ext2: protect inode changes in the SETVERSION and SETFLAGS ioctls

Unlock mutex after i_flags and i_ctime updates in the EXT2_IOC_SETFLAGS
ioctl.

Use i_mutex in the EXT2_IOC_SETVERSION ioctl to protect i_ctime and
i_generation updates and make the ioctl consistent since i_mutex is
also used in other places to protect timestamps and inode changes.

Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Djalal Harouni <tixxdz@opendz.org>
Signed-off-by: Jan Kara <jack@suse.cz>

diff --git a/fs/ext2/ioctl.c b/fs/ext2/ioctl.c
index 1089f760c8470f25c0cac5744c880de9377775d5..2de655f5d625365a3aed996d00c0a73d4052559d 100644 (file)
--- a/fs/ext2/ioctl.c
+++ b/fs/ext2/ioctl.c
@@ -77,10 +77,11 @@ long ext2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
                flags = flags & EXT2_FL_USER_MODIFIABLE;
                flags |= oldflags & ~EXT2_FL_USER_MODIFIABLE;
                ei->i_flags = flags;
-               mutex_unlock(&inode->i_mutex);
 
                ext2_set_inode_flags(inode);
                inode->i_ctime = CURRENT_TIME_SEC;
+               mutex_unlock(&inode->i_mutex);
+
                mark_inode_dirty(inode);
 setflags_out:
                mnt_drop_write_file(filp);
@@ -88,20 +89,29 @@ setflags_out:
        }
        case EXT2_IOC_GETVERSION:
                return put_user(inode->i_generation, (int __user *) arg);
-       case EXT2_IOC_SETVERSION:
+       case EXT2_IOC_SETVERSION: {
+               __u32 generation;
+
                if (!inode_owner_or_capable(inode))
                        return -EPERM;
                ret = mnt_want_write_file(filp);
                if (ret)
                        return ret;
-               if (get_user(inode->i_generation, (int __user *) arg)) {
+               if (get_user(generation, (int __user *) arg)) {
                        ret = -EFAULT;
-               } else {
-                       inode->i_ctime = CURRENT_TIME_SEC;
-                       mark_inode_dirty(inode);
+                       goto setversion_out;
                }
+
+               mutex_lock(&inode->i_mutex);
+               inode->i_ctime = CURRENT_TIME_SEC;
+               inode->i_generation = generation;
+               mutex_unlock(&inode->i_mutex);
+
+               mark_inode_dirty(inode);
+setversion_out:
                mnt_drop_write_file(filp);
                return ret;
+       }
        case EXT2_IOC_GETRSVSZ:
                if (test_opt(inode->i_sb, RESERVATION)
                        && S_ISREG(inode->i_mode)