ext4: Improve error handling in mballoc

Don't call BUG_ON on file system failures. Instead use ext4_error and
also handle the continue case properly.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

1 files changed, 23 insertions, 11 deletions

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 4258d3289a6f..500d3920d41d 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -3736,20 +3736,23 @@ ext4_mb_discard_group_preallocations(struct super_block *sb,
 
         bitmap_bh = ext4_read_block_bitmap(sb, group);
         if (bitmap_bh == NULL) {
-                /* error handling here */
-                ext4_mb_release_desc(&e4b);
-                BUG_ON(bitmap_bh == NULL);
+                ext4_error(sb, __func__, "Error in reading block "
+                                "bitmap for %lu\n", group);
+                return 0;
         }
 
         err = ext4_mb_load_buddy(sb, group, &e4b);
-        BUG_ON(err != 0); /* error handling here */
+        if (err) {
+                ext4_error(sb, __func__, "Error in loading buddy "
+                                "information for %lu\n", group);
+                put_bh(bitmap_bh);
+                return 0;
+        }
 
         if (needed == 0)
                 needed = EXT4_BLOCKS_PER_GROUP(sb) + 1;
 
-        grp = ext4_get_group_info(sb, group);
         INIT_LIST_HEAD(&list);
-
         ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);
 repeat:
         ext4_lock_group(sb, group);
@@ -3906,13 +3909,18 @@ repeat:
                 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, NULL);
 
                 err = ext4_mb_load_buddy(sb, group, &e4b);
-                BUG_ON(err != 0); /* error handling here */
+                if (err) {
+                        ext4_error(sb, __func__, "Error in loading buddy "
+                                        "information for %lu\n", group);
+                        continue;
+                }
 
                 bitmap_bh = ext4_read_block_bitmap(sb, group);
                 if (bitmap_bh == NULL) {
-                        /* error handling here */
+                        ext4_error(sb, __func__, "Error in reading block "
+                                        "bitmap for %lu\n", group);
                         ext4_mb_release_desc(&e4b);
-                        BUG_ON(bitmap_bh == NULL);
+                        continue;
                 }
 
                 ext4_lock_group(sb, group);
@@ -4423,11 +4431,15 @@ do_more:
                 count -= overflow;
         }
         bitmap_bh = ext4_read_block_bitmap(sb, block_group);
-        if (!bitmap_bh)
+        if (!bitmap_bh) {
+                err = -EIO;
                 goto error_return;
+        }
         gdp = ext4_get_group_desc(sb, block_group, &gd_bh);
-        if (!gdp)
+        if (!gdp) {
+                err = -EIO;
                 goto error_return;
+        }
 
         if (in_range(ext4_block_bitmap(sb, gdp), block, count) ||
             in_range(ext4_inode_bitmap(sb, gdp), block, count) ||