Initial implemenation of extents support for e2fsprogs.  This is enough
so that e2fsck will pass a valid filesystem containing extents.

Eventually this will be split into a patch for the library changes, and
a separate patch for e2fsck, followed by test cases for e2fsprogs.
---
 e2fsck/message.c          |    2 +
 e2fsck/pass1.c            |   86 ++++++-
 e2fsck/problem.c          |    5 +
 e2fsck/problem.h          |    3 +
 lib/ext2fs/Makefile.in    |   68 +++++-
 lib/ext2fs/ext2_err.et.in |   40 +++-
 lib/ext2fs/ext2fs.h       |   62 +++++-
 lib/ext2fs/ext3_extents.h |   20 ++
 lib/ext2fs/extent.c       |  616 +++++++++++++++++++++++++++++++++++++++++++++
 lib/ext2fs/extent_dbg.ct  |   32 +++
 10 files changed, 926 insertions(+), 8 deletions(-)
 create mode 100644 lib/ext2fs/extent.c
 create mode 100644 lib/ext2fs/extent_dbg.ct

diff --git a/e2fsck/message.c b/e2fsck/message.c
index b2e3e0f..accf3a0 100644
--- a/e2fsck/message.c
+++ b/e2fsck/message.c
@@ -80,6 +80,7 @@
  *     @S      superblock
  *     @u      unattached
  *     @v      device
+ *     @x      extent
  *     @z      zero-length
  */
 
@@ -134,6 +135,7 @@ static const char *abbrevs[] = {
        N_("[EMAIL PROTECTED]"),
        N_("uunattached"),
        N_("vdevice"),
+       N_("xextent"),
        N_("zzero-length"),
        "@@",
        0
diff --git a/e2fsck/pass1.c b/e2fsck/pass1.c
index 7fba823..f9b7ea3 100644
--- a/e2fsck/pass1.c
+++ b/e2fsck/pass1.c
@@ -908,10 +908,11 @@ void e2fsck_pass1(e2fsck_t ctx)
                        ctx->fs_dind_count++;
                if (inode->i_block[EXT2_TIND_BLOCK])
                        ctx->fs_tind_count++;
-               if (inode->i_block[EXT2_IND_BLOCK] ||
-                   inode->i_block[EXT2_DIND_BLOCK] ||
-                   inode->i_block[EXT2_TIND_BLOCK] ||
-                   inode->i_file_acl) {
+               if (!(inode->i_flags & EXT4_EXTENTS_FL) &&
+                   (inode->i_block[EXT2_IND_BLOCK] ||
+                    inode->i_block[EXT2_DIND_BLOCK] ||
+                    inode->i_block[EXT2_TIND_BLOCK] ||
+                    inode->i_file_acl)) {
                        inodes_to_process[process_inode_count].ino = ino;
                        inodes_to_process[process_inode_count].inode = *inode;
                        process_inode_count++;
@@ -1488,6 +1489,78 @@ void e2fsck_clear_inode(e2fsck_t ctx, ext2_ino_t ino,
        e2fsck_write_inode(ctx, ino, inode, source);
 }
 
