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authorChris Mason <chris.mason@oracle.com>2008-01-24 16:13:08 -0500
committerChris Mason <chris.mason@oracle.com>2008-09-25 11:03:59 -0400
commitd1310b2e0cd98eb1348553e69b73827b436dca7b (patch)
treef55e9c380df0f3a7e9fb792b2308b52b632b90aa /fs/btrfs/extent_io.h
parent5f56406aabdf5444d040c5955effc665b1d0dbaf (diff)
downloadlinux-d1310b2e0cd98eb1348553e69b73827b436dca7b.tar.bz2
Btrfs: Split the extent_map code into two parts
There is now extent_map for mapping offsets in the file to disk and extent_io for state tracking, IO submission and extent_bufers. The new extent_map code shifts from [start,end] pairs to [start,len], and pushes the locking out into the caller. This allows a few performance optimizations and is easier to use. A number of extent_map usage bugs were fixed, mostly with failing to remove extent_map entries when changing the file. Signed-off-by: Chris Mason <chris.mason@oracle.com>
Diffstat (limited to 'fs/btrfs/extent_io.h')
-rw-r--r--fs/btrfs/extent_io.h193
1 files changed, 193 insertions, 0 deletions
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
new file mode 100644
index 000000000000..06be1fe84b29
--- /dev/null
+++ b/fs/btrfs/extent_io.h
@@ -0,0 +1,193 @@
+#ifndef __EXTENTIO__
+#define __EXTENTIO__
+
+#include <linux/rbtree.h>
+
+/* bits for the extent state */
+#define EXTENT_DIRTY 1
+#define EXTENT_WRITEBACK (1 << 1)
+#define EXTENT_UPTODATE (1 << 2)
+#define EXTENT_LOCKED (1 << 3)
+#define EXTENT_NEW (1 << 4)
+#define EXTENT_DELALLOC (1 << 5)
+#define EXTENT_DEFRAG (1 << 6)
+#define EXTENT_DEFRAG_DONE (1 << 7)
+#define EXTENT_BUFFER_FILLED (1 << 8)
+#define EXTENT_CSUM (1 << 9)
+#define EXTENT_IOBITS (EXTENT_LOCKED | EXTENT_WRITEBACK)
+
+/*
+ * page->private values. Every page that is controlled by the extent
+ * map has page->private set to one.
+ */
+#define EXTENT_PAGE_PRIVATE 1
+#define EXTENT_PAGE_PRIVATE_FIRST_PAGE 3
+
+struct extent_io_ops {
+ int (*fill_delalloc)(struct inode *inode, u64 start, u64 end);
+ int (*writepage_io_hook)(struct page *page, u64 start, u64 end);
+ int (*readpage_io_hook)(struct page *page, u64 start, u64 end);
+ int (*readpage_end_io_hook)(struct page *page, u64 start, u64 end);
+ void (*writepage_end_io_hook)(struct page *page, u64 start, u64 end);
+};
+
+struct extent_io_tree {
+ struct rb_root state;
+ struct address_space *mapping;
+ u64 dirty_bytes;
+ rwlock_t lock;
+ struct extent_io_ops *ops;
+ spinlock_t lru_lock;
+ struct list_head buffer_lru;
+ int lru_size;
+};
+
+struct extent_state {
+ u64 start;
+ u64 end; /* inclusive */
+ int in_tree;
+ struct rb_node rb_node;
+ wait_queue_head_t wq;
+ atomic_t refs;
+ unsigned long state;
+
+ /* for use by the FS */
+ u64 private;
+
+ struct list_head list;
+};
+
+struct extent_buffer {
+ u64 start;
+ unsigned long len;
+ char *map_token;
+ char *kaddr;
+ unsigned long map_start;
+ unsigned long map_len;
+ struct page *first_page;
+ struct list_head lru;
+ atomic_t refs;
+ int flags;
+};
+
+struct extent_map_tree;
+
+typedef struct extent_map *(get_extent_t)(struct inode *inode,
+ struct page *page,
+ size_t page_offset,
+ u64 start, u64 len,
+ int create);
+
+void extent_io_tree_init(struct extent_io_tree *tree,
+ struct address_space *mapping, gfp_t mask);
+void extent_io_tree_empty_lru(struct extent_io_tree *tree);
+int try_release_extent_mapping(struct extent_map_tree *map,
+ struct extent_io_tree *tree, struct page *page);
+int lock_extent(struct extent_io_tree *tree, u64 start, u64 end, gfp_t mask);
+int unlock_extent(struct extent_io_tree *tree, u64 start, u64 end, gfp_t mask);
+int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
+ get_extent_t *get_extent);
+int __init extent_io_init(void);
+void extent_io_exit(void);
+
+u64 count_range_bits(struct extent_io_tree *tree,
+ u64 *start, u64 search_end,
+ u64 max_bytes, unsigned long bits);
+
+int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
+ int bits, int filled);
+int clear_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
