Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/fs/open.c |
| 3 | * |
| 4 | * Copyright (C) 1991, 1992 Linus Torvalds |
| 5 | */ |
| 6 | |
| 7 | #include <linux/string.h> |
| 8 | #include <linux/mm.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 9 | #include <linux/file.h> |
Al Viro | 9f3acc3 | 2008-04-24 07:44:08 -0400 | [diff] [blame] | 10 | #include <linux/fdtable.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 11 | #include <linux/quotaops.h> |
Robert Love | 0eeca28 | 2005-07-12 17:06:03 -0400 | [diff] [blame] | 12 | #include <linux/fsnotify.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 13 | #include <linux/module.h> |
| 14 | #include <linux/slab.h> |
| 15 | #include <linux/tty.h> |
| 16 | #include <linux/namei.h> |
| 17 | #include <linux/backing-dev.h> |
Randy Dunlap | 16f7e0f | 2006-01-11 12:17:46 -0800 | [diff] [blame] | 18 | #include <linux/capability.h> |
Andrew G. Morgan | 086f731 | 2008-07-04 09:59:58 -0700 | [diff] [blame] | 19 | #include <linux/securebits.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 20 | #include <linux/security.h> |
| 21 | #include <linux/mount.h> |
| 22 | #include <linux/vfs.h> |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 23 | #include <linux/fcntl.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 24 | #include <asm/uaccess.h> |
| 25 | #include <linux/fs.h> |
Yoav Zach | ef3daed | 2005-06-23 00:09:58 -0700 | [diff] [blame] | 26 | #include <linux/personality.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 27 | #include <linux/pagemap.h> |
| 28 | #include <linux/syscalls.h> |
Dipankar Sarma | ab2af1f | 2005-09-09 13:04:13 -0700 | [diff] [blame] | 29 | #include <linux/rcupdate.h> |
Amy Griffis | 73241cc | 2005-11-03 16:00:25 +0000 | [diff] [blame] | 30 | #include <linux/audit.h> |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 31 | #include <linux/falloc.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | |
David Howells | 726c334 | 2006-06-23 02:02:58 -0700 | [diff] [blame] | 33 | int vfs_statfs(struct dentry *dentry, struct kstatfs *buf) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | { |
| 35 | int retval = -ENODEV; |
| 36 | |
David Howells | 726c334 | 2006-06-23 02:02:58 -0700 | [diff] [blame] | 37 | if (dentry) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | retval = -ENOSYS; |
David Howells | 726c334 | 2006-06-23 02:02:58 -0700 | [diff] [blame] | 39 | if (dentry->d_sb->s_op->statfs) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 40 | memset(buf, 0, sizeof(*buf)); |
David Howells | 726c334 | 2006-06-23 02:02:58 -0700 | [diff] [blame] | 41 | retval = security_sb_statfs(dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | if (retval) |
| 43 | return retval; |
David Howells | 726c334 | 2006-06-23 02:02:58 -0700 | [diff] [blame] | 44 | retval = dentry->d_sb->s_op->statfs(dentry, buf); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 45 | if (retval == 0 && buf->f_frsize == 0) |
| 46 | buf->f_frsize = buf->f_bsize; |
| 47 | } |
| 48 | } |
| 49 | return retval; |
| 50 | } |
| 51 | |
| 52 | EXPORT_SYMBOL(vfs_statfs); |
| 53 | |
David Howells | 726c334 | 2006-06-23 02:02:58 -0700 | [diff] [blame] | 54 | static int vfs_statfs_native(struct dentry *dentry, struct statfs *buf) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 55 | { |
| 56 | struct kstatfs st; |
| 57 | int retval; |
| 58 | |
David Howells | 726c334 | 2006-06-23 02:02:58 -0700 | [diff] [blame] | 59 | retval = vfs_statfs(dentry, &st); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 60 | if (retval) |
| 61 | return retval; |
| 62 | |
| 63 | if (sizeof(*buf) == sizeof(st)) |
| 64 | memcpy(buf, &st, sizeof(st)); |
| 65 | else { |
| 66 | if (sizeof buf->f_blocks == 4) { |
Jon Tollefson | f4a67cc | 2008-07-23 21:27:55 -0700 | [diff] [blame] | 67 | if ((st.f_blocks | st.f_bfree | st.f_bavail | |
| 68 | st.f_bsize | st.f_frsize) & |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 69 | 0xffffffff00000000ULL) |
| 70 | return -EOVERFLOW; |
| 71 | /* |
| 72 | * f_files and f_ffree may be -1; it's okay to stuff |
| 73 | * that into 32 bits |
| 74 | */ |
| 75 | if (st.f_files != -1 && |
| 76 | (st.f_files & 0xffffffff00000000ULL)) |
| 77 | return -EOVERFLOW; |
| 78 | if (st.f_ffree != -1 && |
| 79 | (st.f_ffree & 0xffffffff00000000ULL)) |
| 80 | return -EOVERFLOW; |
| 81 | } |
| 82 | |
| 83 | buf->f_type = st.f_type; |
| 84 | buf->f_bsize = st.f_bsize; |
| 85 | buf->f_blocks = st.f_blocks; |
| 86 | buf->f_bfree = st.f_bfree; |
| 87 | buf->f_bavail = st.f_bavail; |
| 88 | buf->f_files = st.f_files; |
| 89 | buf->f_ffree = st.f_ffree; |
| 90 | buf->f_fsid = st.f_fsid; |
| 91 | buf->f_namelen = st.f_namelen; |
| 92 | buf->f_frsize = st.f_frsize; |
| 93 | memset(buf->f_spare, 0, sizeof(buf->f_spare)); |
| 94 | } |
| 95 | return 0; |
| 96 | } |
| 97 | |
David Howells | 726c334 | 2006-06-23 02:02:58 -0700 | [diff] [blame] | 98 | static int vfs_statfs64(struct dentry *dentry, struct statfs64 *buf) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 99 | { |
| 100 | struct kstatfs st; |
| 101 | int retval; |
| 102 | |
David Howells | 726c334 | 2006-06-23 02:02:58 -0700 | [diff] [blame] | 103 | retval = vfs_statfs(dentry, &st); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 104 | if (retval) |
| 105 | return retval; |
| 106 | |
| 107 | if (sizeof(*buf) == sizeof(st)) |
| 108 | memcpy(buf, &st, sizeof(st)); |
| 109 | else { |
| 110 | buf->f_type = st.f_type; |
| 111 | buf->f_bsize = st.f_bsize; |
| 112 | buf->f_blocks = st.f_blocks; |
| 113 | buf->f_bfree = st.f_bfree; |
| 114 | buf->f_bavail = st.f_bavail; |
| 115 | buf->f_files = st.f_files; |
| 116 | buf->f_ffree = st.f_ffree; |
| 117 | buf->f_fsid = st.f_fsid; |
| 118 | buf->f_namelen = st.f_namelen; |
| 119 | buf->f_frsize = st.f_frsize; |
| 120 | memset(buf->f_spare, 0, sizeof(buf->f_spare)); |
| 121 | } |
| 122 | return 0; |
| 123 | } |
| 124 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 125 | asmlinkage long sys_statfs(const char __user *pathname, struct statfs __user * buf) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 126 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 127 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 128 | int error; |
| 129 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 130 | error = user_path(pathname, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 131 | if (!error) { |
| 132 | struct statfs tmp; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 133 | error = vfs_statfs_native(path.dentry, &tmp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 134 | if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) |
| 135 | error = -EFAULT; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 136 | path_put(&path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 137 | } |
| 138 | return error; |
| 139 | } |
| 140 | |
| 141 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 142 | asmlinkage long sys_statfs64(const char __user *pathname, size_t sz, struct statfs64 __user *buf) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 143 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 144 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 145 | long error; |
| 146 | |
| 147 | if (sz != sizeof(*buf)) |
| 148 | return -EINVAL; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 149 | error = user_path(pathname, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 150 | if (!error) { |
| 151 | struct statfs64 tmp; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 152 | error = vfs_statfs64(path.dentry, &tmp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 153 | if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) |
