mirror of
https://github.com/torvalds/linux.git
synced 2024-12-05 02:23:16 +00:00
2b82892565
Conflicts: security/keys/internal.h security/keys/process_keys.c security/keys/request_key.c Fixed conflicts above by using the non 'tsk' versions. Signed-off-by: James Morris <jmorris@namei.org>
393 lines
9.4 KiB
C
393 lines
9.4 KiB
C
/*
|
|
* linux/fs/fat/file.c
|
|
*
|
|
* Written 1992,1993 by Werner Almesberger
|
|
*
|
|
* regular file handling primitives for fat-based filesystems
|
|
*/
|
|
|
|
#include <linux/capability.h>
|
|
#include <linux/module.h>
|
|
#include <linux/mount.h>
|
|
#include <linux/time.h>
|
|
#include <linux/buffer_head.h>
|
|
#include <linux/writeback.h>
|
|
#include <linux/backing-dev.h>
|
|
#include <linux/blkdev.h>
|
|
#include <linux/fsnotify.h>
|
|
#include <linux/security.h>
|
|
#include "fat.h"
|
|
|
|
int fat_generic_ioctl(struct inode *inode, struct file *filp,
|
|
unsigned int cmd, unsigned long arg)
|
|
{
|
|
struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
|
|
u32 __user *user_attr = (u32 __user *)arg;
|
|
|
|
switch (cmd) {
|
|
case FAT_IOCTL_GET_ATTRIBUTES:
|
|
{
|
|
u32 attr;
|
|
|
|
mutex_lock(&inode->i_mutex);
|
|
attr = fat_make_attrs(inode);
|
|
mutex_unlock(&inode->i_mutex);
|
|
|
|
return put_user(attr, user_attr);
|
|
}
|
|
case FAT_IOCTL_SET_ATTRIBUTES:
|
|
{
|
|
u32 attr, oldattr;
|
|
int err, is_dir = S_ISDIR(inode->i_mode);
|
|
struct iattr ia;
|
|
|
|
err = get_user(attr, user_attr);
|
|
if (err)
|
|
return err;
|
|
|
|
mutex_lock(&inode->i_mutex);
|
|
|
|
err = mnt_want_write(filp->f_path.mnt);
|
|
if (err)
|
|
goto up_no_drop_write;
|
|
|
|
/*
|
|
* ATTR_VOLUME and ATTR_DIR cannot be changed; this also
|
|
* prevents the user from turning us into a VFAT
|
|
* longname entry. Also, we obviously can't set
|
|
* any of the NTFS attributes in the high 24 bits.
|
|
*/
|
|
attr &= 0xff & ~(ATTR_VOLUME | ATTR_DIR);
|
|
/* Merge in ATTR_VOLUME and ATTR_DIR */
|
|
attr |= (MSDOS_I(inode)->i_attrs & ATTR_VOLUME) |
|
|
(is_dir ? ATTR_DIR : 0);
|
|
oldattr = fat_make_attrs(inode);
|
|
|
|
/* Equivalent to a chmod() */
|
|
ia.ia_valid = ATTR_MODE | ATTR_CTIME;
|
|
ia.ia_ctime = current_fs_time(inode->i_sb);
|
|
if (is_dir)
|
|
ia.ia_mode = fat_make_mode(sbi, attr, S_IRWXUGO);
|
|
else {
|
|
ia.ia_mode = fat_make_mode(sbi, attr,
|
|
S_IRUGO | S_IWUGO | (inode->i_mode & S_IXUGO));
|
|
}
|
|
|
|
/* The root directory has no attributes */
|
|
if (inode->i_ino == MSDOS_ROOT_INO && attr != ATTR_DIR) {
|
|
err = -EINVAL;
|
|
goto up;
|
|
}
|
|
|
|
if (sbi->options.sys_immutable) {
|
|
if ((attr | oldattr) & ATTR_SYS) {
|
|
if (!capable(CAP_LINUX_IMMUTABLE)) {
|
|
err = -EPERM;
|
|
goto up;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* The security check is questionable... We single
|
|
* out the RO attribute for checking by the security
|
|
* module, just because it maps to a file mode.
