From 7d41870d65db028234333c68e60a034ac335557a Mon Sep 17 00:00:00 2001 From: Xiubo Li Date: Wed, 8 Mar 2023 10:21:44 +0800 Subject: [PATCH] ceph: implement writeback livelock avoidance using page tagging While the mapped IOs continue if we try to flush a file's buffer we can see that the fsync() won't complete until the IOs finish. This is analogous to Jan Kara's commit (f446daaea9d4 mm: implement writeback livelock avoidance using page tagging), we will try to avoid livelocks of writeback when some steadily creates dirty pages in a mapping we are writing out. Signed-off-by: Xiubo Li Reviewed-by: Ilya Dryomov Signed-off-by: Ilya Dryomov --- fs/ceph/addr.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c index d5335f445233..6bb251a4d613 100644 --- a/fs/ceph/addr.c +++ b/fs/ceph/addr.c @@ -808,6 +808,7 @@ static int ceph_writepages_start(struct address_space *mapping, bool should_loop, range_whole = false; bool done = false; bool caching = ceph_is_cache_enabled(inode); + xa_mark_t tag; if (wbc->sync_mode == WB_SYNC_NONE && fsc->write_congested) @@ -834,6 +835,11 @@ static int ceph_writepages_start(struct address_space *mapping, start_index = wbc->range_cyclic ? mapping->writeback_index : 0; index = start_index; + if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages) { + tag = PAGECACHE_TAG_TOWRITE; + } else { + tag = PAGECACHE_TAG_DIRTY; + } retry: /* find oldest snap context with dirty data */ snapc = get_oldest_context(inode, &ceph_wbc, NULL); @@ -872,6 +878,9 @@ retry: dout(" non-head snapc, range whole\n"); } + if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages) + tag_pages_for_writeback(mapping, index, end); + ceph_put_snap_context(last_snapc); last_snapc = snapc; @@ -888,7 +897,7 @@ retry: get_more_pages: nr_folios = filemap_get_folios_tag(mapping, &index, - end, PAGECACHE_TAG_DIRTY, &fbatch); + end, tag, &fbatch); dout("pagevec_lookup_range_tag got %d\n", nr_folios); if (!nr_folios && !locked_pages) break;