From patchwork Tue Mar 23 19:59:40 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Andr=C3=A9_Almeida?= X-Patchwork-Id: 12159179 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,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 33A32C433DB for ; Tue, 23 Mar 2021 20:00:13 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id D703F619C8 for ; Tue, 23 Mar 2021 20:00:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D703F619C8 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=collabora.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 750006B0133; Tue, 23 Mar 2021 16:00:12 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 6FF936B0147; Tue, 23 Mar 2021 16:00:12 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5A0306B0149; Tue, 23 Mar 2021 16:00:12 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0158.hostedemail.com [216.40.44.158]) by kanga.kvack.org (Postfix) with ESMTP id 384E76B0133 for ; Tue, 23 Mar 2021 16:00:12 -0400 (EDT) Received: from smtpin34.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 04E611DF9 for ; Tue, 23 Mar 2021 20:00:12 +0000 (UTC) X-FDA: 77952205464.34.F3245BC Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [46.235.227.227]) by imf13.hostedemail.com (Postfix) with ESMTP id 34827E0011C0 for ; Tue, 23 Mar 2021 20:00:11 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: tonyk) with ESMTPSA id C6F111F44DBA From: =?utf-8?q?Andr=C3=A9_Almeida?= To: Hugh Dickins , Andrew Morton , Alexander Viro Cc: krisman@collabora.com, smcv@collabora.com, kernel@collabora.com, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Daniel Rosenberg , =?utf-8?q?Andr=C3=A9_Almeida?= Subject: [RFC PATCH 3/4] mm: shmem: Add IOCTL support for tmpfs Date: Tue, 23 Mar 2021 16:59:40 -0300 Message-Id: <20210323195941.69720-4-andrealmeid@collabora.com> X-Mailer: git-send-email 2.31.0 In-Reply-To: <20210323195941.69720-1-andrealmeid@collabora.com> References: <20210323195941.69720-1-andrealmeid@collabora.com> MIME-Version: 1.0 X-Stat-Signature: co7wj18frasmgmcxaujt551og5xp9d3d X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 34827E0011C0 Received-SPF: none (collabora.com>: No applicable sender policy available) receiver=imf13; identity=mailfrom; envelope-from=""; helo=bhuna.collabora.co.uk; client-ip=46.235.227.227 X-HE-DKIM-Result: none/none X-HE-Tag: 1616529611-246924 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Implement IOCTL operations for files to set/get file flags. Implement the only supported flag by now, that is S_CASEFOLD. Signed-off-by: André Almeida --- include/linux/shmem_fs.h | 4 ++ mm/shmem.c | 84 +++++++++++++++++++++++++++++++++++++++- 2 files changed, 87 insertions(+), 1 deletion(-) diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h index 29ee64352807..2c89c5a66508 100644 --- a/include/linux/shmem_fs.h +++ b/include/linux/shmem_fs.h @@ -140,4 +140,8 @@ extern int shmem_mfill_zeropage_pte(struct mm_struct *dst_mm, dst_addr) ({ BUG(); 0; }) #endif +#define TMPFS_CASEFOLD_FL 0x40000000 /* Casefolded file */ +#define TMPFS_USER_FLS TMPFS_CASEFOLD_FL /* Userspace supported flags */ +#define TMPFS_FLS S_CASEFOLD /* Kernel supported flags */ + #endif diff --git a/mm/shmem.c b/mm/shmem.c index 20df81763995..2f2c996d215b 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -258,6 +258,7 @@ static inline void shmem_inode_unacct_blocks(struct inode *inode, long pages) static const struct super_operations shmem_ops; const struct address_space_operations shmem_aops; static const struct file_operations shmem_file_operations; +static const struct file_operations shmem_dir_operations; static const struct inode_operations shmem_inode_operations; static const struct inode_operations shmem_dir_inode_operations; static const struct inode_operations shmem_special_inode_operations; @@ -2347,7 +2348,7 @@ static struct inode *shmem_get_inode(struct super_block *sb, const struct inode /* Some things misbehave if size == 0 on a directory */ inode->i_size = 2 * BOGO_DIRENT_SIZE; inode->i_op = &shmem_dir_inode_operations; - inode->i_fop = &simple_dir_operations; + inode->i_fop = &shmem_dir_operations; break; case S_IFLNK: /* @@ -2838,6 +2839,76 @@ static long shmem_fallocate(struct file *file, int mode, loff_t offset, return error; } +static long shmem_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + int ret; + u32 fsflags = 0, old, new = 0; + struct inode *inode = file_inode(file); + struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb); + + switch (cmd) { + case FS_IOC_GETFLAGS: + if ((inode->i_flags & S_CASEFOLD) && S_ISDIR(inode->i_mode)) + fsflags |= TMPFS_CASEFOLD_FL; + + if (put_user(fsflags, (int __user *)arg)) + return -EFAULT; + + return 0; + + case FS_IOC_SETFLAGS: + if (get_user(fsflags, (int __user *)arg)) + return -EFAULT; + + old = inode->i_flags; + + if (fsflags & ~TMPFS_USER_FLS) + return -EINVAL; + + if (fsflags & TMPFS_CASEFOLD_FL) { + if (!sbinfo->casefold) { + pr_err("tmpfs: casefold disabled at this mount point\n"); + return -EOPNOTSUPP; + } + + if (!S_ISDIR(inode->i_mode)) + return -ENOTDIR; + + if (!simple_empty(file_dentry(file))) + return -ENOTEMPTY; + + new |= S_CASEFOLD; + } else if (old & S_CASEFOLD) { + if (!simple_empty(file_dentry(file))) + return -ENOTEMPTY; + } + + ret = mnt_want_write_file(file); + if (ret) + return ret; + + inode_lock(inode); + + ret = vfs_ioc_setflags_prepare(inode, old, new); + if (ret) { + inode_unlock(inode); + mnt_drop_write_file(file); + return ret; + } + + inode_set_flags(inode, new, TMPFS_FLS); + + inode_unlock(inode); + mnt_drop_write_file(file); + return 0; + + default: + return -ENOTTY; + } + + return 0; +} + static int shmem_statfs(struct dentry *dentry, struct kstatfs *buf) { struct shmem_sb_info *sbinfo = SHMEM_SB(dentry->d_sb); @@ -3916,6 +3987,7 @@ static const struct file_operations shmem_file_operations = { .splice_read = generic_file_splice_read, .splice_write = iter_file_splice_write, .fallocate = shmem_fallocate, + .unlocked_ioctl = shmem_ioctl, #endif }; @@ -3928,6 +4000,16 @@ static const struct inode_operations shmem_inode_operations = { #endif }; +static const struct file_operations shmem_dir_operations = { + .open = dcache_dir_open, + .release = dcache_dir_close, + .llseek = dcache_dir_lseek, + .read = generic_read_dir, + .iterate_shared = dcache_readdir, + .fsync = noop_fsync, + .unlocked_ioctl = shmem_ioctl, +}; + static const struct inode_operations shmem_dir_inode_operations = { #ifdef CONFIG_TMPFS .create = shmem_create,