diff options
author | Randy Dunlap <rdunlap@xenotime.net> | 2006-10-11 04:21:07 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-10-11 14:14:16 -0400 |
commit | d0d856e8bd6e697cb44b2b4dd038f3bec576a70e (patch) | |
tree | c069f410d607e40faf30107efe719dc2d068283b /fs/ext4 | |
parent | 471d4011a9862efff02094388b8fe8cd67683c38 (diff) |
[PATCH] ext4: clean up comments in ext4-extents patch
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'fs/ext4')
-rw-r--r-- | fs/ext4/extents.c | 226 |
1 files changed, 128 insertions, 98 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 32526061a17d..e06e937a52b8 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c | |||
@@ -44,7 +44,10 @@ | |||
44 | #include <asm/uaccess.h> | 44 | #include <asm/uaccess.h> |
45 | 45 | ||
46 | 46 | ||
47 | /* this macro combines low and hi parts of phys. blocknr into ext4_fsblk_t */ | 47 | /* |
48 | * ext_pblock: | ||
49 | * combine low and high parts of physical block number into ext4_fsblk_t | ||
50 | */ | ||
48 | static inline ext4_fsblk_t ext_pblock(struct ext4_extent *ex) | 51 | static inline ext4_fsblk_t ext_pblock(struct ext4_extent *ex) |
49 | { | 52 | { |
50 | ext4_fsblk_t block; | 53 | ext4_fsblk_t block; |
@@ -55,7 +58,10 @@ static inline ext4_fsblk_t ext_pblock(struct ext4_extent *ex) | |||
55 | return block; | 58 | return block; |
56 | } | 59 | } |
57 | 60 | ||
58 | /* this macro combines low and hi parts of phys. blocknr into ext4_fsblk_t */ | 61 | /* |
62 | * idx_pblock: | ||
63 | * combine low and high parts of a leaf physical block number into ext4_fsblk_t | ||
64 | */ | ||
59 | static inline ext4_fsblk_t idx_pblock(struct ext4_extent_idx *ix) | 65 | static inline ext4_fsblk_t idx_pblock(struct ext4_extent_idx *ix) |
60 | { | 66 | { |
61 | ext4_fsblk_t block; | 67 | ext4_fsblk_t block; |
@@ -66,7 +72,11 @@ static inline ext4_fsblk_t idx_pblock(struct ext4_extent_idx *ix) | |||
66 | return block; | 72 | return block; |
67 | } | 73 | } |
68 | 74 | ||
69 | /* the routine stores large phys. blocknr into extent breaking it into parts */ | 75 | /* |
76 | * ext4_ext_store_pblock: | ||
77 | * stores a large physical block number into an extent struct, | ||
78 | * breaking it into parts | ||
79 | */ | ||
70 | static inline void ext4_ext_store_pblock(struct ext4_extent *ex, ext4_fsblk_t pb) | 80 | static inline void ext4_ext_store_pblock(struct ext4_extent *ex, ext4_fsblk_t pb) |
71 | { | 81 | { |
72 | ex->ee_start = cpu_to_le32((unsigned long) (pb & 0xffffffff)); | 82 | ex->ee_start = cpu_to_le32((unsigned long) (pb & 0xffffffff)); |
@@ -74,7 +84,11 @@ static inline void ext4_ext_store_pblock(struct ext4_extent *ex, ext4_fsblk_t pb | |||
74 | ex->ee_start_hi = cpu_to_le16((unsigned long) ((pb >> 31) >> 1) & 0xffff); | 84 | ex->ee_start_hi = cpu_to_le16((unsigned long) ((pb >> 31) >> 1) & 0xffff); |
75 | } | 85 | } |
76 | 86 | ||
77 | /* the routine stores large phys. blocknr into index breaking it into parts */ | 87 | /* |
88 | * ext4_idx_store_pblock: | ||
89 | * stores a large physical block number into an index struct, | ||
90 | * breaking it into parts | ||
91 | */ | ||
78 | static inline void ext4_idx_store_pblock(struct ext4_extent_idx *ix, ext4_fsblk_t pb) | 92 | static inline void ext4_idx_store_pblock(struct ext4_extent_idx *ix, ext4_fsblk_t pb) |
79 | { | 93 | { |
80 | ix->ei_leaf = cpu_to_le32((unsigned long) (pb & 0xffffffff)); | 94 | ix->ei_leaf = cpu_to_le32((unsigned long) (pb & 0xffffffff)); |
@@ -179,8 +193,8 @@ static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode, | |||
179 | if ((ex = path[depth].p_ext)) | 193 | if ((ex = path[depth].p_ext)) |
180 | return ext_pblock(ex)+(block-le32_to_cpu(ex->ee_block)); | 194 | return ext_pblock(ex)+(block-le32_to_cpu(ex->ee_block)); |
181 | 195 | ||
182 | /* it looks index is empty | 196 | /* it looks like index is empty; |
183 | * try to find starting from index itself */ | 197 | * try to find starting block from index itself */ |
184 | if (path[depth].p_bh) | 198 | if (path[depth].p_bh) |
185 | return path[depth].p_bh->b_blocknr; | 199 | return path[depth].p_bh->b_blocknr; |
186 | } | 200 | } |
@@ -317,7 +331,8 @@ static void ext4_ext_drop_refs(struct ext4_ext_path *path) | |||
317 | } | 331 | } |
318 | 332 | ||
319 | /* | 333 | /* |
320 | * binary search for closest index by given block | 334 | * ext4_ext_binsearch_idx: |
335 | * binary search for the closest index of the given block | ||
321 | */ | 336 | */ |
