blob: d25a96a148af4cdb966c5d20f720aa944cab10c2 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
*/
#include <linux/slab.h>
#include <linux/compat.h>
#include <linux/cred.h>
#include <linux/buffer_head.h>
#include <linux/blkdev.h>
#include <linux/fsnotify.h>
#include <linux/security.h>
#include <linux/msdos_fs.h>
#include <linux/writeback.h>
#include "exfat_raw.h"
#include "exfat_fs.h"
static int exfat_cont_expand(struct inode *inode, loff_t size)
{
int ret;
unsigned int num_clusters, new_num_clusters, last_clu;
struct exfat_inode_info *ei = EXFAT_I(inode);
struct super_block *sb = inode->i_sb;
struct exfat_sb_info *sbi = EXFAT_SB(sb);
struct exfat_chain clu;
ret = inode_newsize_ok(inode, size);
if (ret)
return ret;
num_clusters = EXFAT_B_TO_CLU_ROUND_UP(ei->i_size_ondisk, sbi);
new_num_clusters = EXFAT_B_TO_CLU_ROUND_UP(size, sbi);
if (new_num_clusters == num_clusters)
goto out;
exfat_chain_set(&clu, ei->start_clu, num_clusters, ei->flags);
ret = exfat_find_last_cluster(sb, &clu, &last_clu);
if (ret)
return ret;
clu.dir = (last_clu == EXFAT_EOF_CLUSTER) ?
EXFAT_EOF_CLUSTER : last_clu + 1;
clu.size = 0;
clu.flags = ei->flags;
ret = exfat_alloc_cluster(inode, new_num_clusters - num_clusters,
&clu, IS_DIRSYNC(inode));
if (ret)
return ret;
/* Append new clusters to chain */
if (clu.flags != ei->flags) {
exfat_chain_cont_cluster(sb, ei->start_clu, num_clusters);
ei->flags = ALLOC_FAT_CHAIN;
}
if (clu.flags == ALLOC_FAT_CHAIN)
if (exfat_ent_set(sb, last_clu, clu.dir))
goto free_clu;
if (num_clusters == 0)
ei->start_clu = clu.dir;
out:
inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
/* Expanded range not zeroed, do not update valid_size */
i_size_write(inode, size);
ei->i_size_aligned = round_up(size, sb->s_blocksize);
ei->i_size_ondisk = ei->i_size_aligned;
inode->i_blocks = round_up(size, sbi->cluster_size) >> 9;
if (IS_DIRSYNC(inode))
return write_inode_now(inode, 1);
mark_inode_dirty(inode);
return 0;
free_clu:
exfat_free_cluster(inode, &clu);
return -EIO;
}
static bool exfat_allow_set_time(struct exfat_sb_info *sbi, struct inode *inode)
{
mode_t allow_utime = sbi->options.allow_utime;
if (!uid_eq(current_fsuid(), inode->i_uid)) {
if (in_group_p(inode->i_gid))
allow_utime >>= 3;
if (allow_utime & MAY_WRITE)
return true;
}
/* use a default check */
return false;
}
static int exfat_sanitize_mode(const struct exfat_sb_info *sbi,
struct inode *inode, umode_t *mode_ptr)
{
mode_t i_mode, mask, perm;
i_mode = inode->i_mode;
mask = (S_ISREG(i_mode) || S_ISLNK(i_mode)) ?
sbi->options.fs_fmask : sbi->options.fs_dmask;
perm = *mode_ptr & ~(S_IFMT | mask);
/* Of the r and x bits, all (subject to umask) must be present.*/
if ((perm & 0555) != (i_mode & 0555))
return -EPERM;
if (exfat_mode_can_hold_ro(inode)) {
/*
* Of the w bits, either all (subject to umask) or none must
* be present.
*/
if ((perm & 0222) && ((perm & 0222) != (0222 & ~mask)))
return -EPERM;
} else {
/*
* If exfat_mode_can_hold_ro(inode) is false, can't change
* w bits.
