--- /dev/null
+ Documentation/filesystems/ext2.txt | 16 ++
+ fs/ext3/Makefile | 2
+ fs/ext3/inode.c | 3
+ fs/ext3/iopen.c | 239 +++++++++++++++++++++++++++++++++++++
+ fs/ext3/iopen.h | 15 ++
+ fs/ext3/namei.c | 13 ++
+ fs/ext3/super.c | 11 +
+ include/linux/ext3_fs.h | 2
+ 8 files changed, 300 insertions(+), 1 deletion(-)
+
+--- linux-2.6.0-test1/Documentation/filesystems/ext2.txt~iopen-2.6.0 2002-11-11 06:28:06.000000000 +0300
++++ linux-2.6.0-test1-alexey/Documentation/filesystems/ext2.txt 2003-08-24 13:02:02.000000000 +0400
+@@ -35,6 +35,22 @@ resgid=n The group ID which may use th
+
+ sb=n Use alternate superblock at this location.
+
++iopen Makes an invisible pseudo-directory called
++ __iopen__ available in the root directory
++ of the filesystem. Allows open-by-inode-
++ number. i.e., inode 3145 can be accessed
++ via /mntpt/__iopen__/3145
++
++iopen_nopriv This option makes the iopen directory be
++ world-readable. This may be safer since it
++ allows daemons to run as an unprivileged user,
++ however it significantly changes the security
++ model of a Unix filesystem, since previously
++ all files under a mode 700 directory were not
++ generally avilable even if the
++ permissions on the file itself is
++ world-readable.
++
+ grpquota,noquota,quota,usrquota Quota options are silently ignored by ext2.
+
+
+--- linux-2.6.0-test1/fs/ext3/inode.c~iopen-2.6.0 2003-08-24 13:00:36.000000000 +0400
++++ linux-2.6.0-test1-alexey/fs/ext3/inode.c 2003-08-24 13:02:02.000000000 +0400
+@@ -37,6 +37,7 @@
+ #include <linux/mpage.h>
+ #include <linux/uio.h>
+ #include "xattr.h"
++#include "iopen.h"
+ #include "acl.h"
+
+ /*
+@@ -2477,6 +2478,8 @@ void ext3_read_inode(struct inode * inod
+ ei->i_acl = EXT3_ACL_NOT_CACHED;
+ ei->i_default_acl = EXT3_ACL_NOT_CACHED;
+ #endif
++ if (ext3_iopen_get_inode(inode))
++ return;
+ if (ext3_get_inode_loc(inode, &iloc, 0))
+ goto bad_inode;
+ bh = iloc.bh;
+--- /dev/null 2003-01-30 13:24:37.000000000 +0300
++++ linux-2.6.0-test1-alexey/fs/ext3/iopen.c 2003-08-24 13:02:02.000000000 +0400
+@@ -0,0 +1,239 @@
++
++
++/*
++ * linux/fs/ext3/iopen.c
++ *
++ * Special support for open by inode number
++ *
++ * Copyright (C) 2001 by Theodore Ts'o (tytso@alum.mit.edu).
++ *
++ * This file may be redistributed under the terms of the GNU General
++ * Public License.
++ */
++
++#include <linux/sched.h>
++#include <linux/fs.h>
++#include <linux/ext3_jbd.h>
++#include <linux/jbd.h>
++#include <linux/ext3_fs.h>
++#include <linux/smp_lock.h>
++#include "iopen.h"
++
++#ifndef assert
++#define assert(test) J_ASSERT(test)
++#endif
++
++#define IOPEN_NAME_LEN 32
++
++/*
++ * This implements looking up an inode by number.
