By default, when ioctl(SG_IORECEIVE) is used in multiple requests
mode (mrq) the response array is built in completion order. And the
completion order isn't necessarily submission order which can be a
nuisance. This new flag allows the user to specify where (via an
index in the v4::request_priority field) a given request's response
will be placed in the response array associated with a mrq
ioctl(SG_IORECEIVE) call.
Signed-off-by: Douglas Gilbert <dgilbert@xxxxxxxxxxxx>
---
drivers/scsi/sg.c | 43 +++++++++++++++++++++++++++---------------
include/uapi/scsi/sg.h | 1 +
2 files changed, 29 insertions(+), 15 deletions(-)
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index a76ab2c59553..37a3361dec31 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -1552,8 +1552,11 @@ sg_mrq_sanity(struct sg_mrq_hold *mhp, bool is_svb)
hp->response = cop->response;
hp->max_response_len = cop->max_response_len;
}
- if (!is_svb)
+ if (!is_svb) {
+ if (cop->flags & SGV4_FLAG_REC_ORDER)
+ hp->flags |= SGV4_FLAG_REC_ORDER;
continue;
+ }
/* mrq share variable blocking (svb) additional constraints checked here */
if (unlikely(flags & (SGV4_FLAG_COMPLETE_B4 | SGV4_FLAG_KEEP_SHARE))) {
SG_LOG(1, sfp, "%s: %s %u: no KEEP_SHARE with svb\n", __func__, rip, k);
@@ -2775,7 +2778,7 @@ sg_common_write(struct sg_comm_wr_t *cwrp)
srp->s_hdr4.cmd_len = h4p->request_len;
srp->s_hdr4.dir = dir;
srp->s_hdr4.out_resid = 0;
- srp->s_hdr4.mrq_ind = 0;
+ srp->s_hdr4.mrq_ind = (rq_flags & SGV4_FLAG_REC_ORDER) ? h4p->request_priority : 0;
if (dir == SG_DXFER_TO_DEV) {
srp->s_hdr4.wr_offset = cwrp->wr_offset;
srp->s_hdr4.wr_len = dlen;
@@ -3053,7 +3056,7 @@ sg_receive_v4(struct sg_fd *sfp, struct sg_request *srp, void __user *p, struct
static int
sg_mrq_iorec_complets(struct sg_fd *sfp, bool non_block, int max_mrqs, struct sg_io_v4 *rsp_arr)
{
- int k;
+ int k, idx;
int res = 0;
struct sg_request *srp;
@@ -3062,8 +3065,15 @@ sg_mrq_iorec_complets(struct sg_fd *sfp, bool non_block, int max_mrqs, struct sg
if (!sg_mrq_get_ready_srp(sfp, &srp))
break;
if (IS_ERR(srp))
- return k ? k : PTR_ERR(srp);
- res = sg_receive_v4(sfp, srp, NULL, rsp_arr + k);
+ return k ? k /* some but not all */ : PTR_ERR(srp);
+ if (srp->rq_flags & SGV4_FLAG_REC_ORDER) {
+ idx = srp->s_hdr4.mrq_ind;
+ if (idx >= max_mrqs)
+ idx = 0; /* overwrite index 0 when trouble */
+ } else {
+ idx = k; /* completion order */
+ }
+ res = sg_receive_v4(sfp, srp, NULL, rsp_arr + idx);
if (unlikely(res))
return res;
rsp_arr[k].info |= SG_INFO_MRQ_FINI;
@@ -3077,7 +3087,14 @@ sg_mrq_iorec_complets(struct sg_fd *sfp, bool non_block, int max_mrqs, struct sg
return res; /* signal --> -ERESTARTSYS */
if (IS_ERR(srp))
return k ? k : PTR_ERR(srp);
- res = sg_receive_v4(sfp, srp, NULL, rsp_arr + k);
+ if (srp->rq_flags & SGV4_FLAG_REC_ORDER) {
+ idx = srp->s_hdr4.mrq_ind;
+ if (idx >= max_mrqs)
+ idx = 0;
+ } else {
+ idx = k;
+ }
+ res = sg_receive_v4(sfp, srp, NULL, rsp_arr + idx);
if (unlikely(res))
return res;
rsp_arr[k].info |= SG_INFO_MRQ_FINI;
@@ -7619,7 +7636,8 @@ sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
/* Writes debug info for one sg_request in obp buffer */
static int
-sg_proc_debug_sreq(struct sg_request *srp, int to, bool t_in_ns, bool inactive, char *obp, int len)
+sg_proc_debug_sreq(struct sg_request *srp, int to, bool t_in_ns, bool inactive, char *obp,
+ int len)
{
bool is_v3v4, v4, is_dur;
int n = 0;
@@ -7659,13 +7677,8 @@ sg_proc_debug_sreq(struct sg_request *srp, int to, bool t_in_ns, bool inactive,
n += scnprintf(obp + n, len - n, " sgat=%d", srp->sgatp->num_sgat);
cp = (srp->rq_flags & SGV4_FLAG_HIPRI) ? "hipri " : "";
n += scnprintf(obp + n, len - n, " %sop=0x%02x\n", cp, srp->cmd_opcode);
- if (inactive && rq_st != SG_RQ_INACTIVE) {
- if (xa_get_mark(&srp->parentfp->srp_arr, srp->rq_idx, SG_XA_RQ_INACTIVE))
- cp = "still marked inactive, BAD";
- else
- cp = "no longer marked inactive";
- n += scnprintf(obp + n, len - n, " <<< xarray %s >>>\n", cp);
- }
+ if (inactive && rq_st != SG_RQ_INACTIVE)
+ n += scnprintf(obp + n, len - n, " <<< inconsistent state >>>\n");
return n;
}
@@ -7749,7 +7762,7 @@ sg_proc_debug_fd(struct sg_fd *fp, char *obp, int len, unsigned long idx, bool r
n += scnprintf(obp + n, len - n, " rq_bm=0x%lx", srp->frq_bm[0]);
n += sg_proc_debug_sreq(srp, fp->timeout, t_in_ns, true, obp + n, len - n);
++k;
- if ((k % 8) == 0) { /* don't hold up isr_s too long */
+ if ((k % 8) == 0) { /* don't hold up things too long */
xa_unlock_irqrestore(&fp->srp_arr, iflags);
cpu_relax();
xa_lock_irqsave(&fp->srp_arr, iflags);
diff --git a/include/uapi/scsi/sg.h b/include/uapi/scsi/sg.h
index 236ac4678f71..871073d1a8d3 100644
--- a/include/uapi/scsi/sg.h
+++ b/include/uapi/scsi/sg.h
@@ -128,6 +128,7 @@ typedef struct sg_io_hdr {
#define SGV4_FLAG_KEEP_SHARE 0x20000 /* ... buffer for another dout command */
#define SGV4_FLAG_MULTIPLE_REQS 0x40000 /* 1 or more sg_io_v4-s in data-in */
#define SGV4_FLAG_ORDERED_WR 0x80000 /* svb: issue in-order writes */
+#define SGV4_FLAG_REC_ORDER 0x100000 /* receive order in v4:request_priority */
/* Output (potentially OR-ed together) in v3::info or v4::info field */
#define SG_INFO_OK_MASK 0x1
--
2.25.1