|
|
*/
|
|
err = security_inode_setattr(filp->f_path.dentry, &ia);
|
|
if (err)
|
|
goto up;
|
|
|
|
/* This MUST be done before doing anything irreversible... */
|
|
err = fat_setattr(filp->f_path.dentry, &ia);
|
|
if (err)
|
|
goto up;
|
|
|
|
fsnotify_change(filp->f_path.dentry, ia.ia_valid);
|
|
if (sbi->options.sys_immutable) {
|
|
if (attr & ATTR_SYS)
|
|
inode->i_flags |= S_IMMUTABLE;
|
|
else
|
|
inode->i_flags &= S_IMMUTABLE;
|
|
}
|
|
|
|
fat_save_attrs(inode, attr);
|
|
mark_inode_dirty(inode);
|
|
up:
|
|
mnt_drop_write(filp->f_path.mnt);
|
|
up_no_drop_write:
|
|
mutex_unlock(&inode->i_mutex);
|
|
return err;
|
|
}
|
|
default:
|
|
return -ENOTTY; /* Inappropriate ioctl for device */
|
|
}
|
|
}
|
|
|
|
static int fat_file_release(struct inode *inode, struct file *filp)
|
|
{
|
|
if ((filp->f_mode & FMODE_WRITE) &&
|
|
MSDOS_SB(inode->i_sb)->options.flush) {
|
|
fat_flush_inodes(inode->i_sb, inode, NULL);
|
|
congestion_wait(WRITE, HZ/10);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
const struct file_operations fat_file_operations = {
|
|
.llseek = generic_file_llseek,
|
|
.read = do_sync_read,
|
|
.write = do_sync_write,
|
|
.aio_read = generic_file_aio_read,
|
|
.aio_write = generic_file_aio_write,
|
|
.mmap = generic_file_mmap,
|
|
.release = fat_file_release,
|
|
.ioctl = fat_generic_ioctl,
|
|
.fsync = file_fsync,
|
|
.splice_read = generic_file_splice_read,
|
|
};
|
|
|
|
static int fat_cont_expand(struct inode *inode, loff_t size)
|
|
{
|
|
struct address_space *mapping = inode->i_mapping;
|
|
loff_t start = inode->i_size, count = size - inode->i_size;
|
|
int err;
|
|
|
|
err = generic_cont_expand_simple(inode, size);
|
|
if (err)
|
|
goto out;
|
|
|
|
inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
|
|
mark_inode_dirty(inode);
|
|
if (IS_SYNC(inode))
|
|
err = sync_page_range_nolock(inode, mapping, start, count);
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
/* Free all clusters after the skip'th cluster. */
|
|
static int fat_free(struct inode *inode, int skip)
|
|
{
|
|
struct super_block *sb = inode->i_sb;
|
|
int err, wait, free_start, i_start, i_logstart;
|
|
|
|
if (MSDOS_I(inode)->i_start == 0)
|
|
return 0;
|
|
|
|
fat_cache_inval_inode(inode);
|
|
|
|
wait = IS_DIRSYNC(inode);
|
|
i_start = free_start = MSDOS_I(inode)->i_start;
|
|
i_logstart = MSDOS_I(inode)->i_logstart;
|
|
|
|
/* First, we write the new file size. */
|
|
if (!skip) {
|
|
MSDOS_I(inode)->i_start = 0;
|
|
MSDOS_I(inode)->i_logstart = 0;
|
|
}
|
|
MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
|
|
inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
|
|
if (wait) {
|
|
err = fat_sync_inode(inode);
