From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f66.google.com ([74.125.82.66]:33002 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751052AbdAON5x (ORCPT ); Sun, 15 Jan 2017 08:57:53 -0500 From: Amir Goldstein To: Miklos Szeredi Cc: Al Viro , linux-unionfs@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH 2/6] ovl: check if upperdir fs supports O_TMPFILE Date: Sun, 15 Jan 2017 15:57:28 +0200 Message-Id: <1484488652-611-3-git-send-email-amir73il@gmail.com> In-Reply-To: <1484488652-611-1-git-send-email-amir73il@gmail.com> References: <1484488652-611-1-git-send-email-amir73il@gmail.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: This is needed for choosing between concurrent copyup using O_TMPFILE and legacy copyup using workdir+rename. Signed-off-by: Amir Goldstein --- fs/overlayfs/overlayfs.h | 9 +++++++++ fs/overlayfs/ovl_entry.h | 1 + fs/overlayfs/super.c | 10 ++++++++++ fs/overlayfs/util.c | 18 ++++++++++++++++++ 4 files changed, 38 insertions(+) diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index 8af450b..190b03f 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -127,6 +127,14 @@ static inline int ovl_do_whiteout(struct inode *dir, struct dentry *dentry) return err; } +static inline int ovl_do_tmpfile(struct inode *dir, struct dentry *dentry, + umode_t mode) +{ + int err = vfs_tmpfile(dir, dentry, mode); + pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err); + return err; +} + static inline struct inode *ovl_inode_real(struct inode *inode, bool *is_upper) { unsigned long x = (unsigned long) READ_ONCE(inode->i_private); @@ -169,6 +177,7 @@ void ovl_dentry_version_inc(struct dentry *dentry); u64 ovl_dentry_version_get(struct dentry *dentry); bool ovl_is_whiteout(struct dentry *dentry); struct file *ovl_path_open(struct path *path, int flags); +struct dentry *ovl_alloc_tmpfile(struct dentry *parent, umode_t mode); /* namei.c */ int ovl_path_next(int idx, struct dentry *dentry, struct path *path); diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h index d14bca1..65f24000 100644 --- a/fs/overlayfs/ovl_entry.h +++ b/fs/overlayfs/ovl_entry.h @@ -27,6 +27,7 @@ struct ovl_fs { struct ovl_config config; /* creds of process who forced instantiation of super block */ const struct cred *creator_cred; + bool tmpfile; }; /* private information held for every overlayfs dentry */ diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 20f48ab..a6c42f5 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -825,6 +825,8 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) * creation of workdir in previous step. */ if (ufs->workdir) { + struct dentry *temp; + err = ovl_check_d_type_supported(&workpath); if (err < 0) goto out_put_workdir; @@ -836,6 +838,14 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) */ if (!err) pr_warn("overlayfs: upper fs needs to support d_type.\n"); + + /* Check if upper/work fs supports O_TMPFILE */ + temp = ovl_alloc_tmpfile(ufs->workdir, S_IFREG | 0); + ufs->tmpfile = !IS_ERR(temp); + if (ufs->tmpfile) + dput(temp); + else + pr_warn("overlayfs: upper fs does not support tmpfile.\n"); } } diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c index 952286f..e6facb1 100644 --- a/fs/overlayfs/util.c +++ b/fs/overlayfs/util.c @@ -263,3 +263,21 @@ struct file *ovl_path_open(struct path *path, int flags) { return dentry_open(path, flags | O_NOATIME, current_cred()); } + +struct dentry *ovl_alloc_tmpfile(struct dentry *parent, umode_t mode) +{ + static const struct qstr name = QSTR_INIT("/", 1); + struct dentry *temp; + struct inode *dir = parent->d_inode; + int err; + + temp = d_alloc(parent, &name); + if (unlikely(!temp)) + return ERR_PTR(-ENOMEM); + + err = ovl_do_tmpfile(dir, temp, mode); + if (unlikely(err)) + return ERR_PTR(err); + + return temp; +} -- 2.7.4