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* [PATCH 0/6] kernel tinification: optionally compile out splice family of syscalls (splice, vmsplice, tee and sendfile)
@ 2014-11-23 14:20 ` Pieter Smith
  0 siblings, 0 replies; 58+ messages in thread
From: Pieter Smith @ 2014-11-23 14:20 UTC (permalink / raw)
  To: pieter
  Cc: Josh Triplett, Alexander Duyck, Alexander Viro,
	Alexei Starovoitov, Andrew Morton, Bertrand Jacquin,
	Catalina Mocanu, Daniel Borkmann, David S. Miller, Eric Dumazet,
	Eric W. Biederman, Fabian Frederick,
	open list:FUSE: FILESYSTEM...,
	Geert Uytterhoeven, Hugh Dickins, Iulia Manda, Jan Beulich,
	J. Bruce Fields, Jeff Layton, open list:ABI/API, linux-fsdevel,
	open list, Luis R. Rodriguez, Matt Turner, Mel Gorman,
	Michael S. Tsirkin, Miklos Szeredi,
	open list:NETWORKING [GENERAL],
	Oleg Nesterov, Paul Durrant, Paul E. McKenney, Peter Foley,
	Thomas Graf, Tom Herbert, Willem de Bruijn, Xiao Guangrong,
	蔡正龙

REPO: https://github.com/smipi1/linux-tinification.git

BRANCH: tiny/config-syscall-splice

BACKGROUND: This patch-set forms part of the Linux Kernel Tinification effort (
  https://tiny.wiki.kernel.org/).

GOAL: Support compiling out the splice family of syscalls (splice, vmsplice,
  tee and sendfile) along with all supporting infrastructure if not needed.
  Many embedded systems will not need the splice-family syscalls. Omitting them
  saves space.

STRATEGY:
a. With the goal of eventually compiling out fs/splice.c, several functions
   that are only used in support of the the splice family of syscalls are moved
   into fs/splice.c from fs/read_write.c. The kernel_write function that is not
   used to support the splice syscalls is moved to fs/read_write.c:
     0001-fs-move-sendfile-syscall-into-fs-splice.patch
     0002-fs-moved-kernel_write-to-fs-read_write.patch

b. Introduce an EXPERT kernel configuration option; CONFIG_SYSCALL_SPLICE; to
   compile out the splice family of syscalls. This removes all userspace uses
   of the splice infrastructure.
     0003-fs-splice-support-compiling-out-splice-family-syscal.patch

c. Splice exports an operations struct, nosteal_pipe_buf_ops. Eliminate the 
   use of this struct when CONFIG_SYSCALL_SPLICE is undefined, so that splice
   can later be compiled out:
     0004-fs-fuse-support-compiling-out-splice.patch
     0005-net-core-support-compiling-out-splice.patch

e. Compile out fs/splice.c. Functions exported by fs/splice are mocked out with
   failing static inlines. This is done so as to all but eliminate the
   maintenance burden on file-system drivers.
     0006-fs-splice-full-support-for-compiling-out-splice.patch

RESULTS: A tinyconfig bloat-o-meter score for the entire patch-set:

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

Pieter Smith (6):
  fs: move sendfile syscall into fs/splice
  fs: moved kernel_write to fs/read_write
  fs/splice: support compiling out splice-family syscalls
  fs/fuse: support compiling out splice
  net/core: support compiling out splice
  fs/splice: full support for compiling out splice

 fs/Makefile            |   3 +-
 fs/fuse/dev.c          |   4 +-
 fs/read_write.c        | 181 +++------------------------------------------
 fs/splice.c            | 194 +++++++++++++++++++++++++++++++++++++++++++++----
 include/linux/fs.h     |  32 ++++++++
 include/linux/skbuff.h |   9 +++
 include/linux/splice.h |  42 +++++++++++
 init/Kconfig           |  10 +++
 kernel/sys_ni.c        |   8 ++
 net/core/skbuff.c      |   9 ++-
 10 files changed, 300 insertions(+), 192 deletions(-)

-- 
2.1.0


^ permalink raw reply	[flat|nested] 58+ messages in thread

* [PATCH 0/6] kernel tinification: optionally compile out splice family of syscalls (splice, vmsplice, tee and sendfile)
@ 2014-11-23 14:20 ` Pieter Smith
  0 siblings, 0 replies; 58+ messages in thread
From: Pieter Smith @ 2014-11-23 14:20 UTC (permalink / raw)
  To: pieter
  Cc: Josh Triplett, Alexander Duyck, Alexander Viro,
	Alexei Starovoitov, Andrew Morton, Bertrand Jacquin,
	Catalina Mocanu, Daniel Borkmann, David S. Miller, Eric Dumazet,
	Eric W. Biederman, Fabian Frederick,
	open list:FUSE: FILESYSTEM...,
	Geert Uytterhoeven, Hugh Dickins, Iulia Manda, Jan Beulich,
	J. Bruce Fields, Jeff Layton, open list:ABI/API, linux-fsdevel,
	linux-kernel

REPO: https://github.com/smipi1/linux-tinification.git

BRANCH: tiny/config-syscall-splice

BACKGROUND: This patch-set forms part of the Linux Kernel Tinification effort (
  https://tiny.wiki.kernel.org/).

GOAL: Support compiling out the splice family of syscalls (splice, vmsplice,
  tee and sendfile) along with all supporting infrastructure if not needed.
  Many embedded systems will not need the splice-family syscalls. Omitting them
  saves space.

STRATEGY:
a. With the goal of eventually compiling out fs/splice.c, several functions
   that are only used in support of the the splice family of syscalls are moved
   into fs/splice.c from fs/read_write.c. The kernel_write function that is not
   used to support the splice syscalls is moved to fs/read_write.c:
     0001-fs-move-sendfile-syscall-into-fs-splice.patch
     0002-fs-moved-kernel_write-to-fs-read_write.patch

b. Introduce an EXPERT kernel configuration option; CONFIG_SYSCALL_SPLICE; to
   compile out the splice family of syscalls. This removes all userspace uses
   of the splice infrastructure.
     0003-fs-splice-support-compiling-out-splice-family-syscal.patch

c. Splice exports an operations struct, nosteal_pipe_buf_ops. Eliminate the 
   use of this struct when CONFIG_SYSCALL_SPLICE is undefined, so that splice
   can later be compiled out:
     0004-fs-fuse-support-compiling-out-splice.patch
     0005-net-core-support-compiling-out-splice.patch

e. Compile out fs/splice.c. Functions exported by fs/splice are mocked out with
   failing static inlines. This is done so as to all but eliminate the
   maintenance burden on file-system drivers.
     0006-fs-splice-full-support-for-compiling-out-splice.patch

RESULTS: A tinyconfig bloat-o-meter score for the entire patch-set:

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

Pieter Smith (6):
  fs: move sendfile syscall into fs/splice
  fs: moved kernel_write to fs/read_write
  fs/splice: support compiling out splice-family syscalls
  fs/fuse: support compiling out splice
  net/core: support compiling out splice
  fs/splice: full support for compiling out splice

 fs/Makefile            |   3 +-
 fs/fuse/dev.c          |   4 +-
 fs/read_write.c        | 181 +++------------------------------------------
 fs/splice.c            | 194 +++++++++++++++++++++++++++++++++++++++++++++----
 include/linux/fs.h     |  32 ++++++++
 include/linux/skbuff.h |   9 +++
 include/linux/splice.h |  42 +++++++++++
 init/Kconfig           |  10 +++
 kernel/sys_ni.c        |   8 ++
 net/core/skbuff.c      |   9 ++-
 10 files changed, 300 insertions(+), 192 deletions(-)

-- 
2.1.0


^ permalink raw reply	[flat|nested] 58+ messages in thread

* [PATCH 0/6] kernel tinification: optionally compile out splice family of syscalls (splice, vmsplice, tee and sendfile)
@ 2014-11-23 14:20 ` Pieter Smith
  0 siblings, 0 replies; 58+ messages in thread
From: Pieter Smith @ 2014-11-23 14:20 UTC (permalink / raw)
  To: pieter
  Cc: Josh Triplett, Alexander Duyck, Alexander Viro,
	Alexei Starovoitov, Andrew Morton, Bertrand Jacquin,
	Catalina Mocanu, Daniel Borkmann, David S. Miller, Eric Dumazet,
	Eric W. Biederman, Fabian Frederick,
	open list:FUSE: FILESYSTEM...,
	Geert Uytterhoeven, Hugh Dickins, Iulia Manda, Jan Beulich,
	J. Bruce Fields, Jeff Layton, open list:ABI/API, linux-fsdevel,
	linux-kernel

REPO: https://github.com/smipi1/linux-tinification.git

BRANCH: tiny/config-syscall-splice

BACKGROUND: This patch-set forms part of the Linux Kernel Tinification effort (
  https://tiny.wiki.kernel.org/).

GOAL: Support compiling out the splice family of syscalls (splice, vmsplice,
  tee and sendfile) along with all supporting infrastructure if not needed.
  Many embedded systems will not need the splice-family syscalls. Omitting them
  saves space.

STRATEGY:
a. With the goal of eventually compiling out fs/splice.c, several functions
   that are only used in support of the the splice family of syscalls are moved
   into fs/splice.c from fs/read_write.c. The kernel_write function that is not
   used to support the splice syscalls is moved to fs/read_write.c:
     0001-fs-move-sendfile-syscall-into-fs-splice.patch
     0002-fs-moved-kernel_write-to-fs-read_write.patch

b. Introduce an EXPERT kernel configuration option; CONFIG_SYSCALL_SPLICE; to
   compile out the splice family of syscalls. This removes all userspace uses
   of the splice infrastructure.
     0003-fs-splice-support-compiling-out-splice-family-syscal.patch

c. Splice exports an operations struct, nosteal_pipe_buf_ops. Eliminate the 
   use of this struct when CONFIG_SYSCALL_SPLICE is undefined, so that splice
   can later be compiled out:
     0004-fs-fuse-support-compiling-out-splice.patch
     0005-net-core-support-compiling-out-splice.patch

e. Compile out fs/splice.c. Functions exported by fs/splice are mocked out with
   failing static inlines. This is done so as to all but eliminate the
   maintenance burden on file-system drivers.
     0006-fs-splice-full-support-for-compiling-out-splice.patch

RESULTS: A tinyconfig bloat-o-meter score for the entire patch-set:

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

Pieter Smith (6):
  fs: move sendfile syscall into fs/splice
  fs: moved kernel_write to fs/read_write
  fs/splice: support compiling out splice-family syscalls
  fs/fuse: support compiling out splice
  net/core: support compiling out splice
  fs/splice: full support for compiling out splice

 fs/Makefile            |   3 +-
 fs/fuse/dev.c          |   4 +-
 fs/read_write.c        | 181 +++------------------------------------------
 fs/splice.c            | 194 +++++++++++++++++++++++++++++++++++++++++++++----
 include/linux/fs.h     |  32 ++++++++
 include/linux/skbuff.h |   9 +++
 include/linux/splice.h |  42 +++++++++++
 init/Kconfig           |  10 +++
 kernel/sys_ni.c        |   8 ++
 net/core/skbuff.c      |   9 ++-
 10 files changed, 300 insertions(+), 192 deletions(-)

-- 
2.1.0


^ permalink raw reply	[flat|nested] 58+ messages in thread

* [PATCH 1/6] fs: move sendfile syscall into fs/splice
@ 2014-11-23 14:20   ` Pieter Smith
  0 siblings, 0 replies; 58+ messages in thread
From: Pieter Smith @ 2014-11-23 14:20 UTC (permalink / raw)
  To: pieter
  Cc: Josh Triplett, Alexander Duyck, Alexander Viro,
	Alexei Starovoitov, Andrew Morton, Bertrand Jacquin,
	Catalina Mocanu, Daniel Borkmann, David S. Miller, Eric Dumazet,
	Eric W. Biederman, Fabian Frederick,
	open list:FUSE: FILESYSTEM...,
	Geert Uytterhoeven, Hugh Dickins, Iulia Manda, Jan Beulich,
	J. Bruce Fields, Jeff Layton, open list:ABI/API, linux-fsdevel,
	open list, Luis R. Rodriguez, Matt Turner, Mel Gorman,
	Michael S. Tsirkin, Miklos Szeredi,
	open list:NETWORKING [GENERAL],
	Oleg Nesterov, Paul Durrant, Paul E. McKenney, Peter Foley,
	Thomas Graf, Tom Herbert, Willem de Bruijn, Xiao Guangrong,
	蔡正龙

sendfile functionally forms part of the splice group of syscalls (splice,
vmsplice and tee). Grouping sendfile with splice paves the way to compiling out
the splice group of syscalls for embedded systems that do not need these.

add/remove: 0/0 grow/shrink: 7/2 up/down: 86/-61 (25)
function                                     old     new   delta
file_start_write                              34      68     +34
file_end_write                                29      58     +29
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
sys_tee                                      497     491      -6
sys_splice                                  1075    1020     -55

Signed-off-by: Pieter Smith <pieter@boesman.nl>
---
 fs/read_write.c | 175 -------------------------------------------------------
 fs/splice.c     | 178 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 178 insertions(+), 175 deletions(-)

diff --git a/fs/read_write.c b/fs/read_write.c
index 7d9318c..d9451ba 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1191,178 +1191,3 @@ COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd,
 }
 #endif
 
-static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
-		  	   size_t count, loff_t max)
-{
-	struct fd in, out;
-	struct inode *in_inode, *out_inode;
-	loff_t pos;
-	loff_t out_pos;
-	ssize_t retval;
-	int fl;
-
-	/*
-	 * Get input file, and verify that it is ok..
-	 */
-	retval = -EBADF;
-	in = fdget(in_fd);
-	if (!in.file)
-		goto out;
-	if (!(in.file->f_mode & FMODE_READ))
-		goto fput_in;
-	retval = -ESPIPE;
-	if (!ppos) {
-		pos = in.file->f_pos;
-	} else {
-		pos = *ppos;
-		if (!(in.file->f_mode & FMODE_PREAD))
-			goto fput_in;
-	}
-	retval = rw_verify_area(READ, in.file, &pos, count);
-	if (retval < 0)
-		goto fput_in;
-	count = retval;
-
-	/*
-	 * Get output file, and verify that it is ok..
-	 */
-	retval = -EBADF;
-	out = fdget(out_fd);
-	if (!out.file)
-		goto fput_in;
-	if (!(out.file->f_mode & FMODE_WRITE))
-		goto fput_out;
-	retval = -EINVAL;
-	in_inode = file_inode(in.file);
-	out_inode = file_inode(out.file);
-	out_pos = out.file->f_pos;
-	retval = rw_verify_area(WRITE, out.file, &out_pos, count);
-	if (retval < 0)
-		goto fput_out;
-	count = retval;
-
-	if (!max)
-		max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes);
-
-	if (unlikely(pos + count > max)) {
-		retval = -EOVERFLOW;
-		if (pos >= max)
-			goto fput_out;
-		count = max - pos;
-	}
-
-	fl = 0;
-#if 0
-	/*
-	 * We need to debate whether we can enable this or not. The
-	 * man page documents EAGAIN return for the output at least,
-	 * and the application is arguably buggy if it doesn't expect
-	 * EAGAIN on a non-blocking file descriptor.
-	 */
-	if (in.file->f_flags & O_NONBLOCK)
-		fl = SPLICE_F_NONBLOCK;
-#endif
-	file_start_write(out.file);
-	retval = do_splice_direct(in.file, &pos, out.file, &out_pos, count, fl);
-	file_end_write(out.file);
-
-	if (retval > 0) {
-		add_rchar(current, retval);
-		add_wchar(current, retval);
-		fsnotify_access(in.file);
-		fsnotify_modify(out.file);
-		out.file->f_pos = out_pos;
-		if (ppos)
-			*ppos = pos;
-		else
-			in.file->f_pos = pos;
-	}
-
-	inc_syscr(current);
-	inc_syscw(current);
-	if (pos > max)
-		retval = -EOVERFLOW;
-
-fput_out:
-	fdput(out);
-fput_in:
-	fdput(in);
-out:
-	return retval;
-}
-
-SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, off_t __user *, offset, size_t, count)
-{
-	loff_t pos;
-	off_t off;
-	ssize_t ret;
-
-	if (offset) {
-		if (unlikely(get_user(off, offset)))
-			return -EFAULT;
-		pos = off;
-		ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS);
-		if (unlikely(put_user(pos, offset)))
-			return -EFAULT;
-		return ret;
-	}
-
-	return do_sendfile(out_fd, in_fd, NULL, count, 0);
-}
-
-SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, size_t, count)
-{
-	loff_t pos;
-	ssize_t ret;
-
-	if (offset) {
-		if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t))))
-			return -EFAULT;
-		ret = do_sendfile(out_fd, in_fd, &pos, count, 0);
-		if (unlikely(put_user(pos, offset)))
-			return -EFAULT;
-		return ret;
-	}
-
-	return do_sendfile(out_fd, in_fd, NULL, count, 0);
-}
-
-#ifdef CONFIG_COMPAT
-COMPAT_SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd,
-		compat_off_t __user *, offset, compat_size_t, count)
-{
-	loff_t pos;
-	off_t off;
-	ssize_t ret;
-
-	if (offset) {
-		if (unlikely(get_user(off, offset)))
-			return -EFAULT;
-		pos = off;
-		ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS);
-		if (unlikely(put_user(pos, offset)))
-			return -EFAULT;
-		return ret;
-	}
-
-	return do_sendfile(out_fd, in_fd, NULL, count, 0);
-}
-
-COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd,
-		compat_loff_t __user *, offset, compat_size_t, count)
-{
-	loff_t pos;
-	ssize_t ret;
-
-	if (offset) {
-		if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t))))
-			return -EFAULT;
-		ret = do_sendfile(out_fd, in_fd, &pos, count, 0);
-		if (unlikely(put_user(pos, offset)))
-			return -EFAULT;
-		return ret;
-	}
-
-	return do_sendfile(out_fd, in_fd, NULL, count, 0);
-}
-#endif
diff --git a/fs/splice.c b/fs/splice.c
index f5cb9ba..c1a2861 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -28,6 +28,7 @@
 #include <linux/export.h>
 #include <linux/syscalls.h>
 #include <linux/uio.h>
+#include <linux/fsnotify.h>
 #include <linux/security.h>
 #include <linux/gfp.h>
 #include <linux/socket.h>
@@ -2039,3 +2040,180 @@ SYSCALL_DEFINE4(tee, int, fdin, int, fdout, size_t, len, unsigned int, flags)
 