322 | static void | 337 | static void |
323 | ext4_ext_binsearch_idx(struct inode *inode, struct ext4_ext_path *path, int block) | 338 | ext4_ext_binsearch_idx(struct inode *inode, struct ext4_ext_path *path, int block) |
@@ -375,7 +390,8 @@ ext4_ext_binsearch_idx(struct inode *inode, struct ext4_ext_path *path, int bloc | |||
375 | } | 390 | } |
376 | 391 | ||
377 | /* | 392 | /* |
378 | * binary search for closest extent by given block | 393 | * ext4_ext_binsearch: |
394 | * binary search for closest extent of the given block | ||
379 | */ | 395 | */ |
380 | static void | 396 | static void |
381 | ext4_ext_binsearch(struct inode *inode, struct ext4_ext_path *path, int block) | 397 | ext4_ext_binsearch(struct inode *inode, struct ext4_ext_path *path, int block) |
@@ -388,8 +404,8 @@ ext4_ext_binsearch(struct inode *inode, struct ext4_ext_path *path, int block) | |||
388 | 404 | ||
389 | if (eh->eh_entries == 0) { | 405 | if (eh->eh_entries == 0) { |
390 | /* | 406 | /* |
391 | * this leaf is empty yet: | 407 | * this leaf is empty: |
392 | * we get such a leaf in split/add case | 408 | * we get such a leaf in split/add case |
393 | */ | 409 | */ |
394 | return; | 410 | return; |
395 | } | 411 | } |
@@ -520,8 +536,9 @@ err: | |||
520 | } | 536 | } |
521 | 537 | ||
522 | /* | 538 | /* |
523 | * insert new index [logical;ptr] into the block at cupr | 539 | * ext4_ext_insert_index: |
524 | * it check where to insert: before curp or after curp | 540 | * insert new index [@logical;@ptr] into the block at @curp; |
541 | * check where to insert: before @curp or after @curp | ||
525 | */ | 542 | */ |
526 | static int ext4_ext_insert_index(handle_t *handle, struct inode *inode, | 543 | static int ext4_ext_insert_index(handle_t *handle, struct inode *inode, |
527 | struct ext4_ext_path *curp, | 544 | struct ext4_ext_path *curp, |
@@ -574,13 +591,14 @@ static int ext4_ext_insert_index(handle_t *handle, struct inode *inode, | |||
574 | } | 591 | } |
575 | 592 | ||
576 | /* | 593 | /* |
577 | * routine inserts new subtree into the path, using free index entry | 594 | * ext4_ext_split: |
578 | * at depth 'at: | 595 | * inserts new subtree into the path, using free index entry |
579 | * - allocates all needed blocks (new leaf and all intermediate index blocks) | 596 | * at depth @at: |
580 | * - makes decision where to split | 597 | * - allocates all needed blocks (new leaf and all intermediate index blocks) |
581 | * - moves remaining extens and index entries (right to the split point) | 598 | * - makes decision where to split |
582 | * into the newly allocated blocks | 599 | * - moves remaining extents and index entries (right to the split point) |
583 | * - initialize subtree | 600 | * into the newly allocated blocks |
601 | * - initializes subtree | ||
584 | */ | 602 | */ |
585 | static int ext4_ext_split(handle_t *handle, struct inode *inode, | 603 | static int ext4_ext_split(handle_t *handle, struct inode *inode, |
586 | struct ext4_ext_path *path, | 604 | struct ext4_ext_path *path, |
@@ -598,14 +616,14 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode, | |||
598 | int err = 0; | 616 | int err = 0; |
599 | 617 | ||
600 | /* make decision: where to split? */ | 618 | /* make decision: where to split? */ |
601 | /* FIXME: now desicion is simplest: at current extent */ | 619 | /* FIXME: now decision is simplest: at current extent */ |
602 | 620 | ||
603 | /* if current leaf will be splitted, then we should use | 621 | /* if current leaf will be split, then we should use |
604 | * border from split point */ | 622 | * border from split point */ |
605 | BUG_ON(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr)); | 623 | BUG_ON(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr)); |
606 | if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) { | 624 | if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) { |
607 | border = path[depth].p_ext[1].ee_block; | 625 | border = path[depth].p_ext[1].ee_block; |
608 | ext_debug("leaf will be splitted." | 626 | ext_debug("leaf will be split." |
609 | " next leaf starts at %d\n", | 627 | " next leaf starts at %d\n", |
610 | le32_to_cpu(border)); | 628 | le32_to_cpu(border)); |
611 | } else { | 629 | } else { |
@@ -616,16 +634,16 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode, | |||
616 | } | 634 | } |
617 | 635 | ||
618 | /* | 636 | /* |
619 | * if error occurs, then we break processing | 637 | * If error occurs, then we break processing |
