From nobody Sun Dec 14 13:57:46 2025 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DFE391FCCE7 for ; Wed, 5 Feb 2025 18:18:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738779509; cv=none; b=eKSgHOdeLDfUzO4Z2s77yLfWPYCEBJZULscBLU4/7HoifuKwO0dGBgL7b3w1c+Nn3iWk1kXM94+wIG7KZPTI36J2GTKXGTA63qGptST1HafHrSj7TTsyjVp+idheBwiYB/56FzxjI/rhj6TC/Ug6fnhwYzKRa0KvLGitzK9KpUw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738779509; c=relaxed/simple; bh=ODnxcr1GdYUsjFENMi2i2f3qxVNrskw1WAi5/5b2ptM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=fWCXjWBuypnITJADZSpMJKKDC2m23vNfSlDpAnNi69bhJ7sSG/9h6F4NYF5HvKiQBoR+CR3ccR4/HpktsknBDoOWa+qp0nkDmUzvjIengxogxN1hNCvuLw9ujf30qHTQixPnM9KFGsBtl9SCE791i4Rx+3UZJIniYke+oW8gwNQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=H06uae4J; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="H06uae4J" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1738779506; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=dy17xqtR8bKzLOlpEcmAmdsSUGFFIgAoYai7nMDmujU=; b=H06uae4JynmyVdXtmP2QQQYb0NwmYMcDPBN8ginln6NLoMMD6hVYzYHKsciZz/593yyChT y0ihrV4tsJLJbPGVpANEGnr2fZCHn42diLraikq4JnLr04C7DPrKFYiUxTv3gtkYfj2MtF JUYbgHAnZk7mG6Dl/v36IaspfNafLIk= Received: from mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-84-ChlUq0RpPzO6uf2fT8SGXg-1; Wed, 05 Feb 2025 13:18:22 -0500 X-MC-Unique: ChlUq0RpPzO6uf2fT8SGXg-1 X-Mimecast-MFC-AGG-ID: ChlUq0RpPzO6uf2fT8SGXg Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 35FE51955F16; Wed, 5 Feb 2025 18:18:20 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.45.224.10]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with SMTP id 5C572195608D; Wed, 5 Feb 2025 18:18:15 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Wed, 5 Feb 2025 19:17:53 +0100 (CET) Date: Wed, 5 Feb 2025 19:17:47 +0100 From: Oleg Nesterov To: Christian Brauner , Jeff Layton , Linus Torvalds Cc: David Howells , "Gautham R. Shenoy" , K Prateek Nayak , Mateusz Guzik , Neeraj Upadhyay , Oliver Sang , Swapnil Sapkal , WangYuli , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 1/2] pipe: introduce struct file_operations pipeanon_fops Message-ID: <20250205181747.GB13817@redhat.com> References: <20250205181716.GA13817@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20250205181716.GA13817@redhat.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" So that fifos and anonymous pipes could have different f_op methods. Preparation to simplify the next patch. Signed-off-by: Oleg Nesterov Reviewed-by: Jeff Layton Tested-by: K Prateek Nayak --- fs/pipe.c | 25 ++++++++++++++++++++----- 1 file changed, 20 insertions(+), 5 deletions(-) diff --git a/fs/pipe.c b/fs/pipe.c index 94b59045ab44..2eacfde61e74 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -878,6 +878,8 @@ static const struct dentry_operations pipefs_dentry_ope= rations =3D { .d_dname =3D pipefs_dname, }; =20 +static const struct file_operations pipeanon_fops; + static struct inode * get_pipe_inode(void) { struct inode *inode =3D new_inode_pseudo(pipe_mnt->mnt_sb); @@ -895,7 +897,7 @@ static struct inode * get_pipe_inode(void) inode->i_pipe =3D pipe; pipe->files =3D 2; pipe->readers =3D pipe->writers =3D 1; - inode->i_fop =3D &pipefifo_fops; + inode->i_fop =3D &pipeanon_fops; =20 /* * Mark the inode dirty from the very beginning, @@ -938,7 +940,7 @@ int create_pipe_files(struct file **res, int flags) =20 f =3D alloc_file_pseudo(inode, pipe_mnt, "", O_WRONLY | (flags & (O_NONBLOCK | O_DIRECT)), - &pipefifo_fops); + &pipeanon_fops); if (IS_ERR(f)) { free_pipe_info(inode->i_pipe); iput(inode); @@ -949,7 +951,7 @@ int create_pipe_files(struct file **res, int flags) f->f_pipe =3D 0; =20 res[0] =3D alloc_file_clone(f, O_RDONLY | (flags & O_NONBLOCK), - &pipefifo_fops); + &pipeanon_fops); if (IS_ERR(res[0])) { put_pipe_info(inode, inode->i_pipe); fput(f); @@ -1107,8 +1109,8 @@ static void wake_up_partner(struct pipe_inode_info *p= ipe) =20 static int fifo_open(struct inode *inode, struct file *filp) { + bool