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libext2fs: fix potential resource leak in ext2fs_file_write
[tools/e2fsprogs.git] / lib / ext2fs / fileio.c
index d876cd1..a0b5d97 100644 (file)
@@ -1,27 +1,24 @@
 /*
  * fileio.c --- Simple file I/O routines
- * 
+ *
  * Copyright (C) 1997 Theodore Ts'o.
  *
  * %Begin-Header%
- * This file may be redistributed under the terms of the GNU Public
- * License.
+ * 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 EXT2_FLAT_INCLUDES
 #include "ext2_fs.h"
-#else
-#include <linux/ext2_fs.h>
-#endif
-
 #include "ext2fs.h"
+#include "ext2fsP.h"
 
 struct ext2_file {
        errcode_t               magic;
@@ -29,14 +26,23 @@ struct ext2_file {
        ext2_ino_t              ino;
        struct ext2_inode       inode;
        int                     flags;
-       ext2_off_t              pos;
-       blk_t                   blockno;
-       blk_t                   physblock;
+       __u64                   pos;
+       blk64_t                 blockno;
+       blk64_t                 physblock;
        char                    *buf;
 };
 
-errcode_t ext2fs_file_open(ext2_filsys fs, ext2_ino_t ino,
-                          int flags, ext2_file_t *ret)
+struct block_entry {
+       blk64_t         physblock;
+       unsigned char   sha[EXT2FS_SHA512_LENGTH];
+};
+typedef struct block_entry *block_entry_t;
+
+#define BMAP_BUFFER (file->buf + fs->blocksize)
+
+errcode_t ext2fs_file_open2(ext2_filsys fs, ext2_ino_t ino,
+                           struct ext2_inode *inode,
+                           int flags, ext2_file_t *ret)
 {
        ext2_file_t     file;
        errcode_t       retval;
@@ -49,34 +55,44 @@ errcode_t ext2fs_file_open(ext2_filsys fs, ext2_ino_t ino,
            !(fs->flags & EXT2_FLAG_RW))
                return EXT2_ET_RO_FILSYS;
 
-       retval = ext2fs_get_mem(sizeof(struct ext2_file), (void **) &file);
+       retval = ext2fs_get_mem(sizeof(struct ext2_file), &file);
        if (retval)
                return retval;
-       
+
        memset(file, 0, sizeof(struct ext2_file));
        file->magic = EXT2_ET_MAGIC_EXT2_FILE;
        file->fs = fs;
        file->ino = ino;
        file->flags = flags & EXT2_FILE_MASK;
 
-       retval = ext2fs_read_inode(fs, ino, &file->inode);
-       if (retval)
-               goto fail;
-       
-       retval = ext2fs_get_mem(fs->blocksize * 2, (void **) &file->buf);
+       if (inode) {
+               memcpy(&file->inode, inode, sizeof(struct ext2_inode));
+       } else {
+               retval = ext2fs_read_inode(fs, ino, &file->inode);
+               if (retval)
+                       goto fail;
+       }
+
+       retval = ext2fs_get_array(3, fs->blocksize, &file->buf);
        if (retval)
                goto fail;
 
        *ret = file;
        return 0;
-       
+
 fail:
        if (file->buf)
-               ext2fs_free_mem((void **) &file->buf);
-       ext2fs_free_mem((void **) &file);
+               ext2fs_free_mem(&file->buf);
+       ext2fs_free_mem(&file);
        return retval;
 }
 
+errcode_t ext2fs_file_open(ext2_filsys fs, ext2_ino_t ino,
+                          int flags, ext2_file_t *ret)
+{
+       return ext2fs_file_open2(fs, ino, NULL, flags, ret);
+}
+
 /*
  * This function returns the filesystem handle of a file from the structure
  */
@@ -88,33 +104,70 @@ ext2_filsys ext2fs_file_get_fs(ext2_file_t file)
 }
 
