[Cluster-devel] [PATCH] gfs2: Another gfs2_walk_metadata fix

[Andreas Gruenbacher]

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: sta...@vger.kernel.org # v5.3+
Signed-off-by: Andreas Gruenbacher <agrue...@redhat.com>
---
 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 936a8ec6b48e..6306eaae378b 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;
 }
 

base-commit: fbe051ea4adf66950e2f23e71ace8eeb4e0e1c73
-- 
2.25.3