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linux-uek4-block.patch
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linux-uek4-block.patch
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From 3f69bce820fae1f93831381705db9667f2ec836e Mon Sep 17 00:00:00 2001
From: Dongli Zhang <[email protected]>
Date: Thu, 23 Apr 2020 16:51:32 -0700
Subject: [PATCH 1/1] linux uek4 block
v4.1.12-124.16.4
Signed-off-by: Dongli Zhang <[email protected]>
---
block/blk-merge.c | 26 ++++++++++++++
drivers/block/oracleasm/driver.c | 4 +++
drivers/block/xen-blkfront.c | 58 ++++++++++++++++++++++++++++++++
drivers/xen/grant-table.c | 10 ++++++
4 files changed, 98 insertions(+)
diff --git a/block/blk-merge.c b/block/blk-merge.c
index de471fe17d20..990e7bd3e978 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -240,6 +240,32 @@ single_segment:
* map a request to scatterlist, return number of sg entries setup. Caller
* must make sure sg can hold rq->nr_phys_segments entries
*/
+/*
+ * called by:
+ * - arch/um/drivers/ubd_kern.c|1288| <<do_ubd_request>> dev->end_sg = blk_rq_map_sg(q, req, dev->sg);
+ * - block/bsg-lib.c|100| <<bsg_map_buffer>> buf->sg_cnt = blk_rq_map_sg(req->q, req, buf->sg_list);
+ * - drivers/block/DAC960.c|3354| <<DAC960_process_queue>> Command->SegmentCount = blk_rq_map_sg(req_q,
+ * - drivers/block/DAC960.c|3433| <<DAC960_queue_partial_rw>> (void )blk_rq_map_sg(req_q, Command->Request, Command->cmd_sglist);
+ * - drivers/block/cciss.c|3340| <<do_cciss_request>> seg = blk_rq_map_sg(q, creq, tmp_sg);
+ * - drivers/block/cpqarray.c|936| <<do_ida_request>> seg = blk_rq_map_sg(q, creq, tmp_sg);
+ * - drivers/block/mtip32xx/mtip32xx.c|3727| <<mtip_submit_request>> nents = blk_rq_map_sg(hctx->queue, rq, cmd->sg);
+ * - drivers/block/skd_main.c|894| <<skd_preop_sg_list>> n_sg = blk_rq_map_sg(skdev->queue, req, sg);
+ * - drivers/block/sunvdc.c|630| <<__create_rw_desc>> nsg = blk_rq_map_sg(req->q, req, sg);
+ * - drivers/block/sx8.c|873| <<carm_rq_fn>> n_elem = blk_rq_map_sg(q, rq, sg);
+ * - drivers/block/virtio_blk.c|204| <<virtio_queue_rq>> num = blk_rq_map_sg(hctx->queue, vbr->req, vbr->sg);
+ * - drivers/block/xen-blkfront.c|745| <<blkif_queue_rw_req>> num_sg = blk_rq_map_sg(req->q, req, rinfo->shadow[id].sg);
+ * - drivers/ide/ide-io.c|229| <<ide_map_sg>> cmd->sg_nents = blk_rq_map_sg(drive->queue, rq, sg);
+ * - drivers/memstick/core/ms_block.c|1907| <<msb_io_work>> blk_rq_map_sg(msb->queue, msb->req, sg);
+ * - drivers/memstick/core/mspro_block.c|707| <<mspro_block_issue_req>> msb->seg_count = blk_rq_map_sg(msb->block_req->q,
+ * - drivers/mmc/card/queue.c|478| <<mmc_queue_packed_map_sg>> sg_len += blk_rq_map_sg(mq->queue, req, __sg);
+ * - drivers/mmc/card/queue.c|504| <<mmc_queue_map_sg>> return blk_rq_map_sg(mq->queue, mqrq->req, mqrq->sg);
+ * - drivers/mmc/card/queue.c|513| <<mmc_queue_map_sg>> sg_len = blk_rq_map_sg(mq->queue, mqrq->req, mqrq->bounce_sg);
