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-rw-r--r--lib/ext2fs/extent.c1877
1 files changed, 1877 insertions, 0 deletions
diff --git a/lib/ext2fs/extent.c b/lib/ext2fs/extent.c
new file mode 100644
index 0000000..82e75cc
--- /dev/null
+++ b/lib/ext2fs/extent.c
@@ -0,0 +1,1877 @@
+/*
+ * 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 "config.h"
+#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"
+
+#undef DEBUG
+
+/*
+ * 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;
+ blk64_t 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;
+ int max_paths;
+ 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);
+
+}
+
+static void dump_path(const char *tag, struct ext2_extent_handle *handle,
+ struct extent_path *path)
+{
+ struct extent_path *ppp = path;
+ printf("%s: level=%d\n", tag, handle->level);
+
+ do {
+ printf("%s: path=%ld buf=%p entries=%d max_entries=%d left=%d "
+ "visit_num=%d flags=0x%x end_blk=%llu curr=%p(%ld)\n",
+ tag, (ppp - handle->path), ppp->buf, ppp->entries,
+ ppp->max_entries, ppp->left, ppp->visit_num, ppp->flags,
+ ppp->end_blk, ppp->curr, ppp->curr - (void *)ppp->buf);
+ printf(" ");
+ dbg_show_header((struct ext3_extent_header *)ppp->buf);
+ if (ppp->curr) {
+ printf(" ");
+ dbg_show_index(ppp->curr);
+ printf(" ");
+ dbg_show_extent(ppp->curr);
+ }
+ ppp--;
+ } while (ppp >= handle->path);
+ fflush(stdout);
+
+ return;
+}
+
+#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)
+#define dump_path(tag, handle, path) 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_paths; 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);
+
+ handle->max_paths = handle->max_depth + 1;
+ retval = ext2fs_get_memzero(handle->max_paths *
+ sizeof(struct extent_path),
+ &handle->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].blk = 0;
+ 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, *tp;
+ 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, l;
+ int failed_csum = 0;
+
+ 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);
+ for (l = handle->level, tp = path; l > 0; l--, tp--) {
+ if (blk == tp->blk)
+ return EXT2_ET_EXTENT_CYCLE;
+ }
+ newpath->blk = blk;
+ 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;
+ }
+
+ if (!(handle->fs->flags & EXT2_FLAG_IGNORE_CSUM_ERRORS) &&
+ !ext2fs_extent_block_csum_verify(handle->fs, handle->ino,
+ eh))
+ failed_csum = 1;
+
+ newpath->left = newpath->entries =
+ ext2fs_le16_to_cpu(eh->eh_entries);
+ newpath->max_entries = ext2fs_le16_to_cpu(eh->eh_max);
+
+ /* Make sure there is at least one extent present */
+ if (newpath->left <= 0)
+ return EXT2_ET_EXTENT_NO_DOWN;
+
+ 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;
+
+ if (failed_csum)
+ return EXT2_ET_EXTENT_CSUM_INVALID;
+
+ return 0;
+}
+
+static errcode_t update_path(ext2_extent_handle_t handle)
+{
+ blk64_t blk;
+ errcode_t retval;
+ struct ext3_extent_idx *ix;
+ struct ext3_extent_header *eh;
+
+ 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);
+
+ /* then update the checksum */
+ eh = (struct ext3_extent_header *)
+ handle->path[handle->level].buf;
+ retval = ext2fs_extent_block_csum_set(handle->fs, handle->ino,
+ eh);
+ if (retval)
+ return retval;
+
+ 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,
+ * it will simply return.
+ *
+ * Note a subtlety of this function -- if there happen to be two extents
+ * mapping the same lblk and someone calls fix_parents on the second of the two
+ * extents, the position of the extent handle after the call will be the second
+ * extent if nothing happened, or the first extent if something did. A caller
+ * in this situation must use ext2fs_extent_goto() after calling this function.
+ * Or simply don't map the same lblk with two extents, ever.
+ */
+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;
+}
+
+static int splitting_at_eof(struct ext2_extent_handle *handle,
+ struct extent_path *path)
+{
+ struct extent_path *ppp = path;
+ dump_path(__func__, handle, path);
+
+ if (handle->level == 0)
+ return 0;
+
+ do {
+ if (ppp->left)
+ return 0;
+ ppp--;
+ } while (ppp >= handle->path);
+
+ return 1;
+}
+
+/*
+ * allocate a new block, move half the current node to it, and update parent
+ *
+ * handle will be left pointing at original record.
