/*- * See the file LICENSE for redistribution information. * * Copyright (c) 2000-2003 * Sleepycat Software. All rights reserved. * * $Id: db_vrfy.c,v 1.2 2004/03/30 01:21:24 jtownsen Exp $ */ #include "db_config.h" #ifndef lint static const char revid[] = "$Id: db_vrfy.c,v 1.2 2004/03/30 01:21:24 jtownsen Exp $"; #endif /* not lint */ #ifndef NO_SYSTEM_INCLUDES #include #include #endif #include "db_int.h" #include "dbinc/db_page.h" #include "dbinc/db_shash.h" #include "dbinc/db_swap.h" #include "dbinc/db_verify.h" #include "dbinc/btree.h" #include "dbinc/hash.h" #include "dbinc/lock.h" #include "dbinc/mp.h" #include "dbinc/qam.h" #include "dbinc/txn.h" /* * This is the code for DB->verify, the DB database consistency checker. * For now, it checks all subdatabases in a database, and verifies * everything it knows how to (i.e. it's all-or-nothing, and one can't * check only for a subset of possible problems). */ static u_int __db_guesspgsize __P((DB_ENV *, DB_FH *)); static int __db_is_valid_magicno __P((u_int32_t, DBTYPE *)); static int __db_is_valid_pagetype __P((u_int32_t)); static int __db_meta2pgset __P((DB *, VRFY_DBINFO *, db_pgno_t, u_int32_t, DB *)); static int __db_salvage_subdbpg __P((DB *, VRFY_DBINFO *, PAGE *, void *, int (*)(void *, const void *), u_int32_t)); static int __db_salvage_subdbs __P((DB *, VRFY_DBINFO *, void *, int(*)(void *, const void *), u_int32_t, int *)); static int __db_salvage_unknowns __P((DB *, VRFY_DBINFO *, void *, int (*)(void *, const void *), u_int32_t)); static int __db_verify_arg __P((DB *, const char *, u_int32_t)); static int __db_vrfy_freelist __P((DB *, VRFY_DBINFO *, db_pgno_t, u_int32_t)); static int __db_vrfy_invalid __P((DB *, VRFY_DBINFO *, PAGE *, db_pgno_t, u_int32_t)); static int __db_vrfy_orderchkonly __P((DB *, VRFY_DBINFO *, const char *, const char *, u_int32_t)); static int __db_vrfy_pagezero __P((DB *, VRFY_DBINFO *, DB_FH *, u_int32_t)); static int __db_vrfy_subdbs __P((DB *, VRFY_DBINFO *, const char *, u_int32_t)); static int __db_vrfy_structure __P((DB *, VRFY_DBINFO *, const char *, db_pgno_t, u_int32_t)); static int __db_vrfy_walkpages __P((DB *, VRFY_DBINFO *, void *, int (*)(void *, const void *), u_int32_t)); /* * __db_verify_pp -- * DB->verify public interface. * * PUBLIC: int __db_verify_pp * PUBLIC: __P((DB *, const char *, const char *, FILE *, u_int32_t)); */ int __db_verify_pp(dbp, file, database, outfile, flags) DB *dbp; const char *file, *database; FILE *outfile; u_int32_t flags; { /* * __db_verify_pp is a wrapper to __db_verify_internal, which lets * us pass appropriate equivalents to FILE * in from the non-C APIs. */ return (__db_verify_internal(dbp, file, database, outfile, __db_pr_callback, flags)); } /* * __db_verify_internal -- * * PUBLIC: int __db_verify_internal __P((DB *, const char *, * PUBLIC: const char *, void *, int (*)(void *, const void *), u_int32_t)); */ int __db_verify_internal(dbp, fname, dname, handle, callback, flags) DB *dbp; const char *fname, *dname; void *handle; int (*callback) __P((void *, const void *)); u_int32_t flags; { DB_ENV *dbenv; int ret; dbenv = dbp->dbenv; PANIC_CHECK(dbenv); DB_ILLEGAL_AFTER_OPEN(dbp, "DB->verify"); if ((ret = __db_verify_arg(dbp, dname, flags)) != 0) return (ret); /* * Forbid working in an environment that uses transactions or * locking; we're going to be looking at the file freely, * and while we're not going to modify it, we aren't obeying * locking conventions either. */ if (TXN_ON(dbenv) || LOCKING_ON(dbenv) || LOGGING_ON(dbenv)) { __db_err(dbenv, "DB->verify may not be used with transactions, logging, or locking"); return (EINVAL); } return (__db_verify(dbp, fname, dname, handle, callback, flags)); } /* * __db_verify_arg -- * Check DB->verify arguments. */ static int __db_verify_arg(dbp, dname, flags) DB *dbp; const char *dname; u_int32_t flags; { DB_ENV *dbenv; int ret; dbenv = dbp->dbenv; #undef OKFLAGS #define OKFLAGS (DB_AGGRESSIVE | DB_NOORDERCHK | DB_ORDERCHKONLY | \ DB_PRINTABLE | DB_SALVAGE) if ((ret = __db_fchk(dbenv, "DB->verify", flags, OKFLAGS)) != 0) return (ret); /* * DB_SALVAGE is mutually exclusive with the other flags except * DB_AGGRESSIVE and DB_PRINTABLE. */ if (LF_ISSET(DB_SALVAGE) && (flags & ~DB_AGGRESSIVE & ~DB_PRINTABLE) != DB_SALVAGE) return (__db_ferr(dbenv, "__db_verify", 1)); /* DB_AGGRESSIVE and DB_PRINTABLE are only meaningful when salvaging. */ if ((LF_ISSET(DB_AGGRESSIVE) || LF_ISSET(DB_PRINTABLE)) && !LF_ISSET(DB_SALVAGE)) return (__db_ferr(dbenv, "__db_verify", 1)); if (LF_ISSET(DB_ORDERCHKONLY) && flags != DB_ORDERCHKONLY) return (__db_ferr(dbenv, "__db_verify", 1)); if (LF_ISSET(DB_ORDERCHKONLY) && dname == NULL) { __db_err(dbenv, "DB_ORDERCHKONLY requires a database name"); return (EINVAL); } return (0); } /* * __db_verify -- * Walk the entire file page-by-page, either verifying with or without * dumping in db_dump -d format, or DB_SALVAGE-ing whatever key/data * pairs can be found and dumping them in standard (db_load-ready) * dump format. * * (Salvaging isn't really a verification operation, but we put it * here anyway because it requires essentially identical top-level * code.) * * flags may be 0, DB_NOORDERCHK, DB_ORDERCHKONLY, or DB_SALVAGE * (and optionally DB_AGGRESSIVE). * * PUBLIC: int __db_verify __P((DB *, const char *, * PUBLIC: const char *, void *, int (*)(void *, const void *), u_int32_t)); */ int __db_verify(dbp, name, subdb, handle, callback, flags) DB *dbp; const char *name, *subdb; void *handle; int (*callback) __P((void *, const void *)); u_int32_t flags; { DB_ENV *dbenv; DB_FH *fhp; VRFY_DBINFO *vdp; int has, isbad, ret, t_ret; char *real_name; dbenv = dbp->dbenv; fhp = NULL; vdp = NULL; real_name = NULL; has = ret = isbad = 0; F_SET(dbp, DB_AM_VERIFYING); /* Initialize any feedback function. */ if (!LF_ISSET(DB_SALVAGE) && dbp->db_feedback != NULL) dbp->db_feedback(dbp, DB_VERIFY, 0); /* * We don't know how large the cache is, and if the database * in question uses a small page size--which we don't know * yet!--it may be uncomfortably small for the default page * size [#2143]. However, the things we need temporary * databases for in dbinfo are largely tiny, so using a * 1024-byte pagesize is probably not going to be a big hit, * and will make us fit better into small spaces. */ if ((ret = __db_vrfy_dbinfo_create(dbenv, 1024, &vdp)) != 0) goto err; /* * Note whether the user has requested that we use printable * chars where possible. We won't get here with this flag if * we're not salvaging. */ if (LF_ISSET(DB_PRINTABLE)) F_SET(vdp, SALVAGE_PRINTABLE); /* Find the real name of the file. */ if ((ret = __db_appname(dbenv, DB_APP_DATA, name, 0, NULL, &real_name)) != 0) goto err; /* * Our first order of business is to verify page 0, which is * the metadata page for the master database of subdatabases * or of the only database in the file. We want to do this by hand * rather than just calling __db_open in case it's corrupt--various * things in __db_open might act funny. * * Once we know the metadata page is healthy, I believe that it's * safe to open the database normally and then use the page swapping * code, which makes life easier. */ if ((ret = __os_open(dbenv, real_name, DB_OSO_RDONLY, 0444, &fhp)) != 0) goto err; /* Verify the metadata page 0; set pagesize and type. */ if ((ret = __db_vrfy_pagezero(dbp, vdp, fhp, flags)) != 0) { if (ret == DB_VERIFY_BAD) isbad = 1; else goto err; } /* * We can assume at this point that dbp->pagesize and dbp->type are * set correctly, or at least as well as they can be, and that * locking, logging, and txns are not in use. Thus we can trust * the memp code not to look at the page, and thus to be safe * enough to use. * * The dbp is not open, but the file is open in the fhp, and we * cannot assume that __db_open is safe. Call __db_dbenv_setup, * the [safe] part of __db_open that initializes the environment-- * and the mpool--manually. */ if ((ret = __db_dbenv_setup(dbp, NULL, name, TXN_INVALID, DB_ODDFILESIZE | DB_RDONLY)) != 0) return (ret); /* * Set our name in the Queue subsystem; we may need it later * to deal with extents. */ if (dbp->type == DB_QUEUE && (ret = __qam_set_ext_data(dbp, name)) != 0) return (ret); /* Mark the dbp as opened, so that we correctly handle its close. */ F_SET(dbp, DB_AM_OPEN_CALLED); /* Find out the page number of the last page in the database. */ __memp_last_pgno(dbp->mpf, &vdp->last_pgno); /* * DB_ORDERCHKONLY is a special case; our file consists of * several subdatabases, which use different hash, bt_compare, * and/or dup_compare functions. Consequently, we couldn't verify * sorting and hashing simply by calling DB->verify() on the file. * DB_ORDERCHKONLY allows us to come back and check those things; it * requires a subdatabase, and assumes that everything but that * database's sorting/hashing is correct. */ if (LF_ISSET(DB_ORDERCHKONLY)) { ret = __db_vrfy_orderchkonly(dbp, vdp, name, subdb, flags); goto done; } /* * When salvaging, we use a db to keep track of whether we've seen a * given overflow or dup page in the course of traversing normal data. * If in the end we have not, we assume its key got lost and print it * with key "UNKNOWN". */ if (LF_ISSET(DB_SALVAGE)) { if ((ret = __db_salvage_init(vdp)) != 0) return (ret); /* * If we're not being aggressive, attempt to crack subdbs. * "has" will indicate whether the attempt has succeeded * (even in part), meaning that we have some semblance of * subdbs; on the walkpages pass, we print out * whichever data pages we have not seen. */ if (!LF_ISSET(DB_AGGRESSIVE) && (__db_salvage_subdbs(dbp, vdp, handle, callback, flags, &has)) != 0) isbad = 1; /* * If we have subdatabases, we need to signal that if * any keys are found that don't belong to a subdatabase, * they'll need to have an "__OTHER__" subdatabase header * printed first. Flag this. Else, print a header for * the normal, non-subdb database. */ if (has == 1) F_SET(vdp, SALVAGE_PRINTHEADER); } if ((ret = __db_vrfy_walkpages(dbp, vdp, handle, callback, flags)) != 0) { if (ret == DB_VERIFY_BAD) isbad = 1; else if (ret != 0) goto err; } /* If we're verifying, verify inter-page structure. */ if (!LF_ISSET(DB_SALVAGE) && isbad == 0) if ((ret = __db_vrfy_structure(dbp, vdp, name, 0, flags)) != 0) { if (ret == DB_VERIFY_BAD) isbad = 1; else if (ret != 0) goto err; } /* * If we're salvaging, output with key UNKNOWN any overflow or dup pages * we haven't been able to put in context. Then destroy the salvager's * state-saving database. */ if (LF_ISSET(DB_SALVAGE)) { if ((ret = __db_salvage_unknowns(dbp, vdp, handle, callback, flags)) != 0) isbad = 1; /* No return value, since there's little we can do. */ __db_salvage_destroy(vdp); } if (0) { /* Don't try to strerror() DB_VERIFY_FATAL; it's private. */ err: if (ret == DB_VERIFY_FATAL) ret = DB_VERIFY_BAD; __db_err(dbenv, "%s: %s", name, db_strerror(ret)); } if (LF_ISSET(DB_SALVAGE) && (has == 0 || F_ISSET(vdp, SALVAGE_PRINTFOOTER))) (void)__db_prfooter(handle, callback); /* Send feedback that we're done. */ done: if (!LF_ISSET(DB_SALVAGE) && dbp->db_feedback != NULL) dbp->db_feedback(dbp, DB_VERIFY, 100); if (fhp != NULL && (t_ret = __os_closehandle(dbenv, fhp)) != 0 && ret == 0) ret = t_ret; if (dbp != NULL && (t_ret = __db_close(dbp, NULL, 0)) != 0 && ret == 0) ret = t_ret; if (vdp != NULL && (t_ret = __db_vrfy_dbinfo_destroy(dbenv, vdp)) != 0 && ret == 0) ret = t_ret; if (real_name != NULL) __os_free(dbenv, real_name); if ((ret == 0 && isbad == 1) || ret == DB_VERIFY_FATAL) ret = DB_VERIFY_BAD; return (ret); } /* * __db_vrfy_pagezero -- * Verify the master metadata page. Use seek, read, and a local buffer * rather than the DB paging code, for safety. * * Must correctly (or best-guess) set dbp->type and dbp->pagesize. */ static int __db_vrfy_pagezero(dbp, vdp, fhp, flags) DB *dbp; VRFY_DBINFO *vdp; DB_FH *fhp; u_int32_t flags; { DBMETA *meta; DB_ENV *dbenv; VRFY_PAGEINFO *pip; db_pgno_t freelist; size_t nr; int isbad, ret, swapped; u_int8_t mbuf[DBMETASIZE]; isbad = ret = swapped = 0; freelist = 0; dbenv = dbp->dbenv; meta = (DBMETA *)mbuf; dbp->type = DB_UNKNOWN; /* * Seek to the metadata page. * Note that if we're just starting a verification, dbp->pgsize * may be zero; this is okay, as we want page zero anyway and * 0*0 == 0. */ if ((ret = __os_seek(dbenv, fhp, 0, 0, 0, 0, DB_OS_SEEK_SET)) != 0 || (ret = __os_read(dbenv, fhp, mbuf, DBMETASIZE, &nr)) != 0) { __db_err(dbenv, "Metadata page %lu cannot be read: %s", (u_long)PGNO_BASE_MD, db_strerror(ret)); return (ret); } if (nr != DBMETASIZE) { EPRINT((dbenv, "Page %lu: Incomplete metadata page", (u_long)PGNO_BASE_MD)); return (DB_VERIFY_FATAL); } if ((ret = __db_chk_meta(dbenv, dbp, meta, 1)) != 0) { EPRINT((dbenv, "Page %lu: metadata page corrupted", (u_long)PGNO_BASE_MD)); isbad = 1; if (ret != -1) { EPRINT((dbenv, "Page %lu: could not check metadata page", (u_long)PGNO_BASE_MD)); return (DB_VERIFY_FATAL); } } /* * Check all of the fields that we can. * * 08-11: Current page number. Must == pgno. * Note that endianness doesn't matter--it's zero. */ if (meta->pgno != PGNO_BASE_MD) { isbad = 1; EPRINT((dbenv, "Page %lu: pgno incorrectly set to %lu", (u_long)PGNO_BASE_MD, (u_long)meta->pgno)); } /* 12-15: Magic number. Must be one of valid set. */ if (__db_is_valid_magicno(meta->magic, &dbp->type)) swapped = 0; else { M_32_SWAP(meta->magic); if (__db_is_valid_magicno(meta->magic, &dbp->type)) swapped = 1; else { isbad = 1; EPRINT((dbenv, "Page %lu: bad magic number %lu", (u_long)PGNO_BASE_MD, (u_long)meta->magic)); } } /* * 16-19: Version. Must be current; for now, we * don't support verification of old versions. */ if (swapped) M_32_SWAP(meta->version); if ((dbp->type == DB_BTREE && (meta->version > DB_BTREEVERSION || meta->version < DB_BTREEOLDVER)) || (dbp->type == DB_HASH && (meta->version > DB_HASHVERSION || meta->version < DB_HASHOLDVER)) || (dbp->type == DB_QUEUE && (meta->version > DB_QAMVERSION || meta->version < DB_QAMOLDVER))) { isbad = 1; EPRINT((dbenv, "Page %lu: unsupported DB version %lu; extraneous errors may result", (u_long)PGNO_BASE_MD, (u_long)meta->version)); } /* * 20-23: Pagesize. Must be power of two, * greater than 512, and less than 64K. */ if (swapped) M_32_SWAP(meta->pagesize); if (IS_VALID_PAGESIZE(meta->pagesize)) dbp->pgsize = meta->pagesize; else { isbad = 1; EPRINT((dbenv, "Page %lu: bad page size %lu", (u_long)PGNO_BASE_MD, (u_long)meta->pagesize)); /* * Now try to settle on a pagesize to use. * If the user-supplied one is reasonable, * use it; else, guess. */ if (!IS_VALID_PAGESIZE(dbp->pgsize)) dbp->pgsize = __db_guesspgsize(dbenv, fhp); } /* * 25: Page type. Must be correct for dbp->type, * which is by now set as well as it can be. */ /* Needs no swapping--only one byte! */ if ((dbp->type == DB_BTREE && meta->type != P_BTREEMETA) || (dbp->type == DB_HASH && meta->type != P_HASHMETA) || (dbp->type == DB_QUEUE && meta->type != P_QAMMETA)) { isbad = 1; EPRINT((dbenv, "Page %lu: bad page type %lu", (u_long)PGNO_BASE_MD, (u_long)meta->type)); } /* * 28-31: Free list page number. * We'll verify its sensibility when we do inter-page * verification later; for now, just store it. */ if (swapped) M_32_SWAP(meta->free); freelist = meta->free; /* * Initialize vdp->pages to fit a single pageinfo structure for * this one page. We'll realloc later when we know how many * pages there are. */ if ((ret = __db_vrfy_getpageinfo(vdp, PGNO_BASE_MD, &pip)) != 0) return (ret); pip->pgno = PGNO_BASE_MD; pip->type = meta->type; /* * Signal that we still have to check the info specific to * a given type of meta page. */ F_SET(pip, VRFY_INCOMPLETE); pip->free = freelist; if ((ret = __db_vrfy_putpageinfo(dbenv, vdp, pip)) != 0) return (ret); /* Set up the dbp's fileid. We don't use the regular open path. */ memcpy(dbp->fileid, meta->uid, DB_FILE_ID_LEN); if (swapped == 1) F_SET(dbp, DB_AM_SWAP); return (isbad ? DB_VERIFY_BAD : 0); } /* * __db_vrfy_walkpages -- * Main loop of the verifier/salvager. Walks through, * page by page, and verifies all pages and/or prints all data pages. */ static int __db_vrfy_walkpages(dbp, vdp, handle, callback, flags) DB *dbp; VRFY_DBINFO *vdp; void *handle; int (*callback) __P((void *, const void *)); u_int32_t flags; { DB_ENV *dbenv; DB_MPOOLFILE *mpf; PAGE *h; db_pgno_t i; int ret, t_ret, isbad; dbenv = dbp->dbenv; mpf = dbp->mpf; ret = isbad = t_ret = 0; #define OKFLAGS (DB_AGGRESSIVE | DB_NOORDERCHK | DB_ORDERCHKONLY | \ DB_PRINTABLE | DB_SALVAGE) if ((ret = __db_fchk(dbenv, "__db_vrfy_walkpages", flags, OKFLAGS)) != 0) return (ret); for (i = 0; i <= vdp->last_pgno; i++) { /* * If DB_SALVAGE is set, we inspect our database of * completed pages, and skip any we've already printed in * the subdb pass. */ if (LF_ISSET(DB_SALVAGE) && (__db_salvage_isdone(vdp, i) != 0)) continue; /* * If an individual page get fails, keep going if and only * if we're salvaging. */ if ((t_ret = __memp_fget(mpf, &i, 0, &h)) != 0) { if (ret == 0) ret = t_ret; if (LF_ISSET(DB_SALVAGE)) continue; else return (ret); } if (LF_ISSET(DB_SALVAGE)) { /* * We pretty much don't want to quit unless a * bomb hits. May as well return that something * was screwy, however. */ if ((t_ret = __db_salvage(dbp, vdp, i, h, handle, callback, flags)) != 0) { if (ret == 0) ret = t_ret; isbad = 1; } } else { /* * If we are not salvaging, and we get any error * other than DB_VERIFY_BAD, return immediately; * it may not be safe to proceed. If we get * DB_VERIFY_BAD, keep going; listing more errors * may make it easier to diagnose problems and * determine the magnitude of the corruption. */ /* * Verify info common to all page * types. */ if (i != PGNO_BASE_MD) { ret = __db_vrfy_common(dbp, vdp, h, i, flags); if (ret == DB_VERIFY_BAD) isbad = 1; else if (ret != 0) goto err; } switch (TYPE(h)) { case P_INVALID: ret = __db_vrfy_invalid(dbp, vdp, h, i, flags); break; case __P_DUPLICATE: isbad = 1; EPRINT((dbenv, "Page %lu: old-style duplicate page", (u_long)i)); break; case P_HASH: ret = __ham_vrfy(dbp, vdp, h, i, flags); break; case P_IBTREE: case P_IRECNO: case P_LBTREE: case P_LDUP: ret = __bam_vrfy(dbp, vdp, h, i, flags); break; case P_LRECNO: ret = __ram_vrfy_leaf(dbp, vdp, h, i, flags); break; case P_OVERFLOW: ret = __db_vrfy_overflow(dbp, vdp, h, i, flags); break; case P_HASHMETA: ret = __ham_vrfy_meta(dbp, vdp, (HMETA *)h, i, flags); break; case P_BTREEMETA: ret = __bam_vrfy_meta(dbp, vdp, (BTMETA *)h, i, flags); break; case P_QAMMETA: ret = __qam_vrfy_meta(dbp, vdp, (QMETA *)h, i, flags); break; case P_QAMDATA: ret = __qam_vrfy_data(dbp, vdp, (QPAGE *)h, i, flags); break; default: EPRINT((dbenv, "Page %lu: unknown page type %lu", (u_long)i, (u_long)TYPE(h))); isbad = 1; break; } /* * Set up error return. */ if (ret == DB_VERIFY_BAD) isbad = 1; else if (ret != 0) goto err; /* * Provide feedback to the application about our * progress. The range 0-50% comes from the fact * that this is the first of two passes through the * database (front-to-back, then top-to-bottom). */ if (dbp->db_feedback != NULL) dbp->db_feedback(dbp, DB_VERIFY, (int)((i + 1) * 50 / (vdp->last_pgno + 1))); } /* * Just as with the page get, bail if and only if we're * not salvaging. */ if ((t_ret = __memp_fput(mpf, h, 0)) != 0) { if (ret == 0) ret = t_ret; if (!LF_ISSET(DB_SALVAGE)) return (ret); } } /* * If we've seen a Queue metadata page, we may need to walk Queue * extent pages that won't show up between 0 and vdp->last_pgno. */ if (F_ISSET(vdp, VRFY_QMETA_SET) && (t_ret = __qam_vrfy_walkqueue(dbp, vdp, handle, callback, flags)) != 0) { if (ret == 0) ret = t_ret; if (t_ret == DB_VERIFY_BAD) isbad = 1; else if (!LF_ISSET(DB_SALVAGE)) return (ret); } if (0) { err: if ((t_ret = __memp_fput(mpf, h, 0)) != 0) return (ret == 0 ? t_ret : ret); } return ((isbad == 1 && ret == 0) ? DB_VERIFY_BAD : ret); } /* * __db_vrfy_structure-- * After a beginning-to-end walk through the database has been * completed, put together the information that has been collected * to verify the overall database structure. * * Should only be called if we want to do a database verification, * i.e. if DB_SALVAGE is not set. */ static int __db_vrfy_structure(dbp, vdp, dbname, meta_pgno, flags) DB *dbp; VRFY_DBINFO *vdp; const char *dbname; db_pgno_t meta_pgno; u_int32_t flags; { DB *pgset; DB_ENV *dbenv; VRFY_PAGEINFO *pip; db_pgno_t i; int ret, isbad, hassubs, p; isbad = 0; pip = NULL; dbenv = dbp->dbenv; pgset = vdp->pgset; if ((ret = __db_fchk(dbenv, "DB->verify", flags, OKFLAGS)) != 0) return (ret); if (LF_ISSET(DB_SALVAGE)) { __db_err(dbenv, "__db_vrfy_structure called with DB_SALVAGE"); return (EINVAL); } /* * Providing feedback here is tricky; in most situations, * we fetch each page one more time, but we do so in a top-down * order that depends on the access method. Worse, we do this * recursively in btree, such that on any call where we're traversing * a subtree we don't know where that subtree is in the whole database; * worse still, any given database may be one of several subdbs. * * The solution is to decrement a counter vdp->pgs_remaining each time * we verify (and call feedback on) a page. We may over- or * under-count, but the structure feedback function will ensure that we * never give a percentage under 50 or over 100. (The first pass * covered the range 0-50%.) */ if (dbp->db_feedback != NULL) vdp->pgs_remaining = vdp->last_pgno + 1; /* * Call the appropriate function to downwards-traverse the db type. */ switch (dbp->type) { case DB_BTREE: case DB_RECNO: if ((ret = __bam_vrfy_structure(dbp, vdp, 0, flags)) != 0) { if (ret == DB_VERIFY_BAD) isbad = 1; else goto err; } /* * If we have subdatabases and we know that the database is, * thus far, sound, it's safe to walk the tree of subdatabases. * Do so, and verify the structure of the databases within. */ if ((ret = __db_vrfy_getpageinfo(vdp, 0, &pip)) != 0) goto err; hassubs = F_ISSET(pip, VRFY_HAS_SUBDBS) ? 