| blob | 44dfac5212856567195068f9570e65f8857709c5 |
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 */
58 /*
59 * Used in xfs_itruncate(). This is the maximum number of extents
60 * freed from a file in a single transaction.
61 */
62 #define XFS_ITRUNC_MAX_EXTENTS 2
70 #ifdef DEBUG
71 /*
72 * Make sure that the extents in the given memory buffer
73 * are valid.
74 */
75 STATIC void
80 xfs_exntfmt_t fmt)
81 {
83 xfs_bmbt_irec_t irec;
84 xfs_bmbt_rec_t rec;
93 else
97 }
98 }
100 #define xfs_validate_extents(ifp, nrecs, disk, fmt)
103 /*
104 * Check that none of the inode's in the buffer have a next
105 * unlinked field of 0.
106 */
107 #if defined(DEBUG)
108 void
112 {
124 "Detected a bogus zero next_unlinked field in incore inode buffer 0x%p. About to pop an ASSERT.",
125 bp);
127 }
128 }
129 }
130 #endif
132 /*
133 * This routine is called to map an inode number within a file
134 * system to the buffer containing the on-disk version of the
135 * inode. It returns a pointer to the buffer containing the
136 * on-disk inode in the bpp parameter, and in the dip parameter
137 * it returns a pointer to the on-disk inode within that buffer.
138 *
139 * If a non-zero error is returned, then the contents of bpp and
140 * dipp are undefined.
141 *
142 * Use xfs_imap() to determine the size and location of the
143 * buffer to read from disk.
144 */
145 STATIC int
149 xfs_ino_t ino,
153 {
155 xfs_imap_t imap;
160 /*
161 * Call the space management code to find the location of the
162 * inode on disk.
163 */
168 "xfs_inotobp: xfs_imap() returned an "
171 }
173 /*
174 * If the inode number maps to a block outside the bounds of the
175 * file system then return NULL rather than calling read_buf
176 * and panicing when we get an error from the driver.
177 */
181 "xfs_inotobp: inode number (%llu + %d) maps to a block outside the bounds "
186 }
188 /*
189 * Read in the buffer. If tp is NULL, xfs_trans_read_buf() will
190 * default to just a read_buf() call.
191 */
197 "xfs_inotobp: xfs_trans_read_buf() returned an "
200 }
202 di_ok =
206 XFS_RANDOM_ITOBP_INOTOBP))) {
210 "xfs_inotobp: XFS_TEST_ERROR() returned an "
213 }
217 /*
218 * Set *dipp to point to the on-disk inode in the buffer.
219 */
224 }
227 /*
228 * This routine is called to map an inode to the buffer containing
229 * the on-disk version of the inode. It returns a pointer to the
230 * buffer containing the on-disk inode in the bpp parameter, and in
231 * the dip parameter it returns a pointer to the on-disk inode within
232 * that buffer.
233 *
234 * If a non-zero error is returned, then the contents of bpp and
235 * dipp are undefined.
236 *
237 * If the inode is new and has not yet been initialized, use xfs_imap()
238 * to determine the size and location of the buffer to read from disk.
239 * If the inode has already been mapped to its buffer and read in once,
240 * then use the mapping information stored in the inode rather than
241 * calling xfs_imap(). This allows us to avoid the overhead of looking
242 * at the inode btree for small block file systems (see xfs_dilocate()).
243 * We can tell whether the inode has been mapped in before by comparing
244 * its disk block address to 0. Only uninitialized inodes will have
245 * 0 for the disk block address.
246 */
247 int
254 xfs_daddr_t bno,
255 uint imap_flags)
256 {
257 xfs_imap_t imap;
264 /*
265 * Call the space management code to find the location of the
266 * inode on disk.
267 */
273 /*
274 * If the inode number maps to a block outside the bounds
275 * of the file system then return NULL rather than calling
276 * read_buf and panicing when we get an error from the
277 * driver.
278 */
281 #ifdef DEBUG
283 "(imap.im_blkno (0x%llx) "
284 "+ imap.im_len (0x%llx)) > "
285 " XFS_FSB_TO_BB(mp, "
292 }
294 /*
295 * Fill in the fields in the inode that will be used to
296 * map the inode to its buffer from now on.
297 */
302 /*
303 * We've already mapped the inode once, so just use the
304 * mapping that we saved the first time.
305 */
309 }
312 /*
313 * Read in the buffer. If tp is NULL, xfs_trans_read_buf() will
314 * default to just a read_buf() call.
315 */
319 #ifdef DEBUG
321 "xfs_trans_read_buf() returned error %d, "
327 }
329 /*
330 * Validate the magic number and version of every inode in the buffer
331 * (if DEBUG kernel) or the first inode in the buffer, otherwise.
332 * No validation is done here in userspace (xfs_repair).
333 */
334 #if !defined(__KERNEL__)
336 #elif defined(DEBUG)
340 #endif
351 XFS_ERRTAG_ITOBP_INOTOBP,
352 XFS_RANDOM_ITOBP_INOTOBP))) {
356 }
357 #ifdef DEBUG
359 "Device %s - bad inode magic/vsn "
364 #endif
369 }
370 }
374 /*
375 * Mark the buffer as an inode buffer now that it looks good
376 */
379 /*
380 * Set *dipp to point to the on-disk inode in the buffer.
381 */
385 }
387 /*
388 * Move inode type and inode format specific information from the
389 * on-disk inode to the in-core inode. For fifos, devs, and sockets
390 * this means set if_rdev to the proper value. For files, directories,
391 * and symlinks this means to bring in the in-line data or extent
392 * pointers. For a file in B-tree format, only the root is immediately
393 * brought in-core. The rest will be in-lined in if_extents when it
394 * is first referenced (see xfs_iread_extents()).
395 */
396 STATIC int
400 {
404 xfs_fsize_t di_size;
423 }
425 if (unlikely(INT_GET(dip->di_core.di_forkoff, ARCH_CONVERT) > ip->i_mount->m_sb.sb_inodesize)) {
433 }
444 }
454 /*
455 * no local regular files yet
456 */
459 "corrupt inode %Lu "
463 XFS_ERRLEVEL_LOW,
466 }
471 "corrupt inode %Lu "
476 XFS_ERRLEVEL_LOW,
479 }
494 }
500 }
503 }
525 }
530 }
532 }
534 /*
535 * The file is in-lined in the on-disk inode.
536 * If it fits into if_inline_data, then copy
537 * it there, otherwise allocate a buffer for it
538 * and copy the data there. Either way, set
539 * if_data to point at the data.
540 * If we allocate a buffer for the data, make
541 * sure that its size is a multiple of 4 and
542 * record the real size in i_real_bytes.
543 */
544 STATIC int
550 {
554 /*
555 * If the size is unreasonable, then something
556 * is wrong and we just bail out rather than crash in
557 * kmem_alloc() or memcpy() below.
558 */
561 "corrupt inode %Lu "
568 }
578 }
586 }
588 /*
589 * The file consists of a set of extents all
590 * of which fit into the on-disk inode.
591 * If there are few enough extents to fit into
592 * the if_inline_ext, then copy them there.
593 * Otherwise allocate a buffer for them and copy
594 * them into it. Either way, set if_extents
595 * to point at the extents.
596 */
597 STATIC int
602 {
613 /*
614 * If the number of extents is unreasonable, then something
615 * is wrong and we just bail out rather than crash in
616 * kmem_alloc() or memcpy() below.
617 */
625 }
632 else
642 ARCH_CONVERT);
644 ARCH_CONVERT);
645 }
647 whichfork);
653 XFS_ERRLEVEL_LOW,
656 }
657 }
660 }
662 /*
663 * The file has too many extents to fit into
664 * the inode, so they are in B-tree format.
665 * Allocate a buffer for the root of the B-tree
666 * and copy the root into it. The i_extents
667 * field will remain NULL until all of the
668 * extents are read in (when they are needed).
