Commits
Lee Duncan committed c743e44fbb1
[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>