| blob | bc46c0a133d373d3afffad99f1323a8d15b52c19 |
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>
53 /*
54 * Used in xfs_itruncate_extents(). This is the maximum number of extents
55 * freed from a file in a single transaction.
56 */
57 #define XFS_ITRUNC_MAX_EXTENTS 2
64 #ifdef DEBUG
65 /*
66 * Make sure that the extents in the given memory buffer
67 * are valid.
68 */
69 STATIC void
73 xfs_exntfmt_t fmt)
74 {
75 xfs_bmbt_irec_t irec;
76 xfs_bmbt_rec_host_t rec;
86 }
87 }
89 #define xfs_validate_extents(ifp, nrecs, fmt)
92 /*
93 * Check that none of the inode's in the buffer have a next
94 * unlinked field of 0.
95 */
96 #if defined(DEBUG)
97 void
101 {
114 bp);
116 }
117 }
118 }
119 #endif
121 /*
122 * Find the buffer associated with the given inode map
123 * We do basic validation checks on the buffer once it has been
124 * retrieved from disk.
125 */
126 STATIC int
132 uint buf_flags,
133 uint iget_flags)
134 {
149 }
151 }
153 /*
154 * Validate the magic number and version of every inode in the buffer
155 * (if DEBUG kernel) or the first inode in the buffer, otherwise.
156 */
157 #ifdef DEBUG
161 #endif
172 XFS_ERRTAG_ITOBP_INOTOBP,
173 XFS_RANDOM_ITOBP_INOTOBP))) {
177 }
180 #ifdef DEBUG
186 #endif
189 }
190 }
195 }
197 /*
198 * This routine is called to map an inode number within a file
199 * system to the buffer containing the on-disk version of the
200 * inode. It returns a pointer to the buffer containing the
201 * on-disk inode in the bpp parameter, and in the dip parameter
202 * it returns a pointer to the on-disk inode within that buffer.
203 *
204 * If a non-zero error is returned, then the contents of bpp and
205 * dipp are undefined.
206 *
207 * Use xfs_imap() to determine the size and location of the
208 * buffer to read from disk.
209 */
210 int
214 xfs_ino_t ino,
218 uint imap_flags)
219 {
237 }
240 /*
241 * This routine is called to map an inode to the buffer containing
242 * the on-disk version of the inode. It returns a pointer to the
243 * buffer containing the on-disk inode in the bpp parameter, and in
244 * the dip parameter it returns a pointer to the on-disk inode within
245 * that buffer.
246 *
247 * If a non-zero error is returned, then the contents of bpp and
248 * dipp are undefined.
249 *
250 * The inode is expected to already been mapped to its buffer and read
251 * in once, thus we can use the mapping information stored in the inode
252 * rather than calling xfs_imap(). This allows us to avoid the overhead
253 * of looking at the inode btree for small block file systems
254 * (see xfs_imap()).
255 */
256 int
263 uint buf_flags)
264 {
279 }
284 }
286 /*
287 * Move inode type and inode format specific information from the
288 * on-disk inode to the in-core inode. For fifos, devs, and sockets
289 * this means set if_rdev to the proper value. For files, directories,
290 * and symlinks this means to bring in the in-line data or extent
291 * pointers. For a file in B-tree format, only the root is immediately
292 * brought in-core. The rest will be in-lined in if_extents when it
293 * is first referenced (see xfs_iread_extents()).
294 */
295 STATIC int
299 {
303 xfs_fsize_t di_size;
318 }
327 }
337 }
348 }
358 /*
359 * no local regular files yet
360 */
366 XFS_ERRLEVEL_LOW,
369 }
378 XFS_ERRLEVEL_LOW,
381 }
396 }
402 }
405 }
423 XFS_ERRLEVEL_LOW,
426 }
439 }
444 }
446 }
448 /*
449 * The file is in-lined in the on-disk inode.
450 * If it fits into if_inline_data, then copy
451 * it there, otherwise allocate a buffer for it
452 * and copy the data there. Either way, set
453 * if_data to point at the data.
454 * If we allocate a buffer for the data, make
455 * sure that its size is a multiple of 4 and
456 * record the real size in i_real_bytes.
457 */
458 STATIC int
464 {
468 /*
469 * If the size is unreasonable, then something
470 * is wrong and we just bail out rather than crash in
471 * kmem_alloc() or memcpy() below.
472 */
481 }
491 }
499 }
501 /*
502 * The file consists of a set of extents all
503 * of which fit into the on-disk inode.
504 * If there are few enough extents to fit into
505 * the if_inline_ext, then copy them there.
506 * Otherwise allocate a buffer for them and copy
507 * them into it. Either way, set if_extents
508 * to point at the extents.
509 */
510 STATIC int
515 {
526 /*
527 * If the number of extents is unreasonable, then something
528 * is wrong and we just bail out rather than crash in
529 * kmem_alloc() or memcpy() below.
530 */
537 }
544 else
555 }
562 XFS_ERRLEVEL_LOW,
565 }
566 }
569 }
571 /*
572 * The file has too many extents to fit into
573 * the inode, so they are in B-tree format.
574 * Allocate a buffer for the root of the B-tree
575 * and copy the root into it. The i_extents
576 * field will remain NULL until all of the
577 * extents are read in (when they are needed).
578 */
579 STATIC int
584 {
587 /* REFERENCED */
596 /*
597 * blow out if -- fork has less extents than can fit in
598 * fork (fork shouldn't be a btree format), root btree
599 * block has more records than can fit into the fork,
600 * or the number of extents is greater than the number of
601 * blocks.
