ext4: fix ext4_discard_allocated_blocks() if we can't allocate the pa struct

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / fs / ext4 / mballoc.c

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 16bb6591561b38ce36826ce6bc17b690f7ac4d07..35220866fbbff5d354d56180ab6a6f759ea8d935 100644 (file)
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -3177,8 +3177,27 @@ static void ext4_mb_collect_stats(struct ext4_allocation_context *ac)
 static void ext4_discard_allocated_blocks(struct ext4_allocation_context *ac)
 {
        struct ext4_prealloc_space *pa = ac->ac_pa;
+       struct ext4_buddy e4b;
+       int err;
 
-       if (pa && pa->pa_type == MB_INODE_PA)
+       if (pa == NULL) {
+               err = ext4_mb_load_buddy(ac->ac_sb, ac->ac_f_ex.fe_group, &e4b);
+               if (err) {
+                       /*
+                        * This should never happen since we pin the
+                        * pages in the ext4_allocation_context so
+                        * ext4_mb_load_buddy() should never fail.
+                        */
+                       WARN(1, "mb_load_buddy failed (%d)", err);
+                       return;
+               }
+               ext4_lock_group(ac->ac_sb, ac->ac_f_ex.fe_group);
+               mb_free_blocks(ac->ac_inode, &e4b, ac->ac_f_ex.fe_start,
+                              ac->ac_f_ex.fe_len);
+               ext4_unlock_group(ac->ac_sb, ac->ac_f_ex.fe_group);
+               return;
+       }
+       if (pa->pa_type == MB_INODE_PA)
                pa->pa_free += ac->ac_b_ex.fe_len;
 }