diff options
Diffstat (limited to 'fs/block_dev.c')
-rw-r--r-- | fs/block_dev.c | 113 |
1 files changed, 73 insertions, 40 deletions
diff --git a/fs/block_dev.c b/fs/block_dev.c index c2a85b587922..eb657ab94060 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -349,7 +349,7 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages) loff_t pos = iocb->ki_pos; blk_qc_t qc = BLK_QC_T_NONE; gfp_t gfp; - ssize_t ret; + int ret; if ((pos | iov_iter_alignment(iter)) & (bdev_logical_block_size(bdev) - 1)) @@ -386,8 +386,6 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages) ret = 0; for (;;) { - int err; - bio_set_dev(bio, bdev); bio->bi_iter.bi_sector = pos >> 9; bio->bi_write_hint = iocb->ki_hint; @@ -395,10 +393,8 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages) bio->bi_end_io = blkdev_bio_end_io; bio->bi_ioprio = iocb->ki_ioprio; - err = bio_iov_iter_get_pages(bio, iter); - if (unlikely(err)) { - if (!ret) - ret = err; + ret = bio_iov_iter_get_pages(bio, iter); + if (unlikely(ret)) { bio->bi_status = BLK_STS_IOERR; bio_endio(bio); break; @@ -421,7 +417,6 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages) if (nowait) bio->bi_opf |= (REQ_NOWAIT | REQ_NOWAIT_INLINE); - dio->size += bio->bi_iter.bi_size; pos += bio->bi_iter.bi_size; nr_pages = iov_iter_npages(iter, BIO_MAX_PAGES); @@ -433,10 +428,11 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages) polled = true; } + dio->size += bio->bi_iter.bi_size; qc = submit_bio(bio); if (qc == BLK_QC_T_EAGAIN) { - if (!ret) - ret = -EAGAIN; + dio->size -= bio->bi_iter.bi_size; + ret = -EAGAIN; goto error; } @@ -459,18 +455,17 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages) atomic_inc(&dio->ref); } + dio->size += bio->bi_iter.bi_size; qc = submit_bio(bio); if (qc == BLK_QC_T_EAGAIN) { - if (!ret) - ret = -EAGAIN; + dio->size -= bio->bi_iter.bi_size; + ret = -EAGAIN; goto error; } - ret += bio->bi_iter.bi_size; bio = bio_alloc(gfp, nr_pages); if (!bio) { - if (!ret) - ret = -EAGAIN; + ret = -EAGAIN; goto error; } } @@ -495,6 +490,8 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages) out: if (!ret) ret = blk_status_to_errno(dio->bio.bi_status); + if (likely(!ret)) + ret = dio->size; bio_put(&dio->bio); return ret; @@ -1181,8 +1178,7 @@ static struct gendisk *bdev_get_gendisk(struct block_device *bdev, int *partno) * Pointer to the block device containing @bdev on success, ERR_PTR() * value on failure. */ -static struct block_device *bd_start_claiming(struct block_device *bdev, - void *holder) +struct block_device *bd_start_claiming(struct block_device *bdev, void *holder) { struct gendisk *disk; struct block_device *whole; @@ -1229,6 +1225,62 @@ static struct block_device *bd_start_claiming(struct block_device *bdev, return ERR_PTR(err); } } +EXPORT_SYMBOL(bd_start_claiming); + +static void bd_clear_claiming(struct block_device *whole, void *holder) +{ + lockdep_assert_held(&bdev_lock); + /* tell others that we're done */ + BUG_ON(whole->bd_claiming != holder); + whole->bd_claiming = NULL; + wake_up_bit(&whole->bd_claiming, 0); +} + +/** + * bd_finish_claiming - finish claiming of a block device + * @bdev: block device of interest + * @whole: whole block device (returned from bd_start_claiming()) + * @holder: holder that has claimed @bdev + * + * Finish exclusive open of a block device. Mark the device as exlusively + * open by the holder and wake up all waiters for exclusive open to finish. + */ +void bd_finish_claiming(struct block_device *bdev, struct block_device *whole, + void *holder) +{ + spin_lock(&bdev_lock); + BUG_ON(!bd_may_claim(bdev, whole, holder)); + /* + * Note that for a whole device bd_holders will be incremented twice, + * and bd_holder will be set to bd_may_claim before being set to holder + */ + whole->bd_holders++; + whole->bd_holder = bd_may_claim; + bdev->bd_holders++; + bdev->bd_holder = holder; + bd_clear_claiming(whole, holder); + spin_unlock(&bdev_lock); +} +EXPORT_SYMBOL(bd_finish_claiming); + +/** + * bd_abort_claiming - abort claiming of a block device + * @bdev: block device of interest + * @whole: whole block device (returned from bd_start_claiming()) + * @holder: holder that has claimed @bdev + * + * Abort claiming of a block device when the exclusive open failed. This can be + * also used when exclusive open is not actually desired and we just needed + * to block other exclusive openers for a while. + */ +void bd_abort_claiming(struct block_device *bdev, struct block_device *whole, + void *holder) +{ + spin_lock(&bdev_lock); + bd_clear_claiming(whole, holder); + spin_unlock(&bdev_lock); +} +EXPORT_SYMBOL(bd_abort_claiming); #ifdef CONFIG_SYSFS struct bd_holder_disk { @@ -1698,29 +1750,10 @@ int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder) /* finish claiming */ mutex_lock(&bdev->bd_mutex); - spin_lock(&bdev_lock); - - if (!res) { - BUG_ON(!bd_may_claim(bdev, whole, holder)); - /* - * Note that for a whole device bd_holders - * will be incremented twice, and bd_holder - * will be set to bd_may_claim before being - * set to holder - */ - whole->bd_holders++; - whole->bd_holder = bd_may_claim; - bdev->bd_holders++; - bdev->bd_holder = holder; - } - - /* tell others that we're done */ - BUG_ON(whole->bd_claiming != holder); - whole->bd_claiming = NULL; - wake_up_bit(&whole->bd_claiming, 0); - - spin_unlock(&bdev_lock); - + if (!res) + bd_finish_claiming(bdev, whole, holder); + else + bd_abort_claiming(bdev, whole, holder); /* * Block event polling for write claims if requested. Any * write holder makes the write_holder state stick until |