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path: root/drivers/block/loop.c
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Diffstat (limited to 'drivers/block/loop.c')
-rw-r--r--drivers/block/loop.c383
1 files changed, 226 insertions, 157 deletions
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 13dbe2f16882..4212288ab157 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -228,26 +228,36 @@ static void __loop_update_dio(struct loop_device *lo, bool dio)
blk_mq_unfreeze_queue(lo->lo_queue);
}
+/**
+ * loop_validate_block_size() - validates the passed in block size
+ * @bsize: size to validate
+ */
static int
-figure_loop_size(struct loop_device *lo, loff_t offset, loff_t sizelimit)
+loop_validate_block_size(unsigned short bsize)
{
- 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 (bsize < 512 || bsize > PAGE_SIZE || !is_power_of_2(bsize))
+ return -EINVAL;
- 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);
- /* let user-space know about the new size */
- kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, KOBJ_CHANGE);
return 0;
}
+/**
+ * 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)
+{
+ struct block_device *bdev = lo->lo_device;
+
+ bd_set_size(bdev, size << SECTOR_SHIFT);
+
+ set_capacity_revalidate_and_notify(lo->lo_disk, size, false);
+}
+
static inline int
lo_do_transfer(struct loop_device *lo, int cmd,
struct page *rpage, unsigned roffs,
@@ -952,23 +962,125 @@ static void loop_update_rotational(struct loop_device *lo)
blk_queue_flag_clear(QUEUE_FLAG_NONROT, q);
}
-static int loop_set_fd(struct loop_device *lo, fmode_t mode,
- struct block_device *bdev, unsigned int arg)
+static int
+loop_release_xfer(struct loop_device *lo)
+{
+ int err = 0;
+ struct loop_func_table *xfer = lo->lo_encryption;
+
+ if (xfer) {
+ if (xfer->release)
+ err = xfer->release(lo);
+ lo->transfer = NULL;
+ lo->lo_encryption = NULL;
+ module_put(xfer->owner);
+ }
+ return err;
+}
+
+static int
+loop_init_xfer(struct loop_device *lo, struct loop_func_table *xfer,
+ const struct loop_info64 *i)
+{
+ int err = 0;
+
+ if (xfer) {
+ struct module *owner = xfer->owner;
+
+ if (!try_module_get(owner))
+ return -EINVAL;
+ if (xfer->init)
+ err = xfer->init(lo, i);
+ if (err)
+ module_put(owner);
+ else
+ lo->lo_encryption = xfer;
+ }
+ return err;
+}
+
+/**
+ * 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_from_info(struct loop_device *lo,
+ const struct loop_info64 *info)
+{
+ int err;
+ struct loop_func_table *xfer;
+ kuid_t uid = current_uid();
+
+ if ((unsigned int) info->lo_encrypt_key_size > LO_KEY_SIZE)
+ return -EINVAL;
+
+ err = loop_release_xfer(lo);
+ if (err)
+ return err;
+
+ if (info->lo_encrypt_type) {
+ unsigned int type = info->lo_encrypt_type;
+
+ if (type >= MAX_LO_CRYPT)
+ return -EINVAL;
+ xfer = xfer_funcs[type];
+ if (xfer == NULL)
+ return -EINVAL;
+ } else
+ xfer = NULL;
+
+ err = loop_init_xfer(lo, xfer, info);
+ if (err)
+ return err;
+
+ 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);
+ lo->lo_file_name[LO_NAME_SIZE-1] = 0;
+ lo->lo_crypt_name[LO_NAME_SIZE-1] = 0;
+
+ if (!xfer)
+ xfer = &none_funcs;
+ lo->transfer = xfer->transfer;
+ lo->ioctl = xfer->ioctl;
+
+ lo->lo_flags = info->lo_flags;
+
+ lo->lo_encrypt_key_size = info->lo_encrypt_key_size;
+ lo->lo_init[0] = info->lo_init[0];
+ lo->lo_init[1] = info->lo_init[1];
+ if (info->lo_encrypt_key_size) {
+ memcpy(lo->lo_encrypt_key, info->lo_encrypt_key,
+ info->lo_encrypt_key_size);
+ lo->lo_key_owner = uid;
+ }
+
+ return 0;
+}
+
+static int loop_configure(struct loop_device *lo, fmode_t mode,
+ struct block_device *bdev,
+ const struct loop_config *config)
{
struct file *file;
struct inode *inode;
struct address_space *mapping;
struct block_device *claimed_bdev = NULL;
- int lo_flags = 0;
int error;
loff_t size;
bool partscan;
+ unsigned short bsize;
/* This is safe, since we have a reference from open(). */
__module_get(THIS_MODULE);
error = -EBADF;
- file = fget(arg);
+ file = fget(config->fd);
if (!file)
goto out;
@@ -977,7 +1089,7 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode,
* here to avoid changing device under exclusive owner.
