summaryrefslogtreecommitdiffstats
path: root/drivers/scsi/st.h
diff options
context:
space:
mode:
authorLee Duncan <lduncan@suse.com>2012-03-01 12:41:01 -0800
committerJames Bottomley <JBottomley@Parallels.com>2012-03-27 08:26:34 +0100
commitc743e44fbb1f8668941e83de07662b1ecd33d083 (patch)
treec0a5eacf103f566942b8e8e7c222b3fa588657a4 /drivers/scsi/st.h
parent3194eef325c126d1f3bfa28317e2acd78292250d (diff)
downloadop-kernel-dev-c743e44fbb1f8668941e83de07662b1ecd33d083.zip
op-kernel-dev-c743e44fbb1f8668941e83de07662b1ecd33d083.tar.gz
[SCSI] st: expand ability to write immediate filemarks
The st tape driver recently added the MTWEOFI ioctl, which writes a tape filemark (EOF), like the MTWEOF ioctl, except that MTWEOFI returns immediately. This makes certain applications, like backup software, run much more quickly on buffered tape drives. Since legacy applications do not know about this new MTWEOFI ioctl, this patch adds a new ioctl option that tells the st driver to return immediately when writing an EOF (i.e. a filemark). This new flag is much like the existing flag that tells the st driver to perform writes (and certain other IOs) immediately, but this new flag only applies to writing EOFs. This new feature is controlled via the MTSETDRVBUFFER ioctl, using the newly-defined MT_ST_NOWAIT_EOF flag. Use of this new feature is displayed via the sysfs tape "options" attribute. The st documentation was updated to mention this new flag, as well as the problems that can occur from using it. Signed-off-by: Lee Duncan <lduncan@suse.com> Acked-by: Kai Makisara <kai.makisara@kolumbus.fi> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Diffstat (limited to 'drivers/scsi/st.h')
-rw-r--r--drivers/scsi/st.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/scsi/st.h b/drivers/scsi/st.h
index f91a67c..ea35632 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 */
OpenPOWER on IntegriCloud