Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933112AbaLDRxA (ORCPT ); Thu, 4 Dec 2014 12:53:00 -0500 Received: from mail-wi0-f174.google.com ([209.85.212.174]:46039 "EHLO mail-wi0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932474AbaLDRw2 (ORCPT ); Thu, 4 Dec 2014 12:52:28 -0500 From: Pieter Smith To: linux-kernel@vger.kernel.org Cc: Josh Triplett , Pieter Smith , Alexander Duyck , Alexander Viro , Alexei Starovoitov , Andrew Morton , Bertrand Jacquin , Catalina Mocanu , Daniel Borkmann , "David S. Miller" , Eric Dumazet , "Eric W. Biederman" , Fabian Frederick , fuse-devel@lists.sourceforge.net (open list:FUSE: FILESYSTEM...), Geert Uytterhoeven , Hugh Dickins , Iulia Manda , Jan Beulich , "J. Bruce Fields" , Jeff Layton , linux-api@vger.kernel.org (open list:ABI/API), linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org (open list:KERNEL NFSD, SUNR...), "Luis R. Rodriguez" , Matt Turner , Mel Gorman , "Michael S. Tsirkin" , Miklos Szeredi , netdev@vger.kernel.org (open list:NETWORKING [GENERAL]), Oleg Nesterov , Paul Durrant , "Paul E. McKenney" , Peter Foley , Thomas Graf , Tom Herbert , Trond Myklebust , Willem de Bruijn , Xiao Guangrong , =?UTF-8?q?=E8=94=A1=E6=AD=A3=E9=BE=99?= Subject: [PATCH v6 7/7] fs/splice: full support for compiling out splice Date: Thu, 4 Dec 2014 18:50:55 +0100 Message-Id: <1417715473-24110-8-git-send-email-pieter@boesman.nl> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1417715473-24110-1-git-send-email-pieter@boesman.nl> References: <1417715473-24110-1-git-send-email-pieter@boesman.nl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Entirely compile out splice translation unit when the system is configured without splice family of syscalls (i.e. CONFIG_SYSCALL_SPLICE is undefined). Exported fs/splice functions are transparently mocked out with static inlines. Because userspace support for splice has already been removed by this patch-set, the exported functions cannot be called anyway. Mocking them out prevents a maintenance burden on file system drivers. The bloat score resulting from this patch given a tinyconfig is: add/remove: 0/25 grow/shrink: 0/5 up/down: 0/-4845 (-4845) function old new delta pipe_to_null 4 - -4 generic_pipe_buf_nosteal 6 - -6 spd_release_page 10 - -10 PageUptodate 22 11 -11 lock_page 36 24 -12 page_cache_pipe_buf_release 16 - -16 splice_write_null 24 4 -20 page_cache_pipe_buf_ops 20 - -20 nosteal_pipe_buf_ops 20 - -20 default_pipe_buf_ops 20 - -20 generic_splice_sendpage 24 - -24 splice_shrink_spd 27 - -27 direct_splice_actor 47 - -47 default_file_splice_write 49 - -49 wakeup_pipe_writers 54 - -54 write_pipe_buf 71 - -71 page_cache_pipe_buf_confirm 80 - -80 splice_grow_spd 87 - -87 splice_from_pipe 93 - -93 splice_from_pipe_next 106 - -106 pipe_to_sendpage 109 - -109 page_cache_pipe_buf_steal 114 - -114 generic_file_splice_read 131 8 -123 do_splice_direct 148 - -148 __splice_from_pipe 246 - -246 splice_direct_to_actor 416 - -416 splice_to_pipe 417 - -417 default_file_splice_read 688 - -688 iter_file_splice_write 702 4 -698 __generic_file_splice_read 1109 - -1109 The bloat score for the entire CONFIG_SYSCALL_SPLICE patch-set is: add/remove: 0/41 grow/shrink: 5/7 up/down: 23/-8422 (-8399) function old new delta sys_pwritev 115 122 +7 sys_preadv 115 122 +7 fdput_pos 29 36 +7 sys_pwrite64 115 116 +1 sys_pread64 115 116 +1 pipe_to_null 4 - -4 generic_pipe_buf_nosteal 6 - -6 spd_release_page 10 - -10 fdput 11 - -11 PageUptodate 22 11 -11 lock_page 36 24 -12 signal_pending 39 26 -13 fdget 56 42 -14 page_cache_pipe_buf_release 16 - -16 user_page_pipe_buf_ops 20 - -20 splice_write_null 24 4 -20 page_cache_pipe_buf_ops 20 - -20 nosteal_pipe_buf_ops 20 - -20 default_pipe_buf_ops 20 - -20 generic_splice_sendpage 24 - -24 user_page_pipe_buf_steal 25 - -25 splice_shrink_spd 27 - -27 pipe_to_user 43 - -43 direct_splice_actor 47 - -47 default_file_splice_write 49 - -49 wakeup_pipe_writers 54 - -54 wakeup_pipe_readers 54 - -54 write_pipe_buf 71 - -71 page_cache_pipe_buf_confirm 80 - -80 splice_grow_spd 87 - -87 do_splice_to 87 - -87 ipipe_prep.part 92 - -92 splice_from_pipe 93 - -93 splice_from_pipe_next 107 - -107 pipe_to_sendpage 109 - -109 page_cache_pipe_buf_steal 114 - -114 opipe_prep.part 119 - -119 sys_sendfile 122 - -122 generic_file_splice_read 131 8 -123 sys_sendfile64 126 - -126 sys_vmsplice 137 - -137 do_splice_direct 148 - -148 vmsplice_to_user 205 - -205 __splice_from_pipe 246 - -246 splice_direct_to_actor 348 - -348 splice_to_pipe 371 - -371 do_sendfile 492 - -492 sys_tee 497 - -497 vmsplice_to_pipe 558 - -558 default_file_splice_read 688 - -688 iter_file_splice_write 702 4 -698 sys_splice 1075 - -1075 __generic_file_splice_read 1109 - -1109 Signed-off-by: Pieter Smith --- fs/Makefile | 3 ++- fs/splice.c | 2 -- include/linux/fs.h | 26 ++++++++++++++++++++++++++ include/linux/splice.h | 42 ++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 70 insertions(+), 3 deletions(-) diff --git a/fs/Makefile b/fs/Makefile index fb7646e..9395622 100644 --- a/fs/Makefile +++ b/fs/Makefile @@ -10,7 +10,7 @@ obj-y := open.o read_write.o file_table.o super.o \ ioctl.o readdir.o select.o dcache.o inode.o \ attr.o bad_inode.o file.o filesystems.o namespace.o \ seq_file.o xattr.o libfs.o fs-writeback.o \ - pnode.o splice.o sync.o utimes.o \ + pnode.o sync.o utimes.o \ stack.o fs_struct.o statfs.o fs_pin.o ifeq ($(CONFIG_BLOCK),y) @@ -22,6 +22,7 @@ endif obj-$(CONFIG_PROC_FS) += proc_namespace.o obj-$(CONFIG_FSNOTIFY) += notify/ +obj-$(CONFIG_SYSCALL_SPLICE) += splice.o obj-$(CONFIG_EPOLL) += eventpoll.o obj-$(CONFIG_ANON_INODES) += anon_inodes.o obj-$(CONFIG_SIGNALFD) += signalfd.o diff --git a/fs/splice.c b/fs/splice.c index 7c4c695..44b201b 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -1316,7 +1316,6 @@ long do_splice_direct(struct file *in, loff_t *ppos, struct file *out, return ret; } -#ifdef CONFIG_SYSCALL_SPLICE static int splice_pipe_to_pipe(struct pipe_inode_info *ipipe, struct pipe_inode_info *opipe, size_t len, unsigned int flags); @@ -2201,5 +2200,4 @@ COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, return do_sendfile(out_fd, in_fd, NULL, count, 0); } #endif -#endif diff --git a/include/linux/fs.h b/include/linux/fs.h index a957d43..138107e 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2444,6 +2444,7 @@ extern int blkdev_fsync(struct file *filp, loff_t start, loff_t end, extern void block_sync_page(struct page *page); /* fs/splice.c */ +#ifdef CONFIG_SYSCALL_SPLICE extern ssize_t generic_file_splice_read(struct file *, loff_t *, struct pipe_inode_info *, size_t, unsigned int); extern ssize_t default_file_splice_read(struct file *, loff_t *, @@ -2452,6 +2453,31 @@ extern ssize_t iter_file_splice_write(struct pipe_inode_info *, struct file *, loff_t *, size_t, unsigned int); extern ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe, struct file *out, loff_t *, size_t len, unsigned int flags); +#else +static inline ssize_t generic_file_splice_read(struct file *in, loff_t *ppos, + struct pipe_inode_info *pipe, size_t len, unsigned int flags) +{ + return -EPERM; +} + +static inline ssize_t default_file_splice_read(struct file *in, loff_t *ppos, + struct pipe_inode_info *pipe, size_t len, unsigned int flags) +{ + return -EPERM; +} + +static inline ssize_t iter_file_splice_write(struct pipe_inode_info *pipe, + struct file *out, loff_t *ppos, size_t len, unsigned int flags) +{ + return -EPERM; +} + +static inline ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe, + struct file *out, loff_t *ppos, size_t len, unsigned int flags) +{ + return -EPERM; +} +#endif extern void file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping); diff --git a/include/linux/splice.h b/include/linux/splice.h index da2751d..34570d8 100644 --- a/include/linux/splice.h +++ b/include/linux/splice.h @@ -65,6 +65,7 @@ typedef int (splice_actor)(struct pipe_inode_info *, struct pipe_buffer *, typedef int (splice_direct_actor)(struct pipe_inode_info *, struct splice_desc *); +#ifdef CONFIG_SYSCALL_SPLICE extern ssize_t splice_from_pipe(struct pipe_inode_info *, struct file *, loff_t *, size_t, unsigned int, splice_actor *); @@ -74,13 +75,54 @@ extern ssize_t splice_to_pipe(struct pipe_inode_info *, struct splice_pipe_desc *); extern ssize_t splice_direct_to_actor(struct file *, struct splice_desc *, splice_direct_actor *); +#else +static inline ssize_t splice_from_pipe(struct pipe_inode_info *pipe, struct file *out, + loff_t *ppos, size_t len, unsigned int flags, + splice_actor *actor) +{ + return -EPERM; +} + +static inline ssize_t __splice_from_pipe(struct pipe_inode_info *pipe, struct splice_desc *sd, + splice_actor *actor) +{ + return -EPERM; +} + +static inline ssize_t splice_to_pipe(struct pipe_inode_info *pipe, + struct splice_pipe_desc *spd) +{ + return -EPERM; +} + +static inline ssize_t splice_direct_to_actor(struct file *in, struct splice_desc *sd, + splice_direct_actor *actor) +{ + return -EPERM; +} +#endif /* * for dynamic pipe sizing */ +#ifdef CONFIG_SYSCALL_SPLICE extern int splice_grow_spd(const struct pipe_inode_info *, struct splice_pipe_desc *); extern void splice_shrink_spd(struct splice_pipe_desc *); extern void spd_release_page(struct splice_pipe_desc *, unsigned int); +#else +static inline int splice_grow_spd(const struct pipe_inode_info *pipe, struct splice_pipe_desc *spd) +{ + return -EPERM; +} + +static inline void splice_shrink_spd(struct splice_pipe_desc *spd) +{ +} + +static inline void spd_release_page(struct splice_pipe_desc *spd, unsigned int i) +{ +} +#endif extern const struct pipe_buf_operations page_cache_pipe_buf_ops; #endif -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/