[SCSI] aacraid: add support for FUA

Back in the beginning of last year we disabled mode page 8 and mode page
3f requests through device quirk bits instead of enhancing the driver to
respond to these mode pages because there was no apparent added value.

The Firmware that supports the new communication commands supports the
ability to force a write around of the adapter cache on a command by
command basis. In the attached patch we enable mode page 8 and 3f and
spoof the results as needed in order to *convince* the layers above to
submit writes with the FUA (Force Unit Attention) bit set if the file
system or application requires it, if the Firmware supports the write
through, or instead to submit a SYNCHRONIZE_CACHE if the Firmware does
not. The added value here is for file systems that benefit from this
functionality and for clustering or redundancy scenarios.

Caveats: By convince, we are responding with a minimal short 3 byte
content mode page 8, with only the data the SCSI layer needs and that we
can fill confidently. Applications that require the customarily larger
mode page 8 results may be confused by this(?). The FUA, or the
SYNCHRONIZE_CACHE only affect the cache on the controller. Our firmware
by default ensure that the underlying physical drives of the array have
their cache turned off so normally this is not a problem.

This attached patch is against current scsi-misc-2.6 and was unit tested
on RHEL5. Since this is a feature enhancement, it should not be
considered for any current stabilization efforts.

Signed-off-by: Mark Salyzyn <aacraid@adaptec.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

1 files changed, 49 insertions, 13 deletions

diff --git a/drivers/scsi/aacraid/aachba.c b/drivers/scsi/aacraid/aachba.c
index 1e82c69b36b0..a333e62fc487 100644
--- a/drivers/scsi/aacraid/aachba.c
+++ b/drivers/scsi/aacraid/aachba.c
@@ -822,7 +822,7 @@ static int aac_read_raw_io(struct fib * fib, struct scsi_cmnd * cmd, u64 lba, u3
 	readcmd->block[1] = cpu_to_le32((u32)((lba&0xffffffff00000000LL)>>32));
 	readcmd->count = cpu_to_le32(count<<9);
 	readcmd->cid = cpu_to_le16(scmd_id(cmd));
-	readcmd->flags = cpu_to_le16(1);
+	readcmd->flags = cpu_to_le16(IO_TYPE_READ);
 	readcmd->bpTotal = 0;
 	readcmd->bpComplete = 0;
 
@@ -901,7 +901,7 @@ static int aac_read_block(struct fib * fib, struct scsi_cmnd * cmd, u64 lba, u32
 			  (void *) cmd);
 }
 
-static int aac_write_raw_io(struct fib * fib, struct scsi_cmnd * cmd, u64 lba, u32 count)
+static int aac_write_raw_io(struct fib * fib, struct scsi_cmnd * cmd, u64 lba, u32 count, int fua)
 {
 	u16 fibsize;
 	struct aac_raw_io *writecmd;
@@ -911,7 +911,9 @@ static int aac_write_raw_io(struct fib * fib, struct scsi_cmnd * cmd, u64 lba, u
 	writecmd->block[1] = cpu_to_le32((u32)((lba&0xffffffff00000000LL)>>32));
 	writecmd->count = cpu_to_le32(count<<9);
 	writecmd->cid = cpu_to_le16(scmd_id(cmd));
-	writecmd->flags = 0;
+	writecmd->flags = fua ?
+		cpu_to_le16(IO_TYPE_WRITE|IO_SUREWRITE) :
+		cpu_to_le16(IO_TYPE_WRITE);
 	writecmd->bpTotal = 0;
 	writecmd->bpComplete = 0;
 
@@ -930,7 +932,7 @@ static int aac_write_raw_io(struct fib * fib, struct scsi_cmnd * cmd, u64 lba, u
 			  (void *) cmd);
 }
 
-static int aac_write_block64(struct fib * fib, struct scsi_cmnd * cmd, u64 lba, u32 count)
+static int aac_write_block64(struct fib * fib, struct scsi_cmnd * cmd, u64 lba, u32 count, int fua)
 {
 	u16 fibsize;
 	struct aac_write64 *writecmd;
@@ -961,7 +963,7 @@ static int aac_write_block64(struct fib * fib, struct scsi_cmnd * cmd, u64 lba,
 			  (void *) cmd);
 }
 
-static int aac_write_block(struct fib * fib, struct scsi_cmnd * cmd, u64 lba, u32 count)
+static int aac_write_block(struct fib * fib, struct scsi_cmnd * cmd, u64 lba, u32 count, int fua)
 {
 	u16 fibsize;
 	struct aac_write *writecmd;
@@ -1495,6 +1497,7 @@ static int aac_write(struct scsi_cmnd * scsicmd)
 {
 	u64 lba;
 	u32 count;
+	int fua;
 	int status;
 	struct aac_dev *dev;
 	struct fib * cmd_fibcontext;
@@ -1509,6 +1512,7 @@ static int aac_write(struct scsi_cmnd * scsicmd)
 		count = scsicmd->cmnd[4];
 		if (count == 0)
 			count = 256;
+		fua = 0;
 	} else if (scsicmd->cmnd[0] == WRITE_16) { /* 16 byte command */
 		dprintk((KERN_DEBUG "aachba: received a write(16) command on id %d.\n", scmd_id(scsicmd)));
 
@@ -1521,6 +1525,7 @@ static int aac_write(struct scsi_cmnd * scsicmd)
 			(scsicmd->cmnd[8] << 8) | scsicmd->cmnd[9];
 		count = (scsicmd->cmnd[10] << 24) | (scsicmd->cmnd[11] << 16) |
 			(scsicmd->cmnd[12] << 8) | scsicmd->cmnd[13];
+		fua = scsicmd->cmnd[1] & 0x8;
 	} else if (scsicmd->cmnd[0] == WRITE_12) { /* 12 byte command */
 		dprintk((KERN_DEBUG "aachba: received a write(12) command on id %d.\n", scmd_id(scsicmd)));
 