is_pipe =3D inode->i_fop =3D=3D &pipeanon_fops; struct pipe_inode_info *pipe; - bool is_pipe =3D inode->i_sb->s_magic =3D=3D PIPEFS_MAGIC; int ret; =20 filp->f_pipe =3D 0; @@ -1241,6 +1243,17 @@ const struct file_operations pipefifo_fops =3D { .splice_write =3D iter_file_splice_write, }; =20 +static const struct file_operations pipeanon_fops =3D { + .open =3D fifo_open, + .read_iter =3D pipe_read, + .write_iter =3D pipe_write, + .poll =3D pipe_poll, + .unlocked_ioctl =3D pipe_ioctl, + .release =3D pipe_release, + .fasync =3D pipe_fasync, + .splice_write =3D iter_file_splice_write, +}; + /* * Currently we rely on the pipe array holding a power-of-2 number * of pages. Returns 0 on error. @@ -1388,7 +1401,9 @@ struct pipe_inode_info *get_pipe_info(struct file *fi= le, bool for_splice) { struct pipe_inode_info *pipe =3D file->private_data; =20 - if (file->f_op !=3D &pipefifo_fops || !pipe) + if (!pipe) + return NULL; + if (file->f_op !=3D &pipefifo_fops && file->f_op !=3D &pipeanon_fops) return NULL; if (for_splice && pipe_has_watch_queue(pipe)) return NULL; --=20 2.25.1.362.g51ebf55 From nobody Sun Dec 14 13:57:46 2025 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5313E1FCF5B for ; Wed, 5 Feb 2025 18:18:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738779536; cv=none; b=aO+4u+yyjWJFBf50J05UopKo+v6AinIPtn5Ejsb+fk+kO9R35+vLUXG5Dg7w9lfThcXbXhvbzmt/XPfyiurQySG7GBi6cxezSYO/FScIg7cW4xer8OafzvV+fgJxu25Jf9iPUfnKUk/rmve4klf9XFwiBXCISq2ZXx0j+m7wYZY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738779536; c=relaxed/simple; bh=McltsGuhrdjKSLzYSZ2RB5cGI/ob/Aq3P+nHQ5SQmI8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=q6D+SUu0eHSkNWBjwAplIgu31mVYaEEdtHCaYUxjUzMRCDsAgcWZ8vXxRWVD16oru65gUh0BohG2Revw1U8pSoW+7F79cMwvJYmGDuHKX/EYtECfXiZoGSNIWruacgPXQAVqJqDAn/YBd4K2SQflmXZV6Nhk0epMDzvhyL9kcuc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=emBfVIXU; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="emBfVIXU" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1738779532; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=YAZPH6LoBdfmC4eKY2rMSg24boi4M+z/rfTpR2/KoTE=; b=emBfVIXUDf1Jk3+EAIhqPB12nPCCDD9WO10wHaEUoiQh6zXbzcb8ljXKmDY5tLt+FTzR0L oS9sfdZ4XyheMlQK4XrKUTPRVhdy71V8jYN/ioYkgrHZEzQ2UV0vraLdPalQb+RDfsIwEX gFCckK9bZo4DkbKOv1EyOQhtyDvU3BM= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-531-eyRvOxkLMm-K86gnIv0iOQ-1; Wed, 05 Feb 2025 13:18:47 -0500 X-MC-Unique: eyRvOxkLMm-K86gnIv0iOQ-1 X-Mimecast-MFC-AGG-ID: eyRvOxkLMm-K86gnIv0iOQ Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 7D59A180087B; Wed, 5 Feb 2025 18:18:45 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.45.224.10]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with SMTP id 8DD721800265; Wed, 5 Feb 2025 18:18:40 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Wed, 5 Feb 2025 19:18:18 +0100 (CET) Date: Wed, 5 Feb 2025 19:18:12 +0100 From: Oleg Nesterov To: Christian Brauner , Jeff Layton , Linus Torvalds Cc: David Howells , "Gautham R. Shenoy" , K Prateek Nayak , Mateusz Guzik , Neeraj Upadhyay , Oliver Sang , Swapnil Sapkal , WangYuli , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 2/2] pipe: don't update {a,c,m}time for anonymous pipes Message-ID: <20250205181812.GC13817@redhat.com> References: <20250205181716.GA13817@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20250205181716.GA13817@redhat.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" These numbers are visible in fstat() but hopefully nobody uses this information and file_accessed/file_update_time are not that cheap. Stupid test-case: #include #include #include #include #include #include static char buf[17 * 4096]; static struct timeval TW, TR; int wr(int fd, int size) { int c, r; struct timeval t0, t1; gettimeofday(&t0, NULL); for (c =3D 0; (r =3D write(fd, buf, size)) > 0; c +=3D r); gettimeofday(&t1, NULL); timeradd(&TW, &t1, &TW); timersub(&TW, &t0, &TW); return c; } int rd(int fd, int size) { int c, r; struct timeval t0, t1; gettimeofday(&t0, NULL); for (c =3D 0; (r =3D read(fd, buf, size)) > 0; c +=3D r); gettimeofday(&t1, NULL); timeradd(&TR, &t1, &TR); timersub(&TR, &t0, &TR); return c; } int main(int argc, const char *argv[]) { int fd[2], nb =3D 1, loop, size; assert(argc =3D=3D 3); loop =3D atoi(argv[1]); size =3D atoi(argv[2]); assert(pipe(fd) =3D=3D 0); assert(ioctl(fd[0], FIONBIO, &nb) =3D=3D 0); assert(ioctl(fd[1], FIONBIO, &nb) =3D=3D 0); assert(size <=3D sizeof(buf)); while (loop--) assert(wr(fd[1], size) =3D=3D rd(fd[0], size)); struct timeval tt; timeradd(&TW, &TR, &tt); printf("TW =3D %lu.%03lu TR =3D %lu.%03lu TT =3D %lu.%03lu\n", TW.tv_sec, TW.tv_usec/1000, TR.tv_sec, TR.tv_usec/1000, tt.tv_sec, tt.tv_usec/1000); return 0; } Before: # for i in 1 2 3; do /host/tmp/test 10000 100; done TW =3D 8.047 TR =3D 5.845 TT =3D 13.893 TW =3D 8.091 TR =3D 5.872 TT =3D 13.963 TW =3D 8.083 TR =3D 5.885 TT =3D 13.969 After: # for i in 1 2 3; do /host/tmp/test 10000 100; done TW =3D 4.752 TR =3D 4.664 TT =3D 9.416 TW =3D 4.684 TR =3D 4.608 TT =3D 9.293 TW =3D 4.736 TR =3D 4.652 TT =3D 9.388 Signed-off-by: Oleg Nesterov Reviewed-by: Jeff Layton Tested-by: K Prateek Nayak --- fs/pipe.c | 41 +++++++++++++++++++++++++++++------------ 1 file changed, 29 insertions(+), 12 deletions(-) diff --git a/fs/pipe.c b/fs/pipe.c index 2eacfde61e74..2ae75adfba64 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -248,7 +248,7 @@ static inline unsigned int pipe_update_tail(struct pipe= _inode_info *pipe, } =20 static ssize_t -pipe_read(struct kiocb *iocb, struct iov_iter *to) +anon_pipe_read(struct kiocb *iocb, struct iov_iter *to) { size_t total_len =3D iov_iter_count(to); struct file *filp =3D iocb->ki_filp; @@ -404,8 +404,15 @@ pipe_read(struct kiocb *iocb, struct iov_iter *to) if (wake_next_reader) wake_up_interruptible_sync_poll(&pipe->rd_wait, EPOLLIN | EPOLLRDNORM); kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT); + return ret; +} + +static ssize_t +fifo_pipe_read(struct kiocb *iocb, struct iov_iter *to) +{ + int ret =3D anon_pipe_read(iocb, to); if (ret > 0) - file_accessed(filp); + file_accessed(iocb->ki_filp); return ret; } =20 @@ -426,7 +433,7 @@ static inline bool pipe_writable(const struct pipe_inod= e_info *pipe) } =20 static ssize_t -pipe_write(struct kiocb *iocb, struct iov_iter *from) +anon_pipe_write(struct kiocb *iocb, struct iov_iter *from) { struct file *filp =3D iocb->ki_filp; struct pipe_inode_info *pipe =3D filp->private_data; @@ -604,11 +611,21 @@ pipe_write(struct kiocb *iocb, struct iov_iter *from) kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); if (wake_next_writer) wake_up_interruptible_sync_poll(&pipe->wr_wait, EPOLLOUT | EPOLLWRNORM); - if (ret > 0 && sb_start_write_trylock(file_inode(filp)->i_sb)) { - int err =3D file_update_time(filp); - if (err) - ret =3D err; - sb_end_write(file_inode(filp)->i_sb); + return ret; +} + +static ssize_t +fifo_pipe_write(struct kiocb *iocb, struct iov_iter *from) +{ + int ret =3D anon_pipe_write(iocb, from); + if (ret > 0) { + struct file *filp =3D iocb->ki_filp; + if (sb_start_write_trylock(file_inode(filp)->i_sb)) { + int err =3D file_update_time(filp); + if (err) + ret =3D err; + sb_end_write(file_inode(filp)->i_sb); + } } return ret; } @@ -1234,8 +1251,8 @@ static int fifo_open(struct inode *inode, struct file= *filp) =20 const struct file_operations pipefifo_fops =3D { .open =3D fifo_open, - .read_iter =3D pipe_read, - .write_iter =3D pipe_write, + .read_iter =3D fifo_pipe_read, + .write_iter =3D fifo_pipe_write, .poll =3D pipe_poll, .unlocked_ioctl =3D pipe_ioctl, .release =3D pipe_release, @@ -1245,8 +1262,8 @@ const struct file_operations pipefifo_fops =3D { =20 static const struct file_operations pipeanon_fops =3D { .open =3D fifo_open, - .read_iter =3D pipe_read, - .write_iter =3D pipe_write, + .read_iter =3D anon_pipe_read, + .write_iter =3D anon_pipe_write, .poll =3D pipe_poll, .unlocked_ioctl =3D pipe_ioctl, .release =3D pipe_release, --=20 2.25.1.362.g51ebf55