On Thu, Aug 21, 2014 at 03:09:10PM +1000, Dave Chinner wrote: > From: Chris Mason <clm@xxxxxx> > > xfs is using truncate_pagecache_range to invalidate the page cache > during DIO reads. This is different from the other filesystems who > only invalidate pages during DIO writes. > > truncate_pagecache_range is meant to be used when we are freeing the > underlying data structs from disk, so it will zero any partial > ranges in the page. This means a DIO read can zero out part of the > page cache page, and it is possible the page will stay in cache. > > buffered reads will find an up to date page with zeros instead of > the data actually on disk. > > This patch fixes things by using invalidate_inode_pages2_range > instead. It preserves the page cache invalidation, but won't zero > any pages. > > [dchinner: catch error and warn if it fails. Comment.] > > cc: stable@xxxxxxxxxxxxxxx > Signed-off-by: Chris Mason <clm@xxxxxx> > Reviewed-by: Dave Chinner <dchinner@xxxxxxxxxx> > Signed-off-by: Dave Chinner <david@xxxxxxxxxxxxx> > --- Reviewed-by: Brian Foster <bfoster@xxxxxxxxxx> > fs/xfs/xfs_file.c | 11 ++++++++++- > 1 file changed, 10 insertions(+), 1 deletion(-) > > diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c > index 076b170..827cfb2 100644 > --- a/fs/xfs/xfs_file.c > +++ b/fs/xfs/xfs_file.c > @@ -296,7 +296,16 @@ xfs_file_read_iter( > xfs_rw_iunlock(ip, XFS_IOLOCK_EXCL); > return ret; > } > - truncate_pagecache_range(VFS_I(ip), pos, -1); > + > + /* > + * Invalidate whole pages. This can return an error if > + * we fail to invalidate a page, but this should never > + * happen on XFS. Warn if it does fail. > + */ > + ret = invalidate_inode_pages2_range(VFS_I(ip)->i_mapping, > + pos >> PAGE_CACHE_SHIFT, -1); > + WARN_ON_ONCE(ret); > + ret = 0; > } > xfs_rw_ilock_demote(ip, XFS_IOLOCK_EXCL); > } > -- > 2.0.0 > > _______________________________________________ > xfs mailing list > xfs@xxxxxxxxxxx > http://oss.sgi.com/mailman/listinfo/xfs _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
