From dae6ad8f37529963ae7df52baaccf056b38f210e Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 26 Jun 2011 11:50:15 -0400 Subject: [PATCH] new helpers: kern_path_create/user_path_create combination of kern_path_parent() and lookup_create(). Does *not* expose struct nameidata to caller. Syscalls converted to that... Signed-off-by: Al Viro --- fs/namei.c | 154 ++++++++++++++++++++-------------------- fs/ocfs2/refcounttree.c | 49 +++---------- include/linux/namei.h | 2 + net/unix/af_unix.c | 38 +++++----- 4 files changed, 106 insertions(+), 137 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index f49d6abfa799..b292eb03d9d2 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2311,6 +2311,35 @@ fail: } EXPORT_SYMBOL_GPL(lookup_create); +struct dentry *kern_path_create(int dfd, const char *pathname, struct path *path, int is_dir) +{ + struct nameidata nd; + struct dentry *res; + int error = do_path_lookup(dfd, pathname, LOOKUP_PARENT, &nd); + if (error) + return ERR_PTR(error); + res = lookup_create(&nd, is_dir); + if (IS_ERR(res)) { + mutex_unlock(&nd.path.dentry->d_inode->i_mutex); + path_put(&nd.path); + } + *path = nd.path; + return res; +} +EXPORT_SYMBOL(kern_path_create); + +struct dentry *user_path_create(int dfd, const char __user *pathname, struct path *path, int is_dir) +{ + char *tmp = getname(pathname); + struct dentry *res; + if (IS_ERR(tmp)) + return ERR_CAST(tmp); + res = kern_path_create(dfd, tmp, path, is_dir); + putname(tmp); + return res; +} +EXPORT_SYMBOL(user_path_create); + int vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) { int error = may_create(dir, dentry); @@ -2359,54 +2388,46 @@ static int may_mknod(mode_t mode) SYSCALL_DEFINE4(mknodat, int, dfd, const char __user *, filename, int, mode, unsigned, dev) { - int error; - char *tmp; struct dentry *dentry; - struct nameidata nd; + struct path path; + int error; if (S_ISDIR(mode)) return -EPERM; - error = user_path_parent(dfd, filename, &nd, &tmp); - if (error) - return error; + dentry = user_path_create(dfd, filename, &path, 0); + if (IS_ERR(dentry)) + return PTR_ERR(dentry); - dentry = lookup_create(&nd, 0); - if (IS_ERR(dentry)) { - error = PTR_ERR(dentry); - goto out_unlock; - } - if (!IS_POSIXACL(nd.path.dentry->d_inode)) + if (!IS_POSIXACL(path.dentry->d_inode)) mode &= ~current_umask(); error = may_mknod(mode); if (error) goto out_dput; - error = mnt_want_write(nd.path.mnt); + error = mnt_want_write(path.mnt); if (error) goto out_dput; - error = security_path_mknod(&nd.path, dentry, mode, dev); + error = security_path_mknod(&path, dentry, mode, dev); if (error) goto out_drop_write; switch (mode & S_IFMT) { case 0: case S_IFREG: - error = vfs_create(nd.path.dentry->d_inode,dentry,mode,NULL); + error = vfs_create(path.dentry->d_inode,dentry,mode,NULL); break; case S_IFCHR: case S_IFBLK: - error = vfs_mknod(nd.path.dentry->d_inode,dentry,mode, + error = vfs_mknod(path.dentry->d_inode,dentry,mode, new_decode_dev(dev)); break; case S_IFIFO: case S_IFSOCK: - error = vfs_mknod(nd.path.dentry->d_inode,dentry,mode,0); + error = vfs_mknod(path.dentry->d_inode,dentry,mode,0); break; } out_drop_write: - mnt_drop_write(nd.path.mnt); + mnt_drop_write(path.mnt); out_dput: dput(dentry); -out_unlock: - mutex_unlock(&nd.path.dentry->d_inode->i_mutex); - path_put(&nd.path); - putname(tmp); + mutex_unlock(&path.dentry->d_inode->i_mutex); + path_put(&path); return error; } @@ -2439,38 +2460,29 @@ int vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) SYSCALL_DEFINE3(mkdirat, int, dfd, const char __user *, pathname, int, mode) { - int error = 0; - char * tmp; struct dentry *dentry; - struct nameidata nd; - - error = user_path_parent(dfd, pathname, &nd, &tmp); - if (error) - goto out_err; + struct path path; + int error; - dentry = lookup_create(&nd, 1); - error = PTR_ERR(dentry); + dentry = user_path_create(dfd, pathname, &path, 1); if (IS_ERR(dentry)) - goto out_unlock; + return PTR_ERR(dentry); - if (!IS_POSIXACL(nd.path.dentry->d_inode)) + if (!IS_POSIXACL(path.dentry->d_inode)) mode &= ~current_umask(); - error = mnt_want_write(nd.path.mnt); + error = mnt_want_write(path.mnt); if (error) goto out_dput; - error = security_path_mkdir(&nd.path, dentry, mode); + error = security_path_mkdir(&path, dentry, mode); if (error) goto out_drop_write; - error = vfs_mkdir(nd.path.dentry->d_inode, dentry, mode); + error = vfs_mkdir(path.dentry->d_inode, dentry, mode); out_drop_write: - mnt_drop_write(nd.path.mnt); + mnt_drop_write(path.mnt); out_dput: dput(dentry); -out_unlock: - mutex_unlock(&nd.path.dentry->d_inode->i_mutex); - path_put(&nd.path); - putname(tmp); -out_err: + mutex_unlock(&path.dentry->d_inode->i_mutex); + path_put(&path); return error; } @@ -2730,38 +2742,31 @@ SYSCALL_DEFINE3(symlinkat, const char __user *, oldname, { int error; char *from; - char *to; struct dentry *dentry; - struct nameidata nd; + struct path path; from = getname(oldname); if (IS_ERR(from)) return PTR_ERR(from); - error = user_path_parent(newdfd, newname, &nd, &to); - if (error) - goto out_putname; - - dentry = lookup_create(&nd, 0); + dentry = user_path_create(newdfd, newname, &path, 0); error = PTR_ERR(dentry); if (IS_ERR(dentry)) - goto out_unlock; + goto out_putname; - error = mnt_want_write(nd.path.mnt); + error = mnt_want_write(path.mnt); if (error) goto out_dput; - error = security_path_symlink(&nd.path, dentry, from); + error = security_path_symlink(&path, dentry, from); if (error) goto out_drop_write; - error = vfs_symlink(nd.path.dentry->d_inode, dentry, from); + error = vfs_symlink(path.dentry->d_inode, dentry, from); out_drop_write: - mnt_drop_write(nd.path.mnt); + mnt_drop_write(path.mnt); out_dput: dput(dentry); -out_unlock: - mutex_unlock(&nd.path.dentry->d_inode->i_mutex); - path_put(&nd.path); - putname(to); + mutex_unlock(&path.dentry->d_inode->i_mutex); + path_put(&path); out_putname: putname(from); return error; @@ -2826,11 +2831,9 @@ SYSCALL_DEFINE5(linkat, int, olddfd, const char __user *, oldname, int, newdfd, const char __user *, newname, int, flags) { struct dentry *new_dentry; - struct nameidata nd; - struct path old_path; + struct path old_path, new_path; int how = 0; int error; - char *to; if ((flags & ~(AT_SYMLINK_FOLLOW | AT_EMPTY_PATH)) != 0) return -EINVAL; @@ -2852,32 +2855,27 @@ SYSCALL_DEFINE5(linkat, int, olddfd, const char __user *, oldname, if (error) return error; - error = user_path_parent(newdfd, newname, &nd, &to); - if (error) - goto