CIFS: Force reval dentry if LOOKUP_REVAL flag is set

BugLink: https://bugs.launchpad.net/bugs/1848750
commit 0b3d0ef9840f7be202393ca9116b857f6f793715 upstream.

Mark inode for force revalidation if LOOKUP_REVAL flag is set.
This tells the client to actually send a QueryInfo request to
the server to obtain the latest metadata in case a directory
or a file were changed remotely. Only do that if the client
doesn't have a lease for the file to avoid unneeded round
trips to the server.

Cc: <stable@vger.kernel.org>
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index be424e81e3ad98e20f65de41572d87a569a28c7b..1cc1f298e01aa07bf44a5a59ecd254366ce5403a 100644 (file)
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -738,10 +738,16 @@ cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
 static int
 cifs_d_revalidate(struct dentry *direntry, unsigned int flags)
 {
+       struct inode *inode;
+
        if (flags & LOOKUP_RCU)
                return -ECHILD;
 
        if (d_really_is_positive(direntry)) {
+               inode = d_inode(direntry);
+               if ((flags & LOOKUP_REVAL) && !CIFS_CACHE_READ(CIFS_I(inode)))
+                       CIFS_I(inode)->time = 0; /* force reval */
+
                if (cifs_revalidate_dentry(direntry))
                        return 0;
                else {
@@ -752,7 +758,7 @@ cifs_d_revalidate(struct dentry *direntry, unsigned int flags)
                         * attributes will have been updated by
                         * cifs_revalidate_dentry().
                         */
-                       if (IS_AUTOMOUNT(d_inode(direntry)) &&
+                       if (IS_AUTOMOUNT(inode) &&
                           !(direntry->d_flags & DCACHE_NEED_AUTOMOUNT)) {
                                spin_lock(&direntry->d_lock);
                                direntry->d_flags |= DCACHE_NEED_AUTOMOUNT;