rbd: move to obj_req->img_extents

In preparation for rbd "fancy" striping, replace obj_req->img_offset
with obj_req->img_extents.  A single starting offset isn't sufficient
because we want only one OSD request per object and will merge adjacent
object extents in ceph_file_to_extents().  The final object extent may
map into multiple different byte ranges in the image.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
This commit is contained in:
Ilya Dryomov 2018-02-06 19:26:33 +01:00
parent 43df3d35c0
commit 86bd7998fa

View File

@ -253,7 +253,8 @@ struct rbd_obj_request {
};
struct rbd_img_request *img_request;
u64 img_offset;
struct ceph_file_extent *img_extents;
u32 num_img_extents;
union {
struct ceph_bio_iter bio_pos;
@ -1279,14 +1280,6 @@ static void rbd_obj_zero_range(struct rbd_obj_request *obj_req, u32 off,
}
}
static bool obj_request_overlaps_parent(struct rbd_obj_request *obj_request)
{
struct rbd_device *rbd_dev = obj_request->img_request->rbd_dev;
return obj_request->img_offset <
round_up(rbd_dev->parent_overlap, rbd_obj_bytes(&rbd_dev->header));
}
static void rbd_obj_request_get(struct rbd_obj_request *obj_request)
{
dout("%s: obj %p (was %d)\n", __func__, obj_request,
@ -1415,6 +1408,12 @@ static bool rbd_obj_is_tail(struct rbd_obj_request *obj_req)
rbd_dev->layout.object_size;
}
static u64 rbd_obj_img_extents_bytes(struct rbd_obj_request *obj_req)
{
return ceph_file_extents_bytes(obj_req->img_extents,
obj_req->num_img_extents);
}
static bool rbd_img_is_write(struct rbd_img_request *img_req)
{
switch (img_req->op_type) {
@ -1544,6 +1543,7 @@ static void rbd_obj_request_destroy(struct kref *kref)
rbd_assert(0);
}
kfree(obj_request->img_extents);
if (obj_request->copyup_bvecs) {
for (i = 0; i < obj_request->copyup_bvec_count; i++) {
if (obj_request->copyup_bvecs[i].bv_page)
@ -1718,6 +1718,53 @@ static void rbd_parent_request_destroy(struct kref *kref)
rbd_img_request_destroy(kref);
}
static void prune_extents(struct ceph_file_extent *img_extents,
u32 *num_img_extents, u64 overlap)
{
u32 cnt = *num_img_extents;
/* drop extents completely beyond the overlap */
while (cnt && img_extents[cnt - 1].fe_off >= overlap)
cnt--;
if (cnt) {
struct ceph_file_extent *ex = &img_extents[cnt - 1];
/* trim final overlapping extent */
if (ex->fe_off + ex->fe_len > overlap)
ex->fe_len = overlap - ex->fe_off;
}
*num_img_extents = cnt;
}
/*
* Determine the byte range(s) covered by either just the object extent
* or the entire object in the parent image.
*/
static int rbd_obj_calc_img_extents(struct rbd_obj_request *obj_req,
bool entire)
{
struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
int ret;
if (!rbd_dev->parent_overlap)
return 0;
ret = ceph_extent_to_file(&rbd_dev->layout, obj_req->ex.oe_objno,
entire ? 0 : obj_req->ex.oe_off,
entire ? rbd_dev->layout.object_size :
obj_req->ex.oe_len,
&obj_req->img_extents,
&obj_req->num_img_extents);
if (ret)
return ret;
prune_extents(obj_req->img_extents, &obj_req->num_img_extents,
rbd_dev->parent_overlap);
return 0;
}
static void rbd_osd_req_setup_data(struct rbd_obj_request *obj_req, u32 which)
{
switch (obj_req->img_request->data_type) {
@ -1803,7 +1850,12 @@ static int rbd_obj_setup_write(struct rbd_obj_request *obj_req)
unsigned int num_osd_ops, which = 0;
int ret;
if (obj_request_overlaps_parent(obj_req)) {
/* reverse map the entire object onto the parent */
ret = rbd_obj_calc_img_extents(obj_req, true);
if (ret)
return ret;
if (obj_req->num_img_extents) {
obj_req->write_state = RBD_OBJ_WRITE_GUARD;
num_osd_ops = 3; /* stat + setallochint + write/writefull */
} else {
@ -1815,7 +1867,7 @@ static int rbd_obj_setup_write(struct rbd_obj_request *obj_req)
if (!obj_req->osd_req)
return -ENOMEM;
if (obj_request_overlaps_parent(obj_req)) {
if (obj_req->num_img_extents) {
ret = __rbd_obj_setup_stat(obj_req, which++);
if (ret)
return ret;
@ -1831,7 +1883,7 @@ static void __rbd_obj_setup_discard(struct rbd_obj_request *obj_req,
u16 opcode;
if (rbd_obj_is_entire(obj_req)) {
if (obj_request_overlaps_parent(obj_req)) {
if (obj_req->num_img_extents) {
opcode = CEPH_OSD_OP_TRUNCATE;
} else {
osd_req_op_init(obj_req->osd_req, which++,
@ -1858,11 +1910,16 @@ static int rbd_obj_setup_discard(struct rbd_obj_request *obj_req)
unsigned int num_osd_ops, which = 0;
int ret;
/* reverse map the entire object onto the parent */
ret = rbd_obj_calc_img_extents(obj_req, true);
if (ret)
return ret;
if (rbd_obj_is_entire(obj_req)) {
obj_req->write_state = RBD_OBJ_WRITE_FLAT;
