From: Christoph Hellwig Date: Fri, 24 Oct 2025 08:04:17 +0000 (+0200) Subject: mm,btrfs: add a filemap_flush_nr helper X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=7fabcb7fbabbcddd9dc42dbe4c92d18ce3e54283;p=thirdparty%2Flinux.git mm,btrfs: add a filemap_flush_nr helper Abstract out the btrfs-specific behavior of kicking off I/O on a number of pages on an address_space into a well-defined helper. Note: there is no kerneldoc comment for the new function because it is not part of the public API. Signed-off-by: Christoph Hellwig Link: https://patch.msgid.link/20251024080431.324236-7-hch@lst.de Reviewed-by: David Hildenbrand Reviewed-by: Damien Le Moal Reviewed-by: Johannes Thumshirn Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index b97d6c1f77727..d12b8116addea 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -8752,19 +8752,10 @@ static int start_delalloc_inodes(struct btrfs_root *root, long *nr_to_write, btrfs_queue_work(root->fs_info->flush_workers, &work->work); } else { - struct writeback_control wbc = { - .nr_to_write = *nr_to_write, - .sync_mode = WB_SYNC_NONE, - .range_start = 0, - .range_end = LLONG_MAX, - }; - - ret = filemap_fdatawrite_wbc(tmp_inode->i_mapping, - &wbc); + ret = filemap_flush_nr(tmp_inode->i_mapping, + nr_to_write); btrfs_add_delayed_iput(inode); - if (*nr_to_write != LONG_MAX) - *nr_to_write = wbc.nr_to_write; if (ret || *nr_to_write <= 0) goto out; } diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 09b581c1d878d..cebdf160d3ddf 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -38,6 +38,7 @@ int filemap_invalidate_pages(struct address_space *mapping, int write_inode_now(struct inode *, int sync); int filemap_fdatawrite(struct address_space *); int filemap_flush(struct address_space *); +int filemap_flush_nr(struct address_space *mapping, long *nr_to_write); int filemap_fdatawait_keep_errors(struct address_space *mapping); int filemap_fdatawait_range(struct address_space *, loff_t lstart, loff_t lend); int filemap_fdatawait_range_keep_errors(struct address_space *mapping, diff --git a/mm/filemap.c b/mm/filemap.c index 99d6919af60da..e344b79a012d6 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -474,6 +474,28 @@ int filemap_flush(struct address_space *mapping) } EXPORT_SYMBOL(filemap_flush); +/* + * Start writeback on @nr_to_write pages from @mapping. No one but the existing + * btrfs caller should be using this. Talk to linux-mm if you think adding a + * new caller is a good idea. + */ +int filemap_flush_nr(struct address_space *mapping, long *nr_to_write) +{ + struct writeback_control wbc = { + .nr_to_write = *nr_to_write, + .sync_mode = WB_SYNC_NONE, + .range_start = 0, + .range_end = LLONG_MAX, + }; + int ret; + + ret = filemap_fdatawrite_wbc(mapping, &wbc); + if (!ret) + *nr_to_write = wbc.nr_to_write; + return ret; +} +EXPORT_SYMBOL_FOR_MODULES(filemap_flush_nr, "btrfs"); + /** * filemap_range_has_page - check if a page exists in range. * @mapping: address space within which to check