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authorBrian Foster <bfoster@redhat.com>2019-02-07 10:45:46 -0800
committerDarrick J. Wong <darrick.wong@oracle.com>2019-02-11 16:07:01 -0800
commit8473fee340e37711b9ac6a5cc591305ccaaa4778 (patch)
treea6e4eb63b46dfe5837960d8dbc69a578db45aae9 /fs/xfs/xfs_buf.h
parent01e68f40bf7846b58d2734aa11b0cbcaadbeaa3e (diff)
downloadlwn-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.h2
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__ */