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>
This commit is contained in:
Kent Overstreet
2013-09-24 16:26:05 -07:00
parent d57a5f7c66
commit 458b76ed2f
10 changed files with 93 additions and 86 deletions

View File

@@ -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);