1 Documentation/filesystems/ext2.txt | 16 ++
4 fs/ext3/iopen.c | 259 +++++++++++++++++++++++++++++++++++++
8 include/linux/ext3_fs.h | 2
9 8 files changed, 318 insertions(+), 2 deletions(-)
11 Index: linux-2.4.21-chaos/Documentation/filesystems/ext2.txt
12 ===================================================================
13 --- linux-2.4.21-chaos.orig/Documentation/filesystems/ext2.txt 2002-05-08 01:53:59.000000000 +0400
14 +++ linux-2.4.21-chaos/Documentation/filesystems/ext2.txt 2003-12-12 16:19:04.000000000 +0300
17 sb=n Use alternate superblock at this location.
19 +iopen Makes an invisible pseudo-directory called
20 + __iopen__ available in the root directory
21 + of the filesystem. Allows open-by-inode-
22 + number. i.e., inode 3145 can be accessed
23 + via /mntpt/__iopen__/3145
25 +iopen_nopriv This option makes the iopen directory be
26 + world-readable. This may be safer since it
27 + allows daemons to run as an unprivileged user,
28 + however it significantly changes the security
29 + model of a Unix filesystem, since previously
30 + all files under a mode 700 directory were not
31 + generally avilable even if the
32 + permissions on the file itself is
35 grpquota,noquota,quota,usrquota Quota options are silently ignored by ext2.
38 Index: linux-2.4.21-chaos/fs/ext3/Makefile
39 ===================================================================
40 --- linux-2.4.21-chaos.orig/fs/ext3/Makefile 2003-12-12 16:18:36.000000000 +0300
41 +++ linux-2.4.21-chaos/fs/ext3/Makefile 2003-12-12 16:19:04.000000000 +0300
44 export-objs := ext3-exports.o
46 -obj-y := balloc.o bitmap.o dir.o file.o fsync.o ialloc.o inode.o \
47 +obj-y := balloc.o bitmap.o dir.o file.o fsync.o ialloc.o inode.o iopen.o \
48 ioctl.o namei.o super.o symlink.o hash.o ext3-exports.o
51 Index: linux-2.4.21-chaos/fs/ext3/inode.c
52 ===================================================================
53 --- linux-2.4.21-chaos.orig/fs/ext3/inode.c 2003-12-12 16:19:02.000000000 +0300
54 +++ linux-2.4.21-chaos/fs/ext3/inode.c 2003-12-12 16:19:05.000000000 +0300
56 #include <linux/highuid.h>
57 #include <linux/quotaops.h>
58 #include <linux/module.h>
62 * SEARCH_FROM_ZERO forces each block allocation to search from the start
64 struct buffer_head *bh;
67 + if (ext3_iopen_get_inode(inode))
70 if(ext3_get_inode_loc(inode, &iloc))
73 Index: linux-2.4.21-chaos/fs/ext3/iopen.c
74 ===================================================================
75 --- linux-2.4.21-chaos.orig/fs/ext3/iopen.c 2003-01-30 13:24:37.000000000 +0300
76 +++ linux-2.4.21-chaos/fs/ext3/iopen.c 2003-12-12 16:19:05.000000000 +0300
79 + * linux/fs/ext3/iopen.c
81 + * Special support for open by inode number
83 + * Copyright (C) 2001 by Theodore Ts'o (tytso@alum.mit.edu).
85 + * This file may be redistributed under the terms of the GNU General
90 + * - there is only ever a single DCACHE_NFSD_DISCONNECTED dentry alias
91 + * for an inode at one time.
92 + * - there are never both connected and DCACHE_NFSD_DISCONNECTED dentry
93 + * aliases on an inode at the same time.
95 + * If we have any connected dentry aliases for an inode, use one of those
96 + * in iopen_lookup(). Otherwise, we instantiate a single NFSD_DISCONNECTED
97 + * dentry for this inode, which thereafter will be found by the dcache
98 + * when looking up this inode number in __iopen__, so we don't return here
101 + * If we get an inode via a regular name lookup, then we "rename" the
102 + * NFSD_DISCONNECTED dentry to the proper name and parent. This ensures
103 + * existing users of the disconnected dentry will continue to use the same
104 + * dentry as the connected users, and there will never be both kinds of
105 + * dentry aliases at one time.
