1 files changed, 21 insertions, 11 deletions

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 25f809dc45a3..89b59cb7f9b8 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1182,6 +1182,17 @@ static int ext4_da_reserve_space(struct inode *inode, ext4_lblk_t lblock)
         struct ext4_inode_info *ei = EXT4_I(inode);
         unsigned int md_needed;
         int ret;
+        ext4_lblk_t save_last_lblock;
+        int save_len;
+
+        /*
+         * We will charge metadata quota at writeout time; this saves
+         * us from metadata over-estimation, though we may go over by
+         * a small amount in the end.  Here we just reserve for data.
+         */
+        ret = dquot_reserve_block(inode, EXT4_C2B(sbi, 1));
+        if (ret)
+                return ret;
 
         /*
          * recalculate the amount of metadata blocks to reserve
@@ -1190,32 +1201,31 @@ static int ext4_da_reserve_space(struct inode *inode, ext4_lblk_t lblock)
          */
 repeat:
         spin_lock(&ei->i_block_reservation_lock);
+        /*
+         * ext4_calc_metadata_amount() has side effects, which we have
+         * to be prepared undo if we fail to claim space.
+         */
+        save_len = ei->i_da_metadata_calc_len;
+        save_last_lblock = ei->i_da_metadata_calc_last_lblock;
         md_needed = EXT4_NUM_B2C(sbi,
                                  ext4_calc_metadata_amount(inode, lblock));
         trace_ext4_da_reserve_space(inode, md_needed);
-        spin_unlock(&ei->i_block_reservation_lock);
 
         /*
-         * We will charge metadata quota at writeout time; this saves
-         * us from metadata over-estimation, though we may go over by
-         * a small amount in the end.  Here we just reserve for data.
-         */
-        ret = dquot_reserve_block(inode, EXT4_C2B(sbi, 1));
-        if (ret)
-                return ret;
-        /*
          * We do still charge estimated metadata to the sb though;
          * we cannot afford to run out of free blocks.
          */
         if (ext4_claim_free_clusters(sbi, md_needed + 1, 0)) {
-                dquot_release_reservation_block(inode, EXT4_C2B(sbi, 1));
+                ei->i_da_metadata_calc_len = save_len;
+                ei->i_da_metadata_calc_last_lblock = save_last_lblock;
+                spin_unlock(&ei->i_block_reservation_lock);
                 if (ext4_should_retry_alloc(inode->i_sb, &retries)) {
                         yield();
                         goto repeat;
                 }
+                dquot_release_reservation_block(inode, EXT4_C2B(sbi, 1));
                 return -ENOSPC;
         }
-        spin_lock(&ei->i_block_reservation_lock);
         ei->i_reserved_data_blocks++;
         ei->i_reserved_meta_blocks += md_needed;
         spin_unlock(&ei->i_block_reservation_lock);