[SCSI] megaraid_sas: Add fpRead/WriteCapable, fpRead/WriteAcrossStripe checks

The following patch for megaraid_sas fixes the fastpath code decision
logic to use fpRead/WriteCapable, fpRead/WriteAcrossStripe flags
instead of the old logic.  This fixes a bug where fastpath writes
could be sent to a read only LD.

Signed-off-by: Adam Radford <aradford@gmail.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
This commit is contained in:
adam radford 2012-03-19 19:50:00 -07:00 committed by James Bottomley
parent 5738f99643
commit c1529fa25e

View file

@ -362,15 +362,20 @@ MR_BuildRaidContext(struct megasas_instance *instance,
/* assume this IO needs the full row - we'll adjust if not true */
regSize = stripSize;
/* If IO spans more than 1 strip, fp is not possible
FP is not possible for writes on non-0 raid levels
FP is not possible if LD is not capable */
if (num_strips > 1 || (!isRead && raid->level != 0) ||
!raid->capability.fpCapable) {
/* Check if we can send this I/O via FastPath */
if (raid->capability.fpCapable) {
if (isRead)
io_info->fpOkForIo = (raid->capability.fpReadCapable &&
((num_strips == 1) ||
raid->capability.
fpReadAcrossStripe));
else
io_info->fpOkForIo = (raid->capability.fpWriteCapable &&
((num_strips == 1) ||
raid->capability.
fpWriteAcrossStripe));
} else
io_info->fpOkForIo = FALSE;
} else {
io_info->fpOkForIo = TRUE;
}
if (numRows == 1) {
/* single-strip IOs can always lock only the data needed */