/* * pass3.c -- pass #3 of e2fsck: Check for directory connectivity * * Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999 Theodore Ts'o. * * %Begin-Header% * This file may be redistributed under the terms of the GNU Public * License. * %End-Header% * * Pass #3 assures that all directories are connected to the * filesystem tree, using the following algorithm: * * First, the root directory is checked to make sure it exists; if * not, e2fsck will offer to create a new one. It is then marked as * "done". * * Then, pass3 interates over all directory inodes; for each directory * it attempts to trace up the filesystem tree, using dirinfo.parent * until it reaches a directory which has been marked "done". If it * can not do so, then the directory must be disconnected, and e2fsck * will offer to reconnect it to /lost+found. While it is chasing * parent pointers up the filesystem tree, if pass3 sees a directory * twice, then it has detected a filesystem loop, and it will again * offer to reconnect the directory to /lost+found in to break the * filesystem loop. * * Pass 3 also contains the subroutine, e2fsck_reconnect_file() to * reconnect inodes to /lost+found; this subroutine is also used by * pass 4. e2fsck_reconnect_file() calls get_lost_and_found(), which * is responsible for creating /lost+found if it does not exist. * * Pass 3 frees the following data structures: * - The dirinfo directory information cache. */ #ifdef HAVE_ERRNO_H #include <errno.h> #endif #include "e2fsck.h" #include "problem.h" static void check_root(e2fsck_t ctx); static int check_directory(e2fsck_t ctx, ext2_ino_t ino, struct problem_context *pctx); static void fix_dotdot(e2fsck_t ctx, ext2_ino_t ino, ext2_ino_t parent); static ext2fs_inode_bitmap inode_loop_detect = 0; static ext2fs_inode_bitmap inode_done_map = 0; void e2fsck_pass3(e2fsck_t ctx) { ext2_filsys fs = ctx->fs; struct dir_info_iter *iter; #ifdef RESOURCE_TRACK struct resource_track rtrack; #endif struct problem_context pctx; struct dir_info *dir; unsigned long maxdirs, count; init_resource_track(&rtrack, ctx->fs->io); clear_problem_context(&pctx); #ifdef MTRACE mtrace_print("Pass 3"); #endif if (!(ctx->options & E2F_OPT_PREEN)) fix_problem(ctx, PR_3_PASS_HEADER, &pctx); /* * Allocate some bitmaps to do loop detection. */ pctx.errcode = ext2fs_allocate_inode_bitmap(fs, _("inode done bitmap"), &inode_done_map); if (pctx.errcode) { pctx.num = 2; fix_problem(ctx, PR_3_ALLOCATE_IBITMAP_ERROR, &pctx); ctx->flags |= E2F_FLAG_ABORT; goto abort_exit; } print_resource_track(ctx, _("Peak memory"), &ctx->global_rtrack, NULL); check_root(ctx); if (ctx->flags & E2F_FLAG_SIGNAL_MASK) goto abort_exit; ext2fs_mark_inode_bitmap(inode_done_map, EXT2_ROOT_INO); maxdirs = e2fsck_get_num_dirinfo(ctx); count = 1; if (ctx->progress) if ((ctx->progress)(ctx, 3, 0, maxdirs)) goto abort_exit; iter = e2fsck_dir_info_iter_begin(ctx); while ((dir = e2fsck_dir_info_iter(ctx, iter)) != 0) { if (ctx->flags & E2F_FLAG_SIGNAL_MASK) goto abort_exit; if (ctx->progress && (ctx->progress)(ctx, 3, count++, maxdirs)) goto abort_exit; if (ext2fs_test_inode_bitmap(ctx->inode_dir_map, dir->ino)) if (check_directory(ctx, dir->ino, &pctx)) goto