X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=fs%2Fmpage.c;h=42381bd6543b1abd5446961424234f6d83234f13;hb=0a02604628c49037e1de2091d75462fd856b26ed;hp=5df564366f36b5ea287245b3b5fd060ab1012f31;hpb=eebd2aa355692afaf9906f62118620f1a1c19dbb;p=safe%2Fjmp%2Flinux-2.6

diff --git a/fs/mpage.c b/fs/mpage.c
index 5df5643..42381bd 100644
--- a/fs/mpage.c
+++ b/fs/mpage.c
@@ -6,7 +6,7 @@
  * Contains functions related to preparing and submitting BIOs which contain
  * multiple pagecache pages.
  *
- * 15May2002	akpm@zip.com.au
+ * 15May2002	Andrew Morton
  *		Initial version
  * 27Jun2002	axboe@suse.de
  *		use bio_add_page() to build bio's just the right size
@@ -240,7 +240,6 @@ do_mpage_readpage(struct bio *bio, struct page *page, unsigned nr_pages,
 				first_hole = page_block;
 			page_block++;
 			block_in_file++;
-			clear_buffer_mapped(map_bh);
 			continue;
 		}
 
@@ -307,7 +306,10 @@ alloc_new:
 		goto alloc_new;
 	}
 
-	if (buffer_boundary(map_bh) || (first_hole != blocks_per_page))
+	relative_block = block_in_file - *first_logical_block;
+	nblocks = map_bh->b_size >> blkbits;
+	if ((buffer_boundary(map_bh) && relative_block == nblocks) ||
+	    (first_hole != blocks_per_page))
 		bio = mpage_bio_submit(READ, bio);
 	else
 		*last_block_in_bio = blocks[blocks_per_page - 1];
@@ -325,16 +327,12 @@ confused:
 }
 
 /**
- * mpage_readpages - populate an address space with some pages, and
- *                       start reads against them.
- *
+ * mpage_readpages - populate an address space with some pages & start reads against them
  * @mapping: the address_space
  * @pages: The address of a list_head which contains the target pages.  These
  *   pages have their ->index populated and are otherwise uninitialised.
- *
  *   The page at @pages->prev has the lowest file offset, and reads should be
  *   issued in @pages->prev to @pages->next order.
- *
  * @nr_pages: The number of pages at *@pages
  * @get_block: The filesystem's block mapper function.
  *
@@ -360,6 +358,7 @@ confused:
  * So an mpage read of the first 16 blocks of an ext2 file will cause I/O to be
  * submitted in the following order:
  * 	12 0 1 2 3 4 5 6 7 8 9 10 11 13 14 15 16
+ *
  * because the indirect block has to be read to get the mappings of blocks
  * 13,14,15,16.  Obviously, this impacts performance.
  *
@@ -380,7 +379,8 @@ mpage_readpages(struct address_space *mapping, struct list_head *pages,
 	struct buffer_head map_bh;
 	unsigned long first_logical_block = 0;
 
-	clear_buffer_mapped(&map_bh);
+	map_bh.b_state = 0;
+	map_bh.b_size = 0;
 	for (page_idx = 0; page_idx < nr_pages; page_idx++) {
 		struct page *page = list_entry(pages->prev, struct page, lru);
 
@@ -413,7 +413,8 @@ int mpage_readpage(struct page *page, get_block_t get_block)
 	struct buffer_head map_bh;
 	unsigned long first_logical_block = 0;
 
-	clear_buffer_mapped(&map_bh);
+	map_bh.b_state = 0;
+	map_bh.b_size = 0;
 	bio = do_mpage_readpage(bio, page, 1, &last_block_in_bio,
 			&map_bh, &first_logical_block, get_block);
 	if (bio)
@@ -438,6 +439,7 @@ EXPORT_SYMBOL(mpage_readpage);
  * written, so it can intelligently allocate a suitably-sized BIO.  For now,
  * just allocate full-size (16-page) BIOs.
  */
+
 struct mpage_data {
 	struct bio *bio;
 	sector_t last_block_in_bio;
@@ -446,7 +448,7 @@ struct mpage_data {
 };
 
 static int __mpage_writepage(struct page *page, struct writeback_control *wbc,
-			     void *data)
+		      void *data)
 {
 	struct mpage_data *mpd = data;
 	struct bio *bio = mpd->bio;
@@ -656,9 +658,7 @@ out:
 }
 
 /**
- * mpage_writepages - walk the list of dirty pages of the given
- * address space and writepage() all of them.
- * 
+ * mpage_writepages - walk the list of dirty pages of the given address space & writepage() all of them
  * @mapping: address space structure to write
  * @wbc: subtract the number of written pages from *@wbc->nr_to_write
  * @get_block: the filesystem's block mapper function.