From: Rusty Russell <rusty@rustcorp.com.au>
Date: Tue, 1 Mar 2011 12:49:19 +0000 (+1030)
Subject: tdb2: rework io functions to return enum TDB_ERROR.
X-Git-Url: https://git.ozlabs.org/?p=ccan;a=commitdiff_plain;h=012f68a0738e2190580f4639321d18ad5f4611c2

tdb2: rework io functions to return enum TDB_ERROR.

We have a series of I/O functions which change depending on whether we're
inside a transaction or not.  This makes them return enum TDB_ERROR instead
of int.
---

diff --git a/ccan/tdb2/check.c b/ccan/tdb2/check.c
index b01495a8..54e5bb1c 100644
--- a/ccan/tdb2/check.c
+++ b/ccan/tdb2/check.c
@@ -416,6 +416,8 @@ static bool check_free(struct tdb_context *tdb,
 		       tdb_off_t prev, unsigned int ftable,
 		       unsigned int bucket)
 {
+	enum TDB_ERROR ecode;
+
 	if (frec_magic(frec) != TDB_FREE_MAGIC) {
 		tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
 			   "tdb_check: offset %llu bad magic 0x%llx",
@@ -429,10 +431,14 @@ static bool check_free(struct tdb_context *tdb,
 		return false;
 	}
 
-	if (tdb->methods->oob(tdb, off
-			      + frec_len(frec) + sizeof(struct tdb_used_record),
-			      false))
+	ecode = tdb->methods->oob(tdb, off
+				  + frec_len(frec)
+				  + sizeof(struct tdb_used_record),
+				  false);
+	if (ecode != TDB_SUCCESS) {
+		tdb->ecode = ecode;
 		return false;
+	}
 	if (size_to_bucket(frec_len(frec)) != bucket) {
 		tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
 			   "tdb_check: offset %llu in wrong bucket %u vs %u",
@@ -509,11 +515,15 @@ static bool check_free_table(struct tdb_context *tdb,
 size_t dead_space(struct tdb_context *tdb, tdb_off_t off)
 {
 	size_t len;
+	enum TDB_ERROR ecode;
 
 	for (len = 0; off + len < tdb->map_size; len++) {
 		char c;
-		if (tdb->methods->tread(tdb, off, &c, 1))
+		ecode = tdb->methods->tread(tdb, off, &c, 1);
+		if (ecode != TDB_SUCCESS) {
+			tdb->ecode = ecode;
 			return 0;
+		}
 		if (c != 0 && c != 0x43)
 			break;
 	}
diff --git a/ccan/tdb2/free.c b/ccan/tdb2/free.c
index bface0a3..83ad7ff5 100644
--- a/ccan/tdb2/free.c
+++ b/ccan/tdb2/free.c
@@ -625,7 +625,9 @@ static int tdb_expand(struct tdb_context *tdb, tdb_len_t size)
 		return 0;
 	}
 
-	if (tdb->methods->expand_file(tdb, wanted) == -1) {
+	ecode = tdb->methods->expand_file(tdb, wanted);
+	if (ecode != TDB_SUCCESS) {
+		tdb->ecode = ecode;
 		tdb_unlock_expand(tdb, F_WRLCK);
 		return -1;
 	}
diff --git a/ccan/tdb2/io.c b/ccan/tdb2/io.c
index f326d98b..a0c5f523 100644
--- a/ccan/tdb2/io.c
+++ b/ccan/tdb2/io.c
@@ -67,7 +67,8 @@ void tdb_mmap(struct tdb_context *tdb)
    if necessary
    note that "len" is the minimum length needed for the db
 */
-static int tdb_oob(struct tdb_context *tdb, tdb_off_t len, bool probe)
+static enum TDB_ERROR tdb_oob(struct tdb_context *tdb, tdb_off_t len,
+			      bool probe)
 {
 	struct stat st;
 	enum TDB_ERROR ecode;
@@ -87,20 +88,19 @@ static int tdb_oob(struct tdb_context *tdb, tdb_off_t len, bool probe)
 				 (long long)len,
 				 (long long)tdb->map_size);
 		}
-		return -1;
+		return TDB_ERR_IO;
 	}
 
 	ecode = tdb_lock_expand(tdb, F_RDLCK);
 	if (ecode != TDB_SUCCESS) {
-		tdb->ecode = ecode;
-		return -1;
+		return ecode;
 	}
 
 	if (fstat(tdb->fd, &st) != 0) {
 		tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
 			   "Failed to fstat file: %s", strerror(errno));
 		tdb_unlock_expand(tdb, F_RDLCK);
-		return -1;
+		return TDB_ERR_IO;
 	}
 
 	tdb_unlock_expand(tdb, F_RDLCK);
@@ -111,7 +111,7 @@ static int tdb_oob(struct tdb_context *tdb, tdb_off_t len, bool probe)
 				   "tdb_oob len %zu beyond eof at %zu",
 				   (size_t)len, st.st_size);
 		}
-		return -1;
+		return TDB_ERR_IO;
 	}
 
 	/* Unmap, update size, remap */
@@ -119,7 +119,7 @@ static int tdb_oob(struct tdb_context *tdb, tdb_off_t len, bool probe)
 
 	tdb->map_size = st.st_size;
 	tdb_mmap(tdb);
-	return 0;
+	return TDB_SUCCESS;
 }
 