*/
if (!(mode & FMODE_EXCL)) {
- claimed_bdev = bd_start_claiming(bdev, loop_set_fd);
+ claimed_bdev = bd_start_claiming(bdev, loop_configure);
if (IS_ERR(claimed_bdev)) {
error = PTR_ERR(claimed_bdev);
goto out_putf;
@@ -999,52 +1111,58 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode,
mapping = file->f_mapping;
inode = mapping->host;
+ size = get_loop_size(lo, file);
+
+ if ((config->info.lo_flags & ~LOOP_CONFIGURE_SETTABLE_FLAGS) != 0) {
+ error = -EINVAL;
+ goto out_unlock;
+ }
+
+ if (config->block_size) {
+ error = loop_validate_block_size(config->block_size);
+ if (error)
+ goto out_unlock;
+ }
+
+ error = loop_set_status_from_info(lo, &config->info);
+ if (error)
+ goto out_unlock;
+
if (!(file->f_mode & FMODE_WRITE) || !(mode & FMODE_WRITE) ||
!file->f_op->write_iter)
- lo_flags |= LO_FLAGS_READ_ONLY;
+ lo->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;
- error = 0;
-
- set_device_ro(bdev, (lo_flags & LO_FLAGS_READ_ONLY) != 0);
+ set_device_ro(bdev, (lo->lo_flags & LO_FLAGS_READ_ONLY) != 0);
- lo->use_dio = false;
+ lo->use_dio = lo->lo_flags & LO_FLAGS_DIRECT_IO;
lo->lo_device = bdev;
- lo->lo_flags = lo_flags;
lo->lo_backing_file = file;
- lo->transfer = NULL;
- lo->ioctl = NULL;
- lo->lo_sizelimit = 0;
lo->old_gfp_mask = mapping_gfp_mask(mapping);
mapping_set_gfp_mask(mapping, lo->old_gfp_mask & ~(__GFP_IO|__GFP_FS));
- if (!(lo_flags & LO_FLAGS_READ_ONLY) && file->f_op->fsync)
+ if (!(lo->lo_flags & LO_FLAGS_READ_ONLY) && file->f_op->fsync)
blk_queue_write_cache(lo->lo_queue, true, false);
- if (io_is_direct(lo->lo_backing_file) && inode->i_sb->s_bdev) {
+ if (config->block_size)
+ bsize = config->block_size;
+ else if (io_is_direct(lo->lo_backing_file) && inode->i_sb->s_bdev)
/* In case of direct I/O, match underlying block size */
- unsigned short bsize = bdev_logical_block_size(
- inode->i_sb->s_bdev);
+ bsize = bdev_logical_block_size(inode->i_sb->s_bdev);
+ else
+ bsize = 512;
- blk_queue_logical_block_size(lo->lo_queue, bsize);
- blk_queue_physical_block_size(lo->lo_queue, bsize);
- blk_queue_io_min(lo->lo_queue, bsize);
- }
+ blk_queue_logical_block_size(lo->lo_queue, bsize);
+ blk_queue_physical_block_size(lo->lo_queue, bsize);
+ blk_queue_io_min(lo->lo_queue, bsize);
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);
@@ -1062,14 +1180,14 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode,
if (partscan)
loop_reread_partitions(lo, bdev);
if (claimed_bdev)
- bd_abort_claiming(bdev, claimed_bdev, loop_set_fd);
+ bd_abort_claiming(bdev, claimed_bdev, loop_configure);
return 0;
out_unlock:
mutex_unlock(&loop_ctl_mutex);
out_bdev:
if (claimed_bdev)
- bd_abort_claiming(bdev, claimed_bdev, loop_set_fd);
+ bd_abort_claiming(bdev, claimed_bdev, loop_configure);
out_putf:
fput(file);
out:
@@ -1078,43 +1196,6 @@ out:
return error;
}
-static int
-loop_release_xfer(struct loop_device *lo)
-{
- int err = 0;
- struct loop_func_table *xfer = lo->lo_encryption;
-
- if (xfer) {
- if (xfer->release)
- err = xfer->release(lo);
- lo->transfer = NULL;
- lo->lo_encryption = NULL;
- module_put(xfer->owner);
- }
- return err;
-}
-
-static int
-loop_init_xfer(struct loop_device *lo, struct loop_func_table *xfer,
- const struct loop_info64 *i)
-{
- int err = 0;
-
- if (xfer) {
- struct module *owner = xfer->owner;
-
- if (!try_module_get(owner))
- return -EINVAL;
- if (xfer->init)
- err = xfer->init(lo, i);
- if (err)
- module_put(owner);
- else
- lo->lo_encryption = xfer;
- }
- return err;
-}
-
static int __loop_clr_fd(struct loop_device *lo, bool release)
{
struct file *filp = NULL;
@@ -1263,10 +1344,11 @@ static int
loop_set_status(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;
+ kuid_t uid = current_uid();
+ int prev_lo_flags;
bool partscan = false;
+ bool size_changed = false;
err = mutex_lock_killable(&loop_ctl_mutex);
if (err)
@@ -1281,13 +1363,10 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info)
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) {
+ size_changed = true;
sync_blockdev(lo->lo_device);
kill_bdev(lo->lo_device);
}
@@ -1295,79 +1374,44 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info)
/* I/O need to be drained during transfer transition */
blk_mq_freeze_queue(lo->lo_queue);
- err = loop_release_xfer(lo);
- if (err)
+ if (size_changed && lo->lo_device->bd_inode->i_mapping->nrpages) {
+ /* If any pages were dirtied after kill_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;
+ }
- if (info->lo_encrypt_type) {
- unsigned int type = info->lo_encrypt_type;
-
- if (type >= MAX_LO_CRYPT) {
- err = -EINVAL;
- goto out_unfreeze;
- }
- xfer = xfer_funcs[type];
- if (xfer == NULL) {
- err = -EINVAL;
- goto out_unfreeze;
- }
- } else
- xfer = NULL;
+ prev_lo_flags = lo->lo_flags;
- err = loop_init_xfer(lo, xfer, info);
+ err = loop_set_status_from_info(lo, info);
if (err)
goto out_unfreeze;
- 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;
- }
+ /* Mask out flags that can't be set using LOOP_SET_STATUS. */
+ lo->lo_flags &= ~LOOP_SET_STATUS_SETTABLE_FLAGS;
+ /* For those flags, use the previous values instead */
+ lo->lo_flags |= prev_lo_flags & ~LOOP_SET_STATUS_SETTABLE_FLAGS;
+ /* For flags that can't be cleared, use previous values too */
+ lo->lo_flags |= prev_lo_flags & ~LOOP_SET_STATUS_CLEARABLE_FLAGS;
+
+ 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);
- memcpy(lo->lo_file_name, info->lo_file_name, LO_NAME_SIZE);
- memcpy(lo->lo_crypt_name, info->lo_crypt_name, LO_NAME_SIZE);
- lo->lo_file_name[LO_NAME_SIZE-1] = 0;
- lo->lo_crypt_name[LO_NAME_SIZE-1] = 0;
-
- if (!xfer)
- xfer = &none_funcs;
- lo->transfer = xfer->transfer;
- lo->ioctl = xfer->ioctl;
-
- if ((lo->lo_flags & LO_FLAGS_AUTOCLEAR) !=
- (info->lo_flags & LO_FLAGS_AUTOCLEAR))
- lo->lo_flags ^= LO_FLAGS_AUTOCLEAR;
-
- lo->lo_encrypt_key_size = info->lo_encrypt_key_size;
- lo->lo_init[0] = info->lo_init[0];
- lo->lo_init[1] = info->lo_init[1];
- if (info->lo_encrypt_key_size) {
- memcpy(lo->lo_encrypt_key, info->lo_encrypt_key,
- info->lo_encrypt_key_size);
- lo->lo_key_owner = uid;
- }
-
/* update dio if lo_offset or transfer is changed */
__loop_update_dio(lo, lo->use_dio);
out_unfreeze:
blk_mq_unfreeze_queue(lo->lo_queue);
