X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=fs%2Fbuffer.c;h=38653e36e2252189dfad1cbf8f31f5473d2ccb00;hb=5a6c9b60b4cc15b22d3102b0033e5cb842125456;hp=f95805019639a54f993b3271ed3c8b8a45c478ad;hpb=fb3b80614438f8b73b3879a19350439d6aa402da;p=linux-2.6-omap-h63xx.git

diff --git a/fs/buffer.c b/fs/buffer.c
index f9580501963..38653e36e22 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -580,7 +580,7 @@ EXPORT_SYMBOL(mark_buffer_async_write);
 /*
  * The buffer's backing address_space's private_lock must be held
  */
-static inline void __remove_assoc_queue(struct buffer_head *bh)
+static void __remove_assoc_queue(struct buffer_head *bh)
 {
 	list_del_init(&bh->b_assoc_buffers);
 	WARN_ON(!bh->b_assoc_map);
@@ -1720,7 +1720,7 @@ static int __block_write_full_page(struct inode *inode, struct page *page,
 		 */
 		if (wbc->sync_mode != WB_SYNC_NONE || !wbc->nonblocking) {
 			lock_buffer(bh);
-		} else if (test_set_buffer_locked(bh)) {
+		} else if (!trylock_buffer(bh)) {
 			redirty_page_for_writepage(wbc, page);
 			continue;
 		}
@@ -2095,6 +2095,52 @@ int generic_write_end(struct file *file, struct address_space *mapping,
 }
 EXPORT_SYMBOL(generic_write_end);
 
+/*
+ * block_is_partially_uptodate checks whether buffers within a page are
+ * uptodate or not.
+ *
+ * Returns true if all buffers which correspond to a file portion
+ * we want to read are uptodate.
+ */
+int block_is_partially_uptodate(struct page *page, read_descriptor_t *desc,
+					unsigned long from)
+{
+	struct inode *inode = page->mapping->host;
+	unsigned block_start, block_end, blocksize;
+	unsigned to;
+	struct buffer_head *bh, *head;
+	int ret = 1;
+
+	if (!page_has_buffers(page))
+		return 0;
+
+	blocksize = 1 << inode->i_blkbits;
+	to = min_t(unsigned, PAGE_CACHE_SIZE - from, desc->count);
+	to = from + to;
+	if (from < blocksize && to > PAGE_CACHE_SIZE - blocksize)
+		return 0;
+
+	head = page_buffers(page);
+	bh = head;
+	block_start = 0;
+	do {
+		block_end = block_start + blocksize;
+		if (block_end > from && block_start < to) {
+			if (!buffer_uptodate(bh)) {
+				ret = 0;
+				break;
+			}
+			if (block_end >= to)
+				break;
+		}
+		block_start = block_end;
+		bh = bh->b_this_page;
+	} while (bh != head);
+
+	return ret;
+}
+EXPORT_SYMBOL(block_is_partially_uptodate);
+
 /*
  * Generic "read page" function for block devices that have the normal
  * get_block functionality. This is most of the block device filesystems.
@@ -2954,7 +3000,7 @@ void ll_rw_block(int rw, int nr, struct buffer_head *bhs[])
 
 		if (rw == SWRITE || rw == SWRITE_SYNC)
 			lock_buffer(bh);
-		else if (test_set_buffer_locked(bh))
+		else if (!trylock_buffer(bh))
 			continue;
 
 		if (rw == WRITE || rw == SWRITE || rw == SWRITE_SYNC) {