Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 into for-linus-1

* 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6: (9356 commits)
  [media] rc: update for bitop name changes
  fs: simplify iget & friends
  fs: pull inode->i_lock up out of writeback_single_inode
  fs: rename inode_lock to inode_hash_lock
  fs: move i_wb_list out from under inode_lock
  fs: move i_sb_list out from under inode_lock
  fs: remove inode_lock from iput_final and prune_icache
  fs: Lock the inode LRU list separately
  fs: factor inode disposal
  fs: protect inode->i_state with inode->i_lock
  lib, arch: add filter argument to show_mem and fix private implementations
  SLUB: Write to per cpu data when allocating it
  slub: Fix debugobjects with lockless fastpath
  autofs4: Do not potentially dereference NULL pointer returned by fget() in autofs_dev_ioctl_setpipefd()
  autofs4 - remove autofs4_lock
  autofs4 - fix d_manage() return on rcu-walk
  autofs4 - fix autofs4_expire_indirect() traversal
  autofs4 - fix dentry leak in autofs4_expire_direct()
  autofs4 - reinstate last used update on access
  vfs - check non-mountpoint dentry might block in __follow_mount_rcu()
  ...

NOTE!

This merge commit was created to fix compilation error. The block
tree was merged upstream and removed the 'elv_queue_empty()'
function which the new 'mtdswap' driver is using. So a simple
merge of the mtd tree with upstream does not compile. And the
mtd tree has already be published, so re-basing it is not an option.

To fix this unfortunate situation, I had to merge upstream into the
mtd-2.6.git tree without committing, put the fixup patch on top of
this, and then commit this. The result is that we do not have commits
which do not compile.

In other words, this merge commit "merges" 3 things: the MTD tree, the
upstream tree, and the fixup patch.

