From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Martin K. Petersen" Subject: Re: [PATCH] scsi: Check if the device support WRITE_SAME_10 Date: Thu, 06 Jun 2013 22:15:55 -0400 Message-ID: References: <51AC1440.7020505@zytor.com> <51AC3283.4000403@zytor.com> <51ACBAA0.40604@zytor.com> <51ACD511.4030604@zytor.com> <51AD2485.9000601@zytor.com> <51AF0CCF.8000909@itwm.fraunhofer.de> <51AF232C.8060209@itwm.fraunhofer.de> <51AF34E0.3030609@itwm.fraunhofer.de> <51AF9AF2.5000907@itwm.fraunhofer.de> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <51AF9AF2.5000907@itwm.fraunhofer.de> (Bernd Schubert's message of "Wed, 05 Jun 2013 22:09:22 +0200") Sender: linux-scsi-owner@vger.kernel.org To: Bernd Schubert Cc: "Martin K. Petersen" , Joe Lawrence , "H. Peter Anvin" , Dan Williams , linux-raid , linux-scsi List-Id: linux-raid.ids >>>>> "Bernd" == Bernd Schubert writes: >> max_t(unsigned long, max, SD_MAX_WS10_BLOCKS); Bernd> Max? Not min_t()? Brain fart. Updated patch with a few other adjustments. I have tested this on a couple of JBODs with a mishmash of SATA and SAS drives, including a few specimens that report MAX WRITE SAME BLOCKS. -- Martin K. Petersen Oracle Linux Engineering [PATCH] sd: Update WRITE SAME heuristics SATA drives located behind a SAS controller would incorrectly receive WRITE SAME commands. Tweak the heuristics so that: - If REPORT SUPPORTED OPERATION CODES is provided we will use that to choose between WRITE SAME(16), WRITE SAME(10) and disabled. This also fixes an issue with the old code which would issue WRITE SAME(10) despite the command not being whitelisted in REPORT SUPPORTED OPERATION CODES. - If REPORT SUPPORTED OPERATION CODES is not provided we will fall back to WRITE SAME(10) unless the device has an ATA Information VPD page. The assumption is that a SATL which is smart enough to implement WRITE SAME would also provide REPORT SUPPORTED OPERATION CODES. To facilitate the new heuristics scsi_report_opcode() has been modified to so we can distinguish between "operation not supported" and "RSOC not supported". Reported-by: H. Peter Anvin Signed-off-by: Martin K. Petersen Cc: diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c index 2c0d0ec..3b1ea34 100644 --- a/drivers/scsi/scsi.c +++ b/drivers/scsi/scsi.c @@ -1070,8 +1070,8 @@ EXPORT_SYMBOL_GPL(scsi_get_vpd_page); * @opcode: opcode for command to look up * * Uses the REPORT SUPPORTED OPERATION CODES to look up the given - * opcode. Returns 0 if RSOC fails or if the command opcode is - * unsupported. Returns 1 if the device claims to support the command. + * opcode. Returns -EINVAL if RSOC fails, 0 if the command opcode is + * unsupported and 1 if the device claims to support the command. */ int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer, unsigned int len, unsigned char opcode) @@ -1081,7 +1081,7 @@ int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer, int result; if (sdev->no_report_opcodes || sdev->scsi_level < SCSI_SPC_3) - return 0; + return -EINVAL; memset(cmd, 0, 16); cmd[0] = MAINTENANCE_IN; @@ -1097,7 +1097,7 @@ int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer, if (result && scsi_sense_valid(&sshdr) && sshdr.sense_key == ILLEGAL_REQUEST && (sshdr.asc == 0x20 || sshdr.asc == 0x24) && sshdr.ascq == 0x00) - return 0; + return -EINVAL; if ((buffer[1] & 3) == 3) /* Command supported */ return 1; diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index a37eda9..420e763 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -442,8 +442,10 @@ sd_store_write_same_blocks(struct device *dev, struct device_attribute *attr, if (max == 0) sdp->no_write_same = 1; - else if (max <= SD_MAX_WS16_BLOCKS) + else if (max <= SD_MAX_WS16_BLOCKS) { + sdp->no_write_same = 0; sdkp->max_ws_blocks = max; + } sd_config_write_same(sdkp); @@ -750,7 +752,6 @@ static void sd_config_write_same(struct scsi_disk *sdkp) { struct request_queue *q = sdkp->disk->queue; unsigned int logical_block_size = sdkp->device->sector_size; - unsigned int blocks = 0; if (sdkp->device->no_write_same) { sdkp->max_ws_blocks = 0; @@ -762,18 +763,20 @@ static void sd_config_write_same(struct scsi_disk *sdkp) * blocks per I/O unless the device explicitly advertises a * bigger limit. */ - if (sdkp->max_ws_blocks == 0) - sdkp->max_ws_blocks = SD_MAX_WS10_BLOCKS; - - if (sdkp->ws16 || sdkp->max_ws_blocks > SD_MAX_WS10_BLOCKS) - blocks = min_not_zero(sdkp->max_ws_blocks, - (u32)SD_MAX_WS16_BLOCKS); - else - blocks = min_not_zero(sdkp->max_ws_blocks, - (u32)SD_MAX_WS10_BLOCKS); + if (sdkp->max_ws_blocks > SD_MAX_WS10_BLOCKS) + sdkp->max_ws_blocks = min_not_zero(sdkp->max_ws_blocks, + (u32)SD_MAX_WS16_BLOCKS); + else if (sdkp->ws16 || sdkp->ws10 || sdkp->device->no_report_opcodes) + sdkp->max_ws_blocks = min_not_zero(sdkp->max_ws_blocks, + (u32)SD_MAX_WS10_BLOCKS); + else { + sdkp->device->no_write_same = 1; + sdkp->max_ws_blocks = 0; + } out: - blk_queue_max_write_same_sectors(q, blocks * (logical_block_size >> 9)); + blk_queue_max_write_same_sectors(q, sdkp->max_ws_blocks * + (logical_block_size >> 9)); } /** @@ -2645,9 +2648,24 @@ static void sd_read_block_provisioning(struct scsi_disk *sdkp) static void sd_read_write_same(struct scsi_disk *sdkp, unsigned char *buffer) { - if (scsi_report_opcode(sdkp->device, buffer, SD_BUF_SIZE, - WRITE_SAME_16)) + struct scsi_device *sdev = sdkp->device; + + if (scsi_report_opcode(sdev, buffer, SD_BUF_SIZE, INQUIRY) < 0) { + sdev->no_report_opcodes = 1; + + /* Disable WRITE SAME if REPORT SUPPORTED OPERATION + * CODES is unsupported and the device has an ATA + * Information VPD page (SAT). + */ + if (!scsi_get_vpd_page(sdev, 0x89, buffer, SD_BUF_SIZE)) + sdev->no_write_same = 1; + } + + if (scsi_report_opcode(sdev, buffer, SD_BUF_SIZE, WRITE_SAME_16) == 1) sdkp->ws16 = 1; + + if (scsi_report_opcode(sdev, buffer, SD_BUF_SIZE, WRITE_SAME) == 1) + sdkp->ws10 = 1; } static int sd_try_extended_inquiry(struct scsi_device *sdp) diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h index 2386aeb..7a049de 100644 --- a/drivers/scsi/sd.h +++ b/drivers/scsi/sd.h @@ -84,6 +84,7 @@ struct scsi_disk { unsigned lbpws : 1; unsigned lbpws10 : 1; unsigned lbpvpd : 1; + unsigned ws10 : 1; unsigned ws16 : 1; }; #define to_scsi_disk(obj) container_of(obj,struct scsi_disk,dev)