+static void scan_extent_node(e2fsck_t ctx, struct problem_context *pctx,
+                            ext2_extent_handle_t ehandle)
+{
+       struct ext2fs_extent    extent;
+       blk_t                   blk;
+       e2_blkcnt_t             blockcnt;
+       int                     i;
+       int                     is_dir, is_leaf;
+
+
+       pctx->errcode = ext2fs_extent_get(ehandle, EXT2_EXTENT_FIRST_SIB,
+                                         &extent);
+       while (!pctx->errcode) {
+               is_leaf = extent.e_flags & EXT2_EXTENT_FLAGS_LEAF;
+               is_dir = LINUX_S_ISDIR(pctx->inode->i_mode);
+
+               if (!is_leaf) {
+                       mark_block_used(ctx, extent.e_pblk);
+                       pctx->errcode = ext2fs_extent_get(ehandle, 
+                                                 EXT2_EXTENT_DOWN, &extent);
+                       scan_extent_node(ctx, pctx, ehandle);
+                       pctx->errcode = ext2fs_extent_get(ehandle, 
+                                                 EXT2_EXTENT_UP, &extent);
+                       goto next;
+               }
+                       
+               for (blk = extent.e_pblk, blockcnt = extent.e_lblk, i = 0;
+                    i < extent.e_len;
+                    blk++, blockcnt++, i++) {
+                       mark_block_used(ctx, blk);
+
+                       if (is_dir) {
+                               pctx->errcode = 
ext2fs_add_dir_block(ctx->fs->dblist, pctx->ino, blk, blockcnt);
+                               if (pctx->errcode) {
+                                       pctx->blk = blk;
+                                       pctx->num = blockcnt;
+                                       fix_problem(ctx, PR_1_ADD_DBLOCK, pctx);
+                                       /* Should never get here */
+                                       ctx->flags |= E2F_FLAG_ABORT;
+                                       return;
+                               }
+                       }
+               }
+       next:
+               pctx->errcode = ext2fs_extent_get(ehandle, 
+                                                 EXT2_EXTENT_NEXT_SIB,
+                                                 &extent);
+       }
+}
+
+
+static void check_blocks_extents(e2fsck_t ctx, struct problem_context *pctx,
+                                char *block_buf)
+{
+       struct ext2_inode       *inode = pctx->inode;
+       ext2_extent_handle_t    ehandle;
+       ext2_filsys             fs = ctx->fs;
+       ext2_ino_t              ino = pctx->ino;
+
+       pctx->errcode = ext2fs_extent_open(fs, ino, &ehandle);
+       if (pctx->errcode &&
+           fix_problem(ctx, PR_1_READ_EXTENT, pctx)) {
+               e2fsck_clear_inode(ctx, ino, inode, 0, "check_blocks_extents");
+               return;
+       }
+
+       scan_extent_node(ctx, pctx, ehandle);
+
+       ext2fs_extent_free(ehandle);
+       
+}
+
 /*
  * This subroutine is called on each inode to account for all of the
  * blocks used by that inode.
@@ -1503,6 +1576,11 @@ static void check_blocks(e2fsck_t ctx, struct 
problem_context *pctx,
        int             dirty_inode = 0;
        __u64           size;
        
+       if (inode->i_flags & EXT4_EXTENTS_FL) {
+               check_blocks_extents(ctx, pctx, block_buf);
+               return;
+       }
+
        pb.ino = ino;
        pb.num_blocks = 0;
        pb.last_block = -1;
diff --git a/e2fsck/problem.c b/e2fsck/problem.c
index 0b6fd39..8c8be7e 100644
--- a/e2fsck/problem.c
+++ b/e2fsck/problem.c
@@ -784,6 +784,11 @@ static struct e2fsck_problem problem_table[] = {
          N_("@i %i is a %It but it looks like it is really a directory.\n"),
          PROMPT_FIX, 0 },
 
+       /* Error while reading extent tree */
+       { PR_1_READ_EXTENT,
+         N_("Error while reading over @x tree in @i %i: %m\n"),
+         PROMPT_CLEAR_INODE, 0 },
+
        /* Pass 1b errors */
 
        /* Pass 1B: Rescan for duplicate/bad blocks */
diff --git a/e2fsck/problem.h b/e2fsck/problem.h
index f5f7212..538dee2 100644
--- a/e2fsck/problem.h
+++ b/e2fsck/problem.h
@@ -455,6 +455,9 @@ struct problem_context {
 /* inode appears to be a directory */
 #define PR_1_TREAT_AS_DIRECTORY                0x010055
 
+/* Error while reading extent tree */
+#define PR_1_READ_EXTENT               0x010056
+
 /*
  * Pass 1b errors
  */
diff --git a/lib/ext2fs/Makefile.in b/lib/ext2fs/Makefile.in
index 03ce131..f3edbf7 100644
--- a/lib/ext2fs/Makefile.in
+++ b/lib/ext2fs/Makefile.in
@@ -10,6 +10,8 @@ INSTALL = @INSTALL@
 @[EMAIL PROTECTED] = bb_compat.o fileio.o \
 @DEBUGFS_CMT@  inode_io.o namei.o write_bb_file.o 
 
+MK_CMDS=       _SS_DIR_OVERRIDE=../ss ../ss/mk_cmds
+
 @[EMAIL PROTECTED] = dupfs.o test_io.o 
 
