[stgt] [PATCH 2/3] bs_sheepdog.c: use multithread for scsi command submission
Hitoshi Mitake
mitake.hitoshi at gmail.com
Sun Oct 6 17:27:51 CEST 2013
Current bs_sheepdog.c uses only one thread per logical unit. This
patch let it use nr_iothreads as a number of threads per logical
unit by per thread connection and rwlocking inode object. This change
is effective in the case of reading one logical unit by many clients.
Signed-off-by: Hitoshi Mitake <mitake.hitoshi at lab.ntt.co.jp>
---
usr/bs_sheepdog.c | 148 +++++++++++++++++++++++++++++++++++++++++++++++++-----
1 file changed, 136 insertions(+), 12 deletions(-)
diff --git a/usr/bs_sheepdog.c b/usr/bs_sheepdog.c
index 87c7986..329cebb 100644
--- a/usr/bs_sheepdog.c
+++ b/usr/bs_sheepdog.c
@@ -31,6 +31,7 @@
#include <netinet/tcp.h>
#include <sys/epoll.h>
#include <sys/socket.h>
+#include <pthread.h>
#include "list.h"
#include "tgtd.h"
@@ -209,13 +210,29 @@ struct sheepdog_inode {
#define SD_INODE_SIZE (sizeof(struct sheepdog_inode))
-struct sheepdog_access_info {
+struct sheepdog_fd_list {
int fd;
+ pthread_t id;
+
+ struct list_head list;
+};
+
+struct sheepdog_access_info {
+ /*
+ * maximum length of fd_list_head: nr_iothreads + 1
+ * (+ 1 is for main thread)
+ *
+ * TODO: more effective data structure for handling massive parallel
+ * access
+ */
+ struct list_head fd_list_head;
+ pthread_rwlock_t fd_list_lock;
uint32_t min_dirty_data_idx;
uint32_t max_dirty_data_idx;
struct sheepdog_inode inode;
+ pthread_rwlock_t inode_lock;
};
static inline int is_data_obj_writeable(struct sheepdog_inode *inode,
@@ -347,6 +364,64 @@ success:
return fd;
}
+static int get_my_fd(struct sheepdog_access_info *ai)
+{
+ pthread_t self_id = pthread_self();
+ struct sheepdog_fd_list *p;
+ int fd;
+
+ pthread_rwlock_rdlock(&ai->fd_list_lock);
+ list_for_each_entry(p, &ai->fd_list_head, list) {
+ if (p->id == self_id) {
+ pthread_rwlock_unlock(&ai->fd_list_lock);
+ return p->fd;
+ }
+ }
+ pthread_rwlock_unlock(&ai->fd_list_lock);
+
+ fd = connect_to_sdog(NULL, NULL);
+ if (fd < 0)
+ return -1;
+
+ p = zalloc(sizeof(*p));
+ if (!p) {
+ close(fd);
+ return -1;
+ }
+
+ p->id = self_id;
+ p->fd = fd;
+ INIT_LIST_HEAD(&p->list);
+
+ pthread_rwlock_wrlock(&ai->fd_list_lock);
+ list_add_tail(&p->list, &ai->fd_list_head);
+ pthread_rwlock_unlock(&ai->fd_list_lock);
+
+ return p->fd;
+}
+
+static void close_my_fd(struct sheepdog_access_info *ai, int fd)
+{
+ struct sheepdog_fd_list *p;
+ int closed = 0;
+
+ pthread_rwlock_wrlock(&ai->fd_list_lock);
+ list_for_each_entry(p, &ai->fd_list_head, list) {
+ if (p->fd == fd) {
+ close(fd);
+ list_del(&p->list);
+ free(p);
+ closed = 1;
+
+ break;
+ }
+ }
+ pthread_rwlock_unlock(&ai->fd_list_lock);
+
+ if (!closed)
+ eprintf("unknown fd to close: %d\n", fd);
+}
+
static int do_read(int sockfd, void *buf, int len)
{
int ret;
@@ -486,6 +561,7 @@ static int reload_inode(struct sheepdog_access_info *ai)
int ret;
char tag[SD_MAX_VDI_TAG_LEN];
uint32_t vid;
+ int fd;
memset(tag, 0, sizeof(tag));
@@ -493,7 +569,11 @@ static int reload_inode(struct sheepdog_access_info *ai)
if (ret)
return -1;
- read_object(ai->fd, (char *)&ai->inode, vid_to_vdi_oid(vid),
+ fd = get_my_fd(ai);
+ if (fd < 0)
+ return -1;
+
+ read_object(fd, (char *)&ai->inode, vid_to_vdi_oid(vid),
ai->inode.nr_copies, SD_INODE_SIZE, 0);
return 0;
}
@@ -573,6 +653,7 @@ static int sd_sync(struct sheepdog_access_info *ai)
struct sheepdog_obj_req hdr;
struct sheepdog_obj_rsp *rsp = (struct sheepdog_obj_rsp *)&hdr;
unsigned int wlen = 0, rlen;
+ int fd;
memset(&hdr, 0, sizeof(hdr));
@@ -580,7 +661,11 @@ static int sd_sync(struct sheepdog_access_info *ai)
hdr.opcode = SD_OP_FLUSH_VDI;
hdr.oid = vid_to_vdi_oid(ai->inode.vdi_id);
- ret = do_req(ai->fd, (struct sheepdog_req *)&hdr, NULL, &wlen, &rlen);
+ fd = get_my_fd(ai);
+ if (fd < 0)
+ return -1;
+
