Patch "NFSD: fix regression with setting ACLs." has been added to the 5.10-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    NFSD: fix regression with setting ACLs.

to the 5.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     nfsd-fix-regression-with-setting-acls.patch
and it can be found in the queue-5.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 35850d46e15cf52f7e67df32d589681968d1b88e
Author: NeilBrown <neilb@xxxxxxx>
Date:   Thu Sep 8 12:08:40 2022 +1000

    NFSD: fix regression with setting ACLs.
    
    [ Upstream commit 00801cd92d91e94aa04d687f9bb9a9104e7c3d46 ]
    
    A recent patch moved ACL setting into nfsd_setattr().
    Unfortunately it didn't work as nfsd_setattr() aborts early if
    iap->ia_valid is 0.
    
    Remove this test, and instead avoid calling notify_change() when
    ia_valid is 0.
    
    This means that nfsd_setattr() will now *always* lock the inode.
    Previously it didn't if only a ATTR_MODE change was requested on a
    symlink (see Commit 15b7a1b86d66 ("[PATCH] knfsd: fix setattr-on-symlink
    error return")). I don't think this change really matters.
    
    Fixes: c0cbe70742f4 ("NFSD: add posix ACLs to struct nfsd_attrs")
    Signed-off-by: NeilBrown <neilb@xxxxxxx>
    Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
    [ cel: backported to 5.10.y, prior to idmapped mounts ]
    Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 5a7fee4ee2079..95f2e4549c034 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -299,6 +299,10 @@ commit_metadata(struct svc_fh *fhp)
 static void
 nfsd_sanitize_attrs(struct inode *inode, struct iattr *iap)
 {
+	/* Ignore mode updates on symlinks */
+	if (S_ISLNK(inode->i_mode))
+		iap->ia_valid &= ~ATTR_MODE;
+
 	/* sanitize the mode change */
 	if (iap->ia_valid & ATTR_MODE) {
 		iap->ia_mode &= S_IALLUGO;
@@ -366,7 +370,7 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	int		accmode = NFSD_MAY_SATTR;
 	umode_t		ftype = 0;
 	__be32		err;
-	int		host_err;
+	int		host_err = 0;
 	bool		get_write_count;
 	bool		size_change = (iap->ia_valid & ATTR_SIZE);
 
@@ -404,13 +408,6 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	dentry = fhp->fh_dentry;
 	inode = d_inode(dentry);
 
-	/* Ignore any mode updates on symlinks */
-	if (S_ISLNK(inode->i_mode))
-		iap->ia_valid &= ~ATTR_MODE;
-
-	if (!iap->ia_valid)
-		return 0;
-
 	nfsd_sanitize_attrs(inode, iap);
 
 	if (check_guard && guardtime != inode->i_ctime.tv_sec)
@@ -461,8 +458,10 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp,
 			goto out_unlock;
 	}
 
-	iap->ia_valid |= ATTR_CTIME;
-	host_err = notify_change(dentry, iap, NULL);
+	if (iap->ia_valid) {
+		iap->ia_valid |= ATTR_CTIME;
+		host_err = notify_change(dentry, iap, NULL);
+	}
 
 out_unlock:
 	if (attr->na_seclabel && attr->na_seclabel->len)