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-rw-r--r--lib/ext2fs/undo_io.c1108
1 files changed, 1108 insertions, 0 deletions
diff --git a/lib/ext2fs/undo_io.c b/lib/ext2fs/undo_io.c
new file mode 100644
index 0000000..f4a6d52
--- /dev/null
+++ b/lib/ext2fs/undo_io.c
@@ -0,0 +1,1108 @@
+/*
+ * undo_io.c --- This is the undo io manager that copies the old data that
+ * copies the old data being overwritten into a tdb database
+ *
+ * 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 Library
+ * General Public License, version 2.
+ * %End-Header%
+ */
+
+#ifndef _LARGEFILE_SOURCE
+#define _LARGEFILE_SOURCE
+#endif
+#ifndef _LARGEFILE64_SOURCE
+#define _LARGEFILE64_SOURCE
+#endif
+
+#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>
+#ifdef __linux__
+#include <sys/utsname.h>
+#endif
+#if HAVE_SYS_STAT_H
+#include <sys/stat.h>
+#endif
+#if HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+#if HAVE_SYS_RESOURCE_H
+#include <sys/resource.h>
+#endif
+#include <limits.h>
+
+#include "ext2_fs.h"
+#include "ext2fs.h"
+#include "ext2fsP.h"
+
+#ifdef __GNUC__
+#define ATTR(x) __attribute__(x)
+#else
+#define ATTR(x)
+#endif
+
+#undef DEBUG
+
+#ifdef DEBUG
+# define dbg_printf(f, a...) do {printf(f, ## a); fflush(stdout); } while (0)
+#else
+# define dbg_printf(f, a...)
+#endif
+
+/*
+ * For checking structure magic numbers...
+ */
+
+#define EXT2_CHECK_MAGIC(struct, code) \
+ if ((struct)->magic != (code)) return (code)
+/*
+ * 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 */
+ __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 this 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 __STDC_VERSION__ >= 199901L
+ struct undo_key keys[]; /* keys, which come immediately after */
+#else
+ struct undo_key keys[0]; /* keys, which come immediately after */
+#endif
+};
+
+struct undo_private_data {
+ int magic;
+
+ /* the undo file io channel */
+ io_channel undo_file;
+ blk64_t undo_blk_num; /* next free block */
+ blk64_t key_blk_num; /* current key block location */
+ blk64_t super_blk_num; /* superblock location */
+ blk64_t first_key_blk; /* first key block location */
+ struct undo_key_block *keyb;
+ size_t num_keys, keys_in_block;
+
+ /* The backing io channel */
+ io_channel real;
+
+ unsigned long long tdb_data_size;
+ int tdb_written;
+
+ /* to support offset in unix I/O manager */
+ ext2_loff_t offset;
+
+ ext2fs_block_bitmap written_block_map;
+ struct struct_ext2_filsys fake_fs;
+ char *tdb_file;
+ struct undo_header hdr;
+};
+#define KEYS_PER_BLOCK(d) (((d)->tdb_data_size / sizeof(struct undo_key)) - 1)
+
+#define E2UNDO_FEATURE_COMPAT_FS_OFFSET 0x1 /* the filesystem offset */
+
+static inline void e2undo_set_feature_fs_offset(struct undo_header *header) {
+ header->f_compat |= ext2fs_le32_to_cpu(E2UNDO_FEATURE_COMPAT_FS_OFFSET);
+}
+
+static inline void e2undo_clear_feature_fs_offset(struct undo_header *header) {
+ header->f_compat &= ~ext2fs_le32_to_cpu(E2UNDO_FEATURE_COMPAT_FS_OFFSET);
+}
+
+static io_manager undo_io_backing_manager;
+static char *tdb_file;
+static int actual_size;
+
+errcode_t set_undo_io_backing_manager(io_manager manager)
+{
+ /*
+ * We may want to do some validation later
+ */
+ undo_io_backing_manager = manager;
+ return 0;
+}
+
+errcode_t set_undo_io_backup_file(char *file_name)
