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-rw-r--r--lib/ext2fs/mkjournal.c654
1 files changed, 654 insertions, 0 deletions
diff --git a/lib/ext2fs/mkjournal.c b/lib/ext2fs/mkjournal.c
new file mode 100644
index 0000000..54772dd
--- /dev/null
+++ b/lib/ext2fs/mkjournal.c
@@ -0,0 +1,654 @@
+/*
+ * 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>
+#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_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;
+
+ 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);
+ 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,
+ 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