From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8CB5CC43387 for ; Wed, 16 Jan 2019 17:50:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5F4A8206C2 for ; Wed, 16 Jan 2019 17:50:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20150623.gappssmtp.com header.i=@kernel-dk.20150623.gappssmtp.com header.b="KUkWfNfA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727718AbfAPRu2 (ORCPT ); Wed, 16 Jan 2019 12:50:28 -0500 Received: from mail-it1-f193.google.com ([209.85.166.193]:38405 "EHLO mail-it1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727709AbfAPRu1 (ORCPT ); Wed, 16 Jan 2019 12:50:27 -0500 Received: by mail-it1-f193.google.com with SMTP id h65so3904412ith.3 for ; Wed, 16 Jan 2019 09:50:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=scNBCeOhysecepgCupm97WAYtsMfIFMGuolJ4I0NyhI=; b=KUkWfNfAwzOsYUappIVQ3wQO5c0RI0RVWA9luoA5JxT7r2kpQGBI3ozhoypllKk8rs Si2eOsOHg6B5dfhwVdq9hCbw8l1XI8XgoYChm8nudSNbDfsAPVt3gVrSnqRJ7yhTMTG2 PCHSQqt8JCTDQ6gdxaY8RwApCpU6KCPRNU8XLUWX2GI/KnXt1jJgUxXFlTWqDrU7IiPR IAyvYHNURt+WY8KDnJLZAAW1H8qKKq1AvY3DgDxEzMutBSVJvtX8F/2XevZj0wkaIQ6Y wxSxUlkSznCKAb7s8pFER7fjq/9Njh47r/bX1id2F/zjRy8GFUFeO6BAA4GK4widejc1 WPKA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=scNBCeOhysecepgCupm97WAYtsMfIFMGuolJ4I0NyhI=; b=aq+Jh5QKe/n84nw1W2LlDIB2w3dxN0+FRJeUUeEddTeUmEGckxp9nIWEO/yjkHLXI0 m94jTt+qlq3EVn6k+hNXMq+/YQ/vZJbp8sSa1Su9zwec5iV7AkN97RLwKyPqYatfmibq WdE1KJkmTDVRalG1EbqU/8X1+dbdqJAGT3zWeMXRg6M37woY52T49xTY+bF4/6UbP2sv taAumfrsYD6UiWKPG3asEn0eCDL0RBLOp15OKPJzaASzZDyR/CsCksdEkn0cBZAyRklM k7ESZPRTWeejicRyqHt8O5nqSByqI6s5miZ5L4fSJPLWcU5eD+jsC5FGr94IlJ1FxZ5s y0ZQ== X-Gm-Message-State: AJcUukfXV11zHDhzZIV4cP3bUegAcCwmqTBfsgoz/4/1G3Dgjn/TiVkb M1f0iV8FqSPY+98vwExyzFr33w== X-Google-Smtp-Source: ALg8bN73QvlAwdPC6SdjczMFygU0EfjVWQ/CRqJ18DSYo2IoOL/4a8RbfN7/N3Ob3f5Sq+ai9rjSZQ== X-Received: by 2002:a24:4545:: with SMTP id y66mr5830905ita.174.1547661026358; Wed, 16 Jan 2019 09:50:26 -0800 (PST) Received: from x1.localdomain ([216.160.245.98]) by smtp.gmail.com with ESMTPSA id x128sm3705690itb.8.2019.01.16.09.50.24 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 16 Jan 2019 09:50:25 -0800 (PST) From: Jens Axboe To: linux-fsdevel@vger.kernel.org, linux-aio@kvack.org, linux-block@vger.kernel.org, linux-arch@vger.kernel.org Cc: hch@lst.de, jmoyer@redhat.com, avi@scylladb.com, Jens Axboe Subject: [PATCH 08/15] fs: add fget_many() and fput_many() Date: Wed, 16 Jan 2019 10:49:56 -0700 Message-Id: <20190116175003.17880-9-axboe@kernel.dk> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190116175003.17880-1-axboe@kernel.dk> References: <20190116175003.17880-1-axboe@kernel.dk> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Some uses cases repeatedly get and put references to the same file, but the only exposed interface is doing these one at the time. As each of these entail an atomic inc or dec on a shared structure, that cost can add up. Add fget_many(), which works just like fget(), except it takes an argument for how many references to get on the file. Ditto fput_many(), which can drop an arbitrary number of references to a file. Signed-off-by: Jens Axboe --- fs/file.c | 15 ++++++++++----- fs/file_table.c | 9 +++++++-- include/linux/file.h | 2 ++ include/linux/fs.h | 4 +++- 4 files changed, 22 insertions(+), 8 deletions(-) diff --git a/fs/file.c b/fs/file.c index 3209ee271c41..e0d7ce70e860 100644 --- a/fs/file.c +++ b/fs/file.c @@ -705,7 +705,7 @@ void do_close_on_exec(struct files_struct *files) spin_unlock(&files->file_lock); } -static struct file *__fget(unsigned int fd, fmode_t mask) +static struct file *__fget(unsigned int fd, fmode_t mask, unsigned int refs) { struct files_struct *files = current->files; struct file *file; @@ -720,7 +720,7 @@ static struct file *__fget(unsigned int fd, fmode_t mask) */ if (file->f_mode & mask) file = NULL; - else if (!get_file_rcu(file)) + else if (!get_file_rcu_many(file, refs)) goto loop; } rcu_read_unlock(); @@ -728,15 +728,20 @@ static struct file *__fget(unsigned int fd, fmode_t mask) return file; } +struct file *fget_many(unsigned int fd, unsigned int refs) +{ + return __fget(fd, FMODE_PATH, refs); +} + struct file *fget(unsigned int fd) { - return __fget(fd, FMODE_PATH); + return fget_many(fd, 1); } EXPORT_SYMBOL(fget); struct file *fget_raw(unsigned int fd) { - return __fget(fd, 0); + return __fget(fd, 0, 1); } EXPORT_SYMBOL(fget_raw); @@ -767,7 +772,7 @@ static unsigned long __fget_light(unsigned int fd, fmode_t mask) return 0; return (unsigned long)file; } else { - file = __fget(fd, mask); + file = __fget(fd, mask, 1); if (!file) return 0; return FDPUT_FPUT | (unsigned long)file; diff --git a/fs/file_table.c b/fs/file_table.c index 5679e7fcb6b0..155d7514a094 100644 --- a/fs/file_table.c +++ b/fs/file_table.c @@ -326,9 +326,9 @@ void flush_delayed_fput(void) static DECLARE_DELAYED_WORK(delayed_fput_work, delayed_fput); -void fput(struct file *file) +void fput_many(struct file *file, unsigned int refs) { - if (atomic_long_dec_and_test(&file->f_count)) { + if (atomic_long_sub_and_test(refs, &file->f_count)) { struct task_struct *task = current; if (likely(!in_interrupt() && !(task->flags & PF_KTHREAD))) { @@ -347,6 +347,11 @@ void fput(struct file *file) } } +void fput(struct file *file) +{ + fput_many(file, 1); +} + /* * synchronous analog of fput(); for kernel threads that might be needed * in some umount() (and thus can't use flush_delayed_fput() without diff --git a/include/linux/file.h b/include/linux/file.h index 6b2fb032416c..3fcddff56bc4 100644 --- a/include/linux/file.h +++ b/include/linux/file.h @@ -13,6 +13,7 @@ struct file; extern void fput(struct file *); +extern void fput_many(struct file *, unsigned int); struct file_operations; struct vfsmount; @@ -44,6 +45,7 @@ static inline void fdput(struct fd fd) } extern struct file *fget(unsigned int fd); +extern struct file *fget_many(unsigned int fd, unsigned int refs); extern struct file *fget_raw(unsigned int fd); extern unsigned long __fdget(unsigned int fd); extern unsigned long __fdget_raw(unsigned int fd); diff --git a/include/linux/fs.h b/include/linux/fs.h index ccb0b7a63aa5..acaad78b6781 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -952,7 +952,9 @@ static inline struct file *get_file(struct file *f) atomic_long_inc(&f->f_count); return f; } -#define get_file_rcu(x) atomic_long_inc_not_zero(&(x)->f_count) +#define get_file_rcu_many(x, cnt) \ + atomic_long_add_unless(&(x)->f_count, (cnt), 0) +#define get_file_rcu(x) get_file_rcu_many((x), 1) #define fput_atomic(x) atomic_long_add_unless(&(x)->f_count, -1, 1) #define file_count(x) atomic_long_read(&(x)->f_count) -- 2.17.1