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| author | sreekanth.reddy@lsi.com <sreekanth.reddy@lsi.com> | 2012-07-17 15:57:05 +0530 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-09-14 10:00:25 -0700 |
| commit | 7a4601c0bfde4ed50c54f30c32c5677e3daec4f9 (patch) | |
| tree | 54dcd326a9b53c50fc085940ee0837c8ae36046e /drivers/scsi/mpt2sas | |
| parent | 797efad403c63c9a94a8f78e06ccb3aa5b4980a9 (diff) | |
| download | lwn-7a4601c0bfde4ed50c54f30c32c5677e3daec4f9.tar.gz lwn-7a4601c0bfde4ed50c54f30c32c5677e3daec4f9.zip | |
SCSI: mpt2sas: Fix for Driver oops, when loading driver with max_queue_depth command line option to a very small value
commit 338b131a3269881c7431234855c93c219b0979b6 upstream.
If the specified max_queue_depth setting is less than the
expected number of internal commands, then driver will calculate
the queue depth size to a negitive number. This negitive number
is actually a very large number because variable is unsigned
16bit integer. So, the driver will ask for a very large amount of
memory for message frames and resulting into oops as memory
allocation routines will not able to handle such a large request.
So, in order to limit this kind of oops, The driver need to set
the max_queue_depth to a scsi mid layer's can_queue value. Then
the overall message frames required for IO is minimum of either
(max_queue_depth plus internal commands) or the IOC global
credits.
Signed-off-by: Sreekanth Reddy <sreekanth.reddy@lsi.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/scsi/mpt2sas')
| -rw-r--r-- | drivers/scsi/mpt2sas/mpt2sas_base.c | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/drivers/scsi/mpt2sas/mpt2sas_base.c b/drivers/scsi/mpt2sas/mpt2sas_base.c index 3f03342b3030..c4cef569540b 100644 --- a/drivers/scsi/mpt2sas/mpt2sas_base.c +++ b/drivers/scsi/mpt2sas/mpt2sas_base.c @@ -2417,10 +2417,13 @@ _base_allocate_memory_pools(struct MPT2SAS_ADAPTER *ioc, int sleep_flag) } /* command line tunables for max controller queue depth */ - if (max_queue_depth != -1) - max_request_credit = (max_queue_depth < facts->RequestCredit) - ? max_queue_depth : facts->RequestCredit; - else + if (max_queue_depth != -1 && max_queue_depth != 0) { + max_request_credit = min_t(u16, max_queue_depth + + ioc->hi_priority_depth + ioc->internal_depth, + facts->RequestCredit); + if (max_request_credit > MAX_HBA_QUEUE_DEPTH) + max_request_credit = MAX_HBA_QUEUE_DEPTH; + } else max_request_credit = min_t(u16, facts->RequestCredit, MAX_HBA_QUEUE_DEPTH); @@ -2495,7 +2498,7 @@ _base_allocate_memory_pools(struct MPT2SAS_ADAPTER *ioc, int sleep_flag) /* set the scsi host can_queue depth * with some internal commands that could be outstanding */ - ioc->shost->can_queue = ioc->scsiio_depth - (2); + ioc->shost->can_queue = ioc->scsiio_depth; dinitprintk(ioc, printk(MPT2SAS_INFO_FMT "scsi host: " "can_queue depth (%d)\n", ioc->name, ioc->shost->can_queue)); |