1 : 0; if ((ret = __db_vrfy_putpageinfo(dbenv, vdp, pip)) != 0) goto err; pip = NULL; if (isbad == 0 && hassubs) if ((ret = __db_vrfy_subdbs(dbp, vdp, dbname, flags)) != 0) { if (ret == DB_VERIFY_BAD) isbad = 1; else goto err; } break; case DB_HASH: if ((ret = __ham_vrfy_structure(dbp, vdp, 0, flags)) != 0) { if (ret == DB_VERIFY_BAD) isbad = 1; else goto err; } break; case DB_QUEUE: if ((ret = __qam_vrfy_structure(dbp, vdp, flags)) != 0) { if (ret == DB_VERIFY_BAD) isbad = 1; } /* * Queue pages may be unreferenced and totally zeroed, if * they're empty; queue doesn't have much structure, so * this is unlikely to be wrong in any troublesome sense. * Skip to "err". */ goto err; case DB_UNKNOWN: default: /* This should only happen if the verifier is somehow broken. */ DB_ASSERT(0); ret = EINVAL; goto err; } /* Walk free list. */ if ((ret = __db_vrfy_freelist(dbp, vdp, meta_pgno, flags)) == DB_VERIFY_BAD) isbad = 1; /* * If structure checks up until now have failed, it's likely that * checking what pages have been missed will result in oodles of * extraneous error messages being EPRINTed. Skip to the end * if this is the case; we're going to be printing at least one * error anyway, and probably all the more salient ones. */ if (ret != 0 || isbad == 1) goto err; /* * Make sure no page has been missed and that no page is still marked * "all zeroes" (only certain hash pages can be, and they're unmarked * in __ham_vrfy_structure). */ for (i = 0; i < vdp->last_pgno + 1; i++) { if ((ret = __db_vrfy_getpageinfo(vdp, i, &pip)) != 0) goto err; if ((ret = __db_vrfy_pgset_get(pgset, i, &p)) != 0) goto err; if (pip->type == P_OVERFLOW) { if ((u_int32_t)p != pip->refcount) { EPRINT((dbenv, "Page %lu: overflow refcount %lu, referenced %lu times", (u_long)i, (u_long)pip->refcount, (u_long)p)); isbad = 1; } } else if (p == 0) { EPRINT((dbenv, "Page %lu: unreferenced page", (u_long)i)); isbad = 1; } if (F_ISSET(pip, VRFY_IS_ALLZEROES)) { EPRINT((dbenv, "Page %lu: totally zeroed page", (u_long)i)); isbad = 1; } if ((ret = __db_vrfy_putpageinfo(dbenv, vdp, pip)) != 0) goto err; pip = NULL; } err: if (pip != NULL) (void)__db_vrfy_putpageinfo(dbenv, vdp, pip); return ((isbad == 1 && ret == 0) ? DB_VERIFY_BAD : ret); } /* * __db_is_valid_pagetype */ static int __db_is_valid_pagetype(type) u_int32_t type; { switch (type) { case P_INVALID: /* Order matches ordinal value. */ case P_HASH: case P_IBTREE: case P_IRECNO: case P_LBTREE: case P_LRECNO: case P_OVERFLOW: case P_HASHMETA: case P_BTREEMETA: case P_QAMMETA: case P_QAMDATA: case P_LDUP: return (1); default: break; } return (0); } /* * __db_is_valid_magicno */ static int __db_is_valid_magicno(magic, typep) u_int32_t magic; DBTYPE *typep; { switch (magic) { case DB_BTREEMAGIC: *typep = DB_BTREE; return (1); case DB_HASHMAGIC: *typep = DB_HASH; return (1); case DB_QAMMAGIC: *typep = DB_QUEUE; return (1); default: break; } *typep = DB_UNKNOWN; return (0); } /* * __db_vrfy_common -- * Verify info common to all page types. * * PUBLIC: int __db_vrfy_common * PUBLIC: __P((DB *, VRFY_DBINFO *, PAGE *, db_pgno_t, u_int32_t)); */ int __db_vrfy_common(dbp, vdp, h, pgno, flags) DB *dbp; VRFY_DBINFO *vdp; PAGE *h; db_pgno_t pgno; u_int32_t flags; { DB_ENV *dbenv; VRFY_PAGEINFO *pip; int ret, t_ret; u_int8_t *p; dbenv = dbp->dbenv; if ((ret = __db_vrfy_getpageinfo(vdp, pgno, &pip)) != 0) return (ret); pip->pgno = pgno; F_CLR(pip, VRFY_IS_ALLZEROES); /* * Hash expands the table by leaving some pages between the * old last and the new last totally zeroed. Its pgin function * should fix things, but we might not be using that (e.g. if * we're a subdatabase). * * Queue will create sparse files if sparse record numbers are used. */ if (pgno != 0 && PGNO(h) == 0) { for (p = (u_int8_t *)h; p < (u_int8_t *)h + dbp->pgsize; p++) if (*p != 0) { EPRINT((dbenv, "Page %lu: partially zeroed page", (u_long)pgno)); ret = DB_VERIFY_BAD; goto err; } /* * It's totally zeroed; mark it as a hash, and we'll * check that that makes sense structurally later. * (The queue verification doesn't care, since queues * don't really have much in the way of structure.) */ pip->type = P_HASH; F_SET(pip, VRFY_IS_ALLZEROES); ret = 0; goto err; /* well, not really an err. */ } if (PGNO(h) != pgno) { EPRINT((dbenv, "Page %lu: bad page number %lu", (u_long)pgno, (u_long)h->pgno)); ret = DB_VERIFY_BAD; } if (!__db_is_valid_pagetype(h->type)) { EPRINT((dbenv, "Page %lu: bad page type %lu", (u_long)pgno, (u_long)h->type)); ret = DB_VERIFY_BAD; } pip->type = h->type; err: if ((t_ret = __db_vrfy_putpageinfo(dbenv, vdp, pip)) != 0 && ret == 0) ret = t_ret; return (ret); } /* * __db_vrfy_invalid -- * Verify P_INVALID page. * (Yes, there's not much to do here.) */ static int __db_vrfy_invalid(dbp, vdp, h, pgno, flags) DB *dbp; VRFY_DBINFO *vdp; PAGE *h; db_pgno_t pgno; u_int32_t flags; { DB_ENV *dbenv; VRFY_PAGEINFO *pip; int ret, t_ret; dbenv = dbp->dbenv; if ((ret = __db_vrfy_getpageinfo(vdp, pgno, &pip)) != 0) return (ret); pip->next_pgno = pip->prev_pgno = 0; if (!IS_VALID_PGNO(NEXT_PGNO(h))) { EPRINT((dbenv, "Page %lu: invalid next_pgno %lu", (u_long)pgno, (u_long)NEXT_PGNO(h))); ret = DB_VERIFY_BAD; } else pip->next_pgno = NEXT_PGNO(h); if ((t_ret = __db_vrfy_putpageinfo(dbenv, vdp, pip)) != 0 && ret == 0) ret = t_ret; return (ret); } /* * __db_vrfy_datapage -- * Verify elements common to data pages (P_HASH, P_LBTREE, * P_IBTREE, P_IRECNO, P_LRECNO, P_OVERFLOW, P_DUPLICATE)--i.e., * those defined in the PAGE structure. * * Called from each of the per-page routines, after the * all-page-type-common elements of pip have been verified and filled * in. * * PUBLIC: int __db_vrfy_datapage * PUBLIC: __P((DB *, VRFY_DBINFO *, PAGE *, db_pgno_t, u_int32_t)); */ int __db_vrfy_datapage(dbp, vdp, h, pgno, flags) DB *dbp; VRFY_DBINFO *vdp; PAGE *h; db_pgno_t pgno; u_int32_t flags; { DB_ENV *dbenv; VRFY_PAGEINFO *pip; int isbad, ret, t_ret; dbenv = dbp->dbenv; if ((ret = __db_vrfy_getpageinfo(vdp, pgno, &pip)) != 0) return (ret); isbad = 0; /* * prev_pgno and next_pgno: store for inter-page checks, * verify that they point to actual pages and not to self. * * !!! * Internal btree pages do not maintain these fields (indeed, * they overload them). Skip. */ if (TYPE(h) != P_IBTREE && TYPE(h) != P_IRECNO) { if (!IS_VALID_PGNO(PREV_PGNO(h)) || PREV_PGNO(h) == pip->pgno) { isbad = 1; EPRINT((dbenv, "Page %lu: invalid prev_pgno %lu", (u_long)pip->pgno, (u_long)PREV_PGNO(h))); } if (!IS_VALID_PGNO(NEXT_PGNO(h)) || NEXT_PGNO(h) == pip->pgno) { isbad = 1; EPRINT((dbenv, "Page %lu: invalid next_pgno %lu", (u_long)pip->pgno, (u_long)NEXT_PGNO(h))); } pip->prev_pgno = PREV_PGNO(h); pip->next_pgno = NEXT_PGNO(h); } /* * Verify the number of entries on the page. * There is no good way to determine if this is accurate; the * best we can do is verify that it's not more than can, in theory, * fit on the page. Then, we make sure there are at least * this many valid elements in inp[], and hope that this catches * most cases. */ if (TYPE(h) != P_OVERFLOW) { if (BKEYDATA_PSIZE(0) * NUM_ENT(h) > dbp->pgsize) { isbad = 1; EPRINT((dbenv, "Page %lu: too many entries: %lu", (u_long)pgno, (u_long)NUM_ENT(h))); } pip->entries = NUM_ENT(h); } /* * btree level. Should be zero unless we're a btree; * if we are a btree, should be between LEAFLEVEL and MAXBTREELEVEL, * and we need to save it off. */ switch (TYPE(h)) { case P_IBTREE: case P_IRECNO: if (LEVEL(h) < LEAFLEVEL + 1) { isbad = 1; EPRINT((dbenv, "Page %lu: bad btree level %lu", (u_long)pgno, (u_long)LEVEL(h))); } pip->bt_level = LEVEL(h); break; case P_LBTREE: case P_LDUP: case P_LRECNO: if (LEVEL(h) != LEAFLEVEL) { isbad = 1; EPRINT((dbenv, "Page %lu: btree leaf page has incorrect level %lu", (u_long)pgno, (u_long)LEVEL(h))); } break; default: if (LEVEL(h) != 0) { isbad = 1; EPRINT((dbenv, "Page %lu: nonzero level %lu in non-btree database", (u_long)pgno, (u_long)LEVEL(h))); } break; } /* * Even though inp[] occurs in all PAGEs, we look at it in the * access-method-specific code, since btree and hash treat * item lengths very differently, and one of the most important * things we want to verify is that the data--as specified * by offset and length--cover the right part of the page * without overlaps, gaps, or violations of the page boundary. */ if ((t_ret = __db_vrfy_putpageinfo(dbenv, vdp, pip)) != 0 && ret == 0) ret = t_ret; return ((ret == 0 && isbad == 1) ? DB_VERIFY_BAD : ret); } /* * __db_vrfy_meta-- * Verify the access-method common parts of a meta page, using * normal mpool routines. * * PUBLIC: int __db_vrfy_meta * PUBLIC: __P((DB *, VRFY_DBINFO *, DBMETA *, db_pgno_t, u_int32_t)); */ int __db_vrfy_meta(dbp, vdp, meta, pgno, flags) DB *dbp; VRFY_DBINFO *vdp; DBMETA *meta; db_pgno_t pgno; u_int32_t flags; { DB_ENV *dbenv; DBTYPE dbtype, magtype; VRFY_PAGEINFO *pip; int isbad, ret, t_ret; isbad = 0; dbenv = dbp->dbenv; if ((ret = __db_vrfy_getpageinfo(vdp, pgno, &pip)) != 0) return (ret); /* type plausible for a meta page */ switch (meta->type) { case P_BTREEMETA: dbtype = DB_BTREE; break; case P_HASHMETA: dbtype = DB_HASH; break; case P_QAMMETA: dbtype = DB_QUEUE; break; default: /* The verifier should never let us get here. */ DB_ASSERT(0); ret = EINVAL; goto err; } /* magic number valid */ if (!__db_is_valid_magicno(meta->magic, &magtype)) { isbad = 1; EPRINT((dbenv, "Page %lu: invalid magic number", (u_long)pgno)); } if (magtype != dbtype) { isbad = 1; EPRINT((dbenv, "Page %lu: magic number does not match database type", (u_long)pgno)); } /* version */ if ((dbtype == DB_BTREE && (meta->version > DB_BTREEVERSION || meta->version < DB_BTREEOLDVER)) || (dbtype == DB_HASH && (meta->version > DB_HASHVERSION || meta->version < DB_HASHOLDVER)) || (dbtype == DB_QUEUE && (meta->version > DB_QAMVERSION || meta->version < DB_QAMOLDVER))) { isbad = 1; EPRINT((dbenv, "Page %lu: unsupported database version %lu; extraneous errors may result", (u_long)pgno, (u_long)meta->version)); } /* pagesize */ if (meta->pagesize != dbp->pgsize) { isbad = 1; EPRINT((dbenv, "Page %lu: invalid pagesize %lu", (u_long)pgno, (u_long)meta->pagesize)); } /* free list */ /* * If this is not the main, master-database meta page, it * should not have a free list. */ if (pgno != PGNO_BASE_MD && meta->free != PGNO_INVALID) { isbad = 1; EPRINT((dbenv, "Page %lu: nonempty free list on subdatabase metadata page", (u_long)pgno)); } /* Can correctly be PGNO_INVALID--that's just the end of the list. */ if (meta->free != PGNO_INVALID && IS_VALID_PGNO(meta->free)) pip->free = meta->free; else if (!IS_VALID_PGNO(meta->free)) { isbad = 1; EPRINT((dbenv, "Page %lu: nonsensical free list pgno %lu", (u_long)pgno, (u_long)meta->free)); } /* * We have now verified the common fields of the metadata page. * Clear the flag that told us they had been incompletely checked. */ F_CLR(pip, VRFY_INCOMPLETE); err: if ((t_ret = __db_vrfy_putpageinfo(dbenv, vdp, pip)) != 0 && ret == 0) ret = t_ret; return ((ret == 0 && isbad == 1) ? DB_VERIFY_BAD : ret); } /* * __db_vrfy_freelist -- * Walk free list, checking off pages and verifying absence of * loops. */ static int __db_vrfy_freelist(dbp, vdp, meta, flags) DB *dbp; VRFY_DBINFO *vdp; db_pgno_t meta; u_int32_t flags; { DB *pgset; DB_ENV *dbenv; VRFY_PAGEINFO *pip; db_pgno_t cur_pgno, next_pgno; int p, ret, t_ret; pgset = vdp->pgset; DB_ASSERT(pgset != NULL); dbenv = dbp->dbenv; if ((ret = __db_vrfy_getpageinfo(vdp, meta, &pip)) != 0) return (ret); for (next_pgno = pip->free; next_pgno != PGNO_INVALID; next_pgno = pip->next_pgno) { cur_pgno = pip->pgno; if ((ret = __db_vrfy_putpageinfo(dbenv, vdp, pip)) != 0) return (ret); /* This shouldn't happen, but just in case. */ if (!IS_VALID_PGNO(next_pgno)) { EPRINT((dbenv, "Page %lu: invalid next_pgno %lu on free list page", (u_long)cur_pgno, (u_long)next_pgno)); return (DB_VERIFY_BAD); } /* Detect cycles. */ if ((ret = __db_vrfy_pgset_get(pgset, next_pgno, &p)) != 0) return (ret); if (p != 0) { EPRINT((dbenv, "Page %lu: page %lu encountered a second time on free list", (u_long)cur_pgno, (u_long)next_pgno)); return (DB_VERIFY_BAD); } if ((ret = __db_vrfy_pgset_inc(pgset, next_pgno)) != 0) return (ret); if ((ret = __db_vrfy_getpageinfo(vdp, next_pgno, &pip)) != 0) return (ret); if (pip->type != P_INVALID) { EPRINT((dbenv, "Page %lu: non-invalid page %lu on free list", (u_long)cur_pgno, (u_long)next_pgno)); ret = DB_VERIFY_BAD; /* unsafe to continue */ break; } } if ((t_ret = __db_vrfy_putpageinfo(dbenv, vdp, pip)) != 0) ret = t_ret; return (ret); } /* * __db_vrfy_subdbs -- * Walk the known-safe master database of subdbs with a cursor, * verifying the structure of each subdatabase we encounter. */ static int __db_vrfy_subdbs(dbp, vdp, dbname, flags) DB *dbp; VRFY_DBINFO *vdp; const char *dbname; u_int32_t flags; { DB *mdbp; DBC *dbc; DBT key, data; DB_ENV *dbenv; VRFY_PAGEINFO *pip; db_pgno_t meta_pgno; int ret, t_ret, isbad; u_int8_t type; isbad = 0; dbc = NULL; dbenv = dbp->dbenv; if ((ret = __db_master_open(dbp, NULL, dbname, DB_RDONLY, 0, &mdbp)) != 0) return (ret); if ((ret = __db_cursor_int(mdbp, NULL, DB_BTREE, PGNO_INVALID, 0, DB_LOCK_INVALIDID, &dbc)) != 0) goto err; memset(&key, 0, sizeof(key)); memset(&data, 0, sizeof(data)); while ((ret = __db_c_get(dbc, &key, &data, DB_NEXT)) == 0) { if (data.size != sizeof(db_pgno_t)) { EPRINT((dbenv, "Subdatabase entry not page-number size")); isbad = 1; goto err; } memcpy(&meta_pgno, data.data, data.size); /* * Subdatabase meta pgnos are stored in network byte * order for cross-endian compatibility. Swap if appropriate. */ DB_NTOHL(&meta_pgno); if (meta_pgno == PGNO_INVALID || meta_pgno > vdp->last_pgno) { EPRINT((dbenv, "Subdatabase entry references invalid page %lu", (u_long)meta_pgno)); isbad = 1; goto err; } if ((ret = __db_vrfy_getpageinfo(vdp, meta_pgno, &pip)) != 0) goto err; type = pip->type; if ((ret = __db_vrfy_putpageinfo(dbenv, vdp, pip)) != 0) goto err; switch (type) { case P_BTREEMETA: if ((ret = __bam_vrfy_structure( dbp, vdp, meta_pgno, flags)) != 0) { if (ret == DB_VERIFY_BAD) isbad = 1; else goto err; } break; case P_HASHMETA: if ((ret = __ham_vrfy_structure( dbp, vdp, meta_pgno, flags)) != 0) { if (ret == DB_VERIFY_BAD) isbad = 1; else goto err; } break; case P_QAMMETA: default: EPRINT((dbenv, "Subdatabase entry references page %lu of invalid type %lu", (u_long)meta_pgno, (u_long)type)); ret = DB_VERIFY_BAD; goto err; } } if (ret == DB_NOTFOUND) ret = 0; err: if (dbc != NULL && (t_ret = __db_c_close(dbc)) != 0 && ret == 0) ret = t_ret; if ((t_ret = __db_close(mdbp, NULL, 0)) != 0 && ret == 0) ret = t_ret; return ((ret == 0 && isbad == 1) ? DB_VERIFY_BAD : ret); } /* * __db_vrfy_struct_feedback -- * Provide feedback during top-down database structure traversal. * (See comment at the beginning of __db_vrfy_structure.) * * PUBLIC: void __db_vrfy_struct_feedback __P((DB *, VRFY_DBINFO *)); */ void __db_vrfy_struct_feedback(dbp, vdp) DB *dbp; VRFY_DBINFO *vdp; { int progress; if (dbp->db_feedback == NULL) return; if (vdp->pgs_remaining > 0) vdp->pgs_remaining--; /* Don't allow a feedback call of 100 until we're really done. */ progress = 100 - (int)(vdp->pgs_remaining * 50 / (vdp->last_pgno + 1)); dbp->db_feedback(dbp, DB_VERIFY, progress == 100 ? 