/*

 * mkjournal.c --- make a journal for a filesystem

 *

 * Copyright (C) 2000 Theodore Ts'o.

 *

 * %Begin-Header%

 * This file may be redistributed under the terms of the GNU Library

 * General Public License, version 2.

 * %End-Header%

 */

#include "config.h"

#include <stdio.h>

#include <string.h>

#include <assert.h>

#if HAVE_UNISTD_H

#include <unistd.h>

#endif

#if HAVE_ERRNO_H

#include <errno.h>

#endif

#include <fcntl.h>

#if HAVE_SYS_STAT_H

#include <sys/stat.h>

#endif

#if HAVE_SYS_TYPES_H

#include <sys/types.h>

#endif

#if HAVE_SYS_IOCTL_H

#include <sys/ioctl.h>

#endif

#if HAVE_NETINET_IN_H

#include <netinet/in.h>

#endif

#include "ext2_fs.h"

#include "e2p/e2p.h"

#include "ext2fsP.h"

#include "kernel-jbd.h"

/*

 * This function automatically sets up the journal superblock and

 * returns it as an allocated block.

 */

errcode_t ext2fs_create_journal_superblock2(ext2_filsys fs,

             struct ext2fs_journal_params *jparams,

             int flags, char **ret_jsb)

{

  errcode_t   retval;

  journal_superblock_t  *jsb;

  if (jparams->num_journal_blocks < JBD2_MIN_JOURNAL_BLOCKS)

    return EXT2_ET_JOURNAL_TOO_SMALL;

  if ((retval = ext2fs_get_mem(fs->blocksize, &jsb)))

    return retval;

  memset (jsb, 0, fs->blocksize);

  jsb->s_header.h_magic = htonl(JBD2_MAGIC_NUMBER);

  if (flags & EXT2_MKJOURNAL_V1_SUPER)

    jsb->s_header.h_blocktype = htonl(JBD2_SUPERBLOCK_V1);

  else

    jsb->s_header.h_blocktype = htonl(JBD2_SUPERBLOCK_V2);

  jsb->s_blocksize = htonl(fs->blocksize);

  jsb->s_maxlen = htonl(jparams->num_journal_blocks + jparams->num_fc_blocks);

  jsb->s_nr_users = htonl(1);

  jsb->s_first = htonl(1);

  jsb->s_sequence = htonl(1);

  jsb->s_num_fc_blks = htonl(jparams->num_fc_blocks);

  memcpy(jsb->s_uuid, fs->super->s_uuid, sizeof(fs->super->s_uuid));

  /*

   * If we're creating an external journal device, we need to

   * adjust these fields.

   */

  if (ext2fs_has_feature_journal_dev(fs->super)) {

    jsb->s_nr_users = 0;

    jsb->s_first = htonl(ext2fs_journal_sb_start(fs->blocksize) + 1);

  }

  *ret_jsb = (char *) jsb;

  return 0;

}

errcode_t ext2fs_create_journal_superblock(ext2_filsys fs, __u32 num_blocks,

          int flags, char **ret_sb)

{

  struct ext2fs_journal_params jparams;

  jparams.num_journal_blocks = num_blocks;

  jparams.num_fc_blocks = 0;

  return ext2fs_create_journal_superblock2(fs, &jparams, flags, ret_sb);

}

/*

 * This function writes a journal using POSIX routines.  It is used

 * for creating external journals and creating journals on live

 * filesystems.

 */

static errcode_t write_journal_file(ext2_filsys fs, char *filename,

            struct ext2fs_journal_params *jparams,

            int flags)

{

  errcode_t retval;

  char    *buf = 0;

  int   fd, ret_size;

  blk_t   i;

  if ((retval = ext2fs_create_journal_superblock2(fs, jparams, flags,

                   &buf)))

    return retval;

  /* Open the device or journal file */

  if ((fd = open(filename, O_WRONLY)) < 0) {

    retval = errno;

    goto errfree;

  }

  /* Write the superblock out */

  retval = EXT2_ET_SHORT_WRITE;

  ret_size = write(fd, buf, fs->blocksize);

  if (ret_size < 0) {

    retval = errno;

    goto errout;

  }

  if (ret_size != (int) fs->blocksize)

    goto errout;

  memset(buf, 0, fs->blocksize);

  if (flags & EXT2_MKJOURNAL_LAZYINIT)

    goto success;

  for (i = 1; i < jparams->num_journal_blocks + jparams->num_fc_blocks; i++) {

    ret_size = write(fd, buf, fs->blocksize);

    if (ret_size < 0) {

      retval = errno;

      goto errout;

    }

    if (ret_size != (int) fs->blocksize)

      goto errout;

  }

success:

  retval = 0;

errout:

  close(fd);

errfree:

  ext2fs_free_mem(&buf);

  return retval;

}

/*

 * Convenience function which zeros out _num_ blocks starting at

 * _blk_.  In case of an error, the details of the error is returned

 * via _ret_blk_ and _ret_count_ if they are non-NULL pointers.

 * Returns 0 on success, and an error code on an error.

 *

 * As a special case, if the first argument is NULL, then it will

 * attempt to free the static zeroizing buffer.  (This is to keep

 * programs that check for memory leaks happy.)

 */

#define MAX_STRIDE_LENGTH (4194304 / (int) fs->blocksize)

errcode_t ext2fs_zero_blocks2(ext2_filsys fs, blk64_t blk, int num,

            blk64_t *ret_blk, int *ret_count)

{

  int   j, count;

  static void *buf;

  static int  stride_length;

  errcode_t retval;

  /* If fs is null, clean up the static buffer and return */

  if (!fs) {

    if (buf) {

      free(buf);

      buf = 0;

      stride_length = 0;

    }

    return 0;

  }

  /* Deal with zeroing less than 1 block */

  if (num <= 0)

    return 0;

  /* Try a zero out command, if supported */

  retval = io_channel_zeroout(fs->io, blk, num);

  if (retval == 0)

    return 0;

  /* Allocate the zeroizing buffer if necessary */

  if (num > stride_length && stride_length < MAX_STRIDE_LENGTH) {

    void *p;

    int new_stride = num;

    if (new_stride > MAX_STRIDE_LENGTH)

      new_stride = MAX_STRIDE_LENGTH;

    p = realloc(buf, fs->blocksize * new_stride);

    if (!p)

      return EXT2_ET_NO_MEMORY;

    buf = p;

    stride_length = new_stride;

    memset(buf, 0, fs->blocksize * stride_length);

  }

  /* OK, do the write loop */

  j=0;

  while (j < num) {

    if (blk % stride_length) {

      count = stride_length - (blk % stride_length);

      if (count > (num - j))

        count = num - j;

    } else {

      count = num - j;

      if (count > stride_length)

        count = stride_length;

    }

    retval = io_channel_write_blk64(fs->io, blk, count, buf);

    if (retval) {

      if (ret_count)

        *ret_count = count;

      if (ret_blk)

        *ret_blk = blk;

      return retval;

    }

    j += count; blk += count;

  }

  return 0;

}

errcode_t ext2fs_zero_blocks(ext2_filsys fs, blk_t blk, int num,

           blk_t *ret_blk, int *ret_count)

{

  blk64_t ret_blk2;

  errcode_t retval;

  retval = ext2fs_zero_blocks2(fs, blk, num, &ret_blk2, ret_count);

  if (retval)

    *ret_blk = (blk_t) ret_blk2;

  return retval;

}

/*

 * Calculate the initial goal block to be roughly at the middle of the

 * filesystem.  Pick a group that has the largest number of free

 * blocks.

 */

static blk64_t get_midpoint_journal_block(ext2_filsys fs)

{

  dgrp_t  group, start, end, i, log_flex;

  group = ext2fs_group_of_blk2(fs, (ext2fs_blocks_count(fs->super) -

           fs->super->s_first_data_block) / 2);

  log_flex = 1U << fs->super->s_log_groups_per_flex;

  if (fs->super->s_log_groups_per_flex && (group > log_flex)) {

    group = group & ~(log_flex - 1);

    while ((group < fs->group_desc_count) &&

           ext2fs_bg_free_blocks_count(fs, group) == 0)

      group++;

    if (group == fs->group_desc_count)

      group = 0;

    start = group;

  } else

    start = (group > 0) ? group-1 : group;

  end = ((group+1) < fs->group_desc_count) ? group+1 : group;

  group = start;

  for (i = start + 1; i <= end; i++)

    if (ext2fs_bg_free_blocks_count(fs, i) >

        ext2fs_bg_free_blocks_count(fs, group))

      group = i;

  return ext2fs_group_first_block2(fs, group);

}

/*

 * This function creates a journal using direct I/O routines.

 */

static errcode_t write_journal_inode(ext2_filsys fs, ext2_ino_t journal_ino,

             struct ext2fs_journal_params *jparams,

             blk64_t goal, int flags)

{

  char      *buf;

  errcode_t   retval;

  struct ext2_inode inode;

  unsigned long long  inode_size;

  int     falloc_flags = EXT2_FALLOCATE_FORCE_INIT;

  blk64_t     zblk;

  time_t      now;

  if ((retval = ext2fs_create_journal_superblock2(fs, jparams, flags,

                   &buf)))

    return retval;

  if ((retval = ext2fs_read_bitmaps(fs)))

    goto out2;

  if ((retval = ext2fs_read_inode(fs, journal_ino, &inode)))

    goto out2;

  if (inode.i_blocks > 0) {

    retval = EEXIST;

    goto out2;

  }

  if (goal == ~0ULL)

    goal = get_midpoint_journal_block(fs);

  if (ext2fs_has_feature_extents(fs->super))

    inode.i_flags |= EXT4_EXTENTS_FL;

  if (!(flags & EXT2_MKJOURNAL_LAZYINIT))

    falloc_flags |= EXT2_FALLOCATE_ZERO_BLOCKS;

  inode_size = (unsigned long long)fs->blocksize *

      (jparams->num_journal_blocks + jparams->num_fc_blocks);

  now = ext2fsP_get_time(fs);

  ext2fs_inode_xtime_set(&inode, i_mtime, now);

  ext2fs_inode_xtime_set(&inode, i_ctime, now);

  inode.i_links_count = 1;

  inode.i_mode = LINUX_S_IFREG | 0600;

  retval = ext2fs_inode_size_set(fs, &inode, inode_size);

  if (retval)

    goto out2;

  retval = ext2fs_fallocate(fs, falloc_flags, journal_ino,

          &inode, goal, 0,

          jparams->num_journal_blocks + jparams->num_fc_blocks);

  if (retval)

    goto out2;

  if ((retval = ext2fs_write_new_inode(fs, journal_ino, &inode)))

    goto out2;

  retval = ext2fs_bmap2(fs, journal_ino, &inode, NULL, 0, 0, NULL, &zblk);

  if (retval)

    goto out2;

  retval = io_channel_write_blk64(fs->io, zblk, 1, buf);

  if (retval)

    goto out2;

  memcpy(fs->super->s_jnl_blocks, inode.i_block, EXT2_N_BLOCKS*4);

  fs->super->s_jnl_blocks[15] = inode.i_size_high;

  fs->super->s_jnl_blocks[16] = inode.i_size;

  fs->super->s_jnl_backup_type = EXT3_JNL_BACKUP_BLOCKS;

  ext2fs_mark_super_dirty(fs);

out2:

  ext2fs_free_mem(&buf);

  return retval;

}

/*

 * Find a reasonable journal file size (in blocks) given the number of blocks

 * in the filesystem.  For very small filesystems, it is not reasonable to

 * have a journal that fills more than half of the filesystem.

 *

 * n.b. comments assume 4k blocks

 */

int ext2fs_default_journal_size(__u64 num_blocks)

{

  if (num_blocks < 2048)

    return -1;

  if (num_blocks < 32768)   /* 128 MB */

    return (1024);     /* 4 MB */

  if (num_blocks < 256*1024) /* 1 GB */

    return (4096);     /* 16 MB */

  if (num_blocks < 512*1024) /* 2 GB */

    return (8192);     /* 32 MB */

  if (num_blocks < 4096*1024) /* 16 GB */

    return (16384);     /* 64 MB */

  if (num_blocks < 8192*1024) /* 32 GB */

    return (32768);     /* 128 MB */

  if (num_blocks < 16384*1024) /* 64 GB */

    return (65536);     /* 256 MB */

  if (num_blocks < 32768*1024) /* 128 GB */

    return (131072);   /* 512 MB */

  return 262144;       /* 1 GB */

}

errcode_t ext2fs_get_journal_params(struct ext2fs_journal_params *params,

    ext2_filsys fs)

{

  blk_t total_blks;

  int ret;

  memset(params, 0, sizeof(*params));

  if (ext2fs_has_feature_journal_dev(fs->super)) {

    total_blks = ext2fs_blocks_count(fs->super);

    if (total_blks < JBD2_MIN_JOURNAL_BLOCKS)

      return EXT2_ET_JOURNAL_TOO_SMALL;

    if (!ext2fs_has_feature_fast_commit(fs->super)) {

      params->num_journal_blocks = total_blks;

      params->num_fc_blocks = 0;

      return 0;

    }

    params->num_journal_blocks = ext2fs_blocks_count(fs->super) *

        EXT2_JOURNAL_TO_FC_BLKS_RATIO /

        (EXT2_JOURNAL_TO_FC_BLKS_RATIO + 1);

    if (JBD2_MIN_JOURNAL_BLOCKS > params->num_journal_blocks)

      params->num_journal_blocks = JBD2_MIN_JOURNAL_BLOCKS;

    params->num_fc_blocks = total_blks - params->num_journal_blocks;

    return 0;

  }

  ret = ext2fs_default_journal_size(ext2fs_blocks_count(fs->super));

  if (ret < 0)

    return EXT2_ET_JOURNAL_TOO_SMALL;

  params->num_journal_blocks = ret;

  if (ext2fs_has_feature_fast_commit(fs->super))

    params->num_fc_blocks = params->num_journal_blocks /

      EXT2_JOURNAL_TO_FC_BLKS_RATIO;

  return 0;

}

int ext2fs_journal_sb_start(int blocksize)

{

  if (blocksize == EXT2_MIN_BLOCK_SIZE)

    return 2;

  return 1;

}

/*

 * This function adds a journal device to a filesystem

 */

errcode_t ext2fs_add_journal_device(ext2_filsys fs, ext2_filsys journal_dev)

{

  struct stat st;

  errcode_t retval;

  char    buf[SUPERBLOCK_SIZE];

  journal_superblock_t  *jsb;

  int   start;

  __u32   i, nr_users;

  /* Make sure the device exists and is a block device */

  if (stat(journal_dev->device_name, &st) < 0)

    return errno;

  if (!S_ISBLK(st.st_mode))

    return EXT2_ET_JOURNAL_NOT_BLOCK; /* Must be a block device */

  /* Get the journal superblock */

  start = ext2fs_journal_sb_start(journal_dev->blocksize);

  if ((retval = io_channel_read_blk64(journal_dev->io, start,

              -SUPERBLOCK_SIZE,

              buf)))

    return retval;

  jsb = (journal_superblock_t *) buf;

  if ((jsb->s_header.h_magic != (unsigned) ntohl(JBD2_MAGIC_NUMBER)) ||

      (jsb->s_header.h_blocktype != (unsigned) ntohl(JBD2_SUPERBLOCK_V2)))

    return EXT2_ET_NO_JOURNAL_SB;

  if (ntohl(jsb->s_blocksize) != (unsigned long) fs->blocksize)

    return EXT2_ET_UNEXPECTED_BLOCK_SIZE;

