4 * Copyright (C) 1991, 1992 Linus Torvalds
5 * changes by Thomas Schoebel-Theuer
8 #include <linux/module.h>
9 #include <linux/time.h>
11 #include <linux/string.h>
12 #include <linux/smp_lock.h>
13 #include <linux/capability.h>
14 #include <linux/fsnotify.h>
15 #include <linux/fcntl.h>
16 #include <linux/quotaops.h>
17 #include <linux/security.h>
18 #include <linux/proc_fs.h>
19 #include <linux/devpts_fs.h>
20 #include <linux/vs_base.h>
22 /* Taken over from the old code... */
24 /* POSIX UID/GID verification for setting inode attributes. */
25 int inode_change_ok(struct inode *inode, struct iattr *attr)
28 unsigned int ia_valid = attr->ia_valid;
30 /* If force is set do it anyway. */
31 if (ia_valid & ATTR_FORCE)
34 /* Make sure a caller can chown. */
35 if ((ia_valid & ATTR_UID) &&
36 (current->fsuid != inode->i_uid ||
37 attr->ia_uid != inode->i_uid) && !capable(CAP_CHOWN))
40 /* Make sure caller can chgrp. */
41 if ((ia_valid & ATTR_GID) &&
42 (current->fsuid != inode->i_uid ||
43 (!in_group_p(attr->ia_gid) && attr->ia_gid != inode->i_gid)) &&
47 /* Make sure a caller can chmod. */
48 if (ia_valid & ATTR_MODE) {
49 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
51 /* Also check the setgid bit! */
52 if (!in_group_p((ia_valid & ATTR_GID) ? attr->ia_gid :
53 inode->i_gid) && !capable(CAP_FSETID))
54 attr->ia_mode &= ~S_ISGID;
57 /* Check for setting the inode time. */
58 if (ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET)) {
59 if (current->fsuid != inode->i_uid && !capable(CAP_FOWNER))
63 /* Check for evil vserver activity */
64 if (vx_check(0, VS_ADMIN))
67 if (IS_BARRIER(inode)) {
68 vxwprintk(1, "xid=%d messing with the barrier.",
72 switch (inode->i_sb->s_magic) {
73 case PROC_SUPER_MAGIC:
74 /* maybe allow that in the future? */
75 vxwprintk(1, "xid=%d messing with the procfs.",
78 case DEVPTS_SUPER_MAGIC:
79 /* devpts is xid tagged */
80 if (vx_check((xid_t)inode->i_tag, VS_IDENT))
82 vxwprintk(1, "xid=%d messing with the devpts.",
92 EXPORT_SYMBOL(inode_change_ok);
94 int inode_setattr(struct inode * inode, struct iattr * attr)
96 unsigned int ia_valid = attr->ia_valid;
98 if (ia_valid & ATTR_SIZE &&
99 attr->ia_size != i_size_read(inode)) {
100 int error = vmtruncate(inode, attr->ia_size);
105 if (ia_valid & ATTR_UID)
106 inode->i_uid = attr->ia_uid;
107 if (ia_valid & ATTR_GID)
108 inode->i_gid = attr->ia_gid;
109 if ((ia_valid & ATTR_TAG) && IS_TAGGED(inode))
110 inode->i_tag = attr->ia_tag;
111 if (ia_valid & ATTR_ATIME)
112 inode->i_atime = timespec_trunc(attr->ia_atime,
113 inode->i_sb->s_time_gran);
114 if (ia_valid & ATTR_MTIME)
115 inode->i_mtime = timespec_trunc(attr->ia_mtime,
116 inode->i_sb->s_time_gran);
117 if (ia_valid & ATTR_CTIME)
118 inode->i_ctime = timespec_trunc(attr->ia_ctime,
119 inode->i_sb->s_time_gran);
120 if (ia_valid & ATTR_MODE) {
121 umode_t mode = attr->ia_mode;
123 if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
125 inode->i_mode = mode;
127 mark_inode_dirty(inode);
131 EXPORT_SYMBOL(inode_setattr);
133 int notify_change(struct dentry * dentry, struct iattr * attr)
135 struct inode *inode = dentry->d_inode;
139 unsigned int ia_valid = attr->ia_valid;
141 mode = inode->i_mode;
142 now = current_fs_time(inode->i_sb);
144 attr->ia_ctime = now;
145 if (!(ia_valid & ATTR_ATIME_SET))
146 attr->ia_atime = now;
147 if (!(ia_valid & ATTR_MTIME_SET))
148 attr->ia_mtime = now;
149 if (ia_valid & ATTR_KILL_SUID) {
150 attr->ia_valid &= ~ATTR_KILL_SUID;
151 if (mode & S_ISUID) {
152 if (!(ia_valid & ATTR_MODE)) {
153 ia_valid = attr->ia_valid |= ATTR_MODE;
154 attr->ia_mode = inode->i_mode;
156 attr->ia_mode &= ~S_ISUID;
159 if (ia_valid & ATTR_KILL_SGID) {
160 attr->ia_valid &= ~ ATTR_KILL_SGID;
161 if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) {
162 if (!(ia_valid & ATTR_MODE)) {
163 ia_valid = attr->ia_valid |= ATTR_MODE;
164 attr->ia_mode = inode->i_mode;
166 attr->ia_mode &= ~S_ISGID;
172 if (ia_valid & ATTR_SIZE)
173 down_write(&dentry->d_inode->i_alloc_sem);
175 if (inode->i_op && inode->i_op->setattr) {
176 error = security_inode_setattr(dentry, attr);
178 error = inode->i_op->setattr(dentry, attr);
180 error = inode_change_ok(inode, attr);
182 error = security_inode_setattr(dentry, attr);
184 if ((ia_valid & ATTR_UID && attr->ia_uid != inode->i_uid) ||
185 (ia_valid & ATTR_GID && attr->ia_gid != inode->i_gid) ||
186 (ia_valid & ATTR_TAG && attr->ia_tag != inode->i_tag))
187 error = DQUOT_TRANSFER(inode, attr) ? -EDQUOT : 0;
189 error = inode_setattr(inode, attr);
193 if (ia_valid & ATTR_SIZE)
194 up_write(&dentry->d_inode->i_alloc_sem);
197 fsnotify_change(dentry, ia_valid);
202 EXPORT_SYMBOL(notify_change);