 	return error;
 }
+
+static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
+			   size_t count, loff_t max)
+{
+	struct fd in, out;
+	struct inode *in_inode, *out_inode;
+	loff_t pos;
+	loff_t out_pos;
+	ssize_t retval;
+	int fl;
+
+	/*
+	 * Get input file, and verify that it is ok..
+	 */
+	retval = -EBADF;
+	in = fdget(in_fd);
+	if (!in.file)
+		goto out;
+	if (!(in.file->f_mode & FMODE_READ))
+		goto fput_in;
+	retval = -ESPIPE;
+	if (!ppos) {
+		pos = in.file->f_pos;
+	} else {
+		pos = *ppos;
+		if (!(in.file->f_mode & FMODE_PREAD))
+			goto fput_in;
+	}
+	retval = rw_verify_area(READ, in.file, &pos, count);
+	if (retval < 0)
+		goto fput_in;
+	count = retval;
+
+	/*
+	 * Get output file, and verify that it is ok..
+	 */
+	retval = -EBADF;
+	out = fdget(out_fd);
+	if (!out.file)
+		goto fput_in;
+	if (!(out.file->f_mode & FMODE_WRITE))
+		goto fput_out;
+	retval = -EINVAL;
+	in_inode = file_inode(in.file);
+	out_inode = file_inode(out.file);
+	out_pos = out.file->f_pos;
+	retval = rw_verify_area(WRITE, out.file, &out_pos, count);
+	if (retval < 0)
+		goto fput_out;
+	count = retval;
+
+	if (!max)
+		max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes);
+
+	if (unlikely(pos + count > max)) {
+		retval = -EOVERFLOW;
+		if (pos >= max)
+			goto fput_out;
+		count = max - pos;
+	}
+
+	fl = 0;
+#if 0
+	/*
+	 * We need to debate whether we can enable this or not. The
+	 * man page documents EAGAIN return for the output at least,
+	 * and the application is arguably buggy if it doesn't expect
+	 * EAGAIN on a non-blocking file descriptor.
+	 */
+	if (in.file->f_flags & O_NONBLOCK)
+		fl = SPLICE_F_NONBLOCK;
+#endif
+	file_start_write(out.file);
+	retval = do_splice_direct(in.file, &pos, out.file, &out_pos, count, fl);
+	file_end_write(out.file);
+
+	if (retval > 0) {
+		add_rchar(current, retval);
+		add_wchar(current, retval);
+		fsnotify_access(in.file);
+		fsnotify_modify(out.file);
+		out.file->f_pos = out_pos;
+		if (ppos)
+			*ppos = pos;
+		else
+			in.file->f_pos = pos;
+	}
+
+	inc_syscr(current);
+	inc_syscw(current);
+	if (pos > max)
+		retval = -EOVERFLOW;
+
+fput_out:
+	fdput(out);
+fput_in:
+	fdput(in);
+out:
+	return retval;
+}
+
+SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, off_t __user *, offset, size_t, count)
+{
+	loff_t pos;
+	off_t off;
+	ssize_t ret;
+
+	if (offset) {
+		if (unlikely(get_user(off, offset)))
+			return -EFAULT;
+		pos = off;
+		ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS);
+		if (unlikely(put_user(pos, offset)))
+			return -EFAULT;
+		return ret;
+	}
+
+	return do_sendfile(out_fd, in_fd, NULL, count, 0);
+}
+
+SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, size_t, count)
+{
+	loff_t pos;
+	ssize_t ret;
+
+	if (offset) {
+		if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t))))
+			return -EFAULT;
+		ret = do_sendfile(out_fd, in_fd, &pos, count, 0);
+		if (unlikely(put_user(pos, offset)))
+			return -EFAULT;
+		return ret;
+	}
+
+	return do_sendfile(out_fd, in_fd, NULL, count, 0);
+}
+
+#ifdef CONFIG_COMPAT
+COMPAT_SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd,
+		compat_off_t __user *, offset, compat_size_t, count)
+{
+	loff_t pos;
+	off_t off;
+	ssize_t ret;
+
+	if (offset) {
+		if (unlikely(get_user(off, offset)))
+			return -EFAULT;
+		pos = off;
+		ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS);
+		if (unlikely(put_user(pos, offset)))
+			return -EFAULT;
+		return ret;
+	}
+
+	return do_sendfile(out_fd, in_fd, NULL, count, 0);
+}
+
+COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd,
+		compat_loff_t __user *, offset, compat_size_t, count)
+{
+	loff_t pos;
+	ssize_t ret;
+
+	if (offset) {
+		if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t))))
+			return -EFAULT;
+		ret = do_sendfile(out_fd, in_fd, &pos, count, 0);
+		if (unlikely(put_user(pos, offset)))
+			return -EFAULT;
+		return ret;
+	}
+
+	return do_sendfile(out_fd, in_fd, NULL, count, 0);
+}
+#endif
+
-- 
2.1.0


^ permalink raw reply related	[flat|nested] 58+ messages in thread

* [PATCH 1/6] fs: move sendfile syscall into fs/splice
@ 2014-11-23 14:20   ` Pieter Smith
  0 siblings, 0 replies; 58+ messages in thread
From: Pieter Smith @ 2014-11-23 14:20 UTC (permalink / raw)
  To: pieter-qeJ+1H9vRZbz+pZb47iToQ
  Cc: Josh Triplett, Alexander Duyck, Alexander Viro,
	Alexei Starovoitov, Andrew Morton, Bertrand Jacquin,
	Catalina Mocanu, Daniel Borkmann, David S. Miller, Eric Dumazet,
	Eric W. Biederman, Fabian Frederick,
	open list:FUSE: FILESYSTEM...,
	Geert Uytterhoeven, Hugh Dickins, Iulia Manda, Jan Beulich,
	J. Bruce Fields, Jeff Layton, open list:ABI/API,
	linux-fsdevel-u79uwXL29TY76Z2rM5mHXA, linux-kernel

sendfile functionally forms part of the splice group of syscalls (splice,
vmsplice and tee). Grouping sendfile with splice paves the way to compiling out
the splice group of syscalls for embedded systems that do not need these.

add/remove: 0/0 grow/shrink: 7/2 up/down: 86/-61 (25)
function                                     old     new   delta
file_start_write                              34      68     +34
file_end_write                                29      58     +29
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
sys_tee                                      497     491      -6
sys_splice                                  1075    1020     -55

Signed-off-by: Pieter Smith <pieter-qeJ+1H9vRZbz+pZb47iToQ@public.gmane.org>
---
 fs/read_write.c | 175 -------------------------------------------------------
 fs/splice.c     | 178 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 178 insertions(+), 175 deletions(-)

diff --git a/fs/read_write.c b/fs/read_write.c
index 7d9318c..d9451ba 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1191,178 +1191,3 @@ COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd,
 }
 #endif
 
-static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
-		  	   size_t count, loff_t max)
-{
-	struct fd in, out;
-	struct inode *in_inode, *out_inode;
-	loff_t pos;
-	loff_t out_pos;
-	ssize_t retval;
-	int fl;
-
-	/*
-	 * Get input file, and verify that it is ok..
-	 */
-	retval = -EBADF;
-	in = fdget(in_fd);
-	if (!in.file)
-		goto out;
-	if (!(in.file->f_mode & FMODE_READ))
-		goto fput_in;
-	retval = -ESPIPE;
-	if (!ppos) {
-		pos = in.file->f_pos;
-	} else {
-		pos = *ppos;
-		if (!(in.file->f_mode & FMODE_PREAD))
-			goto fput_in;
-	}
-	retval = rw_verify_area(READ, in.file, &pos, count);
-	if (retval < 0)
-		goto fput_in;
-	count = retval;
-
-	/*
-	 * Get output file, and verify that it is ok..
-	 */
-	retval = -EBADF;
-	out = fdget(out_fd);
-	if (!out.file)
-		goto fput_in;
-	if (!(out.file->f_mode & FMODE_WRITE))
-		goto fput_out;
-	retval = -EINVAL;
-	in_inode = file_inode(in.file);
-	out_inode = file_inode(out.file);
-	out_pos = out.file->f_pos;
-	retval = rw_verify_area(WRITE, out.file, &out_pos, count);
-	if (retval < 0)
-		goto fput_out;
-	count = retval;
-
-	if (!max)
-		max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes);
-
-	if (unlikely(pos + count > max)) {
-		retval = -EOVERFLOW;
-		if (pos >= max)
-			goto fput_out;
-		count = max - pos;
-	}
-
-	fl = 0;
-#if 0
-	/*
-	 * We need to debate whether we can enable this or not. The
-	 * man page documents EAGAIN return for the output at least,
-	 * and the application is arguably buggy if it doesn't expect
-	 * EAGAIN on a non-blocking file descriptor.
-	 */
-	if (in.file->f_flags & O_NONBLOCK)
-		fl = SPLICE_F_NONBLOCK;
-#endif
-	file_start_write(out.file);
-	retval = do_splice_direct(in.file, &pos, out.file, &out_pos, count, fl);
-	file_end_write(out.file);
-
-	if (retval > 0) {
-		add_rchar(current, retval);
-		add_wchar(current, retval);
-		fsnotify_access(in.file);
-		fsnotify_modify(out.file);
-		out.file->f_pos = out_pos;
-		if (ppos)
-			*ppos = pos;
-		else
-			in.file->f_pos = pos;
-	}
-
-	inc_syscr(current);
-	inc_syscw(current);
-	if (pos > max)
-		retval = -EOVERFLOW;
-
-fput_out:
-	fdput(out);
-fput_in:
-	fdput(in);
-out:
-	return retval;
-}
-
-SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, off_t __user *, offset, size_t, count)
-{
-	loff_t pos;
-	off_t off;
-	ssize_t ret;
-
-	if (offset) {
-		if (unlikely(get_user(off, offset)))
-			return -EFAULT;
-		pos = off;
-		ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS);
-		if (unlikely(put_user(pos, offset)))
-			return -EFAULT;
-		return ret;
-	}
-
-	return do_sendfile(out_fd, in_fd, NULL, count, 0);
-}
-
-SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, size_t, count)
-{
-	loff_t pos;
-	ssize_t ret;
-
-	if (offset) {
-		if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t))))
-			return -EFAULT;
-		ret = do_sendfile(out_fd, in_fd, &pos, count, 0);
-		if (unlikely(put_user(pos, offset)))
-			return -EFAULT;
-		return ret;
-	}
-
-	return do_sendfile(out_fd, in_fd, NULL, count, 0);
-}
-
-#ifdef CONFIG_COMPAT
-COMPAT_SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd,
-		compat_off_t __user *, offset, compat_size_t, count)
-{
-	loff_t pos;
-	off_t off;
-	ssize_t ret;
-
-	if (offset) {
-		if (unlikely(get_user(off, offset)))
-			return -EFAULT;
-		pos = off;
-		ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS);
-		if (unlikely(put_user(pos, offset)))
-			return -EFAULT;
-		return ret;
-	}
-
-	return do_sendfile(out_fd, in_fd, NULL, count, 0);
-}
-
-COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd,
-		compat_loff_t __user *, offset, compat_size_t, count)
-{
-	loff_t pos;
-	ssize_t ret;
-
-	if (offset) {
-		if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t))))
-			return -EFAULT;
-		ret = do_sendfile(out_fd, in_fd, &pos, count, 0);
-		if (unlikely(put_user(pos, offset)))
-			return -EFAULT;
-		return ret;
-	}
-
-	return do_sendfile(out_fd, in_fd, NULL, count, 0);
-}
-#endif
diff --git a/fs/splice.c b/fs/splice.c
index f5cb9ba..c1a2861 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -28,6 +28,7 @@
 #include <linux/export.h>
 #include <linux/syscalls.h>
 #include <linux/uio.h>
+#include <linux/fsnotify.h>
 #include <linux/security.h>
 #include <linux/gfp.h>
 #include <linux/socket.h>
@@ -2039,3 +2040,180 @@ SYSCALL_DEFINE4(tee, int, fdin, int, fdout, size_t, len, unsigned int, flags)
 
