diff options
Diffstat (limited to 'misc/e2undo.c')
-rw-r--r-- | misc/e2undo.c | 658 |
1 files changed, 658 insertions, 0 deletions
diff --git a/misc/e2undo.c b/misc/e2undo.c new file mode 100644 index 0000000..bc78fb2 --- /dev/null +++ b/misc/e2undo.c @@ -0,0 +1,658 @@ +/* + * e2undo.c - Replay an undo log onto an ext2/3/4 filesystem + * + * Copyright IBM Corporation, 2007 + * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> + * + * %Begin-Header% + * This file may be redistributed under the terms of the GNU Public + * License. + * %End-Header% + */ + +#include "config.h" +#include <stdio.h> +#include <stdlib.h> +#ifdef HAVE_GETOPT_H +#include <getopt.h> +#endif +#include <fcntl.h> +#if HAVE_ERRNO_H +#include <errno.h> +#endif +#include <unistd.h> +#include <libgen.h> +#include "ext2fs/ext2fs.h" +#include "support/nls-enable.h" + +#undef DEBUG + +#ifdef DEBUG +# define dbg_printf(f, a...) do {printf(f, ## a); fflush(stdout); } while (0) +#else +# define dbg_printf(f, a...) +#endif + +/* + * Undo file format: The file is cut up into undo_header.block_size blocks. + * The first block contains the header. + * The second block contains the superblock. + * There is then a repeating series of blocks as follows: + * A key block, which contains undo_keys to map the following data blocks. + * Data blocks + * (Note that there are pointers to the first key block and the sb, so this + * order isn't strictly necessary.) + */ +#define E2UNDO_MAGIC "E2UNDO02" +#define KEYBLOCK_MAGIC 0xCADECADE + +#define E2UNDO_STATE_FINISHED 0x1 /* undo file is complete */ + +#define E2UNDO_MIN_BLOCK_SIZE 1024 /* undo blocks are no less than 1KB */ +#define E2UNDO_MAX_BLOCK_SIZE 1048576 /* undo blocks are no more than 1MB */ + +struct undo_header { + char magic[8]; /* "E2UNDO02" */ + __le64 num_keys; /* how many keys? */ + __le64 super_offset; /* where in the file is the superblock copy? */ + __le64 key_offset; /* where do the key/data block chunks start? */ + __le32 block_size; /* block size of the undo file */ + __le32 fs_block_size; /* block size of the target device */ + __le32 sb_crc; /* crc32c of the superblock */ + __le32 state; /* e2undo state flags */ + __le32 f_compat; /* compatible features (none so far) */ + __le32 f_incompat; /* incompatible features (none so far) */ + __le32 f_rocompat; /* ro compatible features (none so far) */ + __le32 pad32; /* padding for fs_offset */ + __le64 fs_offset; /* filesystem offset */ + __u8 padding[436]; /* padding */ + __le32 header_crc; /* crc32c of the header (but not this field) */ +}; + +#define E2UNDO_MAX_EXTENT_BLOCKS 512 /* max extent size, in blocks */ + +struct undo_key { + __le64 fsblk; /* where in the fs does the block go */ + __le32 blk_crc; /* crc32c of the block */ + __le32 size; /* how many bytes in this block? */ +}; + +struct undo_key_block { + __le32 magic; /* KEYBLOCK_MAGIC number */ + __le32 crc; /* block checksum */ + __le64 reserved; /* zero */ +#if __GNUC_PREREQ (4, 8) +#pragma GCC diagnostic push +#pragma GCC diagnostic ignored "-Wpedantic" +#endif + struct undo_key keys[0]; /* keys, which