+{
+ tdb_file = strdup(file_name);
+
+ if (tdb_file == NULL) {
+ return EXT2_ET_NO_MEMORY;
+ }
+
+ return 0;
+}
+
+static errcode_t write_undo_indexes(struct undo_private_data *data, int flush)
+{
+ errcode_t retval;
+ struct ext2_super_block super;
+ io_channel channel;
+ int block_size;
+ __u32 sb_crc, hdr_crc;
+
+ /* Spit out a key block, if there's any data */
+ if (data->keys_in_block) {
+ data->keyb->magic = ext2fs_cpu_to_le32(KEYBLOCK_MAGIC);
+ data->keyb->crc = 0;
+ data->keyb->crc = ext2fs_cpu_to_le32(
+ ext2fs_crc32c_le(~0,
+ (unsigned char *)data->keyb,
+ data->tdb_data_size));
+ dbg_printf("Writing keyblock to blk %llu\n", data->key_blk_num);
+ retval = io_channel_write_blk64(data->undo_file,
+ data->key_blk_num,
+ 1, data->keyb);
+ if (retval)
+ return retval;
+ /* Move on to the next key block if it's full. */
+ if (data->keys_in_block == KEYS_PER_BLOCK(data)) {
+ memset(data->keyb, 0, data->tdb_data_size);
+ data->keys_in_block = 0;
+ data->key_blk_num = data->undo_blk_num;
+ data->undo_blk_num++;
+ }
+ }
+
+ /* Prepare superblock for write */
+ channel = data->real;
+ block_size = channel->block_size;
+
+ io_channel_set_blksize(channel, SUPERBLOCK_OFFSET);
+ retval = io_channel_read_blk64(channel, 1, -SUPERBLOCK_SIZE, &super);
+ if (retval)
+ goto err_out;
+ sb_crc = ext2fs_crc32c_le(~0, (unsigned char *)&super, SUPERBLOCK_SIZE);
+ super.s_magic = ~super.s_magic;
+
+ /* Write the undo header to disk. */
+ memcpy(data->hdr.magic, E2UNDO_MAGIC, sizeof(data->hdr.magic));
+ data->hdr.num_keys = ext2fs_cpu_to_le64(data->num_keys);
+ data->hdr.super_offset = ext2fs_cpu_to_le64(data->super_blk_num);
+ data->hdr.key_offset = ext2fs_cpu_to_le64(data->first_key_blk);
+ data->hdr.fs_block_size = ext2fs_cpu_to_le32(block_size);
+ data->hdr.sb_crc = ext2fs_cpu_to_le32(sb_crc);
+ data->hdr.fs_offset = ext2fs_cpu_to_le64(data->offset);
+ if (data->offset)
+ e2undo_set_feature_fs_offset(&data->hdr);
+ else
+ e2undo_clear_feature_fs_offset(&data->hdr);
+ hdr_crc = ext2fs_crc32c_le(~0, (unsigned char *)&data->hdr,
+ sizeof(data->hdr) -
+ sizeof(data->hdr.header_crc));
+ data->hdr.header_crc = ext2fs_cpu_to_le32(hdr_crc);
+ retval = io_channel_write_blk64(data->undo_file, 0,
+ -(int)sizeof(data->hdr),
+ &data->hdr);
+ if (retval)
+ goto err_out;
+
+ /*
+ * Record the entire superblock (in FS byte order) so that we can't
+ * apply e2undo files to the wrong FS or out of order.
+ */
+ dbg_printf("Writing superblock to block %llu\n", data->super_blk_num);
+ retval = io_channel_write_blk64(data->undo_file, data->super_blk_num,
+ -SUPERBLOCK_SIZE, &super);
+ if (retval)
+ goto err_out;
+
+ if (flush)
+ retval = io_channel_flush(data->undo_file);
+err_out:
+ io_channel_set_blksize(channel, block_size);
+ return retval;
+}
+
+static errcode_t undo_setup_tdb(struct undo_private_data *data)
+{
+ int i;
+ errcode_t retval;
+
+ if (data->tdb_written == 1)
+ return 0;
+
+ data->tdb_written = 1;
+
+ /* Make a bitmap to track what we've written */
+ memset(&data->fake_fs, 0, sizeof(data->fake_fs));
+ data->fake_fs.blocksize = data->tdb_data_size;
+ retval = ext2fs_alloc_generic_bmap(&data->fake_fs,
+ EXT2_ET_MAGIC_BLOCK_BITMAP64,
+ EXT2FS_BMAP64_RBTREE,
+ 0, ~1ULL, ~1ULL,
+ "undo block map", &data->written_block_map);
+ if (retval)
+ return retval;
