1 files changed, 188 insertions, 247 deletions

diff --git a/fs/ksmbd/vfs.c b/fs/ksmbd/vfs.c
index cef07d7fb7dc..778c152708e4 100644
--- a/fs/ksmbd/vfs.c
+++ b/fs/ksmbd/vfs.c
@@ -18,6 +18,7 @@
 #include <linux/vmalloc.h>
 #include <linux/sched/xacct.h>
 #include <linux/crc32c.h>
+#include <linux/namei.h>
 
 #include "glob.h"
 #include "oplock.h"
@@ -35,19 +36,6 @@
 #include "mgmt/user_session.h"
 #include "mgmt/user_config.h"
 
-static char *extract_last_component(char *path)
-{
-	char *p = strrchr(path, '/');
-
-	if (p && p[1] != '\0') {
-		*p = '\0';
-		p++;
-	} else {
-		p = NULL;
-	}
-	return p;
-}
-
 static void ksmbd_vfs_inherit_owner(struct ksmbd_work *work,
 				    struct inode *parent_inode,
 				    struct inode *inode)
@@ -61,65 +49,77 @@ static void ksmbd_vfs_inherit_owner(struct ksmbd_work *work,
 
 /**
  * ksmbd_vfs_lock_parent() - lock parent dentry if it is stable
- *
- * the parent dentry got by dget_parent or @parent could be
- * unstable, we try to lock a parent inode and lookup the
- * child dentry again.
- *
- * the reference count of @parent isn't incremented.
  */
-int ksmbd_vfs_lock_parent(struct mnt_idmap *idmap, struct dentry *parent,
-			  struct dentry *child)
+int ksmbd_vfs_lock_parent(struct dentry *parent, struct dentry *child)
 {
-	struct dentry *dentry;
-	int ret = 0;
-
 	inode_lock_nested(d_inode(parent), I_MUTEX_PARENT);
-	dentry = lookup_one(idmap, child->d_name.name, parent,
-			    child->d_name.len);
-	if (IS_ERR(dentry)) {
-		ret = PTR_ERR(dentry);
-		goto out_err;
-	}
-
-	if (dentry != child) {
-		ret = -ESTALE;
-		dput(dentry);
-		goto out_err;
+	if (child->d_parent != parent) {
+		inode_unlock(d_inode(parent));
+		return -ENOENT;
 	}
 
-	dput(dentry);
 	return 0;
-out_err:
-	inode_unlock(d_inode(parent));
-	return ret;
 }
 
-int ksmbd_vfs_may_delete(struct mnt_idmap *idmap,
-			 struct dentry *dentry)
+static int ksmbd_vfs_path_lookup_locked(struct ksmbd_share_config *share_conf,
+					char *pathname, unsigned int flags,
+					struct path *path)
 {
-	struct dentry *parent;
-	int ret;
+	struct qstr last;
+	struct filename *filename;
+	struct path *root_share_path = &share_conf->vfs_path;
+	int err, type;
+	struct path parent_path;
+	struct dentry *d;
+
+	if (pathname[0] == '\0') {
+		pathname = share_conf->path;
+		root_share_path = NULL;
+	} else {
+		flags |= LOOKUP_BENEATH;
+	}
 
-	parent = dget_parent(dentry);
-	ret = ksmbd_vfs_lock_parent(idmap, parent, dentry);
-	if (ret) {
-		dput(parent);
-		return ret;
+	filename = getname_kernel(pathname);
+	if (IS_ERR(filename))
+		return PTR_ERR(filename);
+
+	err = vfs_path_parent_lookup(filename, flags,
+				     &parent_path, &last, &type,
+				     root_share_path);
+	putname(filename);
+	if (err)
+		return err;
+
+	if (unlikely(type != LAST_NORM)) {
+		path_put(&parent_path);
+		return -ENOENT;
 	}
 
-	ret = inode_permission(idmap, d_inode(parent),
-			       MAY_EXEC | MAY_WRITE);
+	inode_lock_nested(parent_path.dentry->d_inode, I_MUTEX_PARENT);
+	d = lookup_one_qstr_excl(&last, parent_path.dentry, 0);
+	if (IS_ERR(d))
+		goto err_out;
 
-	inode_unlock(d_inode(parent));
-	dput(parent);
-	return ret;
+	if (d_is_negative(d)) {
+		dput(d);
+		goto err_out;
+	}
+
+	path->dentry = d;
+	path->mnt = share_conf->vfs_path.mnt;
+	path_put(&parent_path);
+
+	return 0;
+
+err_out:
+	inode_unlock(parent_path.dentry->d_inode);
+	path_put(&parent_path);
+	return -ENOENT;
 }
 
 int ksmbd_vfs_query_maximal_access(struct mnt_idmap *idmap,
 				   struct dentry *dentry, __le32 *daccess)
 {
-	struct dentry *parent;
 	int ret = 0;
 
 	*daccess = cpu_to_le32(FILE_READ_ATTRIBUTES | READ_CONTROL);
@@ -136,18 +136,9 @@ int ksmbd_vfs_query_maximal_access(struct mnt_idmap *idmap,
 	if (!inode_permission(idmap, d_inode(dentry), MAY_OPEN | MAY_EXEC))
 		*daccess |= FILE_EXECUTE_LE;
 
-	parent = dget_parent(dentry);
-	ret = ksmbd_vfs_lock_parent(idmap, parent, dentry);
-	if (ret) {
-		dput(parent);
-		return ret;
-	}
-
-	if (!inode_permission(idmap, d_inode(parent), MAY_EXEC | MAY_WRITE))
+	if (!inode_permission(idmap, d_inode(dentry->d_parent), MAY_EXEC | MAY_WRITE))
 		*daccess |= FILE_DELETE_LE;
 
-	inode_unlock(d_inode(parent));
-	dput(parent);
 	return ret;
 }
 
@@ -580,54 +571,32 @@ int ksmbd_vfs_fsync(struct ksmbd_work *work, u64 fid, u64 p_id)
  *
  * Return:	0 on success, otherwise error
  */
-int ksmbd_vfs_remove_file(struct ksmbd_work *work, char *name)
+int ksmbd_vfs_remove_file(struct ksmbd_work *work, const struct path *path)
 {
 	struct mnt_idmap *idmap;
-	struct path path;
-	struct dentry *parent;
+	struct dentry *parent = path->dentry->d_parent;
 	int err;
 
 	if (ksmbd_override_fsids(work))
 		return -ENOMEM;
 
-	err = ksmbd_vfs_kern_path(work, name, LOOKUP_NO_SYMLINKS, &path, false);
-	if (err) {
-		ksmbd_debug(VFS, "can't get %s, err %d\n", name, err);
-		ksmbd_revert_fsids(work);
-		return err;
-	}
-
-	idmap = mnt_idmap(path.mnt);
-	parent = dget_parent(path.dentry);
-	err = ksmbd_vfs_lock_parent(idmap, parent, path.dentry);
-	if (err) {
-		dput(parent);
-		path_put(&path);
-		ksmbd_revert_fsids(work);
-		return err;
-	}
-
-	if (!d_inode(path.dentry)->i_nlink) {
+	if (!d_inode(path->dentry)->i_nlink) {
 		err = -ENOENT;
 		goto out_err;
 	}
 
-	if (S_ISDIR(d_inode(path.dentry)->i_mode)) {
-		err = vfs_rmdir(idmap, d_inode(parent), path.dentry);
+	idmap = mnt_idmap(path->mnt);
+	if (S_ISDIR(d_inode(path->dentry)->i_mode)) {
+		err = vfs_rmdir(idmap, d_inode(parent), path->dentry);
 		if (err && err != -ENOTEMPTY)
-			ksmbd_debug(VFS, "%s: rmdir failed, err %d\n", name,
-				    err);
+			ksmbd_debug(VFS, "rmdir failed, err %d\n", err);
 	} else {
-		err = vfs_unlink(idmap, d_inode(parent), path.dentry, NULL);
+		err = vfs_unlink(idmap, d_inode(parent), path->dentry, NULL);
 		if (err)
-			ksmbd_debug(VFS, "%s: unlink failed, err %d\n", name,
-				    err);
+			ksmbd_debug(VFS, "unlink failed, err %d\n", err);
 	}
 
 out_err:
-	inode_unlock(d_inode(parent));
-	dput(parent);
-	path_put(&path);
 	ksmbd_revert_fsids(work);
 	return err;
 }
@@ -686,149 +655,114 @@ out1:
 	return err;
 }
 
