configurable sftp_buf_sz.

default value 131072 is derived from qemu/block/ssh.c.
we need more investigaion.

5 files changed, 56 insertions, 42 deletions

diff --git a/src/file.c b/src/file.c
index 9250dff..aeb86f4 100644
--- a/src/file.c
+++ b/src/file.c
@@ -588,19 +588,23 @@ static sftp_file chunk_open_remote(const char *path, int flags, mode_t mode, siz
 }
 
 static int chunk_copy_internal(struct chunk *c, int fd, sftp_file sf,
-                               size_t buf_sz, bool reverse, size_t *counter)
+                               size_t sftp_buf_sz, size_t io_buf_sz,
+                               bool reverse, size_t *counter)
 {
         int remaind, read_bytes, write_bytes;
-        char buf[buf_sz];
+        char buf[io_buf_sz];
 
-        /* if reverse is false, copy fd->sf. if true, copy sf->fd */
+        /* if reverse is false, copy fd->sf (local to remote).
+         * if reverse is true, copy sf->fd (remote to local)
+         */
 
         for (remaind = c->len; remaind > 0;) {
 
                 if (!reverse)
-                        read_bytes = read(fd, buf, min(remaind, buf_sz));
+                        read_bytes = read(fd, buf, min(remaind, io_buf_sz));
                 else
-                        read_bytes = sftp_read2(sf, buf, min(remaind, buf_sz));
+                        read_bytes = sftp_read2(sf, buf, min(remaind, io_buf_sz),
+                                                sftp_buf_sz);
 
                 if (read_bytes < 0) {
                         pr_err("failed to read %s: %s\n", c->f->dst_path,
@@ -610,7 +614,7 @@ static int chunk_copy_internal(struct chunk *c, int fd, sftp_file sf,
                 }
 
                 if (!reverse)
-                        write_bytes = sftp_write2(sf, buf, read_bytes);
+                        write_bytes = sftp_write2(sf, buf, read_bytes, sftp_buf_sz);
                 else
                         write_bytes = write(fd, buf, read_bytes);
 
@@ -633,7 +637,8 @@ static int chunk_copy_internal(struct chunk *c, int fd, sftp_file sf,
         return 0;
 }
 
-static int chunk_copy_local_to_remote(struct chunk *c, sftp_session sftp, size_t buf_sz,
+static int chunk_copy_local_to_remote(struct chunk *c, sftp_session sftp,
+                                      size_t sftp_buf_sz, size_t io_buf_sz,
                                       size_t *counter)
 {
         struct file *f = c->f;
@@ -657,7 +662,8 @@ static int chunk_copy_local_to_remote(struct chunk *c, sftp_session sftp, size_t
                 goto out;
         }
 
-        if ((ret = chunk_copy_internal(c, fd, sf, buf_sz, false, counter)) < 0)
+        ret = chunk_copy_internal(c, fd, sf, sftp_buf_sz, io_buf_sz, false, counter);
+        if (ret< 0)
                 goto out;
 
         if ((mode = chunk_get_mode(f->path, NULL)) < 0) {
@@ -676,7 +682,8 @@ out:
         return ret;
 }
 
-static int chunk_copy_remote_to_local(struct chunk *c, sftp_session sftp, size_t buf_sz,
+static int chunk_copy_remote_to_local(struct chunk *c, sftp_session sftp,
+                                      size_t sftp_buf_sz, size_t io_buf_sz,
                                       size_t *counter)
 {
         struct file *f = c->f;
@@ -700,7 +707,8 @@ static int chunk_copy_remote_to_local(struct chunk *c, sftp_session sftp, size_t
                 goto out;
         }
 
-        if ((ret = chunk_copy_internal(c, fd, sf, buf_sz, true, counter)) < 0)
+        ret = chunk_copy_internal(c, fd, sf, sftp_buf_sz, io_buf_sz, true, counter);
+        if (ret< 0)
                 goto out;
 
 out:
@@ -714,7 +722,8 @@ out:
 
 
 
