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UBIFS: use anonymous device

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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>
This commit is contained in:
Artem Bityutskiy
2009-05-25 19:23:04 +03:00
parent 8eec2f36fb
commit 7c83f5cb55
1 changed files with 4 additions and 17 deletions
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21
fs/ubifs/super.c
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@@ -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_magic = UBIFS_SUPER_MAGIC;
sb->s_blocksize = UBIFS_BLOCK_SIZE; sb->s_blocksize = UBIFS_BLOCK_SIZE;
sb->s_blocksize_bits = UBIFS_BLOCK_SHIFT; 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); sb->s_maxbytes = c->max_inode_sz = key_max_inode_size(c);
if (c->max_inode_sz > MAX_LFS_FILESIZE) if (c->max_inode_sz > MAX_LFS_FILESIZE)
sb->s_maxbytes = 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) static int sb_test(struct super_block *sb, void *data)
{ {
dev_t *dev = data; dev_t *dev = data;
struct ubifs_info *c = sb->s_fs_info;
return sb->s_dev == *dev; return c->vi.cdev == *dev;
}
static int sb_set(struct super_block *sb, void *data)
{
dev_t *dev = data;
sb->s_dev = *dev;
return 0;
} }
static int ubifs_get_sb(struct file_system_type *fs_type, int flags, 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); 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)) { if (IS_ERR(sb)) {
err = PTR_ERR(sb); err = PTR_ERR(sb);
goto out_close; goto out_close;
@@ -2068,16 +2060,11 @@ out_close:
return err; return err;
} }
static void ubifs_kill_sb(struct super_block *sb)
{
generic_shutdown_super(sb);
}
static struct file_system_type ubifs_fs_type = { static struct file_system_type ubifs_fs_type = {
.name = "ubifs", .name = "ubifs",
.owner = THIS_MODULE, .owner = THIS_MODULE,
.get_sb = ubifs_get_sb, .get_sb = ubifs_get_sb,
.kill_sb = ubifs_kill_sb .kill_sb = kill_anon_super,
}; };
/* /*