[Devel] [PATCH RHEL8 COMMIT] ve/proc: increment position in "next" seq_operations callback

[Konstantin Khorenko]

The commit is pushed to "branch-rh8-4.18.0-240.1.1.vz8.5.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh8-4.18.0-240.1.1.vz8.5.39
------>
commit 1f4b6a6907b0f7954adaaaafe95d1c316cb17c37
Author: Vasily Averin <vvs at virtuozzo.com>
Date:   Thu Jun 10 19:43:11 2021 +0300

    ve/proc: increment position in "next" seq_operations callback
    
    "next" callback of struct "seq_operations" should move the iterator
    forward to the next position in the sequence.
    
    Some Virtuozzo specific proc files skip such increment,
    and trigger incorrect file output.
    
    https://bugs.openvz.org/browse/OVZ-7158
    
    Signed-off-by: Vasily Averin <vvs at virtuozzo.com>
    
    (cherry-picked from vz7 commit 0a458a0598b4 ("ve/proc: increment position in
    "next" seq_operations callback"))
    
    https://jira.sw.ru/browse/PSBM-127849
    Signed-off-by: Valeriy Vdovin <valeriy.vdovin at virtuozzo.com>
---
 drivers/net/venetdev.c | 2 +-
 kernel/ve/vecalls.c    | 5 +++--
 kernel/ve/vzstat.c     | 1 +
 3 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/net/venetdev.c b/drivers/net/venetdev.c
index 4c5e3cb180e7..9d898bcbc6db 100644
--- a/drivers/net/venetdev.c
+++ b/drivers/net/venetdev.c
@@ -841,6 +841,7 @@ static void *veip_seq_next(struct seq_file *m, void *v, loff_t *pos)
 	struct hlist_node *p;
 	int i;
 
+	(*pos)++;
 	if (v == SEQ_START_TOKEN)
 		goto find;
 
@@ -854,7 +855,6 @@ static void *veip_seq_next(struct seq_file *m, void *v, loff_t *pos)
 		if (p != NULL) {
 			m->private = (void *)(long)(i + 1);
 found:
-			(*pos)++;
 			return p;
 		}
 	}
diff --git a/kernel/ve/vecalls.c b/kernel/ve/vecalls.c
index dcda8c0753c8..04e3d41dfed6 100644
--- a/kernel/ve/vecalls.c
+++ b/kernel/ve/vecalls.c
@@ -181,9 +181,10 @@ static void *ve_seq_start(struct seq_file *m, loff_t *pos)
 
 static void *ve_seq_next(struct seq_file *m, void *v, loff_t *pos)
 {
-	if (!ve_is_super(get_exec_env()))
+	if (!ve_is_super(get_exec_env())) {
+		(*pos)++;
 		return NULL;
-	else
+	} else
 		return seq_list_next(v, &ve_list_head, pos);
 }
 
diff --git a/kernel/ve/vzstat.c b/kernel/ve/vzstat.c
index 0fb0cfbb0407..db8de1b9dba0 100644
--- a/kernel/ve/vzstat.c
+++ b/kernel/ve/vzstat.c
@@ -626,6 +626,7 @@ static void *empty_seq_start(struct seq_file *m, loff_t *pos)
 
 static void *empty_seq_next(struct seq_file *m, void *v, loff_t *pos)
 {
+	(*pos)++;
 	return NULL;
 }