[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>

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/splice.c b/fs/splice.c
index 8fa9217ed58..a285fd746dc 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;
                         }
                         /*