Commit 4d479cf0 authored Nov 17, 2011 by Josef Bacik Committed by Chris Mason Nov 20, 2011

Btrfs: sectorsize align offsets in fiemap

We've been hitting BUG()'s in btrfs_cont_expand and btrfs_fallocate and anywhere
else that calls btrfs_get_extent while running xfstests 13 in a loop. This is
because fiemap is calling btrfs_get_extent with non-sectorsize aligned offsets,
which will end up adding mappings that are not sectorsize aligned, which will
cause problems in some cases for subsequent calls to btrfs_get_extent for
similar areas that are sectorsize aligned. With this patch I ran xfstests 13 in
a loop for a couple of hours and didn't hit the problem that I could previously
hit in at most 20 minutes. Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>

parent f7d61dcd

fs/btrfs/extent_io.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -3366,6 +3366,9 @@ int extent_fiemap(struct inode inode, struct fiemap_extent_info fieinfo,
		return -ENOMEM;
		path->leave_spinning = 1;

		start = ALIGN(start, BTRFS_I(inode)->root->sectorsize);
		len = ALIGN(len, BTRFS_I(inode)->root->sectorsize);

		/*
		* lookup the last file extent. We're not using i_size here
		* because there might be preallocation past i_size
		@@ -3413,7 +3416,7 @@ int extent_fiemap(struct inode inode, struct fiemap_extent_info fieinfo,
		lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + len, 0,
		&cached_state, GFP_NOFS);

		em = get_extent_skip_holes(inode, off, last_for_get_extent,
		em = get_extent_skip_holes(inode, start, last_for_get_extent,
		get_extent);
		if (!em)
		goto out;