/*
* extent.c --- routines to implement extents support
*
* Copyright (C) 2007 Theodore Ts'o.
*
* %Begin-Header%
* This file may be redistributed under the terms of the GNU Library
* General Public License, version 2.
* %End-Header%
*/
#include <stdio.h>
#include <string.h>
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#if HAVE_ERRNO_H
#include <errno.h>
#endif
#if HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#if HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#include "ext2_fs.h"
#include "ext2fsP.h"
#include "e2image.h"
/*
* Definitions to be dropped in lib/ext2fs/ext2fs.h
*/
/*
* Private definitions
*/
struct extent_path {
char *buf;
int entries;
int max_entries;
int left;
int visit_num;
int flags;
blk64_t end_blk;
void *curr;
};
struct ext2_extent_handle {
errcode_t magic;
ext2_filsys fs;
ext2_ino_t ino;
struct ext2_inode *inode;
struct ext2_inode inodebuf;
int type;
int level;
int max_depth;
struct extent_path *path;
};
struct ext2_extent_path {
errcode_t magic;
int leaf_height;
blk64_t lblk;
};
/*
* Useful Debugging stuff
*/
#ifdef DEBUG
static void dbg_show_header(struct ext3_extent_header *eh)
{
printf("header: magic=%x entries=%u max=%u depth=%u generation=%u\n",
ext2fs_le16_to_cpu(eh->eh_magic),
ext2fs_le16_to_cpu(eh->eh_entries),
ext2fs_le16_to_cpu(eh->eh_max),
ext2fs_le16_to_cpu(eh->eh_depth),
ext2fs_le32_to_cpu(eh->eh_generation));
}
static void dbg_show_index(struct ext3_extent_idx *ix)
{
printf("index: block=%u leaf=%u leaf_hi=%u unused=%u\n",
ext2fs_le32_to_cpu(ix->ei_block),
ext2fs_le32_to_cpu(ix->ei_leaf),
ext2fs_le16_to_cpu(ix->ei_leaf_hi),
ext2fs_le16_to_cpu(ix->ei_unused));
}
static void dbg_show_extent(struct ext3_extent *ex)
{
printf("extent: block=%u-%u len=%u start=%u start_hi=%u\n",
ext2fs_le32_to_cpu(ex->ee_block),
ext2fs_le32_to_cpu(ex->ee_block) +
ext2fs_le16_to_cpu(ex->ee_len) - 1,
ext2fs_le16_to_cpu(ex->ee_len),
ext2fs_le32_to_cpu(ex->ee_start),
ext2fs_le16_to_cpu(ex->ee_start_hi));
}
static void dbg_print_extent(char *desc, struct ext2fs_extent *extent)
{
if (desc)
printf("%s: ", desc);
printf("extent: lblk %llu--%llu, len %u, pblk %llu, flags: ",
extent->e_lblk, extent->e_lblk + extent->e_len - 1,
extent->e_len, extent->e_pblk);
if (extent->e_flags & EXT2_EXTENT_FLAGS_LEAF)
fputs("LEAF ", stdout);
if (extent->e_flags & EXT2_EXTENT_FLAGS_UNINIT)
fputs("UNINIT ", stdout);
if (extent->e_flags & EXT2_EXTENT_FLAGS_SECOND_VISIT)
fputs("2ND_VISIT ", stdout);
if (!extent->e_flags)
fputs("(none)", stdout);
fputc('\n', stdout);
}
#else
#define dbg_show_header(eh) do { } while (0)
#define dbg_show_index(ix) do { } while (0)
#define dbg_show_extent(ex) do { } while (0)
#define dbg_print_extent(desc, ex) do { } while (0)
#endif
/*
* Verify the extent header as being sane
*/
errcode_t ext2fs_extent_header_verify(void *ptr, int size)
{
int eh_max, entry_size;
struct ext3_extent_header *eh = ptr;
dbg_show_header(eh);
if (ext2fs_le16_to_cpu(eh->eh_magic) != EXT3_EXT_MAGIC)
return EXT2_ET_EXTENT_HEADER_BAD;
if (ext2fs_le16_to_cpu(eh->eh_entries) > ext2fs_le16_to_cpu(eh->eh_max))
return EXT2_ET_EXTENT_HEADER_BAD;
if (eh->eh_depth == 0)
entry_size = sizeof(struct ext3_extent);
else
entry_size = sizeof(struct ext3_extent_idx);
eh_max = (size - sizeof(*eh)) / entry_size;
/* Allow two extent-sized items at the end of the block, for
* ext4_extent_tail with checksum in the future. */
if ((ext2fs_le16_to_cpu(eh->eh_max) > eh_max) ||
(ext2fs_le16_to_cpu(eh->eh_max) < (eh_max - 2)))
return EXT2_ET_EXTENT_HEADER_BAD;
return 0;
}
/*
* Begin functions to handle an inode's extent information
*/
void ext2fs_extent_free(ext2_extent_handle_t handle)
{
int i;
if (!handle)
return;
if (handle->path) {
for (i=1; i <= handle->max_depth; i++) {
if (handle->path[i].buf)
ext2fs_free_mem(&handle->path[i].buf);
}
ext2fs_free_mem(&handle->path);
}
ext2fs_free_mem(&handle);
}
errcode_t ext2fs_extent_open(ext2_filsys fs, ext2_ino_t ino,
ext2_extent_handle_t *ret_handle)
{
return ext2fs_extent_open2(fs, ino, NULL, ret_handle);
}
errcode_t ext2fs_extent_open2(ext2_filsys fs, ext2_ino_t ino,
struct ext2_inode *inode,
ext2_extent_handle_t *ret_handle)
{
struct ext2_extent_handle *handle;
errcode_t retval;
int i;
struct ext3_extent_header *eh;
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
if (!inode)
if ((ino == 0) || (ino > fs->super->s_inodes_count))
return EXT2_ET_BAD_INODE_NUM;
retval = ext2fs_get_mem(sizeof(struct ext2_extent_handle), &handle);
if (retval)
return retval;
memset(handle, 0, sizeof(struct ext2_extent_handle));
handle->ino = ino;
handle->fs = fs;
if (inode) {
