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Use the newly introduced "pipe->head_tail" member to read the head and the tail atomically and not miss any updates between the reads. Signed-off-by: K Prateek Nayak --- fs/splice.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/splice.c b/fs/splice.c index 28cfa63aa236..e51f33aca032 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -1682,13 +1682,14 @@ static int ipipe_prep(struct pipe_inode_info *pipe, unsigned int flags) */ static int opipe_prep(struct pipe_inode_info *pipe, unsigned int flags) { + union pipe_index idx = { .head_tail = READ_ONCE(pipe->head_tail) }; int ret; /* * Check pipe occupancy without the inode lock first. This function * is speculative anyways, so missing one is ok. */ - if (!pipe_full(pipe->head, pipe->tail, pipe->max_usage)) + if (!pipe_full(idx.head, idx.tail, READ_ONCE(pipe->max_usage))) return 0; ret = 0;