Merge tag 'for-3.8-merge' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs

Pull new F2FS filesystem from Jaegeuk Kim:
 "Introduce a new file system, Flash-Friendly File System (F2FS), to
  Linux 3.8.

  Highlights:
   - Add initial f2fs source codes
   - Fix an endian conversion bug
   - Fix build failures on random configs
   - Fix the power-off-recovery routine
   - Minor cleanup, coding style, and typos patches"

From the Kconfig help text:

  F2FS is based on Log-structured File System (LFS), which supports
  versatile "flash-friendly" features. The design has been focused on
  addressing the fundamental issues in LFS, which are snowball effect
  of wandering tree and high cleaning overhead.

  Since flash-based storages show different characteristics according to
  the internal geometry or flash memory management schemes aka FTL, F2FS
  and tools support various parameters not only for configuring on-disk
  layout, but also for selecting allocation and cleaning algorithms.

and there's an article by Neil Brown about it on lwn.net:

  http://lwn.net/Articles/518988/

* tag 'for-3.8-merge' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (36 commits)
  f2fs: fix tracking parent inode number
  f2fs: cleanup the f2fs_bio_alloc routine
  f2fs: introduce accessor to retrieve number of dentry slots
  f2fs: remove redundant call to f2fs_put_page in delete entry
  f2fs: make use of GFP_F2FS_ZERO for setting gfp_mask
  f2fs: rewrite f2fs_bio_alloc to make it simpler
  f2fs: fix a typo in f2fs documentation
  f2fs: remove unused variable
  f2fs: move error condition for mkdir at proper place
  f2fs: remove unneeded initialization
  f2fs: check read only condition before beginning write out
  f2fs: remove unneeded memset from init_once
  f2fs: show error in case of invalid mount arguments
  f2fs: fix the compiler warning for uninitialized use of variable
  f2fs: resolve build failures
  f2fs: adjust kernel coding style
  f2fs: fix endian conversion bugs reported by sparse
  f2fs: remove unneeded version.h header file from f2fs.h
  f2fs: update the f2fs document
  f2fs: update Kconfig and Makefile
  ...

25 files changed, 12651 insertions, 0 deletions

diff --git a/fs/Kconfig b/fs/Kconfig
index eaff24a1950..cfe512fd1ca 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -220,6 +220,7 @@ source "fs/pstore/Kconfig"
 source "fs/sysv/Kconfig"
 source "fs/ufs/Kconfig"
 source "fs/exofs/Kconfig"
+source "fs/f2fs/Kconfig"
 
 endif # MISC_FILESYSTEMS
 
diff --git a/fs/Makefile b/fs/Makefile
index 1d7af79288a..9d53192236f 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -123,6 +123,7 @@ obj-$(CONFIG_DEBUG_FS)		+= debugfs/
 obj-$(CONFIG_OCFS2_FS)		+= ocfs2/
 obj-$(CONFIG_BTRFS_FS)		+= btrfs/
 obj-$(CONFIG_GFS2_FS)           += gfs2/
+obj-$(CONFIG_F2FS_FS)		+= f2fs/
 obj-y				+= exofs/ # Multiple modules
 obj-$(CONFIG_CEPH_FS)		+= ceph/
 obj-$(CONFIG_PSTORE)		+= pstore/
diff --git a/fs/f2fs/Kconfig b/fs/f2fs/Kconfig
new file mode 100644
index 00000000000..fd27e7e6326
--- /dev/null
+++ b/fs/f2fs/Kconfig
@@ -0,0 +1,53 @@
+config F2FS_FS
+	tristate "F2FS filesystem support (EXPERIMENTAL)"
+	depends on BLOCK
+	help
+	  F2FS is based on Log-structured File System (LFS), which supports
+	  versatile "flash-friendly" features. The design has been focused on
+	  addressing the fundamental issues in LFS, which are snowball effect
+	  of wandering tree and high cleaning overhead.
+
+	  Since flash-based storages show different characteristics according to
+	  the internal geometry or flash memory management schemes aka FTL, F2FS
+	  and tools support various parameters not only for configuring on-disk
+	  layout, but also for selecting allocation and cleaning algorithms.
+
+	  If unsure, say N.
+
+config F2FS_STAT_FS
+	bool "F2FS Status Information"
+	depends on F2FS_FS && DEBUG_FS
+	default y
+	help
+	  /sys/kernel/debug/f2fs/ contains information about all the partitions
+	  mounted as f2fs. Each file shows the whole f2fs information.
