struct kiocb has a 2 bytes hole that developed post commit 41d36a9f3e53 ("fs: remove kiocb.ki_hint"). But write hint has made a comeback with commit 449813515d3e ("block, fs: Restore the per-bio/request data lifetime fields"). This patch uses the leftover space in kiocb to carve 1 byte field ki_write_hint. Restore the code that operates on kiocb to use ki_write_hint instead of inode hint value. This does not bring any behavior change, but needed to enable per-io hints (by another patch). Signed-off-by: Kanchan Joshi <joshi.k@xxxxxxxxxxx> Signed-off-by: Nitesh Shetty <nj.shetty@xxxxxxxxxxx> Reviewed-by: Hannes Reinecke <hare@xxxxxxx> --- block/fops.c | 6 +++--- fs/aio.c | 1 + fs/cachefiles/io.c | 1 + fs/direct-io.c | 2 +- fs/iomap/direct-io.c | 2 +- include/linux/fs.h | 8 ++++++++ io_uring/rw.c | 1 + 7 files changed, 16 insertions(+), 5 deletions(-) diff --git a/block/fops.c b/block/fops.c index e696ae53bf1e..85b9b97d372c 100644 --- a/block/fops.c +++ b/block/fops.c @@ -74,7 +74,7 @@ static ssize_t __blkdev_direct_IO_simple(struct kiocb *iocb, bio_init(&bio, bdev, vecs, nr_pages, dio_bio_write_op(iocb)); } bio.bi_iter.bi_sector = pos >> SECTOR_SHIFT; - bio.bi_write_hint = file_inode(iocb->ki_filp)->i_write_hint; + bio.bi_write_hint = iocb->ki_write_hint; bio.bi_ioprio = iocb->ki_ioprio; if (iocb->ki_flags & IOCB_ATOMIC) bio.bi_opf |= REQ_ATOMIC; @@ -203,7 +203,7 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, for (;;) { bio->bi_iter.bi_sector = pos >> SECTOR_SHIFT; - bio->bi_write_hint = file_inode(iocb->ki_filp)->i_write_hint; + bio->bi_write_hint = iocb->ki_write_hint; bio->bi_private = dio; bio->bi_end_io = blkdev_bio_end_io; bio->bi_ioprio = iocb->ki_ioprio; @@ -319,7 +319,7 @@ static ssize_t __blkdev_direct_IO_async(struct kiocb *iocb, dio->flags = 0; dio->iocb = iocb; bio->bi_iter.bi_sector = pos >> SECTOR_SHIFT; - bio->bi_write_hint = file_inode(iocb->ki_filp)->i_write_hint; + bio->bi_write_hint = iocb->ki_write_hint; bio->bi_end_io = blkdev_bio_end_io_async; bio->bi_ioprio = iocb->ki_ioprio; diff --git a/fs/aio.c b/fs/aio.c index e8920178b50f..db618817e670 100644 --- a/fs/aio.c +++ b/fs/aio.c @@ -1517,6 +1517,7 @@ static int aio_prep_rw(struct kiocb *req, const struct iocb *iocb, int rw_type) req->ki_flags = req->ki_filp->f_iocb_flags | IOCB_AIO_RW; if (iocb->aio_flags & IOCB_FLAG_RESFD) req->ki_flags |= IOCB_EVENTFD; + req->ki_write_hint = file_write_hint(req->ki_filp); if (iocb->aio_flags & IOCB_FLAG_IOPRIO) { /* * If the IOCB_FLAG_IOPRIO flag of aio_flags is set, then diff --git a/fs/cachefiles/io.c b/fs/cachefiles/io.c index 6a821a959b59..c3db102ae64e 100644 --- a/fs/cachefiles/io.c +++ b/fs/cachefiles/io.c @@ -309,6 +309,7 @@ int __cachefiles_write(struct cachefiles_object *object, ki->iocb.ki_pos = start_pos; ki->iocb.ki_flags = IOCB_DIRECT | IOCB_WRITE; ki->iocb.ki_ioprio = get_current_ioprio(); + ki->iocb.ki_write_hint = file_write_hint(file); ki->object = object; ki->start = start_pos; ki->len = len; diff --git a/fs/direct-io.c b/fs/direct-io.c index bbd05f1a2145..73629e26becb 100644 --- a/fs/direct-io.c +++ b/fs/direct-io.c @@ -409,7 +409,7 @@ dio_bio_alloc(struct dio *dio, struct dio_submit *sdio, bio->bi_end_io = dio_bio_end_io; if (dio->is_pinned) bio_set_flag(bio, BIO_PAGE_PINNED); - bio->bi_write_hint = file_inode(dio->iocb->ki_filp)->i_write_hint; + bio->bi_write_hint = dio->iocb->ki_write_hint; sdio->bio = bio; sdio->logical_offset_in_bio = sdio->cur_page_fs_offset; diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c index f637aa0706a3..fff43f121ee6 100644 --- a/fs/iomap/direct-io.c +++ b/fs/iomap/direct-io.c @@ -397,7 +397,7 @@ static loff_t iomap_dio_bio_iter(const struct iomap_iter *iter, fscrypt_set_bio_crypt_ctx(bio, inode, pos >> inode->i_blkbits, GFP_KERNEL); bio->bi_iter.bi_sector = iomap_sector(iomap, pos); - bio->bi_write_hint = inode->i_write_hint; + bio->bi_write_hint = dio->iocb->ki_write_hint; bio->bi_ioprio = dio->iocb->ki_ioprio; bio->bi_private = dio; bio->bi_end_io = iomap_dio_bio_end_io; diff --git a/include/linux/fs.h b/include/linux/fs.h index e3c603d01337..3dfe6de7b611 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -370,6 +370,7 @@ struct kiocb { void *private; int ki_flags; u16 ki_ioprio; /* See linux/ioprio.h */ + enum rw_hint ki_write_hint; union { /* * Only used for async buffered reads, where it denotes the @@ -2337,12 +2338,18 @@ static inline bool HAS_UNMAPPED_ID(struct mnt_idmap *idmap, !vfsgid_valid(i_gid_into_vfsgid(idmap, inode)); } +static inline enum rw_hint file_write_hint(struct file *filp) +{ + return file_inode(filp)->i_write_hint; +} + static inline void init_sync_kiocb(struct kiocb *kiocb, struct file *filp) { *kiocb = (struct kiocb) { .ki_filp = filp, .ki_flags = filp->f_iocb_flags, .ki_ioprio = get_current_ioprio(), + .ki_write_hint = file_write_hint(filp), }; } @@ -2353,6 +2360,7 @@ static inline void kiocb_clone(struct kiocb *kiocb, struct kiocb *kiocb_src, .ki_filp = filp, .ki_flags = kiocb_src->ki_flags, .ki_ioprio = kiocb_src->ki_ioprio, + .ki_write_hint = kiocb_src->ki_write_hint, .ki_pos = kiocb_src->ki_pos, }; } diff --git a/io_uring/rw.c b/io_uring/rw.c index f023ff49c688..510123d3d837 100644 --- a/io_uring/rw.c +++ b/io_uring/rw.c @@ -1023,6 +1023,7 @@ int io_write(struct io_kiocb *req, unsigned int issue_flags) if (unlikely(ret)) return ret; req->cqe.res = iov_iter_count(&io->iter); + rw->kiocb.ki_write_hint = file_write_hint(rw->kiocb.ki_filp); if (force_nonblock) { /* If the file doesn't support async, just async punt */ -- 2.25.1