620 | * and turn filesystem read-only. so, index won't | 638 | * and mark filesystem read-only. index won't |
621 | * be inserted and tree will be in consistent | 639 | * be inserted and tree will be in consistent |
622 | * state. next mount will repair buffers too | 640 | * state. Next mount will repair buffers too. |
623 | */ | 641 | */ |
624 | 642 | ||
625 | /* | 643 | /* |
626 | * get array to track all allocated blocks | 644 | * Get array to track all allocated blocks. |
627 | * we need this to handle errors and free blocks | 645 | * We need this to handle errors and free blocks |
628 | * upon them | 646 | * upon them. |
629 | */ | 647 | */ |
630 | ablocks = kmalloc(sizeof(ext4_fsblk_t) * depth, GFP_NOFS); | 648 | ablocks = kmalloc(sizeof(ext4_fsblk_t) * depth, GFP_NOFS); |
631 | if (!ablocks) | 649 | if (!ablocks) |
@@ -661,7 +679,7 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode, | |||
661 | neh->eh_depth = 0; | 679 | neh->eh_depth = 0; |
662 | ex = EXT_FIRST_EXTENT(neh); | 680 | ex = EXT_FIRST_EXTENT(neh); |
663 | 681 | ||
664 | /* move remain of path[depth] to the new leaf */ | 682 | /* move remainder of path[depth] to the new leaf */ |
665 | BUG_ON(path[depth].p_hdr->eh_entries != path[depth].p_hdr->eh_max); | 683 | BUG_ON(path[depth].p_hdr->eh_entries != path[depth].p_hdr->eh_max); |
666 | /* start copy from next extent */ | 684 | /* start copy from next extent */ |
667 | /* TODO: we could do it by single memmove */ | 685 | /* TODO: we could do it by single memmove */ |
@@ -813,11 +831,12 @@ cleanup: | |||
813 | } | 831 | } |
814 | 832 | ||
815 | /* | 833 | /* |
816 | * routine implements tree growing procedure: | 834 | * ext4_ext_grow_indepth: |
817 | * - allocates new block | 835 | * implements tree growing procedure: |
818 | * - moves top-level data (index block or leaf) into the new block | 836 | * - allocates new block |
819 | * - initialize new top-level, creating index that points to the | 837 | * - moves top-level data (index block or leaf) into the new block |
820 | * just created block | 838 | * - initializes new top-level, creating index that points to the |
839 | * just created block | ||
821 | */ | 840 | */ |
822 | static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode, | 841 | static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode, |
823 | struct ext4_ext_path *path, | 842 | struct ext4_ext_path *path, |
@@ -892,8 +911,9 @@ out: | |||
892 | } | 911 | } |
893 | 912 | ||
894 | /* | 913 | /* |
895 | * routine finds empty index and adds new leaf. if no free index found | 914 | * ext4_ext_create_new_leaf: |
896 | * then it requests in-depth growing | 915 | * finds empty index and adds new leaf. |
916 | * if no free index is found, then it requests in-depth growing. | ||
897 | */ | 917 | */ |
898 | static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode, | 918 | static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode, |
899 | struct ext4_ext_path *path, | 919 | struct ext4_ext_path *path, |
@@ -912,8 +932,8 @@ repeat: | |||
912 | curp--; | 932 | curp--; |
913 | } | 933 | } |
914 | 934 | ||
915 | /* we use already allocated block for index block | 935 | /* we use already allocated block for index block, |
916 | * so, subsequent data blocks should be contigoues */ | 936 | * so subsequent data blocks should be contiguous */ |
917 | if (EXT_HAS_FREE_INDEX(curp)) { | 937 | if (EXT_HAS_FREE_INDEX(curp)) { |
918 | /* if we found index with free entry, then use that | 938 | /* if we found index with free entry, then use that |
919 | * entry: create all needed subtree and add new leaf */ | 939 | * entry: create all needed subtree and add new leaf */ |
@@ -943,12 +963,12 @@ repeat: | |||
943 | } | 963 | } |
944 | 964 | ||
945 | /* | 965 | /* |
946 | * only first (depth 0 -> 1) produces free space | 966 | * only first (depth 0 -> 1) produces free space; |
947 | * in all other cases we have to split growed tree | 967 | * in all other cases we have to split the grown tree |
948 | */ | 968 | */ |
949 | depth = ext_depth(inode); | 969 | depth = ext_depth(inode); |
950 | if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) { | 970 | if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) { |
951 | /* now we need split */ | 971 | /* now we need to split */ |
952 | goto repeat; | 972 | goto repeat; |
953 | } | 973 | } |
954 | } | 974 | } |
@@ -958,10 +978,11 @@ out: | |||
958 | } | 978 | } |
959 | 979 | ||
960 | /* | 980 | /* |
