diff options
author | David Howells <dhowells@redhat.com> | 2023-06-07 21:19:10 +0300 |
---|---|---|
committer | Jakub Kicinski <kuba@kernel.org> | 2023-06-09 05:40:30 +0300 |
commit | 2bfc66850952b6921b2033b09729ec59eabbc81d (patch) | |
tree | 67e88596326f668e7e2bae15c9dda5e65e5b2681 | |
parent | 2dc334f1a63a8839b88483a3e73c0f27c9c1791c (diff) | |
download | linux-2bfc66850952b6921b2033b09729ec59eabbc81d.tar.xz |
splice, net: Add a splice_eof op to file-ops and socket-ops
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=V579PDYvkpnTobCLGczbgxpMgGmmhqiTyE34Cpi5Gg@mail.gmail.com/
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>
-rw-r--r-- | fs/splice.c | 31 | ||||
-rw-r--r-- | include/linux/fs.h | 1 | ||||
-rw-r--r-- | include/linux/net.h | 1 | ||||
-rw-r--r-- | include/linux/splice.h | 1 | ||||
-rw-r--r-- | include/net/sock.h | 1 | ||||
-rw-r--r-- | net/socket.c | 10 |
6 files changed, 44 insertions, 1 deletions
diff --git a/fs/splice.c b/fs/splice.c index e337630aed64..67dbd85db207 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -970,6 +970,17 @@ static long do_splice_from(struct pipe_inode_info *pipe, struct file *out, } /* + * 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. */ static long do_splice_to(struct file *in, loff_t *ppos, @@ -1068,7 +1079,7 @@ 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; @@ -1108,6 +1119,15 @@ done: 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 @@ -1136,6 +1156,14 @@ 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 @@ -1161,6 +1189,7 @@ 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 df92f4b3d122..de2cb1132f07 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1796,6 +1796,7 @@ 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 b73ad8e3c212..8defc8f1d82e 100644 --- a/include/linux/net.h +++ b/include/linux/net.h @@ -210,6 +210,7 @@ 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 991ae318b6eb..4fab18a6e371 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 6f428a7f3567..2790133b4b76 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 c4d9104418c8..b778fc03c6e0 100644 --- a/net/socket.c +++ b/net/socket.c @@ -130,6 +130,7 @@ static int sock_fasync(int fd, struct file *filp, int on); 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) @@ -163,6 +164,7 @@ static const struct file_operations socket_file_ops = { .fasync = sock_fasync, .splice_write = splice_to_socket, .splice_read = sock_splice_read, + .splice_eof = sock_splice_eof, .show_fdinfo = sock_show_fdinfo, }; @@ -1076,6 +1078,14 @@ 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; |