602 */
613 }
618 /*
619 * Copy and convert from the on-disk structure
620 * to the in-memory structure.
621 */
629 }
631 STATIC void
635 {
665 }
667 void
671 {
701 }
703 STATIC uint
705 __uint16_t di_flags)
706 {
738 }
741 }
743 uint
746 {
751 }
753 uint
756 {
759 }
761 /*
762 * Read the disk inode attributes into the in-core inode structure.
763 */
764 int
769 uint iget_flags)
770 {
775 /*
776 * Fill in the location information in the in-core inode.
777 */
782 /*
783 * Get pointers to the on-disk inode and the buffer containing it.
784 */
791 /*
792 * If we got something that isn't an inode it means someone
793 * (nfs or dmi) has a stale handle.
794 */
796 #ifdef DEBUG
803 }
805 /*
806 * If the on-disk inode is already linked to a directory
807 * entry, copy all of the inode into the in-core inode.
808 * xfs_iformat() handles copying in the inode format
809 * specific information.
810 * Otherwise, just get the truly permanent information.
811 */
816 #ifdef DEBUG
821 }
827 /*
828 * Make sure to pull in the mode here as well in
829 * case the inode is released without being used.
830 * This ensures that xfs_inactive() will see that
831 * the inode is already free and not try to mess
832 * with the uninitialized part of it.
833 */
835 }
837 /*
838 * The inode format changed when we moved the link count and
839 * made it 32 bits long. If this is an old format inode,
840 * convert it in memory to look like a new one. If it gets
841 * flushed to disk we will convert back before flushing or
842 * logging it. We zero out the new projid field and the old link
843 * count field. We'll handle clearing the pad field (the remains
844 * of the old uuid field) when we actually convert the inode to
845 * the new format. We don't change the version number so that we
846 * can distinguish this from a real new format inode.
847 */
852 }
856 /*
857 * Mark the buffer containing the inode as something to keep
858 * around for a while. This helps to keep recently accessed
859 * meta-data in-core longer.
860 */
863 /*
864 * Use xfs_trans_brelse() to release the buffer containing the
865 * on-disk inode, because it was acquired with xfs_trans_read_buf()
866 * in xfs_itobp() above. If tp is NULL, this is just a normal
867 * brelse(). If we're within a transaction, then xfs_trans_brelse()
868 * will only release the buffer if it is not dirty within the
869 * transaction. It will be OK to release the buffer in this case,
870 * because inodes on disk are never destroyed and we will be
871 * locking the new in-core inode before putting it in the hash
872 * table where other processes can find it. Thus we don't have
873 * to worry about the inode being changed just because we released
874 * the buffer.
875 */
876 out_brelse:
879 }
881 /*
882 * Read in extents from a btree-format inode.
883 * Allocate and fill in if_extents. Real work is done in xfs_bmap.c.
884 */
885 int
890 {
893 xfs_extnum_t nextents;
899 }
903 /*
904 * We know that the size is valid (it's checked in iformat_btree)
905 */
914 }
917 }
919 /*
920 * Allocate an inode on disk and return a copy of its in-core version.
921 * The in-core inode is locked exclusively. Set mode, nlink, and rdev
922 * appropriately within the inode. The uid and gid for the inode are
923 * set according to the contents of the given cred structure.
924 *
925 * Use xfs_dialloc() to allocate the on-disk inode. If xfs_dialloc()
926 * has a free inode available, call xfs_iget()
927 * to obtain the in-core version of the allocated inode. Finally,
928 * fill in the inode and log its initial contents. In this case,
929 * ialloc_context would be set to NULL and call_again set to false.
930 *
931 * If xfs_dialloc() does not have an available inode,
932 * it will replenish its supply by doing an allocation. Since we can
933 * only do one allocation within a transaction without deadlocks, we
934 * must commit the current transaction before returning the inode itself.
935 * In this case, therefore, we will set call_again to true and return.
936 * The caller should then commit the current transaction, start a new
937 * transaction, and call xfs_ialloc() again to actually get the inode.
938 *
939 * To ensure that some other process does not grab the inode that
940 * was allocated during the first call to xfs_ialloc(), this routine
941 * also returns the [locked] bp pointing to the head of the freelist
942 * as ialloc_context. The caller should hold this buffer across
943 * the commit and pass it back into this routine on the second call.
944 *
945 * If we are allocating quota inodes, we do not have a parent inode
946 * to attach to or associate with (i.e. pip == NULL) because they
947 * are not linked into the directory structure - they are attached
948 * directly to the superblock - and so have no parent.
949 */
950 int
954 umode_t mode,
955 xfs_nlink_t nlink,
956 xfs_dev_t rdev,
957 prid_t prid,
962 {
963 xfs_ino_t ino;
965 uint flags;
967 timespec_t tv;
970 /*
971 * Call the space management code to pick
972 * the on-disk inode to be allocated.
973 */
981 }
984 /*
985 * Get the in-core inode with the lock held exclusively.
986 * This is because we're setting fields here we need
987 * to prevent others from looking at until we're done.
988 */
1004 /*
1005 * If the superblock version is up to where we support new format
1006 * inodes and this is currently an old format inode, then change
1007 * the inode version number now. This way we only do the conversion
1008 * here rather than here and in the flush/logging code.
1009 */
1013 /*
1014 * We've already zeroed the old link count, the projid field,
1015 * and the pad field.
1016 */
1017 }
1019 /*
1020 * Project ids won't be stored on disk if we are using a version 1 inode.
1021 */
1029 }
1030 }
1032 /*
1033 * If the group ID of the new file does not match the effective group
1034 * ID or one of the supplementary group IDs, the S_ISGID bit is cleared
1035 * (and only if the irix_sgid_inherit compatibility variable is set).
1036 */
1041 }
1053 /*
1054 * di_gen will have been taken care of in xfs_iread.
1055 */
1072 /*
1073 * we can't set up filestreams until after the VFS inode
1074 * is set up properly.
1075 */
1078 /* fall through */
1089 }
1096 }
1097 }
1099 xfs_inherit_noatime)
1102 xfs_inherit_nodump)
1105 xfs_inherit_sync)
1108 xfs_inherit_nosymlinks)
1113 xfs_inherit_nodefrag)
1118 }
1119 /* FALLTHROUGH */
1128 }
1129 /*
1130 * Attribute fork settings for new inode.
1131 */
1135 /*
1136 * Log the new values stuffed into the inode.
1137 */
1141 /* now that we have an i_mode we can setup inode ops and unlock */
1144 /* now we have set up the vfs inode we can associate the filestream */
1151 }
1155 }
1157 /*
1158 * Free up the underlying blocks past new_size. The new size must be smaller
1159 * than the current size. This routine can be used both for the attribute and
1160 * data fork, and does not modify the inode size, which is left to the caller.
1161 *
1162 * The transaction passed to this routine must have made a permanent log
1163 * reservation of at least XFS_ITRUNCATE_LOG_RES. This routine may commit the
1164 * given transaction and start new ones, so make sure everything involved in
1165 * the transaction is tidy before calling here. Some transaction will be
1166 * returned to the caller to be committed. The incoming transaction must
1167 * already include the inode, and both inode locks must be held exclusively.
1168 * The inode must also be "held" within the transaction. On return the inode
1169 * will be "held" within the returned transaction. This routine does NOT
1170 * require any disk space to be reserved for it within the transaction.
1171 *
1172 * If we get an error, we must return with the inode locked and linked into the
1173 * current transaction. This keeps things simple for the higher level code,
1174 * because it always knows that the inode is locked and held in the transaction
1175 * that returns to it whether errors occur or not. We don't mark the inode
1176 * dirty on error so that transactions can be easily aborted if possible.
1177 */
1178 int
1183 xfs_fsize_t new_size)
1184 {
1188 xfs_bmap_free_t free_list;
1189 xfs_fsblock_t first_block;
1190 xfs_fileoff_t first_unmap_block;
1191 xfs_fileoff_t last_block;
1192 xfs_filblks_t unmap_len;
1206 /*
1207 * Since it is possible for space to become allocated beyond
1208 * the end of the file (in a crash where the space is allocated
1209 * but the inode size is not yet updated), simply remove any
1210 * blocks which show up between the new EOF and the maximum
1211 * possible file size. If the first block to be removed is
1212 * beyond the maximum file size (ie it is the same as last_block),
1213 * then there is nothing to do.
1214 */
1227 XFS_ITRUNC_MAX_EXTENTS,
1233 /*
1234 * Duplicate the transaction that has the permanent
1235 * reservation and commit the old transaction.
1236 */
1244 /*
1245 * Mark the inode dirty so it will be logged and
1246 * moved forward in the log as part of every commit.
1247 */
1249 }
1260 /*
1261 * Transaction commit worked ok so we can drop the extra ticket
1262 * reference that we gained in xfs_trans_dup()
1263 */
1267 XFS_TRANS_PERM_LOG_RES,
1268 XFS_ITRUNCATE_LOG_COUNT);
1271 }
1273 /*
1274 * Always re-log the inode so that our permanent transaction can keep
1275 * on rolling it forward in the log.
1276 */
1281 out:
1284 out_bmap_cancel:
1285 /*
1286 * If the bunmapi call encounters an error, return to the caller where
1287 * the transaction can be properly aborted. We just need to make sure
1288 * we're not holding any resources that we were not when we came in.
1289 */
1292 }
1294 /*
1295 * This is called when the inode's link count goes to 0.
1296 * We place the on-disk inode on a list in the AGI. It
1297 * will be pulled from this list when the inode is freed.
1298 */
1299 int
1303 {
1309 xfs_agino_t agino;
1319 /*
1320 * Get the agi buffer first. It ensures lock ordering
1321 * on the list.
1322 */
1328 /*
1329 * Get the index into the agi hash table for the
1330 * list this inode will go on.
1331 */
1339 /*
1340 * There is already another inode in the bucket we need
1341 * to add ourselves to. Add us at the front of the list.
1342 * Here we put the head pointer into our next pointer,
1343 * and then we fall through to point the head at us.
1344 */
1357 }
1359 /*
1360 * Point the bucket head pointer at the inode being inserted.
1361 */
1369 }
1371 /*
1372 * Pull the on-disk inode from the AGI unlinked list.
1373 */
1374 STATIC int
1378 {
1379 xfs_ino_t next_ino;
1385 xfs_agnumber_t agno;
1386 xfs_agino_t agino;
1387 xfs_agino_t next_agino;
1397 /*
1398 * Get the agi buffer first. It ensures lock ordering
1399 * on the list.
1400 */
1407 /*
1408 * Get the index into the agi hash table for the
1409 * list this inode will go on.
1410 */
1418 /*
1419 * We're at the head of the list. Get the inode's
1420 * on-disk buffer to see if there is anyone after us
1421 * on the list. Only modify our next pointer if it
1422 * is not already NULLAGINO. This saves us the overhead
1423 * of dealing with the buffer when there is no need to
1424 * change it.
1425 */
1431 }
1444 }
1445 /*
1446 * Point the bucket head pointer at the next inode.
