btrfs: add missing discards when unpinning extents with -o discard
When we clear the dirty bits in btrfs_delete_unused_bgs for extents
in the empty block group, it results in btrfs_finish_extent_commit being
unable to discard the freed extents.
The block group removal patch added an alternate path to forget extents
other than btrfs_finish_extent_commit. As a result, any extents that
would be freed when the block group is removed aren't discarded. In my
test run, with a large copy of mixed sized files followed by removal, it
left nearly 2/3 of extents undiscarded.
To clean up the block groups, we add the removed block group onto a list
that will be discarded after transaction commit.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Tested-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h
index eb09c20..edc2fbc 100644
--- a/fs/btrfs/transaction.h
+++ b/fs/btrfs/transaction.h
@@ -74,6 +74,8 @@
*/
struct mutex cache_write_mutex;
spinlock_t dirty_bgs_lock;
+ struct list_head deleted_bgs;
+ spinlock_t deleted_bgs_lock;
struct btrfs_delayed_ref_root delayed_refs;
int aborted;
int dirty_bg_run;