669 */
670 STATIC int
675 {
678 /* REFERENCED */
687 /*
688 * blow out if -- fork has less extents than can fit in
689 * fork (fork shouldn't be a btree format), root btree
690 * block has more records than can fit into the fork,
691 * or the number of extents is greater than the number of
692 * blocks.
693 */
704 }
709 /*
710 * Copy and convert from the on-disk structure
711 * to the in-memory structure.
712 */
719 }
721 /*
722 * xfs_xlate_dinode_core - translate an xfs_inode_core_t between ondisk
723 * and native format
724 *
725 * buf = on-disk representation
726 * dip = native representation
727 * dir = direction - +ve -> disk to native
728 * -ve -> native to disk
729 */
730 void
732 xfs_caddr_t buf,
735 {
758 }
785 }
787 STATIC uint
789 __uint16_t di_flags)
790 {
820 }
823 }
825 uint
828 {
833 }
835 uint
838 {
841 }
843 /*
844 * Given a mount structure and an inode number, return a pointer
845 * to a newly allocated in-core inode corresponding to the given
846 * inode number.
847 *
848 * Initialize the inode's attributes and extent pointers if it
849 * already has them (it will not if the inode has no links).
850 */
851 int
855 xfs_ino_t ino,
857 xfs_daddr_t bno,
858 uint imap_flags)
859 {
872 /*
873 * Get pointer's to the on-disk inode and the buffer containing it.
874 * If the inode number refers to a block outside the file system
875 * then xfs_itobp() will return NULL. In this case we should
876 * return NULL as well. Set i_blkno to 0 so that xfs_itobp() will
877 * know that this is a new incore inode.
878 */
883 }
885 /*
886 * Initialize inode's trace buffers.
887 * Do this before xfs_iformat in case it adds entries.
888 */
889 #ifdef XFS_BMAP_TRACE
891 #endif
892 #ifdef XFS_BMBT_TRACE
894 #endif
895 #ifdef XFS_RW_TRACE
897 #endif
898 #ifdef XFS_ILOCK_TRACE
900 #endif
901 #ifdef XFS_DIR2_TRACE
903 #endif
905 /*
906 * If we got something that isn't an inode it means someone
907 * (nfs or dmi) has a stale handle.
908 */
912 #ifdef DEBUG
914 "dip->di_core.di_magic (0x%x) != "
917 XFS_DINODE_MAGIC);
920 }
922 /*
923 * If the on-disk inode is already linked to a directory
924 * entry, copy all of the inode into the in-core inode.
925 * xfs_iformat() handles copying in the inode format
926 * specific information.
927 * Otherwise, just get the truly permanent information.
928 */
936 #ifdef DEBUG
939 error);
942 }
948 /*
949 * Make sure to pull in the mode here as well in
950 * case the inode is released without being used.
951 * This ensures that xfs_inactive() will see that
952 * the inode is already free and not try to mess
953 * with the uninitialized part of it.
954 */
956 /*
957 * Initialize the per-fork minima and maxima for a new
958 * inode here. xfs_iformat will do it for old inodes.
959 */
962 }
966 /*
967 * The inode format changed when we moved the link count and
968 * made it 32 bits long. If this is an old format inode,
969 * convert it in memory to look like a new one. If it gets
970 * flushed to disk we will convert back before flushing or
971 * logging it. We zero out the new projid field and the old link
972 * count field. We'll handle clearing the pad field (the remains
973 * of the old uuid field) when we actually convert the inode to
974 * the new format. We don't change the version number so that we
975 * can distinguish this from a real new format inode.
976 */
981 }
985 /*
986 * Mark the buffer containing the inode as something to keep
987 * around for a while. This helps to keep recently accessed
988 * meta-data in-core longer.
989 */
992 /*
993 * Use xfs_trans_brelse() to release the buffer containing the
994 * on-disk inode, because it was acquired with xfs_trans_read_buf()
995 * in xfs_itobp() above. If tp is NULL, this is just a normal
996 * brelse(). If we're within a transaction, then xfs_trans_brelse()
997 * will only release the buffer if it is not dirty within the
998 * transaction. It will be OK to release the buffer in this case,
999 * because inodes on disk are never destroyed and we will be
1000 * locking the new in-core inode before putting it in the hash
1001 * table where other processes can find it. Thus we don't have
1002 * to worry about the inode being changed just because we released
1003 * the buffer.
1004 */
1008 }
1010 /*
1011 * Read in extents from a btree-format inode.
1012 * Allocate and fill in if_extents. Real work is done in xfs_bmap.c.
1013 */
1014 int
1019 {
1022 xfs_extnum_t nextents;
1029 }
1034 /*
1035 * We know that the size is valid (it's checked in iformat_btree)
1036 */
1046 }
1049 }
1051 /*
1052 * Allocate an inode on disk and return a copy of its in-core version.
1053 * The in-core inode is locked exclusively. Set mode, nlink, and rdev
1054 * appropriately within the inode. The uid and gid for the inode are
1055 * set according to the contents of the given cred structure.
1056 *
1057 * Use xfs_dialloc() to allocate the on-disk inode. If xfs_dialloc()
1058 * has a free inode available, call xfs_iget()
1059 * to obtain the in-core version of the allocated inode. Finally,
1060 * fill in the inode and log its initial contents. In this case,
1061 * ialloc_context would be set to NULL and call_again set to false.
1062 *
1063 * If xfs_dialloc() does not have an available inode,
1064 * it will replenish its supply by doing an allocation. Since we can
1065 * only do one allocation within a transaction without deadlocks, we
1066 * must commit the current transaction before returning the inode itself.
1067 * In this case, therefore, we will set call_again to true and return.
1068 * The caller should then commit the current transaction, start a new
1069 * transaction, and call xfs_ialloc() again to actually get the inode.
1070 *
1071 * To ensure that some other process does not grab the inode that
1072 * was allocated during the first call to xfs_ialloc(), this routine
1073 * also returns the [locked] bp pointing to the head of the freelist
1074 * as ialloc_context. The caller should hold this buffer across
1075 * the commit and pass it back into this routine on the second call.
1076 */
1077 int
1081 mode_t mode,
1082 xfs_nlink_t nlink,
1083 xfs_dev_t rdev,
1085 xfs_prid_t prid,
1090 {
1091 xfs_ino_t ino;
1094 uint flags;
1097 /*
1098 * Call the space management code to pick
1099 * the on-disk inode to be allocated.
1100 */
1105 }
1109 }
1112 /*
1113 * Get the in-core inode with the lock held exclusively.
1114 * This is because we're setting fields here we need
1115 * to prevent others from looking at until we're done.
1116 */
1121 }
1134 /*
1135 * If the superblock version is up to where we support new format
1136 * inodes and this is currently an old format inode, then change
1137 * the inode version number now. This way we only do the conversion
1138 * here rather than here and in the flush/logging code.
1139 */
1143 /*
1144 * We've already zeroed the old link count, the projid field,
1145 * and the pad field.
1146 */
1147 }
1149 /*
1150 * Project ids won't be stored on disk if we are using a version 1 inode.
1151 */
1159 }
1160 }
1162 /*
1163 * If the group ID of the new file does not match the effective group
1164 * ID or one of the supplementary group IDs, the S_ISGID bit is cleared
1165 * (and only if the irix_sgid_inherit compatibility variable is set).
1166 */
1171 }
1177 /*
1178 * di_gen will have been taken care of in xfs_iread.
1179 */
1206 }
1211 }
1215 }
1216 }
1218 xfs_inherit_noatime)
1221 xfs_inherit_nodump)
1224 xfs_inherit_sync)
1227 xfs_inherit_nosymlinks)
1232 xfs_inherit_nodefrag)
1235 }
1236 /* FALLTHROUGH */
1245 }
1246 /*
1247 * Attribute fork settings for new inode.
1248 */
1252 /*
1253 * Log the new values stuffed into the inode.
