ext4: Fix NULL dereference in ext4_ext_migrate()'s error handling

[sfrench/cifs-2.6.git] / fs / ext4 / migrate.c

diff --git a/fs/ext4/migrate.c b/fs/ext4/migrate.c
index f2a9cf498ecda12ddde2c7fb1a73a40c64767ade..fe64d9f79852f1dc22764cfa00f261c84858107b 100644 (file)
--- a/fs/ext4/migrate.c
+++ b/fs/ext4/migrate.c
@@ -59,7 +59,8 @@ static int finish_range(handle_t *handle, struct inode *inode,
        /*
         * Make sure the credit we accumalated is not really high
         */
-       if (needed && handle->h_buffer_credits >= EXT4_RESERVE_TRANS_BLOCKS) {
+       if (needed && ext4_handle_has_enough_credits(handle,
+                                               EXT4_RESERVE_TRANS_BLOCKS)) {
                retval = ext4_journal_restart(handle, needed);
                if (retval)
                        goto err_out;
@@ -229,7 +230,7 @@ static int extend_credit_for_blkdel(handle_t *handle, struct inode *inode)
 {
        int retval = 0, needed;
 
-       if (handle->h_buffer_credits > EXT4_RESERVE_TRANS_BLOCKS)
+       if (ext4_handle_has_enough_credits(handle, EXT4_RESERVE_TRANS_BLOCKS+1))
                return 0;
        /*
         * We are freeing a blocks. During this we touch
@@ -458,13 +459,13 @@ int ext4_ext_migrate(struct inode *inode)
        struct list_blocks_struct lb;
        unsigned long max_entries;
 
-       if (!test_opt(inode->i_sb, EXTENTS))
-               /*
-                * if mounted with noextents we don't allow the migrate
-                */
-               return -EINVAL;
-
-       if ((EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL))
+       /*
+        * If the filesystem does not support extents, or the inode
+        * already is extent-based, error out.
+        */
+       if (!EXT4_HAS_INCOMPAT_FEATURE(inode->i_sb,
+                                      EXT4_FEATURE_INCOMPAT_EXTENTS) ||
+           (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL))
                return -EINVAL;
 
        if (S_ISLNK(inode->i_mode) && inode->i_blocks == 0)
@@ -480,7 +481,7 @@ int ext4_ext_migrate(struct inode *inode)
                                        + 1);
        if (IS_ERR(handle)) {
                retval = PTR_ERR(handle);
-               goto err_out;
+               return retval;
        }
        tmp_inode = ext4_new_inode(handle,
                                inode->i_sb->s_root->d_inode,
@@ -488,8 +489,7 @@ int ext4_ext_migrate(struct inode *inode)
        if (IS_ERR(tmp_inode)) {
                retval = -ENOMEM;
                ext4_journal_stop(handle);
-               tmp_inode = NULL;
-               goto err_out;
+               return retval;
        }
        i_size_write(tmp_inode, i_size_read(inode));
        /*
@@ -617,8 +617,7 @@ err_out:
 
        ext4_journal_stop(handle);
 
-       if (tmp_inode)
-               iput(tmp_inode);
+       iput(tmp_inode);
 
        return retval;
 }