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| author | Sami Liedes <sami.liedes@iki.fi> | 2012-03-10 22:36:12 +0200 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2012-03-25 18:55:14 -0400 |
| commit | c1a1e7fc24d6e37f931bbb8eeb29c90243f0a55d (patch) | |
| tree | cea143dad327453bd99166d501e077121df77155 /lib/ext2fs/alloc.c | |
| parent | 5f7c04972fefa8198c34f231a9e8a5430705b4ab (diff) | |
| download | e2fsprogs-c1a1e7fc24d6e37f931bbb8eeb29c90243f0a55d.tar.gz | |
libext2fs: Implement ext2fs_find_first_zero_generic_bmap().
This function searches a bitmap for the first zero bit within a range.
It checks if there is a bitmap backend specific implementation
available (if the relevant field in bitmap_ops is non-NULL). If not,
it uses a generic and slow method by repeatedly calling test_bmap() in
a loop. Also change ext2fs_new_inode() to use this new function.
This change in itself does not result in a large speedup, rather it
refactors the code in preparation for the introduction of a faster
find_first_zero() for bitarray based bitmaps.
Signed-off-by: Sami Liedes <sami.liedes@iki.fi>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'lib/ext2fs/alloc.c')
| -rw-r--r-- | lib/ext2fs/alloc.c | 48 |
1 files changed, 27 insertions, 21 deletions
diff --git a/lib/ext2fs/alloc.c b/lib/ext2fs/alloc.c index bcdc2d44..752c4da1 100644 --- a/lib/ext2fs/alloc.c +++ b/lib/ext2fs/alloc.c @@ -106,10 +106,10 @@ errcode_t ext2fs_new_inode(ext2_filsys fs, ext2_ino_t dir, int mode EXT2FS_ATTR((unused)), ext2fs_inode_bitmap map, ext2_ino_t *ret) { - ext2_ino_t dir_group = 0; - ext2_ino_t i; - ext2_ino_t start_inode; - ext2_ino_t ino_in_group; + ext2_ino_t start_inode = 0; + ext2_ino_t i, ino_in_group, upto, first_zero; + errcode_t retval; + dgrp_t group; EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); @@ -118,31 +118,37 @@ errcode_t ext2fs_new_inode(ext2_filsys fs, ext2_ino_t dir, if (!map) return EXT2_ET_NO_INODE_BITMAP; - if (dir > 0) - dir_group = (dir - 1) / EXT2_INODES_PER_GROUP(fs->super); - - start_inode = (dir_group * EXT2_INODES_PER_GROUP(fs->super)) + 1; + if (dir > 0) { + group = (dir - 1) / EXT2_INODES_PER_GROUP(fs->super); + start_inode = (group * EXT2_INODES_PER_GROUP(fs->super)) + 1; + } if (start_inode < EXT2_FIRST_INODE(fs->super)) start_inode = EXT2_FIRST_INODE(fs->super); if (start_inode > fs->super->s_inodes_count) return EXT2_ET_INODE_ALLOC_FAIL; i = start_inode; - ino_in_group = (i - 1) % EXT2_INODES_PER_GROUP(fs->super); - do { - if (ino_in_group == 0) - check_inode_uninit(fs, map, (i - 1) / - EXT2_INODES_PER_GROUP(fs->super)); - - if (!ext2fs_fast_test_inode_bitmap2(map, i)) + ino_in_group = (i - 1) % EXT2_INODES_PER_GROUP(fs->super); + group = (i - 1) / EXT2_INODES_PER_GROUP(fs->super); + + check_inode_uninit(fs, map, group); + upto = i + (EXT2_INODES_PER_GROUP(fs->super) - ino_in_group); + if (i < start_inode && upto >= start_inode) + upto = start_inode - 1; + if (upto > fs->super->s_inodes_count) + upto = fs->super->s_inodes_count; + + retval = ext2fs_find_first_zero_inode_bitmap2(map, i, upto, + &first_zero); + if (retval == 0) { + i = first_zero; break; - if (++ino_in_group == EXT2_INODES_PER_GROUP(fs->super)) - ino_in_group = 0; - if (++i > fs->super->s_inodes_count) { - i = EXT2_FIRST_INODE(fs->super); - ino_in_group = ((i - 1) % - EXT2_INODES_PER_GROUP(fs->super)); } + if (retval != ENOENT) + return EXT2_ET_INODE_ALLOC_FAIL; + i = upto + 1; + if (i > fs->super->s_inodes_count) + i = EXT2_FIRST_INODE(fs->super); } while (i != start_inode); if (ext2fs_test_inode_bitmap2(map, i)) |