419 строки
9.1 KiB
C
419 строки
9.1 KiB
C
/*
|
|
* 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 "ext2.h"
|
|
#include "xattr.h"
|
|
#include "acl.h"
|
|
|
|
/*
|
|
* Couple of helper functions - make the code slightly cleaner.
|
|
*/
|
|
|
|
static inline void ext2_inc_count(struct inode *inode)
|
|
{
|
|
inode->i_nlink++;
|
|
mark_inode_dirty(inode);
|
|
}
|
|
|
|
static inline void ext2_dec_count(struct inode *inode)
|
|
{
|
|
inode->i_nlink--;
|
|
mark_inode_dirty(inode);
|
|
}
|
|
|
|
static inline int ext2_add_nondir(struct dentry *dentry, struct inode *inode)
|
|
{
|
|
int err = ext2_add_link(dentry, inode);
|
|
if (!err) {
|
|
d_instantiate(dentry, inode);
|
|
return 0;
|
|
}
|
|
ext2_dec_count(inode);
|
|
iput(inode);
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* Methods themselves.
|
|
*/
|
|
|
|
static struct dentry *ext2_lookup(struct inode * dir, struct dentry *dentry, struct nameidata *nd)
|
|
{
|
|
struct inode * inode;
|
|
ino_t ino;
|
|
|
|
if (dentry->d_name.len > EXT2_NAME_LEN)
|
|
return ERR_PTR(-ENAMETOOLONG);
|
|
|
|
ino = ext2_inode_by_name(dir, dentry);
|
|
inode = NULL;
|
|
if (ino) {
|
|
inode = iget(dir->i_sb, ino);
|
|
if (!inode)
|
|
return ERR_PTR(-EACCES);
|
|
}
|
|
if (inode)
|
|
return d_splice_alias(inode, dentry);
|
|
d_add(dentry, inode);
|
|
return NULL;
|
|
}
|
|
|
|
struct dentry *ext2_get_parent(struct dentry *child)
|
|
{
|
|
unsigned long ino;
|
|
struct dentry *parent;
|
|
struct inode *inode;
|
|
struct dentry dotdot;
|
|
|
|
dotdot.d_name.name = "..";
|
|
dotdot.d_name.len = 2;
|
|
|
|
ino = ext2_inode_by_name(child->d_inode, &dotdot);
|
|
if (!ino)
|
|
return ERR_PTR(-ENOENT);
|
|
inode = iget(child->d_inode->i_sb, ino);
|
|
|
|
if (!inode)
|
|
return ERR_PTR(-EACCES);
|
|
parent = d_alloc_anon(inode);
|
|
if (!parent) {
|
|
iput(inode);
|
|
parent = ERR_PTR(-ENOMEM);
|
|
}
|
|
return parent;
|
|
}
|
|
|
|
/*
|
|
* 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 inode * dir, struct dentry * dentry, int mode, struct nameidata *nd)
|
|
{
|
|
struct inode * inode = ext2_new_inode (dir, mode);
|
|
int err = PTR_ERR(inode);
|
|
if (!IS_ERR(inode)) {
|
|
inode->i_op = &ext2_file_inode_operations;
|
|
inode->i_fop = &ext2_file_operations;
|
|
if (test_opt(inode->i_sb, NOBH))
|
|
inode->i_mapping->a_ops = &ext2_nobh_aops;
|
|
else
|
|
inode->i_mapping->a_ops = &ext2_aops;
|
|
mark_inode_dirty(inode);
|
|
err = ext2_add_nondir(dentry, inode);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
static int ext2_mknod (struct inode * dir, struct dentry *dentry, int mode, dev_t rdev)
|
|
{
|
|
struct inode * inode;
|
|
int err;
|
|
|
|
if (!new_valid_dev(rdev))
|
|
return -EINVAL;
|
|
|
|
inode = ext2_new_inode (dir, mode);
|
|
err = PTR_ERR(inode);
|
|
if (!IS_ERR(inode)) {
|
|
init_special_inode(inode, inode->i_mode, rdev);
|
|
#ifdef CONFIG_EXT2_FS_XATTR
|
|
inode->i_op = &ext2_special_inode_operations;
|
|
#endif
|
|
mark_inode_dirty(inode);
|
|
err = ext2_add_nondir(dentry, inode);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
static int ext2_symlink (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;
|
|
|
|
inode = ext2_new_inode (dir, S_IFLNK | S_IRWXUGO);
|
|
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;
|
|
if (test_opt(inode->i_sb, NOBH))
|
|
inode->i_mapping->a_ops = &ext2_nobh_aops;
|
|
else
|
|
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;
|
|
memcpy((char*)(EXT2_I(inode)->i_data),symname,l);
|
|
inode->i_size = l-1;
|
|
}
|
|
mark_inode_dirty(inode);
|
|
|
|
err = ext2_add_nondir(dentry, inode);
|
|
out:
|
|
return err;
|
|
|
|
out_fail:
|
|
ext2_dec_count(inode);
|
|
iput (inode);
|
|
goto out;
|
|
}
|
|
|
|
static int ext2_link (struct dentry * old_dentry, struct inode * dir,
|
|
struct dentry *dentry)
|
|
{
|
|
struct inode *inode = old_dentry->d_inode;
|
|
|
|
if (inode->i_nlink >= EXT2_LINK_MAX)
|
|
return -EMLINK;
|
|
|
|
inode->i_ctime = CURRENT_TIME_SEC;
|
|
ext2_inc_count(inode);
|
|
atomic_inc(&inode->i_count);
|
|
|
|
