From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sun, 20 Oct 2002 05:31:08 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sun, 20 Oct 2002 05:30:38 -0400 Received: from SNAP.THUNK.ORG ([216.175.175.173]:8660 "EHLO snap.thunk.org") by vger.kernel.org with ESMTP id ; Sun, 20 Oct 2002 05:29:33 -0400 To: linux-kernel@vger.kernel.org Subject: [PATCH] ext2/3 updates for 2.5.44 (4/11): mbcache infrastructure for xattrs From: tytso@mit.edu Message-Id: Date: Sun, 20 Oct 2002 05:35:37 -0400 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org # The following is the BitKeeper ChangeSet Log # -------------------------------------------- # 02/10/20 tytso@snap.thunk.org 1.813 # Port of the 0.8.50 xattr-mbcache patch to 2.5. (Shrinker API, hch cleanups) # (now uses struct block_device * to index devices, and uses hash.h for hash function) # # This patch creates a meta block cache which is utilized by the ext3 and # ext2 extended attribute patch (patches 2 and 3, respectively). This # cache allows directory blocks to be indexed by multiple keys. In the # case of the extended attribute patches, it is used to look up blocks by # both the block number and by the hash of the extended attributes. This # is extremely important to allow the sharing of acl's when stored as # extended attributes. Otherwise every single file would require its own, # separate, one block overhead to store then ACL, even though there might # be a large number of files that have the same ACL. # -------------------------------------------- # # fs/Config.in | 11 # fs/Makefile | 4 # fs/mbcache.c | 702 ++++++++++++++++++++++++++++++++++++++++++++++++ # include/linux/mbcache.h | 72 ++++ # 4 files changed, 788 insertions(+), 1 deletion(-) # diff -Nru a/fs/Config.in b/fs/Config.in --- a/fs/Config.in Sun Oct 20 04:40:53 2002 +++ b/fs/Config.in Sun Oct 20 04:40:53 2002 @@ -182,6 +182,17 @@ define_tristate CONFIG_ZISOFS_FS n fi +# Meta block cache for Extended Attributes (ext2/ext3) +if [ "$CONFIG_EXT2_FS_XATTR" = "y" -o "$CONFIG_EXT3_FS_XATTR" = "y" ]; then + if [ "$CONFIG_EXT2_FS" = "y" -o "$CONFIG_EXT3_FS" = "y" ]; then + define_tristate CONFIG_FS_MBCACHE y + else + if [ "$CONFIG_EXT2_FS" = "m" -o "$CONFIG_EXT3_FS" = "m" ]; then + define_tristate CONFIG_FS_MBCACHE m + fi + fi +fi + mainmenu_option next_comment comment 'Partition Types' source fs/partitions/Config.in diff -Nru a/fs/Makefile b/fs/Makefile --- a/fs/Makefile Sun Oct 20 04:40:53 2002 +++ b/fs/Makefile Sun Oct 20 04:40:53 2002 @@ -6,7 +6,7 @@ # export-objs := open.o dcache.o buffer.o bio.o inode.o dquot.o mpage.o aio.o \ - fcntl.o read_write.o dcookies.o + fcntl.o read_write.o dcookies.o mbcache.o obj-y := open.o read_write.o devices.o file_table.o buffer.o \ bio.o super.o block_dev.o char_dev.o stat.o exec.o pipe.o \ @@ -29,6 +29,8 @@ obj-y += binfmt_script.o obj-$(CONFIG_BINFMT_ELF) += binfmt_elf.o + +obj-$(CONFIG_FS_MBCACHE) += mbcache.o obj-$(CONFIG_QUOTA) += dquot.o obj-$(CONFIG_QFMT_V1) += quota_v1.o diff -Nru a/fs/mbcache.c b/fs/mbcache.c --- /dev/null Wed Dec 31 16:00:00 1969 +++ b/fs/mbcache.c Sun Oct 20 04:40:53 2002 @@ -0,0 +1,702 @@ +/* + * linux/fs/mbcache.c + * (C) 2001-2002 Andreas Gruenbacher, + */ + +/* + * Filesystem Meta Information Block Cache (mbcache) + * + * The mbcache caches blocks of block devices that need to be located + * by their device/block number, as well as by other criteria (such + * as the block's contents). + * + * There can only be one cache entry in a cache per device and block number. + * Additional indexes need not be unique in this sense. The number of + * additional indexes (=other criteria) can be hardwired (at compile time) + * or specified at cache create time. + * + * Each cache entry is of fixed size. An entry may be `valid' or `invalid' + * in the cache. A valid entry is in the main hash tables of the cache, + * and may also be in the lru list. An invalid entry is not in any hashes + * or lists. + * + * A valid cache entry is only in the lru list if no handles refer to it. + * Invalid cache entries will be freed when the last handle to the cache + * entry is released. + */ + +#include +#include + +#include +#include +#include +#include +#include +#include +#include + + +#ifdef MB_CACHE_DEBUG +# define mb_debug(f...) do { \ + printk(KERN_DEBUG f); \ + printk("\n"); \ + } while (0) +#define mb_assert(c) do { if (!(c)) \ + printk(KERN_ERR "assertion " #c " failed\n"); \ + } while(0) +#else +# define mb_debug(f...) do { } while(0) +# define mb_assert(c) do { } while(0) +#endif +#define mb_error(f...) do { \ + printk(KERN_ERR f); \ + printk("\n"); \ + } while(0) + +MODULE_AUTHOR("Andreas Gruenbacher "); +MODULE_DESCRIPTION("Meta block cache (for extended attributes)"); +MODULE_LICENSE("GPL"); + +EXPORT_SYMBOL(mb_cache_create); +EXPORT_SYMBOL(mb_cache_shrink); +EXPORT_SYMBOL(mb_cache_destroy); +EXPORT_SYMBOL(mb_cache_entry_alloc); +EXPORT_SYMBOL(mb_cache_entry_insert); +EXPORT_SYMBOL(mb_cache_entry_release); +EXPORT_SYMBOL(mb_cache_entry_takeout); +EXPORT_SYMBOL(mb_cache_entry_free); +EXPORT_SYMBOL(mb_cache_entry_dup); +EXPORT_SYMBOL(mb_cache_entry_get); +#if !defined(MB_CACHE_INDEXES_COUNT) || (MB_CACHE_INDEXES_COUNT > 0) +EXPORT_SYMBOL(mb_cache_entry_find_first); +EXPORT_SYMBOL(mb_cache_entry_find_next); +#endif + + +/* + * Global data: list of all mbcache's, lru list, and a spinlock for + * accessing cache data structures on SMP machines. (The lru list is + * global across all mbcaches.) + */ + +static LIST_HEAD(mb_cache_list); +static LIST_HEAD(mb_cache_lru_list); +static spinlock_t mb_cache_spinlock = SPIN_LOCK_UNLOCKED; +static struct shrinker *mb_shrinker; + +static inline int +mb_cache_indexes(struct mb_cache *cache) +{ +#ifdef MB_CACHE_INDEXES_COUNT + return MB_CACHE_INDEXES_COUNT; +#else + return cache->c_indexes_count; +#endif +} + +/* + * What the mbcache registers as to get shrunk dynamically. + */ + +static int mb_cache_shrink_fn(int nr_to_scan, unsigned int gfp_mask); + +static inline void +__mb_cache_entry_takeout_lru(struct mb_cache_entry *ce) +{ + if (!list_empty(&ce->e_lru_list)) + list_del_init(&ce->e_lru_list); +} + + +static inline void +__mb_cache_entry_into_lru(struct mb_cache_entry *ce) +{ + list_add(&ce->e_lru_list, &mb_cache_lru_list); +} + + +static inline int +__mb_cache_entry_in_lru(struct mb_cache_entry *ce) +{ + return (!list_empty(&ce->e_lru_list)); +} + + +/* + * Insert the cache entry into all hashes. + */ +static inline void +__mb_cache_entry_link(struct mb_cache_entry *ce) +{ + struct mb_cache *cache = ce->e_cache; + unsigned int bucket; + int n; + + bucket = hash_long((unsigned long)ce->e_bdev + + (ce->e_block & 