open-style analog of vfs_path_lookup()
new function: file_open_root(dentry, mnt, name, flags) opens the file
vfs_path_lookup would arrive to.
Note that name can be empty; in that case the usual requirement that
dentry should be a directory is lifted.
open-coded equivalents switched to it, may_open() got down exactly
one caller and became static.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/namei.c b/fs/namei.c
index 8ee7785..abc8d2d 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1487,11 +1487,13 @@
nd->depth = 0;
if (flags & LOOKUP_ROOT) {
struct inode *inode = nd->root.dentry->d_inode;
- if (!inode->i_op->lookup)
- return -ENOTDIR;
- retval = inode_permission(inode, MAY_EXEC);
- if (retval)
- return retval;
+ if (*name) {
+ if (!inode->i_op->lookup)
+ return -ENOTDIR;
+ retval = inode_permission(inode, MAY_EXEC);
+ if (retval)
+ return retval;
+ }
nd->path = nd->root;
nd->inode = inode;
if (flags & LOOKUP_RCU) {
@@ -1937,7 +1939,7 @@
return error;
}
-int may_open(struct path *path, int acc_mode, int flag)
+static int may_open(struct path *path, int acc_mode, int flag)
{
struct dentry *dentry = path->dentry;
struct inode *inode = dentry->d_inode;
@@ -2250,11 +2252,10 @@
}
static struct file *path_openat(int dfd, const char *pathname,
- const struct open_flags *op, int flags)
+ struct nameidata *nd, const struct open_flags *op, int flags)
{
struct file *base = NULL;
struct file *filp;
- struct nameidata nd;
struct path path;
int count = 0;
int error;
@@ -2264,27 +2265,27 @@
return ERR_PTR(-ENFILE);
filp->f_flags = op->open_flag;
- nd.intent.open.file = filp;
- nd.intent.open.flags = open_to_namei_flags(op->open_flag);
- nd.intent.open.create_mode = op->mode;
+ nd->intent.open.file = filp;
+ nd->intent.open.flags = open_to_namei_flags(op->open_flag);
+ nd->intent.open.create_mode = op->mode;
- error = path_init(dfd, pathname, flags | LOOKUP_PARENT, &nd, &base);
+ error = path_init(dfd, pathname, flags | LOOKUP_PARENT, nd, &base);
if (unlikely(error))
goto out_filp;
current->total_link_count = 0;
- error = link_path_walk(pathname, &nd);
+ error = link_path_walk(pathname, nd);
if (unlikely(error))
goto out_filp;
- filp = do_last(&nd, &path, op, pathname);
+ filp = do_last(nd, &path, op, pathname);
while (unlikely(!filp)) { /* trailing symlink */
struct path link = path;
struct inode *linki = link.dentry->d_inode;
void *cookie;
- if (!(nd.flags & LOOKUP_FOLLOW) || count++ == 32) {
- path_put_conditional(&path, &nd);
- path_put(&nd.path);
+ if (!(nd->flags & LOOKUP_FOLLOW) || count++ == 32) {
+ path_put_conditional(&path, nd);
+ path_put(&nd->path);
filp = ERR_PTR(-ELOOP);
break;
}
@@ -2299,23 +2300,23 @@
* have to putname() it when we are done. Procfs-like symlinks
* just set LAST_BIND.
*/
- nd.flags |= LOOKUP_PARENT;
- nd.flags &= ~(LOOKUP_OPEN|LOOKUP_CREATE|LOOKUP_EXCL);
- error = __do_follow_link(&link, &nd, &cookie);
+ nd->flags |= LOOKUP_PARENT;
+ nd->flags &= ~(LOOKUP_OPEN|LOOKUP_CREATE|LOOKUP_EXCL);
+ error = __do_follow_link(&link, nd, &cookie);
if (unlikely(error))
filp = ERR_PTR(error);
else
- filp = do_last(&nd, &path, op, pathname);
+ filp = do_last(nd, &path, op, pathname);
if (!IS_ERR(cookie) && linki->i_op->put_link)
- linki->i_op->put_link(link.dentry, &nd, cookie);
+ linki->i_op->put_link(link.dentry, nd, cookie);
path_put(&link);
}
out:
- if (nd.root.mnt && !(nd.flags & LOOKUP_ROOT))
- path_put(&nd.root);
+ if (nd->root.mnt && !(nd->flags & LOOKUP_ROOT))
+ path_put(&nd->root);
if (base)
fput(base);
- release_open_intent(&nd);
+ release_open_intent(nd);
return filp;
out_filp:
@@ -2326,16 +2327,39 @@
struct file *do_filp_open(int dfd, const char *pathname,
const struct open_flags *op, int flags)
{
+ struct nameidata nd;
struct file *filp;
- filp = path_openat(dfd, pathname, op, flags | LOOKUP_RCU);
+ filp = path_openat(dfd, pathname, &nd, op, flags | LOOKUP_RCU);
if (unlikely(filp == ERR_PTR(-ECHILD)))
- filp = path_openat(dfd, pathname, op, flags);
+ filp = path_openat(dfd, pathname, &nd, op, flags);
if (unlikely(filp == ERR_PTR(-ESTALE)))
- filp = path_openat(dfd, pathname, op, flags | LOOKUP_REVAL);
+ filp = path_openat(dfd, pathname, &nd, op, flags | LOOKUP_REVAL);
return filp;
}
+struct file *do_file_open_root(struct dentry *dentry, struct vfsmount *mnt,
+ const char *name, const struct open_flags *op, int flags)
+{
+ struct nameidata nd;
+ struct file *file;
+
+ nd.root.mnt = mnt;
+ nd.root.dentry = dentry;
+
+ flags |= LOOKUP_ROOT;
+
+ if (dentry->d_inode->i_op->follow_link)
+ return ERR_PTR(-ELOOP);
+
+ file = path_openat(-1, name, &nd, op, flags | LOOKUP_RCU);
+ if (unlikely(file == ERR_PTR(-ECHILD)))
+ file = path_openat(-1, name, &nd, op, flags);
+ if (unlikely(file == ERR_PTR(-ESTALE)))
+ file = path_openat(-1, name, &nd, op, flags | LOOKUP_REVAL);
+ return file;
+}
+
/**
* lookup_create - lookup a dentry, creating it if it doesn't exist
* @nd: nameidata info