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592 lines
14 KiB
C
592 lines
14 KiB
C
/*
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* mkjournal.c --- make a journal for a filesystem
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*
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* Copyright (C) 2000 Theodore Ts'o.
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*
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* %Begin-Header%
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* This file may be redistributed under the terms of the GNU Library
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* General Public License, version 2.
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* %End-Header%
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*/
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#include "config.h"
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#include <stdio.h>
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#include <string.h>
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#if HAVE_UNISTD_H
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#include <unistd.h>
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#endif
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#if HAVE_ERRNO_H
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#include <errno.h>
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#endif
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#include <fcntl.h>
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#include <time.h>
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#if HAVE_SYS_STAT_H
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#include <sys/stat.h>
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#endif
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#if HAVE_SYS_TYPES_H
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#include <sys/types.h>
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#endif
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#if HAVE_SYS_IOCTL_H
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#include <sys/ioctl.h>
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#endif
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#if HAVE_NETINET_IN_H
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#include <netinet/in.h>
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#endif
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#ifdef _MSC_VER
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#include <io.h>
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#endif
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#include "ext2_fs.h"
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#include "ext2fs.h"
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#include "kernel-jbd.h"
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/*
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* This function automatically sets up the journal superblock and
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* returns it as an allocated block.
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*/
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errcode_t ext2fs_create_journal_superblock(ext2_filsys fs,
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__u32 num_blocks, int flags,
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char **ret_jsb)
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{
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errcode_t retval;
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journal_superblock_t *jsb;
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if (num_blocks < JBD2_MIN_JOURNAL_BLOCKS)
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return EXT2_ET_JOURNAL_TOO_SMALL;
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if ((retval = ext2fs_get_mem(fs->blocksize, &jsb)))
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return retval;
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memset (jsb, 0, fs->blocksize);
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jsb->s_header.h_magic = htonl(JBD2_MAGIC_NUMBER);
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if (flags & EXT2_MKJOURNAL_V1_SUPER)
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jsb->s_header.h_blocktype = htonl(JBD2_SUPERBLOCK_V1);
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else
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jsb->s_header.h_blocktype = htonl(JBD2_SUPERBLOCK_V2);
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jsb->s_blocksize = htonl(fs->blocksize);
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jsb->s_maxlen = htonl(num_blocks);
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jsb->s_nr_users = htonl(1);
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jsb->s_first = htonl(1);
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jsb->s_sequence = htonl(1);
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memcpy(jsb->s_uuid, fs->super->s_uuid, sizeof(fs->super->s_uuid));
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/*
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* If we're creating an external journal device, we need to
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* adjust these fields.
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*/
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if (ext2fs_has_feature_journal_dev(fs->super)) {
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jsb->s_nr_users = 0;
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jsb->s_first = htonl(ext2fs_journal_sb_start(fs->blocksize) + 1);
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}
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*ret_jsb = (char *) jsb;
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return 0;
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}
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/*
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* This function writes a journal using POSIX routines. It is used
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* for creating external journals and creating journals on live
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* filesystems.
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*/
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static errcode_t write_journal_file(ext2_filsys fs, char *filename,
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blk_t num_blocks, int flags)
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{
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errcode_t retval;
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char *buf = 0;
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int fd, ret_size;
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blk_t i;
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if ((retval = ext2fs_create_journal_superblock(fs, num_blocks, flags,
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&buf)))
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return retval;
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/* Open the device or journal file */
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if ((fd = open(filename, O_WRONLY)) < 0) {
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retval = errno;
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goto errfree;
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}
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/* Write the superblock out */
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retval = EXT2_ET_SHORT_WRITE;
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ret_size = write(fd, buf, fs->blocksize);
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if (ret_size < 0) {
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retval = errno;
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goto errout;
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}
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if (ret_size != (int) fs->blocksize)
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goto errout;
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memset(buf, 0, fs->blocksize);
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if (flags & EXT2_MKJOURNAL_LAZYINIT)
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goto success;
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for (i = 1; i < num_blocks; i++) {
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ret_size = write(fd, buf, fs->blocksize);
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if (ret_size < 0) {
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retval = errno;
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goto errout;
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}
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if (ret_size != (int) fs->blocksize)
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goto errout;
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}
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success:
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retval = 0;
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errout:
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close(fd);
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errfree:
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ext2fs_free_mem(&buf);
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return retval;
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}
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/*
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* Convenience function which zeros out _num_ blocks starting at
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* _blk_. In case of an error, the details of the error is returned
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* via _ret_blk_ and _ret_count_ if they are non-NULL pointers.
