Commit 34088780 authored by Chris Mason's avatar Chris Mason Committed by David Woodhouse

Btrfs: i386 fixes from axboe

Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent 6cbd5570
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
......@@ -106,7 +106,7 @@ struct buffer_head *btrfs_find_create_tree_block(struct btrfs_root *root,
int err;
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)
return NULL;
......
......@@ -112,7 +112,7 @@ static int dirty_and_release_pages(struct btrfs_trans_handle *trans,
if (buffer_mapped(bh) && bh->b_blocknr == 0) {
struct btrfs_key key;
struct btrfs_path *path;
char *ptr;
char *ptr, *kaddr;
u32 datasize;
/* 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_FILE_EXTENT_INLINE);
ptr = btrfs_file_extent_inline_start(ei);
kaddr = kmap_atomic(bh->b_page, KM_USER0);
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]);
btrfs_free_path(path);
} else if (buffer_mapped(bh)) {
......
......@@ -1754,6 +1754,7 @@ static int create_subvol(struct btrfs_root *root, char *name, int namelen)
BTRFS_I(dir)->block_group, S_IFDIR | 0700);
inode->i_op = &btrfs_dir_inode_operations;
inode->i_fop = &btrfs_dir_file_operations;
new_root->inode = inode;
ret = btrfs_make_empty_dir(trans, new_root, new_dirid, new_dirid);
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);
BUG_ON(ret);
iput(inode);
mutex_unlock(&root->fs_info->fs_mutex);
btrfs_btree_balance_dirty(root);
return 0;
......
......@@ -18,6 +18,7 @@
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/sched.h>
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment