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| author | Artem Bityutskiy <Artem.Bityutskiy@nokia.com> | 2009-05-25 19:23:04 +0300 |
|---|---|---|
| committer | Artem Bityutskiy <Artem.Bityutskiy@nokia.com> | 2009-05-26 12:37:11 +0300 |
| commit | 7c83f5cb551b2e5c4934933fda006636f7424123 (patch) | |
| tree | 6b4393743ee63ffdbfb734d3f2daf059e8874508 /fs/ubifs | |
| parent | 8eec2f36fb869f1e6d81d834bbbd487941222fc8 (diff) | |
| download | lwn-7c83f5cb551b2e5c4934933fda006636f7424123.tar.gz lwn-7c83f5cb551b2e5c4934933fda006636f7424123.zip | |
UBIFS: use anonymous device
UBIFS has erroneuosly set 'sb->s_dev' to the UBI volume
character device major/minor. This may lead to clashes
if there is another FS mounted to a block device with
the same major/minor numbers. User-space programs which
use 'stat->st_dev' may get confused because of this.
This problem was found by Al Viro. He also pointed the
way to fix the problem - use 'set_anon_super()' and
'kill_anon_super()' VFS helpers.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Diffstat (limited to 'fs/ubifs')
| -rw-r--r-- | fs/ubifs/super.c | 21 |
1 files changed, 4 insertions, 17 deletions
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c index 052514ca2792..42b818daa162 100644 --- a/fs/ubifs/super.c +++ b/fs/ubifs/super.c @@ -1945,7 +1945,6 @@ static int ubifs_fill_super(struct super_block *sb, void *data, int silent) sb->s_magic = UBIFS_SUPER_MAGIC; sb->s_blocksize = UBIFS_BLOCK_SIZE; sb->s_blocksize_bits = UBIFS_BLOCK_SHIFT; - sb->s_dev = c->vi.cdev; sb->s_maxbytes = c->max_inode_sz = key_max_inode_size(c); if (c->max_inode_sz > MAX_LFS_FILESIZE) sb->s_maxbytes = c->max_inode_sz = MAX_LFS_FILESIZE; @@ -1990,16 +1989,9 @@ out_free: static int sb_test(struct super_block *sb, void *data) { dev_t *dev = data; + struct ubifs_info *c = sb->s_fs_info; - return sb->s_dev == *dev; -} - -static int sb_set(struct super_block *sb, void *data) -{ - dev_t *dev = data; - - sb->s_dev = *dev; - return 0; + return c->vi.cdev == *dev; } static int ubifs_get_sb(struct file_system_type *fs_type, int flags, @@ -2027,7 +2019,7 @@ static int ubifs_get_sb(struct file_system_type *fs_type, int flags, dbg_gen("opened ubi%d_%d", vi.ubi_num, vi.vol_id); - sb = sget(fs_type, &sb_test, &sb_set, &vi.cdev); + sb = sget(fs_type, &sb_test, &set_anon_super, &vi.cdev); if (IS_ERR(sb)) { err = PTR_ERR(sb); goto out_close; @@ -2068,16 +2060,11 @@ out_close: return err; } -static void ubifs_kill_sb(struct super_block *sb) -{ - generic_shutdown_super(sb); -} - static struct file_system_type ubifs_fs_type = { .name = "ubifs", .owner = THIS_MODULE, .get_sb = ubifs_get_sb, - .kill_sb = ubifs_kill_sb + .kill_sb = kill_anon_super, }; /* |