|
|
if (err) {
|
|
MSDOS_I(inode)->i_start = i_start;
|
|
MSDOS_I(inode)->i_logstart = i_logstart;
|
|
return err;
|
|
}
|
|
} else
|
|
mark_inode_dirty(inode);
|
|
|
|
/* Write a new EOF, and get the remaining cluster chain for freeing. */
|
|
if (skip) {
|
|
struct fat_entry fatent;
|
|
int ret, fclus, dclus;
|
|
|
|
ret = fat_get_cluster(inode, skip - 1, &fclus, &dclus);
|
|
if (ret < 0)
|
|
return ret;
|
|
else if (ret == FAT_ENT_EOF)
|
|
return 0;
|
|
|
|
fatent_init(&fatent);
|
|
ret = fat_ent_read(inode, &fatent, dclus);
|
|
if (ret == FAT_ENT_EOF) {
|
|
fatent_brelse(&fatent);
|
|
return 0;
|
|
} else if (ret == FAT_ENT_FREE) {
|
|
fat_fs_panic(sb,
|
|
"%s: invalid cluster chain (i_pos %lld)",
|
|
__func__, MSDOS_I(inode)->i_pos);
|
|
ret = -EIO;
|
|
} else if (ret > 0) {
|
|
err = fat_ent_write(inode, &fatent, FAT_ENT_EOF, wait);
|
|
if (err)
|
|
ret = err;
|
|
}
|
|
fatent_brelse(&fatent);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
free_start = ret;
|
|
}
|
|
inode->i_blocks = skip << (MSDOS_SB(sb)->cluster_bits - 9);
|
|
|
|
/* Freeing the remained cluster chain */
|
|
return fat_free_clusters(inode, free_start);
|
|
}
|
|
|
|
void fat_truncate(struct inode *inode)
|
|
{
|
|
struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
|
|
const unsigned int cluster_size = sbi->cluster_size;
|
|
int nr_clusters;
|
|
|
|
/*
|
|
* This protects against truncating a file bigger than it was then
|
|
* trying to write into the hole.
|
|
*/
|
|
if (MSDOS_I(inode)->mmu_private > inode->i_size)
|
|
MSDOS_I(inode)->mmu_private = inode->i_size;
|
|
|
|
nr_clusters = (inode->i_size + (cluster_size - 1)) >> sbi->cluster_bits;
|
|
|
|
fat_free(inode, nr_clusters);
|
|
fat_flush_inodes(inode->i_sb, inode, NULL);
|
|
}
|
|
|
|
int fat_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
|
|
{
|
|
struct inode *inode = dentry->d_inode;
|
|
generic_fillattr(inode, stat);
|
|
stat->blksize = MSDOS_SB(inode->i_sb)->cluster_size;
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(fat_getattr);
|
|
|
|
static int fat_sanitize_mode(const struct msdos_sb_info *sbi,
|
|
struct inode *inode, umode_t *mode_ptr)
|
|
{
|
|
mode_t mask, perm;
|
|
|
|
/*
|
|
* Note, the basic check is already done by a caller of
|
|
* (attr->ia_mode & ~FAT_VALID_MODE)
|
|
*/
|
|
|
|
if (S_ISREG(inode->i_mode))
|
|
mask = sbi->options.fs_fmask;
|
|
else
|
|
mask = sbi->options.fs_dmask;
|
|
|
|
perm = *mode_ptr & ~(S_IFMT | mask);
|
|
|
|
/*
|
|
* Of the r and x bits, all (subject to umask) must be present. Of the
|
|
* w bits, either all (subject to umask) or none must be present.
|
|
*
|
|
* If fat_mode_can_hold_ro(inode) is false, can't change w bits.
|
|
*/
|
|
if ((perm & (S_IRUGO | S_IXUGO)) != (inode->i_mode & (S_IRUGO|S_IXUGO)))
|
|
return -EPERM;
|
|
if (fat_mode_can_hold_ro(inode)) {
|
|
if ((perm & S_IWUGO) && ((perm & S_IWUGO) != (S_IWUGO & ~mask)))
|
|
return -EPERM;
|
|
} else {
|
|
if ((perm & S_IWUGO) != (S_IWUGO & ~mask))
|
|
return -EPERM;
|
|
}
|
|
|
|
*mode_ptr &= S_IFMT | perm;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int fat_allow_set_time(struct msdos_sb_info *sbi, struct inode *inode)
|
|
{
|
|
mode_t allow_utime = sbi->options.allow_utime;
|
|
|
|
if (current_fsuid() != inode->i_uid) {
|
|
if (in_group_p(inode->i_gid))
|
|
allow_utime >>= 3;
|
|
if (allow_utime & MAY_WRITE)
|
|
return 1;
|
|
}
|
|
|
|
/* use a default check */
|
|
return 0;
|
|
}
|
|
|
|
#define TIMES_SET_FLAGS (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)
|
|
/* valid file mode bits */
|
|
#define FAT_VALID_MODE (S_IFREG | S_IFDIR | S_IRWXUGO)
|
|
|
|
int fat_setattr(struct dentry *dentry, struct iattr *attr)
|
|
{
|
|
struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb);
|
|
struct inode *inode = dentry->d_inode;
|
|
unsigned int ia_valid;
|
|
int error;
|
|
|
|
/*
|
|
* Expand the file. Since inode_setattr() updates ->i_size
|
|
* before calling the ->truncate(), but FAT needs to fill the
|
|
* hole before it.
|
|
*/
|
|
if (attr->ia_valid & ATTR_SIZE) {
|
|
if (attr->ia_size > inode->i_size) {
|
|
error = fat_cont_expand(inode, attr->ia_size);
|
|
if (error || attr->ia_valid == ATTR_SIZE)
|
|
goto out;
|
|
attr->ia_valid &= ~ATTR_SIZE;
|
|
}
|
|
}
|
|
|
|
/* Check for setting the inode time. */
|
|
ia_valid = attr->ia_valid;
|
|
if (ia_valid & TIMES_SET_FLAGS) {
|
|
if (fat_allow_set_time(sbi, inode))
|
|
attr->ia_valid &= ~TIMES_SET_FLAGS;
|
|
}
|
|
|
|
error = inode_change_ok(inode, attr);
|
|
attr->ia_valid = ia_valid;
|
|
if (error) {
|
|
if (sbi->options.quiet)
|
|
error = 0;
|
|
goto out;
|
|
}
|
|
|
|
if (((attr->ia_valid & ATTR_UID) &&
|
|
(attr->ia_uid != sbi->options.fs_uid)) ||
|
|
((attr->ia_valid & ATTR_GID) &&
|
|
(attr->ia_gid != sbi->options.fs_gid)) ||
|
|
((attr->ia_valid & ATTR_MODE) &&
|
|
(attr->ia_mode & ~FAT_VALID_MODE)))
|
|
error = -EPERM;
|
|
|
|
if (error) {
|
|
if (sbi->options.quiet)
|
|
error = 0;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* We don't return -EPERM here. Yes, strange, but this is too
|
|
* old behavior.
|
|
*/
|
|
if (attr->ia_valid & ATTR_MODE) {
|
|
if (fat_sanitize_mode(sbi, inode, &attr->ia_mode) < 0)
|
|
attr->ia_valid &= ~ATTR_MODE;
|
|
}
|
|
|
|
if (attr->ia_valid)
|
|
error = inode_setattr(inode, attr);
|
|
out:
|
|
return error;
|
|
}
|
|
EXPORT_SYMBOL_GPL(fat_setattr);
|
|
|
|
const struct inode_operations fat_file_inode_operations = {
|
|
.truncate = fat_truncate,
|
|
.setattr = fat_setattr,
|
|
.getattr = fat_getattr,
|
|
};
|