From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f65.google.com ([74.125.82.65]:35218 "EHLO mail-wm0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750858AbdAPRq1 (ORCPT ); Mon, 16 Jan 2017 12:46:27 -0500 From: Amir Goldstein To: Miklos Szeredi Cc: Al Viro , linux-unionfs@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH v3 2/6] ovl: check if upperdir fs supports O_TMPFILE Date: Mon, 16 Jan 2017 19:46:01 +0200 Message-Id: <1484588765-9397-3-git-send-email-amir73il@gmail.com> In-Reply-To: <1484588765-9397-1-git-send-email-amir73il@gmail.com> References: <1484588765-9397-1-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 ++++++++++ 3 files changed, 20 insertions(+) diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index 8af450b..d5984c4 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -127,6 +127,15 @@ static inline int ovl_do_whiteout(struct inode *dir, struct dentry *dentry) return err; } +static inline struct dentry *ovl_do_tmpfile(struct dentry *dentry, umode_t mode) +{ + struct dentry *ret = vfs_tmpfile(dentry->d_inode, dentry, mode, 0); + int err = IS_ERR(ret) ? PTR_ERR(ret) : 0; + + pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err); + return ret; +} + static inline struct inode *ovl_inode_real(struct inode *inode, bool *is_upper) { unsigned long x = (unsigned long) READ_ONCE(inode->i_private); 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..ff05065 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_do_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"); } } -- 2.7.4