| blob | e569bf5d6cf0d9509356e93aef781048202c669b |
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 #include <linux/log2.h>
59 /*
60 * Used in xfs_itruncate(). This is the maximum number of extents
61 * freed from a file in a single transaction.
62 */
63 #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
79 xfs_exntfmt_t fmt)
80 {
81 xfs_bmbt_irec_t irec;
82 xfs_bmbt_rec_host_t rec;
92 }
93 }
95 #define xfs_validate_extents(ifp, nrecs, fmt)
98 /*
99 * Check that none of the inode's in the buffer have a next
100 * unlinked field of 0.
101 */
102 #if defined(DEBUG)
103 void
107 {
119 "Detected a bogus zero next_unlinked field in incore inode buffer 0x%p. About to pop an ASSERT.",
120 bp);
122 }
123 }
124 }
125 #endif
127 /*
128 * Find the buffer associated with the given inode map
129 * We do basic validation checks on the buffer once it has been
130 * retrieved from disk.
131 */
132 STATIC int
138 uint buf_flags,
139 uint imap_flags)
140 {
151 "xfs_imap_to_bp: xfs_trans_read_buf()returned "
156 }
158 }
160 /*
161 * Validate the magic number and version of every inode in the buffer
162 * (if DEBUG kernel) or the first inode in the buffer, otherwise.
163 */
164 #ifdef DEBUG
168 #endif
179 XFS_ERRTAG_ITOBP_INOTOBP,
180 XFS_RANDOM_ITOBP_INOTOBP))) {
184 }
187 #ifdef DEBUG
189 "Device %s - bad inode magic/vsn "
194 #endif
197 }
198 }
202 /*
203 * Mark the buffer as an inode buffer now that it looks good
204 */
209 }
211 /*
212 * This routine is called to map an inode number within a file
213 * system to the buffer containing the on-disk version of the
214 * inode. It returns a pointer to the buffer containing the
215 * on-disk inode in the bpp parameter, and in the dip parameter
216 * it returns a pointer to the on-disk inode within that buffer.
217 *
218 * If a non-zero error is returned, then the contents of bpp and
219 * dipp are undefined.
220 *
221 * Use xfs_imap() to determine the size and location of the
222 * buffer to read from disk.
223 */
224 STATIC int
228 xfs_ino_t ino,
232 {
233 xfs_imap_t imap;
250 }
253 /*
254 * This routine is called to map an inode to the buffer containing
255 * the on-disk version of the inode. It returns a pointer to the
256 * buffer containing the on-disk inode in the bpp parameter, and in
257 * the dip parameter it returns a pointer to the on-disk inode within
258 * that buffer.
259 *
260 * If a non-zero error is returned, then the contents of bpp and
261 * dipp are undefined.
262 *
263 * If the inode is new and has not yet been initialized, use xfs_imap()
264 * to determine the size and location of the buffer to read from disk.
265 * If the inode has already been mapped to its buffer and read in once,
266 * then use the mapping information stored in the inode rather than
267 * calling xfs_imap(). This allows us to avoid the overhead of looking
268 * at the inode btree for small block file systems (see xfs_dilocate()).
269 * We can tell whether the inode has been mapped in before by comparing
270 * its disk block address to 0. Only uninitialized inodes will have
271 * 0 for the disk block address.
272 */
273 int
280 xfs_daddr_t bno,
281 uint imap_flags,
282 uint buf_flags)
283 {
284 xfs_imap_t imap;
295 /*
296 * Fill in the fields in the inode that will be used to
297 * map the inode to its buffer from now on.
298 */
303 /*
304 * We've already mapped the inode once, so just use the
305 * mapping that we saved the first time.
306 */
310 }
322 }
327 }
329 /*
330 * Move inode type and inode format specific information from the
331 * on-disk inode to the in-core inode. For fifos, devs, and sockets
332 * this means set if_rdev to the proper value. For files, directories,
333 * and symlinks this means to bring in the in-line data or extent
334 * pointers. For a file in B-tree format, only the root is immediately
335 * brought in-core. The rest will be in-lined in if_extents when it
336 * is first referenced (see xfs_iread_extents()).
337 */
338 STATIC int
342 {
346 xfs_fsize_t di_size;
364 }
374 }
385 }
396 /*
397 * no local regular files yet
398 */
401 "corrupt inode %Lu "
405 XFS_ERRLEVEL_LOW,
408 }
413 "corrupt inode %Lu "
418 XFS_ERRLEVEL_LOW,
421 }
436 }
442 }
445 }
467 }
472 }
474 }
476 /*
477 * The file is in-lined in the on-disk inode.
478 * If it fits into if_inline_data, then copy
479 * it there, otherwise allocate a buffer for it
480 * and copy the data there. Either way, set
481 * if_data to point at the data.
482 * If we allocate a buffer for the data, make
483 * sure that its size is a multiple of 4 and
484 * record the real size in i_real_bytes.
485 */
486 STATIC int
492 {
496 /*
497 * If the size is unreasonable, then something
498 * is wrong and we just bail out rather than crash in
499 * kmem_alloc() or memcpy() below.
500 */
503 "corrupt inode %Lu "
510 }
520 }
528 }
530 /*
531 * The file consists of a set of extents all
532 * of which fit into the on-disk inode.
533 * If there are few enough extents to fit into
534 * the if_inline_ext, then copy them there.
535 * Otherwise allocate a buffer for them and copy
536 * them into it. Either way, set if_extents
537 * to point at the extents.
538 */
539 STATIC int
544 {
555 /*
556 * If the number of extents is unreasonable, then something
557 * is wrong and we just bail out rather than crash in
558 * kmem_alloc() or memcpy() below.
559 */
567 }
574 else
585 }
592 XFS_ERRLEVEL_LOW,
595 }
596 }
599 }
601 /*
602 * The file has too many extents to fit into
603 * the inode, so they are in B-tree format.
604 * Allocate a buffer for the root of the B-tree
605 * and copy the root into it. The i_extents
606 * field will remain NULL until all of the
607 * extents are read in (when they are needed).
608 */
609 STATIC int
614 {
617 /* REFERENCED */
626 /*
627 * blow out if -- fork has less extents than can fit in
628 * fork (fork shouldn't be a btree format), root btree
629 * block has more records than can fit into the fork,
630 * or the number of extents is greater than the number of
631 * blocks.
632 */
643 }
648 /*
649 * Copy and convert from the on-disk structure
650 * to the in-memory structure.
651 */
658 }
660 void
664 {
693 }
695 void
699 {
728 }
730 STATIC uint
732 __uint16_t di_flags)
733 {
765 }
768 }
770 uint
773 {
778 }
780 uint
783 {
788 }
790 /*
791 * Given a mount structure and an inode number, return a pointer
792 * to a newly allocated in-core inode corresponding to the given
793 * inode number.
794 *
795 * Initialize the inode's attributes and extent pointers if it
796 * already has them (it will not if the inode has no links).
797 */
798 int
802 xfs_ino_t ino,
804 xfs_daddr_t bno,
805 uint imap_flags)
806 {
820 /*
821 * Get pointer's to the on-disk inode and the buffer containing it.
822 * If the inode number refers to a block outside the file system
823 * then xfs_itobp() will return NULL. In this case we should
824 * return NULL as well. Set i_blkno to 0 so that xfs_itobp() will
825 * know that this is a new incore inode.
826 */
831 }
833 /*
834 * Initialize inode's trace buffers.
835 * Do this before xfs_iformat in case it adds entries.