- if (!err && (info->lo_flags & LO_FLAGS_PARTSCAN) &&
- !(lo->lo_flags & LO_FLAGS_PARTSCAN)) {
- lo->lo_flags |= LO_FLAGS_PARTSCAN;
+ if (!err && (lo->lo_flags & LO_FLAGS_PARTSCAN) &&
+ !(prev_lo_flags & LO_FLAGS_PARTSCAN)) {
lo->lo_disk->flags &= ~GENHD_FL_NO_PART_SCAN;
bdev = lo->lo_device;
partscan = true;
@@ -1531,10 +1575,15 @@ loop_get_status64(struct loop_device *lo, struct loop_info64 __user *arg) {
static int loop_set_capacity(struct loop_device *lo)
{
+ loff_t size;
+
if (unlikely(lo->lo_state != Lo_bound))
return -ENXIO;
- return figure_loop_size(lo, lo->lo_offset, lo->lo_sizelimit);
+ size = get_loop_size(lo, lo->lo_backing_file);
+ loop_set_size(lo, size);
+
+ return 0;
}
static int loop_set_dio(struct loop_device *lo, unsigned long arg)
@@ -1558,8 +1607,9 @@ static int loop_set_block_size(struct loop_device *lo, unsigned long arg)
if (lo->lo_state != Lo_bound)
return -ENXIO;
- if (arg < 512 || arg > PAGE_SIZE || !is_power_of_2(arg))
- return -EINVAL;
+ err = loop_validate_block_size(arg);
+ if (err)
+ return err;
if (lo->lo_queue->limits.logical_block_size == arg)
return 0;
@@ -1617,11 +1667,31 @@ static int lo_ioctl(struct block_device *bdev, fmode_t mode,
unsigned int cmd, unsigned long arg)
{
struct loop_device *lo = bdev->bd_disk->private_data;
+ void __user *argp = (void __user *) arg;
int err;
switch (cmd) {
- case LOOP_SET_FD:
- return loop_set_fd(lo, mode, bdev, arg);
+ case LOOP_SET_FD: {
+ /*
+ * Legacy case - pass in a zeroed out struct loop_config with
+ * only the file descriptor set , which corresponds with the
+ * default parameters we'd have used otherwise.
+ */
+ struct loop_config config;
+
+ memset(&config, 0, sizeof(config));
+ config.fd = arg;
+
+ return loop_configure(lo, mode, bdev, &config);
+ }
+ case LOOP_CONFIGURE: {
+ struct loop_config config;
+
+ if (copy_from_user(&config, argp, sizeof(config)))
+ return -EFAULT;
+
+ return loop_configure(lo, mode, bdev, &config);
+ }
case LOOP_CHANGE_FD:
return loop_change_fd(lo, bdev, arg);
case LOOP_CLR_FD:
@@ -1629,21 +1699,19 @@ static int lo_ioctl(struct block_device *bdev, fmode_t mode,
case LOOP_SET_STATUS:
err = -EPERM;
if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) {
- err = loop_set_status_old(lo,
- (struct loop_info __user *)arg);
+ err = loop_set_status_old(lo, argp);
}
break;
case LOOP_GET_STATUS:
- return loop_get_status_old(lo, (struct loop_info __user *) arg);
+ return loop_get_status_old(lo, argp);
case LOOP_SET_STATUS64:
err = -EPERM;
if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) {
- err = loop_set_status64(lo,
- (struct loop_info64 __user *) arg);
+ err = loop_set_status64(lo, argp);
}
break;
case LOOP_GET_STATUS64:
- return loop_get_status64(lo, (struct loop_info64 __user *) arg);
+ return loop_get_status64(lo, argp);
case LOOP_SET_CAPACITY:
case LOOP_SET_DIRECT_IO:
case LOOP_SET_BLOCK_SIZE:
@@ -1795,6 +1863,7 @@ static int lo_compat_ioctl(struct block_device *bdev, fmode_t mode,
case LOOP_CLR_FD:
case LOOP_GET_STATUS64:
case LOOP_SET_STATUS64:
+ case LOOP_CONFIGURE:
arg = (unsigned long) compat_ptr(arg);
/* fall through */
case LOOP_SET_FD: