Messages in this thread | | | Subject | Re: [PATCH v1 11/11] mtd: new support oops logger based on pstore/blk | From | liaoweixiong <> | Date | Thu, 23 Jan 2020 15:03:25 +0800 |
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hi Vignesh Raghavendra,
On 2020/1/23 下午12:24, Vignesh Raghavendra wrote: > Hi > > On 20/01/20 6:33 am, WeiXiong Liao wrote: > [...] >> +static inline int mtdpstore_panic_block_isbad(struct mtdpstore_context *cxt, >> + loff_t off) >> +{ >> + struct mtd_info *mtd = cxt->mtd; >> + u64 blknum = div_u64(off, mtd->erasesize); >> + >> + return test_bit(blknum, cxt->badmap); >> +} >> + >> +static inline void mtdpstore_mark_used(struct mtdpstore_context *cxt, >> + loff_t off) >> +{ >> + u64 zonenum = div_u64(off, cxt->bo_info.dmesg_size); >> + >> + pr_debug("mark zone %llu used\n", zonenum); > > Please replace pr_*() with dev_*() throughout the patch. Device pointer > should be available via struct mtd_info >
OK. I will fix it later. Thank you.
> Regards > Vignesh > >> + set_bit(zonenum, cxt->usedmap); >> +} >> + >> +static inline void mtdpstore_mark_unused(struct mtdpstore_context *cxt, >> + loff_t off) >> +{ >> + u64 zonenum = div_u64(off, cxt->bo_info.dmesg_size); >> + >> + pr_debug("mark zone %llu unused\n", zonenum); >> + clear_bit(zonenum, cxt->usedmap); >> +} >> + >> +static inline void mtdpstore_block_mark_unused(struct mtdpstore_context *cxt, >> + loff_t off) >> +{ >> + u64 zonenum = div_u64(off, cxt->bo_info.dmesg_size); >> + u32 zonecnt = cxt->mtd->erasesize / cxt->bo_info.dmesg_size; >> + >> + while (zonecnt > 0) { >> + pr_debug("mark zone %llu unused\n", zonenum); >> + clear_bit(zonenum, cxt->usedmap); >> + zonenum++; >> + zonecnt--; >> + } >> +} >> + >> +static inline int mtdpstore_is_used(struct mtdpstore_context *cxt, loff_t off) >> +{ >> + u64 zonenum = div_u64(off, cxt->bo_info.dmesg_size); >> + u64 blknum = div_u64(off, cxt->mtd->erasesize); >> + >> + if (test_bit(blknum, cxt->badmap)) >> + return true; >> + return test_bit(zonenum, cxt->usedmap); >> +} >> + >> +static int mtdpstore_block_is_used(struct mtdpstore_context *cxt, >> + loff_t off) >> +{ >> + u64 zonenum = div_u64(off, cxt->bo_info.dmesg_size); >> + u32 zonecnt = cxt->mtd->erasesize / cxt->bo_info.dmesg_size; >> + >> + while (zonecnt > 0) { >> + if (test_bit(zonenum, cxt->usedmap)) >> + return true; >> + zonenum++; >> + zonecnt--; >> + } >> + return false; >> +} >> + >> +static int mtdpstore_is_empty(struct mtdpstore_context *cxt, char *buf, >> + size_t size) >> +{ >> + struct mtd_info *mtd = cxt->mtd; >> + size_t sz; >> + int i; >> + >> + sz = min_t(uint32_t, size, mtd->writesize / 4); >> + for (i = 0; i < sz; i++) { >> + if (buf[i] != (char)0xFF) >> + return false; >> + } >> + return true; >> +} >> + >> +static void mtdpstore_mark_removed(struct mtdpstore_context *cxt, loff_t off) >> +{ >> + u64 zonenum = div_u64(off, cxt->bo_info.dmesg_size); >> + >> + pr_debug("mark zone %llu removed\n", zonenum); >> + set_bit(zonenum, cxt->rmmap); >> +} >> + >> +static void mtdpstore_block_clear_removed(struct mtdpstore_context *cxt, >> + loff_t off) >> +{ >> + u64 zonenum = div_u64(off, cxt->bo_info.dmesg_size); >> + u32 zonecnt = cxt->mtd->erasesize / cxt->bo_info.dmesg_size; >> + >> + while (zonecnt > 0) { >> + clear_bit(zonenum, cxt->rmmap); >> + zonenum++; >> + zonecnt--; >> + } >> +} >> + >> +static int mtdpstore_block_is_removed(struct mtdpstore_context *cxt, >> + loff_t off) >> +{ >> + u64 