836 */
837 #ifdef XFS_INODE_TRACE
839 #endif
840 #ifdef XFS_BMAP_TRACE
842 #endif
843 #ifdef XFS_BMBT_TRACE
845 #endif
846 #ifdef XFS_RW_TRACE
848 #endif
849 #ifdef XFS_ILOCK_TRACE
851 #endif
852 #ifdef XFS_DIR2_TRACE
854 #endif
856 /*
857 * If we got something that isn't an inode it means someone
858 * (nfs or dmi) has a stale handle.
859 */
863 #ifdef DEBUG
865 "dip->di_core.di_magic (0x%x) != "
868 XFS_DINODE_MAGIC);
871 }
873 /*
874 * If the on-disk inode is already linked to a directory
875 * entry, copy all of the inode into the in-core inode.
876 * xfs_iformat() handles copying in the inode format
877 * specific information.
878 * Otherwise, just get the truly permanent information.
879 */
886 #ifdef DEBUG
889 error);
892 }
898 /*
899 * Make sure to pull in the mode here as well in
900 * case the inode is released without being used.
901 * This ensures that xfs_inactive() will see that
902 * the inode is already free and not try to mess
903 * with the uninitialized part of it.
904 */
906 /*
907 * Initialize the per-fork minima and maxima for a new
908 * inode here. xfs_iformat will do it for old inodes.
909 */
912 }
916 /*
917 * The inode format changed when we moved the link count and
918 * made it 32 bits long. If this is an old format inode,
919 * convert it in memory to look like a new one. If it gets
920 * flushed to disk we will convert back before flushing or
921 * logging it. We zero out the new projid field and the old link
922 * count field. We'll handle clearing the pad field (the remains
923 * of the old uuid field) when we actually convert the inode to
924 * the new format. We don't change the version number so that we
925 * can distinguish this from a real new format inode.
926 */
931 }
936 /*
937 * Mark the buffer containing the inode as something to keep
938 * around for a while. This helps to keep recently accessed
939 * meta-data in-core longer.
940 */
943 /*
944 * Use xfs_trans_brelse() to release the buffer containing the
945 * on-disk inode, because it was acquired with xfs_trans_read_buf()
946 * in xfs_itobp() above. If tp is NULL, this is just a normal
947 * brelse(). If we're within a transaction, then xfs_trans_brelse()
948 * will only release the buffer if it is not dirty within the
949 * transaction. It will be OK to release the buffer in this case,
950 * because inodes on disk are never destroyed and we will be
951 * locking the new in-core inode before putting it in the hash
952 * table where other processes can find it. Thus we don't have
953 * to worry about the inode being changed just because we released
954 * the buffer.
955 */
959 }
961 /*
962 * Read in extents from a btree-format inode.
963 * Allocate and fill in if_extents. Real work is done in xfs_bmap.c.
964 */
965 int
970 {
973 xfs_extnum_t nextents;
980 }
985 /*
986 * We know that the size is valid (it's checked in iformat_btree)
987 */
997 }
1000 }
1002 /*
1003 * Allocate an inode on disk and return a copy of its in-core version.
1004 * The in-core inode is locked exclusively. Set mode, nlink, and rdev
1005 * appropriately within the inode. The uid and gid for the inode are
1006 * set according to the contents of the given cred structure.
1007 *
1008 * Use xfs_dialloc() to allocate the on-disk inode. If xfs_dialloc()
1009 * has a free inode available, call xfs_iget()
1010 * to obtain the in-core version of the allocated inode. Finally,
1011 * fill in the inode and log its initial contents. In this case,
1012 * ialloc_context would be set to NULL and call_again set to false.
1013 *
1014 * If xfs_dialloc() does not have an available inode,
1015 * it will replenish its supply by doing an allocation. Since we can
1016 * only do one allocation within a transaction without deadlocks, we
1017 * must commit the current transaction before returning the inode itself.
1018 * In this case, therefore, we will set call_again to true and return.
1019 * The caller should then commit the current transaction, start a new
1020 * transaction, and call xfs_ialloc() again to actually get the inode.
1021 *
1022 * To ensure that some other process does not grab the inode that
1023 * was allocated during the first call to xfs_ialloc(), this routine
1024 * also returns the [locked] bp pointing to the head of the freelist
1025 * as ialloc_context. The caller should hold this buffer across
1026 * the commit and pass it back into this routine on the second call.
1027 *
1028 * If we are allocating quota inodes, we do not have a parent inode
1029 * to attach to or associate with (i.e. pip == NULL) because they
1030 * are not linked into the directory structure - they are attached
1031 * directly to the superblock - and so have no parent.
1032 */
1033 int
1037 mode_t mode,
1038 xfs_nlink_t nlink,
1039 xfs_dev_t rdev,
1041 xfs_prid_t prid,
1046 {
1047 xfs_ino_t ino;
1050 uint flags;
1053 /*
1054 * Call the space management code to pick
1055 * the on-disk inode to be allocated.
1056 */
1061 }
1065 }
1068 /*
1069 * Get the in-core inode with the lock held exclusively.
1070 * This is because we're setting fields here we need
1071 * to prevent others from looking at until we're done.
1072 */
1077 }
1090 /*
1091 * If the superblock version is up to where we support new format
1092 * inodes and this is currently an old format inode, then change
1093 * the inode version number now. This way we only do the conversion
1094 * here rather than here and in the flush/logging code.
1095 */
1099 /*
1100 * We've already zeroed the old link count, the projid field,
1101 * and the pad field.
1102 */
1103 }
1105 /*
1106 * Project ids won't be stored on disk if we are using a version 1 inode.
1107 */
1115 }
1116 }
1118 /*
1119 * If the group ID of the new file does not match the effective group
1120 * ID or one of the supplementary group IDs, the S_ISGID bit is cleared
1121 * (and only if the irix_sgid_inherit compatibility variable is set).
1122 */
1127 }
1134 /*
1135 * di_gen will have been taken care of in xfs_iread.
1136 */
1159 }
1160 /* fall through */
1171 }
1178 }
1179 }
1181 xfs_inherit_noatime)
1184 xfs_inherit_nodump)
1187 xfs_inherit_sync)
1190 xfs_inherit_nosymlinks)
1195 xfs_inherit_nodefrag)
1200 }
1201 /* FALLTHROUGH */
1210 }
1211 /*
1212 * Attribute fork settings for new inode.
1213 */
1217 /*
1218 * Log the new values stuffed into the inode.
1219 */
1222 /* now that we have an i_mode we can setup inode ops and unlock */
1227 }
1229 /*
1230 * Check to make sure that there are no blocks allocated to the
1231 * file beyond the size of the file. We don't check this for
1232 * files with fixed size extents or real time extents, but we
1233 * at least do it for regular files.
1234 */
1235 #ifdef DEBUG
1236 void
1240 xfs_fsize_t isize)
1241 {
1242 xfs_fileoff_t map_first;
1257 /*
1258 * The filesystem could be shutting down, so bmapi may return
1259 * an error.
1260 */
1264 map_first),
1270 }
1273 /*
1274 * Calculate the last possible buffered byte in a file. This must
1275 * include data that was buffered beyond the EOF by the write code.
1276 * This also needs to deal with overflowing the xfs_fsize_t type
1277 * which can happen for sizes near the limit.
1278 *
1279 * We also need to take into account any blocks beyond the EOF. It
1280 * may be the case that they were buffered by a write which failed.
1281 * In that case the pages will still be in memory, but the inode size
1282 * will never have been updated.
1283 */
1284 xfs_fsize_t
1287 {
1289 xfs_fsize_t last_byte;
1290 xfs_fileoff_t last_block;
1291 xfs_fileoff_t size_last_block;
1297 /*
1298 * Only check for blocks beyond the EOF if the extents have
1299 * been read in. This eliminates the need for the inode lock,
1300 * and it also saves us from looking when it really isn't
1301 * necessary.
