Re: [PATCH v2 04/11] pstore/blk: blkoops: support console recorder

From: Kees Cook
Date: Wed Mar 18 2020 - 14:17:14 EST

Next message: Kees Cook: "Re: [PATCH v2 05/11] pstore/blk: blkoops: support ftrace recorder"
Previous message: Mathieu Poirier: "Re: [PATCH 02/13] coresight: cti: Add sysfs coresight mgmt register access"
Next in thread: WeiXiong Liao: "Re: [PATCH v2 04/11] pstore/blk: blkoops: support console recorder"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

On Fri, Feb 07, 2020 at 08:25:48PM +0800, WeiXiong Liao wrote:
> Support recorder for console. To enable console recorder, just make
> console_size be greater than 0 and a multiple of 4096.
>
> Signed-off-by: WeiXiong Liao <liaoweixiong@xxxxxxxxxxxxxxxxx>
> ---
> fs/pstore/Kconfig | 12 ++++++
> fs/pstore/blkoops.c | 11 +++++
> fs/pstore/blkzone.c | 101 ++++++++++++++++++++++++++++++++++-----------
> include/linux/blkoops.h | 6 ++-
> include/linux/pstore_blk.h | 8 +++-
> 5 files changed, 112 insertions(+), 26 deletions(-)
>
> diff --git a/fs/pstore/Kconfig b/fs/pstore/Kconfig
> index bbf1fdb5eaa7..5f0a42823028 100644
> --- a/fs/pstore/Kconfig
> +++ b/fs/pstore/Kconfig
> @@ -198,6 +198,18 @@ config PSTORE_BLKOOPS_PMSG_SIZE
> NOTE that, both kconfig and module parameters can configure blkoops,
> but module parameters have priority over kconfig.
>
> +config PSTORE_BLKOOPS_CONSOLE_SIZE
> + int "console size in kbytes for blkoops"
> + depends on PSTORE_BLKOOPS
> + depends on PSTORE_CONSOLE
> + default 64

Same tricks here as for the PMSG.