abort_exit; } e2fsck_dir_info_iter_end(ctx, iter); /* * Force the creation of /lost+found if not present */ if ((ctx->flags & E2F_OPT_READONLY) == 0) e2fsck_get_lost_and_found(ctx, 1); /* * If there are any directories that need to be indexed or * optimized, do it here. */ e2fsck_rehash_directories(ctx); abort_exit: e2fsck_free_dir_info(ctx); if (inode_loop_detect) { ext2fs_free_inode_bitmap(inode_loop_detect); inode_loop_detect = 0; } if (inode_done_map) { ext2fs_free_inode_bitmap(inode_done_map); inode_done_map = 0; } print_resource_track(ctx, _("Pass 3"), &rtrack, ctx->fs->io); } /* * This makes sure the root inode is present; if not, we ask if the * user wants us to create it. Not creating it is a fatal error. */ static void check_root(e2fsck_t ctx) { ext2_filsys fs = ctx->fs; blk_t blk; struct ext2_inode inode; char * block; struct problem_context pctx; clear_problem_context(&pctx); if (ext2fs_test_inode_bitmap(ctx->inode_used_map, EXT2_ROOT_INO)) { /* * If the root inode is not a directory, die here. The * user must have answered 'no' in pass1 when we * offered to clear it. */ if (!(ext2fs_test_inode_bitmap(ctx->inode_dir_map, EXT2_ROOT_INO))) { fix_problem(ctx, PR_3_ROOT_NOT_DIR_ABORT, &pctx); ctx->flags |= E2F_FLAG_ABORT; } return; } if (!fix_problem(ctx, PR_3_NO_ROOT_INODE, &pctx)) { fix_problem(ctx, PR_3_NO_ROOT_INODE_ABORT, &pctx); ctx->flags |= E2F_FLAG_ABORT; return; } e2fsck_read_bitmaps(ctx); /* * First, find a free block */ pctx.errcode = ext2fs_new_block(fs, 0, ctx->block_found_map, &blk); if (pctx.errcode) { pctx.str = "ext2fs_new_block"; fix_problem(ctx, PR_3_CREATE_ROOT_ERROR, &pctx); ctx->flags |= E2F_FLAG_ABORT; return; } ext2fs_mark_block_bitmap(ctx->block_found_map, blk); ext2fs_mark_block_bitmap(fs->block_map, blk); ext2fs_mark_bb_dirty(fs); /* * Now let's create the actual data block for the inode */ pctx.errcode = ext2fs_new_dir_block(fs, EXT2_ROOT_INO, EXT2_ROOT_INO, &block); if (pctx.errcode) { pctx.str = "ext2fs_new_dir_block"; fix_problem(ctx, PR_3_CREATE_ROOT_ERROR, &pctx); ctx->flags |= E2F_FLAG_ABORT; return; } pctx.errcode = ext2fs_write_dir_block(fs, blk, block); if (pctx.errcode) { pctx.str = "ext2fs_write_dir_block"; fix_problem(ctx, PR_3_CREATE_ROOT_ERROR, &pctx); ctx->flags |= E2F_FLAG_ABORT; return; } ext2fs_free_mem(&block); /* * Set up the inode structure */ memset(&inode, 0, sizeof(inode)); inode.i_mode = 040755; inode.i_size = fs->blocksize; inode.i_atime = inode.i_ctime = inode.i_mtime = ctx->now; inode.i_links_count = 2; ext2fs_iblk_set(fs, &inode, 1); inode.i_block[0] = blk; /* * Write out the inode. */ pctx.errcode = ext2fs_write_new_inode(fs, EXT2_ROOT_INO, &inode); if (pctx.errcode) { pctx.str = "ext2fs_write_inode"; fix_problem(ctx, PR_3_CREATE_ROOT_ERROR, &pctx); ctx->flags |= E2F_FLAG_ABORT; return; } /* * Miscellaneous bookkeeping... */ e2fsck_add_dir_info(ctx, EXT2_ROOT_INO, EXT2_ROOT_INO); ext2fs_icount_store(ctx->inode_count, EXT2_ROOT_INO, 2); ext2fs_icount_store(ctx->inode_link_info, EXT2_ROOT_INO, 2); ext2fs_mark_inode_bitmap(ctx->inode_used_map, EXT2_ROOT_INO); ext2fs_mark_inode_bitmap(ctx->inode_dir_map, EXT2_ROOT_INO); ext2fs_mark_inode_bitmap(fs->inode_map, EXT2_ROOT_INO); ext2fs_mark_ib_dirty(fs); } /* * This