141 lines
3.5 KiB
C
141 lines
3.5 KiB
C
/*
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* Persistent Storage - platform driver interface parts.
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*
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* Copyright (C) 2007-2008 Google, Inc.
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* Copyright (C) 2010 Intel Corporation <tony.luck@intel.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, see <http://www.gnu.org/licenses/>.
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*/
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#define pr_fmt(fmt) "pstore: " fmt
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#include <linux/types.h>
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#include <linux/pstore.h>
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#include <linux/string.h>
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#include <linux/kernel.h>
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#include <linux/spinlock.h>
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#include <linux/mutex.h>
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#include <malloc.h>
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#include <printk.h>
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#include <module.h>
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#include "internal.h"
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struct pstore_info *psinfo;
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static char *backend;
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/* How much of the console log to snapshot */
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static unsigned long kmsg_bytes = 10240;
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void pstore_set_kmsg_bytes(int bytes)
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{
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kmsg_bytes = bytes;
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}
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static int pstore_write_compat(enum pstore_type_id type,
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enum kmsg_dump_reason reason,
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u64 *id, unsigned int part, int count,
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bool compressed, size_t size,
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struct pstore_info *psi)
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{
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return psi->write_buf(type, reason, id, part, psinfo->buf, compressed,
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size, psi);
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}
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/*
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* platform specific persistent storage driver registers with
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* us here. If pstore is already mounted, call the platform
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* read function right away to populate the file system. If not
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* then the pstore mount code will call us later to fill out
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* the file system.
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*
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* Register with kmsg_dump to save last part of console log on panic.
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*/
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int pstore_register(struct pstore_info *psi)
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{
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if (backend && strcmp(backend, psi->name))
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return -EPERM;
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spin_lock(&pstore_lock);
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if (psinfo) {
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spin_unlock(&pstore_lock);
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return -EBUSY;
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}
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if (!psi->write)
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psi->write = pstore_write_compat;
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psinfo = psi;
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mutex_init(&psinfo->read_mutex);
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spin_unlock(&pstore_lock);
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pstore_get_records(0);
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pr_info("Registered %s as persistent store backend\n", psi->name);
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return 0;
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}
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EXPORT_SYMBOL_GPL(pstore_register);
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/*
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* Read all the records from the persistent store. Create
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* files in our filesystem. Don't warn about -EEXIST errors
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* when we are re-scanning the backing store looking to add new
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* error records.
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*/
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void pstore_get_records(int quiet)
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{
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struct pstore_info *psi = psinfo;
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char *buf = NULL;
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ssize_t size;
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u64 id;
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int count;
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enum pstore_type_id type;
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int failed = 0, rc;
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bool compressed;
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int unzipped_len = -1;
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if (!psi)
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return;
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mutex_lock(&psi->read_mutex);
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if (psi->open && psi->open(psi))
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goto out;
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while ((size = psi->read(&id, &type, &count, &buf, &compressed,
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psi)) > 0) {
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if (compressed && (type == PSTORE_TYPE_DMESG)) {
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pr_err("barebox does not have ramoops compression support\n");
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continue;
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}
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rc = pstore_mkfile(type, psi->name, id, count, buf,
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compressed, (size_t)size, psi);
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if (unzipped_len < 0) {
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/* Free buffer other than big oops */
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kfree(buf);
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buf = NULL;
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} else
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unzipped_len = -1;
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if (rc && (rc != -EEXIST || !quiet))
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failed++;
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}
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if (psi->close)
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psi->close(psi);
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out:
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mutex_unlock(&psi->read_mutex);
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if (failed)
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pr_warn("failed to load %d record(s) from '%s'\n",
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failed, psi->name);
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}
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