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-rw-r--r--kernel/fs/pstore/inode.c483
1 files changed, 483 insertions, 0 deletions
diff --git a/kernel/fs/pstore/inode.c b/kernel/fs/pstore/inode.c
new file mode 100644
index 000000000..3adcc4669
--- /dev/null
+++ b/kernel/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");