scsi: cxlflash: Handle AFU sync failures

AFU sync operations are not currently evaluated for failure. This is
acceptable for paths where there is not a dependency on the AFU being
consistent with the host. Examples include link reset events and LUN
cleanup operations. On paths where there is a dependency, such as a LUN
open, a sync failure should be acted upon.

In the event of AFU sync failures, either log or cleanup as appropriate for
operations that are dependent on a successful sync completion.

Update documentation to reflect behavior in the event of an AFU sync
failure.

Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com>
Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Uma Krishnan 2017-06-21 21:14:30 -05:00 committed by Martin K. Petersen
parent 0b09e71118
commit c2c292f450
3 changed files with 107 additions and 27 deletions

View File

@ -257,6 +257,12 @@ DK_CXLFLASH_VLUN_RESIZE
operating in the virtual mode and used to program a LUN translation
table that the AFU references when provided with a resource handle.
This ioctl can return -EAGAIN if an AFU sync operation takes too long.
In addition to returning a failure to user, cxlflash will also schedule
an asynchronous AFU reset. Should the user choose to retry the operation,
it is expected to succeed. If this ioctl fails with -EAGAIN, the user
can either retry the operation or treat it as a failure.
DK_CXLFLASH_RELEASE
-------------------
This ioctl is responsible for releasing a previously obtained
@ -309,6 +315,12 @@ DK_CXLFLASH_VLUN_CLONE
clone. This is to avoid a stale entry in the file descriptor table of the
child process.
This ioctl can return -EAGAIN if an AFU sync operation takes too long.
In addition to returning a failure to user, cxlflash will also schedule
an asynchronous AFU reset. Should the user choose to retry the operation,
it is expected to succeed. If this ioctl fails with -EAGAIN, the user
can either retry the operation or treat it as a failure.
DK_CXLFLASH_VERIFY
------------------
This ioctl is used to detect various changes such as the capacity of

View File

@ -56,6 +56,19 @@ static void marshal_det_to_rele(struct dk_cxlflash_detach *detach,
release->context_id = detach->context_id;
}
/**
* marshal_udir_to_rele() - translate udirect to release structure
* @udirect: Source structure from which to translate/copy.
* @release: Destination structure for the translate/copy.
*/
static void marshal_udir_to_rele(struct dk_cxlflash_udirect *udirect,
struct dk_cxlflash_release *release)
{
release->hdr = udirect->hdr;
release->context_id = udirect->context_id;
release->rsrc_handle = udirect->rsrc_handle;
}
/**
* cxlflash_free_errpage() - frees resources associated with global error page
*/
@ -622,6 +635,7 @@ int _cxlflash_disk_release(struct scsi_device *sdev,
res_hndl_t rhndl = release->rsrc_handle;
int rc = 0;
int rcr = 0;
u64 ctxid = DECODE_CTXID(release->context_id),
rctxid = release->context_id;
@ -686,8 +700,12 @@ int _cxlflash_disk_release(struct scsi_device *sdev,
rhte_f1->dw = 0;
dma_wmb(); /* Make RHT entry bottom-half clearing visible */
if (!ctxi->err_recovery_active)
cxlflash_afu_sync(afu, ctxid, rhndl, AFU_HW_SYNC);
if (!ctxi->err_recovery_active) {
rcr = cxlflash_afu_sync(afu, ctxid, rhndl, AFU_HW_SYNC);
if (unlikely(rcr))
dev_dbg(dev, "%s: AFU sync failed rc=%d\n",
__func__, rcr);
}
break;
default:
WARN(1, "Unsupported LUN mode!");
@ -1929,6 +1947,7 @@ static int cxlflash_disk_direct_open(struct scsi_device *sdev, void *arg)
struct afu *afu = cfg->afu;
struct llun_info *lli = sdev->hostdata;
struct glun_info *gli = lli->parent;
struct dk_cxlflash_release rel = { { 0 }, 0 };
struct dk_cxlflash_udirect *pphys = (struct dk_cxlflash_udirect *)arg;
@ -1970,13 +1989,18 @@ static int cxlflash_disk_direct_open(struct scsi_device *sdev, void *arg)
rsrc_handle = (rhte - ctxi->rht_start);
rht_format1(rhte, lli->lun_id[sdev->channel], ctxi->rht_perms, port);
cxlflash_afu_sync(afu, ctxid, rsrc_handle, AFU_LW_SYNC);
last_lba = gli->max_lba;
pphys->hdr.return_flags = 0;
pphys->last_lba = last_lba;
pphys->rsrc_handle = rsrc_handle;
rc = cxlflash_afu_sync(afu, ctxid, rsrc_handle, AFU_LW_SYNC);
if (unlikely(rc)) {
dev_dbg(dev, "%s: AFU sync failed rc=%d\n", __func__, rc);
goto err2;
}
out:
if (likely(ctxi))
put_context(ctxi);
@ -1984,6 +2008,10 @@ out:
__func__, rsrc_handle, rc, last_lba);
return rc;
err2:
marshal_udir_to_rele(pphys, &rel);
_cxlflash_disk_release(sdev, ctxi, &rel);
goto out;
err1:
cxlflash_lun_detach(gli);
goto out;

View File

@ -594,7 +594,9 @@ static int grow_lxt(struct afu *afu,
rhte->lxt_cnt = my_new_size;
dma_wmb(); /* Make RHT entry's LXT table size update visible */
cxlflash_afu_sync(afu, ctxid, rhndl, AFU_LW_SYNC);
rc = cxlflash_afu_sync(afu, ctxid, rhndl, AFU_LW_SYNC);
if (unlikely(rc))
rc = -EAGAIN;
/* free old lxt if reallocated */
if (lxt != lxt_old)
@ -673,8 +675,11 @@ static int shrink_lxt(struct afu *afu,
rhte->lxt_start = lxt;
dma_wmb(); /* Make RHT entry's LXT table update visible */
if (needs_sync)
cxlflash_afu_sync(afu, ctxid, rhndl, AFU_HW_SYNC);
if (needs_sync) {
rc = cxlflash_afu_sync(afu, ctxid, rhndl, AFU_HW_SYNC);
if (unlikely(rc))
rc = -EAGAIN;
}
if (needs_ws) {
/*
@ -792,6 +797,21 @@ int _cxlflash_vlun_resize(struct scsi_device *sdev,
rc = grow_lxt(afu, sdev, ctxid, rhndl, rhte, &new_size);
else if (new_size < rhte->lxt_cnt)
rc = shrink_lxt(afu, sdev, rhndl, rhte, ctxi, &new_size);
else {
/*
* Rare case where there is already sufficient space, just
* need to perform a translation sync with the AFU. This
* scenario likely follows a previous sync failure during
* a resize operation. Accordingly, perform the heavyweight
* form of translation sync as it is unknown which type of
* resize failed previously.
*/
rc = cxlflash_afu_sync(afu, ctxid, rhndl, AFU_HW_SYNC);
if (unlikely(rc)) {
rc = -EAGAIN;
goto out;
}
}
resize->hdr.return_flags = 0;
resize->last_lba = (new_size * MC_CHUNK_SIZE * gli->blk_len);
@ -1084,10 +1104,13 @@ static int clone_lxt(struct afu *afu,
{
struct cxlflash_cfg *cfg = afu->parent;
struct device *dev = &cfg->dev->dev;
struct sisl_lxt_entry *lxt;
struct sisl_lxt_entry *lxt = NULL;
bool locked = false;
u32 ngrps;
u64 aun; /* chunk# allocated by block allocator */
int i, j;
int j;
int i = 0;
int rc = 0;
ngrps = LXT_NUM_GROUPS(rhte_src->lxt_cnt);
@ -1095,33 +1118,29 @@ static int clone_lxt(struct afu *afu,
/* allocate new LXTs for clone */
lxt = kzalloc((sizeof(*lxt) * LXT_GROUP_SIZE * ngrps),
GFP_KERNEL);
if (unlikely(!lxt))
return -ENOMEM;
if (unlikely(!lxt)) {
rc = -ENOMEM;
goto out;
}
/* copy over */
memcpy(lxt, rhte_src->lxt_start,
(sizeof(*lxt) * rhte_src->lxt_cnt));
/* clone the LBAs in block allocator via ref_cnt */
/* clone the LBAs in block allocator via ref_cnt, note that the
* block allocator mutex must be held until it is established
* that this routine will complete without the need for a
* cleanup.
*/
mutex_lock(&blka->mutex);
locked = true;
for (i = 0; i < rhte_src->lxt_cnt; i++) {
aun = (lxt[i].rlba_base >> MC_CHUNK_SHIFT);
if (ba_clone(&blka->ba_lun, aun) == -1ULL) {
/* free the clones already made */
for (j = 0; j < i; j++) {
aun = (lxt[j].rlba_base >>
MC_CHUNK_SHIFT);
ba_free(&blka->ba_lun, aun);
}
mutex_unlock(&blka->mutex);
kfree(lxt);
return -EIO;
rc = -EIO;
goto err;
}
}
mutex_unlock(&blka->mutex);
} else {
lxt = NULL;
}
/*
@ -1136,10 +1155,31 @@ static int clone_lxt(struct afu *afu,
rhte->lxt_cnt = rhte_src->lxt_cnt;
dma_wmb(); /* Make RHT entry's LXT table size update visible */
cxlflash_afu_sync(afu, ctxid, rhndl, AFU_LW_SYNC);
rc = cxlflash_afu_sync(afu, ctxid, rhndl, AFU_LW_SYNC);
if (unlikely(rc)) {
rc = -EAGAIN;
goto err2;
}
dev_dbg(dev, "%s: returning\n", __func__);
return 0;
out:
if (locked)
mutex_unlock(&blka->mutex);
dev_dbg(dev, "%s: returning rc=%d\n", __func__, rc);
return rc;
err2:
/* Reset the RHTE */
rhte->lxt_cnt = 0;
dma_wmb();
rhte->lxt_start = NULL;
dma_wmb();
err:
/* free the clones already made */
for (j = 0; j < i; j++) {
aun = (lxt[j].rlba_base >> MC_CHUNK_SHIFT);
ba_free(&blka->ba_lun, aun);
}
kfree(lxt);
goto out;
}
/**