+
+ /* Allocate key block */
+ retval = ext2fs_get_mem(data->tdb_data_size, &data->keyb);
+ if (retval)
+ return retval;
+ data->key_blk_num = data->first_key_blk;
+
+ /* Record block size */
+ dbg_printf("Undo block size %llu\n", data->tdb_data_size);
+ dbg_printf("Keys per block %llu\n", KEYS_PER_BLOCK(data));
+ data->hdr.block_size = ext2fs_cpu_to_le32(data->tdb_data_size);
+ io_channel_set_blksize(data->undo_file, data->tdb_data_size);
+
+ /* Ensure that we have space for header blocks */
+ for (i = 0; i <= 2; i++) {
+ retval = io_channel_read_blk64(data->undo_file, i, 1,
+ data->keyb);
+ if (retval)
+ memset(data->keyb, 0, data->tdb_data_size);
+ retval = io_channel_write_blk64(data->undo_file, i, 1,
+ data->keyb);
+ if (retval)
+ return retval;
+ retval = io_channel_flush(data->undo_file);
+ if (retval)
+ return retval;
+ }
+ memset(data->keyb, 0, data->tdb_data_size);
+ return 0;
+}
+
+static errcode_t undo_write_tdb(io_channel channel,
+ unsigned long long block, int count)
+
+{
+ int size, sz;
+ unsigned long long block_num, backing_blk_num;
+ errcode_t retval = 0;
+ ext2_loff_t offset;
+ struct undo_private_data *data;
+ unsigned char *read_ptr;
+ unsigned long long end_block;
+ unsigned long long data_size;
+ struct undo_key *key;
+ __u32 blk_crc;
+
+ data = (struct undo_private_data *) channel->private_data;
+
+ if (data->undo_file == NULL) {
+ /*
+ * Transaction database not initialized
+ */
+ return 0;
+ }
+
+ if (count == 1)
+ size = channel->block_size;
+ else {
+ if (count < 0)
+ size = -count;
+ else
+ size = count * channel->block_size;
+ }
+
+ retval = undo_setup_tdb(data);
+ if (retval)
+ return retval;
+ /*
+ * Data is stored in tdb database as blocks of tdb_data_size size
+ * This helps in efficient lookup further.
+ *
+ * We divide the disk to blocks of tdb_data_size.
+ */
+ offset = (block * channel->block_size) + data->offset ;
+ block_num = offset / data->tdb_data_size;
+ end_block = (offset + size - 1) / data->tdb_data_size;
+
+ while (block_num <= end_block) {
+ __u32 keysz;
+
+ /*
+ * Check if we have the record already
+ */
+ if (ext2fs_test_block_bitmap2(data->written_block_map,
+ block_num)) {
+ /* Try the next block */
+ block_num++;
+ continue;
+ }
+ ext2fs_mark_block_bitmap2(data->written_block_map, block_num);
+
+ /*
+ * Read one block using the backing I/O manager
+ * The backing I/O manager block size may be
+ * different from the tdb_data_size.
+ * Also we need to recalculate the block number with respect
+ * to the backing I/O manager.
+ */
+ offset = block_num * data->tdb_data_size +
+ (data->offset % data->tdb_data_size);
+ backing_blk_num = (offset - data->offset) / channel->block_size;
+
+ retval = ext2fs_get_mem(data->tdb_data_size, &read_ptr);
+ if (retval) {
+ return retval;
+ }
+
+ memset(read_ptr, 0, data->tdb_data_size);
+ actual_size = 0;
+ if ((data->tdb_data_size % channel->block_size) == 0)
+ sz = data->tdb_data_size / channel->block_size;
+ else
+ sz = -data->tdb_data_size;
+ retval = io_channel_read_blk64(data->real, backing_blk_num,
+ sz, read_ptr);
+ if (retval) {
+ if (retval != EXT2_ET_SHORT_READ) {
+ free(read_ptr);
+ return retval;
+ }
+ /*
+ * short read so update the record size
+ * accordingly
+ */
+ data_size = actual_size;
+ } else {
+ data_size = data->tdb_data_size;
