Initial import

1 files changed, 483 insertions, 0 deletions

diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
new file mode 100644
index 000000000..3adcc4669
--- /dev/null
+++ b/fs/pstore/inode.c
@@ -0,0 +1,483 @@
+/*
+ * 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/seq_file.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 <linux/syslog.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;
+	int	count;
+	ssize_t	size;
+	char	data[];
+};
+
+struct pstore_ftrace_seq_data {
+	const void *ptr;
+	size_t off;
+	size_t size;
+};
+
+#define REC_SIZE sizeof(struct pstore_ftrace_record)
+
+static void *pstore_ftrace_seq_start(struct seq_file *s, loff_t *pos)
+{
+	struct pstore_private *ps = s->private;
+	struct pstore_ftrace_seq_data *data;
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return NULL;
+
+	data->off = ps->size % REC_SIZE;
+	data->off += *pos * REC_SIZE;
+	if (data->off + REC_SIZE > ps->size) {
+		kfree(data);
+		return NULL;
+	}
+
+	return data;
+
+}
+
+static void pstore_ftrace_seq_stop(struct seq_file *s, void *v)
+{
+	kfree(v);
+}
+
+static void *pstore_ftrace_seq_next(struct seq_file *s, void *v, loff_t *pos)
+{
+	struct pstore_private *ps = s->private;
+	struct pstore_ftrace_seq_data *data = v;
+
+	data->off += REC_SIZE;
+	if (data->off + REC_SIZE > ps->size)
+		return NULL;
+
+	(*pos)++;
+	return data;
+}
+
+static int pstore_ftrace_seq_show(struct seq_file *s, void *v)
+{
+	struct pstore_private *ps = s->private;
+	struct pstore_ftrace_seq_data *data = v;
+	struct pstore_ftrace_record *rec = (void *)(ps->data + data->off);
+
+	seq_printf(s, "%d %08lx  %08lx  %pf <- %pF\n",
+		pstore_ftrace_decode_cpu(rec), rec->ip, rec->parent_ip,
+		(void *)rec->ip, (void *)rec->parent_ip);
+
+	return 0;
+}
+
+static const struct seq_operations pstore_ftrace_seq_ops = {
+	.start	= pstore_ftrace_seq_start,
+	.next	= pstore_ftrace_seq_next,
+	.stop	= pstore_ftrace_seq_stop,
+	.show	= pstore_ftrace_seq_show,
+};
+
+static int pstore_check_syslog_permissions(struct pstore_private *ps)
+{
+	switch (ps->type) {
+	case PSTORE_TYPE_DMESG:
+	case PSTORE_TYPE_CONSOLE:
+		return check_syslog_permissions(SYSLOG_ACTION_READ_ALL,
+			SYSLOG_FROM_READER);
+	default:
+		return 0;
+	}
+}
+
+static ssize_t pstore_file_read(struct file *file, char __user *userbuf,
+						size_t count, loff_t *ppos)
+{
+	struct seq_file *sf = file->private_data;
+	struct pstore_private *ps = sf->private;
+
+	if (ps->type == PSTORE_TYPE_FTRACE)
+		return seq_read(file, userbuf, count, ppos);
+	return simple_read_from_buffer(userbuf, count, ppos, ps->data, ps->size);
+}
+
+static int pstore_file_open(struct inode *inode, struct file *file)
+{
+	struct pstore_private *ps = inode->i_private;
+	struct seq_file *sf;
+	int err;
+	const struct seq_operations *sops = NULL;
+
+	err = pstore_check_syslog_permissions(ps);
+	if (err)
+		return err;
+
+	if (ps->type == PSTORE_TYPE_FTRACE)
+		sops = &pstore_ftrace_seq_ops;
+
+	err = seq_open(file, sops);
+	if (err < 0)
+		return err;
+
+	sf = file->private_data;
+	sf->private = ps;
+
+	return 0;
+}
+
