new helper: lookup_positive_unlocked()
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.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index 6e826b4..a37e1b1 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -2507,15 +2507,10 @@ int dquot_quota_on_mount(struct super_block *sb, char *qf_name,
struct dentry *dentry;
int error;
- dentry = lookup_one_len_unlocked(qf_name, sb->s_root, strlen(qf_name));
+ dentry = lookup_positive_unlocked(qf_name, sb->s_root, strlen(qf_name));
if (IS_ERR(dentry))
return PTR_ERR(dentry);
- if (d_really_is_negative(dentry)) {
- error = -ENOENT;
- goto out;
- }
-
error = security_quota_on(dentry);
if (!error)
error = vfs_load_quota_inode(d_inode(dentry), type, format_id,