 @[EMAIL PROTECTED] = imager.o
@@ -35,6 +37,7 @@ OBJS= $(DEBUGFS_LIB_OBJS) $(RESIZE_LIB_OBJS) 
$(E2IMAGE_LIB_OBJS) \
        dir_iterate.o \
        expanddir.o \
        ext_attr.o \
+       extent.o \
        finddev.o \
        flushb.o \
        freefs.o \
@@ -90,6 +93,7 @@ SRCS= ext2_err.c \
        $(srcdir)/dupfs.c \
        $(srcdir)/expanddir.c \
        $(srcdir)/ext_attr.c \
+       $(srcdir)/extent.c \
        $(srcdir)/fileio.c \
        $(srcdir)/finddev.c \
        $(srcdir)/flushb.c \
@@ -239,6 +243,68 @@ ext2_tdbtool: tdbtool.o
        @echo " LD $@"
        @$(CC) -o ext2_tdbtool tdbtool.o tdb.o
 
+extent_dbg.c: $(srcdir)/extent_dbg.ct
+       @echo " MK_CMDS $<"
+       @$(MK_CMDS) $(srcdir)/extent_dbg.ct
+
+debug_cmds.c debug_cmds.h: $(top_srcdir)/debugfs/debug_cmds.ct
+       @echo " MK_CMDS $<@"
+       @$(MK_CMDS) $(top_srcdir)/debugfs/debug_cmds.ct
+
+DEBUG_OBJS= debug_cmds.o debugfs.o util.o ncheck.o icheck.o ls.o \
+       lsdel.o dump.o set_fields.o logdump.o htree.o unused.o
+
+debugfs.o: $(top_srcdir)/debugfs/debugfs.c
+       @echo " CC $<"
+       @$(CC) $(ALL_CFLAGS) -c $< -o $@
+
+util.o: $(top_srcdir)/debugfs/util.c
+       @echo " CC $<"
+       @$(CC) $(ALL_CFLAGS) -c $< -o $@
+
+ncheck.o: $(top_srcdir)/debugfs/ncheck.c
+       @echo " CC $<"
+       @$(CC) $(ALL_CFLAGS) -c $< -o $@
+
+icheck.o: $(top_srcdir)/debugfs/icheck.c
+       @echo " CC $<"
+       @$(CC) $(ALL_CFLAGS) -c $< -o $@
+
+ls.o: $(top_srcdir)/debugfs/ls.c
+       @echo " CC $<"
+       @$(CC) $(ALL_CFLAGS) -c $< -o $@
+
+lsdel.o: $(top_srcdir)/debugfs/lsdel.c
+       @echo " CC $<"
+       @$(CC) $(ALL_CFLAGS) -c $< -o $@
+
+dump.o: $(top_srcdir)/debugfs/dump.c
+       @echo " CC $<"
+       @$(CC) $(ALL_CFLAGS) -c $< -o $@
+
+set_fields.o: $(top_srcdir)/debugfs/set_fields.c
+       @echo " CC $<"
+       @$(CC) $(ALL_CFLAGS) -c $< -o $@
+
+logdump.o: $(top_srcdir)/debugfs/logdump.c
+       @echo " CC $<"
+       @$(CC) $(ALL_CFLAGS) -c $< -o $@
+
+htree.o: $(top_srcdir)/debugfs/htree.c
+       @echo " CC $<"
+       @$(CC) $(ALL_CFLAGS) -c $< -o $@
+
+unused.o: $(top_srcdir)/debugfs/unused.c
+       @echo " CC $<"
+       @$(CC) $(ALL_CFLAGS) -c $< -o $@
+
+tst_extents: $(srcdir)/extent.c extent_dbg.c $(DEBUG_OBJS) $(LIBSS) $(LIBE2P) 
$(DEPLIBUUID) $(DEPLIBBLKID)
+       @echo " LD $@"
+       @$(CC) -o tst_extents $(srcdir)/extent.c extent_dbg.c \
+               $(ALL_CFLAGS) -DDEBUG $(DEBUG_OBJS) $(LIBSS) $(LIBE2P) \
+               $(LIBUUID) $(STATIC_LIBEXT2FS) $(LIBBLKID) $(LIBCOM_ERR) \
+               -I $(top_srcdir)/debugfs
+
 mkjournal: mkjournal.c $(STATIC_LIBEXT2FS)
        @echo " LD $@"
        @$(CC) -o mkjournal $(srcdir)/mkjournal.c -DDEBUG $(STATIC_LIBEXT2FS) 
$(LIBCOM_ERR) $(ALL_CFLAGS)
@@ -282,7 +348,7 @@ clean::
                tst_badblocks tst_iscan ext2_err.et ext2_err.c ext2_err.h \
                tst_byteswap tst_ismounted tst_getsize tst_sectgetsize \
                tst_bitops tst_types tst_icount tst_super_size \
-               ext2_tdbtool mkjournal \
+               ext2_tdbtool mkjournal debug_cmds.c \
                ../libext2fs.a ../libext2fs_p.a ../libext2fs_chk.a
 