961 | * returns allocated block in subsequent extent or EXT_MAX_BLOCK | 981 | * ext4_ext_next_allocated_block: |
962 | * NOTE: it consider block number from index entry as | 982 | * returns allocated block in subsequent extent or EXT_MAX_BLOCK. |
963 | * allocated block. thus, index entries have to be consistent | 983 | * NOTE: it considers block number from index entry as |
964 | * with leafs | 984 | * allocated block. Thus, index entries have to be consistent |
985 | * with leaves. | ||
965 | */ | 986 | */ |
966 | static unsigned long | 987 | static unsigned long |
967 | ext4_ext_next_allocated_block(struct ext4_ext_path *path) | 988 | ext4_ext_next_allocated_block(struct ext4_ext_path *path) |
@@ -993,6 +1014,7 @@ ext4_ext_next_allocated_block(struct ext4_ext_path *path) | |||
993 | } | 1014 | } |
994 | 1015 | ||
995 | /* | 1016 | /* |
1017 | * ext4_ext_next_leaf_block: | ||
996 | * returns first allocated block from next leaf or EXT_MAX_BLOCK | 1018 | * returns first allocated block from next leaf or EXT_MAX_BLOCK |
997 | */ | 1019 | */ |
998 | static unsigned ext4_ext_next_leaf_block(struct inode *inode, | 1020 | static unsigned ext4_ext_next_leaf_block(struct inode *inode, |
@@ -1021,8 +1043,9 @@ static unsigned ext4_ext_next_leaf_block(struct inode *inode, | |||
1021 | } | 1043 | } |
1022 | 1044 | ||
1023 | /* | 1045 | /* |
1024 | * if leaf gets modified and modified extent is first in the leaf | 1046 | * ext4_ext_correct_indexes: |
1025 | * then we have to correct all indexes above | 1047 | * if leaf gets modified and modified extent is first in the leaf, |
1048 | * then we have to correct all indexes above. | ||
1026 | * TODO: do we need to correct tree in all cases? | 1049 | * TODO: do we need to correct tree in all cases? |
1027 | */ | 1050 | */ |
1028 | int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode, | 1051 | int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode, |
@@ -1050,7 +1073,7 @@ int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode, | |||
1050 | } | 1073 | } |
1051 | 1074 | ||
1052 | /* | 1075 | /* |
1053 | * TODO: we need correction if border is smaller then current one | 1076 | * TODO: we need correction if border is smaller than current one |
1054 | */ | 1077 | */ |
1055 | k = depth - 1; | 1078 | k = depth - 1; |
1056 | border = path[depth].p_ext->ee_block; | 1079 | border = path[depth].p_ext->ee_block; |
@@ -1085,7 +1108,7 @@ ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1, | |||
1085 | /* | 1108 | /* |
1086 | * To allow future support for preallocated extents to be added | 1109 | * To allow future support for preallocated extents to be added |
1087 | * as an RO_COMPAT feature, refuse to merge to extents if | 1110 | * as an RO_COMPAT feature, refuse to merge to extents if |
1088 | * can result in the top bit of ee_len being set | 1111 | * this can result in the top bit of ee_len being set. |
1089 | */ | 1112 | */ |
1090 | if (le16_to_cpu(ex1->ee_len) + le16_to_cpu(ex2->ee_len) > EXT_MAX_LEN) | 1113 | if (le16_to_cpu(ex1->ee_len) + le16_to_cpu(ex2->ee_len) > EXT_MAX_LEN) |
1091 | return 0; | 1114 | return 0; |
@@ -1100,9 +1123,10 @@ ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1, | |||
1100 | } | 1123 | } |
1101 | 1124 | ||
1102 | /* | 1125 | /* |
1103 | * this routine tries to merge requsted extent into the existing | 1126 | * ext4_ext_insert_extent: |
1104 | * extent or inserts requested extent as new one into the tree, | 1127 | * tries to merge requsted extent into the existing extent or |
1105 | * creating new leaf in no-space case | 1128 | * inserts requested extent as new one into the tree, |
1129 | * creating new leaf in the no-space case. | ||
1106 | */ | 1130 | */ |
1107 | int ext4_ext_insert_extent(handle_t *handle, struct inode *inode, | 1131 | int ext4_ext_insert_extent(handle_t *handle, struct inode *inode, |
1108 | struct ext4_ext_path *path, | 1132 | struct ext4_ext_path *path, |
@@ -1163,8 +1187,8 @@ repeat: | |||
1163 | } | 1187 | } |
1164 | 1188 | ||
1165 | /* | 1189 | /* |
1166 | * there is no free space in found leaf | 1190 | * There is no free space in the found leaf. |
1167 | * we're gonna add new leaf in the tree | 1191 | * We're gonna add a new leaf in the tree. |
1168 | */ | 1192 | */ |
1169 | err = ext4_ext_create_new_leaf(handle, inode, path, newext); | 1193 | err = ext4_ext_create_new_leaf(handle, inode, path, newext); |
1170 | if (err) | 1194 | if (err) |
@@ -1377,7 +1401,8 @@ ext4_ext_put_in_cache(struct inode *inode, __u32 block, | |||