 	return error;
 }
+
+static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
+			   size_t count, loff_t max)
+{
+	struct fd in, out;
+	struct inode *in_inode, *out_inode;
+	loff_t pos;
+	loff_t out_pos;
+	ssize_t retval;
+	int fl;
+
+	/*
+	 * Get input file, and verify that it is ok..
+	 */
+	retval = -EBADF;
+	in = fdget(in_fd);
+	if (!in.file)
+		goto out;
+	if (!(in.file->f_mode & FMODE_READ))
+		goto fput_in;
+	retval = -ESPIPE;
+	if (!ppos) {
+		pos = in.file->f_pos;
+	} else {
+		pos = *ppos;
+		if (!(in.file->f_mode & FMODE_PREAD))
+			goto fput_in;
+	}
+	retval = rw_verify_area(READ, in.file, &pos, count);
+	if (retval < 0)
+		goto fput_in;
+	count = retval;
+
+	/*
+	 * Get output file, and verify that it is ok..
+	 */
+	retval = -EBADF;
+	out = fdget(out_fd);
+	if (!out.file)
+		goto fput_in;
+	if (!(out.file->f_mode & FMODE_WRITE))
+		goto fput_out;
+	retval = -EINVAL;
+	in_inode = file_inode(in.file);
+	out_inode = file_inode(out.file);
+	out_pos = out.file->f_pos;
+	retval = rw_verify_area(WRITE, out.file, &out_pos, count);
+	if (retval < 0)
+		goto fput_out;
+	count = retval;
+
+	if (!max)
+		max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes);
+
+	if (unlikely(pos + count > max)) {
+		retval = -EOVERFLOW;
+		if (pos >= max)
+			goto fput_out;
+		count = max - pos;
+	}
+
+	fl = 0;
+#if 0
+	/*
+	 * We need to debate whether we can enable this or not. The
+	 * man page documents EAGAIN return for the output at least,
+	 * and the application is arguably buggy if it doesn't expect
+	 * EAGAIN on a non-blocking file descriptor.
+	 */
+	if (in.file->f_flags & O_NONBLOCK)
+		fl = SPLICE_F_NONBLOCK;
+#endif
+	file_start_write(out.file);
+	retval = do_splice_direct(in.file, &pos, out.file, &out_pos, count, fl);
+	file_end_write(out.file);
+
+	if (retval > 0) {
+		add_rchar(current, retval);
+		add_wchar(current, retval);
+		fsnotify_access(in.file);
+		fsnotify_modify(out.file);
+		out.file->f_pos = out_pos;
+		if (ppos)
+			*ppos = pos;
+		else
+			in.file->f_pos = pos;
+	}
+
+	inc_syscr(current);
+	inc_syscw(current);
+	if (pos > max)
+		retval = -EOVERFLOW;
+
+fput_out:
+	fdput(out);
+fput_in:
+	fdput(in);
+out:
+	return retval;
+}
+
+SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, off_t __user *, offset, size_t, count)
+{
+	loff_t pos;
+	off_t off;
+	ssize_t ret;
+
+	if (offset) {
+		if (unlikely(get_user(off, offset)))
+			return -EFAULT;
+		pos = off;
+		ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS);
+		if (unlikely(put_user(pos, offset)))
+			return -EFAULT;
+		return ret;
+	}
+
+	return do_sendfile(out_fd, in_fd, NULL, count, 0);
+}
+
+SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, size_t, count)
+{
+	loff_t pos;
+	ssize_t ret;
+
+	if (offset) {
+		if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t))))
+			return -EFAULT;
+		ret = do_sendfile(out_fd, in_fd, &pos, count, 0);
+		if (unlikely(put_user(pos, offset)))
+			return -EFAULT;
+		return ret;
+	}
+
+	return do_sendfile(out_fd, in_fd, NULL, count, 0);
+}
+
+#ifdef CONFIG_COMPAT
+COMPAT_SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd,
+		compat_off_t __user *, offset, compat_size_t, count)
+{
+	loff_t pos;
+	off_t off;
+	ssize_t ret;
+
+	if (offset) {
+		if (unlikely(get_user(off, offset)))
+			return -EFAULT;
+		pos = off;
+		ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS);
+		if (unlikely(put_user(pos, offset)))
+			return -EFAULT;
+		return ret;
+	}
+
+	return do_sendfile(out_fd, in_fd, NULL, count, 0);
+}
+
+COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd,
+		compat_loff_t __user *, offset, compat_size_t, count)
+{
+	loff_t pos;
+	ssize_t ret;
+
+	if (offset) {
+		if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t))))
+			return -EFAULT;
+		ret = do_sendfile(out_fd, in_fd, &pos, count, 0);
+		if (unlikely(put_user(pos, offset)))
+			return -EFAULT;
+		return ret;
+	}
+
+	return do_sendfile(out_fd, in_fd, NULL, count, 0);
+}
+#endif
+
-- 
2.1.0

^ permalink raw reply related	[flat|nested] 58+ messages in thread

* [PATCH 1/6] fs: move sendfile syscall into fs/splice
@ 2014-11-23 14:20   ` Pieter Smith
  0 siblings, 0 replies; 58+ messages in thread
From: Pieter Smith @ 2014-11-23 14:20 UTC (permalink / raw)
  To: pieter-qeJ+1H9vRZbz+pZb47iToQ
  Cc: Josh Triplett, Alexander Duyck, Alexander Viro,
	Alexei Starovoitov, Andrew Morton, Bertrand Jacquin,
	Catalina Mocanu, Daniel Borkmann, David S. Miller, Eric Dumazet,
	Eric W. Biederman, Fabian Frederick,
	open list:FUSE: FILESYSTEM...,
	Geert Uytterhoeven, Hugh Dickins, Iulia Manda, Jan Beulich,
	J. Bruce Fields, Jeff Layton, open list:ABI/API,
	linux-fsdevel-u79uwXL29TY76Z2rM5mHXA, linux-kernel

sendfile functionally forms part of the splice group of syscalls (splice,
vmsplice and tee). Grouping sendfile with splice paves the way to compiling out
the splice group of syscalls for embedded systems that do not need these.

add/remove: 0/0 grow/shrink: 7/2 up/down: 86/-61 (25)
function                                     old     new   delta
file_start_write                              34      68     +34
file_end_write                                29      58     +29
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
sys_tee                                      497     491      -6
sys_splice                                  1075    1020     -55

Signed-off-by: Pieter Smith <pieter-qeJ+1H9vRZbz+pZb47iToQ@public.gmane.org>
---
 fs/read_write.c | 175 -------------------------------------------------------
 fs/splice.c     | 178 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 178 insertions(+), 175 deletions(-)

diff --git a/fs/read_write.c b/fs/read_write.c
index 7d9318c..d9451ba 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1191,178 +1191,3 @@ COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd,
 }
 #endif
 
-static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
-		  	   size_t count, loff_t max)
-{
-	struct fd in, out;
-	struct inode *in_inode, *out_inode;
-	loff_t pos;
-	loff_t out_pos;
-	ssize_t retval;
-	int fl;
-
-	/*
-	 * Get input file, and verify that it is ok..
-	 */
-	retval = -EBADF;
-	in = fdget(in_fd);
-	if (!in.file)
-		goto out;
-	if (!(in.file->f_mode & FMODE_READ))
-		goto fput_in;
-	retval = -ESPIPE;
-	if (!ppos) {
-		pos = in.file->f_pos;
-	} else {
-		pos = *ppos;
-		if (!(in.file->f_mode & FMODE_PREAD))
-			goto fput_in;
-	}
-	retval = rw_verify_area(READ, in.file, &pos, count);
-	if (retval < 0)
-		goto fput_in;
-	count = retval;
-
-	/*
-	 * Get output file, and verify that it is ok..
-	 */
-	retval = -EBADF;
-	out = fdget(out_fd);
-	if (!out.file)
-		goto fput_in;
-	if (!(out.file->f_mode & FMODE_WRITE))
-		goto fput_out;
-	retval = -EINVAL;
-	in_inode = file_inode(in.file);
-	out_inode = file_inode(out.file);
-	out_pos = out.file->f_pos;
-	retval = rw_verify_area(WRITE, out.file, &out_pos, count);
-	if (retval < 0)
-		goto fput_out;
-	count = retval;
-
-	if (!max)
-		max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes);
-
-	if (unlikely(pos + count > max)) {
-		retval = -EOVERFLOW;
-		if (pos >= max)
-			goto fput_out;
-		count = max - pos;
-	}
-
-	fl = 0;
-#if 0
-	/*
-	 * We need to debate whether we can enable this or not. The
-	 * man page documents EAGAIN return for the output at least,
-	 * and the application is arguably buggy if it doesn't expect
-	 * EAGAIN on a non-blocking file descriptor.
-	 */
-	if (in.file->f_flags & O_NONBLOCK)
-		fl = SPLICE_F_NONBLOCK;
-#endif
-	file_start_write(out.file);
-	retval = do_splice_direct(in.file, &pos, out.file, &out_pos, count, fl);
-	file_end_write(out.file);
-
-	if (retval > 0) {
-		add_rchar(current, retval);
-		add_wchar(current, retval);
-		fsnotify_access(in.file);
-		fsnotify_modify(out.file);
-		out.file->f_pos = out_pos;
-		if (ppos)
-			*ppos = pos;
-		else
-			in.file->f_pos = pos;
-	}
-
-	inc_syscr(current);
-	inc_syscw(current);
-	if (pos > max)
-		retval = -EOVERFLOW;
-
-fput_out:
-	fdput(out);
-fput_in:
-	fdput(in);
-out:
-	return retval;
-}
-
-SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, off_t __user *, offset, size_t, count)
-{
-	loff_t pos;
-	off_t off;
-	ssize_t ret;
-
-	if (offset) {
-		if (unlikely(get_user(off, offset)))
-			return -EFAULT;
-		pos = off;
-		ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS);
-		if (unlikely(put_user(pos, offset)))
-			return -EFAULT;
-		return ret;
-	}
-
-	return do_sendfile(out_fd, in_fd, NULL, count, 0);
-}
-
-SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, size_t, count)
-{
-	loff_t pos;
-	ssize_t ret;
-
-	if (offset) {
-		if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t))))
-			return -EFAULT;
-		ret = do_sendfile(out_fd, in_fd, &pos, count, 0);
-		if (unlikely(put_user(pos, offset)))
-			return -EFAULT;
-		return ret;
-	}
-
-	return do_sendfile(out_fd, in_fd, NULL, count, 0);
-}
-
-#ifdef CONFIG_COMPAT
-COMPAT_SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd,
-		compat_off_t __user *, offset, compat_size_t, count)
-{
-	loff_t pos;
-	off_t off;
-	ssize_t ret;
-
-	if (offset) {
-		if (unlikely(get_user(off, offset)))
-			return -EFAULT;
-		pos = off;
-		ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS);
-		if (unlikely(put_user(pos, offset)))
-			return -EFAULT;
-		return ret;
-	}
-
-	return do_sendfile(out_fd, in_fd, NULL, count, 0);
-}
-
-COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd,
-		compat_loff_t __user *, offset, compat_size_t, count)
-{
-	loff_t pos;
-	ssize_t ret;
-
-	if (offset) {
-		if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t))))
-			return -EFAULT;
-		ret = do_sendfile(out_fd, in_fd, &pos, count, 0);
-		if (unlikely(put_user(pos, offset)))
-			return -EFAULT;
-		return ret;
-	}
-
-	return do_sendfile(out_fd, in_fd, NULL, count, 0);
-}
-#endif
diff --git a/fs/splice.c b/fs/splice.c
index f5cb9ba..c1a2861 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -28,6 +28,7 @@
 #include <linux/export.h>
 #include <linux/syscalls.h>
 #include <linux/uio.h>
+#include <linux/fsnotify.h>
 #include <linux/security.h>
 #include <linux/gfp.h>
 #include <linux/socket.h>
@@ -2039,3 +2040,180 @@ SYSCALL_DEFINE4(tee, int, fdin, int, fdout, size_t, len, unsigned int, flags)
 
 	return error;
 }
+
+static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
+			   size_t count, loff_t max)
+{
+	struct fd in, out;
+	struct inode *in_inode, *out_inode;
+	loff_t pos;
+	loff_t out_pos;
+	ssize_t retval;
+	int fl;
+
+	/*
+	 * Get input file, and verify that it is ok..
+	 */
+	retval = -EBADF;
+	in = fdget(in_fd);
+	if (!in.file)
+		goto out;
+	if (!(in.file->f_mode & FMODE_READ))
+		goto fput_in;
+	retval = -ESPIPE;
+	if (!ppos) {
+		pos = in.file->f_pos;
+	} else {
+		pos = *ppos;
+		if (!(in.file->f_mode & FMODE_PREAD))
+			goto fput_in;
+	}
+	retval = rw_verify_area(READ, in.file, &pos, count);
+	if (retval < 0)
+		goto fput_in;
+	count = retval;
+
+	/*
+	 * Get output file, and verify that it is ok..
+	 */
+	retval = -EBADF;
+	out = fdget(out_fd);
+	if (!out.file)
+		goto fput_in;
+	if (!(out.file->f_mode & FMODE_WRITE))
+		goto fput_out;
+	retval = -EINVAL;
+	in_inode = file_inode(in.file);
+	out_inode = file_inode(out.file);
+	out_pos = out.file->f_pos;
+	retval = rw_verify_area(WRITE, out.file, &out_pos, count);
+	if (retval < 0)
+		goto fput_out;
+	count = retval;
+
+	if (!max)
+		max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes);
+
+	if (unlikely(pos + count > max)) {
+		retval = -EOVERFLOW;
+		if (pos >= max)
+			goto fput_out;
+		count = max - pos;
+	}
+
+	fl = 0;
+#if 0
+	/*
+	 * We need to debate whether we can enable this or not. The
+	 * man page documents EAGAIN return for the output at least,
+	 * and the application is arguably buggy if it doesn't expect
+	 * EAGAIN on a non-blocking file descriptor.
+	 */
+	if (in.file->f_flags & O_NONBLOCK)
+		fl = SPLICE_F_NONBLOCK;
+#endif
+	file_start_write(out.file);
+	retval = do_splice_direct(in.file, &pos, out.file, &out_pos, count, fl);
+	file_end_write(out.file);
+
+	if (retval > 0) {
+		add_rchar(current, retval);
+		add_wchar(current, retval);
+		fsnotify_access(in.file);
+		fsnotify_modify(out.file);
+		out.file->f_pos = out_pos;
+		if (ppos)
+			*ppos = pos;
+		else
+			in.file->f_pos = pos;
+	}
+
+	inc_syscr(current);
+	inc_syscw(current);
+	if (pos > max)
+		retval = -EOVERFLOW;
+
+fput_out:
+	fdput(out);
+fput_in:
+	fdput(in);
+out:
+	return retval;
+}
+
+SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, off_t __user *, offset, size_t, count)
+{
+	loff_t pos;
+	off_t off;
+	ssize_t ret;
+
+	if (offset) {
+		if (unlikely(get_user(off, offset)))
+			return -EFAULT;
+		pos = off;
+		ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS);
+		if (unlikely(put_user(pos, offset)))
+			return -EFAULT;
+		return ret;
+	}
+
+	return do_sendfile(out_fd, in_fd, NULL, count, 0);
+}
+
+SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, size_t, count)
+{
+	loff_t pos;
+	ssize_t ret;
+
+	if (offset) {
+		if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t))))
+			return -EFAULT;
+		ret = do_sendfile(out_fd, in_fd, &pos, count, 0);
+		if (unlikely(put_user(pos, offset)))
+			return -EFAULT;
+		return ret;
+	}
+
+	return do_sendfile(out_fd, in_fd, NULL, count, 0);
+}
+
+#ifdef CONFIG_COMPAT
+COMPAT_SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd,
+		compat_off_t __user *, offset, compat_size_t, count)
+{
+	loff_t pos;
+	off_t off;
+	ssize_t ret;
+
+	if (offset) {
+		if (unlikely(get_user(off, offset)))
+			return -EFAULT;
+		pos = off;
+		ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS);
+		if (unlikely(put_user(pos, offset)))
+			return -EFAULT;
+		return ret;
+	}
+
+	return do_sendfile(out_fd, in_fd, NULL, count, 0);
+}
+
+COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd,
+		compat_loff_t __user *, offset, compat_size_t, count)
+{
+	loff_t pos;
+	ssize_t ret;
+
+	if (offset) {
+		if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t))))
+			return -EFAULT;
+		ret = do_sendfile(out_fd, in_fd, &pos, count, 0);
+		if (unlikely(put_user(pos, offset)))
+			return -EFAULT;
+		return ret;
+	}
+
+	return do_sendfile(out_fd, in_fd, NULL, count, 0);
+}
+#endif
+
-- 
2.1.0

^ permalink raw reply related	[flat|nested] 58+ messages in thread

* [PATCH 2/6] fs: moved kernel_write to fs/read_write
  2014-11-23 14:20 ` Pieter Smith
  (?)
@ 2014-11-23 14:20   ` Pieter Smith
  -1 siblings, 0 replies; 58+ messages in thread
From: Pieter Smith @ 2014-11-23 14:20 UTC (permalink / raw)
  To: pieter
  Cc: Josh Triplett, Alexander Duyck, Alexander Viro,
	Alexei Starovoitov, Andrew Morton, Bertrand Jacquin,
	Catalina Mocanu, Daniel Borkmann, David S. Miller, Eric Dumazet,
	Eric W. Biederman, Fabian Frederick,
	open list:FUSE: FILESYSTEM...,
	Geert Uytterhoeven, Hugh Dickins, Iulia Manda, Jan Beulich,
	J. Bruce Fields, Jeff Layton, open list:ABI/API, linux-fsdevel,
	open list, Luis R. Rodriguez, Matt Turner, Mel Gorman,
	Michael S. Tsirkin, Miklos Szeredi,
	open list:NETWORKING [GENERAL],
	Oleg Nesterov, Paul Durrant, Paul E. McKenney, Peter Foley,
	Thomas Graf, Tom Herbert, Willem de Bruijn, Xiao Guangrong,
	蔡正龙

kernel_write shares infrastructure with the read_write translation unit but not
with the splice translation unit. Grouping kernel_write with the read_write
translation unit is more logical. It also paves the way to compiling out the
splice group of syscalls for embedded systems that do not need them.

