Most of the callers of lookup_one_len_unlocked() treat negatives are ERR_PTR(-ENOENT). Provide a helper that would do just that. Note that a pinned positive dentry remains positive - it's ->d_inode is stable, etc.; a pinned _negative_ dentry can become positive at any point as long as you are not holding its parent at least shared. So using lookup_one_len_unlocked() needs to be careful; lookup_positive_unlocked() is safer and that's what the callers end up open-coding anyway.
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| @@ -60,6 +60,7 @@ extern int kern_path_mountpoint(int, const char *, struct path *, unsigned int); · 59 unmodified lines | ||
| 60 | 60 | extern struct dentry *try_lookup_one_len(const char *, struct dentry *, int); |
| 61 | 61 | extern struct dentry *lookup_one_len(const char *, struct dentry *, int); |
| 62 | 62 | extern struct dentry *lookup_one_len_unlocked(const char *, struct dentry *, int); |
| 63 | +extern struct dentry *lookup_positive_unlocked(const char *, struct dentry *, int); | |
| 63 | 64 | |
| 64 | 65 | extern int follow_down_one(struct path *); |
| 65 | 66 | extern int follow_down(struct path *); |