From c07dfcb45877fbc6798fa042bab3c4b85378efd4 Mon Sep 17 00:00:00 2001 From: Tahsin Erdogan Date: Thu, 22 Jun 2017 10:29:53 -0400 Subject: [PATCH] mbcache: make mbcache naming more generic Make names more generic so that mbcache usage is not limited to block sharing. In a subsequent patch in the series ("ext4: xattr inode deduplication"), we start using the mbcache code for sharing xattr inodes. With that patch, old mb_cache_entry.e_block field could be holding either a block number or an inode number. Signed-off-by: Tahsin Erdogan Signed-off-by: Theodore Ts'o --- fs/ext2/xattr.c | 18 ++++++++--------- fs/ext4/xattr.c | 10 +++++----- fs/mbcache.c | 43 ++++++++++++++++++++--------------------- include/linux/mbcache.h | 11 +++++------ 4 files changed, 40 insertions(+), 42 deletions(-) diff --git a/fs/ext2/xattr.c b/fs/ext2/xattr.c index fbdb8f171893..1e5f76070580 100644 --- a/fs/ext2/xattr.c +++ b/fs/ext2/xattr.c @@ -493,8 +493,8 @@ bad_block: ext2_error(sb, "ext2_xattr_set", * This must happen under buffer lock for * ext2_xattr_set2() to reliably detect modified block */ - mb_cache_entry_delete_block(EXT2_SB(sb)->s_mb_cache, - hash, bh->b_blocknr); + mb_cache_entry_delete(EXT2_SB(sb)->s_mb_cache, hash, + bh->b_blocknr); /* keep the buffer locked while modifying it. */ } else { @@ -721,8 +721,8 @@ ext2_xattr_set2(struct inode *inode, struct buffer_head *old_bh, * This must happen under buffer lock for * ext2_xattr_set2() to reliably detect freed block */ - mb_cache_entry_delete_block(ext2_mb_cache, - hash, old_bh->b_blocknr); + mb_cache_entry_delete(ext2_mb_cache, hash, + old_bh->b_blocknr); /* Free the old block. */ ea_bdebug(old_bh, "freeing"); ext2_free_blocks(inode, old_bh->b_blocknr, 1); @@ -795,8 +795,8 @@ ext2_xattr_delete_inode(struct inode *inode) * This must happen under buffer lock for ext2_xattr_set2() to * reliably detect freed block */ - mb_cache_entry_delete_block(EXT2_SB(inode->i_sb)->s_mb_cache, - hash, bh->b_blocknr); + mb_cache_entry_delete(EXT2_SB(inode->i_sb)->s_mb_cache, hash, + bh->b_blocknr); ext2_free_blocks(inode, EXT2_I(inode)->i_file_acl, 1); get_bh(bh); bforget(bh); @@ -907,11 +907,11 @@ again: while (ce) { struct buffer_head *bh; - bh = sb_bread(inode->i_sb, ce->e_block); + bh = sb_bread(inode->i_sb, ce->e_value); if (!bh) { ext2_error(inode->i_sb, "ext2_xattr_cache_find", "inode %ld: block %ld read error", - inode->i_ino, (unsigned long) ce->e_block); + inode->i_ino, (unsigned long) ce->e_value); } else { lock_buffer(bh); /* @@ -931,7 +931,7 @@ again: } else if (le32_to_cpu(HDR(bh)->h_refcount) > EXT2_XATTR_REFCOUNT_MAX) { ea_idebug(inode, "block %ld refcount %d>%d", - (unsigned long) ce->e_block, + (unsigned long) ce->e_value, le32_to_cpu(HDR(bh)->h_refcount), EXT2_XATTR_REFCOUNT_MAX); } else if (!ext2_xattr_cmp(header, HDR(bh))) { diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c index fed54001c9e6..85da7792afd0 100644 --- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -678,7 +678,7 @@ ext4_xattr_release_block(handle_t *handle, struct inode *inode, * This must happen under buffer lock for * ext4_xattr_block_set() to reliably detect freed block */ - mb_cache_entry_delete_block(ext4_mb_cache, hash, bh->b_blocknr); + mb_cache_entry_delete(ext4_mb_cache, hash, bh->b_blocknr); get_bh(bh); unlock_buffer(bh); ext4_free_blocks(handle, inode, bh, 