1302 */
1305 XFS_DATA_FORK);
1308 }
1311 }
1318 }
1322 }
1324 }
1326 #if defined(XFS_RW_TRACE)
1327 STATIC void
1332 xfs_fsize_t new_size,
1333 xfs_off_t toss_start,
1334 xfs_off_t toss_finish)
1335 {
1338 }
1357 }
1358 #else
1359 #define xfs_itrunc_trace(tag, ip, flag, new_size, toss_start, toss_finish)
1360 #endif
1362 /*
1363 * Start the truncation of the file to new_size. The new size
1364 * must be smaller than the current size. This routine will
1365 * clear the buffer and page caches of file data in the removed
1366 * range, and xfs_itruncate_finish() will remove the underlying
1367 * disk blocks.
1368 *
1369 * The inode must have its I/O lock locked EXCLUSIVELY, and it
1370 * must NOT have the inode lock held at all. This is because we're
1371 * calling into the buffer/page cache code and we can't hold the
1372 * inode lock when we do so.
1373 *
1374 * We need to wait for any direct I/Os in flight to complete before we
1375 * proceed with the truncate. This is needed to prevent the extents
1376 * being read or written by the direct I/Os from being removed while the
1377 * I/O is in flight as there is no other method of synchronising
1378 * direct I/O with the truncate operation. Also, because we hold
1379 * the IOLOCK in exclusive mode, we prevent new direct I/Os from being
1380 * started until the truncate completes and drops the lock. Essentially,
1381 * the vn_iowait() call forms an I/O barrier that provides strict ordering
1382 * between direct I/Os and the truncate operation.
1383 *
1384 * The flags parameter can have either the value XFS_ITRUNC_DEFINITE
1385 * or XFS_ITRUNC_MAYBE. The XFS_ITRUNC_MAYBE value should be used
1386 * in the case that the caller is locking things out of order and
1387 * may not be able to call xfs_itruncate_finish() with the inode lock
1388 * held without dropping the I/O lock. If the caller must drop the
1389 * I/O lock before calling xfs_itruncate_finish(), then xfs_itruncate_start()
1390 * must be called again with all the same restrictions as the initial
1391 * call.
1392 */
1393 int
1396 uint flags,
1397 xfs_fsize_t new_size)
1398 {
1399 xfs_fsize_t last_byte;
1400 xfs_off_t toss_start;
1413 /* wait for the completion of any pending DIOs */
1417 /*
1418 * Call toss_pages or flushinval_pages to get rid of pages
1419 * overlapping the region being removed. We have to use
1420 * the less efficient flushinval_pages in the case that the
1421 * caller may not be able to finish the truncate without
1422 * dropping the inode's I/O lock. Make sure
1423 * to catch any pages brought in by buffers overlapping
1424 * the EOF by searching out beyond the isize by our
1425 * block size. We round new_size up to a block boundary
1426 * so that we don't toss things on the same block as
1427 * new_size but before it.
1428 *
1429 * Before calling toss_page or flushinval_pages, make sure to
1430 * call remapf() over the same region if the file is mapped.
1431 * This frees up mapped file references to the pages in the
1432 * given range and for the flushinval_pages case it ensures
1433 * that we get the latest mapped changes flushed out.
1434 */
1438 /*
1439 * The place to start tossing is beyond our maximum
1440 * file size, so there is no way that the data extended
1441 * out there.
1442 */
1444 }
1447 last_byte);
1455 }
1456 }
1458 #ifdef DEBUG
1461 }
1462 #endif
1464 }
1466 /*
1467 * Shrink the file to the given new_size. The new size must be smaller than
1468 * the current size. This will free up the underlying blocks in the removed
1469 * range after a call to xfs_itruncate_start() or xfs_atruncate_start().
1470 *
1471 * The transaction passed to this routine must have made a permanent log
1472 * reservation of at least XFS_ITRUNCATE_LOG_RES. This routine may commit the
1473 * given transaction and start new ones, so make sure everything involved in
1474 * the transaction is tidy before calling here. Some transaction will be
1475 * returned to the caller to be committed. The incoming transaction must
1476 * already include the inode, and both inode locks must be held exclusively.
1477 * The inode must also be "held" within the transaction. On return the inode
1478 * will be "held" within the returned transaction. This routine does NOT
1479 * require any disk space to be reserved for it within the transaction.
1480 *
1481 * The fork parameter must be either xfs_attr_fork or xfs_data_fork, and it
1482 * indicates the fork which is to be truncated. For the attribute fork we only
1483 * support truncation to size 0.
1484 *
1485 * We use the sync parameter to indicate whether or not the first transaction
1486 * we perform might have to be synchronous. For the attr fork, it needs to be
1487 * so if the unlink of the inode is not yet known to be permanent in the log.
1488 * This keeps us from freeing and reusing the blocks of the attribute fork
1489 * before the unlink of the inode becomes permanent.
1490 *
1491 * For the data fork, we normally have to run synchronously if we're being
1492 * called out of the inactive path or we're being called out of the create path
1493 * where we're truncating an existing file. Either way, the truncate needs to
1494 * be sync so blocks don't reappear in the file with altered data in case of a
1495 * crash. wsync filesystems can run the first case async because anything that
1496 * shrinks the inode has to run sync so by the time we're called here from
1497 * inactive, the inode size is permanently set to 0.
1498 *
1499 * Calls from the truncate path always need to be sync unless we're in a wsync
1500 * filesystem and the file has already been unlinked.
1501 *
1502 * The caller is responsible for correctly setting the sync parameter. It gets
1503 * too hard for us to guess here which path we're being called out of just
1504 * based on inode state.
1505 *
1506 * If we get an error, we must return with the inode locked and linked into the
1507 * current transaction. This keeps things simple for the higher level code,
1508 * because it always knows that the inode is locked and held in the transaction
1509 * that returns to it whether errors occur or not. We don't mark the inode
1510 * dirty on error so that transactions can be easily aborted if possible.
1511 */
1512 int
1516 xfs_fsize_t new_size,
1519 {
1520 xfs_fsblock_t first_block;
1521 xfs_fileoff_t first_unmap_block;
1522 xfs_fileoff_t last_block;
1528 xfs_bmap_free_t free_list;
1544 /*
1545 * We only support truncating the entire attribute fork.
1546 */
1549 }
1552 /*
1553 * The first thing we do is set the size to new_size permanently
1554 * on disk. This way we don't have to worry about anyone ever
1555 * being able to look at the data being freed even in the face
1556 * of a crash. What we're getting around here is the case where
1557 * we free a block, it is allocated to another file, it is written
1558 * to, and then we crash. If the new data gets written to the
1559 * file but the log buffers containing the free and reallocation
1560 * don't, then we'd end up with garbage in the blocks being freed.
1561 * As long as we make the new_size permanent before actually
1562 * freeing any blocks it doesn't matter if they get writtten to.
1563 *
1564 * The callers must signal into us whether or not the size
1565 * setting here must be synchronous. There are a few cases
1566 * where it doesn't have to be synchronous. Those cases
1567 * occur if the file is unlinked and we know the unlink is
1568 * permanent or if the blocks being truncated are guaranteed
1569 * to be beyond the inode eof (regardless of the link count)
1570 * and the eof value is permanent. Both of these cases occur
1571 * only on wsync-mounted filesystems. In those cases, we're
1572 * guaranteed that no user will ever see the data in the blocks
1573 * that are being truncated so the truncate can run async.
1574 * In the free beyond eof case, the file may wind up with
1575 * more blocks allocated to it than it needs if we crash
1576 * and that won't get fixed until the next time the file
1577 * is re-opened and closed but that's ok as that shouldn't
1578 * be too many blocks.