> + help
> + This just sets size of console (console_size) for pstore/blk. The
> + size is in KB and must be a multiple of 4.
> +
> + NOTE that, both kconfig and module parameters can configure blkoops,
> + but module parameters have priority over kconfig.
> +
> config PSTORE_BLKOOPS_BLKDEV
> string "block device for blkoops"
> depends on PSTORE_BLKOOPS
> diff --git a/fs/pstore/blkoops.c b/fs/pstore/blkoops.c
> index 02e6e4c1f965..05990bc3b168 100644
> --- a/fs/pstore/blkoops.c
> +++ b/fs/pstore/blkoops.c
> @@ -20,6 +20,10 @@
> module_param(pmsg_size, long, 0400);
> MODULE_PARM_DESC(pmsg_size, "pmsg size in kbytes");
>
> +static long console_size = -1;
> +module_param(console_size, long, 0400);
> +MODULE_PARM_DESC(console_size, "console size in kbytes");
> +
> static int dump_oops = -1;
> module_param(dump_oops, int, 0400);
> MODULE_PARM_DESC(total_size, "whether dump oops");
> @@ -70,6 +74,12 @@
> #define DEFAULT_PMSG_SIZE 0
> #endif
>
> +#ifdef CONFIG_PSTORE_BLKOOPS_CONSOLE_SIZE
> +#define DEFAULT_CONSOLE_SIZE CONFIG_PSTORE_BLKOOPS_CONSOLE_SIZE
> +#else
> +#define DEFAULT_CONSOLE_SIZE 0
> +#endif
> +
> #ifdef CONFIG_PSTORE_BLKOOPS_DUMP_OOPS
> #define DEFAULT_DUMP_OOPS CONFIG_PSTORE_BLKOOPS_DUMP_OOPS
> #else
> @@ -124,6 +134,7 @@ int blkoops_register_device(struct blkoops_device *bo_dev)
>
> verify_size(dmesg_size, DEFAULT_DMESG_SIZE, 4096);
> verify_size(pmsg_size, DEFAULT_PMSG_SIZE, 4096);
> + verify_size(console_size, DEFAULT_CONSOLE_SIZE, 4096);
> #undef verify_size
> dump_oops = !!(dump_oops < 0 ? DEFAULT_DUMP_OOPS : dump_oops);
>
> diff --git a/fs/pstore/blkzone.c b/fs/pstore/blkzone.c
> index a3464252d52e..9a7e9b06ccf7 100644
> --- a/fs/pstore/blkzone.c
> +++ b/fs/pstore/blkzone.c
> @@ -88,9 +88,11 @@ struct blkz_zone {
> struct blkz_context {
> struct blkz_zone **dbzs; /* dmesg block zones */
> struct blkz_zone *pbz; /* Pmsg block zone */
> + struct blkz_zone *cbz; /* console block zone */
> unsigned int dmesg_max_cnt;
> unsigned int dmesg_read_cnt;
> unsigned int pmsg_read_cnt;
> + unsigned int console_read_cnt;
> unsigned int dmesg_write_cnt;
> /*
> * the counter should be recovered when recover.
> @@ -111,6 +113,9 @@ struct blkz_context {
> };
> static struct blkz_context blkz_cxt;
>
> +static void blkz_flush_all_dirty_zones(struct work_struct *);
> +static DECLARE_WORK(blkz_cleaner, blkz_flush_all_dirty_zones);
> +
> enum blkz_flush_mode {
> FLUSH_NONE = 0,
> FLUSH_PART,
> @@ -200,6 +205,9 @@ static int blkz_zone_write(struct blkz_zone *zone,
> return 0;
> set_dirty:
> atomic_set(&zone->dirty, true);
> + /* flush dirty zones nicely */
> + if (wcnt == -EBUSY && !is_on_panic())
> + schedule_work(&blkz_cleaner);
> return -EBUSY;
> }
>
> @@ -266,6 +274,15 @@ static int blkz_move_zone(struct blkz_zone *old, struct blkz_zone *new)
> return 0;
> }
>
> +static void blkz_flush_all_dirty_zones(struct work_struct *work)
> +{
> + struct blkz_context *cxt = &blkz_cxt;
> +
> + blkz_flush_dirty_zone(cxt->pbz);
> + blkz_flush_dirty_zone(cxt->cbz);
> + blkz_flush_dirty_zones(cxt->dbzs, cxt->dmesg_max_cnt);
> +}
> +
> static int blkz_recover_dmesg_data(struct blkz_context *cxt)
> {
> struct blkz_info *info = cxt->bzinfo;
> @@ -419,15 +436,13 @@ static int blkz_recover_dmesg(struct blkz_context *cxt)
> return ret;
> }
>
> -static int blkz_recover_pmsg(struct blkz_context *cxt)
> +static int blkz_recover_zone(struct blkz_context *cxt, struct blkz_zone *zone)
> {
> struct blkz_info *info = cxt->bzinfo;
> struct blkz_buffer *oldbuf;
> - struct blkz_zone *zone = NULL;
> int ret = 0;
> ssize_t rcnt, len;
>
> - zone = cxt->pbz;
> if (!zone || zone->oldbuf)
> return 0;
>
> @@ -493,7 +508,11 @@ static inline int blkz_recovery(struct blkz_context *cxt)
> if (ret)
> goto recover_fail;
>
> - ret = blkz_recover_pmsg(cxt);
> + ret = blkz_recover_zone(cxt, cxt->pbz);
> + if (ret)
> + goto recover_fail;
> +
> + ret = blkz_recover_zone(cxt, cxt->cbz);
> if (ret)
> goto recover_fail;
>
> @@ -512,6 +531,7 @@ static int blkz_pstore_open(struct pstore_info *psi)
>
> cxt->dmesg_read_cnt = 0;
> cxt->pmsg_read_cnt = 0;
> + cxt->console_read_cnt = 0;
> return 0;
> }
>
> @@ -539,7 +559,7 @@ static inline int blkz_dmesg_erase(struct blkz_context *cxt,
> return blkz_zone_write(zone, FLUSH_META, NULL, 0, 0);
> }
>
> -static inline int blkz_pmsg_erase(struct blkz_context *cxt,
> +static inline int blkz_record_erase(struct blkz_context *cxt,
> struct blkz_zone *zone)
> {
> if (unlikely(!blkz_old_ok(zone)))
> @@ -566,9 +586,10 @@ static int blkz_pstore_erase(struct pstore_record *record)
> case PSTORE_TYPE_DMESG:
> return blkz_dmesg_erase(cxt, cxt->dbzs[record->id]);
> case PSTORE_TYPE_PMSG:
> - return blkz_pmsg_erase(cxt, cxt->pbz);
> - default:
> - return -EINVAL;
> + return blkz_record_erase(cxt, cxt->pbz);
> + case PSTORE_TYPE_CONSOLE:
> + return blkz_record_erase(cxt, cxt->cbz);
> + default: return -EINVAL;
> }
> }
>
> @@ -653,17 +674,15 @@ static int notrace blkz_dmesg_write(struct blkz_context *cxt,
> return 0;
> }
>
> -static int notrace blkz_pmsg_write(struct blkz_context *cxt,
> - struct pstore_record *record)
> +static int notrace blkz_record_write(struct blkz_context *cxt,
> + struct blkz_zone *zone, struct pstore_record *record)

How about generalizing this earlier in the patch series instead of
mutating it here?

