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author | Dave Chinner <dchinner@redhat.com> | 2013-06-12 06:19:08 +0400 |
---|---|---|
committer | Ben Myers <bpm@sgi.com> | 2013-06-15 00:59:31 +0400 |
commit | 088c9f67c3f53339d2bc20b42a9cb904901fdc5d (patch) | |
tree | 1003460d2eda850a2efe0c648818638aed1c4c4a /fs/xfs/xfs_btree.c | |
parent | 5170711df79b284cf95b3924322e8ac4c0fd6c76 (diff) | |
download | linux-088c9f67c3f53339d2bc20b42a9cb904901fdc5d.tar.xz |
xfs: ensure btree root split sets blkno correctly
For CRC enabled filesystems, the BMBT is rooted in an inode, so it
passes through a different code path on root splits than the
freespace and inode btrees. This is much less traversed by xfstests
than the other trees. When testing on a 1k block size filesystem,
I've been seeing ASSERT failures in generic/234 like:
XFS: Assertion failed: cur->bc_btnum != XFS_BTNUM_BMAP || cur->bc_private.b.allocated == 0, file: fs/xfs/xfs_btree.c, line: 317
which are generally preceded by a lblock check failure. I noticed
this in the bmbt stats:
$ pminfo -f xfs.btree.block_map
xfs.btree.block_map.lookup
value 39135
xfs.btree.block_map.compare
value 268432
xfs.btree.block_map.insrec
value 15786
xfs.btree.block_map.delrec
value 13884
xfs.btree.block_map.newroot
value 2
xfs.btree.block_map.killroot
value 0
.....
Very little coverage of root splits and merges. Indeed, on a 4k
filesystem, block_map.newroot and block_map.killroot are both zero.
i.e. the code is not exercised at all, and it's the only generic
btree infrastructure operation that is not exercised by a default run
of xfstests.
Turns out that on a 1k filesystem, generic/234 accounts for one of
those two root splits, and that is somewhat of a smoking gun. In
fact, it's the same problem we saw in the directory/attr code where
headers are memcpy()d from one block to another without updating the
self describing metadata.
Simple fix - when copying the header out of the root block, make
sure the block number is updated correctly.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
(cherry picked from commit ade1335afef556df6538eb02e8c0dc91fbd9cc37)
Diffstat (limited to 'fs/xfs/xfs_btree.c')
-rw-r--r-- | fs/xfs/xfs_btree.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/fs/xfs/xfs_btree.c b/fs/xfs/xfs_btree.c index 8804b8a3c310..0903960410a2 100644 --- a/fs/xfs/xfs_btree.c +++ b/fs/xfs/xfs_btree.c @@ -2544,7 +2544,17 @@ xfs_btree_new_iroot( if (error) goto error0; + /* + * we can't just memcpy() the root in for CRC enabled btree blocks. + * In that case have to also ensure the blkno remains correct + */ memcpy(cblock, block, xfs_btree_block_len(cur)); + if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS) { + if (cur->bc_flags & XFS_BTREE_LONG_PTRS) + cblock->bb_u.l.bb_blkno = cpu_to_be64(cbp->b_bn); + else + cblock->bb_u.s.bb_blkno = cpu_to_be64(cbp->b_bn); + } be16_add_cpu(&block->bb_level, 1); xfs_btree_set_numrecs(block, 1); |