diff options
| -rw-r--r-- | Documentation/scsi/st.txt | 7 | ||||
| -rw-r--r-- | drivers/scsi/st.c | 40 | ||||
| -rw-r--r-- | drivers/scsi/st.h | 3 | ||||
| -rw-r--r-- | drivers/scsi/st_options.h | 6 | ||||
| -rw-r--r-- | include/linux/mtio.h | 1 |
5 files changed, 51 insertions, 6 deletions
diff --git a/Documentation/scsi/st.txt b/Documentation/scsi/st.txt index b7be95b..38f8118 100644 --- a/Documentation/scsi/st.txt +++ b/Documentation/scsi/st.txt @@ -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 diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c index 0a52d9d..a4361a8 100644 --- a/drivers/scsi/st.c +++ b/drivers/scsi/st.c @@ -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; diff --git a/drivers/scsi/st.h b/drivers/scsi/st.h index 5931726..b92712f 100644 --- a/drivers/scsi/st.h +++ b/drivers/scsi/st.h @@ -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 */ diff --git a/drivers/scsi/st_options.h b/drivers/scsi/st_options.h index b6b5c9c..d2f9479 100644 --- a/drivers/scsi/st_options.h +++ b/drivers/scsi/st_options.h @@ -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 diff --git a/include/linux/mtio.h b/include/linux/mtio.h index 6f8d2d4..ef01d6a 100644 --- a/include/linux/mtio.h +++ b/include/linux/mtio.h @@ -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 |