Signed-off-by: Pieter Smith <pieter@boesman.nl>
---
 fs/read_write.c | 16 ++++++++++++++++
 fs/splice.c     | 16 ----------------
 2 files changed, 16 insertions(+), 16 deletions(-)

diff --git a/fs/read_write.c b/fs/read_write.c
index d9451ba..f4c8d8b 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1191,3 +1191,19 @@ COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd,
 }
 #endif
 
+ssize_t kernel_write(struct file *file, const char *buf, size_t count,
+			    loff_t pos)
+{
+	mm_segment_t old_fs;
+	ssize_t res;
+
+	old_fs = get_fs();
+	set_fs(get_ds());
+	/* The cast to a user pointer is valid due to the set_fs() */
+	res = vfs_write(file, (__force const char __user *)buf, count, &pos);
+	set_fs(old_fs);
+
+	return res;
+}
+EXPORT_SYMBOL(kernel_write);
+
diff --git a/fs/splice.c b/fs/splice.c
index c1a2861..44b201b 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -583,22 +583,6 @@ static ssize_t kernel_readv(struct file *file, const struct iovec *vec,
 	return res;
 }
 
-ssize_t kernel_write(struct file *file, const char *buf, size_t count,
-			    loff_t pos)
-{
-	mm_segment_t old_fs;
-	ssize_t res;
-
-	old_fs = get_fs();
-	set_fs(get_ds());
-	/* The cast to a user pointer is valid due to the set_fs() */
-	res = vfs_write(file, (__force const char __user *)buf, count, &pos);
-	set_fs(old_fs);
-
-	return res;
-}
-EXPORT_SYMBOL(kernel_write);
-
 ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
 				 struct pipe_inode_info *pipe, size_t len,
 				 unsigned int flags)
-- 
2.1.0


^ permalink raw reply related	[flat|nested] 58+ messages in thread

* [PATCH 2/6] fs: moved kernel_write to fs/read_write
@ 2014-11-23 14:20   ` Pieter Smith
  0 siblings, 0 replies; 58+ messages in thread
From: Pieter Smith @ 2014-11-23 14:20 UTC (permalink / raw)
  To: pieter
  Cc: Josh Triplett, Alexander Duyck, Alexander Viro,
	Alexei Starovoitov, Andrew Morton, Bertrand Jacquin,
	Catalina Mocanu, Daniel Borkmann, David S. Miller, Eric Dumazet,
	Eric W. Biederman, Fabian Frederick,
	open list:FUSE: FILESYSTEM...,
	Geert Uytterhoeven, Hugh Dickins, Iulia Manda, Jan Beulich,
	J. Bruce Fields, Jeff Layton, open list:ABI/API, linux-fsdevel,
	linux-kernel

kernel_write shares infrastructure with the read_write translation unit but not
with the splice translation unit. Grouping kernel_write with the read_write
translation unit is more logical. It also paves the way to compiling out the
splice group of syscalls for embedded systems that do not need them.

Signed-off-by: Pieter Smith <pieter@boesman.nl>
---
 fs/read_write.c | 16 ++++++++++++++++
 fs/splice.c     | 16 ----------------
 2 files changed, 16 insertions(+), 16 deletions(-)

diff --git a/fs/read_write.c b/fs/read_write.c
index d9451ba..f4c8d8b 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1191,3 +1191,19 @@ COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd,
 }
 #endif
 
+ssize_t kernel_write(struct file *file, const char *buf, size_t count,
+			    loff_t pos)
+{
+	mm_segment_t old_fs;
+	ssize_t res;
+
+	old_fs = get_fs();
+	set_fs(get_ds());
+	/* The cast to a user pointer is valid due to the set_fs() */
+	res = vfs_write(file, (__force const char __user *)buf, count, &pos);
+	set_fs(old_fs);
+
+	return res;
+}
+EXPORT_SYMBOL(kernel_write);
+
diff --git a/fs/splice.c b/fs/splice.c
index c1a2861..44b201b 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -583,22 +583,6 @@ static ssize_t kernel_readv(struct file *file, const struct iovec *vec,
 	return res;
 }
 
-ssize_t kernel_write(struct file *file, const char *buf, size_t count,
-			    loff_t pos)
-{
-	mm_segment_t old_fs;
-	ssize_t res;
-
-	old_fs = get_fs();
-	set_fs(get_ds());
-	/* The cast to a user pointer is valid due to the set_fs() */
-	res = vfs_write(file, (__force const char __user *)buf, count, &pos);
-	set_fs(old_fs);
-
-	return res;
-}
-EXPORT_SYMBOL(kernel_write);
-
 ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
 				 struct pipe_inode_info *pipe, size_t len,
 				 unsigned int flags)
-- 
2.1.0

^ permalink raw reply related	[flat|nested] 58+ messages in thread

* [PATCH 2/6] fs: moved kernel_write to fs/read_write
@ 2014-11-23 14:20   ` Pieter Smith
  0 siblings, 0 replies; 58+ messages in thread
From: Pieter Smith @ 2014-11-23 14:20 UTC (permalink / raw)
  To: pieter
  Cc: Josh Triplett, Alexander Duyck, Alexander Viro,
	Alexei Starovoitov, Andrew Morton, Bertrand Jacquin,
	Catalina Mocanu, Daniel Borkmann, David S. Miller, Eric Dumazet,
	Eric W. Biederman, Fabian Frederick,
	open list:FUSE: FILESYSTEM...,
	Geert Uytterhoeven, Hugh Dickins, Iulia Manda, Jan Beulich,
	J. Bruce Fields, Jeff Layton, open list:ABI/API, linux-fsdevel,
	linux-kernel

kernel_write shares infrastructure with the read_write translation unit but not
with the splice translation unit. Grouping kernel_write with the read_write
translation unit is more logical. It also paves the way to compiling out the
splice group of syscalls for embedded systems that do not need them.

Signed-off-by: Pieter Smith <pieter@boesman.nl>
---
 fs/read_write.c | 16 ++++++++++++++++
 fs/splice.c     | 16 ----------------
 2 files changed, 16 insertions(+), 16 deletions(-)

diff --git a/fs/read_write.c b/fs/read_write.c
index d9451ba..f4c8d8b 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1191,3 +1191,19 @@ COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd,
 }
 #endif
 
+ssize_t kernel_write(struct file *file, const char *buf, size_t count,
+			    loff_t pos)
+{
+	mm_segment_t old_fs;
+	ssize_t res;
+
+	old_fs = get_fs();
+	set_fs(get_ds());
+	/* The cast to a user pointer is valid due to the set_fs() */
+	res = vfs_write(file, (__force const char __user *)buf, count, &pos);
+	set_fs(old_fs);
+
+	return res;
+}
+EXPORT_SYMBOL(kernel_write);
+
diff --git a/fs/splice.c b/fs/splice.c
index c1a2861..44b201b 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -583,22 +583,6 @@ static ssize_t kernel_readv(struct file *file, const struct iovec *vec,
 	return res;
 }
 
-ssize_t kernel_write(struct file *file, const char *buf, size_t count,
-			    loff_t pos)
-{
-	mm_segment_t old_fs;
-	ssize_t res;
-
-	old_fs = get_fs();
-	set_fs(get_ds());
-	/* The cast to a user pointer is valid due to the set_fs() */
-	res = vfs_write(file, (__force const char __user *)buf, count, &pos);
-	set_fs(old_fs);
-
-	return res;
-}
-EXPORT_SYMBOL(kernel_write);
-
 ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
 				 struct pipe_inode_info *pipe, size_t len,
 				 unsigned int flags)
-- 
2.1.0

^ permalink raw reply related	[flat|nested] 58+ messages in thread

* [PATCH 3/6] fs/splice: support compiling out splice-family syscalls
  2014-11-23 14:20 ` Pieter Smith
  (?)
@ 2014-11-23 14:20   ` Pieter Smith
  -1 siblings, 0 replies; 58+ messages in thread
From: Pieter Smith @ 2014-11-23 14:20 UTC (permalink / raw)
  To: pieter
  Cc: Josh Triplett, Alexander Duyck, Alexander Viro,
	Alexei Starovoitov, Andrew Morton, Bertrand Jacquin,
	Catalina Mocanu, Daniel Borkmann, David S. Miller, Eric Dumazet,
	Eric W. Biederman, Fabian Frederick,
	open list:FUSE: FILESYSTEM...,
	Geert Uytterhoeven, Hugh Dickins, Iulia Manda, Jan Beulich,
	J. Bruce Fields, Jeff Layton, open list:ABI/API, linux-fsdevel,
	open list, Luis R. Rodriguez, Matt Turner, Mel Gorman,
	Michael S. Tsirkin, Miklos Szeredi,
	open list:NETWORKING [GENERAL],
	Oleg Nesterov, Paul Durrant, Paul E. McKenney, Peter Foley,
	Thomas Graf, Tom Herbert, Willem de Bruijn, Xiao Guangrong,
	蔡正龙

Many embedded systems will not need the splice-family syscalls (splice,
vmsplice, tee and sendfile). Omitting them saves space.  This adds a new EXPERT
config option CONFIG_SYSCALL_SPLICE (default y) to support compiling them out.

The goal is to completely compile out fs/splice. To achieve this, the remaining
patch-set will deal with fs/splice exports. As far as possible, the impact on
other device drivers will be minimized so as to reduce the maintenance burden
of CONFIG_SYSCALL_SPLICE.

The use of exported functions will be solved by transparently mocking them out
with static inlines. Use of the exported pipe_buf_operations struct however
require direct modification in fs/fuse and net/core. The next two patches will
deal with this.

Once all exports are solved, fs/splice can be compiled out.

The bloat benefit of this patch given a tinyconfig is:

add/remove: 0/16 grow/shrink: 2/5 up/down: 114/-3693 (-3579)
function                                     old     new   delta
splice_direct_to_actor                       348     416     +68
splice_to_pipe                               371     417     +46
splice_from_pipe_next                        107     106      -1
fdput                                         11       -     -11
signal_pending                                39      26     -13
fdget                                         56      42     -14
user_page_pipe_buf_ops                        20       -     -20
user_page_pipe_buf_steal                      25       -     -25
file_end_write                                58      29     -29
file_start_write                              68      34     -34
pipe_to_user                                  43       -     -43
wakeup_pipe_readers                           54       -     -54
do_splice_to                                  87       -     -87
ipipe_prep.part                               92       -     -92
opipe_prep.part                              119       -    -119
sys_sendfile                                 122       -    -122
sys_sendfile64                               126       -    -126
sys_vmsplice                                 137       -    -137
vmsplice_to_user                             205       -    -205
sys_tee                                      491       -    -491
do_sendfile                                  492       -    -492
vmsplice_to_pipe                             558       -    -558
sys_splice                                  1020       -   -1020

Signed-off-by: Pieter Smith <pieter@boesman.nl>
---
 fs/splice.c     |  2 ++
 init/Kconfig    | 10 ++++++++++
 kernel/sys_ni.c |  8 ++++++++
 3 files changed, 20 insertions(+)

diff --git a/fs/splice.c b/fs/splice.c
index 44b201b..7c4c695 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -1316,6 +1316,7 @@ 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);
@@ -2200,4 +2201,5 @@ 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/init/Kconfig b/init/Kconfig
index d811d5f..dec9819 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1571,6 +1571,16 @@ config NTP
 	  system clock to an NTP server, you can disable this option to save
 	  space.
 
+config SYSCALL_SPLICE
+	bool "Enable splice/vmsplice/tee/sendfile syscalls" if EXPERT
+	default y
+	help
+	  This option enables the splice, vmsplice, tee and sendfile syscalls. These
+	  are used by applications to: move data between buffers and arbitrary file
+	  descriptors; "copy" data between buffers; or copy data from userspace into
+	  buffers. If building an embedded system where no applications use these
+	  syscalls, 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 d2f5b00..25d5551 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -170,6 +170,14 @@ cond_syscall(sys_fstat);
 cond_syscall(sys_stat);
 cond_syscall(sys_uname);
 cond_syscall(sys_olduname);
+cond_syscall(sys_vmsplice);
+cond_syscall(sys_splice);
+cond_syscall(sys_tee);
+cond_syscall(sys_sendfile);
+cond_syscall(sys_sendfile64);
+cond_syscall(compat_sys_vmsplice);
+cond_syscall(compat_sys_sendfile);
+cond_syscall(compat_sys_sendfile64);
 
 /* arch-specific weak syscall entries */
 cond_syscall(sys_pciconfig_read);
-- 
2.1.0


^ permalink raw reply related	[flat|nested] 58+ messages in thread

* [PATCH 3/6] fs/splice: support compiling out splice-family syscalls
@ 2014-11-23 14:20   ` Pieter Smith
  0 siblings, 0 replies; 58+ messages in thread
From: Pieter Smith @ 2014-11-23 14:20 UTC (permalink / raw)
  To: pieter
  Cc: Josh Triplett, Alexander Duyck, Alexander Viro,
	Alexei Starovoitov, Andrew Morton, Bertrand Jacquin,
	Catalina Mocanu, Daniel Borkmann, David S. Miller, Eric Dumazet,
	Eric W. Biederman, Fabian Frederick,
	open list:FUSE: FILESYSTEM...,
	Geert Uytterhoeven, Hugh Dickins, Iulia Manda, Jan Beulich,
	J. Bruce Fields, Jeff Layton, open list:ABI/API, linux-fsdevel,
	linux-kernel

Many embedded systems will not need the splice-family syscalls (splice,
vmsplice, tee and sendfile). Omitting them saves space.  This adds a new EXPERT
config option CONFIG_SYSCALL_SPLICE (default y) to support compiling them out.

The goal is to completely compile out fs/splice. To achieve this, the remaining
patch-set will deal with fs/splice exports. As far as possible, the impact on
other device drivers will be minimized so as to reduce the maintenance burden
of CONFIG_SYSCALL_SPLICE.

The use of exported functions will be solved by transparently mocking them out
with static inlines. Use of the exported pipe_buf_operations struct however
require direct modification in fs/fuse and net/core. The next two patches will
deal with this.

Once all exports are solved, fs/splice can be compiled out.

The bloat benefit of this patch given a tinyconfig is:

add/remove: 0/16 grow/shrink: 2/5 up/down: 114/-3693 (-3579)
function                                     old     new   delta
splice_direct_to_actor                       348     416     +68
splice_to_pipe                               371     417     +46
splice_from_pipe_next                        107     106      -1
fdput                                         11       -     -11
signal_pending                                39      26     -13
fdget                                         56      42     -14
user_page_pipe_buf_ops                        20       -     -20
user_page_pipe_buf_steal                      25       -     -25
file_end_write                                58      29     -29
file_start_write                              68      34     -34
pipe_to_user                                  43       -     -43
wakeup_pipe_readers                           54       -     -54
do_splice_to                                  87       -     -87
ipipe_prep.part                               92       -     -92
opipe_prep.part                              119       -    -119
sys_sendfile                                 122       -    -122
sys_sendfile64                               126       -    -126
sys_vmsplice                                 137       -    -137
vmsplice_to_user                             205       -    -205
sys_tee                                      491       -    -491
do_sendfile                                  492       -    -492
vmsplice_to_pipe                             558       -    -558
sys_splice                                  1020       -   -1020

Signed-off-by: Pieter Smith <pieter@boesman.nl>
---
 fs/splice.c     |  2 ++
 init/Kconfig    | 10 ++++++++++
 kernel/sys_ni.c |  8 ++++++++
 3 files changed, 20 insertions(+)

diff --git a/fs/splice.c b/fs/splice.c
index 44b201b..7c4c695 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -1316,6 +1316,7 @@ 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);
@@ -2200,4 +2201,5 @@ 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/init/Kconfig b/init/Kconfig
index d811d5f..dec9819 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1571,6 +1571,16 @@ config NTP
 	  system clock to an NTP server, you can disable this option to save
 	  space.
 