handle->inode = inode;
} else {
handle->inode = &handle->inodebuf;
retval = ext2fs_read_inode(fs, ino, handle->inode);
if (retval)
goto errout;
}
eh = (struct ext3_extent_header *) &handle->inode->i_block[0];
for (i=0; i < EXT2_N_BLOCKS; i++)
if (handle->inode->i_block[i])
break;
if (i >= EXT2_N_BLOCKS) {
eh->eh_magic = ext2fs_cpu_to_le16(EXT3_EXT_MAGIC);
eh->eh_depth = 0;
eh->eh_entries = 0;
i = (sizeof(handle->inode->i_block) - sizeof(*eh)) /
sizeof(struct ext3_extent);
eh->eh_max = ext2fs_cpu_to_le16(i);
handle->inode->i_flags |= EXT4_EXTENTS_FL;
}
if (!(handle->inode->i_flags & EXT4_EXTENTS_FL)) {
retval = EXT2_ET_INODE_NOT_EXTENT;
goto errout;
}
retval = ext2fs_extent_header_verify(eh, sizeof(handle->inode->i_block));
if (retval)
goto errout;
handle->max_depth = ext2fs_le16_to_cpu(eh->eh_depth);
handle->type = ext2fs_le16_to_cpu(eh->eh_magic);
retval = ext2fs_get_mem(((handle->max_depth+1) *
sizeof(struct extent_path)),
&handle->path);
memset(handle->path, 0,
(handle->max_depth+1) * sizeof(struct extent_path));
handle->path[0].buf = (char *) handle->inode->i_block;
handle->path[0].left = handle->path[0].entries =
ext2fs_le16_to_cpu(eh->eh_entries);
handle->path[0].max_entries = ext2fs_le16_to_cpu(eh->eh_max);
handle->path[0].curr = 0;
handle->path[0].end_blk =
(EXT2_I_SIZE(handle->inode) + fs->blocksize - 1) >>
EXT2_BLOCK_SIZE_BITS(fs->super);
handle->path[0].visit_num = 1;
handle->level = 0;
handle->magic = EXT2_ET_MAGIC_EXTENT_HANDLE;
*ret_handle = handle;
return 0;
errout:
ext2fs_extent_free(handle);
return retval;
}
/*
* This function is responsible for (optionally) moving through the
* extent tree and then returning the current extent
*/
errcode_t ext2fs_extent_get(ext2_extent_handle_t handle,
int flags, struct ext2fs_extent *extent)
{
struct extent_path *path, *newpath;
struct ext3_extent_header *eh;
struct ext3_extent_idx *ix = 0;
struct ext3_extent *ex;
errcode_t retval;
blk64_t blk;
blk64_t end_blk;
int orig_op, op;
EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);
if (!handle->path)
return EXT2_ET_NO_CURRENT_NODE;
orig_op = op = flags & EXT2_EXTENT_MOVE_MASK;
retry:
path = handle->path + handle->level;
if ((orig_op == EXT2_EXTENT_NEXT) ||
(orig_op == EXT2_EXTENT_NEXT_LEAF)) {
if (handle->level < handle->max_depth) {
/* interior node */
if (path->visit_num == 0) {
path->visit_num++;
op = EXT2_EXTENT_DOWN;
} else if (path->left > 0)
op = EXT2_EXTENT_NEXT_SIB;
else if (handle->level > 0)
op = EXT2_EXTENT_UP;
else
return EXT2_ET_EXTENT_NO_NEXT;
} else {
/* leaf node */
if (path->left > 0)
op = EXT2_EXTENT_NEXT_SIB;
else if (handle->level > 0)
op = EXT2_EXTENT_UP;
else
return EXT2_ET_EXTENT_NO_NEXT;
}
if (op != EXT2_EXTENT_NEXT_SIB) {
#ifdef DEBUG_GET_EXTENT
printf("<<<< OP = %s\n",
(op == EXT2_EXTENT_DOWN) ? "down" :
((op == EXT2_EXTENT_UP) ? "up" : "unknown"));
#endif
}
}
if ((orig_op == EXT2_EXTENT_PREV) ||
(orig_op == EXT2_EXTENT_PREV_LEAF)) {
if (handle->level < handle->max_depth) {
/* interior node */
if (path->visit_num > 0 ) {
/* path->visit_num = 0; */
op = EXT2_EXTENT_DOWN_AND_LAST;
} else if (path->left < path->entries-1)
op = EXT2_EXTENT_PREV_SIB;
else if (handle->level > 0)
op = EXT2_EXTENT_UP;
else
return EXT2_ET_EXTENT_NO_PREV;
} else {
/* leaf node */
if (path->left < path->entries-1)
op = EXT2_EXTENT_PREV_SIB;
else if (handle->level > 0)
op = EXT2_EXTENT_UP;
else
return EXT2_ET_EXTENT_NO_PREV;
}
if (op != EXT2_EXTENT_PREV_SIB) {
#ifdef DEBUG_GET_EXTENT
printf("<<<< OP = %s\n",
(op == EXT2_EXTENT_DOWN_AND_LAST) ? "down/last" :
((op == EXT2_EXTENT_UP) ? "up" : "unknown"));
#endif
}
}
if (orig_op == EXT2_EXTENT_LAST_LEAF) {
if ((handle->level < handle->max_depth) &&
(path->left == 0))
op = EXT2_EXTENT_DOWN;
else
op = EXT2_EXTENT_LAST_SIB;
#ifdef DEBUG_GET_EXTENT
printf("<<<< OP = %s\n",
(op == EXT2_EXTENT_DOWN) ? "down" : "last_sib");
#endif
}
switch (op) {
case EXT2_EXTENT_CURRENT:
ix = path->curr;
break;
case EXT2_EXTENT_ROOT:
handle->level = 0;
path = handle->path + handle->level;
/* fallthrough */
case EXT2_EXTENT_FIRST_SIB:
path->left = path->entries;
path->curr = 0;
/* fallthrough */
case EXT2_EXTENT_NEXT_SIB:
if (path->left <= 0)
return EXT2_ET_EXTENT_NO_NEXT;
if (path->curr) {
ix = path->curr;
ix++;
} else {
eh = (struct ext3_extent_header *) path->buf;
ix = EXT_FIRST_INDEX(eh);
}
path->left--;
path->curr = ix;
path->visit_num = 0;
break;
case EXT2_EXTENT_PREV_SIB:
if (!path->curr ||
path->left+1 >= path->entries)
return EXT2_ET_EXTENT_NO_PREV;
ix = path->curr;
ix--;
path->curr = ix;
path->left++;
if (handle->level < handle->max_depth)
path->visit_num = 1;
