pstore/blk: Support non-block storage devices

Add support for non-block devices (e.g. MTD). A non-block driver calls
pstore_blk_register_device() to register iself.

In addition, pstore/zone is updated to handle non-block devices,
where an erase must be done before a write. Without this, there is no
way to remove records stored to an MTD.

Signed-off-by: WeiXiong Liao <liaoweixiong@allwinnertech.com>
Link: https://lore.kernel.org/lkml/20200511233229.27745-10-keescook@chromium.org/
Co-developed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
This commit is contained in:
WeiXiong Liao
2020-03-25 16:55:05 +08:00
committed by Kees Cook
parent 1525fb3bb6
commit 7dcb7848ba
5 changed files with 115 additions and 49 deletions

View File

@@ -49,6 +49,44 @@ struct pstore_blk_info {
int register_pstore_blk(struct pstore_blk_info *info);
void unregister_pstore_blk(unsigned int major);
/**
* struct pstore_device_info - back-end pstore/blk driver structure.
*
* @total_size: The total size in bytes pstore/blk can use. It must be greater
* than 4096 and be multiple of 4096.
* @flags: Refer to macro starting with PSTORE_FLAGS defined in
* linux/pstore.h. It means what front-ends this device support.
* Zero means all backends for compatible.
* @read: The general read operation. Both of the function parameters
* @size and @offset are relative value to bock device (not the
* whole disk).
* On success, the number of bytes should be returned, others
* means error.
* @write: The same as @read, but the following error number:
* -EBUSY means try to write again later.
* -ENOMSG means to try next zone.
* @erase: The general erase operation for device with special removing
* job. Both of the function parameters @size and @offset are
* relative value to storage.
* Return 0 on success and others on failure.
* @panic_write:The write operation only used for panic case. It's optional
* if you do not care panic log. The parameters are relative
* value to storage.
* On success, the number of bytes should be returned, others
* excluding -ENOMSG mean error. -ENOMSG means to try next zone.
*/
struct pstore_device_info {
unsigned long total_size;
unsigned int flags;
pstore_zone_read_op read;
pstore_zone_write_op write;
pstore_zone_erase_op erase;
pstore_zone_write_op panic_write;
};
int register_pstore_device(struct pstore_device_info *dev);
void unregister_pstore_device(struct pstore_device_info *dev);
/**
* struct pstore_blk_config - the pstore_blk backend configuration
*