From: Trond Myklebust <trond.myklebust@hammerspace.com>
Date: Mon, 8 Mar 2021 14:42:51 -0500
Subject: [PATCH] NFS: Don't revalidate the directory permissions on a lookup
failure
Git-commit: 82e7ca1334ab16e2e04fafded1cab9dfcdc11b40
Patch-mainline: v5.12
References: git-fixes
There should be no reason to expect the directory permissions to change
just because the directory contents changed or a negative lookup timed
out. So let's avoid doing a full call to nfs_mark_for_revalidate() in
that case.
Furthermore, if this is a negative dentry, and we haven't actually done
a new lookup, then we have no reason yet to believe the directory has
changed at all. So let's remove the gratuitous directory inode
invalidation altogether when called from
nfs_lookup_revalidate_negative().
Reported-by: Geert Jansen <gerardu@amazon.com>
Fixes: 5ceb9d7fdaaf ("NFS: Refactor nfs_lookup_revalidate()")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Acked-by: NeilBrown <neilb@suse.com>
---
fs/nfs/dir.c | 20 +++++++++++++++++---
1 file changed, 17 insertions(+), 3 deletions(-)
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1061,6 +1061,15 @@ out_force:
goto out;
}
+static void nfs_mark_dir_for_revalidate(struct inode *inode)
+{
+ struct nfs_inode *nfsi = NFS_I(inode);
+
+ spin_lock(&inode->i_lock);
+ nfsi->cache_validity |= NFS_INO_REVAL_PAGECACHE;
+ spin_unlock(&inode->i_lock);
+}
+
/*
* We judge how long we want to trust negative
* dentries by looking at the parent inode mtime.
@@ -1093,7 +1102,6 @@ nfs_lookup_revalidate_done(struct inode
__func__, dentry);
return 1;
case 0:
- nfs_mark_for_revalidate(dir);
if (inode && S_ISDIR(inode->i_mode)) {
/* Purge readdir caches. */
nfs_zap_caches(inode);
@@ -1174,6 +1182,13 @@ out:
nfs_free_fattr(fattr);
nfs_free_fhandle(fhandle);
nfs4_label_free(label);
+
+ /*
+ * If the lookup failed despite the dentry change attribute being
+ * a match, then we should revalidate the directory cache.
+ */
+ if (!ret && nfs_verify_change_attribute(dir, dentry->d_time))
+ nfs_mark_dir_for_revalidate(dir);
return nfs_lookup_revalidate_done(dir, dentry, inode, ret);
}
@@ -1216,7 +1231,7 @@ nfs_do_lookup_revalidate(struct inode *d
error = nfs_lookup_verify_inode(inode, flags);
if (error) {
if (error == -ESTALE)
- nfs_zap_caches(dir);
+ nfs_mark_dir_for_revalidate(dir);
goto out_bad;
}
nfs_advise_use_readdirplus(dir);
@@ -1709,7 +1724,6 @@ out:
dput(parent);
return 0;
out_error:
- nfs_mark_for_revalidate(dir);
dput(parent);
return error;
}