On Fri, Aug 10, 2018 at 08:54:00AM -0700, Dave Jiang wrote:
>
>
> On 08/10/2018 08:48 AM, Darrick J. Wong wrote:
> > On Wed, Aug 08, 2018 at 10:31:40AM -0700, Dave Jiang wrote:
> >> This patch is the duplicate of ross's fix for ext4 for xfs.
> >>
> >> If the refcount of a page is lowered between the time that it is returned
> >> by dax_busy_page() and when the refcount is again checked in
> >> xfs_break_layouts() => ___wait_var_event(), the waiting function
> >> xfs_wait_dax_page() will never be called. This means that
> >> xfs_break_layouts() will still have 'retry' set to false, so we'll stop
> >> looping and never check the refcount of other pages in this inode.
> >>
> >> Instead, always continue looping as long as dax_layout_busy_page() gives us
> >> a page which it found with an elevated refcount.
> >>
> >> Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
> >> Reviewed-by: Jan Kara <jack@xxxxxxx>
> >> ---
> >>
> >> Sorry resend, forgot to add Jan's reviewed-by.
> >>
> >> v2:
> >> - Rename parameter from did_unlock to retry (Jan)
> >>
> >> fs/xfs/xfs_file.c | 9 ++++-----
> >> 1 file changed, 4 insertions(+), 5 deletions(-)
> >>
> >> diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
> >> index a3e7767a5715..cd6f0d8c4922 100644
> >> --- a/fs/xfs/xfs_file.c
> >> +++ b/fs/xfs/xfs_file.c
> >> @@ -721,12 +721,10 @@ xfs_file_write_iter(
> >>
> >> static void
> >> xfs_wait_dax_page(
> >> - struct inode *inode,
> >> - bool *did_unlock)
> >> + struct inode *inode)
> >> {
> >> struct xfs_inode *ip = XFS_I(inode);
> >>
> >> - *did_unlock = true;
> >> xfs_iunlock(ip, XFS_MMAPLOCK_EXCL);
> >> schedule();
> >> xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
> >> @@ -736,7 +734,7 @@ static int
> >> xfs_break_dax_layouts(
> >> struct inode *inode,
> >> uint iolock,
> >> - bool *did_unlock)
> >> + bool *retry)
> >
> > Uhhh, this hunk doesn't apply. xfs_break_dax_layouts doesn't have an
> > iolock parameter anymore; was this not generated off of xfs for-next?
>
> Sorry. It was generated against 4.18-rc8. I'll respin patch against xfs
> for-next.
I think it's just a matter of taking the old patch and changing
"did_unlock" to "retry", right? If so, I'll just change that and be
done with this one. :)
--D
> >
> > --D
> >
> >> {
> >> struct page *page;
> >>
> >> @@ -746,9 +744,10 @@ xfs_break_dax_layouts(
> >> if (!page)
> >> return 0;
> >>
> >> + *retry = true;
> >> return ___wait_var_event(&page->_refcount,
> >> atomic_read(&page->_refcount) == 1, TASK_INTERRUPTIBLE,
> >> - 0, 0, xfs_wait_dax_page(inode, did_unlock));
> >> + 0, 0, xfs_wait_dax_page(inode));
> >> }
> >>
> >> int
> >>
> >> --
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