+ }
+ if (data_size == 0) {
+ free(read_ptr);
+ block_num++;
+ continue;
+ }
+ dbg_printf("Read %llu bytes from FS block %llu (blk=%llu cnt=%llu)\n",
+ data_size, backing_blk_num, block, data->tdb_data_size);
+ if ((data_size % data->undo_file->block_size) == 0)
+ sz = data_size / data->undo_file->block_size;
+ else
+ sz = -data_size;;
+ /* extend this key? */
+ if (data->keys_in_block) {
+ key = data->keyb->keys + data->keys_in_block - 1;
+ keysz = ext2fs_le32_to_cpu(key->size);
+ } else {
+ key = NULL;
+ keysz = 0;
+ }
+ if (key != NULL &&
+ (ext2fs_le64_to_cpu(key->fsblk) * channel->block_size +
+ channel->block_size - 1 +
+ keysz) / channel->block_size == backing_blk_num &&
+ E2UNDO_MAX_EXTENT_BLOCKS * data->tdb_data_size >
+ keysz + data_size) {
+ blk_crc = ext2fs_le32_to_cpu(key->blk_crc);
+ blk_crc = ext2fs_crc32c_le(blk_crc, read_ptr, data_size);
+ key->blk_crc = ext2fs_cpu_to_le32(blk_crc);
+ key->size = ext2fs_cpu_to_le32(keysz + data_size);
+ } else {
+ data->num_keys++;
+ key = data->keyb->keys + data->keys_in_block;
+ data->keys_in_block++;
+ key->fsblk = ext2fs_cpu_to_le64(backing_blk_num);
+ blk_crc = ext2fs_crc32c_le(~0, read_ptr, data_size);
+ key->blk_crc = ext2fs_cpu_to_le32(blk_crc);
+ key->size = ext2fs_cpu_to_le32(data_size);
+ }
+ dbg_printf("Writing block %llu to offset %llu size %d key %zu\n",
+ block_num,
+ data->undo_blk_num,
+ sz, data->num_keys - 1);
+ retval = io_channel_write_blk64(data->undo_file,
+ data->undo_blk_num, sz, read_ptr);
+ if (retval) {
+ free(read_ptr);
+ return retval;
+ }
+ data->undo_blk_num++;
+ free(read_ptr);
+
+ /* Write out the key block */
+ retval = write_undo_indexes(data, 0);
+ if (retval)
+ return retval;
+
+ /* Next block */
+ block_num++;
+ }
+
+ return retval;
+}
+
+static errcode_t undo_io_read_error(io_channel channel ATTR((unused)),
+ unsigned long block ATTR((unused)),
+ int count ATTR((unused)),
+ void *data ATTR((unused)),
+ size_t size ATTR((unused)),
+ int actual,
+ errcode_t error ATTR((unused)))
+{
+ actual_size = actual;
+ return error;
+}
+
+static void undo_err_handler_init(io_channel channel)
+{
+ channel->read_error = undo_io_read_error;
+}
+
+static int check_filesystem(struct undo_header *hdr, io_channel undo_file,
+ unsigned int blocksize, blk64_t super_block,
+ 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)
+ return retval;
+
+ /*
+ * Compare the FS and the undo file superblock so that we don't
+ * append to something that doesn't match this FS.
+ */
+ retval = ext2fs_get_mem(blocksize, &buf);
+ if (retval)
+ return retval;
+ retval = io_channel_read_blk64(undo_file, super_block,
+ -SUPERBLOCK_SIZE, buf);
+ if (retval)
+ goto out;
+ sb = (struct ext2_super_block *)buf;
+ sb->s_magic = ~sb->s_magic;
+ if (memcmp(&super, buf, sizeof(super))) {
+ retval = -1;
+ goto out;
+ }
+ sb_crc = ext2fs_crc32c_le(~0, (unsigned char *)buf, SUPERBLOCK_SIZE);
+ if (ext2fs_le32_to_cpu(hdr->sb_crc) != sb_crc) {
+ retval = -1;
+ goto out;
+ }
+
+out:
+ ext2fs_free_mem(&buf);
+ return retval;
+}
+
+/*
+ * Try to re-open the undo file, so that we can resume where we left off.
+ * That way, the user can pass the same undo file to various programs as
+ * part of an FS upgrade instead of having to create multiple files and
+ * then apply them in correct order.