108 +#include <linux/sched.h>
109 +#include <linux/fs.h>
110 +#include <linux/locks.h>
111 +#include <linux/ext3_jbd.h>
112 +#include <linux/jbd.h>
113 +#include <linux/ext3_fs.h>
114 +#include <linux/smp_lock.h>
118 +#define assert(test) J_ASSERT(test)
121 +#define IOPEN_NAME_LEN 32
124 + * This implements looking up an inode by number.
126 +static struct dentry *iopen_lookup(struct inode *dir, struct dentry *dentry)
128 + struct inode *inode;
130 + struct list_head *lp;
131 + struct dentry *alternate;
132 + char buf[IOPEN_NAME_LEN];
134 + if (dentry->d_name.len >= IOPEN_NAME_LEN)
135 + return ERR_PTR(-ENAMETOOLONG);
137 + memcpy(buf, dentry->d_name.name, dentry->d_name.len);
138 + buf[dentry->d_name.len] = 0;
140 + if (strcmp(buf, ".") == 0)
142 + else if (strcmp(buf, "..") == 0)
143 + ino = EXT3_ROOT_INO;
145 + ino = simple_strtoul(buf, 0, 0);
147 + if ((ino != EXT3_ROOT_INO &&
148 + //ino != EXT3_ACL_IDX_INO &&
149 + //ino != EXT3_ACL_DATA_INO &&
150 + ino < EXT3_FIRST_INO(dir->i_sb)) ||
151 + ino > le32_to_cpu(dir->i_sb->u.ext3_sb.s_es->s_inodes_count))
152 + return ERR_PTR(-ENOENT);
154 + inode = iget(dir->i_sb, ino);
156 + return ERR_PTR(-EACCES);
157 + if (is_bad_inode(inode)) {
159 + return ERR_PTR(-ENOENT);
162 + assert(list_empty(&dentry->d_alias)); /* d_instantiate */
163 + assert(list_empty(&dentry->d_hash)); /* d_rehash */
165 + /* preferrably return a connected dentry */
166 + spin_lock(&dcache_lock);
167 + list_for_each(lp, &inode->i_dentry) {
168 + alternate = list_entry(lp, struct dentry, d_alias);
169 + assert(!(alternate->d_flags & DCACHE_NFSD_DISCONNECTED));
172 + if (!list_empty(&inode->i_dentry)) {
173 + alternate = list_entry(inode->i_dentry.next,
174 + struct dentry, d_alias);
175 + dget_locked(alternate);
176 + alternate->d_vfs_flags |= DCACHE_REFERENCED;
178 + spin_unlock(&dcache_lock);
181 + dentry->d_flags |= DCACHE_NFSD_DISCONNECTED;
183 + /* d_add(), but don't drop dcache_lock before adding dentry to inode */
184 + list_add(&dentry->d_alias, &inode->i_dentry); /* d_instantiate */
185 + dentry->d_inode = inode;
187 + __d_rehash(dentry, 0); /* d_rehash */
188 + spin_unlock(&dcache_lock);
193 +#define do_switch(x,y) do { \
194 + __typeof__ (x) __tmp = x; \
195 + x = y; y = __tmp; } while (0)
197 +static inline void switch_names(struct dentry *dentry, struct dentry *target)
199 + const unsigned char *old_name, *new_name;
201 + memcpy(dentry->d_iname, target->d_iname, DNAME_INLINE_LEN);
202 + old_name = target->d_name.name;
203 + new_name = dentry->d_name.name;
204 + if (old_name == target->d_iname)
205 + old_name = dentry->d_iname;
206 + if (new_name == dentry->d_iname)
207 + new_name = target->d_iname;
208 + target->d_name.name = new_name;
209 + dentry->d_name.name = old_name;
212 +/* This function is spliced into ext3_lookup and does the move of a
213 + * disconnected dentry (if it exists) to a connected dentry.
214 + * Caller must hold dcache_lock.
