Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable

fs/Kconfig

@@ -268,6 +268,25 @@ config OCFS2_COMPAT_JBD
 	  is backwards compatible with JBD.  It is safe to say N here.
 	  However, if you really want to use the original JBD, say Y here.
 
+config BTRFS_FS
+	tristate "Btrfs filesystem (EXPERIMENTAL) Unstable disk format"
+	depends on EXPERIMENTAL
+	select LIBCRC32C
+	select ZLIB_INFLATE
+	select ZLIB_DEFLATE
+	help
+	  Btrfs is a new filesystem with extents, writable snapshotting,
+	  support for multiple devices and many more features.
+
+	  Btrfs is highly experimental, and THE DISK FORMAT IS NOT YET
+	  FINALIZED.  You should say N here unless you are interested in
+	  testing Btrfs with non-critical data.
+
+	  To compile this file system support as a module, choose M here. The
+	  module will be called btrfs.
+
+	  If unsure, say N.
+
 endif # BLOCK
 
 config DNOTIFY

fs/Makefile

@@ -121,4 +121,5 @@ obj-$(CONFIG_HOSTFS)		+= hostfs/
 obj-$(CONFIG_HPPFS)		+= hppfs/
 obj-$(CONFIG_DEBUG_FS)		+= debugfs/
 obj-$(CONFIG_OCFS2_FS)		+= ocfs2/
+obj-$(CONFIG_BTRFS_FS)		+= btrfs/
 obj-$(CONFIG_GFS2_FS)           += gfs2/

fs/btrfs/INSTALL

+Install Instructions
+
+Btrfs puts snapshots and subvolumes into the root directory of the FS.  This
+directory can only be changed by btrfsctl right now, and normal filesystem
+operations do not work on it.  The default subvolume is called 'default',
+and you can create files and directories in mount_point/default
+
+Btrfs uses libcrc32c in the kernel for file and metadata checksums.  You need
+to compile the kernel with:
+
+CONFIG_LIBCRC32C=m
+
+libcrc32c can be static as well.  Once your kernel is setup, typing make in the
+btrfs module sources will build against the running kernel.  When the build is
+complete:
+
+modprobe libcrc32c
+insmod btrfs.ko
+
+The Btrfs utility programs require libuuid to build.  This can be found
+in the e2fsprogs sources, and is usually available as libuuid or
+e2fsprogs-devel from various distros.
+
+Building the utilities is just make ; make install.  The programs go
+into /usr/local/bin.  The commands available are:
+
+mkfs.btrfs: create a filesystem
+
+btrfsctl: control program to create snapshots and subvolumes:
+
+	mount /dev/sda2 /mnt
+	btrfsctl -s new_subvol_name /mnt
+	btrfsctl -s snapshot_of_default /mnt/default
+	btrfsctl -s snapshot_of_new_subvol /mnt/new_subvol_name
+	btrfsctl -s snapshot_of_a_snapshot /mnt/snapshot_of_new_subvol
+	ls /mnt
+	default snapshot_of_a_snapshot snapshot_of_new_subvol
+	new_subvol_name snapshot_of_default
+
+	Snapshots and subvolumes cannot be deleted right now, but you can
+	rm -rf all the files and directories inside them.
+
+btrfsck: do a limited check of the FS extent trees.</li>
+
+debug-tree: print all of the FS metadata in text form.  Example:
+
+	debug-tree /dev/sda2 >& big_output_file
+

fs/btrfs/Makefile

+ifneq ($(KERNELRELEASE),)
+# kbuild part of makefile
+
+obj-$(CONFIG_BTRFS_FS) := btrfs.o
+btrfs-y := super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \
+	   file-item.o inode-item.o inode-map.o disk-io.o \
+	   transaction.o inode.o file.o tree-defrag.o \
+	   extent_map.o sysfs.o struct-funcs.o xattr.o ordered-data.o \
+	   extent_io.o volumes.o async-thread.o ioctl.o locking.o orphan.o \
+	   ref-cache.o export.o tree-log.o acl.o free-space-cache.o zlib.o \
+	   compression.o
+else
+
+# Normal Makefile
+
+KERNELDIR := /lib/modules/`uname -r`/build
+all:
+	$(MAKE) -C $(KERNELDIR) M=`pwd` CONFIG_BTRFS_FS=m modules
+
+modules_install:
+	$(MAKE) -C $(KERNELDIR) M=`pwd` modules_install
+clean:
+	$(MAKE) -C $(KERNELDIR) M=`pwd` clean
+
+endif

