ext4: handle errors in ext4_rename

Checking return code from ext4_journal_get_write_access() is important
with snapshots, because this function invokes COW, so may return new
errors, such as ENOSPC.

We move the call to ext4_journal_get_write_access earlier in the
function, to simplify error handling in the case that this function
returns returns an error.

Signed-off-by: Amir Goldstein <amir73il@users.sf.net>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 5485390..ad87584 100644 (file)
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -2409,6 +2409,10 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
                if (!new_inode && new_dir != old_dir &&
                    EXT4_DIR_LINK_MAX(new_dir))
                        goto end_rename;
+               BUFFER_TRACE(dir_bh, "get_write_access");
+               retval = ext4_journal_get_write_access(handle, dir_bh);
+               if (retval)
+                       goto end_rename;
        }
        if (!new_bh) {
                retval = ext4_add_entry(handle, new_dentry, old_inode);
@@ -2416,7 +2420,9 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
                        goto end_rename;
        } else {
                BUFFER_TRACE(new_bh, "get write access");
-               ext4_journal_get_write_access(handle, new_bh);
+               retval = ext4_journal_get_write_access(handle, new_bh);
+               if (retval)
+                       goto end_rename;
                new_de->inode = cpu_to_le32(old_inode->i_ino);
                if (EXT4_HAS_INCOMPAT_FEATURE(new_dir->i_sb,
                                              EXT4_FEATURE_INCOMPAT_FILETYPE))
@@ -2477,8 +2483,6 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
        old_dir->i_ctime = old_dir->i_mtime = ext4_current_time(old_dir);
        ext4_update_dx_flag(old_dir);
        if (dir_bh) {
-               BUFFER_TRACE(dir_bh, "get_write_access");
-               ext4_journal_get_write_access(handle, dir_bh);
                PARENT_INO(dir_bh->b_data, new_dir->i_sb->s_blocksize) =
                                                cpu_to_le32(new_dir->i_ino);
                BUFFER_TRACE(dir_bh, "call ext4_handle_dirty_metadata");