come immediately after */ +#if __GNUC_PREREQ (4, 8) +#pragma GCC diagnostic pop +#endif +}; + +struct undo_key_info { + blk64_t fsblk; + blk64_t fileblk; + __u32 blk_crc; + unsigned int size; +}; + +struct undo_context { + struct undo_header hdr; + io_channel undo_file; + unsigned int blocksize, fs_blocksize; + blk64_t super_block; + size_t num_keys; + struct undo_key_info *keys; +}; +#define KEYS_PER_BLOCK(d) (((d)->blocksize / sizeof(struct undo_key)) - 1) + +#define E2UNDO_FEATURE_COMPAT_FS_OFFSET 0x1 /* the filesystem offset */ + +static inline int e2undo_has_feature_fs_offset(struct undo_header *header) { + return ext2fs_le32_to_cpu(header->f_compat) & + E2UNDO_FEATURE_COMPAT_FS_OFFSET; +} + +static char *prg_name; +static char *undo_file; + +static void usage(void) +{ + fprintf(stderr, + _("Usage: %s [-f] [-h] [-n] [-o offset] [-v] [-z undo_file] <transaction file> <filesystem>\n"), prg_name); + exit(1); +} + +static void dump_header(struct undo_header *hdr) +{ + printf("nr keys:\t%llu\n", + (unsigned long long) ext2fs_le64_to_cpu(hdr->num_keys)); + printf("super block:\t%llu\n", + (unsigned long long) ext2fs_le64_to_cpu(hdr->super_offset)); + printf("key block:\t%llu\n", + (unsigned long long) ext2fs_le64_to_cpu(hdr->key_offset)); + printf("block size:\t%u\n", ext2fs_le32_to_cpu(hdr->block_size)); + printf("fs block size:\t%u\n", ext2fs_le32_to_cpu(hdr->fs_block_size)); + printf("super crc:\t0x%x\n", ext2fs_le32_to_cpu(hdr->sb_crc)); + printf("state:\t\t0x%x\n", ext2fs_le32_to_cpu(hdr->state)); + printf("compat:\t\t0x%x\n", ext2fs_le32_to_cpu(hdr->f_compat)); + printf("incompat:\t0x%x\n", ext2fs_le32_to_cpu(hdr->f_incompat)); + printf("rocompat:\t0x%x\n", ext2fs_le32_to_cpu(hdr->f_rocompat)); + if (e2undo_has_feature_fs_offset(hdr)) + printf("fs offset:\t%llu\n", + (unsigned long long) ext2fs_le64_to_cpu(hdr->fs_offset)); + printf("header crc:\t0x%x\n", ext2fs_le32_to_cpu(hdr->header_crc)); +} + +static void print_undo_mismatch(struct ext2_super_block *fs_super, + struct ext2_super_block *undo_super) +{ + printf("%s", + _("The file system superblock doesn't match the undo file.\n")); + if (memcmp(fs_super->s_uuid, undo_super->s_uuid, + sizeof(fs_super->s_uuid))) + printf("%s", _("UUID does not match.\n")); + if (fs_super->s_mtime != undo_super->s_mtime) + printf("%s", _("Last mount time does not match.\n")); + if (fs_super->s_wtime != undo_super->s_wtime) + printf("%s", _("Last write time does not match.\n")); + if (fs_super->s_kbytes_written != undo_super->s_kbytes_written) + printf("%s", _("Lifetime write counter does not match.\n")); +} + +static int check_filesystem(struct undo_context *ctx, io_channel channel) +{ + struct ext2_super_block super, *sb; + char *buf; + __u32 sb_crc; + errcode_t retval; + + io_channel_set_blksize(channel, SUPERBLOCK_OFFSET); + retval = io_channel_read_blk64(channel, 1, -SUPERBLOCK_SIZE, &super); + if (retval) { + com_err(prg_name, retval, + "%s", _("while reading filesystem superblock.")); + return retval; + } + + /* + * Compare the FS and the undo file superblock so that we can't apply + * e2undo "patches" out of order. + */ + retval = ext2fs_get_mem(ctx->blocksize, &buf); + if (retval) { + com_err(prg_name, retval, "%s", _("while allocating memory")); + return retval; + } + retval = io_channel_read_blk64(ctx->undo_file, ctx->super_block, + -SUPERBLOCK_SIZE, buf); + if (retval) { + com_err(prg_name, retval, "%s", _("while fetching superblock")); + goto out; + } + sb = (struct ext2_super_block *)buf; + sb->s_magic = ~sb->s_magic; + if (memcmp(&super, buf, sizeof(super))) { + print_undo_mismatch(&super, (struct ext2_super_block *)buf); + retval = -1; + goto out; + } + sb_crc = ext2fs_crc32c_le(~0, (unsigned char *)buf, SUPERBLOCK_SIZE); + if (ext2fs_le32_to_cpu(ctx->hdr.sb_crc) != sb_crc) { + fprintf(stderr, + _("Undo file superblock checksum doesn't match.\n")); + retval = -1; + goto out; + } + +out: + ext2fs_free_mem(&buf); + return retval; +} + +static int key_compare(const void *a, const void *b) +{ + const struct undo_key_info *ka, *kb; + + ka = a; + kb = b; + return ka->fsblk - kb->fsblk; +} + +static int e2undo_setup_tdb(const char *name, io_manager *io_ptr) +{ + errcode_t retval = 0; + const char *tdb_dir; + char *tdb_file = NULL; + char *dev_name, *tmp_name; + + /* (re)open a specific undo file */ + if (undo_file && undo_file[0] != 0) { + retval = set_undo_io_backing_manager(*io_ptr); + if (retval) + goto err; + *io_ptr = undo_io_manager; + retval = set_undo_io_backup_file(undo_file); + if (retval) + goto err; + printf(_("Overwriting existing filesystem; this can be undone " + "using the command:\n" + " e2undo %s %s\n\n"), + undo_file, name); + return retval; + } + + /* + * Configuration via a conf file would be + * nice + */ + tdb_dir = getenv("E2FSPROGS_UNDO_DIR"); + if (!tdb_dir) + tdb_dir = "/var/lib/e2fsprogs"; + + if (!strcmp(tdb_dir, "none") || (tdb_dir[0] == 0) || + access(tdb_dir, W_OK)) + return 0; + + tmp_name = strdup(name); + if (!tmp_name) + goto errout; + dev_name = basename(tmp_name); + tdb_file = malloc(strlen(tdb_dir) + 8 + strlen(dev_name) + 7 + 1); + if (!tdb_file) { + free(tmp_name); + goto errout; + } + sprintf(tdb_file, "%s/e2undo-%s.e2undo", tdb_dir, dev_name); + free(tmp_name); + + if ((unlink(tdb_file) < 0) && (errno != ENOENT)) { + retval = errno; + com_err(prg_name, retval, + _("while trying to delete %s"), tdb_file); + goto errout; + } + + retval = set_undo_io_backing_manager(*io_ptr); + if (retval) + goto errout; + *io_ptr = undo_io_manager; + retval = set_undo_io_backup_file(tdb_file); + if (retval) + goto errout; + printf(_("Overwriting existing filesystem; this can be undone " + "using the command:\n" + " e2undo %s %s\n\n"), + tdb_file, name); + + free(tdb_file); + return 0; +errout: + free(tdb_file); +err: + com_err(prg_name, retval, "while trying to setup undo file\n"); + return retval; +} + +int main(int argc, char *argv[]) +{ + int c, force = 0, dry_run = 0, verbose = 0, dump = 0; + io_channel channel; + errcode_t retval; + int mount_flags, csum_error = 0, io_error = 0; + size_t i, keys_per_block; + char *device_name, *tdb_file; + io_manager manager = unix_io_manager; + struct