*
* Given a path increment the reference count to the dentry and the vfsmount.
*/
-void path_get(struct path *path)
+void path_get(const struct path *path)
{
mntget(path->mnt);
dget(path->dentry);
*
* Given a path decrement the reference count to the dentry and the vfsmount.
*/
-void path_put(struct path *path)
+void path_put(const struct path *path)
{
dput(path->dentry);
mntput(path->mnt);
if (likely(!(nd->flags & LOOKUP_JUMPED)))
return 0;
- if (likely(!(dentry->d_flags & DCACHE_OP_REVALIDATE)))
+ if (likely(!(dentry->d_flags & DCACHE_OP_WEAK_REVALIDATE)))
return 0;
- if (likely(!(dentry->d_sb->s_type->fs_flags & FS_REVAL_DOT)))
- return 0;
-
- /* Note: we do not d_invalidate() */
- status = d_revalidate(dentry, nd->flags);
+ status = dentry->d_op->d_weak_revalidate(dentry, nd->flags);
if (status > 0)
return 0;
*need_lookup = false;
dentry = d_lookup(dir, name);
if (dentry) {
- if (d_need_lookup(dentry)) {
- *need_lookup = true;
- } else if (dentry->d_flags & DCACHE_OP_REVALIDATE) {
+ if (dentry->d_flags & DCACHE_OP_REVALIDATE) {
error = d_revalidate(dentry, flags);
if (unlikely(error <= 0)) {
if (error < 0) {
* small and for now I'd prefer to have fast path as straight as possible.
* It _is_ time-critical.
*/
-static int lookup_fast(struct nameidata *nd, struct qstr *name,
+static int lookup_fast(struct nameidata *nd,
struct path *path, struct inode **inode)
{
struct vfsmount *mnt = nd->path.mnt;
*/
if (nd->flags & LOOKUP_RCU) {
unsigned seq;
- dentry = __d_lookup_rcu(parent, name, &seq, nd->inode);
+ dentry = __d_lookup_rcu(parent, &nd->last, &seq, nd->inode);
if (!dentry)
goto unlazy;
return -ECHILD;
nd->seq = seq;
- if (unlikely(d_need_lookup(dentry)))
- goto unlazy;
if (unlikely(dentry->d_flags & DCACHE_OP_REVALIDATE)) {
status = d_revalidate(dentry, nd->flags);
if (unlikely(status <= 0)) {
if (unlazy_walk(nd, dentry))
return -ECHILD;
} else {
- dentry = __d_lookup(parent, name);
+ dentry = __d_lookup(parent, &nd->last);
}
if (unlikely(!dentry))
goto need_lookup;
- if (unlikely(d_need_lookup(dentry))) {
- dput(dentry);
- goto need_lookup;
- }
-
if (unlikely(dentry->d_flags & DCACHE_OP_REVALIDATE) && need_reval)
status = d_revalidate(dentry, nd->flags);
if (unlikely(status <= 0)) {
}
/* Fast lookup failed, do it the slow way */
-static int lookup_slow(struct nameidata *nd, struct qstr *name,
- struct path *path)
+static int lookup_slow(struct nameidata *nd, struct path *path)
{
struct dentry *dentry, *parent;
int err;
BUG_ON(nd->inode != parent->d_inode);
mutex_lock(&parent->d_inode->i_mutex);
- dentry = __lookup_hash(name, parent, nd->flags);
+ dentry = __lookup_hash(&nd->last, parent, nd->flags);
mutex_unlock(&parent->d_inode->i_mutex);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
}
static inline int walk_component(struct nameidata *nd, struct path *path,
- struct qstr *name, int type, int follow)
+ int follow)
{
struct inode *inode;
int err;
* to be able to know about the current root directory and
* parent relationships.
*/
- if (unlikely(type != LAST_NORM))
- return handle_dots(nd, type);
- err = lookup_fast(nd, name, path, &inode);
+ if (unlikely(nd->last_type != LAST_NORM))
+ return handle_dots(nd, nd->last_type);
+ err = lookup_fast(nd, path, &inode);
if (unlikely(err)) {
if (err < 0)
goto out_err;
- err = lookup_slow(nd, name, path);
+ err = lookup_slow(nd, path);
if (err < 0)
goto out_err;
res = follow_link(&link, nd, &cookie);
if (res)
break;
- res = walk_component(nd, path, &nd->last,
- nd->last_type, LOOKUP_FOLLOW);
+ res = walk_component(nd, path, LOOKUP_FOLLOW);
put_link(nd, &link, cookie);
} while (res > 0);
}
}
+ nd->last = this;
+ nd->last_type = type;
+
if (!name[len])
- goto last_component;
+ return 0;
/*
* If it wasn't NUL, we know it was '/'. Skip that
* slash, and continue until no more slashes.