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* Returns 0 on success, and an error code on an error.
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*
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* As a special case, if the first argument is NULL, then it will
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* attempt to free the static zeroizing buffer. (This is to keep
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* programs that check for memory leaks happy.)
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*/
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#define MAX_STRIDE_LENGTH (4194304 / (int) fs->blocksize)
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errcode_t ext2fs_zero_blocks2(ext2_filsys fs, blk64_t blk, int num,
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blk64_t *ret_blk, int *ret_count)
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{
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int j, count;
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static void *buf;
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static int stride_length = 0;
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errcode_t retval;
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/* If fs is null, clean up the static buffer and return */
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if (!fs) {
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if (buf) {
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free(buf);
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buf = 0;
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stride_length = 0;
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}
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return 0;
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}
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/* Deal with zeroing less than 1 block */
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if (num <= 0)
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return 0;
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/* Try a zero out command, if supported */
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retval = io_channel_zeroout(fs->io, blk, num);
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if (retval == 0)
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return 0;
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/* Allocate the zeroizing buffer if necessary */
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if (num > stride_length && stride_length < MAX_STRIDE_LENGTH) {
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void *p;
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int new_stride = num;
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if (new_stride > MAX_STRIDE_LENGTH)
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new_stride = MAX_STRIDE_LENGTH;
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p = realloc(buf, (size_t)fs->blocksize * new_stride);
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if (!p)
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return EXT2_ET_NO_MEMORY;
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buf = p;
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stride_length = new_stride;
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memset(buf, 0, (size_t)fs->blocksize * stride_length);
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}
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/* OK, do the write loop */
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j=0;
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while (j < num) {
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if (blk % stride_length) {
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count = stride_length - (blk % stride_length);
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if (count > (num - j))
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count = num - j;
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} else {
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count = num - j;
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if (count > stride_length)
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count = stride_length;
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}
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retval = io_channel_write_blk64(fs->io, blk, count, buf);
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if (retval) {
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if (ret_count)
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*ret_count = count;
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if (ret_blk)
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*ret_blk = blk;
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return retval;
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}
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j += count; blk += count;
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}
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return 0;
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}
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errcode_t ext2fs_zero_blocks(ext2_filsys fs, blk_t blk, int num,
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blk_t *ret_blk, int *ret_count)
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{
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blk64_t ret_blk2;
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errcode_t retval;
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retval = ext2fs_zero_blocks2(fs, blk, num, &ret_blk2, ret_count);
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if (retval)
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*ret_blk = (blk_t) ret_blk2;
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return retval;
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}
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/*
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* Calculate the initial goal block to be roughly at the middle of the
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* filesystem. Pick a group that has the largest number of free
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* blocks.
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*/
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static blk64_t get_midpoint_journal_block(ext2_filsys fs)
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{
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dgrp_t group, start, end, i, log_flex;
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group = ext2fs_group_of_blk2(fs, (ext2fs_blocks_count(fs->super) -
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fs->super->s_first_data_block) / 2);
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log_flex = 1 << fs->super->s_log_groups_per_flex;
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if (fs->super->s_log_groups_per_flex && (group > log_flex)) {
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group = group & ~(log_flex - 1);
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while ((group < fs->group_desc_count) &&
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ext2fs_bg_free_blocks_count(fs, group) == 0)
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group++;
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if (group == fs->group_desc_count)
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group = 0;
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start = group;
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} else
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start = (group > 0) ? group-1 : group;
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end = ((group+1) < fs->group_desc_count) ? group+1 : group;
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group = start;
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for (i = start + 1; i <= end; i++)
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if (ext2fs_bg_free_blocks_count(fs, i) >
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ext2fs_bg_free_blocks_count(fs, group))
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group = i;
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return ext2fs_group_first_block2(fs, group);
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}
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/*
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* This function creates a journal using direct I/O routines.