++ */
++static struct dentry *iopen_lookup(struct inode * dir, struct dentry *dentry, struct nameidata *nd)
++{
++ struct inode * inode;
++ unsigned long ino;
++ struct list_head *lp;
++ struct dentry *alternate;
++ char buf[IOPEN_NAME_LEN];
++
++ if (dentry->d_name.len >= IOPEN_NAME_LEN)
++ return ERR_PTR(-ENAMETOOLONG);
++
++ memcpy(buf, dentry->d_name.name, dentry->d_name.len);
++ buf[dentry->d_name.len] = 0;
++
++ if (strcmp(buf, ".") == 0)
++ ino = dir->i_ino;
++ else if (strcmp(buf, "..") == 0)
++ ino = EXT3_ROOT_INO;
++ else
++ ino = simple_strtoul(buf, 0, 0);
++
++ if ((ino != EXT3_ROOT_INO &&
++ //ino != EXT3_ACL_IDX_INO &&
++ //ino != EXT3_ACL_DATA_INO &&
++ ino < EXT3_FIRST_INO(dir->i_sb)) ||
++ ino > le32_to_cpu(EXT3_SB(dir->i_sb)->s_es->s_inodes_count))
++ return ERR_PTR(-ENOENT);
++
++ inode = iget(dir->i_sb, ino);
++ if (!inode)
++ return ERR_PTR(-EACCES);
++ if (is_bad_inode(inode)) {
++ iput(inode);
++ return ERR_PTR(-ENOENT);
++ }
++
++ /* preferrably return a connected dentry */
++ spin_lock(&dcache_lock);
++ list_for_each(lp, &inode->i_dentry) {
++ alternate = list_entry(lp, struct dentry, d_alias);
++ assert(!(alternate->d_flags & DCACHE_DISCONNECTED));
++ }
++
++ if (!list_empty(&inode->i_dentry)) {
++ alternate = list_entry(inode->i_dentry.next,
++ struct dentry, d_alias);
++ dget_locked(alternate);
++ alternate->d_vfs_flags |= DCACHE_REFERENCED;
++ iput(inode);
++ spin_unlock(&dcache_lock);
++ return alternate;
++ }
++ dentry->d_flags |= DCACHE_DISCONNECTED;
++ spin_unlock(&dcache_lock);
++
++ d_add(dentry, inode);
++ return NULL;
++}
++
++#define do_switch(x,y) do { \
++ __typeof__ (x) __tmp = x; \
++ x = y; y = __tmp; } while (0)
++
++static inline void switch_names(struct dentry * dentry, struct dentry * target)
++{
++ const unsigned char *old_name, *new_name;
++
++ memcpy(dentry->d_iname, target->d_iname, DNAME_INLINE_LEN);
++ old_name = target->d_name.name;
++ new_name = dentry->d_name.name;
++ if (old_name == target->d_iname)
++ old_name = dentry->d_iname;
++ if (new_name == dentry->d_iname)
++ new_name = target->d_iname;
++ target->d_name.name = new_name;
++ dentry->d_name.name = old_name;
++}
++
++
++struct dentry *iopen_connect_dentry(struct dentry *de, struct inode *inode)
++{
++ struct dentry *tmp, *goal = NULL;
++ struct list_head *lp;
++
++ /* preferrably return a connected dentry */
++ spin_lock(&dcache_lock);
++ /* verify this dentry is really new */
++ assert(!de->d_inode);
++ assert(list_empty(&de->d_subdirs));
++ assert(list_empty(&de->d_alias));
++
++
++ list_for_each(lp, &inode->i_dentry) {
++ tmp = list_entry(lp, struct dentry, d_alias);
++ if (tmp->d_flags & DCACHE_DISCONNECTED) {
++ assert(tmp->d_alias.next == &inode->i_dentry);
++ assert(tmp->d_alias.prev == &inode->i_dentry);
++ goal = tmp;
++ dget_locked(goal);
++ break;
++ }
++ }
++
++ if (!goal) {
++ spin_unlock(&dcache_lock);
++ return NULL;
++ }
++
++ /* Move the goal to the de hash queue */
++ goal->d_flags &= ~DCACHE_DISCONNECTED;
++ hlist_add_before(&goal->d_hash, &de->d_hash);
++ hlist_del(&goal->d_hash);
++
++ list_del(&goal->d_child);
++ list_del(&de->d_child);
++
++ /* Switch the parents and the names.. */
++ switch_names(goal, de);
++ do_switch(goal->d_parent, de->d_parent);
++ do_switch(goal->d_name.len, de->d_name.len);
++ do_switch(goal->d_name.hash, de->d_name.hash);
++
++ /* And add them back to the (new) parent lists */
++ list_add(&goal->d_child, &goal->d_parent->d_subdirs);
++ list_add(&de->d_child, &de->d_parent->d_subdirs);
++
++ spin_unlock(&dcache_lock);
++ return goal;
++}
++
++/*
++ * These are the special structures for the iopen pseudo directory.
