From 5c31b6cedb675199bfd18c08a1223c9b39daedd7 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 12 May 2015 17:32:54 -0400 Subject: [PATCH] namei: saner calling conventions for filename_parentat() a) make it reject ERR_PTR() for name b) make it putname(name) on all other failure exits c) make it return name on success again, simplifies the callers Signed-off-by: Al Viro --- fs/namei.c | 60 ++++++++++++++++++++---------------------------------- 1 file changed, 22 insertions(+), 38 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 628b6eb9415f..484b73cb95e3 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2166,13 +2166,16 @@ static int path_parentat(int dfd, const struct filename *name, return err; } -static int filename_parentat(int dfd, struct filename *name, +static struct filename *filename_parentat(int dfd, struct filename *name, unsigned int flags, struct path *parent, struct qstr *last, int *type) { int retval; - struct nameidata nd, *saved_nd = set_nameidata(&nd); + struct nameidata nd, *saved_nd; + if (IS_ERR(name)) + return name; + saved_nd = set_nameidata(&nd); retval = path_parentat(dfd, name, flags | LOOKUP_RCU, &nd, parent); if (unlikely(retval == -ECHILD)) retval = path_parentat(dfd, name, flags, &nd, parent); @@ -2183,32 +2186,30 @@ static int filename_parentat(int dfd, struct filename *name, *last = nd.last; *type = nd.last_type; audit_inode(name, parent->dentry, LOOKUP_PARENT); + } else { + putname(name); + name = ERR_PTR(retval); } restore_nameidata(saved_nd); - return retval; + return name; } /* does lookup, returns the object with parent locked */ struct dentry *kern_path_locked(const char *name, struct path *path) { - struct filename *filename = getname_kernel(name); + struct filename *filename; + struct dentry *d; struct qstr last; int type; - struct dentry *d; - int err; + filename = filename_parentat(AT_FDCWD, getname_kernel(name), 0, path, + &last, &type); if (IS_ERR(filename)) return ERR_CAST(filename); - - err = filename_parentat(AT_FDCWD, filename, 0, path, &last, &type); - if (err) { - d = ERR_PTR(err); - goto out; - } - if (type != LAST_NORM) { + if (unlikely(type != LAST_NORM)) { path_put(path); - d = ERR_PTR(-EINVAL); - goto out; + putname(filename); + return ERR_PTR(-EINVAL); } mutex_lock_nested(&path->dentry->d_inode->i_mutex, I_MUTEX_PARENT); d = __lookup_hash(&last, path->dentry, 0); @@ -2216,7 +2217,6 @@ struct dentry *kern_path_locked(const char *name, struct path *path) mutex_unlock(&path->dentry->d_inode->i_mutex); path_put(path); } -out: putname(filename); return d; } @@ -2325,21 +2325,9 @@ user_path_parent(int dfd, const char __user *path, int *type, unsigned int flags) { - struct filename *s = getname(path); - int error; - /* only LOOKUP_REVAL is allowed in extra flags */ - flags &= LOOKUP_REVAL; - - if (IS_ERR(s)) - return s; - - error = filename_parentat(dfd, s, flags, parent, last, type); - if (error) { - putname(s); - s = ERR_PTR(error); - } - return s; + return filename_parentat(dfd, getname(path), flags & LOOKUP_REVAL, + parent, last, type); } /** @@ -3403,25 +3391,21 @@ static struct dentry *filename_create(int dfd, struct filename *name, int error; bool is_dir = (lookup_flags & LOOKUP_DIRECTORY); - if (IS_ERR(name)) - return ERR_CAST(name); /* * Note that only LOOKUP_REVAL and LOOKUP_DIRECTORY matter here. Any * other flags passed in are ignored! */ lookup_flags &= LOOKUP_REVAL; - error = filename_parentat(dfd, name, lookup_flags, path, &last, &type); - if (error) { - putname(name); - return ERR_PTR(error); - } + name = filename_parentat(dfd, name, lookup_flags, path, &last, &type); + if (IS_ERR(name)) + return ERR_CAST(name); /* * Yucky last component or no last component at all? * (foo/., foo/.., /////) */ - if (type != LAST_NORM) + if (unlikely(type != LAST_NORM)) goto out; /* don't fail immediately if it's r/o, at least try to report other errors */ -- 2.20.1