summaryrefslogtreecommitdiffstats
path: root/fs/block_dev.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/block_dev.c')
-rw-r--r--fs/block_dev.c113
1 files changed, 73 insertions, 40 deletions
diff --git a/fs/block_dev.c b/fs/block_dev.c
index c2a85b587922d..eb657ab940606 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
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-19 00:39:54 +0000