[PATCH 20/50] mars: add new file drivers/block/mars/xio_bricks/xio.c

[Thomas Schoebel-Theuer]

Signed-off-by: Thomas Schoebel-Theuer <tst@xxxxxxxxxxxxxxxxxx>
---
 drivers/block/mars/xio_bricks/xio.c | 183 ++++++++++++++++++++++++++++++++++++
 1 file changed, 183 insertions(+)
 create mode 100644 drivers/block/mars/xio_bricks/xio.c

diff --git a/drivers/block/mars/xio_bricks/xio.c b/drivers/block/mars/xio_bricks/xio.c
new file mode 100644
index 0000000..cc13478
--- /dev/null
+++ b/drivers/block/mars/xio_bricks/xio.c
@@ -0,0 +1,183 @@
+/*  (c) 2010 Thomas Schoebel-Theuer / 1&1 Internet AG */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/uaccess.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/utsname.h>
+
+#include <linux/xio.h>
+
+/************************************************************/
+
+/*  infrastructure */
+
+struct banning xio_global_ban = {};
+EXPORT_SYMBOL_GPL(xio_global_ban);
+atomic_t xio_global_io_flying = ATOMIC_INIT(0);
+EXPORT_SYMBOL_GPL(xio_global_io_flying);
+
+static char *id;
+
+/* TODO: better use MAC addresses (or motherboard IDs where available).
+ * Or, at least, some checks for MAC addresses should be recorded / added.
+ * When the nodename is misconfigured, data might be scrambled.
+ * MAC addresses should be more secure.
+ * In ideal case, further checks should be added to prohibit accidental
+ * name clashes.
+ */
+char *my_id(void)
+{
+	struct new_utsname *u;
+
+	if (!id) {
+		/* down_read(&uts_sem); // FIXME: this is currenty not EXPORTed from the kernel! */
+		u = utsname();
+		if (u)
+			id = brick_strdup(u->nodename);
+		/* up_read(&uts_sem); */
+	}
+	return id;
+}
+EXPORT_SYMBOL_GPL(my_id);
+
+/************************************************************/
+
+/*  object stuff */
+
+const struct generic_object_type aio_type = {
+	.object_type_name = "aio",
+	.default_size = sizeof(struct aio_object),
+	.object_type_nr = OBJ_TYPE_AIO,
+};
+EXPORT_SYMBOL_GPL(aio_type);
+
+/************************************************************/
+
+/*  brick stuff */
+
+/*******************************************************************/
+
+/*  meta descriptions */
+
+const struct meta xio_info_meta[] = {
+	META_INI(current_size,	  struct xio_info, FIELD_INT),
+	META_INI(tf_align,	  struct xio_info, FIELD_INT),
+	META_INI(tf_min_size,	  struct xio_info, FIELD_INT),
+	{}
+};
+EXPORT_SYMBOL_GPL(xio_info_meta);
+
+const struct meta xio_aio_meta[] = {
+	META_INI(_object_cb.cb_error, struct aio_object, FIELD_INT),
+	META_INI(io_pos,	   struct aio_object, FIELD_INT),
+	META_INI(io_len,	   struct aio_object, FIELD_INT),
+	META_INI(io_may_write,	  struct aio_object, FIELD_INT),
+	META_INI(io_prio,	   struct aio_object, FIELD_INT),
+	META_INI(io_cs_mode,	   struct aio_object, FIELD_INT),
+	META_INI(io_timeout,	   struct aio_object, FIELD_INT),
+	META_INI(io_total_size,   struct aio_object, FIELD_INT),
+	META_INI(io_checksum,	   struct aio_object, FIELD_RAW),
+	META_INI(io_flags,	   struct aio_object, FIELD_INT),
+	META_INI(io_rw,    struct aio_object, FIELD_INT),
+	META_INI(io_id,    struct aio_object, FIELD_INT),
+	META_INI(io_skip_sync,	  struct aio_object, FIELD_INT),
+	{}
+};
+EXPORT_SYMBOL_GPL(xio_aio_meta);
+
+const struct meta xio_timespec_meta[] = {
+	META_INI_TRANSFER(tv_sec,  struct timespec, FIELD_UINT, 8),
+	META_INI_TRANSFER(tv_nsec, struct timespec, FIELD_UINT, 4),
+	{}
+};
+EXPORT_SYMBOL_GPL(xio_timespec_meta);
+
+/************************************************************/
+
+/*  crypto stuff */
+
+#include <linux/scatterlist.h>
+#include <linux/crypto.h>
+
+static struct crypto_hash *xio_tfm;
+static struct semaphore tfm_sem = __SEMAPHORE_INITIALIZER(tfm_sem, 1);
+int xio_digest_size = 0;
+EXPORT_SYMBOL_GPL(xio_digest_size);
+
+void xio_digest(unsigned char *digest, void *data, int len)
+{
+	struct hash_desc desc = {
+		.tfm = xio_tfm,
+		.flags = 0,
+	};
+	struct scatterlist sg;
+
+	memset(digest, 0, xio_digest_size);
+
+	/*  TODO: use per-thread instance, omit locking */
+	down(&tfm_sem);
+
+	crypto_hash_init(&desc);
+	sg_init_table(&sg, 1);
+	sg_set_buf(&sg, data, len);
+	crypto_hash_update(&desc, &sg, sg.length);
+	crypto_hash_final(&desc, digest);
+	up(&tfm_sem);
+}
+EXPORT_SYMBOL_GPL(xio_digest);
+
+void aio_checksum(struct aio_object *aio)
+{
+	unsigned char checksum[xio_digest_size];
+	int len;
+
+	if (aio->io_cs_mode <= 0 || !aio->io_data)
+		goto out_return;
+	xio_digest(checksum, aio->io_data, aio->io_len);
+
+	len = sizeof(aio->io_checksum);
+	if (len > xio_digest_size)
+		len = xio_digest_size;
+	memcpy(&aio->io_checksum, checksum, len);
+out_return:;
+}
+EXPORT_SYMBOL_GPL(aio_checksum);
+
+/*******************************************************************/
+
+/*  init stuff */
+
+int __init init_xio(void)
+{
+	XIO_INF("init_xio()\n");
+
+	xio_tfm = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
+	if (!xio_tfm) {
+		XIO_ERR("cannot alloc crypto hash\n");
+		return -ENOMEM;
+	}
+	if (IS_ERR(xio_tfm)) {
+		XIO_ERR("alloc crypto hash failed, status = %d\n", (int)PTR_ERR(xio_tfm));
+		return PTR_ERR(xio_tfm);
+	}
+	xio_digest_size = crypto_hash_digestsize(xio_tfm);
+	XIO_INF("digest_size = %d\n", xio_digest_size);
+
+	return 0;
+}
+
+void exit_xio(void)
+{
+	XIO_INF("exit_xio()\n");
+
+	if (xio_tfm)
+		crypto_free_hash(xio_tfm);
+
+	if (id) {
+		brick_string_free(id);
+		id = NULL;
+	}
+}
-- 
2.0.0

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