1447 */
1456 /*
1457 * We need to search the list for the inode being freed.
1458 */
1462 /*
1463 * If the last inode wasn't the one pointing to
1464 * us, then release its buffer since we're not
1465 * going to do anything with it.
1466 */
1469 }
1478 }
1482 }
1483 /*
1484 * Now last_ibp points to the buffer previous to us on
1485 * the unlinked list. Pull us from the list.
1486 */
1492 }
1506 }
1507 /*
1508 * Point the previous inode on the list to the next inode.
1509 */
1517 }
1519 }
1521 /*
1522 * A big issue when freeing the inode cluster is is that we _cannot_ skip any
1523 * inodes that are in memory - they all must be marked stale and attached to
1524 * the cluster buffer.
1525 */
1526 STATIC int
1530 xfs_ino_t inum)
1531 {
1537 xfs_daddr_t blkno;
1554 }
1560 /*
1561 * We obtain and lock the backing buffer first in the process
1562 * here, as we have to ensure that any dirty inode that we
1563 * can't get the flush lock on is attached to the buffer.
1564 * If we scan the in-memory inodes first, then buffer IO can
1565 * complete before we get a lock on it, and hence we may fail
1566 * to mark all the active inodes on the buffer stale.
1567 */
1570 XBF_LOCK);
1574 /*
1575 * Walk the inodes already attached to the buffer and mark them
1576 * stale. These will all have the flush locks held, so an
1577 * in-memory inode walk can't lock them. By marking them all
1578 * stale first, we will not attempt to lock them in the loop
1579 * below as the XFS_ISTALE flag will be set.
1580 */
1591 }
1593 }
1596 /*
1597 * For each inode in memory attempt to add it to the inode
1598 * buffer and set it up for being staled on buffer IO
1599 * completion. This is safe as we've locked out tail pushing
1600 * and flushing by locking the buffer.
1601 *
1602 * We have already marked every inode that was part of a
1603 * transaction stale above, which means there is no point in
1604 * even trying to lock them.
1605 */
1607 retry:
1612 /* Inode not in memory, nothing to do */
1616 }
1618 /*
1619 * because this is an RCU protected lookup, we could
1620 * find a recently freed or even reallocated inode
1621 * during the lookup. We need to check under the
1622 * i_flags_lock for a valid inode here. Skip it if it
1623 * is not valid, the wrong inode or stale.
1624 */
1631 }
1634 /*
1635 * Don't try to lock/unlock the current inode, but we
1636 * _cannot_ skip the other inodes that we did not find
1637 * in the list attached to the buffer and are not
1638 * already marked stale. If we can't lock it, back off
1639 * and retry.
1640 */
1646 }
1652 /*
1653 * we don't need to attach clean inodes or those only
1654 * with unlogged changes (which we throw away, anyway).
1655 */
1662 }
1675 }
1679 }
1683 }
1685 /*
1686 * This is called to return an inode to the inode free list.
1687 * The inode should already be truncated to 0 length and have
1688 * no pages associated with it. This routine also assumes that
1689 * the inode is already a part of the transaction.
1690 *
1691 * The on-disk copy of the inode will have been added to the list
1692 * of unlinked inodes in the AGI. We need to remove the inode from
1693 * that list atomically with respect to freeing it here.
1694 */
1695 int
1700 {
1703 xfs_ino_t first_ino;
1714 /*
1715 * Pull the on-disk inode from the AGI unlinked list.
1716 */
1720 }
1725 }
1732 /*
1733 * Bump the generation count so no one will be confused
1734 * by reincarnations of this inode.
1735 */
1744 /*
1745 * Clear the on-disk di_mode. This is to prevent xfs_bulkstat
1746 * from picking up this inode when it is reclaimed (its incore state
1747 * initialzed but not flushed to disk yet). The in-core di_mode is
1748 * already cleared and a corresponding transaction logged.
1749 * The hack here just synchronizes the in-core to on-disk
1750 * di_mode value in advance before the actual inode sync to disk.
1751 * This is OK because the inode is already unlinked and would never
1752 * change its di_mode again for this inode generation.
1753 * This is a temporary hack that would require a proper fix
1754 * in the future.
1755 */
1760 }
1763 }
1765 /*
1766 * Reallocate the space for if_broot based on the number of records
1767 * being added or deleted as indicated in rec_diff. Move the records
1768 * and pointers in if_broot to fit the new size. When shrinking this
1769 * will eliminate holes between the records and pointers created by
1770 * the caller. When growing this will create holes to be filled in
1771 * by the caller.
1772 *
1773 * The caller must not request to add more records than would fit in
1774 * the on-disk inode root. If the if_broot is currently NULL, then
1775 * if we adding records one will be allocated. The caller must also
1776 * not request that the number of records go below zero, although
1777 * it can go to zero.
1778 *
1779 * ip -- the inode whose if_broot area is changing
1780 * ext_diff -- the change in the number of records, positive or negative,
1781 * requested for the if_broot array.
1782 */
1783 void
1788 {
1798 /*
1799 * Handle the degenerate case quietly.
1800 */
1803 }
1807 /*
1808 * If there wasn't any memory allocated before, just
1809 * allocate it now and get out.
1810 */
1816 }
1818 /*
1819 * If there is already an existing if_broot, then we need
1820 * to realloc() it and shift the pointers to their new
1821 * location. The records don't change location because
1822 * they are kept butted up against the btree block header.
1823 */
1839 }
1841 /*
1842 * rec_diff is less than 0. In this case, we are shrinking the
1843 * if_broot buffer. It must already exist. If we go to zero
1844 * records, just get rid of the root and clear the status bit.
