6.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: David Howells dhowells@redhat.com
[ Upstream commit 2bfc66850952b6921b2033b09729ec59eabbc81d ]
Add an optional method, ->splice_eof(), to allow splice to indicate the premature termination of a splice to struct file_operations and struct proto_ops.
This is called if sendfile() or splice() encounters all of the following conditions inside splice_direct_to_actor():
(1) the user did not set SPLICE_F_MORE (splice only), and
(2) an EOF condition occurred (->splice_read() returned 0), and
(3) we haven't read enough to fulfill the request (ie. len > 0 still), and
(4) we have already spliced at least one byte.
A further patch will modify the behaviour of SPLICE_F_MORE to always be passed to the actor if either the user set it or we haven't yet read sufficient data to fulfill the request.
Suggested-by: Linus Torvalds torvalds@linux-foundation.org Link: https://lore.kernel.org/r/CAHk-=wh=V579PDYvkpnTobCLGczbgxpMgGmmhqiTyE34Cpi5G... Signed-off-by: David Howells dhowells@redhat.com Reviewed-by: Jakub Kicinski kuba@kernel.org cc: Jens Axboe axboe@kernel.dk cc: Christoph Hellwig hch@lst.de cc: Al Viro viro@zeniv.linux.org.uk cc: Matthew Wilcox willy@infradead.org cc: Jan Kara jack@suse.cz cc: Jeff Layton jlayton@kernel.org cc: David Hildenbrand david@redhat.com cc: Christian Brauner brauner@kernel.org cc: Chuck Lever chuck.lever@oracle.com cc: Boris Pismenny borisp@nvidia.com cc: John Fastabend john.fastabend@gmail.com cc: linux-mm@kvack.org Signed-off-by: Jakub Kicinski kuba@kernel.org Stable-dep-of: a0002127cd74 ("udp: move udp->no_check6_tx to udp->udp_flags") Signed-off-by: Sasha Levin sashal@kernel.org --- fs/splice.c | 31 ++++++++++++++++++++++++++++++- include/linux/fs.h | 1 + include/linux/net.h | 1 + include/linux/splice.h | 1 + include/net/sock.h | 1 + net/socket.c | 10 ++++++++++ 6 files changed, 44 insertions(+), 1 deletion(-)
diff --git a/fs/splice.c b/fs/splice.c index 5969b7a1d353a..c4ae54deac42c 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -764,6 +764,17 @@ static long do_splice_from(struct pipe_inode_info *pipe, struct file *out, return out->f_op->splice_write(pipe, out, ppos, len, flags); }
+/* + * Indicate to the caller that there was a premature EOF when reading from the + * source and the caller didn't indicate they would be sending more data after + * this. + */ +static void do_splice_eof(struct splice_desc *sd) +{ + if (sd->splice_eof) + sd->splice_eof(sd); +} + /* * Attempt to initiate a splice from a file to a pipe. */ @@ -864,7 +875,7 @@ ssize_t splice_direct_to_actor(struct file *in, struct splice_desc *sd,
ret = do_splice_to(in, &pos, pipe, len, flags); if (unlikely(ret <= 0)) - goto out_release; + goto read_failure;
read_len = ret; sd->total_len = read_len; @@ -904,6 +915,15 @@ ssize_t splice_direct_to_actor(struct file *in, struct splice_desc *sd, file_accessed(in); return bytes;
+read_failure: + /* + * If the user did *not* set SPLICE_F_MORE *and* we didn't hit that + * "use all of len" case that cleared SPLICE_F_MORE, *and* we did a + * "->splice_in()" that returned EOF (ie zero) *and* we have sent at + * least 1 byte *then* we will also do the ->splice_eof() call. + */ + if (ret == 0 && !more && len > 0 && bytes) + do_splice_eof(sd); out_release: /* * If we did an incomplete transfer we must release @@ -932,6 +952,14 @@ static int direct_splice_actor(struct pipe_inode_info *pipe, sd->flags); }