+ */
+static errcode_t try_reopen_undo_file(int undo_fd,
+ struct undo_private_data *data)
+{
+ struct undo_header hdr;
+ struct undo_key *dkey;
+ ext2fs_struct_stat statbuf;
+ unsigned int blocksize, fs_blocksize;
+ blk64_t super_block, lblk;
+ size_t num_keys, keys_per_block, i;
+ __u32 hdr_crc, key_crc;
+ errcode_t retval;
+
+ /* Zero size already? */
+ retval = ext2fs_fstat(undo_fd, &statbuf);
+ if (retval)
+ goto bad_file;
+ if (statbuf.st_size == 0)
+ goto out;
+
+ /* check the file header */
+ retval = io_channel_read_blk64(data->undo_file, 0, -(int)sizeof(hdr),
+ &hdr);
+ if (retval)
+ goto bad_file;
+
+ if (memcmp(hdr.magic, E2UNDO_MAGIC,
+ sizeof(hdr.magic)))
+ goto bad_file;
+ hdr_crc = ext2fs_crc32c_le(~0, (unsigned char *)&hdr,
+ sizeof(struct undo_header) -
+ sizeof(__u32));
+ if (ext2fs_le32_to_cpu(hdr.header_crc) != hdr_crc)
+ goto bad_file;
+ blocksize = ext2fs_le32_to_cpu(hdr.block_size);
+ fs_blocksize = ext2fs_le32_to_cpu(hdr.fs_block_size);
+ if (blocksize > E2UNDO_MAX_BLOCK_SIZE ||
+ blocksize < E2UNDO_MIN_BLOCK_SIZE ||
+ !blocksize || !fs_blocksize)
+ goto bad_file;
+ super_block = ext2fs_le64_to_cpu(hdr.super_offset);
+ num_keys = ext2fs_le64_to_cpu(hdr.num_keys);
+ io_channel_set_blksize(data->undo_file, blocksize);
+ /*
+ * Do not compare hdr.f_compat with the available compatible
+ * features set, because a "missing" compatible feature should
+ * not cause any problems.
+ */
+ if (hdr.f_incompat || hdr.f_rocompat)
+ goto bad_file;
+
+ /* Superblock matches this FS? */
+ if (check_filesystem(&hdr, data->undo_file, blocksize, super_block,
+ data->real) != 0) {
+ retval = EXT2_ET_UNDO_FILE_WRONG;
+ goto out;
+ }
+
+ /* Try to set ourselves up */
+ data->tdb_data_size = blocksize;
+ retval = undo_setup_tdb(data);
+ if (retval)
+ goto bad_file;
+ data->num_keys = num_keys;
+ data->super_blk_num = super_block;
+ data->first_key_blk = ext2fs_le64_to_cpu(hdr.key_offset);
+
+ /* load the written block map */
+ keys_per_block = KEYS_PER_BLOCK(data);
+ lblk = data->first_key_blk;
+ dbg_printf("nr_keys=%lu, kpb=%zu, blksz=%u\n",
+ num_keys, keys_per_block, blocksize);
+ for (i = 0; i < num_keys; i += keys_per_block) {
+ size_t j, max_j;
+ __le32 crc;
+
+ data->key_blk_num = lblk;
+ retval = io_channel_read_blk64(data->undo_file,
+ lblk, 1, data->keyb);
+ if (retval)
+ goto bad_key_replay;
+
+ /* check keys */
+ if (ext2fs_le32_to_cpu(data->keyb->magic) != KEYBLOCK_MAGIC) {
+ retval = EXT2_ET_UNDO_FILE_CORRUPT;
+ goto bad_key_replay;
+ }
+ crc = data->keyb->crc;
+ data->keyb->crc = 0;
+ key_crc = ext2fs_crc32c_le(~0, (unsigned char *)data->keyb,
+ blocksize);
+ if (ext2fs_le32_to_cpu(crc) != key_crc) {
+ retval = EXT2_ET_UNDO_FILE_CORRUPT;
+ goto bad_key_replay;
+ }
+
+ /* load keys from key block */
+ lblk++;
+ max_j = data->num_keys - i;
+ if (max_j > keys_per_block)
+ max_j = keys_per_block;
+ for (j = 0, dkey = data->keyb->keys;
+ j < max_j;
+ j++, dkey++) {
+ blk64_t fsblk = ext2fs_le64_to_cpu(dkey->fsblk);
+ blk64_t undo_blk = fsblk * fs_blocksize / blocksize;
+ size_t size = ext2fs_le32_to_cpu(dkey->size);
+
+ ext2fs_mark_block_bitmap_range2(data->written_block_map,
+ undo_blk,
+ (size + blocksize - 1) / blocksize);
+ lblk += (size + blocksize - 1) / blocksize;
+ data->undo_blk_num = lblk;
+ data->keys_in_block = j + 1;
+ }
+ }
+ dbg_printf("Reopen undo, keyblk=%llu undoblk=%llu nrkeys=%zu kib=%zu\n",
+ data->key_blk_num, data->undo_blk_num, data->num_keys,
+ data->keys_in_block);
+
+ data->hdr.state = hdr.state & ~E2UNDO_STATE_FINISHED;
+ data->hdr.f_compat = hdr.f_compat;
+ data->hdr.f_incompat = hdr.f_incompat;
+ data->hdr.f_rocompat = hdr.f_rocompat;
+ return retval;
+
+bad_key_replay:
+ data->key_blk_num = data->undo_blk_num = 0;
+ data->keys_in_block = 0;
+ ext2fs_free_mem(&data->keyb);
+ ext2fs_free_generic_bitmap(data->written_block_map);