1845 */
1852 else
1856 /*
1857 * First copy over the btree block header.
1858 */
1863 }
1865 /*
1866 * Only copy the records and pointers if there are any.
1867 */
1869 /*
1870 * First copy the records.
1871 */
1876 /*
1877 * Then copy the pointers.
1878 */
1884 }
1891 }
1894 /*
1895 * This is called when the amount of space needed for if_data
1896 * is increased or decreased. The change in size is indicated by
1897 * the number of bytes that need to be added or deleted in the
1898 * byte_diff parameter.
1899 *
1900 * If the amount of space needed has decreased below the size of the
1901 * inline buffer, then switch to using the inline buffer. Otherwise,
1902 * use kmem_realloc() or kmem_alloc() to adjust the size of the buffer
1903 * to what is needed.
1904 *
1905 * ip -- the inode whose if_data area is changing
1906 * byte_diff -- the change in the number of bytes, positive or negative,
1907 * requested for the if_data array.
1908 */
1909 void
1914 {
1921 }
1930 }
1934 /*
1935 * If the valid extents/data can fit in if_inline_ext/data,
1936 * copy them from the malloc'd vector and free it.
1937 */
1943 new_size);
1946 }
1949 /*
1950 * Stuck with malloc/realloc.
1951 * For inline data, the underlying buffer must be
1952 * a multiple of 4 bytes in size so that it can be
1953 * logged and stay on word boundaries. We enforce
1954 * that here.
1955 */
1962 /*
1963 * Only do the realloc if the underlying size
1964 * is really changing.
1965 */
1969 real_size,
1972 }
1979 }
1980 }
1984 }
1986 void
1990 {
1997 }
1999 /*
2000 * If the format is local, then we can't have an extents
2001 * array so just look for an inline data array. If we're
2002 * not local then we may or may not have an extents list,
2003 * so check and free it up if we do.
2004 */
2012 }
2019 }
2026 }
2027 }
2029 /*
2030 * This is called to unpin an inode. The caller must have the inode locked
2031 * in at least shared mode so that the buffer cannot be subsequently pinned
2032 * once someone is waiting for it to be unpinned.
2033 */
2034 static void
2037 {
2042 /* Give the log a push to start the unpinning I/O */
2045 }
2047 static void
2050 {
2062 }
2064 void
2067 {
2070 }
2072 /*
2073 * xfs_iextents_copy()
2074 *
2075 * This is called to copy the REAL extents (as opposed to the delayed
2076 * allocation extents) from the inode into the given buffer. It
2077 * returns the number of bytes copied into the buffer.
2078 *
2079 * If there are no delayed allocation extents, then we can just
2080 * memcpy() the extents into the buffer. Otherwise, we need to
2081 * examine each extent in turn and skip those which are delayed.
2082 */
2083 int
2088 {
2093 xfs_fsblock_t start_block;
2103 /*
2104 * There are some delayed allocation extents in the
2105 * inode, so copy the extents one at a time and skip
2106 * the delayed ones. There must be at least one
2107 * non-delayed extent.
2108 */
2114 /*
2115 * It's a delayed allocation extent, so skip it.
2116 */
2118 }
2120 /* Translate to on disk format */
2123 dp++;
2124 copied++;
2125 }
2130 }
2132 /*
2133 * Each of the following cases stores data into the same region
2134 * of the on-disk inode, so only one of them can be valid at
2135 * any given time. While it is possible to have conflicting formats
2136 * and log flags, e.g. having XFS_ILOG_?DATA set when the fork is
2137 * in EXTENTS format, this can only happen when the fork has
2138 * changed formats after being modified but before being flushed.
2139 * In these cases, the format always takes precedence, because the
2140 * format indicates the current state of the fork.
2141 */
2142 /*ARGSUSED*/
2143 STATIC void
2150 {
2154 #ifdef XFS_TRANS_DEBUG
2156 #endif
2167 /*
2168 * This can happen if we gave up in iformat in an error path,
2169 * for the attribute fork.
2170 */
2174 }
2184 }
2195 whichfork);
2196 }
2205 XFS_BROOT_SIZE_ADJ));
2209 }
2216 }
2225 }
2231 }
2232 }
2234 STATIC int
2238 {
2262 /* really need a gang lookup range call here */
2273 /*
2274 * because this is an RCU protected lookup, we could find a
2275 * recently freed or even reallocated inode during the lookup.
2276 * We need to check under the i_flags_lock for a valid inode
2277 * here. Skip it if it is not valid or the wrong inode.
2278 */
2284 }
2287 /*
2288 * Do an un-protected check to see if the inode is dirty and
2289 * is a candidate for flushing. These checks will be repeated
2290 * later after the appropriate locks are acquired.
2291 */
2295 /*
2296 * Try to get locks. If any are unavailable or it is pinned,
2297 * then this inode cannot be flushed and is skipped.
2298 */
2305 }
2310 }
2312 /*
2313 * arriving here means that this inode can be flushed. First
2314 * re-check that it's dirty before flushing.
2315 */
2322 }
2323 clcount++;
2326 }
2328 }
2333 }
2335 out_free:
2338 out_put:
2343 cluster_corrupt_out:
2344 /*
2345 * Corruption detected in the clustering loop. Invalidate the
2346 * inode buffer and shut down the filesystem.
2347 */
2349 /*
2350 * Clean up the buffer. If it was B_DELWRI, just release it --
2351 * brelse can handle it with no problems. If not, shut down the
2352 * filesystem before releasing the buffer.
