Patch "NFSv4: Fix handling of non-atomic change attrbute updates" 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

    NFSv4: Fix handling of non-atomic change attrbute updates

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:
     nfsv4-fix-handling-of-non-atomic-change-attrbute-upd.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 9885d62e392ac7eebd6bf99a30ba00278abf54f9
Author: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Date:   Fri Jun 25 15:49:31 2021 -0400

    NFSv4: Fix handling of non-atomic change attrbute updates
    
    [ Upstream commit 20cf7d4ea4ad7d9830b01ff7444f6ac64a727a23 ]
    
    If the change attribute update is declared to be non-atomic by the
    server, or our cached value does not match the server's value before the
    operation was performed, then we should declare the inode cache invalid.
    
    On the other hand, if the change to the directory raced with a lookup or
    getattr which already updated the change attribute, then optimise away
    the revalidation.
    
    Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index eda7d7fc84ad0..4c80369e0a837 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -1196,12 +1196,12 @@ nfs4_update_changeattr_locked(struct inode *inode,
 	u64 change_attr = inode_peek_iversion_raw(inode);
 
 	cache_validity |= NFS_INO_INVALID_CTIME | NFS_INO_INVALID_MTIME;
+	if (S_ISDIR(inode->i_mode))
+		cache_validity |= NFS_INO_INVALID_DATA;
 
 	switch (NFS_SERVER(inode)->change_attr_type) {
 	case NFS4_CHANGE_TYPE_IS_UNDEFINED:
-		break;
-	case NFS4_CHANGE_TYPE_IS_TIME_METADATA:
-		if ((s64)(change_attr - cinfo->after) > 0)
+		if (cinfo->after == change_attr)
 			goto out;
 		break;
 	default:
@@ -1209,24 +1209,21 @@ nfs4_update_changeattr_locked(struct inode *inode,
 			goto out;
 	}
 
-	if (cinfo->atomic && cinfo->before == change_attr) {
-		nfsi->attrtimeo_timestamp = jiffies;
-	} else {
-		if (S_ISDIR(inode->i_mode)) {
-			cache_validity |= NFS_INO_INVALID_DATA;
+	inode_set_iversion_raw(inode, cinfo->after);
+	if (!cinfo->atomic || cinfo->before != change_attr) {
+		if (S_ISDIR(inode->i_mode))
 			nfs_force_lookup_revalidate(inode);
-		} else {
-			if (!NFS_PROTO(inode)->have_delegation(inode,
-							       FMODE_READ))
-				cache_validity |= NFS_INO_REVAL_PAGECACHE;
-		}
 
-		if (cinfo->before != change_attr)
-			cache_validity |= NFS_INO_INVALID_ACCESS |
-					  NFS_INO_INVALID_ACL |
-					  NFS_INO_INVALID_XATTR;
+		if (!NFS_PROTO(inode)->have_delegation(inode, FMODE_READ))
+			cache_validity |=
+				NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL |
+				NFS_INO_INVALID_SIZE | NFS_INO_INVALID_OTHER |
+				NFS_INO_INVALID_BLOCKS | NFS_INO_INVALID_NLINK |
+				NFS_INO_INVALID_MODE | NFS_INO_INVALID_XATTR |
+				NFS_INO_REVAL_PAGECACHE;
+		nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
 	}
-	inode_set_iversion_raw(inode, cinfo->after);
+	nfsi->attrtimeo_timestamp = jiffies;
 	nfsi->read_cache_jiffies = timestamp;
 	nfsi->attr_gencount = nfs_inc_attr_generation_counter();
 	nfsi->cache_validity &= ~NFS_INO_INVALID_CHANGE;