btrfs-progs: deal with drop_progress properly in fsck

While testing snapshot deletion with dm-log-writes I saw that I was
failing the fsck sometimes when the fs was actually in the correct
state.  This is because we only skip blocks on the same level of
root_item->drop_level.  If the drop_level < the root level then we could
very well walk into nodes that we wouldn't actually walk into on fs
mount, because the drop_progress is further ahead in the slot of the
root.  Instead only process the slots of the nodes that are above the
drop_progress key.  With this patch in place we no longer improperly
fail to check fs'es that have a drop_progress set with a drop_level <
root level.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Josef Bacik 2019-02-06 15:49:24 -05:00 committed by David Sterba
parent 2a8cec4b12
commit 42a1aaeec4
3 changed files with 21 additions and 6 deletions

View File

@ -6319,15 +6319,28 @@ static int run_next_block(struct btrfs_root *root,
int level;
level = btrfs_header_level(buf);
for (i = 0; i < nritems; i++) {
i = 0;
/*
* If we have a drop key we need to not walk down any slots we
* would have ignored when mounting the fs. These blocks are
* technically unreferenced and don't need to be worried about.
*/
if (ri != NULL && ri->drop_level && level > ri->drop_level) {
ret = btrfs_bin_search(buf, &ri->drop_key, level, &i);
if (ret && i > 0)
i--;
}
for (; i < nritems; i++) {
struct extent_record tmpl;
ptr = btrfs_node_blockptr(buf, i);
size = root->fs_info->nodesize;
btrfs_node_key_to_cpu(buf, &key, i);
if (ri != NULL) {
if ((level == ri->drop_level)
&& is_dropped_key(&key, &ri->drop_key)) {
if ((level == ri->drop_level) &&
is_dropped_key(&key, &ri->drop_key)) {
continue;
}
}

View File

@ -633,8 +633,8 @@ static int generic_bin_search(struct extent_buffer *eb, unsigned long p,
* simple bin_search frontend that does the right thing for
* leaves vs nodes
*/
static int bin_search(struct extent_buffer *eb, const struct btrfs_key *key,
int level, int *slot)
int btrfs_bin_search(struct extent_buffer *eb, const struct btrfs_key *key,
int level, int *slot)
{
if (level == 0)
return generic_bin_search(eb,
@ -1167,7 +1167,7 @@ again:
ret = check_block(fs_info, p, level);
if (ret)
return -1;
ret = bin_search(b, key, level, &slot);
ret = btrfs_bin_search(b, key, level, &slot);
if (level != 0) {
if (ret && slot > 0)
slot -= 1;

View File

@ -2628,6 +2628,8 @@ int btrfs_search_slot_for_read(struct btrfs_root *root,
const struct btrfs_key *key,
struct btrfs_path *p, int find_higher,
int return_any);
int btrfs_bin_search(struct extent_buffer *eb, const struct btrfs_key *key,
int level, int *slot);
int btrfs_find_item(struct btrfs_root *fs_root, struct btrfs_path *found_path,
u64 iobjectid, u64 ioff, u8 key_type,
struct btrfs_key *found_key);