+ */
+static errcode_t extent_node_split(ext2_extent_handle_t handle,
+ int expand_allowed)
+{
+ 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;
+ int no_balance;
+
+ /* 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;
+
+ /* Try to put the index block before the first extent */
+ path = handle->path + handle->level;
+ eh = (struct ext3_extent_header *) path->buf;
+ if (handle->level == handle->max_depth) {
+ struct ext3_extent *ex;
+
+ ex = EXT_FIRST_EXTENT(eh);
+ goal_blk = ext2fs_le32_to_cpu(ex->ee_start) +
+ ((__u64) ext2fs_le16_to_cpu(ex->ee_start_hi) << 32);
+ } else {
+ struct ext3_extent_idx *ix;
+
+ ix = EXT_FIRST_INDEX(eh);
+ goal_blk = ext2fs_le32_to_cpu(ix->ei_leaf) +
+ ((__u64) ext2fs_le16_to_cpu(ix->ei_leaf_hi) << 32);
+ }
+ goal_blk -= EXT2FS_CLUSTER_RATIO(handle->fs);
+ goal_blk &= ~EXT2FS_CLUSTER_MASK(handle->fs);
+
+ /* 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;
+
+ retval = extent_node_split(handle, expand_allowed);
+ 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;
+
+ /*
+ * Normally, we try to split a full node in half. This doesn't turn
+ * out so well if we're tacking extents on the end of the file because
+ * then we're stuck with a tree of half-full extent blocks. This of
+ * course doesn't apply to the root level.
+ */
+ no_balance = expand_allowed ? splitting_at_eof(handle, path) : 0;
+
+ /* 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_memzero((handle->max_paths + 1) *
+ sizeof(struct extent_path),
+ &newpath);
+ if (retval)
+ goto done;
+ } else {
+ if (no_balance)
+ tocopy = 1;
+ 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 && !no_balance) {
+#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)
+ goal_blk = ext2fs_find_inode_goal(handle->fs, handle->ino,
+ handle->inode, 0);
+ 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);
+
+ /* then update the checksum */
+ retval = ext2fs_extent_block_csum_set(handle->fs, handle->ino, neweh);
+ if (retval)
+ goto done;
+
+ /* ...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_paths);
+ handle->path = newpath;
+ newpath = path;
+ path = handle->path;
+ path->entries = 1;
+ path->left = path->max_entries - 1;
+ handle->max_depth++;
+ handle->max_paths++;
+ 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?) */
+ ext2fs_iblk_add_blocks(handle->fs, handle->inode, 1);
+ 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_node_split(ext2_extent_handle_t handle)
+{
+ return extent_node_split(handle, 0);
+}
+
+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 = extent_node_split(handle, 1);
+ 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->left = -1;
+ }
+
+ 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;
+ } 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;
+ /*
+ * Now pointing at inserted extent; move back to prev.
+ *
+ * We cannot use EXT2_EXTENT_PREV to go back; note the
+ * subtlety in the comment for fix_parents().
+ */
+ retval = ext2fs_extent_goto(handle, logical);
+ if (retval)
+ goto done;
+ retval = ext2fs_extent_get(handle,
+ EXT2_EXTENT_CURRENT,
+ &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_fix_parents(handle);
+ 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 save_length;
+ blk64_t save_lblk;
+ struct ext2fs_extent save_extent;
+ errcode_t r2;
+
+#ifdef DEBUG
+ printf("(re/un)mapping in middle of extent\n");
+#endif
+ /* need to split this extent; later */
+ save_lblk = extent.e_lblk;
+ save_length = extent.e_len;
+ save_extent = extent;
+
+ /* 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) {
+ r2 = ext2fs_extent_goto(handle, save_lblk);
+ if (r2 == 0)
+ (void)ext2fs_extent_replace(handle, 0,
+ &save_extent);
+ goto done;
+ }
+ }
+ /* add post-split extent */
+ extent.e_pblk += extent.e_len + 1;
+ extent.e_lblk += extent.e_len + 1;
+ extent.e_len = save_length - extent.e_len - 1;
+ retval = ext2fs_extent_insert(handle,
+ EXT2_EXTENT_INSERT_AFTER, &extent);
+ if (retval) {
+ if (physical) {
+ r2 = ext2fs_extent_goto(handle,
+ newextent.e_lblk);
+ if (r2 == 0)
+ (void)ext2fs_extent_delete(handle, 0);
+ }
+ r2 = ext2fs_extent_goto(handle, save_lblk);
+ if (r2 == 0)
+ (void)ext2fs_extent_replace(handle, 0,
+ &save_extent);
