This patch adds the ability to build an image request whose data
will be written from or read into memory described by a page array.
(Previously only bio lists were supported.)
Originally this was going to define a new function for this purpose
but it was largely identical to the rbd_img_request_fill_bio(). So
instead, rbd_img_request_fill_bio() has been generalized to handle
both types of image request.
For the moment we still only fill image requests with bio data.
Signed-off-by: Alex Elder <elder@xxxxxxxxxxx>
---
drivers/block/rbd.c | 86
+++++++++++++++++++++++++++++++++++++++------------
1 file changed, 66 insertions(+), 20 deletions(-)
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index ac9abab..91fcf36 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -1780,6 +1780,13 @@ static bool rbd_img_obj_end_request(struct
rbd_obj_request *obj_request)
img_request->result = result;
}
+ /* Image object requests don't own their page array */
+
+ if (obj_request->type == OBJ_REQUEST_PAGES) {
+ obj_request->pages = NULL;
+ obj_request->page_count = 0;
+ }
+
if (img_request_child_test(img_request)) {
rbd_assert(img_request->obj_request != NULL);
more = obj_request->which < img_request->obj_request_count - 1;
@@ -1830,30 +1837,48 @@ out:
rbd_img_request_complete(img_request);
}
-static int rbd_img_request_fill_bio(struct rbd_img_request *img_request,
- struct bio *bio_list)
+/*
+ * Split up an image request into one or more object requests, each
+ * to a different object. The the "type" parameter indicates
+ * whether "data_desc" is the pointer to the head of a list of bio
+ * structures, or the base of a page array. In either case this
+ * function assumes data_desc describes memory sufficient to hold
+ * all data described by the image request.
+ */
+static int rbd_img_request_fill(struct rbd_img_request *img_request,
+ enum obj_request_type type,
+ void *data_desc)
{
struct rbd_device *rbd_dev = img_request->rbd_dev;
struct rbd_obj_request *obj_request = NULL;
struct rbd_obj_request *next_obj_request;
bool write_request = img_request_write_test(img_request);
- unsigned int bio_offset;
+ struct bio *bio_list;
+ unsigned int bio_offset = 0;
+ struct page **pages;
u64 img_offset;
u64 resid;
u16 opcode;
- dout("%s: img %p bio %p\n", __func__, img_request, bio_list);
+ dout("%s: img %p type %d data_desc %p\n", __func__, img_request,
+ (int)type, data_desc);
opcode = write_request ? CEPH_OSD_OP_WRITE : CEPH_OSD_OP_READ;
- bio_offset = 0;
img_offset = img_request->offset;
- rbd_assert(img_offset == bio_list->bi_sector << SECTOR_SHIFT);
resid = img_request->length;
rbd_assert(resid > 0);
+
+ if (type == OBJ_REQUEST_BIO) {
+ bio_list = data_desc;
+ rbd_assert(img_offset == bio_list->bi_sector << SECTOR_SHIFT);
+ } else {
+ rbd_assert(type == OBJ_REQUEST_PAGES);
+ pages = data_desc;
+ }
+
while (resid) {
struct ceph_osd_request *osd_req;
const char *object_name;
- unsigned int clone_size;
u64 offset;
u64 length;
@@ -1863,19 +1888,33 @@ static int rbd_img_request_fill_bio(struct
rbd_img_request *img_request,
offset = rbd_segment_offset(rbd_dev, img_offset);
length = rbd_segment_length(rbd_dev, img_offset, resid);
obj_request = rbd_obj_request_create(object_name,
- offset, length,
- OBJ_REQUEST_BIO);
+ offset, length, type);
kfree(object_name); /* object request has its own copy */
if (!obj_request)
goto out_unwind;
- rbd_assert(length <= (u64) UINT_MAX);
- clone_size = (unsigned int) length;
- obj_request->bio_list = bio_chain_clone_range(&bio_list,
- &bio_offset, clone_size,
- GFP_ATOMIC);
- if (!obj_request->bio_list)
- goto out_partial;
+ if (type == OBJ_REQUEST_BIO) {
+ unsigned int clone_size;
+
+ rbd_assert(length <= (u64)UINT_MAX);
+ clone_size = (unsigned int)length;
+ obj_request->bio_list =
+ bio_chain_clone_range(&bio_list,
+ &bio_offset,
+ clone_size,
+ GFP_ATOMIC);
+ if (!obj_request->bio_list)
+ goto out_partial;
+ } else {
+ unsigned int page_count;
+
+ obj_request->pages = pages;
+ page_count = (u32)calc_pages_for(offset, length);
+ obj_request->page_count = page_count;
+ if ((offset + length) & ~PAGE_MASK)
+ page_count--; /* more on last page */
+ pages += page_count;
+ }
osd_req = rbd_osd_req_create(rbd_dev, write_request,
obj_request);
@@ -1886,8 +1925,13 @@ static int rbd_img_request_fill_bio(struct
rbd_img_request *img_request,
osd_req_op_extent_init(osd_req, 0, opcode, offset, length,
0, 0);
- osd_req_op_extent_osd_data_bio(osd_req, 0,
- obj_request->bio_list, obj_request->length);
+ if (type == OBJ_REQUEST_BIO)
+ osd_req_op_extent_osd_data_bio(osd_req, 0,
+ obj_request->bio_list, length);
+ else
+ osd_req_op_extent_osd_data_pages(osd_req, 0,
+ obj_request->pages, length,
+ offset & ~PAGE_MASK, false, false);
if (write_request)
rbd_osd_req_format_write(obj_request);
@@ -2120,7 +2164,8 @@ static void rbd_img_parent_read(struct
rbd_obj_request *obj_request)
rbd_obj_request_get(obj_request);
img_request->obj_request = obj_request;
- result = rbd_img_request_fill_bio(img_request, obj_request->bio_list);
+ result = rbd_img_request_fill(img_request, OBJ_REQUEST_BIO,
+ obj_request->bio_list);
if (result)
goto out_err;
@@ -2425,7 +2470,8 @@ static void rbd_request_fn(struct request_queue *q)
img_request->rq = rq;
- result = rbd_img_request_fill_bio(img_request, rq->bio);
+ result = rbd_img_request_fill(img_request, OBJ_REQUEST_BIO,
+ rq->bio);
if (!result)
result = rbd_img_request_submit(img_request);
if (result)
--
1.7.9.5
--
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