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-rw-r--r--fs/ext2/namei.c443
1 files changed, 443 insertions, 0 deletions
diff --git a/fs/ext2/namei.c b/fs/ext2/namei.c
new file mode 100644
index 000000000..9125eab85
--- /dev/null
+++ b/fs/ext2/namei.c
@@ -0,0 +1,443 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/ext2/namei.c
+ *
+ * Rewrite to pagecache. Almost all code had been changed, so blame me
+ * if the things go wrong. Please, send bug reports to
+ * viro@parcelfarce.linux.theplanet.co.uk
+ *
+ * Stuff here is basically a glue between the VFS and generic UNIXish
+ * filesystem that keeps everything in pagecache. All knowledge of the
+ * directory layout is in fs/ext2/dir.c - it turned out to be easily separatable
+ * and it's easier to debug that way. In principle we might want to
+ * generalize that a bit and turn it into a library. Or not.
+ *
+ * The only non-static object here is ext2_dir_inode_operations.
+ *
+ * TODO: get rid of kmap() use, add readahead.
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ * from
+ *
+ * linux/fs/minix/namei.c
+ *
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ *
+ * Big-endian to little-endian byte-swapping/bitmaps by
+ * David S. Miller (davem@caip.rutgers.edu), 1995
+ */
+
+#include <linux/pagemap.h>
+#include <linux/quotaops.h>
+#include "ext2.h"
+#include "xattr.h"
+#include "acl.h"
+
+static inline int ext2_add_nondir(struct dentry *dentry, struct inode *inode)
+{
+ int err = ext2_add_link(dentry, inode);
+ if (!err) {
+ d_instantiate_new(dentry, inode);
+ return 0;
+ }
+ inode_dec_link_count(inode);
+ discard_new_inode(inode);
+ return err;
+}
+
+/*
+ * Methods themselves.
+ */
+
+static struct dentry *ext2_lookup(struct inode * dir, struct dentry *dentry, unsigned int flags)
+{
+ struct inode * inode;
+ ino_t ino;
+ int res;
+
+ if (dentry->d_name.len > EXT2_NAME_LEN)
+ return ERR_PTR(-ENAMETOOLONG);
+
+ res = ext2_inode_by_name(dir, &dentry->d_name, &ino);
+ if (res) {
+ if (res != -ENOENT)
+ return ERR_PTR(res);
+ inode = NULL;
+ } else {
+ inode = ext2_iget(dir->i_sb, ino);
+ if (inode == ERR_PTR(-ESTALE)) {
+ ext2_error(dir->i_sb, __func__,
+ "deleted inode referenced: %lu",
+ (unsigned long) ino);
+ return ERR_PTR(-EIO);
+ }
+ }
+ return d_splice_alias(inode, dentry);
+}
+
+struct dentry *ext2_get_parent(struct dentry *child)
+{
+ ino_t ino;
+ int res;
+
+ res = ext2_inode_by_name(d_inode(child), &dotdot_name, &ino);
+ if (res)
+ return ERR_PTR(res);
+
+ return d_obtain_alias(ext2_iget(child->d_sb, ino));
+}
+
+/*
+ * By the time this is called, we already have created
+ * the directory cache entry for the new file, but it
+ * is so far negative - it has no inode.
+ *
+ * If the create succeeds, we fill in the inode information
+ * with d_instantiate().