*/
if ((perm & 0222) != (0222 & ~mask))
return -EPERM;
}
*mode_ptr &= S_IFMT | perm;
return 0;
}
/* resize the file length */
int __exfat_truncate(struct inode *inode)
{
unsigned int num_clusters_new, num_clusters_phys;
unsigned int last_clu = EXFAT_FREE_CLUSTER;
struct exfat_chain clu;
struct super_block *sb = inode->i_sb;
struct exfat_sb_info *sbi = EXFAT_SB(sb);
struct exfat_inode_info *ei = EXFAT_I(inode);
/* check if the given file ID is opened */
if (ei->type != TYPE_FILE && ei->type != TYPE_DIR)
return -EPERM;
exfat_set_volume_dirty(sb);
num_clusters_new = EXFAT_B_TO_CLU_ROUND_UP(i_size_read(inode), sbi);
num_clusters_phys = EXFAT_B_TO_CLU_ROUND_UP(ei->i_size_ondisk, sbi);
exfat_chain_set(&clu, ei->start_clu, num_clusters_phys, ei->flags);
if (i_size_read(inode) > 0) {
/*
* Truncate FAT chain num_clusters after the first cluster
* num_clusters = min(new, phys);
*/
unsigned int num_clusters =
min(num_clusters_new, num_clusters_phys);
/*
* Follow FAT chain
* (defensive coding - works fine even with corrupted FAT table
*/
if (clu.flags == ALLOC_NO_FAT_CHAIN) {
clu.dir += num_clusters;
clu.size -= num_clusters;
} else {
while (num_clusters > 0) {
last_clu = clu.dir;
if (exfat_get_next_cluster(sb, &(clu.dir)))
return -EIO;
num_clusters--;
clu.size--;
}
}
} else {
ei->flags = ALLOC_NO_FAT_CHAIN;
ei->start_clu = EXFAT_EOF_CLUSTER;
}
if (i_size_read(inode) < ei->valid_size)
ei->valid_size = i_size_read(inode);
if (ei->type == TYPE_FILE)
ei->attr |= EXFAT_ATTR_ARCHIVE;
/*
* update the directory entry
*
* If the directory entry is updated by mark_inode_dirty(), the
* directory entry will be written after a writeback cycle of
* updating the bitmap/FAT, which may result in clusters being
* freed but referenced by the directory entry in the event of a
* sudden power failure.
* __exfat_write_inode() is called for directory entry, bitmap
* and FAT to be written in a same writeback.
*/
if (__exfat_write_inode(inode, inode_needs_sync(inode)))
return -EIO;
/* cut off from the FAT chain */
if (ei->flags == ALLOC_FAT_CHAIN && last_clu != EXFAT_FREE_CLUSTER &&
last_clu != EXFAT_EOF_CLUSTER) {
if (exfat_ent_set(sb, last_clu, EXFAT_EOF_CLUSTER))
return -EIO;
}
/* invalidate cache and free the clusters */
/* clear exfat cache */
exfat_cache_inval_inode(inode);
/* hint information */
ei->hint_bmap.off = EXFAT_EOF_CLUSTER;
ei->hint_bmap.clu = EXFAT_EOF_CLUSTER;
/* hint_stat will be used if this is directory. */
ei->hint_stat.eidx = 0;
ei->hint_stat.clu = ei->start_clu;
ei->hint_femp.eidx = EXFAT_HINT_NONE;
/* free the clusters */
if (exfat_free_cluster(inode, &clu))
return -EIO;
return 0;
}
void exfat_truncate(struct inode *inode)
{
struct super_block *sb = inode->i_sb;
struct exfat_sb_info *sbi = EXFAT_SB(sb);
struct exfat_inode_info *ei = EXFAT_I(inode);
unsigned int blocksize = i_blocksize(inode);
loff_t aligned_size;
int err;
mutex_lock(&sbi->s_lock);
