As of now we do alloc an empty bio and then use the flag REQ_PREFLUSH
to flush the device cache, instead we can use blkdev_issue_flush()
for this puspose.
Also now no need to check the return when write_dev_flush() is called
with wait = 0
Signed-off-by: Anand Jain <anand.j...@oracle.com>
---
V2
Title of this patch is changed from
btrfs: communicate back ENOMEM when it occurs
And its entirely a new patch, which now use blkdev_issue_flush()
fs/btrfs/disk-io.c | 64 +++++++++++++++---------------------------------------
fs/btrfs/volumes.h | 3 ++-
2 files changed, 19 insertions(+), 48 deletions(-)
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 9de35bca1f67..42bcf98794ec 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -3498,67 +3498,39 @@ static int write_dev_supers(struct btrfs_device *device,
return errors < i ? 0 : -1;
}
-/*
- * endio for the write_dev_flush, this will wake anyone waiting
- * for the barrier when it is done
- */
-static void btrfs_end_empty_barrier(struct bio *bio)
+static void btrfs_dev_issue_flush(struct work_struct *work)
{
- if (bio->bi_private)
- complete(bio->bi_private);
- bio_put(bio);
+ int ret;
+ struct btrfs_device *device;
+
+ device = container_of(work, struct btrfs_device, flush_work);
+
+ /* we are in the commit thread */
+ ret = blkdev_issue_flush(device->bdev, GFP_NOFS, NULL);
+ device->last_flush_error = ret;
+ complete(&device->flush_wait);
}
/*
* trigger flushes for one the devices. If you pass wait == 0, the flushes are
* sent down. With wait == 1, it waits for the previous flush.
- *
- * any device where the flush fails with eopnotsupp are flagged as not-barrier
- * capable
*/
static int write_dev_flush(struct btrfs_device *device, int wait)
{
- struct bio *bio;
- int ret = 0;
-
if (wait) {
- bio = device->flush_bio;
- if (!bio)
- return 0;
+ int ret;
wait_for_completion(&device->flush_wait);
-
- if (bio->bi_error) {
- ret = bio->bi_error;
+ ret = device->last_flush_error;
+ if (ret)
btrfs_dev_stat_inc_and_print(device,
- BTRFS_DEV_STAT_FLUSH_ERRS);
- }
-
- /* drop the reference from the wait == 0 run */
- bio_put(bio);
- device->flush_bio = NULL;
-
+ BTRFS_DEV_STAT_FLUSH_ERRS);
return ret;
}
- /*
- * one reference for us, and we leave it for the
- * caller
- */
- device->flush_bio = NULL;
- bio = btrfs_io_bio_alloc(GFP_NOFS, 0);
- if (!bio)
- return -ENOMEM;
-
- bio->bi_end_io = btrfs_end_empty_barrier;
- bio->bi_bdev = device->bdev;
- bio->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
init_completion(&device->flush_wait);
- bio->bi_private = &device->flush_wait;
- device->flush_bio = bio;
-
- bio_get(bio);
- btrfsic_submit_bio(bio);
+ INIT_WORK(&device->flush_work, btrfs_dev_issue_flush);
+ schedule_work(&device->flush_work);
return 0;
}
@@ -3587,9 +3559,7 @@ static int barrier_all_devices(struct btrfs_fs_info *info)
if (!dev->in_fs_metadata || !dev->writeable)
continue;
- ret = write_dev_flush(dev, 0);
- if (ret)
- errors_send++;
+ write_dev_flush(dev, 0);
}
/* wait for all the barriers */
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index fa0b79422695..1168b78c5f1d 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -123,8 +123,9 @@ struct btrfs_device {
struct list_head resized_list;
/* for sending down flush barriers */
- struct bio *flush_bio;
struct completion flush_wait;
+ struct work_struct flush_work;
+ int last_flush_error;
/* per-device scrub information */
struct scrub_ctx *scrub_device;
--
2.10.0
--
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