 mostlyclean:: clean
diff --git a/lib/ext2fs/ext2_err.et.in b/lib/ext2fs/ext2_err.et.in
index eda4bb4..5d62548 100644
--- a/lib/ext2fs/ext2_err.et.in
+++ b/lib/ext2fs/ext2_err.et.in
@@ -62,8 +62,8 @@ ec    EXT2_ET_MAGIC_E2IMAGE,
 ec     EXT2_ET_MAGIC_INODE_IO_CHANNEL,
        "Wrong magic number for inode io_channel structure"
 
-ec     EXT2_ET_MAGIC_RESERVED_9,
-       "Wrong magic number --- RESERVED_9"
+ec     EXT2_ET_MAGIC_EXTENT_HANDLE,
+       "Wrong magic number for ext4 extent handle"
 
 ec     EXT2_ET_BAD_MAGIC,
        "Bad magic number in super-block"
@@ -326,5 +326,41 @@ ec EXT2_ET_TDB_ERR_NOEXIST,
 ec     EXT2_ET_TDB_ERR_RDONLY,
        "TDB: Write not permitted"
 
+ec     EXT2_ET_EXTENT_HEADER_BAD,
+       "Corrupt extent header"
+
+ec     EXT2_ET_EXTENT_INDEX_BAD,
+       "Corrupt extent index"
+
+ec     EXT2_ET_EXTENT_LEAF_BAD,
+       "Corrupt extent"
+
+ec     EXT2_ET_EXTENT_NO_SPACE,
+       "No free space in extent map"
+
+ec     EXT2_ET_INODE_NOT_EXTENT,
+       "Inode does not use extents"
+
+ec     EXT2_ET_EXTENT_NO_NEXT,
+       "No 'next' extent"
+
+ec     EXT2_ET_EXTENT_NO_PREV,
+       "No 'previous' extent"
+
+ec     EXT2_ET_EXTENT_NO_UP,
+       "No 'up' extent"
+
+ec     EXT2_ET_EXTENT_NO_DOWN,
+       "No 'down' extent"
+
+ec     EXT2_ET_NO_CURRENT_NODE,
+       "No current node"
+
+ec     EXT2_ET_OP_NOT_SUPPORTED,
+       "Ext2fs operation not supported"
+
+ec     EXT2_ET_CANT_INSERT_EXTENT,
+       "No room to insert extent in node"
+
        end
 
diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h
index 83a9091..022d7f4 100644
--- a/lib/ext2fs/ext2fs.h
+++ b/lib/ext2fs/ext2fs.h
@@ -65,6 +65,7 @@ extern "C" {
 
 typedef __u32          ext2_ino_t;
 typedef __u32          blk_t;
+typedef __u64          blk64_t;
 typedef __u32          dgrp_t;
 typedef __u32          ext2_off_t;
 typedef __s64          e2_blkcnt_t;
@@ -285,6 +286,51 @@ struct struct_ext2_filsys {
 #endif
 
