From 7c83f5cb551b2e5c4934933fda006636f7424123 Mon Sep 17 00:00:00 2001 From: Artem Bityutskiy Date: Mon, 25 May 2009 19:23:04 +0300 Subject: [PATCH] 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 --- fs/ubifs/super.c | 21 ++++----------------- 1 file 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, }; /*