Re: [PATCH 08/12] iomap: move folio_unlock out of iomap_writeback_folio
From: Brian Foster <hidden>
Date: 2025-06-27 16:35:24
Also in:
gfs2, linux-block, linux-fsdevel, linux-xfs
On Fri, Jun 27, 2025 at 09:02:41AM +0200, Christoph Hellwig wrote:
From: Joanne Koong <joannelkoong@gmail.com> Move unlocking the folio out of iomap_writeback_folio into the caller. This means the end writeback machinery is now run with the folio locked when no writeback happend, or writeback completed extremely fast.
I notice that folio_end_dropbehind_write() (via folio_end_writeback()) wants to trylock the folio in order to do its thing. Is this going to cause issues with that (i.e. prevent invalidations)? Brian
quoted hunk ↗ jump to hunk
This prepares for exporting iomap_writeback_folio for use in folio laundering. Signed-off-by: Joanne Koong <joannelkoong@gmail.com> [hch: split from a larger patch] Signed-off-by: Christoph Hellwig <hch@lst.de> --- fs/iomap/buffered-io.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-)diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index c28eb6a6eee4..a1dccf4e7063 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c@@ -1656,10 +1656,8 @@ static int iomap_writeback_folio(struct iomap_writeback_ctx *wpc, trace_iomap_writeback_folio(inode, pos, folio_size(folio)); - if (!iomap_writeback_handle_eof(folio, inode, &end_pos)) { - folio_unlock(folio); + if (!iomap_writeback_handle_eof(folio, inode, &end_pos)) return 0; - } WARN_ON_ONCE(end_pos <= pos); if (i_blocks_per_folio(inode, folio) > 1) {@@ -1713,7 +1711,6 @@ static int iomap_writeback_folio(struct iomap_writeback_ctx *wpc, * already at this point. In that case we need to clear the writeback * bit ourselves right after unlocking the page. */ - folio_unlock(folio); if (ifs) { if (atomic_dec_and_test(&ifs->write_bytes_pending)) folio_end_writeback(folio);@@ -1740,8 +1737,10 @@ iomap_writepages(struct iomap_writeback_ctx *wpc) PF_MEMALLOC)) return -EIO; - while ((folio = writeback_iter(mapping, wpc->wbc, folio, &error))) + while ((folio = writeback_iter(mapping, wpc->wbc, folio, &error))) { error = iomap_writeback_folio(wpc, folio); + folio_unlock(folio); + } /* * If @error is non-zero, it means that we have a situation where some-- 2.47.2