-static int ksmbd_validate_entry_in_use(struct dentry *src_dent)
+int ksmbd_vfs_rename(struct ksmbd_work *work, const struct path *old_path,
+		     char *newname, int flags)
 {
-	struct dentry *dst_dent;
-
-	spin_lock(&src_dent->d_lock);
-	list_for_each_entry(dst_dent, &src_dent->d_subdirs, d_child) {
-		struct ksmbd_file *child_fp;
+	struct dentry *old_parent, *new_dentry, *trap;
+	struct dentry *old_child = old_path->dentry;
+	struct path new_path;
+	struct qstr new_last;
+	struct renamedata rd;
+	struct filename *to;
+	struct ksmbd_share_config *share_conf = work->tcon->share_conf;
+	struct ksmbd_file *parent_fp;
+	int new_type;
+	int err, lookup_flags = LOOKUP_NO_SYMLINKS;
 
-		if (d_really_is_negative(dst_dent))
-			continue;
+	if (ksmbd_override_fsids(work))
+		return -ENOMEM;
 
-		child_fp = ksmbd_lookup_fd_inode(d_inode(dst_dent));
-		if (child_fp) {
-			spin_unlock(&src_dent->d_lock);
-			ksmbd_debug(VFS, "Forbid rename, sub file/dir is in use\n");
-			return -EACCES;
-		}
+	to = getname_kernel(newname);
+	if (IS_ERR(to)) {
+		err = PTR_ERR(to);
+		goto revert_fsids;
 	}
-	spin_unlock(&src_dent->d_lock);
 
-	return 0;
-}
+retry:
+	err = vfs_path_parent_lookup(to, lookup_flags | LOOKUP_BENEATH,
+				     &new_path, &new_last, &new_type,
+				     &share_conf->vfs_path);
+	if (err)
+		goto out1;
 
-static int __ksmbd_vfs_rename(struct ksmbd_work *work,
-			      struct mnt_idmap *src_idmap,
-			      struct dentry *src_dent_parent,
-			      struct dentry *src_dent,
-			      struct mnt_idmap *dst_idmap,
-			      struct dentry *dst_dent_parent,
-			      struct dentry *trap_dent,
-			      char *dst_name)
-{
-	struct dentry *dst_dent;
-	int err;
+	if (old_path->mnt != new_path.mnt) {
+		err = -EXDEV;
+		goto out2;
+	}
 
-	if (!work->tcon->posix_extensions) {
-		err = ksmbd_validate_entry_in_use(src_dent);
-		if (err)
-			return err;
+	trap = lock_rename_child(old_child, new_path.dentry);
+
+	old_parent = dget(old_child->d_parent);
+	if (d_unhashed(old_child)) {
+		err = -EINVAL;
+		goto out3;
 	}
 
-	if (d_really_is_negative(src_dent_parent))
-		return -ENOENT;
-	if (d_really_is_negative(dst_dent_parent))
-		return -ENOENT;
-	if (d_really_is_negative(src_dent))
-		return -ENOENT;
-	if (src_dent == trap_dent)
-		return -EINVAL;
+	parent_fp = ksmbd_lookup_fd_inode(d_inode(old_child->d_parent));
+	if (parent_fp) {
+		if (parent_fp->daccess & FILE_DELETE_LE) {
+			pr_err("parent dir is opened with delete access\n");
+			err = -ESHARE;
+			ksmbd_fd_put(work, parent_fp);
+			goto out3;
+		}
+		ksmbd_fd_put(work, parent_fp);
+	}
 
-	if (ksmbd_override_fsids(work))
-		return -ENOMEM;
+	new_dentry = lookup_one_qstr_excl(&new_last, new_path.dentry,
+					  lookup_flags | LOOKUP_RENAME_TARGET);
+	if (IS_ERR(new_dentry)) {
+		err = PTR_ERR(new_dentry);
+		goto out3;
+	}
 
-	dst_dent = lookup_one(dst_idmap, dst_name,
-			      dst_dent_parent, strlen(dst_name));
-	err = PTR_ERR(dst_dent);
-	if (IS_ERR(dst_dent)) {
-		pr_err("lookup failed %s [%d]\n", dst_name, err);
-		goto out;
+	if (d_is_symlink(new_dentry)) {
+		err = -EACCES;
+		goto out4;
 	}
 
