M7350v1_en_gpl

kernel/fs/pstore/Kconfig

@@ -0,0 +1,13 @@
+config PSTORE
+	bool "Persistent store support"
+	default n
+	help
+	   This option enables generic access to platform level
+	   persistent storage via "pstore" filesystem that can
+	   be mounted as /dev/pstore.  Only useful if you have
+	   a platform level driver that registers with pstore to
+	   provide the data, so you probably should just go say "Y"
+	   (or "M") to a platform specific persistent store driver
+	   (e.g. ACPI_APEI on X86) which will select this for you.
+	   If you don't have a platform persistent store driver,
+	   say N.

kernel/fs/pstore/Makefile

@@ -0,0 +1,7 @@
+#
+# Makefile for the linux pstorefs routines.
+#
+
+obj-y += pstore.o
+
+pstore-objs += inode.o platform.o

kernel/fs/pstore/inode.c

@@ -0,0 +1,319 @@
+/*
+ * Persistent Storage - ramfs 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/module.h>
+#include <linux/fs.h>
+#include <linux/fsnotify.h>
+#include <linux/pagemap.h>
+#include <linux/highmem.h>
+#include <linux/time.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/string.h>
+#include <linux/mount.h>
+#include <linux/ramfs.h>
+#include <linux/parser.h>
+#include <linux/sched.h>
+#include <linux/magic.h>
+#include <linux/pstore.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/uaccess.h>
+
+#include "internal.h"
+
+#define	PSTORE_NAMELEN	64
+
+static DEFINE_SPINLOCK(allpstore_lock);
+static LIST_HEAD(allpstore);
+
+struct pstore_private {
+	struct list_head list;
+	struct pstore_info *psi;
+	enum pstore_type_id type;
+	u64	id;
+	ssize_t	size;
+	char	data[];
+};
+
+static ssize_t pstore_file_read(struct file *file, char __user *userbuf,
+						size_t count, loff_t *ppos)
+{
+	struct pstore_private *ps = file->private_data;
+
+	return simple_read_from_buffer(userbuf, count, ppos, ps->data, ps->size);
+}
+
+static const struct file_operations pstore_file_operations = {
+	.open	= simple_open,
+	.read	= pstore_file_read,
+	.llseek	= default_llseek,
+};
+
+/*
+ * When a file is unlinked from our file system we call the
+ * platform driver to erase the record from persistent store.
+ */
+static int pstore_unlink(struct inode *dir, struct dentry *dentry)
+{
+	struct pstore_private *p = dentry->d_inode->i_private;
+
+	if (p->psi->erase)
+		p->psi->erase(p->type, p->id, p->psi);
+
+	return simple_unlink(dir, dentry);
+}
+
+static void pstore_evict_inode(struct inode *inode)
+{
+	struct pstore_private	*p = inode->i_private;
+	unsigned long		flags;
+
+	end_writeback(inode);
+	if (p) {
+		spin_lock_irqsave(&allpstore_lock, flags);
+		list_del(&p->list);
+		spin_unlock_irqrestore(&allpstore_lock, flags);
+		kfree(p);
+	}
+}
+
+static const struct inode_operations pstore_dir_inode_operations = {
+	.lookup		= simple_lookup,
+	.unlink		= pstore_unlink,
+};
+
+static struct inode *pstore_get_inode(struct super_block *sb)
+{
+	struct inode *inode = new_inode(sb);
+	if (inode) {
+		inode->i_ino = get_next_ino();
+		inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+	}
+	return inode;
+}
+
+enum {
+	Opt_kmsg_bytes, Opt_err
+};
+
+static const match_table_t tokens = {
+	{Opt_kmsg_bytes, "kmsg_bytes=%u"},
+	{Opt_err, NULL}
+};
+
+static void parse_options(char *options)
+{
+	char		*p;
+	substring_t	args[MAX_OPT_ARGS];
+	int		option;
+
+	if (!options)
+		return;
+
+	while ((p = strsep(&options, ",")) != NULL) {
+		int token;
+
+		if (!*p)
+			continue;
+
+		token = match_token(p, tokens, args);
+		switch (token) {
+		case Opt_kmsg_bytes:
+			if (!match_int(&args[0], &option))
+				pstore_set_kmsg_bytes(option);
+			break;
+		}
+	}
+}
+
+static int pstore_remount(struct super_block *sb, int *flags, char *data)
+{
+	parse_options(data);
+
+	return 0;
+}
+
+static const struct super_operations pstore_ops = {
+	.statfs		= simple_statfs,
+	.drop_inode	= generic_delete_inode,
+	.evict_inode	= pstore_evict_inode,
+	.remount_fs	= pstore_remount,
+	.show_options	= generic_show_options,
+};
+
+static struct super_block *pstore_sb;