+static loff_t pstore_file_llseek(struct file *file, loff_t off, int whence)
+{
+	struct seq_file *sf = file->private_data;
+
+	if (sf->op)
+		return seq_lseek(file, off, whence);
+	return default_llseek(file, off, whence);
+}
+
+static const struct file_operations pstore_file_operations = {
+	.open		= pstore_file_open,
+	.read		= pstore_file_read,
+	.llseek		= pstore_file_llseek,
+	.release	= seq_release,
+};
+
+/*
+ * 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 = d_inode(dentry)->i_private;
+	int err;
+
+	err = pstore_check_syslog_permissions(p);
+	if (err)
+		return err;
+
+	if (p->psi->erase)
+		p->psi->erase(p->type, p->id, p->count,
+			      d_inode(dentry)->i_ctime, p->psi);
+	else
+		return -EPERM;
+
+	return simple_unlink(dir, dentry);
+}
+
+static void pstore_evict_inode(struct inode *inode)
+{
+	struct pstore_private	*p = inode->i_private;
+	unsigned long		flags;
+
+	clear_inode(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)
+{
+	sync_filesystem(sb);
+	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, int count,
+		  char *data, bool compressed, 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->count = count;
+	private->psi = psi;
+
+	switch (type) {
+	case PSTORE_TYPE_DMESG:
+		scnprintf(name, sizeof(name), "dmesg-%s-%lld%s",
+			  psname, id, compressed ? ".enc.z" : "");
+		break;
+	case PSTORE_TYPE_CONSOLE:
+		scnprintf(name, sizeof(name), "console-%s-%lld", psname, id);
+		break;
+	case PSTORE_TYPE_FTRACE:
+		scnprintf(name, sizeof(name), "ftrace-%s-%lld", psname, id);
+		break;
+	case PSTORE_TYPE_MCE:
+		scnprintf(name, sizeof(name), "mce-%s-%lld", psname, id);
+		break;
+	case PSTORE_TYPE_PPC_RTAS:
+		scnprintf(name, sizeof(name), "rtas-%s-%lld", psname, id);
+		break;
+	case PSTORE_TYPE_PPC_OF:
+		scnprintf(name, sizeof(name), "powerpc-ofw-%s-%lld",
+			  psname, id);
+		break;
+	case PSTORE_TYPE_PPC_COMMON:
+		scnprintf(name, sizeof(name), "powerpc-common-%s-%lld",
+			  psname, id);
+		break;
+	case PSTORE_TYPE_PMSG:
+		scnprintf(name, sizeof(name), "pmsg-%s-%lld", psname, id);
+		break;
+	case PSTORE_TYPE_PPC_OPAL:
+		sprintf(name, "powerpc-opal-%s-%lld", psname, id);
+		break;
+	case PSTORE_TYPE_UNKNOWN:
+		scnprintf(name, sizeof(name), "unknown-%s-%lld", psname, id);
+		break;
+	default:
+		scnprintf(name, sizeof(name), "type%d-%s-%lld",
+			  type, psname, id);
+		break;
+	}
+
+	mutex_lock(&d_inode(root)->i_mutex);
+
+	dentry = d_alloc_name(root, name);
+	if (!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(&d_inode(root)->i_mutex);
+
+	return 0;
+
+fail_lockedalloc:
+	mutex_unlock(&d_inode(root)->i_mutex);
+	kfree(private);
+fail_alloc:
+	iput(inode);
+
+fail:
+	return rc;
+}
+
+static 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)
+{
+	int err;
+
+	/* Create a convenient mount point for people to access pstore */
+	err = sysfs_create_mount_point(fs_kobj, "pstore");
+	if (err)
+		goto out;
+
+	err = register_filesystem(&pstore_fs_type);
+	if (err < 0)
+		sysfs_remove_mount_point(fs_kobj, "pstore");
+
+out:
+	return err;
+}
+module_init(init_pstore_fs)
+
+MODULE_AUTHOR("Tony Luck <tony.luck@intel.com>");
+MODULE_LICENSE("GPL");