diff options
| author | David Howells <dhowells@redhat.com> | 2024-12-13 14:50:09 +0100 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2024-12-20 22:07:57 +0100 |
| commit | 38cf8e945721ffe708fa675507465da7f4f2a9f7 (patch) | |
| tree | 1adb090f9fb3b3f130c4e42e548e3e1eb69b1643 | |
| parent | netfs: Work around recursion by abandoning retry if nothing read (diff) | |
| download | linux-38cf8e945721ffe708fa675507465da7f4f2a9f7.tar.xz linux-38cf8e945721ffe708fa675507465da7f4f2a9f7.zip | |
netfs: Fix ceph copy to cache on write-begin
At the end of netfs_unlock_read_folio() in which folios are marked
appropriately for copying to the cache (either with by being marked dirty
and having their private data set or by having PG_private_2 set) and then
unlocked, the folio_queue struct has the entry pointing to the folio
cleared. This presents a problem for netfs_pgpriv2_write_to_the_cache(),
which is used to write folios marked with PG_private_2 to the cache as it
expects to be able to trawl the folio_queue list thereafter to find the
relevant folios, leading to a hang.
Fix this by not clearing the folio_queue entry if we're going to do the
deprecated copy-to-cache. The clearance will be done instead as the folios
are written to the cache.
This can be reproduced by starting cachefiles, mounting a ceph filesystem
with "-o fsc" and writing to it.
Fixes: 796a4049640b ("netfs: In readahead, put the folio refs as soon extracted")
Reported-by: Max Kellermann <max.kellermann@ionos.com>
Closes: https://lore.kernel.org/r/CAKPOu+_4m80thNy5_fvROoxBm689YtA0dZ-=gcmkzwYSY4syqw@mail.gmail.com/
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241213135013.2964079-10-dhowells@redhat.com
Fixes: ee4cdf7ba857 ("netfs: Speed up buffered reading")
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>
| -rw-r--r-- | fs/netfs/read_collect.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/fs/netfs/read_collect.c b/fs/netfs/read_collect.c index 47ed3a5044e2..e8624f5c7fcc 100644 --- a/fs/netfs/read_collect.c +++ b/fs/netfs/read_collect.c @@ -62,10 +62,14 @@ static void netfs_unlock_read_folio(struct netfs_io_subrequest *subreq, } else { trace_netfs_folio(folio, netfs_folio_trace_read_done); } + + folioq_clear(folioq, slot); } else { // TODO: Use of PG_private_2 is deprecated. if (test_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags)) netfs_pgpriv2_mark_copy_to_cache(subreq, rreq, folioq, slot); + else + folioq_clear(folioq, slot); } if (!test_bit(NETFS_RREQ_DONT_UNLOCK_FOLIOS, &rreq->flags)) { @@ -77,8 +81,6 @@ static void netfs_unlock_read_folio(struct netfs_io_subrequest *subreq, folio_unlock(folio); } } - - folioq_clear(folioq, slot); } /* |