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
Changelog:
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.
v4->v5 Implement a new function for looking for a specific record
type, suggested by Tony Luck.
v5->v6 In function erst_clear_cache, using mutex_lock insead of
mutex_lock_interruptible ensure that the cache is cleared.
If erst_read return value is less than record head length,
consider it as EIO; other error return to caller; creatorid is
not wanted, consider it ENOENT and keep the cache for other types.
Signed-off-by: Liu Xinpeng <liuxp11@xxxxxxxxxxxxxxx>
Reviewed-by: Tony Luck <tony.luck@xxxxxxxxx>
---
arch/x86/kernel/cpu/mce/apei.c | 8 ++--
drivers/acpi/apei/erst-dbg.c | 3 +-
drivers/acpi/apei/erst.c | 77 +++++++++++++++++++++++++++++++---
include/acpi/apei.h | 2 +
4 files changed, 78 insertions(+), 12 deletions(-)
diff --git a/arch/x86/kernel/cpu/mce/apei.c b/arch/x86/kernel/cpu/mce/apei.c
index 0e3ae64d3b76..717192915f28 100644
--- a/arch/x86/kernel/cpu/mce/apei.c
+++ b/arch/x86/kernel/cpu/mce/apei.c
@@ -177,16 +177,14 @@ ssize_t apei_read_mce(struct mce *m, u64 *record_id)
/* no more record */
if (*record_id == APEI_ERST_INVALID_RECORD_ID)
goto out;
- rc = erst_read(*record_id, &rcd.hdr, sizeof(rcd));
+ rc = erst_read_record(*record_id, &rcd.hdr, sizeof(rcd), sizeof(rcd),
+ &CPER_CREATOR_MCE);
/* someone else has cleared the record, try next one */
if (rc == -ENOENT)
goto retry;
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))
- 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..8bc71cdc2270 100644
--- a/drivers/acpi/apei/erst-dbg.c
+++ b/drivers/acpi/apei/erst-dbg.c
@@ -111,7 +111,8 @@ static ssize_t erst_dbg_read(struct file *filp, char __user *ubuf,
goto out;
}
retry:
- rc = len = erst_read(id, erst_dbg_buf, erst_dbg_buf_len);
+ rc = len = erst_read_record(id, erst_dbg_buf, erst_dbg_buf_len,
+ erst_dbg_buf_len, NULL);
/* The record may be cleared by others, try read next record */
if (rc == -ENOENT)
goto retry_next;
diff --git a/drivers/acpi/apei/erst.c b/drivers/acpi/apei/erst.c
index 698d67cee052..ca78b584a65e 100644
--- a/drivers/acpi/apei/erst.c
+++ b/drivers/acpi/apei/erst.c
@@ -856,6 +856,74 @@ ssize_t erst_read(u64 record_id, struct cper_record_header *record,
}
EXPORT_SYMBOL_GPL(erst_read);
+static void erst_clear_cache(u64 record_id)
+{
+ int i;
+ u64 *entries;
+
+ mutex_lock(&erst_record_id_cache.lock);
+
+ 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);
+}
+
+ssize_t erst_read_record(u64 record_id, struct cper_record_header *record,
+ size_t buflen, size_t recordhead, const guid_t *creatorid)
+{
+ ssize_t len;
+
+ /*
+ * if creatorid is NULL, read any record for erst-dbg module
+ */
+ if (creatorid == NULL) {
+ len = erst_read(record_id, record, buflen);
+ if (len == -ENOENT)
+ erst_clear_cache(record_id);
+
+ return len;
+ }
+
+ len = erst_read(record_id, record, buflen);
+ /*
+ * if erst_read return value is -ENOENT skip to next record_id,
+ * and clear the record_id cache.
+ */
+ if (len == -ENOENT) {
+ erst_clear_cache(record_id);
+ goto out;
+ }
+
+ if (len < 0)
+ goto out;
+
+ /*
+ * if erst_read return value is less than record head length,
+ * consider it as -EIO, and clear the record_id cache.
+ */
+ if (len < recordhead) {
+ len = -EIO;
+ erst_clear_cache(record_id);
+ goto out;
+ }
+
+ /*
+ * if creatorid is not wanted, consider it as not found,
+ * for skipping to next record_id.
+ */
+ if (!guid_equal(&record->creator_id, creatorid))
+ len = -ENOENT;
+
+out:
+ return len;
+}
+EXPORT_SYMBOL_GPL(erst_read_record);
+
int erst_clear(u64 record_id)
{
int rc, i;
@@ -996,16 +1064,13 @@ static ssize_t erst_reader(struct pstore_record *record)
goto out;
}
- len = erst_read(record_id, &rcd->hdr, rcd_len);
+ len = erst_read_record(record_id, &rcd->hdr, rcd_len, sizeof(*rcd),
+ &CPER_CREATOR_PSTORE);
/* The record may be cleared by others, try read next record */
if (len == -ENOENT)
goto skip;
- else if (len < 0 || len < sizeof(*rcd)) {
- rc = -EIO;
+ else if (len < 0)
goto out;
- }
- if (!guid_equal(&rcd->hdr.creator_id, &CPER_CREATOR_PSTORE))
- 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..dc60f7db5524 100644
--- a/include/acpi/apei.h
+++ b/include/acpi/apei.h
@@ -46,6 +46,8 @@ int erst_get_record_id_next(int *pos, u64 *record_id);
void erst_get_record_id_end(void);
ssize_t erst_read(u64 record_id, struct cper_record_header *record,
size_t buflen);
+ssize_t erst_read_record(u64 record_id, struct cper_record_header *record,
+ size_t buflen, size_t recordlen, const guid_t *creatorid);
int erst_clear(u64 record_id);
int arch_apei_enable_cmcff(struct acpi_hest_header *hest_hdr, void *data);
--
2.23.0