216 +struct dentry *iopen_connect_dentry(struct dentry *de, struct inode *inode)
218 + struct dentry *tmp, *goal = NULL;
219 + struct list_head *lp;
221 + /* preferrably return a connected dentry */
222 + list_for_each(lp, &inode->i_dentry) {
223 + tmp = list_entry(lp, struct dentry, d_alias);
224 + if (tmp->d_flags & DCACHE_NFSD_DISCONNECTED) {
225 + assert(tmp->d_alias.next == &inode->i_dentry);
226 + assert(tmp->d_alias.prev == &inode->i_dentry);
236 + /* Move the goal to the de hash queue - like d_move() */
237 + goal->d_flags &= ~DCACHE_NFSD_DISCONNECTED;
238 + list_del_init(&goal->d_hash);
240 + list_del(&goal->d_child);
241 + list_del(&de->d_child);
243 + /* Switch the parents and the names.. */
244 + switch_names(goal, de);
245 + do_switch(goal->d_parent, de->d_parent);
246 + do_switch(goal->d_name.len, de->d_name.len);
247 + do_switch(goal->d_name.hash, de->d_name.hash);
249 + /* And add them back to the (new) parent lists */
250 + list_add(&goal->d_child, &goal->d_parent->d_subdirs);
251 + list_add(&de->d_child, &de->d_parent->d_subdirs);
252 + __d_rehash(goal, 0);
258 + * These are the special structures for the iopen pseudo directory.
261 +static struct inode_operations iopen_inode_operations = {
262 + lookup: iopen_lookup, /* BKL held */
265 +static struct file_operations iopen_file_operations = {
266 + read: generic_read_dir,
269 +static int match_dentry(struct dentry *dentry, const char *name)
273 + len = strlen(name);
274 + if (dentry->d_name.len != len)
276 + if (strncmp(dentry->d_name.name, name, len))
282 + * This function is spliced into ext3_lookup and returns 1 the file
283 + * name is __iopen__ and dentry has been filled in appropriately.
285 +int ext3_check_for_iopen(struct inode *dir, struct dentry *dentry)
287 + struct inode *inode;
289 + if (dir->i_ino != EXT3_ROOT_INO ||
290 + !test_opt(dir->i_sb, IOPEN) ||
291 + !match_dentry(dentry, "__iopen__"))
294 + inode = iget(dir->i_sb, EXT3_BAD_INO);
298 + d_add(dentry, inode);
303 + * This function is spliced into read_inode; it returns 1 if inode
304 + * number is the one for /__iopen__, in which case the inode is filled
305 + * in appropriately. Otherwise, this fuction returns 0.
307 +int ext3_iopen_get_inode(struct inode *inode)
309 + if (inode->i_ino != EXT3_BAD_INO)
312 + inode->i_mode = S_IFDIR | S_IRUSR | S_IXUSR;
313 + if (test_opt(inode->i_sb, IOPEN_NOPRIV))
314 + inode->i_mode |= 0777;
317 + inode->i_nlink = 1;
318 + inode->i_size = 4096;
319 + inode->i_atime = CURRENT_TIME;
320 + inode->i_ctime = CURRENT_TIME;
321 + inode->i_mtime = CURRENT_TIME;
322 + inode->u.ext3_i.i_dtime = 0;
323 + inode->i_blksize = PAGE_SIZE; /* This is the optimal IO size
324 + * (for stat), not the fs block
326 + inode->i_blocks = 0;
327 + inode->i_version = 1;
328 + inode->i_generation = 0;
330 + inode->i_op = &iopen_inode_operations;
331 + inode->i_fop = &iopen_file_operations;
332 + inode->i_mapping->a_ops = 0;
336 Index: linux-2.4.21-chaos/fs/ext3/iopen.h
337 ===================================================================
338 --- linux-2.4.21-chaos.orig/fs/ext3/iopen.h 2003-01-30 13:24:37.000000000 +0300
339 +++ linux-2.4.21-chaos/fs/ext3/iopen.h 2003-12-12 16:19:05.000000000 +0300
344 + * Special support for opening files by inode number.
346 + * Copyright (C) 2001 by Theodore Ts'o (tytso@alum.mit.edu).
