Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/fs/attr.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | * changes by Thomas Schoebel-Theuer | |
6 | */ | |
7 | ||
8 | #include <linux/module.h> | |
9 | #include <linux/time.h> | |
10 | #include <linux/mm.h> | |
11 | #include <linux/string.h> | |
16f7e0fe | 12 | #include <linux/capability.h> |
0eeca283 | 13 | #include <linux/fsnotify.h> |
1da177e4 LT |
14 | #include <linux/fcntl.h> |
15 | #include <linux/quotaops.h> | |
16 | #include <linux/security.h> | |
1da177e4 LT |
17 | |
18 | /* Taken over from the old code... */ | |
19 | ||
20 | /* POSIX UID/GID verification for setting inode attributes. */ | |
21 | int inode_change_ok(struct inode *inode, struct iattr *attr) | |
22 | { | |
23 | int retval = -EPERM; | |
24 | unsigned int ia_valid = attr->ia_valid; | |
25 | ||
26 | /* If force is set do it anyway. */ | |
27 | if (ia_valid & ATTR_FORCE) | |
28 | goto fine; | |
29 | ||
30 | /* Make sure a caller can chown. */ | |
31 | if ((ia_valid & ATTR_UID) && | |
32 | (current->fsuid != inode->i_uid || | |
33 | attr->ia_uid != inode->i_uid) && !capable(CAP_CHOWN)) | |
34 | goto error; | |
35 | ||
36 | /* Make sure caller can chgrp. */ | |
37 | if ((ia_valid & ATTR_GID) && | |
38 | (current->fsuid != inode->i_uid || | |
39 | (!in_group_p(attr->ia_gid) && attr->ia_gid != inode->i_gid)) && | |
40 | !capable(CAP_CHOWN)) | |
41 | goto error; | |
42 | ||
43 | /* Make sure a caller can chmod. */ | |
44 | if (ia_valid & ATTR_MODE) { | |
3bd858ab | 45 | if (!is_owner_or_cap(inode)) |
1da177e4 LT |
46 | goto error; |
47 | /* Also check the setgid bit! */ | |
48 | if (!in_group_p((ia_valid & ATTR_GID) ? attr->ia_gid : | |
49 | inode->i_gid) && !capable(CAP_FSETID)) | |
50 | attr->ia_mode &= ~S_ISGID; | |
51 | } | |
52 | ||
53 | /* Check for setting the inode time. */ | |
54 | if (ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET)) { | |
3bd858ab | 55 | if (!is_owner_or_cap(inode)) |
1da177e4 LT |
56 | goto error; |
57 | } | |
58 | fine: | |
59 | retval = 0; | |
60 | error: | |
61 | return retval; | |
62 | } | |
63 | ||
64 | EXPORT_SYMBOL(inode_change_ok); | |
65 | ||
66 | int inode_setattr(struct inode * inode, struct iattr * attr) | |
67 | { | |
68 | unsigned int ia_valid = attr->ia_valid; | |
4a30131e N |
69 | |
70 | if (ia_valid & ATTR_SIZE && | |
71 | attr->ia_size != i_size_read(inode)) { | |
72 | int error = vmtruncate(inode, attr->ia_size); | |
73 | if (error) | |
74 | return error; | |
1da177e4 LT |
75 | } |
76 | ||
77 | if (ia_valid & ATTR_UID) | |
78 | inode->i_uid = attr->ia_uid; | |
79 | if (ia_valid & ATTR_GID) | |
80 | inode->i_gid = attr->ia_gid; | |
81 | if (ia_valid & ATTR_ATIME) | |
82 | inode->i_atime = timespec_trunc(attr->ia_atime, | |
83 | inode->i_sb->s_time_gran); | |
84 | if (ia_valid & ATTR_MTIME) | |
85 | inode->i_mtime = timespec_trunc(attr->ia_mtime, | |
