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| author | Lu Fengqi <lufq.fnst@cn.fujitsu.com> | 2018-02-28 18:13:22 +0800 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2018-03-30 22:15:53 +0200 |
| commit | 905b3d18ae118931839b0a1ece17870073b51484 (patch) | |
| tree | a2c7326b0963b1c4ef7cf553f5494abb25a6c611 /check/mode-lowmem.c | |
| parent | 634e73e9d3464e7a333eda10ef3e5652d8d32293 (diff) | |
btrfs-progs: check/lowmem: Fix false alert of data extent backref lost for snapshot
Btrfs lowmem check reports the following false alert:
------
ERROR: file extent[267 2162688] root 256 owner 5 backref lost
------
The file extent is in the leaf which is shared by file tree 256 and fs
tree.
------
leaf 30605312 items 46 free space 4353 generation 7 owner 5
......
item 45 key (267 EXTENT_DATA 2162688) itemoff 5503 itemsize 53
generation 7 type 2 (prealloc)
prealloc data disk byte 13631488 nr 65536
prealloc data offset 32768 nr 32768
------
And there is the corresponding extent_data_ref item in the extent tree.
------
item 1 key (13631488 EXTENT_DATA_REF 1007496934287921081) itemoff 15274 itemsize 28
extent data backref root 5 objectid 267 offset 2129920 count 1
------
The offset of EXTENT_DATA_REF which is the hash of the owner root objectid,
the inode number and the calculated offset (file offset - extent offset).
What caused the false alert is the code mix up the owner root objectid and
the file tree objectid.
Fixes: b0d360b541f0 ("btrfs-progs: check: introduce function to check data backref in extent tree")
Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'check/mode-lowmem.c')
| -rw-r--r-- | check/mode-lowmem.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/check/mode-lowmem.c b/check/mode-lowmem.c index f37b1b2c..6f1ea8db 100644 --- a/check/mode-lowmem.c +++ b/check/mode-lowmem.c @@ -2689,8 +2689,8 @@ static int check_extent_data_item(struct btrfs_root *root, /* Didn't find inlined data backref, try EXTENT_DATA_REF_KEY */ dbref_key.objectid = btrfs_file_extent_disk_bytenr(eb, fi); dbref_key.type = BTRFS_EXTENT_DATA_REF_KEY; - dbref_key.offset = hash_extent_data_ref(root->objectid, - fi_key.objectid, fi_key.offset - offset); + dbref_key.offset = hash_extent_data_ref(owner, fi_key.objectid, + fi_key.offset - offset); ret = btrfs_search_slot(NULL, root->fs_info->extent_root, &dbref_key, &path, 0, 0); |