 /*
+ * This function returns the pointer to the inode of a file from the structure
+ */
+struct ext2_inode *ext2fs_file_get_inode(ext2_file_t file)
+{
+       if (file->magic != EXT2_ET_MAGIC_EXT2_FILE)
+               return NULL;
+       return &file->inode;
+}
+
+/* This function returns the inode number from the structure */
+ext2_ino_t ext2fs_file_get_inode_num(ext2_file_t file)
+{
+       if (file->magic != EXT2_ET_MAGIC_EXT2_FILE)
+               return 0;
+       return file->ino;
+}
+
+/*
  * This function flushes the dirty block buffer out to disk if
  * necessary.
  */
-static errcode_t ext2fs_file_flush(ext2_file_t file)
+errcode_t ext2fs_file_flush(ext2_file_t file)
 {
        errcode_t       retval;
-       
+       ext2_filsys fs;
+       int             ret_flags;
+       blk64_t         dontcare;
+
        EXT2_CHECK_MAGIC(file, EXT2_ET_MAGIC_EXT2_FILE);
+       fs = file->fs;
 
        if (!(file->flags & EXT2_FILE_BUF_VALID) ||
            !(file->flags & EXT2_FILE_BUF_DIRTY))
                return 0;
 
+       /* Is this an uninit block? */
+       if (file->physblock && file->inode.i_flags & EXT4_EXTENTS_FL) {
+               retval = ext2fs_bmap2(fs, file->ino, &file->inode, BMAP_BUFFER,
+                                     0, file->blockno, &ret_flags, &dontcare);
+               if (retval)
+                       return retval;
+               if (ret_flags & BMAP_RET_UNINIT) {
+                       retval = ext2fs_bmap2(fs, file->ino, &file->inode,
+                                             BMAP_BUFFER, BMAP_SET,
+                                             file->blockno, 0,
+                                             &file->physblock);
+                       if (retval)
+                               return retval;
+               }
+       }
+
        /*
         * OK, the physical block hasn't been allocated yet.
         * Allocate it.
         */
        if (!file->physblock) {
-               retval = ext2fs_bmap(file->fs, file->ino, &file->inode,
-                                    file->buf, BMAP_ALLOC,
-                                    file->blockno, &file->physblock);
+               retval = ext2fs_bmap2(fs, file->ino, &file->inode,
+                                    BMAP_BUFFER, file->ino ? BMAP_ALLOC : 0,
+                                    file->blockno, 0, &file->physblock);
                if (retval)
                        return retval;
        }
 
-       retval = io_channel_write_blk(file->fs->io, file->physblock,
-                                     1, file->buf);
+       retval = io_channel_write_blk64(fs->io, file->physblock, 1, file->buf);
        if (retval)
                return retval;
 
@@ -123,100 +176,227 @@ static errcode_t ext2fs_file_flush(ext2_file_t file)
        return retval;
 }
 
+/*
+ * This function synchronizes the file's block buffer and the current
+ * file position, possibly invalidating block buffer if necessary
+ */
+static errcode_t sync_buffer_position(ext2_file_t file)
+{
+       blk64_t b;
+       errcode_t       retval;
+
+       b = file->pos / file->fs->blocksize;
+       if (b != file->blockno) {
+               retval = ext2fs_file_flush(file);
+               if (retval)
+                       return retval;
+               file->flags &= ~EXT2_FILE_BUF_VALID;
+       }
+       file->blockno = b;
+       return 0;
+}
+
+/*
+ * This function loads the file's block buffer with valid data from
+ * the disk as necessary.
+ *
+ * If dontfill is true, then skip initializing the buffer since we're
+ * going to be replacing its entire contents anyway.  If set, then the
+ * function basically only sets file->physblock and EXT2_FILE_BUF_VALID
+ */
+#define DONTFILL 1
+static errcode_t load_buffer(ext2_file_t file, int dontfill)
+{
+       ext2_filsys     fs = file->fs;
+       errcode_t       retval;
+       int             ret_flags;
+
+       if (!(file->flags & EXT2_FILE_BUF_VALID)) {
+               retval = ext2fs_bmap2(fs, file->ino, &file->inode,
+                                    BMAP_BUFFER, 0, file->blockno, &ret_flags,
+                                    &file->physblock);
+               if (retval)
+                       return retval;
+               if (!dontfill) {
+                       if (file->physblock &&
+                           !(ret_flags & BMAP_RET_UNINIT)) {
+                               retval = io_channel_read_blk64(fs->io,
+                                                              file->physblock,
+                                                              1, file->buf);
+                               if (retval)
+                                       return retval;
+                       } else
+                               memset(file->buf, 0, fs->blocksize);
+               }
+               file->flags |= EXT2_FILE_BUF_VALID;
+       }
+       return 0;
+}
+
+
 errcode_t ext2fs_file_close(ext2_file_t file)
 {
        errcode_t       retval;
-       
+
        EXT2_CHECK_MAGIC(file, EXT2_ET_MAGIC_EXT2_FILE);
 