1579 *
1580 * However, we can't just make all wsync xactions run async
1581 * because there's one call out of the create path that needs
1582 * to run sync where it's truncating an existing file to size
1583 * 0 whose size is > 0.
1584 *
1585 * It's probably possible to come up with a test in this
1586 * routine that would correctly distinguish all the above
1587 * cases from the values of the function parameters and the
1588 * inode state but for sanity's sake, I've decided to let the
1589 * layers above just tell us. It's simpler to correctly figure
1590 * out in the layer above exactly under what conditions we
1591 * can run async and I think it's easier for others read and
1592 * follow the logic in case something has to be changed.
1593 * cscope is your friend -- rcc.
1594 *
1595 * The attribute fork is much simpler.
1596 *
1597 * For the attribute fork we allow the caller to tell us whether
1598 * the unlink of the inode that led to this call is yet permanent
1599 * in the on disk log. If it is not and we will be freeing extents
1600 * in this inode then we make the first transaction synchronous
1601 * to make sure that the unlink is permanent by the time we free
1602 * the blocks.
1603 */
1606 /*
1607 * If we are not changing the file size then do
1608 * not update the on-disk file size - we may be
1609 * called from xfs_inactive_free_eofblocks(). If we
1610 * update the on-disk file size and then the system
1611 * crashes before the contents of the file are
1612 * flushed to disk then the files may be full of
1613 * holes (ie NULL files bug).
1614 */
1619 }
1620 }
1625 }
1631 /*
1632 * Since it is possible for space to become allocated beyond
1633 * the end of the file (in a crash where the space is allocated
1634 * but the inode size is not yet updated), simply remove any
1635 * blocks which show up between the new EOF and the maximum
1636 * possible file size. If the first block to be removed is
1637 * beyond the maximum file size (ie it is the same as last_block),
1638 * then there is nothing to do.
1639 */
1647 }
1649 /*
1650 * Free up up to XFS_ITRUNC_MAX_EXTENTS. xfs_bunmapi()
1651 * will tell us whether it freed the entire range or
1652 * not. If this is a synchronous mount (wsync),
1653 * then we can tell bunmapi to keep all the
1654 * transactions asynchronous since the unlink
1655 * transaction that made this inode inactive has
1656 * already hit the disk. There's no danger of
1657 * the freed blocks being reused, there being a
1658 * crash, and the reused blocks suddenly reappearing
1659 * in this file with garbage in them once recovery
1660 * runs.
1661 */
1667 XFS_ITRUNC_MAX_EXTENTS,
1671 /*
1672 * If the bunmapi call encounters an error,
1673 * return to the caller where the transaction
1674 * can be properly aborted. We just need to
1675 * make sure we're not holding any resources
1676 * that we were not when we came in.
1677 */
1680 }
1682 /*
1683 * Duplicate the transaction that has the permanent
1684 * reservation and commit the old transaction.
1685 */
1689 /* link the inode into the next xact in the chain */
1693 }
1696 /*
1697 * If the bmap finish call encounters an error, return
1698 * to the caller where the transaction can be properly
1699 * aborted. We just need to make sure we're not
1700 * holding any resources that we were not when we came
1701 * in.
1702 *
1703 * Aborting from this point might lose some blocks in
1704 * the file system, but oh well.
1705 */
1708 }
1711 /*
1712 * Mark the inode dirty so it will be logged and
1713 * moved forward in the log as part of every commit.
1714 */
1716 }
1722 /* link the inode into the next transaction in the chain */
1729 XFS_TRANS_PERM_LOG_RES,
1730 XFS_ITRUNCATE_LOG_COUNT);
1733 }
1734 /*
1735 * Only update the size in the case of the data fork, but
1736 * always re-log the inode so that our permanent transaction
1737 * can keep on rolling it forward in the log.
1738 */
1741 /*
1742 * If we are not changing the file size then do
1743 * not update the on-disk file size - we may be
1744 * called from xfs_inactive_free_eofblocks(). If we
1745 * update the on-disk file size and then the system
1746 * crashes before the contents of the file are
1747 * flushed to disk then the files may be full of
1748 * holes (ie NULL files bug).
1749 */
1753 }
1754 }
1764 }
1767 /*
1768 * xfs_igrow_start
1769 *
1770 * Do the first part of growing a file: zero any data in the last
1771 * block that is beyond the old EOF. We need to do this before
1772 * the inode is joined to the transaction to modify the i_size.
1773 * That way we can drop the inode lock and call into the buffer
1774 * cache to get the buffer mapping the EOF.
1775 */
1776 int
1779 xfs_fsize_t new_size,
1781 {
1785 /*
1786 * Zero any pages that may have been created by
1787 * xfs_write_file() beyond the end of the file
1788 * and any blocks between the old and new file sizes.
1789 */
1791 }
1793 /*
1794 * xfs_igrow_finish
1795 *
1796 * This routine is called to extend the size of a file.
1797 * The inode must have both the iolock and the ilock locked
1798 * for update and it must be a part of the current transaction.
1799 * The xfs_igrow_start() function must have been called previously.
1800 * If the change_flag is not zero, the inode change timestamp will
1801 * be updated.
1802 */
1803 void
1807 xfs_fsize_t new_size,
1809 {
1814 /*
1815 * Update the file size. Update the inode change timestamp
1816 * if change_flag set.
1817 */
1824 }
1827 /*
1828 * This is called when the inode's link count goes to 0.
1829 * We place the on-disk inode on a list in the AGI. It
1830 * will be pulled from this list when the inode is freed.
1831 */
1832 int
1836 {
1842 xfs_agnumber_t agno;
1843 xfs_daddr_t agdaddr;
1844 xfs_agino_t agino;
1859 /*
1860 * Get the agi buffer first. It ensures lock ordering
1861 * on the list.
1862 */
1868 /*
1869 * Validate the magic number of the agi block.
1870 */
1872 agi_ok =
1876 XFS_RANDOM_IUNLINK))) {
1880 }
1881 /*
1882 * Get the index into the agi hash table for the
1883 * list this inode will go on.
1884 */
1892 /*
1893 * There is already another inode in the bucket we need
1894 * to add ourselves to. Add us at the front of the list.
1895 * Here we put the head pointer into our next pointer,
1896 * and then we fall through to point the head at us.
1897 */
1903 /* both on-disk, don't endian flip twice */
1911 }
1913 /*
1914 * Point the bucket head pointer at the inode being inserted.
1915 */
1923 }
1925 /*
1926 * Pull the on-disk inode from the AGI unlinked list.
1927 */
1928 STATIC int
1932 {
1933 xfs_ino_t next_ino;
1939 xfs_agnumber_t agno;
1940 xfs_daddr_t agdaddr;
1941 xfs_agino_t agino;
1942 xfs_agino_t next_agino;
1950 /*
1951 * First pull the on-disk inode from the AGI unlinked list.
1952 */
1958 /*
1959 * Get the agi buffer first. It ensures lock ordering
1960 * on the list.
1961 */
1969 }
1970 /*
1971 * Validate the magic number of the agi block.
1972 */
1974 agi_ok =
1978 XFS_RANDOM_IUNLINK_REMOVE))) {
1986 }
1987 /*
1988 * Get the index into the agi hash table for the
1989 * list this inode will go on.
1990 */
1998 /*
1999 * We're at the head of the list. Get the inode's
2000 * on-disk buffer to see if there is anyone after us
2001 * on the list. Only modify our next pointer if it
2002 * is not already NULLAGINO. This saves us the overhead
2003 * of dealing with the buffer when there is no need to
2004 * change it.
2005 */
2012 }
2025 }
2026 /*
2027 * Point the bucket head pointer at the next inode.
