Oren Laadan wrote:
+/*
+ * Helpers to write(read) from(to) kernel space to(from) the checkpoint
+ * image file descriptor (similar to how a core-dump is performed).
+ *
+ * cr_kwrite() - write a kernel-space buffer to the checkpoint image
+ * cr_kread() - read from the checkpoint image to a kernel-space buffer
+ */
+
+int cr_kwrite(struct cr_ctx *ctx, void *addr, int count)
+{
+ struct file *file = ctx->file;
+ mm_segment_t fs;
+ ssize_t nwrite;
+ int nleft;
+
+ fs = get_fs();
+ set_fs(KERNEL_DS);
+ for (nleft = count; nleft; nleft -= nwrite) {
+ nwrite = file->f_op->write(file, addr, nleft, &file->f_pos);
+ if (nwrite < 0) {
+ if (nwrite == -EAGAIN)
+ nwrite = 0;
+ else
set_fs(fs) here
+ return nwrite;
+ }
+ addr += nwrite;
+ }
+ set_fs(fs);
+ ctx->total += count;
+ return 0;
+}
+
+int cr_kread(struct cr_ctx *ctx, void *addr, int count)
+{
+ struct file *file = ctx->file;
+ mm_segment_t fs;
+ ssize_t nread;
+ int nleft;
+
+ fs = get_fs();
+ set_fs(KERNEL_DS);
+ for (nleft = count; nleft; nleft -= nread) {
+ nread = file->f_op->read(file, addr, nleft, &file->f_pos);
+ if (nread <= 0) {
+ if (nread == -EAGAIN) {
+ nread = 0;
+ continue;
+ } else if (nread == 0)
+ nread = -EPIPE; /* unexecpted EOF */
set_fs(fs) here as well
+ return nread;
+ }
+ addr += nread;
+ }
+ set_fs(fs);
+ ctx->total += count;
+ return 0;
+}
+
--
To unsubscribe from this list: send the line "unsubscribe linux-api" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
