scsi: cxlflash: Fix vlun resize failure in the shrink path

The ioctl DK_CAPI_VLUN_RESIZE can fail if the allocated vlun size is
reduced from almost maximum capacity and then increased again.

The shrink_lxt() routine is currently using the SISL_ASTATUS_MASK to
mask the higher 48 bits of the lxt entry. This is unnecessary and
incorrect as it uses a mask designed for the asynchronous interrupt
status register.  When the 4 port support was added to cxlflash, the
SISL_ASTATUS_MASK was updated to reflect the status bits for all 4
ports. This change indirectly affected the shrink_lxt() code path.

To extract the base, simply shift the bits without masking.

Fixes: 565180723294 ("scsi: cxlflash: SISlite updates to support 4 ports")
Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/cxlflash/vlun.c b/drivers/scsi/cxlflash/vlun.c
index bdfb930614604f1aa6d698ae54097b92a6afa8f8..703bf1e9a64a1dd5db0736d8319d1d2229097e69 100644 (file)
--- a/drivers/scsi/cxlflash/vlun.c
+++ b/drivers/scsi/cxlflash/vlun.c
@@ -694,11 +694,7 @@ static int shrink_lxt(struct afu *afu,
        /* Free LBAs allocated to freed chunks */
        mutex_lock(&blka->mutex);
        for (i = delta - 1; i >= 0; i--) {
-               /* Mask the higher 48 bits before shifting, even though
-                * it is a noop
-                */
-               aun = (lxt_old[my_new_size + i].rlba_base & SISL_ASTATUS_MASK);
-               aun = (aun >> MC_CHUNK_SHIFT);
+               aun = lxt_old[my_new_size + i].rlba_base >> MC_CHUNK_SHIFT;
                if (needs_ws)
                        write_same16(sdev, aun, MC_CHUNK_SIZE);
                ba_free(&blka->ba_lun, aun);