/* * 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 <linux/smp_lock.h> #include "sysv.h" static inline void inc_count(struct inode *inode) { inode->i_nlink++; mark_inode_dirty(inode); } static inline void dec_count(struct inode *inode) { inode->i_nlink--; mark_inode_dirty(inode); } 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; } dec_count(inode); iput(inode); return err; } static int sysv_hash(struct dentry *dentry, struct qstr *qstr) { /* Truncate the name in place, avoids having to define a compare function. */ if (qstr->len > SYSV_NAMELEN) { qstr->len = SYSV_NAMELEN; qstr->hash = full_name_hash(qstr->name, qstr->len); } return 0; } struct dentry_operations sysv_dentry_operations = { .d_hash = sysv_hash, }; static struct dentry *sysv_lookup(struct inode * dir, struct dentry * dentry, struct nameidata *nd) { struct inode * inode = NULL; ino_t ino; dentry->d_op = dir->i_sb->s_root->d_op; if (dentry->d_name.len > SYSV_NAMELEN) return ERR_PTR(-ENAMETOOLONG); ino = sysv_inode_by_name(dentry); if (ino) { inode = iget(dir->i_sb, ino); if (!inode) return ERR_PTR(-EACCES); } d_add(dentry, inode); return NULL; } static int sysv_mknod(struct inode * dir, struct dentry * dentry, int 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 inode * dir, struct dentry * dentry, int mode, struct nameidata *nd) { return sysv_mknod(dir, dentry, mode, 0); } static int sysv_symlink(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: dec_count(inode); iput(inode); goto out; } static int sysv_link(struct dentry * old_dentry, struct inode * dir, struct dentry * dentry) { struct inode *inode = old_dentry->d_inode; if (inode->i_nlink >= SYSV_SB(inode->i_sb)->s_link_max) return -EMLINK; inode->i_ctime = CURRENT_TIME_SEC; inc_count(inode); atomic_inc(&inode->i_count); return add_nondir(dentry, inode); } static int sysv_mkdir(struct inode * dir, struct dentry *dentry, int mode) { struct inode * inode; int err = -EMLINK; if (dir->i_nlink >= SYSV_SB(dir->i_sb)->s_link_max) goto out; inc_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); inc_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: dec_count(inode); dec_count(inode); iput(inode); out_dir: dec_count(dir); goto out; } static int sysv_unlink(struct inode * dir, struct dentry * dentry) { struct inode * inode = dentry->d_inode; 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; dec_count(inode); out: return err; } static int sysv_rmdir(struct inode * dir, struct dentry * dentry) { struct inode *inode = dentry->d_inode; int err = -ENOTEMPTY; if (sysv_empty_dir(inode)) { err = sysv_unlink(dir, dentry); if (!err) { inode->i_size = 0; dec_count(inode); dec_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 inode * old_dir, struct dentry * old_dentry, struct inode * new_dir, struct dentry * new_dentry) { struct inode * old_inode = old_dentry->d_inode; struct inode * new_inode = new_dentry->d_inode; 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; 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; inc_count(old_inode); sysv_set_link(new_de, new_page, old_inode); new_inode->i_ctime = CURRENT_TIME_SEC; if (dir_de) new_inode->i_nlink--; dec_count(new_inode); } else { if (dir_de) { err = -EMLINK; if (new_dir->i_nlink >= SYSV_SB(new_dir->i_sb)->s_link_max) goto out_dir; } inc_count(old_inode); err = sysv_add_link(new_dentry, old_inode); if (err) { dec_count(old_inode); goto out_dir; } if (dir_de) inc_count(new_dir); } sysv_delete_entry(old_de, old_page); dec_count(old_inode); if (dir_de) { sysv_set_link(dir_de, dir_page, new_dir); dec_count(old_dir); } return 0; out_dir: if (dir_de) { kunmap(dir_page); page_cache_release(dir_page); } out_old: kunmap(old_page); page_cache_release(old_page); out: return err; } /* * directories can handle most operations... */ 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, };