+ 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;
+
+ /* Sanity check before memmove() */
+ if (path->left < 0)
+ return EXT2_ET_EXTENT_LEAF_BAD;
+
+ 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 = 0;
+ 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 = EXT_MAX_EXTENT_LBLK;
+ info->max_pblk = EXT_MAX_EXTENT_PBLK;
+ info->max_len = EXT_INIT_MAX_LEN;
+ info->max_uninit_len = EXT_UNINIT_MAX_LEN;
+
+ return 0;
+}
+
+static int ul_log2(unsigned long arg)
+{
+ int l = 0;
+
+ arg >>= 1;
+ while (arg) {
+ l++;
+ arg >>= 1;
+ }
+ return l;
+}
+
+size_t ext2fs_max_extent_depth(ext2_extent_handle_t handle)
+{
+ size_t iblock_sz = sizeof(((struct ext2_inode *)NULL)->i_block);
+ size_t iblock_extents = (iblock_sz - sizeof(struct ext3_extent_header)) /
+ sizeof(struct ext3_extent);
+ size_t extents_per_block = (handle->fs->blocksize -
+ sizeof(struct ext3_extent_header)) /
+ sizeof(struct ext3_extent);
+ static unsigned int last_blocksize = 0;
+ static size_t last_result = 0;
+
+ if (last_blocksize && last_blocksize == handle->fs->blocksize)
+ return last_result;
+
+ last_result = 1 + ((ul_log2(EXT_MAX_EXTENT_LBLK) - ul_log2(iblock_extents)) /
+ ul_log2(extents_per_block));
+ last_blocksize = handle->fs->blocksize;
+ return last_result;
+}
+
+errcode_t ext2fs_fix_extents_checksums(ext2_filsys fs, ext2_ino_t ino,
+ struct ext2_inode *inode)
+{
+ ext2_extent_handle_t handle;
+ struct ext2fs_extent extent;
+ errcode_t errcode;
+ int save_flags = fs->flags;
+
+ if (!ext2fs_has_feature_metadata_csum(fs->super) ||
+ (inode && !(inode->i_flags & EXT4_EXTENTS_FL)))
+ return 0;
+
+ errcode = ext2fs_extent_open2(fs, ino, inode, &handle);
+ if (errcode) {
+ if (errcode == EXT2_ET_INODE_NOT_EXTENT)
+ errcode = 0;
+ return errcode;
+ }
+
+ fs->flags &= ~EXT2_FLAG_IGNORE_CSUM_ERRORS;
+ errcode = ext2fs_extent_get(handle, EXT2_EXTENT_ROOT, &extent);
+ if (errcode)
+ goto out;
+
+ do {
+ /* Skip to the end of a block of leaf nodes */
+ if (extent.e_flags & EXT2_EXTENT_FLAGS_LEAF) {
+ errcode = ext2fs_extent_get(handle,
+ EXT2_EXTENT_LAST_SIB,
+ &extent);
+ if (errcode)
+ break;
+ }
+
+ errcode = ext2fs_extent_get(handle, EXT2_EXTENT_NEXT, &extent);
+ if (errcode == EXT2_ET_EXTENT_CSUM_INVALID)
+ errcode = update_path(handle);
+ } while (errcode == 0);
+
+out:
+ /* Ok if we run off the end */
+ if (errcode == EXT2_ET_EXTENT_NO_NEXT)
+ errcode = 0;
+ ext2fs_extent_free(handle);
+ fs->flags = save_flags;
+ return errcode;
+}
+
+errcode_t ext2fs_decode_extent(struct ext2fs_extent *to, void *addr, int len)
+{
+ struct ext3_extent *from = (struct ext3_extent *)addr;
+
+ if (len != sizeof(struct ext3_extent))
+ return EXT2_ET_INVALID_ARGUMENT;
+
+ to->e_pblk = ext2fs_le32_to_cpu(from->ee_start) +
+ ((__u64) ext2fs_le16_to_cpu(from->ee_start_hi)
+ << 32);
+ to->e_lblk = ext2fs_le32_to_cpu(from->ee_block);
+ to->e_len = ext2fs_le16_to_cpu(from->ee_len);
+ to->e_flags = EXT2_EXTENT_FLAGS_LEAF;
+ if (to->e_len > EXT_INIT_MAX_LEN) {
+ to->e_len -= EXT_INIT_MAX_LEN;
+ to->e_flags |= EXT2_EXTENT_FLAGS_UNINIT;
+ }
+
+ return 0;
+}
+
+errcode_t ext2fs_count_blocks(ext2_filsys fs, ext2_ino_t ino,
+ struct ext2_inode *inode, blk64_t *ret_count)
+{
+ ext2_extent_handle_t handle = NULL;
+ struct ext2fs_extent extent;
+ errcode_t errcode;
+ int i;
+ blk64_t blkcount = 0;
+ blk64_t *intermediate_nodes;
+
+ errcode = ext2fs_extent_open2(fs, ino, inode, &handle);
+ if (errcode)
+ goto out;
+
+ errcode = ext2fs_extent_get(handle, EXT2_EXTENT_ROOT, &extent);
+ if (errcode)
+ goto out;
+
+ errcode = ext2fs_get_array(handle->max_depth, sizeof(blk64_t),
+ &intermediate_nodes);
+ if (errcode)
+ goto out;
+
+ blkcount = handle->level;
+ while (!errcode) {
+ if (extent.e_flags & EXT2_EXTENT_FLAGS_LEAF) {
+ blkcount += extent.e_len;
+ for (i = 0; i < handle->level; i++) {
+ if (intermediate_nodes[i] !=
+ handle->path[i].end_blk) {
+ blkcount++;
+ intermediate_nodes[i] =
+ handle->path[i].end_blk;
+ }
+ }
+ }
+ errcode = ext2fs_extent_get(handle, EXT2_EXTENT_NEXT, &extent);
+ }
+ ext2fs_free_mem(&intermediate_nodes);
+out:
+ *ret_count = blkcount;
+ ext2fs_extent_free(handle);
+
+ return 0;
+}
+
+#ifdef DEBUG
+/*
+ * Override debugfs's prompt
+ */
+const char *debug_prog_name = "tst_extents";
+
+#endif
+