diff options
| -rw-r--r-- | fs/pipe.c | 45 | ||||
| -rw-r--r-- | fs/splice.c | 12 | ||||
| -rw-r--r-- | include/linux/pipe_fs_i.h | 2 |
3 files changed, 11 insertions, 48 deletions
diff --git a/fs/pipe.c b/fs/pipe.c index 16fb72e9abf7..8e52b78b4042 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -231,7 +231,6 @@ void generic_pipe_buf_release(struct pipe_inode_info *pipe, } EXPORT_SYMBOL(generic_pipe_buf_release); -/* New data written to a pipe may be appended to a buffer with this type. */ static const struct pipe_buf_operations anon_pipe_buf_ops = { .confirm = generic_pipe_buf_confirm, .release = anon_pipe_buf_release, @@ -239,40 +238,6 @@ static const struct pipe_buf_operations anon_pipe_buf_ops = { .get = generic_pipe_buf_get, }; -static const struct pipe_buf_operations anon_pipe_buf_nomerge_ops = { - .confirm = generic_pipe_buf_confirm, - .release = anon_pipe_buf_release, - .steal = anon_pipe_buf_steal, - .get = generic_pipe_buf_get, -}; - -static const struct pipe_buf_operations packet_pipe_buf_ops = { - .confirm = generic_pipe_buf_confirm, - .release = anon_pipe_buf_release, - .steal = anon_pipe_buf_steal, - .get = generic_pipe_buf_get, -}; - -/** - * pipe_buf_mark_unmergeable - mark a &struct pipe_buffer as unmergeable - * @buf: the buffer to mark - * - * Description: - * This function ensures that no future writes will be merged into the - * given &struct pipe_buffer. This is necessary when multiple pipe buffers - * share the same backing page. - */ -void pipe_buf_mark_unmergeable(struct pipe_buffer *buf) -{ - if (buf->ops == &anon_pipe_buf_ops) - buf->ops = &anon_pipe_buf_nomerge_ops; -} - -static bool pipe_buf_can_merge(struct pipe_buffer *buf) -{ - return buf->ops == &anon_pipe_buf_ops; -} - /* Done while waiting without holding the pipe lock - thus the READ_ONCE() */ static inline bool pipe_readable(const struct pipe_inode_info *pipe) { @@ -478,7 +443,8 @@ pipe_write(struct kiocb *iocb, struct iov_iter *from) struct pipe_buffer *buf = &pipe->bufs[(head - 1) & mask]; int offset = buf->offset + buf->len; - if (pipe_buf_can_merge(buf) && offset + chars <= PAGE_SIZE) { + if ((buf->flags & PIPE_BUF_FLAG_CAN_MERGE) && + offset + chars <= PAGE_SIZE) { ret = pipe_buf_confirm(pipe, buf); if (ret) goto out; @@ -541,11 +507,10 @@ pipe_write(struct kiocb *iocb, struct iov_iter *from) buf->ops = &anon_pipe_buf_ops; buf->offset = 0; buf->len = 0; - buf->flags = 0; - if (is_packetized(filp)) { - buf->ops = &packet_pipe_buf_ops; + if (is_packetized(filp)) buf->flags = PIPE_BUF_FLAG_PACKET; - } + else + buf->flags = PIPE_BUF_FLAG_CAN_MERGE; pipe->tmp_page = NULL; copied = copy_page_from_iter(page, 0, PAGE_SIZE, from); diff --git a/fs/splice.c b/fs/splice.c index 88942bf177d1..fb9670e7fc1f 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -1624,12 +1624,11 @@ retry: *obuf = *ibuf; /* - * Don't inherit the gift flag, we need to + * Don't inherit the gift and merge flags, we need to * prevent multiple steals of this page. */ obuf->flags &= ~PIPE_BUF_FLAG_GIFT; - - pipe_buf_mark_unmergeable(obuf); + obuf->flags &= ~PIPE_BUF_FLAG_CAN_MERGE; obuf->len = len; ibuf->offset += len; @@ -1717,12 +1716,11 @@ static int link_pipe(struct pipe_inode_info *ipipe, *obuf = *ibuf; /* - * Don't inherit the gift flag, we need to - * prevent multiple steals of this page. + * Don't inherit the gift and merge flag, we need to prevent + * multiple steals of this page. */ obuf->flags &= ~PIPE_BUF_FLAG_GIFT; - - pipe_buf_mark_unmergeable(obuf); + obuf->flags &= ~PIPE_BUF_FLAG_CAN_MERGE; if (obuf->len > len) obuf->len = len; diff --git a/include/linux/pipe_fs_i.h b/include/linux/pipe_fs_i.h index ae58fad7f1e0..3f7b07b38824 100644 --- a/include/linux/pipe_fs_i.h +++ b/include/linux/pipe_fs_i.h @@ -8,6 +8,7 @@ #define PIPE_BUF_FLAG_ATOMIC 0x02 /* was atomically mapped */ #define PIPE_BUF_FLAG_GIFT 0x04 /* page is a gift */ #define PIPE_BUF_FLAG_PACKET 0x08 /* read() as a packet */ +#define PIPE_BUF_FLAG_CAN_MERGE 0x10 /* can merge buffers */ /** * struct pipe_buffer - a linux kernel pipe buffer @@ -233,7 +234,6 @@ int generic_pipe_buf_confirm(struct pipe_inode_info *, struct pipe_buffer *); int generic_pipe_buf_steal(struct pipe_inode_info *, struct pipe_buffer *); int generic_pipe_buf_nosteal(struct pipe_inode_info *, struct pipe_buffer *); void generic_pipe_buf_release(struct pipe_inode_info *, struct pipe_buffer *); -void pipe_buf_mark_unmergeable(struct pipe_buffer *buf); extern const struct pipe_buf_operations nosteal_pipe_buf_ops; |