> {
> - struct blkz_zone *zone;
> size_t start, rem;
> int cnt = record->size;
> bool is_full_data = false;
> char *buf = record->buf;
>
> - zone = cxt->pbz;
> - if (!zone)
> + if (!zone || !record)
> return -ENOSPC;
>
> if (atomic_read(&zone->buffer->datalen) >= zone->buffer_size)
> @@ -710,11 +729,20 @@ static int notrace blkz_pstore_write(struct pstore_record *record)
> record->reason == KMSG_DUMP_PANIC)
> atomic_set(&cxt->on_panic, 1);
>
> + /*
> + * if on panic, do not write except dmesg records
> + * Fix case that panic_write prints log which wakes up console recorder.
> + */
> + if (is_on_panic() && record->type != PSTORE_TYPE_DMESG)
> + return -EBUSY;
> +
> switch (record->type) {
> case PSTORE_TYPE_DMESG:
> return blkz_dmesg_write(cxt, record);
> + case PSTORE_TYPE_CONSOLE:
> + return blkz_record_write(cxt, cxt->cbz, record);
> case PSTORE_TYPE_PMSG:
> - return blkz_pmsg_write(cxt, record);
> + return blkz_record_write(cxt, cxt->pbz, record);
> default:
> return -EINVAL;
> }
> @@ -738,6 +766,13 @@ static struct blkz_zone *blkz_read_next_zone(struct blkz_context *cxt)
> return zone;
> }
>
> + if (cxt->console_read_cnt == 0) {
> + cxt->console_read_cnt++;
> + zone = cxt->cbz;
> + if (blkz_old_ok(zone))
> + return zone;
> + }
> +
> return NULL;
> }
>
> @@ -799,7 +834,7 @@ static ssize_t blkz_dmesg_read(struct blkz_zone *zone,
> return size + hlen;
> }
>
> -static ssize_t blkz_pmsg_read(struct blkz_zone *zone,
> +static ssize_t blkz_record_read(struct blkz_zone *zone,
> struct pstore_record *record)
> {
> size_t size, start;
> @@ -825,7 +860,7 @@ static ssize_t blkz_pmsg_read(struct blkz_zone *zone,
> static ssize_t blkz_pstore_read(struct pstore_record *record)
> {
> struct blkz_context *cxt = record->psi->data;
> - ssize_t (*blkz_read)(struct blkz_zone *zone,
> + ssize_t (*readop)(struct blkz_zone *zone,
> struct pstore_record *record);
> struct blkz_zone *zone;
> ssize_t ret;
> @@ -843,17 +878,19 @@ static ssize_t blkz_pstore_read(struct pstore_record *record)
> record->type = zone->type;
> switch (record->type) {
> case PSTORE_TYPE_DMESG:
> - blkz_read = blkz_dmesg_read;
> + readop = blkz_dmesg_read;
> record->id = cxt->dmesg_read_cnt - 1;
> break;
> + case PSTORE_TYPE_CONSOLE:
> + /* fallthrough */

Since this case has no body, you can leave off the "fallthrough". (But
if you want to mark it anyway, please use "fallthrough;" instead of a
comment.)