break;
case EXT2_EXTENT_LAST_SIB:
eh = (struct ext3_extent_header *) path->buf;
path->curr = EXT_LAST_EXTENT(eh);
ix = path->curr;
path->left = 0;
path->visit_num = 0;
break;
case EXT2_EXTENT_UP:
if (handle->level <= 0)
return EXT2_ET_EXTENT_NO_UP;
handle->level--;
path--;
ix = path->curr;
if ((orig_op == EXT2_EXTENT_PREV) ||
(orig_op == EXT2_EXTENT_PREV_LEAF))
path->visit_num = 0;
break;
case EXT2_EXTENT_DOWN:
case EXT2_EXTENT_DOWN_AND_LAST:
if (!path->curr ||(handle->level >= handle->max_depth))
return EXT2_ET_EXTENT_NO_DOWN;
ix = path->curr;
newpath = path + 1;
if (!newpath->buf) {
retval = ext2fs_get_mem(handle->fs->blocksize,
&newpath->buf);
if (retval)
return retval;
}
blk = ext2fs_le32_to_cpu(ix->ei_leaf) +
((__u64) ext2fs_le16_to_cpu(ix->ei_leaf_hi) << 32);
if ((handle->fs->flags & EXT2_FLAG_IMAGE_FILE) &&
(handle->fs->io != handle->fs->image_io))
memset(newpath->buf, 0, handle->fs->blocksize);
else {
retval = io_channel_read_blk64(handle->fs->io,
blk, 1, newpath->buf);
if (retval)
return retval;
}
handle->level++;
eh = (struct ext3_extent_header *) newpath->buf;
retval = ext2fs_extent_header_verify(eh, handle->fs->blocksize);
if (retval) {
handle->level--;
return retval;
}
newpath->left = newpath->entries =
ext2fs_le16_to_cpu(eh->eh_entries);
newpath->max_entries = ext2fs_le16_to_cpu(eh->eh_max);
if (path->left > 0) {
ix++;
newpath->end_blk = ext2fs_le32_to_cpu(ix->ei_block);
} else
newpath->end_blk = path->end_blk;
path = newpath;
if (op == EXT2_EXTENT_DOWN) {
ix = EXT_FIRST_INDEX((struct ext3_extent_header *) eh);
path->curr = ix;
path->left = path->entries - 1;
path->visit_num = 0;
} else {
ix = EXT_LAST_INDEX((struct ext3_extent_header *) eh);
path->curr = ix;
path->left = 0;
if (handle->level < handle->max_depth)
path->visit_num = 1;
}
#ifdef DEBUG_GET_EXTENT
printf("Down to level %d/%d, end_blk=%llu\n",
handle->level, handle->max_depth,
path->end_blk);
#endif
break;
default:
return EXT2_ET_OP_NOT_SUPPORTED;
}
if (!ix)
return EXT2_ET_NO_CURRENT_NODE;
extent->e_flags = 0;
#ifdef DEBUG_GET_EXTENT
printf("(Left %d)\n", path->left);
#endif
if (handle->level == handle->max_depth) {
ex = (struct ext3_extent *) ix;
extent->e_pblk = ext2fs_le32_to_cpu(ex->ee_start) +
((__u64) ext2fs_le16_to_cpu(ex->ee_start_hi) << 32);
extent->e_lblk = ext2fs_le32_to_cpu(ex->ee_block);
extent->e_len = ext2fs_le16_to_cpu(ex->ee_len);
extent->e_flags |= EXT2_EXTENT_FLAGS_LEAF;
if (extent->e_len > EXT_INIT_MAX_LEN) {
extent->e_len -= EXT_INIT_MAX_LEN;
extent->e_flags |= EXT2_EXTENT_FLAGS_UNINIT;
}
} else {
extent->e_pblk = ext2fs_le32_to_cpu(ix->ei_leaf) +
((__u64) ext2fs_le16_to_cpu(ix->ei_leaf_hi) << 32);
extent->e_lblk = ext2fs_le32_to_cpu(ix->ei_block);
if (path->left > 0) {
ix++;
end_blk = ext2fs_le32_to_cpu(ix->ei_block);
} else
end_blk = path->end_blk;
extent->e_len = end_blk - extent->e_lblk;
}
if (path->visit_num)
extent->e_flags |= EXT2_EXTENT_FLAGS_SECOND_VISIT;
if (((orig_op == EXT2_EXTENT_NEXT_LEAF) ||
(orig_op == EXT2_EXTENT_PREV_LEAF)) &&
(handle->level != handle->max_depth))
goto retry;
if ((orig_op == EXT2_EXTENT_LAST_LEAF) &&
((handle->level != handle->max_depth) ||
(path->left != 0)))
goto retry;
return 0;
}
static errcode_t update_path(ext2_extent_handle_t handle)
{
blk64_t blk;
errcode_t retval;
struct ext3_extent_idx *ix;
if (handle->level == 0) {
retval = ext2fs_write_inode(handle->fs, handle->ino,
handle->inode);
} else {
ix = handle->path[handle->level - 1].curr;
blk = ext2fs_le32_to_cpu(ix->ei_leaf) +
((__u64) ext2fs_le16_to_cpu(ix->ei_leaf_hi) << 32);
retval = io_channel_write_blk64(handle->fs->io,
blk, 1, handle->path[handle->level].buf);
}
return retval;
}
#if 0
errcode_t ext2fs_extent_save_path(ext2_extent_handle_t handle,
ext2_extent_path_t *ret_path)
{
ext2_extent_path_t save_path;
struct ext2fs_extent extent;
struct ext2_extent_info info;
errcode_t retval;
retval = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT, &extent);
if (retval)
return retval;
retval = ext2fs_extent_get_info(handle, &info);
if (retval)
return retval;
retval = ext2fs_get_mem(sizeof(struct ext2_extent_path), &save_path);
if (retval)
return retval;
memset(save_path, 0, sizeof(struct ext2_extent_path));
save_path->magic = EXT2_ET_MAGIC_EXTENT_PATH;
save_path->leaf_height = info.max_depth - info.curr_level - 1;
save_path->lblk = extent.e_lblk;
*ret_path = save_path;
return 0;
}
errcode_t ext2fs_extent_free_path(ext2_extent_path_t path)
{
EXT2_CHECK_MAGIC(path, EXT2_ET_MAGIC_EXTENT_PATH);
ext2fs_free_mem(&path);
return 0;
}
#endif
/*
* Go to the node at leaf_level which contains logical block blk.
