/*
* 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>
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#if HAVE_ERRNO_H
#include <errno.h>
#endif
#include <fcntl.h>
#include <time.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 "ext2fs.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_superblock(ext2_filsys fs,
__u32 num_blocks, int flags,
char **ret_jsb)
{
errcode_t retval;
journal_superblock_t *jsb;
if (num_blocks < JFS_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(JFS_MAGIC_NUMBER);
if (flags & EXT2_MKJOURNAL_V1_SUPER)
jsb->s_header.h_blocktype = htonl(JFS_SUPERBLOCK_V1);
else
jsb->s_header.h_blocktype = htonl(JFS_SUPERBLOCK_V2);
jsb->s_blocksize = htonl(fs->blocksize);
jsb->s_maxlen = htonl(num_blocks);
jsb->s_nr_users = htonl(1);
jsb->s_first = htonl(1);
jsb->s_sequence = htonl(1);
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;
}
/*
* 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,
blk_t num_blocks, int flags)
{
errcode_t retval;
char *buf = 0;
int fd, ret_size;
blk_t i;
if ((retval = ext2fs_create_journal_superblock(fs, num_blocks, 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 < num_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 = 1 << 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,
blk_t num_blocks, 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;
if ((retval = ext2fs_create_journal_superblock(fs, num_blocks, 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 * num_blocks;
inode.i_mtime = inode.i_ctime = fs->now ? fs->now : time(0);
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, num_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 */
}
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(JFS_MAGIC_NUMBER)) ||
(jsb->s_header.h_blocktype != (unsigned) ntohl(JFS_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 > JFS_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_inode2(ext2_filsys fs, blk_t num_blocks,
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 retval;
}
#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, num_blocks, 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,
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, JFS_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