Re: [PATCH] mm for fs: add truncate_pagecache_range

From: Andrew Morton
Date: Fri Mar 23 2012 - 17:01:18 EST


On Fri, 23 Mar 2012 13:46:35 -0700 (PDT)
Hugh Dickins <hughd@xxxxxxxxxx> wrote:

> +/**
> + * truncate_pagecache_range - unmap and remove pagecache that is hole-punched
> + * @inode: inode
> + * @lstart: offset of beginning of hole
> + * @lend: offset of last byte of hole
> + *
> + * This function should typically be called before the filesystem
> + * releases resources associated with the freed range (eg. deallocates
> + * blocks). This way, pagecache will always stay logically coherent
> + * with on-disk format, and the filesystem would not have to deal with
> + * situations such as writepage being called for a page that has already
> + * had its underlying blocks deallocated.
> + */

--- a/mm/truncate.c~mm-for-fs-add-truncate_pagecache_range-fix
+++ a/mm/truncate.c
@@ -639,6 +639,9 @@ int vmtruncate_range(struct inode *inode
* with on-disk format, and the filesystem would not have to deal with
* situations such as writepage being called for a page that has already
* had its underlying blocks deallocated.
+ *
+ * Must be called with inode->i_mapping->i_mutex held.
+ * Takes inode->i_mapping->i_mmap_mutex.
*/
void truncate_pagecache_range(struct inode *inode, loff_t lstart, loff_t lend)
{

yes?
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/