[#LU-8891] disabling statahead changes dentry revalidation behavior

In ll_revalidate_dentry() the test for LOOKUP_RCU in lookup_flags should probably go before the dentry_may_statahead() test:

static int ll_revalidate_dentry(struct dentry *dentry,
                                unsigned int lookup_flags)
{
        struct inode *dir = dentry->d_parent->d_inode;

        /* If this is intermediate component path lookup and we were able to get
         * to this dentry, then its lock has not been revoked and the
         * path component is valid. */
        if (lookup_flags & (LOOKUP_CONTINUE | LOOKUP_PARENT))
                return 1;

        /* Symlink - always valid as long as the dentry was found */
#ifdef HAVE_IOP_GET_LINK
        if (dentry->d_inode && dentry->d_inode->i_op->get_link)
#else
        if (dentry->d_inode && dentry->d_inode->i_op->follow_link)
#endif
                return 1;

        /*
         * VFS warns us that this is the second go around and previous
         * operation failed (most likely open|creat), so this time
         * we better talk to the server via the lookup path by name,
         * not by fid.
         */
        if (lookup_flags & LOOKUP_REVAL)
                return 0;

        if (!dentry_may_statahead(dir, dentry))
                return 1;

#ifndef HAVE_DCACHE_LOCK
        if (lookup_flags & LOOKUP_RCU)
                return -ECHILD;
#endif

        ll_statahead(dir, &dentry, dentry->d_inode == NULL);
        return 1;
}

[LU-8891] disabling statahead changes dentry revalidation behavior Created: 01/Dec/16 Updated: 13/Jun/17 Resolved: 13/Jun/17
Status:	Resolved
Project:	Lustre
Component/s:	None
Affects Version/s:	Lustre 2.9.0
Fix Version/s:	Lustre 2.10.0

[LU-8891] disabling statahead changes dentry revalidation behavior Created: 01/Dec/16 Updated: 13/Jun/17 Resolved: 13/Jun/17