+ data->tdb_written = 0;
+ goto out;
+bad_file:
+ retval = EXT2_ET_UNDO_FILE_CORRUPT;
+out:
+ return retval;
+}
+
+static void undo_atexit(void *p)
+{
+ struct undo_private_data *data = p;
+ errcode_t err;
+
+ err = write_undo_indexes(data, 1);
+ io_channel_close(data->undo_file);
+
+ com_err(data->tdb_file, err, "while force-closing undo file");
+}
+
+static errcode_t undo_open(const char *name, int flags, io_channel *channel)
+{
+ io_channel io = NULL;
+ struct undo_private_data *data = NULL;
+ int undo_fd = -1;
+ errcode_t retval;
+
+ /* We don't support multi-threading, at least for now */
+ flags &= ~IO_FLAG_THREADS;
+ if (name == 0)
+ return EXT2_ET_BAD_DEVICE_NAME;
+ retval = ext2fs_get_mem(sizeof(struct struct_io_channel), &io);
+ if (retval)
+ goto cleanup;
+ memset(io, 0, sizeof(struct struct_io_channel));
+ io->magic = EXT2_ET_MAGIC_IO_CHANNEL;
+ retval = ext2fs_get_mem(sizeof(struct undo_private_data), &data);
+ if (retval)
+ goto cleanup;
+
+ io->manager = undo_io_manager;
+ retval = ext2fs_get_mem(strlen(name)+1, &io->name);
+ if (retval)
+ goto cleanup;
+
+ strcpy(io->name, name);
+ io->private_data = data;
+ io->block_size = 1024;
+ io->read_error = 0;
+ io->write_error = 0;
+ io->refcount = 1;
+
+ memset(data, 0, sizeof(struct undo_private_data));
+ data->magic = EXT2_ET_MAGIC_UNIX_IO_CHANNEL;
+ data->super_blk_num = 1;
+ data->first_key_blk = 2;
+ data->undo_blk_num = 3;
+
+ if (undo_io_backing_manager) {
+ retval = undo_io_backing_manager->open(name, flags,
+ &data->real);
+ if (retval)
+ goto cleanup;
+
+ data->tdb_file = strdup(tdb_file);
+ if (data->tdb_file == NULL)
+ goto cleanup;
+ undo_fd = ext2fs_open_file(data->tdb_file, O_RDWR | O_CREAT,
+ 0600);
+ if (undo_fd < 0)
+ goto cleanup;
+
+ retval = undo_io_backing_manager->open(data->tdb_file,
+ IO_FLAG_RW,
+ &data->undo_file);
+ if (retval)
+ goto cleanup;
+ } else {
+ data->real = NULL;
+ data->undo_file = NULL;
+ }
+
+ if (data->real)
+ io->flags = (io->flags & ~CHANNEL_FLAGS_DISCARD_ZEROES) |
+ (data->real->flags & CHANNEL_FLAGS_DISCARD_ZEROES);
+
+ /*
+ * setup err handler for read so that we know
+ * when the backing manager fails do short read
+ */
+ if (data->real)
+ undo_err_handler_init(data->real);
+
+ if (data->undo_file) {
+ retval = try_reopen_undo_file(undo_fd, data);
+ if (retval)
+ goto cleanup;
+ }
+ retval = ext2fs_add_exit_fn(undo_atexit, data);
+ if (retval)
+ goto cleanup;
+
+ *channel = io;
+ if (undo_fd >= 0)
+ close(undo_fd);
+ return retval;
+
+cleanup:
+ ext2fs_remove_exit_fn(undo_atexit, data);
+ if (undo_fd >= 0)
+ close(undo_fd);
+ if (data && data->undo_file)
+ io_channel_close(data->undo_file);
+ if (data && data->tdb_file)
+ free(data->tdb_file);
+ if (data && data->real)
+ io_channel_close(data->real);
+ if (data)
+ ext2fs_free_mem(&data);
+ if (io && io->name)
+ ext2fs_free_mem(&io->name);
+ if (io)
+ ext2fs_free_mem(&io);
+ return retval;
+}
+
+static errcode_t undo_close(io_channel channel)
+{
+ struct undo_private_data *data;
+ errcode_t err, retval = 0;
+
+ EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
+ data = (struct undo_private_data *) channel->private_data;
+ EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
+
+ if (--channel->refcount > 0)
+ return 0;
+ /* Before closing write the file system identity */
+ if (!getenv("UNDO_IO_SIMULATE_UNFINISHED"))
+ data->hdr.state = ext2fs_cpu_to_le32(E2UNDO_STATE_FINISHED);
+ err = write_undo_indexes(data, 1);
+ ext2fs_remove_exit_fn(undo_atexit, data);
+ if (data->real)
+ retval = io_channel_close(data->real);
+ if (data->tdb_file)
+ free(data->tdb_file);
+ if (data->undo_file)
+ io_channel_close(data->undo_file);
+ ext2fs_free_mem(&data->keyb);
+ if (data->written_block_map)
+ ext2fs_free_generic_bitmap(data->written_block_map);
+ ext2fs_free_mem(&channel->private_data);