 /*
+ * Generic (non-filesystem layout specific) extents structure
+ */
+
+#define EXT2_EXTENT_FLAGS_LEAF         0x0001
+#define EXT2_EXTENT_FLAGS_UNINIT       0x0002
+
+struct ext2fs_extent {
+       blk64_t e_pblk;         /* first physical block */
+       blk64_t e_lblk;         /* first logical block extent covers */
+       __u32   e_len;          /* number of blocks covered by extent */
+       __u32   e_flags;        /* extent flags */
+};
+
+typedef struct ext2_extent_handle *ext2_extent_handle_t;
+
+/*
+ * Flags used by ext2fs_extent_get()
+ */
+#define EXT2_EXTENT_CURRENT    0x0000
+#define EXT2_EXTENT_MOVE_MASK  0x000F
+#define EXT2_EXTENT_ROOT       0x0001
+#define EXT2_EXTENT_FIRST_SIB  0x0002
+#define EXT2_EXTENT_NEXT_SIB   0x0003
+#define EXT2_EXTENT_PREV_SIB   0x0004
+#define EXT2_EXTENT_UP         0x0005
+#define EXT2_EXTENT_DOWN       0x0006
+#define EXT2_EXTENT_NEXT_LEAF  0x0007
+#define EXT2_EXTENT_PREV_LEAF  0x0008
+
+/*
+ * Data structure returned by ext2fs_extent_get_info()
+ */
+struct ext2_extent_info {
+       int             curr_entry;
+       int             curr_level;
+       int             num_entries;
+       int             max_entries;
+       int             bytes_avail;
+       blk64_t         max_lblk;
+       blk64_t         max_pblk;
+       __u32           max_len;
+       __u32           max_uninit_len;
+};
+       
+/*
  * Flags for directory block reading and writing functions
  */
 #define EXT2_DIRBLOCK_V2_STRUCT        0x0001
@@ -437,7 +483,8 @@ typedef struct ext2_icount *ext2_icount_t;
 #define EXT2_LIB_FEATURE_INCOMPAT_SUPP (EXT2_FEATURE_INCOMPAT_FILETYPE|\
                                         EXT3_FEATURE_INCOMPAT_JOURNAL_DEV|\
                                         EXT2_FEATURE_INCOMPAT_META_BG|\
-                                        EXT3_FEATURE_INCOMPAT_RECOVER)
+                                        EXT3_FEATURE_INCOMPAT_RECOVER|\
+                                        EXT3_FEATURE_INCOMPAT_EXTENTS)
 #endif
 #define EXT2_LIB_FEATURE_RO_COMPAT_SUPP        
(EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER|\
                                         EXT2_FEATURE_RO_COMPAT_LARGE_FILE)
@@ -715,6 +762,19 @@ extern errcode_t ext2fs_adjust_ea_refcount(ext2_filsys fs, 
blk_t blk,
                                           char *block_buf,
                                           int adjust, __u32 *newcount);
 
+/* extent.c */
+extern errcode_t ext2fs_extent_open(ext2_filsys fs, ext2_ino_t ino,
+                                   ext2_extent_handle_t *handle);
+extern errcode_t ext2fs_extent_get(ext2_extent_handle_t handle,
+                                  int flags, struct ext2fs_extent *extent);
+extern errcode_t ext2fs_extent_replace(ext2_extent_handle_t handle, int flags,
+                                      struct ext2fs_extent *extent);
+extern errcode_t ext2fs_extent_insert(ext2_extent_handle_t handle, int flags,
+                                     struct ext2fs_extent *extent);
+extern errcode_t ext2fs_extent_delete(ext2_extent_handle_t handle, int flags);
+extern errcode_t ext2fs_extent_get_info(ext2_extent_handle_t handle,
+                                       struct ext2_extent_info *info);
+
 /* fileio.c */
 extern errcode_t ext2fs_file_open2(ext2_filsys fs, ext2_ino_t ino,
                                   struct ext2_inode *inode,
diff --git a/lib/ext2fs/ext3_extents.h b/lib/ext2fs/ext3_extents.h
index c4178c9..ba980e4 100644
--- a/lib/ext2fs/ext3_extents.h
+++ b/lib/ext2fs/ext3_extents.h
@@ -126,6 +126,26 @@ struct ext3_ext_path {
 #define EXT_MAX_BLOCK  0xffffffff
 #define EXT_CACHE_MARK 0xffff
 
+/*
+ * EXT_INIT_MAX_LEN is the maximum number of blocks we can have in an
+ * initialized extent. This is 2^15 and not (2^16 - 1), since we use the
+ * MSB of ee_len field in the extent datastructure to signify if this
+ * particular extent is an initialized extent or an uninitialized (i.e.
+ * preallocated).
+ * EXT_UNINIT_MAX_LEN is the maximum number of blocks we can have in an
+ * uninitialized extent.
+ * If ee_len is <= 0x8000, it is an initialized extent. Otherwise, it is an
+ * uninitialized one. In other words, if MSB of ee_len is set, it is an
+ * uninitialized extent with only one special scenario when ee_len = 0x8000.
+ * In this case we can not have an uninitialized extent of zero length and
+ * thus we make it as a special case of initialized extent with 0x8000 length.
+ * This way we get better extent-to-group alignment for initialized extents.
+ * Hence, the maximum number of blocks we can have in an *initialized*
+ * extent is 2^15 (32768) and in an *uninitialized* extent is 2^15-1 (32767).
+ */
+#define EXT_INIT_MAX_LEN       (1UL << 15)
+#define EXT_UNINIT_MAX_LEN     (EXT_INIT_MAX_LEN - 1)
+
 