+ */
+static int ext2_create (struct user_namespace * mnt_userns,
+ struct inode * dir, struct dentry * dentry,
+ umode_t mode, bool excl)
+{
+ struct inode *inode;
+ int err;
+
+ err = dquot_initialize(dir);
+ if (err)
+ return err;
+
+ inode = ext2_new_inode(dir, mode, &dentry->d_name);
+ if (IS_ERR(inode))
+ return PTR_ERR(inode);
+
+ ext2_set_file_ops(inode);
+ mark_inode_dirty(inode);
+ return ext2_add_nondir(dentry, inode);
+}
+
+static int ext2_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
+ struct file *file, umode_t mode)
+{
+ struct inode *inode = ext2_new_inode(dir, mode, NULL);
+ if (IS_ERR(inode))
+ return PTR_ERR(inode);
+
+ ext2_set_file_ops(inode);
+ mark_inode_dirty(inode);
+ d_tmpfile(file, inode);
+ unlock_new_inode(inode);
+ return finish_open_simple(file, 0);
+}
+
+static int ext2_mknod (struct user_namespace * mnt_userns, struct inode * dir,
+ struct dentry *dentry, umode_t mode, dev_t rdev)
+{
+ struct inode * inode;
+ int err;
+
+ err = dquot_initialize(dir);
+ if (err)
+ return err;
+
+ inode = ext2_new_inode (dir, mode, &dentry->d_name);
+ err = PTR_ERR(inode);
+ if (!IS_ERR(inode)) {
+ init_special_inode(inode, inode->i_mode, rdev);
+ inode->i_op = &ext2_special_inode_operations;
+ mark_inode_dirty(inode);
+ err = ext2_add_nondir(dentry, inode);
+ }
+ return err;
+}
+
+static int ext2_symlink (struct user_namespace * mnt_userns, struct inode * dir,
+ struct dentry * dentry, const char * symname)
+{
+ struct super_block * sb = dir->i_sb;
+ int err = -ENAMETOOLONG;
+ unsigned l = strlen(symname)+1;
+ struct inode * inode;
+
+ if (l > sb->s_blocksize)
+ goto out;
+
+ err = dquot_initialize(dir);
+ if (err)
+ goto out;
+
+ inode = ext2_new_inode (dir, S_IFLNK | S_IRWXUGO, &dentry->d_name);
+ err = PTR_ERR(inode);
+ if (IS_ERR(inode))
+ goto out;
+
+ if (l > sizeof (EXT2_I(inode)->i_data)) {
+ /* slow symlink */
+ inode->i_op = &ext2_symlink_inode_operations;
+ inode_nohighmem(inode);
+ inode->i_mapping->a_ops = &ext2_aops;
+ err = page_symlink(inode, symname, l);
+ if (err)
+ goto out_fail;
+ } else {
+ /* fast symlink */
+ inode->i_op = &ext2_fast_symlink_inode_operations;
+ inode->i_link = (char*)EXT2_I(inode)->i_data;
+ memcpy(inode->i_link, symname, l);
+ inode->i_size = l-1;
+ }
+ mark_inode_dirty(inode);
+
+ err = ext2_add_nondir(dentry, inode);
+out:
+ return err;
+
+out_fail:
+ inode_dec_link_count(inode);
+ discard_new_inode(inode);
+ goto out;
+}
+
+static int ext2_link (struct dentry * old_dentry, struct inode * dir,
+ struct dentry *dentry)
+{
+ struct inode *inode = d_inode(old_dentry);
+ int err;
+
+ err = dquot_initialize(dir);
+ if (err)
+ return err;
+
+ inode->i_ctime = current_time(inode);
+ inode_inc_link_count(inode);
+ ihold(inode);
+
+ err = ext2_add_link(dentry, inode);
+ if (!err) {
+ d_instantiate(dentry, inode);
+ return 0;
+ }
+ inode_dec_link_count(inode);
+ iput(inode);
+ return err;
+}
+
+static int ext2_mkdir(struct user_namespace * mnt_userns,
+ struct inode * dir, struct dentry * dentry, umode_t mode)
+{
+ struct inode * inode;
+ int err;
+
+ err = dquot_initialize(dir);
+ if (err)
+ return err;
+
+ inode_inc_link_count(dir);
+
+ inode = ext2_new_inode(dir, S_IFDIR | mode, &dentry->d_name);
+ err = PTR_ERR(inode);
+ if (IS_ERR(inode))
+ goto out_dir;
+
+ inode->i_op = &ext2_dir_inode_operations;
+ inode->i_fop = &ext2_dir_operations;
+ inode->i_mapping->a_ops = &ext2_aops;
+
+ inode_inc_link_count(inode);
+
+ err = ext2_make_empty(inode, dir);
+ if (err)
+ goto out_fail;
+
+ err = ext2_add_link(dentry, inode);
+ if (err)
+ goto out_fail;
+
+ d_instantiate_new(dentry, inode);
+out:
+ return err;
+
+out_fail:
+ inode_dec_link_count(inode);
+ inode_dec_link_count(inode);
+ discard_new_inode(inode);