1377 | } | 1401 | } |
1378 | 1402 | ||
1379 | /* | 1403 | /* |
1380 | * this routine calculate boundaries of the gap requested block fits into | 1404 | * ext4_ext_put_gap_in_cache: |
1405 | * calculate boundaries of the gap that the requested block fits into | ||
1381 | * and cache this gap | 1406 | * and cache this gap |
1382 | */ | 1407 | */ |
1383 | static inline void | 1408 | static inline void |
@@ -1452,9 +1477,10 @@ ext4_ext_in_cache(struct inode *inode, unsigned long block, | |||
1452 | } | 1477 | } |
1453 | 1478 | ||
1454 | /* | 1479 | /* |
1455 | * routine removes index from the index block | 1480 | * ext4_ext_rm_idx: |
1456 | * it's used in truncate case only. thus all requests are for | 1481 | * removes index from the index block. |
1457 | * last index in the block only | 1482 | * It's used in truncate case only, thus all requests are for |
1483 | * last index in the block only. | ||
1458 | */ | 1484 | */ |
1459 | int ext4_ext_rm_idx(handle_t *handle, struct inode *inode, | 1485 | int ext4_ext_rm_idx(handle_t *handle, struct inode *inode, |
1460 | struct ext4_ext_path *path) | 1486 | struct ext4_ext_path *path) |
@@ -1480,11 +1506,12 @@ int ext4_ext_rm_idx(handle_t *handle, struct inode *inode, | |||
1480 | } | 1506 | } |
1481 | 1507 | ||
1482 | /* | 1508 | /* |
1483 | * This routine returns max. credits extent tree can consume. | 1509 | * ext4_ext_calc_credits_for_insert: |
1510 | * This routine returns max. credits that the extent tree can consume. | ||
1484 | * It should be OK for low-performance paths like ->writepage() | 1511 | * It should be OK for low-performance paths like ->writepage() |
1485 | * To allow many writing process to fit a single transaction, | 1512 | * To allow many writing processes to fit into a single transaction, |
1486 | * caller should calculate credits under truncate_mutex and | 1513 | * the caller should calculate credits under truncate_mutex and |
1487 | * pass actual path. | 1514 | * pass the actual path. |
1488 | */ | 1515 | */ |
1489 | int inline ext4_ext_calc_credits_for_insert(struct inode *inode, | 1516 | int inline ext4_ext_calc_credits_for_insert(struct inode *inode, |
1490 | struct ext4_ext_path *path) | 1517 | struct ext4_ext_path *path) |
@@ -1500,9 +1527,9 @@ int inline ext4_ext_calc_credits_for_insert(struct inode *inode, | |||
1500 | } | 1527 | } |
1501 | 1528 | ||
1502 | /* | 1529 | /* |
1503 | * given 32bit logical block (4294967296 blocks), max. tree | 1530 | * given 32-bit logical block (4294967296 blocks), max. tree |
1504 | * can be 4 levels in depth -- 4 * 340^4 == 53453440000. | 1531 | * can be 4 levels in depth -- 4 * 340^4 == 53453440000. |
1505 | * let's also add one more level for imbalance. | 1532 | * Let's also add one more level for imbalance. |
1506 | */ | 1533 | */ |
1507 | depth = 5; | 1534 | depth = 5; |
1508 | 1535 | ||
@@ -1510,13 +1537,13 @@ int inline ext4_ext_calc_credits_for_insert(struct inode *inode, | |||
1510 | needed = 2; | 1537 | needed = 2; |
1511 | 1538 | ||
1512 | /* | 1539 | /* |
1513 | * tree can be full, so it'd need to grow in depth: | 1540 | * tree can be full, so it would need to grow in depth: |
1514 | * allocation + old root + new root | 1541 | * allocation + old root + new root |
1515 | */ | 1542 | */ |
1516 | needed += 2 + 1 + 1; | 1543 | needed += 2 + 1 + 1; |
1517 | 1544 | ||
1518 | /* | 1545 | /* |
1519 | * Index split can happen, we'd need: | 1546 | * Index split can happen, we would need: |
1520 | * allocate intermediate indexes (bitmap + group) | 1547 | * allocate intermediate indexes (bitmap + group) |
1521 | * + change two blocks at each level, but root (already included) | 1548 | * + change two blocks at each level, but root (already included) |
1522 | */ | 1549 | */ |
@@ -1634,7 +1661,7 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, | |||
1634 | BUG_ON(b != ex_ee_block + ex_ee_len - 1); | 1661 | BUG_ON(b != ex_ee_block + ex_ee_len - 1); |
1635 | } | 1662 | } |
1636 | 1663 | ||
1637 | /* at present, extent can't cross block group */ | 1664 | /* at present, extent can't cross block group: */ |
1638 | /* leaf + bitmap + group desc + sb + inode */ | 1665 | /* leaf + bitmap + group desc + sb + inode */ |
1639 | credits = 5; | 1666 | credits = 5; |
1640 | if (ex == EXT_FIRST_EXTENT(eh)) { | 1667 | if (ex == EXT_FIRST_EXTENT(eh)) { |
@@ -1660,7 +1687,7 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, | |||
1660 | goto out; | 1687 | goto out; |
