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authorSrikant Patnaik2015-01-11 12:28:04 +0530
committerSrikant Patnaik2015-01-11 12:28:04 +0530
commit871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch)
tree8718f573808810c2a1e8cb8fb6ac469093ca2784 /fs/pstore/platform.c
parent9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff)
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Moved, renamed, and deleted files
The original directory structure was scattered and unorganized. Changes are basically to make it look like kernel structure.
Diffstat (limited to 'fs/pstore/platform.c')
-rw-r--r--fs/pstore/platform.c261
1 files changed, 261 insertions, 0 deletions
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
new file mode 100644
index 00000000..82c585f7
--- /dev/null
+++ b/fs/pstore/platform.c
@@ -0,0 +1,261 @@
+/*
+ * Persistent Storage - platform driver interface parts.
+ *
+ * Copyright (C) 2010 Intel Corporation <tony.luck@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <linux/atomic.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/kmsg_dump.h>
+#include <linux/module.h>
+#include <linux/pstore.h>
+#include <linux/string.h>
+#include <linux/timer.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/hardirq.h>
+#include <linux/workqueue.h>
+
+#include "internal.h"
+
+/*
+ * We defer making "oops" entries appear in pstore - see
+ * whether the system is actually still running well enough
+ * to let someone see the entry
+ */
+#define PSTORE_INTERVAL (60 * HZ)
+
+static int pstore_new_entry;
+
+static void pstore_timefunc(unsigned long);
+static DEFINE_TIMER(pstore_timer, pstore_timefunc, 0, 0);
+
+static void pstore_dowork(struct work_struct *);
+static DECLARE_WORK(pstore_work, pstore_dowork);
+
+/*
+ * pstore_lock just protects "psinfo" during
+ * calls to pstore_register()
+ */
+static DEFINE_SPINLOCK(pstore_lock);
+static struct pstore_info *psinfo;
+
+static char *backend;
+
+/* How much of the console log to snapshot */
+static unsigned long kmsg_bytes = 10240;
+
+void pstore_set_kmsg_bytes(int bytes)
+{
+ kmsg_bytes = bytes;
+}
+
+/* Tag each group of saved records with a sequence number */
+static int oopscount;
+
+static const char *get_reason_str(enum kmsg_dump_reason reason)
+{
+ switch (reason) {
+ case KMSG_DUMP_PANIC:
+ return "Panic";
+ case KMSG_DUMP_OOPS:
+ return "Oops";
+ case KMSG_DUMP_EMERG:
+ return "Emergency";
+ case KMSG_DUMP_RESTART:
+ return "Restart";
+ case KMSG_DUMP_HALT:
+ return "Halt";
+ case KMSG_DUMP_POWEROFF:
+ return "Poweroff";
+ default:
+ return "Unknown";
+ }
+}
+
+/*
+ * callback from kmsg_dump. (s2,l2) has the most recently
+ * written bytes, older bytes are in (s1,l1). Save as much
+ * as we can from the end of the buffer.
