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| author | David Howells <dhowells@redhat.com> | 2023-05-22 15:49:51 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2023-05-24 16:42:15 +0200 |
| commit | e69f37bce1b412161e11715adde30dadba0268a2 (patch) | |
| tree | 6266fb21a03f030a7cef26fe5da9d84c0f6c0e11 /fs/splice.c | |
| parent | splice: Rename direct_splice_read() to copy_splice_read() (diff) | |
| download | linux-e69f37bce1b412161e11715adde30dadba0268a2.tar.xz linux-e69f37bce1b412161e11715adde30dadba0268a2.zip | |
splice: Clean up copy_splice_read() a bit
Do a couple of cleanups to copy_splice_read():
(1) Cast to struct page **, not void *.
(2) Simplify the calculation of the number of pages to keep/reclaim in
copy_splice_read().
Suggested-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christian Brauner <brauner@kernel.org>
cc: Jens Axboe <axboe@kernel.dk>
cc: Al Viro <viro@zeniv.linux.org.uk>
cc: David Hildenbrand <david@redhat.com>
cc: John Hubbard <jhubbard@nvidia.com>
cc: linux-mm@kvack.org
cc: linux-block@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/20230522135018.2742245-5-dhowells@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'fs/splice.c')
| -rw-r--r-- | fs/splice.c | 19 |
1 files changed, 7 insertions, 12 deletions
diff --git a/fs/splice.c b/fs/splice.c index 2478e065bc53..f9a9be797b0c 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -311,7 +311,7 @@ ssize_t copy_splice_read(struct file *in, loff_t *ppos, struct kiocb kiocb; struct page **pages; ssize_t ret; - size_t used, npages, chunk, remain, reclaim; + size_t used, npages, chunk, remain, keep = 0; int i; /* Work out how much data we can actually add into the pipe */ @@ -325,7 +325,7 @@ ssize_t copy_splice_read(struct file *in, loff_t *ppos, if (!bv) return -ENOMEM; - pages = (void *)(bv + npages); + pages = (struct page **)(bv + npages); npages = alloc_pages_bulk_array(GFP_USER, npages, pages); if (!npages) { kfree(bv); @@ -348,11 +348,8 @@ ssize_t copy_splice_read(struct file *in, loff_t *ppos, kiocb.ki_pos = *ppos; ret = call_read_iter(in, &kiocb, &to); - reclaim = npages * PAGE_SIZE; - remain = 0; if (ret > 0) { - reclaim -= ret; - remain = ret; + keep = DIV_ROUND_UP(ret, PAGE_SIZE); *ppos = kiocb.ki_pos; file_accessed(in); } else if (ret < 0) { @@ -365,14 +362,12 @@ ssize_t copy_splice_read(struct file *in, loff_t *ppos, } /* Free any pages that didn't get touched at all. */ - reclaim /= PAGE_SIZE; - if (reclaim) { - npages -= reclaim; - release_pages(pages + npages, reclaim); - } + if (keep < npages) + release_pages(pages + keep, npages - keep); /* Push the remaining pages into the pipe. */ - for (i = 0; i < npages; i++) { + remain = ret; + for (i = 0; i < keep; i++) { struct pipe_buffer *buf = pipe_head_buf(pipe); chunk = min_t(size_t, remain, PAGE_SIZE); |