1254 */
1257 /* now that we have an i_mode we can setup inode ops and unlock */
1262 }
1264 /*
1265 * Check to make sure that there are no blocks allocated to the
1266 * file beyond the size of the file. We don't check this for
1267 * files with fixed size extents or real time extents, but we
1268 * at least do it for regular files.
1269 */
1270 #ifdef DEBUG
1271 void
1275 xfs_fsize_t isize)
1276 {
1277 xfs_fileoff_t map_first;
1289 /*
1290 * The filesystem could be shutting down, so bmapi may return
1291 * an error.
1292 */
1296 map_first),
1302 }
1305 /*
1306 * Calculate the last possible buffered byte in a file. This must
1307 * include data that was buffered beyond the EOF by the write code.
1308 * This also needs to deal with overflowing the xfs_fsize_t type
1309 * which can happen for sizes near the limit.
1310 *
1311 * We also need to take into account any blocks beyond the EOF. It
1312 * may be the case that they were buffered by a write which failed.
1313 * In that case the pages will still be in memory, but the inode size
1314 * will never have been updated.
1315 */
1316 xfs_fsize_t
1319 {
1321 xfs_fsize_t last_byte;
1322 xfs_fileoff_t last_block;
1323 xfs_fileoff_t size_last_block;
1329 /*
1330 * Only check for blocks beyond the EOF if the extents have
1331 * been read in. This eliminates the need for the inode lock,
1332 * and it also saves us from looking when it really isn't
1333 * necessary.
1334 */
1337 XFS_DATA_FORK);
1340 }
1343 }
1350 }
1354 }
1356 }
1358 #if defined(XFS_RW_TRACE)
1359 STATIC void
1364 xfs_fsize_t new_size,
1365 xfs_off_t toss_start,
1366 xfs_off_t toss_finish)
1367 {
1370 }
1389 }
1390 #else
1391 #define xfs_itrunc_trace(tag, ip, flag, new_size, toss_start, toss_finish)
1392 #endif
1394 /*
1395 * Start the truncation of the file to new_size. The new size
1396 * must be smaller than the current size. This routine will
1397 * clear the buffer and page caches of file data in the removed
1398 * range, and xfs_itruncate_finish() will remove the underlying
1399 * disk blocks.
1400 *
1401 * The inode must have its I/O lock locked EXCLUSIVELY, and it
1402 * must NOT have the inode lock held at all. This is because we're
1403 * calling into the buffer/page cache code and we can't hold the
1404 * inode lock when we do so.
1405 *
1406 * We need to wait for any direct I/Os in flight to complete before we
1407 * proceed with the truncate. This is needed to prevent the extents
1408 * being read or written by the direct I/Os from being removed while the
1409 * I/O is in flight as there is no other method of synchronising
1410 * direct I/O with the truncate operation. Also, because we hold
1411 * the IOLOCK in exclusive mode, we prevent new direct I/Os from being
1412 * started until the truncate completes and drops the lock. Essentially,
1413 * the vn_iowait() call forms an I/O barrier that provides strict ordering
1414 * between direct I/Os and the truncate operation.
1415 *
1416 * The flags parameter can have either the value XFS_ITRUNC_DEFINITE
1417 * or XFS_ITRUNC_MAYBE. The XFS_ITRUNC_MAYBE value should be used
1418 * in the case that the caller is locking things out of order and
1419 * may not be able to call xfs_itruncate_finish() with the inode lock
1420 * held without dropping the I/O lock. If the caller must drop the
1421 * I/O lock before calling xfs_itruncate_finish(), then xfs_itruncate_start()
1422 * must be called again with all the same restrictions as the initial
1423 * call.
1424 */
1425 void
1428 uint flags,
1429 xfs_fsize_t new_size)
1430 {
1431 xfs_fsize_t last_byte;
1432 xfs_off_t toss_start;
1446 /*
1447 * Call toss_pages or flushinval_pages to get rid of pages
1448 * overlapping the region being removed. We have to use
1449 * the less efficient flushinval_pages in the case that the
1450 * caller may not be able to finish the truncate without
1451 * dropping the inode's I/O lock. Make sure
1452 * to catch any pages brought in by buffers overlapping
1453 * the EOF by searching out beyond the isize by our
1454 * block size. We round new_size up to a block boundary
1455 * so that we don't toss things on the same block as
1456 * new_size but before it.
1457 *
1458 * Before calling toss_page or flushinval_pages, make sure to
1459 * call remapf() over the same region if the file is mapped.
1460 * This frees up mapped file references to the pages in the
1461 * given range and for the flushinval_pages case it ensures
1462 * that we get the latest mapped changes flushed out.
1463 */
1467 /*
1468 * The place to start tossing is beyond our maximum
1469 * file size, so there is no way that the data extended
1470 * out there.
1471 */
1473 }
1476 last_byte);
1482 }
1483 }
1485 #ifdef DEBUG
1488 }
1489 #endif
1490 }
1492 /*
1493 * Shrink the file to the given new_size. The new
1494 * size must be smaller than the current size.
1495 * This will free up the underlying blocks
1496 * in the removed range after a call to xfs_itruncate_start()
1497 * or xfs_atruncate_start().
1498 *
1499 * The transaction passed to this routine must have made
1500 * a permanent log reservation of at least XFS_ITRUNCATE_LOG_RES.
1501 * This routine may commit the given transaction and
1502 * start new ones, so make sure everything involved in
1503 * the transaction is tidy before calling here.
1504 * Some transaction will be returned to the caller to be
1505 * committed. The incoming transaction must already include
1506 * the inode, and both inode locks must be held exclusively.
1507 * The inode must also be "held" within the transaction. On
1508 * return the inode will be "held" within the returned transaction.
1509 * This routine does NOT require any disk space to be reserved
1510 * for it within the transaction.
1511 *
1512 * The fork parameter must be either xfs_attr_fork or xfs_data_fork,
1513 * and it indicates the fork which is to be truncated. For the
1514 * attribute fork we only support truncation to size 0.
1515 *
1516 * We use the sync parameter to indicate whether or not the first
1517 * transaction we perform might have to be synchronous. For the attr fork,
1518 * it needs to be so if the unlink of the inode is not yet known to be
1519 * permanent in the log. This keeps us from freeing and reusing the
1520 * blocks of the attribute fork before the unlink of the inode becomes
1521 * permanent.
1522 *
1523 * For the data fork, we normally have to run synchronously if we're
1524 * being called out of the inactive path or we're being called
1525 * out of the create path where we're truncating an existing file.
1526 * Either way, the truncate needs to be sync so blocks don't reappear
1527 * in the file with altered data in case of a crash. wsync filesystems
1528 * can run the first case async because anything that shrinks the inode
1529 * has to run sync so by the time we're called here from inactive, the
1530 * inode size is permanently set to 0.
1531 *
1532 * Calls from the truncate path always need to be sync unless we're
1533 * in a wsync filesystem and the file has already been unlinked.
1534 *
1535 * The caller is responsible for correctly setting the sync parameter.
1536 * It gets too hard for us to guess here which path we're being called
1537 * out of just based on inode state.
1538 */
1539 int
1543 xfs_fsize_t new_size,
1546 {
1547 xfs_fsblock_t first_block;
1548 xfs_fileoff_t first_unmap_block;
1549 xfs_fileoff_t last_block;
1555 xfs_bmap_free_t free_list;
1572 /*
1573 * We only support truncating the entire attribute fork.
1574 */
1577 }
1580 /*
1581 * The first thing we do is set the size to new_size permanently
1582 * on disk. This way we don't have to worry about anyone ever
1583 * being able to look at the data being freed even in the face
1584 * of a crash. What we're getting around here is the case where
1585 * we free a block, it is allocated to another file, it is written
1586 * to, and then we crash. If the new data gets written to the
1587 * file but the log buffers containing the free and reallocation
1588 * don't, then we'd end up with garbage in the blocks being freed.
