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grub/fs/xfs.c
Vladimir 'phcoder' Serbinenko 2d49abe9e7 merge mainline into asprintf
2010-01-20 07:36:17 +01:00

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/* xfs.c - XFS. */
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2005,2006,2007,2008,2009 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/>.
*/
#include <grub/err.h>
#include <grub/file.h>
#include <grub/mm.h>
#include <grub/misc.h>
#include <grub/disk.h>
#include <grub/dl.h>
#include <grub/types.h>
#include <grub/fshelp.h>
#define XFS_INODE_EXTENTS 9
#define XFS_INODE_FORMAT_INO 1
#define XFS_INODE_FORMAT_EXT 2
#define XFS_INODE_FORMAT_BTREE 3
struct grub_xfs_sblock
{
grub_uint8_t magic[4];
grub_uint32_t bsize;
grub_uint8_t unused1[24];
grub_uint16_t uuid[8];
grub_uint8_t unused2[8];
grub_uint64_t rootino;
grub_uint8_t unused3[20];
grub_uint32_t agsize;
grub_uint8_t unused4[20];
grub_uint8_t label[12];
grub_uint8_t log2_bsize;
grub_uint8_t log2_sect;
grub_uint8_t log2_inode;
grub_uint8_t log2_inop;
grub_uint8_t log2_agblk;
grub_uint8_t unused6[67];
grub_uint8_t log2_dirblk;
} __attribute__ ((packed));
struct grub_xfs_dir_header
{
grub_uint8_t count;
grub_uint8_t smallino;
union
{
grub_uint32_t i4;
grub_uint64_t i8;
} parent __attribute__ ((packed));
} __attribute__ ((packed));
struct grub_xfs_dir_entry
{
grub_uint8_t len;
grub_uint16_t offset;
char name[1];
/* Inode number follows, 32 bits. */
} __attribute__ ((packed));
struct grub_xfs_dir2_entry
{
grub_uint64_t inode;
grub_uint8_t len;
} __attribute__ ((packed));
typedef grub_uint32_t grub_xfs_extent[4];
struct grub_xfs_btree_node
{
grub_uint8_t magic[4];
grub_uint16_t level;
grub_uint16_t numrecs;
grub_uint64_t left;
grub_uint64_t right;
grub_uint64_t keys[1];
} __attribute__ ((packed));
struct grub_xfs_btree_root
{
grub_uint16_t level;
grub_uint16_t numrecs;
grub_uint64_t keys[1];
} __attribute__ ((packed));
struct grub_xfs_inode
{
grub_uint8_t magic[2];
grub_uint16_t mode;
grub_uint8_t version;
grub_uint8_t format;
grub_uint8_t unused2[50];
grub_uint64_t size;
grub_uint64_t nblocks;
grub_uint32_t extsize;
grub_uint32_t nextents;
grub_uint8_t unused3[20];
union
{
char raw[156];
struct dir
{
struct grub_xfs_dir_header dirhead;
struct grub_xfs_dir_entry direntry[1];
} dir;
grub_xfs_extent extents[XFS_INODE_EXTENTS];
struct grub_xfs_btree_root btree;
} data __attribute__ ((packed));
} __attribute__ ((packed));
struct grub_xfs_dirblock_tail
{
grub_uint32_t leaf_count;
grub_uint32_t leaf_stale;
} __attribute__ ((packed));
struct grub_fshelp_node
{
struct grub_xfs_data *data;
grub_uint64_t ino;
int inode_read;
struct grub_xfs_inode inode;
};
struct grub_xfs_data
{
struct grub_xfs_sblock sblock;
grub_disk_t disk;
int pos;
int bsize;
int agsize;
struct grub_fshelp_node diropen;
};
static grub_dl_t my_mod;
/* Filetype information as used in inodes. */
#define FILETYPE_INO_MASK 0170000
