An rbd device's pool name is used to specify the pool to use for an
rbd image when it gets mapped (via rbd_add()). However, only the
pool id can be relied on to be invariant--the name of a pool can
change at any time.
This means that the name of the pool is potentially stale as soon as
the image is mapped, so it's a bad idea to record this information.
So only store the pool id, not its name, in an rbd_dev.
Here are a few specific notes about this change:
- The "pool" name device attribute (/sys/bus/rbd/devices/<N>/pool)
goes away. In its place is a "pool_id" attribute that provide
the numeric pool id for the rbd image.
- rbd_add_parse_args() now returns a pointer to a dynamically-
allocated copy of the pool name taken from the arguments.
- rbd_add() has been changed to handle freeing the pool name,
both in error cases and in the normal case after the pool id
has been recorded.
Signed-off-by: Alex Elder <elder@xxxxxxxxxxx>
---
drivers/block/rbd.c | 74
+++++++++++++++++++++++++++++++-------------------
1 files changed, 46 insertions(+), 28 deletions(-)
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 3aa0ca0..76e978c 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -56,7 +56,6 @@
#define RBD_MINORS_PER_MAJOR 256 /* max minors per blkdev */
#define RBD_MAX_MD_NAME_LEN (RBD_MAX_OBJ_NAME_LEN + sizeof(RBD_SUFFIX))
-#define RBD_MAX_POOL_NAME_LEN 64
#define RBD_MAX_SNAP_NAME_LEN 32
#define RBD_MAX_OPT_LEN 1024
@@ -166,8 +165,7 @@ struct rbd_device {
char obj[RBD_MAX_OBJ_NAME_LEN]; /* rbd image name */
int obj_len;
char obj_md_name[RBD_MAX_MD_NAME_LEN]; /* hdr nm. */
- char pool_name[RBD_MAX_POOL_NAME_LEN];
- int poolid;
+ int pool_id;
struct ceph_osd_event *watch_event;
struct ceph_osd_request *watch_request;
@@ -930,7 +928,7 @@ static int rbd_do_request(struct request *rq,
layout->fl_stripe_unit = cpu_to_le32(1 << RBD_MAX_OBJ_ORDER);
layout->fl_stripe_count = cpu_to_le32(1);
layout->fl_object_size = cpu_to_le32(1 << RBD_MAX_OBJ_ORDER);
- layout->fl_pg_pool = cpu_to_le32(dev->poolid);
+ layout->fl_pg_pool = cpu_to_le32(dev->pool_id);
ceph_calc_raw_layout(osdc, layout, snapid, ofs, &len, &bno,
req, ops);
@@ -1653,7 +1651,7 @@ static int rbd_header_add_snap(struct rbd_device *dev,
return -EINVAL;
monc = &dev->rbd_client->client->monc;
- ret = ceph_monc_create_snapid(monc, dev->poolid, &new_snapid);
+ ret = ceph_monc_create_snapid(monc, dev->pool_id, &new_snapid);
dout("created snapid=%lld\n", new_snapid);
if (ret < 0)
return ret;
@@ -1851,12 +1849,12 @@ static ssize_t rbd_client_id_show(struct device
*dev,
ceph_client_id(rbd_dev->rbd_client->client));
}
-static ssize_t rbd_pool_show(struct device *dev,
+static ssize_t rbd_pool_id_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
- return sprintf(buf, "%s\n", rbd_dev->pool_name);
+ return sprintf(buf, "%d\n", rbd_dev->pool_id);
}
static ssize_t rbd_name_show(struct device *dev,
@@ -1898,7 +1896,7 @@ static ssize_t rbd_image_refresh(struct device *dev,
static DEVICE_ATTR(size, S_IRUGO, rbd_size_show, NULL);
static DEVICE_ATTR(major, S_IRUGO, rbd_major_show, NULL);
static DEVICE_ATTR(client_id, S_IRUGO, rbd_client_id_show, NULL);
-static DEVICE_ATTR(pool, S_IRUGO, rbd_pool_show, NULL);
+static DEVICE_ATTR(pool_id, S_IRUGO, rbd_pool_id_show, NULL);
static DEVICE_ATTR(name, S_IRUGO, rbd_name_show, NULL);
static DEVICE_ATTR(refresh, S_IWUSR, NULL, rbd_image_refresh);
static DEVICE_ATTR(current_snap, S_IRUGO, rbd_snap_show, NULL);
@@ -1908,7 +1906,7 @@ static struct attribute *rbd_attrs[] = {
&dev_attr_size.attr,
&dev_attr_major.attr,
&dev_attr_client_id.attr,
- &dev_attr_pool.attr,
+ &dev_attr_pool_id.attr,
&dev_attr_name.attr,
&dev_attr_current_snap.attr,
&dev_attr_refresh.attr,
@@ -2329,25 +2327,31 @@ static inline char *dup_token(const char **buf,
size_t *lenp)
}
/*
- * This fills in the pool_name, obj, obj_len, snap_name, obj_len,
- * rbd_dev, rbd_md_name, and name fields of the given rbd_dev, based
- * on the list of monitor addresses and other options provided via
- * /sys/bus/rbd/add.
