diff options
Diffstat (limited to 'fs/reiserfs/objectid.c')
| -rw-r--r-- | fs/reiserfs/objectid.c | 101 |
1 files changed, 58 insertions, 43 deletions
diff --git a/fs/reiserfs/objectid.c b/fs/reiserfs/objectid.c index f732d6a5251d..99a5d5dae46a 100644 --- a/fs/reiserfs/objectid.c +++ b/fs/reiserfs/objectid.c @@ -7,7 +7,7 @@ #include <linux/time.h> #include "reiserfs.h" -// find where objectid map starts +/* find where objectid map starts */ #define objectid_map(s,rs) (old_format_only (s) ? \ (__le32 *)((struct reiserfs_super_block_v1 *)(rs) + 1) :\ (__le32 *)((rs) + 1)) @@ -20,7 +20,7 @@ static void check_objectid_map(struct super_block *s, __le32 * map) reiserfs_panic(s, "vs-15010", "map corrupted: %lx", (long unsigned int)le32_to_cpu(map[0])); - // FIXME: add something else here + /* FIXME: add something else here */ } #else @@ -29,19 +29,21 @@ static void check_objectid_map(struct super_block *s, __le32 * map) } #endif -/* When we allocate objectids we allocate the first unused objectid. - Each sequence of objectids in use (the odd sequences) is followed - by a sequence of objectids not in use (the even sequences). We - only need to record the last objectid in each of these sequences - (both the odd and even sequences) in order to fully define the - boundaries of the sequences. A consequence of allocating the first - objectid not in use is that under most conditions this scheme is - extremely compact. The exception is immediately after a sequence - of operations which deletes a large number of objects of - non-sequential objectids, and even then it will become compact - again as soon as more objects are created. Note that many - interesting optimizations of layout could result from complicating - objectid assignment, but we have deferred making them for now. */ +/* + * When we allocate objectids we allocate the first unused objectid. + * Each sequence of objectids in use (the odd sequences) is followed + * by a sequence of objectids not in use (the even sequences). We + * only need to record the last objectid in each of these sequences + * (both the odd and even sequences) in order to fully define the + * boundaries of the sequences. A consequence of allocating the first + * objectid not in use is that under most conditions this scheme is + * extremely compact. The exception is immediately after a sequence + * of operations which deletes a large number of objects of + * non-sequential objectids, and even then it will become compact + * again as soon as more objects are created. Note that many + * interesting optimizations of layout could result from complicating + * objectid assignment, but we have deferred making them for now. + */ /* get unique object identifier */ __u32 reiserfs_get_unused_objectid(struct reiserfs_transaction_handle *th) @@ -64,26 +66,30 @@ __u32 reiserfs_get_unused_objectid(struct reiserfs_transaction_handle *th) return 0; } - /* This incrementation allocates the first unused objectid. That - is to say, the first entry on the objectid map is the first - unused objectid, and by incrementing it we use it. See below - where we check to see if we eliminated a sequence of unused - objectids.... */ + /* + * This incrementation allocates the first unused objectid. That + * is to say, the first entry on the objectid map is the first + * unused objectid, and by incrementing it we use it. See below + * where we check to see if we eliminated a sequence of unused + * objectids.... + */ map[1] = cpu_to_le32(unused_objectid + 1); - /* Now we check to see if we eliminated the last remaining member of - the first even sequence (and can eliminate the sequence by - eliminating its last objectid from oids), and can collapse the - first two odd sequences into one sequence. If so, then the net - result is to eliminate a pair of objectids from oids. We do this - by shifting the entire map to the left. */ + /* + * Now we check to see if we eliminated the last remaining member of + * the first even sequence (and can eliminate the sequence by + * eliminating its last objectid from oids), and can collapse the + * first two odd sequences into one sequence. If so, then the net + * result is to eliminate a pair of objectids from oids. We do this + * by shifting the entire map to the left. + */ if (sb_oid_cursize(rs) > 2 && map[1] == map[2]) { memmove(map + 1, map + 3, (sb_oid_cursize(rs) - 3) * sizeof(__u32)); set_sb_oid_cursize(rs, sb_oid_cursize(rs) - 2); } - journal_mark_dirty(th, s, SB_BUFFER_WITH_SB(s)); + journal_mark_dirty(th, SB_BUFFER_WITH_SB(s)); return unused_objectid; } @@ -97,30 +103,33 @@ void reiserfs_release_objectid(struct reiserfs_transaction_handle *th, int i = 0; BUG_ON(!th->t_trans_id); - //return; + /*return; */ check_objectid_map(s, map); reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1); - journal_mark_dirty(th, s, SB_BUFFER_WITH_SB(s)); - - /* start at the beginning of the objectid map (i = 0) and go to - the end of it (i = disk_sb->s_oid_cursize). Linear search is - what we use, though it is possible that binary search would be - more efficient after performing lots of deletions (which is - when oids is large.) We only check even i's. */ + journal_mark_dirty(th, SB_BUFFER_WITH_SB(s)); + + /* + * start at the beginning of the objectid map (i = 0) and go to + * the end of it (i = disk_sb->s_oid_cursize). Linear search is + * what we use, though it is possible that binary search would be + * more efficient after performing lots of deletions (which is + * when oids is large.) We only check even i's. + */ while (i < sb_oid_cursize(rs)) { if (objectid_to_release == le32_to_cpu(map[i])) { /* This incrementation unallocates the objectid. */ - //map[i]++; le32_add_cpu(&map[i], 1); - /* Did we unallocate the last member of an odd sequence, and can shrink oids? */ + /* + * Did we unallocate the last member of an + * odd sequence, and can shrink oids? + */ if (map[i] == map[i + 1]) { /* shrink objectid map */ memmove(map + i, map + i + 2, (sb_oid_cursize(rs) - i - 2) * sizeof(__u32)); - //disk_sb->s_oid_cursize -= 2; set_sb_oid_cursize(rs, sb_oid_cursize(rs) - 2); RFALSE(sb_oid_cursize(rs) < 2 || @@ -135,14 +144,19 @@ void reiserfs_release_objectid(struct reiserfs_transaction_handle *th, objectid_to_release < le32_to_cpu(map[i + 1])) { /* size of objectid map is not changed */ if (objectid_to_release + 1 == le32_to_cpu(map[i + 1])) { - //objectid_map[i+1]--; le32_add_cpu(&map[i + 1], -1); return; } - /* JDM comparing two little-endian values for equality -- safe */ + /* + * JDM comparing two little-endian values for + * equality -- safe + */ + /* + * objectid map must be expanded, but + * there is no space + */ if (sb_oid_cursize(rs) == sb_oid_maxsize(rs)) { - /* objectid map must be expanded, but there is no space */ PROC_INFO_INC(s, leaked_oid); return; } @@ -178,8 +192,9 @@ int reiserfs_convert_objectid_map_v1(struct super_block *s) new_objectid_map = (__le32 *) (disk_sb + 1); if (cur_size > new_size) { - /* mark everyone used that was listed as free at the end of the objectid - ** map + /* + * mark everyone used that was listed as free at + * the end of the objectid map */ objectid_map[new_size - 1] = objectid_map[cur_size - 1]; set_sb_oid_cursize(disk_sb, new_size); |