current recorded extent and not the complete maximum extent of the disc.
An empty CD/DVD disc is seen as having an invalid length and given 800 Mb
size. This makes it possible to write to a CD-R using `dd' as some tend to
do.
However when an extent is recorded the initial recorded length is seen as
valid and is thus set as absolute upperbound to read and write actions
preventing extention of the disc.
Committed after consultation on tech-kern with a positive advice by Manuel
Bouyer.
TOC reading. Note that the external interfaces haven't changed. Only the
formatted toc is requestable.
The read msinfo command hasn't been changed in this patch though it could
become more clever using the CD_TOC_MSINFO format.
- rather than embedding bufq_state in driver softc,
have a pointer to the former.
- move bufq related functions from kern/subr_disk.c to kern/subr_bufq.c.
- rename method to strategy for consistency.
- move some definitions which don't need to be exposed to the rest of kernel
from sys/bufq.h to sys/bufq_impl.h.
(is it better to move it to kern/ or somewhere?)
- fix some obvious breakage in dev/qbus/ts.c. (not tested)
everything "scsi_*", since we really are talking about the SCSI command
set, ATAPI transport not withstanding. Improve the names of many structures,
and prepend "SCSI_" onto all SCSI command opcodes. Place items described
by the SCSI Primary Commands document into scsi_spc.h.
for TOC response format 1 and 2 are mandatory on CD/DVD too and provide
more information.
Next an IOCTL needs to be implemented that can read all TOC formats in a
generic way. This is pending.
scsipi_done() from their scsipi_request().
For this, add a struct scsipi_xfer * argument to scsipi_command().
If not NULL scsipi_command() will use this to enqueue this xfer, otherwise
it'll try to allocate a new one. This scsipi_xfer has to be allocated
and initialised by scsipi_make_xs() or equivalent.
In xxstart(), allocate a scsipi_xfer using scsipi_make_xs(), and if not NULL,
dequeue the buffer before calling scsipi_command(). This makes sure that
scsipi_command() will not fail, and also makes sure that xxstart() won't
be called again between the BUFQ_PEEK() and BUFQ_GET().
Fix "dequeued wrong buf" panics reported by Juergen Hannken-Illjes in
private mail and Andreas Wrede on current-users@.
Thanks to Jason Thorpe and Chuck Silver for review, and Andreas Wrede for
testing the patch.
sd3(mpt0:0:1:0): unable to allocate scsipi_xfer
sd3: not queued, error 12
Havard Eidnes's analysis of this problem is that the scsipi_xfer pool is
competing for resources with other pools, including the the inode and vnode
pools which can grow quite large.
*_scsipi_cmd(): don't biodone the buffer if scsipi_make_xs() fails, let the
caller deal with the problem
start function of block devices drivers: dequeue the buffer after the
scsipi_command() call. If scsipi_command() fails with ENOMEM don't dequeue
the buffer, and schedule a callout to call the start function after
some delay.
scsipi_init(): prime the scsipi_xfer_pool with one page. This ensure that
there is always some scsipi_xfer to play with. If scsipi_command() fails
because of pool_get(), we're sure there will be resources available later,
when the pending commands have completed.
Reviewed by Jason Thorpe and Havard Eidnes.
Todo: remove the "unable to allocate scsipi_xfer" and "not queued, error %d"
printfs, but I choose to keep them for now, to help make sure the code does
what it should.
the mode sense request. So fall back on mode sense data including a block
descriptor section.
See also sd.c rev. 1.214. Again: should we bother trying DBD at all?
ready. This avoids gratuitously starting the motor on floppy and CD-ROM
drives, and eliminates the need for the audio playing test in cdopen().
Therefore, also remove PQUIRK_NOSTARTUNIT.
allocation length a little more precisely -- add the space for the header in
cd_mode_sense(). Also delete the XS_CTL_SILENT, since we really do want to
see errors.
Lastly, add a similar wrapper for mode select, simplifying the callers
slightly.
the "bus type" for this.
Merge all the code in the SCSI and ATAPI backends for "cd" devices. All of
the mode page handling and whatnot is general to SCSI MMC devices, and should
never have been separated to begin with. This fixes a variety of problems,
and adds load/unload support for SCSI-attached devices.
reinoud