        retval = ext2fs_file_flush(file);
-       
+
        if (file->buf)
-               ext2fs_free_mem((void **) &file->buf);
-       ext2fs_free_mem((void **) &file);
+               ext2fs_free_mem(&file->buf);
+       ext2fs_free_mem(&file);
 
        return retval;
 }
 
 
+static errcode_t
+ext2fs_file_read_inline_data(ext2_file_t file, void *buf,
+                            unsigned int wanted, unsigned int *got)
+{
+       ext2_filsys fs;
+       errcode_t retval;
+       unsigned int count = 0;
+       size_t size;
+
+       fs = file->fs;
+       retval = ext2fs_inline_data_get(fs, file->ino, &file->inode,
+                                       file->buf, &size);
+       if (retval)
+               return retval;
+
+       if (file->pos >= size)
+               goto out;
+
+       count = size - file->pos;
+       if (count > wanted)
+               count = wanted;
+       memcpy(buf, file->buf + file->pos, count);
+       file->pos += count;
+       buf = (char *) buf + count;
+
+out:
+       if (got)
+               *got = count;
+       return retval;
+}
+
+
 errcode_t ext2fs_file_read(ext2_file_t file, void *buf,
                           unsigned int wanted, unsigned int *got)
 {
        ext2_filsys     fs;
-       errcode_t       retval;
-       blk_t           b, pb;
-       unsigned int    start, left, c, count = 0;
+       errcode_t       retval = 0;
+       unsigned int    start, c, count = 0;
+       __u64           left;
        char            *ptr = (char *) buf;
 
        EXT2_CHECK_MAGIC(file, EXT2_ET_MAGIC_EXT2_FILE);
        fs = file->fs;
 
-again:
-       if (file->pos >= file->inode.i_size)
-               goto done;
+       /* If an inode has inline data, things get complicated. */
+       if (file->inode.i_flags & EXT4_INLINE_DATA_FL)
+               return ext2fs_file_read_inline_data(file, buf, wanted, got);
 
-       b = file->pos / fs->blocksize;
-       if (b != file->blockno) {
-               retval = ext2fs_file_flush(file);
+       while ((file->pos < EXT2_I_SIZE(&file->inode)) && (wanted > 0)) {
+               retval = sync_buffer_position(file);
                if (retval)
                        goto fail;
-               file->flags &= ~EXT2_FILE_BUF_VALID;
-       }
-       file->blockno = b;
-       if (!(file->flags & EXT2_FILE_BUF_VALID)) {
-               retval = ext2fs_bmap(fs, file->ino, &file->inode,
-                                    file->buf, 0, b, &pb);
+               retval = load_buffer(file, 0);
                if (retval)
                        goto fail;
-               if (pb) {
-                       file->physblock = pb;
-                       retval = io_channel_read_blk(fs->io, pb, 1, file->buf);
-                       if (retval)
-                               goto fail;
-               } else {
-                       file->physblock = 0;
-                       memset(file->buf, 0, fs->blocksize);
-               }
-               
-               file->flags |= EXT2_FILE_BUF_VALID;
+
+               start = file->pos % fs->blocksize;
+               c = fs->blocksize - start;
+               if (c > wanted)
+                       c = wanted;
+               left = EXT2_I_SIZE(&file->inode) - file->pos ;
+               if (c > left)
+                       c = left;
+
+               memcpy(ptr, file->buf+start, c);
+               file->pos += c;
+               ptr += c;
+               count += c;
+               wanted -= c;
        }
-       start = file->pos % fs->blocksize;
-       c = fs->blocksize - start;
-       if (c > wanted)
-               c = wanted;
-       left = file->inode.i_size - file->pos ;
-       if (c > left)
-               c = left;
-       
-       memcpy(ptr, file->buf+start, c);
-       file->pos += c;
-       ptr += c;
-       count += c;
-       wanted -= c;
-
-       if (wanted > 0)
-               goto again;
-
-done:
-       if (got)
-               *got = count;
-       return 0;
 
 fail:
-       if (count)
-               goto done;
+       if (got)
+               *got = count;
        return retval;
 }
 
