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author | Denis Vlasenko | 2006-12-26 01:30:59 +0000 |
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committer | Denis Vlasenko | 2006-12-26 01:30:59 +0000 |
commit | c4f623ef2a7980a63de7c9f1d539a656b83f10e7 (patch) | |
tree | a294e28b0112052cb9d58b403554b3390e76f50c /e2fsprogs/old_e2fsprogs/ext2fs/sparse.c | |
parent | 64c54025842f205ad722675105b88044a5b6845a (diff) | |
download | busybox-c4f623ef2a7980a63de7c9f1d539a656b83f10e7.zip busybox-c4f623ef2a7980a63de7c9f1d539a656b83f10e7.tar.gz |
put small subset of e2fsprogs back in the tree:
lsattr, chattr, fsck. Old e2fsprogs tree is in
e2fsprogs/old_e2fsprogs/*.
Diffstat (limited to 'e2fsprogs/old_e2fsprogs/ext2fs/sparse.c')
-rw-r--r-- | e2fsprogs/old_e2fsprogs/ext2fs/sparse.c | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/e2fsprogs/old_e2fsprogs/ext2fs/sparse.c b/e2fsprogs/old_e2fsprogs/ext2fs/sparse.c new file mode 100644 index 0000000..b3d3071 --- /dev/null +++ b/e2fsprogs/old_e2fsprogs/ext2fs/sparse.c @@ -0,0 +1,79 @@ +/* vi: set sw=4 ts=4: */ +/* + * sparse.c --- find the groups in an ext2 filesystem with metadata backups + * + * Copyright (C) 1993, 1994, 1995, 1996 Theodore Ts'o. + * Copyright (C) 2002 Andreas Dilger. + * + * %Begin-Header% + * This file may be redistributed under the terms of the GNU Public + * License. + * %End-Header% + */ + +#include <stdio.h> + +#include "ext2_fs.h" +#include "ext2fsP.h" + +static int test_root(int a, int b) +{ + if (a == 0) + return 1; + while (1) { + if (a == 1) + return 1; + if (a % b) + return 0; + a = a / b; + } +} + +int ext2fs_bg_has_super(ext2_filsys fs, int group_block) +{ + if (!(fs->super->s_feature_ro_compat & + EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER)) + return 1; + + if (test_root(group_block, 3) || (test_root(group_block, 5)) || + test_root(group_block, 7)) + return 1; + + return 0; +} + +/* + * Iterate through the groups which hold BACKUP superblock/GDT copies in an + * ext3 filesystem. The counters should be initialized to 1, 5, and 7 before + * calling this for the first time. In a sparse filesystem it will be the + * sequence of powers of 3, 5, and 7: 1, 3, 5, 7, 9, 25, 27, 49, 81, ... + * For a non-sparse filesystem it will be every group: 1, 2, 3, 4, ... + */ +unsigned int ext2fs_list_backups(ext2_filsys fs, unsigned int *three, + unsigned int *five, unsigned int *seven) +{ + unsigned int *min = three; + int mult = 3; + unsigned int ret; + + if (!(fs->super->s_feature_ro_compat & + EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER)) { + ret = *min; + *min += 1; + return ret; + } + + if (*five < *min) { + min = five; + mult = 5; + } + if (*seven < *min) { + min = seven; + mult = 7; + } + + ret = *min; + *min *= mult; + + return ret; +} |