+
+	  /sys/kernel/debug/f2fs/status includes:
+	    - major file system information managed by f2fs currently
+	    - average SIT information about whole segments
+	    - current memory footprint consumed by f2fs.
+
+config F2FS_FS_XATTR
+	bool "F2FS extended attributes"
+	depends on F2FS_FS
+	default y
+	help
+	  Extended attributes are name:value pairs associated with inodes by
+	  the kernel or by users (see the attr(5) manual page, or visit
+	  <http://acl.bestbits.at/> for details).
+
+	  If unsure, say N.
+
+config F2FS_FS_POSIX_ACL
+	bool "F2FS Access Control Lists"
+	depends on F2FS_FS_XATTR
+	select FS_POSIX_ACL
+	default y
+	help
+	  Posix Access Control Lists (ACLs) support permissions for users and
+	  gourps beyond the owner/group/world scheme.
+
+	  To learn more about Access Control Lists, visit the POSIX ACLs for
+	  Linux website <http://acl.bestbits.at/>.
+
+	  If you don't know what Access Control Lists are, say N
diff --git a/fs/f2fs/Makefile b/fs/f2fs/Makefile
new file mode 100644
index 00000000000..27a0820340b
--- /dev/null
+++ b/fs/f2fs/Makefile
@@ -0,0 +1,7 @@
+obj-$(CONFIG_F2FS_FS) += f2fs.o
+
+f2fs-y		:= dir.o file.o inode.o namei.o hash.o super.o
+f2fs-y		+= checkpoint.o gc.o data.o node.o segment.o recovery.o
+f2fs-$(CONFIG_F2FS_STAT_FS) += debug.o
+f2fs-$(CONFIG_F2FS_FS_XATTR) += xattr.o
+f2fs-$(CONFIG_F2FS_FS_POSIX_ACL) += acl.o
diff --git a/fs/f2fs/acl.c b/fs/f2fs/acl.c
new file mode 100644
index 00000000000..fed74d193ff
--- /dev/null
+++ b/fs/f2fs/acl.c
@@ -0,0 +1,414 @@
+/*
+ * fs/f2fs/acl.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * Portions of this code from linux/fs/ext2/acl.c
+ *
+ * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
+ *
+ * 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.
+ */
+#include <linux/f2fs_fs.h>
+#include "f2fs.h"
+#include "xattr.h"
+#include "acl.h"
+
+#define get_inode_mode(i)	((is_inode_flag_set(F2FS_I(i), FI_ACL_MODE)) ? \
+					(F2FS_I(i)->i_acl_mode) : ((i)->i_mode))
+
+static inline size_t f2fs_acl_size(int count)
+{
+	if (count <= 4) {
+		return sizeof(struct f2fs_acl_header) +
+			count * sizeof(struct f2fs_acl_entry_short);
+	} else {
+		return sizeof(struct f2fs_acl_header) +
+			4 * sizeof(struct f2fs_acl_entry_short) +
+			(count - 4) * sizeof(struct f2fs_acl_entry);
+	}
+}
+
+static inline int f2fs_acl_count(size_t size)
+{
+	ssize_t s;
+	size -= sizeof(struct f2fs_acl_header);
+	s = size - 4 * sizeof(struct f2fs_acl_entry_short);
+	if (s < 0) {
+		if (size % sizeof(struct f2fs_acl_entry_short))
+			return -1;
+		return size / sizeof(struct f2fs_acl_entry_short);
+	} else {
+		if (s % sizeof(struct f2fs_acl_entry))
+			return -1;
+		return s / sizeof(struct f2fs_acl_entry) + 4;
+	}
+}
+
+static struct posix_acl *f2fs_acl_from_disk(const char *value, size_t size)
+{
+	int i, count;
+	struct posix_acl *acl;
+	struct f2fs_acl_header *hdr = (struct f2fs_acl_header *)value;
+	struct f2fs_acl_entry *entry = (struct f2fs_acl_entry *)(hdr + 1);
+	const char *end = value + size;
+
+	if (hdr->a_version != cpu_to_le32(F2FS_ACL_VERSION))
+		return ERR_PTR(-EINVAL);
+
+	count = f2fs_acl_count(size);
+	if (count < 0)
+		return ERR_PTR(-EINVAL);
+	if (count == 0)
+		return NULL;
+
+	acl = posix_acl_alloc(count, GFP_KERNEL);