1661 | 1688 | ||
1662 | if (num == 0) { | 1689 | if (num == 0) { |
1663 | /* this extent is removed entirely mark slot unused */ | 1690 | /* this extent is removed; mark slot entirely unused */ |
1664 | ext4_ext_store_pblock(ex, 0); | 1691 | ext4_ext_store_pblock(ex, 0); |
1665 | eh->eh_entries = cpu_to_le16(le16_to_cpu(eh->eh_entries)-1); | 1692 | eh->eh_entries = cpu_to_le16(le16_to_cpu(eh->eh_entries)-1); |
1666 | } | 1693 | } |
@@ -1692,7 +1719,8 @@ out: | |||
1692 | } | 1719 | } |
1693 | 1720 | ||
1694 | /* | 1721 | /* |
1695 | * returns 1 if current index have to be freed (even partial) | 1722 | * ext4_ext_more_to_rm: |
1723 | * returns 1 if current index has to be freed (even partial) | ||
1696 | */ | 1724 | */ |
1697 | static int inline | 1725 | static int inline |
1698 | ext4_ext_more_to_rm(struct ext4_ext_path *path) | 1726 | ext4_ext_more_to_rm(struct ext4_ext_path *path) |
@@ -1703,7 +1731,7 @@ ext4_ext_more_to_rm(struct ext4_ext_path *path) | |||
1703 | return 0; | 1731 | return 0; |
1704 | 1732 | ||
1705 | /* | 1733 | /* |
1706 | * if truncate on deeper level happened it it wasn't partial | 1734 | * if truncate on deeper level happened, it wasn't partial, |
1707 | * so we have to consider current index for truncation | 1735 | * so we have to consider current index for truncation |
1708 | */ | 1736 | */ |
1709 | if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block) | 1737 | if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block) |
@@ -1729,8 +1757,8 @@ int ext4_ext_remove_space(struct inode *inode, unsigned long start) | |||
1729 | ext4_ext_invalidate_cache(inode); | 1757 | ext4_ext_invalidate_cache(inode); |
1730 | 1758 | ||
1731 | /* | 1759 | /* |
1732 | * we start scanning from right side freeing all the blocks | 1760 | * We start scanning from right side, freeing all the blocks |
1733 | * after i_size and walking into the deep | 1761 | * after i_size and walking into the tree depth-wise. |
1734 | */ | 1762 | */ |
1735 | path = kmalloc(sizeof(struct ext4_ext_path) * (depth + 1), GFP_KERNEL); | 1763 | path = kmalloc(sizeof(struct ext4_ext_path) * (depth + 1), GFP_KERNEL); |
1736 | if (path == NULL) { | 1764 | if (path == NULL) { |
@@ -1749,7 +1777,7 @@ int ext4_ext_remove_space(struct inode *inode, unsigned long start) | |||
1749 | if (i == depth) { | 1777 | if (i == depth) { |
1750 | /* this is leaf block */ | 1778 | /* this is leaf block */ |
1751 | err = ext4_ext_rm_leaf(handle, inode, path, start); | 1779 | err = ext4_ext_rm_leaf(handle, inode, path, start); |
1752 | /* root level have p_bh == NULL, brelse() eats this */ | 1780 | /* root level has p_bh == NULL, brelse() eats this */ |
1753 | brelse(path[i].p_bh); | 1781 | brelse(path[i].p_bh); |
1754 | path[i].p_bh = NULL; | 1782 | path[i].p_bh = NULL; |
1755 | i--; | 1783 | i--; |
@@ -1772,14 +1800,14 @@ int ext4_ext_remove_space(struct inode *inode, unsigned long start) | |||
1772 | BUG_ON(path[i].p_hdr->eh_magic != EXT4_EXT_MAGIC); | 1800 | BUG_ON(path[i].p_hdr->eh_magic != EXT4_EXT_MAGIC); |
1773 | 1801 | ||
1774 | if (!path[i].p_idx) { | 1802 | if (!path[i].p_idx) { |
1775 | /* this level hasn't touched yet */ | 1803 | /* this level hasn't been touched yet */ |
1776 | path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr); | 1804 | path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr); |
1777 | path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1; | 1805 | path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1; |
1778 | ext_debug("init index ptr: hdr 0x%p, num %d\n", | 1806 | ext_debug("init index ptr: hdr 0x%p, num %d\n", |
1779 | path[i].p_hdr, | 1807 | path[i].p_hdr, |
1780 | le16_to_cpu(path[i].p_hdr->eh_entries)); | 1808 | le16_to_cpu(path[i].p_hdr->eh_entries)); |
1781 | } else { | 1809 | } else { |
1782 | /* we've already was here, see at next index */ | 1810 | /* we were already here, see at next index */ |
1783 | path[i].p_idx--; | 1811 | path[i].p_idx--; |
1784 | } | 1812 | } |
1785 | 1813 | ||
@@ -1799,19 +1827,19 @@ int ext4_ext_remove_space(struct inode *inode, unsigned long start) | |||
1799 | break; | 1827 | break; |
1800 | } | 1828 | } |
1801 | 1829 | ||
1802 | /* put actual number of indexes to know is this | 1830 | /* save actual number of indexes since this |
1803 | * number got changed at the next iteration */ | 1831 | * number is changed at the next iteration */ |
1804 | path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries); | 1832 | path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries); |
