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Commit 34088780 authored by Chris Mason's avatar Chris Mason Committed by David Woodhouse
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Btrfs: i386 fixes from axboe

parent 6cbd5570
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fs/btrfs/INSTALL

0 → 100644
+51 −0
Original line number Original line Diff line number Diff line
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 the crypto manager interface in the kernel for file and
metadata checksums.  You need to compile the kernel with:

CONFIG_CRYPTO=y
CONFIG_CRYPTO_MANAGER=m
CONFIG_CRYPTO_CRC32C=m

cryptomanager and crc32c 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 crc32c
modprobe cryptomgr
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
+1 −1
Original line number Original line Diff line number Diff line
@@ -106,7 +106,7 @@ struct buffer_head *btrfs_find_create_tree_block(struct btrfs_root *root,
	int err;
	int err;
	u64 first_block = index << (PAGE_CACHE_SHIFT - blockbits);
	u64 first_block = index << (PAGE_CACHE_SHIFT - blockbits);


	page = grab_cache_page(mapping, index);
	page = find_or_create_page(mapping, index, GFP_NOFS);
	if (!page)
	if (!page)
		return NULL;
		return NULL;


+5 −2
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@@ -112,7 +112,7 @@ static int dirty_and_release_pages(struct btrfs_trans_handle *trans,
		if (buffer_mapped(bh) && bh->b_blocknr == 0) {
		if (buffer_mapped(bh) && bh->b_blocknr == 0) {
			struct btrfs_key key;
			struct btrfs_key key;
			struct btrfs_path *path;
			struct btrfs_path *path;
			char *ptr;
			char *ptr, *kaddr;
			u32 datasize;
			u32 datasize;


			/* create an inline extent, and copy the data in */
			/* create an inline extent, and copy the data in */
@@ -135,8 +135,11 @@ static int dirty_and_release_pages(struct btrfs_trans_handle *trans,
			btrfs_set_file_extent_type(ei,
			btrfs_set_file_extent_type(ei,
						   BTRFS_FILE_EXTENT_INLINE);
						   BTRFS_FILE_EXTENT_INLINE);
			ptr = btrfs_file_extent_inline_start(ei);
			ptr = btrfs_file_extent_inline_start(ei);
			kaddr = kmap_atomic(bh->b_page, KM_USER0);
			btrfs_memcpy(root, path->nodes[0]->b_data,
			btrfs_memcpy(root, path->nodes[0]->b_data,
				     ptr, bh->b_data, offset + write_bytes);
				     ptr, kaddr + bh_offset(bh),
				     offset + write_bytes);
			kunmap_atomic(kaddr, KM_USER0);
			mark_buffer_dirty(path->nodes[0]);
			mark_buffer_dirty(path->nodes[0]);
			btrfs_free_path(path);
			btrfs_free_path(path);
		} else if (buffer_mapped(bh)) {
		} else if (buffer_mapped(bh)) {
+1 −2
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@@ -1754,6 +1754,7 @@ static int create_subvol(struct btrfs_root *root, char *name, int namelen)
				BTRFS_I(dir)->block_group, S_IFDIR | 0700);
				BTRFS_I(dir)->block_group, S_IFDIR | 0700);
	inode->i_op = &btrfs_dir_inode_operations;
	inode->i_op = &btrfs_dir_inode_operations;
	inode->i_fop = &btrfs_dir_file_operations;
	inode->i_fop = &btrfs_dir_file_operations;
	new_root->inode = inode;


	ret = btrfs_make_empty_dir(trans, new_root, new_dirid, new_dirid);
	ret = btrfs_make_empty_dir(trans, new_root, new_dirid, new_dirid);
	BUG_ON(ret);
	BUG_ON(ret);
@@ -1766,8 +1767,6 @@ static int create_subvol(struct btrfs_root *root, char *name, int namelen)
	ret = btrfs_commit_transaction(trans, new_root);
	ret = btrfs_commit_transaction(trans, new_root);
	BUG_ON(ret);
	BUG_ON(ret);


	iput(inode);

	mutex_unlock(&root->fs_info->fs_mutex);
	mutex_unlock(&root->fs_info->fs_mutex);
	btrfs_btree_balance_dirty(root);
	btrfs_btree_balance_dirty(root);
	return 0;
	return 0;
+1 −0
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@@ -18,6 +18,7 @@


#include <linux/module.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/fs.h>
#include <linux/sched.h>
#include "ctree.h"
#include "ctree.h"
#include "disk-io.h"
#include "disk-io.h"
#include "transaction.h"
#include "transaction.h"