block: Kill bio_segments()/bi_vcnt usage

When we start sharing biovecs, keeping bi_vcnt accurate for splits is
going to be error prone - and unnecessary, if we refactor some code.

So bio_segments() has to go - but most of the existing users just needed
to know if the bio had multiple segments, which is easier - add a
bio_multiple_segments() for them.

(Two of the current uses of bio_segments() are going to go away in a
couple patches, but the current implementation of bio_segments() is
unsafe as soon as we start doing driver conversions for immutable
biovecs - so implement a dumb version for bisectability, it'll go away
in a couple patches)

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Neil Brown <neilb@suse.de>
Cc: Nagalakshmi Nandigama <Nagalakshmi.Nandigama@lsi.com>
Cc: Sreekanth Reddy <Sreekanth.Reddy@lsi.com>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>

3 files changed, 13 insertions, 13 deletions

diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c
index 446b85110a1f..0cac7d8fd0f7 100644
--- a/drivers/scsi/libsas/sas_expander.c
+++ b/drivers/scsi/libsas/sas_expander.c
@@ -2163,10 +2163,10 @@ int sas_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
         }
 
         /* do we need to support multiple segments? */
-        if (bio_segments(req->bio) > 1 || bio_segments(rsp->bio) > 1) {
-                printk("%s: multiple segments req %u %u, rsp %u %u\n",
-                       __func__, bio_segments(req->bio), blk_rq_bytes(req),
-                       bio_segments(rsp->bio), blk_rq_bytes(rsp));
+        if (bio_multiple_segments(req->bio) ||
+            bio_multiple_segments(rsp->bio)) {
+                printk("%s: multiple segments req %u, rsp %u\n",
+                       __func__, blk_rq_bytes(req), blk_rq_bytes(rsp));
                 return -EINVAL;
         }
 
diff --git a/drivers/scsi/mpt2sas/mpt2sas_transport.c b/drivers/scsi/mpt2sas/mpt2sas_transport.c
index 7143e86af326..410f4a3e8888 100644
--- a/drivers/scsi/mpt2sas/mpt2sas_transport.c
+++ b/drivers/scsi/mpt2sas/mpt2sas_transport.c
@@ -1943,7 +1943,7 @@ _transport_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
         ioc->transport_cmds.status = MPT2_CMD_PENDING;
 
         /* Check if the request is split across multiple segments */
-        if (bio_segments(req->bio) > 1) {
+        if (bio_multiple_segments(req->bio)) {
                 u32 offset = 0;
 
                 /* Allocate memory and copy the request */
@@ -1975,7 +1975,7 @@ _transport_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
 
         /* Check if the response needs to be populated across
          * multiple segments */
-        if (bio_segments(rsp->bio) > 1) {
+        if (bio_multiple_segments(rsp->bio)) {
                 pci_addr_in = pci_alloc_consistent(ioc->pdev, blk_rq_bytes(rsp),
                     &pci_dma_in);
                 if (!pci_addr_in) {
@@ -2042,7 +2042,7 @@ _transport_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
         sgl_flags = (MPI2_SGE_FLAGS_SIMPLE_ELEMENT |
             MPI2_SGE_FLAGS_END_OF_BUFFER | MPI2_SGE_FLAGS_HOST_TO_IOC);
         sgl_flags = sgl_flags << MPI2_SGE_FLAGS_SHIFT;
-        if (bio_segments(req->bio) > 1) {
+        if (bio_multiple_segments(req->bio)) {
                 ioc->base_add_sg_single(psge, sgl_flags |
                     (blk_rq_bytes(req) - 4), pci_dma_out);
         } else {
@@ -2058,7 +2058,7 @@ _transport_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
             MPI2_SGE_FLAGS_LAST_ELEMENT | MPI2_SGE_FLAGS_END_OF_BUFFER |
             MPI2_SGE_FLAGS_END_OF_LIST);
         sgl_flags = sgl_flags << MPI2_SGE_FLAGS_SHIFT;
-        if (bio_segments(rsp->bio) > 1) {
+        if (bio_multiple_segments(rsp->bio)) {
                 ioc->base_add_sg_single(psge, sgl_flags |
                     (blk_rq_bytes(rsp) + 4), pci_dma_in);
         } else {
@@ -2103,7 +2103,7 @@ _transport_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
                     le16_to_cpu(mpi_reply->ResponseDataLength);
                 /* check if the resp needs to be copied from the allocated
                  * pci mem */
-                if (bio_segments(rsp->bio) > 1) {
+                if (bio_multiple_segments(rsp->bio)) {
                         u32 offset = 0;
                         u32 bytes_to_copy =
                             le16_to_cpu(mpi_reply->ResponseDataLength);
diff --git a/drivers/scsi/mpt3sas/mpt3sas_transport.c b/drivers/scsi/mpt3sas/mpt3sas_transport.c
index 196a67f2e95f..65170cb1a00f 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_transport.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_transport.c
@@ -1926,7 +1926,7 @@ _transport_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
         ioc->transport_cmds.status = MPT3_CMD_PENDING;
 
         /* Check if the request is split across multiple segments */
-        if (req->bio->bi_vcnt > 1) {
+        if (bio_multiple_segments(req->bio)) {
                 u32 offset = 0;
 
                 /* Allocate memory and copy the request */
@@ -1958,7 +1958,7 @@ _transport_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
 
         /* Check if the response needs to be populated across
          * multiple segments */
-        if (rsp->bio->bi_vcnt > 1) {
+        if (bio_multiple_segments(rsp->bio)) {
                 pci_addr_in = pci_alloc_consistent(ioc->pdev, blk_rq_bytes(rsp),
                     &pci_dma_in);
                 if (!pci_addr_in) {
@@ -2019,7 +2019,7 @@ _transport_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
         mpi_request->RequestDataLength = cpu_to_le16(blk_rq_bytes(req) - 4);
         psge = &mpi_request->SGL;
 
-        if (req->bio->bi_vcnt > 1)
+        if (bio_multiple_segments(req->bio))
                 ioc->build_sg(ioc, psge, pci_dma_out, (blk_rq_bytes(req) - 4),
                     pci_dma_in, (blk_rq_bytes(rsp) + 4));
         else
@@ -2064,7 +2064,7 @@ _transport_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
 
                 /* check if the resp needs to be copied from the allocated
                  * pci mem */
-                if (rsp->bio->bi_vcnt > 1) {
+                if (bio_multiple_segments(rsp->bio)) {
                         u32 offset = 0;
                         u32 bytes_to_copy =
                             le16_to_cpu(mpi_reply->ResponseDataLength);