From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pieter Smith Subject: [PATCH 2/2] fs: Support compiling out sendfile Date: Mon, 20 Oct 2014 23:48:37 +0200 Message-ID: <1413841728-1313-2-git-send-email-pieter@boesman.nl> References: <1413841728-1313-1-git-send-email-pieter@boesman.nl> Return-path: In-Reply-To: <1413841728-1313-1-git-send-email-pieter-qeJ+1H9vRZbz+pZb47iToQ@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Alexander Viro Cc: Josh Triplett , Pieter Smith , Andrew Morton , Eric Paris , Matt Turner , Michal Hocko , "Paul E. McKenney" , Fabian Frederick , Tejun Heo , =?UTF-8?q?=E8=94=A1=E6=AD=A3=E9=BE=99?= , "Luis R. Rodriguez" , Peter Foley , Konstantin Khlebnikov , "Eric W. Biederman" , "H. Peter Anvin" , Oleg Nesterov , Andy Lutomirski , David Herrmann , Kees Cook , linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, open list , "open list:ABI/API" List-Id: linux-api@vger.kernel.org Many embedded systems will not need this syscall, and omitting it saves space. Add a new EXPERT config option CONFIG_SENDFILE_SYSCALL (default y) to support compiling it out. bloat-o-meter: add/remove: 0/4 grow/shrink: 5/0 up/down: 23/-751 (-728) 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 fdput 11 - -11 sys_sendfile 122 - -122 sys_sendfile64 126 - -126 do_sendfile 492 - -492 Signed-off-by: Pieter Smith --- fs/Makefile | 3 ++- init/Kconfig | 10 ++++++++++ kernel/sys_ni.c | 4 ++++ 3 files changed, 16 insertions(+), 1 deletion(-) diff --git a/fs/Makefile b/fs/Makefile index 1e3423f..1bbfea7 100644 --- a/fs/Makefile +++ b/fs/Makefile @@ -5,7 +5,7 @@ # Rewritten to use lists instead of if-statements. # -obj-y := open.o read_write.o sendfile.o file_table.o super.o \ +obj-y := open.o read_write.o file_table.o super.o \ char_dev.o stat.o exec.o pipe.o namei.o fcntl.o \ ioctl.o readdir.o select.o dcache.o inode.o \ attr.o bad_inode.o file.o filesystems.o namespace.o \ @@ -38,6 +38,7 @@ obj-$(CONFIG_COMPAT_BINFMT_ELF) += compat_binfmt_elf.o obj-$(CONFIG_BINFMT_ELF_FDPIC) += binfmt_elf_fdpic.o obj-$(CONFIG_BINFMT_SOM) += binfmt_som.o obj-$(CONFIG_BINFMT_FLAT) += binfmt_flat.o +obj-$(CONFIG_SENDFILE_SYSCALL) += sendfile.o obj-$(CONFIG_FS_MBCACHE) += mbcache.o obj-$(CONFIG_FS_POSIX_ACL) += posix_acl.o diff --git a/init/Kconfig b/init/Kconfig index 782a65b..df6785c 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1547,6 +1547,16 @@ config ADVISE_SYSCALLS applications use these syscalls, you can disable this option to save space. +config SENDFILE_SYSCALL + bool "Enable sendfile syscall" if EXPERT + default y + help + This option enables the sendfile syscall, used by applications to copy + data between file descriptors. Because sendfile performs the copying + within the kernel, it is more efficient than the combination of read + and write. If building an embedded system where no applications use + the sendfile syscall, you can disable this option to save space. + config PCI_QUIRKS default y bool "Enable PCI quirk workarounds" if EXPERT diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c index d4709d4..b068de7 100644 --- a/kernel/sys_ni.c +++ b/kernel/sys_ni.c @@ -159,6 +159,10 @@ cond_syscall(sys_uselib); cond_syscall(sys_fadvise64); cond_syscall(sys_fadvise64_64); cond_syscall(sys_madvise); +cond_syscall(sys_sendfile); +cond_syscall(sys_sendfile64); +cond_syscall(compat_sys_sendfile); +cond_syscall(compat_sys_sendfile64); /* arch-specific weak syscall entries */ cond_syscall(sys_pciconfig_read); -- 1.9.1