fs/btrfs/acl.c

+/*
+ * Copyright (C) 2007 Red Hat.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 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 021110-1307, USA.
+ */
+
+#include <linux/fs.h>
+#include <linux/string.h>
+#include <linux/xattr.h>
+#include <linux/posix_acl_xattr.h>
+#include <linux/posix_acl.h>
+#include <linux/sched.h>
+
+#include "ctree.h"
+#include "btrfs_inode.h"
+#include "xattr.h"
+
+#ifdef CONFIG_FS_POSIX_ACL
+
+static void btrfs_update_cached_acl(struct inode *inode,
+				    struct posix_acl **p_acl,
+				    struct posix_acl *acl)
+{
+	spin_lock(&inode->i_lock);
+	if (*p_acl && *p_acl != BTRFS_ACL_NOT_CACHED)
+		posix_acl_release(*p_acl);
+	*p_acl = posix_acl_dup(acl);
+	spin_unlock(&inode->i_lock);
+}
+
+static struct posix_acl *btrfs_get_acl(struct inode *inode, int type)
+{
+	int size;
+	const char *name;
+	char *value = NULL;
+	struct posix_acl *acl = NULL, **p_acl;
+
+	switch (type) {
+	case ACL_TYPE_ACCESS:
+		name = POSIX_ACL_XATTR_ACCESS;
+		p_acl = &BTRFS_I(inode)->i_acl;
+		break;
+	case ACL_TYPE_DEFAULT:
+		name = POSIX_ACL_XATTR_DEFAULT;
+		p_acl = &BTRFS_I(inode)->i_default_acl;
+		break;
+	default:
+		return ERR_PTR(-EINVAL);
+	}
+
+	spin_lock(&inode->i_lock);
+	if (*p_acl != BTRFS_ACL_NOT_CACHED)
+		acl = posix_acl_dup(*p_acl);
+	spin_unlock(&inode->i_lock);
+
+	if (acl)
+		return acl;
+
+
+	size = __btrfs_getxattr(inode, name, "", 0);
+	if (size > 0) {
+		value = kzalloc(size, GFP_NOFS);
+		if (!value)
+			return ERR_PTR(-ENOMEM);
+		size = __btrfs_getxattr(inode, name, value, size);
+		if (size > 0) {
+			acl = posix_acl_from_xattr(value, size);
+			btrfs_update_cached_acl(inode, p_acl, acl);
+		}
+		kfree(value);
+	} else if (size == -ENOENT) {
+		acl = NULL;
+		btrfs_update_cached_acl(inode, p_acl, acl);
+	}
+
+	return acl;
+}
+
+static int btrfs_xattr_get_acl(struct inode *inode, int type,
+			       void *value, size_t size)
+{
+	struct posix_acl *acl;
+	int ret = 0;
+
+	acl = btrfs_get_acl(inode, type);
+
+	if (IS_ERR(acl))
+		return PTR_ERR(acl);
+	if (acl == NULL)
+		return -ENODATA;
+	ret = posix_acl_to_xattr(acl, value, size);
+	posix_acl_release(acl);
+
+	return ret;
+}
+
+/*
+ * Needs to be called with fs_mutex held
+ */
+static int btrfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
+{
+	int ret, size = 0;
+	const char *name;
+	struct posix_acl **p_acl;
+	char *value = NULL;
+	mode_t mode;
+
+	if (acl) {
+		ret = posix_acl_valid(acl);
+		if (ret < 0)
+			return ret;
+		ret = 0;
+	}
+
+	switch (type) {
+	case ACL_TYPE_ACCESS:
+		mode = inode->i_mode;
+		ret = posix_acl_equiv_mode(acl, &mode);
+		if (ret < 0)
+			return ret;
+		ret = 0;
+		inode->i_mode = mode;
+		name = POSIX_ACL_XATTR_ACCESS;
+		p_acl = &BTRFS_I(inode)->i_acl;
+		break;
+	case ACL_TYPE_DEFAULT:
+		if (!S_ISDIR(inode->i_mode))
+			return acl ? -EINVAL : 0;
+		name = POSIX_ACL_XATTR_DEFAULT;
+		p_acl = &BTRFS_I(inode)->i_default_acl;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (acl) {
+		size = posix_acl_xattr_size(acl->a_count);
+		value = kmalloc(size, GFP_NOFS);
+		if (!value) {
+			ret = -ENOMEM;
+			goto out;
+		}
+
+		ret = posix_acl_to_xattr(acl, value, size);
+		if (ret < 0)
+			goto out;
+	}
+
+	ret = __btrfs_setxattr(inode, name, value, size, 0);
+
+out:
+	if (value)
+		kfree(value);
+
+	if (!ret)
+		btrfs_update_cached_acl(inode, p_acl, acl);
+
+	return ret;
+}
+
+static int btrfs_xattr_set_acl(struct inode *inode, int type,
+			       const void *value, size_t size)
+{
+	int ret = 0;
+	struct posix_acl *acl = NULL;
+
+	if (value) {
+		acl = posix_acl_from_xattr(value, size);
+		if (acl == NULL) {
+			value = NULL;
+			size = 0;
+		} else if (IS_ERR(acl)) {