undo_context undo_ctx; + char *buf; + struct undo_key_block *keyb; + struct undo_key *dkey; + struct undo_key_info *ikey; + __u32 key_crc, blk_crc, hdr_crc; + blk64_t lblk; + ext2_filsys fs; + __u64 offset = 0; + char opt_offset_string[40] = { 0 }; + +#ifdef ENABLE_NLS + setlocale(LC_MESSAGES, ""); + setlocale(LC_CTYPE, ""); + bindtextdomain(NLS_CAT_NAME, LOCALEDIR); + textdomain(NLS_CAT_NAME); + set_com_err_gettext(gettext); +#endif + add_error_table(&et_ext2_error_table); + + prg_name = argv[0]; + while ((c = getopt(argc, argv, "fhno:vz:")) != EOF) { + switch (c) { + case 'f': + force = 1; + break; + case 'h': + dump = 1; + break; + case 'n': + dry_run = 1; + break; + case 'o': + offset = strtoull(optarg, &buf, 0); + if (*buf) { + com_err(prg_name, 0, + _("illegal offset - %s"), optarg); + exit(1); + } + /* used to indicate that an offset was specified */ + opt_offset_string[0] = 1; + break; + case 'v': + verbose = 1; + break; + case 'z': + undo_file = optarg; + break; + default: + usage(); + } + } + + if (argc != optind + 2) + usage(); + + tdb_file = argv[optind]; + device_name = argv[optind+1]; + + if (undo_file && strcmp(tdb_file, undo_file) == 0) { + printf(_("Will not write to an undo file while replaying it.\n")); + exit(1); + } + + /* Interpret the undo file */ + retval = manager->open(tdb_file, IO_FLAG_EXCLUSIVE, + &undo_ctx.undo_file); + if (retval) { + com_err(prg_name, errno, + _("while opening undo file `%s'\n"), tdb_file); + exit(1); + } + retval = io_channel_read_blk64(undo_ctx.undo_file, 0, + -(int)sizeof(undo_ctx.hdr), + &undo_ctx.hdr); + if (retval) { + com_err(prg_name, retval, _("while reading undo file")); + exit(1); + } + if (memcmp(undo_ctx.hdr.magic, E2UNDO_MAGIC, + sizeof(undo_ctx.hdr.magic))) { + fprintf(stderr, _("%s: Not an undo file.\n"), tdb_file); + exit(1); + } + if (dump) { + dump_header(&undo_ctx.hdr); + exit(1); + } + hdr_crc = ext2fs_crc32c_le(~0, (unsigned char *)&undo_ctx.hdr, + sizeof(struct undo_header) - + sizeof(__u32)); + if (!force && ext2fs_le32_to_cpu(undo_ctx.hdr.header_crc) != hdr_crc) { + fprintf(stderr, _("%s: Header checksum doesn't match.\n"), + tdb_file); + exit(1); + } + undo_ctx.blocksize = ext2fs_le32_to_cpu(undo_ctx.hdr.block_size); + undo_ctx.fs_blocksize = ext2fs_le32_to_cpu(undo_ctx.hdr.fs_block_size); + if (undo_ctx.blocksize == 0 || undo_ctx.fs_blocksize == 0) { + fprintf(stderr, _("%s: Corrupt undo file header.\n"), tdb_file); + exit(1); + } + if (!force && undo_ctx.blocksize > E2UNDO_MAX_BLOCK_SIZE) { + fprintf(stderr, _("%s: Undo block size too large.\n"), + tdb_file); + exit(1); + } + if (!force && undo_ctx.blocksize < E2UNDO_MIN_BLOCK_SIZE) { + fprintf(stderr, _("%s: Undo block size too small.\n"), + tdb_file); + exit(1); + } + undo_ctx.super_block = ext2fs_le64_to_cpu(undo_ctx.hdr.super_offset); + undo_ctx.num_keys = ext2fs_le64_to_cpu(undo_ctx.hdr.num_keys); + io_channel_set_blksize(undo_ctx.undo_file, undo_ctx.blocksize); + /* + * Do not compare undo_ctx.hdr.f_compat with the available compatible + * features set, because a "missing" compatible feature should + * not cause any problems. + */ + if (!force && (undo_ctx.hdr.f_incompat || undo_ctx.hdr.f_rocompat)) { + fprintf(stderr, _("%s: Unknown undo file feature set.