if (ei->start_clu == 0) {
/*
* Empty start_clu != ~0 (not allocated)
*/
exfat_fs_error(sb, "tried to truncate zeroed cluster.");
goto write_size;
}
err = __exfat_truncate(inode);
if (err)
goto write_size;
inode->i_blocks = round_up(i_size_read(inode), sbi->cluster_size) >> 9;
write_size:
aligned_size = i_size_read(inode);
if (aligned_size & (blocksize - 1)) {
aligned_size |= (blocksize - 1);
aligned_size++;
}
if (ei->i_size_ondisk > i_size_read(inode))
ei->i_size_ondisk = aligned_size;
if (ei->i_size_aligned > i_size_read(inode))
ei->i_size_aligned = aligned_size;
mutex_unlock(&sbi->s_lock);
}
int exfat_getattr(struct mnt_idmap *idmap, const struct path *path,
struct kstat *stat, unsigned int request_mask,
unsigned int query_flags)
{
struct inode *inode = d_backing_inode(path->dentry);
struct exfat_inode_info *ei = EXFAT_I(inode);
generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
exfat_truncate_atime(&stat->atime);
stat->result_mask |= STATX_BTIME;
stat->btime.tv_sec = ei->i_crtime.tv_sec;
stat->btime.tv_nsec = ei->i_crtime.tv_nsec;
stat->blksize = EXFAT_SB(inode->i_sb)->cluster_size;
return 0;
}
int exfat_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
struct iattr *attr)
{
struct exfat_sb_info *sbi = EXFAT_SB(dentry->d_sb);
struct inode *inode = dentry->d_inode;
unsigned int ia_valid;
int error;
if ((attr->ia_valid & ATTR_SIZE) &&
attr->ia_size > i_size_read(inode)) {
error = exfat_cont_expand(inode, attr->ia_size);
if (error || attr->ia_valid == ATTR_SIZE)
return error;
attr->ia_valid &= ~ATTR_SIZE;
}
/* Check for setting the inode time. */
ia_valid = attr->ia_valid;
if ((ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)) &&
exfat_allow_set_time(sbi, inode)) {
attr->ia_valid &= ~(ATTR_MTIME_SET | ATTR_ATIME_SET |
ATTR_TIMES_SET);
}
error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
attr->ia_valid = ia_valid;
if (error)
goto out;
if (((attr->ia_valid & ATTR_UID) &&
!uid_eq(attr->ia_uid, sbi->options.fs_uid)) ||
((attr->ia_valid & ATTR_GID) &&
!gid_eq(attr->ia_gid, sbi->options.fs_gid)) ||
((attr->ia_valid & ATTR_MODE) &&
(attr->ia_mode & ~(S_IFREG | S_IFLNK | S_IFDIR | 0777)))) {
error = -EPERM;
goto out;
}
/*
* We don't return -EPERM here. Yes, strange, but this is too
* old behavior.
*/
if (attr->ia_valid & ATTR_MODE) {
if (exfat_sanitize_mode(sbi, inode, &attr->ia_mode) < 0)
attr->ia_valid &= ~ATTR_MODE;
}
if (attr->ia_valid & ATTR_SIZE)
inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
setattr_copy(&nop_mnt_idmap, inode, attr);
exfat_truncate_inode_atime(inode);
if (attr->ia_valid & ATTR_SIZE) {
error = exfat_block_truncate_page(inode, attr->ia_size);
if (error)
goto out;
down_write(&EXFAT_I(inode)->truncate_lock);
truncate_setsize(inode, attr->ia_size);
/*
* __exfat_write_inode() is called from exfat_truncate(), inode
* is already written by it, so mark_inode_dirty() is unneeded.