 /* Endian conversion: we only ever deal with 8 byte quantities */
@@ -178,6 +178,7 @@ int zero_out(struct tdb_context *tdb, tdb_off_t off, tdb_len_t len)
 {
 	char buf[8192] = { 0 };
 	void *p = tdb->methods->direct(tdb, off, len, true);
+	enum TDB_ERROR ecode;
 
 	assert(!tdb->read_only);
 	if (p) {
@@ -186,8 +187,11 @@ int zero_out(struct tdb_context *tdb, tdb_off_t off, tdb_len_t len)
 	}
 	while (len) {
 		unsigned todo = len < sizeof(buf) ? len : sizeof(buf);
-		if (tdb->methods->twrite(tdb, off, buf, todo) == -1)
+		ecode = tdb->methods->twrite(tdb, off, buf, todo);
+		if (ecode != TDB_SUCCESS) {
+			tdb->ecode = ecode;
 			return -1;
+		}
 		len -= todo;
 		off += todo;
 	}
@@ -211,22 +215,25 @@ tdb_off_t tdb_read_off(struct tdb_context *tdb, tdb_off_t off)
 }
 
 /* write a lump of data at a specified offset */
-static int tdb_write(struct tdb_context *tdb, tdb_off_t off,
-		     const void *buf, tdb_len_t len)
+static enum TDB_ERROR tdb_write(struct tdb_context *tdb, tdb_off_t off,
+				const void *buf, tdb_len_t len)
 {
+	enum TDB_ERROR ecode;
+
 	if (tdb->read_only) {
-		tdb_logerr(tdb, TDB_ERR_RDONLY, TDB_LOG_USE_ERROR,
-			   "Write to read-only database");
-		return -1;
+		return tdb_logerr(tdb, TDB_ERR_RDONLY, TDB_LOG_USE_ERROR,
+				  "Write to read-only database");
 	}
 
 	/* FIXME: Bogus optimization? */
 	if (len == 0) {
-		return 0;
+		return TDB_SUCCESS;
 	}
 
-	if (tdb->methods->oob(tdb, off + len, 0) != 0)
-		return -1;
+	ecode = tdb->methods->oob(tdb, off + len, 0);
+	if (ecode != TDB_SUCCESS) {
+		return ecode;
+	}
 
 	if (tdb->map_ptr) {
 		memcpy(off + (char *)tdb->map_ptr, buf, len);
@@ -238,22 +245,24 @@ static int tdb_write(struct tdb_context *tdb, tdb_off_t off,
 			if (ret >= 0)
 				errno = ENOSPC;
 
-			tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
-				   "tdb_write: %zi at %zu len=%zu (%s)",
-				   ret, (size_t)off, (size_t)len,
-				   strerror(errno));
-			return -1;
+			return tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
+					  "tdb_write: %zi at %zu len=%zu (%s)",
+					  ret, (size_t)off, (size_t)len,
+					  strerror(errno));
 		}
 	}
-	return 0;
+	return TDB_SUCCESS;
 }
 
 /* read a lump of data at a specified offset */
-static int tdb_read(struct tdb_context *tdb, tdb_off_t off, void *buf,
-		    tdb_len_t len)
+static enum TDB_ERROR tdb_read(struct tdb_context *tdb, tdb_off_t off,
+			       void *buf, tdb_len_t len)
 {
-	if (tdb->methods->oob(tdb, off + len, 0) != 0) {
-		return -1;
+	enum TDB_ERROR ecode;
+
+	ecode = tdb->methods->oob(tdb, off + len, 0);
+	if (ecode != TDB_SUCCESS) {
+		return ecode;
 	}
 
 	if (tdb->map_ptr) {
@@ -261,22 +270,22 @@ static int tdb_read(struct tdb_context *tdb, tdb_off_t off, void *buf,
 	} else {
 		ssize_t r = pread(tdb->fd, buf, len, off);
 		if (r != len) {
-			tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
-				   "tdb_read failed with %zi at %zu "
-				   "len=%zu (%s) map_size=%zu",
-				   r, (size_t)off, (size_t)len,
-				   strerror(errno),
-				   (size_t)tdb->map_size);
-			return -1;
+			return tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
+					  "tdb_read failed with %zi at %zu "
+					  "len=%zu (%s) map_size=%zu",
+					  r, (size_t)off, (size_t)len,
+					  strerror(errno),
+					  (size_t)tdb->map_size);
 		}
 	}
-	return 0;
+	return TDB_SUCCESS;
 }
 
 int tdb_write_convert(struct tdb_context *tdb, tdb_off_t off,
 		      const void *rec, size_t len)
 {
-	int ret;
+	enum TDB_ERROR ecode;
+
 	if (unlikely((tdb->flags & TDB_CONVERT))) {
 		void *conv = malloc(len);
 		if (!conv) {
@@ -286,21 +295,30 @@ int tdb_write_convert(struct tdb_context *tdb, tdb_off_t off,
 			return -1;
 		}
 		memcpy(conv, rec, len);
-		ret = tdb->methods->twrite(tdb, off,
+		ecode = tdb->methods->twrite(tdb, off,
 					   tdb_convert(tdb, conv, len), len);
 		free(conv);
-	} else
-		ret = tdb->methods->twrite(tdb, off, rec, len);
+	} else {
+		ecode = tdb->methods->twrite(tdb, off, rec, len);
+	}
 