2028 */
2037 /*
2038 * We need to search the list for the inode being freed.
2039 */
2043 /*
2044 * If the last inode wasn't the one pointing to
2045 * us, then release its buffer since we're not
2046 * going to do anything with it.
2047 */
2050 }
2059 }
2063 }
2064 /*
2065 * Now last_ibp points to the buffer previous to us on
2066 * the unlinked list. Pull us from the list.
2067 */
2074 }
2088 }
2089 /*
2090 * Point the previous inode on the list to the next inode.
2091 */
2099 }
2101 }
2103 STATIC void
2107 xfs_ino_t inum)
2108 {
2114 xfs_daddr_t blkno;
2130 }
2139 /*
2140 * Look for each inode in memory and attempt to lock it,
2141 * we can be racing with flush and tail pushing here.
2142 * any inode we get the locks on, add to an array of
2143 * inode items to process later.
2144 *
2145 * The get the buffer lock, we could beat a flush
2146 * or tail pushing thread to the lock here, in which
2147 * case they will go looking for the inode buffer
2148 * and fail, we need some other form of interlock
2149 * here.
2150 */
2157 /* Inode not in memory or we found it already,
2158 * nothing to do
2159 */
2163 }
2168 }
2170 /* If we can get the locks then add it to the
2171 * list, otherwise by the time we get the bp lock
2172 * below it will already be attached to the
2173 * inode buffer.
2174 */
2176 /* This inode will already be locked - by us, lets
2177 * keep it that way.
2178 */
2187 }
2188 }
2191 }
2202 }
2205 }
2206 }
2208 }
2212 XFS_BUF_LOCK);
2225 pre_flushed++;
2226 }
2228 }
2239 }
2253 }
2254 }
2259 }
2263 }
2265 /*
2266 * This is called to return an inode to the inode free list.
2267 * The inode should already be truncated to 0 length and have
2268 * no pages associated with it. This routine also assumes that
2269 * the inode is already a part of the transaction.
2270 *
2271 * The on-disk copy of the inode will have been added to the list
2272 * of unlinked inodes in the AGI. We need to remove the inode from
2273 * that list atomically with respect to freeing it here.
2274 */
2275 int
2280 {
2283 xfs_ino_t first_ino;
2296 /*
2297 * Pull the on-disk inode from the AGI unlinked list.
2298 */
2302 }
2307 }
2316 /*
2317 * Bump the generation count so no one will be confused
2318 * by reincarnations of this inode.
2319 */
2328 /*
2329 * Clear the on-disk di_mode. This is to prevent xfs_bulkstat
2330 * from picking up this inode when it is reclaimed (its incore state
2331 * initialzed but not flushed to disk yet). The in-core di_mode is
2332 * already cleared and a corresponding transaction logged.
2333 * The hack here just synchronizes the in-core to on-disk
2334 * di_mode value in advance before the actual inode sync to disk.
2335 * This is OK because the inode is already unlinked and would never
2336 * change its di_mode again for this inode generation.
2337 * This is a temporary hack that would require a proper fix
2338 * in the future.
2339 */
2344 }
2347 }
2349 /*
2350 * Reallocate the space for if_broot based on the number of records
2351 * being added or deleted as indicated in rec_diff. Move the records
2352 * and pointers in if_broot to fit the new size. When shrinking this
2353 * will eliminate holes between the records and pointers created by
2354 * the caller. When growing this will create holes to be filled in
2355 * by the caller.
2356 *
2357 * The caller must not request to add more records than would fit in
2358 * the on-disk inode root. If the if_broot is currently NULL, then
2359 * if we adding records one will be allocated. The caller must also
2360 * not request that the number of records go below zero, although
2361 * it can go to zero.
2362 *
2363 * ip -- the inode whose if_broot area is changing
2364 * ext_diff -- the change in the number of records, positive or negative,
2365 * requested for the if_broot array.
2366 */
2367 void
2372 {
2381 /*
2382 * Handle the degenerate case quietly.
2383 */
2386 }
2390 /*
2391 * If there wasn't any memory allocated before, just
2392 * allocate it now and get out.
2393 */
2397 KM_SLEEP);
2400 }
2402 /*
2403 * If there is already an existing if_broot, then we need
2404 * to realloc() it and shift the pointers to their new
2405 * location. The records don't change location because
2406 * they are kept butted up against the btree block header.
2407 */
2413 new_size,
2415 KM_SLEEP);
2425 }
2427 /*
2428 * rec_diff is less than 0. In this case, we are shrinking the
2429 * if_broot buffer. It must already exist. If we go to zero
2430 * records, just get rid of the root and clear the status bit.
2431 */
2438 else
2442 /*
2443 * First copy over the btree block header.
2444 */
2449 }
2451 /*
2452 * Only copy the records and pointers if there are any.
2453 */
2455 /*
2456 * First copy the records.
2457 */
2464 /*
2465 * Then copy the pointers.
2466 */
2472 }
2479 }
2482 /*
2483 * This is called when the amount of space needed for if_data
2484 * is increased or decreased. The change in size is indicated by
2485 * the number of bytes that need to be added or deleted in the
2486 * byte_diff parameter.
2487 *
2488 * If the amount of space needed has decreased below the size of the
2489 * inline buffer, then switch to using the inline buffer. Otherwise,
2490 * use kmem_realloc() or kmem_alloc() to adjust the size of the buffer
2491 * to what is needed.
2492 *
2493 * ip -- the inode whose if_data area is changing
2494 * byte_diff -- the change in the number of bytes, positive or negative,
2495 * requested for the if_data array.
2496 */
2497 void
2502 {
2509 }
2518 }
2522 /*
2523 * If the valid extents/data can fit in if_inline_ext/data,
2524 * copy them from the malloc'd vector and free it.
2525 */
2531 new_size);
2534 }
2537 /*
2538 * Stuck with malloc/realloc.
2539 * For inline data, the underlying buffer must be
2540 * a multiple of 4 bytes in size so that it can be
2541 * logged and stay on word boundaries. We enforce
2542 * that here.
2543 */
2549 /*
2550 * Only do the realloc if the underlying size
2551 * is really changing.
2552 */
2556 real_size,
2558 KM_SLEEP);
2559 }
2565 }
2566 }
2570 }
2575 /*
2576 * Map inode to disk block and offset.
2577 *
2578 * mp -- the mount point structure for the current file system
2579 * tp -- the current transaction
2580 * ino -- the inode number of the inode to be located
2581 * imap -- this structure is filled in with the information necessary
2582 * to retrieve the given inode from disk
2583 * flags -- flags to pass to xfs_dilocate indicating whether or not
2584 * lookups in the inode btree were OK or not
2585 */
2586 int
2590 xfs_ino_t ino,
2592 uint flags)
2593 {
2594 xfs_fsblock_t fsbno;
2611 /*
2612 * If the inode number maps to a block outside the bounds
2613 * of the file system then return NULL rather than calling
2614 * read_buf and panicing when we get an error from the
2615 * driver.
2616 */
2620 "(imap->im_blkno (0x%llx) + imap->im_len (0x%llx)) > "
2626 }
2628 }
2630 void
2634 {
2641 }
2643 /*
2644 * If the format is local, then we can't have an extents
2645 * array so just look for an inline data array. If we're
2646 * not local then we may or may not have an extents list,
2647 * so check and free it up if we do.
2648 */
2656 }
2663 }
2670 }
2671 }
2673 /*
2674 * This is called free all the memory associated with an inode.
2675 * It must free the inode itself and any buffers allocated for
2676 * if_extents/if_data and if_broot. It must also free the lock
2677 * associated with the inode.
2678 */
2679 void
2682 {
2689 }
2696 #ifdef XFS_INODE_TRACE
2698 #endif
2699 #ifdef XFS_BMAP_TRACE
2701 #endif
2702 #ifdef XFS_BMBT_TRACE
2704 #endif
2705 #ifdef XFS_RW_TRACE
2707 #endif
2708 #ifdef XFS_ILOCK_TRACE
2710 #endif
2711 #ifdef XFS_DIR2_TRACE
2713 #endif
2715 /*
2716 * Only if we are shutting down the fs will we see an
2717 * inode still in the AIL. If it is there, we should remove
2718 * it to prevent a use-after-free from occurring.
2719 */
2729 else
2731 }
2733 }
2735 }
2738 /*
2739 * Increment the pin count of the given buffer.
2740 * This value is protected by ipinlock spinlock in the mount structure.
2741 */
2742 void
2745 {
2749 }
2751 /*
2752 * Decrement the pin count of the given inode, and wake up
2753 * anyone in xfs_iwait_unpin() if the count goes to 0. The
2754 * inode must have been previously pinned with a call to xfs_ipin().
2755 */
2756 void
2759 {
2764 }
2766 /*
2767 * This is called to unpin an inode. It can be directed to wait or to return
2768 * immediately without waiting for the inode to be unpinned. The caller must
2769 * have the inode locked in at least shared mode so that the buffer cannot be
2770 * subsequently pinned once someone is waiting for it to be unpinned.
2771 */
2772 STATIC void
2776 {
2783 /* Give the log a push to start the unpinning I/O */
2788 }
2793 {
2795 }
2800 {
2802 }
2805 /*
2806 * xfs_iextents_copy()
2807 *
2808 * This is called to copy the REAL extents (as opposed to the delayed
2809 * allocation extents) from the inode into the given buffer. It
2810 * returns the number of bytes copied into the buffer.
2811 *
2812 * If there are no delayed allocation extents, then we can just
2813 * memcpy() the extents into the buffer. Otherwise, we need to
2814 * examine each extent in turn and skip those which are delayed.
2815 */
2816 int
2821 {
2826 xfs_fsblock_t start_block;
2836 /*
2837 * There are some delayed allocation extents in the
2838 * inode, so copy the extents one at a time and skip
2839 * the delayed ones. There must be at least one
2840 * non-delayed extent.
2841 */
2847 /*
2848 * It's a delayed allocation extent, so skip it.
2849 */
2851 }
2853 /* Translate to on disk format */
2856 dp++;
2857 copied++;
2858 }
2863 }
2865 /*
2866 * Each of the following cases stores data into the same region
2867 * of the on-disk inode, so only one of them can be valid at
2868 * any given time. While it is possible to have conflicting formats
2869 * and log flags, e.g. having XFS_ILOG_?DATA set when the fork is
2870 * in EXTENTS format, this can only happen when the fork has
2871 * changed formats after being modified but before being flushed.
2872 * In these cases, the format always takes precedence, because the
2873 * format indicates the current state of the fork.
2874 */
2875 /*ARGSUSED*/
2876 STATIC void
2883 {
2887 #ifdef XFS_TRANS_DEBUG
2889 #endif
2900 /*
2901 * This can happen if we gave up in iformat in an error path,
2902 * for the attribute fork.
2903 */
2907 }
2917 }
2931 whichfork);
2932 }
2941 XFS_BROOT_SIZE_ADJ));
2945 }
2952 }
2960 }
2966 }
2967 }
2969 STATIC int
2973 {
2998 /* really need a gang lookup range call here */
3008 /* if the inode lies outside this cluster, we're done. */
3011 /*
3012 * Do an un-protected check to see if the inode is dirty and
3013 * is a candidate for flushing. These checks will be repeated
3014 * later after the appropriate locks are acquired.
3015 */
3019 /*
3020 * Try to get locks. If any are unavailable or it is pinned,
3021 * then this inode cannot be flushed and is skipped.
3022 */
3029 }
3034 }
3036 /*
3037 * arriving here means that this inode can be flushed. First
3038 * re-check that it's dirty before flushing.
3039 */
3046 }
3047 clcount++;
3050 }
3052 }
3057 }
3059 out_free:
3065 cluster_corrupt_out:
3066 /*
3067 * Corruption detected in the clustering loop. Invalidate the
3068 * inode buffer and shut down the filesystem.
3069 */
3071 /*
3072 * Clean up the buffer. If it was B_DELWRI, just release it --
3073 * brelse can handle it with no problems. If not, shut down the
3074 * filesystem before releasing the buffer.
3075 */
3083 /*
3084 * Just like incore_relse: if we have b_iodone functions,
3085 * mark the buffer as an error and call them. Otherwise
3086 * mark it as stale and brelse.
3087 */
3098 }
3099 }
3101 /*
3102 * Unlocks the flush lock
3103 */
3107 }
3109 /*
3110 * xfs_iflush() will write a modified inode's changes out to the
3111 * inode's on disk home. The caller must have the inode lock held
3112 * in at least shared mode and the inode flush semaphore must be
3113 * held as well. The inode lock will still be held upon return from
3114 * the call and the caller is free to unlock it.
3115 * The inode flush lock will be unlocked when the inode reaches the disk.
3116 * The flags indicate how the inode's buffer should be written out.
3117 */
3118 int
3121 uint flags)
3122 {
3141 /*
3142 * If the inode isn't dirty, then just release the inode
3143 * flush lock and do nothing.
3144 */
3150 }
3152 /*
3153 * We can't flush the inode until it is unpinned, so wait for it if we
3154 * are allowed to block. We know noone new can pin it, because we are
3155 * holding the inode lock shared and you need to hold it exclusively to
3156 * pin the inode.
3157 *
3158 * If we are not allowed to block, force the log out asynchronously so
3159 * that when we come back the inode will be unpinned. If other inodes
3160 * in the same cluster are dirty, they will probably write the inode
3161 * out for us if they occur after the log force completes.
3162 */
3167 }
3170 /*
3171 * This may have been unpinned because the filesystem is shutting
3172 * down forcibly. If that's the case we must not write this inode
3173 * to disk, because the log record didn't make it to disk!
3174 */
3181 }
3183 /*
3184 * Decide how buffer will be flushed out. This is done before
3185 * the call to xfs_iflush_int because this field is zeroed by it.
3186 */
3188 /*
3189 * Flush out the inode buffer according to the directions
3190 * of the caller. In the cases where the caller has given
3191 * us a choice choose the non-delwri case. This is because
3192 * the inode is in the AIL and we need to get it out soon.
3193 */
3211 }
3230 }
3231 }
3233 /*
3234 * Get the buffer containing the on-disk inode.
3235 */
3241 }
3243 /*
3244 * First flush out the inode that xfs_iflush was called with.
3245 */
3250 /*
3251 * If the buffer is pinned then push on the log now so we won't
3252 * get stuck waiting in the write for too long.
3253 */
3257 /*
3258 * inode clustering:
3259 * see if other inodes can be gathered into this write
3260 */
3271 }
3274 corrupt_out:
3277 cluster_corrupt_out:
3278 /*
3279 * Unlocks the flush lock
3280 */
3283 }
3286 STATIC int
3290 {
3294 #ifdef XFS_TRANS_DEBUG
3296 #endif
3307 /*
3308 * If the inode isn't dirty, then just release the inode
3309 * flush lock and do nothing.
3310 */
3314 }
3316 /* set *dip = inode's place in the buffer */
3319 /*
3320 * Clear i_update_core before copying out the data.
3321 * This is for coordination with our timestamp updates
3322 * that don't hold the inode lock. They will always
3323 * update the timestamps BEFORE setting i_update_core,
3324 * so if we clear i_update_core after they set it we
3325 * are guaranteed to see their updates to the timestamps.