subroutine is responsible for making sure that a particular * directory is connected to the root; if it isn't we trace it up as * far as we can go, and then offer to connect the resulting parent to * the lost+found. We have to do loop detection; if we ever discover * a loop, we treat that as a disconnected directory and offer to * reparent it to lost+found. * * However, loop detection is expensive, because for very large * filesystems, the inode_loop_detect bitmap is huge, and clearing it * is non-trivial. Loops in filesystems are also a rare error case, * and we shouldn't optimize for error cases. So we try two passes of * the algorithm. The first time, we ignore loop detection and merely * increment a counter; if the counter exceeds some extreme threshold, * then we try again with the loop detection bitmap enabled. */ static int check_directory(e2fsck_t ctx, ext2_ino_t dir, struct problem_context *pctx) { ext2_filsys fs = ctx->fs; ext2_ino_t ino = dir, parent; int loop_pass = 0, parent_count = 0; while (1) { /* * Mark this inode as being "done"; by the time we * return from this function, the inode we either be * verified as being connected to the directory tree, * or we will have offered to reconnect this to * lost+found. * * If it was marked done already, then we've reached a * parent we've already checked. */ if (ext2fs_mark_inode_bitmap(inode_done_map, ino)) break; if (e2fsck_dir_info_get_parent(ctx, ino, &parent)) { fix_problem(ctx, PR_3_NO_DIRINFO, pctx); return 0; } /* * If this directory doesn't have a parent, or we've * seen the parent once already, then offer to * reparent it to lost+found */ if (!parent || (loop_pass && (ext2fs_test_inode_bitmap(inode_loop_detect, parent)))) { pctx->ino = ino; if (fix_problem(ctx, PR_3_UNCONNECTED_DIR, pctx)) { if (e2fsck_reconnect_file(ctx, pctx->ino)) ext2fs_unmark_valid(fs); else { fix_dotdot(ctx, pctx->ino, ctx->lost_and_found); parent = ctx->lost_and_found; } } break; } ino = parent; if (loop_pass) { ext2fs_mark_inode_bitmap(inode_loop_detect, ino); } else if (parent_count++ > 2048) { /* * If we've run into a path depth that's * greater than 2048, try again with the inode * loop bitmap turned on and start from the * top. */ loop_pass = 1; if (inode_loop_detect) ext2fs_clear_inode_bitmap(inode_loop_detect); else { pctx->errcode = ext2fs_allocate_inode_bitmap(fs, _("inode loop detection bitmap"), &inode_loop_detect); if (pctx->errcode) { pctx->num = 1; fix_problem(ctx, PR_3_ALLOCATE_IBITMAP_ERROR, pctx); ctx->flags |= E2F_FLAG_ABORT; return -1; } } ino = dir; } } /* * Make sure that .. and the parent directory are the same; * offer to fix it if not. */ pctx->ino = dir; if (e2fsck_dir_info_get_dotdot(ctx, dir, &pctx->ino2) || e2fsck_dir_info_get_parent(ctx, dir, &pctx->dir)) { fix_problem(ctx, PR_3_NO_DIRINFO, pctx); return 0; } if (pctx->ino2 != pctx->dir) { if (fix_problem(ctx, PR_3_BAD_DOT_DOT, pctx)) fix_dotdot(ctx, dir, pctx->dir); } return 0; } /* * This routine gets the lost_and_found inode, making it a directory * if necessary */ ext2_ino_t e2fsck_get_lost_and_found(e2fsck_t ctx, int fix) { ext2_filsys fs = ctx->fs; ext2_ino_t ino; blk_t blk; errcode_t retval; struct ext2_inode inode; char * block; static