| Message ID | 20170331163313.31821-23-hch@lst.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Christoph Hellwig <hch@lst.de> writes: > Now that we have REQ_OP_WRITE_ZEROES implemented for all devices that > support efficient zeroing of devices we can remove the call to s/of devices/ > blkdev_issue_discard. This means we only have two ways of zeroing > left and can simply the code. simplify > + * Note that this function may fail with -EOPNOTSUPP if the driver supports > + * efficient zeroing operation, but the device capabilities can only be > + * discovered by trial and error. In this case the caller should call the > + * function again, and it will use the fallback path. Maybe: "Note that this function may fail with -EOPNOTSUPP if the driver signals zeroing offload support but the device fails to process the command (for some devices there is no non-destructive way to verify whether this operation is actually supported). If -EOPNOTSUPP is returned, the caller should retry the blkdev_issue_zeroout() and the fallback path will be used." Otherwise OK. Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
diff --git a/block/blk-lib.c b/block/blk-lib.c index 2f882e22890b..7c27211570fa 100644 --- a/block/blk-lib.c +++ b/block/blk-lib.c @@ -279,6 +279,11 @@ static int __blkdev_issue_write_zeroes(struct block_device *bdev, * Zero-fill a block range, either using hardware offload or by explicitly * writing zeroes to the device. * + * Note that this function may fail with -EOPNOTSUPP if the driver supports + * efficient zeroing operation, but the device capabilities can only be + * discovered by trial and error. In this case the caller should call the + * function again, and it will use the fallback path. + * * If a device is using logical block provisioning, the underlying space will * not be released if %flags contains BLKDEV_ZERO_NOUNMAP. * @@ -349,12 +354,6 @@ int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, struct bio *bio = NULL; struct blk_plug plug; - if (!(flags & BLKDEV_ZERO_NOUNMAP)) { - if (!blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask, - BLKDEV_DISCARD_ZERO)) - return 0; - } - blk_start_plug(&plug); ret = __blkdev_issue_zeroout(bdev, sector, nr_sects, gfp_mask, &bio, flags);
Now that we have REQ_OP_WRITE_ZEROES implemented for all devices that support efficient zeroing of devices we can remove the call to blkdev_issue_discard. This means we only have two ways of zeroing left and can simply the code. Signed-off-by: Christoph Hellwig <hch@lst.de> --- block/blk-lib.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-)