X-Git-Url: http://git.rot13.org/?a=blobdiff_plain;f=fs%2Fblock_dev.c;h=575076c018f4789c3c5f313f56b7b09674604baf;hb=5ee2ae7fb2079c5775d8802cd282140d71632a2d;hp=d9bdf2b3ade2922a0564a4630f3b3ce461d1c176;hpb=975a8e3ed2b9eab9f062a1e0ba7fe180e15204e1;p=powerpc.git

diff --git a/fs/block_dev.c b/fs/block_dev.c
index d9bdf2b3ad..575076c018 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -129,6 +129,46 @@ blkdev_get_block(struct inode *inode, sector_t iblock,
 	return 0;
 }
 
+static int
+blkdev_get_blocks(struct inode *inode, sector_t iblock,
+		struct buffer_head *bh, int create)
+{
+	sector_t end_block = max_block(I_BDEV(inode));
+	unsigned long max_blocks = bh->b_size >> inode->i_blkbits;
+
+	if ((iblock + max_blocks) > end_block) {
+		max_blocks = end_block - iblock;
+		if ((long)max_blocks <= 0) {
+			if (create)
+				return -EIO;	/* write fully beyond EOF */
+			/*
+			 * It is a read which is fully beyond EOF.  We return
+			 * a !buffer_mapped buffer
+			 */
+			max_blocks = 0;
+		}
+	}
+
+	bh->b_bdev = I_BDEV(inode);
+	bh->b_blocknr = iblock;
+	bh->b_size = max_blocks << inode->i_blkbits;
+	if (max_blocks)
+		set_buffer_mapped(bh);
+	return 0;
+}
+
+static ssize_t
+blkdev_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
+			loff_t offset, unsigned long nr_segs)
+{
+	struct file *file = iocb->ki_filp;
+	struct inode *inode = file->f_mapping->host;
+
+	return blockdev_direct_IO_no_locking(rw, iocb, inode, I_BDEV(inode),
+				iov, offset, nr_segs, blkdev_get_blocks, NULL);
+}
+
+#if 0
 static int blk_end_aio(struct bio *bio, unsigned int bytes_done, int error)
 {
 	struct kiocb *iocb = bio->bi_private;
@@ -323,6 +363,7 @@ backout:
 		return PTR_ERR(page);
 	goto completion;
 }
+#endif
 
 static int blkdev_writepage(struct page *page, struct writeback_control *wbc)
 {
@@ -448,7 +489,7 @@ static void bdev_clear_inode(struct inode *inode)
 	spin_unlock(&bdev_lock);
 }
 
-static struct super_operations bdev_sops = {
+static const struct super_operations bdev_sops = {
 	.statfs = simple_statfs,
 	.alloc_inode = bdev_alloc_inode,
 	.destroy_inode = bdev_destroy_inode,
@@ -1060,6 +1101,13 @@ static int __blkdev_get(struct block_device *bdev, mode_t mode, unsigned flags,
 			int for_part);
 static int __blkdev_put(struct block_device *bdev, int for_part);
 
+/*
+ * bd_mutex locking:
+ *
+ *  mutex_lock(part->bd_mutex)
+ *    mutex_lock_nested(whole->bd_mutex, 1)
+ */
+
 static int do_open(struct block_device *bdev, struct file *file, int for_part)
 {
 	struct module *owner = NULL;