Fedora kernel-2.6.17-1.2142_FC4 patched with stable patch-2.6.17.4-vs2.0.2-rc26.diff

[linux-2.6.git] / include / linux / buffer_head.h

diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index 802c91e..08033f3 100644 (file)
--- 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;
 }
 
 /*