+config SYSCALL_SPLICE
+	bool "Enable splice/vmsplice/tee/sendfile syscalls" if EXPERT
+	default y
+	help
+	  This option enables the splice, vmsplice, tee and sendfile syscalls. These
+	  are used by applications to: move data between buffers and arbitrary file
+	  descriptors; "copy" data between buffers; or copy data from userspace into
+	  buffers. If building an embedded system where no applications use these
+	  syscalls, 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 d2f5b00..25d5551 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -170,6 +170,14 @@ cond_syscall(sys_fstat);
 cond_syscall(sys_stat);
 cond_syscall(sys_uname);
 cond_syscall(sys_olduname);
+cond_syscall(sys_vmsplice);
+cond_syscall(sys_splice);
+cond_syscall(sys_tee);
+cond_syscall(sys_sendfile);
+cond_syscall(sys_sendfile64);
+cond_syscall(compat_sys_vmsplice);
+cond_syscall(compat_sys_sendfile);
+cond_syscall(compat_sys_sendfile64);
 
 /* arch-specific weak syscall entries */
 cond_syscall(sys_pciconfig_read);
-- 
2.1.0

^ permalink raw reply related	[flat|nested] 58+ messages in thread

* [PATCH 3/6] fs/splice: support compiling out splice-family syscalls
@ 2014-11-23 14:20   ` Pieter Smith
  0 siblings, 0 replies; 58+ messages in thread
From: Pieter Smith @ 2014-11-23 14:20 UTC (permalink / raw)
  To: pieter
  Cc: Josh Triplett, Alexander Duyck, Alexander Viro,
	Alexei Starovoitov, Andrew Morton, Bertrand Jacquin,
	Catalina Mocanu, Daniel Borkmann, David S. Miller, Eric Dumazet,
	Eric W. Biederman, Fabian Frederick,
	open list:FUSE: FILESYSTEM...,
	Geert Uytterhoeven, Hugh Dickins, Iulia Manda, Jan Beulich,
	J. Bruce Fields, Jeff Layton, open list:ABI/API, linux-fsdevel,
	linux-kernel

Many embedded systems will not need the splice-family syscalls (splice,
vmsplice, tee and sendfile). Omitting them saves space.  This adds a new EXPERT
config option CONFIG_SYSCALL_SPLICE (default y) to support compiling them out.

The goal is to completely compile out fs/splice. To achieve this, the remaining
patch-set will deal with fs/splice exports. As far as possible, the impact on
other device drivers will be minimized so as to reduce the maintenance burden
of CONFIG_SYSCALL_SPLICE.

The use of exported functions will be solved by transparently mocking them out
with static inlines. Use of the exported pipe_buf_operations struct however
require direct modification in fs/fuse and net/core. The next two patches will
deal with this.

Once all exports are solved, fs/splice can be compiled out.

The bloat benefit of this patch given a tinyconfig is:

add/remove: 0/16 grow/shrink: 2/5 up/down: 114/-3693 (-3579)
function                                     old     new   delta
splice_direct_to_actor                       348     416     +68
splice_to_pipe                               371     417     +46
splice_from_pipe_next                        107     106      -1
fdput                                         11       -     -11
signal_pending                                39      26     -13
fdget                                         56      42     -14
user_page_pipe_buf_ops                        20       -     -20
user_page_pipe_buf_steal                      25       -     -25
file_end_write                                58      29     -29
file_start_write                              68      34     -34
pipe_to_user                                  43       -     -43
wakeup_pipe_readers                           54       -     -54
do_splice_to                                  87       -     -87
ipipe_prep.part                               92       -     -92
opipe_prep.part                              119       -    -119
sys_sendfile                                 122       -    -122
sys_sendfile64                               126       -    -126
sys_vmsplice                                 137       -    -137
vmsplice_to_user                             205       -    -205
sys_tee                                      491       -    -491
do_sendfile                                  492       -    -492
vmsplice_to_pipe                             558       -    -558
sys_splice                                  1020       -   -1020

Signed-off-by: Pieter Smith <pieter@boesman.nl>
---
 fs/splice.c     |  2 ++
 init/Kconfig    | 10 ++++++++++
 kernel/sys_ni.c |  8 ++++++++
 3 files changed, 20 insertions(+)

diff --git a/fs/splice.c b/fs/splice.c
index 44b201b..7c4c695 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -1316,6 +1316,7 @@ 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);
@@ -2200,4 +2201,5 @@ 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/init/Kconfig b/init/Kconfig
index d811d5f..dec9819 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1571,6 +1571,16 @@ config NTP
 	  system clock to an NTP server, you can disable this option to save
 	  space.
 
+config SYSCALL_SPLICE
+	bool "Enable splice/vmsplice/tee/sendfile syscalls" if EXPERT
+	default y
+	help
+	  This option enables the splice, vmsplice, tee and sendfile syscalls. These
+	  are used by applications to: move data between buffers and arbitrary file
+	  descriptors; "copy" data between buffers; or copy data from userspace into
+	  buffers. If building an embedded system where no applications use these
+	  syscalls, 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 d2f5b00..25d5551 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -170,6 +170,14 @@ cond_syscall(sys_fstat);
 cond_syscall(sys_stat);
 cond_syscall(sys_uname);
 cond_syscall(sys_olduname);
+cond_syscall(sys_vmsplice);
+cond_syscall(sys_splice);
+cond_syscall(sys_tee);
+cond_syscall(sys_sendfile);
+cond_syscall(sys_sendfile64);
+cond_syscall(compat_sys_vmsplice);
+cond_syscall(compat_sys_sendfile);
+cond_syscall(compat_sys_sendfile64);
 
 /* arch-specific weak syscall entries */
 cond_syscall(sys_pciconfig_read);
-- 
2.1.0

^ permalink raw reply related	[flat|nested] 58+ messages in thread

* [PATCH 4/6] fs/fuse: support compiling out splice
  2014-11-23 14:20 ` Pieter Smith
  (?)
@ 2014-11-23 14:20   ` Pieter Smith
  -1 siblings, 0 replies; 58+ messages in thread
From: Pieter Smith @ 2014-11-23 14:20 UTC (permalink / raw)
  To: pieter
  Cc: Josh Triplett, Alexander Duyck, Alexander Viro,
	Alexei Starovoitov, Andrew Morton, Bertrand Jacquin,
	Catalina Mocanu, Daniel Borkmann, David S. Miller, Eric Dumazet,
	Eric W. Biederman, Fabian Frederick,
	open list:FUSE: FILESYSTEM...,
	Geert Uytterhoeven, Hugh Dickins, Iulia Manda, Jan Beulich,
	J. Bruce Fields, Jeff Layton, open list:ABI/API, linux-fsdevel,
	open list, Luis R. Rodriguez, Matt Turner, Mel Gorman,
	Michael S. Tsirkin, Miklos Szeredi,
	open list:NETWORKING [GENERAL],
	Oleg Nesterov, Paul Durrant, Paul E. McKenney, Peter Foley,
	Thomas Graf, Tom Herbert, Willem de Bruijn, Xiao Guangrong,
	蔡正龙

To implement splice support, fs/fuse makes use of nosteal_pipe_buf_ops. This
struct is exported by fs/splice. The goal of the larger patch set is to
completely compile out fs/splice, so uses of the exported struct need to be
compiled out along with fs/splice.

This patch therefore compiles out splice support in fs/fuse when
CONFIG_SYSCALL_SPLICE is undefined.

Signed-off-by: Pieter Smith <pieter@boesman.nl>
---
 fs/fuse/dev.c      | 4 ++--
 include/linux/fs.h | 6 ++++++
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index ca88731..f8f92a4 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -1291,7 +1291,7 @@ static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov,
 	return fuse_dev_do_read(fc, file, &cs, iov_length(iov, nr_segs));
 }
 
-static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
+static ssize_t __maybe_unused fuse_dev_splice_read(struct file *in, loff_t *ppos,
 				    struct pipe_inode_info *pipe,
 				    size_t len, unsigned int flags)
 {
@@ -2144,7 +2144,7 @@ const struct file_operations fuse_dev_operations = {
 	.llseek		= no_llseek,
 	.read		= do_sync_read,
 	.aio_read	= fuse_dev_read,
-	.splice_read	= fuse_dev_splice_read,
+	.splice_read	= __splice_p(fuse_dev_splice_read),
 	.write		= do_sync_write,
 	.aio_write	= fuse_dev_write,
 	.splice_write	= fuse_dev_splice_write,
diff --git a/include/linux/fs.h b/include/linux/fs.h
index a957d43..04c0975 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2443,6 +2443,12 @@ extern int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
 			int datasync);
 extern void block_sync_page(struct page *page);
 
+#ifdef CONFIG_SYSCALL_SPLICE
+#define __splice_p(x) x
+#else
+#define __splice_p(x) NULL
+#endif
+
 /* fs/splice.c */
 extern ssize_t generic_file_splice_read(struct file *, loff_t *,
 		struct pipe_inode_info *, size_t, unsigned int);
-- 
2.1.0


^ permalink raw reply related	[flat|nested] 58+ messages in thread

* [PATCH 4/6] fs/fuse: support compiling out splice
@ 2014-11-23 14:20   ` Pieter Smith
  0 siblings, 0 replies; 58+ messages in thread
From: Pieter Smith @ 2014-11-23 14:20 UTC (permalink / raw)
  To: pieter
  Cc: Josh Triplett, Alexander Duyck, Alexander Viro,
	Alexei Starovoitov, Andrew Morton, Bertrand Jacquin,
	Catalina Mocanu, Daniel Borkmann, David S. Miller, Eric Dumazet,
	Eric W. Biederman, Fabian Frederick,
	open list:FUSE: FILESYSTEM...,
	Geert Uytterhoeven, Hugh Dickins, Iulia Manda, Jan Beulich,
	J. Bruce Fields, Jeff Layton, open list:ABI/API, linux-fsdevel,
	linux-kernel

To implement splice support, fs/fuse makes use of nosteal_pipe_buf_ops. This
struct is exported by fs/splice. The goal of the larger patch set is to
completely compile out fs/splice, so uses of the exported struct need to be
compiled out along with fs/splice.

This patch therefore compiles out splice support in fs/fuse when
CONFIG_SYSCALL_SPLICE is undefined.

Signed-off-by: Pieter Smith <pieter@boesman.nl>
---
 fs/fuse/dev.c      | 4 ++--
 include/linux/fs.h | 6 ++++++
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index ca88731..f8f92a4 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -1291,7 +1291,7 @@ static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov,
 	return fuse_dev_do_read(fc, file, &cs, iov_length(iov, nr_segs));
 }
 
-static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
+static ssize_t __maybe_unused fuse_dev_splice_read(struct file *in, loff_t *ppos,
 				    struct pipe_inode_info *pipe,
 				    size_t len, unsigned int flags)
 {
@@ -2144,7 +2144,7 @@ const struct file_operations fuse_dev_operations = {
 	.llseek		= no_llseek,
 	.read		= do_sync_read,
 	.aio_read	= fuse_dev_read,
-	.splice_read	= fuse_dev_splice_read,
+	.splice_read	= __splice_p(fuse_dev_splice_read),
 	.write		= do_sync_write,
 	.aio_write	= fuse_dev_write,
 	.splice_write	= fuse_dev_splice_write,
diff --git a/include/linux/fs.h b/include/linux/fs.h
index a957d43..04c0975 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2443,6 +2443,12 @@ extern int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
 			int datasync);
 extern void block_sync_page(struct page *page);
 
+#ifdef CONFIG_SYSCALL_SPLICE
+#define __splice_p(x) x
+#else
+#define __splice_p(x) NULL
+#endif
+
 /* fs/splice.c */
 extern ssize_t generic_file_splice_read(struct file *, loff_t *,
 		struct pipe_inode_info *, size_t, unsigned int);
-- 
2.1.0

^ permalink raw reply related	[flat|nested] 58+ messages in thread

* [PATCH 4/6] fs/fuse: support compiling out splice
@ 2014-11-23 14:20   ` Pieter Smith
  0 siblings, 0 replies; 58+ messages in thread
From: Pieter Smith @ 2014-11-23 14:20 UTC (permalink / raw)
  To: pieter
  Cc: Josh Triplett, Alexander Duyck, Alexander Viro,
	Alexei Starovoitov, Andrew Morton, Bertrand Jacquin,
	Catalina Mocanu, Daniel Borkmann, David S. Miller, Eric Dumazet,
	Eric W. Biederman, Fabian Frederick,
	open list:FUSE: FILESYSTEM...,
	Geert Uytterhoeven, Hugh Dickins, Iulia Manda, Jan Beulich,
	J. Bruce Fields, Jeff Layton, open list:ABI/API, linux-fsdevel,
	linux-kernel

To implement splice support, fs/fuse makes use of nosteal_pipe_buf_ops. This
struct is exported by fs/splice. The goal of the larger patch set is to
completely compile out fs/splice, so uses of the exported struct need to be
compiled out along with fs/splice.

This patch therefore compiles out splice support in fs/fuse when
CONFIG_SYSCALL_SPLICE is undefined.

Signed-off-by: Pieter Smith <pieter@boesman.nl>
---
 fs/fuse/dev.c      | 4 ++--
 include/linux/fs.h | 6 ++++++
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index ca88731..f8f92a4 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -1291,7 +1291,7 @@ static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov,
 	return fuse_dev_do_read(fc, file, &cs, iov_length(iov, nr_segs));
 }
 
-static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
+static ssize_t __maybe_unused fuse_dev_splice_read(struct file *in, loff_t *ppos,
 				    struct pipe_inode_info *pipe,
 				    size_t len, unsigned int flags)
 {
@@ -2144,7 +2144,7 @@ const struct file_operations fuse_dev_operations = {
 	.llseek		= no_llseek,
 	.read		= do_sync_read,
 	.aio_read	= fuse_dev_read,
-	.splice_read	= fuse_dev_splice_read,
+	.splice_read	= __splice_p(fuse_dev_splice_read),
 	.write		= do_sync_write,
 	.aio_write	= fuse_dev_write,
 	.splice_write	= fuse_dev_splice_write,
diff --git a/include/linux/fs.h b/include/linux/fs.h
index a957d43..04c0975 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2443,6 +2443,12 @@ extern int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
 			int datasync);
 extern void block_sync_page(struct page *page);
 
+#ifdef CONFIG_SYSCALL_SPLICE
+#define __splice_p(x) x
+#else
+#define __splice_p(x) NULL
+#endif
+
 /* fs/splice.c */
 extern ssize_t generic_file_splice_read(struct file *, loff_t *,
 		struct pipe_inode_info *, size_t, unsigned int);
-- 
2.1.0

^ permalink raw reply related	[flat|nested] 58+ messages in thread

* [PATCH 5/6] net/core: support compiling out splice
@ 2014-11-23 14:20   ` Pieter Smith
  0 siblings, 0 replies; 58+ messages in thread
From: Pieter Smith @ 2014-11-23 14:20 UTC (permalink / raw)
  To: pieter
  Cc: Josh Triplett, Alexander Duyck, Alexander Viro,
	Alexei Starovoitov, Andrew Morton, Bertrand Jacquin,
	Catalina Mocanu, Daniel Borkmann, David S. Miller, Eric Dumazet,
	Eric W. Biederman, Fabian Frederick,
	open list:FUSE: FILESYSTEM...,
	Geert Uytterhoeven, Hugh Dickins, Iulia Manda, Jan Beulich,
	J. Bruce Fields, Jeff Layton, open list:ABI/API, linux-fsdevel,
	open list, Luis R. Rodriguez, Matt Turner, Mel Gorman,
	Michael S. Tsirkin, Miklos Szeredi,
	open list:NETWORKING [GENERAL],
	Oleg Nesterov, Paul Durrant, Paul E. McKenney, Peter Foley,
	Thomas Graf, Tom Herbert, Willem de Bruijn, Xiao Guangrong,
	蔡正龙

To implement splice support, net/core makes use of nosteal_pipe_buf_ops. This
struct is exported by fs/splice. The goal of the larger patch set is to
completely compile out fs/splice, so uses of the exported struct need to be
compiled out along with fs/splice.