0xffffff), cache->c_bucket_bits); + list_add(&ce->e_block_list, &cache->c_block_hash[bucket]); + for (n=0; ne_indexes[n].o_key, + cache->c_bucket_bits); + list_add(&ce->e_indexes[n].o_list, + &cache->c_indexes_hash[n][bucket]); + } +} + + +/* + * Remove the cache entry from all hashes. + */ +static inline void +__mb_cache_entry_unlink(struct mb_cache_entry *ce) +{ + int n; + + list_del_init(&ce->e_block_list); + for (n = 0; n < mb_cache_indexes(ce->e_cache); n++) + list_del(&ce->e_indexes[n].o_list); +} + + +static inline int +__mb_cache_entry_is_linked(struct mb_cache_entry *ce) +{ + return (!list_empty(&ce->e_block_list)); +} + + +static inline struct mb_cache_entry * +__mb_cache_entry_read(struct mb_cache_entry *ce) +{ + __mb_cache_entry_takeout_lru(ce); + atomic_inc(&ce->e_used); + return ce; +} + + +static inline void +__mb_cache_entry_forget(struct mb_cache_entry *ce) +{ + struct mb_cache *cache = ce->e_cache; + + mb_assert(atomic_read(&ce->e_used) == 0); + atomic_dec(&cache->c_entry_count); + if (cache->c_op.free) + cache->c_op.free(ce); + kmem_cache_free(cache->c_entry_cache, ce); +} + + +static inline void +__mb_cache_entry_release_unlock(struct mb_cache_entry *ce) +{ + if (atomic_dec_and_test(&ce->e_used)) { + if (!__mb_cache_entry_is_linked(ce)) + goto forget; + __mb_cache_entry_into_lru(ce); + } + spin_unlock(&mb_cache_spinlock); + return; +forget: + spin_unlock(&mb_cache_spinlock); + __mb_cache_entry_forget(ce); +} + + +/* + * mb_cache_shrink_fn() memory pressure callback + * + * This function is called by the kernel memory management when memory + * gets low. + * + * @nr_to_scan: Number of objects to scan + * @gfp_mask: (ignored) + * + * Returns the number of objects which are present in the cache. + */ +static int +mb_cache_shrink_fn(int nr_to_scan, unsigned int gfp_mask) +{ + LIST_HEAD(free_list); + struct list_head *l; + int count = 0; + + spin_lock(&mb_cache_spinlock); + list_for_each_prev(l, &mb_cache_list) { + struct mb_cache *cache = + list_entry(l, struct mb_cache, c_cache_list); + mb_debug("cache %s (%d)", cache->c_name, + atomic_read(&cache->c_entry_count)); + count += atomic_read(&cache->c_entry_count); + } + mb_debug("trying to free %d entries", nr_to_scan); + if (nr_to_scan == 0) { + spin_unlock(&mb_cache_spinlock); + goto out; + } + while (nr_to_scan && !list_empty(&mb_cache_lru_list)) { + struct mb_cache_entry *ce = + list_entry(mb_cache_lru_list.prev, + struct mb_cache_entry, e_lru_list); + list_move(&ce->e_lru_list, &free_list); + if (__mb_cache_entry_is_linked(ce)) + __mb_cache_entry_unlink(ce); + nr_to_scan--; + } + spin_unlock(&mb_cache_spinlock); + l = free_list.prev; + while (l != &free_list) { + struct mb_cache_entry *ce = list_entry(l, + struct mb_cache_entry, e_lru_list); + l = l->prev; + __mb_cache_entry_forget(ce); + count--; + } +out: + mb_debug("%d remaining entries ", count); + return count; +} + + +/* + * mb_cache_create() create a new cache + * + * All entries in one cache are equal size. Cache entries may be from + * multiple devices. If this is the first mbcache created, registers + * the cache with kernel memory management. Returns NULL if no more + * memory was available. + * + * @name: name of the cache (informal) + * @cache_op: contains the callback called when freeing a cache entry + * @entry_size: The size of a cache entry, including + * struct mb_cache_entry + * @indexes_count: number of additional indexes in the cache. Must equal + * MB_CACHE_INDEXES_COUNT if the number of indexes is + * hardwired. + * @bucket_bits: log2(number of hash buckets) + */ +struct mb_cache * +mb_cache_create(const char *name, struct mb_cache_op *cache_op, + size_t entry_size, int indexes_count, int bucket_bits) +{ + int m=0, n, bucket_count = 1 << bucket_bits; + struct mb_cache *cache = NULL; + + if(entry_size < sizeof(struct mb_cache_entry) + + indexes_count * sizeof(struct mb_cache_entry_index)) + return NULL; + + cache = kmalloc(sizeof(struct mb_cache) + + indexes_count * sizeof(struct list_head), GFP_KERNEL); + if (!cache) + goto fail; + cache->c_name = name; + if (cache_op) + cache->c_op.free = cache_op->free; + else + cache->c_op.free = NULL; + atomic_set(&cache->c_entry_count, 0); + cache->c_bucket_bits = bucket_bits; +#ifdef MB_CACHE_INDEXES_COUNT + mb_assert(indexes_count == MB_CACHE_INDEXES_COUNT); +#else + cache->c_indexes_count = indexes_count; +#endif + cache->c_block_hash = kmalloc(bucket_count * sizeof(struct list_head), + GFP_KERNEL); + if (!cache->c_block_hash) + goto fail; + for (n=0; nc_block_hash[n]); + for (m=0; mc_indexes_hash[m] = kmalloc(bucket_count * + sizeof(struct list_head), + GFP_KERNEL); + if (!cache->c_indexes_hash[m]) + goto fail; + for (n=0; nc_indexes_hash[m][n]); + } + cache->c_entry_cache = kmem_cache_create(name, entry_size, 0, + 0 /*SLAB_POISON | SLAB_RED_ZONE*/, NULL, NULL); + if (!cache->c_entry_cache) + goto fail; + + spin_lock(&mb_cache_spinlock); + if (list_empty(&mb_cache_list)) { + if (mb_shrinker) { + printk(KERN_ERR "%s: already have a shrinker!\n", + __FUNCTION__); + remove_shrinker(mb_shrinker); + } + mb_shrinker = set_shrinker(DEFAULT_SEEKS, mb_cache_shrink_fn); + } + list_add(&cache->c_cache_list, &mb_cache_list); + spin_unlock(&mb_cache_spinlock); + return cache; + +fail: + if (cache) { + while (--m >= 0) + kfree(cache->c_indexes_hash[m]); + if (cache->c_block_hash) + kfree(cache->c_block_hash); + kfree(cache); + } + return NULL; +} + + +/* + * mb_cache_shrink() + * + * Removes all cache entires of a device from the cache. All cache entries + * currently in use cannot be freed, and thus remain in the cache. All others + * are freed. + * + * @cache: which cache to shrink + * @bdev: which device's cache entries to shrink + */ +void +mb_cache_shrink(struct mb_cache *cache, struct block_device *bdev) +{ + LIST_HEAD(free_list); + struct list_head *l; + + spin_lock(&mb_cache_spinlock); + l = mb_cache_lru_list.prev; + while (l != &mb_cache_lru_list) { + struct mb_cache_entry *ce = + list_entry(l, struct mb_cache_entry, e_lru_list); + l = l->prev; + if (ce->e_bdev == bdev) { + list_move(&ce->e_lru_list, &free_list); + if (__mb_cache_entry_is_linked(ce)) + __mb_cache_entry_unlink(ce); + } + } + spin_unlock(&mb_cache_spinlock); + l = free_list.prev; + while (l != &free_list) { + struct mb_cache_entry *ce = + list_entry(l, struct mb_cache_entry, e_lru_list); + l = l->prev; + __mb_cache_entry_forget(ce); + } +} + + +/* + * mb_cache_destroy() + * + * Shrinks the cache to its minimum possible size (hopefully 0 entries), + * and then destroys it. If this was the last mbcache, un-registers the + * mbcache from kernel memory management. + */ +void +mb_cache_destroy(struct mb_cache *cache) +{ + LIST_HEAD(free_list); + struct list_head *l; + int n; + + spin_lock(&mb_cache_spinlock); + l = mb_cache_lru_list.prev; + while (l != &mb_cache_lru_list) { + struct mb_cache_entry *ce = + list_entry(l, struct mb_cache_entry, e_lru_list); + l = l->prev; + if (ce->e_cache == cache) { + list_move(&ce->e_lru_list, &free_list); + if (__mb_cache_entry_is_linked(ce)) + __mb_cache_entry_unlink(ce); + } + } + list_del(&cache->c_cache_list); + if (list_empty(&mb_cache_list) && mb_shrinker) { + remove_shrinker(mb_shrinker); + mb_shrinker = 0; + } + spin_unlock(&mb_cache_spinlock); + + l = free_list.prev; + while (l != &free_list) { + struct mb_cache_entry *ce = + list_entry(l, struct mb_cache_entry, e_lru_list); + l = l->prev; + __mb_cache_entry_forget(ce); + } + + if (atomic_read(&cache->c_entry_count) > 0) { + mb_error("cache %s: %d orphaned entries", + cache->c_name, + atomic_read(&cache->c_entry_count)); + } + + kmem_cache_destroy(cache->c_entry_cache); + + for (n=0; n < mb_cache_indexes(cache); n++) + kfree(cache->c_indexes_hash[n]); + kfree(cache->c_block_hash); + + kfree(cache); +} + + +/* + * mb_cache_entry_alloc() + * + * Allocates a new cache entry. The new entry will not be valid initially, + * and thus cannot be looked up yet. It should be filled with data, and + * then inserted into the cache using mb_cache_entry_insert(). Returns NULL + * if no more memory was available. + */ +struct mb_cache_entry * +mb_cache_entry_alloc(struct mb_cache *cache) +{ + struct mb_cache_entry *ce; + + atomic_inc(&cache->c_entry_count); + ce = kmem_cache_alloc(cache->c_entry_cache, GFP_KERNEL); + if (ce) { + INIT_LIST_HEAD(&ce->e_lru_list); + INIT_LIST_HEAD(&ce->e_block_list); + ce->e_cache = cache; + atomic_set(&ce->e_used, 1); + } + return ce; +} + + +/* + * mb_cache_entry_insert() + * + * Inserts an entry that was allocated using mb_cache_entry_alloc() into + * the cache. After this, the cache entry can be looked up, but is not yet + * in the lru list as the caller still holds a handle to it. Returns 0 on + * success, or -EBUSY if a cache entry for that device + inode exists + * already (this may happen after a failed lookup, but when another process + * has inserted the same cache entry in the meantime). + * + * @bdev: device the cache entry belongs to + * @block: block number + * @keys: array of additional keys. There must be indexes_count entries + * in the array (as specified when creating the cache). + */ +int +mb_cache_entry_insert(struct mb_cache_entry *ce, struct block_device *bdev, + sector_t block, unsigned int keys[]) +{ + struct mb_cache *cache = ce->e_cache; + unsigned int bucket; + struct list_head *l; + int error = -EBUSY, n; + + bucket = hash_long((unsigned long)bdev + (block & 0xffffffff), + cache->c_bucket_bits); + spin_lock(&mb_cache_spinlock); + list_for_each_prev(l, &cache->c_block_hash[bucket]) { + struct mb_cache_entry *ce = + list_entry(l, struct mb_cache_entry, e_block_list); + if (ce->e_bdev == bdev && ce->e_block == block) + goto out; + } + mb_assert(!