1589 * As long as we make the new_size permanent before actually
1590 * freeing any blocks it doesn't matter if they get writtten to.
1591 *
1592 * The callers must signal into us whether or not the size
1593 * setting here must be synchronous. There are a few cases
1594 * where it doesn't have to be synchronous. Those cases
1595 * occur if the file is unlinked and we know the unlink is
1596 * permanent or if the blocks being truncated are guaranteed
1597 * to be beyond the inode eof (regardless of the link count)
1598 * and the eof value is permanent. Both of these cases occur
1599 * only on wsync-mounted filesystems. In those cases, we're
1600 * guaranteed that no user will ever see the data in the blocks
1601 * that are being truncated so the truncate can run async.
1602 * In the free beyond eof case, the file may wind up with
1603 * more blocks allocated to it than it needs if we crash
1604 * and that won't get fixed until the next time the file
1605 * is re-opened and closed but that's ok as that shouldn't
1606 * be too many blocks.
1607 *
1608 * However, we can't just make all wsync xactions run async
1609 * because there's one call out of the create path that needs
1610 * to run sync where it's truncating an existing file to size
1611 * 0 whose size is > 0.
1612 *
1613 * It's probably possible to come up with a test in this
1614 * routine that would correctly distinguish all the above
1615 * cases from the values of the function parameters and the
1616 * inode state but for sanity's sake, I've decided to let the
1617 * layers above just tell us. It's simpler to correctly figure
1618 * out in the layer above exactly under what conditions we
1619 * can run async and I think it's easier for others read and
1620 * follow the logic in case something has to be changed.
1621 * cscope is your friend -- rcc.
1622 *
1623 * The attribute fork is much simpler.
1624 *
1625 * For the attribute fork we allow the caller to tell us whether
1626 * the unlink of the inode that led to this call is yet permanent
1627 * in the on disk log. If it is not and we will be freeing extents
1628 * in this inode then we make the first transaction synchronous
1629 * to make sure that the unlink is permanent by the time we free
1630 * the blocks.
1631 */
1636 }
1641 }
1647 /*
1648 * Since it is possible for space to become allocated beyond
1649 * the end of the file (in a crash where the space is allocated
1650 * but the inode size is not yet updated), simply remove any
1651 * blocks which show up between the new EOF and the maximum
1652 * possible file size. If the first block to be removed is
1653 * beyond the maximum file size (ie it is the same as last_block),
1654 * then there is nothing to do.
1655 */
1663 }
1665 /*
1666 * Free up up to XFS_ITRUNC_MAX_EXTENTS. xfs_bunmapi()
1667 * will tell us whether it freed the entire range or
1668 * not. If this is a synchronous mount (wsync),
1669 * then we can tell bunmapi to keep all the
1670 * transactions asynchronous since the unlink
1671 * transaction that made this inode inactive has
1672 * already hit the disk. There's no danger of
1673 * the freed blocks being reused, there being a
1674 * crash, and the reused blocks suddenly reappearing
1675 * in this file with garbage in them once recovery
1676 * runs.
1677 */
1683 XFS_ITRUNC_MAX_EXTENTS,
1687 /*
1688 * If the bunmapi call encounters an error,
1689 * return to the caller where the transaction
1690 * can be properly aborted. We just need to
1691 * make sure we're not holding any resources
1692 * that we were not when we came in.
1693 */
1696 }
1698 /*
1699 * Duplicate the transaction that has the permanent
1700 * reservation and commit the old transaction.
1701 */
1706 /*
1707 * If the bmap finish call encounters an error,
1708 * return to the caller where the transaction
1709 * can be properly aborted. We just need to
1710 * make sure we're not holding any resources
1711 * that we were not when we came in.
1712 *
1713 * Aborting from this point might lose some
1714 * blocks in the file system, but oh well.
1715 */
1718 /*
1719 * If the passed in transaction committed
1720 * in xfs_bmap_finish(), then we want to
1721 * add the inode to this one before returning.
1722 * This keeps things simple for the higher
1723 * level code, because it always knows that
1724 * the inode is locked and held in the
1725 * transaction that returns to it whether
1726 * errors occur or not. We don't mark the
1727 * inode dirty so that this transaction can
1728 * be easily aborted if possible.
1729 */
1733 }
1735 }
1738 /*
1739 * The first xact was committed,
1740 * so add the inode to the new one.
1741 * Mark it dirty so it will be logged
1742 * and moved forward in the log as
1743 * part of every commit.
1744 */
1749 }
1754 XFS_TRANS_PERM_LOG_RES,
1755 XFS_ITRUNCATE_LOG_COUNT);
1756 /*
1757 * Add the inode being truncated to the next chained
1758 * transaction.
1759 */
1764 }
1765 /*
1766 * Only update the size in the case of the data fork, but
1767 * always re-log the inode so that our permanent transaction
1768 * can keep on rolling it forward in the log.
1769 */
1773 }
1783 }
1786 /*
1787 * xfs_igrow_start
1788 *
1789 * Do the first part of growing a file: zero any data in the last
1790 * block that is beyond the old EOF. We need to do this before
1791 * the inode is joined to the transaction to modify the i_size.
1792 * That way we can drop the inode lock and call into the buffer
1793 * cache to get the buffer mapping the EOF.
1794 */
1795 int
1798 xfs_fsize_t new_size,
1800 {
1807 /*
1808 * Zero any pages that may have been created by
1809 * xfs_write_file() beyond the end of the file
1810 * and any blocks between the old and new file sizes.
1811 */
1815 }
1817 /*
1818 * xfs_igrow_finish
1819 *
1820 * This routine is called to extend the size of a file.
1821 * The inode must have both the iolock and the ilock locked
1822 * for update and it must be a part of the current transaction.
1823 * The xfs_igrow_start() function must have been called previously.
1824 * If the change_flag is not zero, the inode change timestamp will
1825 * be updated.
1826 */
1827 void
1831 xfs_fsize_t new_size,
1833 {
1839 /*
1840 * Update the file size. Update the inode change timestamp
1841 * if change_flag set.
1842 */
1848 }
1851 /*
1852 * This is called when the inode's link count goes to 0.
1853 * We place the on-disk inode on a list in the AGI. It
1854 * will be pulled from this list when the inode is freed.
1855 */
1856 int
1860 {
1866 xfs_agnumber_t agno;
1867 xfs_daddr_t agdaddr;
1868 xfs_agino_t agino;
1883 /*
1884 * Get the agi buffer first. It ensures lock ordering
1885 * on the list.
1886 */
1891 }
1892 /*
1893 * Validate the magic number of the agi block.
1894 */
1896 agi_ok =
1900 XFS_RANDOM_IUNLINK))) {
1904 }
1905 /*
1906 * Get the index into the agi hash table for the
1907 * list this inode will go on.
1908 */
1916 /*
1917 * There is already another inode in the bucket we need
1918 * to add ourselves to. Add us at the front of the list.
1919 * Here we put the head pointer into our next pointer,
1920 * and then we fall through to point the head at us.
1921 */
1925 }
1928 /* both on-disk, don't endian flip twice */
1936 }
1938 /*
1939 * Point the bucket head pointer at the inode being inserted.
1940 */
1948 }
1950 /*
1951 * Pull the on-disk inode from the AGI unlinked list.
1952 */
1953 STATIC int
1957 {
1958 xfs_ino_t next_ino;
1964 xfs_agnumber_t agno;
1965 xfs_daddr_t agdaddr;
1966 xfs_agino_t agino;
1967 xfs_agino_t next_agino;
1975 /*
1976 * First pull the on-disk inode from the AGI unlinked list.
1977 */
1983 /*
1984 * Get the agi buffer first. It ensures lock ordering
1985 * on the list.
1986 */
1994 }
1995 /*
1996 * Validate the magic number of the agi block.
1997 */
1999 agi_ok =
2003 XFS_RANDOM_IUNLINK_REMOVE))) {
2011 }
2012 /*
2013 * Get the index into the agi hash table for the
2014 * list this inode will go on.
