diff options
Diffstat (limited to 'fs/minix/namei.c')
| -rw-r--r-- | fs/minix/namei.c | 291 |
1 files changed, 291 insertions, 0 deletions
diff --git a/fs/minix/namei.c b/fs/minix/namei.c new file mode 100644 index 000000000..5525ba367 --- /dev/null +++ b/fs/minix/namei.c @@ -0,0 +1,291 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * linux/fs/minix/namei.c + * + * Copyright (C) 1991, 1992 Linus Torvalds + */ + +#include "minix.h" + +static int add_nondir(struct dentry *dentry, struct inode *inode) +{ + int err = minix_add_link(dentry, inode); + if (!err) { + d_instantiate(dentry, inode); + return 0; + } + inode_dec_link_count(inode); + iput(inode); + return err; +} + +static struct dentry *minix_lookup(struct inode * dir, struct dentry *dentry, unsigned int flags) +{ + struct inode * inode = NULL; + ino_t ino; + + if (dentry->d_name.len > minix_sb(dir->i_sb)->s_namelen) + return ERR_PTR(-ENAMETOOLONG); + + ino = minix_inode_by_name(dentry); + if (ino) + inode = minix_iget(dir->i_sb, ino); + return d_splice_alias(inode, dentry); +} + +static int minix_mknod(struct mnt_idmap *idmap, struct inode *dir, + struct dentry *dentry, umode_t mode, dev_t rdev) +{ + struct inode *inode; + + if (!old_valid_dev(rdev)) + return -EINVAL; + + inode = minix_new_inode(dir, mode); + if (IS_ERR(inode)) + return PTR_ERR(inode); + + minix_set_inode(inode, rdev); + mark_inode_dirty(inode); + return add_nondir(dentry, inode); +} + +static int minix_tmpfile(struct mnt_idmap *idmap, struct inode *dir, + struct file *file, umode_t mode) +{ + struct inode *inode = minix_new_inode(dir, mode); + + if (IS_ERR(inode)) + return finish_open_simple(file, PTR_ERR(inode)); + minix_set_inode(inode, 0); + mark_inode_dirty(inode); + d_tmpfile(file, inode); + return finish_open_simple(file, 0); +} + +static int minix_create(struct mnt_idmap *idmap, struct inode *dir, + struct dentry *dentry, umode_t mode) +{ + return minix_mknod(&nop_mnt_idmap, dir, dentry, mode, 0); +} + +static int minix_symlink(struct mnt_idmap *idmap, struct inode *dir, + struct dentry *dentry, const char *symname) +{ + int i = strlen(symname)+1; + struct inode * inode; + int err; + + if (i > dir->i_sb->s_blocksize) + return -ENAMETOOLONG; + + inode = minix_new_inode(dir, S_IFLNK | 0777); + if (IS_ERR(inode)) + return PTR_ERR(inode); + + minix_set_inode(inode, 0); + err = page_symlink(inode, symname, i); + if (unlikely(err)) { + inode_dec_link_count(inode); + iput(inode); + return err; + } + return add_nondir(dentry, inode); +} + +static int minix_link(struct dentry * old_dentry, struct inode * dir, + struct dentry *dentry) +{ + struct inode *inode = d_inode(old_dentry); + + inode_set_ctime_current(inode); + inode_inc_link_count(inode); + ihold(inode); + return add_nondir(dentry, inode); +} + +static struct dentry *minix_mkdir(struct mnt_idmap *idmap, struct inode *dir, + struct dentry *dentry, umode_t mode) +{ + struct inode * inode; + int err; + + inode = minix_new_inode(dir, mode); + if (IS_ERR(inode)) + return ERR_CAST(inode); + + inode_inc_link_count(dir); + minix_set_inode(inode, 0); + inode_inc_link_count(inode); + + err = minix_make_empty(inode, dir); + if (err) + goto out_fail; + + err = minix_add_link(dentry, inode); + if (err) + goto out_fail; + + d_instantiate(dentry, inode); +out: + return ERR_PTR(err); + +out_fail: + inode_dec_link_count(inode); + inode_dec_link_count(inode); + iput(inode); + inode_dec_link_count(dir); + goto out; +} + +static int minix_unlink(struct inode * dir, struct dentry *dentry) +{ + struct inode * inode = d_inode(dentry); + struct folio *folio; + struct minix_dir_entry * de; + int err; + + if (inode->i_nlink == 0) { + minix_error_inode(inode, "inode has corrupted nlink"); + return -EFSCORRUPTED; + } + + de = minix_find_entry(dentry, &folio); + if (!de) + return -ENOENT; + err = minix_delete_entry(de, folio); + folio_release_kmap(folio, de); + + if (err) + return err; + inode_set_ctime_to_ts(inode, inode_get_ctime(dir)); + inode_dec_link_count(inode); + return 0; +} + +static int minix_rmdir(struct inode * dir, struct dentry *dentry) +{ + struct inode * inode = d_inode(dentry); + int err = -EFSCORRUPTED; + + if (dir->i_nlink <= 2) { + minix_error_inode(dir, "inode has corrupted nlink"); + goto out; + } + + err = -ENOTEMPTY; + if (!minix_empty_dir(inode)) + goto out; + + err = minix_unlink(dir, dentry); + if (!err) { + inode_dec_link_count(dir); + inode_dec_link_count(inode); + } + +out: + return err; +} + +static int minix_rename(struct mnt_idmap *idmap, + 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 folio * dir_folio = NULL; + struct minix_dir_entry * dir_de = NULL; + struct folio *old_folio; + struct minix_dir_entry * old_de; + int err = -ENOENT; + + if (flags & ~RENAME_NOREPLACE) + return -EINVAL; + + old_de = minix_find_entry(old_dentry, &old_folio); + if (!old_de) + goto out; + + if (S_ISDIR(old_inode->i_mode)) { + err = -EIO; + dir_de = minix_dotdot(old_inode, &dir_folio); + if (!dir_de) + goto out_old; + } + + if (new_inode) { + struct folio *new_folio; + struct minix_dir_entry * new_de; + + err = -ENOTEMPTY; + if (dir_de && !minix_empty_dir(new_inode)) + goto out_dir; + + err = -EFSCORRUPTED; + if (new_inode->i_nlink == 0 || (dir_de && new_inode->i_nlink != 2)) { + minix_error_inode(new_inode, "inode has corrupted nlink"); + goto out_dir; + } + + if (dir_de && old_dir->i_nlink <= 2) { + minix_error_inode(old_dir, "inode has corrupted nlink"); + goto out_dir; + } + + err = -ENOENT; + new_de = minix_find_entry(new_dentry, &new_folio); + if (!new_de) + goto out_dir; + err = minix_set_link(new_de, new_folio, old_inode); + folio_release_kmap(new_folio, new_de); + if (err) + goto out_dir; + inode_set_ctime_current(new_inode); + if (dir_de) + drop_nlink(new_inode); + inode_dec_link_count(new_inode); + } else { + err = minix_add_link(new_dentry, old_inode); + if (err) + goto out_dir; + if (dir_de) + inode_inc_link_count(new_dir); + } + + err = minix_delete_entry(old_de, old_folio); + if (err) + goto out_dir; + + mark_inode_dirty(old_inode); + + if (dir_de) { + err = minix_set_link(dir_de, dir_folio, new_dir); + if (!err) + inode_dec_link_count(old_dir); + } +out_dir: + if (dir_de) + folio_release_kmap(dir_folio, dir_de); +out_old: + folio_release_kmap(old_folio, old_de); +out: + return err; +} + +/* + * directories can handle most operations... + */ +const struct inode_operations minix_dir_inode_operations = { + .create = minix_create, + .lookup = minix_lookup, + .link = minix_link, + .unlink = minix_unlink, + .symlink = minix_symlink, + .mkdir = minix_mkdir, + .rmdir = minix_rmdir, + .mknod = minix_mknod, + .rename = minix_rename, + .getattr = minix_getattr, + .tmpfile = minix_tmpfile, +}; |