6.12-stable review patch. If anyone has any objections, please let me know.
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From: David Howells dhowells@redhat.com
[ Upstream commit d0327c824338cdccad058723a31d038ecd553409 ]
When the caching for a cookie is temporarily disabled (e.g. due to a DIO write on that file), future copying to the cache for that file is disabled until all fds open on that file are closed. However, if netfslib is using the deprecated PG_private_2 method (such as is currently used by ceph), and decides it wants to copy to the cache, netfs_advance_write() will just bail at the first check seeing that the cache stream is unavailable, and indicate that it dealt with all the content.
This means that we have no subrequests to provide notifications to drive the state machine or even to pin the request and the request just gets discarded, leaving the folios with PG_private_2 set.
Fix this by jumping directly to cancel the request if the cache is not available. That way, we don't remove mark3 from the folio_queue list and netfs_pgpriv2_cancel() will clean up the folios.
This was found by running the generic/013 xfstest against ceph with an active cache and the "-o fsc" option passed to ceph. That would usually hang
Fixes: ee4cdf7ba857 ("netfs: Speed up buffered reading") Reported-by: Max Kellermann max.kellermann@ionos.com Closes: https://lore.kernel.org/r/CAKPOu+_4m80thNy5_fvROoxBm689YtA0dZ-=gcmkzwYSY4syq... Signed-off-by: David Howells dhowells@redhat.com Link: https://lore.kernel.org/r/20241213135013.2964079-11-dhowells@redhat.com cc: Jeff Layton jlayton@kernel.org cc: Ilya Dryomov idryomov@gmail.com cc: Xiubo Li xiubli@redhat.com cc: netfs@lists.linux.dev cc: ceph-devel@vger.kernel.org cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner brauner@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- fs/netfs/read_pgpriv2.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/fs/netfs/read_pgpriv2.c b/fs/netfs/read_pgpriv2.c index ba5af89d37fa..54d5004fec18 100644 --- a/fs/netfs/read_pgpriv2.c +++ b/fs/netfs/read_pgpriv2.c @@ -170,6 +170,10 @@ void netfs_pgpriv2_write_to_the_cache(struct netfs_io_request *rreq)
trace_netfs_write(wreq, netfs_write_trace_copy_to_cache); netfs_stat(&netfs_n_wh_copy_to_cache); + if (!wreq->io_streams[1].avail) { + netfs_put_request(wreq, false, netfs_rreq_trace_put_return); + goto couldnt_start; + }
for (;;) { error = netfs_pgpriv2_copy_folio(wreq, folio);