[PATCH 5.6 071/194] gfs2: Another gfs2_walk_metadata fix

Greg Kroah-Hartman
2020-05-18T18:02:43Z

From: Andreas Gruenbacher <agruenba@redhat.com>

[ Upstream commit 566a2ab3c9005f62e784bd39022d58d34ef4365c ]

Make sure we don't walk past the end of the metadata in gfs2_walk_metadata: the
inode holds fewer pointers than indirect blocks.

Slightly clean up gfs2_iomap_get.

Fixes: a27a0c9b6a20 ("gfs2: gfs2_walk_metadata fix")
Cc: stable@vger.kernel.org # v5.3+
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/gfs2/bmap.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index 08f6fbb3655e2..31ed264356253 100644
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -528,10 +528,12 @@ static int gfs2_walk_metadata(struct inode *inode, struct metapath *mp,

/* Advance in metadata tree. */
(mp->mp_list[hgt])++;
- if (mp->mp_list[hgt] >= sdp->sd_inptrs) {
- if (!hgt)
+ if (hgt) {
+ if (mp->mp_list[hgt] >= sdp->sd_inptrs)
+ goto lower_metapath;
+ } else {
+ if (mp->mp_list[hgt] >= sdp->sd_diptrs)
break;
- goto lower_metapath;
}

fill_up_metapath:
@@ -876,10 +878,9 @@ static int gfs2_iomap_get(struct inode *inode, loff_t pos, loff_t length,
ret = -ENOENT;
goto unlock;
} else {
- /* report a hole */
iomap->offset = pos;
iomap->length = length;
- goto do_alloc;
+ goto hole_found;
}
}
iomap->length = size;
@@ -933,8 +934,6 @@ static int gfs2_iomap_get(struct inode *inode, loff_t pos, loff_t length,
return ret;

do_alloc:
- iomap->addr = IOMAP_NULL_ADDR;
- iomap->type = IOMAP_HOLE;
if (flags & IOMAP_REPORT) {
if (pos >= size)
ret = -ENOENT;
@@ -956,6 +955,9 @@ static int gfs2_iomap_get(struct inode *inode, loff_t pos, loff_t length,
if (pos < size && height == ip->i_height)
ret = gfs2_hole_size(inode, lblock, len, mp, iomap);
}
+hole_found:
+ iomap->addr = IOMAP_NULL_ADDR;
+ iomap->type = IOMAP_HOLE;
goto out;
}

--
2.20.1