X-Git-Url: https://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Ftdb2%2Ftdb.c;h=03d51c2192313a7ce6f9c6e270b92405619fed3c;hp=dfa68451e51a878d4be75f5431121ff1f012b9d4;hb=04cf551d15ee93716aa0462adadc0a3891480813;hpb=51a56b52627e635566253a3fae081c3f466b6bb6

diff --git a/ccan/tdb2/tdb.c b/ccan/tdb2/tdb.c
index dfa68451..03d51c21 100644
--- a/ccan/tdb2/tdb.c
+++ b/ccan/tdb2/tdb.c
@@ -22,6 +22,24 @@ static bool tdb_already_open(dev_t device, ino_t ino)
 	return false;
 }
 
+static bool read_all(int fd, void *buf, size_t len)
+{
+	while (len) {
+		ssize_t ret;
+		ret = read(fd, buf, len);
+		if (ret < 0)
+			return false;
+		if (ret == 0) {
+			/* ETOOSHORT? */
+			errno = EWOULDBLOCK;
+			return false;
+		}
+		buf = (char *)buf + ret;
+		len -= ret;
+	}
+	return true;
+}
+
 static uint64_t random_number(struct tdb_context *tdb)
 {
 	int fd;
@@ -30,7 +48,7 @@ static uint64_t random_number(struct tdb_context *tdb)
 
 	fd = open("/dev/urandom", O_RDONLY);
 	if (fd >= 0) {
-		if (tdb_read_all(fd, &ret, sizeof(ret))) {
+		if (read_all(fd, &ret, sizeof(ret))) {
 			tdb_logerr(tdb, TDB_SUCCESS, TDB_DEBUG_TRACE,
 				 "tdb_open: random from /dev/urandom");
 			close(fd);
@@ -83,6 +101,7 @@ static int tdb_new_database(struct tdb_context *tdb,
 	/* We make it up in memory, then write it out if not internal */
 	struct new_database newdb;
 	unsigned int magic_len;
+	ssize_t rlen;
 
 	/* Fill in the header */
 	newdb.hdr.version = TDB_VERSION;
@@ -135,10 +154,13 @@ static int tdb_new_database(struct tdb_context *tdb,
 	if (ftruncate(tdb->fd, 0) == -1)
 		return -1;
 
-	if (!tdb_pwrite_all(tdb->fd, &newdb, sizeof(newdb), 0)) {
+	rlen = write(tdb->fd, &newdb, sizeof(newdb));
+	if (rlen != sizeof(newdb)) {
+		if (rlen >= 0)
+			errno = ENOSPC;
 		tdb_logerr(tdb, TDB_ERR_IO, TDB_DEBUG_FATAL,
-			   "tdb_new_database: failed to write: %s",
-			   strerror(errno));
+			   "tdb_new_database: %zi writing header: %s",
+			   rlen, strerror(errno));
 		return -1;
 	}
 	return 0;
@@ -153,6 +175,7 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
 	int saved_errno = 0;
 	uint64_t hash_test;
 	unsigned v;
+	ssize_t rlen;
 	struct tdb_header hdr;
 	struct tdb_attribute_seed *seed = NULL;
 
@@ -253,17 +276,25 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
 		goto fail;
 	}
 
-	if (!tdb_pread_all(tdb->fd, &hdr, sizeof(hdr), 0)
-	    || strcmp(hdr.magic_food, TDB_MAGIC_FOOD) != 0) {
-		if (!(open_flags & O_CREAT)) {
-			tdb_logerr(tdb, TDB_ERR_IO, TDB_DEBUG_ERROR,
-				   "tdb_open: %s is not a tdb file", name);
-			goto fail;
-		}
+	/* If they used O_TRUNC, read will return 0. */
+	rlen = read(tdb->fd, &hdr, sizeof(hdr));
+	if (rlen == 0 && (open_flags & O_CREAT)) {
 		if (tdb_new_database(tdb, seed, &hdr) == -1) {
 			goto fail;
 		}
-	} else if (hdr.version != TDB_VERSION) {
+	} else if (rlen < 0) {
+		tdb_logerr(tdb, TDB_ERR_IO, TDB_DEBUG_ERROR,
+			   "tdb_open: error %s reading %s",
+			   strerror(errno), name);
+		goto fail;
+	} else if (rlen < sizeof(hdr)
+		   || strcmp(hdr.magic_food, TDB_MAGIC_FOOD) != 0) {
+		tdb_logerr(tdb, TDB_ERR_IO, TDB_DEBUG_ERROR,
+			   "tdb_open: %s is not a tdb file", name);
+		goto fail;
+	}
+
+	if (hdr.version != TDB_VERSION) {
 		if (hdr.version == bswap_64(TDB_VERSION))
 			tdb->flags |= TDB_CONVERT;
 		else {
@@ -422,11 +453,11 @@ static int replace_data(struct tdb_context *tdb,
 	}
 
 	new_off += sizeof(struct tdb_used_record);
-	if (tdb->methods->write(tdb, new_off, key.dptr, key.dsize) == -1)
+	if (tdb->methods->twrite(tdb, new_off, key.dptr, key.dsize) == -1)
 		return -1;
 
 	new_off += key.dsize;
-	if (tdb->methods->write(tdb, new_off, dbuf.dptr, dbuf.dsize) == -1)
+	if (tdb->methods->twrite(tdb, new_off, dbuf.dptr, dbuf.dsize) == -1)
 		return -1;
 
 	/* FIXME: tdb_increment_seqnum(tdb); */
@@ -462,9 +493,9 @@ int tdb_store(struct tdb_context *tdb,
 						   key.dsize, dbuf.dsize,
 						   &rec, h.h))
 					goto fail;
-				if (tdb->methods->write(tdb, off + sizeof(rec)
-							+ key.dsize,
-							dbuf.dptr, dbuf.dsize))
+				if (tdb->methods->twrite(tdb, off + sizeof(rec)
+							 + key.dsize,
+							 dbuf.dptr, dbuf.dsize))
 					goto fail;
 				tdb_unlock_hashes(tdb, h.hlock_start,
 						  h.hlock_range, F_WRLCK);
@@ -517,8 +548,8 @@ int tdb_append(struct tdb_context *tdb,
 				goto fail;
 
 			off += sizeof(rec) + key.dsize + old_dlen;
-			if (tdb->methods->write(tdb, off, dbuf.dptr,
-						dbuf.dsize) == -1)
+			if (tdb->methods->twrite(tdb, off, dbuf.dptr,
+						 dbuf.dsize) == -1)
 				goto fail;
 
 			/* FIXME: tdb_increment_seqnum(tdb); */
@@ -535,8 +566,8 @@ int tdb_append(struct tdb_context *tdb,
 				   (size_t)(key.dsize+old_dlen+dbuf.dsize));
 			goto fail;
 		}
-		if (tdb->methods->read(tdb, off + sizeof(rec) + key.dsize,
-				       newdata, old_dlen) != 0) {
+		if (tdb->methods->tread(tdb, off + sizeof(rec) + key.dsize,
+					newdata, old_dlen) != 0) {
 			free(newdata);
 			goto fail;
 		}