From 1fcdf534885b65e6d39780a5a89e9dfc5431cf68 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 3 Apr 2009 16:42:44 +0100 Subject: 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 Acked-by: Steve Dickson Acked-by: Trond Myklebust Acked-by: Al Viro Tested-by: Daire Byrne --- fs/nfs/fscache-index.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) (limited to 'fs/nfs') 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 @@ -291,6 +291,30 @@ 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 @@ -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, }; -- cgit v1.2.3