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author | Liu Bo <bo.li.liu@oracle.com> | 2018-01-05 20:51:15 +0100 |
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committer | David Sterba <dsterba@suse.com> | 2018-01-22 16:08:22 +0100 |
commit | 9a7e10e7ba66ce23c8fdc1cac18cade7a0f6840d (patch) | |
tree | 729a770af9be2aa7e61fe7fa2d4ac5bc5dea0bc8 | |
parent | Btrfs: extent map selftest: dio write vs dio read (diff) | |
download | linux-9a7e10e7ba66ce23c8fdc1cac18cade7a0f6840d.tar.xz linux-9a7e10e7ba66ce23c8fdc1cac18cade7a0f6840d.zip |
Btrfs: add WARN_ONCE to detect unexpected error from merge_extent_mapping
This is a subtle case, so in order to understand the problem, it'd be good
to know the content of existing and em when any error occurs.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
-rw-r--r-- | fs/btrfs/extent_map.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c index 6fe8b14e11cf..914662428dbd 100644 --- a/fs/btrfs/extent_map.c +++ b/fs/btrfs/extent_map.c @@ -562,17 +562,24 @@ int btrfs_add_extent_mapping(struct extent_map_tree *em_tree, *em_in = existing; ret = 0; } else { + u64 orig_start = em->start; + u64 orig_len = em->len; + /* * The existing extent map is the one nearest to * the [start, start + len) range which overlaps */ ret = merge_extent_mapping(em_tree, existing, em, start); - free_extent_map(existing); if (ret) { free_extent_map(em); *em_in = NULL; + WARN_ONCE(ret, +"unexpected error %d: merge existing(start %llu len %llu) with em(start %llu len %llu)\n", + ret, existing->start, existing->len, + orig_start, orig_len); } + free_extent_map(existing); } } |