-	return ret;
+	if (ecode != TDB_SUCCESS) {
+		tdb->ecode = ecode;
+		return -1;
+	}
+	return 0;
 }
 
 int tdb_read_convert(struct tdb_context *tdb, tdb_off_t off,
 		      void *rec, size_t len)
 {
-	int ret = tdb->methods->tread(tdb, off, rec, len);
+	enum TDB_ERROR ecode = tdb->methods->tread(tdb, off, rec, len);
 	tdb_convert(tdb, rec, len);
-	return ret;
+	if (ecode != TDB_SUCCESS) {
+		tdb->ecode = ecode;
+		return -1;
+	}
+	return 0;
 }
 
 int tdb_write_off(struct tdb_context *tdb, tdb_off_t off, tdb_off_t val)
@@ -326,6 +344,7 @@ static void *_tdb_alloc_read(struct tdb_context *tdb, tdb_off_t offset,
 			     tdb_len_t len, unsigned int prefix)
 {
 	void *buf;
+	enum TDB_ERROR ecode;
 
 	/* some systems don't like zero length malloc */
 	buf = malloc(prefix + len ? prefix + len : 1);
@@ -333,10 +352,13 @@ static void *_tdb_alloc_read(struct tdb_context *tdb, tdb_off_t offset,
 		tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_USE_ERROR,
 			   "tdb_alloc_read malloc failed len=%zu",
 			   (size_t)(prefix + len));
-	} else if (unlikely(tdb->methods->tread(tdb, offset, buf+prefix, len)
-			    == -1)) {
-		free(buf);
-		buf = NULL;
+	} else {
+		ecode = tdb->methods->tread(tdb, offset, buf+prefix, len);
+		if (unlikely(ecode != TDB_SUCCESS)) {
+			tdb->ecode = ecode;
+			free(buf);
+			buf = NULL;
+		}
 	}
 	return buf;
 }
@@ -372,22 +394,21 @@ static int fill(struct tdb_context *tdb,
 
 /* expand a file.  we prefer to use ftruncate, as that is what posix
   says to use for mmap expansion */
-static int tdb_expand_file(struct tdb_context *tdb, tdb_len_t addition)
+static enum TDB_ERROR tdb_expand_file(struct tdb_context *tdb,
+				      tdb_len_t addition)
 {
 	char buf[8192];
 
 	if (tdb->read_only) {
-		tdb_logerr(tdb, TDB_ERR_RDONLY, TDB_LOG_USE_ERROR,
-			   "Expand on read-only database");
-		return -1;
+		return tdb_logerr(tdb, TDB_ERR_RDONLY, TDB_LOG_USE_ERROR,
+				  "Expand on read-only database");
 	}
 
 	if (tdb->flags & TDB_INTERNAL) {
 		char *new = realloc(tdb->map_ptr, tdb->map_size + addition);
 		if (!new) {
-			tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
-				   "No memory to expand database");
-			return -1;
+			return tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
+					  "No memory to expand database");
 		}
 		tdb->map_ptr = new;
 		tdb->map_size += addition;
@@ -405,11 +426,11 @@ static int tdb_expand_file(struct tdb_context *tdb, tdb_len_t addition)
 		   disk. This must be done with write, not via mmap */
 		memset(buf, 0x43, sizeof(buf));
 		if (fill(tdb, buf, sizeof(buf), tdb->map_size, addition) == -1)
-			return -1;
+			return tdb->ecode;
 		tdb->map_size += addition;
 		tdb_mmap(tdb);
 	}
-	return 0;
+	return TDB_SUCCESS;
 }
 
 const void *tdb_access_read(struct tdb_context *tdb,
@@ -517,7 +538,7 @@ static void *tdb_direct(struct tdb_context *tdb, tdb_off_t off, size_t len,
 	if (unlikely(!tdb->map_ptr))
 		return NULL;
 
-	if (unlikely(tdb_oob(tdb, off + len, true) == -1))
+	if (unlikely(tdb_oob(tdb, off + len, true) != TDB_SUCCESS))
 		return NULL;
 	return (char *)tdb->map_ptr + off;
 }
diff --git a/ccan/tdb2/private.h b/ccan/tdb2/private.h
index 4ecda6a5..f0b5cae5 100644
--- a/ccan/tdb2/private.h
+++ b/ccan/tdb2/private.h
@@ -379,10 +379,12 @@ struct tdb_context {
 };
 
 struct tdb_methods {
-	int (*tread)(struct tdb_context *, tdb_off_t, void *, tdb_len_t);
-	int (*twrite)(struct tdb_context *, tdb_off_t, const void *, tdb_len_t);
-	int (*oob)(struct tdb_context *, tdb_off_t, bool);
-	int (*expand_file)(struct tdb_context *, tdb_len_t);
+	enum TDB_ERROR (*tread)(struct tdb_context *, tdb_off_t, void *,
+				tdb_len_t);
+	enum TDB_ERROR (*twrite)(struct tdb_context *, tdb_off_t, const void *,
+				 tdb_len_t);
+	enum TDB_ERROR (*oob)(struct tdb_context *, tdb_off_t, bool);
+	enum TDB_ERROR (*expand_file)(struct tdb_context *, tdb_len_t);
 	void *(*direct)(struct tdb_context *, tdb_off_t, size_t, bool);
 };
 
diff --git a/ccan/tdb2/tdb.c b/ccan/tdb2/tdb.c
index 093d3d6d..ba5d3759 100644
--- a/ccan/tdb2/tdb.c
+++ b/ccan/tdb2/tdb.c
@@ -429,6 +429,7 @@ static int replace_data(struct tdb_context *tdb,
 			bool growing)
 {
 	tdb_off_t new_off;
+	enum TDB_ERROR ecode;
 