*
* leaf_level is height from the leaf node level, i.e.
* leaf_level 0 is at leaf node, leaf_level 1 is 1 above etc.
*
* If "blk" has no mapping (hole) then handle is left at last
* extent before blk.
*/
errcode_t ext2fs_extent_goto2(ext2_extent_handle_t handle,
int leaf_level, blk64_t blk)
{
struct ext2fs_extent extent;
errcode_t retval;
retval = ext2fs_extent_get(handle, EXT2_EXTENT_ROOT, &extent);
if (retval) {
if (retval == EXT2_ET_EXTENT_NO_NEXT)
retval = EXT2_ET_EXTENT_NOT_FOUND;
return retval;
}
if (leaf_level > handle->max_depth) {
#ifdef DEBUG
printf("leaf level %d greater than tree depth %d\n",
leaf_level, handle->max_depth);
#endif
return EXT2_ET_OP_NOT_SUPPORTED;
}
#ifdef DEBUG
printf("goto extent ino %u, level %d, %llu\n", handle->ino,
leaf_level, blk);
#endif
#ifdef DEBUG_GOTO_EXTENTS
dbg_print_extent("root", &extent);
#endif
while (1) {
if (handle->max_depth - handle->level == leaf_level) {
/* block is in this &extent */
if ((blk >= extent.e_lblk) &&
(blk < extent.e_lblk + extent.e_len))
return 0;
if (blk < extent.e_lblk) {
retval = ext2fs_extent_get(handle,
EXT2_EXTENT_PREV_SIB,
&extent);
return EXT2_ET_EXTENT_NOT_FOUND;
}
retval = ext2fs_extent_get(handle,
EXT2_EXTENT_NEXT_SIB,
&extent);
if (retval == EXT2_ET_EXTENT_NO_NEXT)
return EXT2_ET_EXTENT_NOT_FOUND;
if (retval)
return retval;
continue;
}
retval = ext2fs_extent_get(handle, EXT2_EXTENT_NEXT_SIB,
&extent);
if (retval == EXT2_ET_EXTENT_NO_NEXT)
goto go_down;
if (retval)
return retval;
#ifdef DEBUG_GOTO_EXTENTS
dbg_print_extent("next", &extent);
#endif
if (blk == extent.e_lblk)
goto go_down;
if (blk > extent.e_lblk)
continue;
retval = ext2fs_extent_get(handle, EXT2_EXTENT_PREV_SIB,
&extent);
if (retval)
return retval;
#ifdef DEBUG_GOTO_EXTENTS
dbg_print_extent("prev", &extent);
#endif
go_down:
retval = ext2fs_extent_get(handle, EXT2_EXTENT_DOWN,
&extent);
if (retval)
return retval;
#ifdef DEBUG_GOTO_EXTENTS
dbg_print_extent("down", &extent);
#endif
}
}
errcode_t ext2fs_extent_goto(ext2_extent_handle_t handle,
blk64_t blk)
{
return ext2fs_extent_goto2(handle, 0, blk);
}
/*
* Traverse back up to root fixing parents of current node as needed.
*
* If we changed start of first entry in a node, fix parent index start
* and so on.
*
* Safe to call for any position in node; if not at the first entry,
* will simply return.
*/
errcode_t ext2fs_extent_fix_parents(ext2_extent_handle_t handle)
{
int retval = 0;
int orig_height;
blk64_t start;
struct extent_path *path;
struct ext2fs_extent extent;
struct ext2_extent_info info;
EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);
if (!(handle->fs->flags & EXT2_FLAG_RW))
return EXT2_ET_RO_FILSYS;
if (!handle->path)
return EXT2_ET_NO_CURRENT_NODE;
path = handle->path + handle->level;
if (!path->curr)
return EXT2_ET_NO_CURRENT_NODE;
retval = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT, &extent);
if (retval)
goto done;
/* modified node's start block */
start = extent.e_lblk;
if ((retval = ext2fs_extent_get_info(handle, &info)))
return retval;
orig_height = info.max_depth - info.curr_level;
/* traverse up until index not first, or startblk matches, or top */
while (handle->level > 0 &&
(path->left == path->entries - 1)) {
retval = ext2fs_extent_get(handle, EXT2_EXTENT_UP, &extent);
if (retval)
goto done;
if (extent.e_lblk == start)
break;
path = handle->path + handle->level;
extent.e_len += (extent.e_lblk - start);
extent.e_lblk = start;
retval = ext2fs_extent_replace(handle, 0, &extent);
if (retval)
goto done;
update_path(handle);
}
/* put handle back to where we started */
retval = ext2fs_extent_goto2(handle, orig_height, start);
done:
return retval;
}
errcode_t ext2fs_extent_replace(ext2_extent_handle_t handle,
int flags EXT2FS_ATTR((unused)),
struct ext2fs_extent *extent)
{
struct extent_path *path;
struct ext3_extent_idx *ix;
struct ext3_extent *ex;
EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);
if (!(handle->fs->flags & EXT2_FLAG_RW))
return EXT2_ET_RO_FILSYS;
if (!handle->path)
return EXT2_ET_NO_CURRENT_NODE;
path = handle->path + handle->level;
if (!path->curr)
return EXT2_ET_NO_CURRENT_NODE;
#ifdef DEBUG
printf("extent replace: %u ", handle->ino);
dbg_print_extent(0, extent);
#endif
if (handle->level == handle->max_depth) {
ex = path->curr;
ex->ee_block = ext2fs_cpu_to_le32(extent->e_lblk);
ex->ee_start = ext2fs_cpu_to_le32(extent->e_pblk & 0xFFFFFFFF);
ex->ee_start_hi = ext2fs_cpu_to_le16(extent->e_pblk >> 32);
if (extent->e_flags & EXT2_EXTENT_FLAGS_UNINIT) {
if (extent->e_len > EXT_UNINIT_MAX_LEN)
return EXT2_ET_EXTENT_INVALID_LENGTH;
ex->ee_len = ext2fs_cpu_to_le16(extent->e_len +
EXT_INIT_MAX_LEN);
} else {
if (extent->e_len > EXT_INIT_MAX_LEN)
return EXT2_ET_EXTENT_INVALID_LENGTH;
ex->ee_len = ext2fs_cpu_to_le16(extent->e_len);
}
} else {
ix = path->curr;
ix->ei_leaf = ext2fs_cpu_to_le32(extent->e_pblk & 0xFFFFFFFF);
ix->ei_leaf_hi = ext2fs_cpu_to_le16(extent->e_pblk >> 32);
ix->ei_block = ext2fs_cpu_to_le32(extent->e_lblk);
ix->ei_unused = 0;
}
update_path(handle);
return 0;
}
/*
* allocate a new block, move half the current node to it, and update parent
*
* handle will be left pointing at original record.