#define FILETYPE_INO_REG 0100000
#define FILETYPE_INO_DIRECTORY 0040000
#define FILETYPE_INO_SYMLINK 0120000
#define GRUB_XFS_INO_AGBITS(data) \
((data)->sblock.log2_agblk + (data)->sblock.log2_inop)
#define GRUB_XFS_INO_INOINAG(data, ino) \
(grub_be_to_cpu64 (ino) & ((1LL << GRUB_XFS_INO_AGBITS (data)) - 1))
#define GRUB_XFS_INO_AG(data,ino) \
(grub_be_to_cpu64 (ino) >> GRUB_XFS_INO_AGBITS (data))
#define GRUB_XFS_FSB_TO_BLOCK(data, fsb) \
(((fsb) >> (data)->sblock.log2_agblk) * (data)->agsize \
+ ((fsb) & ((1LL << (data)->sblock.log2_agblk) - 1)))
#define GRUB_XFS_EXTENT_OFFSET(exts,ex) \
((grub_be_to_cpu32 (exts[ex][0]) & ~(1 << 31)) << 23 \
| grub_be_to_cpu32 (exts[ex][1]) >> 9)
#define GRUB_XFS_EXTENT_BLOCK(exts,ex) \
((grub_uint64_t) (grub_be_to_cpu32 (exts[ex][1]) \
& (0x1ff)) << 43 \
| (grub_uint64_t) grub_be_to_cpu32 (exts[ex][2]) << 11 \
| grub_be_to_cpu32 (exts[ex][3]) >> 21)
#define GRUB_XFS_EXTENT_SIZE(exts,ex) \
(grub_be_to_cpu32 (exts[ex][3]) & ((1 << 20) - 1))
#define GRUB_XFS_ROUND_TO_DIRENT(pos) ((((pos) + 8 - 1) / 8) * 8)
#define GRUB_XFS_NEXT_DIRENT(pos,len) \
(pos) + GRUB_XFS_ROUND_TO_DIRENT (8 + 1 + len + 2)
static inline grub_uint64_t
grub_xfs_inode_block (struct grub_xfs_data *data,
grub_uint64_t ino)
{
long long int inoinag = GRUB_XFS_INO_INOINAG (data, ino);
long long ag = GRUB_XFS_INO_AG (data, ino);
long long block;
block = (inoinag >> data->sblock.log2_inop) + ag * data->agsize;
block <<= (data->sblock.log2_bsize - GRUB_DISK_SECTOR_BITS);
return block;
}
static inline int
grub_xfs_inode_offset (struct grub_xfs_data *data,
grub_uint64_t ino)
{
int inoag = GRUB_XFS_INO_INOINAG (data, ino);
return ((inoag & ((1 << data->sblock.log2_inop) - 1)) <<
data->sblock.log2_inode);
}
static grub_err_t
grub_xfs_read_inode (struct grub_xfs_data *data, grub_uint64_t ino,
struct grub_xfs_inode *inode)
{
grub_uint64_t block = grub_xfs_inode_block (data, ino);
int offset = grub_xfs_inode_offset (data, ino);
/* Read the inode. */
if (grub_disk_read (data->disk, block, offset,
1 << data->sblock.log2_inode, inode))
return grub_errno;
if (grub_strncmp ((char *) inode->magic, "IN", 2))
return grub_error (GRUB_ERR_BAD_FS, "not a correct XFS inode");
return 0;
}
static grub_disk_addr_t
grub_xfs_read_block (grub_fshelp_node_t node, grub_disk_addr_t fileblock)
{
struct grub_xfs_btree_node *leaf = 0;
int ex, nrec;
grub_xfs_extent *exts;
grub_uint64_t ret = 0;
if (node->inode.format == XFS_INODE_FORMAT_BTREE)
{
grub_uint64_t *keys;
leaf = grub_malloc (node->data->sblock.bsize);
if (leaf == 0)
return 0;
nrec = grub_be_to_cpu16 (node->inode.data.btree.numrecs);
keys = &node->inode.data.btree.keys[0];
do
{
int i;
for (i = 0; i < nrec; i++)
{
if (fileblock < grub_be_to_cpu64 (keys[i]))
break;
}
/* Sparse block. */
if (i == 0)
{
grub_free (leaf);
return 0;
}
if (grub_disk_read (node->data->disk,
grub_be_to_cpu64 (keys[i - 1 + nrec])