86 | inode->i_sb->s_time_gran); | |
87 | if (ia_valid & ATTR_CTIME) | |
88 | inode->i_ctime = timespec_trunc(attr->ia_ctime, | |
89 | inode->i_sb->s_time_gran); | |
90 | if (ia_valid & ATTR_MODE) { | |
91 | umode_t mode = attr->ia_mode; | |
92 | ||
93 | if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID)) | |
94 | mode &= ~S_ISGID; | |
95 | inode->i_mode = mode; | |
96 | } | |
97 | mark_inode_dirty(inode); | |
4a30131e N |
98 | |
99 | return 0; | |
1da177e4 | 100 | } |
1da177e4 LT |
101 | EXPORT_SYMBOL(inode_setattr); |
102 | ||
1da177e4 LT |
103 | int notify_change(struct dentry * dentry, struct iattr * attr) |
104 | { | |
105 | struct inode *inode = dentry->d_inode; | |
106 | mode_t mode; | |
107 | int error; | |
108 | struct timespec now; | |
109 | unsigned int ia_valid = attr->ia_valid; | |
110 | ||
1da177e4 LT |
111 | mode = inode->i_mode; |
112 | now = current_fs_time(inode->i_sb); | |
113 | ||
114 | attr->ia_ctime = now; | |
115 | if (!(ia_valid & ATTR_ATIME_SET)) | |
116 | attr->ia_atime = now; | |
117 | if (!(ia_valid & ATTR_MTIME_SET)) | |
118 | attr->ia_mtime = now; | |
119 | if (ia_valid & ATTR_KILL_SUID) { | |
120 | attr->ia_valid &= ~ATTR_KILL_SUID; | |
121 | if (mode & S_ISUID) { | |
122 | if (!(ia_valid & ATTR_MODE)) { | |
123 | ia_valid = attr->ia_valid |= ATTR_MODE; | |
124 | attr->ia_mode = inode->i_mode; | |
125 | } | |
126 | attr->ia_mode &= ~S_ISUID; | |
127 | } | |
128 | } | |
129 | if (ia_valid & ATTR_KILL_SGID) { | |
130 | attr->ia_valid &= ~ ATTR_KILL_SGID; | |
131 | if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) { | |
132 | if (!(ia_valid & ATTR_MODE)) { | |
133 | ia_valid = attr->ia_valid |= ATTR_MODE; | |
134 | attr->ia_mode = inode->i_mode; | |
135 | } | |
136 | attr->ia_mode &= ~S_ISGID; | |
137 | } | |
138 | } | |
139 | if (!attr->ia_valid) | |
140 | return 0; | |
141 | ||
142 | if (ia_valid & ATTR_SIZE) | |
143 | down_write(&dentry->d_inode->i_alloc_sem); | |
144 | ||
145 | if (inode->i_op && inode->i_op->setattr) { | |
146 | error = security_inode_setattr(dentry, attr); | |
147 | if (!error) | |
148 | error = inode->i_op->setattr(dentry, attr); | |
149 | } else { | |
150 | error = inode_change_ok(inode, attr); | |
151 | if (!error) | |
152 | error = security_inode_setattr(dentry, attr); | |
153 | if (!error) { | |
154 | if ((ia_valid & ATTR_UID && attr->ia_uid != inode->i_uid) || | |
155 | (ia_valid & ATTR_GID && attr->ia_gid != inode->i_gid)) | |
156 | error = DQUOT_TRANSFER(inode, attr) ? -EDQUOT : 0; | |
157 | if (!error) | |
158 | error = inode_setattr(inode, attr); | |
159 | } | |
160 | } | |
161 | ||
162 | if (ia_valid & ATTR_SIZE) | |
163 | up_write(&dentry->d_inode->i_alloc_sem); | |
164 | ||
0eeca283 RL |
165 | if (!error) |
166 | fsnotify_change(dentry, ia_valid); | |
167 | ||
1da177e4 LT |
168 | return error; |
169 | } | |
170 | ||
171 | EXPORT_SYMBOL(notify_change); |