fs/direct-io: Reduce the size of struct dio

Reduce the size of struct dio by combining the 'op' and 'op_flags' into
the new 'opf' member. Use the new blk_opf_t type to improve static type
checking. This patch does not change any functionality.

Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220714180729.1065367-49-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/direct-io.c b/fs/direct-io.c
index 840752006f601aab0c23924425da77ea0e8ae39f..94b71440c332f40c22f08c1c1e716a66cd9bde47 100644 (file)
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -117,8 +117,7 @@ struct dio_submit {
 /* dio_state communicated between submission path and end_io */
 struct dio {
        int flags;                      /* doesn't change */
-       int op;
-       int op_flags;
+       blk_opf_t opf;                  /* request operation type and flags */
        struct gendisk *bio_disk;
        struct inode *inode;
        loff_t i_size;                  /* i_size when submitted */
@@ -167,12 +166,13 @@ static inline unsigned dio_pages_present(struct dio_submit *sdio)
  */
 static inline int dio_refill_pages(struct dio *dio, struct dio_submit *sdio)
 {
+       const enum req_op dio_op = dio->opf & REQ_OP_MASK;
        ssize_t ret;
 
        ret = iov_iter_get_pages(sdio->iter, dio->pages, LONG_MAX, DIO_PAGES,
                                &sdio->from);
 
-       if (ret < 0 && sdio->blocks_available && (dio->op == REQ_OP_WRITE)) {
+       if (ret < 0 && sdio->blocks_available && dio_op == REQ_OP_WRITE) {
                struct page *page = ZERO_PAGE(0);
                /*
                 * A memory fault, but the filesystem has some outstanding
@@ -234,6 +234,7 @@ static inline struct page *dio_get_page(struct dio *dio,
  */
 static ssize_t dio_complete(struct dio *dio, ssize_t ret, unsigned int flags)
 {
+       const enum req_op dio_op = dio->opf & REQ_OP_MASK;
        loff_t offset = dio->iocb->ki_pos;
        ssize_t transferred = 0;
        int err;
@@ -251,7 +252,7 @@ static ssize_t dio_complete(struct dio *dio, ssize_t ret, unsigned int flags)
                transferred = dio->result;
 
                /* Check for short read case */
-               if ((dio->op == REQ_OP_READ) &&
+               if (dio_op == REQ_OP_READ &&
                    ((offset + transferred) > dio->i_size))
                        transferred = dio->i_size - offset;
                /* ignore EFAULT if some IO has been done */
@@ -286,7 +287,7 @@ static ssize_t dio_complete(struct dio *dio, ssize_t ret, unsigned int flags)
         * zeros from unwritten extents.
         */
        if (flags & DIO_COMPLETE_INVALIDATE &&
-           ret > 0 && dio->op == REQ_OP_WRITE &&
+           ret > 0 && dio_op == REQ_OP_WRITE &&
            dio->inode->i_mapping->nrpages) {
                err = invalidate_inode_pages2_range(dio->inode->i_mapping,
                                        offset >> PAGE_SHIFT,
@@ -305,7 +306,7 @@ static ssize_t dio_complete(struct dio *dio, ssize_t ret, unsigned int flags)
                 */
                dio->iocb->ki_pos += transferred;
 
-               if (ret > 0 && dio->op == REQ_OP_WRITE)
+               if (ret > 0 && dio_op == REQ_OP_WRITE)
                        ret = generic_write_sync(dio->iocb, ret);
                dio->iocb->ki_complete(dio->iocb, ret);
        }
@@ -329,6 +330,7 @@ static blk_status_t dio_bio_complete(struct dio *dio, struct bio *bio);
 static void dio_bio_end_aio(struct bio *bio)
 {
        struct dio *dio = bio->bi_private;
+       const enum req_op dio_op = dio->opf & REQ_OP_MASK;
        unsigned long remaining;
        unsigned long flags;
        bool defer_completion = false;
@@ -353,7 +355,7 @@ static void dio_bio_end_aio(struct bio *bio)
                 */
                if (dio->result)
                        defer_completion = dio->defer_completion ||
-                                          (dio->op == REQ_OP_WRITE &&
+                                          (dio_op == REQ_OP_WRITE &&
                                            dio->inode->i_mapping->nrpages);
                if (defer_completion) {
                        INIT_WORK(&dio->complete_work, dio_aio_complete_work);
@@ -396,7 +398,7 @@ dio_bio_alloc(struct dio *dio, struct dio_submit *sdio,
         * bio_alloc() is guaranteed to return a bio when allowed to sleep and
         * we request a valid number of vectors.
         */
-       bio = bio_alloc(bdev, nr_vecs, dio->op | dio->op_flags, GFP_KERNEL);
+       bio = bio_alloc(bdev, nr_vecs, dio->opf, GFP_KERNEL);
        bio->bi_iter.bi_sector = first_sector;
        if (dio->is_async)
                bio->bi_end_io = dio_bio_end_aio;
@@ -415,6 +417,7 @@ dio_bio_alloc(struct dio *dio, struct dio_submit *sdio,
  */
 static inline void dio_bio_submit(struct dio *dio, struct dio_submit *sdio)
 {
+       const enum req_op dio_op = dio->opf & REQ_OP_MASK;
        struct bio *bio = sdio->bio;
        unsigned long flags;
 
