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Make / in btrfs refer to real root, not the default volume.

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Modify mkrelpath to work even if device is mounted with subvolid option.
This commit is contained in:
Vladimir Serbinenko 2013-10-28 01:37:19 +01:00
parent 11d81fc6d1
commit 82591fa6e7
6 changed files with 311 additions and 123 deletions
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9
ChangeLog
View file

@ -1,6 +1,11 @@
2013-10-14 Andrey Borzenkov <arvidjaar@gmail.com>
2013-10-28 Vladimir Serbinenko <phcoder@gmail.com>
* Makefile.util.def: Add grub-core/kern/disk_common.c to library
Make / in btrfs refer to real root, not the default volume.
Modify mkrelpath to work even if device is mounted with subvolid option.
2013-10-28 Andrey Borzenkov <arvidjaar@gmail.com>
* Makefile.util.def: Add grub-core/kern/disk_common.c to library
extra_dist.
* grub-core/Makefile.core.def: Add kern/disk_common.c to disk module
extra_dist.

122
grub-core/fs/btrfs.c
View file

@ -1,7 +1,7 @@
/* btrfs.c - B-tree file system. */
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2010 Free Software Foundation, Inc.
* Copyright (C) 2010,2011,2012,2013 Free Software Foundation, Inc.
*
* GRUB is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@ -28,6 +28,7 @@
#include <grub/deflate.h>
#include <minilzo.h>
#include <grub/i18n.h>
#include <grub/btrfs.h>
GRUB_MOD_LICENSE ("GPLv3+");
@ -106,24 +107,6 @@ struct grub_btrfs_data
struct grub_btrfs_extent_data *extent;
};
enum
{
GRUB_BTRFS_ITEM_TYPE_INODE_ITEM = 0x01,
GRUB_BTRFS_ITEM_TYPE_INODE_REF = 0x0c,
GRUB_BTRFS_ITEM_TYPE_DIR_ITEM = 0x54,
GRUB_BTRFS_ITEM_TYPE_EXTENT_ITEM = 0x6c,
GRUB_BTRFS_ITEM_TYPE_ROOT_ITEM = 0x84,
GRUB_BTRFS_ITEM_TYPE_DEVICE = 0xd8,
GRUB_BTRFS_ITEM_TYPE_CHUNK = 0xe4
};
struct grub_btrfs_key
{
grub_uint64_t object_id;
grub_uint8_t type;
grub_uint64_t offset;
} __attribute__ ((packed));
struct grub_btrfs_chunk_item
{
grub_uint64_t size;
@ -188,13 +171,6 @@ struct grub_btrfs_leaf_descriptor
} *data;
};
struct grub_btrfs_root_item
{
grub_uint8_t dummy[0xb0];
grub_uint64_t tree;
grub_uint64_t inode;
};
struct grub_btrfs_time
{
grub_int64_t sec;
@ -1196,6 +1172,40 @@ grub_btrfs_extent_read (struct grub_btrfs_data *data,
return pos - pos0;
}
static grub_err_t
get_root (struct grub_btrfs_data *data, struct grub_btrfs_key *key,
grub_uint64_t *tree, grub_uint8_t *type)
{
grub_err_t err;
grub_disk_addr_t elemaddr;
grub_size_t elemsize;
struct grub_btrfs_key key_out, key_in;
struct grub_btrfs_root_item ri;
key_in.object_id = GRUB_BTRFS_ROOT_VOL_OBJECTID;
key_in.offset = 0;
key_in.type = GRUB_BTRFS_ITEM_TYPE_ROOT_ITEM;
err = lower_bound (data, &key_in, &key_out,
data->sblock.root_tree,
&elemaddr, &elemsize, NULL, 0);
if (err)
return err;