3326 * I believe that this depends on strongly ordered memory
3327 * semantics, but we have that. We use the SYNCHRONIZE
3328 * macro to make sure that the compiler does not reorder
3329 * the i_update_core access below the data copy below.
3330 */
3334 /*
3335 * Make sure to get the latest atime from the Linux inode.
3336 */
3345 }
3352 }
3362 }
3373 }
3374 }
3377 XFS_RANDOM_IFLUSH_5)) {
3383 ip);
3385 }
3392 }
3393 /*
3394 * bump the flush iteration count, used to detect flushes which
3395 * postdate a log record during recovery.
3396 */
3400 /*
3401 * Copy the dirty parts of the inode into the on-disk
3402 * inode. We always copy out the core of the inode,
3403 * because if the inode is dirty at all the core must
3404 * be.
3405 */
3408 /* Wrap, we never let the log put out DI_MAX_FLUSH */
3412 /*
3413 * If this is really an old format inode and the superblock version
3414 * has not been updated to support only new format inodes, then
3415 * convert back to the old inode format. If the superblock version
3416 * has been updated, then make the conversion permanent.
3417 */
3422 /*
3423 * Convert it back.
3424 */
3428 /*
3429 * The superblock version has already been bumped,
3430 * so just make the conversion to the new inode
3431 * format permanent.
3432 */
3441 }
3442 }
3449 /*
3450 * We've recorded everything logged in the inode, so we'd
3451 * like to clear the ilf_fields bits so we don't log and
3452 * flush things unnecessarily. However, we can't stop
3453 * logging all this information until the data we've copied
3454 * into the disk buffer is written to disk. If we did we might
3455 * overwrite the copy of the inode in the log with all the
3456 * data after re-logging only part of it, and in the face of
3457 * a crash we wouldn't have all the data we need to recover.
3458 *
3459 * What we do is move the bits to the ili_last_fields field.
3460 * When logging the inode, these bits are moved back to the
3461 * ilf_fields field. In the xfs_iflush_done() routine we
3462 * clear ili_last_fields, since we know that the information
3463 * those bits represent is permanently on disk. As long as
3464 * the flush completes before the inode is logged again, then
3465 * both ilf_fields and ili_last_fields will be cleared.
3466 *
3467 * We can play with the ilf_fields bits here, because the inode
3468 * lock must be held exclusively in order to set bits there
3469 * and the flush lock protects the ili_last_fields bits.
3470 * Set ili_logged so the flush done
3471 * routine can tell whether or not to look in the AIL.
3472 * Also, store the current LSN of the inode so that we can tell
3473 * whether the item has moved in the AIL from xfs_iflush_done().
3474 * In order to read the lsn we need the AIL lock, because
3475 * it is a 64 bit value that cannot be read atomically.
3476 */
3487 /*
3488 * Attach the function xfs_iflush_done to the inode's
3489 * buffer. This will remove the inode from the AIL
3490 * and unlock the inode's flush lock when the inode is
3491 * completely written to disk.
3492 */
3499 /*
3500 * We're flushing an inode which is not in the AIL and has
3501 * not been logged but has i_update_core set. For this
3502 * case we can use a B_DELWRI flush and immediately drop
3503 * the inode flush lock because we can avoid the whole
3504 * AIL state thing. It's OK to drop the flush lock now,
3505 * because we've already locked the buffer and to do anything
3506 * you really need both.
3507 */
3512 }
3514 }
3518 corrupt_out:
3520 }
3523 /*
3524 * Flush all inactive inodes in mp.
3525 */
3526 void
3529 {
3533 again:
3540 /* Make sure we skip markers inserted by sync */
3544 }
3551 }
3557 out:
3559 }
3561 #ifdef XFS_ILOCK_TRACE
3564 void
3566 {
3575 }
3576 #endif
3578 /*
3579 * Return a pointer to the extent record at file index idx.
3580 */
3581 xfs_bmbt_rec_host_t *
3585 {
3600 }
3601 }
3603 /*
3604 * Insert new item(s) into the extent records for incore inode
3605 * fork 'ifp'. 'count' new items are inserted at index 'idx'.
3606 */
3607 void
3613 {
3620 }
3622 /*
3623 * This is called when the amount of space required for incore file
3624 * extents needs to be increased. The ext_diff parameter stores the
3625 * number of new extents being added and the idx parameter contains
3626 * the extent index where the new extents will be added. If the new
3627 * extents are being appended, then we just need to (re)allocate and
3628 * initialize the space. Otherwise, if the new extents are being
3629 * inserted into the middle of the existing entries, a bit more work
3630 * is required to make room for the new extents to be inserted. The
3631 * caller is responsible for filling in the new extent entries upon
3632 * return.
3633 */
3634 void
3639 {
3648 /*
3649 * If the new number of extents (nextents + ext_diff)
3650 * fits inside the inode, then continue to use the inline
3651 * extent buffer.
3652 */
3659 }
3663 }
3664 /*
3665 * Otherwise use a linear (direct) extent list.
3666 * If the extents are currently inside the inode,
3667 * xfs_iext_realloc_direct will switch us from
3668 * inline to direct extent allocation mode.
3669 */
3677 }
3678 }
3679 /* Indirection array */
3692 }
3693 /* Extents fit in target extent page */
3701 }
3704 }
3705 /* Insert a new extent page */
3709 }
3710 /*
3711 * If extent(s) are being appended to the last page in
3712 * the indirection array and the new extent(s) don't fit
3713 * in the page, then erp is NULL and erp_idx is set to
3714 * the next index needed in the indirection array.
3715 */
3724 erp_idx++;
3725 }
3726 }
3727 }
3728 }
3730 }
3732 /*
3733 * This is called when incore extents are being added to the indirection
3734 * array and the new extents do not fit in the target extent list. The
3735 * erp_idx parameter contains the irec index for the target extent list
3736 * in the indirection array, and the idx parameter contains the extent
3737 * index within the list. The number of extents being added is stored
3738 * in the count parameter.
3739 *
3740 * |-------| |-------|
3741 * | | | | idx - number of extents before idx
3742 * | idx | | count |
3743 * | | | | count - number of extents being inserted at idx
3744 * |-------| |-------|
3745 * | count | | nex2 | nex2 - number of extents after idx + count
3746 * |-------| |-------|
3747 */
3748 void
3754 {
3768 /*
3769 * Save second part of target extent list
3770 * (all extents past */
3778 }
3780 /*
3781 * Add the new extents to the end of the target
3782 * list, then allocate new irec record(s) and
3783 * extent buffer(s) as needed to store the rest
3784 * of the new extents.
3785 */
3792 }
3794 erp_idx++;
3800 }
3802 /* Add nex2 extents back to indirection array */
3804 xfs_extnum_t ext_avail;
3810 /*
3811 * If nex2 extents fit in the current page, append
3812 * nex2_ep after the new extents.
3813 */
3816 }
3817 /*
3818 * Otherwise, check if space is available in the
3819 * next page.
3820 */
3824 erp_idx++;
3825 erp++;
3826 /* Create a hole for nex2 extents */
3829 }
3830 /*
3831 * Final choice, create a new extent page for
3832 * nex2 extents.
3833 */
3835 erp_idx++;
3837 }
3842 }
3843 }
3845 /*
3846 * This is called when the amount of space required for incore file
3847 * extents needs to be decreased. The ext_diff parameter stores the
3848 * number of extents to be removed and the idx parameter contains
3849 * the extent index where the extents will be removed from.
