Messages in this thread Patch in this message | | | From | David Howells <> | Subject | [PATCH v19 07/15] splice: Do splice read from a file without using ITER_PIPE | Date | Wed, 15 Mar 2023 16:35:41 +0000 |
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Make generic_file_splice_read() use filemap_splice_read() and direct_splice_read() rather than using an ITER_PIPE and call_read_iter().
With this, ITER_PIPE is no longer used.
Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> cc: Jens Axboe <axboe@kernel.dk> cc: Steve French <smfrench@gmail.com> 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-cifs@vger.kernel.org cc: linux-fsdevel@vger.kernel.org ---
Notes: ver #18) - Split out the change to cifs to make it use generic_file_splice_read(). - Split out the unexport of filemap_splice_read() (still needed by cifs).
fs/splice.c | 30 +++++++----------------------- 1 file changed, 7 insertions(+), 23 deletions(-)
diff --git a/fs/splice.c b/fs/splice.c index 90ccd3666dca..f46dd1fb367b 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -387,29 +387,13 @@ ssize_t generic_file_splice_read(struct file *in, loff_t *ppos, struct pipe_inode_info *pipe, size_t len, unsigned int flags) { - struct iov_iter to; - struct kiocb kiocb; - int ret; - - iov_iter_pipe(&to, ITER_DEST, pipe, len); - init_sync_kiocb(&kiocb, in); - kiocb.ki_pos = *ppos; - ret = call_read_iter(in, &kiocb, &to); - if (ret > 0) { - *ppos = kiocb.ki_pos; - file_accessed(in); - } else if (ret < 0) { - /* free what was emitted */ - pipe_discard_from(pipe, to.start_head); - /* - * callers of ->splice_read() expect -EAGAIN on - * "can't put anything in there", rather than -EFAULT. - */ - if (ret == -EFAULT) - ret = -EAGAIN; - } - - return ret; + if (unlikely(*ppos >= file_inode(in)->i_sb->s_maxbytes)) + return 0; + if (unlikely(!len)) + return 0; + if (in->f_flags & O_DIRECT) + return direct_splice_read(in, ppos, pipe, len, flags); + return filemap_splice_read(in, ppos, pipe, len, flags); } EXPORT_SYMBOL(generic_file_splice_read);
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