+			return PTR_ERR(acl);
+		}
+	}
+
+	ret = btrfs_set_acl(inode, acl, type);
+
+	posix_acl_release(acl);
+
+	return ret;
+}
+
+
+static int btrfs_xattr_acl_access_get(struct inode *inode, const char *name,
+				      void *value, size_t size)
+{
+	return btrfs_xattr_get_acl(inode, ACL_TYPE_ACCESS, value, size);
+}
+
+static int btrfs_xattr_acl_access_set(struct inode *inode, const char *name,
+				      const void *value, size_t size, int flags)
+{
+	return btrfs_xattr_set_acl(inode, ACL_TYPE_ACCESS, value, size);
+}
+
+static int btrfs_xattr_acl_default_get(struct inode *inode, const char *name,
+				       void *value, size_t size)
+{
+	return btrfs_xattr_get_acl(inode, ACL_TYPE_DEFAULT, value, size);
+}
+
+static int btrfs_xattr_acl_default_set(struct inode *inode, const char *name,
+				       const void *value, size_t size, int flags)
+{
+	return btrfs_xattr_set_acl(inode, ACL_TYPE_DEFAULT, value, size);
+}
+
+int btrfs_check_acl(struct inode *inode, int mask)
+{
+	struct posix_acl *acl;
+	int error = -EAGAIN;
+
+	acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS);
+
+	if (IS_ERR(acl))
+		return PTR_ERR(acl);
+	if (acl) {
+		error = posix_acl_permission(inode, acl, mask);
+		posix_acl_release(acl);
+	}
+
+	return error;
+}
+
+/*
+ * btrfs_init_acl is already generally called under fs_mutex, so the locking
+ * stuff has been fixed to work with that.  If the locking stuff changes, we
+ * need to re-evaluate the acl locking stuff.
+ */
+int btrfs_init_acl(struct inode *inode, struct inode *dir)
+{
+	struct posix_acl *acl = NULL;
+	int ret = 0;
+
+	/* this happens with subvols */
+	if (!dir)
+		return 0;
+
+	if (!S_ISLNK(inode->i_mode)) {
+		if (IS_POSIXACL(dir)) {
+			acl = btrfs_get_acl(dir, ACL_TYPE_DEFAULT);
+			if (IS_ERR(acl))
+				return PTR_ERR(acl);
+		}
+
+		if (!acl)
+			inode->i_mode &= ~current->fs->umask;
+	}
+
+	if (IS_POSIXACL(dir) && acl) {
+		struct posix_acl *clone;
+		mode_t mode;
+
+		if (S_ISDIR(inode->i_mode)) {
+			ret = btrfs_set_acl(inode, acl, ACL_TYPE_DEFAULT);
+			if (ret)
+				goto failed;
+		}
+		clone = posix_acl_clone(acl, GFP_NOFS);
+		ret = -ENOMEM;
+		if (!clone)
+			goto failed;
+
+		mode = inode->i_mode;
+		ret = posix_acl_create_masq(clone, &mode);
+		if (ret >= 0) {
+			inode->i_mode = mode;
+			if (ret > 0) {
+				/* we need an acl */
+				ret = btrfs_set_acl(inode, clone,
+						    ACL_TYPE_ACCESS);
+			}
+		}
+	}
+failed:
+	posix_acl_release(acl);
+
+	return ret;
+}
+
+int btrfs_acl_chmod(struct inode *inode)
+{
+	struct posix_acl *acl, *clone;
+	int ret = 0;
+
+	if (S_ISLNK(inode->i_mode))
+		return -EOPNOTSUPP;
+
+	if (!IS_POSIXACL(inode))
+		return 0;
+
+	acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS);
+	if (IS_ERR(acl) || !acl)
+		return PTR_ERR(acl);
+
+	clone = posix_acl_clone(acl, GFP_KERNEL);
+	posix_acl_release(acl);
+	if (!clone)
+		return -ENOMEM;
+
+	ret = posix_acl_chmod_masq(clone, inode->i_mode);
+	if (!ret)
+		ret = btrfs_set_acl(inode, clone, ACL_TYPE_ACCESS);
+
+	posix_acl_release(clone);
+
+	return ret;
+}
+
+struct xattr_handler btrfs_xattr_acl_default_handler = {
+	.prefix = POSIX_ACL_XATTR_DEFAULT,
+	.get	= btrfs_xattr_acl_default_get,
+	.set	= btrfs_xattr_acl_default_set,
+};
+
+struct xattr_handler btrfs_xattr_acl_access_handler = {
+	.prefix = POSIX_ACL_XATTR_ACCESS,
+	.get	= btrfs_xattr_acl_access_get,
+	.set	= btrfs_xattr_acl_access_set,
+};
+
+#else /* CONFIG_FS_POSIX_ACL */
+
+int btrfs_acl_chmod(struct inode *inode)
+{
+	return 0;
+}
+
+int btrfs_init_acl(struct inode *inode, struct inode *dir)
+{
+	return 0;
+}
+
+int btrfs_check_acl(struct inode *inode, int mask)
+{
+	return 0;
+}
+
+#endif /* CONFIG_FS_POSIX_ACL */