| 154 | error = -EFAULT; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 155 | path_put(&path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 156 | } |
| 157 | return error; |
| 158 | } |
| 159 | |
| 160 | |
| 161 | asmlinkage long sys_fstatfs(unsigned int fd, struct statfs __user * buf) |
| 162 | { |
| 163 | struct file * file; |
| 164 | struct statfs tmp; |
| 165 | int error; |
| 166 | |
| 167 | error = -EBADF; |
| 168 | file = fget(fd); |
| 169 | if (!file) |
| 170 | goto out; |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 171 | error = vfs_statfs_native(file->f_path.dentry, &tmp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 172 | if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) |
| 173 | error = -EFAULT; |
| 174 | fput(file); |
| 175 | out: |
| 176 | return error; |
| 177 | } |
| 178 | |
| 179 | asmlinkage long sys_fstatfs64(unsigned int fd, size_t sz, struct statfs64 __user *buf) |
| 180 | { |
| 181 | struct file * file; |
| 182 | struct statfs64 tmp; |
| 183 | int error; |
| 184 | |
| 185 | if (sz != sizeof(*buf)) |
| 186 | return -EINVAL; |
| 187 | |
| 188 | error = -EBADF; |
| 189 | file = fget(fd); |
| 190 | if (!file) |
| 191 | goto out; |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 192 | error = vfs_statfs64(file->f_path.dentry, &tmp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 193 | if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) |
| 194 | error = -EFAULT; |
| 195 | fput(file); |
| 196 | out: |
| 197 | return error; |
| 198 | } |
| 199 | |
NeilBrown | 4a30131 | 2006-01-08 01:02:39 -0800 | [diff] [blame] | 200 | int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs, |
| 201 | struct file *filp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 202 | { |
| 203 | int err; |
| 204 | struct iattr newattrs; |
| 205 | |
| 206 | /* Not pretty: "inode->i_size" shouldn't really be signed. But it is. */ |
| 207 | if (length < 0) |
| 208 | return -EINVAL; |
| 209 | |
| 210 | newattrs.ia_size = length; |
NeilBrown | 4a30131 | 2006-01-08 01:02:39 -0800 | [diff] [blame] | 211 | newattrs.ia_valid = ATTR_SIZE | time_attrs; |
Miklos Szeredi | cc4e69d | 2005-11-07 00:59:49 -0800 | [diff] [blame] | 212 | if (filp) { |
| 213 | newattrs.ia_file = filp; |
| 214 | newattrs.ia_valid |= ATTR_FILE; |
| 215 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 216 | |
Linus Torvalds | 7b82dc0 | 2007-05-08 20:10:00 -0700 | [diff] [blame] | 217 | /* Remove suid/sgid on truncate too */ |
| 218 | newattrs.ia_valid |= should_remove_suid(dentry); |
| 219 | |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 220 | mutex_lock(&dentry->d_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 221 | err = notify_change(dentry, &newattrs); |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 222 | mutex_unlock(&dentry->d_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 223 | return err; |
| 224 | } |
| 225 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 226 | static long do_sys_truncate(const char __user *pathname, loff_t length) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 227 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 228 | struct path path; |
| 229 | struct inode *inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 230 | int error; |
| 231 | |
| 232 | error = -EINVAL; |
| 233 | if (length < 0) /* sorry, but loff_t says... */ |
| 234 | goto out; |
| 235 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 236 | error = user_path(pathname, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 237 | if (error) |
| 238 | goto out; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 239 | inode = path.dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 240 | |
| 241 | /* For directories it's -EISDIR, for other non-regulars - -EINVAL */ |
| 242 | error = -EISDIR; |
| 243 | if (S_ISDIR(inode->i_mode)) |
| 244 | goto dput_and_out; |
| 245 | |
| 246 | error = -EINVAL; |
| 247 | if (!S_ISREG(inode->i_mode)) |
| 248 | goto dput_and_out; |
| 249 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 250 | error = mnt_want_write(path.mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 251 | if (error) |
| 252 | goto dput_and_out; |
| 253 | |
Al Viro | 256984a | 2008-07-22 08:09:30 -0400 | [diff] [blame] | 254 | error = inode_permission(inode, MAY_WRITE); |
Dave Hansen | 9ac9b84 | 2008-02-15 14:37:52 -0800 | [diff] [blame] | 255 | if (error) |
| 256 | goto mnt_drop_write_and_out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 257 | |
| 258 | error = -EPERM; |
Miklos Szeredi | c82e42d | 2008-06-24 16:50:12 +0200 | [diff] [blame] | 259 | if (IS_APPEND(inode)) |
Dave Hansen | 9ac9b84 | 2008-02-15 14:37:52 -0800 | [diff] [blame] | 260 | goto mnt_drop_write_and_out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 261 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 262 | error = get_write_access(inode); |
| 263 | if (error) |
Dave Hansen | 9ac9b84 | 2008-02-15 14:37:52 -0800 | [diff] [blame] | 264 | goto mnt_drop_write_and_out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 265 | |
david m. richter | 9700382 | 2007-07-31 00:39:12 -0700 | [diff] [blame] | 266 | /* |
| 267 | * Make sure that there are no leases. get_write_access() protects |
| 268 | * against the truncate racing with a lease-granting setlease(). |
| 269 | */ |
| 270 | error = break_lease(inode, FMODE_WRITE); |
| 271 | if (error) |
| 272 | goto put_write_and_out; |
| 273 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 274 | error = locks_verify_truncate(inode, NULL, length); |
Kentaro Takeda | be6d3e5 | 2008-12-17 13:24:15 +0900 | [diff] [blame] | 275 | if (!error) |
| 276 | error = security_path_truncate(&path, length, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 277 | if (!error) { |
| 278 | DQUOT_INIT(inode); |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 279 | error = do_truncate(path.dentry, length, 0, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 280 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 281 | |
david m. richter | 9700382 | 2007-07-31 00:39:12 -0700 | [diff] [blame] | 282 | put_write_and_out: |
| 283 | put_write_access(inode); |
Dave Hansen | 9ac9b84 | 2008-02-15 14:37:52 -0800 | [diff] [blame] | 284 | mnt_drop_write_and_out: |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 285 | mnt_drop_write(path.mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 286 | dput_and_out: |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 287 | path_put(&path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 288 | out: |
| 289 | return error; |
| 290 | } |
| 291 | |
| 292 | asmlinkage long sys_truncate(const char __user * path, unsigned long length) |
| 293 | { |
| 294 | /* on 32-bit boxen it will cut the range 2^31--2^32-1 off */ |
| 295 | return do_sys_truncate(path, (long)length); |
| 296 | } |
| 297 | |
Matt Mackall | b01ec0e | 2006-01-08 01:05:20 -0800 | [diff] [blame] | 298 | static long do_sys_ftruncate(unsigned int fd, loff_t length, int small) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 299 | { |
| 300 | struct inode * inode; |
| 301 | struct dentry *dentry; |
| 302 | struct file * file; |
| 303 | int error; |
| 304 | |
| 305 | error = -EINVAL; |
| 306 | if (length < 0) |
| 307 | goto out; |
| 308 | error = -EBADF; |
| 309 | file = fget(fd); |
| 310 | if (!file) |
| 311 | goto out; |
| 312 | |
| 313 | /* explicitly opened as large or we are on 64-bit box */ |
| 314 | if (file->f_flags & O_LARGEFILE) |
| 315 | small = 0; |
| 316 | |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 317 | dentry = file->f_path.dentry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 318 | inode = dentry->d_inode; |
