AFS: AFS fixups

Make some miscellaneous changes to the AFS filesystem:

 (1) Assert RCU barriers on module exit to make sure RCU has finished with
     callbacks in this module.

 (2) Correctly handle the AFS server returning a zero-length read.

 (3) Split out data zapping calls into one function (afs_zap_data).

 (4) Rename some afs_file_*() functions to afs_*() where they apply to
     non-regular files too.

 (5) Be consistent about the presentation of volume ID:vnode ID in debugging
     output.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 20 insertions, 17 deletions

diff --git a/fs/afs/fsclient.c b/fs/afs/fsclient.c
index e54e6c2ad343..1e65fee36413 100644
--- a/fs/afs/fsclient.c
+++ b/fs/afs/fsclient.c
@@ -206,7 +206,7 @@ int afs_fs_fetch_file_status(struct afs_server *server,
         struct afs_call *call;
         __be32 *bp;
 
-        _enter(",%x,{%x:%d},,",
+        _enter(",%x,{%x:%u},,",
                key_serial(key), vnode->fid.vid, vnode->fid.vnode);
 
         call = afs_alloc_flat_call(&afs_RXFSFetchStatus, 16, (21 + 3 + 6) * 4);
@@ -265,25 +265,20 @@ static int afs_deliver_fs_fetch_data(struct afs_call *call,
                 call->offset = 0;
                 call->unmarshall++;
 
-                if (call->count < PAGE_SIZE) {
-                        page = call->reply3;
-                        buffer = kmap_atomic(page, KM_USER0);
-                        memset(buffer + PAGE_SIZE - call->count, 0,
-                               call->count);
-                        kunmap_atomic(buffer, KM_USER0);
-                }
-
                 /* extract the returned data */
         case 2:
                 _debug("extract data");
-                page = call->reply3;
-                buffer = kmap_atomic(page, KM_USER0);
-                ret = afs_extract_data(call, skb, last, buffer, call->count);
-                kunmap_atomic(buffer, KM_USER0);
-                switch (ret) {
-                case 0:         break;
-                case -EAGAIN:   return 0;
-                default:        return ret;
+                if (call->count > 0) {
+                        page = call->reply3;
+                        buffer = kmap_atomic(page, KM_USER0);
+                        ret = afs_extract_data(call, skb, last, buffer,
+                                               call->count);
+                        kunmap_atomic(buffer, KM_USER0);
+                        switch (ret) {
+                        case 0:         break;
+                        case -EAGAIN:   return 0;
+                        default:        return ret;
+                        }
                 }
 
                 call->offset = 0;
@@ -318,6 +313,14 @@ static int afs_deliver_fs_fetch_data(struct afs_call *call,
         if (!last)
                 return 0;
 
+        if (call->count < PAGE_SIZE) {
+                _debug("clear");
+                page = call->reply3;
+                buffer = kmap_atomic(page, KM_USER0);
+                memset(buffer + call->count, 0, PAGE_SIZE - call->count);
+                kunmap_atomic(buffer, KM_USER0);
+        }
+
         _leave(" = 0 [done]");
         return 0;
 }