target/iblock: Add parameter to specify read-only devices
see https://bugzilla.redhat.com/show_bug.cgi?id=818855
Adds a parameter so read-only block devices may be registered as
LIO backstores.
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c
index 244fff4..c2d4ccb 100644
--- a/drivers/target/target_core_iblock.c
+++ b/drivers/target/target_core_iblock.c
@@ -96,6 +96,7 @@
struct request_queue *q;
struct queue_limits *limits;
u32 dev_flags = 0;
+ fmode_t mode;
int ret = -EINVAL;
if (!ib_dev) {
@@ -117,8 +118,11 @@
pr_debug( "IBLOCK: Claiming struct block_device: %s\n",
ib_dev->ibd_udev_path);
- bd = blkdev_get_by_path(ib_dev->ibd_udev_path,
- FMODE_WRITE|FMODE_READ|FMODE_EXCL, ib_dev);
+ mode = FMODE_READ|FMODE_EXCL;
+ if (!ib_dev->ibd_readonly)
+ mode |= FMODE_WRITE;
+
+ bd = blkdev_get_by_path(ib_dev->ibd_udev_path, mode, ib_dev);
if (IS_ERR(bd)) {
ret = PTR_ERR(bd);
goto failed;
@@ -323,11 +327,12 @@
}
enum {
- Opt_udev_path, Opt_force, Opt_err
+ Opt_udev_path, Opt_readonly, Opt_force, Opt_err
};
static match_table_t tokens = {
{Opt_udev_path, "udev_path=%s"},
+ {Opt_readonly, "readonly=%d"},
{Opt_force, "force=%d"},
{Opt_err, NULL}
};
@@ -340,6 +345,7 @@
char *orig, *ptr, *arg_p, *opts;
substring_t args[MAX_OPT_ARGS];
int ret = 0, token;
+ unsigned long tmp_readonly;
opts = kstrdup(page, GFP_KERNEL);
if (!opts)
@@ -372,6 +378,22 @@
ib_dev->ibd_udev_path);
ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
break;
+ case Opt_readonly:
+ arg_p = match_strdup(&args[0]);
+ if (!arg_p) {
+ ret = -ENOMEM;
+ break;
+ }
+ ret = strict_strtoul(arg_p, 0, &tmp_readonly);
+ kfree(arg_p);
+ if (ret < 0) {
+ pr_err("strict_strtoul() failed for"
+ " readonly=\n");
+ goto out;
+ }
+ ib_dev->ibd_readonly = tmp_readonly;
+ pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly);
+ break;
case Opt_force:
break;
default:
@@ -411,11 +433,10 @@
if (bd)
bl += sprintf(b + bl, "iBlock device: %s",
bdevname(bd, buf));
- if (ibd->ibd_flags & IBDF_HAS_UDEV_PATH) {
- bl += sprintf(b + bl, " UDEV PATH: %s\n",
+ if (ibd->ibd_flags & IBDF_HAS_UDEV_PATH)
+ bl += sprintf(b + bl, " UDEV PATH: %s",
ibd->ibd_udev_path);
- } else
- bl += sprintf(b + bl, "\n");
+ bl += sprintf(b + bl, " readonly: %d\n", ibd->ibd_readonly);
bl += sprintf(b + bl, " ");
if (bd) {
diff --git a/drivers/target/target_core_iblock.h b/drivers/target/target_core_iblock.h
index 66cf7b9..533627a 100644
--- a/drivers/target/target_core_iblock.h
+++ b/drivers/target/target_core_iblock.h
@@ -18,6 +18,7 @@
u32 ibd_flags;
struct bio_set *ibd_bio_set;
struct block_device *ibd_bd;
+ bool ibd_readonly;
} ____cacheline_aligned;
#endif /* TARGET_CORE_IBLOCK_H */