__mb_cache_entry_is_linked(ce)); + ce->e_bdev = bdev; + ce->e_block = block; + for (n=0; ne_indexes[n].o_key = keys[n]; + __mb_cache_entry_link(ce); +out: + spin_unlock(&mb_cache_spinlock); + return error; +} + + +/* + * mb_cache_entry_release() + * + * Release a handle to a cache entry. When the last handle to a cache entry + * is released it is either freed (if it is invalid) or otherwise inserted + * in to the lru list. + */ +void +mb_cache_entry_release(struct mb_cache_entry *ce) +{ + spin_lock(&mb_cache_spinlock); + __mb_cache_entry_release_unlock(ce); +} + + +/* + * mb_cache_entry_takeout() + * + * Take a cache entry out of the cache, making it invalid. The entry can later + * be re-inserted using mb_cache_entry_insert(), or released using + * mb_cache_entry_release(). + */ +void +mb_cache_entry_takeout(struct mb_cache_entry *ce) +{ + spin_lock(&mb_cache_spinlock); + mb_assert(!__mb_cache_entry_in_lru(ce)); + if (__mb_cache_entry_is_linked(ce)) + __mb_cache_entry_unlink(ce); + spin_unlock(&mb_cache_spinlock); +} + + +/* + * mb_cache_entry_free() + * + * This is equivalent to the sequence mb_cache_entry_takeout() -- + * mb_cache_entry_release(). + */ +void +mb_cache_entry_free(struct mb_cache_entry *ce) +{ + spin_lock(&mb_cache_spinlock); + mb_assert(!__mb_cache_entry_in_lru(ce)); + if (__mb_cache_entry_is_linked(ce)) + __mb_cache_entry_unlink(ce); + __mb_cache_entry_release_unlock(ce); +} + + +/* + * mb_cache_entry_dup() + * + * Duplicate a handle to a cache entry (does not duplicate the cache entry + * itself). After the call, both the old and the new handle must be released. + */ +struct mb_cache_entry * +mb_cache_entry_dup(struct mb_cache_entry *ce) +{ + atomic_inc(&ce->e_used); + return ce; +} + + +/* + * mb_cache_entry_get() + * + * Get a cache entry by device / block number. (There can only be one entry + * in the cache per device and block.) Returns NULL if no such cache entry + * exists. + */ +struct mb_cache_entry * +mb_cache_entry_get(struct mb_cache *cache, struct block_device *bdev, + sector_t block) +{ + unsigned int bucket; + struct list_head *l; + struct mb_cache_entry *ce; + + bucket = hash_long((unsigned long)bdev + (block & 0xffffffff), + cache->c_bucket_bits); + spin_lock(&mb_cache_spinlock); + list_for_each(l, &cache->c_block_hash[bucket]) { + ce = list_entry(l, struct mb_cache_entry, e_block_list); + if (ce->e_bdev == bdev && ce->e_block == block) { + ce = __mb_cache_entry_read(ce); + goto cleanup; + } + } + ce = NULL; + +cleanup: + spin_unlock(&mb_cache_spinlock); + return ce; +} + +#if !defined(MB_CACHE_INDEXES_COUNT) || (MB_CACHE_INDEXES_COUNT > 0) + +static struct mb_cache_entry * +__mb_cache_entry_find(struct list_head *l, struct list_head *head, + int index, struct block_device *bdev, unsigned int key) +{ + while (l != head) { + struct mb_cache_entry *ce = + list_entry(l, struct mb_cache_entry, + e_indexes[index].o_list); + if (ce->e_bdev == bdev && + ce->e_indexes[index].o_key == key) { + ce = __mb_cache_entry_read(ce); + if (ce) + return ce; + } + l = l->next; + } + return NULL; +} + + +/* + * mb_cache_entry_find_first() + * + * Find the first cache entry on a given device with a certain key in + * an additional index. Additonal matches can be found with + * mb_cache_entry_find_next(). Returns NULL if no match was found. + * + * @cache: the cache to search + * @index: the number of the additonal index to search (0<=indexc_bucket_bits); + struct list_head *l; + struct mb_cache_entry *ce; + + mb_assert(index < mb_cache_indexes(cache)); + spin_lock(&mb_cache_spinlock); + l = cache->c_indexes_hash[index][bucket].next; + ce = __mb_cache_entry_find(l, &cache->c_indexes_hash[index][bucket], + index, bdev, key); + spin_unlock(&mb_cache_spinlock); + return ce; +} + + +/* + * mb_cache_entry_find_next() + * + * Find the next cache entry on a given device with a certain key in an + * additional index. Returns NULL if no match could be found. The previous + * entry is atomatically released, so that mb_cache_entry_find_next() can + * be called like this: + * + * entry = mb_cache_entry_find_first(); + * while (entry) { + * ... + * entry = mb_cache_entry_find_next(entry, ...); + * } + * + * @prev: The previous match + * @index: the number of the additonal index to search (0<=indexe_cache; + unsigned int bucket = hash_long(key, cache->c_bucket_bits); + struct list_head *l; + struct mb_cache_entry *ce; + + mb_assert(index < mb_cache_indexes(cache)); + spin_lock(&mb_cache_spinlock); + l = prev->e_indexes[index].o_list.next; + ce = __mb_cache_entry_find(l, &cache->c_indexes_hash[index][bucket], + index, bdev, key); + __mb_cache_entry_release_unlock(prev); + return ce; +} + +#endif /* !defined(MB_CACHE_INDEXES_COUNT) || (MB_CACHE_INDEXES_COUNT > 0) */ diff -Nru a/include/linux/mbcache.h b/include/linux/mbcache.h --- /dev/null Wed Dec 31 16:00:00 1969 +++ b/include/linux/mbcache.h Sun Oct 20 04:40:53 2002 @@ -0,0 +1,72 @@ +/* + File: linux/mbcache.h + + (C) 2001 by Andreas Gruenbacher, +*/ + +/* Hardwire the number of additional indexes */ +#define MB_CACHE_INDEXES_COUNT 1 + +struct mb_cache_entry; + +struct mb_cache_op { + void (*free)(struct mb_cache_entry *); +}; + +struct mb_cache { + struct list_head c_cache_list; + const char *c_name; + struct mb_cache_op c_op; + atomic_t c_entry_count; + int c_bucket_bits; +#ifndef MB_CACHE_INDEXES_COUNT + int c_indexes_count; +#endif + kmem_cache_t *c_entry_cache; + struct list_head *c_block_hash; + struct list_head *c_indexes_hash[0]; +}; + +struct mb_cache_entry_index { + struct list_head o_list; + unsigned int o_key; +}; + +struct mb_cache_entry { + struct list_head e_lru_list; + struct mb_cache *e_cache; + atomic_t e_used; + struct block_device *e_bdev; + sector_t e_block; + struct list_head e_block_list; + struct mb_cache_entry_index e_indexes[0]; +}; + +/* Functions on caches */ + +struct mb_cache * mb_cache_create(const char *, struct mb_cache_op *, size_t, + int, int); +void mb_cache_shrink(struct mb_cache *, struct block_device *); +void mb_cache_destroy(struct mb_cache *); + +/* Functions on cache entries */ + +struct mb_cache_entry *mb_cache_entry_alloc(struct mb_cache *); +int mb_cache_entry_insert(struct mb_cache_entry *, struct block_device *, + sector_t, unsigned int[]); +void mb_cache_entry_rehash(struct mb_cache_entry *, unsigned int[]); +void mb_cache_entry_release(struct mb_cache_entry *); +void mb_cache_entry_takeout(struct mb_cache_entry *); +void mb_cache_entry_free(struct mb_cache_entry *); +struct mb_cache_entry *mb_cache_entry_dup(struct mb_cache_entry *); +struct mb_cache_entry *mb_cache_entry_get(struct mb_cache *, + struct block_device *, + sector_t); +#if !defined(MB_CACHE_INDEXES_COUNT) || (MB_CACHE_INDEXES_COUNT > 0) +struct mb_cache_entry *mb_cache_entry_find_first(struct mb_cache *cache, int, + struct block_device *, + unsigned int); +struct mb_cache_entry *mb_cache_entry_find_next(struct mb_cache_entry *, int, + struct block_device *, + unsigned int); +#endif