| 319 | error = -EINVAL; |
| 320 | if (!S_ISREG(inode->i_mode) || !(file->f_mode & FMODE_WRITE)) |
| 321 | goto out_putf; |
| 322 | |
| 323 | error = -EINVAL; |
| 324 | /* Cannot ftruncate over 2^31 bytes without large file support */ |
| 325 | if (small && length > MAX_NON_LFS) |
| 326 | goto out_putf; |
| 327 | |
| 328 | error = -EPERM; |
| 329 | if (IS_APPEND(inode)) |
| 330 | goto out_putf; |
| 331 | |
| 332 | error = locks_verify_truncate(inode, file, length); |
| 333 | if (!error) |
Kentaro Takeda | be6d3e5 | 2008-12-17 13:24:15 +0900 | [diff] [blame] | 334 | error = security_path_truncate(&file->f_path, length, |
| 335 | ATTR_MTIME|ATTR_CTIME); |
| 336 | if (!error) |
Peter Staubach | 6e656be | 2006-06-25 05:48:36 -0700 | [diff] [blame] | 337 | error = do_truncate(dentry, length, ATTR_MTIME|ATTR_CTIME, file); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 338 | out_putf: |
| 339 | fput(file); |
| 340 | out: |
| 341 | return error; |
| 342 | } |
| 343 | |
| 344 | asmlinkage long sys_ftruncate(unsigned int fd, unsigned long length) |
| 345 | { |
Linus Torvalds | 0a489cb | 2006-04-18 13:02:48 -0700 | [diff] [blame] | 346 | long ret = do_sys_ftruncate(fd, length, 1); |
Linus Torvalds | 385910f | 2006-04-18 13:22:59 -0700 | [diff] [blame] | 347 | /* avoid REGPARM breakage on x86: */ |
Roland McGrath | 54a0151 | 2008-04-10 15:37:38 -0700 | [diff] [blame] | 348 | asmlinkage_protect(2, ret, fd, length); |
Linus Torvalds | 0a489cb | 2006-04-18 13:02:48 -0700 | [diff] [blame] | 349 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 350 | } |
| 351 | |
| 352 | /* LFS versions of truncate are only needed on 32 bit machines */ |
| 353 | #if BITS_PER_LONG == 32 |
Heiko Carstens | 6673e0c | 2009-01-14 14:14:02 +0100 | [diff] [blame^] | 354 | SYSCALL_DEFINE(truncate64)(const char __user * path, loff_t length) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 355 | { |
| 356 | return do_sys_truncate(path, length); |
| 357 | } |
Heiko Carstens | 6673e0c | 2009-01-14 14:14:02 +0100 | [diff] [blame^] | 358 | #ifdef CONFIG_HAVE_SYSCALL_WRAPPERS |
| 359 | asmlinkage long SyS_truncate64(long path, loff_t length) |
| 360 | { |
| 361 | return SYSC_truncate64((const char __user *) path, length); |
| 362 | } |
| 363 | SYSCALL_ALIAS(sys_truncate64, SyS_truncate64); |
| 364 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 365 | |
Heiko Carstens | 6673e0c | 2009-01-14 14:14:02 +0100 | [diff] [blame^] | 366 | SYSCALL_DEFINE(ftruncate64)(unsigned int fd, loff_t length) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 367 | { |
Linus Torvalds | 0a489cb | 2006-04-18 13:02:48 -0700 | [diff] [blame] | 368 | long ret = do_sys_ftruncate(fd, length, 0); |
Linus Torvalds | 385910f | 2006-04-18 13:22:59 -0700 | [diff] [blame] | 369 | /* avoid REGPARM breakage on x86: */ |
Roland McGrath | 54a0151 | 2008-04-10 15:37:38 -0700 | [diff] [blame] | 370 | asmlinkage_protect(2, ret, fd, length); |
Linus Torvalds | 0a489cb | 2006-04-18 13:02:48 -0700 | [diff] [blame] | 371 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 372 | } |
Heiko Carstens | 6673e0c | 2009-01-14 14:14:02 +0100 | [diff] [blame^] | 373 | #ifdef CONFIG_HAVE_SYSCALL_WRAPPERS |
| 374 | asmlinkage long SyS_ftruncate64(long fd, loff_t length) |
| 375 | { |
| 376 | return SYSC_ftruncate64((unsigned int) fd, length); |
| 377 | } |
| 378 | SYSCALL_ALIAS(sys_ftruncate64, SyS_ftruncate64); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 379 | #endif |
Heiko Carstens | 6673e0c | 2009-01-14 14:14:02 +0100 | [diff] [blame^] | 380 | #endif /* BITS_PER_LONG == 32 */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 381 | |
Heiko Carstens | 6673e0c | 2009-01-14 14:14:02 +0100 | [diff] [blame^] | 382 | SYSCALL_DEFINE(fallocate)(int fd, int mode, loff_t offset, loff_t len) |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 383 | { |
| 384 | struct file *file; |
| 385 | struct inode *inode; |
| 386 | long ret = -EINVAL; |
| 387 | |
| 388 | if (offset < 0 || len <= 0) |
| 389 | goto out; |
| 390 | |
| 391 | /* Return error if mode is not supported */ |
| 392 | ret = -EOPNOTSUPP; |
| 393 | if (mode && !(mode & FALLOC_FL_KEEP_SIZE)) |
| 394 | goto out; |
| 395 | |
| 396 | ret = -EBADF; |
| 397 | file = fget(fd); |
| 398 | if (!file) |
| 399 | goto out; |
| 400 | if (!(file->f_mode & FMODE_WRITE)) |
| 401 | goto out_fput; |
| 402 | /* |
| 403 | * Revalidate the write permissions, in case security policy has |
| 404 | * changed since the files were opened. |
| 405 | */ |
| 406 | ret = security_file_permission(file, MAY_WRITE); |
| 407 | if (ret) |
| 408 | goto out_fput; |
| 409 | |
| 410 | inode = file->f_path.dentry->d_inode; |
| 411 | |
| 412 | ret = -ESPIPE; |
| 413 | if (S_ISFIFO(inode->i_mode)) |
| 414 | goto out_fput; |
| 415 | |
| 416 | ret = -ENODEV; |
| 417 | /* |
| 418 | * Let individual file system decide if it supports preallocation |
| 419 | * for directories or not. |
| 420 | */ |
| 421 | if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode)) |
| 422 | goto out_fput; |
| 423 | |
| 424 | ret = -EFBIG; |
| 425 | /* Check for wrap through zero too */ |
| 426 | if (((offset + len) > inode->i_sb->s_maxbytes) || ((offset + len) < 0)) |
| 427 | goto out_fput; |
| 428 | |
Al Viro | acfa438 | 2008-12-04 10:06:33 -0500 | [diff] [blame] | 429 | if (inode->i_op->fallocate) |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 430 | ret = inode->i_op->fallocate(inode, mode, offset, len); |
| 431 | else |
Ulrich Drepper | 0d786d4 | 2007-07-23 18:43:46 -0700 | [diff] [blame] | 432 | ret = -EOPNOTSUPP; |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 433 | |
| 434 | out_fput: |
| 435 | fput(file); |
| 436 | out: |
| 437 | return ret; |
| 438 | } |
Heiko Carstens | 6673e0c | 2009-01-14 14:14:02 +0100 | [diff] [blame^] | 439 | #ifdef CONFIG_HAVE_SYSCALL_WRAPPERS |
| 440 | asmlinkage long SyS_fallocate(long fd, long mode, loff_t offset, loff_t len) |
| 441 | { |
| 442 | return SYSC_fallocate((int)fd, (int)mode, offset, len); |
| 443 | } |
| 444 | SYSCALL_ALIAS(sys_fallocate, SyS_fallocate); |
| 445 | #endif |
Amit Arora | 97ac735 | 2007-07-17 21:42:44 -0400 | [diff] [blame] | 446 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 447 | /* |
| 448 | * access() needs to use the real uid/gid, not the effective uid/gid. |
| 449 | * We do this by temporarily clearing all FS-related capabilities and |
| 450 | * switching the fsuid/fsgid around to the real ones. |
| 451 | */ |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 452 | asmlinkage long sys_faccessat(int dfd, const char __user *filename, int mode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 453 | { |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 454 | const struct cred *old_cred; |
| 455 | struct cred *override_cred; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 456 | struct path path; |
Al Viro | 256984a | 2008-07-22 08:09:30 -0400 | [diff] [blame] | 457 | struct inode *inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 458 | int res; |
| 459 | |
| 460 | if (mode & ~S_IRWXO) /* where's F_OK, X_OK, W_OK, R_OK? */ |
| 461 | return -EINVAL; |
| 462 | |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 463 | override_cred = prepare_creds(); |
| 464 | if (!override_cred) |
| 465 | return -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 466 | |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 467 | override_cred->fsuid = override_cred->uid; |
| 468 | override_cred->fsgid = override_cred->gid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 469 | |