if (key_in.object_id != key_out.object_id
|| key_in.type != key_out.type
|| key_in.offset != key_out.offset)
return grub_error (GRUB_ERR_BAD_FS, "no root");
err = grub_btrfs_read_logical (data, elemaddr, &ri,
sizeof (ri), 0);
if (err)
return err;
key->type = GRUB_BTRFS_ITEM_TYPE_DIR_ITEM;
key->offset = 0;
key->object_id = grub_cpu_to_le64_compile_time (GRUB_BTRFS_OBJECT_ID_CHUNK);
*tree = ri.tree;
*type = GRUB_BTRFS_DIR_ITEM_TYPE_DIRECTORY;
return GRUB_ERR_NONE;
}
static grub_err_t
find_path (struct grub_btrfs_data *data,
const char *path, struct grub_btrfs_key *key,
@ -1208,42 +1218,31 @@ find_path (struct grub_btrfs_data *data,
grub_size_t allocated = 0;
struct grub_btrfs_dir_item *direl = NULL;
struct grub_btrfs_key key_out;
int skip_default;
const char *ctoken;
grub_size_t ctokenlen;
char *path_alloc = NULL;
char *origpath = NULL;
unsigned symlinks_max = 32;
*type = GRUB_BTRFS_DIR_ITEM_TYPE_DIRECTORY;
*tree = data->sblock.root_tree;
key->object_id = data->sblock.root_dir_objectid;
key->type = GRUB_BTRFS_ITEM_TYPE_DIR_ITEM;
key->offset = 0;
skip_default = 1;
err = get_root (data, key, tree, type);
if (err)
return err;
origpath = grub_strdup (path);
if (!origpath)
return grub_errno;
while (1)
{
if (!skip_default)
{
while (path[0] == '/')
path++;
if (!path[0])
break;
slash = grub_strchr (path, '/');
if (!slash)
slash = path + grub_strlen (path);
ctoken = path;
ctokenlen = slash - path;
}
else
{
ctoken = "default";
ctokenlen = sizeof ("default") - 1;
}
while (path[0] == '/')
path++;
if (!path[0])
break;
slash = grub_strchr (path, '/');
if (!slash)
slash = path + grub_strlen (path);
ctoken = path;
ctokenlen = slash - path;
if (*type != GRUB_BTRFS_DIR_ITEM_TYPE_DIRECTORY)
{
@ -1254,10 +1253,8 @@ find_path (struct grub_btrfs_data *data,
if (ctokenlen == 1 && ctoken[0] == '.')
{
if (!skip_default)
path = slash;
skip_default = 0;
continue;
path = slash;
continue;
}
if (ctokenlen == 2 && ctoken[0] == '.' && ctoken[1] == '.')
{
@ -1287,9 +1284,7 @@ find_path (struct grub_btrfs_data *data,
*type = GRUB_BTRFS_DIR_ITEM_TYPE_DIRECTORY;
key->object_id = key_out.offset;
if (!skip_default)
path = slash;
skip_default = 0;
path = slash;
continue;
}
@ -1359,9 +1354,7 @@ find_path (struct grub_btrfs_data *data,
return err;
}
if (!skip_default)
path = slash;
skip_default = 0;
path = slash;
if (cdirel->type == GRUB_BTRFS_DIR_ITEM_TYPE_SYMLINK)
{
struct grub_btrfs_inode inode;
@ -1411,12 +1404,9 @@ find_path (struct grub_btrfs_data *data,
path = path_alloc = tmp;
if (path[0] == '/')
{
*type = GRUB_BTRFS_DIR_ITEM_TYPE_DIRECTORY;
*tree = data->sblock.root_tree;
key->object_id = data->sblock.root_dir_objectid;
key->type = GRUB_BTRFS_ITEM_TYPE_DIR_ITEM;
key->offset = 0;
skip_default = 1;
err = get_root (data, key, tree, type);
if (err)
return err;
}
continue;
}

