I saw an oops down this path when trying to create a new file on a UDF
filesystem which was internally marked as readonly, but mounted rw:
udf_create
udf_new_inode
new_inode
alloc_inode
udf_alloc_inode
udf_new_block
returns EIO due to readonlyness
iput (on error)
udf_put_inode
udf_discard_prealloc
udf_next_aext
udf_current_aext
udf_get_fileshortad
OOPS
the udf_discard_prealloc() path was examining uninitialized fields of the
udf inode.
udf_discard_prealloc() already has this code to short-circuit the discard
path if no extents are preallocated:
if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB ||
inode->i_size == UDF_I_LENEXTENTS(inode))
{
return;
}
so if we initialize UDF_I_LENEXTENTS(inode) = 0 earlier in udf_new_inode,
we won't try to free the (not) preallocated blocks, since this will match
the i_size = 0 set when the inode was initialized.
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
225add6196