Andrew G. Morgan | 086f731 | 2008-07-04 09:59:58 -0700 | [diff] [blame] | 470 | if (!issecure(SECURE_NO_SETUID_FIXUP)) { |
David Howells | 1cdcbec | 2008-11-14 10:39:14 +1100 | [diff] [blame] | 471 | /* Clear the capabilities if we switch to a non-root user */ |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 472 | if (override_cred->uid) |
| 473 | cap_clear(override_cred->cap_effective); |
Andrew G. Morgan | 086f731 | 2008-07-04 09:59:58 -0700 | [diff] [blame] | 474 | else |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 475 | override_cred->cap_effective = |
| 476 | override_cred->cap_permitted; |
Andrew G. Morgan | 086f731 | 2008-07-04 09:59:58 -0700 | [diff] [blame] | 477 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 478 | |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 479 | old_cred = override_creds(override_cred); |
| 480 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 481 | res = user_path_at(dfd, filename, LOOKUP_FOLLOW, &path); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 482 | if (res) |
| 483 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 484 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 485 | inode = path.dentry->d_inode; |
Al Viro | 256984a | 2008-07-22 08:09:30 -0400 | [diff] [blame] | 486 | |
| 487 | if ((mode & MAY_EXEC) && S_ISREG(inode->i_mode)) { |
Al Viro | 3052447 | 2008-07-22 00:02:33 -0400 | [diff] [blame] | 488 | /* |
| 489 | * MAY_EXEC on regular files is denied if the fs is mounted |
| 490 | * with the "noexec" flag. |
| 491 | */ |
| 492 | res = -EACCES; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 493 | if (path.mnt->mnt_flags & MNT_NOEXEC) |
Al Viro | 3052447 | 2008-07-22 00:02:33 -0400 | [diff] [blame] | 494 | goto out_path_release; |
| 495 | } |
| 496 | |
Al Viro | 256984a | 2008-07-22 08:09:30 -0400 | [diff] [blame] | 497 | res = inode_permission(inode, mode | MAY_ACCESS); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 498 | /* SuS v2 requires we report a read only fs too */ |
Al Viro | 256984a | 2008-07-22 08:09:30 -0400 | [diff] [blame] | 499 | if (res || !(mode & S_IWOTH) || special_file(inode->i_mode)) |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 500 | goto out_path_release; |
Dave Hansen | 2f676cb | 2008-02-15 14:37:55 -0800 | [diff] [blame] | 501 | /* |
| 502 | * This is a rare case where using __mnt_is_readonly() |
| 503 | * is OK without a mnt_want/drop_write() pair. Since |
| 504 | * no actual write to the fs is performed here, we do |
| 505 | * not need to telegraph to that to anyone. |
| 506 | * |
| 507 | * By doing this, we accept that this access is |
| 508 | * inherently racy and know that the fs may change |
| 509 | * state before we even see this result. |
| 510 | */ |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 511 | if (__mnt_is_readonly(path.mnt)) |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 512 | res = -EROFS; |
| 513 | |
| 514 | out_path_release: |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 515 | path_put(&path); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 516 | out: |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 517 | revert_creds(old_cred); |
| 518 | put_cred(override_cred); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 519 | return res; |
| 520 | } |
| 521 | |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 522 | asmlinkage long sys_access(const char __user *filename, int mode) |
| 523 | { |
| 524 | return sys_faccessat(AT_FDCWD, filename, mode); |
| 525 | } |
| 526 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 527 | asmlinkage long sys_chdir(const char __user * filename) |
| 528 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 529 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 530 | int error; |
| 531 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 532 | error = user_path_dir(filename, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 533 | if (error) |
| 534 | goto out; |
| 535 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 536 | error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_ACCESS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 537 | if (error) |
| 538 | goto dput_and_out; |
| 539 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 540 | set_fs_pwd(current->fs, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 541 | |
| 542 | dput_and_out: |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 543 | path_put(&path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 544 | out: |
| 545 | return error; |
| 546 | } |
| 547 | |
| 548 | asmlinkage long sys_fchdir(unsigned int fd) |
| 549 | { |
| 550 | struct file *file; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 551 | struct inode *inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 552 | int error; |
| 553 | |
| 554 | error = -EBADF; |
| 555 | file = fget(fd); |
| 556 | if (!file) |
| 557 | goto out; |
| 558 | |
Jan Blunck | ac748a0 | 2008-02-14 19:34:39 -0800 | [diff] [blame] | 559 | inode = file->f_path.dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 560 | |
| 561 | error = -ENOTDIR; |
| 562 | if (!S_ISDIR(inode->i_mode)) |
| 563 | goto out_putf; |
| 564 | |
Al Viro | 256984a | 2008-07-22 08:09:30 -0400 | [diff] [blame] | 565 | error = inode_permission(inode, MAY_EXEC | MAY_ACCESS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 566 | if (!error) |
Jan Blunck | ac748a0 | 2008-02-14 19:34:39 -0800 | [diff] [blame] | 567 | set_fs_pwd(current->fs, &file->f_path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 568 | out_putf: |
| 569 | fput(file); |
| 570 | out: |
| 571 | return error; |
| 572 | } |
| 573 | |
| 574 | asmlinkage long sys_chroot(const char __user * filename) |
| 575 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 576 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 577 | int error; |
| 578 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 579 | error = user_path_dir(filename, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 580 | if (error) |
| 581 | goto out; |
| 582 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 583 | error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_ACCESS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 584 | if (error) |
| 585 | goto dput_and_out; |
| 586 | |
| 587 | error = -EPERM; |
| 588 | if (!capable(CAP_SYS_CHROOT)) |
| 589 | goto dput_and_out; |
| 590 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 591 | set_fs_root(current->fs, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 592 | error = 0; |
| 593 | dput_and_out: |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 594 | path_put(&path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 595 | out: |
| 596 | return error; |
| 597 | } |
| 598 | |
| 599 | asmlinkage long sys_fchmod(unsigned int fd, mode_t mode) |
| 600 | { |
| 601 | struct inode * inode; |
| 602 | struct dentry * dentry; |
| 603 | struct file * file; |
| 604 | int err = -EBADF; |
| 605 | struct iattr newattrs; |
| 606 | |
| 607 | file = fget(fd); |
| 608 | if (!file) |
| 609 | goto out; |
| 610 | |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 611 | dentry = file->f_path.dentry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 612 | inode = dentry->d_inode; |
| 613 | |
Al Viro | 5a190ae | 2007-06-07 12:19:32 -0400 | [diff] [blame] | 614 | audit_inode(NULL, dentry); |
Amy Griffis | 73241cc | 2005-11-03 16:00:25 +0000 | [diff] [blame] | 615 | |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 616 | err = mnt_want_write(file->f_path.mnt); |