2353 */
2361 /*
2362 * Just like incore_relse: if we have b_iodone functions,
2363 * mark the buffer as an error and call them. Otherwise
2364 * mark it as stale and brelse.
2365 */
2374 }
2375 }
2377 /*
2378 * Unlocks the flush lock
2379 */
2384 }
2386 /*
2387 * xfs_iflush() will write a modified inode's changes out to the
2388 * inode's on disk home. The caller must have the inode lock held
2389 * in at least shared mode and the inode flush completion must be
2390 * active as well. The inode lock will still be held upon return from
2391 * the call and the caller is free to unlock it.
2392 * The inode flush will be completed when the inode reaches the disk.
2393 * The flags indicate how the inode's buffer should be written out.
2394 */
2395 int
2398 uint flags)
2399 {
2416 /*
2417 * We can't flush the inode until it is unpinned, so wait for it if we
2418 * are allowed to block. We know no one new can pin it, because we are
2419 * holding the inode lock shared and you need to hold it exclusively to
2420 * pin the inode.
2421 *
2422 * If we are not allowed to block, force the log out asynchronously so
2423 * that when we come back the inode will be unpinned. If other inodes
2424 * in the same cluster are dirty, they will probably write the inode
2425 * out for us if they occur after the log force completes.
2426 */
2431 }
2434 /*
2435 * For stale inodes we cannot rely on the backing buffer remaining
2436 * stale in cache for the remaining life of the stale inode and so
2437 * xfs_itobp() below may give us a buffer that no longer contains
2438 * inodes below. We have to check this after ensuring the inode is
2439 * unpinned so that it is safe to reclaim the stale inode after the
2440 * flush call.
2441 */
2445 }
2447 /*
2448 * This may have been unpinned because the filesystem is shutting
2449 * down forcibly. If that's the case we must not write this inode
2450 * to disk, because the log record didn't make it to disk!
2451 */
2457 }
2459 /*
2460 * Get the buffer containing the on-disk inode.
2461 */
2467 }
2469 /*
2470 * First flush out the inode that xfs_iflush was called with.
2471 */
2476 /*
2477 * If the buffer is pinned then push on the log now so we won't
2478 * get stuck waiting in the write for too long.
2479 */
2483 /*
2484 * inode clustering:
2485 * see if other inodes can be gathered into this write
2486 */
2493 else
2499 corrupt_out:
2502 cluster_corrupt_out:
2503 /*
2504 * Unlocks the flush lock
2505 */
2508 }
2511 STATIC int
2515 {
2519 #ifdef XFS_TRANS_DEBUG
2521 #endif
2531 /* set *dip = inode's place in the buffer */
2540 }
2547 }
2557 }
2568 }
2569 }
2572 XFS_RANDOM_IFLUSH_5)) {
2574 "%s: detected corrupt incore inode %Lu, "
2580 }
2587 }
2588 /*
2589 * bump the flush iteration count, used to detect flushes which
2590 * postdate a log record during recovery.
2591 */
2595 /*
2596 * Copy the dirty parts of the inode into the on-disk
2597 * inode. We always copy out the core of the inode,
2598 * because if the inode is dirty at all the core must
2599 * be.
2600 */
2603 /* Wrap, we never let the log put out DI_MAX_FLUSH */
2607 /*
2608 * If this is really an old format inode and the superblock version
2609 * has not been updated to support only new format inodes, then
2610 * convert back to the old inode format. If the superblock version
2611 * has been updated, then make the conversion permanent.
2612 */
2616 /*
2617 * Convert it back.
2618 */
2622 /*
2623 * The superblock version has already been bumped,
2624 * so just make the conversion to the new inode
2625 * format permanent.
2626 */
2635 }
2636 }
2643 /*
2644 * We've recorded everything logged in the inode, so we'd like to clear
2645 * the ili_fields bits so we don't log and flush things unnecessarily.
2646 * However, we can't stop logging all this information until the data
2647 * we've copied into the disk buffer is written to disk. If we did we
2648 * might overwrite the copy of the inode in the log with all the data
2649 * after re-logging only part of it, and in the face of a crash we
2650 * wouldn't have all the data we need to recover.
2651 *
2652 * What we do is move the bits to the ili_last_fields field. When
2653 * logging the inode, these bits are moved back to the ili_fields field.
2654 * In the xfs_iflush_done() routine we clear ili_last_fields, since we
2655 * know that the information those bits represent is permanently on
2656 * disk. As long as the flush completes before the inode is logged
2657 * again, then both ili_fields and ili_last_fields will be cleared.
2658 *
2659 * We can play with the ili_fields bits here, because the inode lock
2660 * must be held exclusively in order to set bits there and the flush
2661 * lock protects the ili_last_fields bits. Set ili_logged so the flush
2662 * done routine can tell whether or not to look in the AIL. Also, store
2663 * the current LSN of the inode so that we can tell whether the item has
2664 * moved in the AIL from xfs_iflush_done(). In order to read the lsn we
2665 * need the AIL lock, because it is a 64 bit value that cannot be read
2666 * atomically.
2667 */
2676 /*
2677 * Attach the function xfs_iflush_done to the inode's
2678 * buffer. This will remove the inode from the AIL
2679 * and unlock the inode's flush lock when the inode is
2680 * completely written to disk.
2681 */
2687 /*
2688 * We're flushing an inode which is not in the AIL and has
2689 * not been logged. For this case we can immediately drop
2690 * the inode flush lock because we can avoid the whole
2691 * AIL state thing. It's OK to drop the flush lock now,
2692 * because we've already locked the buffer and to do anything
2693 * you really need both.