+ */
+static void pstore_dump(struct kmsg_dumper *dumper,
+ enum kmsg_dump_reason reason,
+ const char *s1, unsigned long l1,
+ const char *s2, unsigned long l2)
+{
+ unsigned long s1_start, s2_start;
+ unsigned long l1_cpy, l2_cpy;
+ unsigned long size, total = 0;
+ char *dst;
+ const char *why;
+ u64 id;
+ int hsize, ret;
+ unsigned int part = 1;
+ unsigned long flags = 0;
+ int is_locked = 0;
+
+ why = get_reason_str(reason);
+
+ if (in_nmi()) {
+ is_locked = spin_trylock(&psinfo->buf_lock);
+ if (!is_locked)
+ pr_err("pstore dump routine blocked in NMI, may corrupt error record\n");
+ } else
+ spin_lock_irqsave(&psinfo->buf_lock, flags);
+ oopscount++;
+ while (total < kmsg_bytes) {
+ dst = psinfo->buf;
+ hsize = sprintf(dst, "%s#%d Part%d\n", why, oopscount, part);
+ size = psinfo->bufsize - hsize;
+ dst += hsize;
+
+ l2_cpy = min(l2, size);
+ l1_cpy = min(l1, size - l2_cpy);
+
+ if (l1_cpy + l2_cpy == 0)
+ break;
+
+ s2_start = l2 - l2_cpy;
+ s1_start = l1 - l1_cpy;
+
+ memcpy(dst, s1 + s1_start, l1_cpy);
+ memcpy(dst + l1_cpy, s2 + s2_start, l2_cpy);
+
+ ret = psinfo->write(PSTORE_TYPE_DMESG, reason, &id, part,
+ hsize + l1_cpy + l2_cpy, psinfo);
+ if (ret == 0 && reason == KMSG_DUMP_OOPS && pstore_is_mounted())
+ pstore_new_entry = 1;
+ l1 -= l1_cpy;
+ l2 -= l2_cpy;
+ total += l1_cpy + l2_cpy;
+ part++;
+ }
+ if (in_nmi()) {
+ if (is_locked)
+ spin_unlock(&psinfo->buf_lock);
+ } else
+ spin_unlock_irqrestore(&psinfo->buf_lock, flags);
+}
+
+static struct kmsg_dumper pstore_dumper = {
+ .dump = pstore_dump,
+};
+
+/*
+ * platform specific persistent storage driver registers with
+ * us here. If pstore is already mounted, call the platform
+ * read function right away to populate the file system. If not
+ * then the pstore mount code will call us later to fill out
+ * the file system.
+ *
+ * Register with kmsg_dump to save last part of console log on panic.
+ */
+int pstore_register(struct pstore_info *psi)
+{
+ struct module *owner = psi->owner;
+
+ spin_lock(&pstore_lock);
+ if (psinfo) {
+ spin_unlock(&pstore_lock);
+ return -EBUSY;
+ }
+
+ if (backend && strcmp(backend, psi->name)) {
+ spin_unlock(&pstore_lock);
+ return -EINVAL;
+ }
+
+ psinfo = psi;
+ mutex_init(&psinfo->read_mutex);
+ spin_unlock(&pstore_lock);
+
+ if (owner && !try_module_get(owner)) {
+ psinfo = NULL;
+ return -EINVAL;
+ }
+
+ if (pstore_is_mounted())
+ pstore_get_records(0);
+
+ kmsg_dump_register(&pstore_dumper);
+
+ pstore_timer.expires = jiffies + PSTORE_INTERVAL;
+ add_timer(&pstore_timer);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(pstore_register);
+
+/*
+ * Read all the records from the persistent store. Create
+ * files in our filesystem. Don't warn about -EEXIST errors
+ * when we are re-scanning the backing store looking to add new
+ * error records.
+ */
+void pstore_get_records(int quiet)
+{
+ struct pstore_info *psi = psinfo;
+ char *buf = NULL;
+ ssize_t size;
+ u64 id;
+ enum pstore_type_id type;
+ struct timespec time;
+ int failed = 0, rc;
+
+ if (!psi)
+ return;
+
+ mutex_lock(&psi->read_mutex);
+ if (psi->open && psi->open(psi))
+ goto out;
+
+ while ((size = psi->read(&id, &type, &time, &buf, psi)) > 0) {
+ rc = pstore_mkfile(type, psi->name, id, buf, (size_t)size,
+ time, psi);
+ kfree(buf);
+ buf = NULL;
+ if (rc && (rc != -EEXIST || !quiet))
+ failed++;
+ }
+ if (psi->close)
+ psi->close(psi);
+out:
+ mutex_unlock(&psi->read_mutex);
+
+ if (failed)
+ printk(KERN_WARNING "pstore: failed to load %d record(s) from '%s'\n",
+ failed, psi->name);
+}
+
+static void pstore_dowork(struct work_struct *work)
+{
+ pstore_get_records(1);
+}
+
+static void pstore_timefunc(unsigned long dummy)
+{
+ if (pstore_new_entry) {
+ pstore_new_entry = 0;
+ schedule_work(&pstore_work);
+ }
+
+ mod_timer(&pstore_timer, jiffies + PSTORE_INTERVAL);
+}
+
+module_param(backend, charp, 0444);
+MODULE_PARM_DESC(backend, "Pstore backend to use");