Messages in this thread | | | Date | Wed, 9 Jul 2008 06:55:40 -0700 | From | Arjan van de Ven <> | Subject | Re: [PATCH 3/3] Add timeout feature |
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On Wed, 9 Jul 2008 21:49:58 +1000 Dave Chinner <david@fromorbit.com> wrote:
> > (e) none of the above. The kernel compilation will appear to pause > until the filesystem is unfrozen. No other visible effect should > occur. It will get blocked in a write or filesystem transaction > because the fs is frozen. > > Look at vfs_check_frozen() - any call to that will block if the > filesystem is frozen or being frozen. The generic hook is in > __generic_file_aio_write_nolock() and various other filesystems have > calls in their specific write paths (fuse, ntfs, ocfs2, xfs, xip) to > do this.
yeah and mmap doesn't happen > > For all other modifications, filesystem specific methods of > blocking transactions are used. XFS uses vfs_check_frozen() in > xfs_trans_alloc(), ext3 (and probably ocfs2) do it via > their ->write_super_lockfs method calling journal_lock_updates(), > ext4 via jbd2_lock_updates() and so on....
and what if it's the process that you need to unfreeze the fs later? Good luck.
-- If you want to reach me at my work email, use arjan@linux.intel.com For development, discussion and tips for power savings, visit http://www.lesswatts.org
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