len++;
} while (unlikely(name[len] == '/'));
if (!name[len])
- goto last_component;
+ return 0;
+
name += len;
- err = walk_component(nd, &next, &this, type, LOOKUP_FOLLOW);
+ err = walk_component(nd, &next, LOOKUP_FOLLOW);
if (err < 0)
return err;
if (err)
return err;
}
- if (can_lookup(nd->inode))
- continue;
- err = -ENOTDIR;
- break;
- /* here ends the main loop */
-
-last_component:
- nd->last = this;
- nd->last_type = type;
- return 0;
+ if (!can_lookup(nd->inode)) {
+ err = -ENOTDIR;
+ break;
+ }
}
terminate_walk(nd);
return err;
if (flags & LOOKUP_ROOT) {
struct inode *inode = nd->root.dentry->d_inode;
if (*name) {
- if (!inode->i_op->lookup)
+ if (!can_lookup(inode))
return -ENOTDIR;
retval = inode_permission(inode, MAY_EXEC);
if (retval)
get_fs_pwd(current->fs, &nd->path);
}
} else {
+ /* Caller must check execute permissions on the starting path component */
struct fd f = fdget_raw(dfd);
struct dentry *dentry;
dentry = f.file->f_path.dentry;
if (*name) {
- if (!S_ISDIR(dentry->d_inode->i_mode)) {
+ if (!can_lookup(dentry->d_inode)) {
fdput(f);
return -ENOTDIR;
}
-
- retval = inode_permission(dentry->d_inode, MAY_EXEC);
- if (retval) {
- fdput(f);
- return retval;
- }
}
nd->path = f.file->f_path;
nd->flags |= LOOKUP_FOLLOW | LOOKUP_DIRECTORY;
nd->flags &= ~LOOKUP_PARENT;
- return walk_component(nd, path, &nd->last, nd->last_type,
- nd->flags & LOOKUP_FOLLOW);
+ return walk_component(nd, path, nd->flags & LOOKUP_FOLLOW);
}
/* Returns 0 and nd will be valid on success; Retuns error, otherwise. */
* path-walking is complete.
*/
static struct filename *
-user_path_parent(int dfd, const char __user *path, struct nameidata *nd)
+user_path_parent(int dfd, const char __user *path, struct nameidata *nd,
+ 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_lookup(dfd, s, LOOKUP_PARENT, nd);
+ error = filename_lookup(dfd, s, flags | LOOKUP_PARENT, nd);
if (error) {
putname(s);
return ERR_PTR(error);
if (open_flag & O_PATH && !(nd->flags & LOOKUP_FOLLOW))
symlink_ok = true;
/* we _can_ be in RCU mode here */
- error = lookup_fast(nd, &nd->last, path, &inode);
+ error = lookup_fast(nd, path, &inode);
if (likely(!error))
goto finish_lookup;
goto out;
if ((*opened & FILE_CREATED) ||
- !S_ISREG(file->f_path.dentry->d_inode->i_mode))
+ !S_ISREG(file_inode(file)->i_mode))
will_truncate = false;
audit_inode(name, file->f_path.dentry, 0);
int error;
file = get_empty_filp();
- if (!file)
- return ERR_PTR(-ENFILE);
+ if (IS_ERR(file))
+ return file;
file->f_flags = op->open_flag;
return file;
}
-struct dentry *kern_path_create(int dfd, const char *pathname, struct path *path, int is_dir)
+struct dentry *kern_path_create(int dfd, const char *pathname,
+ struct path *path, unsigned int lookup_flags)
{
struct dentry *dentry = ERR_PTR(-EEXIST);
struct nameidata nd;
int err2;
- int error = do_path_lookup(dfd, pathname, LOOKUP_PARENT, &nd);
+ int error;
+ bool is_dir = (lookup_flags & LOOKUP_DIRECTORY);
+
+ /*
+ * Note that only LOOKUP_REVAL and LOOKUP_DIRECTORY matter here. Any
+ * other flags passed in are ignored!
+ */
+ lookup_flags &= LOOKUP_REVAL;
+
+ error = do_path_lookup(dfd, pathname, LOOKUP_PARENT|lookup_flags, &nd);
if (error)
return ERR_PTR(error);
}
EXPORT_SYMBOL(done_path_create);
-struct dentry *user_path_create(int dfd, const char __user *pathname, struct path *path, int is_dir)
+struct dentry *user_path_create(int dfd, const char __user *pathname,
+ struct path *path, unsigned int lookup_flags)
{
struct filename *tmp = getname(pathname);
struct dentry *res;
if (IS_ERR(tmp))
return ERR_CAST(tmp);
- res = kern_path_create(dfd, tmp->name, path, is_dir);
+ res = kern_path_create(dfd, tmp->name, path, lookup_flags);
putname(tmp);
return res;
}
struct dentry *dentry;
struct path path;
int error;
+ unsigned int lookup_flags = 0;
error = may_mknod(mode);
if (error)
return error;
-
- dentry = user_path_create(dfd, filename, &path, 0);
+retry:
+ dentry = user_path_create(dfd, filename, &path, lookup_flags);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
}
out:
done_path_create(&path, dentry);
+ if (retry_estale(error, lookup_flags)) {
+ lookup_flags |= LOOKUP_REVAL;
+ goto retry;
+ }
return error;
}
struct dentry *dentry;
struct path path;
int error;
+ unsigned int lookup_flags = LOOKUP_DIRECTORY;
- dentry = user_path_create(dfd, pathname, &path, 1);
+retry:
+ dentry = user_path_create(dfd, pathname, &path, lookup_flags);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
if (!error)
error = vfs_mkdir(path.dentry->d_inode, dentry, mode);
done_path_create(&path, dentry);
+ if (retry_estale(error, lookup_flags)) {
+ lookup_flags |= LOOKUP_REVAL;
+ goto retry;
+ }
return error;
}
struct filename *name;
struct dentry *dentry;
struct nameidata nd;
-
- name = user_path_parent(dfd, pathname, &nd);
+ unsigned int lookup_flags = 0;
+retry:
+ name = user_path_parent(dfd, pathname, &nd, lookup_flags);
if (IS_ERR(name))
return PTR_ERR(name);
exit1:
path_put(&nd.path);
putname(name);
+ if (retry_estale(error, lookup_flags)) {
+ lookup_flags |= LOOKUP_REVAL;
+ goto retry;
+ }
return error;
}
struct dentry *dentry;
struct nameidata nd;
struct inode *inode = NULL;
-
- name = user_path_parent(dfd, pathname, &nd);
+ unsigned int lookup_flags = 0;
+retry:
+ name = user_path_parent(dfd, pathname, &nd, lookup_flags);
if (IS_ERR(name))
return PTR_ERR(name);
exit1:
path_put(&nd.path);
putname(name);
+ if (retry_estale(error, lookup_flags)) {
+ lookup_flags |= LOOKUP_REVAL;
+ inode = NULL;
+ goto retry;
+ }
return error;
slashes:
struct filename *from;
struct dentry *dentry;
struct path path;
+ unsigned int lookup_flags = 0;
from = getname(oldname);
if (IS_ERR(from))
return PTR_ERR(from);
-
- dentry = user_path_create(newdfd, newname, &path, 0);
+retry:
+ dentry = user_path_create(newdfd, newname, &path, lookup_flags);
error = PTR_ERR(dentry);
if (IS_ERR(dentry))
goto out_putname;
if (!error)
error = vfs_symlink(path.dentry->d_inode, dentry, from->name);
done_path_create(&path, dentry);
+ if (retry_estale(error, lookup_flags)) {
+ lookup_flags |= LOOKUP_REVAL;
+ goto retry;
+ }
out_putname:
putname(from);
return error;
if (flags & AT_SYMLINK_FOLLOW)
how |= LOOKUP_FOLLOW;
-
+retry:
error = user_path_at(olddfd, oldname, how, &old_path);
if (error)
return error;
- new_dentry = user_path_create(newdfd, newname, &new_path, 0);
+ new_dentry = user_path_create(newdfd, newname, &new_path,
+ (how & LOOKUP_REVAL));
error = PTR_ERR(new_dentry);
if (IS_ERR(new_dentry))
goto out;
error = vfs_link(old_path.dentry, new_path.dentry->d_inode, new_dentry);
out_dput:
done_path_create(&new_path, new_dentry);
+ if (retry_estale(error, how)) {
+ how |= LOOKUP_REVAL;
+ goto retry;
+ }
out:
path_put(&old_path);
struct nameidata oldnd, newnd;
struct filename *from;
struct filename *to;
+ unsigned int lookup_flags = 0;
+ bool should_retry = false;
int error;
-
- from = user_path_parent(olddfd, oldname, &oldnd);
+retry:
+ from = user_path_parent(olddfd, oldname, &oldnd, lookup_flags);
if (IS_ERR(from)) {
error = PTR_ERR(from);
goto exit;
}
- to = user_path_parent(newdfd, newname, &newnd);
+ to = user_path_parent(newdfd, newname, &newnd, lookup_flags);
if (IS_ERR(to)) {
error = PTR_ERR(to);
goto exit1;
unlock_rename(new_dir, old_dir);
mnt_drop_write(oldnd.path.mnt);
exit2:
+ if (retry_estale(error, lookup_flags))
+ should_retry = true;
path_put(&newnd.path);
putname(to);
exit1:
path_put(&oldnd.path);
putname(from);
+ if (should_retry) {
+ should_retry = false;
+ lookup_flags |= LOOKUP_REVAL;
+ goto retry;
+ }
exit:
return error;
}