+	if (!acl)
+		return ERR_PTR(-ENOMEM);
+
+	for (i = 0; i < count; i++) {
+
+		if ((char *)entry > end)
+			goto fail;
+
+		acl->a_entries[i].e_tag  = le16_to_cpu(entry->e_tag);
+		acl->a_entries[i].e_perm = le16_to_cpu(entry->e_perm);
+
+		switch (acl->a_entries[i].e_tag) {
+		case ACL_USER_OBJ:
+		case ACL_GROUP_OBJ:
+		case ACL_MASK:
+		case ACL_OTHER:
+			acl->a_entries[i].e_id = ACL_UNDEFINED_ID;
+			entry = (struct f2fs_acl_entry *)((char *)entry +
+					sizeof(struct f2fs_acl_entry_short));
+			break;
+
+		case ACL_USER:
+			acl->a_entries[i].e_uid =
+				make_kuid(&init_user_ns,
+						le32_to_cpu(entry->e_id));
+			entry = (struct f2fs_acl_entry *)((char *)entry +
+					sizeof(struct f2fs_acl_entry));
+			break;
+		case ACL_GROUP:
+			acl->a_entries[i].e_gid =
+				make_kgid(&init_user_ns,
+						le32_to_cpu(entry->e_id));
+			entry = (struct f2fs_acl_entry *)((char *)entry +
+					sizeof(struct f2fs_acl_entry));
+			break;
+		default:
+			goto fail;
+		}
+	}
+	if ((char *)entry != end)
+		goto fail;
+	return acl;
+fail:
+	posix_acl_release(acl);
+	return ERR_PTR(-EINVAL);
+}
+
+static void *f2fs_acl_to_disk(const struct posix_acl *acl, size_t *size)
+{
+	struct f2fs_acl_header *f2fs_acl;
+	struct f2fs_acl_entry *entry;
+	int i;
+
+	f2fs_acl = kmalloc(sizeof(struct f2fs_acl_header) + acl->a_count *
+			sizeof(struct f2fs_acl_entry), GFP_KERNEL);
+	if (!f2fs_acl)
+		return ERR_PTR(-ENOMEM);
+
+	f2fs_acl->a_version = cpu_to_le32(F2FS_ACL_VERSION);
+	entry = (struct f2fs_acl_entry *)(f2fs_acl + 1);
+
+	for (i = 0; i < acl->a_count; i++) {
+
+		entry->e_tag  = cpu_to_le16(acl->a_entries[i].e_tag);
+		entry->e_perm = cpu_to_le16(acl->a_entries[i].e_perm);
+
+		switch (acl->a_entries[i].e_tag) {
+		case ACL_USER:
+			entry->e_id = cpu_to_le32(
+					from_kuid(&init_user_ns,
+						acl->a_entries[i].e_uid));
+			entry = (struct f2fs_acl_entry *)((char *)entry +
+					sizeof(struct f2fs_acl_entry));
+			break;
+		case ACL_GROUP:
+			entry->e_id = cpu_to_le32(
+					from_kgid(&init_user_ns,
+						acl->a_entries[i].e_gid));
+			entry = (struct f2fs_acl_entry *)((char *)entry +
+					sizeof(struct f2fs_acl_entry));
+			break;
+		case ACL_USER_OBJ:
+		case ACL_GROUP_OBJ:
+		case ACL_MASK:
+		case ACL_OTHER:
+			entry = (struct f2fs_acl_entry *)((char *)entry +
+					sizeof(struct f2fs_acl_entry_short));
+			break;
+		default:
+			goto fail;
+		}
+	}
+	*size = f2fs_acl_size(acl->a_count);
+	return (void *)f2fs_acl;
+
+fail:
+	kfree(f2fs_acl);
+	return ERR_PTR(-EINVAL);
+}
+
+struct posix_acl *f2fs_get_acl(struct inode *inode, int type)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
+	int name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT;
+	void *value = NULL;
+	struct posix_acl *acl;
+	int retval;
+
+	if (!test_opt(sbi, POSIX_ACL))
+		return NULL;
+
+	acl = get_cached_acl(inode, type);
+	if (acl != ACL_NOT_CACHED)
+		return acl;
+
+	if (type == ACL_TYPE_ACCESS)
+		name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;
+
+	retval = f2fs_getxattr(inode, name_index, "", NULL, 0);
+	if (retval > 0) {
+		value = kmalloc(retval, GFP_KERNEL);
+		if (!value)
+			return ERR_PTR(-ENOMEM);
+		retval = f2fs_getxattr(inode, name_index, "", value, retval);
+	}
+
+	if (retval < 0) {
+		if (retval == -ENODATA)