 
-errcode_t ext2fs_file_write(ext2_file_t file, void *buf,
+static errcode_t
+ext2fs_file_write_inline_data(ext2_file_t file, const void *buf,
+                             unsigned int nbytes, unsigned int *written)
+{
+       ext2_filsys fs;
+       errcode_t retval;
+       unsigned int count = 0;
+       size_t size;
+
+       fs = file->fs;
+       retval = ext2fs_inline_data_get(fs, file->ino, &file->inode,
+                                       file->buf, &size);
+       if (retval)
+               return retval;
+
+       if (file->pos < size) {
+               count = nbytes - file->pos;
+               memcpy(file->buf + file->pos, buf, count);
+
+               retval = ext2fs_inline_data_set(fs, file->ino, &file->inode,
+                                               file->buf, count);
+               if (retval == EXT2_ET_INLINE_DATA_NO_SPACE)
+                       goto expand;
+               if (retval)
+                       return retval;
+
+               file->pos += count;
+
+               /* Update inode size */
+               if (count != 0 && EXT2_I_SIZE(&file->inode) < file->pos) {
+                       errcode_t       rc;
+
+                       rc = ext2fs_file_set_size2(file, file->pos);
+                       if (retval == 0)
+                               retval = rc;
+               }
+
+               if (written)
+                       *written = count;
+               return 0;
+       }
+
+expand:
+       retval = ext2fs_inline_data_expand(fs, file->ino);
+       if (retval)
+               return retval;
+       /*
+        * reload inode and return no space error
+        *
+        * XXX: file->inode could be copied from the outside
+        * in ext2fs_file_open2().  We have no way to modify
+        * the outside inode.
+        */
+       retval = ext2fs_read_inode(fs, file->ino, &file->inode);
+       if (retval)
+               return retval;
+       return EXT2_ET_INLINE_DATA_NO_SPACE;
+}
+
+
+errcode_t ext2fs_file_write(ext2_file_t file, const void *buf,
                            unsigned int nbytes, unsigned int *written)
 {
        ext2_filsys     fs;
-       errcode_t       retval;
-       blk_t           b, pb;
-       unsigned int            start, c, count = 0;
-       char            *ptr = (char *) buf;
+       errcode_t       retval = 0;
+       unsigned int    start, c, count = 0;
+       const char      *ptr = (const char *) buf;
+       block_entry_t   new_block = NULL, old_block = NULL;
+       int             bmap_flags = 0;
 
        EXT2_CHECK_MAGIC(file, EXT2_ET_MAGIC_EXT2_FILE);
        fs = file->fs;
@@ -224,56 +404,110 @@ errcode_t ext2fs_file_write(ext2_file_t file, void *buf,
        if (!(file->flags & EXT2_FILE_WRITE))
                return EXT2_ET_FILE_RO;
 