num_osd_ops = 1; /* truncate/delete */
} else {
if (obj_request_overlaps_parent(obj_req)) {
if (obj_req->num_img_extents) {
obj_req->write_state = RBD_OBJ_WRITE_GUARD;
num_osd_ops = 2; /* stat + truncate/zero */
} else {
@ -1875,8 +1932,7 @@ static int rbd_obj_setup_discard(struct rbd_obj_request *obj_req)
if (!obj_req->osd_req)
return -ENOMEM;
if (!rbd_obj_is_entire(obj_req) &&
obj_request_overlaps_parent(obj_req)) {
if (!rbd_obj_is_entire(obj_req) && obj_req->num_img_extents) {
ret = __rbd_obj_setup_stat(obj_req, which++);
if (ret)
return ret;
@ -1980,8 +2036,6 @@ static int rbd_img_request_fill(struct rbd_img_request *img_request,
ceph_bvec_iter_advance(&bvec_it, length);
}
obj_request->img_offset = img_offset;
img_offset += length;
resid -= length;
}
@ -2009,14 +2063,15 @@ static void rbd_img_request_submit(struct rbd_img_request *img_request)
rbd_img_request_put(img_request);
}
static int rbd_obj_read_from_parent(struct rbd_obj_request *obj_req,
u64 img_offset, u32 bytes)
static int rbd_obj_read_from_parent(struct rbd_obj_request *obj_req)
{
struct rbd_img_request *img_req = obj_req->img_request;
struct rbd_img_request *child_img_req;
int ret;
child_img_req = rbd_parent_request_create(obj_req, img_offset, bytes);
child_img_req = rbd_parent_request_create(obj_req,
obj_req->img_extents[0].fe_off,
obj_req->img_extents[0].fe_len);
if (!child_img_req)
return -ENOMEM;
@ -2038,7 +2093,7 @@ static int rbd_obj_read_from_parent(struct rbd_obj_request *obj_req,
} else {
struct ceph_bvec_iter it = {
.bvecs = obj_req->copyup_bvecs,
.iter = { .bi_size = bytes },
.iter = { .bi_size = obj_req->img_extents[0].fe_len },
};
ret = rbd_img_request_fill(child_img_req, OBJ_REQUEST_BVECS,
@ -2059,19 +2114,23 @@ static bool rbd_obj_handle_read(struct rbd_obj_request *obj_req)
int ret;
if (obj_req->result == -ENOENT &&
obj_req->img_offset < rbd_dev->parent_overlap &&
!obj_req->tried_parent) {
u64 obj_overlap = min(obj_req->ex.oe_len,
rbd_dev->parent_overlap - obj_req->img_offset);
obj_req->tried_parent = true;
ret = rbd_obj_read_from_parent(obj_req, obj_req->img_offset,
obj_overlap);
rbd_dev->parent_overlap && !obj_req->tried_parent) {
/* reverse map this object extent onto the parent */
ret = rbd_obj_calc_img_extents(obj_req, false);
if (ret) {
obj_req->result = ret;
return true;
}
return false;
if (obj_req->num_img_extents) {
obj_req->tried_parent = true;
ret = rbd_obj_read_from_parent(obj_req);
if (ret) {
obj_req->result = ret;
return true;
}
return false;
}
}
/*
@ -2189,11 +2248,12 @@ static int setup_copyup_bvecs(struct rbd_obj_request *obj_req, u64 obj_overlap)
static int rbd_obj_handle_write_guard(struct rbd_obj_request *obj_req)
{
struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
u64 img_offset;
u64 obj_overlap;
int ret;
if (!obj_request_overlaps_parent(obj_req)) {
rbd_assert(obj_req->num_img_extents);
prune_extents(obj_req->img_extents, &obj_req->num_img_extents,
rbd_dev->parent_overlap);
if (!obj_req->num_img_extents) {
/*
* The overlap has become 0 (most likely because the
* image has been flattened). Use rbd_obj_issue_copyup()
@ -2207,29 +2267,12 @@ static int rbd_obj_handle_write_guard(struct rbd_obj_request *obj_req)
return rbd_obj_issue_copyup(obj_req, 0);
}
/*
* Determine the byte range covered by the object in the
* child image to which the original request was to be sent.
*/
img_offset = obj_req->img_offset - obj_req->ex.oe_off;
obj_overlap = rbd_dev->layout.object_size;
/*
* There is no defined parent data beyond the parent
* overlap, so limit what we read at that boundary if
* necessary.
*/
if (img_offset + obj_overlap > rbd_dev->parent_overlap) {
rbd_assert(img_offset < rbd_dev->parent_overlap);
obj_overlap = rbd_dev->parent_overlap - img_offset;
}
ret = setup_copyup_bvecs(obj_req, obj_overlap);
ret = setup_copyup_bvecs(obj_req, rbd_obj_img_extents_bytes(obj_req));
if (ret)
return ret;
obj_req->write_state = RBD_OBJ_WRITE_COPYUP;
return rbd_obj_read_from_parent(obj_req, img_offset, obj_overlap);
return rbd_obj_read_from_parent(obj_req);
}
static bool rbd_obj_handle_write(struct rbd_obj_request *obj_req)
@ -2335,6 +2378,9 @@ static void rbd_img_end_child_request(struct rbd_img_request *img_req)
struct rbd_obj_request *obj_req = img_req->obj_request;
rbd_assert(test_bit(IMG_REQ_CHILD, &img_req->flags));
rbd_assert((!img_req->result &&
img_req->xferred == rbd_obj_img_extents_bytes(obj_req)) ||
(img_req->result < 0 && !img_req->xferred));
obj_req->result = img_req->result;
obj_req->xferred = img_req->xferred;