  /* Check and see if this filesystem has already been added */

  nr_users = ntohl(jsb->s_nr_users);

  if (nr_users > JBD2_USERS_MAX)

    return EXT2_ET_CORRUPT_JOURNAL_SB;

  for (i=0; i < nr_users; i++) {

    if (memcmp(fs->super->s_uuid,

         &jsb->s_users[i*16], 16) == 0)

      break;

  }

  if (i >= nr_users) {

    memcpy(&jsb->s_users[nr_users*16],

           fs->super->s_uuid, 16);

    jsb->s_nr_users = htonl(nr_users+1);

  }

  /* Writeback the journal superblock */

  if ((retval = io_channel_write_blk64(journal_dev->io, start,

              -SUPERBLOCK_SIZE, buf)))

    return retval;

  fs->super->s_journal_inum = 0;

  fs->super->s_journal_dev = st.st_rdev;

  memcpy(fs->super->s_journal_uuid, jsb->s_uuid,

         sizeof(fs->super->s_journal_uuid));

  memset(fs->super->s_jnl_blocks, 0, sizeof(fs->super->s_jnl_blocks));

  ext2fs_set_feature_journal(fs->super);

  ext2fs_mark_super_dirty(fs);

  return 0;

}

/*

 * This function adds a journal inode to a filesystem, using either

 * POSIX routines if the filesystem is mounted, or using direct I/O

 * functions if it is not.

 */

errcode_t ext2fs_add_journal_inode3(ext2_filsys fs, struct ext2fs_journal_params *jparams,

            blk64_t goal, int flags)

{

  errcode_t   retval;

  ext2_ino_t    journal_ino;

  struct stat   st;

  char      jfile[1024];

  int     mount_flags;

  int     fd = -1;

  if (flags & EXT2_MKJOURNAL_NO_MNT_CHECK)

    mount_flags = 0;

  else if ((retval = ext2fs_check_mount_point(fs->device_name,

                &mount_flags,

                jfile, sizeof(jfile)-10)))

    return retval;

  if (mount_flags & EXT2_MF_MOUNTED) {

#if HAVE_EXT2_IOCTLS

    int f = 0;

#endif

    strcat(jfile, "/.journal");

    /*

     * If .../.journal already exists, make sure any

     * immutable or append-only flags are cleared.

     */

#if defined(HAVE_CHFLAGS) && defined(UF_NODUMP)

    (void) chflags (jfile, 0);

#else

#if HAVE_EXT2_IOCTLS

    fd = open(jfile, O_RDONLY);

    if (fd >= 0) {

      retval = ioctl(fd, EXT2_IOC_SETFLAGS, &f);

      close(fd);

      if (retval)

        return errno;

    }

#endif

#endif

    /* Create the journal file */

    if ((fd = open(jfile, O_CREAT|O_WRONLY, 0600)) < 0)

      return errno;

    /* Note that we can't do lazy journal initialization for mounted

     * filesystems, since the zero writing is also allocating the

     * journal blocks.  We could use fallocate, but not all kernels

     * support that, and creating a journal on a mounted ext2

     * filesystems is extremely rare these days...  Ignore it. */

    flags &= ~EXT2_MKJOURNAL_LAZYINIT;

    if ((retval = write_journal_file(fs, jfile, jparams, flags)))

      goto errout;

    /* Get inode number of the journal file */

    if (fstat(fd, &st) < 0) {

      retval = errno;

      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

    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,

              jparams, 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_inode2(ext2_filsys fs, blk_t num_blocks,

            blk64_t goal, int flags)

{

  struct ext2fs_journal_params jparams;

  jparams.num_journal_blocks = num_blocks;

  jparams.num_fc_blocks = 0;

  return ext2fs_add_journal_inode3(fs, &jparams, goal, flags);

}

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