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>
(based on commit cc0538b62c)
This commit is contained in:
Alex Elder 2012-08-10 13:12:07 -07:00 committed by Greg Kroah-Hartman
parent e4a4a559d2
commit 5833a91327

View file

@ -71,7 +71,8 @@
#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)
@ -95,6 +96,7 @@ struct rbd_image_header {
struct rbd_options {
int notify_timeout;
bool read_only;
};
/*
@ -180,7 +182,7 @@ 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;
@ -346,12 +348,21 @@ 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 rbdopt_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}
};
@ -376,6 +387,8 @@ 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);
}
@ -384,6 +397,12 @@ static int parse_rbd_opts_token(char *c, void *private)
case Opt_notify_timeout:
rbdopt->notify_timeout = intval;
break;
case Opt_read_only:
rbdopt->read_only = true;
break;
case Opt_read_write:
rbdopt->read_only = false;
break;
default:
BUG_ON(token);
}
@ -407,6 +426,7 @@ static struct rbd_client *rbd_get_client(const char *mon_addr,
return ERR_PTR(-ENOMEM);
rbd_opts->notify_timeout = RBD_NOTIFY_TIMEOUT_DEFAULT;
rbd_opts->read_only = RBD_READ_ONLY_DEFAULT;
opt = ceph_parse_options(options, mon_addr,
mon_addr + mon_addr_len,
@ -590,7 +610,7 @@ static int rbd_header_set_snap(struct rbd_device *dev, u64 *size)
snapc->seq = 0;
dev->snap_id = CEPH_NOSNAP;
dev->snap_exists = false;
dev->read_only = 0;
dev->read_only = dev->rbd_client->rbd_opts->read_only;
if (size)
*size = header->image_size;
} else {
@ -599,7 +619,7 @@ static int rbd_header_set_snap(struct rbd_device *dev, u64 *size)
goto done;
dev->snap_id = snapc->seq;
dev->snap_exists = true;
dev->read_only = 1;
dev->read_only = true; /* No choice for snapshots */
}
ret = 0;