[PATCH v1 04/11] pstore/blk: blkoops: support console recorder

WeiXiong Liao
2020-01-20T01:04:11Z

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@allwinnertech.com>
---
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 656d63dc3f01..af83ae59f31a 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
+ help
+ This just sets size of console (console_size) for pstore/blk. The
+ value must be a multiple of 4096.
+
+ 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 b3bd004fad1a..91754795d612 100644
--- a/fs/pstore/blkoops.c
+++ b/fs/pstore/blkoops.c
@@ -35,6 +35,10 @@
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");
@@ -85,6 +89,12 @@
#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
@@ -139,6 +149,7 @@ 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 1c9a75c21e39..1bb914a2622a 100644
--- a/fs/pstore/blkzone.c
+++ b/fs/pstore/blkzone.c
@@ -104,9 +104,11 @@ 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.
@@ -127,6 +129,9 @@ 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,
@@ -216,6 +221,9 @@ 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;
}

@@ -282,6 +290,15 @@ 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;
@@ -435,15 +452,13 @@ 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;

@@ -509,7 +524,11 @@ 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;

@@ -528,6 +547,7 @@ 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;
}

@@ -555,7 +575,7 @@ 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)))
@@ -582,9 +602,10 @@ 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;
}
}

@@ -669,17 +690,15 @@ 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)
{
- 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)
@@ -726,11 +745,20 @@ 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;
}
@@ -754,6 +782,13 @@ 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;
}

@@ -815,7 +850,7 @@ 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;
@@ -841,7 +876,7 @@ 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;
@@ -859,17 +894,19 @@ 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 */
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;
@@ -1017,15 +1054,25 @@ 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:
@@ -1043,7 +1090,7 @@ 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;
}
@@ -1071,6 +1118,7 @@ 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

@@ -1103,6 +1151,7 @@ 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) {
@@ -1124,11 +1173,15 @@ 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) {
@@ -1155,6 +1208,8 @@ 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