++ */
++
++static struct inode_operations iopen_inode_operations = {
++ lookup: iopen_lookup, /* BKL held */
++};
++
++static struct file_operations iopen_file_operations = {
++ read: generic_read_dir,
++};
++
++static int match_dentry(struct dentry *dentry, const char *name)
++{
++ int len;
++
++ len = strlen(name);
++ if (dentry->d_name.len != len)
++ return 0;
++ if (strncmp(dentry->d_name.name, name, len))
++ return 0;
++ return 1;
++}
++
++/*
++ * This function is spliced into ext3_lookup and returns 1 the file
++ * name is __iopen__ and dentry has been filled in appropriately.
++ */
++int ext3_check_for_iopen(struct inode * dir, struct dentry *dentry)
++{
++ struct inode * inode;
++
++ if (dir->i_ino != EXT3_ROOT_INO ||
++ !test_opt(dir->i_sb, IOPEN) ||
++ !match_dentry(dentry, "__iopen__"))
++ return 0;
++
++ inode = iget(dir->i_sb, EXT3_BAD_INO);
++
++ if (!inode)
++ return 0;
++ d_add(dentry, inode);
++ return 1;
++}
++
++/*
++ * This function is spliced into read_inode; it returns 1 if inode
++ * number is the one for /__iopen__, in which case the inode is filled
++ * in appropriately. Otherwise, this fuction returns 0.
++ */
++int ext3_iopen_get_inode(struct inode * inode)
++{
++ if (inode->i_ino != EXT3_BAD_INO)
++ return 0;
++
++ inode->i_mode = S_IFDIR | S_IRUSR | S_IXUSR;
++ if (test_opt(inode->i_sb, IOPEN_NOPRIV))
++ inode->i_mode |= 0777;
++ inode->i_uid = 0;
++ inode->i_gid = 0;
++ inode->i_nlink = 1;
++ inode->i_size = 4096;
++ inode->i_atime = CURRENT_TIME;
++ inode->i_ctime = CURRENT_TIME;
++ inode->i_mtime = CURRENT_TIME;
++ EXT3_I(inode)->i_dtime = 0;
++ inode->i_blksize = PAGE_SIZE; /* This is the optimal IO size
++ * (for stat), not the fs block
++ * size */
++ inode->i_blocks = 0;
++ inode->i_version = 1;
++ inode->i_generation = 0;
++
++ inode->i_op = &iopen_inode_operations;
++ inode->i_fop = &iopen_file_operations;
++ inode->i_mapping->a_ops = 0;
++
++ return 1;
++}
+--- /dev/null 2003-01-30 13:24:37.000000000 +0300
++++ linux-2.6.0-test1-alexey/fs/ext3/iopen.h 2003-08-24 13:02:02.000000000 +0400
+@@ -0,0 +1,15 @@
++/*
++ * iopen.h
++ *
++ * Special support for opening files by inode number.
++ *
++ * Copyright (C) 2001 by Theodore Ts'o (tytso@alum.mit.edu).
++ *
++ * This file may be redistributed under the terms of the GNU General
++ * Public License.
