From: Jens Axboe <axboe@suse.de>
Date: Wed, 3 May 2006 08:58:22 +0000 (+0200)
Subject: [PATCH] splice: redo page lookup if add_to_page_cache() returns -EEXIST
X-Git-Tag: v2.6.17-rc4~44^2~1
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a0548871ed267ae12eb1c860c5aaebd9e466b34e;p=linux-2.6

[PATCH] splice: redo page lookup if add_to_page_cache() returns -EEXIST

This can happen quite easily, if several processes are trying to splice
the same file at the same time. It's not a failure, it just means someone
raced with us in allocating this file page. So just dump the allocated
page and relookup the original.

Signed-off-by: Jens Axboe <axboe@suse.de>
---

diff --git a/fs/splice.c b/fs/splice.c
index 8fa9217ed5..a285fd746d 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -324,6 +324,8 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
 					      mapping_gfp_mask(mapping));
 			if (unlikely(error)) {
 				page_cache_release(page);
+				if (error == -EEXIST)
+					continue;
 				break;
 			}
 			/*