+			acl = NULL;
+		else
+			acl = ERR_PTR(retval);
+	} else {
+		acl = f2fs_acl_from_disk(value, retval);
+	}
+	kfree(value);
+	if (!IS_ERR(acl))
+		set_cached_acl(inode, type, acl);
+
+	return acl;
+}
+
+static int f2fs_set_acl(struct inode *inode, int type, struct posix_acl *acl)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	int name_index;
+	void *value = NULL;
+	size_t size = 0;
+	int error;
+
+	if (!test_opt(sbi, POSIX_ACL))
+		return 0;
+	if (S_ISLNK(inode->i_mode))
+		return -EOPNOTSUPP;
+
+	switch (type) {
+	case ACL_TYPE_ACCESS:
+		name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;
+		if (acl) {
+			error = posix_acl_equiv_mode(acl, &inode->i_mode);
+			if (error < 0)
+				return error;
+			set_acl_inode(fi, inode->i_mode);
+			if (error == 0)
+				acl = NULL;
+		}
+		break;
+
+	case ACL_TYPE_DEFAULT:
+		name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT;
+		if (!S_ISDIR(inode->i_mode))
+			return acl ? -EACCES : 0;
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	if (acl) {
+		value = f2fs_acl_to_disk(acl, &size);
+		if (IS_ERR(value)) {
+			cond_clear_inode_flag(fi, FI_ACL_MODE);
+			return (int)PTR_ERR(value);
+		}
+	}
+
+	error = f2fs_setxattr(inode, name_index, "", value, size);
+
+	kfree(value);
+	if (!error)
+		set_cached_acl(inode, type, acl);
+
+	cond_clear_inode_flag(fi, FI_ACL_MODE);
+	return error;
+}
+
+int f2fs_init_acl(struct inode *inode, struct inode *dir)
+{
+	struct posix_acl *acl = NULL;
+	struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
+	int error = 0;
+
+	if (!S_ISLNK(inode->i_mode)) {
+		if (test_opt(sbi, POSIX_ACL)) {
+			acl = f2fs_get_acl(dir, ACL_TYPE_DEFAULT);
+			if (IS_ERR(acl))
+				return PTR_ERR(acl);
+		}
+		if (!acl)
+			inode->i_mode &= ~current_umask();
+	}
+
+	if (test_opt(sbi, POSIX_ACL) && acl) {
+
+		if (S_ISDIR(inode->i_mode)) {
+			error = f2fs_set_acl(inode, ACL_TYPE_DEFAULT, acl);
+			if (error)
+				goto cleanup;
+		}
+		error = posix_acl_create(&acl, GFP_KERNEL, &inode->i_mode);
+		if (error < 0)
+			return error;
+		if (error > 0)
+			error = f2fs_set_acl(inode, ACL_TYPE_ACCESS, acl);
+	}
+cleanup:
+	posix_acl_release(acl);
+	return error;
+}
+
+int f2fs_acl_chmod(struct inode *inode)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
+	struct posix_acl *acl;
+	int error;
+	mode_t mode = get_inode_mode(inode);
+
+	if (!test_opt(sbi, POSIX_ACL))
+		return 0;
+	if (S_ISLNK(mode))
+		return -EOPNOTSUPP;
+
+	acl = f2fs_get_acl(inode, ACL_TYPE_ACCESS);
+	if (IS_ERR(acl) || !acl)
+		return PTR_ERR(acl);
+
+	error = posix_acl_chmod(&acl, GFP_KERNEL, mode);
+	if (error)
+		return error;
+	error = f2fs_set_acl(inode, ACL_TYPE_ACCESS, acl);
+	posix_acl_release(acl);
+	return error;
+}
+
+static size_t f2fs_xattr_list_acl(struct dentry *dentry, char *list,
+		size_t list_size, const char *name, size_t name_len, int type)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
+	const char *xname = POSIX_ACL_XATTR_DEFAULT;
+	size_t size;
+
+	if (!test_opt(sbi, POSIX_ACL))
+		return 0;
+
+	if (type == ACL_TYPE_ACCESS)
+		xname = POSIX_ACL_XATTR_ACCESS;
+
+	size = strlen(xname) + 1;
+	if (list && size <= list_size)
+		memcpy(list, xname, size);
+	return size;
+}
+
+static int f2fs_xattr_get_acl(struct dentry *dentry, const char *name,
