svn commit: r250193 - head/sys/fs/msdosfs

[John Baldwin]

On Thursday, May 02, 2013 4:00:11 pm Konstantin Belousov wrote:
> Author: kib
> Date: Thu May  2 20:00:11 2013
> New Revision: 250193
> URL: http://svnweb.freebsd.org/changeset/base/250193
> 
> Log:
>   The fsync(2) call should sync the vnode in such way that even after
>   system crash which happen after successfull fsync() return, the data
>   is accessible.  For msdosfs, this means that FAT entries for the file
>   must be written.
>   
>   Since we do not track the FAT blocks containing entries for the
>   current file, just do a sloppy sync of the devvp vnode for the mount,
>   which buffers, among other things, contain FAT blocks.
>   
>   Simultaneously, for deupdat():
>   - optimize by clearing the modified flags before short-circuiting a
>     return, if the mount is read-only;
>   - only ignore the rest of the function for denode with DE_MODIFIED
>     flag clear when the waitfor argument is false.  The directory buffer
>     for the entry might be of delayed write;
>   - microoptimize by comparing the updated directory entry with the
>     current block content;
>   - try to cluster the write, fall back to bawrite() if low on
>     resources.
>   
>   Based on the submission by:	bde
>   MFC after:	2 weeks

Does this fix kern/62762?

-- 
John Baldwin