+ fs-epoll-use-a-per-cpu-counter-for-users-watches-count-fix.patch added to -mm tree

+ fs-epoll-use-a-per-cpu-counter-for-users-watches-count-fix.patch added to -mm tree

[akpm]

The patch titled
     Subject: fs-epoll-use-a-per-cpu-counter-for-users-watches-count-fix
has been added to the -mm tree.  Its filename is
     fs-epoll-use-a-per-cpu-counter-for-users-watches-count-fix.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/fs-epoll-use-a-per-cpu-counter-for-users-watches-count-fix.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/fs-epoll-use-a-per-cpu-counter-for-users-watches-count-fix.patch

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next and is updated
there every 3-4 working days

------------------------------------------------------
From: Andrew Morton <akpm@linux-foundation.org>
Subject: fs-epoll-use-a-per-cpu-counter-for-users-watches-count-fix

fix build, fix printk typo

Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Anton Blanchard <anton@ozlabs.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 kernel/user.c |   10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

--- a/kernel/user.c~fs-epoll-use-a-per-cpu-counter-for-users-watches-count-fix
+++ a/kernel/user.c
@@ -138,7 +138,9 @@ static void free_user(struct user_struct
 {
 	uid_hash_remove(up);
 	spin_unlock_irqrestore(&uidhash_lock, flags);
+#ifdef CONFIG_EPOLL
 	percpu_counter_destroy(&up->epoll_watches);
+#endif
 	kmem_cache_free(uid_cachep, up);
 }
 
@@ -186,10 +188,12 @@ struct user_struct *alloc_uid(kuid_t uid
 
 		new->uid = uid;
 		refcount_set(&new->__count, 1);
+#ifdef CONFIG_EPOLL
 		if (percpu_counter_init(&new->epoll_watches, 0, GFP_KERNEL)) {
 			kmem_cache_free(uid_cachep, new);
 			return NULL;
 		}
+#endif
 		ratelimit_state_init(&new->ratelimit, HZ, 100);
 		ratelimit_set_flags(&new->ratelimit, RATELIMIT_MSG_ON_RELEASE);
 
@@ -200,7 +204,9 @@ struct user_struct *alloc_uid(kuid_t uid
 		spin_lock_irq(&uidhash_lock);
 		up = uid_hash_find(uid, hashent);
 		if (up) {
+#ifdef CONFIG_EPOLL
 			percpu_counter_destroy(&new->epoll_watches);
+#endif
 			kmem_cache_free(uid_cachep, new);
 		} else {
 			uid_hash_insert(new, hashent);
@@ -222,8 +228,10 @@ static int __init uid_cache_init(void)
 	for(n = 0; n < UIDHASH_SZ; ++n)
 		INIT_HLIST_HEAD(uidhash_table + n);
 
+#ifdef CONFIG_EPOLL
 	if (percpu_counter_init(&root_user.epoll_watches, 0, GFP_KERNEL))
-		panic("percpu cpunter alloc failed");
+		panic("percpu counter alloc failed");
+#endif
 
 	/* Insert the root user immediately (init already runs as root) */
 	spin_lock_irq(&uidhash_lock);
_

Patches currently in -mm which might be from akpm@linux-foundation.org are

mm.patch
lazy-tlb-allow-lazy-tlb-mm-refcounting-to-be-configurable-fix.patch
mm-compaction-optimize-proactive-compaction-deferrals-fix.patch
mm-compaction-support-triggering-of-proactive-compaction-by-user-fix.patch
mm-mempolicy-convert-from-atomic_t-to-refcount_t-on-mempolicy-refcnt-fix.patch
fs-epoll-use-a-per-cpu-counter-for-users-watches-count-fix.patch
log-if-a-core-dump-is-aborted-due-to-changed-file-permissions-fix.patch
linux-next-rejects.patch
kernel-forkc-export-kernel_thread-to-modules.patch

+ fs-epoll-use-a-per-cpu-counter-for-users-watches-count-fix.patch added to -mm tree

[akpm]

The patch titled
     Subject: fs-epoll-use-a-per-cpu-counter-for-users-watches-count-fix
has been added to the -mm tree.  Its filename is
     fs-epoll-use-a-per-cpu-counter-for-users-watches-count-fix.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/fs-epoll-use-a-per-cpu-counter-for-users-watches-count-fix.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/fs-epoll-use-a-per-cpu-counter-for-users-watches-count-fix.patch

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next and is updated
there every 3-4 working days

------------------------------------------------------
From: Randy Dunlap <rdunlap@infradead.org>
Subject: fs-epoll-use-a-per-cpu-counter-for-users-watches-count-fix

fix build errors in kernel/user.c when CONFIG_EPOLL=n

Also fix typo: "cpunter" -"counter" in a panic message.

[npiggin@gmail.com: move ifdefs into wrapper functions, slightly improve panic message]
Link: https://lkml.kernel.org/r/1628051945.fens3r99ox.astroid@bobo.none
Fixes: e75b89477811 ("fs/epoll: use a per-cpu counter for user's watches count")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 kernel/user.c |   25 ++++++++++++++++++++-----
 1 file changed, 20 insertions(+), 5 deletions(-)

--- a/kernel/user.c~fs-epoll-use-a-per-cpu-counter-for-users-watches-count-fix
+++ a/kernel/user.c
@@ -129,6 +129,21 @@ static struct user_struct *uid_hash_find
 	return NULL;
 }
 
+static int user_epoll_alloc(struct user_struct *up)
+{
+#ifdef CONFIG_EPOLL
+	return percpu_counter_init(&up->epoll_watches, 0, GFP_KERNEL);
+#endif
+	return 0;
+}
+
+static void user_epoll_free(struct user_struct *up)
+{
+#ifdef CONFIG_EPOLL
+	percpu_counter_destroy(&up->epoll_watches);
+#endif
+}
+
 /* IRQs are disabled and uidhash_lock is held upon function entry.
  * IRQ state (as stored in flags) is restored and uidhash_lock released
  * upon function exit.
@@ -138,7 +153,7 @@ static void free_user(struct user_struct
 {
 	uid_hash_remove(up);
 	spin_unlock_irqrestore(&uidhash_lock, flags);
-	percpu_counter_destroy(&up->epoll_watches);
+	user_epoll_free(up);
 	kmem_cache_free(uid_cachep, up);
 }
 
@@ -186,7 +201,7 @@ struct user_struct *alloc_uid(kuid_t uid
 
 		new->uid = uid;
 		refcount_set(&new->__count, 1);
-		if (percpu_counter_init(&new->epoll_watches, 0, GFP_KERNEL)) {
+		if (user_epoll_alloc(new)) {
 			kmem_cache_free(uid_cachep, new);
 			return NULL;
 		}
@@ -200,7 +215,7 @@ struct user_struct *alloc_uid(kuid_t uid
 		spin_lock_irq(&uidhash_lock);
 		up = uid_hash_find(uid, hashent);
 		if (up) {
-			percpu_counter_destroy(&new->epoll_watches);
+			user_epoll_free(new);
 			kmem_cache_free(uid_cachep, new);
 		} else {
 			uid_hash_insert(new, hashent);
@@ -222,8 +237,8 @@ static int __init uid_cache_init(void)
 	for(n = 0; n < UIDHASH_SZ; ++n)
 		INIT_HLIST_HEAD(uidhash_table + n);
 
-	if (percpu_counter_init(&root_user.epoll_watches, 0, GFP_KERNEL))
-		panic("percpu cpunter alloc failed");
+	if (user_epoll_alloc(&root_user))
+		panic("root_user epoll percpu counter alloc failed");
 
 	/* Insert the root user immediately (init already runs as root) */
 	spin_lock_irq(&uidhash_lock);
_

Patches currently in -mm which might be from rdunlap@infradead.org are

fs-epoll-use-a-per-cpu-counter-for-users-watches-count-fix.patch
scripts-check_extable-fix-typo-in-user-error-message.patch