+		void *buffer, size_t size, int type)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
+	struct posix_acl *acl;
+	int error;
+
+	if (strcmp(name, "") != 0)
+		return -EINVAL;
+	if (!test_opt(sbi, POSIX_ACL))
+		return -EOPNOTSUPP;
+
+	acl = f2fs_get_acl(dentry->d_inode, type);
+	if (IS_ERR(acl))
+		return PTR_ERR(acl);
+	if (!acl)
+		return -ENODATA;
+	error = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);
+	posix_acl_release(acl);
+
+	return error;
+}
+
+static int f2fs_xattr_set_acl(struct dentry *dentry, const char *name,
+		const void *value, size_t size, int flags, int type)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
+	struct inode *inode = dentry->d_inode;
+	struct posix_acl *acl = NULL;
+	int error;
+
+	if (strcmp(name, "") != 0)
+		return -EINVAL;
+	if (!test_opt(sbi, POSIX_ACL))
+		return -EOPNOTSUPP;
+	if (!inode_owner_or_capable(inode))
+		return -EPERM;
+
+	if (value) {
+		acl = posix_acl_from_xattr(&init_user_ns, value, size);
+		if (IS_ERR(acl))
+			return PTR_ERR(acl);
+		if (acl) {
+			error = posix_acl_valid(acl);
+			if (error)
+				goto release_and_out;
+		}
+	} else {
+		acl = NULL;
+	}
+
+	error = f2fs_set_acl(inode, type, acl);
+
+release_and_out:
+	posix_acl_release(acl);
+	return error;
+}
+
+const struct xattr_handler f2fs_xattr_acl_default_handler = {
+	.prefix = POSIX_ACL_XATTR_DEFAULT,
+	.flags = ACL_TYPE_DEFAULT,
+	.list = f2fs_xattr_list_acl,
+	.get = f2fs_xattr_get_acl,
+	.set = f2fs_xattr_set_acl,
+};
+
+const struct xattr_handler f2fs_xattr_acl_access_handler = {
+	.prefix = POSIX_ACL_XATTR_ACCESS,
+	.flags = ACL_TYPE_ACCESS,
+	.list = f2fs_xattr_list_acl,
+	.get = f2fs_xattr_get_acl,
+	.set = f2fs_xattr_set_acl,
+};
diff --git a/fs/f2fs/acl.h b/fs/f2fs/acl.h
new file mode 100644
index 00000000000..80f43067441
--- /dev/null
+++ b/fs/f2fs/acl.h
@@ -0,0 +1,57 @@
+/*
+ * fs/f2fs/acl.h
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * Portions of this code from linux/fs/ext2/acl.h
+ *
+ * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
+ *
+ * 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.
+ */
+#ifndef __F2FS_ACL_H__
+#define __F2FS_ACL_H__
+
+#include <linux/posix_acl_xattr.h>
+
+#define F2FS_ACL_VERSION	0x0001
+
+struct f2fs_acl_entry {
+	__le16 e_tag;
+	__le16 e_perm;
+	__le32 e_id;
+};
+
+struct f2fs_acl_entry_short {
+	__le16 e_tag;
+	__le16 e_perm;
+};
+
+struct f2fs_acl_header {
+	__le32 a_version;
+};
+
+#ifdef CONFIG_F2FS_FS_POSIX_ACL
+
+extern struct posix_acl *f2fs_get_acl(struct inode *inode, int type);
+extern int f2fs_acl_chmod(struct inode *inode);
+extern int f2fs_init_acl(struct inode *inode, struct inode *dir);
+#else
+#define f2fs_check_acl	NULL
+#define f2fs_get_acl	NULL
+#define f2fs_set_acl	NULL
+
+static inline int f2fs_acl_chmod(struct inode *inode)
+{
+	return 0;
+}
+
+static inline int f2fs_init_acl(struct inode *inode, struct inode *dir)
+{
+	return 0;
+}
+#endif
+#endif /* __F2FS_ACL_H__ */
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
new file mode 100644
index 00000000000..6ef36c37e2b
--- /dev/null
+++ b/fs/f2fs/checkpoint.c
@@ -0,0 +1,794 @@
+/*
+ * fs/f2fs/checkpoint.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.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.