 	/* Allocate a new record. */
 	new_off = alloc(tdb, key.dsize, dbuf.dsize, h->h, TDB_USED_MAGIC,
@@ -450,12 +451,18 @@ static int replace_data(struct tdb_context *tdb,
 	}
 
 	new_off += sizeof(struct tdb_used_record);
-	if (tdb->methods->twrite(tdb, new_off, key.dptr, key.dsize) == -1)
+	ecode = tdb->methods->twrite(tdb, new_off, key.dptr, key.dsize);
+	if (ecode != TDB_SUCCESS) {
+		tdb->ecode = ecode;
 		return -1;
+	}
 
 	new_off += key.dsize;
-	if (tdb->methods->twrite(tdb, new_off, dbuf.dptr, dbuf.dsize) == -1)
+	ecode = tdb->methods->twrite(tdb, new_off, dbuf.dptr, dbuf.dsize);
+	if (ecode != TDB_SUCCESS) {
+		tdb->ecode = ecode;
 		return -1;
+	}
 
 	/* FIXME: tdb_increment_seqnum(tdb); */
 	return 0;
@@ -469,6 +476,7 @@ int tdb_store(struct tdb_context *tdb,
 	tdb_len_t old_room = 0;
 	struct tdb_used_record rec;
 	int ret;
+	enum TDB_ERROR ecode;
 
 	off = find_and_lock(tdb, key, F_WRLCK, &h, &rec, NULL);
 	if (unlikely(off == TDB_OFF_ERR))
@@ -490,10 +498,15 @@ int tdb_store(struct tdb_context *tdb,
 						   key.dsize, dbuf.dsize,
 						   &rec, h.h))
 					goto fail;
-				if (tdb->methods->twrite(tdb, off + sizeof(rec)
-							 + key.dsize,
-							 dbuf.dptr, dbuf.dsize))
+				ecode = tdb->methods->twrite(tdb,
+							     off + sizeof(rec)
+							     + key.dsize,
+							     dbuf.dptr,
+							     dbuf.dsize);
+				if (ecode != TDB_SUCCESS) {
+					tdb->ecode = ecode;
 					goto fail;
+				}
 				tdb_unlock_hashes(tdb, h.hlock_start,
 						  h.hlock_range, F_WRLCK);
 				return 0;
@@ -528,6 +541,7 @@ int tdb_append(struct tdb_context *tdb,
 	tdb_len_t old_room = 0, old_dlen;
 	unsigned char *newdata;
 	struct tdb_data new_dbuf;
+	enum TDB_ERROR ecode;
 	int ret;
 
 	off = find_and_lock(tdb, key, F_WRLCK, &h, &rec, NULL);
@@ -545,9 +559,12 @@ int tdb_append(struct tdb_context *tdb,
 				goto fail;
 
 			off += sizeof(rec) + key.dsize + old_dlen;
-			if (tdb->methods->twrite(tdb, off, dbuf.dptr,
-						 dbuf.dsize) == -1)
+			ecode = tdb->methods->twrite(tdb, off, dbuf.dptr,
+						     dbuf.dsize);
+			if (ecode != TDB_SUCCESS) {
+				tdb->ecode = ecode;
 				goto fail;
+			}
 
 			/* FIXME: tdb_increment_seqnum(tdb); */
 			tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range,
@@ -563,8 +580,10 @@ int tdb_append(struct tdb_context *tdb,
 				   (size_t)(key.dsize+old_dlen+dbuf.dsize));
 			goto fail;
 		}
-		if (tdb->methods->tread(tdb, off + sizeof(rec) + key.dsize,
-					newdata, old_dlen) != 0) {
+		ecode = tdb->methods->tread(tdb, off + sizeof(rec) + key.dsize,
+					    newdata, old_dlen);
+		if (ecode != TDB_SUCCESS) {
+			tdb->ecode = ecode;
 			free(newdata);
 			goto fail;
 		}
diff --git a/ccan/tdb2/transaction.c b/ccan/tdb2/transaction.c
index cb516f18..2c9f354a 100644
--- a/ccan/tdb2/transaction.c
+++ b/ccan/tdb2/transaction.c
@@ -125,16 +125,18 @@ struct tdb_transaction {
   read while in a transaction. We need to check first if the data is in our list
   of transaction elements, then if not do a real read
 */
-static int transaction_read(struct tdb_context *tdb, tdb_off_t off, void *buf,
-			    tdb_len_t len)
+static enum TDB_ERROR transaction_read(struct tdb_context *tdb, tdb_off_t off,
+				       void *buf, tdb_len_t len)
 {
 	size_t blk;
+	enum TDB_ERROR ecode;
 