 #define EXT_FIRST_EXTENT(__hdr__) \
        ((struct ext3_extent *) (((char *) (__hdr__)) +         \
diff --git a/lib/ext2fs/extent.c b/lib/ext2fs/extent.c
new file mode 100644
index 0000000..a6f4f65
--- /dev/null
+++ b/lib/ext2fs/extent.c
@@ -0,0 +1,616 @@
+/*
+ * 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 Public
+ * License.
+ * %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"
+#include "ss/ss.h"
+
+/*
+ * Definitions to be dropped in lib/ext2fs/ext2fs.h
+ */
+
+/*
+ * Private definitions
+ */
+
+struct extent_path {
+       char            *buf;
+       int             entries;
+       int             max_entries;
+       int             left;
+       blk64_t         end_blk;
+       void            *curr;
+};
+       
+
+struct ext2_extent_handle {
+       errcode_t               magic;
+       ext2_filsys             fs;
+       ext2_ino_t              ino;
+       struct ext2_inode       *inode;
+       int                     type;
+       int                     level;
+       int                     max_depth;
+       struct extent_path      *path;
+};
+
+/*
+ *  Useful Debugging stuff
+ */
+
+#ifdef DEBUG
+#define EXT_DEBUG
+#endif
+
+#ifdef EXT_DEBUG
+static void ext_show_header(struct ext3_extent_header *eh)
+{
+       printf("header: magic=%x entries=%u max=%u depth=%u generation=%u\n",
+              eh->eh_magic, eh->eh_entries, eh->eh_max, eh->eh_depth,
+              eh->eh_generation);
+}
+
+static void ext_show_index(struct ext3_extent_idx *ix)
+{
+       printf("index: block=%u leaf=%u leaf_hi=%u unused=%u\n",
+              ix->ei_block, ix->ei_leaf, ix->ei_leaf_hi, ix->ei_unused);
+}
+
+static void ext_show_extent(struct ext3_extent *ex)
+{
+       printf("extent: block=%u-%u len=%u start=%u start_hi=%u\n",
+              ex->ee_block, ex->ee_block + ex->ee_len - 1,
+              ex->ee_len, ex->ee_start, ex->ee_start_hi);
+}
+
+#define ext_printf(fmt, args...) printf(fmt, ## args)
+#else
+#define ext_show_header(eh) do { } while (0)
+#define ext_show_index(ix) do { } while (0)
+#define ext_show_extent(ex) do { } while (0)
+#define ext_printf(fmt, args...) do { } while (0)
+#endif
+
+/*
+ * Begin functions to handle an inode's extent information
+ */
+
+extern void ext2fs_extent_free(ext2_extent_handle_t handle)
+{
+       int                     i;
+
+       if (!handle)
+               return;
+
+       if (handle->inode)
+               ext2fs_free_mem(&handle->inode);
+       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);
+}
+
+extern errcode_t ext2fs_extent_open(ext2_filsys fs, ext2_ino_t ino,
+                                   ext2_extent_handle_t *ret_handle)
+{
+       struct ext2_extent_handle       *handle;
+       errcode_t                       retval;
+       int                             isize = EXT2_INODE_SIZE(fs->super);
+       struct ext3_extent_header       *eh;
+       struct ext3_extent_idx          *ix;
+
+       EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
+
+       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));
+
+       retval = ext2fs_get_mem(isize, &handle->inode);
+       if (retval)
+               goto errout;
+
+       handle->ino = ino;
+       handle->fs = fs;
+
+       retval = ext2fs_read_inode_full(fs, ino, handle->inode, isize);
+       if (retval)
+               goto errout;
+
+       if (!(handle->inode->i_flags & EXT4_EXTENTS_FL))
+               return EXT2_ET_INODE_NOT_EXTENT;
+
+       eh = (struct ext3_extent_header *) &handle->inode->i_block;
+
+       if (ext2fs_le16_to_cpu(eh->eh_magic) != EXT3_EXT_MAGIC)
+               return EXT2_ET_EXTENT_HEADER_BAD;
+
+       ext_show_header(eh);
+
+       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 = 
+               ((((__u64) handle->inode->i_size_high << 32) +
+                 handle->inode->i_size + (fs->blocksize - 1))
+                >> EXT2_BLOCK_SIZE_BITS(fs->super));
+       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;
+       blk_t                           blk;
+       blk64_t                         end_blk;
+
+       EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);
+
+       if (!handle->path)
+               return EXT2_ET_NO_CURRENT_NODE;
+
+       path = handle->path + handle->level;
+       switch (flags & EXT2_EXTENT_MOVE_MASK) {
+       case EXT2_EXTENT_CURRENT:
+               ix = path->curr;
+               break;
+       case EXT2_EXTENT_ROOT:
+               handle->level = 0;
+       case EXT2_EXTENT_FIRST_SIB:
+               path->left = path->entries;
+               path->curr = 0;
+       case EXT2_EXTENT_NEXT_SIB:
+               if (path->curr) {
+                       if (path->left <= 0)
+                               return EXT2_ET_EXTENT_NO_NEXT;
+                       ix = path->curr;
+                       ix++;
+               } else {
+                       if (path->entries == 0)
+                               return EXT2_ET_EXTENT_NO_NEXT;
+                       eh = (struct ext3_extent_header *) path->buf;
+                       ix = EXT_FIRST_INDEX(eh);
+               }
+               path->left--;
+               path->curr = ix;
+               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++;
+               break;
+       case EXT2_EXTENT_UP:
+               if (handle->level <= 0)
+                       return EXT2_ET_EXTENT_NO_UP;
+               handle->level--;
+               path--;
+               ix = path->curr;
+               break;
+       case EXT2_EXTENT_DOWN:
+               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));
+               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_blk(handle->fs->io, 
+                                                    blk, 1, newpath->buf);
+                       if (retval)
+                               return retval;
+               }
+               handle->level++;
+
+               eh = (struct ext3_extent_header *) newpath->buf;
+
+               ext_show_header(eh);
+               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;
+
+               ix = EXT_FIRST_INDEX((struct ext3_extent_header *) eh);
+               newpath->curr = ix;
+               newpath->left = newpath->entries - 1;
+               path = newpath;
+
+               ext_printf("Down to level %d/%d, end_blk=%llu\n",
+                          handle->level, handle->max_depth,
+                          path->end_blk);
+
+               break;
+       default:
+               return EXT2_ET_OP_NOT_SUPPORTED;
+       }
+
+       if (!ix)
+               return EXT2_ET_NO_CURRENT_NODE;
+
+       ext_printf("Left is now: %d\n", path->left);
+
+       extent->e_flags = 0;
+
+       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;
+       }
+
+       return 0;
+}
+
+static errcode_t update_path(ext2_extent_handle_t handle)
+{
+       struct extent_path              *path;
+       blk64_t                         blk;
+       errcode_t                       retval;
+       struct ext3_extent_idx          *ix;
+
+       if (handle->level == 0) {
+               retval = ext2fs_write_inode_full(handle->fs, handle->ino, 
+                          handle->inode, EXT2_INODE_SIZE(handle->fs->super));
+       } 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_blk(handle->fs->io, 
+                                     blk, 1, handle->path[handle->level].buf);
+       }
+       return retval;
+}
+
+errcode_t ext2fs_extent_replace(ext2_extent_handle_t handle, int flags,
+                               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->path)
+               return EXT2_ET_NO_CURRENT_NODE;
+
+       path = handle->path + handle->level;
+       if (!path->curr)
+               return EXT2_ET_NO_CURRENT_NODE;
+
+       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);
+               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;
+}
+
+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->path)
+               return EXT2_ET_NO_CURRENT_NODE;
+
+       path = handle->path + handle->level;
+
+       eh = (struct ext3_extent_header *) path->buf;
+       if (path->curr) {
+               ix = path->curr;
+               ix++;
+       } else
+               path->curr = ix = EXT_FIRST_INDEX(eh);
+               
+       if (path->left)
+               memmove(ix, ix + 1, 
+                       path->left * sizeof(struct ext3_extent_idx));
+       path->left++;
+       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;
