aboutsummaryrefslogtreecommitdiff
path: root/fs/sysv/namei.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/sysv/namei.c')
-rw-r--r--fs/sysv/namei.c318
1 files changed, 318 insertions, 0 deletions
diff --git a/fs/sysv/namei.c b/fs/sysv/namei.c
new file mode 100644
index 00000000000..7f0e4b53085
--- /dev/null
+++ b/fs/sysv/namei.c
@@ -0,0 +1,318 @@
+/*
+ * 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,
+};