const char name[] = "lost+found"; struct problem_context pctx; if (ctx->lost_and_found) return ctx->lost_and_found; clear_problem_context(&pctx); retval = ext2fs_lookup(fs, EXT2_ROOT_INO, name, sizeof(name)-1, 0, &ino); if (retval && !fix) return 0; if (!retval) { if (ext2fs_test_inode_bitmap(ctx->inode_dir_map, ino)) { ctx->lost_and_found = ino; return ino; } /* Lost+found isn't a directory! */ if (!fix) return 0; pctx.ino = ino; if (!fix_problem(ctx, PR_3_LPF_NOTDIR, &pctx)) return 0; /* OK, unlink the old /lost+found file. */ pctx.errcode = ext2fs_unlink(fs, EXT2_ROOT_INO, name, ino, 0); if (pctx.errcode) { pctx.str = "ext2fs_unlink"; fix_problem(ctx, PR_3_CREATE_LPF_ERROR, &pctx); return 0; } (void) e2fsck_dir_info_set_parent(ctx, ino, 0); e2fsck_adjust_inode_count(ctx, ino, -1); } else if (retval != EXT2_ET_FILE_NOT_FOUND) { pctx.errcode = retval; fix_problem(ctx, PR_3_ERR_FIND_LPF, &pctx); } if (!fix_problem(ctx, PR_3_NO_LF_DIR, 0)) return 0; /* * Read the inode and block bitmaps in; we'll be messing with * them. */ e2fsck_read_bitmaps(ctx); /* * First, find a free block */ retval = ext2fs_new_block(fs, 0, ctx->block_found_map, &blk); if (retval) { pctx.errcode = retval; fix_problem(ctx, PR_3_ERR_LPF_NEW_BLOCK, &pctx); return 0; } ext2fs_mark_block_bitmap(ctx->block_found_map, blk); ext2fs_block_alloc_stats(fs, blk, +1); /* * Next find a free inode. */ retval = ext2fs_new_inode(fs, EXT2_ROOT_INO, 040700, ctx->inode_used_map, &ino); if (retval) { pctx.errcode = retval; fix_problem(ctx, PR_3_ERR_LPF_NEW_INODE, &pctx); return 0; } ext2fs_mark_inode_bitmap(ctx->inode_used_map, ino); ext2fs_mark_inode_bitmap(ctx->inode_dir_map, ino); ext2fs_inode_alloc_stats2(fs, ino, +1, 1); /* * Now let's create the actual data block for the inode */ retval = ext2fs_new_dir_block(fs, ino, EXT2_ROOT_INO, &block); if (retval) { pctx.errcode = retval; fix_problem(ctx, PR_3_ERR_LPF_NEW_DIR_BLOCK, &pctx); return 0; } retval = ext2fs_write_dir_block(fs, blk, block); ext2fs_free_mem(&block); if (retval) { pctx.errcode = retval; fix_problem(ctx, PR_3_ERR_LPF_WRITE_BLOCK, &pctx); return 0; } /* * Set up the inode structure */ memset(&inode, 0, sizeof(inode)); inode.i_mode = 040700; inode.i_size = fs->blocksize; inode.i_atime = inode.i_ctime = inode.i_mtime = ctx->now; inode.i_links_count = 2; ext2fs_iblk_set(fs, &inode, 1); inode.i_block[0] = blk; /* * Next, write out the inode. */ pctx.errcode = ext2fs_write_new_inode(fs, ino, &inode); if (pctx.errcode) { pctx.str = "ext2fs_write_inode"; fix_problem(ctx, PR_3_CREATE_LPF_ERROR, &pctx); return 0; } /* * Finally, create the directory link */ pctx.errcode = ext2fs_link(fs, EXT2_ROOT_INO, name, ino, EXT2_FT_DIR); if (pctx.errcode) { pctx.str = "ext2fs_link"; fix_problem(ctx, PR_3_CREATE_LPF_ERROR, &pctx); return 0; } /* * Miscellaneous bookkeeping that needs to be kept straight. */ e2fsck_add_dir_info(ctx, ino, EXT2_ROOT_INO); e2fsck_adjust_inode_count(ctx, EXT2_ROOT_INO, 1); ext2fs_icount_store(ctx->inode_count, ino, 2); ext2fs_icount_store(ctx->inode_link_info, ino, 2); ctx->lost_and_found = ino; #if 0 printf("/lost+found created; inode #%lu\n", ino); #endif return ino; } /* * This routine will connect a file to lost+found */ int e2fsck_reconnect_file(e2fsck_t ctx, ext2_ino_t ino) { ext2_filsys fs = ctx->fs; errcode_t retval; char name[80]; struct problem_context pctx; struct ext2_inode inode; int file_type = 0; clear_problem_context(&pctx); pctx.ino = ino; if (!ctx->bad_lost_and_found && !ctx->lost_and_found) { if (e2fsck_get_lost_and_found(ctx, 1) == 0) ctx->bad_lost_and_found++; } if (ctx->bad_lost_and_found) { fix_problem(ctx, PR_3_NO_LPF, &pctx); return 1; } sprintf(name, "#%u", ino); if (ext2fs_read_inode(fs, ino, &inode) == 0) file_type = ext2_file_type(inode.i_mode); retval = ext2fs_link(fs, ctx->lost_and_found, name, ino, file_type); if (retval == EXT2_ET_DIR_NO_SPACE) { if (!fix_problem(ctx, PR_3_EXPAND_LF_DIR, &pctx)) return 1; retval = e2fsck_expand_directory(ctx, ctx->lost_and_found, 1, 0); if (retval) { pctx.errcode = retval; fix_problem(ctx, PR_3_CANT_EXPAND_LPF, &pctx); return 1; } retval = ext2fs_link(fs, ctx->lost_and_found, name, ino, file_type); } if (retval) { pctx.errcode = retval; fix_problem(ctx, PR_3_CANT_RECONNECT, &pctx); return 1; } e2fsck_adjust_inode_count(ctx, ino, 1); return 0; } /* * Utility routine to adjust the inode counts on an inode. */ errcode_t e2fsck_adjust_inode_count(e2fsck_t ctx, ext2_ino_t ino, int adj) { ext2_filsys fs = ctx->fs; errcode_t retval; struct ext2_inode inode; if (!ino) return 0; retval = ext2fs_read_inode(fs, ino, &inode); if (retval) return retval; #if 0 printf("Adjusting link count for inode %lu by %d (from %d)\n", ino, adj, inode.i_links_count); #endif if (adj == 1) { ext2fs_icount_increment(ctx->inode_count, ino, 0); if (inode.i_links_count == (__u16) ~0) return 0; ext2fs_icount_increment(ctx->inode_link_info, ino, 0); inode.i_links_count++; } else if (adj == -1) { ext2fs_icount_decrement(ctx->inode_count, ino, 0); if (inode.i_links_count == 0) return 0; ext2fs_icount_decrement(ctx->inode_link_info, ino, 0); inode.i_links_count--; } retval = ext2fs_write_inode(fs, ino, &inode); if (retval) return retval; return 0; } /* * Fix parent --- this routine fixes up the parent of a directory. */ struct fix_dotdot_struct { ext2_filsys fs; ext2_ino_t parent; int done; e2fsck_t ctx; }; static int fix_dotdot_proc(struct ext2_dir_entry *dirent, int offset EXT2FS_ATTR((unused)), int blocksize EXT2FS_ATTR((unused)), char *buf EXT2FS_ATTR((unused)), void *priv_data) { struct fix_dotdot_struct *fp = (struct fix_dotdot_struct *) priv_data; errcode_t retval; struct problem_context pctx; if ((dirent->name_len & 0xFF) != 2) return 0; if (strncmp(dirent->name, "..", 2)) return 0; clear_problem_context(&pctx); retval = e2fsck_adjust_inode_count(fp->ctx, dirent->inode, -1); if (retval) { pctx.errcode = retval; fix_problem(fp->ctx, PR_3_ADJUST_INODE, &pctx); } retval = e2fsck_adjust_inode_count(fp->ctx, fp->parent, 1); if (retval) { pctx.errcode = retval; fix_problem(fp->ctx, PR_3_ADJUST_INODE, &pctx); } dirent->inode = fp->parent; if (fp->ctx->fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_FILETYPE) dirent->name_len = (dirent->name_len & 0xFF) | (EXT2_FT_DIR << 8); else dirent->name_len = dirent->name_len & 0xFF; fp->done++; return DIRENT_ABORT | DIRENT_CHANGED; } static void fix_dotdot(e2fsck_t ctx, ext2_ino_t ino, ext2_ino_t parent) { ext2_filsys fs = ctx->fs; errcode_t retval; struct fix_dotdot_struct fp; struct problem_context pctx; fp.fs = fs; fp.parent = parent; fp.done = 0; fp.ctx = ctx; #if 0 printf("Fixing '..' of inode %lu to be %lu...