This patch therefore compiles out splice support in net/core when
CONFIG_SYSCALL_SPLICE is undefined. The compiled out function skb_splice_bits
is transparently mocked out with a static inline. The greater patch set removes
userspace splice support so it cannot be called anyway.

Signed-off-by: Pieter Smith <pieter@boesman.nl>
---
 include/linux/skbuff.h | 9 +++++++++
 net/core/skbuff.c      | 9 ++++++---
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index a59d934..54a50c1 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -2640,9 +2640,18 @@ int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len);
 int skb_store_bits(struct sk_buff *skb, int offset, const void *from, int len);
 __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, u8 *to,
 			      int len, __wsum csum);
+#ifdef CONFIG_SYSCALL_SPLICE
 int skb_splice_bits(struct sk_buff *skb, unsigned int offset,
 		    struct pipe_inode_info *pipe, unsigned int len,
 		    unsigned int flags);
+#else
+static inline int skb_splice_bits(struct sk_buff *skb, unsigned int offset,
+		    struct pipe_inode_info *pipe, unsigned int len,
+		    unsigned int flags)
+{
+	return -EPERM;
+}
+#endif
 void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
 unsigned int skb_zerocopy_headlen(const struct sk_buff *from);
 int skb_zerocopy(struct sk_buff *to, struct sk_buff *from,
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 61059a0..74fad8a 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -1781,9 +1781,9 @@ static bool __splice_segment(struct page *page, unsigned int poff,
  * Map linear and fragment data from the skb to spd. It reports true if the
  * pipe is full or if we already spliced the requested length.
  */
-static bool __skb_splice_bits(struct sk_buff *skb, struct pipe_inode_info *pipe,
-			      unsigned int *offset, unsigned int *len,
-			      struct splice_pipe_desc *spd, struct sock *sk)
+static bool __maybe_unused __skb_splice_bits(struct sk_buff *skb, struct pipe_inode_info *pipe,
+					     unsigned int *offset, unsigned int *len,
+					     struct splice_pipe_desc *spd, struct sock *sk)
 {
 	int seg;
 
@@ -1821,6 +1821,7 @@ static bool __skb_splice_bits(struct sk_buff *skb, struct pipe_inode_info *pipe,
  * the frag list, if such a thing exists. We'd probably need to recurse to
  * handle that cleanly.
  */
+#ifdef CONFIG_SYSCALL_SPLICE
 int skb_splice_bits(struct sk_buff *skb, unsigned int offset,
 		    struct pipe_inode_info *pipe, unsigned int tlen,
 		    unsigned int flags)
@@ -1876,6 +1877,8 @@ done:
 
 	return ret;
 }
+#endif /* #ifdef CONFIG_SYSCALL_SPLICE */
+
 
 /**
  *	skb_store_bits - store bits from kernel buffer to skb
-- 
2.1.0


^ permalink raw reply related	[flat|nested] 58+ messages in thread

* [PATCH 5/6] net/core: support compiling out splice
@ 2014-11-23 14:20   ` Pieter Smith
  0 siblings, 0 replies; 58+ messages in thread
From: Pieter Smith @ 2014-11-23 14:20 UTC (permalink / raw)
  To: pieter-qeJ+1H9vRZbz+pZb47iToQ
  Cc: Michael S. Tsirkin, Bertrand Jacquin, Oleg Nesterov,
	J. Bruce Fields, Eric Dumazet, 蔡正龙,
	Jeff Layton, Tom Herbert, Alexei Starovoitov, Miklos Szeredi,
	Peter Foley, Hugh Dickins, Xiao Guangrong, Geert Uytterhoeven,
	Mel Gorman, Matt Turner, Paul E. McKenney, Alexander Duyck,
	open list:FUSE: FILESYSTEM...,
	Luis R. Rodriguez, Josh Triplett

To implement splice support, net/core makes use of nosteal_pipe_buf_ops. This
struct is exported by fs/splice. The goal of the larger patch set is to
completely compile out fs/splice, so uses of the exported struct need to be
compiled out along with fs/splice.

This patch therefore compiles out splice support in net/core when
CONFIG_SYSCALL_SPLICE is undefined. The compiled out function skb_splice_bits
is transparently mocked out with a static inline. The greater patch set removes
userspace splice support so it cannot be called anyway.

Signed-off-by: Pieter Smith <pieter-qeJ+1H9vRZbz+pZb47iToQ@public.gmane.org>
---
 include/linux/skbuff.h | 9 +++++++++
 net/core/skbuff.c      | 9 ++++++---
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index a59d934..54a50c1 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -2640,9 +2640,18 @@ int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len);
 int skb_store_bits(struct sk_buff *skb, int offset, const void *from, int len);
 __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, u8 *to,
 			      int len, __wsum csum);
+#ifdef CONFIG_SYSCALL_SPLICE
 int skb_splice_bits(struct sk_buff *skb, unsigned int offset,
 		    struct pipe_inode_info *pipe, unsigned int len,
 		    unsigned int flags);
+#else
+static inline int skb_splice_bits(struct sk_buff *skb, unsigned int offset,
+		    struct pipe_inode_info *pipe, unsigned int len,
+		    unsigned int flags)
+{
+	return -EPERM;
+}
+#endif
 void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
 unsigned int skb_zerocopy_headlen(const struct sk_buff *from);
 int skb_zerocopy(struct sk_buff *to, struct sk_buff *from,
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 61059a0..74fad8a 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -1781,9 +1781,9 @@ static bool __splice_segment(struct page *page, unsigned int poff,
  * Map linear and fragment data from the skb to spd. It reports true if the
  * pipe is full or if we already spliced the requested length.
  */
-static bool __skb_splice_bits(struct sk_buff *skb, struct pipe_inode_info *pipe,
-			      unsigned int *offset, unsigned int *len,
-			      struct splice_pipe_desc *spd, struct sock *sk)
+static bool __maybe_unused __skb_splice_bits(struct sk_buff *skb, struct pipe_inode_info *pipe,
+					     unsigned int *offset, unsigned int *len,
+					     struct splice_pipe_desc *spd, struct sock *sk)
 {
 	int seg;
 
@@ -1821,6 +1821,7 @@ static bool __skb_splice_bits(struct sk_buff *skb, struct pipe_inode_info *pipe,
  * the frag list, if such a thing exists. We'd probably need to recurse to
  * handle that cleanly.
  */
+#ifdef CONFIG_SYSCALL_SPLICE
 int skb_splice_bits(struct sk_buff *skb, unsigned int offset,
 		    struct pipe_inode_info *pipe, unsigned int tlen,
 		    unsigned int flags)
@@ -1876,6 +1877,8 @@ done:
 
 	return ret;
 }
+#endif /* #ifdef CONFIG_SYSCALL_SPLICE */
+
 
 /**
  *	skb_store_bits - store bits from kernel buffer to skb
-- 
2.1.0


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^ permalink raw reply related	[flat|nested] 58+ messages in thread

* [PATCH 6/6] fs/splice: full support for compiling out splice
@ 2014-11-23 14:20   ` Pieter Smith
  0 siblings, 0 replies; 58+ messages in thread
From: Pieter Smith @ 2014-11-23 14:20 UTC (permalink / raw)
  To: pieter
  Cc: Josh Triplett, Alexander Duyck, Alexander Viro,
	Alexei Starovoitov, Andrew Morton, Bertrand Jacquin,
	Catalina Mocanu, Daniel Borkmann, David S. Miller, Eric Dumazet,
	Eric W. Biederman, Fabian Frederick,
	open list:FUSE: FILESYSTEM...,
	Geert Uytterhoeven, Hugh Dickins, Iulia Manda, Jan Beulich,
	J. Bruce Fields, Jeff Layton, open list:ABI/API, linux-fsdevel,
	open list, Luis R. Rodriguez, Matt Turner, Mel Gorman,
	Michael S. Tsirkin, Miklos Szeredi,
	open list:NETWORKING [GENERAL],
	Oleg Nesterov, Paul Durrant, Paul E. McKenney, Peter Foley,
	Thomas Graf, Tom Herbert, Willem de Bruijn, Xiao Guangrong,
	蔡正龙

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 <pieter@boesman.nl>
---
 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 04c0975..9b3054e 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2449,6 +2449,7 @@ extern void block_sync_page(struct page *page);
 #define __splice_p(x) NULL
 #endif
 
+#ifdef CONFIG_SYSCALL_SPLICE
 /* fs/splice.c */
 extern ssize_t generic_file_splice_read(struct file *, loff_t *,
 		struct pipe_inode_info *, size_t, unsigned int);
@@ -2458,6 +2459,31 @@ 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..5097a79 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 /* #ifdef CONFIG_SYSCALL_SPLICE */
+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 /* #ifdef CONFIG_SYSCALL_SPLICE */
 
 /*
  * 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 /* #ifdef CONFIG_SYSCALL_SPLICE */
+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 /* #ifdef CONFIG_SYSCALL_SPLICE */
 
 extern const struct pipe_buf_operations page_cache_pipe_buf_ops;
 #endif
-- 
2.1.0


^ permalink raw reply related	[flat|nested] 58+ messages in thread

* [PATCH 6/6] fs/splice: full support for compiling out splice
@ 2014-11-23 14:20   ` Pieter Smith
  0 siblings, 0 replies; 58+ messages in thread
From: Pieter Smith @ 2014-11-23 14:20 UTC (permalink / raw)
  To: pieter-qeJ+1H9vRZbz+pZb47iToQ
  Cc: Michael S. Tsirkin, Bertrand Jacquin, Oleg Nesterov,
	J. Bruce Fields, Eric Dumazet, 蔡正龙,
	Jeff Layton, Tom Herbert, Alexei Starovoitov, Miklos Szeredi,
	Peter Foley, Hugh Dickins, Xiao Guangrong, Geert Uytterhoeven,
	Mel Gorman, Matt Turner, Paul E. McKenney, Alexander Duyck,
	open list:FUSE: FILESYSTEM...,
	Luis R. Rodriguez, Josh Triplett

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 <pieter-qeJ+1H9vRZbz+pZb47iToQ@public.gmane.org>
---
 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 04c0975..9b3054e 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2449,6 +2449,7 @@ extern void block_sync_page(struct page *page);
 #define __splice_p(x) NULL
 #endif
 
+#ifdef CONFIG_SYSCALL_SPLICE
 /* fs/splice.c */
 extern ssize_t generic_file_splice_read(struct file *, loff_t *,
 		struct pipe_inode_info *, size_t, unsigned int);
@@ -2458,6 +2459,31 @@ 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..5097a79 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 /* #ifdef CONFIG_SYSCALL_SPLICE */
+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 /* #ifdef CONFIG_SYSCALL_SPLICE */
 
 /*
  * 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 /* #ifdef CONFIG_SYSCALL_SPLICE */
+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 /* #ifdef CONFIG_SYSCALL_SPLICE */
 
 extern const struct pipe_buf_operations page_cache_pipe_buf_ops;
 #endif
-- 
2.1.0


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^ permalink raw reply related	[flat|nested] 58+ messages in thread

* Re: [PATCH 0/6] kernel tinification: optionally compile out splice family of syscalls (splice, vmsplice, tee and sendfile)
@ 2014-11-23 18:46   ` David Miller
  0 siblings, 0 replies; 58+ messages in thread
From: David Miller @ 2014-11-23 18:46 UTC (permalink / raw)
  To: pieter
  Cc: josh, alexander.h.duyck, viro, ast, akpm, beber, catalina.mocanu,
	dborkman, edumazet, ebiederm, fabf, fuse-devel, geert, hughd,
	iulia.manda21, JBeulich, bfields, jlayton, linux-api,
	linux-fsdevel, linux-kernel, mcgrof, mattst88, mgorman, mst,
	miklos, netdev, oleg, Paul.Durrant, paulmck, pefoley2, tgraf,
	therbert, willemb, xiaoguangrong, zhenglong.cai


Truly removing sendfile/sendpage means that you can't even compile NFS
into the tree.

I cannot take this patch series seriously, sorry.

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [PATCH 0/6] kernel tinification: optionally compile out splice family of syscalls (splice, vmsplice, tee and sendfile)
@ 2014-11-23 18:46   ` David Miller
  0 siblings, 0 replies; 58+ messages in thread
From: David Miller @ 2014-11-23 18:46 UTC (permalink / raw)
  To: pieter-qeJ+1H9vRZbz+pZb47iToQ
  Cc: josh-iaAMLnmF4UmaiuxdJuQwMA,
	alexander.h.duyck-ral2JQCrhuEAvxtiuMwx3w,
	viro-RmSDqhL/yNMiFSDQTTA3OLVCufUGDwFn,
	ast-uqk4Ao+rVK5Wk0Htik3J/w,
	akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b,
	beber-2YnHqweIUXrk1uMJSBkQmQ,
	catalina.mocanu-Re5JQEeQqe8AvxtiuMwx3w,
	dborkman-H+wXaHxf7aLQT0dZR+AlfA, edumazet-hpIqsD4AKlfQT0dZR+AlfA,
	ebiederm-aS9lmoZGLiVWk0Htik3J/w, fabf-AgBVmzD5pcezQB+pC5nmwQ,
	fuse-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f,
	geert-Td1EMuHUCqxL1ZNQvxDV9g, hughd-hpIqsD4AKlfQT0dZR+AlfA,
	iulia.manda21-Re5JQEeQqe8AvxtiuMwx3w, JBeulich-IBi9RG/b67k,
	bfields-uC3wQj2KruNg9hUCZPvPmw, jlayton-vpEMnDpepFuMZCB2o+C8xQ,
	linux-api-u79uwXL29TY76Z2rM5mHXA,
	linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA, mcgrof-IBi9RG/b67k,
	mattst88-Re5JQEeQqe8AvxtiuMwx3w, mgorman-l3A5Bk7waGM,
	mst-H+wXaHxf7aLQT0dZR+AlfA, miklos-sUDqSbJrdHQHWmgEVkV9KA,
	netdev-u79uwXL29TY76Z2rM5mHXA, oleg-H+wXaHxf7aLQT0dZR+AlfA,
	Paul.Durrant-Sxgqhf6Nn4DQT0dZR+AlfA,
	paulmck-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8,
	pefoley2-lY0TAiDIAFlBDgjK7y7TUQ, tgraf-G/eBtMaohhA,
	therbert-hpIqsD4AKlfQT0dZR+AlfA, willemb-hpIqsD4AKlfQT0dZR+AlfA,
	xiaoguangrong-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8,
	zhenglong.cai-TJRtMXcVgQTM1kAEIRd3EQ


Truly removing sendfile/sendpage means that you can't even compile NFS
into the tree.

I cannot take this patch series seriously, sorry.