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*/
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static errcode_t write_journal_inode(ext2_filsys fs, ext2_ino_t journal_ino,
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blk_t num_blocks, blk64_t goal, int flags)
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{
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char *buf;
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errcode_t retval;
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struct ext2_inode inode;
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unsigned long long inode_size;
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int falloc_flags = EXT2_FALLOCATE_FORCE_INIT;
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blk64_t zblk;
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if ((retval = ext2fs_create_journal_superblock(fs, num_blocks, flags,
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&buf)))
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return retval;
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if ((retval = ext2fs_read_bitmaps(fs)))
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goto out2;
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if ((retval = ext2fs_read_inode(fs, journal_ino, &inode)))
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goto out2;
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if (inode.i_blocks > 0) {
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retval = EEXIST;
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goto out2;
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}
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if (goal == ~0ULL)
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goal = get_midpoint_journal_block(fs);
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if (ext2fs_has_feature_extents(fs->super))
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inode.i_flags |= EXT4_EXTENTS_FL;
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if (!(flags & EXT2_MKJOURNAL_LAZYINIT))
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falloc_flags |= EXT2_FALLOCATE_ZERO_BLOCKS;
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inode_size = (unsigned long long)fs->blocksize * num_blocks;
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inode.i_mtime = inode.i_ctime = fs->now ? fs->now : time(0);
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inode.i_links_count = 1;
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inode.i_mode = LINUX_S_IFREG | 0600;
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retval = ext2fs_inode_size_set(fs, &inode, inode_size);
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if (retval)
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goto out2;
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retval = ext2fs_fallocate(fs, falloc_flags, journal_ino,
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&inode, goal, 0, num_blocks);
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if (retval)
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goto out2;
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if ((retval = ext2fs_write_new_inode(fs, journal_ino, &inode)))
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goto out2;
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retval = ext2fs_bmap2(fs, journal_ino, &inode, NULL, 0, 0, NULL, &zblk);
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if (retval)
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goto out2;
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retval = io_channel_write_blk64(fs->io, zblk, 1, buf);
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if (retval)
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goto out2;
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memcpy(fs->super->s_jnl_blocks, inode.i_block, EXT2_N_BLOCKS*4);
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fs->super->s_jnl_blocks[15] = inode.i_size_high;
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fs->super->s_jnl_blocks[16] = inode.i_size;
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fs->super->s_jnl_backup_type = EXT3_JNL_BACKUP_BLOCKS;
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ext2fs_mark_super_dirty(fs);
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out2:
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ext2fs_free_mem(&buf);
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return retval;
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}
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/*
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* Find a reasonable journal file size (in blocks) given the number of blocks
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* in the filesystem. For very small filesystems, it is not reasonable to
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* have a journal that fills more than half of the filesystem.
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*
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* n.b. comments assume 4k blocks
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*/
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int ext2fs_default_journal_size(__u64 num_blocks)
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{
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if (num_blocks < 2048)
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return -1;
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if (num_blocks < 32768) /* 128 MB */
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return (1024); /* 4 MB */
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if (num_blocks < 256*1024) /* 1 GB */
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return (4096); /* 16 MB */
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if (num_blocks < 512*1024) /* 2 GB */
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return (8192); /* 32 MB */
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if (num_blocks < 4096*1024) /* 16 GB */
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return (16384); /* 64 MB */
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if (num_blocks < 8192*1024) /* 32 GB */
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return (32768); /* 128 MB */
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if (num_blocks < 16384*1024) /* 64 GB */
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return (65536); /* 256 MB */
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if (num_blocks < 32768*1024) /* 128 GB */
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return (131072); /* 512 MB */
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return 262144; /* 1 GB */
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}
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int ext2fs_journal_sb_start(int blocksize)
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{
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if (blocksize == EXT2_MIN_BLOCK_SIZE)
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return 2;
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return 1;
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}
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/*
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* This function adds a journal device to a filesystem
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*/
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errcode_t ext2fs_add_journal_device(ext2_filsys fs, ext2_filsys journal_dev)
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{
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struct stat st;
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errcode_t retval;
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char buf[SUPERBLOCK_SIZE];
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journal_superblock_t *jsb;
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int start;
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__u32 i, nr_users;
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/* Make sure the device exists and is a block device */
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if (stat(journal_dev->device_name, &st) < 0)
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return errno;
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if (!S_ISBLK(st.st_mode))
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return EXT2_ET_JOURNAL_NOT_BLOCK; /* Must be a block device */
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/* Get the journal superblock */
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start = ext2fs_journal_sb_start(journal_dev->blocksize);
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if ((retval = io_channel_read_blk64(journal_dev->io, start,
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-SUPERBLOCK_SIZE,
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buf)))
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return retval;
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jsb = (journal_superblock_t *) buf;
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if ((jsb->s_header.h_magic != (unsigned) ntohl(JBD2_MAGIC_NUMBER)) ||
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(jsb->s_header.h_blocktype != (unsigned) ntohl(JBD2_SUPERBLOCK_V2)))
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return EXT2_ET_NO_JOURNAL_SB;
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if (ntohl(jsb->s_blocksize) != (unsigned long) fs->blocksize)
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return EXT2_ET_UNEXPECTED_BLOCK_SIZE;
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/* Check and see if this filesystem has already been added */
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nr_users = ntohl(jsb->s_nr_users);
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if (nr_users > JBD2_USERS_MAX)
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return EXT2_ET_CORRUPT_JOURNAL_SB;
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for (i=0; i < nr_users; i++) {
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if (memcmp(fs->super->s_uuid,
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&jsb->s_users[i*16], 16) == 0)
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break;
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}
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if (i >= nr_users) {
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memcpy(&jsb->s_users[nr_users*16],
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fs->super->s_uuid, 16);
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jsb->s_nr_users = htonl(nr_users+1);
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}
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/* Writeback the journal superblock */
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if ((retval = io_channel_write_blk64(journal_dev->io, start,
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-SUPERBLOCK_SIZE, buf)))
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return retval;
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fs->super->s_journal_inum = 0;
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fs->super->s_journal_dev = st.st_rdev;
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memcpy(fs->super->s_journal_uuid, jsb->s_uuid,
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sizeof(fs->super->s_journal_uuid));
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memset(fs->super->s_jnl_blocks, 0, sizeof(fs->super->s_jnl_blocks));
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ext2fs_set_feature_journal(fs->super);
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ext2fs_mark_super_dirty(fs);
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return 0;
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}
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/*
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* This function adds a journal inode to a filesystem, using either
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* POSIX routines if the filesystem is mounted, or using direct I/O
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* functions if it is not.
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*/
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errcode_t ext2fs_add_journal_inode2(ext2_filsys fs, blk_t num_blocks,
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blk64_t goal, int flags)
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{
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errcode_t retval;
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ext2_ino_t journal_ino;
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struct stat st;
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char jfile[1024];
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int mount_flags;
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int fd = -1;
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if (flags & EXT2_MKJOURNAL_NO_MNT_CHECK)
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mount_flags = 0;
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else if ((retval = ext2fs_check_mount_point(fs->device_name,
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&mount_flags,
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jfile, sizeof(jfile)-10)))
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return retval;
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if (mount_flags & EXT2_MF_MOUNTED) {
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#if HAVE_EXT2_IOCTLS
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int f = 0;
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#endif
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strcat(jfile, "/.journal");
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/*
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* If .../.journal already exists, make sure any
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* immutable or append-only flags are cleared.