194
grub-core/osdep/linux/getroot.c
View file

@ -49,15 +49,18 @@
#include <sys/wait.h>
#include <btrfs/ioctl.h>
#include <linux/types.h>
#include <linux/major.h>
#include <linux/raid/md_p.h>
#include <linux/raid/md_u.h>
#include <grub/i18n.h>
#include <grub/emu/exec.h>
#include <grub/btrfs.h>
#define LVM_DEV_MAPPER_STRING "/dev/mapper/"
#if 0
/* Defines taken from btrfs/ioctl.h. */
struct btrfs_ioctl_dev_info_args
@ -82,7 +85,7 @@ struct btrfs_ioctl_fs_info_args
struct btrfs_ioctl_dev_info_args)
#define BTRFS_IOC_FS_INFO _IOR(0x94, 31, \
struct btrfs_ioctl_fs_info_args)
#endif
static int
grub_util_is_imsm (const char *os_dev);
@ -224,6 +227,117 @@ grub_find_root_devices_from_btrfs (const char *dir)
return ret;
}
static char *
get_btrfs_fs_prefix (const char *mount_path)
{
struct btrfs_ioctl_ino_lookup_args args;
struct stat st;
int fd;
grub_uint64_t tree_id, inode_id;
char *ret = NULL;
fd = open (mount_path, O_RDONLY);
if (fd < 0)
return NULL;
memset (&args, 0, sizeof(args));
args.objectid = GRUB_BTRFS_TREE_ROOT_OBJECTID;
if (ioctl (fd, BTRFS_IOC_INO_LOOKUP, &args) < 0)
return NULL;
tree_id = args.treeid;
if (fstat (fd, &st) < 0)
return NULL;
inode_id = st.st_ino;
while (tree_id != GRUB_BTRFS_ROOT_VOL_OBJECTID
|| inode_id != GRUB_BTRFS_TREE_ROOT_OBJECTID)
{
grub_uint64_t *nid;
const char *name;
size_t namelen;
struct btrfs_ioctl_search_args sargs;
char *old;
memset (&sargs, 0, sizeof(sargs));
if (inode_id == GRUB_BTRFS_TREE_ROOT_OBJECTID)
{
struct grub_btrfs_root_backref *br;
sargs.key.tree_id = 1;
sargs.key.min_objectid = tree_id;
sargs.key.max_objectid = tree_id;
sargs.key.min_offset = 0;
sargs.key.max_offset = ~0ULL;
sargs.key.min_transid = 0;
sargs.key.max_transid = ~0ULL;
sargs.key.min_type = GRUB_BTRFS_ITEM_TYPE_ROOT_BACKREF;
sargs.key.max_type = GRUB_BTRFS_ITEM_TYPE_ROOT_BACKREF;
sargs.key.nr_items = 1;
if (ioctl (fd, BTRFS_IOC_TREE_SEARCH, &sargs) < 0)
return NULL;
if (sargs.key.nr_items == 0)
return NULL;
nid = (grub_uint64_t *) (sargs.buf + 16);
tree_id = *nid;
br = (struct grub_btrfs_root_backref *) (sargs.buf + 32);
inode_id = br->inode_id;
name = br->name;
namelen = br->n;
}
else
{
struct grub_btrfs_inode_ref *ir;
sargs.key.tree_id = tree_id;
sargs.key.min_objectid = inode_id;
sargs.key.max_objectid = inode_id;
sargs.key.min_offset = 0;
sargs.key.max_offset = ~0ULL;
sargs.key.min_transid = 0;
sargs.key.max_transid = ~0ULL;
sargs.key.min_type = GRUB_BTRFS_ITEM_TYPE_INODE_REF;
sargs.key.max_type = GRUB_BTRFS_ITEM_TYPE_INODE_REF;
if (ioctl (fd, BTRFS_IOC_TREE_SEARCH, &sargs) < 0)
return NULL;
if (sargs.key.nr_items == 0)
return NULL;
nid = (grub_uint64_t *) (sargs.buf + 16);
inode_id = *nid;
ir = (struct grub_btrfs_inode_ref *) (sargs.buf + 32);
name = ir->name;
namelen = ir->n;
}
old = ret;
ret = xmalloc (namelen + (old ? strlen (old) : 0) + 2);