fs/btrfs/async-thread.h

+/*
+ * Copyright (C) 2007 Oracle.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 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 021110-1307, USA.
+ */
+
+#ifndef __BTRFS_ASYNC_THREAD_
+#define __BTRFS_ASYNC_THREAD_
+
+struct btrfs_worker_thread;
+
+/*
+ * This is similar to a workqueue, but it is meant to spread the operations
+ * across all available cpus instead of just the CPU that was used to
+ * queue the work.  There is also some batching introduced to try and
+ * cut down on context switches.
+ *
+ * By default threads are added on demand up to 2 * the number of cpus.
+ * Changing struct btrfs_workers->max_workers is one way to prevent
+ * demand creation of kthreads.
+ *
+ * the basic model of these worker threads is to embed a btrfs_work
+ * structure in your own data struct, and use container_of in a
+ * work function to get back to your data struct.
+ */
+struct btrfs_work {
+	/*
+	 * func should be set to the function you want called
+	 * your work struct is passed as the only arg
+	 *
+	 * ordered_func must be set for work sent to an ordered work queue,
+	 * and it is called to complete a given work item in the same
+	 * order they were sent to the queue.
+	 */
+	void (*func)(struct btrfs_work *work);
+	void (*ordered_func)(struct btrfs_work *work);
+	void (*ordered_free)(struct btrfs_work *work);
+
+	/*
+	 * flags should be set to zero.  It is used to make sure the
+	 * struct is only inserted once into the list.
+	 */
+	unsigned long flags;
+
+	/* don't touch these */
+	struct btrfs_worker_thread *worker;
+	struct list_head list;
+	struct list_head order_list;
+};
+
+struct btrfs_workers {
+	/* current number of running workers */
+	int num_workers;
+
+	/* max number of workers allowed.  changed by btrfs_start_workers */
+	int max_workers;
+
+	/* once a worker has this many requests or fewer, it is idle */
+	int idle_thresh;
+
+	/* force completions in the order they were queued */
+	int ordered;
+
+	/* list with all the work threads.  The workers on the idle thread
+	 * may be actively servicing jobs, but they haven't yet hit the
+	 * idle thresh limit above.
+	 */
+	struct list_head worker_list;
+	struct list_head idle_list;
+
+	/*
+	 * when operating in ordered mode, this maintains the list
+	 * of work items waiting for completion
+	 */
+	struct list_head order_list;
+
+	/* lock for finding the next worker thread to queue on */
+	spinlock_t lock;
+
+	/* extra name for this worker, used for current->name */
+	char *name;
+};
+
+int btrfs_queue_worker(struct btrfs_workers *workers, struct btrfs_work *work);
+int btrfs_start_workers(struct btrfs_workers *workers, int num_workers);
+int btrfs_stop_workers(struct btrfs_workers *workers);
+void btrfs_init_workers(struct btrfs_workers *workers, char *name, int max);
+int btrfs_requeue_work(struct btrfs_work *work);
+#endif

fs/btrfs/btrfs_inode.h

+/*
+ * Copyright (C) 2007 Oracle.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 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 021110-1307, USA.
+ */
+
+#ifndef __BTRFS_I__
+#define __BTRFS_I__
+
+#include "extent_map.h"
+#include "extent_io.h"
+#include "ordered-data.h"
+
+/* in memory btrfs inode */
+struct btrfs_inode {
+	/* which subvolume this inode belongs to */
+	struct btrfs_root *root;
+
+	/* the block group preferred for allocations.  This pointer is buggy
+	 * and needs to be replaced with a bytenr instead
+	 */
+	struct btrfs_block_group_cache *block_group;
+
+	/* key used to find this inode on disk.  This is used by the code
+	 * to read in roots of subvolumes
+	 */
+	struct btrfs_key location;
+
+	/* the extent_tree has caches of all the extent mappings to disk */
+	struct extent_map_tree extent_tree;
+
+	/* the io_tree does range state (DIRTY, LOCKED etc) */
+	struct extent_io_tree io_tree;
+
+	/* special utility tree used to record which mirrors have already been
+	 * tried when checksums fail for a given block
+	 */
+	struct extent_io_tree io_failure_tree;
+
+	/* held while inserting checksums to avoid races */
+	struct mutex csum_mutex;
+
+	/* held while inesrting or deleting extents from files */
+	struct mutex extent_mutex;
+
+	/* held while logging the inode in tree-log.c */
+	struct mutex log_mutex;
+
+	/* used to order data wrt metadata */
+	struct btrfs_ordered_inode_tree ordered_tree;
+
+	/* standard acl pointers */
+	struct posix_acl *i_acl;
+	struct posix_acl *i_default_acl;
+
+	/* for keeping track of orphaned inodes */
+	struct list_head i_orphan;
+
+	/* list of all the delalloc inodes in the FS.  There are times we need
+	 * to write all the delalloc pages to disk, and this list is used
+	 * to walk them all.
+	 */
+	struct list_head delalloc_inodes;
+
+	/* full 64 bit generation number, struct vfs_inode doesn't have a big
+	 * enough field for this.
+	 */
+	u64 generation;
+
+	/*
+	 * transid of the trans_handle that last modified this inode
+	 */
+	u64 last_trans;
+	/*
+	 * transid that last logged this inode
+	 */
+	u64 logged_trans;
+
+	/*
+	 * trans that last made a change that should be fully fsync'd.  This
+	 * gets reset to zero each time the inode is logged
+	 */
+	u64 log_dirty_trans;
+
+	/* total number of bytes pending delalloc, used by stat to calc the
+	 * real block usage of the file
+	 */
+	u64 delalloc_bytes;
+
+	/*
+	 * the size of the file stored in the metadata on disk.  data=ordered
+	 * means the in-memory i_size might be larger than the size on disk
+	 * because not all the blocks are written yet.
+	 */
+	u64 disk_i_size;
+
+	/* flags field from the on disk inode */
+	u32 flags;
+
+	/*
+	 * if this is a directory then index_cnt is the counter for the index
+	 * number for new files that are created
+	 */
+	u64 index_cnt;
+
+	struct inode vfs_inode;
+};
+
+static inline struct btrfs_inode *BTRFS_I(struct inode *inode)
+{
+	return container_of(inode, struct btrfs_inode, vfs_inode);
+}
+
+static inline void btrfs_i_size_write(struct inode *inode, u64 size)
+{
+	inode->i_size = size;
+	BTRFS_I(inode)->disk_i_size = size;
+}
+
+
+#endif

fs/btrfs/compat.h

+#ifndef _COMPAT_H_
+#define _COMPAT_H_
+
+#define btrfs_drop_nlink(inode) drop_nlink(inode)
+#define btrfs_inc_nlink(inode)	inc_nlink(inode)
+
+#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,27)
+static inline struct dentry *d_obtain_alias(struct inode *inode)
+{
+	struct dentry *d;
+
+	if (!inode)
+		return NULL;
+	if (IS_ERR(inode))
+		return ERR_CAST(inode);
+
+	d = d_alloc_anon(inode);
+	if (!d)
+		iput(inode);
+	return d;
+}
+#endif
+
+#endif /* _COMPAT_H_ */

fs/btrfs/compression.h

+/*
+ * Copyright (C) 2008 Oracle.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 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 021110-1307, USA.
+ */
+
+#ifndef __BTRFS_COMPRESSION_
+#define __BTRFS_COMPRESSION_
+
+int btrfs_zlib_decompress(unsigned char *data_in,
+			  struct page *dest_page,
+			  unsigned long start_byte,
+			  size_t srclen, size_t destlen);
+int btrfs_zlib_compress_pages(struct address_space *mapping,
+			      u64 start, unsigned long len,
+			      struct page **pages,
+			      unsigned long nr_dest_pages,
+			      unsigned long *out_pages,
+			      unsigned long *total_in,
+			      unsigned long *total_out,
+			      unsigned long max_out);
+int btrfs_zlib_decompress_biovec(struct page **pages_in,
+			      u64 disk_start,
+			      struct bio_vec *bvec,
+			      int vcnt,
+			      size_t srclen);
+void btrfs_zlib_exit(void);
+int btrfs_submit_compressed_write(struct inode *inode, u64 start,
+				  unsigned long len, u64 disk_start,
+				  unsigned long compressed_len,
+				  struct page **compressed_pages,
+				  unsigned long nr_pages);
+int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
+				 int mirror_num, unsigned long bio_flags);
+#endif