2694 */
2699 }
2701 }
2705 corrupt_out:
2707 }
2709 void
2712 {
2725 }
2728 }
2730 /*
2731 * Return a pointer to the extent record at file index idx.
2732 */
2733 xfs_bmbt_rec_host_t *
2737 {
2754 }
2755 }
2757 /*
2758 * Insert new item(s) into the extent records for incore inode
2759 * fork 'ifp'. 'count' new items are inserted at index 'idx'.
2760 */
2761 void
2768 {
2778 }
2780 /*
2781 * This is called when the amount of space required for incore file
2782 * extents needs to be increased. The ext_diff parameter stores the
2783 * number of new extents being added and the idx parameter contains
2784 * the extent index where the new extents will be added. If the new
2785 * extents are being appended, then we just need to (re)allocate and
2786 * initialize the space. Otherwise, if the new extents are being
2787 * inserted into the middle of the existing entries, a bit more work
2788 * is required to make room for the new extents to be inserted. The
2789 * caller is responsible for filling in the new extent entries upon
2790 * return.
2791 */
2792 void
2797 {
2806 /*
2807 * If the new number of extents (nextents + ext_diff)
2808 * fits inside the inode, then continue to use the inline
2809 * extent buffer.
2810 */
2817 }
2820 }
2821 /*
2822 * Otherwise use a linear (direct) extent list.
2823 * If the extents are currently inside the inode,
2824 * xfs_iext_realloc_direct will switch us from
2825 * inline to direct extent allocation mode.
2826 */
2834 }
2835 }
2836 /* Indirection array */
2849 }
2850 /* Extents fit in target extent page */
2858 }
2861 }
2862 /* Insert a new extent page */
2866 }
2867 /*
2868 * If extent(s) are being appended to the last page in
2869 * the indirection array and the new extent(s) don't fit
2870 * in the page, then erp is NULL and erp_idx is set to
2871 * the next index needed in the indirection array.
2872 */
2881 erp_idx++;
2882 }
2883 }
2884 }
2885 }
2887 }
2889 /*
2890 * This is called when incore extents are being added to the indirection
2891 * array and the new extents do not fit in the target extent list. The
2892 * erp_idx parameter contains the irec index for the target extent list
2893 * in the indirection array, and the idx parameter contains the extent
2894 * index within the list. The number of extents being added is stored
2895 * in the count parameter.
2896 *
2897 * |-------| |-------|
2898 * | | | | idx - number of extents before idx
2899 * | idx | | count |
2900 * | | | | count - number of extents being inserted at idx
2901 * |-------| |-------|
2902 * | count | | nex2 | nex2 - number of extents after idx + count
2903 * |-------| |-------|
2904 */
2905 void
2911 {
2925 /*
2926 * Save second part of target extent list
2927 * (all extents past */
2935 }
2937 /*
2938 * Add the new extents to the end of the target
2939 * list, then allocate new irec record(s) and
2940 * extent buffer(s) as needed to store the rest
2941 * of the new extents.
2942 */
2949 }
2951 erp_idx++;
2957 }
2959 /* Add nex2 extents back to indirection array */
2961 xfs_extnum_t ext_avail;
2967 /*
2968 * If nex2 extents fit in the current page, append
2969 * nex2_ep after the new extents.
2970 */
2973 }
2974 /*
2975 * Otherwise, check if space is available in the
2976 * next page.
2977 */
2981 erp_idx++;
2982 erp++;
2983 /* Create a hole for nex2 extents */
2986 }
2987 /*
2988 * Final choice, create a new extent page for
2989 * nex2 extents.
2990 */
2992 erp_idx++;
2994 }
2999 }
3000 }
3002 /*
3003 * This is called when the amount of space required for incore file
3004 * extents needs to be decreased. The ext_diff parameter stores the
3005 * number of extents to be removed and the idx parameter contains
3006 * the extent index where the extents will be removed from.
3007 *
3008 * If the amount of space needed has decreased below the linear
3009 * limit, XFS_IEXT_BUFSZ, then switch to using the contiguous
3010 * extent array. Otherwise, use kmem_realloc() to adjust the
3011 * size to what is needed.
3012 */
3013 void
3019 {
3038 }
3040 }
3042 /*
3043 * This removes ext_diff extents from the inline buffer, beginning
3044 * at extent index idx.
3045 */
3046 void
3051 {
3070 }
3071 }
3073 /*
3074 * This removes ext_diff extents from a linear (direct) extent list,
3075 * beginning at extent index idx. If the extents are being removed
3076 * from the end of the list (ie. truncate) then we just need to re-
3077 * allocate the list to remove the extra space. Otherwise, if the
3078 * extents are being removed from the middle of the existing extent
3079 * entries, then we first need to move the extent records beginning
3080 * at idx + ext_diff up in the list to overwrite the records being
3081 * removed, then remove the extra space via kmem_realloc.
3082 */
3083 void
3088 {
3100 }
3101 /* Move extents up in the list (if needed) */
3107 }
3110 /*
3111 * Reallocate the direct extent list. If the extents
3112 * will fit inside the inode then xfs_iext_realloc_direct
3113 * will switch from direct to inline extent allocation
3114 * mode for us.
3115 */
3118 }
3120 /*
3121 * This is called when incore extents are being removed from the
3122 * indirection array and the extents being removed span multiple extent
3123 * buffers. The idx parameter contains the file extent index where we
3124 * want to begin removing extents, and the count parameter contains
3125 * how many extents need to be removed.