-	err = -ENOTEMPTY;
-	if (dst_dent != trap_dent && !d_really_is_positive(dst_dent)) {
-		struct renamedata rd = {
-			.old_mnt_idmap	= src_idmap,
-			.old_dir	= d_inode(src_dent_parent),
-			.old_dentry	= src_dent,
-			.new_mnt_idmap	= dst_idmap,
-			.new_dir	= d_inode(dst_dent_parent),
-			.new_dentry	= dst_dent,
-		};
-		err = vfs_rename(&rd);
+	if ((flags & RENAME_NOREPLACE) && d_is_positive(new_dentry)) {
+		err = -EEXIST;
+		goto out4;
 	}
-	if (err)
-		pr_err("vfs_rename failed err %d\n", err);
-	if (dst_dent)
-		dput(dst_dent);
-out:
-	ksmbd_revert_fsids(work);
-	return err;
-}
 
-int ksmbd_vfs_fp_rename(struct ksmbd_work *work, struct ksmbd_file *fp,
-			char *newname)
-{
-	struct mnt_idmap *idmap;
-	struct path dst_path;
-	struct dentry *src_dent_parent, *dst_dent_parent;
-	struct dentry *src_dent, *trap_dent, *src_child;
-	char *dst_name;
-	int err;
+	if (old_child == trap) {
+		err = -EINVAL;
+		goto out4;
+	}
 
-	dst_name = extract_last_component(newname);
-	if (!dst_name) {
-		dst_name = newname;
-		newname = "";
+	if (new_dentry == trap) {
+		err = -ENOTEMPTY;
+		goto out4;
 	}
 
-	src_dent_parent = dget_parent(fp->filp->f_path.dentry);
-	src_dent = fp->filp->f_path.dentry;
+	rd.old_mnt_idmap	= mnt_idmap(old_path->mnt),
+	rd.old_dir		= d_inode(old_parent),
+	rd.old_dentry		= old_child,
+	rd.new_mnt_idmap	= mnt_idmap(new_path.mnt),
+	rd.new_dir		= new_path.dentry->d_inode,
+	rd.new_dentry		= new_dentry,
+	rd.flags		= flags,
+	err = vfs_rename(&rd);
+	if (err)
+		ksmbd_debug(VFS, "vfs_rename failed err %d\n", err);
 
-	err = ksmbd_vfs_kern_path(work, newname,
-				  LOOKUP_NO_SYMLINKS | LOOKUP_DIRECTORY,
-				  &dst_path, false);
-	if (err) {
-		ksmbd_debug(VFS, "Cannot get path for %s [%d]\n", newname, err);
-		goto out;
+out4:
+	dput(new_dentry);
+out3:
+	dput(old_parent);
+	unlock_rename(old_parent, new_path.dentry);
+out2:
+	path_put(&new_path);
+
+	if (retry_estale(err, lookup_flags)) {
+		lookup_flags |= LOOKUP_REVAL;
+		goto retry;
 	}
-	dst_dent_parent = dst_path.dentry;
-
-	trap_dent = lock_rename(src_dent_parent, dst_dent_parent);
-	dget(src_dent);
-	dget(dst_dent_parent);
-	idmap = file_mnt_idmap(fp->filp);
-	src_child = lookup_one(idmap, src_dent->d_name.name, src_dent_parent,
-			       src_dent->d_name.len);
-	if (IS_ERR(src_child)) {
-		err = PTR_ERR(src_child);
-		goto out_lock;
-	}
-
-	if (src_child != src_dent) {
-		err = -ESTALE;
-		dput(src_child);
-		goto out_lock;
-	}
-	dput(src_child);
-
-	err = __ksmbd_vfs_rename(work,
-				 idmap,
-				 src_dent_parent,
-				 src_dent,
-				 mnt_idmap(dst_path.mnt),
-				 dst_dent_parent,
-				 trap_dent,
-				 dst_name);
-out_lock:
-	dput(src_dent);
-	dput(dst_dent_parent);
-	unlock_rename(src_dent_parent, dst_dent_parent);
-	path_put(&dst_path);
-out:
-	dput(src_dent_parent);
+out1:
+	putname(to);
+revert_fsids:
+	ksmbd_revert_fsids(work);
 	return err;
 }
 
@@ -1079,14 +1013,16 @@ int ksmbd_vfs_remove_xattr(struct mnt_idmap *idmap,
 	return vfs_removexattr(idmap, dentry, attr_name);
 }
 
-int ksmbd_vfs_unlink(struct mnt_idmap *idmap,
-		     struct dentry *dir, struct dentry *dentry)
+int ksmbd_vfs_unlink(struct file *filp)
 {
 	int err = 0;
+	struct dentry *dir, *dentry = filp->f_path.dentry;
+	struct mnt_idmap *idmap = file_mnt_idmap(filp);
 