fs/btrfs/crc32c.h

+/*
+ * Copyright (C) 2008 Oracle.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 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 021110-1307, USA.
+ */
+
+#ifndef __BTRFS_CRC32C__
+#define __BTRFS_CRC32C__
+#include <asm/byteorder.h>
+#include <linux/crc32c.h>
+#include <linux/version.h>
+
+/* #define CONFIG_BTRFS_HW_SUM 1 */
+
+#ifdef CONFIG_BTRFS_HW_SUM
+#ifdef CONFIG_X86
+/*
+ * Using hardware provided CRC32 instruction to accelerate the CRC32 disposal.
+ * CRC32C polynomial:0x1EDC6F41(BE)/0x82F63B78(LE)
+ * CRC32 is a new instruction in Intel SSE4.2, the reference can be found at:
+ * http://www.intel.com/products/processor/manuals/
+ * Intel(R) 64 and IA-32 Architectures Software Developer's Manual
+ * Volume 2A: Instruction Set Reference, A-M
+ */
+
+#include <asm/cpufeature.h>
+#include <asm/processor.h>
+
+#define X86_FEATURE_XMM4_2     (4*32+20) /* Streaming SIMD Extensions-4.2 */
+#define cpu_has_xmm4_2         boot_cpu_has(X86_FEATURE_XMM4_2)
+
+#ifdef CONFIG_X86_64
+#define REX_PRE	"0x48, "
+#define SCALE_F	8
+#else
+#define REX_PRE
+#define SCALE_F	4
+#endif
+
+static inline u32 btrfs_crc32c_le_hw_byte(u32 crc, unsigned char const *data,
+				   size_t length)
+{
+	while (length--) {
+		__asm__ __volatile__(
+			".byte 0xf2, 0xf, 0x38, 0xf0, 0xf1"
+			:"=S"(crc)
+			:"0"(crc), "c"(*data)
+		);
+		data++;
+	}
+
+	return crc;
+}
+
+static inline u32 __pure btrfs_crc32c_le_hw(u32 crc, unsigned char const *p,
+				     size_t len)
+{
+	unsigned int iquotient = len / SCALE_F;
+	unsigned int iremainder = len % SCALE_F;
+#ifdef CONFIG_X86_64
+	u64 *ptmp = (u64 *)p;
+#else
+	u32 *ptmp = (u32 *)p;
+#endif
+
+	while (iquotient--) {
+		__asm__ __volatile__(
+			".byte 0xf2, " REX_PRE "0xf, 0x38, 0xf1, 0xf1;"
+			:"=S"(crc)
+			:"0"(crc), "c"(*ptmp)
+		);
+		ptmp++;
+	}
+
+	if (iremainder)
+		crc = btrfs_crc32c_le_hw_byte(crc, (unsigned char *)ptmp,
+					      iremainder);
+
+	return crc;
+}
+#endif /* CONFIG_BTRFS_HW_SUM */
+
+static inline u32 __btrfs_crc32c(u32 crc, unsigned char const *address,
+				 size_t len)
+{
+#ifdef CONFIG_BTRFS_HW_SUM
+	if (cpu_has_xmm4_2)
+		return btrfs_crc32c_le_hw(crc, address, len);
+#endif
+	return crc32c_le(crc, address, len);
+}
+
+#else
+
+#define __btrfs_crc32c(seed, data, length) crc32c(seed, data, length)
+
+#endif /* CONFIG_X86 */
+
+/**
+ * implementation of crc32c_le() changed in linux-2.6.23,
+ * has of v0.13 btrfs-progs is using the latest version.
+ * We must workaround older implementations of crc32c_le()
+ * found on older kernel versions.
+ */
+#define btrfs_crc32c(seed, data, length) \
+	__btrfs_crc32c(seed, (unsigned char const *)data, length)
+#endif
+

