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-2.4.19.SuSE/Documentation/filesystems/ext2.txt
12 ===================================================================
13 --- linux-2.4.19.SuSE.orig/Documentation/filesystems/ext2.txt Wed Jul 11 15:44:45 2001
14 +++ linux-2.4.19.SuSE/Documentation/filesystems/ext2.txt Sun Nov 16 01:27:31 2003
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-2.4.19.SuSE/fs/ext3/Makefile
39 ===================================================================
40 --- linux-2.4.19.SuSE.orig/fs/ext3/Makefile Sun Nov 16 00:40:59 2003
41 +++ linux-2.4.19.SuSE/fs/ext3/Makefile Sun Nov 16 01:27:31 2003
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-2.4.19.SuSE/fs/ext3/inode.c
52 ===================================================================
53 --- linux-2.4.19.SuSE.orig/fs/ext3/inode.c Sun Nov 16 01:26:04 2003
54 +++ linux-2.4.19.SuSE/fs/ext3/inode.c Sun Nov 16 01:27:31 2003
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-2.4.19.SuSE/fs/ext3/iopen.c
74 ===================================================================
75 --- linux-2.4.19.SuSE.orig/fs/ext3/iopen.c Sun Nov 16 01:27:31 2003
76 +++ linux-2.4.19.SuSE/fs/ext3/iopen.c Sun Nov 16 01:27:31 2003
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 + /* preferrably return a connected dentry */
163 + spin_lock(&dcache_lock);
164 + list_for_each(lp, &inode->i_dentry) {
165 + alternate = list_entry(lp, struct dentry, d_alias);
166 + assert(!(alternate->d_flags & DCACHE_NFSD_DISCONNECTED));
169 + if (!list_empty(&inode->i_dentry)) {
170 + alternate = list_entry(inode->i_dentry.next,
171 + struct dentry, d_alias);
172 + dget_locked(alternate);
173 + alternate->d_vfs_flags |= DCACHE_REFERENCED;
175 + spin_unlock(&dcache_lock);
178 + dentry->d_flags |= DCACHE_NFSD_DISCONNECTED;
179 + spin_unlock(&dcache_lock);
181 + d_add(dentry, inode);
185 +#define do_switch(x,y) do { \
186 + __typeof__ (x) __tmp = x; \
187 + x = y; y = __tmp; } while (0)
189 +static inline void switch_names(struct dentry *dentry, struct dentry *target)
191 + const unsigned char *old_name, *new_name;
193 + memcpy(dentry->d_iname, target->d_iname, DNAME_INLINE_LEN);
194 + old_name = target->d_name.name;
195 + new_name = dentry->d_name.name;
196 + if (old_name == target->d_iname)
197 + old_name = dentry->d_iname;
198 + if (new_name == dentry->d_iname)
199 + new_name = target->d_iname;
200 + target->d_name.name = new_name;
201 + dentry->d_name.name = old_name;
204 +/* This function is spliced into ext3_lookup and does the move of a
205 + * disconnected dentry (if it exists) to a connected dentry.
207 +struct dentry *iopen_connect_dentry(struct dentry *de, struct inode *inode)
209 + struct dentry *tmp, *goal = NULL;
210 + struct list_head *lp;
212 + /* preferrably return a connected dentry */
213 + spin_lock(&dcache_lock);
214 + /* verify this dentry is really new */
215 + assert(!de->d_inode);
216 + assert(list_empty(&de->d_subdirs));
217 + assert(list_empty(&de->d_alias));
220 + list_for_each(lp, &inode->i_dentry) {
221 + tmp = list_entry(lp, struct dentry, d_alias);
222 + if (tmp->d_flags & DCACHE_NFSD_DISCONNECTED) {
223 + assert(tmp->d_alias.next == &inode->i_dentry);
224 + assert(tmp->d_alias.prev == &inode->i_dentry);
232 + spin_unlock(&dcache_lock);
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);
253 + spin_unlock(&dcache_lock);
259 + * These are the special structures for the iopen pseudo directory.
262 +static struct inode_operations iopen_inode_operations = {
263 + lookup: iopen_lookup, /* BKL held */
266 +static struct file_operations iopen_file_operations = {
267 + read: generic_read_dir,
270 +static int match_dentry(struct dentry *dentry, const char *name)
274 + len = strlen(name);
275 + if (dentry->d_name.len != len)
277 + if (strncmp(dentry->d_name.name, name, len))
283 + * This function is spliced into ext3_lookup and returns 1 the file
284 + * name is __iopen__ and dentry has been filled in appropriately.
286 +int ext3_check_for_iopen(struct inode *dir, struct dentry *dentry)
288 + struct inode *inode;
290 + if (dir->i_ino != EXT3_ROOT_INO ||
291 + !test_opt(dir->i_sb, IOPEN) ||
292 + !match_dentry(dentry, "__iopen__"))
295 + inode = iget(dir->i_sb, EXT3_BAD_INO);
299 + d_add(dentry, inode);
304 + * This function is spliced into read_inode; it returns 1 if inode
305 + * number is the one for /__iopen__, in which case the inode is filled
306 + * in appropriately. Otherwise, this fuction returns 0.