@@ -426,7 +429,7 @@ static inline void dio_bio_submit(struct dio *dio, struct dio_submit *sdio)
        dio->refcount++;
        spin_unlock_irqrestore(&dio->bio_lock, flags);
 
-       if (dio->is_async && dio->op == REQ_OP_READ && dio->should_dirty)
+       if (dio->is_async && dio_op == REQ_OP_READ && dio->should_dirty)
                bio_set_pages_dirty(bio);
 
        dio->bio_disk = bio->bi_bdev->bd_disk;
@@ -492,7 +495,8 @@ static struct bio *dio_await_one(struct dio *dio)
 static blk_status_t dio_bio_complete(struct dio *dio, struct bio *bio)
 {
        blk_status_t err = bio->bi_status;
-       bool should_dirty = dio->op == REQ_OP_READ && dio->should_dirty;
+       const enum req_op dio_op = dio->opf & REQ_OP_MASK;
+       bool should_dirty = dio_op == REQ_OP_READ && dio->should_dirty;
 
        if (err) {
                if (err == BLK_STS_AGAIN && (bio->bi_opf & REQ_NOWAIT))
@@ -619,6 +623,7 @@ static int dio_set_defer_completion(struct dio *dio)
 static int get_more_blocks(struct dio *dio, struct dio_submit *sdio,
                           struct buffer_head *map_bh)
 {
+       const enum req_op dio_op = dio->opf & REQ_OP_MASK;
        int ret;
        sector_t fs_startblk;   /* Into file, in filesystem-sized blocks */
        sector_t fs_endblk;     /* Into file, in filesystem-sized blocks */
@@ -653,7 +658,7 @@ static int get_more_blocks(struct dio *dio, struct dio_submit *sdio,
                 * which may decide to handle it or also return an unmapped
                 * buffer head.
                 */
-               create = dio->op == REQ_OP_WRITE;
+               create = dio_op == REQ_OP_WRITE;
                if (dio->flags & DIO_SKIP_HOLES) {
                        i_size = i_size_read(dio->inode);
                        if (i_size && fs_startblk <= (i_size - 1) >> i_blkbits)
@@ -801,10 +806,11 @@ submit_page_section(struct dio *dio, struct dio_submit *sdio, struct page *page,
                    unsigned offset, unsigned len, sector_t blocknr,
                    struct buffer_head *map_bh)
 {
+       const enum req_op dio_op = dio->opf & REQ_OP_MASK;
        int ret = 0;
        int boundary = sdio->boundary;  /* dio_send_cur_page may clear it */
 
-       if (dio->op == REQ_OP_WRITE) {
+       if (dio_op == REQ_OP_WRITE) {
                /*
                 * Read accounting is performed in submit_bio()
                 */
@@ -917,6 +923,7 @@ static inline void dio_zero_block(struct dio *dio, struct dio_submit *sdio,
 static int do_direct_IO(struct dio *dio, struct dio_submit *sdio,
                        struct buffer_head *map_bh)
 {
+       const enum req_op dio_op = dio->opf & REQ_OP_MASK;
        const unsigned blkbits = sdio->blkbits;
        const unsigned i_blkbits = blkbits + sdio->blkfactor;
        int ret = 0;
@@ -992,7 +999,7 @@ do_holes:
                                loff_t i_size_aligned;
 
                                /* AKPM: eargh, -ENOTBLK is a hack */
-                               if (dio->op == REQ_OP_WRITE) {
+                               if (dio_op == REQ_OP_WRITE) {
                                        put_page(page);
                                        return -ENOTBLK;
                                }
@@ -1196,12 +1203,11 @@ ssize_t __blockdev_direct_IO(struct kiocb *iocb, struct inode *inode,
 
        dio->inode = inode;
        if (iov_iter_rw(iter) == WRITE) {
-               dio->op = REQ_OP_WRITE;
-               dio->op_flags = REQ_SYNC | REQ_IDLE;
+               dio->opf = REQ_OP_WRITE | REQ_SYNC | REQ_IDLE;
                if (iocb->ki_flags & IOCB_NOWAIT)
-                       dio->op_flags |= REQ_NOWAIT;
+                       dio->opf |= REQ_NOWAIT;
        } else {
-               dio->op = REQ_OP_READ;
+               dio->opf = REQ_OP_READ;
        }
 
        /*