 	/* break it down into block sized ops */
 	while (len + (off % getpagesize()) > getpagesize()) {
 		tdb_len_t len2 = getpagesize() - (off % getpagesize());
-		if (transaction_read(tdb, off, buf, len2) != 0) {
-			return -1;
+		ecode = transaction_read(tdb, off, buf, len2);
+		if (ecode != TDB_SUCCESS) {
+			return ecode;
 		}
 		len -= len2;
 		off += len2;
@@ -142,7 +144,7 @@ static int transaction_read(struct tdb_context *tdb, tdb_off_t off, void *buf,
 	}
 
 	if (len == 0) {
-		return 0;
+		return TDB_SUCCESS;
 	}
 
 	blk = off / getpagesize();
@@ -151,8 +153,8 @@ static int transaction_read(struct tdb_context *tdb, tdb_off_t off, void *buf,
 	if (tdb->transaction->num_blocks <= blk ||
 	    tdb->transaction->blocks[blk] == NULL) {
 		/* nope, do a real read */
-		if (tdb->transaction->io_methods->tread(tdb, off, buf, len)
-		    != 0) {
+		ecode = tdb->transaction->io_methods->tread(tdb, off, buf, len);
+		if (ecode != TDB_SUCCESS) {
 			goto fail;
 		}
 		return 0;
@@ -161,43 +163,45 @@ static int transaction_read(struct tdb_context *tdb, tdb_off_t off, void *buf,
 	/* it is in the block list. Now check for the last block */
 	if (blk == tdb->transaction->num_blocks-1) {
 		if (len > tdb->transaction->last_block_size) {
+			ecode = TDB_ERR_IO;
 			goto fail;
 		}
 	}
 
 	/* now copy it out of this block */
 	memcpy(buf, tdb->transaction->blocks[blk] + (off % getpagesize()), len);
-	return 0;
+	return TDB_SUCCESS;
 
 fail:
-	tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
-		   "transaction_read: failed at off=%zu len=%zu",
-		   (size_t)off, (size_t)len);
 	tdb->transaction->transaction_error = 1;
-	return -1;
+	return tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
+			  "transaction_read: failed at off=%zu len=%zu",
+			  (size_t)off, (size_t)len);
 }
 
 
 /*
   write while in a transaction
 */
-static int transaction_write(struct tdb_context *tdb, tdb_off_t off,
-			     const void *buf, tdb_len_t len)
+static enum TDB_ERROR transaction_write(struct tdb_context *tdb, tdb_off_t off,
+					const void *buf, tdb_len_t len)
 {
 	size_t blk;
+	enum TDB_ERROR ecode;
 
 	/* Only a commit is allowed on a prepared transaction */
 	if (tdb->transaction->prepared) {
-		tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_ERROR,
-			 "transaction_write: transaction already prepared,"
-			 " write not allowed");
+		ecode = tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_ERROR,
+				   "transaction_write: transaction already"
+				   " prepared, write not allowed");
 		goto fail;
 	}
 
 	/* break it up into block sized chunks */
 	while (len + (off % getpagesize()) > getpagesize()) {
 		tdb_len_t len2 = getpagesize() - (off % getpagesize());
-		if (transaction_write(tdb, off, buf, len2) != 0) {
+		ecode = transaction_write(tdb, off, buf, len2);
+		if (ecode != TDB_SUCCESS) {
 			return -1;
 		}
 		len -= len2;
@@ -208,7 +212,7 @@ static int transaction_write(struct tdb_context *tdb, tdb_off_t off,
 	}
 
 	if (len == 0) {
-		return 0;
+		return TDB_SUCCESS;
 	}
 
 	blk = off / getpagesize();
@@ -226,8 +230,9 @@ static int transaction_write(struct tdb_context *tdb, tdb_off_t off,
 				(blk+1)*sizeof(uint8_t *));
 		}
 		if (new_blocks == NULL) {
-			tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
-				   "transaction_write: failed to allocate");
+			ecode = tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
+					   "transaction_write:"
+					   " failed to allocate");
 			goto fail;
 		}
 		memset(&new_blocks[tdb->transaction->num_blocks], 0,
@@ -241,8 +246,9 @@ static int transaction_write(struct tdb_context *tdb, tdb_off_t off,
 	if (tdb->transaction->blocks[blk] == NULL) {
 		tdb->transaction->blocks[blk] = (uint8_t *)calloc(getpagesize(), 1);
 		if (tdb->transaction->blocks[blk] == NULL) {
-			tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
-				   "transaction_write: failed to allocate");
+			ecode = tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
+					   "transaction_write:"
+					   " failed to allocate");
 			goto fail;
 		}
 		if (tdb->transaction->old_map_size > blk * getpagesize()) {
@@ -250,13 +256,17 @@ static int transaction_write(struct tdb_context *tdb, tdb_off_t off,
 			if (len2 + (blk * getpagesize()) > tdb->transaction->old_map_size) {
 				len2 = tdb->transaction->old_map_size - (blk * getpagesize());
 			}
-			if (tdb->transaction->io_methods->tread(tdb, blk * getpagesize(),
-								tdb->transaction->blocks[blk],
-								len2) != 0) {
-				tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
-					   "transaction_write: failed to"
-					   " read old block: %s",
-					   strerror(errno));
+			ecode = tdb->transaction->io_methods->tread(tdb,
+					blk * getpagesize(),
+					tdb->transaction->blocks[blk],
+					len2);
+			if (ecode != TDB_SUCCESS) {
+				ecode = tdb_logerr(tdb, ecode,
+						   TDB_LOG_ERROR,
+						   "transaction_write:"
+						   " failed to"
+						   " read old block: %s",
+						   strerror(errno));
 				SAFE_FREE(tdb->transaction->blocks[blk]);
 				goto fail;
 			}
@@ -278,11 +288,11 @@ static int transaction_write(struct tdb_context *tdb, tdb_off_t off,
 		}
 	}
 