308 +int ext3_iopen_get_inode(struct inode *inode)
310 + if (inode->i_ino != EXT3_BAD_INO)
313 + inode->i_mode = S_IFDIR | S_IRUSR | S_IXUSR;
314 + if (test_opt(inode->i_sb, IOPEN_NOPRIV))
315 + inode->i_mode |= 0777;
318 + inode->i_nlink = 1;
319 + inode->i_size = 4096;
320 + inode->i_atime = CURRENT_TIME;
321 + inode->i_ctime = CURRENT_TIME;
322 + inode->i_mtime = CURRENT_TIME;
323 + inode->u.ext3_i.i_dtime = 0;
324 + inode->i_blksize = PAGE_SIZE; /* This is the optimal IO size
325 + * (for stat), not the fs block
327 + inode->i_blocks = 0;
328 + inode->i_version = 1;
329 + inode->i_generation = 0;
331 + inode->i_op = &iopen_inode_operations;
332 + inode->i_fop = &iopen_file_operations;
333 + inode->i_mapping->a_ops = 0;
337 Index: linux-2.4.19.SuSE/fs/ext3/iopen.h
338 ===================================================================
339 --- linux-2.4.19.SuSE.orig/fs/ext3/iopen.h Sun Nov 16 01:27:31 2003
340 +++ linux-2.4.19.SuSE/fs/ext3/iopen.h Sun Nov 16 01:27:31 2003
345 + * Special support for opening files by inode number.
347 + * Copyright (C) 2001 by Theodore Ts'o (tytso@alum.mit.edu).
349 + * This file may be redistributed under the terms of the GNU General
353 +extern int ext3_check_for_iopen(struct inode *dir, struct dentry *dentry);
354 +extern int ext3_iopen_get_inode(struct inode *inode);
355 Index: linux-2.4.19.SuSE/fs/ext3/namei.c
356 ===================================================================
357 --- linux-2.4.19.SuSE.orig/fs/ext3/namei.c Sun Nov 16 01:23:20 2003
358 +++ linux-2.4.19.SuSE/fs/ext3/namei.c Sun Nov 16 01:27:31 2003
360 #include <linux/string.h>
361 #include <linux/locks.h>
362 #include <linux/quotaops.h>
367 * define how far ahead to read directories while searching them.
368 @@ -922,16 +922,21 @@
372 +struct dentry *iopen_connect_dentry(struct dentry *de, struct inode *inode);
374 static struct dentry *ext3_lookup(struct inode * dir, struct dentry *dentry)
376 struct inode * inode;
377 struct ext3_dir_entry_2 * de;
378 struct buffer_head * bh;
379 + struct dentry *alternate = NULL;
381 if (dentry->d_name.len > EXT3_NAME_LEN)
382 return ERR_PTR(-ENAMETOOLONG);
384 + if (ext3_check_for_iopen(dir, dentry))
387 bh = ext3_find_entry(dentry, &de);
391 return ERR_PTR(-EACCES);
395 + if (inode && (alternate = iopen_connect_dentry(dentry, inode))) {
400 d_add(dentry, inode);
403 Index: linux-2.4.19.SuSE/fs/ext3/super.c
404 ===================================================================
405 --- linux-2.4.19.SuSE.orig/fs/ext3/super.c Sun Nov 16 01:19:22 2003
406 +++ linux-2.4.19.SuSE/fs/ext3/super.c Sun Nov 16 01:27:31 2003
408 || !strcmp (this_char, "quota")
409 || !strcmp (this_char, "usrquota"))
410 /* Don't do anything ;-) */ ;
411 + else if (!strcmp (this_char, "iopen")) {
412 + set_opt (sbi->s_mount_opt, IOPEN);
413 + clear_opt (sbi->s_mount_opt, IOPEN_NOPRIV);
414 + } else if (!strcmp (this_char, "noiopen")) {
415 + clear_opt (sbi->s_mount_opt, IOPEN);
416 + clear_opt (sbi->s_mount_opt, IOPEN_NOPRIV);
418 + else if (!strcmp (this_char, "iopen_nopriv")) {
419 + set_opt (sbi->s_mount_opt, IOPEN);
420 + set_opt (sbi->s_mount_opt, IOPEN_NOPRIV);
422 else if (!strcmp (this_char, "journal")) {
424 /* Eventually we will want to be able to create
425 Index: linux-2.4.19.SuSE/include/linux/ext3_fs.h
426 ===================================================================
427 --- linux-2.4.19.SuSE.orig/include/linux/ext3_fs.h Sun Nov 16 01:25:42 2003
428 +++ linux-2.4.19.SuSE/include/linux/ext3_fs.h Sun Nov 16 01:30:05 2003
430 #define EXT3_MOUNT_XATTR_USER 0x4000 /* Extended user attributes */
431 #define EXT3_MOUNT_POSIX_ACL 0x8000 /* POSIX Access Control Lists */
432 #define EXT3_MOUNT_ASYNCDEL 0x20000 /* Delayed deletion */
433 +#define EXT3_MOUNT_IOPEN 0x40000 /* Allow access via iopen */
434 +#define EXT3_MOUNT_IOPEN_NOPRIV 0x80000 /* Make iopen world-readable */
436 /* Compatibility, for having both ext2_fs.h and ext3_fs.h included at once */
437 #ifndef _LINUX_EXT2_FS_H