From aa489bba1604c95dab3caccca46fb07b71316151 Mon Sep 17 00:00:00 2001
From: Mike Christie <michaelc@cs.wisc.edu>
Date: Wed, 29 Jul 2015 04:23:39 -0500
Subject: [PATCH] rbd: add support for scatterlist obj_request_type
References: fate#318836
Patch-mainline: Not yet, SES2 clustered LIO/RBD
This adds support for a scatterlist rbd obj_request_type, so LIO
can pass down its sg to rbd.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Acked-by: David Disseldorp <ddiss@suse.de>
---
drivers/block/rbd.c | 105 ++++++++++++++++++++++++++++++++++++++++++++++------
1 file changed, 94 insertions(+), 11 deletions(-)
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -44,6 +44,7 @@
#include <linux/slab.h>
#include <linux/idr.h>
#include <linux/workqueue.h>
+#include <linux/scatterlist.h>
#include "rbd_types.h"
@@ -210,7 +211,7 @@ struct rbd_obj_request;
typedef void (*rbd_obj_callback_t)(struct rbd_obj_request *);
enum obj_request_type {
- OBJ_REQUEST_NODATA, OBJ_REQUEST_BIO, OBJ_REQUEST_PAGES
+ OBJ_REQUEST_NODATA, OBJ_REQUEST_BIO, OBJ_REQUEST_PAGES, OBJ_REQUEST_SG,
};
enum obj_operation_type {
@@ -266,6 +267,10 @@ struct rbd_obj_request {
struct page **pages;
u32 page_count;
};
+ struct {
+ struct scatterlist *sg;
+ unsigned int init_sg_offset;
+ };
};
struct page **copyup_pages;
u32 copyup_page_count;
@@ -297,16 +302,22 @@ struct rbd_img_request {
u64 snap_id; /* for reads */
struct ceph_snap_context *snapc; /* for writes */
};
- union {
- struct request *rq; /* block request */
- struct rbd_obj_request *obj_request; /* obj req initiator */
- };
+
+ struct request *rq; /* block request */
+ struct rbd_obj_request *obj_request; /* obj req initiator */
+
struct page **copyup_pages;
u32 copyup_page_count;
spinlock_t completion_lock;/* protects next_completion */
u32 next_completion;
rbd_img_callback_t callback;
+ /*
+ * xferred is the bytes that have successfully been transferred.
+ * completed is the bytes that have been accounted for and includes
+ * both failed and successfully transffered bytes.
+ */
u64 xferred;/* aggregate bytes transferred */
+ u64 completed;
int result; /* first nonzero obj_request result */
u32 obj_request_count;
@@ -1272,6 +1283,34 @@ static void zero_bio_chain(struct bio *c
}
}
+static void zero_sg(struct scatterlist *sgl, u64 start, u64 length)
+{
+ struct scatterlist *sg = sgl;
+ u64 end = start + length;
+ u64 pos = 0;
+
+ while (pos < end && sg) {
+ if (pos + sg->length > start) {
+ int sg_offset = max_t(int, start - pos, 0);
+ unsigned int length = min_t(unsigned int,
+ sg->length - sg_offset,
+ end - pos);
+ void *kaddr;
+ unsigned long flags;
+
+ local_irq_save(flags);
+ kaddr = kmap_atomic(sg_page(sg));
+ memset(kaddr + sg_offset + sg->offset, 0, length);
+ flush_dcache_page(sg_page(sg));
+ kunmap_atomic(kaddr);
+ local_irq_restore(flags);
+ }
+
+ pos += sg->length;
+ sg = sg_next(sg);
+ }
+}
+
/*
* similar to zero_bio_chain(), zeros data defined by a page array,
* starting at the given byte offset from the start of the array and
@@ -1546,6 +1585,7 @@ static bool obj_request_type_valid(enum
case OBJ_REQUEST_NODATA:
case OBJ_REQUEST_BIO:
case OBJ_REQUEST_PAGES:
+ case OBJ_REQUEST_SG:
return true;
default:
return false;
@@ -1729,14 +1769,18 @@ rbd_img_obj_request_read_callback(struct
if (obj_request->result == -ENOENT) {
if (obj_request->type == OBJ_REQUEST_BIO)
zero_bio_chain(obj_request->bio_list, 0);
- else
+ else if (obj_request->type == OBJ_REQUEST_PAGES)
zero_pages(obj_request->pages, 0, length);
+ else if (obj_request->type == OBJ_REQUEST_SG)
+ zero_sg(obj_request->sg, 0, length);
obj_request->result = 0;
} else if (xferred < length && !obj_request->result) {
if (obj_request->type == OBJ_REQUEST_BIO)