fs/btrfs/disk-io.h

+/*
+ * Copyright (C) 2007 Oracle.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 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 021110-1307, USA.
+ */
+
+#ifndef __DISKIO__
+#define __DISKIO__
+
+#define BTRFS_SUPER_INFO_OFFSET (16 * 1024)
+#define BTRFS_SUPER_INFO_SIZE 4096
+struct btrfs_device;
+struct btrfs_fs_devices;
+
+struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
+				      u32 blocksize, u64 parent_transid);
+int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
+			 u64 parent_transid);
+struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
+						   u64 bytenr, u32 blocksize);
+int clean_tree_block(struct btrfs_trans_handle *trans,
+		     struct btrfs_root *root, struct extent_buffer *buf);
+struct btrfs_root *open_ctree(struct super_block *sb,
+			      struct btrfs_fs_devices *fs_devices,
+			      char *options);
+int close_ctree(struct btrfs_root *root);
+int write_ctree_super(struct btrfs_trans_handle *trans,
+		      struct btrfs_root *root);
+int btrfs_commit_super(struct btrfs_root *root);
+struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
+					    u64 bytenr, u32 blocksize);
+struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
+					u64 root_objectid);
+struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
+				      struct btrfs_key *location,
+				      const char *name, int namelen);
+struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
+					       struct btrfs_key *location);
+struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
+					      struct btrfs_key *location);
+int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info);
+int btrfs_insert_dev_radix(struct btrfs_root *root,
+			   struct block_device *bdev,
+			   u64 device_id,
+			   u64 block_start,
+			   u64 num_blocks);
+void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr);
+int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root);
+void btrfs_mark_buffer_dirty(struct extent_buffer *buf);
+int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid);
+int btrfs_set_buffer_uptodate(struct extent_buffer *buf);
+int wait_on_tree_block_writeback(struct btrfs_root *root,
+				 struct extent_buffer *buf);
+int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid);
+u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len);
+void btrfs_csum_final(u32 crc, char *result);
+int btrfs_open_device(struct btrfs_device *dev);
+int btrfs_verify_block_csum(struct btrfs_root *root,
+			    struct extent_buffer *buf);
+int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
+			int metadata);
+int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
+			int rw, struct bio *bio, int mirror_num,
+			unsigned long bio_flags,
+			extent_submit_bio_hook_t *submit_bio_start,
+			extent_submit_bio_hook_t *submit_bio_done);
+
+int btrfs_congested_async(struct btrfs_fs_info *info, int iodone);
+unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info);
+int btrfs_write_tree_block(struct extent_buffer *buf);
+int btrfs_wait_tree_block_writeback(struct extent_buffer *buf);
+int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
+			     struct btrfs_fs_info *fs_info);
+int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
+			     struct btrfs_fs_info *fs_info);
+int btree_lock_page_hook(struct page *page);
+#endif