<< (node->data->sblock.log2_bsize
- GRUB_DISK_SECTOR_BITS),
0, node->data->sblock.bsize, leaf))
return 0;
if (grub_strncmp ((char *) leaf->magic, "BMAP", 4))
{
grub_free (leaf);
grub_error (GRUB_ERR_BAD_FS, "not a correct XFS BMAP node");
return 0;
}
nrec = grub_be_to_cpu16 (leaf->numrecs);
keys = &leaf->keys[0];
} while (leaf->level);
exts = (grub_xfs_extent *) keys;
}
else if (node->inode.format == XFS_INODE_FORMAT_EXT)
{
nrec = grub_be_to_cpu32 (node->inode.nextents);
exts = &node->inode.data.extents[0];
}
else
{
grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
"XFS does not support inode format %d yet",
node->inode.format);
return 0;
}
/* Iterate over each extent to figure out which extent has
the block we are looking for. */
for (ex = 0; ex < nrec; ex++)
{
grub_uint64_t start = GRUB_XFS_EXTENT_BLOCK (exts, ex);
grub_uint64_t offset = GRUB_XFS_EXTENT_OFFSET (exts, ex);
grub_uint64_t size = GRUB_XFS_EXTENT_SIZE (exts, ex);
/* Sparse block. */
if (fileblock < offset)
break;
else if (fileblock < offset + size)
{
ret = (fileblock - offset + start);
break;
}
}
if (leaf)
grub_free (leaf);
return GRUB_XFS_FSB_TO_BLOCK(node->data, ret);
}
/* Read LEN bytes from the file described by DATA starting with byte
POS. Return the amount of read bytes in READ. */
static grub_ssize_t
grub_xfs_read_file (grub_fshelp_node_t node,
void NESTED_FUNC_ATTR (*read_hook) (grub_disk_addr_t sector,
unsigned offset, unsigned length),
int pos, grub_size_t len, char *buf)
{
return grub_fshelp_read_file (node->data->disk, node, read_hook,
pos, len, buf, grub_xfs_read_block,
grub_be_to_cpu64 (node->inode.size),
node->data->sblock.log2_bsize
- GRUB_DISK_SECTOR_BITS);
}
static char *
grub_xfs_read_symlink (grub_fshelp_node_t node)
{
int size = grub_be_to_cpu64 (node->inode.size);
switch (node->inode.format)
{
case XFS_INODE_FORMAT_INO:
return grub_strndup (node->inode.data.raw, size);
case XFS_INODE_FORMAT_EXT:
{
char *symlink;
grub_ssize_t numread;
symlink = grub_malloc (size + 1);
if (!symlink)
return 0;
numread = grub_xfs_read_file (node, 0, 0, size, symlink);
if (numread != size)
{
grub_free (symlink);
return 0;
}
symlink[size] = '\0';
return symlink;
}
}
return 0;
}
static enum grub_fshelp_filetype
grub_xfs_mode_to_filetype (grub_uint16_t mode)
{
if ((grub_be_to_cpu16 (mode)
& FILETYPE_INO_MASK) == FILETYPE_INO_DIRECTORY)
return GRUB_FSHELP_DIR;
else if ((grub_be_to_cpu16 (mode)
& FILETYPE_INO_MASK) == FILETYPE_INO_SYMLINK)
return GRUB_FSHELP_SYMLINK;
else if ((grub_be_to_cpu16 (mode)
& FILETYPE_INO_MASK) == FILETYPE_INO_REG)
return GRUB_FSHELP_REG;
return GRUB_FSHELP_UNKNOWN;
}
static int
grub_xfs_iterate_dir (grub_fshelp_node_t dir,
int NESTED_FUNC_ATTR
(*hook) (const char *filename,
enum grub_fshelp_filetype filetype,
grub_fshelp_node_t node))
{
struct grub_fshelp_node *diro = (struct grub_fshelp_node *) dir;
auto int NESTED_FUNC_ATTR call_hook (grub_uint64_t ino, char *filename);
