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author | Brian Foster <bfoster@redhat.com> | 2019-02-07 10:45:46 -0800 |
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committer | Darrick J. Wong <darrick.wong@oracle.com> | 2019-02-11 16:07:01 -0800 |
commit | 8473fee340e37711b9ac6a5cc591305ccaaa4778 (patch) | |
tree | a6e4eb63b46dfe5837960d8dbc69a578db45aae9 /fs/xfs/xfs_buf.h | |
parent | 01e68f40bf7846b58d2734aa11b0cbcaadbeaa3e (diff) | |
download | lwn-8473fee340e37711b9ac6a5cc591305ccaaa4778.tar.gz lwn-8473fee340e37711b9ac6a5cc591305ccaaa4778.zip |
xfs: distinguish between inobt and finobt magic values
The inode btree verifier code is shared between the inode btree and
free inode btree because the underlying metadata formats are
essentially equivalent. A side effect of this is that the verifier
cannot determine whether a particular btree block should have an
inobt or finobt magic value.
This logic allows an unfortunate xfs_repair bug to escape detection
where certain level > 0 nodes of the finobt are stamped with inobt
magic by xfs_repair finobt reconstruction. This is fortunately not a
severe problem since the inode btree magic values do not contribute
to any changes in kernel behavior, but we do need a means to detect
and prevent this problem in the future.
Add a field to xfs_buf_ops to store the v4 and v5 superblock magic
values expected by a particular verifier. Add a helper to check an
on-disk magic value against the value expected by the verifier. Call
the helper from the shared [f]inobt verifier code for magic value
verification. This ensures that the inode btree blocks each have the
appropriate magic value based on specific tree type and superblock
version.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Diffstat (limited to 'fs/xfs/xfs_buf.h')
-rw-r--r-- | fs/xfs/xfs_buf.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h index 1c436a85b71d..44f9423a1861 100644 --- a/fs/xfs/xfs_buf.h +++ b/fs/xfs/xfs_buf.h @@ -125,6 +125,7 @@ struct xfs_buf_map { struct xfs_buf_ops { char *name; + uint32_t magic[2]; /* v4 and v5 on disk magic values */ void (*verify_read)(struct xfs_buf *); void (*verify_write)(struct xfs_buf *); xfs_failaddr_t (*verify_struct)(struct xfs_buf *bp); @@ -386,5 +387,6 @@ extern int xfs_setsize_buftarg(xfs_buftarg_t *, unsigned int); #define xfs_readonly_buftarg(buftarg) bdev_read_only((buftarg)->bt_bdev) int xfs_buf_reverify(struct xfs_buf *bp, const struct xfs_buf_ops *ops); +bool xfs_verify_magic(struct xfs_buf *bp, uint32_t dmagic); #endif /* __XFS_BUF_H__ */ |