+ */
+#include <linux/fs.h>
+#include <linux/bio.h>
+#include <linux/mpage.h>
+#include <linux/writeback.h>
+#include <linux/blkdev.h>
+#include <linux/f2fs_fs.h>
+#include <linux/pagevec.h>
+#include <linux/swap.h>
+
+#include "f2fs.h"
+#include "node.h"
+#include "segment.h"
+
+static struct kmem_cache *orphan_entry_slab;
+static struct kmem_cache *inode_entry_slab;
+
+/*
+ * We guarantee no failure on the returned page.
+ */
+struct page *grab_meta_page(struct f2fs_sb_info *sbi, pgoff_t index)
+{
+	struct address_space *mapping = sbi->meta_inode->i_mapping;
+	struct page *page = NULL;
+repeat:
+	page = grab_cache_page(mapping, index);
+	if (!page) {
+		cond_resched();
+		goto repeat;
+	}
+
+	/* We wait writeback only inside grab_meta_page() */
+	wait_on_page_writeback(page);
+	SetPageUptodate(page);
+	return page;
+}
+
+/*
+ * We guarantee no failure on the returned page.
+ */
+struct page *get_meta_page(struct f2fs_sb_info *sbi, pgoff_t index)
+{
+	struct address_space *mapping = sbi->meta_inode->i_mapping;
+	struct page *page;
+repeat:
+	page = grab_cache_page(mapping, index);
+	if (!page) {
+		cond_resched();
+		goto repeat;
+	}
+	if (f2fs_readpage(sbi, page, index, READ_SYNC)) {
+		f2fs_put_page(page, 1);
+		goto repeat;
+	}
+	mark_page_accessed(page);
+
+	/* We do not allow returning an errorneous page */
+	return page;
+}
+
+static int f2fs_write_meta_page(struct page *page,
+				struct writeback_control *wbc)
+{
+	struct inode *inode = page->mapping->host;
+	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
+	int err;
+
+	wait_on_page_writeback(page);
+
+	err = write_meta_page(sbi, page, wbc);
+	if (err) {
+		wbc->pages_skipped++;
+		set_page_dirty(page);
+	}
+
+	dec_page_count(sbi, F2FS_DIRTY_META);
+
+	/* In this case, we should not unlock this page */
+	if (err != AOP_WRITEPAGE_ACTIVATE)
+		unlock_page(page);
+	return err;
+}
+
+static int f2fs_write_meta_pages(struct address_space *mapping,
+				struct writeback_control *wbc)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(mapping->host->i_sb);
+	struct block_device *bdev = sbi->sb->s_bdev;
+	long written;
+
+	if (wbc->for_kupdate)
+		return 0;
+
+	if (get_pages(sbi, F2FS_DIRTY_META) == 0)
+		return 0;
+
+	/* if mounting is failed, skip writing node pages */
+	mutex_lock(&sbi->cp_mutex);
+	written = sync_meta_pages(sbi, META, bio_get_nr_vecs(bdev));
+	mutex_unlock(&sbi->cp_mutex);
+	wbc->nr_to_write -= written;
+	return 0;
+}
+
+long sync_meta_pages(struct f2fs_sb_info *sbi, enum page_type type,
+						long nr_to_write)
+{
+	struct address_space *mapping = sbi->meta_inode->i_mapping;
+	pgoff_t index = 0, end = LONG_MAX;
+	struct pagevec pvec;
+	long nwritten = 0;
+	struct writeback_control wbc = {
+		.for_reclaim = 0,
+	};
+
+	pagevec_init(&pvec, 0);
+
+	while (index <= end) {
+		int i, nr_pages;
+		nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
+				PAGECACHE_TAG_DIRTY,
+				min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
+		if (nr_pages == 0)
+			break;
+
+		for (i = 0; i < nr_pages; i++) {
+			struct page *page = pvec.pages[i];
+			lock_page(page);
+			BUG_ON(page->mapping != mapping);
+			BUG_ON(!PageDirty(page));
+			clear_page_dirty_for_io(page);
+			f2fs_write_meta_page(page, &wbc);
