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-rw-r--r--fs/sysv/namei.c278
1 files changed, 278 insertions, 0 deletions
diff --git a/fs/sysv/namei.c b/fs/sysv/namei.c
new file mode 100644
index 000000000..b2e6abc06
--- /dev/null
+++ b/fs/sysv/namei.c
@@ -0,0 +1,278 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/sysv/namei.c
+ *
+ * minix/namei.c
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ *
+ * coh/namei.c
+ * Copyright (C) 1993 Pascal Haible, Bruno Haible
+ *
+ * sysv/namei.c
+ * Copyright (C) 1993 Bruno Haible
+ * Copyright (C) 1997, 1998 Krzysztof G. Baranowski
+ */
+
+#include <linux/pagemap.h>
+#include "sysv.h"
+
+static int add_nondir(struct dentry *dentry, struct inode *inode)
+{
+ int err = sysv_add_link(dentry, inode);
+ if (!err) {
+ d_instantiate(dentry, inode);
+ return 0;
+ }
+ inode_dec_link_count(inode);
+ iput(inode);
+ return err;
+}
+
+static struct dentry *sysv_lookup(struct inode * dir, struct dentry * dentry, unsigned int flags)
+{
+ struct inode * inode = NULL;
+ ino_t ino;
+
+ if (dentry->d_name.len > SYSV_NAMELEN)
+ return ERR_PTR(-ENAMETOOLONG);
+ ino = sysv_inode_by_name(dentry);
+ if (ino)
+ inode = sysv_iget(dir->i_sb, ino);
+ return d_splice_alias(inode, dentry);
+}
+
+static int sysv_mknod(struct user_namespace *mnt_userns, struct inode *dir,
+ struct dentry *dentry, umode_t mode, dev_t rdev)
+{
+ struct inode * inode;
+ int err;
+
+ if (!old_valid_dev(rdev))
+ return -EINVAL;
+
+ inode = sysv_new_inode(dir, mode);
+ err = PTR_ERR(inode);
+
+ if (!IS_ERR(inode)) {
+ sysv_set_inode(inode, rdev);
+ mark_inode_dirty(inode);
+ err = add_nondir(dentry, inode);
+ }
+ return err;
+}
+
+static int sysv_create(struct user_namespace *mnt_userns, struct inode *dir,
+ struct dentry *dentry, umode_t mode, bool excl)
+{
+ return sysv_mknod(&init_user_ns, dir, dentry, mode, 0);
+}
+
+static int sysv_symlink(struct user_namespace *mnt_userns, struct inode *dir,
+ struct dentry *dentry, const char *symname)
+{
+ int err = -ENAMETOOLONG;
+ int l = strlen(symname)+1;
+ struct inode * inode;
+
+ if (l > dir->i_sb->s_blocksize)
+ goto out;
+
+ inode = sysv_new_inode(dir, S_IFLNK|0777);
+ err = PTR_ERR(inode);
+ if (IS_ERR(inode))
+ goto out;
+
+ sysv_set_inode(inode, 0);
+ err = page_symlink(inode, symname, l);
+ if (err)
+ goto out_fail;
+
+ mark_inode_dirty(inode);
+ err = add_nondir(dentry, inode);
+out:
+ return err;
+
+out_fail:
+ inode_dec_link_count(inode);
+ iput(inode);
+ goto out;
+}
+
+static int sysv_link(struct dentry * old_dentry, struct inode * dir,
+ struct dentry * dentry)
+{
+ struct inode *inode = d_inode(old_dentry);
+
+ inode->i_ctime = current_time(inode);
+ inode_inc_link_count(inode);
+ ihold(inode);
+
+ return add_nondir(dentry, inode);
+}
+
+static int sysv_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+ struct dentry *dentry, umode_t mode)
+{
+ struct inode * inode;
+ int err;
+
+ inode_inc_link_count(dir);
+
+ inode = sysv_new_inode(dir, S_IFDIR|mode);
+ err = PTR_ERR(inode);
+ if (IS_ERR(inode))
+ goto out_dir;
+
+ sysv_set_inode(inode, 0);
+
+ inode_inc_link_count(inode);
+
+ err = sysv_make_empty(inode, dir);