ret[0] = '/';
memcpy (ret + 1, name, namelen);
if (old)
{
strcpy (ret + 1 + namelen, old);
free (old);
}
else
ret[1+namelen] = '\0';
}
if (!ret)
return xstrdup ("/");
return ret;
}
char **
grub_find_root_devices_from_mountinfo (const char *dir, char **relroot)
{
@ -332,6 +446,7 @@ grub_find_root_devices_from_mountinfo (const char *dir, char **relroot)
for (i = entry_len - 1; i >= 0; i--)
{
char **ret = NULL;
char *fs_prefix = NULL;
if (!*entries[i].device)
continue;
@ -348,45 +463,52 @@ grub_find_root_devices_from_mountinfo (const char *dir, char **relroot)
if (relroot)
{
if (!slash)
*relroot = xasprintf ("/@%s", entries[i].enc_root);
fs_prefix = xasprintf ("/@%s", entries[i].enc_root);
else if (strchr (slash + 1, '@'))
*relroot = xasprintf ("/%s%s", slash + 1, entries[i].enc_root);
fs_prefix = xasprintf ("/%s%s", slash + 1, entries[i].enc_root);
else
*relroot = xasprintf ("/%s@%s", slash + 1, entries[i].enc_root);
fs_prefix = xasprintf ("/%s@%s", slash + 1,
entries[i].enc_root);
}
}
else if (grub_strcmp (entries[i].fstype, "btrfs") == 0)
{
ret = grub_find_root_devices_from_btrfs (dir);
if (relroot)
{
char *ptr;
*relroot = xmalloc (strlen (entries[i].enc_root) +
2 + strlen (dir));
ptr = grub_stpcpy (*relroot, entries[i].enc_root);
if (strlen (dir) > strlen (entries[i].enc_path))
{
while (ptr > *relroot && *(ptr - 1) == '/')
ptr--;
if (dir[strlen (entries[i].enc_path)] != '/')
*ptr++ = '/';
ptr = grub_stpcpy (ptr, dir + strlen (entries[i].enc_path));
}
*ptr = 0;
}
fs_prefix = get_btrfs_fs_prefix (entries[i].enc_path);
}
if (!ret)
{
ret = xmalloc (2 * sizeof (ret[0]));
ret[0] = strdup (entries[i].device);
ret[1] = 0;
if (relroot)
*relroot = strdup (entries[i].enc_root);
}
free (buf);
free (entries);
fclose (fp);
return ret;
if (!fs_prefix)
fs_prefix = entries[i].enc_root;
if (relroot)
{
char *ptr;
grub_size_t enc_root_len = strlen (fs_prefix);
grub_size_t enc_path_len = strlen (entries[i].enc_path);
grub_size_t dir_strlen = strlen (dir);
*relroot = xmalloc (enc_root_len +
2 + dir_strlen);
ptr = grub_stpcpy (*relroot, fs_prefix);
if (dir_strlen > enc_path_len)
{
while (ptr > *relroot && *(ptr - 1) == '/')
ptr--;
if (dir[enc_path_len] != '/')
*ptr++ = '/';
ptr = grub_stpcpy (ptr, dir + enc_path_len);
}
*ptr = 0;
}
if (fs_prefix != entries[i].enc_root)
free (fs_prefix);
free (buf);
free (entries);
fclose (fp);
return ret;
}
free (buf);
@ -913,3 +1035,23 @@ grub_util_get_grub_dev_os (const char *os_dev)
return grub_dev;
}
char *
grub_make_system_path_relative_to_its_root_os (const char *path)
{
char *bind = NULL;
grub_size_t len;
grub_free (grub_find_root_devices_from_mountinfo (path, &bind));
if (bind && bind[0])
{
len = strlen (bind);
while (len > 0 && bind[len - 1] == '/')
{
bind[len - 1] = '\0';
len--;
}
return bind;
}
grub_free (bind);
return NULL;
}

