From c4f895cbe1e95aab633207fb19c650b7c984c01a Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Wed, 19 Apr 2006 15:56:12 +0200 Subject: [PATCH] [PATCH] splice: cleanup the SPLICE_F_NONBLOCK handling - generic_file_splice_read() more readable and correct - Don't bail on page allocation with NONBLOCK set, just don't allow direct blocking on IO (eg lock_page). Signed-off-by: Jens Axboe --- fs/splice.c | 30 ++++++++++++++++-------------- 1 file changed, 16 insertions(+), 14 deletions(-) diff --git a/fs/splice.c b/fs/splice.c index 7e8585574726..78cd264340f2 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -278,14 +278,6 @@ find_page: */ page = find_get_page(mapping, index); if (!page) { - /* - * If in nonblock mode then dont block on - * readpage (we've kicked readahead so there - * will be asynchronous progress): - */ - if (flags & SPLICE_F_NONBLOCK) - break; - /* * page didn't exist, allocate one */ @@ -307,6 +299,13 @@ find_page: * If the page isn't uptodate, we may need to start io on it */ if (!PageUptodate(page)) { + /* + * If in nonblock mode then dont block on waiting + * for an in-flight io page + */ + if (flags & SPLICE_F_NONBLOCK) + break; + lock_page(page); /* @@ -400,17 +399,20 @@ ssize_t generic_file_splice_read(struct file *in, loff_t *ppos, while (len) { ret = __generic_file_splice_read(in, ppos, pipe, len, flags); - if (ret <= 0) + if (ret < 0) break; + else if (!ret) { + if (spliced) + break; + if (flags & SPLICE_F_NONBLOCK) { + ret = -EAGAIN; + break; + } + } *ppos += ret; len -= ret; spliced += ret; - - if (!(flags & SPLICE_F_NONBLOCK)) - continue; - ret = -EAGAIN; - break; } if (spliced) -- 2.20.1