-	err = ksmbd_vfs_lock_parent(idmap, dir, dentry);
+	dir = dget_parent(dentry);
+	err = ksmbd_vfs_lock_parent(dir, dentry);
 	if (err)
-		return err;
+		goto out;
 	dget(dentry);
 
 	if (S_ISDIR(d_inode(dentry)->i_mode))
@@ -1098,6 +1034,8 @@ int ksmbd_vfs_unlink(struct mnt_idmap *idmap,
 	inode_unlock(d_inode(dir));
 	if (err)
 		ksmbd_debug(VFS, "failed to delete, err %d\n", err);
+out:
+	dput(dir);
 
 	return err;
 }
@@ -1200,7 +1138,7 @@ static int ksmbd_vfs_lookup_in_dir(const struct path *dir, char *name,
 }
 
 /**
- * ksmbd_vfs_kern_path() - lookup a file and get path info
+ * ksmbd_vfs_kern_path_locked() - lookup a file and get path info
  * @name:	file path that is relative to share
  * @flags:	lookup flags
  * @path:	if lookup succeed, return path info
@@ -1208,24 +1146,20 @@ static int ksmbd_vfs_lookup_in_dir(const struct path *dir, char *name,
  *
  * Return:	0 on success, otherwise error
  */
-int ksmbd_vfs_kern_path(struct ksmbd_work *work, char *name,
-			unsigned int flags, struct path *path, bool caseless)
+int ksmbd_vfs_kern_path_locked(struct ksmbd_work *work, char *name,
+			       unsigned int flags, struct path *path,
+			       bool caseless)
 {
 	struct ksmbd_share_config *share_conf = work->tcon->share_conf;
 	int err;
+	struct path parent_path;
 
-	flags |= LOOKUP_BENEATH;
-	err = vfs_path_lookup(share_conf->vfs_path.dentry,
-			      share_conf->vfs_path.mnt,
-			      name,
-			      flags,
-			      path);
+	err = ksmbd_vfs_path_lookup_locked(share_conf, name, flags, path);
 	if (!err)
-		return 0;
+		return err;
 
 	if (caseless) {
 		char *filepath;
-		struct path parent;
 		size_t path_len, remain_len;
 
 		filepath = kstrdup(name, GFP_KERNEL);
@@ -1235,10 +1169,10 @@ int ksmbd_vfs_kern_path(struct ksmbd_work *work, char *name,
 		path_len = strlen(filepath);
 		remain_len = path_len;
 
-		parent = share_conf->vfs_path;
-		path_get(&parent);
+		parent_path = share_conf->vfs_path;
+		path_get(&parent_path);
 
-		while (d_can_lookup(parent.dentry)) {
+		while (d_can_lookup(parent_path.dentry)) {
 			char *filename = filepath + path_len - remain_len;
 			char *next = strchrnul(filename, '/');
 			size_t filename_len = next - filename;
@@ -1247,12 +1181,11 @@ int ksmbd_vfs_kern_path(struct ksmbd_work *work, char *name,
 			if (filename_len == 0)
 				break;
 
-			err = ksmbd_vfs_lookup_in_dir(&parent, filename,
+			err = ksmbd_vfs_lookup_in_dir(&parent_path, filename,
 						      filename_len,
 						      work->conn->um);
-			path_put(&parent);
 			if (err)
-				goto out;
+				goto out2;
 
 			next[0] = '\0';
 
@@ -1260,23 +1193,31 @@ int ksmbd_vfs_kern_path(struct ksmbd_work *work, char *name,
 					      share_conf->vfs_path.mnt,
 					      filepath,
 					      flags,
-					      &parent);
+					      path);
 			if (err)
-				goto out;
-			else if (is_last) {
-				*path = parent;
-				goto out;
-			}
+				goto out2;
+			else if (is_last)
+				goto out1;
+			path_put(&parent_path);
+			parent_path = *path;
 
 			next[0] = '/';
 			remain_len -= filename_len + 1;
 		}
 
-		path_put(&parent);
 		err = -EINVAL;
-out:
+out2:
+		path_put(&parent_path);
+out1:
 		kfree(filepath);
 	}
+
+	if (!err) {
+		err = ksmbd_vfs_lock_parent(parent_path.dentry, path->dentry);
+		if (err)
+			dput(path->dentry);
+		path_put(&parent_path);
+	}
 	return err;
 }