/*
* linux/fs/fat/file.c
*
* Written 1992,1993 by Werner Almesberger
*
* regular file handling primitives for fat-based filesystems
*/
#include <linux/module.h>
#include <linux/time.h>
#include <linux/msdos_fs.h>
#include <linux/smp_lock.h>
#include <linux/buffer_head.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;
if (inode->i_ino == MSDOS_ROOT_INO)
attr = ATTR_DIR;
else
attr = fat_attr(inode);
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;
down(&inode->i_sem);
if (IS_RDONLY(inode)) {
err = -EROFS;
goto up;
}
/*
* 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_attr(inode);
/* Equivalent to a chmod() */
ia.ia_valid = ATTR_MODE | ATTR_CTIME;
if (is_dir) {
ia.ia_mode = MSDOS_MKMODE(attr,
S_IRWXUGO & ~sbi->options.fs_dmask)
| S_IFDIR;
} else {
ia.ia_mode = MSDOS_MKMODE(attr,
(S_IRUGO | S_IWUGO | (inode->i_mode & S_IXUGO))
& ~sbi->options.fs_fmask)
| S_IFREG;
}
/* 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;
}
}
}
/* This MUST be done before doing anything irreversible... */
err = notify_change(filp->f_dentry, &ia);
if (err)
goto up;
if (sbi->options.sys_immutable) {
if (attr & ATTR_SYS)
inode->i_flags |= S_IMMUTABLE;
else
inode->i_flags &= S_IMMUTABLE;
}
MSDOS_I(inode)->i_attrs = attr & ATTR_UNUSED;
mark_inode_dirty(inode);
up:
up(&inode->i_sem);
return err;
}
default:
return -ENOTTY; /* Inappropriate ioctl for device */
}
}
struct file_operations fat_file_operations = {
.llseek = generic_file_llseek,
.read = do_sync_read,
.write = do_sync_write,
.readv = generic_file_readv,
.writev = generic_file_writev,
.aio_read = generic_file_aio_read,
.aio_write = generic_file_aio_write,
.mmap = generic_file_mmap,
.ioctl = fat_generic_ioctl,
.fsync = file_fsync,
.sendfile = generic_file_sendfile,
};
int fat_notify_change(struct dentry *dentry, struct iattr *attr)
{
struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb);
struct inode *inode = dentry->d_inode;
int mask, error = 0;
lock_kernel();
/* FAT cannot truncate to a longer file */
if (attr->ia_valid & ATTR_SIZE) {
if (attr->ia_size > inode->i_size) {
error = -EPERM;
goto out;
}
}
error = inode_change_ok(inode, attr);
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 & ~MSDOS_VALID_MODE)))
error = -EPERM;
if (error) {
if (sbi->options.quiet)
error = 0;
goto out;
}
error = inode_setattr(inode, attr);
if (error)
goto out;
if (S_ISDIR(inode->i_mode))
mask = sbi->options.fs_dmask;
else
mask = sbi->options.fs_fmask;
inode->i_mode &= S_IFMT | (S_IRWXUGO & ~mask);
out:
unlock_kernel();
return error;
}
EXPORT_SYMBOL(fat_notify_change);
/* 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;
/*
* Write a new EOF, and get the remaining cluster chain for freeing.
*/
wait = IS_DIRSYNC(inode);
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)",
__FUNCTION__, 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;
i_start = i_logstart = 0;
fat_cache_inval_inode(inode);
} else {
fat_cache_inval_inode(inode);
i_start = free_start = MSDOS_I(inode)->i_start;
i_logstart = MSDOS_I(inode)->i_logstart;
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)
goto error;
} else
mark_inode_dirty(inode);
inode->i_blocks = skip << (MSDOS_SB(sb)->cluster_bits - 9);
/* Freeing the remained cluster chain */
return fat_free_clusters(inode, free_start);
error:
if (i_start) {
MSDOS_I(inode)->i_start = i_start;
MSDOS_I(inode)->i_logstart = i_logstart;
}
return err;
}
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;
lock_kernel();
fat_free(inode, nr_clusters);
unlock_kernel();
}
struct inode_operations fat_file_inode_operations = {
.truncate = fat_truncate,
.setattr = fat_notify_change,
};