99 : progress); } /* * __db_vrfy_orderchkonly -- * Do an sort-order/hashing check on a known-otherwise-good subdb. */ static int __db_vrfy_orderchkonly(dbp, vdp, name, subdb, flags) DB *dbp; VRFY_DBINFO *vdp; const char *name, *subdb; u_int32_t flags; { BTMETA *btmeta; DB *mdbp, *pgset; DBC *pgsc; DBT key, data; DB_ENV *dbenv; DB_MPOOLFILE *mpf; HASH *h_internal; HMETA *hmeta; PAGE *h, *currpg; db_pgno_t meta_pgno, p, pgno; u_int32_t bucket; int t_ret, ret; pgset = NULL; pgsc = NULL; dbenv = dbp->dbenv; mpf = dbp->mpf; currpg = h = NULL; LF_CLR(DB_NOORDERCHK); /* Open the master database and get the meta_pgno for the subdb. */ if ((ret = __db_master_open(dbp, NULL, name, DB_RDONLY, 0, &mdbp)) != 0) goto err; memset(&key, 0, sizeof(key)); key.data = (void *)subdb; key.size = (u_int32_t)strlen(subdb); memset(&data, 0, sizeof(data)); if ((ret = __db_get(mdbp, NULL, &key, &data, 0)) != 0) goto err; if (data.size != sizeof(db_pgno_t)) { EPRINT((dbenv, "Subdatabase entry of invalid size")); ret = DB_VERIFY_BAD; goto err; } memcpy(&meta_pgno, data.data, data.size); /* * Subdatabase meta pgnos are stored in network byte * order for cross-endian compatibility. Swap if appropriate. */ DB_NTOHL(&meta_pgno); if ((ret = __memp_fget(mpf, &meta_pgno, 0, &h)) != 0) goto err; if ((ret = __db_vrfy_pgset(dbenv, dbp->pgsize, &pgset)) != 0) goto err; switch (TYPE(h)) { case P_BTREEMETA: btmeta = (BTMETA *)h; if (F_ISSET(&btmeta->dbmeta, BTM_RECNO)) { /* Recnos have no order to check. */ ret = 0; goto err; } if ((ret = __db_meta2pgset(dbp, vdp, meta_pgno, flags, pgset)) != 0) goto err; if ((ret = __db_cursor_int(pgset, NULL, dbp->type, PGNO_INVALID, 0, DB_LOCK_INVALIDID, &pgsc)) != 0) goto err; while ((ret = __db_vrfy_pgset_next(pgsc, &p)) == 0) { if ((ret = __memp_fget(mpf, &p, 0, &currpg)) != 0) goto err; if ((ret = __bam_vrfy_itemorder(dbp, NULL, currpg, p, NUM_ENT(currpg), 1, F_ISSET(&btmeta->dbmeta, BTM_DUP), flags)) != 0) goto err; if ((ret = __memp_fput(mpf, currpg, 0)) != 0) goto err; currpg = NULL; } /* * The normal exit condition for the loop above is DB_NOTFOUND. * If we see that, zero it and continue on to cleanup. * Otherwise, it's a real error and will be returned. */ if (ret == DB_NOTFOUND) ret = 0; break; case P_HASHMETA: hmeta = (HMETA *)h; h_internal = (HASH *)dbp->h_internal; /* * Make sure h_charkey is right. */ if (h_internal == NULL) { EPRINT((dbenv, "Page %lu: DB->h_internal field is NULL", (u_long)meta_pgno)); ret = DB_VERIFY_BAD; goto err; } if (h_internal->h_hash == NULL) h_internal->h_hash = hmeta->dbmeta.version < 5 ? __ham_func4 : __ham_func5; if (hmeta->h_charkey != h_internal->h_hash(dbp, CHARKEY, sizeof(CHARKEY))) { EPRINT((dbenv, "Page %lu: incorrect hash function for database", (u_long)meta_pgno)); ret = DB_VERIFY_BAD; goto err; } /* * Foreach bucket, verify hashing on each page in the * corresponding chain of pages. */ for (bucket = 0; bucket <= hmeta->max_bucket; bucket++) { pgno = BS_TO_PAGE(bucket, hmeta->spares); while (pgno != PGNO_INVALID) { if ((ret = __memp_fget(mpf, &pgno, 0, &currpg)) != 0) goto err; if ((ret = __ham_vrfy_hashing(dbp, NUM_ENT(currpg), hmeta, bucket, pgno, flags, h_internal->h_hash)) != 0) goto err; pgno = NEXT_PGNO(currpg); if ((ret = __memp_fput(mpf, currpg, 0)) != 0) goto err; currpg = NULL; } } break; default: EPRINT((dbenv, "Page %lu: database metapage of bad type %lu", (u_long)meta_pgno, (u_long)TYPE(h))); ret = DB_VERIFY_BAD; break; } err: if (pgsc != NULL && (t_ret = __db_c_close(pgsc)) != 0 && ret == 0) ret = t_ret; if (pgset != NULL && (t_ret = __db_close(pgset, NULL, 0)) != 0 && ret == 0) ret = t_ret; if (h != NULL && (t_ret = __memp_fput(mpf, h, 0)) != 0) ret = t_ret; if (currpg != NULL && (t_ret = __memp_fput(mpf, currpg, 0)) != 0) ret = t_ret; if ((t_ret = __db_close(mdbp, NULL, 0)) != 0) ret = t_ret; return (ret); } /* * __db_salvage -- * Walk through a page, salvaging all likely or plausible (w/ * DB_AGGRESSIVE) key/data pairs. * * PUBLIC: int __db_salvage __P((DB *, VRFY_DBINFO *, db_pgno_t, * PUBLIC: PAGE *, void *, int (*)(void *, const void *), u_int32_t)); */ int __db_salvage(dbp, vdp, pgno, h, handle, callback, flags) DB *dbp; VRFY_DBINFO *vdp; db_pgno_t pgno; PAGE *h; void *handle; int (*callback) __P((void *, const void *)); u_int32_t flags; { int ret; DB_ASSERT(LF_ISSET(DB_SALVAGE)); /* If we got this page in the subdb pass, we can safely skip it. */ if (__db_salvage_isdone(vdp, pgno)) return (0); switch (TYPE(h)) { case P_HASHMETA: ret = __ham_vrfy_meta(dbp, vdp, (HMETA *)h, pgno, flags); break; case P_BTREEMETA: ret = __bam_vrfy_meta(dbp, vdp, (BTMETA *)h, pgno, flags); break; case P_QAMMETA: ret = __qam_vrfy_meta(dbp, vdp, (QMETA *)h, pgno, flags); break; case P_HASH: return (__ham_salvage(dbp, vdp, pgno, h, handle, callback, flags)); case P_LBTREE: return (__bam_salvage(dbp, vdp, pgno, P_LBTREE, h, handle, callback, NULL, flags)); case P_LDUP: return (__db_salvage_markneeded(vdp, pgno, SALVAGE_LDUP)); case P_OVERFLOW: return (__db_salvage_markneeded(vdp, pgno, SALVAGE_OVERFLOW)); case P_LRECNO: /* * Recnos are tricky -- they may represent dup pages, or * they may be subdatabase/regular database pages in their * own right. If the former, they need to be printed with a * key, preferably when we hit the corresponding datum in * a btree/hash page. If the latter, there is no key. * * If a database is sufficiently frotzed, we're not going * to be able to get this right, so we best-guess: just * mark it needed now, and if we're really a normal recno * database page, the "unknowns" pass will pick us up. */ return (__db_salvage_markneeded(vdp, pgno, SALVAGE_LRECNO)); case P_QAMDATA: return (__qam_salvage(dbp, vdp, pgno, h, handle, callback, flags)); case P_IBTREE: case P_INVALID: case P_IRECNO: case __P_DUPLICATE: default: /* XXX: Should we be more aggressive here? */ return (0); } return (ret != 0 ? ret : __db_prheader(dbp, NULL, 0, 1, handle, callback, vdp, PGNO_BASE_MD)); } /* * __db_salvage_unknowns -- * Walk through the salvager database, printing with key "UNKNOWN" * any pages we haven't dealt with. */ static int __db_salvage_unknowns(dbp, vdp, handle, callback, flags) DB *dbp; VRFY_DBINFO *vdp; void *handle; int (*callback) __P((void *, const void *)); u_int32_t flags; { DBT unkdbt, key, *dbt; DB_ENV *dbenv; DB_MPOOLFILE *mpf; PAGE *h; db_pgno_t pgno; u_int32_t pgtype; int ret, err_ret; void *ovflbuf; dbenv = dbp->dbenv; mpf = dbp->mpf; memset(&unkdbt, 0, sizeof(DBT)); unkdbt.size = (u_int32_t)strlen("UNKNOWN") + 1; unkdbt.data = "UNKNOWN"; if ((ret = __os_malloc(dbenv, dbp->pgsize, &ovflbuf)) != 0) return (ret); err_ret = 0; while ((ret = __db_salvage_getnext(vdp, &pgno, &pgtype)) == 0) { dbt = NULL; if ((ret = __memp_fget(mpf, &pgno, 0, &h)) != 0) { err_ret = ret; continue; } switch (pgtype) { case SALVAGE_LDUP: case SALVAGE_LRECNODUP: dbt = &unkdbt; /* FALLTHROUGH */ case SALVAGE_LBTREE: case SALVAGE_LRECNO: if ((ret = __bam_salvage(dbp, vdp, pgno, pgtype, h, handle, callback, dbt, flags)) != 0) err_ret = ret; break; case SALVAGE_OVERFLOW: /* * XXX: * This may generate multiple "UNKNOWN" keys in * a database with no dups. What to do? */ if ((ret = __db_safe_goff(dbp, vdp, pgno, &key, &ovflbuf, flags)) != 0 || (ret = __db_prdbt(&key, 0, " ", handle, callback, 0, vdp)) != 0 || (ret = __db_prdbt(&unkdbt, 0, " ", handle, callback, 0, vdp)) != 0) err_ret = ret; break; case SALVAGE_HASH: if ((ret = __ham_salvage( dbp, vdp, pgno, h, handle, callback, flags)) != 0) err_ret = ret; break; case SALVAGE_INVALID: case SALVAGE_IGNORE: default: /* * Shouldn't happen, but if it does, just do what the * nice man says. */ DB_ASSERT(0); break; } if ((ret = __memp_fput(mpf, h, 0)) != 0) err_ret = ret; } __os_free(dbenv, ovflbuf); if (err_ret != 0 && ret == 0) ret = err_ret; return (ret == DB_NOTFOUND ? 