[PATCH 4.14 48/65] CIFS: Force reval dentry if LOOKUP_REVAL flag is set

From: Greg Kroah-Hartman
Date: Wed Oct 16 2019 - 17:56:40 EST


From: Pavel Shilovsky <piastryyy@xxxxxxxxx>

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@xxxxxxxxxxxxxxx>
Signed-off-by: Pavel Shilovsky <pshilov@xxxxxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
fs/cifs/dir.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -841,10 +841,16 @@ lookup_out:
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 {
@@ -855,7 +861,7 @@ cifs_d_revalidate(struct dentry *direntr
* 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;