*/
errcode_t ext2fs_extent_node_split(ext2_extent_handle_t handle)
{
errcode_t retval = 0;
blk64_t new_node_pblk;
blk64_t new_node_start;
blk64_t orig_lblk;
blk64_t goal_blk = 0;
int orig_height;
char *block_buf = NULL;
struct ext2fs_extent extent;
struct extent_path *path, *newpath = 0;
struct ext3_extent_header *eh, *neweh;
int tocopy;
int new_root = 0;
struct ext2_extent_info info;
/* basic sanity */
EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);
if (!(handle->fs->flags & EXT2_FLAG_RW))
return EXT2_ET_RO_FILSYS;
if (!handle->path)
return EXT2_ET_NO_CURRENT_NODE;
#ifdef DEBUG
printf("splitting node at level %d\n", handle->level);
#endif
retval = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT, &extent);
if (retval)
goto done;
retval = ext2fs_extent_get_info(handle, &info);
if (retval)
goto done;
/* save the position we were originally splitting... */
orig_height = info.max_depth - info.curr_level;
orig_lblk = extent.e_lblk;
/* Is there room in the parent for a new entry? */
if (handle->level &&
(handle->path[handle->level - 1].entries >=
handle->path[handle->level - 1].max_entries)) {
#ifdef DEBUG
printf("parent level %d full; splitting it too\n",
handle->level - 1);
#endif
/* split the parent */
retval = ext2fs_extent_get(handle, EXT2_EXTENT_UP, &extent);
if (retval)
goto done;
goal_blk = extent.e_pblk;
retval = ext2fs_extent_node_split(handle);
if (retval)
goto done;
/* get handle back to our original split position */
retval = ext2fs_extent_goto2(handle, orig_height, orig_lblk);
if (retval)
goto done;
}
/* At this point, parent should have room for this split */
path = handle->path + handle->level;
if (!path->curr)
return EXT2_ET_NO_CURRENT_NODE;
/* extent header of the current node we'll split */
eh = (struct ext3_extent_header *)path->buf;
/* splitting root level means moving them all out */
if (handle->level == 0) {
new_root = 1;
tocopy = ext2fs_le16_to_cpu(eh->eh_entries);
retval = ext2fs_get_mem(((handle->max_depth+2) *
sizeof(struct extent_path)),
&newpath);
if (retval)
goto done;
memset(newpath, 0,
((handle->max_depth+2) * sizeof(struct extent_path)));
} else {
tocopy = ext2fs_le16_to_cpu(eh->eh_entries) / 2;
}
#ifdef DEBUG
printf("will copy out %d of %d entries at level %d\n",
tocopy, ext2fs_le16_to_cpu(eh->eh_entries),
handle->level);
#endif
if (!tocopy) {
#ifdef DEBUG
printf("Nothing to copy to new block!\n");
#endif
retval = EXT2_ET_CANT_SPLIT_EXTENT;
goto done;
}
/* first we need a new block, or can do nothing. */
block_buf = malloc(handle->fs->blocksize);
if (!block_buf) {
retval = ENOMEM;
goto done;
}
if (!goal_blk) {
dgrp_t group = ext2fs_group_of_ino(handle->fs, handle->ino);
__u8 log_flex = handle->fs->super->s_log_groups_per_flex;
if (log_flex)
group = group & ~((1 << (log_flex)) - 1);
goal_blk = ext2fs_group_first_block2(handle->fs, group);
}
retval = ext2fs_alloc_block2(handle->fs, goal_blk, block_buf,
&new_node_pblk);
if (retval)
goto done;
#ifdef DEBUG
printf("will copy to new node at block %lu\n",
(unsigned long) new_node_pblk);
#endif
/* Copy data into new block buffer */
/* First the header for the new block... */
neweh = (struct ext3_extent_header *) block_buf;
memcpy(neweh, eh, sizeof(struct ext3_extent_header));
neweh->eh_entries = ext2fs_cpu_to_le16(tocopy);
neweh->eh_max = ext2fs_cpu_to_le16((handle->fs->blocksize -
sizeof(struct ext3_extent_header)) /
sizeof(struct ext3_extent));
/* then the entries for the new block... */
memcpy(EXT_FIRST_INDEX(neweh),
EXT_FIRST_INDEX(eh) +
(ext2fs_le16_to_cpu(eh->eh_entries) - tocopy),
sizeof(struct ext3_extent_idx) * tocopy);
new_node_start = ext2fs_le32_to_cpu(EXT_FIRST_INDEX(neweh)->ei_block);
/* ...and write the new node block out to disk. */
retval = io_channel_write_blk64(handle->fs->io, new_node_pblk, 1,
block_buf);
if (retval)
goto done;
/* OK! we've created the new node; now adjust the tree */
/* current path now has fewer active entries, we copied some out */
if (handle->level == 0) {
memcpy(newpath, path,