| 617 | if (err) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 618 | goto out_putf; |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 619 | mutex_lock(&inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 620 | if (mode == (mode_t) -1) |
| 621 | mode = inode->i_mode; |
| 622 | newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); |
| 623 | newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; |
| 624 | err = notify_change(dentry, &newattrs); |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 625 | mutex_unlock(&inode->i_mutex); |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 626 | mnt_drop_write(file->f_path.mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 627 | out_putf: |
| 628 | fput(file); |
| 629 | out: |
| 630 | return err; |
| 631 | } |
| 632 | |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 633 | asmlinkage long sys_fchmodat(int dfd, const char __user *filename, |
| 634 | mode_t mode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 635 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 636 | struct path path; |
| 637 | struct inode *inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 638 | int error; |
| 639 | struct iattr newattrs; |
| 640 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 641 | error = user_path_at(dfd, filename, LOOKUP_FOLLOW, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 642 | if (error) |
| 643 | goto out; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 644 | inode = path.dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 645 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 646 | error = mnt_want_write(path.mnt); |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 647 | if (error) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 648 | goto dput_and_out; |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 649 | mutex_lock(&inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 650 | if (mode == (mode_t) -1) |
| 651 | mode = inode->i_mode; |
| 652 | newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); |
| 653 | newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 654 | error = notify_change(path.dentry, &newattrs); |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 655 | mutex_unlock(&inode->i_mutex); |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 656 | mnt_drop_write(path.mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 657 | dput_and_out: |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 658 | path_put(&path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 659 | out: |
| 660 | return error; |
| 661 | } |
| 662 | |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 663 | asmlinkage long sys_chmod(const char __user *filename, mode_t mode) |
| 664 | { |
| 665 | return sys_fchmodat(AT_FDCWD, filename, mode); |
| 666 | } |
| 667 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 668 | static int chown_common(struct dentry * dentry, uid_t user, gid_t group) |
| 669 | { |
Miklos Szeredi | beb29e0 | 2008-07-01 15:01:29 +0200 | [diff] [blame] | 670 | struct inode *inode = dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 671 | int error; |
| 672 | struct iattr newattrs; |
| 673 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 674 | newattrs.ia_valid = ATTR_CTIME; |
| 675 | if (user != (uid_t) -1) { |
| 676 | newattrs.ia_valid |= ATTR_UID; |
| 677 | newattrs.ia_uid = user; |
| 678 | } |
| 679 | if (group != (gid_t) -1) { |
| 680 | newattrs.ia_valid |= ATTR_GID; |
| 681 | newattrs.ia_gid = group; |
| 682 | } |
| 683 | if (!S_ISDIR(inode->i_mode)) |
Serge E. Hallyn | b537677 | 2007-10-16 23:31:36 -0700 | [diff] [blame] | 684 | newattrs.ia_valid |= |
| 685 | ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV; |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 686 | mutex_lock(&inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 687 | error = notify_change(dentry, &newattrs); |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 688 | mutex_unlock(&inode->i_mutex); |
Miklos Szeredi | beb29e0 | 2008-07-01 15:01:29 +0200 | [diff] [blame] | 689 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 690 | return error; |
| 691 | } |
| 692 | |
| 693 | asmlinkage long sys_chown(const char __user * filename, uid_t user, gid_t group) |
| 694 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 695 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 696 | int error; |
| 697 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 698 | error = user_path(filename, &path); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 699 | if (error) |
| 700 | goto out; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 701 | error = mnt_want_write(path.mnt); |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 702 | if (error) |
| 703 | goto out_release; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 704 | error = chown_common(path.dentry, user, group); |
| 705 | mnt_drop_write(path.mnt); |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 706 | out_release: |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 707 | path_put(&path); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 708 | out: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 709 | return error; |
| 710 | } |
| 711 | |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 712 | asmlinkage long sys_fchownat(int dfd, const char __user *filename, uid_t user, |
| 713 | gid_t group, int flag) |
| 714 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 715 | struct path path; |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 716 | int error = -EINVAL; |
| 717 | int follow; |
| 718 | |
| 719 | if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0) |
| 720 | goto out; |
| 721 | |
| 722 | follow = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 723 | error = user_path_at(dfd, filename, follow, &path); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 724 | if (error) |
| 725 | goto out; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 726 | error = mnt_want_write(path.mnt); |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 727 | if (error) |
| 728 | goto out_release; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 729 | error = chown_common(path.dentry, user, group); |
| 730 | mnt_drop_write(path.mnt); |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 731 | out_release: |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 732 | path_put(&path); |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 733 | out: |
| 734 | return error; |
| 735 | } |
| 736 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 737 | asmlinkage long sys_lchown(const char __user * filename, uid_t user, gid_t group) |
| 738 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 739 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 740 | int error; |
| 741 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 742 | error = user_lpath(filename, &path); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 743 | if (error) |
| 744 | goto out; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 745 | error = mnt_want_write(path.mnt); |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 746 | if (error) |
| 747 | goto out_release; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 748 | error = chown_common(path.dentry, user, group); |
| 749 | mnt_drop_write(path.mnt); |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 750 | out_release: |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 751 | path_put(&path); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 752 | out: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 753 | return error; |
| 754 | } |
| 755 | |
| 756 | |
| 757 | asmlinkage long sys_fchown(unsigned int fd, uid_t user, gid_t group) |
