When reserving space, at space-info.c:__reserve_bytes(), we assert that
either the current task is not holding a transacion handle, or, if it is,
that the flush method is not BTRFS_RESERVE_FLUSH_ALL. This is because that
flush method can trigger transaction commits, and therefore could lead to
a deadlock.
However there are other 2 flush methods that can trigger transaction
commits:
1) BTRFS_RESERVE_FLUSH_ALL_STEAL
2) BTRFS_RESERVE_FLUSH_EVICT
So update the assertion to check the flush method is also not one those
two methods if the current task is holding a transaction handle.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
bool pending_tickets;
ASSERT(orig_bytes);
- ASSERT(!current->journal_info || flush != BTRFS_RESERVE_FLUSH_ALL);
+ /*
+ * If have a transaction handle (current->journal_info != NULL), then
+ * the flush method can not be neither BTRFS_RESERVE_FLUSH_ALL* nor
+ * BTRFS_RESERVE_FLUSH_EVICT, as we could deadlock because those
+ * flushing methods can trigger transaction commits.
+ */
+ if (current->journal_info) {
+ /* One assert per line for easier debugging. */
+ ASSERT(flush != BTRFS_RESERVE_FLUSH_ALL);
+ ASSERT(flush != BTRFS_RESERVE_FLUSH_ALL_STEAL);
+ ASSERT(flush != BTRFS_RESERVE_FLUSH_EVICT);
+ }
if (flush == BTRFS_RESERVE_FLUSH_DATA)
async_work = &fs_info->async_data_reclaim_work;