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authorDavid Howells <dhowells@redhat.com>2009-04-03 19:42:44 +0400
committerDavid Howells <dhowells@redhat.com>2009-04-03 19:42:44 +0400
commit1fcdf534885b65e6d39780a5a89e9dfc5431cf68 (patch)
tree2710681cd36e5ba1a6460082061464242c175772 /fs/nfs/fscache-index.c
parent545db45f0fc0d4203b045047798ce156972a3056 (diff)
downloadlinux-1fcdf534885b65e6d39780a5a89e9dfc5431cf68.tar.xz
NFS: Add read context retention for FS-Cache to call back with
Add read context retention so that FS-Cache can call back into NFS when a read operation on the cache fails EIO rather than reading data. This permits NFS to then fetch the data from the server instead using the appropriate security context. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Steve Dickson <steved@redhat.com> Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Tested-by: Daire Byrne <Daire.Byrne@framestore.com>
Diffstat (limited to 'fs/nfs/fscache-index.c')
-rw-r--r--fs/nfs/fscache-index.c26
1 files changed, 26 insertions, 0 deletions
diff --git a/fs/nfs/fscache-index.c b/fs/nfs/fscache-index.c
index a119b5691e7c..5b1006480bc2 100644
--- a/fs/nfs/fscache-index.c
+++ b/fs/nfs/fscache-index.c
@@ -292,6 +292,30 @@ static void nfs_fscache_inode_now_uncached(void *cookie_netfs_data)
}
/*
+ * Get an extra reference on a read context.
+ * - This function can be absent if the completion function doesn't require a
+ * context.
+ * - The read context is passed back to NFS in the event that a data read on the
+ * cache fails with EIO - in which case the server must be contacted to
+ * retrieve the data, which requires the read context for security.
+ */
+static void nfs_fh_get_context(void *cookie_netfs_data, void *context)
+{
+ get_nfs_open_context(context);
+}
+
+/*
+ * Release an extra reference on a read context.
+ * - This function can be absent if the completion function doesn't require a
+ * context.
+ */
+static void nfs_fh_put_context(void *cookie_netfs_data, void *context)
+{
+ if (context)
+ put_nfs_open_context(context);
+}
+
+/*
* Define the inode object for FS-Cache. This is used to describe an inode
* object to fscache_acquire_cookie(). It is keyed by the NFS file handle for
* an inode.
@@ -308,4 +332,6 @@ const struct fscache_cookie_def nfs_fscache_inode_object_def = {
.get_aux = nfs_fscache_inode_get_aux,
.check_aux = nfs_fscache_inode_check_aux,
.now_uncached = nfs_fscache_inode_now_uncached,
+ .get_context = nfs_fh_get_context,
+ .put_context = nfs_fh_put_context,
};