Read a record is cleared by others, but the deleted record cache entry is
still created by erst_get_record_id_next. When next enumerate the records,
get the cached deleted record, then erst_read return -ENOENT and try to
get next record, loop back to first ID will return 0 in function
__erst_record_id_cache_add_one and then set record_id as
APEI_ERST_INVALID_RECORD_ID, finished this time read operation.
It will result in read the records just in the cache hereafter.
This patch cleared the deleted record cache, fix the issue that
"./erst-inject -p" shows record counts not equal to "./erst-inject -n".
A reproducer of the problem(retry many times):
[root@localhost erst-inject]# ./erst-inject -c 0xaaaaa00011
[root@localhost erst-inject]# ./erst-inject -p
rc: 273
rcd sig: CPER
rcd id: 0xaaaaa00012
rc: 273
rcd sig: CPER
rcd id: 0xaaaaa00013
rc: 273
rcd sig: CPER
rcd id: 0xaaaaa00014
[root@localhost erst-inject]# ./erst-inject -i 0xaaaaa000006
[root@localhost erst-inject]# ./erst-inject -i 0xaaaaa000007
[root@localhost erst-inject]# ./erst-inject -i 0xaaaaa000008
[root@localhost erst-inject]# ./erst-inject -p
rc: 273
rcd sig: CPER
rcd id: 0xaaaaa00012
rc: 273
rcd sig: CPER
rcd id: 0xaaaaa00013
rc: 273
rcd sig: CPER
rcd id: 0xaaaaa00014
[root@localhost erst-inject]# ./erst-inject -n
total error record count: 6
v1->v2 fix style problems
v2->v3 fix apei_read_mce called erst_get_record_id_next and modify
the commit message.
v3->v4 add erst_clear_cache in another retry.
Signed-off-by: Liu Xinpeng <liuxp11@xxxxxxxxxxxxxxx>
---
arch/x86/kernel/cpu/mce/apei.c | 9 ++++++---
drivers/acpi/apei/erst-dbg.c | 4 +++-
drivers/acpi/apei/erst.c | 34 +++++++++++++++++++++++++++++++---
include/acpi/apei.h | 1 +
4 files changed, 41 insertions(+), 7 deletions(-)
diff --git a/arch/x86/kernel/cpu/mce/apei.c b/arch/x86/kernel/cpu/mce/apei.c
index 0e3ae64d3b76..d77de72a91d2 100644
--- a/arch/x86/kernel/cpu/mce/apei.c
+++ b/arch/x86/kernel/cpu/mce/apei.c
@@ -179,14 +179,17 @@ ssize_t apei_read_mce(struct mce *m, u64 *record_id)
goto out;
rc = erst_read(*record_id, &rcd.hdr, sizeof(rcd));
/* someone else has cleared the record, try next one */
- if (rc == -ENOENT)
+ if (rc == -ENOENT) {
+ erst_clear_cache(*record_id);
goto retry;
- else if (rc < 0)
+ } else if (rc < 0)
goto out;
/* try to skip other type records in storage */
else if (rc != sizeof(rcd) ||
- !guid_equal(&rcd.hdr.creator_id, &CPER_CREATOR_MCE))
+ !guid_equal(&rcd.hdr.creator_id, &CPER_CREATOR_MCE)) {
+ erst_clear_cache(*record_id);
goto retry;
+ }
memcpy(m, &rcd.mce, sizeof(*m));
rc = sizeof(*m);
out:
diff --git a/drivers/acpi/apei/erst-dbg.c b/drivers/acpi/apei/erst-dbg.c
index c740f0faad39..5b8164280a17 100644
--- a/drivers/acpi/apei/erst-dbg.c
+++ b/drivers/acpi/apei/erst-dbg.c
@@ -113,8 +113,10 @@ static ssize_t erst_dbg_read(struct file *filp, char __user *ubuf,
retry:
rc = len = erst_read(id, erst_dbg_buf, erst_dbg_buf_len);
/* The record may be cleared by others, try read next record */
- if (rc == -ENOENT)
+ if (rc == -ENOENT) {
+ erst_clear_cache(id);
goto retry_next;
+ }
if (rc < 0)
goto out;
if (len > ERST_DBG_RECORD_LEN_MAX) {
diff --git a/drivers/acpi/apei/erst.c b/drivers/acpi/apei/erst.c
index 698d67cee052..07d69dc7fd62 100644
--- a/drivers/acpi/apei/erst.c
+++ b/drivers/acpi/apei/erst.c
@@ -856,6 +856,31 @@ ssize_t erst_read(u64 record_id, struct cper_record_header *record,
}
EXPORT_SYMBOL_GPL(erst_read);
+int erst_clear_cache(u64 record_id)
+{
+ int rc, i;
+ u64 *entries;
+
+ if (erst_disable)
+ return -ENODEV;
+
+ rc = mutex_lock_interruptible(&erst_record_id_cache.lock);
+ if (rc)
+ return rc;
+
+ entries = erst_record_id_cache.entries;
+ for (i = 0; i < erst_record_id_cache.len; i++) {
+ if (entries[i] == record_id)
+ entries[i] = APEI_ERST_INVALID_RECORD_ID;
+ }
+ __erst_record_id_cache_compact();
+
+ mutex_unlock(&erst_record_id_cache.lock);
+
+ return rc;
+}
+EXPORT_SYMBOL_GPL(erst_clear_cache);
+
int erst_clear(u64 record_id)
{
int rc, i;
@@ -998,14 +1023,17 @@ static ssize_t erst_reader(struct pstore_record *record)
len = erst_read(record_id, &rcd->hdr, rcd_len);
/* The record may be cleared by others, try read next record */
- if (len == -ENOENT)
+ if (len == -ENOENT) {
+ erst_clear_cache(record_id);
goto skip;
- else if (len < 0 || len < sizeof(*rcd)) {
+ } else if (len < 0 || len < sizeof(*rcd)) {
rc = -EIO;
goto out;
}
- if (!guid_equal(&rcd->hdr.creator_id, &CPER_CREATOR_PSTORE))
+ if (!guid_equal(&rcd->hdr.creator_id, &CPER_CREATOR_PSTORE)) {
+ erst_clear_cache(record_id);
goto skip;
+ }
record->buf = kmalloc(len, GFP_KERNEL);
if (record->buf == NULL) {
diff --git a/include/acpi/apei.h b/include/acpi/apei.h
index afaca3a075e8..f8c11ff4115a 100644
--- a/include/acpi/apei.h
+++ b/include/acpi/apei.h
@@ -47,6 +47,7 @@ void erst_get_record_id_end(void);
ssize_t erst_read(u64 record_id, struct cper_record_header *record,
size_t buflen);
int erst_clear(u64 record_id);
+int erst_clear_cache(u64 record_id);
int arch_apei_enable_cmcff(struct acpi_hest_header *hest_hdr, void *data);
void arch_apei_report_mem_error(int sev, struct cper_sec_mem_err *mem_err);
--
2.23.0