zero_bio_chain(obj_request->bio_list, xferred);
- else
+ else if (obj_request->type == OBJ_REQUEST_PAGES)
zero_pages(obj_request->pages, xferred, length);
+ else if (obj_request->type == OBJ_REQUEST_SG)
+ zero_sg(obj_request->sg, xferred, length);
}
obj_request->xferred = length;
obj_request_done_set(obj_request);
@@ -2080,6 +2124,7 @@ static void rbd_obj_request_destroy(stru
rbd_assert(obj_request_type_valid(obj_request->type));
switch (obj_request->type) {
case OBJ_REQUEST_NODATA:
+ case OBJ_REQUEST_SG:
break; /* Nothing to do */
case OBJ_REQUEST_BIO:
if (obj_request->bio_list)
@@ -2181,6 +2226,7 @@ static struct rbd_img_request *rbd_img_r
img_request->offset = offset;
img_request->length = length;
img_request->flags = 0;
+ img_request->completed = 0;
if (op_type == OBJ_OP_DISCARD) {
img_request_discard_set(img_request);
img_request->snapc = snapc;
@@ -2306,6 +2352,7 @@ static bool rbd_img_obj_end_request(stru
*/
xferred = obj_request->length;
}
+ img_request->completed += xferred;
/* Image object requests don't own their page array */
@@ -2317,12 +2364,15 @@ static bool rbd_img_obj_end_request(stru
if (img_request_child_test(img_request)) {
rbd_assert(img_request->obj_request != NULL);
more = obj_request->which < img_request->obj_request_count - 1;
- } else {
- rbd_assert(img_request->rq != NULL);
-
+ } else if (img_request->rq) {
more = blk_update_request(img_request->rq, result, xferred);
if (!more)
__blk_mq_end_request(img_request->rq, result);
+ } else {
+ if (img_request->completed < img_request->length)
+ more = true;
+ else
+ more = false;
}
return more;
@@ -2427,6 +2477,10 @@ static void rbd_img_obj_request_fill(str
osd_req_op_extent_osd_data_pages(osd_request, num_ops,
obj_request->pages, length,
offset & ~PAGE_MASK, false, false);
+ else if (obj_request->type == OBJ_REQUEST_SG)
+ osd_req_op_extent_osd_data_sg(osd_request, num_ops,
+ obj_request->sg,
+ obj_request->init_sg_offset, length);
/* Discards are also writes */
if (op_type == OBJ_OP_WRITE || op_type == OBJ_OP_DISCARD)
@@ -2452,7 +2506,9 @@ static int rbd_img_request_fill(struct r
struct rbd_obj_request *next_obj_request;
struct bio *bio_list = NULL;
unsigned int bio_offset = 0;
+ unsigned int sg_offset = 0;
struct page **pages = NULL;
+ struct scatterlist *sgl = NULL;
enum obj_operation_type op_type;
u64 img_offset;
u64 resid;
@@ -2471,6 +2527,8 @@ static int rbd_img_request_fill(struct r
bio_list->bi_iter.bi_sector << SECTOR_SHIFT);
} else if (type == OBJ_REQUEST_PAGES) {
pages = data_desc;
+ } else if (type == OBJ_REQUEST_SG) {
+ sgl = data_desc;
}
while (resid) {
@@ -2518,6 +2576,27 @@ static int rbd_img_request_fill(struct r
if ((offset + length) & ~PAGE_MASK)
page_count--; /* more on last page */
pages += page_count;
+ } else if (type == OBJ_REQUEST_SG) {
+ u64 sg_length = 0;
+
+ obj_request->init_sg_offset = sg_offset;
+ obj_request->sg = sgl;
+ do {
+ sg_length += (sgl->length - sg_offset);
+ sg_offset = 0;
+ if (sg_length > length) {
+ sg_offset = sgl->length -
+ (sg_length - length);
+ break;
+ }
+ /*
+ * For WRITE_SAME we have a single sg that
+ * is written possibly multiple times over
+ * img_request->length bytes.
+ */
+ if (sg_next(sgl))
+ sgl = sg_next(sgl);
+ } while (true);
}
osd_req = rbd_osd_req_create(rbd_dev, op_type,
@@ -3073,9 +3152,13 @@ static void rbd_img_parent_read(struct r
if (obj_request->type == OBJ_REQUEST_BIO)
result = rbd_img_request_fill(img_request, OBJ_REQUEST_BIO,
obj_request->bio_list);
- else
+ else if (obj_request->type == OBJ_REQUEST_PAGES)
result = rbd_img_request_fill(img_request, OBJ_REQUEST_PAGES,
obj_request->pages);
+ else
+ result = rbd_img_request_fill(img_request, OBJ_REQUEST_SG,
+ obj_request->sg);
+
if (result)
goto out_err;