ext4: Free resources in ext4_mb_init()'s error paths

In commit 79a77c5ac, we move ext4_mb_init_backend after the allocation
of s_locality_group to avoid memory leak in error path, but there are
still some other error paths in ext4_mb_init that need to do the same
work. So this patch adds all the error patch for ext4_mb_init. And all
the pointers are reset to NULL in case the caller may double free them.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 15 insertions, 8 deletions

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 1c83161090f8..8c005c028203 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2504,7 +2504,7 @@ int ext4_mb_init(struct super_block *sb, int needs_recovery)
         sbi->s_locality_groups = alloc_percpu(struct ext4_locality_group);
         if (sbi->s_locality_groups == NULL) {
                 ret = -ENOMEM;
-                goto out;
+                goto out_free_groupinfo_slab;
         }
         for_each_possible_cpu(i) {
                 struct ext4_locality_group *lg;
@@ -2517,9 +2517,8 @@ int ext4_mb_init(struct super_block *sb, int needs_recovery)
 
         /* init file for buddy data */
         ret = ext4_mb_init_backend(sb);
-        if (ret != 0) {
-                goto out;
-        }
+        if (ret != 0)
+                goto out_free_locality_groups;
 
         if (sbi->s_proc)
                 proc_create_data("mb_groups", S_IRUGO, sbi->s_proc,
@@ -2527,11 +2526,19 @@ int ext4_mb_init(struct super_block *sb, int needs_recovery)
 
         if (sbi->s_journal)
                 sbi->s_journal->j_commit_callback = release_blocks_on_commit;
+
+        return 0;
+
+out_free_locality_groups:
+        free_percpu(sbi->s_locality_groups);
+        sbi->s_locality_groups = NULL;
+out_free_groupinfo_slab:
+        ext4_groupinfo_destroy_slabs();
 out:
-        if (ret) {
-                kfree(sbi->s_mb_offsets);
-                kfree(sbi->s_mb_maxs);
-        }
+        kfree(sbi->s_mb_offsets);
+        sbi->s_mb_offsets = NULL;
+        kfree(sbi->s_mb_maxs);
+        sbi->s_mb_maxs = NULL;
         return ret;
 }