1805 | i++; | 1833 | i++; |
1806 | } else { | 1834 | } else { |
1807 | /* we finish processing this index, go up */ | 1835 | /* we finished processing this index, go up */ |
1808 | if (path[i].p_hdr->eh_entries == 0 && i > 0) { | 1836 | if (path[i].p_hdr->eh_entries == 0 && i > 0) { |
1809 | /* index is empty, remove it | 1837 | /* index is empty, remove it; |
1810 | * handle must be already prepared by the | 1838 | * handle must be already prepared by the |
1811 | * truncatei_leaf() */ | 1839 | * truncatei_leaf() */ |
1812 | err = ext4_ext_rm_idx(handle, inode, path + i); | 1840 | err = ext4_ext_rm_idx(handle, inode, path + i); |
1813 | } | 1841 | } |
1814 | /* root level have p_bh == NULL, brelse() eats this */ | 1842 | /* root level has p_bh == NULL, brelse() eats this */ |
1815 | brelse(path[i].p_bh); | 1843 | brelse(path[i].p_bh); |
1816 | path[i].p_bh = NULL; | 1844 | path[i].p_bh = NULL; |
1817 | i--; | 1845 | i--; |
@@ -1822,8 +1850,8 @@ int ext4_ext_remove_space(struct inode *inode, unsigned long start) | |||
1822 | /* TODO: flexible tree reduction should be here */ | 1850 | /* TODO: flexible tree reduction should be here */ |
1823 | if (path->p_hdr->eh_entries == 0) { | 1851 | if (path->p_hdr->eh_entries == 0) { |
1824 | /* | 1852 | /* |
1825 | * truncate to zero freed all the tree | 1853 | * truncate to zero freed all the tree, |
1826 | * so, we need to correct eh_depth | 1854 | * so we need to correct eh_depth |
1827 | */ | 1855 | */ |
1828 | err = ext4_ext_get_access(handle, inode, path); | 1856 | err = ext4_ext_get_access(handle, inode, path); |
1829 | if (err == 0) { | 1857 | if (err == 0) { |
@@ -1912,7 +1940,7 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode, | |||
1912 | if (goal == EXT4_EXT_CACHE_GAP) { | 1940 | if (goal == EXT4_EXT_CACHE_GAP) { |
1913 | if (!create) { | 1941 | if (!create) { |
1914 | /* block isn't allocated yet and | 1942 | /* block isn't allocated yet and |
1915 | * user don't want to allocate it */ | 1943 | * user doesn't want to allocate it */ |
1916 | goto out2; | 1944 | goto out2; |
1917 | } | 1945 | } |
1918 | /* we should allocate requested block */ | 1946 | /* we should allocate requested block */ |
@@ -1921,7 +1949,7 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode, | |||
1921 | newblock = iblock | 1949 | newblock = iblock |
1922 | - le32_to_cpu(newex.ee_block) | 1950 | - le32_to_cpu(newex.ee_block) |
1923 | + ext_pblock(&newex); | 1951 | + ext_pblock(&newex); |
1924 | /* number of remain blocks in the extent */ | 1952 | /* number of remaining blocks in the extent */ |
1925 | allocated = le16_to_cpu(newex.ee_len) - | 1953 | allocated = le16_to_cpu(newex.ee_len) - |
1926 | (iblock - le32_to_cpu(newex.ee_block)); | 1954 | (iblock - le32_to_cpu(newex.ee_block)); |
1927 | goto out; | 1955 | goto out; |
@@ -1941,8 +1969,8 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode, | |||
1941 | depth = ext_depth(inode); | 1969 | depth = ext_depth(inode); |
1942 | 1970 | ||
1943 | /* | 1971 | /* |
1944 | * consistent leaf must not be empty | 1972 | * consistent leaf must not be empty; |
1945 | * this situations is possible, though, _during_ tree modification | 1973 | * this situation is possible, though, _during_ tree modification; |
1946 | * this is why assert can't be put in ext4_ext_find_extent() | 1974 | * this is why assert can't be put in ext4_ext_find_extent() |
1947 | */ | 1975 | */ |
1948 | BUG_ON(path[depth].p_ext == NULL && depth != 0); | 1976 | BUG_ON(path[depth].p_ext == NULL && depth != 0); |
@@ -1960,10 +1988,10 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode, | |||
1960 | */ | 1988 | */ |
1961 | if (ee_len > EXT_MAX_LEN) | 1989 | if (ee_len > EXT_MAX_LEN) |
1962 | goto out2; | 1990 | goto out2; |
1963 | /* if found exent covers block, simple return it */ | 1991 | /* if found extent covers block, simply return it */ |
1964 | if (iblock >= ee_block && iblock < ee_block + ee_len) { | 1992 | if (iblock >= ee_block && iblock < ee_block + ee_len) { |
1965 | newblock = iblock - ee_block + ee_start; | 1993 | newblock = iblock - ee_block + ee_start; |
1966 | /* number of remain blocks in the extent */ | 1994 | /* number of remaining blocks in the extent */ |
1967 | allocated = ee_len - (iblock - ee_block); | 1995 | allocated = ee_len - (iblock - ee_block); |
1968 | ext_debug("%d fit into %lu:%d -> "E3FSBLK"\n", (int) iblock, | 1996 | ext_debug("%d fit into %lu:%d -> "E3FSBLK"\n", (int) iblock, |
