ACPI: APEI: Fix missing ERST record id

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

Signed-off-by: Liu Xinpeng <liuxp11@chinatelecom.cn>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/arch/x86/kernel/cpu/mce/apei.c b/arch/x86/kernel/cpu/mce/apei.c
index 0e3ae64..7171929 100644 (file)
--- a/arch/x86/kernel/cpu/mce/apei.c
+++ b/arch/x86/kernel/cpu/mce/apei.c
@@ -177,16 +177,14 @@ retry:
        /* 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 c740f0f..8bc71cd 100644 (file)
--- a/drivers/acpi/apei/erst-dbg.c
+++ b/drivers/acpi/apei/erst-dbg.c
@@ -111,7 +111,8 @@ retry_next:
                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 698d67c..31b077e 100644 (file)
--- 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 recordlen, 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 < recordlen) {
+               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 @@ skip:
                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 afaca3a..dc60f7d 100644 (file)
--- 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);