@@ -1581,7 +1581,7 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length,
struct bio *bio;
bool need_zeroout = false;
bool use_fua = false;
- int nr_pages, ret;
+ int nr_pages, ret = 0;
size_t copied = 0;
if ((pos | length | align) & ((1 << blkbits) - 1))
@@ -1646,8 +1646,14 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length,
ret = bio_iov_iter_get_pages(bio, &iter);
if (unlikely(ret)) {
+ /*
+ * We have to stop part way through an IO. We must fall
+ * through to the sub-block tail zeroing here, otherwise
+ * this short IO may expose stale data in the tail of
+ * the block we haven't written data to.
+ */
bio_put(bio);
- return copied ? copied : ret;
+ goto zero_tail;
}
n = bio->bi_iter.bi_size;
@@ -1684,6 +1690,7 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length,
* the block tail in the latter case, we can expose stale data via mmap
* reads of the EOF block.
*/
+zero_tail:
if (need_zeroout ||
((dio->flags & IOMAP_DIO_WRITE) && pos >= i_size_read(inode))) {
/* zero out from the end of the write to the end of the block */
@@ -1691,7 +1698,7 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length,
if (pad)
iomap_dio_zero(dio, iomap, pos, fs_block_size - pad);
}
- return copied;
+ return copied ? copied : ret;
}
static loff_t
@@ -1866,6 +1873,15 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
dio->wait_for_completion = true;
ret = 0;
}
+
+ /*
+ * Splicing to pipes can fail on a full pipe. We have to
+ * swallow this to make it look like a short IO
+ * otherwise the higher splice layers will completely
+ * mishandle the error and stop moving data.
+ */
+ if (ret == -EFAULT)
+ ret = 0;
break;
}
pos += ret;