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| author | Pavel Begunkov <asml.silence@gmail.com> | 2021-01-09 16:02:57 +0000 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-01-25 08:58:24 -0700 |
| commit | 0f1d344feb534555a0dcd0beafb7211a37c5355e (patch) | |
| tree | 762d8e337b77776ae4f473d788de25f2709594a9 | |
| parent | 684da7628d93bbdcfba9081b917d99f29ad04c23 (diff) | |
| download | linux-0f1d344feb534555a0dcd0beafb7211a37c5355e.tar.gz | |
splice: don't generate zero-len segement bvecs
iter_file_splice_write() may spawn bvec segments with zero-length. In preparation for prohibiting them, filter out by hand at splice level. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | fs/splice.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/fs/splice.c b/fs/splice.c index 866d5c2367b2..474fb8b5562a 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -662,12 +662,14 @@ iter_file_splice_write(struct pipe_inode_info *pipe, struct file *out, /* build the vector */ left = sd.total_len; - for (n = 0; !pipe_empty(head, tail) && left && n < nbufs; tail++, n++) { + for (n = 0; !pipe_empty(head, tail) && left && n < nbufs; tail++) { struct pipe_buffer *buf = &pipe->bufs[tail & mask]; size_t this_len = buf->len; - if (this_len > left) - this_len = left; + /* zero-length bvecs are not supported, skip them */ + if (!this_len) + continue; + this_len = min(this_len, left); ret = pipe_buf_confirm(pipe, buf); if (unlikely(ret)) { @@ -680,6 +682,7 @@ iter_file_splice_write(struct pipe_inode_info *pipe, struct file *out, array[n].bv_len = this_len; array[n].bv_offset = buf->offset; left -= this_len; + n++; } iov_iter_bvec(&from, WRITE, array, n, sd.total_len - left); |