diff options
author | Trond Myklebust <Trond.Myklebust@netapp.com> | 2011-06-14 12:18:11 -0400 |
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committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2011-07-12 13:40:28 -0400 |
commit | 47cb498e9316314e7e681f417135589195ad78a7 (patch) | |
tree | 2f48649123504119c8ab200300b919b040a0897b /fs/nfs | |
parent | e885de1a5bc9f46ef8f934c5a7602c89d2d51e8d (diff) | |
download | linux-47cb498e9316314e7e681f417135589195ad78a7.tar.bz2 |
NFSv4.1: Clean ups for the device id cache
The fact that the global device id cache holds a reference to the
nfs4_deviceid_node until it is invisible to rcu lookups implies that
we can always assume that the reference count is non-zero in
_find_get_deviceid.
Also clean up nfs4_put_deviceid_node and the removal of the device id
from the cache.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs/nfs')
-rw-r--r-- | fs/nfs/pnfs.h | 1 | ||||
-rw-r--r-- | fs/nfs/pnfs_dev.c | 44 |
2 files changed, 11 insertions, 34 deletions
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h index dd54351ae6ac..1cfc96f8c45b 100644 --- a/fs/nfs/pnfs.h +++ b/fs/nfs/pnfs.h @@ -198,7 +198,6 @@ struct nfs4_deviceid_node { void nfs4_print_deviceid(const struct nfs4_deviceid *dev_id); struct nfs4_deviceid_node *nfs4_find_get_deviceid(const struct pnfs_layoutdriver_type *, const struct nfs_client *, const struct nfs4_deviceid *); -struct nfs4_deviceid_node *nfs4_unhash_put_deviceid(const struct pnfs_layoutdriver_type *, const struct nfs_client *, const struct nfs4_deviceid *); void nfs4_delete_deviceid(const struct pnfs_layoutdriver_type *, const struct nfs_client *, const struct nfs4_deviceid *); void nfs4_init_deviceid_node(struct nfs4_deviceid_node *, const struct pnfs_layoutdriver_type *, diff --git a/fs/nfs/pnfs_dev.c b/fs/nfs/pnfs_dev.c index f0f8e1e22f6c..fb9498d91f6a 100644 --- a/fs/nfs/pnfs_dev.c +++ b/fs/nfs/pnfs_dev.c @@ -100,8 +100,8 @@ _find_get_deviceid(const struct pnfs_layoutdriver_type *ld, rcu_read_lock(); d = _lookup_deviceid(ld, clp, id, hash); - if (d && !atomic_inc_not_zero(&d->ref)) - d = NULL; + if (d != NULL) + atomic_inc(&d->ref); rcu_read_unlock(); return d; } @@ -115,15 +115,15 @@ nfs4_find_get_deviceid(const struct pnfs_layoutdriver_type *ld, EXPORT_SYMBOL_GPL(nfs4_find_get_deviceid); /* - * Unhash and put deviceid + * Remove a deviceid from cache * * @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 pnfs_layoutdriver_type *ld, +void +nfs4_delete_deviceid(const struct pnfs_layoutdriver_type *ld, const struct nfs_client *clp, const struct nfs4_deviceid *id) { struct nfs4_deviceid_node *d; @@ -134,7 +134,7 @@ nfs4_unhash_put_deviceid(const struct pnfs_layoutdriver_type *ld, rcu_read_unlock(); if (!d) { spin_unlock(&nfs4_deviceid_lock); - return NULL; + return; } hlist_del_init_rcu(&d->node); spin_unlock(&nfs4_deviceid_lock); @@ -142,28 +142,7 @@ nfs4_unhash_put_deviceid(const struct pnfs_layoutdriver_type *ld, /* 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 pnfs_layoutdriver_type *ld, - const struct nfs_client *clp, const struct nfs4_deviceid *id) -{ - struct nfs4_deviceid_node *d; - - d = nfs4_unhash_put_deviceid(ld, clp, id); - if (!d) - return; - d->ld->free_deviceid_node(d); + d->ld->free_deviceid_node(d); } EXPORT_SYMBOL_GPL(nfs4_delete_deviceid); @@ -221,16 +200,15 @@ EXPORT_SYMBOL_GPL(nfs4_insert_deviceid_node); * * @d deviceid node to put * - * @ret true iff the node was deleted + * return true iff the node was deleted + * Note that since the test for d->ref == 0 is sufficient to establish + * that the node is no longer hashed in the global device id cache. */ bool nfs4_put_deviceid_node(struct nfs4_deviceid_node *d) { - if (!atomic_dec_and_lock(&d->ref, &nfs4_deviceid_lock)) + if (!atomic_dec_and_test(&d->ref)) return false; - hlist_del_init_rcu(&d->node); - spin_unlock(&nfs4_deviceid_lock); - synchronize_rcu(); d->ld->free_deviceid_node(d); return true; } |