out; - error = -EXDEV; - if (old_path.mnt != nd.path.mnt) - goto out_release; - new_dentry = lookup_create(&nd, 0); + new_dentry = user_path_create(newdfd, newname, &new_path, 0); error = PTR_ERR(new_dentry); if (IS_ERR(new_dentry)) - goto out_unlock; - error = mnt_want_write(nd.path.mnt); + goto out; + + error = -EXDEV; + if (old_path.mnt != new_path.mnt) + goto out_dput; + error = mnt_want_write(new_path.mnt); if (error) goto out_dput; - error = security_path_link(old_path.dentry, &nd.path, new_dentry); + error = security_path_link(old_path.dentry, &new_path, new_dentry); if (error) goto out_drop_write; - error = vfs_link(old_path.dentry, nd.path.dentry->d_inode, new_dentry); + error = vfs_link(old_path.dentry, new_path.dentry->d_inode, new_dentry); out_drop_write: - mnt_drop_write(nd.path.mnt); + mnt_drop_write(new_path.mnt); out_dput: dput(new_dentry); -out_unlock: - mutex_unlock(&nd.path.dentry->d_inode->i_mutex); -out_release: - path_put(&nd.path); - putname(to); + mutex_unlock(&new_path.dentry->d_inode->i_mutex); + path_put(&new_path); out: path_put(&old_path); diff --git a/fs/ocfs2/refcounttree.c b/fs/ocfs2/refcounttree.c index ebfd3825f12a..cf7823382664 100644 --- a/fs/ocfs2/refcounttree.c +++ b/fs/ocfs2/refcounttree.c @@ -4368,25 +4368,6 @@ static inline int ocfs2_may_create(struct inode *dir, struct dentry *child) return inode_permission(dir, MAY_WRITE | MAY_EXEC); } -/* copied from user_path_parent. */ -static int ocfs2_user_path_parent(const char __user *path, - struct nameidata *nd, char **name) -{ - char *s = getname(path); - int error; - - if (IS_ERR(s)) - return PTR_ERR(s); - - error = kern_path_parent(s, nd); - if (error) - putname(s); - else - *name = s; - - return error; -} - /** * ocfs2_vfs_reflink - Create a reference-counted link * @@ -4460,10 +4441,8 @@ int ocfs2_reflink_ioctl(struct inode *inode, bool preserve) { struct dentry *new_dentry; - struct nameidata nd; - struct path old_path; + struct path old_path, new_path; int error; - char *to = NULL; if (!ocfs2_refcount_tree(OCFS2_SB(inode->i_sb))) return -EOPNOTSUPP; @@ -4474,39 +4453,33 @@ int ocfs2_reflink_ioctl(struct inode *inode, return error; } - error = ocfs2_user_path_parent(newname, &nd, &to); - if (error) { + new_dentry = user_path_create(AT_FDCWD, newname, &new_path, 0); + error = PTR_ERR(new_dentry); + if (IS_ERR(new_dentry)) { mlog_errno(error); goto out; } error = -EXDEV; - if (old_path.mnt != nd.path.mnt) - goto out_release; - new_dentry = lookup_create(&nd, 0); - error = PTR_ERR(new_dentry); - if (IS_ERR(new_dentry)) { + if (old_path.mnt != new_path.mnt) { mlog_errno(error); - goto out_unlock; + goto out_dput; } - error = mnt_want_write(nd.path.mnt); + error = mnt_want_write(new_path.mnt); if (error) { mlog_errno(error); goto out_dput; } error = ocfs2_vfs_reflink(old_path.dentry, - nd.path.dentry->d_inode, + new_path.dentry->d_inode, new_dentry, preserve); - mnt_drop_write(nd.path.mnt); + mnt_drop_write(new_path.mnt); out_dput: dput(new_dentry); -out_unlock: - mutex_unlock(&nd.path.dentry->d_inode->i_mutex); -out_release: - path_put(&nd.path); - putname(to); + mutex_unlock(&new_path.dentry->d_inode->i_mutex); + path_put(&new_path); out: path_put(&old_path); diff --git a/include/linux/namei.h b/include/linux/namei.h index 3439ab862e1d..b8cea804d31a 100644 --- a/include/linux/namei.h +++ b/include/linux/namei.h @@ -74,6 +74,8 @@ extern int user_path_at(int, const char __user *, unsigned, struct path *); extern int kern_path(const char *, unsigned, struct path *); +extern struct dentry *kern_path_create(int, const char *, struct path *, int); +extern struct dentry *user_path_create(int, const char __user *, struct path *, int); extern int kern_path_parent(const char *, struct nameidata *); extern int vfs_path_lookup(struct dentry *, struct vfsmount *, const char *, unsigned int, struct nameidata *); diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 0722a25a3a33..ec68e1c05b85 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -808,8 +808,9 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) struct net *net = sock_net(sk); struct unix_sock *u = unix_sk(sk); struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr; + char *sun_path = sunaddr->sun_path; struct dentry *dentry = NULL; - struct nameidata nd; + struct path path; int err; unsigned hash; struct unix_address *addr; @@ -845,48 +846,44 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) addr->hash = hash ^ sk->sk_type; atomic_set(&addr->refcnt, 1); - if (sunaddr->sun_path[0]) { + if (sun_path[0]) { unsigned int mode; err = 0; /* * Get the parent directory, calculate the hash for last * component. */ - err = kern_path_parent(sunaddr->sun_path, &nd); - if (err) - goto out_mknod_parent; - - dentry = lookup_create(&nd, 0); + dentry = kern_path_create(AT_FDCWD, sun_path, &path, 0); err = PTR_ERR(dentry); if (IS_ERR(dentry)) - goto out_mknod_unlock; + goto out_mknod_parent; /* * All right, let's create it. */ mode = S_IFSOCK | (SOCK_INODE(sock)->i_mode & ~current_umask()); - err = mnt_want_write(nd.path.mnt); + err = mnt_want_write(path.mnt); if (err) goto out_mknod_dput; - err = security_path_mknod(&nd.path, dentry, mode, 0); + err = security_path_mknod(&path, dentry, mode, 0); if (err) goto out_mknod_drop_write; - err = vfs_mknod(nd.path.dentry->d_inode, dentry, mode, 0); + err = vfs_mknod(path.dentry->d_inode, dentry, mode, 0); out_mknod_drop_write: - mnt_drop_write(nd.path.mnt); + mnt_drop_write(path.mnt); if (err) goto out_mknod_dput; - mutex_unlock(&nd.path.dentry->d_inode->i_mutex); - dput(nd.path.dentry); - nd.path.dentry = dentry; + mutex_unlock(&path.dentry->d_inode->i_mutex); + dput(path.dentry); + path.dentry = dentry; addr->hash = UNIX_HASH_SIZE; } spin_lock(&unix_table_lock); - if (!sunaddr->sun_path[0]) { + if (!sun_path[0]) { err = -EADDRINUSE; if (__unix_find_socket_byname(net, sunaddr, addr_len, sk->sk_type, hash)) { @@ -897,8 +894,8 @@ out_mknod_drop_write: list = &unix_socket_table[addr->hash]; } else { list = &unix_socket_table[dentry->d_inode->i_ino & (UNIX_HASH_SIZE-1)]; - u->dentry = nd.path.dentry; - u->mnt = nd.path.mnt; + u->dentry = path.dentry; + u->mnt = path.mnt; } err = 0; @@ -915,9 +912,8 @@ out: out_mknod_dput: dput(dentry); -out_mknod_unlock: - mutex_unlock(&nd.path.dentry->d_inode->i_mutex); - path_put(&nd.path); + mutex_unlock(&path.dentry->d_inode->i_mutex); + path_put(&path); out_mknod_parent: if (err == -EEXIST) err = -EADDRINUSE; -- 2.39.5