mirrors/scst
1
0
Fork 0
mirror of https://github.com/SCST-project/scst.git synced 2026-05-14 09:11:27 +00:00
Code Issues Packages Projects Releases Wiki Activity

iscsi-scst: Refactor sendpage functionality in write_data()

Browse Source 
This patch carries out a refactoring of the sendpage functionality in
the write_data() function:

1. Reorganize the logic used to select the sock_sendpage function.
2. Streamline the data sending loop by reducing conditional branches and
   eliminating labels.
3. Adjust the error handling for -EINTR and -EAGAIN to make the code
   cleaner and easier to follow.

This patch doesn't change any functionality.
This commit is contained in:
Gleb Chesnokov
2023-07-06 20:03:56 +03:00
parent c1f7510d80
commit 324bf62e28
1 changed files with 41 additions and 67 deletions
Download Patch File Download Diff File Expand all files Collapse all files

108
iscsi-scst/kernel/nthread.c
View File

@@ -1185,15 +1185,15 @@ static int write_data(struct iscsi_conn *conn)
}
sock = conn->sock;
if (parent_req->scst_cmd &&
parent_req->scst_state != ISCSI_CMD_STATE_AEN &&
scst_cmd_get_dh_data_buff_alloced(parent_req->scst_cmd))
sock_sendpage = sock_no_sendpage;
else
sock_sendpage = sock->ops->sendpage;
flags = MSG_DONTWAIT;
if (sg != write_cmnd->rsp_sg &&
(!parent_req->scst_cmd || parent_req->scst_state == ISCSI_CMD_STATE_AEN ||
!scst_cmd_get_dh_data_buff_alloced(parent_req->scst_cmd)))
sock_sendpage = sock->ops->sendpage;
else
sock_sendpage = sock_no_sendpage;
sg_size = size;
if (sg != write_cmnd->rsp_sg) {
@@ -1222,7 +1222,6 @@ static int write_data(struct iscsi_conn *conn)
}
length = sg[idx].length - offset;
offset += sg[idx].offset;
sock_sendpage = sock_no_sendpage;
TRACE_WRITE("rsp_sg: write_offset %d, sg_size %lu, idx %d, offset %d, length %lu",
conn->write_offset, sg_size, idx, offset, length);
}
@@ -1230,84 +1229,59 @@ static int write_data(struct iscsi_conn *conn)
while (true) {
sendsize = min_t(size_t, size, length);
if (size <= sendsize) {
retry2:
res = sock_sendpage(sock, page, offset, size, flags);
if (sendsize == size)
flags &= ~MSG_MORE;
else
flags |= MSG_MORE;
while (sendsize) {
res = sock_sendpage(sock, page, offset, sendsize, flags);
TRACE_WRITE(
"Final %s sid %#Lx, cid %u, res %d (page index %lu, offset %u, size %lu, cmd %p, page %p)",
"%s sid %#Lx, cid %u, res %d (page index %lu, offset %u, sendsize %lu, size %lu, cmd %p, page %p)",
(sock_sendpage != sock_no_sendpage) ?
"sendpage" : "sock_no_sendpage",
(unsigned long long)conn->session->sid,
conn->cid, res, page->index,
offset, size, write_cmnd, page);
(unsigned long long)conn->session->sid, conn->cid,
res, page->index, offset, sendsize, size,
write_cmnd, page);
if (unlikely(res <= 0)) {
if (res == -EINTR)
goto retry2;
else
goto out_res;
continue;
if (res == -EAGAIN) {
conn->write_offset += sg_size - size;
goto out_iov;
}
goto out_err;
}
if (res == size) {
conn->write_size = 0;
res = saved_size;
goto out;
}
offset += res;
size -= res;
goto retry2;
}
retry1:
res = sock_sendpage(sock, page, offset, sendsize, flags | MSG_MORE);
TRACE_WRITE(
"%s sid %#Lx, cid %u, res %d (page index %lu, offset %u, sendsize %lu, size %lu, cmd %p, page %p)",
(sock_sendpage != sock_no_sendpage) ?
"sendpage" : "sock_no_sendpage",
(unsigned long long)conn->session->sid, conn->cid,
res, page->index, offset, sendsize, size,
write_cmnd, page);
if (unlikely(res <= 0)) {
if (res == -EINTR)
goto retry1;
else
goto out_res;
}
size -= res;
if (res == sendsize) {
idx++;
EXTRACHECKS_BUG_ON(idx >= ref_cmd->sg_cnt);
page = sg_page(&sg[idx]);
length = sg[idx].length;
offset = sg[idx].offset;
} else {
offset += res;
sendsize -= res;
goto retry1;
size -= res;
}
}
out_off:
conn->write_offset += sg_size - size;
if (size == 0)
goto out_iov;
idx++;
EXTRACHECKS_BUG_ON(idx >= ref_cmd->sg_cnt);
page = sg_page(&sg[idx]);
length = sg[idx].length;
offset = sg[idx].offset;
}
out_iov:
conn->write_size = size;
if ((saved_size == size) && res == -EAGAIN)
goto out;
res = saved_size - size;
if (res != -EAGAIN || saved_size != size)
res = saved_size - size;
out:
TRACE_EXIT_RES(res);
return res;
out_res:
if (res == -EAGAIN)
goto out_off;
/* else go through */
out_err:
#ifndef CONFIG_SCST_DEBUG
if (!conn->closing) {