Messages in this thread | | | Date | Fri, 16 Mar 2018 20:04:43 +0100 | From | Christoph Hellwig <> | Subject | Re: [PATCH v6 12/15] xfs: require mmap lock for xfs_break_layouts() |
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On Thu, Mar 15, 2018 at 08:52:29AM -0700, Dan Williams wrote: > In preparation for adding coordination between truncate operations and > busy dax-pages, extend xfs_break_layouts() to assume it must be called > with the mmap lock held. This locking scheme will be required for > coordinating the break of 'dax layouts' (non-idle dax (ZONE_DEVICE) > pages mapped into the file's address space).
This requirement wasn't really there in the last series, why do we require it now?
As far as I can tell all we'd need is to just drop this assert:
> - ASSERT(xfs_isilocked(ip, XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL)); > + ASSERT(xfs_isilocked(ip, XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL > + | XFS_MMAPLOCK_EXCL));
entirely.
> while ((error = break_layout(inode, false) == -EWOULDBLOCK)) { > xfs_iunlock(ip, *iolock); > error = break_layout(inode, true); > - *iolock = XFS_IOLOCK_EXCL; > + *iolock &= ~XFS_IOLOCK_SHARED; > + *iolock |= XFS_IOLOCK_EXCL; > xfs_ilock(ip, *iolock);
And take this one hunk from your patch.
To enable the DAX use case.
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