0, 1, @@ -1113,8 +1113,8 @@ ext4_xattr_block_set(handle_t *handle, struct inode *inode, * ext4_xattr_block_set() to reliably detect modified * block */ - mb_cache_entry_delete_block(ext4_mb_cache, hash, - bs->bh->b_blocknr); + mb_cache_entry_delete(ext4_mb_cache, hash, + bs->bh->b_blocknr); ea_bdebug(bs->bh, "modifying in-place"); error = ext4_xattr_set_entry(i, s, handle, inode); if (!error) { @@ -2236,10 +2236,10 @@ ext4_xattr_cache_find(struct inode *inode, struct ext4_xattr_header *header, while (ce) { struct buffer_head *bh; - bh = sb_bread(inode->i_sb, ce->e_block); + bh = sb_bread(inode->i_sb, ce->e_value); if (!bh) { EXT4_ERROR_INODE(inode, "block %lu read error", - (unsigned long) ce->e_block); + (unsigned long)ce->e_value); } else if (ext4_xattr_cmp(header, BHDR(bh)) == 0) { *pce = ce; return bh; diff --git a/fs/mbcache.c b/fs/mbcache.c index b19be429d655..45a8d52dc991 100644 --- a/fs/mbcache.c +++ b/fs/mbcache.c @@ -10,7 +10,7 @@ /* * 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_block()). + * mb_cache_entry_delete()). * * Ext2 and ext4 use this cache for deduplication of extended attribute blocks. * They use hash of a block contents as a key and block number as a value. @@ -62,15 +62,15 @@ static inline struct hlist_bl_head *mb_cache_entry_head(struct mb_cache *cache, * @cache - cache where the entry should be created * @mask - gfp mask with which the entry should be allocated * @key - key of the entry - * @block - block that contains data - * @reusable - is the block reusable by other inodes? + * @value - value of the entry + * @reusable - is the entry reusable by others? * - * Creates entry in @cache with key @key and records that data is stored in - * block @block. The function returns -EBUSY if entry with the same key - * and for the same block already exists in cache. Otherwise 0 is returned. + * Creates entry in @cache with key @key and value @value. The function returns + * -EBUSY if entry with the same key and value already exists in cache. + * Otherwise 0 is returned. */ int mb_cache_entry_create(struct mb_cache *cache, gfp_t mask, u32 key, - sector_t block, bool reusable) + u64 value, bool reusable) { struct mb_cache_entry *entry, *dup; struct hlist_bl_node *dup_node; @@ -91,12 +91,12 @@ int mb_cache_entry_create(struct mb_cache *cache, gfp_t mask, u32 key, /* One ref for hash, one ref returned */ atomic_set(&entry->e_refcnt, 1); entry->e_key = key; - entry->e_block = block; + entry->e_value = value; entry->e_reusable = reusable; head = mb_cache_entry_head(cache, key); hlist_bl_lock(head); hlist_bl_for_each_entry(dup, dup_node, head, e_hash_list) { - if (dup->e_key == key && dup->e_block == block) { + if (dup->e_key == key && dup->e_value == value) { hlist_bl_unlock(head); kmem_cache_free(mb_entry_cache, entry); return -EBUSY; @@ -187,13 +187,13 @@ struct mb_cache_entry *mb_cache_entry_find_next(struct mb_cache *cache, EXPORT_SYMBOL(mb_cache_entry_find_next); /* - * mb_cache_entry_get - get a cache entry by block number (and key) + * mb_cache_entry_get - get a cache entry by value (and key) * @cache - cache we work with - * @key - key of block number @block - * @block - block number + * @key - key + * @value - value */ struct mb_cache_entry *mb_cache_entry_get(struct mb_cache *cache, u32 key, - sector_t block) + u64 value) { struct hlist_bl_node *node; struct hlist_bl_head *head; @@ -202,7 +202,7 @@ struct mb_cache_entry *mb_cache_entry_get(struct mb_cache *cache, u32 key, head = mb_cache_entry_head(cache, key); hlist_bl_lock(head); hlist_bl_for_each_entry(entry, node, head, e_hash_list) { - if (entry->e_key == key && entry->e_block == block) { + if (entry->e_key == key && entry->e_value == value) { atomic_inc(&entry->e_refcnt); goto out; } @@ -214,15 +214,14 @@ out: } EXPORT_SYMBOL(mb_cache_entry_get); -/* mb_cache_entry_delete_block - remove information about block from cache +/* mb_cache_entry_delete - remove a cache entry * @cache - cache we work with - * @key - key of block @block - * @block - block number + * @key - key + * @value - value * - * Remove entry from cache @cache with key @key with data stored in @block. + * Remove entry from cache @cache with key @key and value @value. */ -void mb_cache_entry_delete_block(struct mb_cache *cache, u32 key, - sector_t block) +void mb_cache_entry_delete(struct mb_cache *cache, u32 key, u64 value) { struct hlist_bl_node *node; struct hlist_bl_head *head; @@ -231,7 +230,7 @@ void mb_cache_entry_delete_block(struct mb_cache *cache, u32 key, head = mb_cache_entry_head(cache, key); hlist_bl_lock(head); hlist_bl_for_each_entry(entry, node, head, e_hash_list) { - if (entry->e_key == key && entry->e_block == block) { + if (entry->e_key == key && entry->e_value == value) { /* We keep hash list reference to keep entry alive */ hlist_bl_del_init(&entry->e_hash_list); hlist_bl_unlock(head); @@ -248,7 +247,7 @@ void mb_cache_entry_delete_block(struct mb_cache *cache, u32 key, } hlist_bl_unlock(head); } -EXPORT_SYMBOL(mb_cache_entry_delete_block); +EXPORT_SYMBOL(mb_cache_entry_delete); /* mb_cache_entry_touch - cache entry got used * @cache - cache the entry belongs to diff --git a/include/linux/mbcache.h b/include/linux/mbcache.h index 86c9a8b480c5..e1bc73414983 100644 --- a/include/linux/mbcache.h +++ b/include/linux/mbcache.h @@ -19,15 +19,15 @@ struct mb_cache_entry { u32 e_key; u32 e_referenced:1; u32 e_reusable:1; - /* Block number of hashed block - stable during lifetime of the entry */ - sector_t e_block; + /* User provided value - stable during lifetime of the entry */ + u64 e_value; }; struct mb_cache *mb_cache_create(int bucket_bits); void mb_cache_destroy(struct mb_cache *cache); int mb_cache_entry_create(struct mb_cache *cache, gfp_t mask, u32 key, - sector_t block, bool reusable); + u64 value, bool reusable); void __mb_cache_entry_free(struct mb_cache_entry *entry); static inline int mb_cache_entry_put(struct mb_cache *cache, struct mb_cache_entry *entry) @@ -38,10 +38,9 @@ static inline int mb_cache_entry_put(struct mb_cache *cache, return 1; } -void mb_cache_entry_delete_block(struct mb_cache *cache, u32 key, - sector_t block); +void mb_cache_entry_delete(struct mb_cache *cache, u32 key, u64 value); struct mb_cache_entry *mb_cache_entry_get(struct mb_cache *cache, u32 key, - sector_t block); + u64 value); struct mb_cache_entry *mb_cache_entry_find_first(struct mb_cache *cache, u32 key); struct mb_cache_entry *mb_cache_entry_find_next(struct mb_cache *cache, -- 2.20.1