X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=fs%2Fblock_dev.c;h=6dcee88c2e5d275fe7df4b3e82caa52375779a74;hb=325ce9e3060960488fa2c1c9eccde5ad85d75e7c;hp=d11d0289f3d24bf9489acba6059c5d8ada9eda52;hpb=1fae4cfb97302289bb5df6a8195eb28385d0b002;p=pandora-kernel.git

diff --git a/fs/block_dev.c b/fs/block_dev.c
index d11d0289f3d2..6dcee88c2e5d 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -404,20 +404,28 @@ static loff_t block_llseek(struct file *file, loff_t offset, int origin)
  *	NULL first argument is nfsd_sync_dir() and that's not a directory.
  */
  
-static int block_fsync(struct file *filp, struct dentry *dentry, int datasync)
+int blkdev_fsync(struct file *filp, struct dentry *dentry, int datasync)
 {
-	struct block_device *bdev = I_BDEV(filp->f_mapping->host);
+	struct inode *bd_inode = filp->f_mapping->host;
+	struct block_device *bdev = I_BDEV(bd_inode);
 	int error;
 
-	error = sync_blockdev(bdev);
-	if (error)
-		return error;
-	
+	/*
+	 * There is no need to serialise calls to blkdev_issue_flush with
+	 * i_mutex and doing so causes performance issues with concurrent
+	 * O_SYNC writers to a block device.
+	 */
+	mutex_unlock(&bd_inode->i_mutex);
+
 	error = blkdev_issue_flush(bdev, NULL);
 	if (error == -EOPNOTSUPP)
 		error = 0;
+
+	mutex_lock(&bd_inode->i_mutex);
+
 	return error;
 }
+EXPORT_SYMBOL(blkdev_fsync);
 
 /*
  * pseudo-fs
@@ -1481,7 +1489,7 @@ const struct file_operations def_blk_fops = {
   	.aio_read	= generic_file_aio_read,
 	.aio_write	= blkdev_aio_write,
 	.mmap		= generic_file_mmap,
-	.fsync		= block_fsync,
+	.fsync		= blkdev_fsync,
 	.unlocked_ioctl	= block_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= compat_blkdev_ioctl,