0 : ret); } /* * Offset of the ith inp array entry, which we can compare to the offset * the entry stores. */ #define INP_OFFSET(dbp, h, i) \ ((db_indx_t)((u_int8_t *)((P_INP(dbp,(h))) + (i)) - (u_int8_t *)(h))) /* * __db_vrfy_inpitem -- * Verify that a single entry in the inp array is sane, and update * the high water mark and current item offset. (The former of these is * used for state information between calls, and is required; it must * be initialized to the pagesize before the first call.) * * Returns DB_VERIFY_FATAL if inp has collided with the data, * since verification can't continue from there; returns DB_VERIFY_BAD * if anything else is wrong. * * PUBLIC: int __db_vrfy_inpitem __P((DB *, PAGE *, * PUBLIC: db_pgno_t, u_int32_t, int, u_int32_t, u_int32_t *, u_int32_t *)); */ int __db_vrfy_inpitem(dbp, h, pgno, i, is_btree, flags, himarkp, offsetp) DB *dbp; PAGE *h; db_pgno_t pgno; u_int32_t i; int is_btree; u_int32_t flags, *himarkp, *offsetp; { BKEYDATA *bk; DB_ENV *dbenv; db_indx_t *inp, offset, len; dbenv = dbp->dbenv; DB_ASSERT(himarkp != NULL); inp = P_INP(dbp, h); /* * Check that the inp array, which grows from the beginning of the * page forward, has not collided with the data, which grow from the * end of the page backward. */ if (inp + i >= (db_indx_t *)((u_int8_t *)h + *himarkp)) { /* We've collided with the data. We need to bail. */ EPRINT((dbenv, "Page %lu: entries listing %lu overlaps data", (u_long)pgno, (u_long)i)); return (DB_VERIFY_FATAL); } offset = inp[i]; /* * Check that the item offset is reasonable: it points somewhere * after the inp array and before the end of the page. */ if (offset <= INP_OFFSET(dbp, h, i) || offset > dbp->pgsize) { EPRINT((dbenv, "Page %lu: bad offset %lu at page index %lu", (u_long)pgno, (u_long)offset, (u_long)i)); return (DB_VERIFY_BAD); } /* Update the high-water mark (what HOFFSET should be) */ if (offset < *himarkp) *himarkp = offset; if (is_btree) { /* * Check alignment; if it's unaligned, it's unsafe to * manipulate this item. */ if (offset != ALIGN(offset, sizeof(u_int32_t))) { EPRINT((dbenv, "Page %lu: unaligned offset %lu at page index %lu", (u_long)pgno, (u_long)offset, (u_long)i)); return (DB_VERIFY_BAD); } /* * Check that the item length remains on-page. */ bk = GET_BKEYDATA(dbp, h, i); /* * We need to verify the type of the item here; * we can't simply assume that it will be one of the * expected three. If it's not a recognizable type, * it can't be considered to have a verifiable * length, so it's not possible to certify it as safe. */ switch (B_TYPE(bk->type)) { case B_KEYDATA: len = bk->len; break; case B_DUPLICATE: case B_OVERFLOW: len = BOVERFLOW_SIZE; break; default: EPRINT((dbenv, "Page %lu: item %lu of unrecognizable type", (u_long)pgno, (u_long)i)); return (DB_VERIFY_BAD); } if ((size_t)(offset + len) > dbp->pgsize) { EPRINT((dbenv, "Page %lu: item %lu extends past page boundary", (u_long)pgno, (u_long)i)); return (DB_VERIFY_BAD); } } if (offsetp != NULL) *offsetp = offset; return (0); } /* * __db_vrfy_duptype-- * Given a page number and a set of flags to __bam_vrfy_subtree, * verify that the dup tree type is correct--i.e., it's a recno * if DUPSORT is not set and a btree if it is. * * PUBLIC: int __db_vrfy_duptype * PUBLIC: __P((DB *, VRFY_DBINFO *, db_pgno_t, u_int32_t)); */ int __db_vrfy_duptype(dbp, vdp, pgno, flags) DB *dbp; VRFY_DBINFO *vdp; db_pgno_t pgno; u_int32_t flags; { DB_ENV *dbenv; VRFY_PAGEINFO *pip; int ret, isbad; dbenv = dbp->dbenv; isbad = 0; if ((ret = __db_vrfy_getpageinfo(vdp, pgno, &pip)) != 0) return (ret); switch (pip->type) { case P_IBTREE: case P_LDUP: if (!LF_ISSET(ST_DUPSORT)) { EPRINT((dbenv, "Page %lu: sorted duplicate set in unsorted-dup database", (u_long)pgno)); isbad = 1; } break; case P_IRECNO: case P_LRECNO: if (LF_ISSET(ST_DUPSORT)) { EPRINT((dbenv, "Page %lu: unsorted duplicate set in sorted-dup database", (u_long)pgno)); isbad = 1; } break; default: /* * If the page is entirely zeroed, its pip->type will be a lie * (we assumed it was a hash page, as they're allowed to be * zeroed); handle this case specially. */ if (F_ISSET(pip, VRFY_IS_ALLZEROES)) ZEROPG_ERR_PRINT(dbenv, pgno, "duplicate page"); else EPRINT((dbenv, "Page %lu: duplicate page of inappropriate type %lu", (u_long)pgno, (u_long)pip->type)); isbad = 1; break; } if ((ret = __db_vrfy_putpageinfo(dbenv, vdp, pip)) != 0) return (ret); return (isbad == 1 ? DB_VERIFY_BAD : 0); } /* * __db_salvage_duptree -- * Attempt to salvage a given duplicate tree, given its alleged root. * * The key that corresponds to this dup set has been passed to us * in DBT *key. Because data items follow keys, though, it has been * printed once already. * * The basic idea here is that pgno ought to be a P_LDUP, a P_LRECNO, a * P_IBTREE, or a P_IRECNO. If it's an internal page, use the verifier * functions to make sure it's safe; if it's not, we simply bail and the * data will have to be printed with no key later on. if it is safe, * recurse on each of its children. * * Whether or not it's safe, if it's a leaf page, __bam_salvage it. * * At all times, use the DB hanging off vdp to mark and check what we've * done, so each page gets printed exactly once and we don't get caught * in any cycles. * * PUBLIC: int __db_salvage_duptree __P((DB *, VRFY_DBINFO *, db_pgno_t, * PUBLIC: DBT *, void *, int (*)(void *, const void *), u_int32_t)); */ int __db_salvage_duptree(dbp, vdp, pgno, key, handle, callback, flags) DB *dbp; VRFY_DBINFO *vdp; db_pgno_t pgno; DBT *key; void *handle; int (*callback) __P((void *, const void *)); u_int32_t flags; { DB_MPOOLFILE *mpf; PAGE *h; int ret, t_ret; mpf = dbp->mpf; if (pgno == PGNO_INVALID || !IS_VALID_PGNO(pgno)) return (DB_VERIFY_BAD); /* We have a plausible page. Try it. */ if ((ret = __memp_fget(mpf, &pgno, 0, &h)) != 0) return (ret); switch (TYPE(h)) { case P_IBTREE: case P_IRECNO: if ((ret = __db_vrfy_common(dbp, vdp, h, pgno, flags)) != 0) goto err; if ((ret = __bam_vrfy(dbp, vdp, h, pgno, flags | DB_NOORDERCHK)) != 0 || (ret = __db_salvage_markdone(vdp, pgno)) != 0) goto err; /* * We have a known-healthy internal page. Walk it. */ if ((ret = __bam_salvage_walkdupint(dbp, vdp, h, key, handle, callback, flags)) != 0) goto err; break; case P_LRECNO: case P_LDUP: if ((ret = __bam_salvage(dbp, vdp, pgno, TYPE(h), h, handle, callback, key, flags)) != 0) goto err; break; default: ret = DB_VERIFY_BAD; goto err; } err: if ((t_ret = __memp_fput(mpf, h, 0)) != 0 && ret == 0) ret = t_ret; return (ret); } /* * __db_salvage_subdbs -- * Check and see if this database has subdbs; if so, try to salvage * them independently. */ static int __db_salvage_subdbs(dbp, vdp, handle, callback, flags, hassubsp) DB *dbp; VRFY_DBINFO *vdp; void *handle; int (*callback) __P((void *, const void *)); u_int32_t flags; int *hassubsp; { BTMETA *btmeta; DB *pgset; DBC *pgsc; DB_MPOOLFILE *mpf; PAGE *h; db_pgno_t p, meta_pgno; int ret, err_ret; pgset = NULL; pgsc = NULL; mpf = dbp->mpf; err_ret = 0; meta_pgno = PGNO_BASE_MD; if ((ret = __memp_fget(mpf, &meta_pgno, 0, &h)) != 0) return (ret); if (TYPE(h) == P_BTREEMETA) btmeta = (BTMETA *)h; else { /* Not a btree metadata, ergo no subdbs, so just return. */ ret = 0; goto err; } /* If it's not a safe page, bail on the attempt. */ if ((ret = __db_vrfy_common(dbp, vdp, h, PGNO_BASE_MD, flags)) != 0 || (ret = __bam_vrfy_meta(dbp, vdp, btmeta, PGNO_BASE_MD, flags)) != 