On 11.06.21 г. 16:53, Josef Bacik wrote: > We use the async_delalloc_pages mechanism to make sure that we've > completed our async work before trying to continue our delalloc > flushing. The reason for this is we need to see any ordered extents > that were created by our delalloc flushing. However we're waking up > before we do the submit work, which is before we create the ordered > extents. This is a pretty wide race window where we could potentially > think there are no ordered extents and thus exit shrink_delalloc > prematurely. Fix this by waking us up after we've done the work to > create ordered extents. > > cc: stable@xxxxxxxxxxxxxxx > Signed-off-by: Josef Bacik <josef@xxxxxxxxxxxxxx> Reviewed-by: Nikolay Borisov <nborisov@xxxxxxxx> > --- > fs/btrfs/inode.c | 10 +++++----- > 1 file changed, 5 insertions(+), 5 deletions(-) > > diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c > index 6cb73ff59c7c..c37271df2c6d 100644 > --- a/fs/btrfs/inode.c > +++ b/fs/btrfs/inode.c > @@ -1271,11 +1271,6 @@ static noinline void async_cow_submit(struct btrfs_work *work) > nr_pages = (async_chunk->end - async_chunk->start + PAGE_SIZE) >> > PAGE_SHIFT; > > - /* atomic_sub_return implies a barrier */ > - if (atomic_sub_return(nr_pages, &fs_info->async_delalloc_pages) < > - 5 * SZ_1M) > - cond_wake_up_nomb(&fs_info->async_submit_wait); > - > /* > * ->inode could be NULL if async_chunk_start has failed to compress, > * in which case we don't have anything to submit, yet we need to > @@ -1284,6 +1279,11 @@ static noinline void async_cow_submit(struct btrfs_work *work) > */ > if (async_chunk->inode) > submit_compressed_extents(async_chunk); > + > + /* atomic_sub_return implies a barrier */ > + if (atomic_sub_return(nr_pages, &fs_info->async_delalloc_pages) < > + 5 * SZ_1M) > + cond_wake_up_nomb(&fs_info->async_submit_wait); > } > > static noinline void async_cow_free(struct btrfs_work *work) >
