From 90db4d4441f58d433ecf74f7e3bd17e0a553c20c Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 17 Oct 2025 05:45:48 +0200 Subject: writeback: allow the file system to override MIN_WRITEBACK_PAGES The relatively low minimal writeback size of 4MiB means that written back inodes on rotational media are switched a lot. Besides introducing additional seeks, this also can lead to extreme file fragmentation on zoned devices when a lot of files are cached relative to the available writeback bandwidth. Add a superblock field that allows the file system to override the default size. Signed-off-by: Christoph Hellwig Link: https://patch.msgid.link/20251017034611.651385-3-hch@lst.de Reviewed-by: Jan Kara Reviewed-by: Darrick J. Wong Signed-off-by: Christian Brauner --- include/linux/writeback.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include/linux/writeback.h') diff --git a/include/linux/writeback.h b/include/linux/writeback.h index 22dd4adc5667..49e1dd96f43e 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -374,4 +374,9 @@ bool redirty_page_for_writepage(struct writeback_control *, struct page *); void sb_mark_inode_writeback(struct inode *inode); void sb_clear_inode_writeback(struct inode *inode); +/* + * 4MB minimal write chunk size + */ +#define MIN_WRITEBACK_PAGES (4096UL >> (PAGE_SHIFT - 10)) + #endif /* WRITEBACK_H */ -- cgit v1.2.3 From 4952f35f0545f3b53dab8d5fd727c4827c2a2778 Mon Sep 17 00:00:00 2001 From: Julian Sun Date: Mon, 29 Sep 2025 19:13:49 +0800 Subject: fs: Make wbc_to_tag() inline and use it in fs. The logic in wbc_to_tag() is widely used in file systems, so modify this function to be inline and use it in file systems. This patch has only passed compilation tests, but it should be fine. Signed-off-by: Julian Sun Reviewed-by: Qu Wenruo Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- fs/btrfs/extent_io.c | 5 +---- fs/ceph/addr.c | 6 +----- fs/ext4/inode.c | 5 +---- fs/f2fs/data.c | 5 +---- fs/gfs2/aops.c | 5 +---- include/linux/writeback.h | 7 +++++++ mm/page-writeback.c | 6 ------ 7 files changed, 12 insertions(+), 27 deletions(-) (limited to 'include/linux/writeback.h') diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index c123a3ef154a..170dd7e80d11 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -2460,10 +2460,7 @@ static int extent_write_cache_pages(struct address_space *mapping, &BTRFS_I(inode)->runtime_flags)) wbc->tagged_writepages = 1; - if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages) - tag = PAGECACHE_TAG_TOWRITE; - else - tag = PAGECACHE_TAG_DIRTY; + tag = wbc_to_tag(wbc); retry: if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages) tag_pages_for_writeback(mapping, index, end); diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c index 322ed268f14a..63b75d214210 100644 --- a/fs/ceph/addr.c +++ b/fs/ceph/addr.c @@ -1045,11 +1045,7 @@ void ceph_init_writeback_ctl(struct address_space *mapping, ceph_wbc->index = ceph_wbc->start_index; ceph_wbc->end = -1; - if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages) { - ceph_wbc->tag = PAGECACHE_TAG_TOWRITE; - } else { - ceph_wbc->tag = PAGECACHE_TAG_DIRTY; - } + ceph_wbc->tag = wbc_to_tag(wbc); ceph_wbc->op_idx = -1; ceph_wbc->num_ops = 0; diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index f9e4ac87211e..58d6194045e2 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -2619,10 +2619,7 @@ static int mpage_prepare_extent_to_map(struct mpage_da_data *mpd) handle_t *handle = NULL; int bpp = ext4_journal_blocks_per_folio(mpd->inode); - if (mpd->wbc->sync_mode == WB_SYNC_ALL || mpd->wbc->tagged_writepages) - tag = PAGECACHE_TAG_TOWRITE; - else - tag = PAGECACHE_TAG_DIRTY; + tag = wbc_to_tag(mpd->wbc); mpd->map.m_len = 0; mpd->next_pos = mpd->start_pos; diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index ef38e62cda8f..826bcfb8230c 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -2986,10 +2986,7 @@ static int f2fs_write_cache_pages(struct address_space *mapping, if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) range_whole = 1; } - if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages) - tag = PAGECACHE_TAG_TOWRITE; - else - tag = PAGECACHE_TAG_DIRTY; + tag = wbc_to_tag(wbc); retry: retry = 0; if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages) diff --git a/fs/gfs2/aops.c b/fs/gfs2/aops.c index 47d74afd63ac..12394fc5dd29 100644 --- a/fs/gfs2/aops.c +++ b/fs/gfs2/aops.c @@ -311,10 +311,7 @@ static int gfs2_write_cache_jdata(struct address_space *mapping, range_whole = 1; cycled = 1; /* ignore range_cyclic tests */ } - if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages) - tag = PAGECACHE_TAG_TOWRITE; - else - tag = PAGECACHE_TAG_DIRTY; + tag = wbc_to_tag(wbc); retry: if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages) diff --git a/include/linux/writeback.h b/include/linux/writeback.h index 49e1dd96f43e..2a81816f7507 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -196,6 +196,13 @@ static inline void wait_on_inode(struct inode *inode) !(READ_ONCE(inode->i_state) & I_NEW)); } +static inline xa_mark_t wbc_to_tag(struct writeback_control *wbc) +{ + if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages) + return PAGECACHE_TAG_TOWRITE; + return PAGECACHE_TAG_DIRTY; +} + #ifdef CONFIG_CGROUP_WRITEBACK #include diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 757bc4d3b5b5..a124ab6a205d 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -2434,12 +2434,6 @@ static bool folio_prepare_writeback(struct address_space *mapping, return true; } -static xa_mark_t wbc_to_tag(struct writeback_control *wbc) -{ - if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages) - return PAGECACHE_TAG_TOWRITE; - return PAGECACHE_TAG_DIRTY; -} static pgoff_t wbc_end(struct writeback_control *wbc) { -- cgit v1.2.3