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authorChristoph Hellwig <hch@lst.de>2023-07-24 06:26:54 -0700
committerDavid Sterba <dsterba@suse.com>2023-08-10 17:04:09 +0200
commit5c25699871112853f231e52d51c576d5c759a020 (patch)
treee58064e2d33900d090d50a298d515c7058a1ea70 /fs
parenteffa24f689ce0948f68c754991a445a8d697d3a8 (diff)
btrfs: don't wait for writeback on clean pages in extent_write_cache_pages
__extent_writepage could have started on more pages than the one it was called for. This happens regularly for zoned file systems, and in theory could happen for compressed I/O if the worker thread was executed very quickly. For such pages extent_write_cache_pages waits for writeback to complete before moving on to the next page, which is highly inefficient as it blocks the flusher thread. Port over the PageDirty check that was added to write_cache_pages in commit 515f4a037fb ("mm: write_cache_pages optimise page cleaning") to fix this. CC: stable@vger.kernel.org # 4.14+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs')
-rw-r--r--fs/btrfs/extent_io.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index c36eb4956f81..ca765d62324f 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2145,6 +2145,12 @@ retry:
continue;
}
+ if (!folio_test_dirty(folio)) {
+ /* Someone wrote it for us. */
+ folio_unlock(folio);
+ continue;
+ }
+
if (wbc->sync_mode != WB_SYNC_NONE) {
if (folio_test_writeback(folio))
submit_write_bio(bio_ctrl, 0);