On 2019/9/18 下午8:08, fdman...@kernel.org wrote:
> From: Filipe Manana <fdman...@suse.com>
>
> Some of the self tests create a test inode, setup some extents and then do
> calls to btrfs_get_extent() to test that the corresponding extent maps
> exist and are correct. However btrfs_get_extent(), since the 5.2 merge
> window, now errors out when it finds a regular or prealloc extent for an
> inode that does not correspond to a regular file (its ->i_mode is not
> S_IFREG). This causes the self tests to fail sometimes, specially when
> KASAN, slub_debug and page poisoning are enabled:
>
> $ modprobe btrfs
> modprobe: ERROR: could not insert 'btrfs': Invalid argument
>
> $ dmesg
> [ 9414.691648] Btrfs loaded, crc32c=crc32c-intel, debug=on, assert=on,
> integrity-checker=on, ref-verify=on
> [ 9414.692655] BTRFS: selftest: sectorsize: 4096 nodesize: 4096
> [ 9414.692658] BTRFS: selftest: running btrfs free space cache tests
> [ 9414.692918] BTRFS: selftest: running extent only tests
> [ 9414.693061] BTRFS: selftest: running bitmap only tests
> [ 9414.693366] BTRFS: selftest: running bitmap and extent tests
> [ 9414.696455] BTRFS: selftest: running space stealing from bitmap to
> extent tests
> [ 9414.697131] BTRFS: selftest: running extent buffer operation tests
> [ 9414.697133] BTRFS: selftest: running btrfs_split_item tests
> [ 9414.697564] BTRFS: selftest: running extent I/O tests
> [ 9414.697583] BTRFS: selftest: running find delalloc tests
> [ 9415.081125] BTRFS: selftest: running find_first_clear_extent_bit test
> [ 9415.081278] BTRFS: selftest: running extent buffer bitmap tests
> [ 9415.124192] BTRFS: selftest: running inode tests
> [ 9415.124195] BTRFS: selftest: running btrfs_get_extent tests
> [ 9415.127909] BTRFS: selftest: running hole first btrfs_get_extent test
> [ 9415.128343] BTRFS critical (device (efault)): regular/prealloc extent
> found for non-regular inode 256
> [ 9415.131428] BTRFS: selftest: fs/btrfs/tests/inode-tests.c:904 expected a
> real extent, got 0
>
> This happens because the test inodes are created without ever initializing
> the i_mode field of the inode, and neither VFS's new_inode() nor the btrfs
> callback btrfs_alloc_inode() initialize the i_mode. Initialization of the
> i_mode is done through the various callbacks used by the VFS to create
> new inodes (regular files, directories, symlinks, tmpfiles, etc), which
> all call btrfs_new_inode() which in turn calls inode_init_owner(), which
> sets the inode's i_mode. Since the tests only uses new_inode() to create
> the test inodes, the i_mode was never initialized.
>
> This always happens on a VM I used with kasan, slub_debug and many other
> debug facilities enabled. It also happened to someone who reported this
> on bugzilla (on a 5.3-rc).
>
> Fix this by setting i_mode to S_IFREG at btrfs_new_test_inode().
>
> Fixes: 6bf9e4bd6a2778 ("btrfs: inode: Verify inode mode to avoid NULL pointer
> dereference")
> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=204397
> Signed-off-by: Filipe Manana <fdman...@suse.com>
Reviewed-by: Qu Wenruo <w...@suse.com>
However I'm interested why it doesn't get triggered reliably.
As I have selftest compiled in everytime.
Is there anything racy caused the bug?
Thanks,
Qu
> ---
> fs/btrfs/tests/btrfs-tests.c | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/fs/btrfs/tests/btrfs-tests.c b/fs/btrfs/tests/btrfs-tests.c
> index b5e80563efaa..99fe9bf3fdac 100644
> --- a/fs/btrfs/tests/btrfs-tests.c
> +++ b/fs/btrfs/tests/btrfs-tests.c
> @@ -52,7 +52,13 @@ static struct file_system_type test_type = {
>
> struct inode *btrfs_new_test_inode(void)
> {
> - return new_inode(test_mnt->mnt_sb);
> + struct inode *inode;
> +
> + inode = new_inode(test_mnt->mnt_sb);
> + if (inode)
> + inode_init_owner(inode, NULL, S_IFREG);
> +
> + return inode;
> }
>
> static int btrfs_init_test_fs(void)
>
signature.asc
Description: OpenPGP digital signature
