Introduce infra macro and data structure for rb-tree based extent cache:
Macros:
* EXT_TREE_VEC_SIZE: indicate vector size for gang lookup in extent tree.
* F2FS_MIN_EXTENT_LEN: indicate minimum length of extent managed in cache.
* EXTENT_CACHE_SHRINK_NUMBER: indicate number of extent in cache will be
shrunk.
Basic data structures for extent cache:
* struct extent_tree: extent tree entry per inode.
* struct extent_node: extent info node linked in extent tree.
Besides, adding new extent cache related fields in f2fs_sb_info.
Signed-off-by: Chao Yu <chao2...@samsung.com>
Signed-off-by: Jaegeuk Kim <jaeg...@kernel.org>
Signed-off-by: Changman Lee <cm224....@samsung.com>
---
fs/f2fs/f2fs.h | 36 ++++++++++++++++++++++++++++++++----
fs/f2fs/node.h | 1 +
2 files changed, 33 insertions(+), 4 deletions(-)
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 8e1d78d..63edc22 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -267,13 +267,33 @@ enum {
#define MAX_DIR_RA_PAGES 4 /* maximum ra pages of dir */
+/* vector size for gang look-up from extent cache that consists of radix tree
*/
+#define EXT_TREE_VEC_SIZE 64
+
/* for in-memory extent cache entry */
-#define F2FS_MIN_EXTENT_LEN 16 /* minimum extent length */
+#define F2FS_MIN_EXTENT_LEN 64 /* minimum extent length */
+
+/* number of extent info in extent cache we try to shrink */
+#define EXTENT_CACHE_SHRINK_NUMBER 128
struct extent_info {
- unsigned int fofs; /* start offset in a file */
- u32 blk; /* start block address of the extent */
- unsigned int len; /* length of the extent */
+ unsigned int fofs; /* start offset in a file */
+ u32 blk; /* start block address of the extent */
+ unsigned int len; /* length of the extent */
+};
+
+struct extent_node {
+ struct rb_node rb_node; /* rb node located in rb-tree */
+ struct list_head list; /* node in global extent list of sbi */
+ struct extent_info ei; /* extent info */
+};
+
+struct extent_tree {
+ nid_t ino; /* inode number */
+ struct rb_root root; /* root of extent info rb-tree */
+ rwlock_t lock; /* protect extent info rb-tree */
+ atomic_t refcount; /* reference count of rb-tree */
+ unsigned int count; /* # of extent node in rb-tree*/
};
/*
@@ -553,6 +573,14 @@ struct f2fs_sb_info {
struct list_head dir_inode_list; /* dir inode list */
spinlock_t dir_inode_lock; /* for dir inode list lock */
+ /* for extent tree cache */
+ struct radix_tree_root extent_tree_root;/* cache extent cache entries */
+ struct rw_semaphore extent_tree_lock; /* locking extent radix tree */
+ struct list_head extent_list; /* lru list for shrinker */
+ spinlock_t extent_lock; /* locking extent lru list */
+ int total_ext_tree; /* extent tree count */
+ atomic_t total_ext_node; /* extent info count */
+
/* basic filesystem units */
unsigned int log_sectors_per_block; /* log2 sectors per block */
unsigned int log_blocksize; /* log2 block size */
diff --git a/fs/f2fs/node.h b/fs/f2fs/node.h
index f405bbf..c56026f 100644
--- a/fs/f2fs/node.h
+++ b/fs/f2fs/node.h
@@ -120,6 +120,7 @@ enum mem_type {
NAT_ENTRIES, /* indicates the cached nat entry */
DIRTY_DENTS, /* indicates dirty dentry pages */
INO_ENTRIES, /* indicates inode entries */
+ EXTENT_CACHE, /* indicates extent cache */
BASE_CHECK, /* check kernel status */
};
--
2.2.1
------------------------------------------------------------------------------
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