2015 */
2023 /*
2024 * We're at the head of the list. Get the inode's
2025 * on-disk buffer to see if there is anyone after us
2026 * on the list. Only modify our next pointer if it
2027 * is not already NULLAGINO. This saves us the overhead
2028 * of dealing with the buffer when there is no need to
2029 * change it.
2030 */
2037 }
2050 }
2051 /*
2052 * Point the bucket head pointer at the next inode.
2053 */
2062 /*
2063 * We need to search the list for the inode being freed.
2064 */
2068 /*
2069 * If the last inode wasn't the one pointing to
2070 * us, then release its buffer since we're not
2071 * going to do anything with it.
2072 */
2075 }
2084 }
2088 }
2089 /*
2090 * Now last_ibp points to the buffer previous to us on
2091 * the unlinked list. Pull us from the list.
2092 */
2099 }
2113 }
2114 /*
2115 * Point the previous inode on the list to the next inode.
2116 */
2124 }
2126 }
2129 {
2133 }
2135 STATIC void
2139 xfs_ino_t inum)
2140 {
2146 xfs_daddr_t blkno;
2163 }
2172 /*
2173 * Look for each inode in memory and attempt to lock it,
2174 * we can be racing with flush and tail pushing here.
2175 * any inode we get the locks on, add to an array of
2176 * inode items to process later.
2177 *
2178 * The get the buffer lock, we could beat a flush
2179 * or tail pushing thread to the lock here, in which
2180 * case they will go looking for the inode buffer
2181 * and fail, we need some other form of interlock
2182 * here.
2183 */
2191 }
2193 /* Inode not in memory or we found it already,
2194 * nothing to do
2195 */
2199 }
2204 }
2206 /* If we can get the locks then add it to the
2207 * list, otherwise by the time we get the bp lock
2208 * below it will already be attached to the
2209 * inode buffer.
2210 */
2212 /* This inode will already be locked - by us, lets
2213 * keep it that way.
2214 */
2223 }
2224 }
2227 }
2238 }
2241 }
2242 }
2245 }
2249 XFS_BUF_LOCK);
2262 pre_flushed++;
2263 }
2265 }
2276 }
2290 }
2291 }
2296 }
2299 }
2301 /*
2302 * This is called to return an inode to the inode free list.
2303 * The inode should already be truncated to 0 length and have
2304 * no pages associated with it. This routine also assumes that
2305 * the inode is already a part of the transaction.
2306 *
2307 * The on-disk copy of the inode will have been added to the list
2308 * of unlinked inodes in the AGI. We need to remove the inode from
2309 * that list atomically with respect to freeing it here.
2310 */
2311 int
2316 {
2319 xfs_ino_t first_ino;
2330 /*
2331 * Pull the on-disk inode from the AGI unlinked list.
2332 */
2336 }
2341 }
2350 /*
2351 * Bump the generation count so no one will be confused
2352 * by reincarnations of this inode.
2353 */
2359 }
2362 }
2364 /*
2365 * Reallocate the space for if_broot based on the number of records
2366 * being added or deleted as indicated in rec_diff. Move the records
2367 * and pointers in if_broot to fit the new size. When shrinking this
2368 * will eliminate holes between the records and pointers created by
2369 * the caller. When growing this will create holes to be filled in
2370 * by the caller.
2371 *
2372 * The caller must not request to add more records than would fit in
2373 * the on-disk inode root. If the if_broot is currently NULL, then
2374 * if we adding records one will be allocated. The caller must also
2375 * not request that the number of records go below zero, although
2376 * it can go to zero.
2377 *
2378 * ip -- the inode whose if_broot area is changing
2379 * ext_diff -- the change in the number of records, positive or negative,
2380 * requested for the if_broot array.
2381 */
2382 void
2387 {
2396 /*
2397 * Handle the degenerate case quietly.
2398 */
2401 }
2405 /*
2406 * If there wasn't any memory allocated before, just
2407 * allocate it now and get out.
2408 */
2412 KM_SLEEP);
2415 }
2417 /*
2418 * If there is already an existing if_broot, then we need
2419 * to realloc() it and shift the pointers to their new
2420 * location. The records don't change location because
2421 * they are kept butted up against the btree block header.
2422 */
2428 new_size,
2430 KM_SLEEP);
2440 }
2442 /*
2443 * rec_diff is less than 0. In this case, we are shrinking the
2444 * if_broot buffer. It must already exist. If we go to zero
2445 * records, just get rid of the root and clear the status bit.
2446 */
2453 else
2457 /*
2458 * First copy over the btree block header.
2459 */
2464 }
2466 /*
2467 * Only copy the records and pointers if there are any.
2468 */
2470 /*
2471 * First copy the records.
2472 */
2479 /*
2480 * Then copy the pointers.
2481 */
2487 }
2494 }
2497 /*
2498 * This is called when the amount of space needed for if_data
2499 * is increased or decreased. The change in size is indicated by
2500 * the number of bytes that need to be added or deleted in the
2501 * byte_diff parameter.
2502 *
2503 * If the amount of space needed has decreased below the size of the
2504 * inline buffer, then switch to using the inline buffer. Otherwise,
2505 * use kmem_realloc() or kmem_alloc() to adjust the size of the buffer
2506 * to what is needed.
2507 *
2508 * ip -- the inode whose if_data area is changing
2509 * byte_diff -- the change in the number of bytes, positive or negative,
2510 * requested for the if_data array.
2511 */
2512 void
2517 {
2524 }
2533 }
2537 /*
2538 * If the valid extents/data can fit in if_inline_ext/data,
2539 * copy them from the malloc'd vector and free it.
2540 */
2546 new_size);
2549 }
2552 /*
2553 * Stuck with malloc/realloc.
2554 * For inline data, the underlying buffer must be
2555 * a multiple of 4 bytes in size so that it can be
2556 * logged and stay on word boundaries. We enforce
2557 * that here.
2558 */
2564 /*
2565 * Only do the realloc if the underlying size
2566 * is really changing.
2567 */
2571 real_size,
2573 KM_SLEEP);
2574 }
2580 }
2581 }
2585 }
2590 /*
2591 * Map inode to disk block and offset.
2592 *
2593 * mp -- the mount point structure for the current file system
2594 * tp -- the current transaction
2595 * ino -- the inode number of the inode to be located
2596 * imap -- this structure is filled in with the information necessary
2597 * to retrieve the given inode from disk
2598 * flags -- flags to pass to xfs_dilocate indicating whether or not
2599 * lookups in the inode btree were OK or not
2600 */
2601 int
2605 xfs_ino_t ino,
2607 uint flags)
2608 {
2609 xfs_fsblock_t fsbno;
2619 }
2626 }
2628 void
2632 {
2639 }
2641 /*
2642 * If the format is local, then we can't have an extents
2643 * array so just look for an inline data array. If we're
2644 * not local then we may or may not have an extents list,
2645 * so check and free it up if we do.
2646 */
2654 }
2661 }
2668 }
2669 }
2671 /*
2672 * This is called free all the memory associated with an inode.
2673 * It must free the inode itself and any buffers allocated for
2674 * if_extents/if_data and if_broot. It must also free the lock
2675 * associated with the inode.
2676 */
2677 void
2680 {
2688 }
2694 #ifdef XFS_BMAP_TRACE
2696 #endif
2697 #ifdef XFS_BMBT_TRACE
2699 #endif
2700 #ifdef XFS_RW_TRACE
2702 #endif
2703 #ifdef XFS_ILOCK_TRACE
2705 #endif
2706 #ifdef XFS_DIR2_TRACE
2708 #endif
2710 /* XXXdpd should be able to assert this but shutdown
2711 * is leaving the AIL behind. */
2715 }
2717 }
2720 /*
2721 * Increment the pin count of the given buffer.
2722 * This value is protected by ipinlock spinlock in the mount structure.
