At the block level bidi request uses req->next_rq pointer for a second
bidi_read request.
At Scsi-midlayer a second scsi_data_buffer structure is used for the
bidi_read part. This bidi scsi_data_buffer is put on
request->next_rq->special. Struct scsi_cmnd is not changed.
- Define scsi_bidi_cmnd() to return true if it is a bidi request and a
second sgtable was allocated.
- Define scsi_in()/scsi_out() to return the in or out scsi_data_buffer
from this command This API is to isolate users from the mechanics of
bidi.
- Define scsi_end_bidi_request() to do what scsi_end_request() does but
for a bidi request. This is necessary because bidi commands are a bit
tricky here. (See comments in body)
- scsi_release_buffers() will also release the bidi_read scsi_data_buffer
- scsi_io_completion() on bidi commands will now call
scsi_end_bidi_request() and return.
- The previous work done in scsi_init_io() is now done in a new
scsi_init_sgtable() (which is 99% identical to old scsi_init_io())
The new scsi_init_io() will call the above twice if needed also for
the bidi_read command. Only at this point is a command bidi.
- In scsi_error.c at scsi_eh_prep/restore_cmnd() make sure bidi-lld is not
confused by a get-sense command that looks like bidi. This is done
by puting NULL at request->next_rq, and restoring.
[jejb: update to sg_table and resolve conflicts
also update to blk-end-request and resolve conflicts]
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
In preparation for bidi we abstract all IO members of scsi_cmnd,
that will need to duplicate, into a substructure.
- Group all IO members of scsi_cmnd into a scsi_data_buffer
structure.
- Adjust accessors to new members.
- scsi_{alloc,free}_sgtable receive a scsi_data_buffer instead of
scsi_cmnd. And work on it.
- Adjust scsi_init_io() and scsi_release_buffers() for above
change.
- Fix other parts of scsi_lib/scsi.c to members migration. Use
accessors where appropriate.
- fix Documentation about scsi_cmnd in scsi_host.h
- scsi_error.c
* Changed needed members of struct scsi_eh_save.
* Careful considerations in scsi_eh_prep/restore_cmnd.
- sd.c and sr.c
* sd and sr would adjust IO size to align on device's block
size so code needs to change once we move to scsi_data_buff
implementation.
* Convert code to use scsi_for_each_sg
* Use data accessors where appropriate.
- tgt: convert libsrp to use scsi_data_buffer
- isd200: This driver still bangs on scsi_cmnd IO members,
so need changing
[jejb: rebased on top of sg_table patches fixed up conflicts
and used the synergy to eliminate use_sg and sg_count]
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Spotted by Paul Jackson <pj@sgi.com>
The error handler rework moved the scatterlist into a globally exposed
structure in scsi_eh.h; unfortunately, the scatterlist include needs
to move from scsi_error.c to scsi_eh.h to allow this to compile
universally.
Acked-by: Paul Jackson <pj@sgi.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
- Drivers/transports that want to send a synchronous REQUEST_SENSE command
as part of their .queuecommand sequence, have 2 new API's that facilitate
in doing so and abstract them from scsi-ml internals.
void scsi_eh_prep_cmnd(struct scsi_cmnd *scmd,
struct scsi_eh_save *sesci, unsigned char *cmnd,
int cmnd_size, int sense_bytes)
Will hijack a command and prepare it for request sense if needed.
And will save any later needed info into a scsi_eh_save structure.
void scsi_eh_restore_cmnd(struct scsi_cmnd* scmd,
struct scsi_eh_save *sesci);
Will undo any changes done to a command by above function. Making
it ready for completion.
- Re-factor scsi_send_eh_cmnd() to use above APIs
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
With Achim patch the last user (gdth) is switched away from scsi_request
so we an kill it now. Also disables some code in i2o_scsi that was
broken since the sg driver stopped using scsi_requests.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
libata implemented a feature to schedule EH without an associated EH
by manipulating shost->host_eh_scheduled in ata_scsi_schedule_eh()
directly. Move this function to scsi_error.c and rename it to
scsi_schedule_eh(). It is now an exported API for SCSI transports and
exported via new header file drivers/scsi/scsi_transport_api.h
This patch also de-export scsi_eh_wakeup() which was exported
specifically for ata_scsi_schedule_eh().
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
libata needs to invoke EH without scmd. This patch adds
shost->host_eh_scheduled to implement such behavior.
Currently the only user of this feature is libata and no general
interface is defined. This patch simply adds handling for
host_eh_scheduled where needed and exports scsi_eh_wakeup() to
modules. The rest is upto libata. This is the result of the
following discussion.
http://thread.gmane.org/gmane.linux.scsi/23853/focus=9760
In short, SCSI host is not supposed to know about exceptions unrelated
to specific device or command. Such exceptions should be handled by
transport layer proper. However, the distinction is not essential to
ATA and libata is planning to depart from SCSI, so, for the time
being, libata will be using SCSI EH to handle such exceptions.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Export two SCSI EH command handling functions. To be used by libata EH.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
This one's slightly more difficult. The transport class uses
REQ_FAILFAST, so another interface (scsi_execute) had to be invented to
take the extra flag. Also, the sense functions are shifted around to
allow spi_execute to place data directly into a struct scsi_sense_hdr.
With this change, there's probably a lot of unnecessary sense buffer
allocation going on which we can fix later.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Boaz Harrosh