\n", ino, parent); #endif clear_problem_context(&pctx); pctx.ino = ino; retval = ext2fs_dir_iterate(fs, ino, DIRENT_FLAG_INCLUDE_EMPTY, 0, fix_dotdot_proc, &fp); if (retval || !fp.done) { pctx.errcode = retval; fix_problem(ctx, retval ? PR_3_FIX_PARENT_ERR : PR_3_FIX_PARENT_NOFIND, &pctx); ext2fs_unmark_valid(fs); } (void) e2fsck_dir_info_set_dotdot(ctx, ino, parent); if (e2fsck_dir_info_set_parent(ctx, ino, ctx->lost_and_found)) fix_problem(ctx, PR_3_NO_DIRINFO, &pctx); return; } /* * These routines are responsible for expanding a /lost+found if it is * too small. */ struct expand_dir_struct { int num; int guaranteed_size; int newblocks; int last_block; errcode_t err; e2fsck_t ctx; }; static int expand_dir_proc(ext2_filsys fs, blk_t *blocknr, e2_blkcnt_t blockcnt, blk_t ref_block EXT2FS_ATTR((unused)), int ref_offset EXT2FS_ATTR((unused)), void *priv_data) { struct expand_dir_struct *es = (struct expand_dir_struct *) priv_data; blk_t new_blk; static blk_t last_blk = 0; char *block; errcode_t retval; e2fsck_t ctx; ctx = es->ctx; if (es->guaranteed_size && blockcnt >= es->guaranteed_size) return BLOCK_ABORT; if (blockcnt > 0) es->last_block = blockcnt; if (*blocknr) { last_blk = *blocknr; return 0; } retval = ext2fs_new_block(fs, last_blk, ctx->block_found_map, &new_blk); if (retval) { es->err = retval; return BLOCK_ABORT; } if (blockcnt > 0) { retval = ext2fs_new_dir_block(fs, 0, 0, &block); if (retval) { es->err = retval; return BLOCK_ABORT; } es->num--; retval = ext2fs_write_dir_block(fs, new_blk, block); } else { retval = ext2fs_get_mem(fs->blocksize, &block); if (retval) { es->err = retval; return BLOCK_ABORT; } memset(block, 0, fs->blocksize); retval = io_channel_write_blk(fs->io, new_blk, 1, block); } if (retval) { es->err = retval; return BLOCK_ABORT; } ext2fs_free_mem(&block); *blocknr = new_blk; ext2fs_mark_block_bitmap(ctx->block_found_map, new_blk); ext2fs_block_alloc_stats(fs, new_blk, +1); es->newblocks++; if (es->num == 0) return (BLOCK_CHANGED | BLOCK_ABORT); else return BLOCK_CHANGED; } errcode_t e2fsck_expand_directory(e2fsck_t ctx, ext2_ino_t dir, int num, int guaranteed_size) { ext2_filsys fs = ctx->fs; errcode_t retval; struct expand_dir_struct es; struct ext2_inode inode; if (!(fs->flags & EXT2_FLAG_RW)) return EXT2_ET_RO_FILSYS; /* * Read the inode and block bitmaps in; we'll be messing with * them. */ e2fsck_read_bitmaps(ctx); retval = ext2fs_check_directory(fs, dir); if (retval) return retval; es.num = num; es.guaranteed_size = guaranteed_size; es.last_block = 0; es.err = 0; es.newblocks = 0; es.ctx = ctx; retval = ext2fs_block_iterate2(fs, dir, BLOCK_FLAG_APPEND, 0, expand_dir_proc, &es); if (es.err) return es.err; /* * Update the size and block count fields in the inode. */ retval = ext2fs_read_inode(fs, dir, &inode); if (retval) return retval; inode.i_size = (es.last_block + 1) * fs->blocksize; ext2fs_iblk_add_blocks(fs, &inode, es.newblocks); e2fsck_write_inode(ctx, dir, &inode, "expand_directory"); return 0; }