patch-2.3.25 linux/fs/buffer.c

• Lines: 138
• Date: Mon Nov 1 11:11:48 1999
• Orig file: v2.3.24/linux/fs/buffer.c
• Orig date: Wed Oct 27 16:34:12 1999

diff -u --recursive --new-file v2.3.24/linux/fs/buffer.c linux/fs/buffer.c
@@ -58,7 +58,7 @@
   6};
 
 #define BUFSIZE_INDEX(X) ((int) buffersize_index[(X)>>9])
-#define MAX_BUF_PER_PAGE (PAGE_SIZE / 512)
+#define MAX_BUF_PER_PAGE (PAGE_CACHE_SIZE / 512)
 #define NR_RESERVED (2*MAX_BUF_PER_PAGE)
 #define MAX_UNUSED_BUFFERS NR_RESERVED+20 /* don't ever have more than this 
 					     number of unused buffer heads */
@@ -823,7 +823,7 @@
 	unsigned long dirty, tot, hard_dirty_limit, soft_dirty_limit;
 
 	dirty = size_buffers_type[BUF_DIRTY] >> PAGE_SHIFT;
-	tot = nr_lru_pages + nr_free_pages + nr_free_highpages;
+	tot = nr_lru_pages + nr_free_pages - nr_free_highpages;
 	hard_dirty_limit = tot * bdf_prm.b_un.nfract / 100;
 	soft_dirty_limit = hard_dirty_limit >> 1;
 
@@ -1293,13 +1293,17 @@
 static void unmap_underlying_metadata(struct buffer_head * bh)
 {
 #if 0
-	bh = get_hash_table(bh->b_dev, bh->b_blocknr, bh->b_size);
-	if (bh) {
-		unmap_buffer(bh);
-		/* Here we could run brelse or bforget. We use
-		   bforget because it will try to put the buffer
-		   in the freelist. */
-		__bforget(bh);
+	if (buffer_new(bh)) {
+		struct buffer_head *old_bh;
+
+		old_bh = get_hash_table(bh->b_dev, bh->b_blocknr, bh->b_size);
+		if (old_bh) {
+			unmap_buffer(old_bh);
+			/* Here we could run brelse or bforget. We use
+			   bforget because it will try to put the buffer
+			   in the freelist. */
+			__bforget(old_bh);
+		}
 	}
 #endif
 }
@@ -1313,7 +1317,7 @@
 	struct dentry *dentry = file->f_dentry;
 	struct inode *inode = dentry->d_inode;
 	int err, i;
-	unsigned long block, offset;
+	unsigned long block;
 	struct buffer_head *bh, *head;
 
 	if (!PageLocked(page))
@@ -1323,12 +1327,10 @@
 		create_empty_buffers(page, inode, inode->i_sb->s_blocksize);
 	head = page->buffers;
 
-	offset = page->offset;
-	block = offset >> inode->i_sb->s_blocksize_bits;
-
-	// FIXME: currently we assume page alignment.
-	if (offset & (PAGE_SIZE-1))
-		BUG();
+	/* The page cache is now PAGE_CACHE_SIZE aligned, period.  We handle old a.out
+	 * and others via unaligned private mappings.
+	 */
+	block = page->index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
 
 	bh = head;
 	i = 0;
@@ -1389,8 +1391,8 @@
 	head = page->buffers;
 
 	bbits = inode->i_sb->s_blocksize_bits;
-	block = page->offset >> bbits;
-	blocks = PAGE_SIZE >> bbits;
+	block = page->index << (PAGE_CACHE_SHIFT - bbits);
+	blocks = PAGE_CACHE_SIZE >> bbits;
 	start_block = offset >> bbits;
 	end_block = (offset + bytes - 1) >> bbits;
 	start_offset = offset & (blocksize - 1);
@@ -1409,9 +1411,6 @@
 		BUG();
 	if (end_block < 0 || end_block >= blocks)
 		BUG();
-	// FIXME: currently we assume page alignment.
-	if (page->offset & (PAGE_SIZE-1))
-		BUG();
 
 	i = 0;
 	bh = head;
@@ -1537,12 +1536,12 @@
 	unsigned long data_offset = offset;
 	int need_balance_dirty;
 
-	offset = inode->i_size - page->offset;
-	if (page->offset>inode->i_size)
+	offset = inode->i_size - (page->index << PAGE_CACHE_SHIFT);
+	if (page->index > (inode->i_size >> PAGE_CACHE_SHIFT))
 		offset = 0;
 	else if (offset >= data_offset)
 		offset = data_offset;
-	bytes += data_offset-offset;
+	bytes += data_offset - offset;
 
 	target_buf = (char *)page_address(page) + offset;
 	target_data = (char *)page_address(page) + data_offset;
@@ -1556,8 +1555,8 @@
 	head = page->buffers;
 
 	bbits = inode->i_sb->s_blocksize_bits;
-	block = page->offset >> bbits;
-	blocks = PAGE_SIZE >> bbits;
+	block = page->index << (PAGE_CACHE_SHIFT - bbits);
+	blocks = PAGE_CACHE_SIZE >> bbits;
 	start_block = offset >> bbits;
 	end_block = (offset + bytes - 1) >> bbits;
 	start_offset = offset & (blocksize - 1);
@@ -1576,9 +1575,6 @@
 		BUG();
 	if (end_block < 0 || end_block >= blocks)
 		BUG();
-	// FIXME: currently we assume page alignment.
-	if (page->offset & (PAGE_SIZE-1))
-		BUG();
 
 	i = 0;
 	bh = head;
@@ -2015,8 +2011,8 @@
 		create_empty_buffers(page, inode, blocksize);
 	head = page->buffers;
 
-	blocks = PAGE_SIZE >> inode->i_sb->s_blocksize_bits;
-	iblock = page->offset >> inode->i_sb->s_blocksize_bits;
+	blocks = PAGE_CACHE_SIZE >> inode->i_sb->s_blocksize_bits;
+	iblock = page->index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
 	bh = head;
 	nr = 0;