diff options
Diffstat (limited to '')
| -rw-r--r-- | lib/ext2fs/mkjournal.c | 654 |
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 |