7.3-stable review patch. If anyone has any objections, please let me know. ------------------ From: Max Kellermann [ Upstream commit 979b7ed4457a04c5a41c36f86052ecc6b76c67d9 ] Readahead acquires caps while the folios are locked. This can deadlock when processing a pending truncate; truncate_pagecache() can then attempt to a folio that is already locked. Return -EAGAIN instead when `NON_BLOCKING` is set, causing the readahead to be abandoned. Cc: stable@vger.kernel.org Fixes: 49870056005c ("ceph: convert ceph_readpages to ceph_readahead") Signed-off-by: Max Kellermann Reviewed-by: Xiubo Li Signed-off-by: Ilya Dryomov Signed-off-by: Sasha Levin --- fs/ceph/caps.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c index bcb04c6cb92cb..86e195c5fd325 100644 --- a/fs/ceph/caps.c +++ b/fs/ceph/caps.c @@ -2889,6 +2889,10 @@ static int try_get_cap_refs(struct inode *inode, int need, int want, } /* finish pending truncate */ + if (ci->i_truncate_pending && (flags & NON_BLOCKING)) { + ret = -EAGAIN; + goto out_unlock; + } while (ci->i_truncate_pending) { spin_unlock(&ci->i_ceph_lock); if (snap_rwsem_locked) { -- 2.53.0