-	return 0;
+	return TDB_SUCCESS;
 
 fail:
 	tdb->transaction->transaction_error = 1;
-	return -1;
+	return ecode;
 }
 
 
@@ -334,33 +344,38 @@ static void transaction_write_existing(struct tdb_context *tdb, tdb_off_t off,
 /*
   out of bounds check during a transaction
 */
-static int transaction_oob(struct tdb_context *tdb, tdb_off_t len, bool probe)
+static enum TDB_ERROR transaction_oob(struct tdb_context *tdb, tdb_off_t len,
+				      bool probe)
 {
 	if (len <= tdb->map_size) {
-		return 0;
+		return TDB_SUCCESS;
 	}
-	tdb->ecode = TDB_ERR_IO;
 	if (!probe) {
 		tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
 			   "tdb_oob len %lld beyond transaction size %lld",
 			   (long long)len,
 			   (long long)tdb->map_size);
 	}
-	return -1;
+	return TDB_ERR_IO;
 }
 
 /*
   transaction version of tdb_expand().
 */
-static int transaction_expand_file(struct tdb_context *tdb, tdb_off_t addition)
+static enum TDB_ERROR transaction_expand_file(struct tdb_context *tdb,
+					      tdb_off_t addition)
 {
+	enum TDB_ERROR ecode;
+
 	/* add a write to the transaction elements, so subsequent
 	   reads see the zero data */
-	if (transaction_write(tdb, tdb->map_size, NULL, addition) != 0) {
-		return -1;
+	ecode = transaction_write(tdb, tdb->map_size, NULL, addition);
+	if (ecode != TDB_SUCCESS) {
+		tdb->ecode = ecode;
+		return ecode;
 	}
 	tdb->map_size += addition;
-	return 0;
+	return ecode;
 }
 
 static void *transaction_direct(struct tdb_context *tdb, tdb_off_t off,
@@ -410,37 +425,37 @@ static const struct tdb_methods transaction_methods = {
 /*
   sync to disk
 */
-static int transaction_sync(struct tdb_context *tdb, tdb_off_t offset, tdb_len_t length)
+static enum TDB_ERROR transaction_sync(struct tdb_context *tdb,
+				       tdb_off_t offset, tdb_len_t length)
 {
 	if (tdb->flags & TDB_NOSYNC) {
-		return 0;
+		return TDB_SUCCESS;
 	}
 
 	if (fsync(tdb->fd) != 0) {
-		tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
-			   "tdb_transaction: fsync failed: %s",
-			   strerror(errno));
-		return -1;
+		return tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
+				  "tdb_transaction: fsync failed: %s",
+				  strerror(errno));
 	}
 #ifdef MS_SYNC
 	if (tdb->map_ptr) {
 		tdb_off_t moffset = offset & ~(getpagesize()-1);
 		if (msync(moffset + (char *)tdb->map_ptr,
 			  length + (offset - moffset), MS_SYNC) != 0) {
-			tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
-				   "tdb_transaction: msync failed: %s",
-				   strerror(errno));
-			return -1;
+			return tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
+					  "tdb_transaction: msync failed: %s",
+					  strerror(errno));
 		}
 	}
 #endif
-	return 0;
+	return TDB_SUCCESS;
 }
 
 
 static void _tdb_transaction_cancel(struct tdb_context *tdb)
 {
 	int i;
+	enum TDB_ERROR ecode;
 
 	if (tdb->transaction == NULL) {
 		tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
@@ -469,11 +484,14 @@ static void _tdb_transaction_cancel(struct tdb_context *tdb)
 		uint64_t invalid = TDB_RECOVERY_INVALID_MAGIC;
 
 		/* remove the recovery marker */
-		if (methods->twrite(tdb, tdb->transaction->magic_offset,
-				    &invalid, sizeof(invalid)) == -1 ||
-		    transaction_sync(tdb, tdb->transaction->magic_offset,
-				     sizeof(invalid)) == -1) {
-			tdb_logerr(tdb, tdb->ecode, TDB_LOG_ERROR,
+		ecode = methods->twrite(tdb, tdb->transaction->magic_offset,
+					&invalid, sizeof(invalid));
+		if (ecode == TDB_SUCCESS)
+			ecode = transaction_sync(tdb,
+						 tdb->transaction->magic_offset,
+						 sizeof(invalid));
+		if (ecode != TDB_SUCCESS) {
+			tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
 				   "tdb_transaction_cancel: failed to remove"
 				   " recovery magic");
 		}
@@ -621,6 +639,7 @@ static int tdb_recovery_allocate(struct tdb_context *tdb,
 	const struct tdb_methods *methods = tdb->transaction->io_methods;
 	tdb_off_t recovery_head;
 	size_t addition;
+	enum TDB_ERROR ecode;
 
