Re: [PATCH v2] ras: cec: Fix debugfs error checking

[Borislav Petkov]

On Thu, Nov 20, 2025 at 04:07:08PM +0800, Haotian Zhang wrote:
> The debugfs_create_dir() and debugfs_create_file() functions return
> ERR_PTR() on error, not NULL. The current null-checks fail to detect
> errors because ERR_PTR() encodes error codes as non-null pointer values.
> 
> Replace the null-checks with IS_ERR() for all debugfs_create_dir() and
> debugfs_create_file() and ras_get_debugfs_root calls to properly
> handle errors.
> 
> Fixes: 011d82611172 ("RAS: Add a Corrected Errors Collector")

git show 011d82611172:fs/debugfs/inode.c
...
struct dentry *debugfs_create_dir(const char *name, struct dentry *parent)
{
        struct dentry *dentry = start_creating(name, parent);
        struct inode *inode;
 
        if (IS_ERR(dentry))
                return NULL;
		^^^^^^^^^^^

So it used to return NULL at the time.

However,

/**     
 * debugfs_create_file - create a file in the debugfs filesystem

	...

 * NOTE: it's expected that most callers should _ignore_ the errors returned
 * by this function. Other debugfs functions handle the fact that the "dentry"
 * passed to them could be an error and they don't crash in that case.
 * Drivers should generally work fine even if debugfs fails to init anyway.
 */

and the _dir() one has the same note. I've been hesitant to remove that error
handling in cec.c until now but I think we can safely zap it. It is
unnecessary clutter by now.

Thx.

-- 
Regards/Gruss,
    Boris.

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