+}
+
+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;
+
+       EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);
+
+       if (!handle->path)
+               return EXT2_ET_NO_CURRENT_NODE;
+
+       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--;
+       }
+       path->entries--;
+       if (path->entries == 0)
+               path->curr = 0;
+
+       eh = (struct ext3_extent_header *) path->buf;
+       eh->eh_entries = ext2fs_cpu_to_le16(path->entries);
+
+       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;
+       struct ext3_extent_idx          *ix;
+       struct ext3_extent              *ex;
+
+       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;
+       }
+
+       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
+
+#include "debugfs.h"
+
+/*
+ * Hook in new commands into debugfs
+ */
+char *debug_prog_name = "tst_extents";
+extern ss_request_table extent_cmds;
+ss_request_table *extra_cmds = &extent_cmds;
+
+ext2_ino_t     current_ino = 0;
+ext2_extent_handle_t current_handle;
+
+void do_inode(int argc, char *argv[])
+{
+       ext2_ino_t      inode;
+       int             i;
+       struct ext3_extent_header *eh;
+       errcode_t retval;
+
+       if (check_fs_open(argv[0]))
+               return;
+
+       if (argc == 1) {
+               if (current_ino)
+                       printf("Current inode is %d\n", current_ino);
+               else
+                       printf("No current inode\n");
+               return;
+       }
+
+       if (common_inode_args_process(argc, argv, &inode, 0)) {
+               return;
+       }
+
+       current_ino = 0;
+
+       retval = ext2fs_extent_open(current_fs, inode, &current_handle);
+       if (retval) {
+               com_err(argv[1], retval, "while opening extent handle");
+               return;
+       }
+
+       current_ino = inode;
+
+       printf("Loaded inode %d\n", current_ino);
+
+       return;
+}
+
+void generic_goto_node(char *cmd_name, int op)
+{
+       struct ext2fs_extent    extent;
+       errcode_t               retval;
+       
+       if (check_fs_open(cmd_name))
+               return;
+
+       retval = ext2fs_extent_get(current_handle, op, &extent);
+       if (retval) {
+               com_err(cmd_name, retval, 0);
+               return;
+       }
+       printf("Extent: lblk %llu, len %lu, pblk %llu, flags: ",
+              extent.e_lblk, 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)
+               fputs("(none)", stdout);
+       fputc('\n', stdout);
+}
+
+
+void do_current_node(int argc, char *argv[])
+{
+       generic_goto_node(argv[0], EXT2_EXTENT_CURRENT);
+}
+
+void do_root_node(int argc, char *argv[])
+{
+       generic_goto_node(argv[0], EXT2_EXTENT_ROOT);
+}
+
+void do_first_sib(int argc, char *argv[])
+{
+       generic_goto_node(argv[0], EXT2_EXTENT_FIRST_SIB);
+}
+
+void do_next_sib(int argc, char *argv[])
+{
+       generic_goto_node(argv[0], EXT2_EXTENT_NEXT_SIB);
+}
+
+void do_prev_sib(int argc, char *argv[])
+{
+       generic_goto_node(argv[0], EXT2_EXTENT_PREV_SIB);
+}
+
+void do_up(int argc, char *argv[])
+{
+       generic_goto_node(argv[0], EXT2_EXTENT_UP);
+}
+
+void do_down(int argc, char *argv[])
+{
+       generic_goto_node(argv[0], EXT2_EXTENT_DOWN);
+}
+
+#endif
diff --git a/lib/ext2fs/extent_dbg.ct b/lib/ext2fs/extent_dbg.ct
new file mode 100644
index 0000000..21ece39
--- /dev/null
+++ b/lib/ext2fs/extent_dbg.ct
@@ -0,0 +1,32 @@
+#
+# Copyright (C) 1993 Theodore Ts'o.  This file may be redistributed
+# under the terms of the GNU Public License.
+#
+command_table extent_cmds;
+
+request do_inode, "Open an inode",
+       inode;
+
+request do_current_node, "Current extent node",
+       current_node, current;
+
+request do_root_node, "Goto root extent",
+       root_node, root;
+
+request do_first_sib, "First sibling",
+       first_sibling, first_sib;
+
+request do_next_sib, "Next sibling",
+       next_sibling, next_sib, next;
+
+request do_prev_sib, "Previous sibling",
+       prev_sibling, prev_sib, prev;
+
+request do_up, "Up node",
+       up_node, up;
+
+request do_down, "Down node",
+       down_node, down;
+
+end;
+
-- 
1.5.3.1.19.gb5ef6

-
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to