From: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> Fix a debug-only build error in ext2/xattr.c: When building without extra debugging, (and with another patch that uses no_printk() instead of <empty> for the ext2-xattr debug-print macros, this build error happens: ../fs/ext2/xattr.c: In function ‘ext2_xattr_cache_insert’: ../fs/ext2/xattr.c:869:18: error: ‘ext2_xattr_cache’ undeclared (first use in this function); did you mean ‘ext2_xattr_list’? atomic_read(&ext2_xattr_cache->c_entry_count)); Fix by moving struct mb_cache from fs/mbcache.c to <linux/mbcache.h>, and then using the correct struct name in the debug-print macro. This wasn't converted when ext2 xattr cache was changed to use mbcache. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> Cc: Jan Kara <jack@xxxxxxxx> Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: linux-ext4@xxxxxxxxxxxxxxx Cc: linux-fsdevel@xxxxxxxxxxxxxxx --- This is ancient, from the beginning of git history. Or just kill of that print of c_entry_count... fs/ext2/xattr.c | 2 +- fs/mbcache.c | 34 ---------------------------------- include/linux/mbcache.h | 35 ++++++++++++++++++++++++++++++++++- 3 files changed, 35 insertions(+), 36 deletions(-) --- linux-next-20200313.orig/fs/ext2/xattr.c +++ linux-next-20200313/fs/ext2/xattr.c @@ -873,7 +873,7 @@ ext2_xattr_cache_insert(struct mb_cache if (error) { if (error == -EBUSY) { ea_bdebug(bh, "already in cache (%d cache entries)", - atomic_read(&ext2_xattr_cache->c_entry_count)); + atomic_read(&cache->c_entry_count)); error = 0; } } else --- linux-next-20200313.orig/fs/mbcache.c +++ linux-next-20200313/fs/mbcache.c @@ -8,40 +8,6 @@ #include <linux/workqueue.h> #include <linux/mbcache.h> -/* - * Mbcache is a simple key-value store. Keys need not be unique, however - * key-value pairs are expected to be unique (we use this fact in - * mb_cache_entry_delete()). - * - * Ext2 and ext4 use this cache for deduplication of extended attribute blocks. - * Ext4 also uses it for deduplication of xattr values stored in inodes. - * They use hash of data as a key and provide a value that may represent a - * block or inode number. That's why keys need not be unique (hash of different - * data may be the same). However user provided value always uniquely - * identifies a cache entry. - * - * We provide functions for creation and removal of entries, search by key, - * and a special "delete entry with given key-value pair" operation. Fixed - * size hash table is used for fast key lookups. - */ - -struct mb_cache { - /* Hash table of entries */ - struct hlist_bl_head *c_hash; - /* log2 of hash table size */ - int c_bucket_bits; - /* Maximum entries in cache to avoid degrading hash too much */ - unsigned long c_max_entries; - /* Protects c_list, c_entry_count */ - spinlock_t c_list_lock; - struct list_head c_list; - /* Number of entries in cache */ - unsigned long c_entry_count; - struct shrinker c_shrink; - /* Work for shrinking when the cache has too many entries */ - struct work_struct c_shrink_work; -}; - static struct kmem_cache *mb_entry_cache; static unsigned long mb_cache_shrink(struct mb_cache *cache, --- linux-next-20200313.orig/include/linux/mbcache.h +++ linux-next-20200313/include/linux/mbcache.h @@ -8,7 +8,40 @@ #include <linux/atomic.h> #include <linux/fs.h> -struct mb_cache; +/* + * Mbcache is a simple key-value store. Keys need not be unique, however + * key-value pairs are expected to be unique (we use this fact in + * mb_cache_entry_delete()). + * + * Ext2 and ext4 use this cache for deduplication of extended attribute blocks. + * Ext4 also uses it for deduplication of xattr values stored in inodes. + * They use hash of data as a key and provide a value that may represent a + * block or inode number. That's why keys need not be unique (hash of different + * data may be the same). However user provided value always uniquely + * identifies a cache entry. + * + * We provide functions for creation and removal of entries, search by key, + * and a special "delete entry with given key-value pair" operation. Fixed + * size hash table is used for fast key lookups. + */ + +struct mb_cache { + /* Hash table of entries */ + struct hlist_bl_head *c_hash; + /* log2 of hash table size */ + int c_bucket_bits; + /* Maximum entries in cache to avoid degrading hash too much */ + unsigned long c_max_entries; + /* Protects c_list, c_entry_count */ + spinlock_t c_list_lock; + struct list_head c_list; + /* Number of entries in cache */ + unsigned long c_entry_count; + struct shrinker c_shrink; + /* Work for shrinking when the cache has too many entries */ + struct work_struct c_shrink_work; +}; + struct mb_cache_entry { /* List of entries in cache - protected by cache->c_list_lock */