+ if (channel->name)
+ ext2fs_free_mem(&channel->name);
+ ext2fs_free_mem(&channel);
+
+ if (err)
+ return err;
+ return retval;
+}
+
+static errcode_t undo_set_blksize(io_channel channel, int blksize)
+{
+ struct undo_private_data *data;
+ errcode_t retval = 0;
+
+ EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
+ data = (struct undo_private_data *) channel->private_data;
+ EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
+
+ if (blksize > E2UNDO_MAX_BLOCK_SIZE || blksize < E2UNDO_MIN_BLOCK_SIZE)
+ return EXT2_ET_INVALID_ARGUMENT;
+
+ if (data->real)
+ retval = io_channel_set_blksize(data->real, blksize);
+ /*
+ * Set the block size used for tdb
+ */
+ if (!data->tdb_data_size || !data->tdb_written)
+ data->tdb_data_size = blksize;
+ channel->block_size = blksize;
+ return retval;
+}
+
+static errcode_t undo_read_blk64(io_channel channel, unsigned long long block,
+ int count, void *buf)
+{
+ errcode_t retval = 0;
+ struct undo_private_data *data;
+
+ EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
+ data = (struct undo_private_data *) channel->private_data;
+ EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
+
+ if (data->real)
+ retval = io_channel_read_blk64(data->real, block, count, buf);
+
+ return retval;
+}
+
+static errcode_t undo_read_blk(io_channel channel, unsigned long block,
+ int count, void *buf)
+{
+ return undo_read_blk64(channel, block, count, buf);
+}
+
+static errcode_t undo_write_blk64(io_channel channel, unsigned long long block,
+ int count, const void *buf)
+{
+ struct undo_private_data *data;
+ errcode_t retval = 0;
+
+ EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
+ data = (struct undo_private_data *) channel->private_data;
+ EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
+ /*
+ * First write the existing content into database
+ */
+ retval = undo_write_tdb(channel, block, count);
+ if (retval)
+ return retval;
+ if (data->real)
+ retval = io_channel_write_blk64(data->real, block, count, buf);
+
+ return retval;
+}
+
+static errcode_t undo_write_blk(io_channel channel, unsigned long block,
+ int count, const void *buf)
+{
+ return undo_write_blk64(channel, block, count, buf);
+}
+
+static errcode_t undo_write_byte(io_channel channel, unsigned long offset,
+ int size, const void *buf)
+{
+ struct undo_private_data *data;
+ errcode_t retval = 0;
+ ext2_loff_t location;
+ unsigned long blk_num, count;;
+
+ EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
+ data = (struct undo_private_data *) channel->private_data;
+ EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
+
+ location = offset + data->offset;
+ blk_num = location/channel->block_size;
+ /*
+ * the size specified may spread across multiple blocks
+ * also make sure we account for the fact that block start
+ * offset for tdb is different from the backing I/O manager
+ * due to possible different block size
+ */
+ count = (size + (location % channel->block_size) +
+ channel->block_size -1)/channel->block_size;
+ retval = undo_write_tdb(channel, blk_num, count);
+ if (retval)
+ return retval;
+ if (data->real && data->real->manager->write_byte)
+ retval = io_channel_write_byte(data->real, offset, size, buf);
+
+ return retval;
+}
+
+static errcode_t undo_discard(io_channel channel, unsigned long long block,
+ unsigned long long count)
+{
+ struct undo_private_data *data;
+ errcode_t retval = 0;
+ int icount;
+
+ EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
+ data = (struct undo_private_data *) channel->private_data;
+ EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
+
+ if (count > INT_MAX)
+ return EXT2_ET_UNIMPLEMENTED;
+ icount = count;
+
+ /*
+ * First write the existing content into database
+ */
+ retval = undo_write_tdb(channel, block, icount);
+ if (retval)
+ return retval;
+ if (data->real)
