diff options
| -rw-r--r-- | fs/btrfs/inode.c | 30 |
1 files changed, 13 insertions, 17 deletions
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 66106b48b478..269da826a40c 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -7411,25 +7411,21 @@ static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend, btrfs_start_ordered_extent(inode, ordered, 1); btrfs_put_ordered_extent(ordered); } else { - /* Screw you mmap */ - ret = btrfs_fdatawrite_range(inode, lockstart, lockend); - if (ret) - break; - ret = filemap_fdatawait_range(inode->i_mapping, - lockstart, - lockend); - if (ret) - break; - /* - * If we found a page that couldn't be invalidated just - * fall back to buffered. + * We could trigger writeback for this range (and wait + * for it to complete) and then invalidate the pages for + * this range (through invalidate_inode_pages2_range()), + * but that can lead us to a deadlock with a concurrent + * call to readpages() (a buffered read or a defrag call + * triggered a readahead) on a page lock due to an + * ordered dio extent we created before but did not have + * yet a corresponding bio submitted (whence it can not + * complete), which makes readpages() wait for that + * ordered extent to complete while holding a lock on + * that page. */ - ret = invalidate_inode_pages2_range(inode->i_mapping, - lockstart >> PAGE_CACHE_SHIFT, - lockend >> PAGE_CACHE_SHIFT); - if (ret) - break; + ret = -ENOTBLK; + break; } cond_resched(); |