From: Keith Busch <keith.busch@intel.com>
To: Vishal Verma <vishal.l.verma@intel.com>,
Dave Jiang <dave.jiang@intel.com>,
linux-nvdimm@lists.01.org
Subject: [PATCH 2/2] ndctl, intel: Fallback to smart cached shutdown_count
Date: Tue, 7 Aug 2018 16:26:56 -0600 [thread overview]
Message-ID: <20180807222656.14346-2-keith.busch@intel.com> (raw)
In-Reply-To: <20180807222656.14346-1-keith.busch@intel.com>
A user space rule saves the unsafe shutdown count to a fixed location
for Intel dimms so that non-root users can read it. If the smart command
submission fails, this patch uses that saved value in a newly added
ndctl_cmd "handle_error" callback. If the cached value is available,
the error handler will override the command status to success, and set
the valid flags for the shutdown count.
Signed-off-by: Keith Busch <keith.busch@intel.com>
---
ndctl/lib/intel.c | 34 +++++++++++++++++++++++++++++++++-
ndctl/lib/libndctl.c | 2 ++
ndctl/lib/private.h | 1 +
3 files changed, 36 insertions(+), 1 deletion(-)
diff --git a/ndctl/lib/intel.c b/ndctl/lib/intel.c
index 0abea1e..83f8203 100644
--- a/ndctl/lib/intel.c
+++ b/ndctl/lib/intel.c
@@ -56,6 +56,38 @@ static struct ndctl_cmd *alloc_intel_cmd(struct ndctl_dimm *dimm,
return cmd;
}
+/*
+ * If provided, read the cached shutdown count in case the user does not have
+ * access rights to run the smart command, and pretend the command was
+ * successful with only the shutdown_count valid.
+ */
+static int intel_smart_handle_error(struct ndctl_cmd *cmd)
+{
+ struct ndctl_dimm *dimm = cmd->dimm;
+ char *path = NULL, shutdown_count[16] = {};
+ int fd, rc = cmd->status;
+
+ if (asprintf(&path, DEF_TMPFS_DIR "/%s/usc",
+ ndctl_dimm_get_unique_id(dimm)) < 0)
+ return rc;
+
+ fd = open(path, O_RDONLY);
+ if (fd < 0)
+ goto free_path;
+
+ if (read(fd, shutdown_count, sizeof(shutdown_count)) < 0)
+ goto close;
+
+ cmd->intel->smart.flags = ND_INTEL_SMART_SHUTDOWN_COUNT_VALID;
+ cmd->intel->smart.shutdown_count = strtoull(shutdown_count, NULL, 0);
+ rc = cmd->status = 0;
+ close:
+ close (fd);
+ free_path:
+ free(path);
+ return rc;
+}
+
static struct ndctl_cmd *intel_dimm_cmd_new_smart(struct ndctl_dimm *dimm)
{
struct ndctl_cmd *cmd;
@@ -67,7 +99,7 @@ static struct ndctl_cmd *intel_dimm_cmd_new_smart(struct ndctl_dimm *dimm)
if (!cmd)
return NULL;
cmd->firmware_status = &cmd->intel->smart.status;
-
+ cmd->handle_error = intel_smart_handle_error;
return cmd;
}
diff --git a/ndctl/lib/libndctl.c b/ndctl/lib/libndctl.c
index 47e005e..d94321e 100644
--- a/ndctl/lib/libndctl.c
+++ b/ndctl/lib/libndctl.c
@@ -2651,6 +2651,8 @@ NDCTL_EXPORT int ndctl_cmd_submit(struct ndctl_cmd *cmd)
close(fd);
out:
cmd->status = rc;
+ if (rc && cmd->handle_error)
+ rc = cmd->handle_error(cmd);
return rc;
}
diff --git a/ndctl/lib/private.h b/ndctl/lib/private.h
index a94f894..5812c85 100644
--- a/ndctl/lib/private.h
+++ b/ndctl/lib/private.h
@@ -255,6 +255,7 @@ struct ndctl_cmd {
int dir;
} iter;
struct ndctl_cmd *source;
+ int (*handle_error)(struct ndctl_cmd *cmd);
union {
struct nd_cmd_ars_cap ars_cap[0];
struct nd_cmd_ars_start ars_start[0];
--
2.14.4
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next prev parent reply other threads:[~2018-08-07 22:26 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-07 22:26 [PATCH 1/2] Create Intel pmem shutdown latch rule Keith Busch
2018-08-07 22:26 ` Keith Busch [this message]
2018-08-07 23:35 ` [PATCH 2/2] ndctl, intel: Fallback to smart cached shutdown_count Verma, Vishal L
2018-08-07 23:35 ` [PATCH 1/2] Create Intel pmem shutdown latch rule Verma, Vishal L
2018-08-08 0:02 ` Verma, Vishal L
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