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>

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 4258d3289a6f82a506f31e42f15605de4336504f..500d3920d41de0851939e203094b6f5741b097a1 100644 (file)
--- 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) ||