diff options
Diffstat (limited to 'fs/sysv/namei.c')
| -rw-r--r-- | fs/sysv/namei.c | 301 |
1 files changed, 301 insertions, 0 deletions
diff --git a/fs/sysv/namei.c b/fs/sysv/namei.c new file mode 100644 index 00000000..e474fbcf --- /dev/null +++ b/fs/sysv/namei.c @@ -0,0 +1,301 @@ +/* + * 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 int sysv_hash(const struct dentry *dentry, const struct inode *inode, + 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; +} + +const 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; + + 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); + if (IS_ERR(inode)) + return ERR_CAST(inode); + } + 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: + 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 = old_dentry->d_inode; + + if (inode->i_nlink >= SYSV_SB(inode->i_sb)->s_link_max) + return -EMLINK; + + inode->i_ctime = CURRENT_TIME_SEC; + inode_inc_link_count(inode); + ihold(inode); + + 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; + 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 = 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; + inode_dec_link_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; + 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 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; + sysv_set_link(new_de, new_page, old_inode); + new_inode->i_ctime = CURRENT_TIME_SEC; + if (dir_de) + drop_nlink(new_inode); + inode_dec_link_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; + } + 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); + page_cache_release(dir_page); + } +out_old: + kunmap(old_page); + page_cache_release(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, +}; |