 	recovery_head = tdb_read_off(tdb, offsetof(struct tdb_header,recovery));
 	if (recovery_head == TDB_OFF_ERR) {
@@ -631,8 +650,9 @@ static int tdb_recovery_allocate(struct tdb_context *tdb,
 	}
 
 	if (recovery_head != 0) {
-		if (methods->tread(tdb, recovery_head, &rec, sizeof(rec))) {
-			tdb_logerr(tdb, tdb->ecode, TDB_LOG_ERROR,
+		ecode = methods->tread(tdb, recovery_head, &rec, sizeof(rec));
+		if (ecode != TDB_SUCCESS) {
+			tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
 				 "tdb_recovery_allocate:"
 				 " failed to read recovery record");
 			return -1;
@@ -688,8 +708,9 @@ static int tdb_recovery_allocate(struct tdb_context *tdb,
 	addition = (tdb->map_size - tdb->transaction->old_map_size) +
 		sizeof(rec) + *recovery_max_size;
 	tdb->map_size = tdb->transaction->old_map_size;
-	if (methods->expand_file(tdb, addition) == -1) {
-		tdb_logerr(tdb, tdb->ecode, TDB_LOG_ERROR,
+	ecode = methods->expand_file(tdb, addition);
+	if (ecode != TDB_SUCCESS) {
+		tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
 			 "tdb_recovery_allocate:"
 			 " failed to create recovery area");
 		return -1;
@@ -703,9 +724,10 @@ static int tdb_recovery_allocate(struct tdb_context *tdb,
 	/* write the recovery header offset and sync - we can sync without a race here
 	   as the magic ptr in the recovery record has not been set */
 	tdb_convert(tdb, &recovery_head, sizeof(recovery_head));
-	if (methods->twrite(tdb, offsetof(struct tdb_header, recovery),
-			    &recovery_head, sizeof(tdb_off_t)) == -1) {
-		tdb_logerr(tdb, tdb->ecode, TDB_LOG_ERROR,
+	ecode = methods->twrite(tdb, offsetof(struct tdb_header, recovery),
+				&recovery_head, sizeof(tdb_off_t));
+	if (ecode != TDB_SUCCESS) {
+		tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
 			 "tdb_recovery_allocate:"
 			 " failed to write recovery head");
 		return -1;
@@ -742,6 +764,7 @@ static int transaction_setup_recovery(struct tdb_context *tdb,
 	tdb_off_t old_map_size = tdb->transaction->old_map_size;
 	uint64_t magic, tailer;
 	int i;
+	enum TDB_ERROR ecode;
 
 	/*
 	  check that the recovery area has enough space
@@ -797,9 +820,11 @@ static int transaction_setup_recovery(struct tdb_context *tdb,
 		/* the recovery area contains the old data, not the
 		   new data, so we have to call the original tdb_read
 		   method to get it */
-		if (methods->tread(tdb, offset,
-				   p + sizeof(offset) + sizeof(length),
-				   length) != 0) {
+		ecode = methods->tread(tdb, offset,
+				       p + sizeof(offset) + sizeof(length),
+				       length);
+		if (ecode != TDB_SUCCESS) {
+			tdb->ecode = ecode;
 			free(data);
 			return -1;
 		}
@@ -812,9 +837,10 @@ static int transaction_setup_recovery(struct tdb_context *tdb,
 	tdb_convert(tdb, p, sizeof(tailer));
 
 	/* write the recovery data to the recovery area */
-	if (methods->twrite(tdb, recovery_offset, data,
-			    sizeof(*rec) + recovery_size) == -1) {
-		tdb_logerr(tdb, tdb->ecode, TDB_LOG_ERROR,
+	ecode = methods->twrite(tdb, recovery_offset, data,
+				sizeof(*rec) + recovery_size);
+	if (ecode != TDB_SUCCESS) {
+		tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
 			 "tdb_transaction_setup_recovery:"
 			 " failed to write recovery data");
 		free(data);
@@ -826,9 +852,11 @@ static int transaction_setup_recovery(struct tdb_context *tdb,
 	/* as we don't have ordered writes, we have to sync the recovery
 	   data before we update the magic to indicate that the recovery
 	   data is present */
-	if (transaction_sync(tdb, recovery_offset,
-			     sizeof(*rec) + recovery_size) == -1) {
+	ecode = transaction_sync(tdb, recovery_offset,
+				 sizeof(*rec) + recovery_size);
+	if (ecode != TDB_SUCCESS) {
 		free(data);
+		tdb->ecode = ecode;
 		return -1;
 	}
 
@@ -840,8 +868,9 @@ static int transaction_setup_recovery(struct tdb_context *tdb,
 	*magic_offset = recovery_offset + offsetof(struct tdb_recovery_record,
 						   magic);
 
-	if (methods->twrite(tdb, *magic_offset, &magic, sizeof(magic)) == -1) {
-		tdb_logerr(tdb, tdb->ecode, TDB_LOG_ERROR,
+	ecode = methods->twrite(tdb, *magic_offset, &magic, sizeof(magic));
+	if (ecode != TDB_SUCCESS) {
+		tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
 			 "tdb_transaction_setup_recovery:"
 			 " failed to write recovery magic");
 		return -1;
@@ -849,7 +878,9 @@ static int transaction_setup_recovery(struct tdb_context *tdb,
 	transaction_write_existing(tdb, *magic_offset, &magic, sizeof(magic));
 