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [PATCH 0/6] kernel tinification: optionally compile out splice family of syscalls (splice, vmsplice, tee and sendfile)
@ 2014-11-23 19:43     ` Josh Triplett
  0 siblings, 0 replies; 58+ messages in thread
From: Josh Triplett @ 2014-11-23 19:43 UTC (permalink / raw)
  To: David Miller
  Cc: pieter, alexander.h.duyck, viro, ast, akpm, beber,
	catalina.mocanu, dborkman, edumazet, ebiederm, fabf, fuse-devel,
	geert, hughd, iulia.manda21, JBeulich, bfields, jlayton,
	linux-api, linux-fsdevel, linux-kernel, mcgrof, mattst88,
	mgorman, mst, miklos, netdev, oleg, Paul.Durrant, paulmck,
	pefoley2, tgraf, therbert, willemb, xiaoguangrong, zhenglong.cai

On Sun, Nov 23, 2014 at 01:46:23PM -0500, David Miller wrote:
> Truly removing sendfile/sendpage means that you can't even compile NFS
> into the tree.

If you mean the in-kernel nfsd (CONFIG_NFSD), that already has a large
stack of "select" and "depends on", both directly and indirectly; adding
a "select SPLICE_SYSCALL" to it seems fine.  (That select does need
adding, though.  Pieter, you need to test-compile more than just
tinyconfig and defconfig.  Try an allyesconfig with *just* splice turned
off, and make sure that compiles.)

Given the requirements of running a file server in the kernel, I'd
expect CONFIG_NFSD to end up with several more selects of optional
functionality in the future.  It seems rather likely that the average
embedded system will be compiling out NFS. :)

Also, this patch series compiles out splice and sendfile, including
several *users* of sendpage; it doesn't compile out the sendpage
support/infrastructure itself.

- Josh Triplett

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [PATCH 0/6] kernel tinification: optionally compile out splice family of syscalls (splice, vmsplice, tee and sendfile)
@ 2014-11-23 19:43     ` Josh Triplett
  0 siblings, 0 replies; 58+ messages in thread
From: Josh Triplett @ 2014-11-23 19:43 UTC (permalink / raw)
  To: David Miller
  Cc: pieter-qeJ+1H9vRZbz+pZb47iToQ,
	alexander.h.duyck-ral2JQCrhuEAvxtiuMwx3w,
	viro-RmSDqhL/yNMiFSDQTTA3OLVCufUGDwFn,
	ast-uqk4Ao+rVK5Wk0Htik3J/w,
	akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b,
	beber-2YnHqweIUXrk1uMJSBkQmQ,
	catalina.mocanu-Re5JQEeQqe8AvxtiuMwx3w,
	dborkman-H+wXaHxf7aLQT0dZR+AlfA, edumazet-hpIqsD4AKlfQT0dZR+AlfA,
	ebiederm-aS9lmoZGLiVWk0Htik3J/w, fabf-AgBVmzD5pcezQB+pC5nmwQ,
	fuse-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f,
	geert-Td1EMuHUCqxL1ZNQvxDV9g, hughd-hpIqsD4AKlfQT0dZR+AlfA,
	iulia.manda21-Re5JQEeQqe8AvxtiuMwx3w, JBeulich-IBi9RG/b67k,
	bfields-uC3wQj2KruNg9hUCZPvPmw, jlayton-vpEMnDpepFuMZCB2o+C8xQ,
	linux-api-u79uwXL29TY76Z2rM5mHXA,
	linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA, mcgrof-IBi9RG/b67k,
	mattst88-Re5JQEeQqe8AvxtiuMwx3w, mgorman-l3A5Bk7waGM,
	mst-H+wXaHxf7aLQT0dZR+AlfA, miklos-sUDqSbJrdHQHWmgEVkV9KA,
	netdev-u79uwXL29TY76Z2rM5mHXA, oleg-H+wXaHxf7aLQT0dZR+AlfA,
	Paul.Durrant-Sxgqhf6Nn4DQT0dZR+AlfA,
	paulmck-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8,
	pefoley2-lY0TAiDIAFlBDgjK7y7TUQ, tgraf-G/eBtMaohhA,
	therbert-hpIqsD4AKlfQT0dZR+AlfA, willemb-hpIqsD4AKlfQT0dZR+AlfA,
	xiaoguangrong-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8,
	zhenglong.cai-TJRtMXcVgQTM1kAEIRd3EQ

On Sun, Nov 23, 2014 at 01:46:23PM -0500, David Miller wrote:
> Truly removing sendfile/sendpage means that you can't even compile NFS
> into the tree.

If you mean the in-kernel nfsd (CONFIG_NFSD), that already has a large
stack of "select" and "depends on", both directly and indirectly; adding
a "select SPLICE_SYSCALL" to it seems fine.  (That select does need
adding, though.  Pieter, you need to test-compile more than just
tinyconfig and defconfig.  Try an allyesconfig with *just* splice turned
off, and make sure that compiles.)

Given the requirements of running a file server in the kernel, I'd
expect CONFIG_NFSD to end up with several more selects of optional
functionality in the future.  It seems rather likely that the average
embedded system will be compiling out NFS. :)

Also, this patch series compiles out splice and sendfile, including
several *users* of sendpage; it doesn't compile out the sendpage
support/infrastructure itself.

- Josh Triplett

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [PATCH 0/6] kernel tinification: optionally compile out splice family of syscalls (splice, vmsplice, tee and sendfile)
  2014-11-23 19:43     ` Josh Triplett
  (?)
@ 2014-11-23 20:30     ` Pieter Smith
  2014-11-23 23:36         ` Josh Triplett
  -1 siblings, 1 reply; 58+ messages in thread
From: Pieter Smith @ 2014-11-23 20:30 UTC (permalink / raw)
  To: Josh Triplett
  Cc: David Miller, alexander.h.duyck, viro, ast, akpm, beber,
	catalina.mocanu, dborkman, edumazet, ebiederm, fabf, fuse-devel,
	geert, hughd, iulia.manda21, JBeulich, bfields, jlayton,
	linux-api, linux-fsdevel, linux-kernel, mcgrof, mattst88,
	mgorman, mst, miklos, netdev, oleg, Paul.Durrant, paulmck,
	pefoley2, tgraf, therbert, willemb, xiaoguangrong, zhenglong.cai

On Sun, Nov 23, 2014 at 11:43:26AM -0800, Josh Triplett wrote:
> On Sun, Nov 23, 2014 at 01:46:23PM -0500, David Miller wrote:
> > Truly removing sendfile/sendpage means that you can't even compile NFS
> > into the tree.
> 
> If you mean the in-kernel nfsd (CONFIG_NFSD), that already has a large
> stack of "select" and "depends on", both directly and indirectly; adding
> a "select SPLICE_SYSCALL" to it seems fine.  (That select does need
> adding, though.  Pieter, you need to test-compile more than just
> tinyconfig and defconfig.  Try an allyesconfig with *just* splice turned
> off, and make sure that compiles.)

Did exacly that. Took forever on my hardware, but no problems.

> Given the requirements of running a file server in the kernel, I'd
> expect CONFIG_NFSD to end up with several more selects of optional
> functionality in the future.  It seems rather likely that the average
> embedded system will be compiling out NFS. :)
> 
> Also, this patch series compiles out splice and sendfile, including
> several *users* of sendpage; it doesn't compile out the sendpage
> support/infrastructure itself.
> 
> - Josh Triplett

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [fuse-devel] [PATCH 4/6] fs/fuse: support compiling out splice
@ 2014-11-23 22:29     ` Richard Weinberger
  0 siblings, 0 replies; 58+ messages in thread
From: Richard Weinberger @ 2014-11-23 22:29 UTC (permalink / raw)
  To: Pieter Smith
  Cc: Michael S. Tsirkin, Bertrand Jacquin, Oleg Nesterov,
	J. Bruce Fields, Eric Dumazet, 蔡正龙,
	Jeff Layton, Tom Herbert, Alexei Starovoitov, Miklos Szeredi,
	Peter Foley, Hugh Dickins, Xiao Guangrong, Geert Uytterhoeven,
	Mel Gorman, Matt Turner, Paul E. McKenney, Alexander Duyck,
	open list:FUSE: FILESYSTEM...,
	Luis R. Rodriguez, Josh Triplett, Catalina Mocanu,
	Fabian Frederick, Thomas Graf, Paul Durrant, Alexander Viro,
	Jan Beulich, Willem de Bruijn, Iulia Manda, open list:ABI/API,
	open list, Daniel Borkmann, Eric W. Biederman,
	open list:NETWORKING [GENERAL],
	linux-fsdevel, Andrew Morton, David S. Miller

On Sun, Nov 23, 2014 at 3:20 PM, Pieter Smith <pieter@boesman.nl> wrote:
> To implement splice support, fs/fuse makes use of nosteal_pipe_buf_ops. This
> struct is exported by fs/splice. The goal of the larger patch set is to
> completely compile out fs/splice, so uses of the exported struct need to be
> compiled out along with fs/splice.
>
> This patch therefore compiles out splice support in fs/fuse when
> CONFIG_SYSCALL_SPLICE is undefined.
>
> Signed-off-by: Pieter Smith <pieter@boesman.nl>
> ---
>  fs/fuse/dev.c      | 4 ++--
>  include/linux/fs.h | 6 ++++++
>  2 files changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
> index ca88731..f8f92a4 100644
> --- a/fs/fuse/dev.c
> +++ b/fs/fuse/dev.c
> @@ -1291,7 +1291,7 @@ static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov,
>         return fuse_dev_do_read(fc, file, &cs, iov_length(iov, nr_segs));
>  }
>
> -static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
> +static ssize_t __maybe_unused fuse_dev_splice_read(struct file *in, loff_t *ppos,
>                                     struct pipe_inode_info *pipe,
>                                     size_t len, unsigned int flags)
>  {
> @@ -2144,7 +2144,7 @@ const struct file_operations fuse_dev_operations = {
>         .llseek         = no_llseek,
>         .read           = do_sync_read,
>         .aio_read       = fuse_dev_read,
> -       .splice_read    = fuse_dev_splice_read,
> +       .splice_read    = __splice_p(fuse_dev_splice_read),
>         .write          = do_sync_write,
>         .aio_write      = fuse_dev_write,
>         .splice_write   = fuse_dev_splice_write,
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index a957d43..04c0975 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -2443,6 +2443,12 @@ extern int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
>                         int datasync);
>  extern void block_sync_page(struct page *page);
>
> +#ifdef CONFIG_SYSCALL_SPLICE
> +#define __splice_p(x) x
> +#else
> +#define __splice_p(x) NULL
> +#endif
> +

This needs to go into a different patch.
One logical change per patch please. :-)

-- 
Thanks,
//richard

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [fuse-devel] [PATCH 4/6] fs/fuse: support compiling out splice
@ 2014-11-23 22:29     ` Richard Weinberger
  0 siblings, 0 replies; 58+ messages in thread
From: Richard Weinberger @ 2014-11-23 22:29 UTC (permalink / raw)
  To: Pieter Smith
  Cc: Michael S. Tsirkin, Bertrand Jacquin, Oleg Nesterov,
	J. Bruce Fields, Eric Dumazet, 蔡正龙,
	Jeff Layton, Tom Herbert, Alexei Starovoitov, Miklos Szeredi,
	Peter Foley, Hugh Dickins, Xiao Guangrong, Geert Uytterhoeven,
	Mel Gorman, Matt Turner, Paul E. McKenney, Alexander Duyck,
	open list:FUSE: FILESYSTEM...,
	Luis R. Rodriguez, Josh Triplett

On Sun, Nov 23, 2014 at 3:20 PM, Pieter Smith <pieter-qeJ+1H9vRZbz+pZb47iToQ@public.gmane.org> wrote:
> To implement splice support, fs/fuse makes use of nosteal_pipe_buf_ops. This
> struct is exported by fs/splice. The goal of the larger patch set is to
> completely compile out fs/splice, so uses of the exported struct need to be
> compiled out along with fs/splice.
>
> This patch therefore compiles out splice support in fs/fuse when
> CONFIG_SYSCALL_SPLICE is undefined.
>
> Signed-off-by: Pieter Smith <pieter-qeJ+1H9vRZbz+pZb47iToQ@public.gmane.org>
> ---
>  fs/fuse/dev.c      | 4 ++--
>  include/linux/fs.h | 6 ++++++
>  2 files changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
> index ca88731..f8f92a4 100644
> --- a/fs/fuse/dev.c
> +++ b/fs/fuse/dev.c
> @@ -1291,7 +1291,7 @@ static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov,
>         return fuse_dev_do_read(fc, file, &cs, iov_length(iov, nr_segs));
>  }
>
> -static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
> +static ssize_t __maybe_unused fuse_dev_splice_read(struct file *in, loff_t *ppos,
>                                     struct pipe_inode_info *pipe,
>                                     size_t len, unsigned int flags)
>  {
> @@ -2144,7 +2144,7 @@ const struct file_operations fuse_dev_operations = {
>         .llseek         = no_llseek,
>         .read           = do_sync_read,
>         .aio_read       = fuse_dev_read,
> -       .splice_read    = fuse_dev_splice_read,
> +       .splice_read    = __splice_p(fuse_dev_splice_read),
>         .write          = do_sync_write,
>         .aio_write      = fuse_dev_write,
>         .splice_write   = fuse_dev_splice_write,
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index a957d43..04c0975 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -2443,6 +2443,12 @@ extern int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
>                         int datasync);
>  extern void block_sync_page(struct page *page);
>
> +#ifdef CONFIG_SYSCALL_SPLICE
> +#define __splice_p(x) x
> +#else
> +#define __splice_p(x) NULL
> +#endif
> +

This needs to go into a different patch.
One logical change per patch please. :-)

-- 
Thanks,
//richard

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [fuse-devel] [PATCH 4/6] fs/fuse: support compiling out splice
  2014-11-23 22:29     ` Richard Weinberger
@ 2014-11-23 23:23       ` Josh Triplett
  -1 siblings, 0 replies; 58+ messages in thread
From: Josh Triplett @ 2014-11-23 23:23 UTC (permalink / raw)
  To: Richard Weinberger
  Cc: Pieter Smith, Michael S. Tsirkin, Bertrand Jacquin,
	Oleg Nesterov, J. Bruce Fields, Eric Dumazet,
	蔡正龙,
	Jeff Layton, Tom Herbert, Alexei Starovoitov, Miklos Szeredi,
	Peter Foley, Hugh Dickins, Xiao Guangrong, Geert Uytterhoeven,
	Mel Gorman, Matt Turner, Paul E. McKenney, Alexander Duyck,
	open list:FUSE: FILESYSTEM...,
	Luis R. Rodriguez, Catalina Mocanu, Fabian Frederick,
	Thomas Graf, Paul Durrant, Alexander Viro, Jan Beulich,
	Willem de Bruijn, Iulia Manda, open list:ABI/API, open list,
	Daniel Borkmann, Eric W. Biederman,
	open list:NETWORKING [GENERAL],
	linux-fsdevel, Andrew Morton, David S. Miller

On Sun, Nov 23, 2014 at 11:29:08PM +0100, Richard Weinberger wrote:
> On Sun, Nov 23, 2014 at 3:20 PM, Pieter Smith <pieter@boesman.nl> wrote:
> > To implement splice support, fs/fuse makes use of nosteal_pipe_buf_ops. This
> > struct is exported by fs/splice. The goal of the larger patch set is to
> > completely compile out fs/splice, so uses of the exported struct need to be
> > compiled out along with fs/splice.
> >
> > This patch therefore compiles out splice support in fs/fuse when
> > CONFIG_SYSCALL_SPLICE is undefined.
> >
> > Signed-off-by: Pieter Smith <pieter@boesman.nl>
> > ---
> >  fs/fuse/dev.c      | 4 ++--
> >  include/linux/fs.h | 6 ++++++
> >  2 files changed, 8 insertions(+), 2 deletions(-)
> >
> > diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
> > index ca88731..f8f92a4 100644
> > --- a/fs/fuse/dev.c
> > +++ b/fs/fuse/dev.c
> > @@ -1291,7 +1291,7 @@ static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov,
> >         return fuse_dev_do_read(fc, file, &cs, iov_length(iov, nr_segs));
> >  }
> >
> > -static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
> > +static ssize_t __maybe_unused fuse_dev_splice_read(struct file *in, loff_t *ppos,
> >                                     struct pipe_inode_info *pipe,
> >                                     size_t len, unsigned int flags)
> >  {
> > @@ -2144,7 +2144,7 @@ const struct file_operations fuse_dev_operations = {
> >         .llseek         = no_llseek,
> >         .read           = do_sync_read,
> >         .aio_read       = fuse_dev_read,
> > -       .splice_read    = fuse_dev_splice_read,
> > +       .splice_read    = __splice_p(fuse_dev_splice_read),
> >         .write          = do_sync_write,
> >         .aio_write      = fuse_dev_write,
> >         .splice_write   = fuse_dev_splice_write,
> > diff --git a/include/linux/fs.h b/include/linux/fs.h
> > index a957d43..04c0975 100644
> > --- a/include/linux/fs.h
> > +++ b/include/linux/fs.h
> > @@ -2443,6 +2443,12 @@ extern int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
> >                         int datasync);
> >  extern void block_sync_page(struct page *page);
> >
> > +#ifdef CONFIG_SYSCALL_SPLICE
> > +#define __splice_p(x) x
> > +#else
> > +#define __splice_p(x) NULL
> > +#endif
> > +
> 
> This needs to go into a different patch.
> One logical change per patch please. :-)

Easy enough to merge this one into the patch introducing
CONFIG_SYSCALL_SPLICE, then.