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*/
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#if defined(HAVE_CHFLAGS) && defined(UF_NODUMP)
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(void) chflags (jfile, 0);
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#else
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#if HAVE_EXT2_IOCTLS
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fd = open(jfile, O_RDONLY);
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if (fd >= 0) {
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retval = ioctl(fd, EXT2_IOC_SETFLAGS, &f);
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close(fd);
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if (retval)
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return retval;
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}
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#endif
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#endif
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/* Create the journal file */
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if ((fd = open(jfile, O_CREAT|O_WRONLY, 0600)) < 0)
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return errno;
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/* Note that we can't do lazy journal initialization for mounted
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* filesystems, since the zero writing is also allocating the
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* journal blocks. We could use fallocate, but not all kernels
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* support that, and creating a journal on a mounted ext2
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* filesystems is extremely rare these days... Ignore it. */
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flags &= ~EXT2_MKJOURNAL_LAZYINIT;
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if ((retval = write_journal_file(fs, jfile, num_blocks, flags)))
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goto errout;
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/* Get inode number of the journal file */
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if (fstat(fd, &st) < 0) {
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retval = errno;
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|
goto errout;
|
|
}
|
|
|
|
#if defined(HAVE_CHFLAGS) && defined(UF_NODUMP)
|
|
retval = fchflags (fd, UF_NODUMP|UF_IMMUTABLE);
|
|
#else
|
|
#if HAVE_EXT2_IOCTLS
|
|
if (ioctl(fd, EXT2_IOC_GETFLAGS, &f) < 0) {
|
|
retval = errno;
|
|
goto errout;
|
|
}
|
|
f |= EXT2_NODUMP_FL | EXT2_IMMUTABLE_FL;
|
|
retval = ioctl(fd, EXT2_IOC_SETFLAGS, &f);
|
|
#endif
|
|
#endif
|
|
// coverity[dead_error_condition]
|
|
if (retval) {
|
|
retval = errno;
|
|
goto errout;
|
|
}
|
|
|
|
if (close(fd) < 0) {
|
|
retval = errno;
|
|
fd = -1;
|
|
goto errout;
|
|
}
|
|
journal_ino = st.st_ino;
|
|
memset(fs->super->s_jnl_blocks, 0,
|
|
sizeof(fs->super->s_jnl_blocks));
|
|
} else {
|
|
if ((mount_flags & EXT2_MF_BUSY) &&
|
|
!(fs->flags & EXT2_FLAG_EXCLUSIVE)) {
|
|
retval = EBUSY;
|
|
goto errout;
|
|
}
|
|
journal_ino = EXT2_JOURNAL_INO;
|
|
if ((retval = write_journal_inode(fs, journal_ino,
|
|
num_blocks, goal, flags)))
|
|
return retval;
|
|
}
|
|
|
|
fs->super->s_journal_inum = journal_ino;
|
|
fs->super->s_journal_dev = 0;
|
|
memset(fs->super->s_journal_uuid, 0,
|
|
sizeof(fs->super->s_journal_uuid));
|
|
ext2fs_set_feature_journal(fs->super);
|
|
|
|
ext2fs_mark_super_dirty(fs);
|
|
return 0;
|
|
errout:
|
|
if (fd >= 0)
|
|
close(fd);
|
|
return retval;
|
|
}
|
|
|
|
errcode_t ext2fs_add_journal_inode(ext2_filsys fs, blk_t num_blocks, int flags)
|
|
{
|
|
return ext2fs_add_journal_inode2(fs, num_blocks, ~0ULL, flags);
|
|
}
|
|
|
|
|
|
#ifdef DEBUG
|
|
main(int argc, char **argv)
|
|
{
|
|
errcode_t retval;
|
|
char *device_name;
|
|
ext2_filsys fs;
|
|
|
|
if (argc < 2) {
|
|
fprintf(stderr, "Usage: %s filesystem\n", argv[0]);
|
|
exit(1);
|
|
}
|
|
device_name = argv[1];
|
|
|
|
retval = ext2fs_open (device_name, EXT2_FLAG_RW, 0, 0,
|
|
unix_io_manager, &fs);
|
|
if (retval) {
|
|
com_err(argv[0], retval, "while opening %s", device_name);
|
|
exit(1);
|
|
}
|
|
|
|
retval = ext2fs_add_journal_inode(fs, JBD2_MIN_JOURNAL_BLOCKS, 0);
|
|
if (retval) {
|
|
com_err(argv[0], retval, "while adding journal to %s",
|
|
device_name);
|
|
exit(1);
|
|
}
|
|
retval = ext2fs_flush(fs);
|
|
if (retval) {
|
|
printf("Warning, had trouble writing out superblocks.\n");
|
|
}
|
|
ext2fs_close_free(&fs);
|
|
exit(0);
|
|
|
|
}
|
|
#endif
|