 	/* ensure the recovery magic marker is on disk */
-	if (transaction_sync(tdb, *magic_offset, sizeof(magic)) == -1) {
+	ecode = transaction_sync(tdb, *magic_offset, sizeof(magic));
+	if (ecode != TDB_SUCCESS) {
+		tdb->ecode = ecode;
 		return -1;
 	}
 
@@ -936,8 +967,9 @@ static int _tdb_transaction_prepare_commit(struct tdb_context *tdb)
 		tdb_len_t add = tdb->map_size - tdb->transaction->old_map_size;
 		/* Restore original map size for tdb_expand_file */
 		tdb->map_size = tdb->transaction->old_map_size;
-		if (methods->expand_file(tdb, add) == -1) {
-			tdb_logerr(tdb, tdb->ecode, TDB_LOG_ERROR,
+		ecode = methods->expand_file(tdb, add);
+		if (ecode != TDB_SUCCESS) {
+			tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
 				 "tdb_transaction_prepare_commit:"
 				 " expansion failed");
 			_tdb_transaction_cancel(tdb);
@@ -965,6 +997,7 @@ int tdb_transaction_commit(struct tdb_context *tdb)
 {
 	const struct tdb_methods *methods;
 	int i;
+	enum TDB_ERROR ecode;
 
 	if (tdb->transaction == NULL) {
 		tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
@@ -1008,9 +1041,10 @@ int tdb_transaction_commit(struct tdb_context *tdb)
 			length = tdb->transaction->last_block_size;
 		}
 
-		if (methods->twrite(tdb, offset, tdb->transaction->blocks[i],
-				    length) == -1) {
-			tdb_logerr(tdb, tdb->ecode, TDB_LOG_ERROR,
+		ecode = methods->twrite(tdb, offset,
+					tdb->transaction->blocks[i], length);
+		if (ecode != TDB_SUCCESS) {
+			tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
 				   "tdb_transaction_commit:"
 				   " write failed during commit");
 
@@ -1031,7 +1065,9 @@ int tdb_transaction_commit(struct tdb_context *tdb)
 	tdb->transaction->num_blocks = 0;
 
 	/* ensure the new data is on disk */
-	if (transaction_sync(tdb, 0, tdb->map_size) == -1) {
+	ecode = transaction_sync(tdb, 0, tdb->map_size);
+	if (ecode != TDB_SUCCESS) {
+		tdb->ecode = ecode;
 		return -1;
 	}
 
@@ -1068,6 +1104,7 @@ int tdb_transaction_recover(struct tdb_context *tdb)
 	tdb_off_t recovery_head, recovery_eof;
 	unsigned char *data, *p;
 	struct tdb_recovery_record rec;
+	enum TDB_ERROR ecode;
 
 	/* find the recovery area */
 	recovery_head = tdb_read_off(tdb, offsetof(struct tdb_header,recovery));
@@ -1114,9 +1151,10 @@ int tdb_transaction_recover(struct tdb_context *tdb)
 	}
 
 	/* read the full recovery data */
-	if (tdb->methods->tread(tdb, recovery_head + sizeof(rec), data,
-				rec.len) == -1) {
-		tdb_logerr(tdb, tdb->ecode, TDB_LOG_ERROR,
+	ecode = tdb->methods->tread(tdb, recovery_head + sizeof(rec), data,
+				    rec.len);
+	if (ecode != TDB_SUCCESS) {
+		tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
 			   "tdb_transaction_recover:"
 			   " failed to read recovery data");
 		return -1;
@@ -1132,9 +1170,10 @@ int tdb_transaction_recover(struct tdb_context *tdb)
 		memcpy(&len, p + sizeof(ofs), sizeof(len));
 		p += sizeof(ofs) + sizeof(len);
 
-		if (tdb->methods->twrite(tdb, ofs, p, len) == -1) {
+		ecode = tdb->methods->twrite(tdb, ofs, p, len);
+		if (ecode != TDB_SUCCESS) {
 			free(data);
-			tdb_logerr(tdb, tdb->ecode, TDB_LOG_ERROR,
+			tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
 				 "tdb_transaction_recover:"
 				 " failed to recover %zu bytes at offset %zu",
 				 (size_t)len, (size_t)ofs);
@@ -1145,8 +1184,9 @@ int tdb_transaction_recover(struct tdb_context *tdb)
 
 	free(data);
 
-	if (transaction_sync(tdb, 0, tdb->map_size) == -1) {
-		tdb_logerr(tdb, tdb->ecode, TDB_LOG_ERROR,
+	ecode = transaction_sync(tdb, 0, tdb->map_size);
+	if (ecode != TDB_SUCCESS) {
+		tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
 			   "tdb_transaction_recover: failed to sync recovery");
 		return -1;
 	}
@@ -1173,8 +1213,9 @@ int tdb_transaction_recover(struct tdb_context *tdb)
 		return -1;
 	}
 
-	if (transaction_sync(tdb, 0, recovery_eof) == -1) {
-		tdb_logerr(tdb, tdb->ecode, TDB_LOG_ERROR,
+	ecode = transaction_sync(tdb, 0, recovery_eof);
+	if (ecode != TDB_SUCCESS) {
+		tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
 			 "tdb_transaction_recover: failed to sync2 recovery");
 		return -1;
 	}