From 8191ecd1d14c6914c660dfa007154860a7908857 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 10 Apr 2008 08:24:25 +0200 Subject: [PATCH] splice: fix infinite loop in generic_file_splice_read() There's a quirky loop in generic_file_splice_read() that could go on indefinitely, if the file splice returns 0 permanently (and not just as a temporary condition). Get rid of the loop and pass back -EAGAIN correctly from __generic_file_splice_read(), so we handle that condition properly as well. Signed-off-by: Jens Axboe --- fs/splice.c | 31 ++++++------------------------- 1 file changed, 6 insertions(+), 25 deletions(-) diff --git a/fs/splice.c b/fs/splice.c index a861bb318ac8..eeb1a86a7014 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -370,8 +370,10 @@ __generic_file_splice_read(struct file *in, loff_t *ppos, * for an in-flight io page */ if (flags & SPLICE_F_NONBLOCK) { - if (TestSetPageLocked(page)) + if (TestSetPageLocked(page)) { + error = -EAGAIN; break; + } } else lock_page(page); @@ -479,9 +481,8 @@ ssize_t generic_file_splice_read(struct file *in, loff_t *ppos, struct pipe_inode_info *pipe, size_t len, unsigned int flags) { - ssize_t spliced; - int ret; loff_t isize, left; + int ret; isize = i_size_read(in->f_mapping->host); if (unlikely(*ppos >= isize)) @@ -491,29 +492,9 @@ ssize_t generic_file_splice_read(struct file *in, loff_t *ppos, if (unlikely(left < len)) len = left; - ret = 0; - spliced = 0; - while (len && !spliced) { - ret = __generic_file_splice_read(in, ppos, pipe, len, flags); - - if (ret < 0) - break; - else if (!ret) { - if (spliced) - break; - if (flags & SPLICE_F_NONBLOCK) { - ret = -EAGAIN; - break; - } - } - + ret = __generic_file_splice_read(in, ppos, pipe, len, flags); + if (ret > 0) *ppos += ret; - len -= ret; - spliced += ret; - } - - if (spliced) - return spliced; return ret; }