+ int bits, gfp_t mask);
+int set_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
+ int bits, gfp_t mask);
+int set_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
+ gfp_t mask);
+int set_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
+ gfp_t mask);
+int set_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
+ gfp_t mask);
+int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
+ gfp_t mask);
+int set_extent_delalloc(struct extent_io_tree *tree, u64 start, u64 end,
+ gfp_t mask);
+int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
+ u64 *start_ret, u64 *end_ret, int bits);
+int extent_invalidatepage(struct extent_io_tree *tree,
+ struct page *page, unsigned long offset);
+int extent_write_full_page(struct extent_io_tree *tree, struct page *page,
+ get_extent_t *get_extent,
+ struct writeback_control *wbc);
+int extent_writepages(struct extent_io_tree *tree,
+ struct address_space *mapping,
+ get_extent_t *get_extent,
+ struct writeback_control *wbc);
+int extent_readpages(struct extent_io_tree *tree,
+ struct address_space *mapping,
+ struct list_head *pages, unsigned nr_pages,
+ get_extent_t get_extent);
+int extent_prepare_write(struct extent_io_tree *tree,
+ struct inode *inode, struct page *page,
+ unsigned from, unsigned to, get_extent_t *get_extent);
+int extent_commit_write(struct extent_io_tree *tree,
+ struct inode *inode, struct page *page,
+ unsigned from, unsigned to);
+sector_t extent_bmap(struct address_space *mapping, sector_t iblock,
+ get_extent_t *get_extent);
+int set_range_dirty(struct extent_io_tree *tree, u64 start, u64 end);
+int set_state_private(struct extent_io_tree *tree, u64 start, u64 private);
+int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private);
+void set_page_extent_mapped(struct page *page);
+
+struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree,
+ u64 start, unsigned long len,
+ struct page *page0,
+ gfp_t mask);
+struct extent_buffer *find_extent_buffer(struct extent_io_tree *tree,
+ u64 start, unsigned long len,
+ gfp_t mask);
+void free_extent_buffer(struct extent_buffer *eb);
+int read_extent_buffer_pages(struct extent_io_tree *tree,
+ struct extent_buffer *eb, u64 start, int wait);
+
+static inline void extent_buffer_get(struct extent_buffer *eb)
+{
+ atomic_inc(&eb->refs);
+}
+
+int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
+ unsigned long start,
+ unsigned long len);
+void read_extent_buffer(struct extent_buffer *eb, void *dst,
+ unsigned long start,
+ unsigned long len);
+void write_extent_buffer(struct extent_buffer *eb, const void *src,
+ unsigned long start, unsigned long len);
+void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
+ unsigned long dst_offset, unsigned long src_offset,
+ unsigned long len);
+void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
+ unsigned long src_offset, unsigned long len);
+void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
+ unsigned long src_offset, unsigned long len);
+void memset_extent_buffer(struct extent_buffer *eb, char c,
+ unsigned long start, unsigned long len);
+int wait_on_extent_buffer_writeback(struct extent_io_tree *tree,
+ struct extent_buffer *eb);
+int clear_extent_buffer_dirty(struct extent_io_tree *tree,
+ struct extent_buffer *eb);
+int set_extent_buffer_dirty(struct extent_io_tree *tree,
+ struct extent_buffer *eb);
+int set_extent_buffer_uptodate(struct extent_io_tree *tree,
+ struct extent_buffer *eb);
+int extent_buffer_uptodate(struct extent_io_tree *tree,
+ struct extent_buffer *eb);
+int map_extent_buffer(struct extent_buffer *eb, unsigned long offset,
+ unsigned long min_len, char **token, char **map,
+ unsigned long *map_start,
+ unsigned long *map_len, int km);
+int map_private_extent_buffer(struct extent_buffer *eb, unsigned long offset,
+ unsigned long min_len, char **token, char **map,
+ unsigned long *map_start,
+ unsigned long *map_len, int km);
+void unmap_extent_buffer(struct extent_buffer *eb, char *token, int km);
+#endif