+ * - drivers/mtd/ubi/block.c|310| <<ubiblock_do_work>> blk_rq_map_sg(req->q, req, pdu->usgl.sg);
+ * - drivers/nvme/host/pci.c|573| <<nvme_map_data>> iod->nents = blk_rq_map_sg(q, req, iod->sg);
+ * - drivers/scsi/scsi_lib.c|1097| <<scsi_init_sgtable>> count = blk_rq_map_sg(req->q, req, sdb->table.sgl);
+ * - drivers/scsi/scsi_transport_fc.c|3683| <<fc_bsg_map_buffer>> buf->sg_cnt = blk_rq_map_sg(req->q, req, buf->sg_list);
+ * - drivers/staging/i2o/i2o_block.c|324| <<i2o_block_sglist_alloc>> nents = blk_rq_map_sg(ireq->req->q, ireq->req, ireq->sg_table);
+ */
int blk_rq_map_sg(struct request_queue *q, struct request *rq,
struct scatterlist *sglist)
{
diff --git a/drivers/block/oracleasm/driver.c b/drivers/block/oracleasm/driver.c
index 5632ee0f1a51..733fc36e1a34 100644
--- a/drivers/block/oracleasm/driver.c
+++ b/drivers/block/oracleasm/driver.c
@@ -961,6 +961,10 @@ out:
} /* asm_update_user_ioc() */
+/*
+ * called by:
+ * - drivers/block/oracleasm/driver.c|1121| <<asm_submit_io>> r = asm_request_alloc();
+ */
static struct asm_request *asm_request_alloc(void)
{
struct asm_request *r;
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 644522b660b7..c7f17d66af55 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -364,9 +364,18 @@ static struct grant *get_grant(grant_ref_t *gref_head,
if (gnt_list_entry->gref != GRANT_INVALID_REF)
return gnt_list_entry;
+ /*
+ * 如果是persistent上面有可能就return了吧
+ * gfn根本用不到
+ */
+
/* Assign a gref to this page */
gnt_list_entry->gref = gnttab_claim_grant_reference(gref_head);
BUG_ON(gnt_list_entry->gref == -ENOSPC);
+ /*
+ * 如果是persistent就不用把gfn map到grant
+ * 因为要copy
+ */
if (info->feature_persistent)
grant_foreign_access(gnt_list_entry, info);
else {
@@ -584,6 +593,10 @@ struct setup_rw_req {
struct blkif_request *extra_ring_req;
};
+/*
+ * 在以下使用blkif_setup_rw_req_grant():
+ * - drivers/block/xen-blkfront.c|832| <<blkif_queue_rw_req>> blkif_setup_rw_req_grant,
+ */
static void blkif_setup_rw_req_grant(unsigned long gfn, unsigned int offset,
unsigned int len, void *data)
{
@@ -615,22 +628,35 @@ static void blkif_setup_rw_req_grant(unsigned long gfn, unsigned int offset,
if ((ring_req->operation == BLKIF_OP_INDIRECT) &&
(grant_idx % GRANTS_PER_INDIRECT_FRAME == 0)) {
+ /* struct blkif_request_segment *segments; */
if (setup->segments)
kunmap_atomic(setup->segments);
n = grant_idx / GRANTS_PER_INDIRECT_FRAME;
gnt_list_entry = get_indirect_grant(&setup->gref_head, rinfo);
shadow->indirect_grants[n] = gnt_list_entry;
+ /*
+ * struct blkif_request_segment *segments;
+ *
+ * 这里调用kmap因为要用这个page存储struct blkif_request_segment
+ * INDIRECT!!!
+ */
setup->segments = kmap_atomic(gnt_list_entry->page);
ring_req->u.indirect.indirect_grefs[n] = gnt_list_entry->gref;
}
+ /*
+ * 分配struct grant
+ */
gnt_list_entry = get_grant(&setup->gref_head, gfn, rinfo);
ref = gnt_list_entry->gref;
/*
* All the grants are stored in the shadow of the first
* request. Therefore we have to use the global index.
