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authorEric Sandeen <sandeen@redhat.com>2013-01-10 10:41:48 -0600
committerBen Myers <bpm@sgi.com>2013-01-16 16:08:55 -0600
commit37f13561de6039b3a916d1510086030d097dea0f (patch)
tree74695b6db519750ef3cf3d583e13da6432a05806
parentab7eac22008f044631c0a3f4be344ebc2cb0e266 (diff)
downloadlinux-stericsson-37f13561de6039b3a916d1510086030d097dea0f.tar.gz
xfs: recalculate leaf entry pointer after compacting a dir2 block
Dave Jones hit this assert when doing a compile on recent git, with CONFIG_XFS_DEBUG enabled: XFS: Assertion failed: (char *)dup - (char *)hdr == be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)), file: fs/xfs/xfs_dir2_data.c, line: 828 Upon further digging, the tag found by xfs_dir2_data_unused_tag_p(dup) contained "2" and not the proper offset, and I found that this value was changed after the memmoves under "Use a stale leaf for our new entry." in xfs_dir2_block_addname(), i.e. memmove(&blp[mid + 1], &blp[mid], (highstale - mid) * sizeof(*blp)); overwrote it. What has happened is that the previous call to xfs_dir2_block_compact() has rearranged things; it changes btp->count as well as the blp array. So after we make that call, we must recalculate the proper pointer to the leaf entries by making another call to xfs_dir2_block_leaf_p(). Dave provided a metadump image which led to a simple reproducer (create a particular filename in the affected directory) and this resolves the testcase as well as the bug on his live system. Thanks also to dchinner for looking at this one with me. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Tested-by: Dave Jones <davej@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
-rw-r--r--fs/xfs/xfs_dir2_block.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/fs/xfs/xfs_dir2_block.c b/fs/xfs/xfs_dir2_block.c
index 7536faaa61e7..12afe07a91d7 100644
--- a/fs/xfs/xfs_dir2_block.c
+++ b/fs/xfs/xfs_dir2_block.c
@@ -355,10 +355,12 @@ xfs_dir2_block_addname(
/*
* If need to compact the leaf entries, do it now.
*/
- if (compact)
+ if (compact) {
xfs_dir2_block_compact(tp, bp, hdr, btp, blp, &needlog,
&lfloghigh, &lfloglow);
- else if (btp->stale) {
+ /* recalculate blp post-compaction */
+ blp = xfs_dir2_block_leaf_p(btp);
+ } else if (btp->stale) {
/*
* Set leaf logging boundaries to impossible state.
* For the no-stale case they're set explicitly.