*/
exfat_truncate(inode);
up_write(&EXFAT_I(inode)->truncate_lock);
} else
mark_inode_dirty(inode);
out:
return error;
}
/*
* modified ioctls from fat/file.c by Welmer Almesberger
*/
static int exfat_ioctl_get_attributes(struct inode *inode, u32 __user *user_attr)
{
u32 attr;
inode_lock_shared(inode);
attr = exfat_make_attr(inode);
inode_unlock_shared(inode);
return put_user(attr, user_attr);
}
static int exfat_ioctl_set_attributes(struct file *file, u32 __user *user_attr)
{
struct inode *inode = file_inode(file);
struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb);
int is_dir = S_ISDIR(inode->i_mode);
u32 attr, oldattr;
struct iattr ia;
int err;
err = get_user(attr, user_attr);
if (err)
goto out;
err = mnt_want_write_file(file);
if (err)
goto out;
inode_lock(inode);
oldattr = exfat_make_attr(inode);
/*
* Mask attributes so we don't set reserved fields.
*/
attr &= (EXFAT_ATTR_READONLY | EXFAT_ATTR_HIDDEN | EXFAT_ATTR_SYSTEM |
EXFAT_ATTR_ARCHIVE);
attr |= (is_dir ? EXFAT_ATTR_SUBDIR : 0);
/* Equivalent to a chmod() */
ia.ia_valid = ATTR_MODE | ATTR_CTIME;
ia.ia_ctime = current_time(inode);
if (is_dir)
ia.ia_mode = exfat_make_mode(sbi, attr, 0777);
else
ia.ia_mode = exfat_make_mode(sbi, attr, 0666 | (inode->i_mode & 0111));
/* The root directory has no attributes */
if (inode->i_ino == EXFAT_ROOT_INO && attr != EXFAT_ATTR_SUBDIR) {
err = -EINVAL;
goto out_unlock_inode;
}
if (((attr | oldattr) & EXFAT_ATTR_SYSTEM) &&
!capable(CAP_LINUX_IMMUTABLE)) {
err = -EPERM;
goto out_unlock_inode;
}
/*
* 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(file_mnt_idmap(file),
file->f_path.dentry, &ia);
if (err)
goto out_unlock_inode;
/* This MUST be done before doing anything irreversible... */
err = exfat_setattr(file_mnt_idmap(file), file->f_path.dentry, &ia);
if (err)
goto out_unlock_inode;
fsnotify_change(file->f_path.dentry, ia.ia_valid);
exfat_save_attr(inode, attr);
mark_inode_dirty(inode);
out_unlock_inode:
inode_unlock(inode);
mnt_drop_write_file(file);
out:
return err;
}
static int exfat_ioctl_fitrim(struct inode *inode, unsigned long arg)
{
struct fstrim_range range;
int ret = 0;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (!bdev_max_discard_sectors(inode->i_sb->s_bdev))
return -EOPNOTSUPP;
if (copy_from_user(&range, (struct fstrim_range __user *)arg, sizeof(range)))
return -EFAULT;
range.minlen = max_t(unsigned int, range.minlen,
bdev_discard_granularity(inode->i_sb->s_bdev));
ret = exfat_trim_fs(inode, &range);
if (ret < 0)
return ret;
if (copy_to_user((struct fstrim_range __user *)arg, &range, sizeof(range)))
return -EFAULT;
return 0;
}
long exfat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
struct inode *inode = file_inode(filp);
u32 __user *user_attr = (u32 __user *)arg;
switch (cmd) {
case FAT_IOCTL_GET_ATTRIBUTES:
return exfat_ioctl_get_attributes(inode, user_attr);
case FAT_IOCTL_SET_ATTRIBUTES:
return exfat_ioctl_set_attributes(filp, user_attr);
case FITRIM:
return exfat_ioctl_fitrim(inode, arg);
default:
return -ENOTTY;
}
}
#ifdef CONFIG_COMPAT
long exfat_compat_ioctl(struct file *filp, unsigned int cmd,
unsigned long arg)
{
