We need a device capable of device barriers so we can test the flush
code. To aid testing, add a per-filesystem status flag that affects the
barriers regerdless of the device capabilities and obviously does not
give the same guarantees.
It's off by default, sysfs tunable will follow.
Signed-off-by: David Sterba <dste...@suse.com>
---
fs/btrfs/ctree.h | 1 +
fs/btrfs/disk-io.c | 8 +++++---
fs/btrfs/volumes.h | 1 +
3 files changed, 7 insertions(+), 3 deletions(-)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index f0f5f28784b6..dcf4404f7d61 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -716,6 +716,7 @@ struct btrfs_delayed_root;
#define BTRFS_FS_LOG1_ERR 12
#define BTRFS_FS_LOG2_ERR 13
#define BTRFS_FS_QUOTA_OVERRIDE 14
+#define BTRFS_FS_FORCE_DEV_FLUSH 15
/*
* Indicate that a whole-filesystem exclusive operation is running
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 59a732a13370..659a3b4645d2 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -3494,7 +3494,8 @@ static void write_dev_flush(struct btrfs_device *device)
struct request_queue *q = bdev_get_queue(device->bdev);
struct bio *bio = device->flush_bio;
- if (!test_bit(QUEUE_FLAG_WC, &q->queue_flags))
+ if (!test_bit(BTRFS_FS_FORCE_DEV_FLUSH, &device->fs_info->flags)
+ && !test_bit(QUEUE_FLAG_WC, &q->queue_flags))
return;
bio_reset(bio);
@@ -3505,6 +3506,7 @@ static void write_dev_flush(struct btrfs_device *device)
bio->bi_private = &device->flush_wait;
submit_bio(bio);
+ device->flush_bio_sent = 1;
}
/*
@@ -3512,12 +3514,12 @@ static void write_dev_flush(struct btrfs_device *device)
*/
static int wait_dev_flush(struct btrfs_device *device)
{
- struct request_queue *q = bdev_get_queue(device->bdev);
struct bio *bio = device->flush_bio;
- if (!test_bit(QUEUE_FLAG_WC, &q->queue_flags))
+ if (!device->flush_bio_sent)
return 0;
+ device->flush_bio_sent = 0;
wait_for_completion_io(&device->flush_wait);
return bio->bi_error;
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 35327efecdbb..6f45fd60d15a 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -75,6 +75,7 @@ struct btrfs_device {
int can_discard;
int is_tgtdev_for_dev_replace;
int last_flush_error;
+ int flush_bio_sent;
#ifdef __BTRFS_NEED_DEVICE_DATA_ORDERED
seqcount_t data_seqcount;
--
2.13.0
--
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