@@ -1081,6 +1081,38 @@ static errcode_t unix_set_option(io_channel channel, const char *option,
#define BLKDISCARD _IO(0x12,119)
#endif
+/*
+ * Try a PUNCH_HOLE to unmap blocks, then BLKDISCARD if that doesn't work.
+ * We prefer PUNCH_HOLE because it invalidates the page cache, even on block
+ * devices.
+ */
+static int __unix_discard(int fd, int is_bdev, off_t offset, off_t len)
+{
+#ifdef BLKDISCARD
+ __u64 range[2];
+#endif
+ int ret = -1;
+
+#if defined(HAVE_FALLOCATE) && defined(FALLOC_FL_PUNCH_HOLE) && defined(FALLOC_FL_KEEP_SIZE)
+ ret = fallocate(fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
+ offset, len);
+ if (ret == 0)
+ return 0;
+#endif
+#ifdef BLKDISCARD
+ if (is_bdev) {
+ range[0] = (__u64)offset;
+ range[1] = (__u64)len;
+
+ ret = ioctl(fd, BLKDISCARD, &range);
+ if (ret == 0)
+ return 0;
+ }
+#endif
+ errno = EOPNOTSUPP;
+ return ret;
+}
+
static errcode_t unix_discard(io_channel channel, unsigned long long block,
unsigned long long count)
{
@@ -1091,31 +1123,10 @@ static errcode_t unix_discard(io_channel channel, unsigned long long block,
data = (struct unix_private_data *) channel->private_data;
EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
- if (channel->flags & CHANNEL_FLAGS_BLOCK_DEVICE) {
-#ifdef BLKDISCARD
- __u64 range[2];
-
- range[0] = (__u64)(block) * channel->block_size + data->offset;
- range[1] = (__u64)(count) * channel->block_size;
-
- ret = ioctl(data->dev, BLKDISCARD, &range);
-#else
- goto unimplemented;
-#endif
- } else {
-#if defined(HAVE_FALLOCATE) && defined(FALLOC_FL_PUNCH_HOLE)
- /*
- * If we are not on block device, try to use punch hole
- * to reclaim free space.
- */
- ret = fallocate(data->dev,
- FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
- (off_t)(block) * channel->block_size + data->offset,
- (off_t)(count) * channel->block_size);
-#else
- goto unimplemented;
-#endif
- }
+ ret = __unix_discard(data->dev,
+ (channel->flags & CHANNEL_FLAGS_BLOCK_DEVICE),
+ (off_t)(block) * channel->block_size + data->offset,
+ (off_t)(count) * channel->block_size);
if (ret < 0) {
if (errno == EOPNOTSUPP)
goto unimplemented;