[PATCH] presto cache keyed by superblock instead of kdev_t

fs/intermezzo/cache.c

@@ -58,16 +58,15 @@ extern kmem_cache_t * presto_dentry_slab;
 #define CACHES_MASK CACHES_SIZE - 1
 static struct list_head presto_caches[CACHES_SIZE];
 
-static inline int presto_cache_hash(kdev_t dev)
+static inline int presto_cache_hash(struct super_block *s)
 {
-        return (CACHES_MASK) & ((0x000F & (major(dev)) << 8) + (0x000F & minor(dev)));
+        return (CACHES_MASK) & ((unsigned long)s >> L1_CACHE_SHIFT);
 }
 
-inline void presto_cache_add(struct presto_cache *cache, kdev_t dev)
+inline void presto_cache_add(struct presto_cache *cache)
 {
         list_add(&cache->cache_chain,
-                 &presto_caches[presto_cache_hash(dev)]);
-        cache->cache_dev = dev;
+                 &presto_caches[presto_cache_hash(cache->cache_sb)]);
 }
 
 inline void presto_cache_init_hash(void)
@@ -79,18 +78,17 @@ inline void presto_cache_init_hash(void)
 }
 
 /* map a device to a cache */
-struct presto_cache *presto_cache_find(kdev_t dev)
+struct presto_cache *presto_cache_find(struct super_block *s)
 {
         struct presto_cache *cache;
         struct list_head *lh, *tmp;
 
-        lh = tmp = &(presto_caches[presto_cache_hash(dev)]);
+        lh = tmp = &(presto_caches[presto_cache_hash(s)]);
         while ( (tmp = lh->next) != lh ) {
                 cache = list_entry(tmp, struct presto_cache, cache_chain);
-                if ( kdev_same(cache->cache_dev, dev) ) {
+                if (cache->cache_sb == s)
                         return cache;
         }
-        }
         return NULL;
 }
 
@@ -101,10 +99,10 @@ struct presto_cache *presto_get_cache(struct inode *inode)
         struct presto_cache *cache;
         ENTRY;
         /* find the correct presto_cache here, based on the device */
-        cache = presto_cache_find(to_kdev_t(inode->i_dev));
+        cache = presto_cache_find(inode->i_sb);
         if ( !cache ) {
-                CERROR("WARNING: no presto cache for dev %x, ino %ld\n",
-                       inode->i_dev, inode->i_ino);
+                CERROR("WARNING: no presto cache for %s, ino %ld\n",
+                       inode->i_sb->s_id, inode->i_ino);
                 EXIT;
                 return NULL;
         }
@@ -122,7 +120,7 @@ int presto_ispresto(struct inode *inode)
         cache = presto_get_cache(inode);
         if ( !cache )
                 return 0;
-        return kdev_same(to_kdev_t(inode->i_dev), cache->cache_dev);
+        return inode->i_sb == cache->cache_sb;
 }
 
 /* setup a cache structure when we need one */

fs/intermezzo/inode.c

@@ -118,7 +118,7 @@ static void presto_put_super(struct super_block *sb)
         int err;
 
         ENTRY;
-        cache = presto_cache_find(to_kdev_t(sb->s_dev));
+        cache = presto_cache_find(sb);
         if (!cache) {
                 EXIT;
                 goto exit;

fs/intermezzo/super.c

@@ -285,7 +285,7 @@ struct super_block * presto_get_sb(struct file_system_type *izo_type,
         cache->cache_root = dget(sb->s_root);
 
         /* we now know the dev of the cache: hash the cache */
-        presto_cache_add(cache, to_kdev_t(sb->s_dev));
+        presto_cache_add(cache);
         err = izo_prepare_fileset(sb->s_root, fileset); 
 
         filter_setup_journal_ops(cache->cache_filter, cache->cache_type); 

include/linux/intermezzo_fs.h

@@ -223,8 +223,6 @@ struct presto_cache {
 
         int   cache_flags;
 
-        kdev_t cache_dev;            /* underlying block device */
-
         char *cache_type;            /* filesystem type of cache */
         struct filter_fs *cache_filter;
 
@@ -425,10 +423,10 @@ int presto_prep(struct dentry *, struct presto_cache **,
                        struct presto_file_set **);
 /* cache.c */
 extern struct presto_cache *presto_cache_init(void);
-extern inline void presto_cache_add(struct presto_cache *cache, kdev_t dev);
+extern inline void presto_cache_add(struct presto_cache *cache);
 extern inline void presto_cache_init_hash(void);
 
-struct presto_cache *presto_cache_find(kdev_t dev);
+struct presto_cache *presto_cache_find(struct super_block *sb);
 
 #define PRESTO_REQLOW  (3 * 4096)
 #define PRESTO_REQHIGH (6 * 4096)