*/
+ /*
+ * struct grant **grants_used;
+ */
shadow->grants_used[setup->grant_idx] = gnt_list_entry;
if (setup->need_copy) {
@@ -692,6 +718,10 @@ static void blkif_setup_extra_req(struct blkif_request *first,
second->operation = first->operation;
}
+/*
+ * called by:
+ * - drivers/block/xen-blkfront.c|866| <<blkif_queue_request>> return blkif_queue_rw_req(req, rinfo);
+ */
static int blkif_queue_rw_req(struct request *req, struct blkfront_ring_info *rinfo)
{
struct blkfront_info *info = rinfo->dev_info;
@@ -703,6 +733,11 @@ static int blkif_queue_rw_req(struct request *req, struct blkfront_ring_info *ri
.grant_idx = 0,
.segments = NULL,
.rinfo = rinfo,
+ /*
+ * 如果是write需要立刻copy, 否则可以等到完成再copy
+ *
+ * 如果cmd_flags=20000010, rq_data_dir(req)返回0
+ */
.need_copy = rq_data_dir(req) && info->feature_persistent,
};
@@ -740,8 +775,14 @@ static int blkif_queue_rw_req(struct request *req, struct blkfront_ring_info *ri
}
/* Fill out a communications ring structure. */
+ /*
+ * 获得rinfo->shadow[id]和blkif_request
+ */
id = blkif_ring_get_request(rinfo, req, &ring_req);
+ /*
+ * 除了block/bsg-lib.c都是只有driver在调用
+ */
num_sg = blk_rq_map_sg(req->q, req, rinfo->shadow[id].sg);
num_grant = 0;
/* Calculate the number of grant used */
@@ -760,6 +801,9 @@ static int blkif_queue_rw_req(struct request *req, struct blkfront_ring_info *ri
* BLKIF_OP_WRITE
*/
BUG_ON(req->cmd_flags & (REQ_FLUSH | REQ_FUA));
+ /*
+ * !!!! 这里的operation是BLKIF_OP_INDIRECT
+ */
ring_req->operation = BLKIF_OP_INDIRECT;
ring_req->u.indirect.indirect_op = rq_data_dir(req) ?
BLKIF_OP_WRITE : BLKIF_OP_READ;
@@ -769,6 +813,9 @@ static int blkif_queue_rw_req(struct request *req, struct blkfront_ring_info *ri
} else {
ring_req->u.rw.sector_number = (blkif_sector_t)blk_rq_pos(req);
ring_req->u.rw.handle = info->handle;
+ /*
+ * !!!! 这里的operation是BLKIF_OP_READ或者BLKIF_OP_WRITE
+ */
ring_req->operation = rq_data_dir(req) ?
BLKIF_OP_WRITE : BLKIF_OP_READ;
if (req->cmd_flags & (REQ_FLUSH | REQ_FUA)) {
@@ -811,6 +858,7 @@ static int blkif_queue_rw_req(struct request *req, struct blkfront_ring_info *ri
}
}
+ /* ring_req的类型是struct blkif_request */
setup.ring_req = ring_req;
setup.id = id;
@@ -821,7 +869,16 @@ static int blkif_queue_rw_req(struct request *req, struct blkfront_ring_info *ri
for_each_sg(rinfo->shadow[id].sg, sg, num_sg, i) {
BUG_ON(sg->offset + sg->length > PAGE_SIZE);
+ /*
+ * 如果是write需要立刻copy, 否则可以等到完成再copy
+ *
+ * 如果cmd_flags=20000010, rq_data_dir(req)返回0
+ */
if (setup.need_copy) {
+ /*
+ * 这里没有真正copy, 只是map
+ * copy在blkif_setup_rw_req_grant()完成
+ */
setup.bvec_off = sg->offset;
setup.bvec_data = kmap_atomic(sg_page(sg));
}
@@ -907,6 +964,7 @@ static int blkif_queue_rq(struct blk_mq_hw_ctx *hctx,
if (blkif_queue_request(qd->rq, rinfo))
goto out_busy;
+ /* 用evtchn notify */
flush_requests(rinfo);
spin_unlock_irqrestore(&rinfo->ring_lock, flags);
return BLK_MQ_RQ_QUEUE_OK;
diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index 7086fb237b50..fff0fe94f146 100644
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -777,6 +777,13 @@ void gnttab_batch_copy(struct gnttab_copy *batch, unsigned count)
}
EXPORT_SYMBOL_GPL(gnttab_batch_copy);
+/*
+ * called by:
+ * - drivers/block/xen-blkfront.c|863| <<blkif_queue_rw_req>> gnttab_foreach_grant_in_range(sg_page(sg),
+ * - drivers/block/xen-blkfront.c|1550| <<blkif_completion>> gnttab_foreach_grant_in_range(sg_page(sg),
+ * - drivers/net/xen-netfront.c|709| <<xennet_make_txreqs>> gnttab_foreach_grant_in_range(page, offset, len,
+ * - include/xen/grant_table.h|264| <<gnttab_for_one_grant>> gnttab_foreach_grant_in_range(page, offset, len, fn, data);
+ */
void gnttab_foreach_grant_in_range(struct page *page,
unsigned int offset,
unsigned int len,
@@ -787,6 +794,9 @@ void gnttab_foreach_grant_in_range(struct page *page,
unsigned int glen;
unsigned long xen_pfn;
+ /*
+ * 当前的page从offset剩下的, 或者len
+ */
len = min_t(unsigned int, PAGE_SIZE - offset, len);
goffset = xen_offset_in_page(offset);
--
2.17.1