X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=include%2Flinux%2Fbuffer_head.h;h=08033f3ac4efea69b9f69814a50ed741dbdb49f9;hb=43bc926fffd92024b46cafaf7350d669ba9ca884;hp=802c91e9b3da8b19c91f0a16c774a9bee342acee;hpb=cee37fe97739d85991964371c1f3a745c00dd236;p=linux-2.6.git

diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index 802c91e9b..08033f3ac 100644
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h
@@ -19,6 +19,9 @@ enum bh_state_bits {
 	BH_Dirty,	/* Is dirty */
 	BH_Lock,	/* Is locked */
 	BH_Req,		/* Has been submitted for I/O */
+	BH_Uptodate_Lock,/* Used by the first bh in a page, to serialise
+			  * IO completion of other buffers in the page
+			  */
 
 	BH_Mapped,	/* Has a disk mapping */
 	BH_New,		/* Disk mapping was newly created by get_block */
@@ -43,25 +46,28 @@ struct address_space;
 typedef void (bh_end_io_t)(struct buffer_head *bh, int uptodate);
 
 /*
- * Keep related fields in common cachelines.  The most commonly accessed
- * field (b_state) goes at the start so the compiler does not generate
- * indexed addressing for it.
+ * Historically, a buffer_head was used to map a single block
+ * within a page, and of course as the unit of I/O through the
+ * filesystem and block layers.  Nowadays the basic I/O unit
+ * is the bio, and buffer_heads are used for extracting block
+ * mappings (via a get_block_t call), for tracking state within
+ * a page (via a page_mapping) and for wrapping bio submission
+ * for backward compatibility reasons (e.g. submit_bh).
  */
 struct buffer_head {
-	/* First cache line: */
 	unsigned long b_state;		/* buffer state bitmap (see above) */
 	struct buffer_head *b_this_page;/* circular list of page's buffers */
 	struct page *b_page;		/* the page this bh is mapped to */
-	atomic_t b_count;		/* users using this block */
-	u32 b_size;			/* block size */
 
-	sector_t b_blocknr;		/* block number */
-	char *b_data;			/* pointer to data block */
+	sector_t b_blocknr;		/* start block number */
+	size_t b_size;			/* size of mapping */
+	char *b_data;			/* pointer to data within the page */
 
 	struct block_device *b_bdev;
 	bh_end_io_t *b_end_io;		/* I/O completion */
  	void *b_private;		/* reserved for b_end_io */
 	struct list_head b_assoc_buffers; /* associated with another mapping */
+	atomic_t b_count;		/* users using this buffer_head */
 };
 
 /*
@@ -123,8 +129,8 @@ BUFFER_FNS(Eopnotsupp, eopnotsupp)
 /* If we *know* page->private refers to buffer_heads */
 #define page_buffers(page)					\
 	({							\
-		BUG_ON(!PagePrivate(page));		\
-		((struct buffer_head *)(page)->private);	\
+		BUG_ON(!PagePrivate(page));			\
+		((struct buffer_head *)page_private(page));	\
 	})
 #define page_has_buffers(page)	PagePrivate(page)
 
@@ -169,7 +175,7 @@ void __brelse(struct buffer_head *);
 void __bforget(struct buffer_head *);
 void __breadahead(struct block_device *, sector_t block, int size);
 struct buffer_head *__bread(struct block_device *, sector_t block, int size);
-struct buffer_head *alloc_buffer_head(unsigned int __nocast gfp_flags);
+struct buffer_head *alloc_buffer_head(gfp_t gfp_flags);
 void free_buffer_head(struct buffer_head * bh);
 void FASTCALL(unlock_buffer(struct buffer_head *bh));
 void FASTCALL(__lock_buffer(struct buffer_head *bh));
@@ -185,17 +191,20 @@ extern int buffer_heads_over_limit;
  * Generic address_space_operations implementations for buffer_head-backed
  * address_spaces.
  */
-int try_to_release_page(struct page * page, int gfp_mask);
-int block_invalidatepage(struct page *page, unsigned long offset);
+int try_to_release_page(struct page * page, gfp_t gfp_mask);
+void block_invalidatepage(struct page *page, unsigned long offset);
+void do_invalidatepage(struct page *page, unsigned long offset);
 int block_write_full_page(struct page *page, get_block_t *get_block,
 				struct writeback_control *wbc);
 int block_read_full_page(struct page*, get_block_t*);
 int block_prepare_write(struct page*, unsigned, unsigned, get_block_t*);
 int cont_prepare_write(struct page*, unsigned, unsigned, get_block_t*,
 				loff_t *);
-int generic_cont_expand(struct inode *inode, loff_t size) ;
+int generic_cont_expand(struct inode *inode, loff_t size);
+int generic_cont_expand_simple(struct inode *inode, loff_t size);
 int block_commit_write(struct page *page, unsigned from, unsigned to);
-int block_sync_page(struct page *);
+void block_sync_page(struct page *);
+void flush_inode_pages (struct inode * inode);
 sector_t generic_block_bmap(struct address_space *, sector_t, get_block_t *);
 int generic_commit_write(struct file *, struct page *, unsigned, unsigned);
 int block_truncate_page(struct address_space *, loff_t, get_block_t *);
@@ -216,7 +225,7 @@ static inline void attach_page_buffers(struct page *page,
 {
 	page_cache_get(page);
 	SetPagePrivate(page);
-	page->private = (unsigned long)head;
+	set_page_private(page, (unsigned long)head);
 }
 
 static inline void get_bh(struct buffer_head *bh)
@@ -272,6 +281,7 @@ map_bh(struct buffer_head *bh, struct super_block *sb, sector_t block)
 	set_buffer_mapped(bh);
 	bh->b_bdev = sb->s_bdev;
 	bh->b_blocknr = block;
+	bh->b_size = sb->s_blocksize;
 }
 
 /*