From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: [PATCH 27/27] scsi: sd: Remove LBPRZ dependency for discards Date: Wed, 5 Apr 2017 19:21:25 +0200 Message-ID: <20170405172125.22600-28-hch@lst.de> References: <20170405172125.22600-1-hch@lst.de> Return-path: In-Reply-To: <20170405172125.22600-1-hch@lst.de> Sender: linux-block-owner@vger.kernel.org To: axboe@kernel.dk, martin.petersen@oracle.com, agk@redhat.com, snitzer@redhat.com, shli@kernel.org, philipp.reisner@linbit.com, lars.ellenberg@linbit.com Cc: linux-block@vger.kernel.org, linux-scsi@vger.kernel.org, drbd-dev@lists.linbit.com, dm-devel@redhat.com, linux-raid@vger.kernel.org List-Id: linux-raid.ids From: "Martin K. Petersen" Separating discards and zeroout operations allows us to remove the LBPRZ block zeroing constraints from discards and honor the device preferences for UNMAP commands. If supported by the device, we'll also choose UNMAP over one of the WRITE SAME variants for discards. Signed-off-by: Martin K. Petersen Signed-off-by: Christoph Hellwig --- drivers/scsi/sd.c | 25 ++++++------------------- 1 file changed, 6 insertions(+), 19 deletions(-) diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index acf9d17b05d8..8cf34a8e3eea 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -685,24 +685,11 @@ static void sd_config_discard(struct scsi_disk *sdkp, unsigned int mode) unsigned int logical_block_size = sdkp->device->sector_size; unsigned int max_blocks = 0; - /* - * When LBPRZ is reported, discard alignment and granularity - * must be fixed to the logical block size. Otherwise the block - * layer will drop misaligned portions of the request which can - * lead to data corruption. If LBPRZ is not set, we honor the - * device preference. - */ - if (sdkp->lbprz) { - q->limits.discard_alignment = 0; - q->limits.discard_granularity = logical_block_size; - } else { - q->limits.discard_alignment = sdkp->unmap_alignment * - logical_block_size; - q->limits.discard_granularity = - max(sdkp->physical_block_size, - sdkp->unmap_granularity * logical_block_size); - } - + q->limits.discard_alignment = + sdkp->unmap_alignment * logical_block_size; + q->limits.discard_granularity = + max(sdkp->physical_block_size, + sdkp->unmap_granularity * logical_block_size); sdkp->provisioning_mode = mode; switch (mode) { @@ -2842,7 +2829,7 @@ static void sd_read_block_limits(struct scsi_disk *sdkp) sd_config_discard(sdkp, SD_LBP_WS16); } else { /* LBP VPD page tells us what to use */ - if (sdkp->lbpu && sdkp->max_unmap_blocks && !sdkp->lbprz) + if (sdkp->lbpu && sdkp->max_unmap_blocks) sd_config_discard(sdkp, SD_LBP_UNMAP); else if (sdkp->lbpws) sd_config_discard(sdkp, SD_LBP_WS16); -- 2.11.0