int NESTED_FUNC_ATTR call_hook (grub_uint64_t ino, char *filename)
{
struct grub_fshelp_node *fdiro;
fdiro = grub_malloc (sizeof (struct grub_fshelp_node)
- sizeof (struct grub_xfs_inode)
+ (1 << diro->data->sblock.log2_inode));
if (!fdiro)
return 0;
/* The inode should be read, otherwise the filetype can
not be determined. */
fdiro->ino = ino;
fdiro->inode_read = 1;
fdiro->data = diro->data;
grub_xfs_read_inode (diro->data, ino, &fdiro->inode);
return hook (filename,
grub_xfs_mode_to_filetype (fdiro->inode.mode),
fdiro);
}
switch (diro->inode.format)
{
case XFS_INODE_FORMAT_INO:
{
struct grub_xfs_dir_entry *de = &diro->inode.data.dir.direntry[0];
int smallino = !diro->inode.data.dir.dirhead.smallino;
int i;
grub_uint64_t parent;
/* If small inode numbers are used to pack the direntry, the
parent inode number is small too. */
if (smallino)
{
parent = grub_be_to_cpu32 (diro->inode.data.dir.dirhead.parent.i4);
parent = grub_cpu_to_be64 (parent);
/* The header is a bit smaller than usual. */
de = (struct grub_xfs_dir_entry *) ((char *) de - 4);
}
else
{
parent = diro->inode.data.dir.dirhead.parent.i8;
}
/* Synthesize the direntries for `.' and `..'. */
if (call_hook (diro->ino, "."))
return 1;
if (call_hook (parent, ".."))
return 1;
for (i = 0; i < diro->inode.data.dir.dirhead.count; i++)
{
grub_uint64_t ino;
void *inopos = (((char *) de)
+ sizeof (struct grub_xfs_dir_entry)
+ de->len - 1);
char name[de->len + 1];
if (smallino)
{
ino = grub_be_to_cpu32 (*(grub_uint32_t *) inopos);
ino = grub_cpu_to_be64 (ino);
}
else
ino = *(grub_uint64_t *) inopos;
grub_memcpy (name, de->name, de->len);
name[de->len] = '\0';
if (call_hook (ino, name))
return 1;
de = ((struct grub_xfs_dir_entry *)
(((char *) de)+ sizeof (struct grub_xfs_dir_entry) + de->len
+ ((smallino ? sizeof (grub_uint32_t)
: sizeof (grub_uint64_t))) - 1));
}
break;
}
case XFS_INODE_FORMAT_BTREE:
case XFS_INODE_FORMAT_EXT:
{
grub_ssize_t numread;
char *dirblock;
grub_uint64_t blk;
int dirblk_size, dirblk_log2;
dirblk_log2 = (dir->data->sblock.log2_bsize
+ dir->data->sblock.log2_dirblk);
dirblk_size = 1 << dirblk_log2;
dirblock = grub_malloc (dirblk_size);
if (! dirblock)
return 0;
/* Iterate over every block the directory has. */
for (blk = 0;
blk < (grub_be_to_cpu64 (dir->inode.size)
>> dirblk_log2);
blk++)
{
/* The header is skipped, the first direntry is stored
from byte 16. */
int pos = 16;
int entries;
int tail_start = (dirblk_size
- sizeof (struct grub_xfs_dirblock_tail));
struct grub_xfs_dirblock_tail *tail;
tail = (struct grub_xfs_dirblock_tail *) &dirblock[tail_start];
numread = grub_xfs_read_file (dir, 0,
blk << dirblk_log2,
dirblk_size, dirblock);
if (numread != dirblk_size)
return 0;
entries = (grub_be_to_cpu32 (tail->leaf_count)
- grub_be_to_cpu32 (tail->leaf_stale));
/* Iterate over all entries within this block. */
while (pos < (dirblk_size