+ if (err)
+ goto out_fail;
+
+ err = sysv_add_link(dentry, inode);
+ if (err)
+ goto out_fail;
+
+ d_instantiate(dentry, inode);
+out:
+ return err;
+
+out_fail:
+ inode_dec_link_count(inode);
+ inode_dec_link_count(inode);
+ iput(inode);
+out_dir:
+ inode_dec_link_count(dir);
+ goto out;
+}
+
+static int sysv_unlink(struct inode * dir, struct dentry * dentry)
+{
+ struct inode * inode = d_inode(dentry);
+ struct page * page;
+ struct sysv_dir_entry * de;
+ int err = -ENOENT;
+
+ de = sysv_find_entry(dentry, &page);
+ if (!de)
+ goto out;
+
+ err = sysv_delete_entry (de, page);
+ if (err)
+ goto out;
+
+ inode->i_ctime = dir->i_ctime;
+ inode_dec_link_count(inode);
+out:
+ return err;
+}
+
+static int sysv_rmdir(struct inode * dir, struct dentry * dentry)
+{
+ struct inode *inode = d_inode(dentry);
+ int err = -ENOTEMPTY;
+
+ if (sysv_empty_dir(inode)) {
+ err = sysv_unlink(dir, dentry);
+ if (!err) {
+ inode->i_size = 0;
+ inode_dec_link_count(inode);
+ inode_dec_link_count(dir);
+ }
+ }
+ return err;
+}
+
+/*
+ * Anybody can rename anything with this: the permission checks are left to the
+ * higher-level routines.
+ */
+static int sysv_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
+ struct dentry *old_dentry, struct inode *new_dir,
+ struct dentry *new_dentry, unsigned int flags)
+{
+ struct inode * old_inode = d_inode(old_dentry);
+ struct inode * new_inode = d_inode(new_dentry);
+ struct page * dir_page = NULL;
+ struct sysv_dir_entry * dir_de = NULL;
+ struct page * old_page;
+ struct sysv_dir_entry * old_de;
+ int err = -ENOENT;
+
+ if (flags & ~RENAME_NOREPLACE)
+ return -EINVAL;
+
+ old_de = sysv_find_entry(old_dentry, &old_page);
+ if (!old_de)
+ goto out;
+
+ if (S_ISDIR(old_inode->i_mode)) {
+ err = -EIO;
+ dir_de = sysv_dotdot(old_inode, &dir_page);
+ if (!dir_de)
+ goto out_old;
+ }
+
+ if (new_inode) {
+ struct page * new_page;
+ struct sysv_dir_entry * new_de;
+
+ err = -ENOTEMPTY;
+ if (dir_de && !sysv_empty_dir(new_inode))
+ goto out_dir;
+
+ err = -ENOENT;
+ new_de = sysv_find_entry(new_dentry, &new_page);
+ if (!new_de)
+ goto out_dir;
+ sysv_set_link(new_de, new_page, old_inode);
+ new_inode->i_ctime = current_time(new_inode);
+ if (dir_de)
+ drop_nlink(new_inode);
+ inode_dec_link_count(new_inode);
+ } else {
+ err = sysv_add_link(new_dentry, old_inode);
+ if (err)
+ goto out_dir;
+ if (dir_de)
+ inode_inc_link_count(new_dir);
+ }
+
+ sysv_delete_entry(old_de, old_page);
+ mark_inode_dirty(old_inode);
+
+ if (dir_de) {
+ sysv_set_link(dir_de, dir_page, new_dir);
+ inode_dec_link_count(old_dir);
+ }
+ return 0;
+
+out_dir:
+ if (dir_de) {
+ kunmap(dir_page);
+ put_page(dir_page);
+ }
+out_old:
+ kunmap(old_page);
+ put_page(old_page);
+out:
+ return err;
+}
+
+/*
+ * directories can handle most operations...
+ */
+const struct inode_operations sysv_dir_inode_operations = {
+ .create = sysv_create,
+ .lookup = sysv_lookup,
+ .link = sysv_link,
+ .unlink = sysv_unlink,
+ .symlink = sysv_symlink,
+ .mkdir = sysv_mkdir,
+ .rmdir = sysv_rmdir,
+ .mknod = sysv_mknod,
+ .rename = sysv_rename,
+ .getattr = sysv_getattr,
+};