+ ret = do_req(fd, (struct sheepdog_req *)&hdr, NULL, &wlen, &rlen);
if (ret) {
eprintf("failed to send a request to the sheep\n");
return -1;
@@ -605,6 +690,7 @@ static int update_inode(struct sheepdog_access_info *ai)
int ret = 0;
uint64_t oid = vid_to_vdi_oid(ai->inode.vdi_id);
uint32_t min, max, offset, data_len;
+ int fd;
min = ai->min_dirty_data_idx;
max = ai->max_dirty_data_idx;
@@ -616,7 +702,12 @@ static int update_inode(struct sheepdog_access_info *ai)
min * sizeof(ai->inode.data_vdi_id[0]);
data_len = (max - min + 1) * sizeof(ai->inode.data_vdi_id[0]);
- ret = write_object(ai->fd, (char *)&ai->inode + offset, oid,
+ fd = get_my_fd(ai);
+ if (fd < 0) {
+ ret = -1;
+ goto end;
+ }
+ ret = write_object(fd, (char *)&ai->inode + offset, oid,
ai->inode.nr_copies, data_len, offset,
0, 0, 0, NULL);
if (ret < 0)
@@ -643,6 +734,16 @@ static int sd_io(struct sheepdog_access_info *ai, int write, char *buf, int len,
uint16_t flags = 0;
int need_update_inode = 0, need_reload_inode;
int nr_copies = ai->inode.nr_copies;
+ int fd;
+
+ fd = get_my_fd(ai);
+ if (fd < 0)
+ return -1;
+
+ if (write)
+ pthread_rwlock_wrlock(&ai->inode_lock);
+ else
+ pthread_rwlock_rdlock(&ai->inode_lock);
for (; idx < max; idx++) {
size = SD_DATA_OBJ_SIZE - obj_offset;
@@ -676,7 +777,7 @@ retry:
}
need_reload_inode = 0;
- ret = write_object(ai->fd, buf + (len - rest),
+ ret = write_object(fd, buf + (len - rest),
oid, nr_copies, size,
obj_offset, create,
old_oid, flags, &need_reload_inode);
@@ -698,7 +799,7 @@ retry:
goto done;
}
- ret = read_object(ai->fd, buf + (len - rest),
+ ret = read_object(fd, buf + (len - rest),
oid, nr_copies, size,
obj_offset);
}
@@ -716,6 +817,8 @@ done:
if (need_update_inode)
ret = update_inode(ai);
+ pthread_rwlock_unlock(&ai->inode_lock);
+
return ret;
}
@@ -780,14 +883,12 @@ static int sd_open(struct sheepdog_access_info *ai, char *filename, int flags)
if (ret)
goto out;
- fd = connect_to_sdog(NULL, NULL);
+ fd = get_my_fd(ai);
if (fd < 0) {
eprintf("failed to connect\n");
goto out;
}
- ai->fd = fd;
-
ai->min_dirty_data_idx = UINT32_MAX;
ai->max_dirty_data_idx = 0;
@@ -808,19 +909,26 @@ static void sd_close(struct sheepdog_access_info *ai)
struct sheepdog_vdi_rsp *rsp = (struct sheepdog_vdi_rsp *)&hdr;
unsigned int wlen = 0, rlen;
int ret;
+ int fd;
memset(&hdr, 0, sizeof(hdr));
hdr.opcode = SD_OP_RELEASE_VDI;
hdr.vdi_id = ai->inode.vdi_id;
- ret = do_req(ai->fd, (struct sheepdog_req *)&hdr, NULL, &wlen, &rlen);
+ fd = get_my_fd(ai);
+ if (fd < 0) {
+ eprintf("couldn't acquire fd for closing sheepdog VDI\n");
+ return;
+ }
+
+ ret = do_req(fd, (struct sheepdog_req *)&hdr, NULL, &wlen, &rlen);
if (!ret && rsp->result != SD_RES_SUCCESS &&
rsp->result != SD_RES_VDI_NOT_LOCKED)
eprintf("%s, %s", sd_strerror(rsp->result), ai->inode.name);
- close(ai->fd);
+ close_my_fd(ai, fd);
}
static void set_medium_error(int *result, uint8_t *key, uint16_t *asc)
@@ -913,15 +1021,31 @@ static void bs_sheepdog_close(struct scsi_lu *lu)
static tgtadm_err bs_sheepdog_init(struct scsi_lu *lu)
{
struct bs_thread_info *info = BS_THREAD_I(lu);
+ struct sheepdog_access_info *ai =
+ (struct sheepdog_access_info *)(info + 1);
- return bs_thread_open(info, bs_sheepdog_request, 1);
+ INIT_LIST_HEAD(&ai->fd_list_head);
+ pthread_rwlock_init(&ai->fd_list_lock, NULL);
+ pthread_rwlock_init(&ai->inode_lock, NULL);
+
+ return bs_thread_open(info, bs_sheepdog_request, nr_iothreads);
}
static void bs_sheepdog_exit(struct scsi_lu *lu)
{
struct bs_thread_info *info = BS_THREAD_I(lu);
+ struct sheepdog_access_info *ai =
+ (struct sheepdog_access_info *)(info + 1);
+
+ struct sheepdog_fd_list *p;
bs_thread_close(info);
+
+ list_for_each_entry(p, &ai->fd_list_head, list) {
+ close(p->fd);
+ list_del(&p->list);
+ free(p);
+ }
}
static struct backingstore_template sheepdog_bst = {
--
1.8.1.2
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