sizeof(struct extent_path) * (handle->max_depth+1));
handle->path = newpath;
newpath = path;
path = handle->path;
path->entries = 1;
path->left = path->max_entries - 1;
handle->max_depth++;
eh->eh_depth = ext2fs_cpu_to_le16(handle->max_depth);
} else {
path->entries -= tocopy;
path->left -= tocopy;
}
eh->eh_entries = ext2fs_cpu_to_le16(path->entries);
/* this writes out the node, incl. the modified header */
retval = update_path(handle);
if (retval)
goto done;
/* now go up and insert/replace index for new node we created */
if (new_root) {
retval = ext2fs_extent_get(handle, EXT2_EXTENT_FIRST_SIB, &extent);
if (retval)
goto done;
extent.e_lblk = new_node_start;
extent.e_pblk = new_node_pblk;
extent.e_len = handle->path[0].end_blk - extent.e_lblk;
retval = ext2fs_extent_replace(handle, 0, &extent);
if (retval)
goto done;
} else {
__u32 new_node_length;
retval = ext2fs_extent_get(handle, EXT2_EXTENT_UP, &extent);
/* will insert after this one; it's length is shorter now */
new_node_length = new_node_start - extent.e_lblk;
extent.e_len -= new_node_length;
retval = ext2fs_extent_replace(handle, 0, &extent);
if (retval)
goto done;
/* now set up the new extent and insert it */
extent.e_lblk = new_node_start;
extent.e_pblk = new_node_pblk;
extent.e_len = new_node_length;
retval = ext2fs_extent_insert(handle, EXT2_EXTENT_INSERT_AFTER, &extent);
if (retval)
goto done;
}
/* get handle back to our original position */
retval = ext2fs_extent_goto2(handle, orig_height, orig_lblk);
if (retval)
goto done;
/* new node hooked in, so update inode block count (do this here?) */
handle->inode->i_blocks += (handle->fs->blocksize *
EXT2FS_CLUSTER_RATIO(handle->fs)) / 512;
retval = ext2fs_write_inode(handle->fs, handle->ino,
handle->inode);
if (retval)
goto done;
done:
if (newpath)
ext2fs_free_mem(&newpath);
free(block_buf);
return retval;
}
errcode_t ext2fs_extent_insert(ext2_extent_handle_t handle, int flags,
struct ext2fs_extent *extent)
{
struct extent_path *path;
struct ext3_extent_idx *ix;
struct ext3_extent_header *eh;
errcode_t retval;
EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);
if (!(handle->fs->flags & EXT2_FLAG_RW))
return EXT2_ET_RO_FILSYS;
if (!handle->path)
return EXT2_ET_NO_CURRENT_NODE;
#ifdef DEBUG
printf("extent insert: %u ", handle->ino);
dbg_print_extent(0, extent);
#endif
path = handle->path + handle->level;
if (path->entries >= path->max_entries) {
if (flags & EXT2_EXTENT_INSERT_NOSPLIT) {
return EXT2_ET_CANT_INSERT_EXTENT;
} else {
#ifdef DEBUG
printf("node full (level %d) - splitting\n",
handle->level);
#endif
retval = ext2fs_extent_node_split(handle);
if (retval)
return retval;
path = handle->path + handle->level;
}
}
eh = (struct ext3_extent_header *) path->buf;
if (path->curr) {
ix = path->curr;
if (flags & EXT2_EXTENT_INSERT_AFTER) {
ix++;
path->left--;
}
} else
ix = EXT_FIRST_INDEX(eh);
path->curr = ix;
if (path->left >= 0)
memmove(ix + 1, ix,
(path->left+1) * sizeof(struct ext3_extent_idx));
path->left++;
path->entries++;
eh = (struct ext3_extent_header *) path->buf;
eh->eh_entries = ext2fs_cpu_to_le16(path->entries);
retval = ext2fs_extent_replace(handle, 0, extent);
if (retval)
goto errout;
retval = update_path(handle);
if (retval)
goto errout;
return 0;
errout:
ext2fs_extent_delete(handle, 0);
return retval;
}
/*
* Sets the physical block for a logical file block in the extent tree.
*
* May: map unmapped, unmap mapped, or remap mapped blocks.
*
* Mapping an unmapped block adds a single-block extent.
*
* Unmapping first or last block modifies extent in-place
* - But may need to fix parent's starts too in first-block case
*
* Mapping any unmapped block requires adding a (single-block) extent
* and inserting into proper point in tree.
*
* Modifying (unmapping or remapping) a block in the middle
* of an extent requires splitting the extent.
* - Remapping case requires new single-block extent.
*
* Remapping first or last block adds an extent.
*
* We really need extent adding to be smart about merging.