++ */
++
++extern int ext3_check_for_iopen(struct inode * dir, struct dentry *dentry);
++extern int ext3_iopen_get_inode(struct inode * inode);
++
++
+--- linux-2.6.0-test1/fs/ext3/Makefile~iopen-2.6.0 2003-08-24 12:58:32.000000000 +0400
++++ linux-2.6.0-test1-alexey/fs/ext3/Makefile 2003-08-24 13:02:40.000000000 +0400
+@@ -5,7 +5,7 @@
+ obj-$(CONFIG_EXT3_FS) += ext3.o
+
+ ext3-y := balloc.o bitmap.o dir.o file.o fsync.o ialloc.o inode.o \
+- ioctl.o namei.o super.o symlink.o hash.o
++ iopen.o ioctl.o namei.o super.o symlink.o hash.o
+
+ ext3-$(CONFIG_EXT3_FS_XATTR) += xattr.o xattr_user.o xattr_trusted.o
+ ext3-$(CONFIG_EXT3_FS_POSIX_ACL) += acl.o
+--- linux-2.6.0-test1/fs/ext3/namei.c~iopen-2.6.0 2003-07-24 15:52:30.000000000 +0400
++++ linux-2.6.0-test1-alexey/fs/ext3/namei.c 2003-08-24 13:02:02.000000000 +0400
+@@ -37,6 +37,7 @@
+ #include <linux/buffer_head.h>
+ #include <linux/smp_lock.h>
+ #include "xattr.h"
++#include "iopen.h"
+ #include "acl.h"
+
+ /*
+@@ -970,15 +971,21 @@ errout:
+ }
+ #endif
+
++struct dentry *iopen_connect_dentry(struct dentry *de, struct inode *inode);
++
+ static struct dentry *ext3_lookup(struct inode * dir, struct dentry *dentry, struct nameidata *nd)
+ {
+ struct inode * inode;
+ struct ext3_dir_entry_2 * de;
+ struct buffer_head * bh;
++ struct dentry *alternate = NULL;
+
+ if (dentry->d_name.len > EXT3_NAME_LEN)
+ return ERR_PTR(-ENAMETOOLONG);
+
++ if (ext3_check_for_iopen(dir, dentry))
++ return NULL;
++
+ bh = ext3_find_entry(dentry, &de);
+ inode = NULL;
+ if (bh) {
+@@ -991,6 +998,12 @@ static struct dentry *ext3_lookup(struct
+ }
+ if (inode)
+ return d_splice_alias(inode, dentry);
++
++ if (inode && (alternate = iopen_connect_dentry(dentry, inode))) {
++ iput(inode);
++ return alternate;
++ }
++
+ d_add(dentry, inode);
+ return NULL;
+ }
+--- linux-2.6.0-test1/fs/ext3/super.c~iopen-2.6.0 2003-08-24 13:00:36.000000000 +0400
++++ linux-2.6.0-test1-alexey/fs/ext3/super.c 2003-08-24 13:02:02.000000000 +0400
+@@ -755,6 +755,17 @@ static int parse_options (char * options
+ || !strcmp (this_char, "quota")
+ || !strcmp (this_char, "usrquota"))
+ /* Don't do anything ;-) */ ;
++ else if (!strcmp (this_char, "iopen")) {
++ set_opt (sbi->s_mount_opt, IOPEN);
++ clear_opt (sbi->s_mount_opt, IOPEN_NOPRIV);
++ } else if (!strcmp (this_char, "noiopen")) {
++ clear_opt (sbi->s_mount_opt, IOPEN);
++ clear_opt (sbi->s_mount_opt, IOPEN_NOPRIV);
++ }
++ else if (!strcmp (this_char, "iopen_nopriv")) {
++ set_opt (sbi->s_mount_opt, IOPEN);
++ set_opt (sbi->s_mount_opt, IOPEN_NOPRIV);
++ }
+ else if (!strcmp (this_char, "journal")) {
+ /* @@@ FIXME */
+ /* Eventually we will want to be able to create
+--- linux-2.6.0-test1/include/linux/ext3_fs.h~iopen-2.6.0 2003-08-24 12:58:57.000000000 +0400
++++ linux-2.6.0-test1-alexey/include/linux/ext3_fs.h 2003-08-24 13:02:02.000000000 +0400
+@@ -324,6 +324,8 @@ struct ext3_inode {
+ #define EXT3_MOUNT_NO_UID32 0x2000 /* Disable 32-bit UIDs */
+ #define EXT3_MOUNT_XATTR_USER 0x4000 /* Extended user attributes */
+ #define EXT3_MOUNT_POSIX_ACL 0x8000 /* POSIX Access Control Lists */
++#define EXT3_MOUNT_IOPEN 0x10000 /* Allow access via iopen */
++#define EXT3_MOUNT_IOPEN_NOPRIV 0x20000 /* Make iopen world-readable */
+
+ /* Compatibility, for having both ext2_fs.h and ext3_fs.h included at once */
+ #ifndef _LINUX_EXT2_FS_H
+
+_