From: Nikolay Borisov Date: Thu, 8 Nov 2018 14:16:38 +0000 (+0200) Subject: btrfs: Check for missing device before bio submission in btrfs_map_bio X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=fc8a168aa9ab1680c2bd52bf9db7c994e0f2524f;p=openwrt%2Fstaging%2Fblogic.git btrfs: Check for missing device before bio submission in btrfs_map_bio Before btrfs_map_bio submits all stripe bios it does a number of checks to ensure the device for every stripe is present. However, it doesn't do a DEV_STATE_MISSING check, instead this is relegated to the lower level btrfs_schedule_bio (in the async submission case, sync submission doesn't check DEV_STATE_MISSING at all). Additionally btrfs_schedule_bios does the duplicate device->bdev check which has already been performed in btrfs_map_bio. This patch moves the DEV_STATE_MISSING check in btrfs_map_bio and removes the duplicate device->bdev check. Doing so ensures that no bio cloning/submission happens for both async/sync requests in the face of missing device. This makes the async io submission path slightly shorter in terms of instruction count. No functional changes. Reviewed-by: Josef Bacik Reviewed-by: Anand Jain Signed-off-by: Nikolay Borisov Reviewed-by: David Sterba Signed-off-by: David Sterba --- diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index e392ca5103cc..bb76263c3ad4 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -6109,12 +6109,6 @@ static noinline void btrfs_schedule_bio(struct btrfs_device *device, int should_queue = 1; struct btrfs_pending_bios *pending_bios; - if (test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state) || - !device->bdev) { - bio_io_error(bio); - return; - } - /* don't bother with additional async steps for reads, right now */ if (bio_op(bio) == REQ_OP_READ) { btrfsic_submit_bio(bio); @@ -6243,7 +6237,8 @@ blk_status_t btrfs_map_bio(struct btrfs_fs_info *fs_info, struct bio *bio, for (dev_nr = 0; dev_nr < total_devs; dev_nr++) { dev = bbio->stripes[dev_nr].dev; - if (!dev || !dev->bdev || + if (!dev || !dev->bdev || test_bit(BTRFS_DEV_STATE_MISSING, + &dev->dev_state) || (bio_op(first_bio) == REQ_OP_WRITE && !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))) { bbio_error(bbio, first_bio, logical);