*/
errcode_t ext2fs_extent_set_bmap(ext2_extent_handle_t handle,
blk64_t logical, blk64_t physical, int flags)
{
errcode_t ec, retval = 0;
int mapped = 1; /* logical is mapped? */
int orig_height;
int extent_uninit = 0;
int prev_uninit = 0;
int next_uninit = 0;
int new_uninit = 0;
int max_len = EXT_INIT_MAX_LEN;
int has_prev, has_next;
blk64_t orig_lblk;
struct extent_path *path;
struct ext2fs_extent extent, next_extent, prev_extent;
struct ext2fs_extent newextent;
struct ext2_extent_info info;
EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);
#ifdef DEBUG
printf("set_bmap ino %u log %lld phys %lld flags %d\n",
handle->ino, logical, physical, flags);
#endif
if (!(handle->fs->flags & EXT2_FLAG_RW))
return EXT2_ET_RO_FILSYS;
if (!handle->path)
return EXT2_ET_NO_CURRENT_NODE;
path = handle->path + handle->level;
if (flags & EXT2_EXTENT_SET_BMAP_UNINIT) {
new_uninit = 1;
max_len = EXT_UNINIT_MAX_LEN;
}
/* if (re)mapping, set up new extent to insert */
if (physical) {
newextent.e_len = 1;
newextent.e_pblk = physical;
newextent.e_lblk = logical;
newextent.e_flags = EXT2_EXTENT_FLAGS_LEAF;
if (new_uninit)
newextent.e_flags |= EXT2_EXTENT_FLAGS_UNINIT;
}
/* special case if the extent tree is completely empty */
if ((handle->max_depth == 0) && (path->entries == 0)) {
retval = ext2fs_extent_insert(handle, 0, &newextent);
return retval;
}
/* save our original location in the extent tree */
if ((retval = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT,
&extent))) {
if (retval != EXT2_ET_NO_CURRENT_NODE)
return retval;
memset(&extent, 0, sizeof(extent));
}
if ((retval = ext2fs_extent_get_info(handle, &info)))
return retval;
orig_height = info.max_depth - info.curr_level;
orig_lblk = extent.e_lblk;
/* go to the logical spot we want to (re/un)map */
retval = ext2fs_extent_goto(handle, logical);
if (retval) {
if (retval == EXT2_ET_EXTENT_NOT_FOUND) {
retval = 0;
mapped = 0;
if (!physical) {
#ifdef DEBUG
printf("block %llu already unmapped\n",
logical);
#endif
goto done;
}
} else
goto done;
}
/*
* This may be the extent *before* the requested logical,
* if it's currently unmapped.
*
* Get the previous and next leaf extents, if they are present.
*/
retval = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT, &extent);
if (retval)
goto done;
if (extent.e_flags & EXT2_EXTENT_FLAGS_UNINIT)
extent_uninit = 1;
retval = ext2fs_extent_get(handle, EXT2_EXTENT_NEXT_LEAF, &next_extent);
if (retval) {
has_next = 0;
if (retval != EXT2_ET_EXTENT_NO_NEXT)
goto done;
} else {
dbg_print_extent("set_bmap: next_extent",
&next_extent);
has_next = 1;
if (next_extent.e_flags & EXT2_EXTENT_FLAGS_UNINIT)
next_uninit = 1;
}
retval = ext2fs_extent_goto(handle, logical);
if (retval && retval != EXT2_ET_EXTENT_NOT_FOUND)
goto done;
retval = ext2fs_extent_get(handle, EXT2_EXTENT_PREV_LEAF, &prev_extent);
if (retval) {
has_prev = 0;
if (retval != EXT2_ET_EXTENT_NO_PREV)
goto done;
} else {
has_prev = 1;
dbg_print_extent("set_bmap: prev_extent",
&prev_extent);
if (prev_extent.e_flags & EXT2_EXTENT_FLAGS_UNINIT)
prev_uninit = 1;
}
retval = ext2fs_extent_goto(handle, logical);
if (retval && retval != EXT2_ET_EXTENT_NOT_FOUND)
goto done;
/* check if already pointing to the requested physical */
if (mapped && (new_uninit == extent_uninit) &&
(extent.e_pblk + (logical - extent.e_lblk) == physical)) {
#ifdef DEBUG
printf("physical block (at %llu) unchanged\n", logical);
#endif
goto done;
}
if (!mapped) {
#ifdef DEBUG
printf("mapping unmapped logical block %llu\n", logical);
#endif
if ((logical == extent.e_lblk + extent.e_len) &&
(physical == extent.e_pblk + extent.e_len) &&
(new_uninit == extent_uninit) &&
((int) extent.e_len < max_len-1)) {
extent.e_len++;
retval = ext2fs_extent_replace(handle, 0, &extent);
} else if ((logical == extent.e_lblk - 1) &&
(physical == extent.e_pblk - 1) &&
(new_uninit == extent_uninit) &&
((int) extent.e_len < max_len - 1)) {
extent.e_len++;
extent.e_lblk--;
extent.e_pblk--;
retval = ext2fs_extent_replace(handle, 0, &extent);
} else if (has_next &&
(logical == next_extent.e_lblk - 1) &&
(physical == next_extent.e_pblk - 1) &&
(new_uninit == next_uninit) &&
((int) next_extent.e_len < max_len - 1)) {
retval = ext2fs_extent_get(handle,
EXT2_EXTENT_NEXT_LEAF,
&next_extent);
if (retval)
goto done;
next_extent.e_len++;
next_extent.e_lblk--;
next_extent.e_pblk--;
retval = ext2fs_extent_replace(handle, 0, &next_extent);
} else if (logical < extent.e_lblk)
retval = ext2fs_extent_insert(handle, 0, &newextent);
else
retval = ext2fs_extent_insert(handle,
EXT2_EXTENT_INSERT_AFTER, &newextent);
if (retval)
goto done;
retval = ext2fs_extent_fix_parents(handle);
if (retval)
goto done;
} else if ((logical == extent.e_lblk) && (extent.e_len == 1)) {
#ifdef DEBUG
printf("(re/un)mapping only block in extent\n");
#endif
if (physical) {
retval = ext2fs_extent_replace(handle, 0, &newextent);
} else {
retval = ext2fs_extent_delete(handle, 0);
if (retval)
goto done;
ec = ext2fs_extent_fix_parents(handle);
if (ec != EXT2_ET_NO_CURRENT_NODE)
retval = ec;
}
if (retval)
goto done;
} else if (logical == extent.e_lblk + extent.e_len - 1) {
#ifdef DEBUG
printf("(re/un)mapping last block in extent\n");
#endif
if (physical) {
if (has_next &&
(logical == (next_extent.e_lblk - 1)) &&
