lkml.org 
[lkml]   [2007]   [Mar]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
Subjectlock_rename for cluster filesystems? (was: Re: [PATCH] prune_icache_sb)
On 12/4/06, Wendy Cheng <wcheng@redhat.com> wrote:
> Russell Cattelan wrote:
> > Wendy Cheng wrote:
> >
> >> Linux kernel, particularly the VFS layer, is starting to show signs
> >> of inadequacy as the software components built upon it keep growing.
> >> I have doubts that it can keep up and handle this complexity with a
> >> development policy like you just described (filesystem is a dumb
> >> layer ?). Aren't these DIO_xxx_LOCKING flags inside
> >> __blockdev_direct_IO() a perfect example why trying to do too many
> >> things inside vfs layer for so many filesystems is a bad idea ? By
> >> the way, since we're on this subject, could we discuss a little bit
> >> about vfs rename call (or I can start another new discussion thread) ?
> >>
> >> Note that linux do_rename() starts with the usual lookup logic,
> >> followed by "lock_rename", then a final round of dentry lookup, and
> >> finally comes to filesystem's i_op->rename call. Since lock_rename()
> >> only calls for vfs layer locks that are local to this particular
> >> machine, for a cluster filesystem, there exists a huge window between
> >> the final lookup and filesystem's i_op->rename calls such that the
> >> file could get deleted from another node before fs can do anything
> >> about it. Is it possible that we could get a new function pointer
> >> (lock_rename) in inode_operations structure so a cluster filesystem
> >> can do proper locking ?
> >
> > It looks like the ocfs2 guys have the similar problem?
> >
> > http://ftp.kernel.org/pub/linux/kernel/people/mfasheh/ocfs2/ocfs2_git_patches/ocfs2-upstream-linus-20060924/0009-PATCH-Allow-file-systems-to-manually-d_move-inside-of-rename.txt
> >
> >
> >
>
> Thanks for the pointer. Same as ocfs2, under current VFS code, both
> GFS1/2 also need FS_ODD_RENAME flag for the rename problem - got an ugly
> ~200 line draft patch ready for GFS1 (and am looking into GFS2 at this
> moment). The issue here is, for GFS, if vfs lock_rename() can call us,
> this complication can be greatly reduced. Will start another thread to
> see whether the wish can be granted.

Hi Wendy,

Have you (or others) made any progress on a possible solution to
simplify handling cluster fs do_rename() races (e.g. your proposed
lock_rename in inode_operations)?

I couldn't find a newer thread that continued this discussion...

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

\
 
 \ /
  Last update: 2007-03-03 04:11    [W:0.041 / U:1.688 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site