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-rw-r--r--Documentation/scsi/st.txt4
-rw-r--r--drivers/scsi/st.c21
-rw-r--r--drivers/scsi/st.h1
-rw-r--r--include/linux/mtio.h1
4 files changed, 24 insertions, 3 deletions
diff --git a/Documentation/scsi/st.txt b/Documentation/scsi/st.txt
index 691ca292c24d..685bf3582abe 100644
--- a/Documentation/scsi/st.txt
+++ b/Documentation/scsi/st.txt
@@ -390,6 +390,10 @@ 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_NOWAIT_EOF enables immediate filemark mode (i.e. when
+ writing a filemark, don't wait for it to complete). Please
+ see the BASICS note about MTWEOFI with respect to the
+ possible dangers of writing immediate filemarks.
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
diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index 9262cdfa4b23..8c663e16fd02 100644
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -1106,6 +1106,12 @@ static int check_tape(struct scsi_tape *STp, struct file *filp)
STp->drv_buffer));
}
STp->drv_write_prot = ((STp->buffer)->b_data[2] & 0x80) != 0;
+ if (!STp->drv_buffer && STp->immediate_filemark) {
+ printk(KERN_WARNING
+ "%s: non-buffered tape: disabling writing immediate filemarks\n",
+ name);
+ STp->immediate_filemark = 0;
+ }
}
st_release_request(SRpnt);
SRpnt = NULL;
@@ -1314,6 +1320,8 @@ static int st_flush(struct file *filp, fl_owner_t id)
memset(cmd, 0, MAX_COMMAND_SIZE);
cmd[0] = WRITE_FILEMARKS;
+ if (STp->immediate_filemark)
+ cmd[1] = 1;
cmd[4] = 1 + STp->two_fm;
SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
@@ -2181,8 +2189,9 @@ 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 sili: %d\n", name, STm->sysv, STp->immediate,
- STp->sili);
+ "%s: sysv: %d nowait: %d sili: %d nowait_filemark: %d\n",
+ name, STm->sysv, STp->immediate, STp->sili,
+ STp->immediate_filemark);
printk(KERN_INFO "%s: debugging: %d\n",
name, debugging);
}
@@ -2224,6 +2233,7 @@ static int st_set_options(struct scsi_tape *STp, long options)
STp->can_partitions = (options & MT_ST_CAN_PARTITIONS) != 0;
STp->scsi2_logical = (options & MT_ST_SCSI2LOGICAL) != 0;
STp->immediate = (options & MT_ST_NOWAIT) != 0;
+ STp->immediate_filemark = (options & MT_ST_NOWAIT_EOF) != 0;
STm->sysv = (options & MT_ST_SYSV) != 0;
STp->sili = (options & MT_ST_SILI) != 0;
DEB( debugging = (options & MT_ST_DEBUGGING) != 0;
@@ -2255,6 +2265,8 @@ static int st_set_options(struct scsi_tape *STp, long options)
STp->scsi2_logical = value;
if ((options & MT_ST_NOWAIT) != 0)
STp->immediate = value;
+ if ((options & MT_ST_NOWAIT_EOF) != 0)
+ STp->immediate_filemark = value;
if ((options & MT_ST_SYSV) != 0)
STm->sysv = value;
if ((options & MT_ST_SILI) != 0)
@@ -2714,7 +2726,8 @@ static int st_int_ioctl(struct scsi_tape *STp, unsigned int cmd_in, unsigned lon
cmd[0] = WRITE_FILEMARKS;
if (cmd_in == MTWSM)
cmd[1] = 2;
- if (cmd_in == MTWEOFI)
+ if (cmd_in == MTWEOFI ||
+ (cmd_in == MTWEOF && STp->immediate_filemark))
cmd[1] |= 1;
cmd[2] = (arg >> 16);
cmd[3] = (arg >> 8);
@@ -4093,6 +4106,7 @@ static int st_probe(struct device *dev)
tpnt->scsi2_logical = ST_SCSI2LOGICAL;
tpnt->sili = ST_SILI;
tpnt->immediate = ST_NOWAIT;
+ tpnt->immediate_filemark = 0;
tpnt->default_drvbuffer = 0xff; /* No forced buffering */
tpnt->partition = 0;
tpnt->new_partition = 0;
@@ -4478,6 +4492,7 @@ st_options_show(struct device *dev, struct device_attribute *attr, char *buf)
options |= STp->scsi2_logical ? MT_ST_SCSI2LOGICAL : 0;
options |= STm->sysv ? MT_ST_SYSV : 0;
options |= STp->immediate ? MT_ST_NOWAIT : 0;
+ options |= STp->immediate_filemark ? MT_ST_NOWAIT_EOF : 0;
options |= STp->sili ? MT_ST_SILI : 0;
l = snprintf(buf, PAGE_SIZE, "0x%08x\n", options);
diff --git a/drivers/scsi/st.h b/drivers/scsi/st.h
index f91a67c6d968..ea35632b986c 100644
--- a/drivers/scsi/st.h
+++ b/drivers/scsi/st.h
@@ -120,6 +120,7 @@ struct scsi_tape {
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 */
+ unsigned char immediate_filemark; /* write filemark immediately */
int tape_type;
int long_timeout; /* timeout for commands known to take long time */
diff --git a/include/linux/mtio.h b/include/linux/mtio.h
index 8f825756c459..18543e2db06f 100644
--- a/include/linux/mtio.h
+++ b/include/linux/mtio.h
@@ -194,6 +194,7 @@ struct mtpos {
#define MT_ST_SYSV 0x1000
#define MT_ST_NOWAIT 0x2000
#define MT_ST_SILI 0x4000
+#define MT_ST_NOWAIT_EOF 0x8000
/* The mode parameters to be controlled. Parameter chosen with bits 20-28 */
#define MT_ST_CLEAR_DEFAULT 0xfffff