From 765927b2d508712d320c8934db963bbe14c3fcec Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 26 Jun 2012 21:58:53 +0400 Subject: switch dentry_open() to struct path, make it grab references itself Signed-off-by: Al Viro --- ipc/mqueue.c | 117 ++++++++++++++++++++++++----------------------------------- 1 file changed, 47 insertions(+), 70 deletions(-) (limited to 'ipc') diff --git a/ipc/mqueue.c b/ipc/mqueue.c index 2dee38d53c73..f8e54f5b9080 100644 --- a/ipc/mqueue.c +++ b/ipc/mqueue.c @@ -721,8 +721,8 @@ static int mq_attr_ok(struct ipc_namespace *ipc_ns, struct mq_attr *attr) /* * Invoked when creating a new queue via sys_mq_open */ -static struct file *do_create(struct ipc_namespace *ipc_ns, struct dentry *dir, - struct dentry *dentry, int oflag, umode_t mode, +static struct file *do_create(struct ipc_namespace *ipc_ns, struct inode *dir, + struct path *path, int oflag, umode_t mode, struct mq_attr *attr) { const struct cred *cred = current_cred(); @@ -732,9 +732,9 @@ static struct file *do_create(struct ipc_namespace *ipc_ns, struct dentry *dir, if (attr) { ret = mq_attr_ok(ipc_ns, attr); if (ret) - goto out; + return ERR_PTR(ret); /* store for use during create */ - dentry->d_fsdata = attr; + path->dentry->d_fsdata = attr; } else { struct mq_attr def_attr; @@ -744,71 +744,51 @@ static struct file *do_create(struct ipc_namespace *ipc_ns, struct dentry *dir, ipc_ns->mq_msgsize_default); ret = mq_attr_ok(ipc_ns, &def_attr); if (ret) - goto out; + return ERR_PTR(ret); } mode &= ~current_umask(); - ret = mnt_want_write(ipc_ns->mq_mnt); + ret = mnt_want_write(path->mnt); if (ret) - goto out; - ret = vfs_create(dir->d_inode, dentry, mode, true); - dentry->d_fsdata = NULL; - if (ret) - goto out_drop_write; - - result = dentry_open(dentry, ipc_ns->mq_mnt, oflag, cred); + return ERR_PTR(ret); + ret = vfs_create(dir, path->dentry, mode, true); + path->dentry->d_fsdata = NULL; + if (!ret) + result = dentry_open(path, oflag, cred); + else + result = ERR_PTR(ret); /* * dentry_open() took a persistent mnt_want_write(), * so we can now drop this one. */ - mnt_drop_write(ipc_ns->mq_mnt); + mnt_drop_write(path->mnt); return result; - -out_drop_write: - mnt_drop_write(ipc_ns->mq_mnt); -out: - dput(dentry); - mntput(ipc_ns->mq_mnt); - return ERR_PTR(ret); } /* Opens existing queue */ -static struct file *do_open(struct ipc_namespace *ipc_ns, - struct dentry *dentry, int oflag) +static struct file *do_open(struct path *path, int oflag) { - int ret; - const struct cred *cred = current_cred(); - static const int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE, MAY_READ | MAY_WRITE }; - - if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY)) { - ret = -EINVAL; - goto err; - } - - if (inode_permission(dentry->d_inode, oflag2acc[oflag & O_ACCMODE])) { - ret = -EACCES; - goto err; - } - - return dentry_open(dentry, ipc_ns->mq_mnt, oflag, cred); - -err: - dput(dentry); - mntput(ipc_ns->mq_mnt); - return ERR_PTR(ret); + int acc; + if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY)) + return ERR_PTR(-EINVAL); + acc = oflag2acc[oflag & O_ACCMODE]; + if (inode_permission(path->dentry->d_inode, acc)) + return ERR_PTR(-EACCES); + return dentry_open(path, oflag, current_cred()); } SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, umode_t, mode, struct mq_attr __user *, u_attr) { - struct dentry *dentry; + struct path path; struct file *filp; char *name; struct mq_attr attr; int fd, error; struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns; + struct dentry *root = ipc_ns->mq_mnt->mnt_root; if (u_attr && copy_from_user(&attr, u_attr, sizeof(struct mq_attr))) return -EFAULT; @@ -822,52 +802,49 @@ SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, umode_t, mode, if (fd < 0) goto out_putname; - mutex_lock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex); - dentry = lookup_one_len(name, ipc_ns->mq_mnt->mnt_root, strlen(name)); - if (IS_ERR(dentry)) { - error = PTR_ERR(dentry); + error = 0; + mutex_lock(&root->d_inode->i_mutex); + path.dentry = lookup_one_len(name, root, strlen(name)); + if (IS_ERR(path.dentry)) { + error = PTR_ERR(path.dentry); goto out_putfd; } - mntget(ipc_ns->mq_mnt); + path.mnt = mntget(ipc_ns->mq_mnt); if (oflag & O_CREAT) { - if (dentry->d_inode) { /* entry already exists */ - audit_inode(name, dentry); + if (path.dentry->d_inode) { /* entry already exists */ + audit_inode(name, path.dentry); if (oflag & O_EXCL) { error = -EEXIST; goto out; } - filp = do_open(ipc_ns, dentry, oflag); + filp = do_open(&path, oflag); } else { - filp = do_create(ipc_ns, ipc_ns->mq_mnt->mnt_root, - dentry, oflag, mode, + filp = do_create(ipc_ns, root->d_inode, + &path, oflag, mode, u_attr ? &attr : NULL); } } else { - if (!dentry->d_inode) { + if (!path.dentry->d_inode) { error = -ENOENT; goto out; } - audit_inode(name, dentry); - filp = do_open(ipc_ns, dentry, oflag); + audit_inode(name, path.dentry); + filp = do_open(&path, oflag); } - if (IS_ERR(filp)) { + if (!IS_ERR(filp)) + fd_install(fd, filp); + else error = PTR_ERR(filp); - goto out_putfd; - } - - fd_install(fd, filp); - goto out_upsem; - out: - dput(dentry); - mntput(ipc_ns->mq_mnt); + path_put(&path); out_putfd: - put_unused_fd(fd); - fd = error; -out_upsem: - mutex_unlock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex); + if (error) { + put_unused_fd(fd); + fd = error; + } + mutex_unlock(&root->d_inode->i_mutex); out_putname: putname(name); return fd; -- cgit v1.2.3-59-g8ed1b