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pnfs: CB_NOTIFY_DEVICEID

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Note: This functionlaity is incomplete as all layout segments referring to
the 'to be removed device id' need to be reaped, and all in flight I/O drained.

[use be32 res in nfs4_callback_devicenotify]
[use nfs_client to qualify deviceid for cb_notify_deviceid]
[use global deviceid cache for CB_NOTIFY_DEVICEID]
[refactor device cache _lookup_deviceid]
[refactor device cache _find_get_deviceid]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[Bug in new global-device-cache code]
[layout_driver MUST set free_deviceid_node if using dev-cache]
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
This commit is contained in:
Marc Eshel
2011-05-22 19:47:09 +03:00
committed by Boaz Harrosh
parent 1775bc342c
commit 1be5683b03
5 changed files with 242 additions and 16 deletions
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97
fs/nfs/pnfs_dev.c
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@@ -66,6 +66,23 @@ nfs4_deviceid_hash(const struct nfs4_deviceid *id)
return x & NFS4_DEVICE_ID_HASH_MASK;
}
static struct nfs4_deviceid_node *
_lookup_deviceid(const struct nfs_client *clp, const struct nfs4_deviceid *id,
long hash)
{
struct nfs4_deviceid_node *d;
struct hlist_node *n;
hlist_for_each_entry_rcu(d, n, &nfs4_deviceid_cache[hash], node)
if (d->nfs_client == clp && !memcmp(&d->deviceid, id, sizeof(*id))) {
if (atomic_read(&d->ref))
return d;
else
continue;
}
return NULL;
}
/*
* Lookup a deviceid in cache and get a reference count on it if found
*
@@ -73,27 +90,77 @@ nfs4_deviceid_hash(const struct nfs4_deviceid *id)
* @id deviceid to look up
*/
struct nfs4_deviceid_node *
nfs4_find_get_deviceid(const struct nfs_client *clp, const struct nfs4_deviceid *id)
_find_get_deviceid(const struct nfs_client *clp, const struct nfs4_deviceid *id,
long hash)
{
struct nfs4_deviceid_node *d;
struct hlist_node *n;
long hash = nfs4_deviceid_hash(id);
rcu_read_lock();
hlist_for_each_entry_rcu(d, n, &nfs4_deviceid_cache[hash], node) {
if (d->nfs_client == clp && !memcmp(&d->deviceid, id, sizeof(*id))) {
if (!atomic_inc_not_zero(&d->ref))
goto fail;
rcu_read_unlock();
return d;
}
}
fail:
d = _lookup_deviceid(clp, id, hash);
if (d && !atomic_inc_not_zero(&d->ref))
d = NULL;
rcu_read_unlock();
return NULL;
return d;
}
struct nfs4_deviceid_node *
nfs4_find_get_deviceid(const struct nfs_client *clp, const struct nfs4_deviceid *id)
{
return _find_get_deviceid(clp, id, nfs4_deviceid_hash(id));
}
EXPORT_SYMBOL_GPL(nfs4_find_get_deviceid);
/*
* Unhash and put deviceid
*
* @clp nfs_client associated with deviceid
* @id the deviceid to unhash
*
* @ret the unhashed node, if found and dereferenced to zero, NULL otherwise.
*/
struct nfs4_deviceid_node *
nfs4_unhash_put_deviceid(const struct nfs_client *clp, const struct nfs4_deviceid *id)
{
struct nfs4_deviceid_node *d;
spin_lock(&nfs4_deviceid_lock);
rcu_read_lock();
d = _lookup_deviceid(clp, id, nfs4_deviceid_hash(id));
rcu_read_unlock();
if (!d) {
spin_unlock(&nfs4_deviceid_lock);
return NULL;
}
hlist_del_init_rcu(&d->node);
spin_unlock(&nfs4_deviceid_lock);
synchronize_rcu();
/* balance the initial ref set in pnfs_insert_deviceid */
if (atomic_dec_and_test(&d->ref))
return d;
return NULL;
}
EXPORT_SYMBOL_GPL(nfs4_unhash_put_deviceid);
/*
* Delete a deviceid from cache
*
* @clp struct nfs_client qualifying the deviceid
* @id deviceid to delete
*/
void
nfs4_delete_deviceid(const struct nfs_client *clp, const struct nfs4_deviceid *id)
{
struct nfs4_deviceid_node *d;
d = nfs4_unhash_put_deviceid(clp, id);
if (!d)
return;
d->ld->free_deviceid_node(d);
}
EXPORT_SYMBOL_GPL(nfs4_delete_deviceid);
void
nfs4_init_deviceid_node(struct nfs4_deviceid_node *d,
const struct pnfs_layoutdriver_type *ld,
@@ -126,13 +193,13 @@ nfs4_insert_deviceid_node(struct nfs4_deviceid_node *new)
long hash;
spin_lock(&nfs4_deviceid_lock);
d = nfs4_find_get_deviceid(new->nfs_client, &new->deviceid);
hash = nfs4_deviceid_hash(&new->deviceid);
d = _find_get_deviceid(new->nfs_client, &new->deviceid, hash);
if (d) {
spin_unlock(&nfs4_deviceid_lock);
return d;
}
hash = nfs4_deviceid_hash(&new->deviceid);
hlist_add_head_rcu(&new->node, &nfs4_deviceid_cache[hash]);
spin_unlock(&nfs4_deviceid_lock);