+out_dir:
+ inode_dec_link_count(dir);
+ goto out;
+}
+
+static int ext2_unlink(struct inode * dir, struct dentry *dentry)
+{
+ struct inode * inode = d_inode(dentry);
+ struct ext2_dir_entry_2 * de;
+ struct page * page;
+ void *page_addr;
+ int err;
+
+ err = dquot_initialize(dir);
+ if (err)
+ goto out;
+
+ de = ext2_find_entry(dir, &dentry->d_name, &page, &page_addr);
+ if (IS_ERR(de)) {
+ err = PTR_ERR(de);
+ goto out;
+ }
+
+ err = ext2_delete_entry (de, page, page_addr);
+ ext2_put_page(page, page_addr);
+ if (err)
+ goto out;
+
+ inode->i_ctime = dir->i_ctime;
+ inode_dec_link_count(inode);
+ err = 0;
+out:
+ return err;
+}
+
+static int ext2_rmdir (struct inode * dir, struct dentry *dentry)
+{
+ struct inode * inode = d_inode(dentry);
+ int err = -ENOTEMPTY;
+
+ if (ext2_empty_dir(inode)) {
+ err = ext2_unlink(dir, dentry);
+ if (!err) {
+ inode->i_size = 0;
+ inode_dec_link_count(inode);
+ inode_dec_link_count(dir);
+ }
+ }
+ return err;
+}
+
+static int ext2_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;
+ void *dir_page_addr;
+ struct ext2_dir_entry_2 * dir_de = NULL;
+ struct page * old_page;
+ void *old_page_addr;
+ struct ext2_dir_entry_2 * old_de;
+ int err;
+
+ if (flags & ~RENAME_NOREPLACE)
+ return -EINVAL;
+
+ err = dquot_initialize(old_dir);
+ if (err)
+ goto out;
+
+ err = dquot_initialize(new_dir);
+ if (err)
+ goto out;
+
+ old_de = ext2_find_entry(old_dir, &old_dentry->d_name, &old_page,
+ &old_page_addr);
+ if (IS_ERR(old_de)) {
+ err = PTR_ERR(old_de);
+ goto out;
+ }
+
+ if (S_ISDIR(old_inode->i_mode)) {
+ err = -EIO;
+ dir_de = ext2_dotdot(old_inode, &dir_page, &dir_page_addr);
+ if (!dir_de)
+ goto out_old;
+ }
+
+ if (new_inode) {
+ void *page_addr;
+ struct page *new_page;
+ struct ext2_dir_entry_2 *new_de;
+
+ err = -ENOTEMPTY;
+ if (dir_de && !ext2_empty_dir (new_inode))
+ goto out_dir;
+
+ new_de = ext2_find_entry(new_dir, &new_dentry->d_name,
+ &new_page, &page_addr);
+ if (IS_ERR(new_de)) {
+ err = PTR_ERR(new_de);
+ goto out_dir;
+ }
+ ext2_set_link(new_dir, new_de, new_page, page_addr, old_inode, 1);
+ ext2_put_page(new_page, page_addr);
+ new_inode->i_ctime = current_time(new_inode);
+ if (dir_de)
+ drop_nlink(new_inode);
+ inode_dec_link_count(new_inode);
+ } else {
+ err = ext2_add_link(new_dentry, old_inode);
+ if (err)
+ goto out_dir;
+ if (dir_de)
+ inode_inc_link_count(new_dir);
+ }
+
+ /*
+ * Like most other Unix systems, set the ctime for inodes on a
+ * rename.
+ */
+ old_inode->i_ctime = current_time(old_inode);
+ mark_inode_dirty(old_inode);
+
+ ext2_delete_entry(old_de, old_page, old_page_addr);
+
+ if (dir_de) {
+ if (old_dir != new_dir)
+ ext2_set_link(old_inode, dir_de, dir_page,
+ dir_page_addr, new_dir, 0);
+
+ ext2_put_page(dir_page, dir_page_addr);
+ inode_dec_link_count(old_dir);
+ }
+
+ ext2_put_page(old_page, old_page_addr);
+ return 0;
+
+out_dir:
+ if (dir_de)
+ ext2_put_page(dir_page, dir_page_addr);
+out_old:
+ ext2_put_page(old_page, old_page_addr);
+out:
+ return err;
+}
+
+const struct inode_operations ext2_dir_inode_operations = {
+ .create = ext2_create,
+ .lookup = ext2_lookup,
+ .link = ext2_link,
+ .unlink = ext2_unlink,
+ .symlink = ext2_symlink,
+ .mkdir = ext2_mkdir,
+ .rmdir = ext2_rmdir,
+ .mknod = ext2_mknod,
+ .rename = ext2_rename,
+ .listxattr = ext2_listxattr,
+ .getattr = ext2_getattr,
+ .setattr = ext2_setattr,
+ .get_acl = ext2_get_acl,
+ .set_acl = ext2_set_acl,
+ .tmpfile = ext2_tmpfile,
+ .fileattr_get = ext2_fileattr_get,
+ .fileattr_set = ext2_fileattr_set,
+};
+
+const struct inode_operations ext2_special_inode_operations = {
+ .listxattr = ext2_listxattr,
+ .getattr = ext2_getattr,
+ .setattr = ext2_setattr,
+ .get_acl = ext2_get_acl,
+ .set_acl = ext2_set_acl,
+};