+ * This fills in the obj, obj_len, snap_name, rbd_dev, rbd_md_name,
+ * and name fields of the given rbd_dev, based on the list of
+ * monitor addresses and other options provided via /sys/bus/rbd/add.
+ *
+ * Returns a pointer to a dynamically-allocated buffer containing
+ * the pool name provided, or a pointer-coded errno if an error
+ * occurs.
*/
-static int rbd_add_parse_args(struct rbd_device *rbd_dev,
+static char *rbd_add_parse_args(struct rbd_device *rbd_dev,
const char *buf,
const char **mon_addrs,
size_t *mon_addrs_size,
char *options,
size_t options_size)
{
- size_t len;
+ size_t len;
+ int ret = -EINVAL;
+ char *pool_name = NULL;
/* The first four tokens are required */
len = next_token(&buf);
if (!len)
- return -EINVAL;
+ goto out_err;
+
*mon_addrs_size = len + 1;
*mon_addrs = buf;
@@ -2355,15 +2359,17 @@ static int rbd_add_parse_args(struct rbd_device
*rbd_dev,
len = copy_token(&buf, options, options_size);
if (!len || len >= options_size)
- return -EINVAL;
+ goto out_err;
- len = copy_token(&buf, rbd_dev->pool_name, sizeof (rbd_dev->pool_name));
- if (!len || len >= sizeof (rbd_dev->pool_name))
- return -EINVAL;
+ pool_name = dup_token(&buf, NULL);
+ if (!pool_name) {
+ ret = -ENOMEM;
+ goto out_err;
+ }
len = copy_token(&buf, rbd_dev->obj, sizeof (rbd_dev->obj));
if (!len || len >= sizeof (rbd_dev->obj))
- return -EINVAL;
+ goto out_err;
/* We have the object length in hand, save it. */
@@ -2382,9 +2388,14 @@ static int rbd_add_parse_args(struct rbd_device
*rbd_dev,
memcpy(rbd_dev->snap_name, RBD_SNAP_HEAD_NAME,
sizeof (RBD_SNAP_HEAD_NAME));
else if (len >= sizeof (rbd_dev->snap_name))
- return -EINVAL;
+ goto out_err;
- return 0;
+ return pool_name;
+
+out_err:
+ kfree(pool_name);
+
+ return ERR_PTR(ret);
}
static ssize_t rbd_add(struct bus_type *bus,
@@ -2396,6 +2407,7 @@ static ssize_t rbd_add(struct bus_type *bus,
size_t mon_addrs_size = 0;
char *options = NULL;
struct ceph_osd_client *osdc;
+ char *pool_name;
int rc = -ENOMEM;
if (!try_module_get(THIS_MODULE))
@@ -2425,10 +2437,14 @@ static ssize_t rbd_add(struct bus_type *bus,
sprintf(rbd_dev->name, "%s%d", RBD_DRV_NAME, rbd_dev->id);
/* parse add command */
- rc = rbd_add_parse_args(rbd_dev, buf, &mon_addrs, &mon_addrs_size,
- options, count);
- if (rc)
+ pool_name = rbd_add_parse_args(rbd_dev, buf,
+ &mon_addrs, &mon_addrs_size,
+ options, count);
+ if (IS_ERR(pool_name)) {
+ rc = PTR_ERR(pool_name);
+ pool_name = NULL;
goto err_put_id;
+ }
rbd_dev->rbd_client = rbd_get_client(mon_addrs, mon_addrs_size - 1,
options);
@@ -2439,10 +2455,10 @@ static ssize_t rbd_add(struct bus_type *bus,
/* pick the pool */
osdc = &rbd_dev->rbd_client->client->osdc;
- rc = ceph_pg_poolid_by_name(osdc->osdmap, rbd_dev->pool_name);
+ rc = ceph_pg_poolid_by_name(osdc->osdmap, pool_name);
if (rc < 0)
goto err_out_client;
- rbd_dev->poolid = rc;
+ rbd_dev->pool_id = rc;
/* register our block device */
rc = register_blkdev(0, rbd_dev->name);
@@ -2453,6 +2469,7 @@ static ssize_t rbd_add(struct bus_type *bus,
rc = rbd_bus_add_dev(rbd_dev);
if (rc)
goto err_out_blkdev;
+ kfree(pool_name);
/*
* At this point cleanup in the event of an error is the job
@@ -2482,6 +2499,7 @@ err_out_blkdev:
err_out_client:
rbd_put_client(rbd_dev);
err_put_id:
+ kfree(pool_name);
rbd_id_put(rbd_dev);
err_nomem:
kfree(options);
--
1.7.5.4
--
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