From:   trondmy@kernel.org
To:     Anna Schumaker <anna.schumaker@netapp.com>
Cc:     linux-nfs@vger.kernel.org
Subject: [PATCH 3/5] NFS: Invalidate negative dentries on all case insensitive directory changes
Date:   Fri, 17 Dec 2021 15:36:56 -0500
Message-Id: <20211217203658.439352-4-trondmy@kernel.org>
In-Reply-To: <20211217203658.439352-3-trondmy@kernel.org>
References: <20211217203658.439352-1-trondmy@kernel.org>
 <20211217203658.439352-2-trondmy@kernel.org>
 <20211217203658.439352-3-trondmy@kernel.org>
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From: Trond Myklebust <trond.myklebust@hammerspace.com>

If we create a file, rename it, or hardlink it, then we need to assume
that cached negative dentries need to be revalidated.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 fs/nfs/dir.c | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 2822681192b0..8ed943081e3d 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1324,6 +1324,14 @@ void nfs_clear_verifier_delegated(struct inode *inode)
 EXPORT_SYMBOL_GPL(nfs_clear_verifier_delegated);
 #endif /* IS_ENABLED(CONFIG_NFS_V4) */
 
+static int nfs_dentry_verify_change(struct inode *dir, struct dentry *dentry)
+{
+	if (nfs_server_capable(dir, NFS_CAP_CASE_INSENSITIVE) &&
+	    d_really_is_negative(dentry))
+		return dentry->d_time == inode_peek_iversion_raw(dir);
+	return nfs_verify_change_attribute(dir, dentry->d_time);
+}
+
 /*
  * A check for whether or not the parent directory has changed.
  * In the case it has, we assume that the dentries are untrustworthy
@@ -1337,7 +1345,7 @@ static int nfs_check_verifier(struct inode *dir, struct dentry *dentry,
 		return 1;
 	if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
 		return 0;
-	if (!nfs_verify_change_attribute(dir, dentry->d_time))
+	if (!nfs_dentry_verify_change(dir, dentry))
 		return 0;
 	/* Revalidate nfsi->cache_change_attribute before we declare a match */
 	if (nfs_mapping_need_revalidate_inode(dir)) {
@@ -1346,7 +1354,7 @@ static int nfs_check_verifier(struct inode *dir, struct dentry *dentry,
 		if (__nfs_revalidate_inode(NFS_SERVER(dir), dir) < 0)
 			return 0;
 	}
-	if (!nfs_verify_change_attribute(dir, dentry->d_time))
+	if (!nfs_dentry_verify_change(dir, dentry))
 		return 0;
 	return 1;
 }
@@ -1539,7 +1547,7 @@ nfs_lookup_revalidate_dentry(struct inode *dir, struct dentry *dentry,
 	 * 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))
+	if (!ret && nfs_dentry_verify_change(dir, dentry))
 		nfs_mark_dir_for_revalidate(dir);
 	return nfs_lookup_revalidate_done(dir, dentry, inode, ret);
 }
@@ -1778,8 +1786,11 @@ struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, unsigned in
 	dir_verifier = nfs_save_change_attribute(dir);
 	trace_nfs_lookup_enter(dir, dentry, flags);
 	error = NFS_PROTO(dir)->lookup(dir, dentry, fhandle, fattr);
-	if (error == -ENOENT)
+	if (error == -ENOENT) {
+		if (nfs_server_capable(dir, NFS_CAP_CASE_INSENSITIVE))
+			dir_verifier = inode_peek_iversion_raw(dir);
 		goto no_entry;
+	}
 	if (error < 0) {
 		res = ERR_PTR(error);
 		goto out;
-- 
2.33.1