348 + * This file may be redistributed under the terms of the GNU General
352 +extern int ext3_check_for_iopen(struct inode *dir, struct dentry *dentry);
353 +extern int ext3_iopen_get_inode(struct inode *inode);
354 +extern struct dentry *iopen_connect_dentry(struct dentry *de,
355 + struct inode *inode);
356 Index: linux-2.4.21-chaos/fs/ext3/namei.c
357 ===================================================================
358 --- linux-2.4.21-chaos.orig/fs/ext3/namei.c 2003-12-12 16:18:59.000000000 +0300
359 +++ linux-2.4.21-chaos/fs/ext3/namei.c 2003-12-12 16:19:05.000000000 +0300
361 #include <linux/string.h>
362 #include <linux/locks.h>
363 #include <linux/quotaops.h>
368 * define how far ahead to read directories while searching them.
369 @@ -922,10 +922,14 @@
370 struct inode * inode;
371 struct ext3_dir_entry_2 * de;
372 struct buffer_head * bh;
373 + struct dentry *alternate = NULL;
375 if (dentry->d_name.len > EXT3_NAME_LEN)
376 return ERR_PTR(-ENAMETOOLONG);
378 + if (ext3_check_for_iopen(dir, dentry))
381 bh = ext3_find_entry(dentry, &de);
385 return ERR_PTR(-EACCES);
388 - d_add(dentry, inode);
390 + /* verify this dentry is really new */
391 + assert(!dentry->d_inode);
392 + assert(list_empty(&dentry->d_alias)); /* d_instantiate */
393 + assert(list_empty(&dentry->d_hash)); /* d_rehash */
394 + assert(list_empty(&dentry->d_subdirs));
396 + spin_lock(&dcache_lock);
397 + if (inode && (alternate = iopen_connect_dentry(dentry, inode))) {
398 + spin_unlock(&dcache_lock);
403 + /* d_add(), but don't drop dcache_lock before adding dentry to inode */
404 + if (inode) /* d_instantiate */
405 + list_add(&dentry->d_alias, &inode->i_dentry);
406 + dentry->d_inode = inode;
408 + __d_rehash(dentry, 0); /* d_rehash */
409 + spin_unlock(&dcache_lock);
414 Index: linux-2.4.21-chaos/fs/ext3/super.c
415 ===================================================================
416 --- linux-2.4.21-chaos.orig/fs/ext3/super.c 2003-12-12 16:18:51.000000000 +0300
417 +++ linux-2.4.21-chaos/fs/ext3/super.c 2003-12-12 16:19:05.000000000 +0300
419 || !strcmp (this_char, "quota")
420 || !strcmp (this_char, "usrquota"))
421 /* Don't do anything ;-) */ ;
422 + else if (!strcmp (this_char, "iopen")) {
423 + set_opt (sbi->s_mount_opt, IOPEN);
424 + clear_opt (sbi->s_mount_opt, IOPEN_NOPRIV);
426 + else if (!strcmp (this_char, "noiopen")) {
427 + clear_opt (sbi->s_mount_opt, IOPEN);
428 + clear_opt (sbi->s_mount_opt, IOPEN_NOPRIV);
430 + else if (!strcmp (this_char, "iopen_nopriv")) {
431 + set_opt (sbi->s_mount_opt, IOPEN);
432 + set_opt (sbi->s_mount_opt, IOPEN_NOPRIV);
434 else if (!strcmp (this_char, "journal")) {
436 /* Eventually we will want to be able to create
437 Index: linux-2.4.21-chaos/include/linux/ext3_fs.h
438 ===================================================================
439 --- linux-2.4.21-chaos.orig/include/linux/ext3_fs.h 2003-12-12 16:19:01.000000000 +0300
440 +++ linux-2.4.21-chaos/include/linux/ext3_fs.h 2003-12-12 16:19:05.000000000 +0300
442 #define EXT3_MOUNT_XATTR_USER 0x4000 /* Extended user attributes */
443 #define EXT3_MOUNT_POSIX_ACL 0x8000 /* POSIX Access Control Lists */
444 #define EXT3_MOUNT_ASYNCDEL 0x20000 /* Delayed deletion */
445 +#define EXT3_MOUNT_IOPEN 0x40000 /* Allow access via iopen */
446 +#define EXT3_MOUNT_IOPEN_NOPRIV 0x80000 /* Make iopen world-readable */
448 /* Compatibility, for having both ext2_fs.h and ext3_fs.h included at once */
449 #ifndef _LINUX_EXT2_FS_H