3850 *
3851 * If the amount of space needed has decreased below the linear
3852 * limit, XFS_IEXT_BUFSZ, then switch to using the contiguous
3853 * extent array. Otherwise, use kmem_realloc() to adjust the
3854 * size to what is needed.
3855 */
3856 void
3861 {
3877 }
3879 }
3881 /*
3882 * This removes ext_diff extents from the inline buffer, beginning
3883 * at extent index idx.
3884 */
3885 void
3890 {
3909 }
3910 }
3912 /*
3913 * This removes ext_diff extents from a linear (direct) extent list,
3914 * beginning at extent index idx. If the extents are being removed
3915 * from the end of the list (ie. truncate) then we just need to re-
3916 * allocate the list to remove the extra space. Otherwise, if the
3917 * extents are being removed from the middle of the existing extent
3918 * entries, then we first need to move the extent records beginning
3919 * at idx + ext_diff up in the list to overwrite the records being
3920 * removed, then remove the extra space via kmem_realloc.
3921 */
3922 void
3927 {
3939 }
3940 /* Move extents up in the list (if needed) */
3946 }
3949 /*
3950 * Reallocate the direct extent list. If the extents
3951 * will fit inside the inode then xfs_iext_realloc_direct
3952 * will switch from direct to inline extent allocation
3953 * mode for us.
3954 */
3957 }
3959 /*
3960 * This is called when incore extents are being removed from the
3961 * indirection array and the extents being removed span multiple extent
3962 * buffers. The idx parameter contains the file extent index where we
3963 * want to begin removing extents, and the count parameter contains
3964 * how many extents need to be removed.
3965 *
3966 * |-------| |-------|
3967 * | nex1 | | | nex1 - number of extents before idx
3968 * |-------| | count |
3969 * | | | | count - number of extents being removed at idx
3970 * | count | |-------|
3971 * | | | nex2 | nex2 - number of extents after idx + count
3972 * |-------| |-------|
3973 */
3974 void
3979 {
3998 /*
3999 * Check for deletion of entire list;
4000 * xfs_iext_irec_remove() updates extent offsets.
4001 */
4008 XFS_IEXT_BUFSZ);
4014 }
4015 }
4016 /* Move extents up (if needed) */
4021 }
4022 /* Zero out rest of page */
4025 /* Update remaining counters */
4030 erp_idx++;
4031 erp++;
4032 }
4035 }
4037 /*
4038 * Create, destroy, or resize a linear (direct) block of extents.
4039 */
4040 void
4044 {
4053 /* Free extent records */
4056 }
4057 /* Resize direct extent list and zero any new bytes */
4059 /* Check if extents will fit inside the inode */
4065 }
4068 }
4072 rnew_size,
4074 KM_SLEEP);
4075 }
4080 }
4081 }
4082 /*
4083 * Switch from the inline extent buffer to a direct
4084 * extent list. Be sure to include the inline extent
4085 * bytes in new_size.
4086 */
4091 }
4093 }
4096 }
4098 /*
4099 * Switch from linear (direct) extent records to inline buffer.
4100 */
4101 void
4105 {
4108 /*
4109 * The inline buffer was zeroed when we switched
4110 * from inline to direct extent allocation mode,
4111 * so we don't need to clear it here.
4112 */
4118 }
4120 /*
4121 * Switch from inline buffer to linear (direct) extent records.
4122 * new_size should already be rounded up to the next power of 2
4123 * by the caller (when appropriate), so use new_size as it is.
4124 * However, since new_size may be rounded up, we can't update
4125 * if_bytes here. It is the caller's responsibility to update
4126 * if_bytes upon return.
4127 */
4128 void
4132 {
4140 }
4142 }
4144 /*
4145 * Resize an extent indirection array to new_size bytes.
4146 */
4147 void
4151 {
4166 }
4167 }
4169 /*
4170 * Switch from indirection array to linear (direct) extent allocations.
4171 */
4172 void
4175 {
4195 }
4196 }
4198 /*
4199 * Free incore file extents.
4200 */
4201 void
4204 {
4212 }
4219 }
4223 }
4225 /*
4226 * Return a pointer to the extent record for file system block bno.
4227 */
4233 {
4248 }
4251 /* Find target extent list */
4259 }
4260 /* Binary search extent records */
4271 /* Convert back to file-based extent index */
4274 }
4277 }
4278 }
4279 /* Convert back to file-based extent index */
4282 }
4288 }
4289 }
4292 }
4294 /*
4295 * Return a pointer to the indirection array entry containing the
4296 * extent record for filesystem block bno. Store the index of the
4297 * target irec in *erp_idxp.
4298 */
4304 {
4328 }
4329 }
4332 }
4334 /*
4335 * Return a pointer to the indirection array entry containing the
4336 * extent record at file extent index *idxp. Store the index of the
4337 * target irec in *erp_idxp and store the page index of the target
4338 * extent record in *idxp.
4339 */
4340 xfs_ext_irec_t *
4346 {
4363 /* Binary search extent irec's */
4379 erp_idx++;
4385 }
4386 }
4390 }
4392 /*
4393 * Allocate and initialize an indirection array once the space needed
4394 * for incore extents increases above XFS_IEXT_BUFSZ.
4395 */
4396 void
4399 {
4416 }
4427 }
4429 /*
4430 * Allocate and initialize a new entry in the indirection array.
4431 */
4432 xfs_ext_irec_t *
4436 {
4444 /* Resize indirection array */
4447 /*
4448 * Move records down in the array so the
4449 * new page can use erp_idx.
4450 */
4454 }
4457 /* Initialize new extent record */
4466 }
4468 /*
4469 * Remove a record from the indirection array.
4470 */
4471 void
4475 {
4487 }
4488 /* Compact extent records */
4492 }
4493 /*
4494 * Manually free the last extent record from the indirection
4495 * array. A call to xfs_iext_realloc_indirect() with a size
4496 * of zero would result in a call to xfs_iext_destroy() which
4497 * would in turn call this function again, creating a nasty
4498 * infinite loop.
4499 */
4506 }
4508 }
4510 /*
4511 * This is called to clean up large amounts of unused memory allocated
4512 * by the indirection array. Before compacting anything though, verify
4513 * that the indirection array is still needed and switch back to the
4514 * linear extent list (or even the inline buffer) if possible. The
4515 * compaction policy is as follows:
4516 *
4517 * Full Compaction: Extents fit into a single page (or inline buffer)
4518 * Full Compaction: Extents occupy less than 10% of allocated space
4519 * Partial Compaction: Extents occupy > 10% and < 50% of allocated space
4520 * No Compaction: Extents occupy at least 50% of allocated space
4521 */
4522 void
4525 {
4544 }
4545 }
4547 /*
4548 * Combine extents from neighboring extent pages.
4549 */
4550 void
4553 {
4569 /*
4570 * Free page before removing extent record
4571 * so er_extoffs don't get modified in
4572 * xfs_iext_irec_remove.
4573 */
4579 erp_idx++;
4580 }
4581 }
4582 }
4584 /*
4585 * Fully compact the extent records managed by the indirection array.
4586 */
4587 void
4590 {
4610 /* Remove next page */
4612 /*
4613 * Free page before removing extent record
4614 * so er_extoffs don't get modified in
4615 * xfs_iext_irec_remove.
4616 */
4623 /* Update next page */
4625 /* Move rest of page up to become next new page */
4632 }
4634 erp_idx++;
4637 else
4639 }
4643 }
4644 }
4646 /*
4647 * This is called to update the er_extoff field in the indirection
4648 * array when extents have been added or removed from one of the
4649 * extent lists. erp_idx contains the irec index to begin updating
4650 * at and ext_diff contains the number of extents that were added
4651 * or removed.
4652 */
4653 void
4658 {
4666 }
4667 }