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rbd: use snap_id not index to look up snap info

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In order to align with what was needed for format 1 rbd images,
rbd_dev_v2_snap_info() was set up to take as argument an index into
the array of snapshot ids in a rbd device's snapshot context.

This switches that around, so we pass the snapshot id instead.
In doing this, rbd_snap_name() now returns a dynamically-allocated
string rather than a fixed one, so there's no need to make a
duplicate in its caller, rbd_dev_spec_update().

This means the following functions take a snapshot id where they
previously used an index value:
    rbd_dev_snap_info()
    rbd_dev_v1_snap_info()
    rbd_dev_v2_snap_info()

A new function, rbd_dev_snap_index(), determines the snap index for
format 1 images and uses it to look up the name.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
This commit is contained in:
Alex Elder 2013-04-30 00:44:33 -05:00 committed by Sage Weil
parent 9682fc6d3a
commit 54cac61fb6
1 changed files with 37 additions and 31 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

68
drivers/block/rbd.c
View file

@ -433,6 +433,8 @@ static void rbd_dev_remove_parent(struct rbd_device *rbd_dev);
static int rbd_dev_refresh(struct rbd_device *rbd_dev);
static int rbd_dev_v2_refresh(struct rbd_device *rbd_dev);
static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
u64 snap_id);
static int rbd_open(struct block_device *bdev, fmode_t mode)
{
@ -838,18 +840,27 @@ static u32 rbd_dev_snap_index(struct rbd_device *rbd_dev, u64 snap_id)
return BAD_SNAP_INDEX;
}
static const char *rbd_dev_v1_snap_name(struct rbd_device *rbd_dev, u64 snap_id)
{
u32 which;
which = rbd_dev_snap_index(rbd_dev, snap_id);
if (which == BAD_SNAP_INDEX)
return NULL;
return _rbd_dev_v1_snap_name(rbd_dev, which);
}
static const char *rbd_snap_name(struct rbd_device *rbd_dev, u64 snap_id)
{
struct rbd_snap *snap;
if (snap_id == CEPH_NOSNAP)
return RBD_SNAP_HEAD_NAME;
list_for_each_entry(snap, &rbd_dev->snaps, node)
if (snap_id == snap->id)
return snap->name;
rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
if (rbd_dev->image_format == 1)
return rbd_dev_v1_snap_name(rbd_dev, snap_id);
return NULL;
return rbd_dev_v2_snap_name(rbd_dev, snap_id);
}
static struct rbd_snap *snap_by_name(struct rbd_device *rbd_dev,
@ -3446,11 +3457,15 @@ static struct rbd_snap *rbd_snap_create(struct rbd_device *rbd_dev,
* Returns a dynamically-allocated snapshot name if successful, or a
* pointer-coded error otherwise.
*/
static const char *rbd_dev_v1_snap_info(struct rbd_device *rbd_dev, u32 which,
u64 *snap_size, u64 *snap_features)
static const char *rbd_dev_v1_snap_info(struct rbd_device *rbd_dev,
u64 snap_id, u64 *snap_size, u64 *snap_features)
{
const char *snap_name;
u32 which;
which = rbd_dev_snap_index(rbd_dev, snap_id);
if (which == BAD_SNAP_INDEX)
return ERR_PTR(-ENOENT);
snap_name = _rbd_dev_v1_snap_name(rbd_dev, which);
if (!snap_name)
return ERR_PTR(-ENOMEM);
@ -3815,12 +3830,6 @@ static int rbd_dev_spec_update(struct rbd_device *rbd_dev)
/* Look up the snapshot name, and make a copy */
snap_name = rbd_snap_name(rbd_dev, spec->snap_id);
if (!snap_name) {
rbd_warn(rbd_dev, "no snapshot with id %llu", spec->snap_id);
ret = -EIO;
goto out_err;
}
snap_name = kstrdup(snap_name, GFP_KERNEL);
if (!snap_name) {
ret = -ENOMEM;
goto out_err;
@ -3909,11 +3918,12 @@ static int rbd_dev_v2_snap_context(struct rbd_device *rbd_dev)
return ret;
}
static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev, u32 which)
static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
u64 snap_id)
{
size_t size;
void *reply_buf;
__le64 snap_id;
__le64 snapid;
int ret;
void *p;
void *end;
@ -3924,11 +3934,10 @@ static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev, u32 which)
if (!reply_buf)
return ERR_PTR(-ENOMEM);
rbd_assert(which < rbd_dev->header.snapc->num_snaps);
snap_id = cpu_to_le64(rbd_dev->header.snapc->snaps[which]);
snapid = cpu_to_le64(snap_id);
ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
"rbd", "get_snapshot_name",
&snap_id, sizeof (snap_id),
&snapid, sizeof (snapid),
reply_buf, size);
dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
if (ret < 0) {
@ -3943,24 +3952,21 @@ static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev, u32 which)
goto out;
dout(" snap_id 0x%016llx snap_name = %s\n",
(unsigned long long)le64_to_cpu(snap_id), snap_name);
(unsigned long long)snap_id, snap_name);
out:
kfree(reply_buf);
return snap_name;
}
static const char *rbd_dev_v2_snap_info(struct rbd_device *rbd_dev, u32 which,
u64 *snap_size, u64 *snap_features)
static const char *rbd_dev_v2_snap_info(struct rbd_device *rbd_dev,
u64 snap_id, u64 *snap_size, u64 *snap_features)
{
u64 snap_id;
u64 size;
u64 features;
const char *snap_name;
int ret;
rbd_assert(which < rbd_dev->header.snapc->num_snaps);
snap_id = rbd_dev->header.snapc->snaps[which];
ret = _rbd_dev_v2_snap_size(rbd_dev, snap_id, NULL, &size);
if (ret)
goto out_err;
@ -3969,7 +3975,7 @@ static const char *rbd_dev_v2_snap_info(struct rbd_device *rbd_dev, u32 which,
if (ret)
goto out_err;
snap_name = rbd_dev_v2_snap_name(rbd_dev, which);
snap_name = rbd_dev_v2_snap_name(rbd_dev, snap_id);
if (!IS_ERR(snap_name)) {
*snap_size = size;
*snap_features = features;
@ -3980,14 +3986,14 @@ static const char *rbd_dev_v2_snap_info(struct rbd_device *rbd_dev, u32 which,
return ERR_PTR(ret);
}
static const char *rbd_dev_snap_info(struct rbd_device *rbd_dev, u32 which,
u64 *snap_size, u64 *snap_features)
static const char *rbd_dev_snap_info(struct rbd_device *rbd_dev,
u64 snap_id, u64 *snap_size, u64 *snap_features)
{
if (rbd_dev->image_format == 1)
return rbd_dev_v1_snap_info(rbd_dev, which,
return rbd_dev_v1_snap_info(rbd_dev, snap_id,
snap_size, snap_features);
if (rbd_dev->image_format == 2)
return rbd_dev_v2_snap_info(rbd_dev, which,
return rbd_dev_v2_snap_info(rbd_dev, snap_id,
snap_size, snap_features);
return ERR_PTR(-EINVAL);
}
@ -4085,7 +4091,7 @@ static int rbd_dev_snaps_update(struct rbd_device *rbd_dev)
continue;
}
snap_name = rbd_dev_snap_info(rbd_dev, index,
snap_name = rbd_dev_snap_info(rbd_dev, snap_id,
&snap_size, &snap_features);
if (IS_ERR(snap_name)) {
ret = PTR_ERR(snap_name);