2723 */
2724 void
2727 {
2731 }
2733 /*
2734 * Decrement the pin count of the given inode, and wake up
2735 * anyone in xfs_iwait_unpin() if the count goes to 0. The
2736 * inode must have been previously pinned with a call to xfs_ipin().
2737 */
2738 void
2741 {
2746 /*
2747 * If the inode is currently being reclaimed, the link between
2748 * the bhv_vnode and the xfs_inode will be broken after the
2749 * XFS_IRECLAIM* flag is set. Hence, if these flags are not
2750 * set, then we can move forward and mark the linux inode dirty
2751 * knowing that it is still valid as it won't freed until after
2752 * the bhv_vnode<->xfs_inode link is broken in xfs_reclaim. The
2753 * i_flags_lock is used to synchronise the setting of the
2754 * XFS_IRECLAIM* flags and the breaking of the link, and so we
2755 * can execute atomically w.r.t to reclaim by holding this lock
2756 * here.
2757 *
2758 * However, we still need to issue the unpin wakeup call as the
2759 * inode reclaim may be blocked waiting for the inode to become
2760 * unpinned.
2761 */
2771 /* make sync come back and flush this inode */
2774 }
2777 }
2778 }
2780 /*
2781 * This is called to wait for the given inode to be unpinned.
2782 * It will sleep until this happens. The caller must have the
2783 * inode locked in at least shared mode so that the buffer cannot
2784 * be subsequently pinned once someone is waiting for it to be
2785 * unpinned.
2786 */
2787 STATIC void
2790 {
2792 xfs_lsn_t lsn;
2798 }
2805 }
2807 /*
2808 * Give the log a push so we don't wait here too long.
2809 */
2813 }
2816 /*
2817 * xfs_iextents_copy()
2818 *
2819 * This is called to copy the REAL extents (as opposed to the delayed
2820 * allocation extents) from the inode into the given buffer. It
2821 * returns the number of bytes copied into the buffer.
2822 *
2823 * If there are no delayed allocation extents, then we can just
2824 * memcpy() the extents into the buffer. Otherwise, we need to
2825 * examine each extent in turn and skip those which are delayed.
2826 */
2827 int
2832 {
2836 #ifdef XFS_BMAP_TRACE
2838 #endif
2842 xfs_fsblock_t start_block;
2852 /*
2853 * There are some delayed allocation extents in the
2854 * inode, so copy the extents one at a time and skip
2855 * the delayed ones. There must be at least one
2856 * non-delayed extent.
2857 */
2864 /*
2865 * It's a delayed allocation extent, so skip it.
2866 */
2868 }
2870 /* Translate to on disk format */
2875 dest_ep++;
2876 copied++;
2877 }
2882 }
2884 /*
2885 * Each of the following cases stores data into the same region
2886 * of the on-disk inode, so only one of them can be valid at
2887 * any given time. While it is possible to have conflicting formats
2888 * and log flags, e.g. having XFS_ILOG_?DATA set when the fork is
2889 * in EXTENTS format, this can only happen when the fork has
2890 * changed formats after being modified but before being flushed.
2891 * In these cases, the format always takes precedence, because the
2892 * format indicates the current state of the fork.
2893 */
2894 /*ARGSUSED*/
2895 STATIC int
2902 {
2906 #ifdef XFS_TRANS_DEBUG
2908 #endif
2919 /*
2920 * This can happen if we gave up in iformat in an error path,
2921 * for the attribute fork.
2922 */
2926 }
2936 }
2950 whichfork);
2951 }
2960 XFS_BROOT_SIZE_ADJ));
2964 }
2971 }
2979 }
2985 }
2988 }
2990 /*
2991 * xfs_iflush() will write a modified inode's changes out to the
2992 * inode's on disk home. The caller must have the inode lock held
2993 * in at least shared mode and the inode flush semaphore must be
2994 * held as well. The inode lock will still be held upon return from
2995 * the call and the caller is free to unlock it.
2996 * The inode flush lock will be unlocked when the inode reaches the disk.
2997 * The flags indicate how the inode's buffer should be written out.
2998 */
2999 int
3002 uint flags)
3003 {
3009 /* REFERENCED */
3027 /*
3028 * If the inode isn't dirty, then just release the inode
3029 * flush lock and do nothing.
3030 */
3037 }
3039 /*
3040 * We can't flush the inode until it is unpinned, so
3041 * wait for it. We know noone new can pin it, because
3042 * we are holding the inode lock shared and you need
3043 * to hold it exclusively to pin the inode.
3044 */
3047 /*
3048 * This may have been unpinned because the filesystem is shutting
3049 * down forcibly. If that's the case we must not write this inode
3050 * to disk, because the log record didn't make it to disk!
3051 */
3058 }
3060 /*
3061 * Get the buffer containing the on-disk inode.
3062 */
3067 }
3069 /*
3070 * Decide how buffer will be flushed out. This is done before
3071 * the call to xfs_iflush_int because this field is zeroed by it.
3072 */
3074 /*
3075 * Flush out the inode buffer according to the directions
3076 * of the caller. In the cases where the caller has given
3077 * us a choice choose the non-delwri case. This is because
3078 * the inode is in the AIL and we need to get it out soon.
3079 */
3096 }
3114 }
3115 }
3117 /*
3118 * First flush out the inode that xfs_iflush was called with.
3119 */
3123 }
3125 /*
3126 * inode clustering:
3127 * see if other inodes can be gathered into this write
3128 */
3137 /*
3138 * Do an un-protected check to see if the inode is dirty and
3139 * is a candidate for flushing. These checks will be repeated
3140 * later after the appropriate locks are acquired.
3141 */
3148 }
3150 /*
3151 * Try to get locks. If any are unavailable,
3152 * then this inode cannot be flushed and is skipped.
3153 */
3155 /* get inode locks (just i_lock) */
3157 /* get inode flush lock */
3159 /* check if pinned */
3161 /* arriving here means that
3162 * this inode can be flushed.
3163 * first re-check that it's
3164 * dirty
3165 */
3170 clcount++;
3174 XFS_ILOCK_SHARED);
3176 }
3179 }
3182 }
3183 }
3185 }
3186 }
3192 }
3194 /*
3195 * If the buffer is pinned then push on the log so we won't
3196 * get stuck waiting in the write for too long.
3197 */
3200 }
3208 }
3211 corrupt_out:
3215 /*
3216 * Unlocks the flush lock
3217 */
3220 cluster_corrupt_out:
3221 /* Corruption detected in the clustering loop. Invalidate the
3222 * inode buffer and shut down the filesystem.
3223 */
3226 /*
3227 * Clean up the buffer. If it was B_DELWRI, just release it --
3228 * brelse can handle it with no problems. If not, shut down the
3229 * filesystem before releasing the buffer.
3230 */
3233 }
3238 /*
3239 * Just like incore_relse: if we have b_iodone functions,
3240 * mark the buffer as an error and call them. Otherwise
3241 * mark it as stale and brelse.
3242 */
3253 }
3254 }
3257 /*
3258 * Unlocks the flush lock
3259 */
3261 }
3264 STATIC int
3268 {
3272 #ifdef XFS_TRANS_DEBUG
3274 #endif
3286 /*
3287 * If the inode isn't dirty, then just release the inode
3288 * flush lock and do nothing.
3289 */
3294 }
3296 /* set *dip = inode's place in the buffer */
3299 /*
3300 * Clear i_update_core before copying out the data.
3301 * This is for coordination with our timestamp updates
3302 * that don't hold the inode lock. They will always
3303 * update the timestamps BEFORE setting i_update_core,
3304 * so if we clear i_update_core after they set it we
3305 * are guaranteed to see their updates to the timestamps.
3306 * I believe that this depends on strongly ordered memory
3307 * semantics, but we have that. We use the SYNCHRONIZE
3308 * macro to make sure that the compiler does not reorder
3309 * the i_update_core access below the data copy below.
