[SCSI] st: add option to use SILI in variable block reads (40f6b36c) · Commits · 戴 / test

Documentation/scsi/st.txt

+6 −1

Original line number	Diff line number	Diff line
		@@ -2,7 +2,7 @@ This file contains brief information about the SCSI tape driver.
		The driver is currently maintained by Kai Mäkisara (email
		Kai.Makisara@kolumbus.fi)

		Last modified: Mon Mar 7 21:14:44 2005 by kai.makisara
		Last modified: Thu Feb 21 21:54:16 2008 by kai.makisara


		BASICS
		@@ -372,6 +372,11 @@ MTSETDRVBUFFER
		MT_ST_SYSV sets the SYSV semantics (mode)
		MT_ST_NOWAIT enables immediate mode (i.e., don't wait for
		the command to finish) for some commands (e.g., rewind)
		MT_ST_SILI enables setting the SILI bit in SCSI commands when
		reading in variable block mode to enhance performance when
		reading blocks shorter than the byte count; set this only
		if you are sure that the drive supports SILI and the HBA
		correctly returns transfer residuals
		MT_ST_DEBUGGING debugging (global; debugging must be
		compiled into the driver)
		MT_ST_SETBOOLEANS

drivers/scsi/st.c

+36 −4

Original line number	Diff line number	Diff line
		@@ -17,7 +17,7 @@
		Last modified: 18-JAN-1998 Richard Gooch <rgooch@atnf.csiro.au> Devfs support
		*/

		static const char *verstr = "20080221";
		static const char *verstr = "20080224";

		#include <linux/module.h>

		@@ -183,6 +183,7 @@ static int modes_defined;

		static struct st_buffer *new_tape_buffer(int, int, int);
		static int enlarge_buffer(struct st_buffer *, int, int);
		static void clear_buffer(struct st_buffer *);
		static void normalize_buffer(struct st_buffer *);
		static int append_to_buffer(const char __user , struct st_buffer , int);
		static int from_buffer(struct st_buffer , char __user , int);
		@@ -442,6 +443,7 @@ static void st_sleep_done(void data, char sense, int result, int resid)

		memcpy(SRpnt->sense, sense, SCSI_SENSE_BUFFERSIZE);
		(STp->buffer)->cmdstat.midlevel_result = SRpnt->result = result;
		(STp->buffer)->cmdstat.residual = resid;
		DEB( STp->write_pending = 0; )

		if (SRpnt->waiting)
		@@ -1159,6 +1161,7 @@ static int st_open(struct inode inode, struct file filp)
		goto err_out;
		}

		(STp->buffer)->cleared = 0;
		(STp->buffer)->writing = 0;
		(STp->buffer)->syscall_result = 0;

		@@ -1432,8 +1435,14 @@ static int setup_buffering(struct scsi_tape STp, const char __user buf,
		if (STp->block_size)
		bufsize = STp->block_size > st_fixed_buffer_size ?
		STp->block_size : st_fixed_buffer_size;
		else
		else {
		bufsize = count;
		/* Make sure that data from previous user is not leaked even if
		HBA does not return correct residual */
		if (is_read && STp->sili && !STbp->cleared)
		clear_buffer(STbp);
		}

		if (bufsize > STbp->buffer_size &&
		!enlarge_buffer(STbp, bufsize, STp->restr_dma)) {
		printk(KERN_WARNING "%s: Can't allocate %d byte tape buffer.\n",
		@@ -1783,6 +1792,8 @@ static long read_tape(struct scsi_tape *STp, long count,
		memset(cmd, 0, MAX_COMMAND_SIZE);
		cmd[0] = READ_6;
		cmd[1] = (STp->block_size != 0);
		if (!cmd[1] && STp->sili)
		cmd[1] \|= 2;
		cmd[2] = blks >> 16;
		cmd[3] = blks >> 8;
		cmd[4] = blks;
		@@ -1911,8 +1922,11 @@ static long read_tape(struct scsi_tape *STp, long count,

		}
		/* End of error handling */
		else /* Read successful */
		else { /* Read successful */
		STbp->buffer_bytes = bytes;
		if (STp->sili) /* In fixed block mode residual is always zero here */
		STbp->buffer_bytes -= STp->buffer->cmdstat.residual;
		}

