Re: [PATCH] Introduce a method to catch mmap_region (was: Recent kernel "mount" slow)

Al Viro
2012-11-29T06:30:49Z

On Thu, Nov 29, 2012 at 06:25:19AM +0000, Al Viro wrote:

> Umm... set_blocksize() is calling kill_bdev(), which does
> truncate_inode_pages(mapping, 0). What's going to happen to data in
> the dirty pages? IO in progress is not the only thing to worry about...

Note that sync_blockdev() a few lines prior to that is good only if we
have no other processes doing write(2) (or dirtying the mmapped pages,
for that matter). The window isn't too wide, but...