Re: [PATCH 67/71] xfs: fail ->bmap for reflink inodes
Christoph Hellwig <[email protected]>
| Newsgroups | gmane.comp.file-systems.xfs.general |
|---|---|
| Message-ID | <[email protected]> |
On Thu, Aug 25, 2016 at 04:39:13PM -0700, Darrick J. Wong wrote: > From: Christoph Hellwig <[email protected]> > > Have xfs_vm_bmap return zero for reflinked files. This hack prevents > using a file with shared blocks as a swap file, because we don't want > to deal with CoW when we're (probably) low on memory. > > Signed-off-by: Christoph Hellwig <[email protected]> > [[email protected]: add a more descriptive changelog] Which happens to be incorrect :) The swap code uses ->bmap to build a logical to physical block map at swapon time (to avoid allocations or even just block mappings under memory pressure I suspect). This means we'd get reliable data corruption when COWing a swap file. > + * The swap code (ab-)uses ->bmap to get a block mapping and then > + * bypasse?? the file system for actual I/O. We really can't allow Also it seems like I introduced some weird character instead of an "s" here.. _______________________________________________ xfs mailing list [email protected] http://oss.sgi.com/mailman/listinfo/xfs