[PATCH] knfsd: change nlm_file to use a hlist

This changes struct nlm_file and the nlm_files hash table to use a hlist
instead of the home-grown lists.

This allows us to remove f_hash which was only used to find the right hash
chain to delete an entry from.

It also increases the size of the nlm_files hash table from 32 to 128.

Signed-off-by: Olaf Kirch <okir@suse.de>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 17 insertions, 28 deletions

diff --git a/fs/lockd/svcsubs.c b/fs/lockd/svcsubs.c
index a92fc5813144..91731353dfa4 100644
--- a/fs/lockd/svcsubs.c
+++ b/fs/lockd/svcsubs.c
@@ -25,9 +25,9 @@
 /*
  * Global file hash table
  */
-#define FILE_HASH_BITS          5
+#define FILE_HASH_BITS          7
 #define FILE_NRHASH             (1<<FILE_HASH_BITS)
-static struct nlm_file *        nlm_files[FILE_NRHASH];
+static struct hlist_head        nlm_files[FILE_NRHASH];
 static DEFINE_MUTEX(nlm_file_mutex);
 
 #ifdef NFSD_DEBUG
@@ -82,6 +82,7 @@ u32
 nlm_lookup_file(struct svc_rqst *rqstp, struct nlm_file **result,
                                         struct nfs_fh *f)
 {
+        struct hlist_node *pos;
         struct nlm_file *file;
         unsigned int    hash;
         u32             nfserr;
@@ -93,7 +94,7 @@ nlm_lookup_file(struct svc_rqst *rqstp, struct nlm_file **result,
         /* Lock file table */
         mutex_lock(&nlm_file_mutex);
 
-        for (file = nlm_files[hash]; file; file = file->f_next)
+        hlist_for_each_entry(file, pos, &nlm_files[hash], f_list)
                 if (!nfs_compare_fh(&file->f_handle, f))
                         goto found;
 
@@ -105,8 +106,8 @@ nlm_lookup_file(struct svc_rqst *rqstp, struct nlm_file **result,
                 goto out_unlock;
 
         memcpy(&file->f_handle, f, sizeof(struct nfs_fh));
-        file->f_hash = hash;
         init_MUTEX(&file->f_sema);
+        INIT_HLIST_NODE(&file->f_list);
         INIT_LIST_HEAD(&file->f_blocks);
 
         /* Open the file. Note that this must not sleep for too long, else
@@ -120,8 +121,7 @@ nlm_lookup_file(struct svc_rqst *rqstp, struct nlm_file **result,
                 goto out_free;
         }
 
-        file->f_next = nlm_files[hash];
-        nlm_files[hash] = file;
+        hlist_add_head(&file->f_list, &nlm_files[hash]);
 
 found:
         dprintk("lockd: found file %p (count %d)\n", file, file->f_count);
@@ -150,22 +150,14 @@ out_free:
 static inline void
 nlm_delete_file(struct nlm_file *file)
 {
-        struct nlm_file **fp, *f;
-
         nlm_debug_print_file("closing file", file);
-
-        fp = nlm_files + file->f_hash;
-        while ((f = *fp) != NULL) {
-                if (f == file) {
-                        *fp = file->f_next;
-                        nlmsvc_ops->fclose(file->f_file);
-                        kfree(file);
-                        return;
-                }
-                fp = &f->f_next;
+        if (!hlist_unhashed(&file->f_list)) {
+                hlist_del(&file->f_list);
+                nlmsvc_ops->fclose(file->f_file);
+                kfree(file);
+        } else {
+                printk(KERN_WARNING "lockd: attempt to release unknown file!\n");
         }
-
-        printk(KERN_WARNING "lockd: attempt to release unknown file!\n");
 }
 
 /*
@@ -236,13 +228,13 @@ nlm_inspect_file(struct nlm_host *host, struct nlm_file *file, int action)
 static int
 nlm_traverse_files(struct nlm_host *host, int action)
 {
-        struct nlm_file *file, **fp;
+        struct hlist_node *pos, *next;
+        struct nlm_file *file;
         int i, ret = 0;
 
         mutex_lock(&nlm_file_mutex);
         for (i = 0; i < FILE_NRHASH; i++) {
-                fp = nlm_files + i;
-                while ((file = *fp) != NULL) {
+                hlist_for_each_entry_safe(file, pos, next, &nlm_files[i], f_list) {
                         file->f_count++;
                         mutex_unlock(&nlm_file_mutex);
 
@@ -256,11 +248,9 @@ nlm_traverse_files(struct nlm_host *host, int action)
                         /* No more references to this file. Let go of it. */
                         if (list_empty(&file->f_blocks) && !file->f_locks
                          && !file->f_shares && !file->f_count) {
-                                *fp = file->f_next;
+                                hlist_del(&file->f_list);
                                 nlmsvc_ops->fclose(file->f_file);
                                 kfree(file);
-                        } else {
-                                fp = &file->f_next;
                         }
                 }
         }
diff --git a/include/linux/lockd/lockd.h b/include/linux/lockd/lockd.h
index 2e740f6a2f77..777a91e1ac8f 100644
--- a/include/linux/lockd/lockd.h
+++ b/include/linux/lockd/lockd.h
@@ -105,7 +105,7 @@ struct nlm_rqst {
  * an NFS client.
  */
 struct nlm_file {
-        struct nlm_file *       f_next;         /* linked list */
+        struct hlist_node       f_list;         /* linked list */
         struct nfs_fh           f_handle;       /* NFS file handle */
         struct file *           f_file;         /* VFS file pointer */
         struct nlm_share *      f_shares;       /* DOS shares */
@@ -113,7 +113,6 @@ struct nlm_file {
         unsigned int            f_locks;        /* guesstimate # of locks */
         unsigned int            f_count;        /* reference count */
         struct semaphore        f_sema;         /* avoid concurrent access */
-        int                     f_hash;         /* hash of f_handle */
 };
 
 /*