> case PSTORE_TYPE_PMSG:
> - blkz_read = blkz_pmsg_read;
> + readop = blkz_record_read;
> break;
> default:
> goto next_zone;
> }
>
> - ret = blkz_read(zone, record);
> + ret = readop(zone, record);
> if (ret == READ_NEXT_ZONE)
> goto next_zone;
> return ret;
> @@ -1001,15 +1038,25 @@ static int blkz_cut_zones(struct blkz_context *cxt)
> goto fail_out;
> }
>
> + off_size += info->console_size;
> + cxt->cbz = blkz_init_zone(PSTORE_TYPE_CONSOLE, &off,
> + info->console_size);
> + if (IS_ERR(cxt->cbz)) {
> + err = PTR_ERR(cxt->cbz);
> + goto free_pmsg;
> + }
> +
> cxt->dbzs = blkz_init_zones(PSTORE_TYPE_DMESG, &off,
> info->total_size - off_size,
> info->dmesg_size, &cxt->dmesg_max_cnt);
> if (IS_ERR(cxt->dbzs)) {
> err = PTR_ERR(cxt->dbzs);
> - goto free_pmsg;
> + goto free_console;
> }
>
> return 0;
> +free_console:
> + blkz_free_zone(&cxt->cbz);
> free_pmsg:
> blkz_free_zone(&cxt->pbz);
> fail_out:
> @@ -1027,7 +1074,7 @@ int blkz_register(struct blkz_info *info)
> return -EINVAL;
> }
>
> - if (!info->dmesg_size && !info->pmsg_size) {
> + if (!info->dmesg_size && !info->pmsg_size && !info->console_size) {
> pr_warn("at least one of the records be non-zero\n");
> return -EINVAL;
> }
> @@ -1055,6 +1102,7 @@ int blkz_register(struct blkz_info *info)
> check_size(total_size, 4096);
> check_size(dmesg_size, SECTOR_SIZE);
> check_size(pmsg_size, SECTOR_SIZE);
> + check_size(console_size, SECTOR_SIZE);
>
> #undef check_size
>
> @@ -1087,6 +1135,7 @@ int blkz_register(struct blkz_info *info)
> pr_debug("\ttotal size : %ld Bytes\n", info->total_size);
> pr_debug("\tdmesg size : %ld Bytes\n", info->dmesg_size);
> pr_debug("\tpmsg size : %ld Bytes\n", info->pmsg_size);
> + pr_debug("\tconsole size : %ld Bytes\n", info->console_size);
>
> err = blkz_cut_zones(cxt);
> if (err) {
> @@ -1108,11 +1157,15 @@ int blkz_register(struct blkz_info *info)
> cxt->pstore.flags |= PSTORE_FLAGS_DMESG;
> if (info->pmsg_size)
> cxt->pstore.flags |= PSTORE_FLAGS_PMSG;
> + if (info->console_size)
> + cxt->pstore.flags |= PSTORE_FLAGS_CONSOLE;
>
> - pr_info("Registered %s as blkzone backend for %s%s%s\n", info->name,
> + pr_info("Registered %s as blkzone backend for %s%s%s%s\n",
> + info->name,
> cxt->dbzs && cxt->bzinfo->dump_oops ? "Oops " : "",
> cxt->dbzs && cxt->bzinfo->panic_write ? "Panic " : "",
> - cxt->pbz ? "Pmsg" : "");
> + cxt->pbz ? "Pmsg " : "",
> + cxt->cbz ? "Console" : "");
>
> err = pstore_register(&cxt->pstore);
> if (err) {
> @@ -1139,6 +1192,8 @@ void blkz_unregister(struct blkz_info *info)
> {
> struct blkz_context *cxt = &blkz_cxt;
>
> + flush_work(&blkz_cleaner);
> +
> pstore_unregister(&cxt->pstore);
> kfree(cxt->pstore.buf);
> cxt->pstore.bufsize = 0;
> diff --git a/include/linux/blkoops.h b/include/linux/blkoops.h
> index fe63739309aa..8f40f225545d 100644
> --- a/include/linux/blkoops.h
> +++ b/include/linux/blkoops.h
> @@ -23,8 +23,10 @@
> * 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, the number of bytes read should be returned.
> - * On error, negative number should be returned.
> + * On success, the number of bytes read/write should be returned.
> + * On error, negative number should be returned. The following returning
> + * number means more:
> + * -EBUSY: pstore/blk should try again later.
> * @panic_write:
> * The write operation only used for panic.
> *
> diff --git a/include/linux/pstore_blk.h b/include/linux/pstore_blk.h
> index af06be25bd01..546375e04419 100644
> --- a/include/linux/pstore_blk.h
> +++ b/include/linux/pstore_blk.h
> @@ -22,6 +22,9 @@
> * @pmsg_size:
> * The size of zone for pmsg. Zero means disabled, othewise, it must be
> * multiple of SECTOR_SIZE(512).
> + * @console_size:
> + * The size of zone for console. Zero means disabled, othewise, it must
> + * be multiple of SECTOR_SIZE(512).
> * @dump_oops:
> * Dump oops and panic log or only panic.
> * @read, @write:
> @@ -33,7 +36,9 @@
> * the relative size of the space provided, not the whole disk/flash.
> *
> * On success, the number of bytes read/write should be returned.
> - * On error, negative number should be returned.
> + * On error, negative number should be returned. The following returning
> + * number means more:
> + * -EBUSY: pstore/blk should try again later.
> * @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
> @@ -54,6 +59,7 @@ struct blkz_info {
> unsigned long total_size;
> unsigned long dmesg_size;
> unsigned long pmsg_size;
> + unsigned long console_size;
> int dump_oops;
> blkz_read_op read;
> blkz_write_op write;
> --
> 1.9.1
>

--
Kees Cook

Next message: Kees Cook: "Re: [PATCH v2 05/11] pstore/blk: blkoops: support ftrace recorder"
Previous message: Mathieu Poirier: "Re: [PATCH 02/13] coresight: cti: Add sysfs coresight mgmt register access"
Next in thread: WeiXiong Liao: "Re: [PATCH v2 04/11] pstore/blk: blkoops: support console recorder"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]