Filipe David Borba Manana
2014-May-07 12:09 UTC
[PATCH] Btrfs-progs: check, fix csum check in the presence of non-inlined refs
When we have non-inlined extent references, we were failing to find the
corresponding extent item for an existing csum item in the csum tree.
Reproducer:
mkfs.btrfs -f /dev/sdd
mount /dev/sdd /mnt
xfs_io -f -c "falloc 780366 135302" /mnt/foo
xfs_io -c "falloc 327680 151552" /mnt/foo
xfs_io -c "pwrite -S 0xff -b 131072 0 131072" /mnt/foo
sync
for i in `seq 1 40`; do btrfs subvolume snapshot /mnt /mnt/snap$i ; done
umount /mnt
btrfs check /dev/sdd
The check command exited with status 1 and the following output:
Checking filesystem on /dev/sdd
UUID: 2416ab5f-9d71-457e-bb13-a27d4f6b399a
checking extents
checking free space cache
checking fs roots
checking csums
There are no extents for csum range 12980224-12984320
Csum exists for 12980224-12984320 but there is no extent record
found 1388544 bytes used err is 1
total csum bytes: 132
total tree bytes: 704512
total fs tree bytes: 573440
total extent tree bytes: 16384
btree space waste bytes: 564479
file data blocks allocated: 19341312
referenced 14606336
Btrfs v3.14.1-94-g80597e7
After this change it no longer erroneously reports a missing extent for the
csum item and exits with a status of 0.
Also added missing btrfs_prev_leaf() return value checks, as we were ignoring
errors and non-existence of left siblings completely.
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
---
cmds-check.c | 38 +++++++++++++++++++++++++++-----------
1 file changed, 27 insertions(+), 11 deletions(-)
diff --git a/cmds-check.c b/cmds-check.c
index 103efc5..18612c8 100644
--- a/cmds-check.c
+++ b/cmds-check.c
@@ -3650,8 +3650,7 @@ static int check_extent_exists(struct btrfs_root *root,
u64 bytenr,
key.objectid = bytenr;
key.type = BTRFS_EXTENT_ITEM_KEY;
- key.offset = 0;
-
+ key.offset = (u64)-1;
again:
ret = btrfs_search_slot(NULL, root->fs_info->extent_root, &key,
path,
@@ -3661,10 +3660,17 @@ again:
btrfs_free_path(path);
return ret;
} else if (ret) {
- if (path->slots[0])
+ if (path->slots[0] > 0) {
path->slots[0]--;
- else
- btrfs_prev_leaf(root, path);
+ } else {
+ ret = btrfs_prev_leaf(root, path);
+ if (ret < 0) {
+ goto out;
+ } else if (ret > 0) {
+ ret = 0;
+ goto out;
+ }
+ }
}
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
@@ -3674,13 +3680,22 @@ again:
* bytenr, so walk back one more just in case. Dear future traveler,
* first congrats on mastering time travel. Now if it's not too much
* trouble could you go back to 2006 and tell Chris to make the
- * BLOCK_GROUP_ITEM_KEY lower than the EXTENT_ITEM_KEY please?
+ * BLOCK_GROUP_ITEM_KEY (and BTRFS_*_REF_KEY) lower than the
+ * EXTENT_ITEM_KEY please?
*/
- if (key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
- if (path->slots[0])
+ while (key.type > BTRFS_EXTENT_ITEM_KEY) {
+ if (path->slots[0] > 0) {
path->slots[0]--;
- else
- btrfs_prev_leaf(root, path);
+ } else {
+ ret = btrfs_prev_leaf(root, path);
+ if (ret < 0) {
+ goto out;
+ } else if (ret > 0) {
+ ret = 0;
+ goto out;
+ }
+ }
+ btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
}
while (num_bytes) {
@@ -3752,7 +3767,8 @@ again:
}
ret = 0;
- if (num_bytes) {
+out:
+ if (num_bytes && !ret) {
fprintf(stderr, "There are no extents for csum range "
"%Lu-%Lu\n", bytenr, bytenr+num_bytes);
ret = 1;
--
1.9.1
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