- (int) sizeof (struct grub_xfs_dir2_entry)))
{
struct grub_xfs_dir2_entry *direntry;
grub_uint16_t *freetag;
char *filename;
direntry = (struct grub_xfs_dir2_entry *) &dirblock[pos];
freetag = (grub_uint16_t *) direntry;
if (*freetag == 0XFFFF)
{
grub_uint16_t *skip = (grub_uint16_t *) (freetag + 1);
/* This entry is not used, go to the next one. */
pos += grub_be_to_cpu16 (*skip);
continue;
}
filename = &dirblock[pos + sizeof (*direntry)];
/* The byte after the filename is for the tag, which
is not used by GRUB. So it can be overwritten. */
filename[direntry->len] = '\0';
if (call_hook (direntry->inode, filename))
{
grub_free (dirblock);
return 1;
}
/* Check if last direntry in this block is
reached. */
entries--;
if (!entries)
break;
/* Select the next directory entry. */
pos = GRUB_XFS_NEXT_DIRENT (pos, direntry->len);
pos = GRUB_XFS_ROUND_TO_DIRENT (pos);
}
}
grub_free (dirblock);
break;
}
default:
grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
"XFS does not support inode format %d yet",
diro->inode.format);
}
return 0;
}
static struct grub_xfs_data *
grub_xfs_mount (grub_disk_t disk)
{
struct grub_xfs_data *data = 0;
data = grub_zalloc (sizeof (struct grub_xfs_data));
if (!data)
return 0;
/* Read the superblock. */
if (grub_disk_read (disk, 0, 0,
sizeof (struct grub_xfs_sblock), &data->sblock))
goto fail;
if (grub_strncmp ((char *) (data->sblock.magic), "XFSB", 4))
{
grub_error (GRUB_ERR_BAD_FS, "not a XFS filesystem");
goto fail;
}
data = grub_realloc (data,
sizeof (struct grub_xfs_data)
- sizeof (struct grub_xfs_inode)
+ (1 << data->sblock.log2_inode));
if (! data)
goto fail;
data->diropen.data = data;
data->diropen.ino = data->sblock.rootino;
data->diropen.inode_read = 1;
data->bsize = grub_be_to_cpu32 (data->sblock.bsize);
data->agsize = grub_be_to_cpu32 (data->sblock.agsize);
data->disk = disk;
data->pos = 0;
grub_xfs_read_inode (data, data->diropen.ino, &data->diropen.inode);
return data;
fail:
if (grub_errno == GRUB_ERR_OUT_OF_RANGE)
grub_error (GRUB_ERR_BAD_FS, "not an XFS filesystem");
grub_free (data);
return 0;
}
static grub_err_t
grub_xfs_dir (grub_device_t device, const char *path,
int (*hook) (const char *filename,
const struct grub_dirhook_info *info))
{
struct grub_xfs_data *data = 0;
struct grub_fshelp_node *fdiro = 0;
auto int NESTED_FUNC_ATTR iterate (const char *filename,
enum grub_fshelp_filetype filetype,
grub_fshelp_node_t node);
int NESTED_FUNC_ATTR iterate (const char *filename,
enum grub_fshelp_filetype filetype,
grub_fshelp_node_t node)
{
struct grub_dirhook_info info;
grub_memset (&info, 0, sizeof (info));
info.dir = ((filetype & GRUB_FSHELP_TYPE_MASK) == GRUB_FSHELP_DIR);
grub_free (node);
return hook (filename, &info);
}
grub_dl_ref (my_mod);
data = grub_xfs_mount (device->disk);
if (!data)
goto mount_fail;
grub_fshelp_find_file (path, &data->diropen, &fdiro, grub_xfs_iterate_dir,
grub_xfs_read_symlink, GRUB_FSHELP_DIR);
