diff options
Diffstat (limited to 'drivers/block')
-rw-r--r-- | drivers/block/loop.c | 185 |
1 files changed, 104 insertions, 81 deletions
diff --git a/drivers/block/loop.c b/drivers/block/loop.c index dffbcc5c4ccf..8396a4f99526 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -226,24 +226,30 @@ static void __loop_update_dio(struct loop_device *lo, bool dio) blk_mq_unfreeze_queue(lo->lo_queue); } -static int -figure_loop_size(struct loop_device *lo, loff_t offset, loff_t sizelimit) +/** + * loop_set_size() - sets device size and notifies userspace + * @lo: struct loop_device to set the size for + * @size: new size of the loop device + * + * Callers must validate that the size passed into this function fits into + * a sector_t, eg using loop_validate_size() + */ +static void loop_set_size(struct loop_device *lo, loff_t size) { - loff_t size = get_size(offset, sizelimit, lo->lo_backing_file); - sector_t x = (sector_t)size; struct block_device *bdev = lo->lo_device; - if (unlikely((loff_t)x != size)) - return -EFBIG; - if (lo->lo_offset != offset) - lo->lo_offset = offset; - if (lo->lo_sizelimit != sizelimit) - lo->lo_sizelimit = sizelimit; - set_capacity(lo->lo_disk, x); - bd_set_size(bdev, (loff_t)get_capacity(bdev->bd_disk) << 9); + set_capacity(lo->lo_disk, size); + bd_set_size(bdev, size << SECTOR_SHIFT); /* let user-space know about the new size */ kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, KOBJ_CHANGE); - return 0; +} + +static void +figure_loop_size(struct loop_device *lo, loff_t offset, loff_t sizelimit) +{ + loff_t size = get_size(offset, sizelimit, lo->lo_backing_file); + + loop_set_size(lo, size); } static inline int @@ -1020,10 +1026,8 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode, !file->f_op->write_iter) lo_flags |= LO_FLAGS_READ_ONLY; - error = -EFBIG; size = get_loop_size(lo, file); - if ((loff_t)(sector_t)size != size) - goto out_unlock; + error = loop_prepare_queue(lo); if (error) goto out_unlock; @@ -1057,11 +1061,8 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode, loop_update_rotational(lo); loop_update_dio(lo); - set_capacity(lo->lo_disk, size); - bd_set_size(bdev, size << 9); loop_sysfs_init(lo); - /* let user-space know about the new size */ - kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, KOBJ_CHANGE); + loop_set_size(lo, size); set_blocksize(bdev, S_ISBLK(inode->i_mode) ? block_size(inode->i_bdev) : PAGE_SIZE); @@ -1275,82 +1276,50 @@ static int loop_clr_fd(struct loop_device *lo) return __loop_clr_fd(lo, false); } +/** + * loop_set_status_from_info - configure device from loop_info + * @lo: struct loop_device to configure + * @info: struct loop_info64 to configure the device with + * + * Configures the loop device parameters according to the passed + * in loop_info64 configuration. + */ static int -loop_set_status(struct loop_device *lo, const struct loop_info64 *info) +loop_set_status_from_info(struct loop_device *lo, + const struct loop_info64 *info) { int err; struct loop_func_table *xfer; kuid_t uid = current_uid(); - struct block_device *bdev; - bool partscan = false; - err = mutex_lock_killable(&loop_ctl_mutex); - if (err) - return err; - if (lo->lo_encrypt_key_size && - !uid_eq(lo->lo_key_owner, uid) && - !capable(CAP_SYS_ADMIN)) { - err = -EPERM; - goto out_unlock; - } - if (lo->lo_state != Lo_bound) { - err = -ENXIO; - goto out_unlock; - } - if ((unsigned int) info->lo_encrypt_key_size > LO_KEY_SIZE) { - err = -EINVAL; - goto out_unlock; - } - - if (lo->lo_offset != info->lo_offset || - lo->lo_sizelimit != info->lo_sizelimit) { - sync_blockdev(lo->lo_device); - invalidate_bdev(lo->lo_device); - } - - /* I/O need to be drained during transfer transition */ - blk_mq_freeze_queue(lo->lo_queue); + if ((unsigned int) info->lo_encrypt_key_size > LO_KEY_SIZE) + return -EINVAL; err = loop_release_xfer(lo); if (err) - goto out_unfreeze; + return err; if (info->lo_encrypt_type) { unsigned int type = info->lo_encrypt_type; - if (type >= MAX_LO_CRYPT) { - err = -EINVAL; - goto out_unfreeze; - } + if (type >= MAX_LO_CRYPT) + return -EINVAL; xfer = xfer_funcs[type]; - if (xfer == NULL) { - err = -EINVAL; - goto out_unfreeze; - } + if (xfer == NULL) + return -EINVAL; } else xfer = NULL; err = loop_init_xfer(lo, xfer, info); if (err) - goto out_unfreeze; + return err; - if (lo->lo_offset != info->lo_offset || - lo->lo_sizelimit != info->lo_sizelimit) { - /* kill_bdev should have truncated all the pages */ - if (lo->lo_device->bd_inode->i_mapping->nrpages) { - err = -EAGAIN; - pr_warn("%s: loop%d (%s) has still dirty pages (nrpages=%lu)\n", - __func__, lo->lo_number, lo->lo_file_name, - lo->lo_device->bd_inode->i_mapping->nrpages); - goto out_unfreeze; - } - if (figure_loop_size(lo, info->lo_offset, info->lo_sizelimit)) { - err = -EFBIG; - goto out_unfreeze; - } - } + /* Avoid assigning overflow values */ + if (info->lo_offset > LLONG_MAX || info->lo_sizelimit > LLONG_MAX) + return -EOVERFLOW; - loop_config_discard(lo); + lo->lo_offset = info->lo_offset; + lo->lo_sizelimit = info->lo_sizelimit; memcpy(lo->lo_file_name, info->lo_file_name, LO_NAME_SIZE); memcpy(lo->lo_crypt_name, info->lo_crypt_name, LO_NAME_SIZE); @@ -1375,6 +1344,63 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info) lo->lo_key_owner = uid; } + return 0; +} + +static int +loop_set_status(struct loop_device *lo, const struct loop_info64 *info) +{ + int err; + struct block_device *bdev; + kuid_t uid = current_uid(); + bool partscan = false; + bool size_changed = false; + + err = mutex_lock_killable(&loop_ctl_mutex); + if (err) + return err; + if (lo->lo_encrypt_key_size && + !uid_eq(lo->lo_key_owner, uid) && + !capable(CAP_SYS_ADMIN)) { + err = -EPERM; + goto out_unlock; + } + if (lo->lo_state != Lo_bound) { + err = -ENXIO; + goto out_unlock; + } + + if (lo->lo_offset != info->lo_offset || + lo->lo_sizelimit != info->lo_sizelimit) { + size_changed = true; + sync_blockdev(lo->lo_device); + invalidate_bdev(lo->lo_device); + } + + /* I/O need to be drained during transfer transition */ + blk_mq_freeze_queue(lo->lo_queue); + + if (size_changed && lo->lo_device->bd_inode->i_mapping->nrpages) { + /* If any pages were dirtied after invalidate_bdev(), try again */ + err = -EAGAIN; + pr_warn("%s: loop%d (%s) has still dirty pages (nrpages=%lu)\n", + __func__, lo->lo_number, lo->lo_file_name, + lo->lo_device->bd_inode->i_mapping->nrpages); + goto out_unfreeze; + } + + err = loop_set_status_from_info(lo, info); + if (err) + goto out_unfreeze; + + if (size_changed) { + loff_t new_size = get_size(lo->lo_offset, lo->lo_sizelimit, + lo->lo_backing_file); + loop_set_size(lo, new_size); + } + + loop_config_discard(lo); + /* update dio if lo_offset or transfer is changed */ __loop_update_dio(lo, lo->use_dio); @@ -1415,11 +1441,6 @@ loop_get_status(struct loop_device *lo, struct loop_info64 *info) info->lo_number = lo->lo_number; info->lo_offset = lo->lo_offset; info->lo_sizelimit = lo->lo_sizelimit; - - /* loff_t vars have been assigned __u64 */ - if (lo->lo_offset < 0 || lo->lo_sizelimit < 0) - return -EOVERFLOW; - info->lo_flags = lo->lo_flags; memcpy(info->lo_file_name, lo->lo_file_name, LO_NAME_SIZE); memcpy(info->lo_crypt_name, lo->lo_crypt_name, LO_NAME_SIZE); @@ -1555,7 +1576,9 @@ static int loop_set_capacity(struct loop_device *lo) if (unlikely(lo->lo_state != Lo_bound)) return -ENXIO; - return figure_loop_size(lo, lo->lo_offset, lo->lo_sizelimit); + figure_loop_size(lo, lo->lo_offset, lo->lo_sizelimit); + + return 0; } static int loop_set_dio(struct loop_device *lo, unsigned long arg) |