Commit Graph

9 Commits

Author SHA1 Message Date
Mike Christie 6000a368cd [SCSI] block: separate failfast into multiple bits.
Multipath is best at handling transport errors. If it gets a device
error then there is not much the multipath layer can do. It will just
access the same device but from a different path.

This patch breaks up failfast into device, transport and driver errors.
The multipath layers (md and dm mutlipath) only ask the lower levels to
fast fail transport errors. The user of failfast, read ahead, will ask
to fast fail on all errors.

Note that blk_noretry_request will return true if any failfast bit
is set. This allows drivers that do not support the multipath failfast
bits to continue to fail on any failfast error like before. Drivers
like scsi that are able to fail fast specific errors can check
for the specific fail fast type. In the next patch I will convert
scsi.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-10-13 09:28:52 -04:00
James Bottomley 7ae628d9d2 [SCSI] scsi_dh: suppress comparison warning
On Mon, 2008-09-22 at 14:56 -0700, akpm@linux-foundation.org wrote:
> From: Andrew Morton <akpm@linux-foundation.org>
>
> s390:
>
> drivers/scsi/device_handler/scsi_dh_emc.c: In function 'parse_sp_info_reply':
> drivers/scsi/device_handler/scsi_dh_emc.c:179: warning: comparison is always false due to limited range of data type
>
> because chars are unsigned, I assume.

Fix by making csdev->buffer explicitly an unsigned char and dropping
the < 0 test.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-10-03 12:11:51 -05:00
FUJITA Tomonori 114f1ea408 [SCSI] scsi_dh: no need to initialize rq->cmd with blk_get_request
blk_get_request initializes rq->cmd (rq_init does) so the users don't
need to do that.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-10-03 11:46:14 -05:00
Mike Anderson c7dbb627a2 [SCSI] scsi_dh: make check_sense return ADD_TO_MLQUEUE
Change scsi_dh check_sense functions to return ADD_TO_MLQUEUE
to allow retries to occur without restriction of blk_noretry_request
check.

Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com>
Acked-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-08-29 09:13:51 -05:00
Adrian Bunk f08c0761d6 make struct scsi_dh_devlist's static
This patch makes several needlessly global struct scsi_dh_devlist's
static.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-11 12:20:31 -07:00
Hannes Reinecke b6ff1b14cd [SCSI] scsi_dh: Update EMC handler
This patch converts the EMC device handler to use a proper
state machine. We now also parse the extended INQUIRY
information to determine if long trespass commands are
supported. And we're now using the long trespass command
correctly. And finally there's now an check at init time
to refuse to attach to devices not supporting EMC-specific
VPD pages.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-26 15:14:51 -04:00
Hannes Reinecke 765cbc6dad [SCSI] scsi_dh: Implement common device table handling
Instead of having each and every driver implement its own
device table scanning code we should rather implement a common
routine and scan the device tables there.
This allows us also to implement a general notifier chain
callback for all device handler instead for one per handler.

[sekharan: Fix rejections caused by conflicting bug fix]
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-26 15:14:51 -04:00
Chandra Seetharaman 33af79d12e scsi_dh: Verify "dev" is a sdev before accessing it.
Before accessing the device data structure in hardware handlers,
make sure it is a indeed a sdev device.

Yinghai Lu <yhlu.kernel@gmail.com> found the bug on Jul 16, 2008,
and later tested/verified the following fix.

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-16 17:54:21 -07:00
Chandra Seetharaman 5e7dccad36 [SCSI] scsi_dh: add EMC Clariion device handler
This adds support for EMC Clariions. This patch has the features that
currently exists in mainline and advanced features from Ed's patches.

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-06-05 09:23:40 -05:00