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. Signed-off-by: Liu Xinpeng <liuxp11@xxxxxxxxxxxxxxx> --- arch/x86/kernel/cpu/mce/apei.c | 5 +++-- drivers/acpi/apei/erst-dbg.c | 4 +++- drivers/acpi/apei/erst.c | 34 +++++++++++++++++++++++++++++++--- include/acpi/apei.h | 1 + 4 files changed, 38 insertions(+), 6 deletions(-) diff --git a/arch/x86/kernel/cpu/mce/apei.c b/arch/x86/kernel/cpu/mce/apei.c index 0e3ae64d3b76..d37d38715231 100644 --- a/arch/x86/kernel/cpu/mce/apei.c +++ b/arch/x86/kernel/cpu/mce/apei.c @@ -179,9 +179,10 @@ 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) || 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