3310 */
3314 /*
3315 * Make sure to get the latest atime from the Linux inode.
3316 */
3325 }
3332 }
3342 }
3353 }
3354 }
3357 XFS_RANDOM_IFLUSH_5)) {
3363 ip);
3365 }
3372 }
3373 /*
3374 * bump the flush iteration count, used to detect flushes which
3375 * postdate a log record during recovery.
3376 */
3380 /*
3381 * Copy the dirty parts of the inode into the on-disk
3382 * inode. We always copy out the core of the inode,
3383 * because if the inode is dirty at all the core must
3384 * be.
3385 */
3388 /* Wrap, we never let the log put out DI_MAX_FLUSH */
3392 /*
3393 * If this is really an old format inode and the superblock version
3394 * has not been updated to support only new format inodes, then
3395 * convert back to the old inode format. If the superblock version
3396 * has been updated, then make the conversion permanent.
3397 */
3402 /*
3403 * Convert it back.
3404 */
3408 /*
3409 * The superblock version has already been bumped,
3410 * so just make the conversion to the new inode
3411 * format permanent.
3412 */
3421 }
3422 }
3426 }
3429 /*
3430 * The only error from xfs_iflush_fork is on the data fork.
3431 */
3433 }
3436 /*
3437 * We've recorded everything logged in the inode, so we'd
3438 * like to clear the ilf_fields bits so we don't log and
3439 * flush things unnecessarily. However, we can't stop
3440 * logging all this information until the data we've copied
3441 * into the disk buffer is written to disk. If we did we might
3442 * overwrite the copy of the inode in the log with all the
3443 * data after re-logging only part of it, and in the face of
3444 * a crash we wouldn't have all the data we need to recover.
3445 *
3446 * What we do is move the bits to the ili_last_fields field.
3447 * When logging the inode, these bits are moved back to the
3448 * ilf_fields field. In the xfs_iflush_done() routine we
3449 * clear ili_last_fields, since we know that the information
3450 * those bits represent is permanently on disk. As long as
3451 * the flush completes before the inode is logged again, then
3452 * both ilf_fields and ili_last_fields will be cleared.
3453 *
3454 * We can play with the ilf_fields bits here, because the inode
3455 * lock must be held exclusively in order to set bits there
3456 * and the flush lock protects the ili_last_fields bits.
3457 * Set ili_logged so the flush done
3458 * routine can tell whether or not to look in the AIL.
3459 * Also, store the current LSN of the inode so that we can tell
3460 * whether the item has moved in the AIL from xfs_iflush_done().
3461 * In order to read the lsn we need the AIL lock, because
3462 * it is a 64 bit value that cannot be read atomically.
3463 */
3474 /*
3475 * Attach the function xfs_iflush_done to the inode's
3476 * buffer. This will remove the inode from the AIL
3477 * and unlock the inode's flush lock when the inode is
3478 * completely written to disk.
3479 */
3486 /*
3487 * We're flushing an inode which is not in the AIL and has
3488 * not been logged but has i_update_core set. For this
3489 * case we can use a B_DELWRI flush and immediately drop
3490 * the inode flush lock because we can avoid the whole
3491 * AIL state thing. It's OK to drop the flush lock now,
3492 * because we've already locked the buffer and to do anything
3493 * you really need both.
3494 */
3499 }
3501 }
3505 corrupt_out:
3507 }
3510 /*
3511 * Flush all inactive inodes in mp.
3512 */
3513 void
3516 {
3520 again:
3527 /* Make sure we skip markers inserted by sync */
3531 }
3538 }
3544 out:
3546 }
3548 /*
3549 * xfs_iaccess: check accessibility of inode for mode.
3550 */
3551 int
3554 mode_t mode,
3556 {
3570 }
3572 /*
3573 * If there's an Access Control List it's used instead of
3574 * the mode bits.
3575 */
3583 }
3585 /*
3586 * If the DACs are ok we don't need any capability check.
3587 */
3590 /*
3591 * Read/write DACs are always overridable.
3592 * Executable DACs are overridable if at least one exec bit is set.
3593 */
3603 #ifdef NOISE
3607 }
3609 }
3611 /*
3612 * xfs_iroundup: round up argument to next power of two
3613 */
3614 uint
3616 uint v)
3617 {
3619 uint m;
3632 }
3635 }
3637 #ifdef XFS_ILOCK_TRACE
3640 void
3642 {
3651 }
3652 #endif
3654 /*
3655 * Return a pointer to the extent record at file index idx.
3656 */
3657 xfs_bmbt_rec_t *
3661 {
3676 }
3677 }
3679 /*
3680 * Insert new item(s) into the extent records for incore inode
3681 * fork 'ifp'. 'count' new items are inserted at index 'idx'.
3682 */
3683 void
3689 {
3698 }
3699 }
3701 /*
3702 * This is called when the amount of space required for incore file
3703 * extents needs to be increased. The ext_diff parameter stores the
3704 * number of new extents being added and the idx parameter contains
3705 * the extent index where the new extents will be added. If the new
3706 * extents are being appended, then we just need to (re)allocate and
3707 * initialize the space. Otherwise, if the new extents are being
3708 * inserted into the middle of the existing entries, a bit more work
3709 * is required to make room for the new extents to be inserted. The
3710 * caller is responsible for filling in the new extent entries upon
3711 * return.
3712 */
3713 void
3718 {
3727 /*
3728 * If the new number of extents (nextents + ext_diff)
3729 * fits inside the inode, then continue to use the inline
3730 * extent buffer.
3731 */
3738 }
3742 }
3743 /*
3744 * Otherwise use a linear (direct) extent list.
3745 * If the extents are currently inside the inode,
3746 * xfs_iext_realloc_direct will switch us from
3747 * inline to direct extent allocation mode.
3748 */
3756 }
3757 }
3758 /* Indirection array */
3771 }
3772 /* Extents fit in target extent page */
3780 }
3783 }
3784 /* Insert a new extent page */
3788 }
3789 /*
3790 * If extent(s) are being appended to the last page in
3791 * the indirection array and the new extent(s) don't fit
3792 * in the page, then erp is NULL and erp_idx is set to
3793 * the next index needed in the indirection array.
3794 */
3803 erp_idx++;
3804 }
3805 }
3806 }
3807 }
3809 }
3811 /*
3812 * This is called when incore extents are being added to the indirection
3813 * array and the new extents do not fit in the target extent list. The
3814 * erp_idx parameter contains the irec index for the target extent list
3815 * in the indirection array, and the idx parameter contains the extent
3816 * index within the list. The number of extents being added is stored
3817 * in the count parameter.
3818 *
3819 * |-------| |-------|
3820 * | | | | idx - number of extents before idx
3821 * | idx | | count |
3822 * | | | | count - number of extents being inserted at idx
3823 * |-------| |-------|
3824 * | count | | nex2 | nex2 - number of extents after idx + count
3825 * |-------| |-------|
3826 */
3827 void
3833 {
3847 /*
3848 * Save second part of target extent list
3849 * (all extents past */
3857 }
3859 /*
3860 * Add the new extents to the end of the target
3861 * list, then allocate new irec record(s) and
3862 * extent buffer(s) as needed to store the rest
3863 * of the new extents.
3864 */
3871 }
3873 erp_idx++;
3879 }
3881 /* Add nex2 extents back to indirection array */
3883 xfs_extnum_t ext_avail;
3889 /*
3890 * If nex2 extents fit in the current page, append
3891 * nex2_ep after the new extents.
3892 */
3895 }
3896 /*
3897 * Otherwise, check if space is available in the
3898 * next page.
3899 */
3903 erp_idx++;
3904 erp++;
3905 /* Create a hole for nex2 extents */
3908 }
3909 /*
3910 * Final choice, create a new extent page for
3911 * nex2 extents.
3912 */
3914 erp_idx++;
3916 }
3921 }
3922 }
3924 /*
3925 * This is called when the amount of space required for incore file
3926 * extents needs to be decreased. The ext_diff parameter stores the
3927 * number of extents to be removed and the idx parameter contains
3928 * the extent index where the extents will be removed from.