-again:
-       b = file->pos / fs->blocksize;
-       if (b != file->blockno) {
-               retval = ext2fs_file_flush(file);
-               if (retval)
-                       goto fail;
-               file->flags &= ~EXT2_FILE_BUF_VALID;
+       /* If an inode has inline data, things get complicated. */
+       if (file->inode.i_flags & EXT4_INLINE_DATA_FL) {
+               retval = ext2fs_file_write_inline_data(file, buf, nbytes,
+                                                      written);
+               if (retval != EXT2_ET_INLINE_DATA_NO_SPACE)
+                       return retval;
+               /* fall through to read data from the block */
+               retval = 0;
        }
-       file->blockno = b;
-       if (!(file->flags & EXT2_FILE_BUF_VALID)) {
-               retval = ext2fs_bmap(fs, file->ino, &file->inode,
-                                    file->buf, BMAP_ALLOC, b, &pb);
+
+       while (nbytes > 0) {
+               retval = sync_buffer_position(file);
                if (retval)
                        goto fail;
-               file->physblock = pb;
-               
-               retval = io_channel_read_blk(fs->io, pb, 1, file->buf);
+
+               start = file->pos % fs->blocksize;
+               c = fs->blocksize - start;
+               if (c > nbytes)
+                       c = nbytes;
+
+               /*
+                * We only need to do a read-modify-update cycle if
+                * we're doing a partial write.
+                */
+               retval = load_buffer(file, (c == fs->blocksize));
                if (retval)
                        goto fail;
-               file->flags |= EXT2_FILE_BUF_VALID;
+
+               file->flags |= EXT2_FILE_BUF_DIRTY;
+               memcpy(file->buf+start, ptr, c);
+
+               /*
+                * OK, the physical block hasn't been allocated yet.
+                * Allocate it.
+                */
+               if (!file->physblock) {
+                       bmap_flags = (file->ino ? BMAP_ALLOC : 0);
+                       if (fs->flags & EXT2_FLAG_SHARE_DUP) {
+                               new_block = calloc(1, sizeof(*new_block));
+                               if (!new_block) {
+                                       retval = EXT2_ET_NO_MEMORY;
+                                       goto fail;
+                               }
+                               ext2fs_sha512((const unsigned char*)file->buf,
+                                               fs->blocksize, new_block->sha);
+                               old_block = ext2fs_hashmap_lookup(
+                                                       fs->block_sha_map,
+                                                       new_block->sha,
+                                                       sizeof(new_block->sha));
+                       }
+
+                       if (old_block) {
+                               file->physblock = old_block->physblock;
+                               bmap_flags |= BMAP_SET;
+                               free(new_block);
+                               new_block = NULL;
+                       }
+
+                       retval = ext2fs_bmap2(fs, file->ino, &file->inode,
+                                             BMAP_BUFFER,
+                                             bmap_flags,
+                                             file->blockno, 0,
+                                             &file->physblock);
+                       if (retval) {
+                               free(new_block);
+                               new_block = NULL;
+                               goto fail;
+                       }
+
+                       if (new_block) {
+                               new_block->physblock = file->physblock;
+                               ext2fs_hashmap_add(fs->block_sha_map, new_block,
+                                       new_block->sha, sizeof(new_block->sha));
+                       }
+
+                       if (bmap_flags & BMAP_SET) {
+                               ext2fs_iblk_add_blocks(fs, &file->inode, 1);
+                               ext2fs_write_inode(fs, file->ino, &file->inode);
+                       }
+               }
+
+               file->pos += c;
+               ptr += c;
+               count += c;
+               nbytes -= c;
        }
-       start = file->pos % fs->blocksize;
-       c = fs->blocksize - start;
-       if (c > nbytes)
-               c = nbytes;
-       
-       file->flags |= EXT2_FILE_BUF_DIRTY;
-       memcpy(file->buf+start, ptr, c);
-       file->pos += c;
-       ptr += c;
-       count += c;
-       nbytes -= c;
-
-       if (nbytes > 0)
-               goto again;
-
-done:
-       if (written)
-               *written = count;
-       return 0;
 
 fail:
-       if (count)
-               goto done;
+       /* Update inode size */
+       if (count != 0 && EXT2_I_SIZE(&file->inode) < file->pos) {
+               errcode_t       rc;
+
+               rc = ext2fs_file_set_size2(file, file->pos);
+               if (retval == 0)
+                       retval = rc;
+       }
+
+       if (written)
+               *written = count;
        return retval;
 }
 
-
-errcode_t ext2fs_file_lseek(ext2_file_t file, ext2_off_t offset,
-                           int whence, ext2_off_t *ret_pos)
+errcode_t ext2fs_file_llseek(ext2_file_t file, __u64 offset,
+                           int whence, __u64 *ret_pos)
 {
        EXT2_CHECK_MAGIC(file, EXT2_ET_MAGIC_EXT2_FILE);
 
@@ -282,7 +516,7 @@ errcode_t ext2fs_file_lseek(ext2_file_t file, ext2_off_t offset,
        else if (whence == EXT2_SEEK_CUR)
                file->pos += offset;
        else if (whence == EXT2_SEEK_END)
-               file->pos = file->inode.i_size + offset;
+               file->pos = EXT2_I_SIZE(&file->inode) + offset;
        else
                return EXT2_ET_INVALID_ARGUMENT;
 
@@ -292,34 +526,135 @@ errcode_t ext2fs_file_lseek(ext2_file_t file, ext2_off_t offset,
        return 0;
 }
 