@@ -1528,10 +1533,12 @@ static int aac_write(struct scsi_cmnd * scsicmd)
 		    | (scsicmd->cmnd[4] << 8) | scsicmd->cmnd[5];
 		count = (scsicmd->cmnd[6] << 24) | (scsicmd->cmnd[7] << 16)
 		      | (scsicmd->cmnd[8] << 8) | scsicmd->cmnd[9];
+		fua = scsicmd->cmnd[1] & 0x8;
 	} else {
 		dprintk((KERN_DEBUG "aachba: received a write(10) command on id %d.\n", scmd_id(scsicmd)));
 		lba = ((u64)scsicmd->cmnd[2] << 24) | (scsicmd->cmnd[3] << 16) | (scsicmd->cmnd[4] << 8) | scsicmd->cmnd[5];
 		count = (scsicmd->cmnd[7] << 8) | scsicmd->cmnd[8];
+		fua = scsicmd->cmnd[1] & 0x8;
 	}
 	dprintk((KERN_DEBUG "aac_write[cpu %d]: lba = %llu, t = %ld.\n",
 	  smp_processor_id(), (unsigned long long)lba, jiffies));
@@ -1546,7 +1553,7 @@ static int aac_write(struct scsi_cmnd * scsicmd)
 		return 0;
 	}
 
-	status = aac_adapter_write(cmd_fibcontext, scsicmd, lba, count);
+	status = aac_adapter_write(cmd_fibcontext, scsicmd, lba, count, fua);
 
 	/*
 	 *	Check that the command queued to the controller
@@ -1883,15 +1890,29 @@ int aac_scsi_cmd(struct scsi_cmnd * scsicmd)
 
 	case MODE_SENSE:
 	{
-		char mode_buf[4];
+		char mode_buf[7];
+		int mode_buf_length = 4;
 
 		dprintk((KERN_DEBUG "MODE SENSE command.\n"));
 		mode_buf[0] = 3;	/* Mode data length */
 		mode_buf[1] = 0;	/* Medium type - default */
-		mode_buf[2] = 0;	/* Device-specific param, bit 8: 0/1 = write enabled/protected */
+		mode_buf[2] = 0;	/* Device-specific param,
+					   bit 8: 0/1 = write enabled/protected
+					   bit 4: 0/1 = FUA enabled */
+		if (dev->raw_io_interface)
+			mode_buf[2] = 0x10;
 		mode_buf[3] = 0;	/* Block descriptor length */
-
-		aac_internal_transfer(scsicmd, mode_buf, 0, sizeof(mode_buf));
+		if (((scsicmd->cmnd[2] & 0x3f) == 8) ||
+		  ((scsicmd->cmnd[2] & 0x3f) == 0x3f)) {
+			mode_buf[0] = 6;
+			mode_buf[4] = 8;
+			mode_buf[5] = 1;
+			mode_buf[6] = 0x04; /* WCE */
+			mode_buf_length = 7;
+			if (mode_buf_length > scsicmd->cmnd[4])
+				mode_buf_length = scsicmd->cmnd[4];
+		}
+		aac_internal_transfer(scsicmd, mode_buf, 0, mode_buf_length);
 		scsicmd->result = DID_OK << 16 | COMMAND_COMPLETE << 8 | SAM_STAT_GOOD;
 		scsicmd->scsi_done(scsicmd);
 
@@ -1899,18 +1920,33 @@ int aac_scsi_cmd(struct scsi_cmnd * scsicmd)
 	}
 	case MODE_SENSE_10:
 	{
-		char mode_buf[8];
+		char mode_buf[11];
+		int mode_buf_length = 8;
 
 		dprintk((KERN_DEBUG "MODE SENSE 10 byte command.\n"));
 		mode_buf[0] = 0;	/* Mode data length (MSB) */
 		mode_buf[1] = 6;	/* Mode data length (LSB) */
 		mode_buf[2] = 0;	/* Medium type - default */
-		mode_buf[3] = 0;	/* Device-specific param, bit 8: 0/1 = write enabled/protected */
+		mode_buf[3] = 0;	/* Device-specific param,
+					   bit 8: 0/1 = write enabled/protected
+					   bit 4: 0/1 = FUA enabled */
+		if (dev->raw_io_interface)
+			mode_buf[3] = 0x10;
 		mode_buf[4] = 0;	/* reserved */
 		mode_buf[5] = 0;	/* reserved */
 		mode_buf[6] = 0;	/* Block descriptor length (MSB) */
 		mode_buf[7] = 0;	/* Block descriptor length (LSB) */
-		aac_internal_transfer(scsicmd, mode_buf, 0, sizeof(mode_buf));
+		if (((scsicmd->cmnd[2] & 0x3f) == 8) ||
+		  ((scsicmd->cmnd[2] & 0x3f) == 0x3f)) {
+			mode_buf[1] = 9;
+			mode_buf[8] = 8;
+			mode_buf[9] = 1;
+			mode_buf[10] = 0x04; /* WCE */
+			mode_buf_length = 11;
+			if (mode_buf_length > scsicmd->cmnd[8])
+				mode_buf_length = scsicmd->cmnd[8];
+		}
+		aac_internal_transfer(scsicmd, mode_buf, 0, mode_buf_length);
 
 		scsicmd->result = DID_OK << 16 | COMMAND_COMPLETE << 8 | SAM_STAT_GOOD;
 		scsicmd->scsi_done(scsicmd);