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>
This commit is contained in:
David Howells 2009-04-03 16:42:44 +01:00
Родитель 545db45f0f
Коммит 1fcdf53488
1 изменённых файлов: 26 добавлений и 0 удалений

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@ -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,
};