On 04/14/2017 02:41 AM, Liu Bo wrote:
On Thu, Apr 06, 2017 at 11:22:47AM +0800, Anand Jain wrote: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() v3: no change v4: no change 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 08b74daf35d0..08cbbee228ee 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -3498,70 +3498,42 @@ 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 */What is the above comment trying to explain?
I had GFP_NOFS to justify when I wrote that. Thanks, Anand
Others look good. Reviewed-by: Liu Bo <bo.li....@oracle.com> Thanks, -liubo+ 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 (device->nobarriers) return 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; } @@ -3590,9 +3562,7 @@ 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 59be81206dd7..0df50bc65578 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -124,8 +124,9 @@ struct btrfs_device { /* for sending down flush barriers */ int nobarriers; - 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 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html-- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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