36
grub-core/osdep/unix/relpath.c
View file

@ -48,7 +48,13 @@ grub_make_system_path_relative_to_its_root (const char *path)
if (p == NULL)
grub_util_error (_("failed to get canonical path of `%s'"), path);
/* For ZFS sub-pool filesystems, could be extended to others (btrfs?). */
#ifdef __linux__
ret = grub_make_system_path_relative_to_its_root_os (p);
if (ret)
return ret;
#endif
/* For ZFS sub-pool filesystems. */
#ifndef __HAIKU__
{
char *dummy;
@ -98,18 +104,6 @@ grub_make_system_path_relative_to_its_root (const char *path)
if (offset == 0)
{
free (buf);
#ifdef __linux__
{
char *bind;
grub_free (grub_find_root_devices_from_mountinfo (buf2, &bind));
if (bind && bind[0] && bind[1])
{
buf3 = bind;
goto parsedir;
}
grub_free (bind);
}
#endif
free (buf2);
if (poolfs)
return xasprintf ("/%s/@", poolfs);
@ -131,25 +125,9 @@ grub_make_system_path_relative_to_its_root (const char *path)
free (buf);
buf3 = xstrdup (buf2 + offset);
buf2[offset] = 0;
#ifdef __linux__
{
char *bind;
grub_free (grub_find_root_devices_from_mountinfo (buf2, &bind));
if (bind && bind[0] && bind[1])
{
char *temp = buf3;
buf3 = grub_xasprintf ("%s%s%s", bind, buf3[0] == '/' ?"":"/", buf3);
grub_free (temp);
}
grub_free (bind);
}
#endif
free (buf2);
#ifdef __linux__
parsedir:
#endif
/* Remove trailing slashes, return empty string if root directory. */
len = strlen (buf3);
while (len > 0 && buf3[len - 1] == '/')

71
include/grub/btrfs.h Normal file
View file

@ -0,0 +1,71 @@
/* btrfs.c - B-tree file system. */
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2010,2011,2012,2013 Free Software Foundation, Inc.
*
* GRUB is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* GRUB 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 GRUB. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef GRUB_BTRFS_H
#define GRUB_BTRFS_H 1
enum
{
GRUB_BTRFS_ITEM_TYPE_INODE_ITEM = 0x01,
GRUB_BTRFS_ITEM_TYPE_INODE_REF = 0x0c,
GRUB_BTRFS_ITEM_TYPE_DIR_ITEM = 0x54,
GRUB_BTRFS_ITEM_TYPE_EXTENT_ITEM = 0x6c,
GRUB_BTRFS_ITEM_TYPE_ROOT_ITEM = 0x84,
GRUB_BTRFS_ITEM_TYPE_ROOT_BACKREF = 0x90,
GRUB_BTRFS_ITEM_TYPE_DEVICE = 0xd8,
GRUB_BTRFS_ITEM_TYPE_CHUNK = 0xe4
};
enum
{
GRUB_BTRFS_ROOT_VOL_OBJECTID = 5,
GRUB_BTRFS_TREE_ROOT_OBJECTID = 0x100,
};
struct grub_btrfs_root_item
{
grub_uint8_t dummy[0xb0];
grub_uint64_t tree;
grub_uint64_t inode;
};
struct grub_btrfs_key
{
grub_uint64_t object_id;
grub_uint8_t type;
grub_uint64_t offset;
} __attribute__ ((packed));
struct grub_btrfs_root_backref
{
grub_uint64_t inode_id;
grub_uint64_t seqnr;
grub_uint16_t n;
char name[0];
};
struct grub_btrfs_inode_ref
{
grub_uint64_t idxid;
grub_uint16_t n;
char name[0];
};
#endif

2
include/grub/emu/getroot.h
View file

@ -36,6 +36,8 @@ void grub_util_pull_device (const char *osname);
char **grub_guess_root_devices (const char *dir);
int grub_util_get_dev_abstraction (const char *os_dev);
char *grub_make_system_path_relative_to_its_root (const char *path);
char *
grub_make_system_path_relative_to_its_root_os (const char *path);
char *grub_util_get_grub_dev (const char *os_dev);
#if defined (__FreeBSD__) || defined(__FreeBSD_kernel__)
void grub_util_follow_gpart_up (const char *name, grub_disk_addr_t *off_out,