From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yw0-f198.google.com (mail-yw0-f198.google.com [209.85.161.198]) by kanga.kvack.org (Postfix) with ESMTP id D4D3C6B0005 for ; Thu, 19 May 2016 11:21:02 -0400 (EDT) Received: by mail-yw0-f198.google.com with SMTP id y6so174353787ywe.0 for ; Thu, 19 May 2016 08:21:02 -0700 (PDT) Received: from mail-qg0-x243.google.com (mail-qg0-x243.google.com. [2607:f8b0:400d:c04::243]) by mx.google.com with ESMTPS id v19si13011726qkb.111.2016.05.19.08.21.01 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 19 May 2016 08:21:01 -0700 (PDT) Received: by mail-qg0-x243.google.com with SMTP id 90so7122400qgz.0 for ; Thu, 19 May 2016 08:21:01 -0700 (PDT) From: Dan Streetman Subject: [PATCHv2] mm/zsmalloc: don't fail if can't create debugfs info Date: Thu, 19 May 2016 11:18:43 -0400 Message-Id: <1463671123-5479-1-git-send-email-ddstreet@ieee.org> In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Minchan Kim Cc: Nitin Gupta , Ganesh Mahendran , Andrew Morton , Sergey Senozhatsky , Seth Jennings , Yu Zhao , Linux-MM , Sergey Senozhatsky , linux-kernel , Dan Streetman , Dan Streetman Change the return type of zs_pool_stat_create() to void, and remove the logic to abort pool creation if the stat debugfs dir/file could not be created. The debugfs stat file is for debugging/information only, and doesn't affect operation of zsmalloc; there is no reason to abort creating the pool if the stat file can't be created. This was seen with zswap, which used the same name for all pool creations, which caused zsmalloc to fail to create a second pool for zswap if CONFIG_ZSMALLOC_STAT was enabled. Signed-off-by: Dan Streetman Cc: Sergey Senozhatsky Cc: Dan Streetman Cc: Minchan Kim --- Changes since v1: -add pr_warn to all stat failure cases -do not prevent module loading on stat failure mm/zsmalloc.c | 51 ++++++++++++++++++++++----------------------------- 1 file changed, 22 insertions(+), 29 deletions(-) diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c index aba39a2..b6d4f25 100644 --- a/mm/zsmalloc.c +++ b/mm/zsmalloc.c @@ -45,6 +45,8 @@ * */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + #include #include #include @@ -483,16 +485,16 @@ static inline unsigned long zs_stat_get(struct size_class *class, #ifdef CONFIG_ZSMALLOC_STAT -static int __init zs_stat_init(void) +static void __init zs_stat_init(void) { - if (!debugfs_initialized()) - return -ENODEV; + if (!debugfs_initialized()) { + pr_warn("debugfs not available, stat dir not created\n"); + return; + } zs_stat_root = debugfs_create_dir("zsmalloc", NULL); if (!zs_stat_root) - return -ENOMEM; - - return 0; + pr_warn("debugfs 'zsmalloc' stat dir creation failed\n"); } static void __exit zs_stat_exit(void) @@ -573,17 +575,19 @@ static const struct file_operations zs_stat_size_ops = { .release = single_release, }; -static int zs_pool_stat_create(struct zs_pool *pool, const char *name) +static void zs_pool_stat_create(struct zs_pool *pool, const char *name) { struct dentry *entry; - if (!zs_stat_root) - return -ENODEV; + if (!zs_stat_root) { + pr_warn("no root stat dir, not creating <%s> stat dir\n", name); + return; + } entry = debugfs_create_dir(name, zs_stat_root); if (!entry) { pr_warn("debugfs dir <%s> creation failed\n", name); - return -ENOMEM; + return; } pool->stat_dentry = entry; @@ -592,10 +596,9 @@ static int zs_pool_stat_create(struct zs_pool *pool, const char *name) if (!entry) { pr_warn("%s: debugfs file entry <%s> creation failed\n", name, "classes"); - return -ENOMEM; + debugfs_remove_recursive(pool->stat_dentry); + pool->stat_dentry = NULL; } - - return 0; } static void zs_pool_stat_destroy(struct zs_pool *pool) @@ -604,18 +607,16 @@ static void zs_pool_stat_destroy(struct zs_pool *pool) } #else /* CONFIG_ZSMALLOC_STAT */ -static int __init zs_stat_init(void) +static void __init zs_stat_init(void) { - return 0; } static void __exit zs_stat_exit(void) { } -static inline int zs_pool_stat_create(struct zs_pool *pool, const char *name) +static inline void zs_pool_stat_create(struct zs_pool *pool, const char *name) { - return 0; } static inline void zs_pool_stat_destroy(struct zs_pool *pool) @@ -623,7 +624,6 @@ static inline void zs_pool_stat_destroy(struct zs_pool *pool) } #endif - /* * For each size class, zspages are divided into different groups * depending on how "full" they are. This was done so that we could @@ -1952,8 +1952,8 @@ struct zs_pool *zs_create_pool(const char *name) prev_class = class; } - if (zs_pool_stat_create(pool, name)) - goto err; + /* debug only, don't abort if it fails */ + zs_pool_stat_create(pool, name); /* * Not critical, we still can use the pool @@ -2015,17 +2015,10 @@ static int __init zs_init(void) zpool_register_driver(&zs_zpool_driver); #endif - ret = zs_stat_init(); - if (ret) { - pr_err("zs stat initialization failed\n"); - goto stat_fail; - } + zs_stat_init(); + return 0; -stat_fail: -#ifdef CONFIG_ZPOOL - zpool_unregister_driver(&zs_zpool_driver); -#endif notifier_fail: zs_unregister_cpu_notifier(); -- 2.7.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org