| 758 | { |
| 759 | struct file * file; |
| 760 | int error = -EBADF; |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 761 | struct dentry * dentry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 762 | |
| 763 | file = fget(fd); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 764 | if (!file) |
| 765 | goto out; |
| 766 | |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 767 | error = mnt_want_write(file->f_path.mnt); |
| 768 | if (error) |
| 769 | goto out_fput; |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 770 | dentry = file->f_path.dentry; |
Al Viro | 5a190ae | 2007-06-07 12:19:32 -0400 | [diff] [blame] | 771 | audit_inode(NULL, dentry); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 772 | error = chown_common(dentry, user, group); |
Dave Hansen | 2af482a | 2008-02-15 14:37:50 -0800 | [diff] [blame] | 773 | mnt_drop_write(file->f_path.mnt); |
| 774 | out_fput: |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 775 | fput(file); |
| 776 | out: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 777 | return error; |
| 778 | } |
| 779 | |
Dave Hansen | 4a3fd21 | 2008-02-15 14:37:48 -0800 | [diff] [blame] | 780 | /* |
| 781 | * You have to be very careful that these write |
| 782 | * counts get cleaned up in error cases and |
| 783 | * upon __fput(). This should probably never |
| 784 | * be called outside of __dentry_open(). |
| 785 | */ |
| 786 | static inline int __get_file_write_access(struct inode *inode, |
| 787 | struct vfsmount *mnt) |
| 788 | { |
| 789 | int error; |
| 790 | error = get_write_access(inode); |
| 791 | if (error) |
| 792 | return error; |
| 793 | /* |
| 794 | * Do not take mount writer counts on |
| 795 | * special files since no writes to |
| 796 | * the mount itself will occur. |
| 797 | */ |
| 798 | if (!special_file(inode->i_mode)) { |
| 799 | /* |
| 800 | * Balanced in __fput() |
| 801 | */ |
| 802 | error = mnt_want_write(mnt); |
| 803 | if (error) |
| 804 | put_write_access(inode); |
| 805 | } |
| 806 | return error; |
| 807 | } |
| 808 | |
Peter Staubach | a1a5b3d | 2005-09-13 01:25:12 -0700 | [diff] [blame] | 809 | static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt, |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 810 | int flags, struct file *f, |
David Howells | 745ca24 | 2008-11-14 10:39:22 +1100 | [diff] [blame] | 811 | int (*open)(struct inode *, struct file *), |
| 812 | const struct cred *cred) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 813 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 814 | struct inode *inode; |
| 815 | int error; |
| 816 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 817 | f->f_flags = flags; |
Al Viro | aeb5d72 | 2008-09-02 15:28:45 -0400 | [diff] [blame] | 818 | f->f_mode = (__force fmode_t)((flags+1) & O_ACCMODE) | FMODE_LSEEK | |
Peter Staubach | a1a5b3d | 2005-09-13 01:25:12 -0700 | [diff] [blame] | 819 | FMODE_PREAD | FMODE_PWRITE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 820 | inode = dentry->d_inode; |
| 821 | if (f->f_mode & FMODE_WRITE) { |
Dave Hansen | 4a3fd21 | 2008-02-15 14:37:48 -0800 | [diff] [blame] | 822 | error = __get_file_write_access(inode, mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 823 | if (error) |
| 824 | goto cleanup_file; |
Dave Hansen | ad775f5 | 2008-02-15 14:38:01 -0800 | [diff] [blame] | 825 | if (!special_file(inode->i_mode)) |
| 826 | file_take_write(f); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 827 | } |
| 828 | |
| 829 | f->f_mapping = inode->i_mapping; |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 830 | f->f_path.dentry = dentry; |
| 831 | f->f_path.mnt = mnt; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 832 | f->f_pos = 0; |
| 833 | f->f_op = fops_get(inode->i_fop); |
| 834 | file_move(f, &inode->i_sb->s_files); |
| 835 | |
David Howells | 745ca24 | 2008-11-14 10:39:22 +1100 | [diff] [blame] | 836 | error = security_dentry_open(f, cred); |
Yuichi Nakamura | 788e7dd | 2007-09-14 09:27:07 +0900 | [diff] [blame] | 837 | if (error) |
| 838 | goto cleanup_all; |
| 839 | |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 840 | if (!open && f->f_op) |
| 841 | open = f->f_op->open; |
| 842 | if (open) { |
| 843 | error = open(inode, f); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 844 | if (error) |
| 845 | goto cleanup_all; |
| 846 | } |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 847 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 848 | f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC); |
| 849 | |
| 850 | file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping); |
| 851 | |
| 852 | /* NB: we're sure to have correct a_ops only after f_op->open */ |
| 853 | if (f->f_flags & O_DIRECT) { |
Carsten Otte | ceffc07 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 854 | if (!f->f_mapping->a_ops || |
| 855 | ((!f->f_mapping->a_ops->direct_IO) && |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 856 | (!f->f_mapping->a_ops->get_xip_mem))) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 857 | fput(f); |
| 858 | f = ERR_PTR(-EINVAL); |
| 859 | } |
| 860 | } |
| 861 | |
| 862 | return f; |
| 863 | |
| 864 | cleanup_all: |
| 865 | fops_put(f->f_op); |
Dave Hansen | 4a3fd21 | 2008-02-15 14:37:48 -0800 | [diff] [blame] | 866 | if (f->f_mode & FMODE_WRITE) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 867 | put_write_access(inode); |
Dave Hansen | ad775f5 | 2008-02-15 14:38:01 -0800 | [diff] [blame] | 868 | if (!special_file(inode->i_mode)) { |
| 869 | /* |
| 870 | * We don't consider this a real |
| 871 | * mnt_want/drop_write() pair |
| 872 | * because it all happenend right |
| 873 | * here, so just reset the state. |
| 874 | */ |
| 875 | file_reset_write(f); |
Dave Hansen | 4a3fd21 | 2008-02-15 14:37:48 -0800 | [diff] [blame] | 876 | mnt_drop_write(mnt); |
Dave Hansen | ad775f5 | 2008-02-15 14:38:01 -0800 | [diff] [blame] | 877 | } |
Dave Hansen | 4a3fd21 | 2008-02-15 14:37:48 -0800 | [diff] [blame] | 878 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 879 | file_kill(f); |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 880 | f->f_path.dentry = NULL; |
| 881 | f->f_path.mnt = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 882 | cleanup_file: |
| 883 | put_filp(f); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 884 | dput(dentry); |
| 885 | mntput(mnt); |
| 886 | return ERR_PTR(error); |
| 887 | } |
| 888 | |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 889 | /** |
| 890 | * lookup_instantiate_filp - instantiates the open intent filp |
| 891 | * @nd: pointer to nameidata |
| 892 | * @dentry: pointer to dentry |
| 893 | * @open: open callback |
| 894 | * |
| 895 | * Helper for filesystems that want to use lookup open intents and pass back |
| 896 | * a fully instantiated struct file to the caller. |
| 897 | * This function is meant to be called from within a filesystem's |
| 898 | * lookup method. |
Oleg Drokin | 9a56c21 | 2006-03-25 03:07:02 -0800 | [diff] [blame] | 899 | * Beware of calling it for non-regular files! Those ->open methods might block |
| 900 | * (e.g. in fifo_open), leaving you with parent locked (and in case of fifo, |
| 901 | * leading to a deadlock, as nobody can open that fifo anymore, because |
| 902 | * another process to open fifo will block on locked parent when doing lookup). |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 903 | * Note that in case of error, nd->intent.open.file is destroyed, but the |
| 904 | * path information remains valid. |
| 905 | * If the open callback is set to NULL, then the standard f_op->open() |
| 906 | * filesystem callback is substituted. |