5 files changed, 538 insertions, 0 deletions

diff --git a/fs/pstore/Kconfig b/fs/pstore/Kconfig
new file mode 100644
index 00000000000..867d0ac026c
--- /dev/null
+++ b/fs/pstore/Kconfig
@@ -0,0 +1,13 @@
+config PSTORE
+	bool "Persistant 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.
diff --git a/fs/pstore/Makefile b/fs/pstore/Makefile
new file mode 100644
index 00000000000..760f4bce7d1
--- /dev/null
+++ b/fs/pstore/Makefile
@@ -0,0 +1,7 @@
+#
+# Makefile for the linux pstorefs routines.
+#
+
+obj-y += pstore.o
+
+pstore-objs += inode.o platform.o
diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
new file mode 100644
index 00000000000..977ed272384
--- /dev/null
+++ b/fs/pstore/inode.c
@@ -0,0 +1,311 @@
+/*
+ * 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/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/uaccess.h>
+
+#include "internal.h"
+
+#define	PSTORE_NAMELEN	64
+
+struct pstore_private {
+	u64	id;
+	int	(*erase)(u64);
+	ssize_t	size;
+	char	data[];
+};
+
+static int pstore_file_open(struct inode *inode, struct file *file)
+{
+	file->private_data = inode->i_private;
+	return 0;
+}
+
+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	= pstore_file_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;
+
+	p->erase(p->id);
+
+	return simple_unlink(dir, dentry);
+}
+
+static void pstore_evict_inode(struct inode *inode)
+{
+	end_writeback(inode);
+	kfree(inode->i_private);
+}
+
+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,
+					const struct inode *dir, int mode, dev_t dev)
+{
+	struct inode *inode = new_inode(sb);
+
+	if (inode) {
+		inode->i_ino = get_next_ino();
+		inode->i_uid = inode->i_gid = 0;
+		inode->i_mode = mode;
+		inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+		switch (mode & S_IFMT) {
+		case S_IFREG:
+			inode->i_fop = &pstore_file_operations;
+			break;
+		case S_IFDIR:
+			inode->i_op = &pstore_dir_inode_operations;
+			inode->i_fop = &simple_dir_operations;
+			inc_nlink(inode);
+			break;
+		}
+	}
+	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, int (*erase)(u64))
+{
+	struct dentry		*root = pstore_sb->s_root;
+	struct dentry		*dentry;
+	struct inode		*inode;
+	int			rc;
+	char			name[PSTORE_NAMELEN];
+	struct pstore_private	*private;
+
+	rc = -ENOMEM;
+	inode = pstore_get_inode(pstore_sb, root->d_inode, S_IFREG | 0444, 0);
+	if (!inode)
+		goto fail;
+	private = kmalloc(sizeof *private + size, GFP_KERNEL);
+	if (!private)
+		goto fail_alloc;
+	private->id = id;
+	private->erase = erase;
+
+	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);
+
+	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 = NULL;
+	struct dentry *root;
+	int err;
+
+	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, NULL, S_IFDIR | 0755, 0);
+	if (!inode) {
+		err = -ENOMEM;
+		goto fail;
+	}
+	/* override ramfs "dir" options so we catch unlink(2) */
+	inode->i_op = &pstore_dir_inode_operations;
+
+	root = d_alloc_root(inode);
+	sb->s_root = root;
+	if (!root) {
+		err = -ENOMEM;
+		goto fail;
+	}
+
+	pstore_get_records();
+
+	return 0;
+fail:
+	iput(inode);
+	return err;
+}
+
+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");
diff --git a/fs/pstore/internal.h b/fs/pstore/internal.h
new file mode 100644
index 00000000000..8c9f23eb164
--- /dev/null
+++ b/fs/pstore/internal.h
@@ -0,0 +1,6 @@
+extern void	pstore_set_kmsg_bytes(int);
+extern void	pstore_get_records(void);
+extern int	pstore_mkfile(enum pstore_type_id, char *psname, u64 id,
+			      char *data, size_t size,
+			      struct timespec time, int (*erase)(u64));
+extern int	pstore_is_mounted(void);
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
new file mode 100644
index 00000000000..f835a25625f
--- /dev/null
+++ b/fs/pstore/platform.c
@@ -0,0 +1,201 @@
+/*
+ * 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/slab.h>
+#include <linux/uaccess.h>
+
+#include "internal.h"
+
+/*
+ * pstore_lock just protects "psinfo" during
+ * calls to pstore_register()
+ */
+static DEFINE_SPINLOCK(pstore_lock);
+static struct pstore_info *psinfo;
+
+/* 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 char *reason_str[] = {
+	"Oops", "Panic", "Kexec", "Restart", "Halt", "Poweroff", "Emergency"
+};
+
+/*
+ * 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, *why;
+	u64		id;
+	int		hsize, part = 1;
+
+	if (reason < ARRAY_SIZE(reason_str))
+		why = reason_str[reason];
+	else
+		why = "Unknown";
+
+	mutex_lock(&psinfo->buf_mutex);
+	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);
+
+		id = psinfo->write(PSTORE_TYPE_DMESG, hsize + l1_cpy + l2_cpy);
+		if (reason == KMSG_DUMP_OOPS && pstore_is_mounted())
+			pstore_mkfile(PSTORE_TYPE_DMESG, psinfo->name, id,
+				      psinfo->buf, hsize + l1_cpy + l2_cpy,
+				      CURRENT_TIME, psinfo->erase);
+		l1 -= l1_cpy;
+		l2 -= l2_cpy;
+		total += l1_cpy + l2_cpy;
+	}
+	mutex_unlock(&psinfo->buf_mutex);
+}
+
+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;
+	}
+	psinfo = psi;
+	spin_unlock(&pstore_lock);
+
+	if (owner && !try_module_get(owner)) {
+		psinfo = NULL;
+		return -EINVAL;
+	}
+
+	if (pstore_is_mounted())
+		pstore_get_records();
+
+	kmsg_dump_register(&pstore_dumper);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pstore_register);
+
+/*
+ * Read all the records from the persistent store. Create and
+ * file files in our filesystem.
+ */
+void pstore_get_records(void)
+{
+	struct pstore_info *psi = psinfo;
+	size_t			size;
+	u64			id;
+	enum pstore_type_id	type;
+	struct timespec		time;
+	int			failed = 0;
+
+	if (!psi)
+		return;
+
+	mutex_lock(&psinfo->buf_mutex);
+	while ((size = psi->read(&id, &type, &time)) > 0) {
+		if (pstore_mkfile(type, psi->name, id, psi->buf, size,
+				  time, psi->erase))
+			failed++;
+	}
+	mutex_unlock(&psinfo->buf_mutex);
+
+	if (failed)
+		printk(KERN_WARNING "pstore: failed to load %d record(s) from '%s'\n",
+		       failed, psi->name);
+}
+
+/*
+ * Call platform driver to write a record to the
+ * persistent store.
+ */
+int pstore_write(enum pstore_type_id type, char *buf, size_t size)
+{
+	u64	id;
+
+	if (!psinfo)
+		return -ENODEV;
+
+	if (size > psinfo->bufsize)
+		return -EFBIG;
+
+	mutex_lock(&psinfo->buf_mutex);
+	memcpy(psinfo->buf, buf, size);
+	id = psinfo->write(type, size);
+	if (pstore_is_mounted())
+		pstore_mkfile(PSTORE_TYPE_DMESG, psinfo->name, id, psinfo->buf,
+			      size, CURRENT_TIME, psinfo->erase);
+	mutex_unlock(&psinfo->buf_mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pstore_write);