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