[PATCH v2 1/7] btrfs: always return -EIOCBQUEUED after btrfs_uring_read_extent_endio

If all bios finish before btrfs_encoded_read_regular_fill_pages()
returns, it calls btrfs_uring_read_extent_endio() and previously
returned the I/O status.  A negative errno then made
btrfs_uring_read_extent() unlock and free while
btrfs_uring_read_finished() did the same again.

Return -EIOCBQUEUED so only the deferred path cleans up.

Reported-by: Yue Sun <[email protected]>
Closes: https://lore.kernel.org/linux-btrfs/[email protected]/
Suggested-by: Jens Axboe <[email protected]>
Fixes: 34310c442e17 ("btrfs: add io_uring command for encoded reads (ENCODED_READ ioctl)")
Signed-off-by: Yang Xiuwei <[email protected]>
---
 fs/btrfs/inode.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index b446c3014b24..8e3cee3845e6 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -9411,7 +9411,6 @@ int btrfs_encoded_read_regular_fill_pages(struct btrfs_inode *inode,
 	struct completion sync_reads;
 	unsigned long i = 0;
 	struct btrfs_bio *bbio;
-	int ret;
 
 	/*
 	 * Fast path for synchronous reads which completes in this call, io_uring
@@ -9458,10 +9457,10 @@ int btrfs_encoded_read_regular_fill_pages(struct btrfs_inode *inode,
 
 	if (uring_ctx) {
 		if (refcount_dec_and_test(&priv->pending_refs)) {
-			ret = blk_status_to_errno(READ_ONCE(priv->status));
-			btrfs_uring_read_extent_endio(uring_ctx, ret);
+			int err = blk_status_to_errno(READ_ONCE(priv->status));
+
+			btrfs_uring_read_extent_endio(uring_ctx, err);
 			kfree(priv);
-			return ret;
 		}
 
 		return -EIOCBQUEUED;
-- 
2.25.1