Re: [PATCH v3] tracefs: Add read-only eventfs filesystem at /sys/kernel/events

Re: [PATCH v3] tracefs: Add read-only eventfs filesystem at /sys/kernel/events

[kernel test robot]

Hi Steven,

kernel test robot noticed the following build errors:

[auto build test ERROR on v7.2]
[also build test ERROR on next-20260819]
[cannot apply to trace/for-next linus/master]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Steven-Rostedt/tracefs-Add-read-only-eventfs-filesystem-at-sys-kernel-events/20260810-160708
base:   v7.2
patch link:    https://lore.kernel.org/r/20260810160708.3460a2fd%40gandalf.local.home
patch subject: [PATCH v3] tracefs: Add read-only eventfs filesystem at /sys/kernel/events
config: x86_64-kexec (https://download.01.org/0day-ci/archive/20260820/202608201957.NHoAQjoy-lkp@intel.com/config)
compiler: clang version 22.1.3 (https://github.com/llvm/llvm-project e9846648fd6183ee6d8cbdb4502213fcf902a211)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260820/202608201957.NHoAQjoy-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202608201957.NHoAQjoy-lkp@intel.com/

All errors (new ones prefixed by >>):

>> fs/tracefs/event_inode.c:38:16: error: use of undeclared identifier 'EVENTFS_SUPER_MAGIC'
      38 |         sb->s_magic = EVENTFS_SUPER_MAGIC;
         |                       ^~~~~~~~~~~~~~~~~~~
   1 error generated.


vim +/EVENTFS_SUPER_MAGIC +38 fs/tracefs/event_inode.c

    30	
    31	static int eventfs_ro_fill_super(struct super_block *sb, struct fs_context *fc)
    32	{
    33		struct inode *inode;
    34		struct dentry *root;
    35	
    36		sb->s_blocksize = PAGE_SIZE;
    37		sb->s_blocksize_bits = PAGE_SHIFT;
  > 38		sb->s_magic = EVENTFS_SUPER_MAGIC;
    39		sb->s_op = &eventfs_ro_super_operations;
    40		sb->s_time_gran = 1;
    41		sb->s_flags |= SB_RDONLY;
    42	
    43		inode = new_inode(sb);
    44		if (!inode)
    45			return -ENOMEM;
    46	
    47		inode->i_ino = 1;
    48		inode->i_mode = S_IFDIR | 0555;
    49		simple_inode_init_ts(inode);
    50		inode->i_op = &simple_dir_inode_operations;
    51		inode->i_fop = &simple_dir_operations;
    52		set_nlink(inode, 2);
    53	
    54		set_default_d_op(sb, &tracefs_dentry_operations);
    55	
    56		root = d_make_root(inode);
    57		if (!root)
    58			return -ENOMEM;
    59	
    60		sb->s_root = root;
    61	
    62		return 0;
    63	}
    64	

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