Read and write slot keys and pages in full

xread and xwrite may move fewer bytes than asked. A short write of the
key left a slot that could never match, a short read of it reported a
collision, and a page write that moved nothing looped for ever.

2 files changed, 7 insertions, 3 deletions

diff --git a/source/cache.c b/source/cache.cindex 60e071b..af391db 100644--- a/source/cache.c+++ b/source/cache.c@@ -85,7 +85,7 @@ static int open_slot(struct cache_slot *slot) 	if (fstat(slot->cache_fd, &slot->st)) 		return errno; -	slot->buflen = xread(slot->cache_fd, slot->buf, sizeof(slot->buf));+	slot->buflen = read_in_full(slot->cache_fd, slot->buf, sizeof(slot->buf)); 	if (slot->buflen < 0) 		return errno; @@ -265,7 +265,7 @@ static int lock_slot(struct cache_slot *slot) 	// start from empty now that nobody else can be writing it. 	if (ftruncate(slot->lock_fd, 0) < 0) 		return errno;-	if (xwrite(slot->lock_fd, slot->key, slot->keylen + 1) < 0)+	if (write_in_full(slot->lock_fd, slot->key, slot->keylen + 1) < 0) 		return errno; 	return 0; }
diff --git a/source/cache.c b/source/cache.c
index 60e071b..af391db 100644
--- a/source/cache.c
+++ b/source/cache.c
@@ -85,7 +85,7 @@ static int open_slot(struct cache_slot *slot)
 	if (fstat(slot->cache_fd, &slot->st))
 		return errno;
 
-	slot->buflen = xread(slot->cache_fd, slot->buf, sizeof(slot->buf));
+	slot->buflen = read_in_full(slot->cache_fd, slot->buf, sizeof(slot->buf));
 	if (slot->buflen < 0)
 		return errno;
 
@@ -265,7 +265,7 @@ static int lock_slot(struct cache_slot *slot)
 	// start from empty now that nobody else can be writing it.
 	if (ftruncate(slot->lock_fd, 0) < 0)
 		return errno;
-	if (xwrite(slot->lock_fd, slot->key, slot->keylen + 1) < 0)
+	if (write_in_full(slot->lock_fd, slot->key, slot->keylen + 1) < 0)
 		return errno;
 	return 0;
 }
diff --git a/source/html.c b/source/html.cindex ef74bb3..367cea7 100644--- a/source/html.c+++ b/source/html.c@@ -65,7 +65,11 @@ static void write_out(const char *data, size_t size) 	while (size) { 		ssize_t written = xwrite(STDOUT_FILENO, data, size); -		if (written < 0)+		// A write that moves nothing would repeat for ever, so it+		// counts as a full device, the way write_in_full treats it.+		if (!written)+			errno = ENOSPC;+		if (written <= 0) 			break; 		data += written; 		size -= written;
diff --git a/source/html.c b/source/html.c
index ef74bb3..367cea7 100644
--- a/source/html.c
+++ b/source/html.c
@@ -65,7 +65,11 @@ static void write_out(const char *data, size_t size)
 	while (size) {
 		ssize_t written = xwrite(STDOUT_FILENO, data, size);
 
-		if (written < 0)
+		// A write that moves nothing would repeat for ever, so it
+		// counts as a full device, the way write_in_full treats it.
+		if (!written)
+			errno = ENOSPC;
+		if (written <= 0)
 			break;
 		data += written;
 		size -= written;