return ext2_add_nondir(dentry, inode);
|
|
}
|
|
|
|
static int ext2_mkdir(struct inode * dir, struct dentry * dentry, int mode)
|
|
{
|
|
struct inode * inode;
|
|
int err = -EMLINK;
|
|
|
|
if (dir->i_nlink >= EXT2_LINK_MAX)
|
|
goto out;
|
|
|
|
ext2_inc_count(dir);
|
|
|
|
inode = ext2_new_inode (dir, S_IFDIR | mode);
|
|
err = PTR_ERR(inode);
|
|
if (IS_ERR(inode))
|
|
goto out_dir;
|
|
|
|
inode->i_op = &ext2_dir_inode_operations;
|
|
inode->i_fop = &ext2_dir_operations;
|
|
if (test_opt(inode->i_sb, NOBH))
|
|
inode->i_mapping->a_ops = &ext2_nobh_aops;
|
|
else
|
|
inode->i_mapping->a_ops = &ext2_aops;
|
|
|
|
ext2_inc_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(dentry, inode);
|
|
out:
|
|
return err;
|
|
|
|
out_fail:
|
|
ext2_dec_count(inode);
|
|
ext2_dec_count(inode);
|
|
iput(inode);
|
|
out_dir:
|
|
ext2_dec_count(dir);
|
|
goto out;
|
|
}
|
|
|
|
static int ext2_unlink(struct inode * dir, struct dentry *dentry)
|
|
{
|
|
struct inode * inode = dentry->d_inode;
|
|
struct ext2_dir_entry_2 * de;
|
|
struct page * page;
|
|
int err = -ENOENT;
|
|
|
|
de = ext2_find_entry (dir, dentry, &page);
|
|
if (!de)
|
|
goto out;
|
|
|
|
err = ext2_delete_entry (de, page);
|
|
if (err)
|
|
goto out;
|
|
|
|
inode->i_ctime = dir->i_ctime;
|
|
ext2_dec_count(inode);
|
|
err = 0;
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
static int ext2_rmdir (struct inode * dir, struct dentry *dentry)
|
|
{
|
|
struct inode * inode = dentry->d_inode;
|
|
int err = -ENOTEMPTY;
|
|
|
|
if (ext2_empty_dir(inode)) {
|
|
err = ext2_unlink(dir, dentry);
|
|
if (!err) {
|
|
inode->i_size = 0;
|
|
ext2_dec_count(inode);
|
|
ext2_dec_count(dir);
|
|
}
|
|
}
|
|
return err;
|
|
}
|
|
|
|
static int ext2_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 ext2_dir_entry_2 * dir_de = NULL;
|
|
struct page * old_page;
|
|
struct ext2_dir_entry_2 * old_de;
|
|
int err = -ENOENT;
|
|
|
|
old_de = ext2_find_entry (old_dir, old_dentry, &old_page);
|
|
if (!old_de)
|
|
goto out;
|
|
|
|
if (S_ISDIR(old_inode->i_mode)) {
|
|
err = -EIO;
|
|
dir_de = ext2_dotdot(old_inode, &dir_page);
|
|
if (!dir_de)
|
|
goto out_old;
|
|
}
|
|
|
|
if (new_inode) {
|
|
struct page *new_page;
|
|
struct ext2_dir_entry_2 *new_de;
|
|
|
|
err = -ENOTEMPTY;
|
|
if (dir_de && !ext2_empty_dir (new_inode))
|
|
goto out_dir;
|
|
|
|
err = -ENOENT;
|
|
new_de = ext2_find_entry (new_dir, new_dentry, &new_page);
|
|
if (!new_de)
|
|
goto out_dir;
|
|
ext2_inc_count(old_inode);
|
|
ext2_set_link(new_dir, new_de, new_page, old_inode);
|
|
new_inode->i_ctime = CURRENT_TIME_SEC;
|
|
if (dir_de)
|
|
new_inode->i_nlink--;
|
|
ext2_dec_count(new_inode);
|
|
} else {
|
|
if (dir_de) {
|
|
err = -EMLINK;
|
|
if (new_dir->i_nlink >= EXT2_LINK_MAX)
|
|
goto out_dir;
|
|
}
|
|
ext2_inc_count(old_inode);
|
|
err = ext2_add_link(new_dentry, old_inode);
|
|
if (err) {
|
|
ext2_dec_count(old_inode);
|
|
goto out_dir;
|
|
}
|
|
if (dir_de)
|
|
ext2_inc_count(new_dir);
|
|
}
|
|
|
|
/*
|
|
* Like most other Unix systems, set the ctime for inodes on a
|
|
* rename.
|
|
* ext2_dec_count() will mark the inode dirty.
|
|
*/
|
|
old_inode->i_ctime = CURRENT_TIME_SEC;
|
|
|
|
ext2_delete_entry (old_de, old_page);
|
|
ext2_dec_count(old_inode);
|
|
|
|
if (dir_de) {
|
|
ext2_set_link(old_inode, dir_de, dir_page, new_dir);
|
|
ext2_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;
|
|
}
|
|
|
|
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,
|
|
#ifdef CONFIG_EXT2_FS_XATTR
|
|
.setxattr = generic_setxattr,
|
|
.getxattr = generic_getxattr,
|
|
.listxattr = ext2_listxattr,
|
|
.removexattr = generic_removexattr,
|
|
#endif
|
|
.setattr = ext2_setattr,
|
|
.permission = ext2_permission,
|
|
};
|
|
|
|
struct inode_operations ext2_special_inode_operations = {
|
|
#ifdef CONFIG_EXT2_FS_XATTR
|
|
.setxattr = generic_setxattr,
|
|
.getxattr = generic_getxattr,
|
|
.listxattr = ext2_listxattr,
|
|
.removexattr = generic_removexattr,
|
|
#endif
|
|
.setattr = ext2_setattr,
|
|
.permission = ext2_permission,
|
|
};
|