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@xxxxxxxxxxxxxxxxx> --- 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 299142b3d8e6..1735476621df 100644 --- a/Documentation/admin-guide/pstore-block.rst +++ b/Documentation/admin-guide/pstore-block.rst @@ -200,6 +200,15 @@ 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 01170b344f00..7cf4731e52f7 100644 --- a/fs/pstore/blkoops.c +++ b/fs/pstore/blkoops.c @@ -164,6 +164,7 @@ 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; @@ -383,10 +384,11 @@ 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 205aeff28992..a17fff77b875 100644 --- a/fs/pstore/blkzone.c +++ b/fs/pstore/blkzone.c @@ -593,11 +593,18 @@ 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