(physical == (next_extent.e_pblk - 1)) &&
(new_uninit == next_uninit) &&
((int) next_extent.e_len < max_len - 1)) {
retval = ext2fs_extent_get(handle,
EXT2_EXTENT_NEXT_LEAF, &next_extent);
if (retval)
goto done;
next_extent.e_len++;
next_extent.e_lblk--;
next_extent.e_pblk--;
retval = ext2fs_extent_replace(handle, 0,
&next_extent);
if (retval)
goto done;
retval = ext2fs_extent_fix_parents(handle);
if (retval)
goto done;
} else
retval = ext2fs_extent_insert(handle,
EXT2_EXTENT_INSERT_AFTER, &newextent);
if (retval)
goto done;
/* Now pointing at inserted extent; move back to prev */
retval = ext2fs_extent_get(handle,
EXT2_EXTENT_PREV_LEAF,
&extent);
if (retval)
goto done;
}
extent.e_len--;
retval = ext2fs_extent_replace(handle, 0, &extent);
if (retval)
goto done;
} else if (logical == extent.e_lblk) {
#ifdef DEBUG
printf("(re/un)mapping first block in extent\n");
#endif
if (physical) {
if (has_prev &&
(logical == (prev_extent.e_lblk +
prev_extent.e_len)) &&
(physical == (prev_extent.e_pblk +
prev_extent.e_len)) &&
(new_uninit == prev_uninit) &&
((int) prev_extent.e_len < max_len-1)) {
retval = ext2fs_extent_get(handle,
EXT2_EXTENT_PREV_LEAF, &prev_extent);
if (retval)
goto done;
prev_extent.e_len++;
retval = ext2fs_extent_replace(handle, 0,
&prev_extent);
} else
retval = ext2fs_extent_insert(handle,
0, &newextent);
if (retval)
goto done;
retval = ext2fs_extent_get(handle,
EXT2_EXTENT_NEXT_LEAF,
&extent);
if (retval)
goto done;
}
extent.e_pblk++;
extent.e_lblk++;
extent.e_len--;
retval = ext2fs_extent_replace(handle, 0, &extent);
if (retval)
goto done;
retval = ext2fs_extent_fix_parents(handle);
if (retval)
goto done;
} else {
__u32 orig_length;
#ifdef DEBUG
printf("(re/un)mapping in middle of extent\n");
#endif
/* need to split this extent; later */
orig_length = extent.e_len;
/* shorten pre-split extent */
extent.e_len = (logical - extent.e_lblk);
retval = ext2fs_extent_replace(handle, 0, &extent);
if (retval)
goto done;
/* insert our new extent, if any */
if (physical) {
/* insert new extent after current */
retval = ext2fs_extent_insert(handle,
EXT2_EXTENT_INSERT_AFTER, &newextent);
if (retval)
goto done;
}
/* add post-split extent */
extent.e_pblk += extent.e_len + 1;
extent.e_lblk += extent.e_len + 1;
extent.e_len = orig_length - extent.e_len - 1;
retval = ext2fs_extent_insert(handle,
EXT2_EXTENT_INSERT_AFTER, &extent);
if (retval)
goto done;
}
done:
/* get handle back to its position */
if (orig_height > handle->max_depth)
orig_height = handle->max_depth; /* In case we shortened the tree */
ext2fs_extent_goto2(handle, orig_height, orig_lblk);
return retval;
}
errcode_t ext2fs_extent_delete(ext2_extent_handle_t handle, int flags)
{
struct extent_path *path;
char *cp;
struct ext3_extent_header *eh;
errcode_t retval = 0;
EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);
if (!(handle->fs->flags & EXT2_FLAG_RW))
return EXT2_ET_RO_FILSYS;
if (!handle->path)
return EXT2_ET_NO_CURRENT_NODE;
#ifdef DEBUG
{
struct ext2fs_extent extent;
retval = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT,
&extent);
if (retval == 0) {
printf("extent delete %u ", handle->ino);
dbg_print_extent(0, &extent);
}
}
#endif
path = handle->path + handle->level;
if (!path->curr)
return EXT2_ET_NO_CURRENT_NODE;
cp = path->curr;
if (path->left) {
memmove(cp, cp + sizeof(struct ext3_extent_idx),
path->left * sizeof(struct ext3_extent_idx));
path->left--;
} else {
struct ext3_extent_idx *ix = path->curr;
ix--;
path->curr = ix;
}
if (--path->entries == 0)
path->curr = 0;
/* if non-root node has no entries left, remove it & parent ptr to it */
if (path->entries == 0 && handle->level) {
if (!(flags & EXT2_EXTENT_DELETE_KEEP_EMPTY)) {
struct ext2fs_extent extent;
retval = ext2fs_extent_get(handle, EXT2_EXTENT_UP,
&extent);
if (retval)
return retval;
retval = ext2fs_extent_delete(handle, flags);
handle->inode->i_blocks -=
(handle->fs->blocksize *
EXT2FS_CLUSTER_RATIO(handle->fs)) / 512;
retval = ext2fs_write_inode(handle->fs, handle->ino,
handle->inode);
ext2fs_block_alloc_stats2(handle->fs,
extent.e_pblk, -1);
}
} else {
eh = (struct ext3_extent_header *) path->buf;
eh->eh_entries = ext2fs_cpu_to_le16(path->entries);
if ((path->entries == 0) && (handle->level == 0))
eh->eh_depth = handle->max_depth = 0;
retval = update_path(handle);
}
return retval;
}
errcode_t ext2fs_extent_get_info(ext2_extent_handle_t handle,
struct ext2_extent_info *info)
{
struct extent_path *path;
EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);
memset(info, 0, sizeof(struct ext2_extent_info));
path = handle->path + handle->level;
if (path) {
if (path->curr)
info->curr_entry = ((char *) path->curr - path->buf) /
sizeof(struct ext3_extent_idx);
else
info->curr_entry = 0;
info->num_entries = path->entries;
info->max_entries = path->max_entries;
info->bytes_avail = (path->max_entries - path->entries) *
sizeof(struct ext3_extent);
}
info->curr_level = handle->level;
info->max_depth = handle->max_depth;
info->max_lblk = ((__u64) 1 << 32) - 1;
info->max_pblk = ((__u64) 1 << 48) - 1;
info->max_len = (1UL << 15);
info->max_uninit_len = (1UL << 15) - 1;
return 0;
}
#ifdef DEBUG
/*
* Override debugfs's prompt
*/
const char *debug_prog_name = "tst_extents";
#endif