+errcode_t ext2fs_file_lseek(ext2_file_t file, ext2_off_t offset,
+                           int whence, ext2_off_t *ret_pos)
+{
+       __u64           loffset, ret_loffset = 0;
+       errcode_t       retval;
+
+       loffset = offset;
+       retval = ext2fs_file_llseek(file, loffset, whence, &ret_loffset);
+       if (ret_pos)
+               *ret_pos = (ext2_off_t) ret_loffset;
+       return retval;
+}
+
+
+/*
+ * This function returns the size of the file, according to the inode
+ */
+errcode_t ext2fs_file_get_lsize(ext2_file_t file, __u64 *ret_size)
+{
+       if (file->magic != EXT2_ET_MAGIC_EXT2_FILE)
+               return EXT2_ET_MAGIC_EXT2_FILE;
+       *ret_size = EXT2_I_SIZE(&file->inode);
+       return 0;
+}
+
 /*
  * This function returns the size of the file, according to the inode
  */
 ext2_off_t ext2fs_file_get_size(ext2_file_t file)
 {
-       if (file->magic != EXT2_ET_MAGIC_EXT2_FILE)
+       __u64   size;
+
+       if (ext2fs_file_get_lsize(file, &size))
                return 0;
-       return file->inode.i_size;
+       if ((size >> 32) != 0)
+               return 0;
+       return size;
+}
+
+/* Zero the parts of the last block that are past EOF. */
+static errcode_t ext2fs_file_zero_past_offset(ext2_file_t file,
+                                             ext2_off64_t offset)
+{
+       ext2_filsys fs = file->fs;
+       char *b = NULL;
+       ext2_off64_t off = offset % fs->blocksize;
+       blk64_t blk;
+       int ret_flags;
+       errcode_t retval;
+
+       if (off == 0)
+               return 0;
+
+       retval = sync_buffer_position(file);
+       if (retval)
+               return retval;
+
+       /* Is there an initialized block at the end? */
+       retval = ext2fs_bmap2(fs, file->ino, NULL, NULL, 0,
+                             offset / fs->blocksize, &ret_flags, &blk);
+       if (retval)
+               return retval;
+       if ((blk == 0) || (ret_flags & BMAP_RET_UNINIT))
+               return 0;
+
+       /* Zero to the end of the block */
+       retval = ext2fs_get_mem(fs->blocksize, &b);
+       if (retval)
+               return retval;
+
+       /* Read/zero/write block */
+       retval = io_channel_read_blk64(fs->io, blk, 1, b);
+       if (retval)
+               goto out;
+
+       memset(b + off, 0, fs->blocksize - off);
+
+       retval = io_channel_write_blk64(fs->io, blk, 1, b);
+       if (retval)
+               goto out;
+
+out:
+       ext2fs_free_mem(&b);
+       return retval;
 }
 
 /*
  * This function sets the size of the file, truncating it if necessary
- * 
- * XXX still need to call truncate
+ *
  */
-errcode_t ext2fs_file_set_size(ext2_file_t file, ext2_off_t size)
+errcode_t ext2fs_file_set_size2(ext2_file_t file, ext2_off64_t size)
 {
+       ext2_off64_t    old_size;
        errcode_t       retval;
+       blk64_t         old_truncate, truncate_block;
+
        EXT2_CHECK_MAGIC(file, EXT2_ET_MAGIC_EXT2_FILE);
-       
-       file->inode.i_size = size;
-       retval = ext2fs_write_inode(file->fs, file->ino, &file->inode);
+
+       if (size && ext2fs_file_block_offset_too_big(file->fs, &file->inode,
+                                       (size - 1) / file->fs->blocksize))
+               return EXT2_ET_FILE_TOO_BIG;
+       truncate_block = ((size + file->fs->blocksize - 1) >>
+                         EXT2_BLOCK_SIZE_BITS(file->fs->super));
+       old_size = EXT2_I_SIZE(&file->inode);
+       old_truncate = ((old_size + file->fs->blocksize - 1) >>
+                     EXT2_BLOCK_SIZE_BITS(file->fs->super));
+
+       retval = ext2fs_inode_size_set(file->fs, &file->inode, size);
        if (retval)
                return retval;
 
-       /* 
-        * XXX truncate inode if necessary
-        */
+       if (file->ino) {
+               retval = ext2fs_write_inode(file->fs, file->ino, &file->inode);
+               if (retval)
+                       return retval;
+       }
 
-       return 0;
+       retval = ext2fs_file_zero_past_offset(file, size);
+       if (retval)
+               return retval;
+
+       if (truncate_block >= old_truncate)
+               return 0;
+
+       return ext2fs_punch(file->fs, file->ino, &file->inode, 0,
+                           truncate_block, ~0ULL);
+}
+
+errcode_t ext2fs_file_set_size(ext2_file_t file, ext2_off_t size)
+{
+       return ext2fs_file_set_size2(file, size);
 }