+static void direct_file_splice_eof(struct splice_desc *sd) +{ + struct file *file = sd->u.file; + + if (file->f_op->splice_eof) + file->f_op->splice_eof(file); +} + /** * do_splice_direct - splices data directly between two files * @in: file to splice from @@ -957,6 +985,7 @@ long do_splice_direct(struct file *in, loff_t *ppos, struct file *out, .flags = flags, .pos = *ppos, .u.file = out, + .splice_eof = direct_file_splice_eof, .opos = opos, }; long ret; diff --git a/include/linux/fs.h b/include/linux/fs.h index b6af6abc7a77f..4a1911dcf834b 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2177,6 +2177,7 @@ struct file_operations { int (*flock) (struct file *, int, struct file_lock *); ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, loff_t *, size_t, unsigned int); ssize_t (*splice_read)(struct file *, loff_t *, struct pipe_inode_info *, size_t, unsigned int); + void (*splice_eof)(struct file *file); int (*setlease)(struct file *, long, struct file_lock **, void **); long (*fallocate)(struct file *file, int mode, loff_t offset, loff_t len); diff --git a/include/linux/net.h b/include/linux/net.h index 18d942bbdf6e0..25baca60f6cba 100644 --- a/include/linux/net.h +++ b/include/linux/net.h @@ -209,6 +209,7 @@ struct proto_ops { int offset, size_t size, int flags); ssize_t (*splice_read)(struct socket *sock, loff_t *ppos, struct pipe_inode_info *pipe, size_t len, unsigned int flags); + void (*splice_eof)(struct socket *sock); int (*set_peek_off)(struct sock *sk, int val); int (*peek_len)(struct socket *sock);
diff --git a/include/linux/splice.h b/include/linux/splice.h index a55179fd60fc3..41a70687be853 100644 --- a/include/linux/splice.h +++ b/include/linux/splice.h @@ -38,6 +38,7 @@ struct splice_desc { struct file *file; /* file to read/write */ void *data; /* cookie */ } u; + void (*splice_eof)(struct splice_desc *sd); /* Unexpected EOF handler */ loff_t pos; /* file position */ loff_t *opos; /* sendfile: output position */ size_t num_spliced; /* number of bytes already spliced */ diff --git a/include/net/sock.h b/include/net/sock.h index d8ed62a8e1a3e..9de9f070537cc 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -1279,6 +1279,7 @@ struct proto { size_t len, int flags, int *addr_len); int (*sendpage)(struct sock *sk, struct page *page, int offset, size_t size, int flags); + void (*splice_eof)(struct socket *sock); int (*bind)(struct sock *sk, struct sockaddr *addr, int addr_len); int (*bind_add)(struct sock *sk, diff --git a/net/socket.c b/net/socket.c index 6f39f7b0cc85c..639d76f20384e 100644 --- a/net/socket.c +++ b/net/socket.c @@ -130,6 +130,7 @@ static ssize_t sock_sendpage(struct file *file, struct page *page, static ssize_t sock_splice_read(struct file *file, loff_t *ppos, struct pipe_inode_info *pipe, size_t len, unsigned int flags); +static void sock_splice_eof(struct file *file);
#ifdef CONFIG_PROC_FS static void sock_show_fdinfo(struct seq_file *m, struct file *f) @@ -164,6 +165,7 @@ static const struct file_operations socket_file_ops = { .sendpage = sock_sendpage, .splice_write = generic_splice_sendpage, .splice_read = sock_splice_read, + .splice_eof = sock_splice_eof, .show_fdinfo = sock_show_fdinfo, };
@@ -1091,6 +1093,14 @@ static ssize_t sock_splice_read(struct file *file, loff_t *ppos, return sock->ops->splice_read(sock, ppos, pipe, len, flags); }
+static void sock_splice_eof(struct file *file) +{ + struct socket *sock = file->private_data; + + if (sock->ops->splice_eof) + sock->ops->splice_eof(sock); +} + static ssize_t sock_read_iter(struct kiocb *iocb, struct iov_iter *to) { struct file *file = iocb->ki_filp;