3929 *
3930 * If the amount of space needed has decreased below the linear
3931 * limit, XFS_IEXT_BUFSZ, then switch to using the contiguous
3932 * extent array. Otherwise, use kmem_realloc() to adjust the
3933 * size to what is needed.
3934 */
3935 void
3940 {
3956 }
3958 }
3960 /*
3961 * This removes ext_diff extents from the inline buffer, beginning
3962 * at extent index idx.
3963 */
3964 void
3969 {
3988 }
3989 }
3991 /*
3992 * This removes ext_diff extents from a linear (direct) extent list,
3993 * beginning at extent index idx. If the extents are being removed
3994 * from the end of the list (ie. truncate) then we just need to re-
3995 * allocate the list to remove the extra space. Otherwise, if the
3996 * extents are being removed from the middle of the existing extent
3997 * entries, then we first need to move the extent records beginning
3998 * at idx + ext_diff up in the list to overwrite the records being
3999 * removed, then remove the extra space via kmem_realloc.
4000 */
4001 void
4006 {
4018 }
4019 /* Move extents up in the list (if needed) */
4025 }
4028 /*
4029 * Reallocate the direct extent list. If the extents
4030 * will fit inside the inode then xfs_iext_realloc_direct
4031 * will switch from direct to inline extent allocation
4032 * mode for us.
4033 */
4036 }
4038 /*
4039 * This is called when incore extents are being removed from the
4040 * indirection array and the extents being removed span multiple extent
4041 * buffers. The idx parameter contains the file extent index where we
4042 * want to begin removing extents, and the count parameter contains
4043 * how many extents need to be removed.
4044 *
4045 * |-------| |-------|
4046 * | nex1 | | | nex1 - number of extents before idx
4047 * |-------| | count |
4048 * | | | | count - number of extents being removed at idx
4049 * | count | |-------|
4050 * | | | nex2 | nex2 - number of extents after idx + count
4051 * |-------| |-------|
4052 */
4053 void
4058 {
4077 /*
4078 * Check for deletion of entire list;
4079 * xfs_iext_irec_remove() updates extent offsets.
4080 */
4087 XFS_IEXT_BUFSZ);
4093 }
4094 }
4095 /* Move extents up (if needed) */
4100 }
4101 /* Zero out rest of page */
4104 /* Update remaining counters */
4109 erp_idx++;
4110 erp++;
4111 }
4114 }
4116 /*
4117 * Create, destroy, or resize a linear (direct) block of extents.
4118 */
4119 void
4123 {
4132 /* Free extent records */
4135 }
4136 /* Resize direct extent list and zero any new bytes */
4138 /* Check if extents will fit inside the inode */
4144 }
4147 }
4151 rnew_size,
4153 KM_SLEEP);
4154 }
4159 }
4160 }
4161 /*
4162 * Switch from the inline extent buffer to a direct
4163 * extent list. Be sure to include the inline extent
4164 * bytes in new_size.
4165 */
4170 }
4172 }
4175 }
4177 /*
4178 * Switch from linear (direct) extent records to inline buffer.
4179 */
4180 void
4184 {
4187 /*
4188 * The inline buffer was zeroed when we switched
4189 * from inline to direct extent allocation mode,
4190 * so we don't need to clear it here.
4191 */
4197 }
4199 /*
4200 * Switch from inline buffer to linear (direct) extent records.
4201 * new_size should already be rounded up to the next power of 2
4202 * by the caller (when appropriate), so use new_size as it is.
4203 * However, since new_size may be rounded up, we can't update
4204 * if_bytes here. It is the caller's responsibility to update
4205 * if_bytes upon return.
4206 */
4207 void
4211 {
4220 }
4222 }
4224 /*
4225 * Resize an extent indirection array to new_size bytes.
4226 */
4227 void
4231 {
4246 }
4247 }
4249 /*
4250 * Switch from indirection array to linear (direct) extent allocations.
4251 */
4252 void
4255 {
4275 }
4276 }
4278 /*
4279 * Free incore file extents.
4280 */
4281 void
4284 {
4292 }
4299 }
4303 }
4305 /*
4306 * Return a pointer to the extent record for file system block bno.
4307 */
4313 {
4328 }
4331 /* Find target extent list */
4339 }
4340 /* Binary search extent records */
4351 /* Convert back to file-based extent index */
4354 }
4357 }
4358 }
4359 /* Convert back to file-based extent index */
4362 }
4368 }
4369 }
4372 }
4374 /*
4375 * Return a pointer to the indirection array entry containing the
4376 * extent record for filesystem block bno. Store the index of the
4377 * target irec in *erp_idxp.
4378 */
4384 {
4408 }
4409 }
4412 }
4414 /*
4415 * Return a pointer to the indirection array entry containing the
4416 * extent record at file extent index *idxp. Store the index of the
4417 * target irec in *erp_idxp and store the page index of the target
4418 * extent record in *idxp.
4419 */
4420 xfs_ext_irec_t *
4426 {
4443 /* Binary search extent irec's */
4459 erp_idx++;
4465 }
4466 }
4470 }
4472 /*
4473 * Allocate and initialize an indirection array once the space needed
4474 * for incore extents increases above XFS_IEXT_BUFSZ.
4475 */
4476 void
4479 {
4497 }
4508 }
4510 /*
4511 * Allocate and initialize a new entry in the indirection array.
4512 */
4513 xfs_ext_irec_t *
4517 {
4525 /* Resize indirection array */
4528 /*
4529 * Move records down in the array so the
4530 * new page can use erp_idx.
4531 */
4535 }
4538 /* Initialize new extent record */
4548 }
4550 /*
4551 * Remove a record from the indirection array.
4552 */
4553 void
4557 {
4569 }
4570 /* Compact extent records */
4574 }
4575 /*
4576 * Manually free the last extent record from the indirection
4577 * array. A call to xfs_iext_realloc_indirect() with a size
4578 * of zero would result in a call to xfs_iext_destroy() which
4579 * would in turn call this function again, creating a nasty
4580 * infinite loop.
4581 */
4588 }
4590 }
4592 /*
4593 * This is called to clean up large amounts of unused memory allocated
4594 * by the indirection array. Before compacting anything though, verify
4595 * that the indirection array is still needed and switch back to the
4596 * linear extent list (or even the inline buffer) if possible. The
4597 * compaction policy is as follows:
4598 *
4599 * Full Compaction: Extents fit into a single page (or inline buffer)
4600 * Full Compaction: Extents occupy less than 10% of allocated space
4601 * Partial Compaction: Extents occupy > 10% and < 50% of allocated space
4602 * No Compaction: Extents occupy at least 50% of allocated space
4603 */
4604 void
4607 {
4626 }
4627 }
4629 /*
4630 * Combine extents from neighboring extent pages.
4631 */
4632 void
4635 {
4651 /*
4652 * Free page before removing extent record
4653 * so er_extoffs don't get modified in
4654 * xfs_iext_irec_remove.
4655 */
4661 erp_idx++;
4662 }
4663 }
4664 }
4666 /*
4667 * Fully compact the extent records managed by the indirection array.
4668 */
4669 void
4672 {
4692 /* Remove next page */
4694 /*
4695 * Free page before removing extent record
4696 * so er_extoffs don't get modified in
4697 * xfs_iext_irec_remove.
4698 */
4705 /* Update next page */
4707 /* Move rest of page up to become next new page */
4714 }
4716 erp_idx++;
4719 else
4721 }
4725 }
4726 }
4728 /*
4729 * This is called to update the er_extoff field in the indirection
4730 * array when extents have been added or removed from one of the
4731 * extent lists. erp_idx contains the irec index to begin updating
4732 * at and ext_diff contains the number of extents that were added
4733 * or removed.
4734 */
4735 void
4740 {
4748 }
4749 }