| 907 | */ |
| 908 | struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry, |
| 909 | int (*open)(struct inode *, struct file *)) |
| 910 | { |
David Howells | 745ca24 | 2008-11-14 10:39:22 +1100 | [diff] [blame] | 911 | const struct cred *cred = current_cred(); |
| 912 | |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 913 | if (IS_ERR(nd->intent.open.file)) |
| 914 | goto out; |
| 915 | if (IS_ERR(dentry)) |
| 916 | goto out_err; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 917 | nd->intent.open.file = __dentry_open(dget(dentry), mntget(nd->path.mnt), |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 918 | nd->intent.open.flags - 1, |
| 919 | nd->intent.open.file, |
David Howells | 745ca24 | 2008-11-14 10:39:22 +1100 | [diff] [blame] | 920 | open, cred); |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 921 | out: |
| 922 | return nd->intent.open.file; |
| 923 | out_err: |
| 924 | release_open_intent(nd); |
| 925 | nd->intent.open.file = (struct file *)dentry; |
| 926 | goto out; |
| 927 | } |
| 928 | EXPORT_SYMBOL_GPL(lookup_instantiate_filp); |
| 929 | |
| 930 | /** |
| 931 | * nameidata_to_filp - convert a nameidata to an open filp. |
| 932 | * @nd: pointer to nameidata |
| 933 | * @flags: open flags |
| 934 | * |
| 935 | * Note that this function destroys the original nameidata |
| 936 | */ |
| 937 | struct file *nameidata_to_filp(struct nameidata *nd, int flags) |
| 938 | { |
David Howells | 745ca24 | 2008-11-14 10:39:22 +1100 | [diff] [blame] | 939 | const struct cred *cred = current_cred(); |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 940 | struct file *filp; |
| 941 | |
| 942 | /* Pick up the filp from the open intent */ |
| 943 | filp = nd->intent.open.file; |
| 944 | /* Has the filesystem initialised the file for us? */ |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 945 | if (filp->f_path.dentry == NULL) |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 946 | filp = __dentry_open(nd->path.dentry, nd->path.mnt, flags, filp, |
David Howells | 745ca24 | 2008-11-14 10:39:22 +1100 | [diff] [blame] | 947 | NULL, cred); |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 948 | else |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 949 | path_put(&nd->path); |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 950 | return filp; |
| 951 | } |
| 952 | |
Peter Staubach | 6fdcc21 | 2005-11-07 00:59:42 -0800 | [diff] [blame] | 953 | /* |
| 954 | * dentry_open() will have done dput(dentry) and mntput(mnt) if it returns an |
| 955 | * error. |
| 956 | */ |
David Howells | 745ca24 | 2008-11-14 10:39:22 +1100 | [diff] [blame] | 957 | struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags, |
| 958 | const struct cred *cred) |
Peter Staubach | a1a5b3d | 2005-09-13 01:25:12 -0700 | [diff] [blame] | 959 | { |
| 960 | int error; |
| 961 | struct file *f; |
| 962 | |
Christoph Hellwig | 322ee5b | 2008-02-15 14:37:24 -0800 | [diff] [blame] | 963 | /* |
| 964 | * We must always pass in a valid mount pointer. Historically |
| 965 | * callers got away with not passing it, but we must enforce this at |
| 966 | * the earliest possible point now to avoid strange problems deep in the |
| 967 | * filesystem stack. |
| 968 | */ |
| 969 | if (!mnt) { |
| 970 | printk(KERN_WARNING "%s called with NULL vfsmount\n", __func__); |
| 971 | dump_stack(); |
| 972 | return ERR_PTR(-EINVAL); |
| 973 | } |
| 974 | |
Peter Staubach | a1a5b3d | 2005-09-13 01:25:12 -0700 | [diff] [blame] | 975 | error = -ENFILE; |
| 976 | f = get_empty_filp(); |
Peter Staubach | 6fdcc21 | 2005-11-07 00:59:42 -0800 | [diff] [blame] | 977 | if (f == NULL) { |
| 978 | dput(dentry); |
| 979 | mntput(mnt); |
Peter Staubach | a1a5b3d | 2005-09-13 01:25:12 -0700 | [diff] [blame] | 980 | return ERR_PTR(error); |
Peter Staubach | 6fdcc21 | 2005-11-07 00:59:42 -0800 | [diff] [blame] | 981 | } |
Peter Staubach | a1a5b3d | 2005-09-13 01:25:12 -0700 | [diff] [blame] | 982 | |
David Howells | 745ca24 | 2008-11-14 10:39:22 +1100 | [diff] [blame] | 983 | return __dentry_open(dentry, mnt, flags, f, NULL, cred); |
Peter Staubach | a1a5b3d | 2005-09-13 01:25:12 -0700 | [diff] [blame] | 984 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 985 | EXPORT_SYMBOL(dentry_open); |
| 986 | |
Matt Mackall | b01ec0e | 2006-01-08 01:05:20 -0800 | [diff] [blame] | 987 | static void __put_unused_fd(struct files_struct *files, unsigned int fd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 988 | { |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 989 | struct fdtable *fdt = files_fdtable(files); |
| 990 | __FD_CLR(fd, fdt->open_fds); |
Eric Dumazet | 0c9e63f | 2006-03-23 03:00:12 -0800 | [diff] [blame] | 991 | if (fd < files->next_fd) |
| 992 | files->next_fd = fd; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 993 | } |
| 994 | |
Harvey Harrison | fc9b52c | 2008-02-08 04:19:52 -0800 | [diff] [blame] | 995 | void put_unused_fd(unsigned int fd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 996 | { |
| 997 | struct files_struct *files = current->files; |
| 998 | spin_lock(&files->file_lock); |
| 999 | __put_unused_fd(files, fd); |
| 1000 | spin_unlock(&files->file_lock); |
| 1001 | } |
| 1002 | |
| 1003 | EXPORT_SYMBOL(put_unused_fd); |
| 1004 | |
| 1005 | /* |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 1006 | * Install a file pointer in the fd array. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1007 | * |
| 1008 | * The VFS is full of places where we drop the files lock between |
| 1009 | * setting the open_fds bitmap and installing the file in the file |
| 1010 | * array. At any such point, we are vulnerable to a dup2() race |
| 1011 | * installing a file in the array before us. We need to detect this and |
| 1012 | * fput() the struct file we are about to overwrite in this case. |
| 1013 | * |
| 1014 | * It should never happen - if we allow dup2() do it, _really_ bad things |
| 1015 | * will follow. |
| 1016 | */ |
| 1017 | |
Harvey Harrison | fc9b52c | 2008-02-08 04:19:52 -0800 | [diff] [blame] | 1018 | void fd_install(unsigned int fd, struct file *file) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1019 | { |
| 1020 | struct files_struct *files = current->files; |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 1021 | struct fdtable *fdt; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1022 | spin_lock(&files->file_lock); |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 1023 | fdt = files_fdtable(files); |
Dipankar Sarma | ab2af1f | 2005-09-09 13:04:13 -0700 | [diff] [blame] | 1024 | BUG_ON(fdt->fd[fd] != NULL); |
| 1025 | rcu_assign_pointer(fdt->fd[fd], file); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1026 | spin_unlock(&files->file_lock); |
| 1027 | } |
| 1028 | |
| 1029 | EXPORT_SYMBOL(fd_install); |
| 1030 | |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 1031 | long do_sys_open(int dfd, const char __user *filename, int flags, int mode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1032 | { |
Miklos Szeredi | e922efc | 2005-09-06 15:18:25 -0700 | [diff] [blame] | 1033 | char *tmp = getname(filename); |
| 1034 | int fd = PTR_ERR(tmp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1035 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1036 | if (!IS_ERR(tmp)) { |
Ulrich Drepper | f23513e | 2007-07-15 23:40:32 -0700 | [diff] [blame] | 1037 | fd = get_unused_fd_flags(flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1038 | if (fd >= 0) { |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 1039 | struct file *f = do_filp_open(dfd, tmp, flags, mode); |
Telemaque Ndizihiwe | fed2fc1 | 2005-06-23 00:10:33 -0700 | [diff] [blame] | 1040 | if (IS_ERR(f)) { |
| 1041 | put_unused_fd(fd); |
| 1042 | fd = PTR_ERR(f); |
| 1043 | } else { |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 1044 | fsnotify_open(f->f_path.dentry); |
Telemaque Ndizihiwe | fed2fc1 | 2005-06-23 00:10:33 -0700 | [diff] [blame] | 1045 | fd_install(fd, f); |
| 1046 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1047 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1048 | putname(tmp); |
| 1049 | } |
| 1050 | return fd; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1051 | } |
Miklos Szeredi | e922efc | 2005-09-06 15:18:25 -0700 | [diff] [blame] | 1052 | |
| 1053 | asmlinkage long sys_open(const char __user *filename, int flags, int mode) |
| 1054 | { |
Linus Torvalds | 385910f | 2006-04-18 13:22:59 -0700 | [diff] [blame] | 1055 | long ret; |
| 1056 | |
Miklos Szeredi | e922efc | 2005-09-06 15:18:25 -0700 | [diff] [blame] | 1057 | if (force_o_largefile()) |
| 1058 | flags |= O_LARGEFILE; |
| 1059 | |
Linus Torvalds | 385910f | 2006-04-18 13:22:59 -0700 | [diff] [blame] | 1060 | ret = do_sys_open(AT_FDCWD, filename, flags, mode); |
| 1061 | /* avoid REGPARM breakage on x86: */ |
Roland McGrath | 54a0151 | 2008-04-10 15:37:38 -0700 | [diff] [blame] | 1062 | asmlinkage_protect(3, ret, filename, flags, mode); |
Linus Torvalds | 385910f | 2006-04-18 13:22:59 -0700 | [diff] [blame] | 1063 | return ret; |
Miklos Szeredi | e922efc | 2005-09-06 15:18:25 -0700 | [diff] [blame] | 1064 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1065 | |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 1066 | asmlinkage long sys_openat(int dfd, const char __user *filename, int flags, |
| 1067 | int mode) |
| 1068 | { |
Linus Torvalds | 385910f | 2006-04-18 13:22:59 -0700 | [diff] [blame] | 1069 | long ret; |
| 1070 | |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 1071 | if (force_o_largefile()) |
| 1072 | flags |= O_LARGEFILE; |
| 1073 | |
Linus Torvalds | 385910f | 2006-04-18 13:22:59 -0700 | [diff] [blame] | 1074 | ret = do_sys_open(dfd, filename, flags, mode); |
| 1075 | /* avoid REGPARM breakage on x86: */ |
Roland McGrath | 54a0151 | 2008-04-10 15:37:38 -0700 | [diff] [blame] | 1076 | asmlinkage_protect(4, ret, dfd, filename, flags, mode); |
Linus Torvalds | 385910f | 2006-04-18 13:22:59 -0700 | [diff] [blame] | 1077 | return ret; |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 1078 | } |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 1079 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1080 | #ifndef __alpha__ |
| 1081 | |
| 1082 | /* |
| 1083 | * For backward compatibility? Maybe this should be moved |
| 1084 | * into arch/i386 instead? |
| 1085 | */ |
| 1086 | asmlinkage long sys_creat(const char __user * pathname, int mode) |
| 1087 | { |
| 1088 | return sys_open(pathname, O_CREAT | O_WRONLY | O_TRUNC, mode); |
| 1089 | } |
| 1090 | |
| 1091 | #endif |
| 1092 | |
| 1093 | /* |
| 1094 | * "id" is the POSIX thread ID. We use the |
| 1095 | * files pointer for this.. |
| 1096 | */ |
| 1097 | int filp_close(struct file *filp, fl_owner_t id) |
| 1098 | { |
Christoph Lameter | 45778ca | 2005-06-23 00:10:17 -0700 | [diff] [blame] | 1099 | int retval = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1100 | |
| 1101 | if (!file_count(filp)) { |
| 1102 | printk(KERN_ERR "VFS: Close: file count is 0\n"); |
Christoph Lameter | 45778ca | 2005-06-23 00:10:17 -0700 | [diff] [blame] | 1103 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1104 | } |
| 1105 | |
Christoph Lameter | 45778ca | 2005-06-23 00:10:17 -0700 | [diff] [blame] | 1106 | if (filp->f_op && filp->f_op->flush) |
Miklos Szeredi | 75e1fcc | 2006-06-23 02:05:12 -0700 | [diff] [blame] | 1107 | retval = filp->f_op->flush(filp, id); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1108 | |
| 1109 | dnotify_flush(filp, id); |
| 1110 | locks_remove_posix(filp, id); |
| 1111 | fput(filp); |
| 1112 | return retval; |
| 1113 | } |
| 1114 | |
| 1115 | EXPORT_SYMBOL(filp_close); |
| 1116 | |
| 1117 | /* |
| 1118 | * Careful here! We test whether the file pointer is NULL before |
| 1119 | * releasing the fd. This ensures that one clone task can't release |
| 1120 | * an fd while another clone is opening it. |
| 1121 | */ |
| 1122 | asmlinkage long sys_close(unsigned int fd) |
| 1123 | { |
| 1124 | struct file * filp; |
| 1125 | struct files_struct *files = current->files; |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 1126 | struct fdtable *fdt; |
Ernie Petrides | ee731f4 | 2006-09-29 02:00:13 -0700 | [diff] [blame] | 1127 | int retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1128 | |
| 1129 | spin_lock(&files->file_lock); |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 1130 | fdt = files_fdtable(files); |
| 1131 | if (fd >= fdt->max_fds) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1132 | goto out_unlock; |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 1133 | filp = fdt->fd[fd]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1134 | if (!filp) |
| 1135 | goto out_unlock; |
Dipankar Sarma | ab2af1f | 2005-09-09 13:04:13 -0700 | [diff] [blame] | 1136 | rcu_assign_pointer(fdt->fd[fd], NULL); |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 1137 | FD_CLR(fd, fdt->close_on_exec); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1138 | __put_unused_fd(files, fd); |
| 1139 | spin_unlock(&files->file_lock); |
Ernie Petrides | ee731f4 | 2006-09-29 02:00:13 -0700 | [diff] [blame] | 1140 | retval = filp_close(filp, files); |
| 1141 | |
| 1142 | /* can't restart close syscall because file table entry was cleared */ |
| 1143 | if (unlikely(retval == -ERESTARTSYS || |
| 1144 | retval == -ERESTARTNOINTR || |
| 1145 | retval == -ERESTARTNOHAND || |
| 1146 | retval == -ERESTART_RESTARTBLOCK)) |
| 1147 | retval = -EINTR; |
| 1148 | |
| 1149 | return retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1150 | |
| 1151 | out_unlock: |
| 1152 | spin_unlock(&files->file_lock); |
| 1153 | return -EBADF; |
| 1154 | } |
| 1155 | |
| 1156 | EXPORT_SYMBOL(sys_close); |
| 1157 | |
| 1158 | /* |
| 1159 | * This routine simulates a hangup on the tty, to arrange that users |
| 1160 | * are given clean terminals at login time. |
| 1161 | */ |
| 1162 | asmlinkage long sys_vhangup(void) |
| 1163 | { |
| 1164 | if (capable(CAP_SYS_TTY_CONFIG)) { |
Alan Cox | 2cb5998 | 2008-10-13 10:40:30 +0100 | [diff] [blame] | 1165 | tty_vhangup_self(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1166 | return 0; |
| 1167 | } |
| 1168 | return -EPERM; |
| 1169 | } |
| 1170 | |
| 1171 | /* |
| 1172 | * Called when an inode is about to be open. |
| 1173 | * We use this to disallow opening large files on 32bit systems if |
| 1174 | * the caller didn't specify O_LARGEFILE. On 64bit systems we force |
| 1175 | * on this flag in sys_open. |
| 1176 | */ |
| 1177 | int generic_file_open(struct inode * inode, struct file * filp) |
| 1178 | { |
| 1179 | if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS) |
Alan Cox | a9c62a1 | 2007-10-16 23:30:22 -0700 | [diff] [blame] | 1180 | return -EOVERFLOW; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1181 | return 0; |
| 1182 | } |
| 1183 | |
| 1184 | EXPORT_SYMBOL(generic_file_open); |
| 1185 | |
| 1186 | /* |
| 1187 | * This is used by subsystems that don't want seekable |
| 1188 | * file descriptors |
| 1189 | */ |
| 1190 | int nonseekable_open(struct inode *inode, struct file *filp) |
| 1191 | { |
| 1192 | filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE); |
| 1193 | return 0; |
| 1194 | } |
| 1195 | |
| 1196 | EXPORT_SYMBOL(nonseekable_open); |