From 52ed1c6305c2159fb5d0bdd98104a4a7d613b1bd Mon Sep 17 00:00:00 2001 From: Jing Xia Date: Tue, 3 Sep 2024 13:40:12 +0800 Subject: [PATCH] btrfs: pass write-hint for buffered IO Commit 449813515d3e ("block, fs: Restore the per-bio/request data lifetime fields") restored write-hint support in btrfs. But that is applicable only for direct IO. This patch supports passing write-hint for buffered IO from btrfs file system to block layer by filling bi_write_hint of struct bio in alloc_new_bio(). There's an ongoing discussion which devices can use that, https://lore.kernel.org/all/20240910150200.6589-6-joshi.k@samsung.com, in SCSI there's support using sd_group_number() and sd_setup_rw32_cmnd(). The hint goes from the application directly to the block device so it's up to the application to set up everything properly to utilize the different hint classes. Link: https://lore.kernel.org/all/20240910150200.6589-6-joshi.k@samsung.com Reviewed-by: Johannes Thumshirn Signed-off-by: Jing Xia [ Add more context and use case. ] Signed-off-by: David Sterba --- fs/btrfs/extent_io.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index f4fb1fb3454a08..3a33629718ada9 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -710,6 +710,7 @@ static void alloc_new_bio(struct btrfs_inode *inode, bbio = btrfs_bio_alloc(BIO_MAX_VECS, bio_ctrl->opf, fs_info, bio_ctrl->end_io_func, NULL); bbio->bio.bi_iter.bi_sector = disk_bytenr >> SECTOR_SHIFT; + bbio->bio.bi_write_hint = inode->vfs_inode.i_write_hint; bbio->inode = inode; bbio->file_offset = file_offset; bio_ctrl->bbio = bbio;