0) goto err; if (!F_ISSET(&btmeta->dbmeta, BTM_SUBDB)) { /* No subdbs, just return. */ ret = 0; goto err; } /* We think we've got subdbs. Mark it so. */ *hassubsp = 1; if ((ret = __memp_fput(mpf, h, 0)) != 0) return (ret); /* * We have subdbs. Try to crack them. * * To do so, get a set of leaf pages in the master * database, and then walk each of the valid ones, salvaging * subdbs as we go. If any prove invalid, just drop them; we'll * pick them up on a later pass. */ if ((ret = __db_vrfy_pgset(dbp->dbenv, dbp->pgsize, &pgset)) != 0) return (ret); if ((ret = __db_meta2pgset(dbp, vdp, PGNO_BASE_MD, flags, pgset)) != 0) goto err; if ((ret = __db_cursor(pgset, NULL, &pgsc, 0)) != 0) goto err; while ((ret = __db_vrfy_pgset_next(pgsc, &p)) == 0) { if ((ret = __memp_fget(mpf, &p, 0, &h)) != 0) { err_ret = ret; continue; } if ((ret = __db_vrfy_common(dbp, vdp, h, p, flags)) != 0 || (ret = __bam_vrfy(dbp, vdp, h, p, flags | DB_NOORDERCHK)) != 0) goto nextpg; if (TYPE(h) != P_LBTREE) goto nextpg; else if ((ret = __db_salvage_subdbpg( dbp, vdp, h, handle, callback, flags)) != 0) err_ret = ret; nextpg: if ((ret = __memp_fput(mpf, h, 0)) != 0) err_ret = ret; } if (ret != DB_NOTFOUND) goto err; if ((ret = __db_c_close(pgsc)) != 0) goto err; ret = __db_close(pgset, NULL, 0); return ((ret == 0 && err_ret != 0) ? err_ret : ret); err: if (pgsc != NULL) (void)__db_c_close(pgsc); if (pgset != NULL) (void)__db_close(pgset, NULL, 0); (void)__memp_fput(mpf, h, 0); return (ret); } /* * __db_salvage_subdbpg -- * Given a known-good leaf page in the master database, salvage all * leaf pages corresponding to each subdb. */ static int __db_salvage_subdbpg(dbp, vdp, master, handle, callback, flags) DB *dbp; VRFY_DBINFO *vdp; PAGE *master; void *handle; int (*callback) __P((void *, const void *)); u_int32_t flags; { BKEYDATA *bkkey, *bkdata; BOVERFLOW *bo; DB *pgset; DBC *pgsc; DBT key; DB_ENV *dbenv; DB_MPOOLFILE *mpf; PAGE *subpg; db_indx_t i; db_pgno_t meta_pgno, p; int ret, err_ret, t_ret; char *subdbname; dbenv = dbp->dbenv; mpf = dbp->mpf; ret = err_ret = 0; subdbname = NULL; if ((ret = __db_vrfy_pgset(dbenv, dbp->pgsize, &pgset)) != 0) return (ret); /* * For each entry, get and salvage the set of pages * corresponding to that entry. */ for (i = 0; i < NUM_ENT(master); i += P_INDX) { bkkey = GET_BKEYDATA(dbp, master, i); bkdata = GET_BKEYDATA(dbp, master, i + O_INDX); /* Get the subdatabase name. */ if (B_TYPE(bkkey->type) == B_OVERFLOW) { /* * We can, in principle anyway, have a subdb * name so long it overflows. Ick. */ bo = (BOVERFLOW *)bkkey; if ((ret = __db_safe_goff(dbp, vdp, bo->pgno, &key, &subdbname, flags)) != 0) { err_ret = DB_VERIFY_BAD; continue; } /* Nul-terminate it. */ if ((ret = __os_realloc(dbenv, key.size + 1, &subdbname)) != 0) goto err; subdbname[key.size] = '\0'; } else if (B_TYPE(bkkey->type) == B_KEYDATA) { if ((ret = __os_realloc(dbenv, bkkey->len + 1, &subdbname)) != 0) goto err; memcpy(subdbname, bkkey->data, bkkey->len); subdbname[bkkey->len] = '\0'; } /* Get the corresponding pgno. */ if (bkdata->len != sizeof(db_pgno_t)) { err_ret = DB_VERIFY_BAD; continue; } memcpy(&meta_pgno, bkdata->data, sizeof(db_pgno_t)); /* * Subdatabase meta pgnos are stored in network byte * order for cross-endian compatibility. Swap if appropriate. */ DB_NTOHL(&meta_pgno); /* If we can't get the subdb meta page, just skip the subdb. */ if (!IS_VALID_PGNO(meta_pgno) || (ret = __memp_fget(mpf, &meta_pgno, 0, &subpg)) != 0) { err_ret = ret; continue; } /* * Verify the subdatabase meta page. This has two functions. * First, if it's bad, we have no choice but to skip the subdb * and let the pages just get printed on a later pass. Second, * the access-method-specific meta verification routines record * the various state info (such as the presence of dups) * that we need for __db_prheader(). */ if ((ret = __db_vrfy_common(dbp, vdp, subpg, meta_pgno, flags)) != 0) { err_ret = ret; (void)__memp_fput(mpf, subpg, 0); continue; } switch (TYPE(subpg)) { case P_BTREEMETA: if ((ret = __bam_vrfy_meta(dbp, vdp, (BTMETA *)subpg, meta_pgno, flags)) != 0) { err_ret = ret; (void)__memp_fput(mpf, subpg, 0); continue; } break; case P_HASHMETA: if ((ret = __ham_vrfy_meta(dbp, vdp, (HMETA *)subpg, meta_pgno, flags)) != 0) { err_ret = ret; (void)__memp_fput(mpf, subpg, 0); continue; } break; default: /* This isn't an appropriate page; skip this subdb. */ err_ret = DB_VERIFY_BAD; continue; } if ((ret = __memp_fput(mpf, subpg, 0)) != 0) { err_ret = ret; continue; } /* Print a subdatabase header. */ if ((ret = __db_prheader(dbp, subdbname, 0, 0, handle, callback, vdp, meta_pgno)) != 0) goto err; if ((ret = __db_meta2pgset(dbp, vdp, meta_pgno, flags, pgset)) != 0) { err_ret = ret; continue; } if ((ret = __db_cursor(pgset, NULL, &pgsc, 0)) != 0) goto err; while ((ret = __db_vrfy_pgset_next(pgsc, &p)) == 0) { if ((ret = __memp_fget(mpf, &p, 0, &subpg)) != 0) { err_ret = ret; continue; } if ((ret = __db_salvage(dbp, vdp, p, subpg, handle, callback, flags)) != 0) err_ret = ret; if ((ret = __memp_fput(mpf, subpg, 0)) != 0) err_ret = ret; } if (ret != DB_NOTFOUND) goto err; if ((ret = __db_c_close(pgsc)) != 0) goto err; if ((ret = __db_prfooter(handle, callback)) != 0) goto err; } err: if (subdbname) __os_free(dbenv, subdbname); if ((t_ret = __db_close(pgset, NULL, 0)) != 0) ret = t_ret; if ((t_ret = __db_salvage_markdone(vdp, PGNO(master))) != 0) return (t_ret); return ((err_ret != 0) ? err_ret : ret); } /* * __db_meta2pgset -- * Given a known-safe meta page number, return the set of pages * corresponding to the database it represents. Return DB_VERIFY_BAD if * it's not a suitable meta page or is invalid. */ static int __db_meta2pgset(dbp, vdp, pgno, flags, pgset) DB *dbp; VRFY_DBINFO *vdp; db_pgno_t pgno; u_int32_t flags; DB *pgset; { DB_MPOOLFILE *mpf; PAGE *h; int ret, t_ret; mpf = dbp->mpf; if ((ret = __memp_fget(mpf, &pgno, 0, &h)) != 0) return (ret); switch (TYPE(h)) { case P_BTREEMETA: ret = __bam_meta2pgset(dbp, vdp, (BTMETA *)h, flags, pgset); break; case P_HASHMETA: ret = __ham_meta2pgset(dbp, vdp, (HMETA *)h, flags, pgset); break; default: ret = DB_VERIFY_BAD; break; } if ((t_ret = __memp_fput(mpf, h, 0)) != 0) return (t_ret); return (ret); } /* * __db_guesspgsize -- * Try to guess what the pagesize is if the one on the meta page * and the one in the db are invalid. */ static u_int __db_guesspgsize(dbenv, fhp) DB_ENV *dbenv; DB_FH *fhp; { db_pgno_t i; size_t nr; u_int32_t guess; u_int8_t type; for (guess = DB_MAX_PGSIZE; guess >= DB_MIN_PGSIZE; guess >>= 1) { /* * We try to read three pages ahead after the first one * and make sure we have plausible types for all of them. * If the seeks fail, continue with a smaller size; * we're probably just looking past the end of the database. * If they succeed and the types are reasonable, also continue * with a size smaller; we may be looking at pages N, * 2N, and 3N for some N > 1. * * As soon as we hit an invalid type, we stop and return * our previous guess; that last one was probably the page size. */ for (i = 1; i <= 3; i++) { if (__os_seek(dbenv, fhp, guess, i, SSZ(DBMETA, type), 0, DB_OS_SEEK_SET) != 0) break; if (__os_read(dbenv, fhp, &type, 1, &nr) != 0 || nr == 0) break; if (type == P_INVALID || type >= P_PAGETYPE_MAX) return (guess << 1); } } /* * If we're just totally confused--the corruption takes up most of the * beginning pages of the database--go with the default size. */ return (DB_DEF_IOSIZE); }