On Fri, May 27, 2016 at 08:32:18PM +0300, Avi Kivity wrote:
> On 05/26/2016 04:02 PM, Christoph Hellwig wrote:
> >Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> >---
> > fs/xfs/xfs_aops.c | 11 +++++++++++
> > 1 file changed, 11 insertions(+)
> >
> >diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
> >index a955552..d053a9e 100644
> >--- a/fs/xfs/xfs_aops.c
> >+++ b/fs/xfs/xfs_aops.c
> >@@ -1829,6 +1829,17 @@ xfs_vm_bmap(
> > trace_xfs_vm_bmap(XFS_I(inode));
> > xfs_ilock(ip, XFS_IOLOCK_SHARED);
> >+
> >+ /*
> >+ * The swap code (ab-)uses ->bmap to get a block mapping and then
> >+ * bypasseѕ the file system for actual I/O. We really can't allow
> >+ * that on reflinks inodes, so we have to skip out here. And yes,
> >+ * 0 is the magic code for a bmap error..
> >+ */
> >+ if (xfs_is_reflink_inode(ip)) {
> >+ xfs_iunlock(ip, XFS_IOLOCK_SHARED);
> >+ return 0;
> >+ }
> > filemap_write_and_wait(mapping);
> > xfs_iunlock(ip, XFS_IOLOCK_SHARED);
> > return generic_block_bmap(mapping, block, xfs_get_blocks);
>
> Don't you also have to prevent a swapfile from being reflinked after it's
> bmapped? Or is that already taken care of?
Already taken care of, at least for XFS.
--D
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