1969 | ee_block, ee_len, newblock); | 1997 | ee_block, ee_len, newblock); |
@@ -1974,17 +2002,18 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode, | |||
1974 | } | 2002 | } |
1975 | 2003 | ||
1976 | /* | 2004 | /* |
1977 | * requested block isn't allocated yet | 2005 | * requested block isn't allocated yet; |
1978 | * we couldn't try to create block if create flag is zero | 2006 | * we couldn't try to create block if create flag is zero |
1979 | */ | 2007 | */ |
1980 | if (!create) { | 2008 | if (!create) { |
1981 | /* put just found gap into cache to speedup subsequest reqs */ | 2009 | /* put just found gap into cache to speed up |
2010 | * subsequent requests */ | ||
1982 | ext4_ext_put_gap_in_cache(inode, path, iblock); | 2011 | ext4_ext_put_gap_in_cache(inode, path, iblock); |
1983 | goto out2; | 2012 | goto out2; |
1984 | } | 2013 | } |
1985 | /* | 2014 | /* |
1986 | * Okay, we need to do block allocation. Lazily initialize the block | 2015 | * Okay, we need to do block allocation. Lazily initialize the block |
1987 | * allocation info here if necessary | 2016 | * allocation info here if necessary. |
1988 | */ | 2017 | */ |
1989 | if (S_ISREG(inode->i_mode) && (!EXT4_I(inode)->i_block_alloc_info)) | 2018 | if (S_ISREG(inode->i_mode) && (!EXT4_I(inode)->i_block_alloc_info)) |
1990 | ext4_init_block_alloc_info(inode); | 2019 | ext4_init_block_alloc_info(inode); |
@@ -2062,9 +2091,9 @@ void ext4_ext_truncate(struct inode * inode, struct page *page) | |||
2062 | ext4_ext_invalidate_cache(inode); | 2091 | ext4_ext_invalidate_cache(inode); |
2063 | 2092 | ||
2064 | /* | 2093 | /* |
2065 | * TODO: optimization is possible here | 2094 | * TODO: optimization is possible here. |
2066 | * probably we need not scaning at all, | 2095 | * Probably we need not scan at all, |
2067 | * because page truncation is enough | 2096 | * because page truncation is enough. |
2068 | */ | 2097 | */ |
2069 | if (ext4_orphan_add(handle, inode)) | 2098 | if (ext4_orphan_add(handle, inode)) |
2070 | goto out_stop; | 2099 | goto out_stop; |
@@ -2078,13 +2107,13 @@ void ext4_ext_truncate(struct inode * inode, struct page *page) | |||
2078 | err = ext4_ext_remove_space(inode, last_block); | 2107 | err = ext4_ext_remove_space(inode, last_block); |
2079 | 2108 | ||
2080 | /* In a multi-transaction truncate, we only make the final | 2109 | /* In a multi-transaction truncate, we only make the final |
2081 | * transaction synchronous */ | 2110 | * transaction synchronous. */ |
2082 | if (IS_SYNC(inode)) | 2111 | if (IS_SYNC(inode)) |
2083 | handle->h_sync = 1; | 2112 | handle->h_sync = 1; |
2084 | 2113 | ||
2085 | out_stop: | 2114 | out_stop: |
2086 | /* | 2115 | /* |
2087 | * If this was a simple ftruncate(), and the file will remain alive | 2116 | * If this was a simple ftruncate() and the file will remain alive, |
2088 | * then we need to clear up the orphan record which we created above. | 2117 | * then we need to clear up the orphan record which we created above. |
2089 | * However, if this was a real unlink then we were called by | 2118 | * However, if this was a real unlink then we were called by |
2090 | * ext4_delete_inode(), and we allow that function to clean up the | 2119 | * ext4_delete_inode(), and we allow that function to clean up the |
@@ -2098,7 +2127,8 @@ out_stop: | |||
2098 | } | 2127 | } |
2099 | 2128 | ||
2100 | /* | 2129 | /* |
2101 | * this routine calculate max number of blocks we could modify | 2130 | * ext4_ext_writepage_trans_blocks: |
2131 | * calculate max number of blocks we could modify | ||
2102 | * in order to allocate new block for an inode | 2132 | * in order to allocate new block for an inode |
2103 | */ | 2133 | */ |
2104 | int ext4_ext_writepage_trans_blocks(struct inode *inode, int num) | 2134 | int ext4_ext_writepage_trans_blocks(struct inode *inode, int num) |
@@ -2107,7 +2137,7 @@ int ext4_ext_writepage_trans_blocks(struct inode *inode, int num) | |||
2107 | 2137 | ||
2108 | needed = ext4_ext_calc_credits_for_insert(inode, NULL); | 2138 | needed = ext4_ext_calc_credits_for_insert(inode, NULL); |
2109 | 2139 | ||
2110 | /* caller want to allocate num blocks, but note it includes sb */ | 2140 | /* caller wants to allocate num blocks, but note it includes sb */ |
2111 | needed = needed * num - (num - 1); | 2141 | needed = needed * num - (num - 1); |
2112 | 2142 | ||
2113 | #ifdef CONFIG_QUOTA | 2143 | #ifdef CONFIG_QUOTA |