diff options
Diffstat (limited to 'e2fsprogs/e2fsck/swapfs.c')
| -rw-r--r-- | e2fsprogs/e2fsck/swapfs.c | 269 |
1 files changed, 269 insertions, 0 deletions
diff --git a/e2fsprogs/e2fsck/swapfs.c b/e2fsprogs/e2fsck/swapfs.c new file mode 100644 index 0000000..8d46404 --- /dev/null +++ b/e2fsprogs/e2fsck/swapfs.c @@ -0,0 +1,269 @@ +/* + * swapfs.c --- byte-swap an ext2 filesystem + * + * Copyright 1996, 1997 by Theodore Ts'o + * + * %Begin-Header% + * This file may be redistributed under the terms of the GNU Public + * License. + * %End-Header% + * + */ + +#ifdef HAVE_ERRNO_H +#include <errno.h> +#endif +#include <et/com_err.h> +#include "e2fsck.h" + +#ifdef ENABLE_SWAPFS + +struct swap_block_struct { + ext2_ino_t ino; + int isdir; + errcode_t errcode; + char *dir_buf; + struct ext2_inode *inode; +}; + +/* + * This is a helper function for block_iterate. We mark all of the + * indirect and direct blocks as changed, so that block_iterate will + * write them out. + */ +static int swap_block(ext2_filsys fs, blk_t *block_nr, int blockcnt, + void *priv_data) +{ + errcode_t retval; + + struct swap_block_struct *sb = (struct swap_block_struct *) priv_data; + + if (sb->isdir && (blockcnt >= 0) && *block_nr) { + retval = ext2fs_read_dir_block(fs, *block_nr, sb->dir_buf); + if (retval) { + sb->errcode = retval; + return BLOCK_ABORT; + } + retval = ext2fs_write_dir_block(fs, *block_nr, sb->dir_buf); + if (retval) { + sb->errcode = retval; + return BLOCK_ABORT; + } + } + if (blockcnt >= 0) { + if (blockcnt < EXT2_NDIR_BLOCKS) + return 0; + return BLOCK_CHANGED; + } + if (blockcnt == BLOCK_COUNT_IND) { + if (*block_nr == sb->inode->i_block[EXT2_IND_BLOCK]) + return 0; + return BLOCK_CHANGED; + } + if (blockcnt == BLOCK_COUNT_DIND) { + if (*block_nr == sb->inode->i_block[EXT2_DIND_BLOCK]) + return 0; + return BLOCK_CHANGED; + } + if (blockcnt == BLOCK_COUNT_TIND) { + if (*block_nr == sb->inode->i_block[EXT2_TIND_BLOCK]) + return 0; + return BLOCK_CHANGED; + } + return BLOCK_CHANGED; +} + +/* + * This function is responsible for byte-swapping all of the indirect, + * block pointers. It is also responsible for byte-swapping directories. + */ +static void swap_inode_blocks(e2fsck_t ctx, ext2_ino_t ino, char *block_buf, + struct ext2_inode *inode) +{ + errcode_t retval; + struct swap_block_struct sb; + + sb.ino = ino; + sb.inode = inode; + sb.dir_buf = block_buf + ctx->fs->blocksize*3; + sb.errcode = 0; + sb.isdir = 0; + if (LINUX_S_ISDIR(inode->i_mode)) + sb.isdir = 1; + + retval = ext2fs_block_iterate(ctx->fs, ino, 0, block_buf, + swap_block, &sb); + if (retval) { + com_err("swap_inode_blocks", retval, + _("while calling ext2fs_block_iterate")); + ctx->flags |= E2F_FLAG_ABORT; + return; + } + if (sb.errcode) { + com_err("swap_inode_blocks", sb.errcode, + _("while calling iterator function")); + ctx->flags |= E2F_FLAG_ABORT; + return; + } +} + +static void swap_inodes(e2fsck_t ctx) +{ + ext2_filsys fs = ctx->fs; + dgrp_t group; + unsigned int i; + ext2_ino_t ino = 1; + char *buf, *block_buf; + errcode_t retval; + struct ext2_inode * inode; + + e2fsck_use_inode_shortcuts(ctx, 1); + + retval = ext2fs_get_mem(fs->blocksize * fs->inode_blocks_per_group, + &buf); + if (retval) { + com_err("swap_inodes", retval, + _("while allocating inode buffer")); + ctx->flags |= E2F_FLAG_ABORT; + return; + } + block_buf = (char *) e2fsck_allocate_memory(ctx, fs->blocksize * 4, + "block interate buffer"); + for (group = 0; group < fs->group_desc_count; group++) { + retval = io_channel_read_blk(fs->io, + fs->group_desc[group].bg_inode_table, + fs->inode_blocks_per_group, buf); + if (retval) { + com_err("swap_inodes", retval, + _("while reading inode table (group %d)"), + group); + ctx->flags |= E2F_FLAG_ABORT; + return; + } + inode = (struct ext2_inode *) buf; + for (i=0; i < fs->super->s_inodes_per_group; + i++, ino++, inode++) { + ctx->stashed_ino = ino; + ctx->stashed_inode = inode; + + if (fs->flags & EXT2_FLAG_SWAP_BYTES_READ) + ext2fs_swap_inode(fs, inode, inode, 0); + + /* + * Skip deleted files. + */ + if (inode->i_links_count == 0) + continue; + + if (LINUX_S_ISDIR(inode->i_mode) || + ((inode->i_block[EXT2_IND_BLOCK] || + inode->i_block[EXT2_DIND_BLOCK] || + inode->i_block[EXT2_TIND_BLOCK]) && + ext2fs_inode_has_valid_blocks(inode))) + swap_inode_blocks(ctx, ino, block_buf, inode); + + if (ctx->flags & E2F_FLAG_SIGNAL_MASK) + return; + + if (fs->flags & EXT2_FLAG_SWAP_BYTES_WRITE) + ext2fs_swap_inode(fs, inode, inode, 1); + } + retval = io_channel_write_blk(fs->io, + fs->group_desc[group].bg_inode_table, + fs->inode_blocks_per_group, buf); + if (retval) { + com_err("swap_inodes", retval, + _("while writing inode table (group %d)"), + group); + ctx->flags |= E2F_FLAG_ABORT; + return; + } + } + ext2fs_free_mem(&buf); + ext2fs_free_mem(&block_buf); + e2fsck_use_inode_shortcuts(ctx, 0); + ext2fs_flush_icache(fs); +} + +#if defined(__powerpc__) && defined(EXT2FS_ENABLE_SWAPFS) +/* + * On the PowerPC, the big-endian variant of the ext2 filesystem + * has its bitmaps stored as 32-bit words with bit 0 as the LSB + * of each word. Thus a bitmap with only bit 0 set would be, as + * a string of bytes, 00 00 00 01 00 ... + * To cope with this, we byte-reverse each word of a bitmap if + * we have a big-endian filesystem, that is, if we are *not* + * byte-swapping other word-sized numbers. + */ +#define EXT2_BIG_ENDIAN_BITMAPS +#endif + +#ifdef EXT2_BIG_ENDIAN_BITMAPS +static void ext2fs_swap_bitmap(ext2fs_generic_bitmap bmap) +{ + __u32 *p = (__u32 *) bmap->bitmap; + int n, nbytes = (bmap->end - bmap->start + 7) / 8; + + for (n = nbytes / sizeof(__u32); n > 0; --n, ++p) + *p = ext2fs_swab32(*p); +} +#endif + + +void swap_filesys(e2fsck_t ctx) +{ + ext2_filsys fs = ctx->fs; +#ifdef RESOURCE_TRACK + struct resource_track rtrack; + + init_resource_track(&rtrack); +#endif + + if (!(ctx->options & E2F_OPT_PREEN)) + printf(_("Pass 0: Doing byte-swap of filesystem\n")); + +#ifdef MTRACE + mtrace_print("Byte swap"); +#endif + + if (fs->super->s_mnt_count) { + fprintf(stderr, _("%s: the filesystem must be freshly " + "checked using fsck\n" + "and not mounted before trying to " + "byte-swap it.\n"), ctx->device_name); + ctx->flags |= E2F_FLAG_ABORT; + return; + } + if (fs->flags & EXT2_FLAG_SWAP_BYTES) { + fs->flags &= ~(EXT2_FLAG_SWAP_BYTES| + EXT2_FLAG_SWAP_BYTES_WRITE); + fs->flags |= EXT2_FLAG_SWAP_BYTES_READ; + } else { + fs->flags &= ~EXT2_FLAG_SWAP_BYTES_READ; + fs->flags |= EXT2_FLAG_SWAP_BYTES_WRITE; + } + swap_inodes(ctx); + if (ctx->flags & E2F_FLAG_SIGNAL_MASK) + return; + if (fs->flags & EXT2_FLAG_SWAP_BYTES_WRITE) + fs->flags |= EXT2_FLAG_SWAP_BYTES; + fs->flags &= ~(EXT2_FLAG_SWAP_BYTES_READ| + EXT2_FLAG_SWAP_BYTES_WRITE); + +#ifdef EXT2_BIG_ENDIAN_BITMAPS + e2fsck_read_bitmaps(ctx); + ext2fs_swap_bitmap(fs->inode_map); + ext2fs_swap_bitmap(fs->block_map); + fs->flags |= EXT2_FLAG_BB_DIRTY | EXT2_FLAG_IB_DIRTY; +#endif + fs->flags &= ~EXT2_FLAG_MASTER_SB_ONLY; + ext2fs_flush(fs); + fs->flags |= EXT2_FLAG_MASTER_SB_ONLY; + +#ifdef RESOURCE_TRACK + if (ctx->options & E2F_OPT_TIME2) + print_resource_track(_("Byte swap"), &rtrack); +#endif +} + +#endif |