		if (STps->drv_block >= 0) {
		if (STp->block_size == 0)
		@@ -2090,7 +2104,8 @@ static void st_log_options(struct scsi_tape * STp, struct st_modedef * STm, char
		name, STm->defaults_for_writes, STp->omit_blklims, STp->can_partitions,
		STp->scsi2_logical);
		printk(KERN_INFO
		"%s: sysv: %d nowait: %d\n", name, STm->sysv, STp->immediate);
		"%s: sysv: %d nowait: %d sili: %d\n", name, STm->sysv, STp->immediate,
		STp->sili);
		printk(KERN_INFO "%s: debugging: %d\n",
		name, debugging);
		}
		@@ -2133,6 +2148,7 @@ static int st_set_options(struct scsi_tape *STp, long options)
		STp->scsi2_logical = (options & MT_ST_SCSI2LOGICAL) != 0;
		STp->immediate = (options & MT_ST_NOWAIT) != 0;
		STm->sysv = (options & MT_ST_SYSV) != 0;
		STp->sili = (options & MT_ST_SILI) != 0;
		DEB( debugging = (options & MT_ST_DEBUGGING) != 0;
		st_log_options(STp, STm, name); )
		} else if (code == MT_ST_SETBOOLEANS \|\| code == MT_ST_CLEARBOOLEANS) {
		@@ -2164,6 +2180,8 @@ static int st_set_options(struct scsi_tape *STp, long options)
		STp->immediate = value;
		if ((options & MT_ST_SYSV) != 0)
		STm->sysv = value;
		if ((options & MT_ST_SILI) != 0)
		STp->sili = value;
		DEB(
		if ((options & MT_ST_DEBUGGING) != 0)
		debugging = value;
		@@ -3655,6 +3673,8 @@ static int enlarge_buffer(struct st_buffer * STbuffer, int new_size, int need_dm
		STbuffer->frp_segs += 1;
		got += b_size;
		STbuffer->buffer_size = got;
		if (STbuffer->cleared)
		memset(page_address(STbuffer->frp[segs].page), 0, b_size);
		segs++;
		}
		STbuffer->b_data = page_address(STbuffer->frp[0].page);
		@@ -3663,6 +3683,17 @@ static int enlarge_buffer(struct st_buffer * STbuffer, int new_size, int need_dm
		}


		/* Make sure that no data from previous user is in the internal buffer */
		static void clear_buffer(struct st_buffer * st_bp)
		{
		int i;

		for (i=0; i < st_bp->frp_segs; i++)
		memset(page_address(st_bp->frp[i].page), 0, st_bp->frp[i].length);
		st_bp->cleared = 1;
		}


		/* Release the extra buffer */
		static void normalize_buffer(struct st_buffer * STbuffer)
		{
		@@ -3987,6 +4018,7 @@ static int st_probe(struct device *dev)
		tpnt->two_fm = ST_TWO_FM;
		tpnt->fast_mteom = ST_FAST_MTEOM;
		tpnt->scsi2_logical = ST_SCSI2LOGICAL;
		tpnt->sili = ST_SILI;
		tpnt->immediate = ST_NOWAIT;
		tpnt->default_drvbuffer = 0xff; /* No forced buffering */
		tpnt->partition = 0;

drivers/scsi/st.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -12,6 +12,7 @@ struct st_cmdstatus {
		int midlevel_result;
		struct scsi_sense_hdr sense_hdr;
		int have_sense;
		int residual;
		u64 uremainder64;
		u8 flags;
		u8 remainder_valid;
		@@ -34,6 +35,7 @@ struct st_request {
		struct st_buffer {
		unsigned char dma; /* DMA-able buffer */
		unsigned char do_dio; /* direct i/o set up? */
		unsigned char cleared; /* internal buffer cleared after open? */
		int buffer_size;
		int buffer_blocks;
		int buffer_bytes;
		@@ -122,6 +124,7 @@ struct scsi_tape {
		unsigned char try_dio_now; /* try direct i/o before next close? */
		unsigned char c_algo; /* compression algorithm */
		unsigned char pos_unknown; /* after reset position unknown */
		unsigned char sili; /* use SILI when reading in variable b mode */
		int tape_type;
		int long_timeout; /* timeout for commands known to take long time */

drivers/scsi/st_options.h

+5 −1

Original line number	Diff line number	Diff line
		@@ -3,7 +3,7 @@

		Copyright 1995-2003 Kai Makisara.

		Last modified: Mon Apr 7 22:49:18 2003 by makisara
		Last modified: Thu Feb 21 21:47:07 2008 by kai.makisara
		*/

		#ifndef _ST_OPTIONS_H
		@@ -94,6 +94,10 @@
		The default is BSD semantics. */
		#define ST_SYSV 0

		/* If ST_SILI is non-zero, the SILI bit is set when reading in variable block
		mode and the block size is determined using the residual returned by the HBA. */
		#define ST_SILI 0

		/* Time to wait for the drive to become ready if blocking open */
		#define ST_BLOCK_SECONDS 120

include/linux/mtio.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -192,6 +192,7 @@ struct mtpos {
		#define MT_ST_SCSI2LOGICAL 0x800
		#define MT_ST_SYSV 0x1000
		#define MT_ST_NOWAIT 0x2000
		#define MT_ST_SILI 0x4000

		/* The mode parameters to be controlled. Parameter chosen with bits 20-28 */
		#define MT_ST_CLEAR_DEFAULT 0xfffff

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