[PATCH v1 09/11] pstore/blk: blkoops: support special removing jobs for dmesg.

WeiXiong Liao
2020-01-20T01:04:34Z

It's one of a series of patches for adaptive to MTD device.

MTD device is not block device. To write to flash device on MTD, erase
must to be done before. However, pstore/blk just set datalen as 0 when
remove, which is not enough for mtd device. That's why this patch here,
to support special jobs when removing pstore/blk record.

Signed-off-by: WeiXiong Liao <liaoweixiong@allwinnertech.com>
---
Documentation/admin-guide/pstore-block.rst | 9 +++++++++
fs/pstore/blkoops.c | 4 +++-
fs/pstore/blkzone.c | 9 ++++++++-
include/linux/blkoops.h | 10 ++++++++++
include/linux/pstore_blk.h | 11 +++++++++++
5 files changed, 41 insertions(+), 2 deletions(-)

diff --git a/Documentation/admin-guide/pstore-block.rst b/Documentation/admin-guide/pstore-block.rst
index f4fc205406aa..e351b0ebd8e5 100644
--- a/Documentation/admin-guide/pstore-block.rst
+++ b/Documentation/admin-guide/pstore-block.rst
@@ -197,6 +197,15 @@ negative number will be returned. The following return numbers mean more:
1. -EBUSY: pstore/blk should try again later.
#. -ENEXT: this zone is used or broken, pstore/blk should try next one.

+erase
+~~~~~
+
+It's generic erase API for pstore/blk, which is requested by non-block device.
+It will be called while pstore record is removing. It's required only when the
+device has special removing jobs. For example, MTD device tries to erase block.
+
+Normally zero should be returned, otherwise it indicates an error.
+
panic_write (for non-block device)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

diff --git a/fs/pstore/blkoops.c b/fs/pstore/blkoops.c
index d9b51880144b..6b74189e5820 100644
--- a/fs/pstore/blkoops.c
+++ b/fs/pstore/blkoops.c
@@ -179,6 +179,7 @@ int blkoops_register_device(struct blkoops_device *bo_dev)
bzinfo->dump_oops = dump_oops;
bzinfo->read = bo_dev->read;
bzinfo->write = bo_dev->write;
+ bzinfo->erase = bo_dev->erase;
bzinfo->panic_write = bo_dev->panic_write;
bzinfo->name = "blkoops";
bzinfo->owner = THIS_MODULE;
@@ -398,10 +399,11 @@ int blkoops_register_blkdev(unsigned int major, unsigned int flags,
bo_dev.total_size = blkoops_bdev_size(bdev);
if (bo_dev.total_size == 0)
goto err_put_bdev;
- bo_dev.panic_write = panic_write ? blkoops_blk_panic_write : NULL;
bo_dev.flags = flags;
bo_dev.read = blkoops_generic_blk_read;
bo_dev.write = blkoops_generic_blk_write;
+ bo_dev.erase = NULL;
+ bo_dev.panic_write = panic_write ? blkoops_blk_panic_write : NULL;

ret = blkoops_register_device(&bo_dev);
if (ret)
diff --git a/fs/pstore/blkzone.c b/fs/pstore/blkzone.c
index 3f58ff85f49c..a006a4a5b012 100644
--- a/fs/pstore/blkzone.c
+++ b/fs/pstore/blkzone.c
@@ -609,11 +609,18 @@ static inline bool blkz_ok(struct blkz_zone *zone)
static inline int blkz_dmesg_erase(struct blkz_context *cxt,
struct blkz_zone *zone)
{
+ size_t size;
+
if (unlikely(!blkz_ok(zone)))
return 0;

atomic_set(&zone->buffer->datalen, 0);
- return blkz_zone_write(zone, FLUSH_META, NULL, 0, 0);
+
+ size = buffer_datalen(zone) + sizeof(*zone->buffer);
+ if (cxt->bzinfo->erase)
+ return cxt->bzinfo->erase(size, zone->off);
+ else
+ return blkz_zone_write(zone, FLUSH_META, NULL, 0, 0);
}

static inline int blkz_record_erase(struct blkz_context *cxt,
diff --git a/include/linux/blkoops.h b/include/linux/blkoops.h
index bc7665d14a98..11cb3036ad5f 100644
--- a/include/linux/blkoops.h
+++ b/include/linux/blkoops.h
@@ -33,6 +33,15 @@
* number means more:
* -EBUSY: pstore/blk should try again later.
* -ENEXT: this zone is used or broken, pstore/blk should try next one.
+ * @erase:
+ * The general (not panic) erase operation. It will be call while pstore
+ * record is removing. It's required only when device have special
+ * removing jobs, for example, MTD device try to erase block.
+ *
+ * Both of the @size and @offset parameters on this interface are
+ * the relative size of the space provided, not the whole disk/flash.
+ *
+ * On success, 0 should be returned. Others mean error.
* @panic_write:
* The write operation only used for panic.
*
@@ -53,6 +62,7 @@ struct blkoops_device {
unsigned long total_size;
blkz_read_op read;
blkz_write_op write;
+ blkz_erase_op erase;
blkz_write_op panic_write;
};

diff --git a/include/linux/pstore_blk.h b/include/linux/pstore_blk.h
index bbbe4fe37f7c..9641969f888f 100644
--- a/include/linux/pstore_blk.h
+++ b/include/linux/pstore_blk.h
@@ -46,6 +46,15 @@
* number means more:
* -EBUSY: pstore/blk should try again later.
* -ENEXT: this zone is used or broken, pstore/blk should try next one.
+ * @erase:
+ * The general (not panic) erase operation. It will be call while pstore
+ * record is removing. It's required only when device have special
+ * removing jobs, for example, MTD device try to erase block.
+ *
+ * Both of the @size and @offset parameters on this interface are
+ * the relative size of the space provided, not the whole disk/flash.
+ *
+ * On success, 0 should be returned. Others mean error.
* @panic_write:
* The write operation only used for panic. It's optional if you do not
* care panic record. If panic occur but blkzone do not recover yet, the
@@ -59,6 +68,7 @@
*/
typedef ssize_t (*blkz_read_op)(char *, size_t, loff_t);
typedef ssize_t (*blkz_write_op)(const char *, size_t, loff_t);
+typedef ssize_t (*blkz_erase_op)(size_t, loff_t);
struct blkz_info {
struct module *owner;
const char *name;
@@ -71,6 +81,7 @@ struct blkz_info {
int dump_oops;
blkz_read_op read;
blkz_write_op write;
+ blkz_erase_op erase;
blkz_write_op panic_write;
};

--
1.9.1