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smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=OooUTIri; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D33E160A44DF; Mon, 2 Nov 2026 15:36:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=OooUTIri Received: by smtp.kernel.org (Postfix) with ESMTPSA id B73BE1F00A18; Mon, 2 Nov 2026 15:36:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793633777; bh=X6qJRwazLqAMPBxaQUbfUiKhNVd3swwk7S8hV3QbYLU=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=OooUTIrihLmaX0ecOMxc1pdtRBYajzq9meyXmQkeP0DiaQKyKrS+8sMUnwdr+7PiP 5MgBgASfz4Cqs3pFNaXpJK7ZTjO7vgGI3My2/antPBnrI1+MOdSd1zj+qooiJ4ICaV BIJ52/VvF/FCa6hizbbV+uOwmFskzerAf8voVYGHnV3D1EZAmyEFP6IWX0i7Zr6339 csbKCtxOQwMs8/SfLOFSVcNDZ361AMeNPRTONuJu2+JifqXyjyZKXaErhyFtf3w5kk F6scfOYl8JZcfW3ErmUit1d0hhKRBJNWMeoLXzwNFCNKHxlvWVpfIrrby5JjZ4oVDC ui/aihse0jGAw== From: Christian Brauner Date: Mon, 02 Nov 2026 16:15:54 +0100 Subject: [PATCH RFC 1/5] proc: drop ->proc_write() X-Mailing-List: linux-modules@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20261102-work-procfs-cleanup-v1-1-c40014bc12f5@kernel.org> References: <20261102-work-procfs-cleanup-v1-0-c40014bc12f5@kernel.org> In-Reply-To: <20261102-work-procfs-cleanup-v1-0-c40014bc12f5@kernel.org> To: linux-fsdevel@vger.kernel.org Cc: Linus Torvalds , Jann Horn , Josef Bacik , Chris Mason , Jeff Layton , NeilBrown , Eric Dumazet , Thomas Gleixner , Al Viro , Jonathan Corbet , Christoph Hellwig , Greg Kroah-Hartman , Joel Granados , Kees Cook , Jan Kara , Jan Kara , linux-kernel@vger.kernel.org, linux-nfs@vger.kernel.org, linux-acpi@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-s390@vger.kernel.org, linux-scsi@vger.kernel.org, linux-um@lists.infradead.org, linux-wireless@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, netdev@vger.kernel.org, ntfs3@lists.linux.dev, platform-driver-x86@vger.kernel.org, coreteam@netfilter.org, kexec@lists.infradead.org, linux-pci@vger.kernel.org, linux-sound@vger.kernel.org, netfilter-devel@vger.kernel.org, dri-devel@lists.freedesktop.org, ibm-acpi-devel@lists.sourceforge.net, jfs-discussion@lists.sourceforge.net, linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-cifs@vger.kernel.org, linux-fbdev@vger.kernel.org, linux-hwmon@vger.kernel.org, linux-mm@kvack.org, linux-sh@vger.kernel.org, linux-usb@vger.kernel.org, samba-technical@lists.samba.org, sparclinux@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-doc@vger.kernel.org, linux-serial@vger.kernel.org, linux-atm-general@lists.sourceforge.net, Takashi Iwai , linux-input@vger.kernel.org, linux-raid@vger.kernel.org, linux-ext4@vger.kernel.org, linux-modules@vger.kernel.org, linux-debuggers@vger.kernel.org, "Christian Brauner (Amutable)" , Chuck Lever X-Mailer: b4 0.17-dev X-Developer-Signature: v=1; a=openpgp-sha256; l=2803; i=brauner@kernel.org; h=from:subject:message-id; bh=8NQNxLblfbpsxn3sguBDLl0w5nxAqb/wMxctobr9n4U=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMWS9WJn43XZq7IsLj08Wbz6eU7B1wmqjv5Fep+R5QvvLx JNEp7ErdJSyMIhxMciKKbI4tJuEyy3nqdhslKkBM4eVCWQIAxenAExktyQjw5pXjyzW+OzOmZdw vz7EubB41eJzrQUpTydtX64uY92vMIGRYe+JqY8NeiT1Qz9fThVgWbbFcKLF5tm1mj9TRJe9XyI dwgkA X-Developer-Key: i=brauner@kernel.org; a=openpgp; fpr=4880B8C9BD0E5106FC070F4F7B3C391EFEA93624 Every writable entry implements ->proc_write_buf() now and procfs copies in what is written before it pins the entry. Remove ->proc_write(). Signed-off-by: Christian Brauner (Amutable) --- fs/proc/generic.c | 2 -- fs/proc/inode.c | 15 +-------------- include/linux/proc_fs.h | 1 - 3 files changed, 1 insertion(+), 17 deletions(-) diff --git a/fs/proc/generic.c b/fs/proc/generic.c index 35dd745a0357..7b2ed3c42d32 100644 --- a/fs/proc/generic.c +++ b/fs/proc/generic.c @@ -469,8 +469,6 @@ static int pde_set_flags(struct proc_dir_entry *pde) pde->flags |= PROC_ENTRY_proc_lseek; } if (proc_ops->proc_write_buf) { - if (WARN_ON_ONCE(proc_ops->proc_write)) - return -EINVAL; pde->flags |= PROC_ENTRY_proc_write_buf; pde->write_size = proc_ops->proc_write_size ?: PAGE_SIZE - 1; if (proc_ops->proc_flags & PROC_ENTRY_SHORT_WRITES) diff --git a/fs/proc/inode.c b/fs/proc/inode.c index 7e4ca5751abb..dac5974d4652 100644 --- a/fs/proc/inode.c +++ b/fs/proc/inode.c @@ -491,14 +491,6 @@ static ssize_t proc_reg_read(struct file *file, char __user *buf, size_t count, return rv; } -static ssize_t pde_write(struct proc_dir_entry *pde, struct file *file, const char __user *buf, size_t count, loff_t *ppos) -{ - const auto write = pde->proc_ops->proc_write; - if (write) - return write(file, buf, count, ppos); - return -EIO; -} - /* * procfs copies in what is written before it pins the entry. A writer that * faults on its buffer then doesn't hold up remove_proc_entry(). @@ -533,15 +525,10 @@ static ssize_t pde_write_buf(struct proc_dir_entry *pde, struct file *file, static ssize_t proc_reg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { struct proc_dir_entry *pde = PDE(file_inode(file)); - ssize_t rv; if (pde_has_proc_write_buf(pde)) return pde_write_buf(pde, file, buf, count, ppos); - if (!pde_pin(pde)) - return -EIO; - rv = pde_write(pde, file, buf, count, ppos); - pde_unpin(pde); - return rv; + return -EIO; } static __poll_t pde_poll(struct proc_dir_entry *pde, struct file *file, struct poll_table_struct *pts) diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h index 2ba4e4a39e13..f21dd826eaa6 100644 --- a/include/linux/proc_fs.h +++ b/include/linux/proc_fs.h @@ -74,7 +74,6 @@ struct proc_ops { int (*proc_open)(struct inode *, struct file *); ssize_t (*proc_read)(struct file *, char __user *, size_t, loff_t *); ssize_t (*proc_read_iter)(struct kiocb *, struct iov_iter *); - ssize_t (*proc_write)(struct file *, const char __user *, size_t, loff_t *); /* * mandatory unless nonseekable_open() or equivalent is used, procfs * seeks seq_file entries itself -- 2.53.0