dir_index: error out instead of BUG on corrupt dx dirs

Convert asserts (BUGs) in dx_probe from bad on-disk data to recoverable
errors with helpful warnings.  With help catching other asserts from Duane
Griffin <duaneg@dghda.com>

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Acked-by: Duane Griffin <duaneg@dghda.com>
Acked-by: Theodore Ts'o <tytso@mit.edu>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/ext3/namei.c b/fs/ext3/namei.c
index 1586807..9d4a898 100644 (file)
--- a/fs/ext3/namei.c
+++ b/fs/ext3/namei.c
@@ -379,13 +379,28 @@ dx_probe(struct dentry *dentry, struct inode *dir,
 
        entries = (struct dx_entry *) (((char *)&root->info) +
                                       root->info.info_length);
-       assert(dx_get_limit(entries) == dx_root_limit(dir,
-                                                     root->info.info_length));
+
+       if (dx_get_limit(entries) != dx_root_limit(dir,
+                                                  root->info.info_length)) {
+               ext3_warning(dir->i_sb, __FUNCTION__,
+                            "dx entry: limit != root limit");
+               brelse(bh);
+               *err = ERR_BAD_DX_DIR;
+               goto fail;
+       }
+
        dxtrace (printk("Look up %x", hash));
        while (1)
        {
                count = dx_get_count(entries);
-               assert (count && count <= dx_get_limit(entries));
+               if (!count || count > dx_get_limit(entries)) {
+                       ext3_warning(dir->i_sb, __FUNCTION__,
+                                    "dx entry: no count or count > limit");
+                       brelse(bh);
+                       *err = ERR_BAD_DX_DIR;
+                       goto fail2;
+               }
+
                p = entries + 1;
                q = entries + count - 1;
                while (p <= q)
@@ -423,8 +438,15 @@ dx_probe(struct dentry *dentry, struct inode *dir,
                if (!(bh = ext3_bread (NULL,dir, dx_get_block(at), 0, err)))
                        goto fail2;
                at = entries = ((struct dx_node *) bh->b_data)->entries;
-               assert (dx_get_limit(entries) == dx_node_limit (dir));
+               if (dx_get_limit(entries) != dx_node_limit (dir)) {
+                       ext3_warning(dir->i_sb, __FUNCTION__,
+                                    "dx entry: limit != node limit");
+                       brelse(bh);
+                       *err = ERR_BAD_DX_DIR;
+                       goto fail2;
+               }
                frame++;
+               frame->bh = NULL;
        }
 fail2:
        while (frame >= frame_in) {
@@ -432,6 +454,10 @@ fail2:
                frame--;
        }
 fail:
+       if (*err == ERR_BAD_DX_DIR)
+               ext3_warning(dir->i_sb, __FUNCTION__,
+                            "Corrupt dir inode %ld, running e2fsck is "
+                            "recommended.", dir->i_ino);
        return NULL;
 }
 

diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index da22497..9468289 100644 (file)
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -379,13 +379,28 @@ dx_probe(struct dentry *dentry, struct inode *dir,
 
        entries = (struct dx_entry *) (((char *)&root->info) +
                                       root->info.info_length);
-       assert(dx_get_limit(entries) == dx_root_limit(dir,
-                                                     root->info.info_length));
+
+       if (dx_get_limit(entries) != dx_root_limit(dir,
+                                                  root->info.info_length)) {
+               ext4_warning(dir->i_sb, __FUNCTION__,
+                            "dx entry: limit != root limit");
+               brelse(bh);
+               *err = ERR_BAD_DX_DIR;
+               goto fail;
+       }
+
        dxtrace (printk("Look up %x", hash));
        while (1)
        {
                count = dx_get_count(entries);
-               assert (count && count <= dx_get_limit(entries));
+               if (!count || count > dx_get_limit(entries)) {
+                       ext4_warning(dir->i_sb, __FUNCTION__,
+                                    "dx entry: no count or count > limit");
+                       brelse(bh);
+                       *err = ERR_BAD_DX_DIR;
+                       goto fail2;
+               }
+
                p = entries + 1;
                q = entries + count - 1;
                while (p <= q)
@@ -423,8 +438,15 @@ dx_probe(struct dentry *dentry, struct inode *dir,
                if (!(bh = ext4_bread (NULL,dir, dx_get_block(at), 0, err)))
                        goto fail2;
                at = entries = ((struct dx_node *) bh->b_data)->entries;
-               assert (dx_get_limit(entries) == dx_node_limit (dir));
+               if (dx_get_limit(entries) != dx_node_limit (dir)) {
+                       ext4_warning(dir->i_sb, __FUNCTION__,
+                                    "dx entry: limit != node limit");
+                       brelse(bh);
+                       *err = ERR_BAD_DX_DIR;
+                       goto fail2;
+               }
                frame++;
+               frame->bh = NULL;
        }
 fail2:
        while (frame >= frame_in) {
@@ -432,6 +454,10 @@ fail2:
                frame--;
        }
 fail:
+       if (*err == ERR_BAD_DX_DIR)
+               ext4_warning(dir->i_sb, __FUNCTION__,
+                            "Corrupt dir inode %ld, running e2fsck is "
+                            "recommended.", dir->i_ino);
        return NULL;
 }