\n"), + tdb_file); + exit(1); + } + + /* open the fs */ + retval = ext2fs_check_if_mounted(device_name, &mount_flags); + if (retval) { + com_err(prg_name, retval, _("Error while determining whether " + "%s is mounted."), device_name); + exit(1); + } + + if (mount_flags & EXT2_MF_MOUNTED) { + com_err(prg_name, retval, "%s", _("e2undo should only be run " + "on unmounted filesystems")); + exit(1); + } + + if (undo_file) { + retval = e2undo_setup_tdb(device_name, &manager); + if (retval) + exit(1); + } + + retval = manager->open(device_name, + IO_FLAG_EXCLUSIVE | (dry_run ? 0 : IO_FLAG_RW), + &channel); + if (retval) { + com_err(prg_name, retval, + _("while opening `%s'"), device_name); + exit(1); + } + + if (*opt_offset_string || e2undo_has_feature_fs_offset(&undo_ctx.hdr)) { + if (!*opt_offset_string) + offset = ext2fs_le64_to_cpu(undo_ctx.hdr.fs_offset); + retval = snprintf(opt_offset_string, sizeof(opt_offset_string), + "offset=%llu", (unsigned long long) offset); + if ((size_t) retval >= sizeof(opt_offset_string)) { + /* should not happen... */ + com_err(prg_name, 0, _("specified offset is too large")); + exit(1); + } + io_channel_set_options(channel, opt_offset_string); + } + + if (!force && check_filesystem(&undo_ctx, channel)) + exit(1); + + /* prepare to read keys */ + retval = ext2fs_get_mem(sizeof(struct undo_key_info) * undo_ctx.num_keys, + &undo_ctx.keys); + if (retval) { + com_err(prg_name, retval, "%s", _("while allocating memory")); + exit(1); + } + ikey = undo_ctx.keys; + retval = ext2fs_get_mem(undo_ctx.blocksize, &keyb); + if (retval) { + com_err(prg_name, retval, "%s", _("while allocating memory")); + exit(1); + } + retval = ext2fs_get_mem(E2UNDO_MAX_EXTENT_BLOCKS * undo_ctx.blocksize, + &buf); + if (retval) { + com_err(prg_name, retval, "%s", _("while allocating memory")); + exit(1); + } + + /* load keys */ + keys_per_block = KEYS_PER_BLOCK(&undo_ctx); + lblk = ext2fs_le64_to_cpu(undo_ctx.hdr.key_offset); + dbg_printf("nr_keys=%lu, kpb=%zu, blksz=%u\n", + undo_ctx.num_keys, keys_per_block, undo_ctx.blocksize); + for (i = 0; i < undo_ctx.num_keys; i += keys_per_block) { + size_t j, max_j; + __le32 crc; + + retval = io_channel_read_blk64(undo_ctx.undo_file, + lblk, 1, keyb); + if (retval) { + com_err(prg_name, retval, "%s", _("while reading keys")); + if (force) { + io_error = 1; + undo_ctx.num_keys = i - 1; + break; + } + exit(1); + } + + /* check keys */ + if (!force && + ext2fs_le32_to_cpu(keyb->magic) != KEYBLOCK_MAGIC) { + fprintf(stderr, _("%s: wrong key magic at %llu\n"), + tdb_file, (unsigned long long) lblk); + exit(1); + } + crc = keyb->crc; + keyb->crc = 0; + key_crc = ext2fs_crc32c_le(~0, (unsigned char *)keyb, + undo_ctx.blocksize); + if (!force && ext2fs_le32_to_cpu(crc) != key_crc) { + fprintf(stderr, + _("%s: key block checksum error at %llu.