+
+int pstore_is_mounted(void)
+{
+	return pstore_sb != NULL;
+}
+
+/*
+ * Make a regular file in the root directory of our file system.
+ * Load it up with "size" bytes of data from "buf".
+ * Set the mtime & ctime to the date that this record was originally stored.
+ */
+int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id,
+		  char *data, size_t size, struct timespec time,
+		  struct pstore_info *psi)
+{
+	struct dentry		*root = pstore_sb->s_root;
+	struct dentry		*dentry;
+	struct inode		*inode;
+	int			rc = 0;
+	char			name[PSTORE_NAMELEN];
+	struct pstore_private	*private, *pos;
+	unsigned long		flags;
+
+	spin_lock_irqsave(&allpstore_lock, flags);
+	list_for_each_entry(pos, &allpstore, list) {
+		if (pos->type == type &&
+		    pos->id == id &&
+		    pos->psi == psi) {
+			rc = -EEXIST;
+			break;
+		}
+	}
+	spin_unlock_irqrestore(&allpstore_lock, flags);
+	if (rc)
+		return rc;
+
+	rc = -ENOMEM;
+	inode = pstore_get_inode(pstore_sb);
+	if (!inode)
+		goto fail;
+	inode->i_mode = S_IFREG | 0444;
+	inode->i_fop = &pstore_file_operations;
+	private = kmalloc(sizeof *private + size, GFP_KERNEL);
+	if (!private)
+		goto fail_alloc;
+	private->type = type;
+	private->id = id;
+	private->psi = psi;
+
+	switch (type) {
+	case PSTORE_TYPE_DMESG:
+		sprintf(name, "dmesg-%s-%lld", psname, id);
+		break;
+	case PSTORE_TYPE_MCE:
+		sprintf(name, "mce-%s-%lld", psname, id);
+		break;
+	case PSTORE_TYPE_UNKNOWN:
+		sprintf(name, "unknown-%s-%lld", psname, id);
+		break;
+	default:
+		sprintf(name, "type%d-%s-%lld", type, psname, id);
+		break;
+	}
+
+	mutex_lock(&root->d_inode->i_mutex);
+
+	rc = -ENOSPC;
+	dentry = d_alloc_name(root, name);
+	if (IS_ERR(dentry))
+		goto fail_lockedalloc;
+
+	memcpy(private->data, data, size);
+	inode->i_size = private->size = size;
+
+	inode->i_private = private;
+
+	if (time.tv_sec)
+		inode->i_mtime = inode->i_ctime = time;
+
+	d_add(dentry, inode);
+
+	spin_lock_irqsave(&allpstore_lock, flags);
+	list_add(&private->list, &allpstore);
+	spin_unlock_irqrestore(&allpstore_lock, flags);
+
+	mutex_unlock(&root->d_inode->i_mutex);
+
+	return 0;
+
+fail_lockedalloc:
+	mutex_unlock(&root->d_inode->i_mutex);
+	kfree(private);
+fail_alloc:
+	iput(inode);
+
+fail:
+	return rc;
+}
+
+int pstore_fill_super(struct super_block *sb, void *data, int silent)
+{
+	struct inode *inode;
+
+	save_mount_options(sb, data);
+
+	pstore_sb = sb;
+
+	sb->s_maxbytes		= MAX_LFS_FILESIZE;
+	sb->s_blocksize		= PAGE_CACHE_SIZE;
+	sb->s_blocksize_bits	= PAGE_CACHE_SHIFT;
+	sb->s_magic		= PSTOREFS_MAGIC;
+	sb->s_op		= &pstore_ops;
+	sb->s_time_gran		= 1;
+
+	parse_options(data);
+
+	inode = pstore_get_inode(sb);
+	if (inode) {
+		inode->i_mode = S_IFDIR | 0755;
+		inode->i_op = &pstore_dir_inode_operations;
+		inode->i_fop = &simple_dir_operations;
+		inc_nlink(inode);
+	}
+	sb->s_root = d_make_root(inode);
+	if (!sb->s_root)
+		return -ENOMEM;
+
+	pstore_get_records(0);
+
+	return 0;
+}
+
+static struct dentry *pstore_mount(struct file_system_type *fs_type,
+	int flags, const char *dev_name, void *data)
+{
+	return mount_single(fs_type, flags, data, pstore_fill_super);
+}
+
+static void pstore_kill_sb(struct super_block *sb)
+{
+	kill_litter_super(sb);
+	pstore_sb = NULL;
+}
+
+static struct file_system_type pstore_fs_type = {
+	.name		= "pstore",
+	.mount		= pstore_mount,
+	.kill_sb	= pstore_kill_sb,
+};
+
+static int __init init_pstore_fs(void)
+{
+	return register_filesystem(&pstore_fs_type);
+}
+module_init(init_pstore_fs)
+
+MODULE_AUTHOR("Tony Luck <tony.luck@intel.com>");
+MODULE_LICENSE("GPL");

kernel/fs/pstore/internal.h

@@ -0,0 +1,6 @@
+extern void	pstore_set_kmsg_bytes(int);
+extern void	pstore_get_records(int);
+extern int	pstore_mkfile(enum pstore_type_id, char *psname, u64 id,
+			      char *data, size_t size,
+			      struct timespec time, struct pstore_info *psi);
+extern int	pstore_is_mounted(void);

kernel/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");