3126 *
3127 * |-------| |-------|
3128 * | nex1 | | | nex1 - number of extents before idx
3129 * |-------| | count |
3130 * | | | | count - number of extents being removed at idx
3131 * | count | |-------|
3132 * | | | nex2 | nex2 - number of extents after idx + count
3133 * |-------| |-------|
3134 */
3135 void
3140 {
3157 /*
3158 * Check for deletion of entire list;
3159 * xfs_iext_irec_remove() updates extent offsets.
3160 */
3167 XFS_IEXT_BUFSZ);
3173 }
3174 }
3175 /* Move extents up (if needed) */
3180 }
3181 /* Zero out rest of page */
3184 /* Update remaining counters */
3189 erp_idx++;
3190 erp++;
3191 }
3194 }
3196 /*
3197 * Create, destroy, or resize a linear (direct) block of extents.
3198 */
3199 void
3203 {
3212 /* Free extent records */
3215 }
3216 /* Resize direct extent list and zero any new bytes */
3218 /* Check if extents will fit inside the inode */
3224 }
3227 }
3231 rnew_size,
3233 }
3238 }
3239 }
3240 /*
3241 * Switch from the inline extent buffer to a direct
3242 * extent list. Be sure to include the inline extent
3243 * bytes in new_size.
3244 */
3249 }
3251 }
3254 }
3256 /*
3257 * Switch from linear (direct) extent records to inline buffer.
3258 */
3259 void
3263 {
3266 /*
3267 * The inline buffer was zeroed when we switched
3268 * from inline to direct extent allocation mode,
3269 * so we don't need to clear it here.
3270 */
3276 }
3278 /*
3279 * Switch from inline buffer to linear (direct) extent records.
3280 * new_size should already be rounded up to the next power of 2
3281 * by the caller (when appropriate), so use new_size as it is.
3282 * However, since new_size may be rounded up, we can't update
3283 * if_bytes here. It is the caller's responsibility to update
3284 * if_bytes upon return.
3285 */
3286 void
3290 {
3298 }
3300 }
3302 /*
3303 * Resize an extent indirection array to new_size bytes.
3304 */
3305 STATIC void
3309 {
3324 }
3325 }
3327 /*
3328 * Switch from indirection array to linear (direct) extent allocations.
3329 */
3330 STATIC void
3333 {
3353 }
3354 }
3356 /*
3357 * Free incore file extents.
3358 */
3359 void
3362 {
3370 }
3377 }
3381 }
3383 /*
3384 * Return a pointer to the extent record for file system block bno.
3385 */
3391 {
3406 }
3409 /* Find target extent list */
3417 }
3418 /* Binary search extent records */
3429 /* Convert back to file-based extent index */
3432 }
3435 }
3436 }
3437 /* Convert back to file-based extent index */
3440 }
3446 }
3447 }
3450 }
3452 /*
3453 * Return a pointer to the indirection array entry containing the
3454 * extent record for filesystem block bno. Store the index of the
3455 * target irec in *erp_idxp.
3456 */
3462 {
3486 }
3487 }
3490 }
3492 /*
3493 * Return a pointer to the indirection array entry containing the
3494 * extent record at file extent index *idxp. Store the index of the
3495 * target irec in *erp_idxp and store the page index of the target
3496 * extent record in *idxp.
3497 */
3498 xfs_ext_irec_t *
3504 {
3523 /* Binary search extent irec's */
3539 erp_idx++;
3545 }
3546 }
3550 }
3552 /*
3553 * Allocate and initialize an indirection array once the space needed
3554 * for incore extents increases above XFS_IEXT_BUFSZ.
3555 */
3556 void
3559 {
3575 }
3586 }
3588 /*
3589 * Allocate and initialize a new entry in the indirection array.
3590 */
3591 xfs_ext_irec_t *
3595 {
3603 /* Resize indirection array */
3606 /*
3607 * Move records down in the array so the
3608 * new page can use erp_idx.
3609 */
3613 }
3616 /* Initialize new extent record */
3625 }
3627 /*
3628 * Remove a record from the indirection array.
3629 */
3630 void
3634 {
3646 }
3647 /* Compact extent records */
3651 }
3652 /*
3653 * Manually free the last extent record from the indirection
3654 * array. A call to xfs_iext_realloc_indirect() with a size
3655 * of zero would result in a call to xfs_iext_destroy() which
3656 * would in turn call this function again, creating a nasty
3657 * infinite loop.
3658 */
3664 }
3666 }
3668 /*
3669 * This is called to clean up large amounts of unused memory allocated
3670 * by the indirection array. Before compacting anything though, verify
3671 * that the indirection array is still needed and switch back to the
3672 * linear extent list (or even the inline buffer) if possible. The
3673 * compaction policy is as follows:
3674 *
3675 * Full Compaction: Extents fit into a single page (or inline buffer)
3676 * Partial Compaction: Extents occupy less than 50% of allocated space
3677 * No Compaction: Extents occupy at least 50% of allocated space
3678 */
3679 void
3682 {
3699 }
3700 }
3702 /*
3703 * Combine extents from neighboring extent pages.
3704 */
3705 void
3708 {
3724 /*
3725 * Free page before removing extent record
3726 * so er_extoffs don't get modified in
3727 * xfs_iext_irec_remove.
3728 */
3734 erp_idx++;
3735 }
3736 }
3737 }
3739 /*
3740 * This is called to update the er_extoff field in the indirection
3741 * array when extents have been added or removed from one of the
3742 * extent lists. erp_idx contains the irec index to begin updating
3743 * at and ext_diff contains the number of extents that were added
3744 * or removed.
3745 */
3746 void
3751 {
3759 }
3760 }