\n"), + tdb_file, (unsigned long long) lblk); + exit(1); + } + + /* load keys from key block */ + lblk++; + max_j = undo_ctx.num_keys - i; + if (max_j > keys_per_block) + max_j = keys_per_block; + for (j = 0, dkey = keyb->keys; + j < max_j; + j++, ikey++, dkey++) { + ikey->fsblk = ext2fs_le64_to_cpu(dkey->fsblk); + ikey->fileblk = lblk; + ikey->blk_crc = ext2fs_le32_to_cpu(dkey->blk_crc); + ikey->size = ext2fs_le32_to_cpu(dkey->size); + lblk += (ikey->size + undo_ctx.blocksize - 1) / + undo_ctx.blocksize; + + if (E2UNDO_MAX_EXTENT_BLOCKS * undo_ctx.blocksize < + ikey->size) { + com_err(prg_name, retval, + _("%s: block %llu is too long."), + tdb_file, + (unsigned long long) ikey->fsblk); + exit(1); + } + + /* check each block's crc */ + retval = io_channel_read_blk64(undo_ctx.undo_file, + ikey->fileblk, + -(int)ikey->size, + buf); + if (retval) { + com_err(prg_name, retval, + _("while fetching block %llu."), + (unsigned long long) ikey->fileblk); + if (!force) + exit(1); + io_error = 1; + continue; + } + + blk_crc = ext2fs_crc32c_le(~0, (unsigned char *)buf, + ikey->size); + if (blk_crc != ikey->blk_crc) { + fprintf(stderr, + _("checksum error in filesystem block " + "%llu (undo blk %llu)\n"), + (unsigned long long) ikey->fsblk, + (unsigned long long) ikey->fileblk); + if (!force) + exit(1); + csum_error = 1; + } + } + } + ext2fs_free_mem(&keyb); + + /* sort keys in fs block order */ + qsort(undo_ctx.keys, undo_ctx.num_keys, sizeof(struct undo_key_info), + key_compare); + + /* replay */ + io_channel_set_blksize(channel, undo_ctx.fs_blocksize); + for (i = 0, ikey = undo_ctx.keys; i < undo_ctx.num_keys; i++, ikey++) { + retval = io_channel_read_blk64(undo_ctx.undo_file, + ikey->fileblk, + -(int)ikey->size, + buf); + if (retval) { + com_err(prg_name, retval, + _("while fetching block %llu."), + (unsigned long long) ikey->fileblk); + io_error = 1; + continue; + } + + if (verbose) + printf("Replayed block of size %u from %llu to %llu\n", + ikey->size, (unsigned long long) ikey->fileblk, + (unsigned long long) ikey->fsblk); + if (dry_run) + continue; + retval = io_channel_write_blk64(channel, ikey->fsblk, + -(int)ikey->size, buf); + if (retval) { + com_err(prg_name, retval, + _("while writing block %llu."), + (unsigned long long) ikey->fsblk); + io_error = 1; + } + } + + if (csum_error) + fprintf(stderr, _("Undo file corruption; run e2fsck NOW!\n")); + if (io_error) + fprintf(stderr, _("IO error during replay; run e2fsck NOW!\n")); + if (!(ext2fs_le32_to_cpu(undo_ctx.hdr.state) & E2UNDO_STATE_FINISHED)) { + force = 1; + fprintf(stderr, _("Incomplete undo record; run e2fsck.\n")); + } + ext2fs_free_mem(&buf); + ext2fs_free_mem(&undo_ctx.keys); + io_channel_close(channel); + + /* If there were problems, try to force a fsck */ + if (!dry_run && (force || csum_error || io_error)) { + retval = ext2fs_open2(device_name, NULL, + EXT2_FLAG_RW | EXT2_FLAG_64BITS, 0, 0, + manager, &fs); + if (retval) + goto out; + fs->super->s_state &= ~EXT2_VALID_FS; + if (csum_error || io_error) + fs->super->s_state |= EXT2_ERROR_FS; + ext2fs_mark_super_dirty(fs); + ext2fs_close_free(&fs); + } + +out: + io_channel_close(undo_ctx.undo_file); + + return csum_error; +} |