 error = XFS_TRANS_RESERVE_QUOTA(mp, tp,
3277                                 ip->i_udquot, ip->i_gdquot, resblks, 0,
3278                                 XFS_QMOPT_RES_REGBLKS);
3279                 if (error)
3280                         goto error1;
3281
3282                 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
3283                 xfs_trans_ihold(tp, ip);
3284
3285                 /*
3286                  * issue the bunmapi() call to free the blocks
3287                  */
3288                 XFS_BMAP_INIT(&free_list, &firstfsb);
3289                 error = xfs_bunmapi(tp, ip, startoffset_fsb,
3290                                   endoffset_fsb - startoffset_fsb,
3291                                   0, 2, &firstfsb, &free_list, NULL, &done);
3292                 if (error) {
3293                         goto error0;
3294                 }
3295
3296                 /*
3297                  * complete the transaction
3298                  */
3299                 error = xfs_bmap_finish(&tp, &free_list, &committed);
3300                 if (error) {
3301                         goto error0;
3302                 }
3303
3304                 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
3305                 xfs_iunlock(ip, XFS_ILOCK_EXCL);
3306         }
3307
3308  out_unlock_iolock:
3309         if (need_iolock)
3310                 xfs_iunlock(ip, XFS_IOLOCK_EXCL);
3311         return error;
3312
3313  error0:
3314         xfs_bmap_cancel(&free_list);
3315  error1:
3316         xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
3317         xfs_iunlock(ip, need_iolock ? (XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL) :
3318                     XFS_ILOCK_EXCL);
3319         return error;
3320 }
3321
3322 /*
3323  * xfs_change_file_space()
3324  *      This routine allocates or frees disk space for the given file.
3325  *      The user specified parameters are checked for alignment and size
3326  *      limitations.
3327  *
3328  * RETURNS:
3329  *       0 on success
3330  *      errno on error
3331  *
3332  */
3333 int
3334 xfs_change_file_space(
3335         xfs_inode_t     *ip,
3336         int             cmd,
3337         xfs_flock64_t   *bf,
3338         xfs_off_t       offset,
3339         int             attr_flags)
3340 {
3341         xfs_mount_t     *mp = ip->i_mount;
3342         int             clrprealloc;
3343         int             error;
3344         xfs_fsize_t     fsize;
3345         int             setprealloc;
3346         xfs_off_t       startoffset;
3347         xfs_off_t       llen;
3348         xfs_trans_t     *tp;
3349         struct iattr    iattr;
3350
3351         xfs_itrace_entry(ip);
3352
3353         if (!S_ISREG(ip->i_d.di_mode))
3354                 return XFS_ERROR(EINVAL);
3355
3356         switch (bf->l_whence) {
3357         case 0: /*SEEK_SET*/
3358                 break;
3359         case 1: /*SEEK_CUR*/
3360                 bf->l_start += offset;
3361                 break;
3362         case 2: /*SEEK_END*/
3363                 bf->l_start += ip->i_size;
3364                 break;
3365         default:
3366                 return XFS_ERROR(EINVAL);
3367         }
3368
3369         llen = bf->l_len > 0 ? bf->l_len - 1 : bf->l_len;
3370
3371         if (   (bf->l_start < 0)
3372             || (bf->l_start > XFS_MAXIOFFSET(mp))
3373             || (bf->l_start + llen < 0)
3374             || (bf->l_start + llen > XFS_MAXIOFFSET(mp)))
3375                 return XFS_ERROR(EINVAL);
3376
3377         bf->l_whence = 0;
3378
3379         startoffset = bf->l_start;
3380         fsize = ip->i_size;
3381
3382         /*
3383          * XFS_IOC_RESVSP and XFS_IOC_UNRESVSP will reserve or unreserve
3384          * file space.
3385          * These calls do NOT zero the data space allocated to the file,
3386          * nor do they change the file size.
3387          *
3388          * XFS_IOC_ALLOCSP and XFS_IOC_FREESP will allocate and free file
3389          * space.
3390          * These calls cause the new file data to be zeroed and the file
3391          * size to be changed.
3392          */
3393         setprealloc = clrprealloc = 0;
3394
3395         switch (cmd) {
3396         case XFS_IOC_RESVSP:
3397         case XFS_IOC_RESVSP64:
3398                 error = xfs_alloc_file_space(ip, startoffset, bf->l_len,
3399                                                                 1, attr_flags);
3400                 if (error)
3401                         return error;
3402                 setprealloc = 1;
3403                 break;
3404
3405         case XFS_IOC_UNRESVSP:
3406         case XFS_IOC_UNRESVSP64:
3407                 if ((error = xfs_free_file_space(ip, startoffset, bf->l_len,
3408                                                                 attr_flags)))
3409                         return error;
3410                 break;
3411
3412         case XFS_IOC_ALLOCSP:
3413         case XFS_IOC_ALLOCSP64:
3414         case XFS_IOC_FREESP:
3415         case XFS_IOC_FREESP64:
3416                 if (startoffset > fsize) {
3417                         error = xfs_alloc_file_space(ip, fsize,
3418                                         startoffset - fsize, 0, attr_flags);
3419                         if (error)
3420                                 break;
3421                 }
3422
3423                 iattr.ia_valid = ATTR_SIZE;
3424                 iattr.ia_size = startoffset;
3425
3426                 error = xfs_setattr(ip, &iattr, attr_flags);
3427
3428                 if (error)
3429                         return error;
3430
3431                 clrprealloc = 1;
3432                 break;
3433
3434         default:
3435                 ASSERT(0);
3436                 return XFS_ERROR(EINVAL);
3437         }
3438
3439         /*
3440          * update the inode timestamp, mode, and prealloc flag bits
3441          */
3442         tp = xfs_trans_alloc(mp, XFS_TRANS_WRITEID);
3443
3444         if ((error = xfs_trans_reserve(tp, 0, XFS_WRITEID_LOG_RES(mp),
3445                                       0, 0, 0))) {
3446                 /* ASSERT(0); */
3447                 xfs_trans_cancel(tp, 0);
3448                 return error;
3449         }
3450
3451         xfs_ilock(ip, XFS_ILOCK_EXCL);
3452
3453         xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
3454         xfs_trans_ihold(tp, ip);
3455
3456         if ((attr_flags & XFS_ATTR_DMI) == 0) {
3457                 ip->i_d.di_mode &= ~S_ISUID;
3458
3459                 /*
3460                  * Note that we don't have to worry about mandatory
3461                  * file locking being disabled here because we only
3462                  * clear the S_ISGID bit if the Group execute bit is
3463                  * on, but if it was on then mandatory locking wouldn't
3464                  * have been enabled.
3465                  */
3466                 if (ip->i_d.di_mode & S_IXGRP)
3467                         ip->i_d.di_mode &= ~S_ISGID;
3468
3469                 xfs_ichgtime(ip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
3470         }
3471         if (setprealloc)
3472                 ip->i_d.di_flags |= XFS_DIFLAG_PREALLOC;
3473         else if (clrprealloc)
3474                 ip->i_d.di_flags &= ~XFS_DIFLAG_PREALLOC;
3475
3476         xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
3477         xfs_trans_set_sync(tp);
3478
3479         error = xfs_trans_commit(tp, 0);
3480
3481         xfs_iunlock(ip, XFS_ILOCK_EXCL);
3482
3483         return error;
3484 }