+			if (nwritten++ >= nr_to_write)
+				break;
+		}
+		pagevec_release(&pvec);
+		cond_resched();
+	}
+
+	if (nwritten)
+		f2fs_submit_bio(sbi, type, nr_to_write == LONG_MAX);
+
+	return nwritten;
+}
+
+static int f2fs_set_meta_page_dirty(struct page *page)
+{
+	struct address_space *mapping = page->mapping;
+	struct f2fs_sb_info *sbi = F2FS_SB(mapping->host->i_sb);
+
+	SetPageUptodate(page);
+	if (!PageDirty(page)) {
+		__set_page_dirty_nobuffers(page);
+		inc_page_count(sbi, F2FS_DIRTY_META);
+		F2FS_SET_SB_DIRT(sbi);
+		return 1;
+	}
+	return 0;
+}
+
+const struct address_space_operations f2fs_meta_aops = {
+	.writepage	= f2fs_write_meta_page,
+	.writepages	= f2fs_write_meta_pages,
+	.set_page_dirty	= f2fs_set_meta_page_dirty,
+};
+
+int check_orphan_space(struct f2fs_sb_info *sbi)
+{
+	unsigned int max_orphans;
+	int err = 0;
+
+	/*
+	 * considering 512 blocks in a segment 5 blocks are needed for cp
+	 * and log segment summaries. Remaining blocks are used to keep
+	 * orphan entries with the limitation one reserved segment
+	 * for cp pack we can have max 1020*507 orphan entries
+	 */
+	max_orphans = (sbi->blocks_per_seg - 5) * F2FS_ORPHANS_PER_BLOCK;
+	mutex_lock(&sbi->orphan_inode_mutex);
+	if (sbi->n_orphans >= max_orphans)
+		err = -ENOSPC;
+	mutex_unlock(&sbi->orphan_inode_mutex);
+	return err;
+}
+
+void add_orphan_inode(struct f2fs_sb_info *sbi, nid_t ino)
+{
+	struct list_head *head, *this;
+	struct orphan_inode_entry *new = NULL, *orphan = NULL;
+
+	mutex_lock(&sbi->orphan_inode_mutex);
+	head = &sbi->orphan_inode_list;
+	list_for_each(this, head) {
+		orphan = list_entry(this, struct orphan_inode_entry, list);
+		if (orphan->ino == ino)
+			goto out;
+		if (orphan->ino > ino)
+			break;
+		orphan = NULL;
+	}
+retry:
+	new = kmem_cache_alloc(orphan_entry_slab, GFP_ATOMIC);
+	if (!new) {
+		cond_resched();
+		goto retry;
+	}
+	new->ino = ino;
+	INIT_LIST_HEAD(&new->list);
+
+	/* add new_oentry into list which is sorted by inode number */
+	if (orphan) {
+		struct orphan_inode_entry *prev;
+
+		/* get previous entry */
+		prev = list_entry(orphan->list.prev, typeof(*prev), list);
+		if (&prev->list != head)
+			/* insert new orphan inode entry */
+			list_add(&new->list, &prev->list);
+		else
+			list_add(&new->list, head);
+	} else {
+		list_add_tail(&new->list, head);
+	}
+	sbi->n_orphans++;
+out:
+	mutex_unlock(&sbi->orphan_inode_mutex);
+}
+
+void remove_orphan_inode(struct f2fs_sb_info *sbi, nid_t ino)
+{
+	struct list_head *this, *next, *head;
+	struct orphan_inode_entry *orphan;
+
+	mutex_lock(&sbi->orphan_inode_mutex);
+	head = &sbi->orphan_inode_list;
+	list_for_each_safe(this, next, head) {
+		orphan = list_entry(this, struct orphan_inode_entry, list);
+		if (orphan->ino == ino) {
+			list_del(&orphan->list);
+			kmem_cache_free(orphan_entry_slab, orphan);
+			sbi->n_orphans--;
+			break;
+		}
+	}
+	mutex_unlock(&sbi->orphan_inode_mutex);
+}
+
+static void recover_orphan_inode(struct f2fs_sb_info *sbi, nid_t ino)
+{
+	struct inode *inode = f2fs_iget(sbi->sb, ino);
+	BUG_ON(IS_ERR(inode));
+	clear_nlink(inode);
+
+	/* truncate all the data during iput */
+	iput(inode);
+}
+
+int recover_orphan_inodes(struct f2fs_sb_info *sbi)
+{
+	block_t start_blk, orphan_blkaddr, i, j;
+