zonenum = div_u64(off, cxt->bo_info.dmesg_size); >> + u32 zonecnt = cxt->mtd->erasesize / cxt->bo_info.dmesg_size; >> + >> + while (zonecnt > 0) { >> + if (test_bit(zonenum, cxt->rmmap)) >> + return true; >> + zonenum++; >> + zonecnt--; >> + } >> + return false; >> +} >> + >> +static int mtdpstore_erase_do(struct mtdpstore_context *cxt, loff_t off) >> +{ >> + struct erase_info erase; >> + int ret; >> + >> + pr_debug("try to erase off 0x%llx\n", off); >> + erase.len = cxt->mtd->erasesize; >> + erase.addr = off; >> + ret = mtd_erase(cxt->mtd, &erase); >> + if (!ret) >> + mtdpstore_block_clear_removed(cxt, off); >> + else >> + pr_err("erase of region [0x%llx, 0x%llx] on \"%s\" failed\n", >> + (unsigned long long)erase.addr, >> + (unsigned long long)erase.len, cxt->bo_info.device); >> + return ret; >> +} >> + >> +/* >> + * called while removing file >> + * >> + * Avoiding over erasing, do erase only when all zones are removed or unused. >> + * Ensure to remove when unregister by reading, erasing and wrtiing back. >> + */ >> +static ssize_t mtdpstore_erase(size_t size, loff_t off) >> +{ >> + struct mtdpstore_context *cxt = &oops_cxt; >> + >> + if (mtdpstore_block_isbad(cxt, off)) >> + return -EIO; >> + >> + mtdpstore_mark_unused(cxt, off); >> + >> + if (likely(mtdpstore_block_is_used(cxt, off))) { >> + mtdpstore_mark_removed(cxt, off); >> + return 0; >> + } >> + >> + /* all zones are unused, erase it */ >> + off = ALIGN_DOWN(off, cxt->mtd->erasesize); >> + return mtdpstore_erase_do(cxt, off); >> +} >> + >> +/* >> + * What is securety for mtdpstore? >> + * As there is no erase for panic case, we should ensure at least one zone >> + * is writable. Otherwise, panic write will be failed. >> + * If zone is used, write operation will return -ENEXT, which means that >> + * pstore/blk will try one by one until get a empty zone. So, it's no need >> + * to ensure next zone is empty, but at least one. >> + */ >> +static int mtdpstore_security(struct mtdpstore_context *cxt, loff_t off) >> +{ >> + int ret = 0, i; >> + u32 zonenum = (u32)div_u64(off, cxt->bo_info.dmesg_size); >> + u32 zonecnt = (u32)div_u64(cxt->mtd->size, cxt->bo_info.dmesg_size); >> + u32 blkcnt = (u32)div_u64(cxt->mtd->size, cxt->mtd->erasesize); >> + u32 erasesize = cxt->mtd->erasesize; >> + >> + for (i = 0; i < zonecnt; i++) { >> + u32 num = (zonenum + i) % zonecnt; >> + >> + /* found empty zone */ >> + if (!test_bit(num, cxt->usedmap)) >> + return 0; >> + } >> + >> + /* If there is no any empty zone, we have no way but to do erase */ >> + off = ALIGN_DOWN(off, erasesize); >> + while (blkcnt--) { >> + div64_u64_rem(off + erasesize, cxt->mtd->size, (u64 *)&off); >> + >> + if (mtdpstore_block_isbad(cxt, off)) >> + continue; >> + >> + ret = mtdpstore_erase_do(cxt, off); >> + if (!ret) { >> + mtdpstore_block_mark_unused(cxt, off); >> + break; >> + } >> + } >> + >> + if (ret) >> + pr_err("all blocks bad!\n"); >> + pr_debug("end security\n"); >> + return ret; >> +} >> + >> +static ssize_t mtdpstore_write(const char *buf, size_t size, loff_t off) >> +{ >> + struct mtdpstore_context *cxt = &oops_cxt; >> + size_t retlen; >> + int ret; >> + >> + if (mtdpstore_block_isbad(cxt, off)) >> + return -ENEXT; >> + >> + /* zone is used, please try next one */ >> + if (mtdpstore_is_used(cxt, off)) >> + return -ENEXT; >> + >> + pr_debug("try to write off 0x%llx size %zu\n", off, size); >> + ret = mtd_write(cxt->mtd, off, size, &retlen, (u_char *)buf); >> + if (ret < 0 || retlen != size) { >> + pr_err("write failure at %lld (%zu of %zu written), err %d\n", >> + off, retlen, size, ret); >> + return -EIO; >> + } >> + mtdpstore_mark_used(cxt, off); >> + >> + mtdpstore_security(cxt, off); >> + return retlen; >> +} >> + >> +/* >> + * All zones will be read as pstore/blk will read zone one by one when do >> + * recover. >> + */ >> +static ssize_t mtdpstore_read(char *buf, size_t size, loff_t off) >> +{ >> + struct mtdpstore_context *cxt = &oops_cxt; >> + size_t retlen; >> + int ret; >> + >> + if (mtdpstore_block_isbad(cxt, off)) >> + return -ENEXT; >> + >> + pr_debug("try to read off 0x%llx size %zu\n", off, size); >> + ret = mtd_read(cxt->mtd, off, size, &retlen, (u_char *)buf); >> + if ((ret < 0 && !mtd_is_bitflip(ret)) || size != retlen) { >> + pr_err("read failure at %lld (%zu of %zu read), err %d\n", >> + off, retlen, size, ret); >> + return -EIO; >> + } >> + >> + if (mtdpstore_is_empty(cxt, buf, size)) >> + mtdpstore_mark_unused(cxt, off); >> + else >> + mtdpstore_mark_used(cxt, off); >> + >> + mtdpstore_security(cxt, off); >> + return retlen; >> +} >> + >> +static ssize_t mtdpstore_panic_write(const char *buf, size_t size, loff_t off) >> +{ >> + struct mtdpstore_context *cxt = &oops_cxt; >> + size_t retlen; >> + int ret; >> + >> + if (mtdpstore_panic_block_isbad(cxt, off)) >> + return -ENEXT; >> + >> + /* zone is used, please try next one */ >> + if (mtdpstore_is_used(cxt, off)) >> + return -ENEXT; >> + >> + ret = mtd_panic_write(cxt->mtd, off, size, &retlen, (u_char *)buf); >> + if (ret < 0 || size != retlen) { >> + pr_err("panic write failure at %lld (%zu of %zu read), err %d\n", >> + off, retlen, size, ret); >> + return -EIO; >> + } >> + mtdpstore_mark_used(cxt, off); >> + >> + return retlen; >> +} >> + >> +static void mtdpstore_notify_add(struct mtd_info *mtd) >> +{ >> + int ret; >> + struct mtdpstore_context *cxt = &oops_cxt; >> + struct blkoops_info *info = &cxt->bo_info; >> + unsigned long longcnt; >> + >> + if (!strcmp(mtd->name, info->device)) >> + cxt->index = mtd->index; >> + >> + if (mtd->index != cxt->index || cxt->index < 0) >> + return; >> + >> + pr_debug("found matching MTD device %s\n", mtd->name); >> + >> + if (mtd->size < info->dmesg_size * 2) { >> + pr_err("MTD partition %d not big enough\n", mtd->index); >> + return; >> + } >> + if (mtd->erasesize < info->dmesg_size) { >> + pr_err("eraseblock size of MTD partition %d too small\n", >> + mtd->index); >> + return; >> + } >> + if (unlikely(info->dmesg_size % mtd->writesize)) { >> + pr_err("record size %lu KB must align to write size %d KB\n", >> + info->dmesg_size / 1024, >> + mtd->writesize / 1024); >> + return; >> + } >> + if (unlikely(mtd->size > MTDPSTORE_MAX_MTD_SIZE)) { >> + pr_err("mtd%d is too large (limit is %d MiB)\n", >> + mtd->index, >> + MTDPSTORE_MAX_MTD_SIZE / 1024 / 1024); >> + return; >> + } >> + >> + longcnt = BITS_TO_LONGS(div_u64(mtd->size, info->dmesg_size)); >> + cxt->rmmap = kcalloc(longcnt, sizeof(long), GFP_KERNEL); >> + cxt->usedmap = kcalloc(longcnt, sizeof(long), GFP_KERNEL); >> + >> + longcnt = BITS_TO_LONGS(div_u64(mtd->size, mtd->erasesize)); >> + cxt->badmap = kcalloc(longcnt, sizeof(long), GFP_KERNEL); >> + >> + cxt->bo_dev.total_size = mtd->size; >> + /* just support dmesg right now */ >> + cxt->bo_dev.flags = BLKOOPS_DEV_SUPPORT_DMESG; >> + cxt->bo_dev.read = mtdpstore_read; >> + cxt->bo_dev.write = mtdpstore_write; >> + cxt->bo_dev.erase = mtdpstore_erase; >> + cxt->bo_dev.panic_write = mtdpstore_panic_write; >> + >> + ret = blkoops_register_device(&cxt->bo_dev); >> + if (ret) { >> + pr_err("mtd%d register to blkoops failed\n", mtd->index); >> + return; >> + } >> + cxt->mtd = mtd; >> + pr_info("Attached to MTD device %d\n", mtd->index); >> +} >> + >> +static int mtdpstore_flush_removed_do(struct mtdpstore_context *cxt, >> + loff_t off, size_t size) >> +{ >> + struct mtd_info *mtd = cxt->mtd; >> + u_char *buf; >> + int ret; >> + size_t retlen; >> + struct erase_info erase; >> + >> + buf = kmalloc(mtd->erasesize, GFP_KERNEL); >> + if (!buf) >> + return -ENOMEM; >> + >> + /* 1st. read to cache */ >> + ret = mtd_read(mtd, off, mtd->erasesize, &retlen, buf); >> + if (ret || retlen != mtd->erasesize) >> + goto free; >> + >> + /* 2nd. erase block */ >> + erase.len = mtd->erasesize; >> + erase.addr = off; >> + ret = mtd_erase(mtd, &erase); >> + if (ret) >> + goto free; >> + >> + /* 3rd. write back */ >> + while (size) { >> + unsigned int zonesize = cxt->bo_info.dmesg_size; >> + >> + /* remove must clear used bit */ >> + if (mtdpstore_is_used(cxt, off)) >> + mtd_write(mtd, off, zonesize, &retlen, buf); >> + >> + off += zonesize; >> + size -= min_t(unsigned int, zonesize, size); >> + } >> + >> +free: >> + kfree(buf); >> + return ret; >> +} >> + >> +static int mtdpstore_flush_removed(struct mtdpstore_context *cxt) >> +{ >> + struct mtd_info *mtd = cxt->mtd; >> + int ret; >> + loff_t off; >> + u32 blkcnt = (u32)div_u64(mtd->size, mtd->erasesize); >> + >> + for (off = 0; blkcnt > 0; blkcnt--, off += mtd->erasesize) { >> + ret = mtdpstore_block_is_removed(cxt, off); >> + if (!ret) { >> + off += mtd->erasesize; >> + continue; >> + } >> + >> + ret = mtdpstore_flush_removed_do(cxt, off, mtd->erasesize); >> + if (ret) >> + return ret; >> + } >> + return 0; >> +} >> + >> +static void mtdpstore_notify_remove(struct mtd_info *mtd) >> +{ >> + struct mtdpstore_context *cxt = &oops_cxt; >> + >> + if (mtd->index != cxt->index || cxt->index < 0) >> + return; >> + >> + mtdpstore_flush_removed(cxt); >> + >> + blkoops_unregister_device(&cxt->bo_dev); >> + kfree(cxt->badmap); >> + kfree(cxt->usedmap); >> + kfree(cxt->rmmap); >> + cxt->mtd = NULL; >> + cxt->index = -1; >> +} >> + >> +static struct mtd_notifier mtdpstore_notifier = { >> + .add = mtdpstore_notify_add, >> + .remove = mtdpstore_notify_remove, >> +}; >> + >> +static int __init mtdpstore_init(void) >> +{ >> + int ret; >> + struct mtdpstore_context *cxt = &oops_cxt; >> + struct blkoops_info *info = &cxt->bo_info; >> + >> + ret = blkoops_info(info); >> + if (unlikely(ret)) >> + return ret; >> + >> + if (strlen(info->device) == 0) { >> + pr_err("mtd device must be supplied\n"); >> + return -EINVAL; >> + } >> + if (!info->dmesg_size) { >> + pr_err("no recorder enabled\n"); >> + return -EINVAL; >> + } >> + >> + /* Setup the MTD device to use */ >> + ret = kstrtoint((char *)info->device, 0, &cxt->index); >> + if (ret) >> + cxt->index = -1; >> + >> + register_mtd_user(&mtdpstore_notifier); >> + return 0; >> +} >> +module_init(mtdpstore_init); >> + >> +static void __exit mtdpstore_exit(void) >> +{ >> + unregister_mtd_user(&mtdpstore_notifier); >> +} >> +module_exit(mtdpstore_exit); >> + >> +MODULE_LICENSE("GPL"); >> +MODULE_AUTHOR("WeiXiong Liao <liaoweixiong@allwinnertech.com>"); >> +MODULE_DESCRIPTION("MTD Oops/Panic console logger/driver"); >> >
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