return exfat_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
}
#endif
int exfat_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
{
struct inode *inode = filp->f_mapping->host;
int err;
err = __generic_file_fsync(filp, start, end, datasync);
if (err)
return err;
err = sync_blockdev(inode->i_sb->s_bdev);
if (err)
return err;
return blkdev_issue_flush(inode->i_sb->s_bdev);
}
static int exfat_file_zeroed_range(struct file *file, loff_t start, loff_t end)
{
int err;
struct inode *inode = file_inode(file);
struct address_space *mapping = inode->i_mapping;
const struct address_space_operations *ops = mapping->a_ops;
while (start < end) {
u32 zerofrom, len;
struct page *page = NULL;
zerofrom = start & (PAGE_SIZE - 1);
len = PAGE_SIZE - zerofrom;
if (start + len > end)
len = end - start;
err = ops->write_begin(file, mapping, start, len, &page, NULL);
if (err)
goto out;
zero_user_segment(page, zerofrom, zerofrom + len);
err = ops->write_end(file, mapping, start, len, len, page, NULL);
if (err < 0)
goto out;
start += len;
balance_dirty_pages_ratelimited(mapping);
cond_resched();
}
out:
return err;
}
static ssize_t exfat_file_write_iter(struct kiocb *iocb, struct iov_iter *iter)
{
ssize_t ret;
struct file *file = iocb->ki_filp;
struct inode *inode = file_inode(file);
struct exfat_inode_info *ei = EXFAT_I(inode);
loff_t pos = iocb->ki_pos;
loff_t valid_size;
inode_lock(inode);
valid_size = ei->valid_size;
ret = generic_write_checks(iocb, iter);
if (ret < 0)
goto unlock;
if (pos > valid_size) {
ret = exfat_file_zeroed_range(file, valid_size, pos);
if (ret < 0 && ret != -ENOSPC) {
exfat_err(inode->i_sb,
"write: fail to zero from %llu to %llu(%zd)",
valid_size, pos, ret);
}
if (ret < 0)
goto unlock;
}
ret = __generic_file_write_iter(iocb, iter);
if (ret < 0)
goto unlock;
inode_unlock(inode);
if (pos > valid_size)
pos = valid_size;
if (iocb_is_dsync(iocb) && iocb->ki_pos > pos) {
ssize_t err = vfs_fsync_range(file, pos, iocb->ki_pos - 1,
iocb->ki_flags & IOCB_SYNC);
if (err < 0)
return err;
}
return ret;
unlock:
inode_unlock(inode);
return ret;
}
static int exfat_file_mmap(struct file *file, struct vm_area_struct *vma)
{
int ret;
struct inode *inode = file_inode(file);
struct exfat_inode_info *ei = EXFAT_I(inode);
loff_t start = ((loff_t)vma->vm_pgoff << PAGE_SHIFT);
loff_t end = min_t(loff_t, i_size_read(inode),
start + vma->vm_end - vma->vm_start);
if ((vma->vm_flags & VM_WRITE) && ei->valid_size < end) {
ret = exfat_file_zeroed_range(file, ei->valid_size, end);
if (ret < 0) {
exfat_err(inode->i_sb,
"mmap: fail to zero from %llu to %llu(%d)",
start, end, ret);
return ret;
}
}
return generic_file_mmap(file, vma);
}
const struct file_operations exfat_file_operations = {
.llseek = generic_file_llseek,
.read_iter = generic_file_read_iter,
.write_iter = exfat_file_write_iter,
.unlocked_ioctl = exfat_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = exfat_compat_ioctl,
#endif
.mmap = exfat_file_mmap,
.fsync = exfat_file_fsync,
.splice_read = filemap_splice_read,
.splice_write = iter_file_splice_write,
};
const struct inode_operations exfat_file_inode_operations = {
.setattr = exfat_setattr,
.getattr = exfat_getattr,
};