-int chunk_copy(struct chunk *c, sftp_session sftp, size_t buf_sz, size_t *counter)
+int chunk_copy(struct chunk *c, sftp_session sftp, size_t sftp_buf_sz, size_t io_buf_sz,
+               size_t *counter)
 {
         struct file *f = c->f;
         int ret = 0;
@@ -724,9 +733,11 @@ int chunk_copy(struct chunk *c, sftp_session sftp, size_t buf_sz, size_t *counte
                  f->dst_path, f->dst_remote ? "(remote)" : "(local)", c->off);
 
         if (f->dst_remote)
-                ret = chunk_copy_local_to_remote(c, sftp, buf_sz, counter);
+                ret = chunk_copy_local_to_remote(c, sftp,
+                                                 sftp_buf_sz, io_buf_sz, counter);
         else
-                ret = chunk_copy_remote_to_local(c, sftp, buf_sz, counter);
+                ret = chunk_copy_remote_to_local(c, sftp,
+                                                 sftp_buf_sz, io_buf_sz, counter);
 
         if (ret < 0)
                 return ret;
diff --git a/src/file.h b/src/file.h
index 9727d15..a598ce8 100644
--- a/src/file.h
+++ b/src/file.h
@@ -70,7 +70,8 @@ int chunk_fill(struct list_head *file_list, struct list_head *chunk_list,
 
 struct chunk *chunk_acquire(struct list_head *chunk_list);
 int chunk_prepare(struct chunk *c, sftp_session sftp);
-int chunk_copy(struct chunk *c, sftp_session sftp, size_t buf_sz, size_t *counter);
+int chunk_copy(struct chunk *c, sftp_session sftp,
+               size_t sftp_buf_sz, size_t io_buf_sz, size_t *counter);
 
 #ifdef DEBUG
 void file_dump(struct list_head *file_list);
diff --git a/src/main.c b/src/main.c
index e307ce4..43fdb86 100644
--- a/src/main.c
+++ b/src/main.c
@@ -19,22 +19,22 @@ int verbose = 0; /* util.h */
 
 
 #define DEFAULT_MIN_CHUNK_SZ    (64 << 20)      /* 64MB */
-#define DEFAULT_BUF_SZ          32768           /* CHANNEL_MAX_PACKET in libssh */
-/* XXX: passing over CHANNEL_MAX_PACKET bytes to sftp_write stalls */
+#define DEFAULT_SFTP_BUF_SZ     131072          /* derived from qemu/block/ssh.c */
+#define DEFAULT_IO_BUF_SZ       DEFAULT_SFTP_BUF_SZ
+/* XXX: need to investigate max buf size for sftp_read/sftp_write */
 
 struct sscp {
         char                    *host;  /* remote host (and username) */
         struct ssh_opts         *opts;  /* ssh parameters */
         sftp_session            ctrl;   /* control sftp session */
 
-
         struct list_head        file_list;
         struct list_head        chunk_list;     /* stack of chunks */
         lock                    chunk_lock;  /* lock for chunk list */
 
         char    *target;
 
-        int     buf_sz;
+        int     sftp_buf_sz, io_buf_sz;
 };
 
 struct sscp_thread {
@@ -69,7 +69,7 @@ void usage(bool print_help) {
         printf("sscp: super scp, copy files over multiple ssh connections\n"
                "\n"
                "Usage: sscp [Cvh] [-n max_conns] [-s min_chunk_sz] [-S max_chunk_sz]\n"
-               "            [-b buf_sz]\n"
+               "            [-b sftp_buf_sz] [-B io_buf_sz]\n"
                "            [-l login_name] [-p port] [-i identity_file]\n"
                "            [-c cipher_spec] source ... target_directory\n"
                "\n");
@@ -80,9 +80,10 @@ void usage(bool print_help) {
         printf("    -n NR_CONNECTIONS  max number of connections (default: # of cpu cores)\n"
                "    -s MIN_CHUNK_SIZE  min chunk size (default: 64MB)\n"
                "    -S MAX_CHUNK_SIZE  max chunk size (default: filesize / nr_conn)\n"
-               "    -b BUFFER_SIZE     buffer size for read/write (default 32768B)\n"
+               "    -b SFTP_BUF_SIZE   buf size for sftp_read/write (default 131072B)\n"
+               "    -B IO_BUF_SIZE     buf size for read/write (default 131072B)\n"
                "                       Note that this value is derived from\n"
-               "                       CHANNEL_MAX_PACKET in libssh.\n"
+               "                       qemu/block/ssh.c. need investigation...\n"
                "\n"
                "    -l LOGIN_NAME      login name\n"
                "    -p PORT            port number\n"
@@ -157,11 +158,12 @@ int main(int argc, char **argv)
         INIT_LIST_HEAD(&sscp.file_list);
         INIT_LIST_HEAD(&sscp.chunk_list);
         lock_init(&sscp.chunk_lock);
-        sscp.buf_sz = DEFAULT_BUF_SZ;
+        sscp.sftp_buf_sz = DEFAULT_SFTP_BUF_SZ;
+        sscp.io_buf_sz = DEFAULT_IO_BUF_SZ;
 
         nr_threads = nr_cpus();
 
