ext4: mballoc avoid use root reserved blocks for non root allocation

mballoc allocation missed check for blocks reserved for root users. Add
ext4_has_free_blocks() check before allocation. Also modified
ext4_has_free_blocks() to support multiple block allocation request.

Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 6 insertions, 1 deletions

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 816ba8cce79a..1666ac184e31 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -4045,6 +4045,12 @@ ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle,
                                             &(ar->len), errp);
                 return block;
         }
+        ar->len = ext4_has_free_blocks(sbi, ar->len);
+
+        if (ar->len == 0) {
+                *errp = -ENOSPC;
+                return 0;
+        }
 
         while (ar->len && DQUOT_ALLOC_BLOCK(ar->inode, ar->len)) {
                 ar->flags |= EXT4_MB_HINT_NOPREALLOC;
@@ -4073,7 +4079,6 @@ ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle,
 
         ac->ac_op = EXT4_MB_HISTORY_PREALLOC;
         if (!ext4_mb_use_preallocated(ac)) {
-
                 ac->ac_op = EXT4_MB_HISTORY_ALLOC;
                 ext4_mb_normalize_request(ac, ar);
 repeat: