From 625b6d105446e82e95ddb28d6fd3d25f84f6c479 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 12 May 2015 16:36:12 -0400 Subject: [PATCH] namei: pass the struct path to store the result down into path_lookupat() Signed-off-by: Al Viro --- fs/namei.c | 72 ++++++++++++++++++++++++++---------------------------- 1 file changed, 34 insertions(+), 38 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 177934c79a04..f4c9c0774b26 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2086,8 +2086,8 @@ static inline int lookup_last(struct nameidata *nd) } /* Returns 0 and nd will be valid on success; Retuns error, otherwise. */ -static int path_lookupat(int dfd, const struct filename *name, - unsigned int flags, struct nameidata *nd) +static int path_lookupat(int dfd, const struct filename *name, unsigned flags, + struct nameidata *nd, struct path *path) { const char *s = path_init(dfd, name, flags, nd); int err; @@ -2108,27 +2108,31 @@ static int path_lookupat(int dfd, const struct filename *name, if (!err && nd->flags & LOOKUP_DIRECTORY) if (!d_can_lookup(nd->path.dentry)) err = -ENOTDIR; - if (err) - terminate_walk(nd); - + if (!err) { + *path = nd->path; + nd->path.mnt = NULL; + nd->path.dentry = NULL; + } + terminate_walk(nd); path_cleanup(nd); return err; } -static int filename_lookup(int dfd, struct filename *name, - unsigned int flags, struct nameidata *nd) +static int filename_lookup(int dfd, struct filename *name, unsigned flags, + struct nameidata *nd, struct path *path) { int retval; struct nameidata *saved_nd = set_nameidata(nd); - retval = path_lookupat(dfd, name, flags | LOOKUP_RCU, nd); + retval = path_lookupat(dfd, name, flags | LOOKUP_RCU, nd, path); if (unlikely(retval == -ECHILD)) - retval = path_lookupat(dfd, name, flags, nd); + retval = path_lookupat(dfd, name, flags, nd, path); if (unlikely(retval == -ESTALE)) - retval = path_lookupat(dfd, name, flags | LOOKUP_REVAL, nd); + retval = path_lookupat(dfd, name, flags | LOOKUP_REVAL, + nd, path); if (likely(!retval)) - audit_inode(name, nd->path.dentry, flags & LOOKUP_PARENT); + audit_inode(name, path->dentry, flags & LOOKUP_PARENT); restore_nameidata(saved_nd); return retval; } @@ -2209,10 +2213,8 @@ int kern_path(const char *name, unsigned int flags, struct path *path) int res = PTR_ERR(filename); if (!IS_ERR(filename)) { - res = filename_lookup(AT_FDCWD, filename, flags, &nd); + res = filename_lookup(AT_FDCWD, filename, flags, &nd, path); putname(filename); - if (!res) - *path = nd.path; } return res; } @@ -2241,9 +2243,7 @@ int vfs_path_lookup(struct dentry *dentry, struct vfsmount *mnt, nd.root.dentry = dentry; nd.root.mnt = mnt; err = filename_lookup(AT_FDCWD, filename, - flags | LOOKUP_ROOT, &nd); - if (!err) - *path = nd.path; + flags | LOOKUP_ROOT, &nd, path); putname(filename); } return err; @@ -2311,10 +2311,8 @@ int user_path_at_empty(int dfd, const char __user *name, unsigned flags, BUG_ON(flags & LOOKUP_PARENT); - err = filename_lookup(dfd, tmp, flags, &nd); + err = filename_lookup(dfd, tmp, flags, &nd, path); putname(tmp); - if (!err) - *path = nd.path; } return err; } @@ -3261,44 +3259,42 @@ static int do_tmpfile(int dfd, struct filename *pathname, struct file *file, int *opened) { static const struct qstr name = QSTR_INIT("/", 1); - struct dentry *dentry, *child; + struct dentry *child; struct inode *dir; + struct path path; int error = path_lookupat(dfd, pathname, - flags | LOOKUP_DIRECTORY, nd); + flags | LOOKUP_DIRECTORY, nd, &path); if (unlikely(error)) return error; - error = mnt_want_write(nd->path.mnt); + error = mnt_want_write(path.mnt); if (unlikely(error)) goto out; + dir = path.dentry->d_inode; /* we want directory to be writable */ - error = inode_permission(nd->inode, MAY_WRITE | MAY_EXEC); + error = inode_permission(dir, MAY_WRITE | MAY_EXEC); if (error) goto out2; - dentry = nd->path.dentry; - dir = dentry->d_inode; if (!dir->i_op->tmpfile) { error = -EOPNOTSUPP; goto out2; } - child = d_alloc(dentry, &name); + child = d_alloc(path.dentry, &name); if (unlikely(!child)) { error = -ENOMEM; goto out2; } - nd->flags &= ~LOOKUP_DIRECTORY; - nd->flags |= op->intent; - dput(nd->path.dentry); - nd->path.dentry = child; - error = dir->i_op->tmpfile(dir, nd->path.dentry, op->mode); + dput(path.dentry); + path.dentry = child; + error = dir->i_op->tmpfile(dir, child, op->mode); if (error) goto out2; - audit_inode(pathname, nd->path.dentry, 0); + audit_inode(pathname, child, 0); /* Don't check for other permissions, the inode was just created */ - error = may_open(&nd->path, MAY_OPEN, op->open_flag); + error = may_open(&path, MAY_OPEN, op->open_flag); if (error) goto out2; - file->f_path.mnt = nd->path.mnt; - error = finish_open(file, nd->path.dentry, NULL, opened); + file->f_path.mnt = path.mnt; + error = finish_open(file, child, NULL, opened); if (error) goto out2; error = open_check_o_direct(file); @@ -3311,9 +3307,9 @@ static int do_tmpfile(int dfd, struct filename *pathname, spin_unlock(&inode->i_lock); } out2: - mnt_drop_write(nd->path.mnt); + mnt_drop_write(path.mnt); out: - path_put(&nd->path); + path_put(&path); return error; } -- 2.20.1