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[193.226.214.223]) by smtp.gmail.com with ESMTPSA id lb22-20020a170907785600b0073bdf71995dsm9849951ejc.139.2022.09.19.07.10.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 19 Sep 2022 07:10:42 -0700 (PDT) From: Miklos Szeredi To: linux-fsdevel@vger.kernel.org Cc: Al Viro , Amir Goldstein , David Howells , Yu-li Lin , Chirantan Ekbote Subject: [PATCH v2 6/8] vfs: move open right after ->tmpfile() Date: Mon, 19 Sep 2022 16:10:29 +0200 Message-Id: <20220919141031.1834447-7-mszeredi@redhat.com> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20220919141031.1834447-1-mszeredi@redhat.com> References: <20220919141031.1834447-1-mszeredi@redhat.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Create a helper finish_open_simple() that opens the file with the original dentry. Handle the error case here as well to simplify callers. Call this helper right after ->tmpfile() is called. Next patch will change the tmpfile API and move this call into tmpfile instances. Signed-off-by: Miklos Szeredi --- fs/namei.c | 65 ++++++++++++++++++++-------------------------- include/linux/fs.h | 9 +++++++ 2 files changed, 37 insertions(+), 37 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 652d09ae66fb..eb1e1956450f 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -3583,11 +3583,12 @@ static int do_open(struct nameidata *nd, * On non-idmapped mounts or if permission checking is to be performed on the * raw inode simply passs init_user_ns. */ -static struct dentry *vfs_tmpfile(struct user_namespace *mnt_userns, - struct dentry *dentry, umode_t mode, int open_flag) +static int vfs_tmpfile(struct user_namespace *mnt_userns, + const struct path *parentpath, + struct file *file, umode_t mode) { - struct dentry *child = NULL; - struct inode *dir = dentry->d_inode; + struct dentry *child; + struct inode *dir = d_inode(parentpath->dentry); struct inode *inode; int error; @@ -3599,28 +3600,34 @@ static struct dentry *vfs_tmpfile(struct user_namespace *mnt_userns, if (!dir->i_op->tmpfile) goto out_err; error = -ENOMEM; - child = d_alloc(dentry, &slash_name); + child = d_alloc(parentpath->dentry, &slash_name); if (unlikely(!child)) goto out_err; + file->f_path.mnt = parentpath->mnt; + file->f_path.dentry = child; mode = vfs_prepare_mode(mnt_userns, dir, mode, mode, mode); error = dir->i_op->tmpfile(mnt_userns, dir, child, mode); + error = finish_open_simple(file, error); + dput(child); + if (error) + goto out_err; + error = may_open(mnt_userns, &file->f_path, 0, file->f_flags); if (error) goto out_err; error = -ENOENT; inode = child->d_inode; if (unlikely(!inode)) goto out_err; - if (!(open_flag & O_EXCL)) { + if (!(file->f_flags & O_EXCL)) { spin_lock(&inode->i_lock); inode->i_state |= I_LINKABLE; spin_unlock(&inode->i_lock); } ima_post_create_tmpfile(mnt_userns, inode); - return child; + return 0; out_err: - dput(child); - return ERR_PTR(error); + return error; } /** @@ -3641,25 +3648,15 @@ struct file *tmpfile_open(struct user_namespace *mnt_userns, { struct file *file; int error; - struct path path = { .mnt = parentpath->mnt }; - - path.dentry = vfs_tmpfile(mnt_userns, parentpath->dentry, mode, open_flag); - if (IS_ERR(path.dentry)) - return ERR_CAST(path.dentry); - - error = may_open(mnt_userns, &path, 0, open_flag); - file = ERR_PTR(error); - if (error) - goto out_dput; - - /* - * This relies on the "noaccount" property of fake open, otherwise - * equivalent to dentry_open(). - */ - file = open_with_fake_path(&path, open_flag, d_inode(path.dentry), cred); -out_dput: - dput(path.dentry); + file = alloc_empty_file_noaccount(open_flag, cred); + if (!IS_ERR(file)) { + error = vfs_tmpfile(mnt_userns, parentpath, file, mode); + if (error) { + fput(file); + file = ERR_PTR(error); + } + } return file; } EXPORT_SYMBOL(tmpfile_open); @@ -3669,26 +3666,20 @@ static int do_tmpfile(struct nameidata *nd, unsigned flags, struct file *file) { struct user_namespace *mnt_userns; - struct dentry *child; struct path path; int error = path_lookupat(nd, flags | LOOKUP_DIRECTORY, &path); + if (unlikely(error)) return error; error = mnt_want_write(path.mnt); if (unlikely(error)) goto out; mnt_userns = mnt_user_ns(path.mnt); - child = vfs_tmpfile(mnt_userns, path.dentry, op->mode, op->open_flag); - error = PTR_ERR(child); - if (IS_ERR(child)) + error = vfs_tmpfile(mnt_userns, &path, file, op->mode); + if (error) goto out2; - dput(path.dentry); - path.dentry = child; - audit_inode(nd->name, child, 0); + audit_inode(nd->name, file->f_path.dentry, 0); /* Don't check for other permissions, the inode was just created */ - error = may_open(mnt_userns, &path, 0, op->open_flag); - if (!error) - error = vfs_open(&path, file); out2: mnt_drop_write(path.mnt); out: diff --git a/include/linux/fs.h b/include/linux/fs.h index a445da4842e0..f0d17eefb966 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2780,6 +2780,15 @@ extern int finish_open(struct file *file, struct dentry *dentry, int (*open)(struct inode *, struct file *)); extern int finish_no_open(struct file *file, struct dentry *dentry); +/* Helper for the simple case when original dentry is used */ +static inline int finish_open_simple(struct file *file, int error) +{ + if (error) + return error; + + return finish_open(file, file->f_path.dentry, NULL); +} + /* fs/dcache.c */ extern void __init vfs_caches_init_early(void); extern void __init vfs_caches_init(void);