return ret_fd;
}
+
+/**
+ * Only talloc the spill buffer once (reallocing when necessary).
+ */
+static char *get_spill_buffer(size_t new_count)
+{
+ static int cur_count = 0;
+ static char *spill_buffer = NULL;
+
+ /* If a sufficiently sized buffer exists, just return. */
+ if (new_count <= cur_count) {
+ SMB_ASSERT(spill_buffer);
+ return spill_buffer;
+ }
+
+ /* Allocate the first time. */
+ if (cur_count == 0) {
+ SMB_ASSERT(!spill_buffer);
+ spill_buffer = talloc_array(NULL, char, new_count);
+ if (spill_buffer) {
+ cur_count = new_count;
+ }
+ return spill_buffer;
+ }
+
+ /* A buffer exists, but it's not big enough, so realloc. */
+ SMB_ASSERT(spill_buffer);
+ spill_buffer = talloc_realloc(NULL, spill_buffer, char, new_count);
+ if (spill_buffer) {
+ cur_count = new_count;
+ }
+ return spill_buffer;
+}
+
+/**
+ * recvfile does zero-copy writes given an fd to write to, and a socket with
+ * some data to write. If recvfile read more than it was able to write, it
+ * spills the data into a buffer. After first reading any additional data
+ * from the socket into the buffer, the spill buffer is then written with a
+ * standard pwrite.
+ */
+ssize_t onefs_sys_recvfile(int fromfd, int tofd, SMB_OFF_T offset,
+ size_t count)
+{
+ char *spill_buffer = NULL;
+ bool socket_drained = false;
+ int ret;
+ off_t total_rbytes = 0;
+ off_t total_wbytes = 0;
+ off_t rbytes;
+ off_t wbytes;
+
+ DEBUG(10,("onefs_recvfile: from = %d, to = %d, offset=%llu, count = "
+ "%lu\n", fromfd, tofd, offset, count));
+
+ if (count == 0) {
+ return 0;
+ }
+
+ /*
+ * Setup up a buffer for recvfile to spill data that has been read
+ * from the socket but not written.
+ */
+ spill_buffer = get_spill_buffer(count);
+ if (spill_buffer == NULL) {
+ ret = -1;
+ goto out;
+ }
+
+ /*
+ * Keep trying recvfile until:
+ * - There is no data left to read on the socket, or
+ * - bytes read != bytes written, or
+ * - An error is returned that isn't EINTR/EAGAIN
+ */
+ do {
+ /* Keep track of bytes read/written for recvfile */
+ rbytes = 0;
+ wbytes = 0;
+
+ DEBUG(10, ("calling recvfile loop, offset + total_wbytes = "
+ "%llu, count - total_rbytes = %llu\n",
+ offset + total_wbytes, count - total_rbytes));
+
+ ret = recvfile(tofd, fromfd, offset + total_wbytes,
+ count - total_wbytes, &rbytes, &wbytes, 0,
+ spill_buffer);
+
+ DEBUG(10, ("recvfile ret = %d, errno = %d, rbytes = %llu, "
+ "wbytes = %llu\n", ret, ret >= 0 ? 0 : errno,
+ rbytes, wbytes));
+
+ /* Update our progress so far */
+ total_rbytes += rbytes;
+ total_wbytes += wbytes;
+
+ } while ((count - total_rbytes) && (rbytes == wbytes) &&
+ (ret == -1 && (errno == EINTR || errno == EAGAIN)));
+
+ DEBUG(10, ("total_rbytes = %llu, total_wbytes = %llu\n",
+ total_rbytes, total_wbytes));
+
+ /* Log if recvfile didn't write everything it read. */
+ if (total_rbytes != total_wbytes) {
+ DEBUG(0, ("partial recvfile: total_rbytes=%llu but "
+ "total_wbytes=%llu, diff = %llu\n", total_rbytes,
+ total_wbytes, total_rbytes - total_wbytes));
+ SMB_ASSERT(total_rbytes > total_wbytes);
+ }
+
+ /*
+ * If there is still data on the socket, read it off.
+ */
+ while (total_rbytes < count) {
+
+ DEBUG(0, ("shallow recvfile, reading %llu\n",
+ count - total_rbytes));
+
+ /*
+ * Read the remaining data into the spill buffer. recvfile
+ * may already have some data in the spill buffer, so start
+ * filling the buffer at total_rbytes - total_wbytes.
+ */
+ ret = sys_read(fromfd,
+ spill_buffer + (total_rbytes - total_wbytes),
+ count - total_rbytes);
+
+ if (ret == -1) {
+ DEBUG(0, ("shallow recvfile read failed: %s\n",
+ strerror(errno)));
+ /* Socket is dead, so treat as if it were drained. */
+ socket_drained = true;
+ goto out;
+ }
+
+ /* Data was read so update the rbytes */
+ total_rbytes += ret;
+ }
+
+ if (total_rbytes != count) {
+ smb_panic("Unread recvfile data still on the socket!");
+ }
+
+ /*
+ * Now write any spilled data + the extra data read off the socket.
+ */
+ while (total_wbytes < count) {
+
+ DEBUG(0, ("partial recvfile, writing %llu\n", count - total_wbytes));
+
+ ret = sys_pwrite(tofd, spill_buffer, count - total_wbytes,
+ offset + total_wbytes);
+
+ if (ret == -1) {
+ DEBUG(0, ("partial recvfile write failed: %s\n",
+ strerror(errno)));
+ goto out;
+ }
+
+ /* Data was written so update the wbytes */
+ total_wbytes += ret;
+ }
+
+ /* Success! */
+ ret = total_wbytes;
+
+out:
+ /* Make sure we always try to drain the socket. */
+ if (!socket_drained && count - total_rbytes) {
+ int saved_errno = errno;
+
+ if (drain_socket(fromfd, count - total_rbytes) !=
+ count - total_rbytes) {
+ /* Socket is dead! */
+ DEBUG(0, ("drain socket failed: %d\n", errno));
+ }
+ errno = saved_errno;
+ }
+
+ return ret;
+}
return SMB_VFS_NEXT_OPEN(handle, fname, fsp, flags, mode);
}
+static ssize_t onefs_recvfile(vfs_handle_struct *handle, int fromfd,
+ files_struct *tofsp, SMB_OFF_T offset,
+ size_t count)
+{
+ ssize_t result;
+
+ START_PROFILE_BYTES(syscall_recvfile, count);
+ result = onefs_sys_recvfile(fromfd, tofsp->fh->fd, offset, count);
+ END_PROFILE(syscall_recvfile);
+ return result;
+}
+
static uint64_t onefs_get_alloc_size(struct vfs_handle_struct *handle,
files_struct *fsp,
const SMB_STRUCT_STAT *sbuf)
SMB_VFS_LAYER_OPAQUE},
{SMB_VFS_OP(onefs_close), SMB_VFS_OP_CLOSE,
SMB_VFS_LAYER_TRANSPARENT},
+ {SMB_VFS_OP(onefs_recvfile), SMB_VFS_OP_RECVFILE,
+ SMB_VFS_LAYER_OPAQUE},
{SMB_VFS_OP(onefs_rename), SMB_VFS_OP_RENAME,
SMB_VFS_LAYER_TRANSPARENT},
{SMB_VFS_OP(onefs_stat), SMB_VFS_OP_STAT,
git.samba.org / metze / samba / wip.git / commitdiff