From cc0538b62c839c2df7b9f8378bb37e3b35faa608 Mon Sep 17 00:00:00 2001
From: Alex Elder <elder@inktank.com>
Date: Fri, 10 Aug 2012 13:12:07 -0700
Subject: [PATCH] rbd: add read_only rbd map option
Add the ability to map an rbd image read-only, by specifying either
"read_only" or "ro" as an option on the rbd "command line." Also
allow the inverse to be explicitly specified using "read_write" or
"rw".
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
---
drivers/block/rbd.c | 28 ++++++++++++++++++++++++----
1 file changed, 24 insertions(+), 4 deletions(-)
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 839ab730a1f3..2db51cef9560 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -69,7 +69,8 @@
#define DEV_NAME_LEN 32
#define MAX_INT_FORMAT_WIDTH ((5 * sizeof (int)) / 2 + 1)
-#define RBD_NOTIFY_TIMEOUT_DEFAULT 10
+#define RBD_NOTIFY_TIMEOUT_DEFAULT 10
+#define RBD_READ_ONLY_DEFAULT false
/*
* block device image metadata (in-memory version)
@@ -91,6 +92,7 @@ struct rbd_image_header {
struct rbd_options {
int notify_timeout;
+ bool read_only;
};
/*
@@ -176,7 +178,7 @@ struct rbd_device {
u64 snap_id; /* current snapshot id */
/* whether the snap_id this device reads from still exists */
bool snap_exists;
- int read_only;
+ bool read_only;
struct list_head node;
@@ -351,12 +353,21 @@ enum {
/* int args above */
Opt_last_string,
/* string args above */
+ Opt_read_only,
+ Opt_read_write,
+ /* Boolean args above */
+ Opt_last_bool,
};
static match_table_t rbd_opts_tokens = {
{Opt_notify_timeout, "notify_timeout=%d"},
/* int args above */
/* string args above */
+ {Opt_read_only, "read_only"},
+ {Opt_read_only, "ro"}, /* Alternate spelling */
+ {Opt_read_write, "read_write"},
+ {Opt_read_write, "rw"}, /* Alternate spelling */
+ /* Boolean args above */
{-1, NULL}
};
@@ -381,6 +392,8 @@ static int parse_rbd_opts_token(char *c, void *private)
} else if (token > Opt_last_int && token < Opt_last_string) {
dout("got string token %d val %s\n", token,
argstr[0].from);
+ } else if (token > Opt_last_string && token < Opt_last_bool) {
+ dout("got Boolean token %d\n", token);
} else {
dout("got token %d\n", token);
}
@@ -389,6 +402,12 @@ static int parse_rbd_opts_token(char *c, void *private)
case Opt_notify_timeout:
rbd_opts->notify_timeout = intval;
break;
+ case Opt_read_only:
+ rbd_opts->read_only = true;
+ break;
+ case Opt_read_write:
+ rbd_opts->read_only = false;
+ break;
default:
BUG_ON(token);
}
@@ -407,6 +426,7 @@ static int rbd_get_client(struct rbd_device *rbd_dev, const char *mon_addr,
struct rbd_client *rbdc;
rbd_opts->notify_timeout = RBD_NOTIFY_TIMEOUT_DEFAULT;
+ rbd_opts->read_only = RBD_READ_ONLY_DEFAULT;
ceph_opts = ceph_parse_options(options, mon_addr,
mon_addr + mon_addr_len,
@@ -620,7 +640,7 @@ static int rbd_header_set_snap(struct rbd_device *rbd_dev, u64 *size)
sizeof (RBD_SNAP_HEAD_NAME))) {
rbd_dev->snap_id = CEPH_NOSNAP;
rbd_dev->snap_exists = false;
- rbd_dev->read_only = 0;
+ rbd_dev->read_only = rbd_dev->rbd_opts.read_only;
if (size)
*size = rbd_dev->header.image_size;
} else {
@@ -632,7 +652,7 @@ static int rbd_header_set_snap(struct rbd_device *rbd_dev, u64 *size)
goto done;
rbd_dev->snap_id = snap_id;
rbd_dev->snap_exists = true;
- rbd_dev->read_only = 1;
+ rbd_dev->read_only = true; /* No choice for snapshots */
}
ret = 0;