-	while ((ch = getopt(argc, argv, "n:s:S:b:l:p:i:c:Cvh")) != -1) {
+	while ((ch = getopt(argc, argv, "n:s:S:b:B:l:p:i:c:Cvh")) != -1) {
 		switch (ch) {
                 case 'n':
                         nr_threads = atoi(optarg);
@@ -201,8 +203,15 @@ int main(int argc, char **argv)
                         }
                         break;
                 case 'b':
-                        sscp.buf_sz = atoi(optarg);
-                        if (sscp.buf_sz < 1) {
+                        sscp.sftp_buf_sz = atoi(optarg);
+                        if (sscp.sftp_buf_sz < 1) {
+                                pr_err("invalid buffer size: %s\n", optarg);
+                                return -1;
+                        }
+                        break;
+                case 'B':
+                        sscp.io_buf_sz = atoi(optarg);
+                        if (sscp.io_buf_sz < 1) {
                                 pr_err("invalid buffer size: %s\n", optarg);
                                 return -1;
                         }
@@ -373,7 +382,8 @@ void *sscp_copy_thread(void *arg)
                 if (chunk_prepare(c, sftp) < 0)
                         break;
 
-                if (chunk_copy(c, sftp, sscp->buf_sz, &t->done) < 0)
+                if (chunk_copy(c, sftp,
+                               sscp->sftp_buf_sz, sscp->io_buf_sz, &t->done) < 0)
                         break;
         }
 
diff --git a/src/ssh.c b/src/ssh.c
index 536b63e..b64e0a9 100644
--- a/src/ssh.c
+++ b/src/ssh.c
@@ -245,21 +245,13 @@ void ssh_sftp_close(sftp_session sftp)
 }
 
 
-/* from libssh/src/channels.c:
- *
- * All implementations MUST be able to process packets with an
- * uncompressed payload length of 32768 bytes or less and a total packet
- * size of 35000 bytes or less.
- */
-#define CHANNEL_MAX_PACKET 32768
-
-int sftp_write2(sftp_file sf, const void *buf, size_t len)
+int sftp_write2(sftp_file sf, const void *buf, size_t len, size_t sftp_buf_sz)
 {
-        int n, ret, nbytes;
+        int ret, nbytes;
 
         for (nbytes = 0; nbytes < len;) {
                 ret = sftp_write(sf, buf + nbytes,
-                                 min(len - nbytes, CHANNEL_MAX_PACKET));
+                                 min(len - nbytes, sftp_buf_sz));
                 if (ret < 0)
                         return ret;
                 nbytes += ret;
@@ -267,13 +259,13 @@ int sftp_write2(sftp_file sf, const void *buf, size_t len)
         return nbytes;
 }
 
-int sftp_read2(sftp_file sf, void *buf, size_t len)
+int sftp_read2(sftp_file sf, void *buf, size_t len, size_t sftp_buf_sz)
 {
-        int n, ret, nbytes;
+        int ret, nbytes;
 
         for (nbytes = 0; nbytes < len;) {
                 ret = sftp_read(sf, buf + nbytes,
-                                min(len - nbytes, CHANNEL_MAX_PACKET));
+                                min(len - nbytes, sftp_buf_sz));
                 if (ret < 0)
                         return ret;
                 nbytes += ret;
diff --git a/src/ssh.h b/src/ssh.h
index 7c57999..fcee29d 100644
--- a/src/ssh.h
+++ b/src/ssh.h
@@ -25,7 +25,7 @@ void ssh_sftp_close(sftp_session sftp);
 #define sftp_ssh(sftp) (sftp)->session
 
 /* wrapping multiple sftp_read|write */
-int sftp_write2(sftp_file sf, const void *buf, size_t len);
-int sftp_read2(sftp_file sf, void *buf, size_t len);
+int sftp_write2(sftp_file sf, const void *buf, size_t len, size_t sftp_buf_sz);
+int sftp_read2(sftp_file sf, void *buf, size_t len, size_t sftp_buf_sz);
 
 #endif /* _SSH_H_ */