+ retval = io_channel_discard(data->real, block, count);
+
+ return retval;
+}
+
+static errcode_t undo_zeroout(io_channel channel, unsigned long long block,
+ unsigned long long count)
+{
+ struct undo_private_data *data;
+ errcode_t retval = 0;
+ int icount;
+
+ EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
+ data = (struct undo_private_data *) channel->private_data;
+ EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
+
+ if (count > INT_MAX)
+ return EXT2_ET_UNIMPLEMENTED;
+ icount = count;
+
+ /*
+ * First write the existing content into database
+ */
+ retval = undo_write_tdb(channel, block, icount);
+ if (retval)
+ return retval;
+ if (data->real)
+ retval = io_channel_zeroout(data->real, block, count);
+
+ return retval;
+}
+
+static errcode_t undo_cache_readahead(io_channel channel,
+ unsigned long long block,
+ unsigned long long count)
+{
+ struct undo_private_data *data;
+ errcode_t retval = 0;
+
+ EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
+ data = (struct undo_private_data *) channel->private_data;
+ EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
+
+ if (data->real)
+ retval = io_channel_cache_readahead(data->real, block, count);
+
+ return retval;
+}
+
+/*
+ * Flush data buffers to disk.
+ */
+static errcode_t undo_flush(io_channel channel)
+{
+ errcode_t retval = 0;
+ struct undo_private_data *data;
+
+ EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
+ data = (struct undo_private_data *) channel->private_data;
+ EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
+
+ if (data->real)
+ retval = io_channel_flush(data->real);
+
+ return retval;
+}
+
+static errcode_t undo_set_option(io_channel channel, const char *option,
+ const char *arg)
+{
+ errcode_t retval = 0;
+ struct undo_private_data *data;
+ unsigned long tmp;
+ char *end;
+
+ EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
+ data = (struct undo_private_data *) channel->private_data;
+ EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
+
+ if (!strcmp(option, "tdb_data_size")) {
+ if (!arg)
+ return EXT2_ET_INVALID_ARGUMENT;
+
+ tmp = strtoul(arg, &end, 0);
+ if (*end)
+ return EXT2_ET_INVALID_ARGUMENT;
+ if (tmp > E2UNDO_MAX_BLOCK_SIZE || tmp < E2UNDO_MIN_BLOCK_SIZE)
+ return EXT2_ET_INVALID_ARGUMENT;
+ if (!data->tdb_data_size || !data->tdb_written) {
+ data->tdb_written = -1;
+ data->tdb_data_size = tmp;
+ }
+ return 0;
+ }
+ /*
+ * Need to support offset option to work with
+ * Unix I/O manager
+ */
+ if (data->real && data->real->manager->set_option) {
+ retval = data->real->manager->set_option(data->real,
+ option, arg);
+ }
+ if (!retval && !strcmp(option, "offset")) {
+ if (!arg)
+ return EXT2_ET_INVALID_ARGUMENT;
+
+ tmp = strtoul(arg, &end, 0);
+ if (*end)
+ return EXT2_ET_INVALID_ARGUMENT;
+ data->offset = tmp;
+ }
+ return retval;
+}
+
+static errcode_t undo_get_stats(io_channel channel, io_stats *stats)
+{
+ errcode_t retval = 0;
+ struct undo_private_data *data;
+
+ EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
+ data = (struct undo_private_data *) channel->private_data;
+ EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
+
+ if (data->real)
+ retval = (data->real->manager->get_stats)(data->real, stats);
+
+ return retval;
+}
+
+static struct struct_io_manager struct_undo_manager = {
+ .magic = EXT2_ET_MAGIC_IO_MANAGER,
+ .name = "Undo I/O Manager",
+ .open = undo_open,
+ .close = undo_close,
+ .set_blksize = undo_set_blksize,
+ .read_blk = undo_read_blk,
+ .write_blk = undo_write_blk,
+ .flush = undo_flush,
+ .write_byte = undo_write_byte,
+ .set_option = undo_set_option,
+ .get_stats = undo_get_stats,
+ .read_blk64 = undo_read_blk64,
+ .write_blk64 = undo_write_blk64,
+ .discard = undo_discard,
+ .zeroout = undo_zeroout,
+ .cache_readahead = undo_cache_readahead,
+};
+
+io_manager undo_io_manager = &struct_undo_manager;