NFSD: Refactor __nfsd_file_close_inode()

[ Upstream commit a845511007a63467fee575353c706806c21218b1 ]

The code that computes the hashval is the same in both callers.

To prevent them from going stale, reframe the documenting comments
to remove descriptions of the underlying hash table structure, which
is about to be replaced.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index d7c74b51eabf375d0f0d7dc3cf376a9fd75e6db4..3925df9124c391bb0d03b279ceb44cd320a0d618 100644 (file)
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -558,39 +558,44 @@ static struct shrinker    nfsd_file_shrinker = {
        .seeks = 1,
 };
 
-static void
-__nfsd_file_close_inode(struct inode *inode, unsigned int hashval,
-                       struct list_head *dispose)
+/*
+ * Find all cache items across all net namespaces that match @inode and
+ * move them to @dispose. The lookup is atomic wrt nfsd_file_acquire().
+ */
+static unsigned int
+__nfsd_file_close_inode(struct inode *inode, struct list_head *dispose)
 {
+       unsigned int            hashval = (unsigned int)hash_long(inode->i_ino,
+                                               NFSD_FILE_HASH_BITS);
+       unsigned int            count = 0;
        struct nfsd_file        *nf;
        struct hlist_node       *tmp;
 
        spin_lock(&nfsd_file_hashtbl[hashval].nfb_lock);
        hlist_for_each_entry_safe(nf, tmp, &nfsd_file_hashtbl[hashval].nfb_head, nf_node) {
-               if (inode == nf->nf_inode)
+               if (inode == nf->nf_inode) {
                        nfsd_file_unhash_and_release_locked(nf, dispose);
+                       count++;
+               }
        }
        spin_unlock(&nfsd_file_hashtbl[hashval].nfb_lock);
+       return count;
 }
 
 /**
  * nfsd_file_close_inode_sync - attempt to forcibly close a nfsd_file
  * @inode: inode of the file to attempt to remove
  *
- * Walk the whole hash bucket, looking for any files that correspond to "inode".
- * If any do, then unhash them and put the hashtable reference to them and
- * destroy any that had their last reference put. Also ensure that any of the
- * fputs also have their final __fput done as well.
+ * Unhash and put, then flush and fput all cache items associated with @inode.
  */
 void
 nfsd_file_close_inode_sync(struct inode *inode)
 {
-       unsigned int            hashval = (unsigned int)hash_long(inode->i_ino,
-                                               NFSD_FILE_HASH_BITS);
        LIST_HEAD(dispose);
+       unsigned int count;
 
-       __nfsd_file_close_inode(inode, hashval, &dispose);
-       trace_nfsd_file_close_inode_sync(inode, !list_empty(&dispose));
+       count = __nfsd_file_close_inode(inode, &dispose);
+       trace_nfsd_file_close_inode_sync(inode, count);
        nfsd_file_dispose_list_sync(&dispose);
 }
 
@@ -598,19 +603,16 @@ nfsd_file_close_inode_sync(struct inode *inode)
  * nfsd_file_close_inode - attempt a delayed close of a nfsd_file
  * @inode: inode of the file to attempt to remove
  *
- * Walk the whole hash bucket, looking for any files that correspond to "inode".
- * If any do, then unhash them and put the hashtable reference to them and
- * destroy any that had their last reference put.
+ * Unhash and put all cache item associated with @inode.
  */
 static void
 nfsd_file_close_inode(struct inode *inode)
 {
-       unsigned int            hashval = (unsigned int)hash_long(inode->i_ino,
-                                               NFSD_FILE_HASH_BITS);
        LIST_HEAD(dispose);
+       unsigned int count;
 
-       __nfsd_file_close_inode(inode, hashval, &dispose);
-       trace_nfsd_file_close_inode(inode, !list_empty(&dispose));
+       count = __nfsd_file_close_inode(inode, &dispose);
+       trace_nfsd_file_close_inode(inode, count);
        nfsd_file_dispose_list_delayed(&dispose);
 }
 

diff --git a/fs/nfsd/trace.h b/fs/nfsd/trace.h
index 655b56c87600b12b136d35c7dac9a2cb027600e3..e82ea1abfbd466157b84c1f63db200d0a700fa05 100644 (file)
--- a/fs/nfsd/trace.h
+++ b/fs/nfsd/trace.h
@@ -847,30 +847,52 @@ TRACE_EVENT(nfsd_file_open,
 
 DECLARE_EVENT_CLASS(nfsd_file_search_class,
        TP_PROTO(
-               struct inode *inode,
-               int found
+               const struct inode *inode,
+               unsigned int count
        ),
-       TP_ARGS(inode, found),
+       TP_ARGS(inode, count),
        TP_STRUCT__entry(
-               __field(struct inode *, inode)
-               __field(int, found)
+               __field(const struct inode *, inode)
+               __field(unsigned int, count)
        ),
        TP_fast_assign(
                __entry->inode = inode;
-               __entry->found = found;
+               __entry->count = count;
        ),
-       TP_printk("inode=%p found=%d",
-               __entry->inode, __entry->found)
+       TP_printk("inode=%p count=%u",
+               __entry->inode, __entry->count)
 );
 
 #define DEFINE_NFSD_FILE_SEARCH_EVENT(name)                            \
 DEFINE_EVENT(nfsd_file_search_class, name,                             \
-       TP_PROTO(struct inode *inode, int found),                       \
-       TP_ARGS(inode, found))
+       TP_PROTO(                                                       \
+               const struct inode *inode,                              \
+               unsigned int count                                      \
+       ),                                                              \
+       TP_ARGS(inode, count))
 
 DEFINE_NFSD_FILE_SEARCH_EVENT(nfsd_file_close_inode_sync);
 DEFINE_NFSD_FILE_SEARCH_EVENT(nfsd_file_close_inode);
-DEFINE_NFSD_FILE_SEARCH_EVENT(nfsd_file_is_cached);
+
+TRACE_EVENT(nfsd_file_is_cached,
+       TP_PROTO(
+               const struct inode *inode,
+               int found
+       ),
+       TP_ARGS(inode, found),
+       TP_STRUCT__entry(
+               __field(const struct inode *, inode)
+               __field(int, found)
+       ),
+       TP_fast_assign(
+               __entry->inode = inode;
+               __entry->found = found;
+       ),
+       TP_printk("inode=%p is %scached",
+               __entry->inode,
+               __entry->found ? "" : "not "
+       )
+);
 
 TRACE_EVENT(nfsd_file_fsnotify_handle_event,
        TP_PROTO(struct inode *inode, u32 mask),