tools/testing/nvdimm: Fix fallthrough warning

[linux-2.6-microblaze.git] / fs / block_dev.c

diff --git a/fs/block_dev.c b/fs/block_dev.c
index c2a85b5..eb657ab 100644 (file)
--- 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