[PATCH v2 23/31] mbcache: make mbcache naming more generic
From: Tahsin Erdogan
Date: Tue Jun 20 2017 - 05:01:36 EST
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 <tahsin@xxxxxxxxxx>
---
v2: updated commit title and description
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 @@ ext2_xattr_cache_find(struct inode *inode, struct ext2_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) {
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 @@ ext2_xattr_cache_find(struct inode *inode, struct ext2_xattr_header *header)
} 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 c09fcffb0878..0b43e0e52e26 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,
@@ -1115,8 +1115,8 @@ 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) {
@@ -2238,10 +2238,10 @@ 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 @@ struct mb_cache_entry *mb_cache_entry_get(struct mb_cache *cache, u32 key,
}
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,
--
2.13.1.518.g3df882009-goog