if (grub_errno)
goto fail;
grub_xfs_iterate_dir (fdiro, iterate);
fail:
if (fdiro != &data->diropen)
grub_free (fdiro);
grub_free (data);
mount_fail:
grub_dl_unref (my_mod);
return grub_errno;
}
/* Open a file named NAME and initialize FILE. */
static grub_err_t
grub_xfs_open (struct grub_file *file, const char *name)
{
struct grub_xfs_data *data;
struct grub_fshelp_node *fdiro = 0;
grub_dl_ref (my_mod);
data = grub_xfs_mount (file->device->disk);
if (!data)
goto mount_fail;
grub_fshelp_find_file (name, &data->diropen, &fdiro, grub_xfs_iterate_dir,
grub_xfs_read_symlink, GRUB_FSHELP_REG);
if (grub_errno)
goto fail;
if (!fdiro->inode_read)
{
grub_xfs_read_inode (data, fdiro->ino, &fdiro->inode);
if (grub_errno)
goto fail;
}
if (fdiro != &data->diropen)
grub_memcpy (&data->diropen, fdiro,
sizeof (struct grub_fshelp_node)
- sizeof (struct grub_xfs_inode)
+ (1 << data->sblock.log2_inode));
file->size = grub_be_to_cpu64 (data->diropen.inode.size);
file->data = data;
file->offset = 0;
return 0;
fail:
if (fdiro != &data->diropen)
grub_free (fdiro);
grub_free (data);
mount_fail:
grub_dl_unref (my_mod);
return grub_errno;
}
static grub_ssize_t
grub_xfs_read (grub_file_t file, char *buf, grub_size_t len)
{
struct grub_xfs_data *data =
(struct grub_xfs_data *) file->data;
return grub_xfs_read_file (&data->diropen, file->read_hook,
file->offset, len, buf);
}
static grub_err_t
grub_xfs_close (grub_file_t file)
{
grub_free (file->data);
grub_dl_unref (my_mod);
return GRUB_ERR_NONE;
}
static grub_err_t
grub_xfs_label (grub_device_t device, char **label)
{
struct grub_xfs_data *data;
grub_disk_t disk = device->disk;
grub_dl_ref (my_mod);
data = grub_xfs_mount (disk);
if (data)
*label = grub_strndup ((char *) (data->sblock.label), 12);
else
*label = 0;
grub_dl_unref (my_mod);
grub_free (data);
return grub_errno;
}
static grub_err_t
grub_xfs_uuid (grub_device_t device, char **uuid)
{
struct grub_xfs_data *data;
grub_disk_t disk = device->disk;
grub_dl_ref (my_mod);
data = grub_xfs_mount (disk);
if (data)
{
*uuid = grub_asprintf ("%04x%04x-%04x-%04x-%04x-%04x%04x%04x",
grub_be_to_cpu16 (data->sblock.uuid[0]),
grub_be_to_cpu16 (data->sblock.uuid[1]),
grub_be_to_cpu16 (data->sblock.uuid[2]),
grub_be_to_cpu16 (data->sblock.uuid[3]),
grub_be_to_cpu16 (data->sblock.uuid[4]),
grub_be_to_cpu16 (data->sblock.uuid[5]),
grub_be_to_cpu16 (data->sblock.uuid[6]),
grub_be_to_cpu16 (data->sblock.uuid[7]));
}
else
*uuid = NULL;
grub_dl_unref (my_mod);
grub_free (data);
return grub_errno;
}
static struct grub_fs grub_xfs_fs =
{
.name = "xfs",
.dir = grub_xfs_dir,
.open = grub_xfs_open,
.read = grub_xfs_read,
.close = grub_xfs_close,
.label = grub_xfs_label,
.uuid = grub_xfs_uuid,
.next = 0
};
GRUB_MOD_INIT(xfs)
{
grub_fs_register (&grub_xfs_fs);
my_mod = mod;
}
GRUB_MOD_FINI(xfs)
{
grub_fs_unregister (&grub_xfs_fs);
}
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