+	if (!is_set_ckpt_flags(F2FS_CKPT(sbi), CP_ORPHAN_PRESENT_FLAG))
+		return 0;
+
+	sbi->por_doing = 1;
+	start_blk = __start_cp_addr(sbi) + 1;
+	orphan_blkaddr = __start_sum_addr(sbi) - 1;
+
+	for (i = 0; i < orphan_blkaddr; i++) {
+		struct page *page = get_meta_page(sbi, start_blk + i);
+		struct f2fs_orphan_block *orphan_blk;
+
+		orphan_blk = (struct f2fs_orphan_block *)page_address(page);
+		for (j = 0; j < le32_to_cpu(orphan_blk->entry_count); j++) {
+			nid_t ino = le32_to_cpu(orphan_blk->ino[j]);
+			recover_orphan_inode(sbi, ino);
+		}
+		f2fs_put_page(page, 1);
+	}
+	/* clear Orphan Flag */
+	clear_ckpt_flags(F2FS_CKPT(sbi), CP_ORPHAN_PRESENT_FLAG);
+	sbi->por_doing = 0;
+	return 0;
+}
+
+static void write_orphan_inodes(struct f2fs_sb_info *sbi, block_t start_blk)
+{
+	struct list_head *head, *this, *next;
+	struct f2fs_orphan_block *orphan_blk = NULL;
+	struct page *page = NULL;
+	unsigned int nentries = 0;
+	unsigned short index = 1;
+	unsigned short orphan_blocks;
+
+	orphan_blocks = (unsigned short)((sbi->n_orphans +
+		(F2FS_ORPHANS_PER_BLOCK - 1)) / F2FS_ORPHANS_PER_BLOCK);
+
+	mutex_lock(&sbi->orphan_inode_mutex);
+	head = &sbi->orphan_inode_list;
+
+	/* loop for each orphan inode entry and write them in Jornal block */
+	list_for_each_safe(this, next, head) {
+		struct orphan_inode_entry *orphan;
+
+		orphan = list_entry(this, struct orphan_inode_entry, list);
+
+		if (nentries == F2FS_ORPHANS_PER_BLOCK) {
+			/*
+			 * an orphan block is full of 1020 entries,
+			 * then we need to flush current orphan blocks
+			 * and bring another one in memory
+			 */
+			orphan_blk->blk_addr = cpu_to_le16(index);
+			orphan_blk->blk_count = cpu_to_le16(orphan_blocks);
+			orphan_blk->entry_count = cpu_to_le32(nentries);
+			set_page_dirty(page);
+			f2fs_put_page(page, 1);
+			index++;
+			start_blk++;
+			nentries = 0;
+			page = NULL;
+		}
+		if (page)
+			goto page_exist;
+
+		page = grab_meta_page(sbi, start_blk);
+		orphan_blk = (struct f2fs_orphan_block *)page_address(page);
+		memset(orphan_blk, 0, sizeof(*orphan_blk));
+page_exist:
+		orphan_blk->ino[nentries++] = cpu_to_le32(orphan->ino);
+	}
+	if (!page)
+		goto end;
+
+	orphan_blk->blk_addr = cpu_to_le16(index);
+	orphan_blk->blk_count = cpu_to_le16(orphan_blocks);
+	orphan_blk->entry_count = cpu_to_le32(nentries);
+	set_page_dirty(page);
+	f2fs_put_page(page, 1);
+end:
+	mutex_unlock(&sbi->orphan_inode_mutex);
+}
+
+static struct page *validate_checkpoint(struct f2fs_sb_info *sbi,
+				block_t cp_addr, unsigned long long *version)
+{
+	struct page *cp_page_1, *cp_page_2 = NULL;
+	unsigned long blk_size = sbi->blocksize;
+	struct f2fs_checkpoint *cp_block;
+	unsigned long long cur_version = 0, pre_version = 0;
+	unsigned int crc = 0;
+	size_t crc_offset;
+
+	/* Read the 1st cp block in this CP pack */
+	cp_page_1 = get_meta_page(sbi, cp_addr);
+
+	/* get the version number */
+	cp_block = (struct f2fs_checkpoint *)page_address(cp_page_1);
+	crc_offset = le32_to_cpu(cp_block->checksum_offset);
+	if (crc_offset >= blk_size)
+		goto invalid_cp1;
+
+	crc = *(unsigned int *)((unsigned char *)cp_block + crc_offset);
+	if (!f2fs_crc_valid(crc, cp_block, crc_offset))
+		goto invalid_cp1;
+
+	pre_version = le64_to_cpu(cp_block->checkpoin