fs/btrfs/export.c

+#include <linux/fs.h>
+#include <linux/types.h>
+#include "ctree.h"
+#include "disk-io.h"
+#include "btrfs_inode.h"
+#include "print-tree.h"
+#include "export.h"
+#include "compat.h"
+
+#define BTRFS_FID_SIZE_NON_CONNECTABLE		(offsetof(struct btrfs_fid, parent_objectid)/4)
+#define BTRFS_FID_SIZE_CONNECTABLE		(offsetof(struct btrfs_fid, parent_root_objectid)/4)
+#define BTRFS_FID_SIZE_CONNECTABLE_ROOT		(sizeof(struct btrfs_fid)/4)
+
+static int btrfs_encode_fh(struct dentry *dentry, u32 *fh, int *max_len,
+			   int connectable)
+{
+	struct btrfs_fid *fid = (struct btrfs_fid *)fh;
+	struct inode *inode = dentry->d_inode;
+	int len = *max_len;
+	int type;
+
+	if ((len < BTRFS_FID_SIZE_NON_CONNECTABLE) ||
+	    (connectable && len < BTRFS_FID_SIZE_CONNECTABLE))
+		return 255;
+
+	len  = BTRFS_FID_SIZE_NON_CONNECTABLE;
+	type = FILEID_BTRFS_WITHOUT_PARENT;
+
+	fid->objectid = BTRFS_I(inode)->location.objectid;
+	fid->root_objectid = BTRFS_I(inode)->root->objectid;
+	fid->gen = inode->i_generation;
+
+	if (connectable && !S_ISDIR(inode->i_mode)) {
+		struct inode *parent;
+		u64 parent_root_id;
+
+		spin_lock(&dentry->d_lock);
+
+		parent = dentry->d_parent->d_inode;
+		fid->parent_objectid = BTRFS_I(parent)->location.objectid;
+		fid->parent_gen = parent->i_generation;
+		parent_root_id = BTRFS_I(parent)->root->objectid;
+
+		spin_unlock(&dentry->d_lock);
+
+		if (parent_root_id != fid->root_objectid) {
+			fid->parent_root_objectid = parent_root_id;
+			len = BTRFS_FID_SIZE_CONNECTABLE_ROOT;
+			type = FILEID_BTRFS_WITH_PARENT_ROOT;
+		} else {
+			len = BTRFS_FID_SIZE_CONNECTABLE;
+			type = FILEID_BTRFS_WITH_PARENT;
+		}
+	}
+
+	*max_len = len;
+	return type;
+}
+
+static struct dentry *btrfs_get_dentry(struct super_block *sb, u64 objectid,
+				       u64 root_objectid, u32 generation)
+{
+	struct btrfs_root *root;
+	struct inode *inode;
+	struct btrfs_key key;
+
+	key.objectid = root_objectid;
+	btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
+	key.offset = (u64)-1;
+
+	root = btrfs_read_fs_root_no_name(btrfs_sb(sb)->fs_info, &key);
+	if (IS_ERR(root))
+		return ERR_CAST(root);
+
+	key.objectid = objectid;
+	btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
+	key.offset = 0;
+
+	inode = btrfs_iget(sb, &key, root, NULL);
+	if (IS_ERR(inode))
+		return (void *)inode;
+
+	if (generation != inode->i_generation) {
+		iput(inode);
+		return ERR_PTR(-ESTALE);
+	}
+
+	return d_obtain_alias(inode);
+}
+
+static struct dentry *btrfs_fh_to_parent(struct super_block *sb, struct fid *fh,
+					 int fh_len, int fh_type)
+{
+	struct btrfs_fid *fid = (struct btrfs_fid *) fh;
+	u64 objectid, root_objectid;
+	u32 generation;
+
+	if (fh_type == FILEID_BTRFS_WITH_PARENT) {
+		if (fh_len !=  BTRFS_FID_SIZE_CONNECTABLE)
+			return NULL;
+		root_objectid = fid->root_objectid;
+	} else if (fh_type == FILEID_BTRFS_WITH_PARENT_ROOT) {
+		if (fh_len != BTRFS_FID_SIZE_CONNECTABLE_ROOT)
+			return NULL;
+		root_objectid = fid->parent_root_objectid;
+	} else
+		return NULL;
+
+	objectid = fid->parent_objectid;
+	generation = fid->parent_gen;
+
+	return btrfs_get_dentry(sb, objectid, root_objectid, generation);
+}
+
+static struct dentry *btrfs_fh_to_dentry(struct super_block *sb, struct fid *fh,
+					 int fh_len, int fh_type)
+{
+	struct btrfs_fid *fid = (struct btrfs_fid *) fh;
+	u64 objectid, root_objectid;
+	u32 generation;
+
+	if ((fh_type != FILEID_BTRFS_WITH_PARENT ||
+	     fh_len != BTRFS_FID_SIZE_CONNECTABLE) &&
+	    (fh_type != FILEID_BTRFS_WITH_PARENT_ROOT ||
+	     fh_len != BTRFS_FID_SIZE_CONNECTABLE_ROOT) &&
+	    (fh_type != FILEID_BTRFS_WITHOUT_PARENT ||
+	     fh_len != BTRFS_FID_SIZE_NON_CONNECTABLE))
+		return NULL;
+
+	objectid = fid->objectid;
+	root_objectid = fid->root_objectid;
+	generation = fid->gen;
+
+	return btrfs_get_dentry(sb, objectid, root_objectid, generation);
+}
+
+static struct dentry *btrfs_get_parent(struct dentry *child)
+{
+	struct inode *dir = child->d_inode;
+	struct btrfs_root *root = BTRFS_I(dir)->root;
+	struct btrfs_key key;
+	struct btrfs_path *path;
+	struct extent_buffer *leaf;
+	int slot;
+	u64 objectid;
+	int ret;
+
+	path = btrfs_alloc_path();
+
+	key.objectid = dir->i_ino;
+	btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
+	key.offset = (u64)-1;
+
+	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+	if (ret < 0) {
+		/* Error */
+		btrfs_free_path(path);
+		return ERR_PTR(ret);
+	}
+	leaf = path->nodes[0];
+	slot = path->slots[0];
+	if (ret) {
+		/* btrfs_search_slot() returns the slot where we'd want to
+		   insert a backref for parent inode #0xFFFFFFFFFFFFFFFF.
+		   The _real_ backref, telling us what the parent inode
+		   _actually_ is, will be in the slot _before_ the one
+		   that btrfs_search_slot() returns. */
+		if (!slot) {
+			/* Unless there is _no_ key in the tree before... */
+			btrfs_free_path(path);
+			return ERR_PTR(-EIO);
+		}
+		slot--;
+	}
+
+	btrfs_item_key_to_cpu(leaf, &key, slot);
+	btrfs_free_path(path);
+
+	if (key.objectid != dir->i_ino || key.type != BTRFS_INODE_REF_KEY)
+		return ERR_PTR(-EINVAL);
+
+	objectid = key.offset;
+
+	/* If we are already at the root of a subvol, return the real root */
+	if (objectid == dir->i_ino)
+		return dget(dir->i_sb->s_root);
+
+	/* Build a new key for the inode item */
+	key.objectid = objectid;
+	btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
+	key.offset = 0;
+
+	return d_obtain_alias(btrfs_iget(root->fs_info->sb, &key, root, NULL));
+}
+
+const struct export_operations btrfs_export_ops = {
+	.encode_fh	= btrfs_encode_fh,
+	.fh_to_dentry	= btrfs_fh_to_dentry,
+	.fh_to_parent	= btrfs_fh_to_parent,
+	.get_parent	= btrfs_get_parent,
+};

fs/btrfs/version.h

+#ifndef __BTRFS_VERSION_H
+#define __BTRFS_VERSION_H
+#define BTRFS_BUILD_VERSION "Btrfs"
+#endif