From 36cfa7b79e36d880cdbf24d0769558be44d0edda Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Tue, 19 Apr 2011 21:00:59 +0930 Subject: tdb: make sure we skip over recovery area correctly. If it's really the recovery area, we can trust the rec_len field, and don't have to go groping for bitpatterns. Signed-off-by: Rusty Russell Autobuild-User: Rusty Russell Autobuild-Date: Tue Apr 19 14:15:22 CEST 2011 on sn-devel-104 --- lib/tdb/common/summary.c | 13 +++++++++++-- lib/tdb/common/tdb_private.h | 4 ++++ lib/tdb/common/transaction.c | 44 +++++++++++++++++++++++++++++--------------- 3 files changed, 44 insertions(+), 17 deletions(-) (limited to 'lib/tdb') diff --git a/lib/tdb/common/summary.c b/lib/tdb/common/summary.c index b222a5993d..171a1a2055 100644 --- a/lib/tdb/common/summary.c +++ b/lib/tdb/common/summary.c @@ -86,12 +86,13 @@ static size_t get_hash_length(struct tdb_context *tdb, unsigned int i) _PUBLIC_ char *tdb_summary(struct tdb_context *tdb) { - tdb_off_t off; + tdb_off_t off, rec_off; struct tally freet, keys, data, dead, extra, hash, uncoal; struct tdb_record rec; char *ret = NULL; bool locked; size_t len, unc = 0; + struct tdb_record recovery; /* Read-only databases use no locking at all: it's best-effort. * We may have a write lock already, so skip that case too. */ @@ -103,6 +104,10 @@ _PUBLIC_ char *tdb_summary(struct tdb_context *tdb) locked = true; } + if (tdb_recovery_area(tdb, tdb->methods, &rec_off, &recovery) != 0) { + goto unlock; + } + tally_init(&freet); tally_init(&keys); tally_init(&data); @@ -135,7 +140,11 @@ _PUBLIC_ char *tdb_summary(struct tdb_context *tdb) case TDB_RECOVERY_INVALID_MAGIC: case 0x42424242: unc++; - rec.rec_len = tdb_dead_space(tdb, off) - sizeof(rec); + /* If it's a valid recovery, we can trust rec_len. */ + if (off != rec_off) { + rec.rec_len = tdb_dead_space(tdb, off) + - sizeof(rec); + } /* Fall through */ case TDB_DEAD_MAGIC: tally_add(&dead, rec.rec_len); diff --git a/lib/tdb/common/tdb_private.h b/lib/tdb/common/tdb_private.h index 0186fb9530..140d4ecec5 100644 --- a/lib/tdb/common/tdb_private.h +++ b/lib/tdb/common/tdb_private.h @@ -238,6 +238,10 @@ void tdb_release_transaction_locks(struct tdb_context *tdb); int tdb_transaction_lock(struct tdb_context *tdb, int ltype, enum tdb_lock_flags lockflags); int tdb_transaction_unlock(struct tdb_context *tdb, int ltype); +int tdb_recovery_area(struct tdb_context *tdb, + const struct tdb_methods *methods, + tdb_off_t *recovery_offset, + struct tdb_record *rec); int tdb_allrecord_lock(struct tdb_context *tdb, int ltype, enum tdb_lock_flags flags, bool upgradable); int tdb_allrecord_unlock(struct tdb_context *tdb, int ltype, bool mark_lock); diff --git a/lib/tdb/common/transaction.c b/lib/tdb/common/transaction.c index e110a08dbc..e4573cb0a9 100644 --- a/lib/tdb/common/transaction.c +++ b/lib/tdb/common/transaction.c @@ -658,6 +658,34 @@ static tdb_len_t tdb_recovery_size(struct tdb_context *tdb) return recovery_size; } +int tdb_recovery_area(struct tdb_context *tdb, + const struct tdb_methods *methods, + tdb_off_t *recovery_offset, + struct tdb_record *rec) +{ + if (tdb_ofs_read(tdb, TDB_RECOVERY_HEAD, recovery_offset) == -1) { + return -1; + } + + if (*recovery_offset == 0) { + rec->rec_len = 0; + return 0; + } + + if (methods->tdb_read(tdb, *recovery_offset, rec, sizeof(*rec), + DOCONV()) == -1) { + return -1; + } + + /* ignore invalid recovery regions: can happen in crash */ + if (rec->magic != TDB_RECOVERY_MAGIC && + rec->magic != TDB_RECOVERY_INVALID_MAGIC) { + *recovery_offset = 0; + rec->rec_len = 0; + } + return 0; +} + /* allocate the recovery area, or use an existing recovery area if it is large enough @@ -671,25 +699,11 @@ static int tdb_recovery_allocate(struct tdb_context *tdb, const struct tdb_methods *methods = tdb->transaction->io_methods; tdb_off_t recovery_head; - if (tdb_ofs_read(tdb, TDB_RECOVERY_HEAD, &recovery_head) == -1) { + if (tdb_recovery_area(tdb, methods, &recovery_head, &rec) == -1) { TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_recovery_allocate: failed to read recovery head\n")); return -1; } - rec.rec_len = 0; - - if (recovery_head != 0) { - if (methods->tdb_read(tdb, recovery_head, &rec, sizeof(rec), DOCONV()) == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_recovery_allocate: failed to read recovery record\n")); - return -1; - } - /* ignore invalid recovery regions: can happen in crash */ - if (rec.magic != TDB_RECOVERY_MAGIC && - rec.magic != TDB_RECOVERY_INVALID_MAGIC) { - recovery_head = 0; - } - } - *recovery_size = tdb_recovery_size(tdb); if (recovery_head != 0 && *recovery_size <= rec.rec_len) { -- cgit