- Josh Triplett

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [fuse-devel] [PATCH 4/6] fs/fuse: support compiling out splice
@ 2014-11-23 23:23       ` Josh Triplett
  0 siblings, 0 replies; 58+ messages in thread
From: Josh Triplett @ 2014-11-23 23:23 UTC (permalink / raw)
  To: Richard Weinberger
  Cc: Pieter Smith, Michael S. Tsirkin, Bertrand Jacquin,
	Oleg Nesterov, J. Bruce Fields, Eric Dumazet,
	蔡正龙,
	Jeff Layton, Tom Herbert, Alexei Starovoitov, Miklos Szeredi,
	Peter Foley, Hugh Dickins, Xiao Guangrong, Geert Uytterhoeven,
	Mel Gorman, Matt Turner, Paul E. McKenney, Alexander Duyck,
	open list:FUSE: FILESYSTEM...,
	Luis R. Rodriguez

On Sun, Nov 23, 2014 at 11:29:08PM +0100, Richard Weinberger wrote:
> On Sun, Nov 23, 2014 at 3:20 PM, Pieter Smith <pieter@boesman.nl> wrote:
> > To implement splice support, fs/fuse makes use of nosteal_pipe_buf_ops. This
> > struct is exported by fs/splice. The goal of the larger patch set is to
> > completely compile out fs/splice, so uses of the exported struct need to be
> > compiled out along with fs/splice.
> >
> > This patch therefore compiles out splice support in fs/fuse when
> > CONFIG_SYSCALL_SPLICE is undefined.
> >
> > Signed-off-by: Pieter Smith <pieter@boesman.nl>
> > ---
> >  fs/fuse/dev.c      | 4 ++--
> >  include/linux/fs.h | 6 ++++++
> >  2 files changed, 8 insertions(+), 2 deletions(-)
> >
> > diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
> > index ca88731..f8f92a4 100644
> > --- a/fs/fuse/dev.c
> > +++ b/fs/fuse/dev.c
> > @@ -1291,7 +1291,7 @@ static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov,
> >         return fuse_dev_do_read(fc, file, &cs, iov_length(iov, nr_segs));
> >  }
> >
> > -static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
> > +static ssize_t __maybe_unused fuse_dev_splice_read(struct file *in, loff_t *ppos,
> >                                     struct pipe_inode_info *pipe,
> >                                     size_t len, unsigned int flags)
> >  {
> > @@ -2144,7 +2144,7 @@ const struct file_operations fuse_dev_operations = {
> >         .llseek         = no_llseek,
> >         .read           = do_sync_read,
> >         .aio_read       = fuse_dev_read,
> > -       .splice_read    = fuse_dev_splice_read,
> > +       .splice_read    = __splice_p(fuse_dev_splice_read),
> >         .write          = do_sync_write,
> >         .aio_write      = fuse_dev_write,
> >         .splice_write   = fuse_dev_splice_write,
> > diff --git a/include/linux/fs.h b/include/linux/fs.h
> > index a957d43..04c0975 100644
> > --- a/include/linux/fs.h
> > +++ b/include/linux/fs.h
> > @@ -2443,6 +2443,12 @@ extern int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
> >                         int datasync);
> >  extern void block_sync_page(struct page *page);
> >
> > +#ifdef CONFIG_SYSCALL_SPLICE
> > +#define __splice_p(x) x
> > +#else
> > +#define __splice_p(x) NULL
> > +#endif
> > +
> 
> This needs to go into a different patch.
> One logical change per patch please. :-)

Easy enough to merge this one into the patch introducing
CONFIG_SYSCALL_SPLICE, then.

- Josh Triplett

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [PATCH 0/6] kernel tinification: optionally compile out splice family of syscalls (splice, vmsplice, tee and sendfile)
  2014-11-23 20:30     ` Pieter Smith
@ 2014-11-23 23:36         ` Josh Triplett
  0 siblings, 0 replies; 58+ messages in thread
From: Josh Triplett @ 2014-11-23 23:36 UTC (permalink / raw)
  To: Pieter Smith
  Cc: David Miller, alexander.h.duyck, viro, ast, akpm, beber,
	catalina.mocanu, dborkman, edumazet, ebiederm, fabf, fuse-devel,
	geert, hughd, iulia.manda21, JBeulich, bfields, jlayton,
	linux-api, linux-fsdevel, linux-kernel, mcgrof, mattst88,
	mgorman, mst, miklos, netdev, oleg, Paul.Durrant, paulmck,
	pefoley2, tgraf, therbert, willemb, xiaoguangrong, zhenglong.cai

On Sun, Nov 23, 2014 at 09:30:40PM +0100, Pieter Smith wrote:
> On Sun, Nov 23, 2014 at 11:43:26AM -0800, Josh Triplett wrote:
> > On Sun, Nov 23, 2014 at 01:46:23PM -0500, David Miller wrote:
> > > Truly removing sendfile/sendpage means that you can't even compile NFS
> > > into the tree.
> > 
> > If you mean the in-kernel nfsd (CONFIG_NFSD), that already has a large
> > stack of "select" and "depends on", both directly and indirectly; adding
> > a "select SPLICE_SYSCALL" to it seems fine.  (That select does need
> > adding, though.  Pieter, you need to test-compile more than just
> > tinyconfig and defconfig.  Try an allyesconfig with *just* splice turned
> > off, and make sure that compiles.)
> 
> Did exacly that. Took forever on my hardware, but no problems.

Ah, I see.  Looking more closely at nfsd, it looks like it already has a
code path for filesystems that don't do splice.  I think, rather than
making nfsd select SPLICE_SYSCALL, that it would suffice to change the
"rqstp->rq_splice_ok = true;" in svc_process_common (net/sunrpc/svc.c)
to:

rqstp->rq_splice_ok = IS_ENABLED(CONFIG_SPLICE_SYSCALL);

Then nfsd should simply *always* fall back to its non-splice support.

That said, given that it seems exceedingly unlikely that anyone would
use the in-kernel nfsd on a system trying to minimize kernel size, it
still seems cleaner to just "select SPLICE_SYSCALL" from NFSD in
Kconfig.  That avoids making any changes at all to the nfsd source in
this patch series.

- Josh Triplett

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [PATCH 0/6] kernel tinification: optionally compile out splice family of syscalls (splice, vmsplice, tee and sendfile)
@ 2014-11-23 23:36         ` Josh Triplett
  0 siblings, 0 replies; 58+ messages in thread
From: Josh Triplett @ 2014-11-23 23:36 UTC (permalink / raw)
  To: Pieter Smith
  Cc: David Miller, alexander.h.duyck-ral2JQCrhuEAvxtiuMwx3w,
	viro-RmSDqhL/yNMiFSDQTTA3OLVCufUGDwFn,
	ast-uqk4Ao+rVK5Wk0Htik3J/w,
	akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b,
	beber-2YnHqweIUXrk1uMJSBkQmQ,
	catalina.mocanu-Re5JQEeQqe8AvxtiuMwx3w,
	dborkman-H+wXaHxf7aLQT0dZR+AlfA, edumazet-hpIqsD4AKlfQT0dZR+AlfA,
	ebiederm-aS9lmoZGLiVWk0Htik3J/w, fabf-AgBVmzD5pcezQB+pC5nmwQ,
	fuse-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f,
	geert-Td1EMuHUCqxL1ZNQvxDV9g, hughd-hpIqsD4AKlfQT0dZR+AlfA,
	iulia.manda21-Re5JQEeQqe8AvxtiuMwx3w, JBeulich-IBi9RG/b67k,
	bfields-uC3wQj2KruNg9hUCZPvPmw, jlayton-vpEMnDpepFuMZCB2o+C8xQ,
	linux-api-u79uwXL29TY76Z2rM5mHXA,
	linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA, mcgrof-IBi9RG/b67k,
	mattst88-Re5JQEeQqe8AvxtiuMwx3w, mgorman-l3A5Bk7waGM,
	mst-H+wXaHxf7aLQT0dZR+AlfA, miklos-sUDqSbJrdHQHWmgEVkV9KA,
	netdev-u79uwXL29TY76Z2rM5mHXA, oleg-H+wXaHxf7aLQT0dZR+AlfA,
	Paul.Durrant-Sxgqhf6Nn4DQT0dZR+AlfA,
	paulmck-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8,
	pefoley2-lY0TAiDIAFlBDgjK7y7TUQ, tgraf-G/eBtMaohhA,
	therbert-hpIqsD4AKlfQT0dZR+AlfA, willemb-hpIqsD4AKlfQT0dZR+AlfA,
	xiaoguangrong-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8,
	zhenglong.cai-TJRtMXcVgQTM1kAEIRd3EQ

On Sun, Nov 23, 2014 at 09:30:40PM +0100, Pieter Smith wrote:
> On Sun, Nov 23, 2014 at 11:43:26AM -0800, Josh Triplett wrote:
> > On Sun, Nov 23, 2014 at 01:46:23PM -0500, David Miller wrote:
> > > Truly removing sendfile/sendpage means that you can't even compile NFS
> > > into the tree.
> > 
> > If you mean the in-kernel nfsd (CONFIG_NFSD), that already has a large
> > stack of "select" and "depends on", both directly and indirectly; adding
> > a "select SPLICE_SYSCALL" to it seems fine.  (That select does need
> > adding, though.  Pieter, you need to test-compile more than just
> > tinyconfig and defconfig.  Try an allyesconfig with *just* splice turned
> > off, and make sure that compiles.)
> 
> Did exacly that. Took forever on my hardware, but no problems.

Ah, I see.  Looking more closely at nfsd, it looks like it already has a
code path for filesystems that don't do splice.  I think, rather than
making nfsd select SPLICE_SYSCALL, that it would suffice to change the
"rqstp->rq_splice_ok = true;" in svc_process_common (net/sunrpc/svc.c)
to:

rqstp->rq_splice_ok = IS_ENABLED(CONFIG_SPLICE_SYSCALL);

Then nfsd should simply *always* fall back to its non-splice support.

That said, given that it seems exceedingly unlikely that anyone would
use the in-kernel nfsd on a system trying to minimize kernel size, it
still seems cleaner to just "select SPLICE_SYSCALL" from NFSD in
Kconfig.  That avoids making any changes at all to the nfsd source in
this patch series.

- Josh Triplett

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [PATCH 0/6] kernel tinification: optionally compile out splice family of syscalls (splice, vmsplice, tee and sendfile)
  2014-11-23 23:36         ` Josh Triplett
  (?)
@ 2014-11-24  0:28         ` Jeff Layton
  2014-11-24  0:32             ` Josh Triplett
  -1 siblings, 1 reply; 58+ messages in thread
From: Jeff Layton @ 2014-11-24  0:28 UTC (permalink / raw)
  To: Josh Triplett
  Cc: Pieter Smith, David Miller, alexander.h.duyck, viro, ast, akpm,
	beber, catalina.mocanu, dborkman, edumazet, ebiederm, fabf,
	fuse-devel, geert, hughd, iulia.manda21, JBeulich, bfields,
	linux-api, linux-fsdevel, linux-kernel, mcgrof, mattst88,
	mgorman, mst, miklos, netdev, oleg, Paul.Durrant, paulmck,
	pefoley2, tgraf, therbert, willemb, xiaoguangrong, zhenglong.cai

On Sun, 23 Nov 2014 15:36:37 -0800
Josh Triplett <josh@joshtriplett.org> wrote:

> On Sun, Nov 23, 2014 at 09:30:40PM +0100, Pieter Smith wrote:
> > On Sun, Nov 23, 2014 at 11:43:26AM -0800, Josh Triplett wrote:
> > > On Sun, Nov 23, 2014 at 01:46:23PM -0500, David Miller wrote:
> > > > Truly removing sendfile/sendpage means that you can't even compile NFS
> > > > into the tree.
> > > 
> > > If you mean the in-kernel nfsd (CONFIG_NFSD), that already has a large
> > > stack of "select" and "depends on", both directly and indirectly; adding
> > > a "select SPLICE_SYSCALL" to it seems fine.  (That select does need
> > > adding, though.  Pieter, you need to test-compile more than just
> > > tinyconfig and defconfig.  Try an allyesconfig with *just* splice turned
> > > off, and make sure that compiles.)
> > 
> > Did exacly that. Took forever on my hardware, but no problems.
> 
> Ah, I see.  Looking more closely at nfsd, it looks like it already has a
> code path for filesystems that don't do splice.  I think, rather than
> making nfsd select SPLICE_SYSCALL, that it would suffice to change the
> "rqstp->rq_splice_ok = true;" in svc_process_common (net/sunrpc/svc.c)
> to:
> 
> rqstp->rq_splice_ok = IS_ENABLED(CONFIG_SPLICE_SYSCALL);
> 
> Then nfsd should simply *always* fall back to its non-splice support.
> 

I'd probably prefer the above, actually. We have to keep supporting
non-splice enabled fs' for the forseeable future, so we may as well
allow people to run nfsd in such configurations. It could even be
useful for testing the non-splice-enabled codepaths.

> That said, given that it seems exceedingly unlikely that anyone would
> use the in-kernel nfsd on a system trying to minimize kernel size, it
> still seems cleaner to just "select SPLICE_SYSCALL" from NFSD in
> Kconfig.  That avoids making any changes at all to the nfsd source in
> this patch series.
> 

-- 
Jeff Layton <jlayton@poochiereds.net>

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [PATCH 0/6] kernel tinification: optionally compile out splice family of syscalls (splice, vmsplice, tee and sendfile)
@ 2014-11-24  0:32             ` Josh Triplett
  0 siblings, 0 replies; 58+ messages in thread
From: Josh Triplett @ 2014-11-24  0:32 UTC (permalink / raw)
  To: Jeff Layton
  Cc: Pieter Smith, David Miller, alexander.h.duyck, viro, ast, akpm,
	beber, catalina.mocanu, dborkman, edumazet, ebiederm, fabf,
	fuse-devel, geert, hughd, iulia.manda21, JBeulich, bfields,
	linux-api, linux-fsdevel, linux-kernel, mcgrof, mattst88,
	mgorman, mst, miklos, netdev, oleg, Paul.Durrant, paulmck,
	pefoley2, tgraf, therbert, willemb, xiaoguangrong, zhenglong.cai

On Sun, Nov 23, 2014 at 07:28:10PM -0500, Jeff Layton wrote:
> On Sun, 23 Nov 2014 15:36:37 -0800
> Josh Triplett <josh@joshtriplett.org> wrote:
> 
> > On Sun, Nov 23, 2014 at 09:30:40PM +0100, Pieter Smith wrote:
> > > On Sun, Nov 23, 2014 at 11:43:26AM -0800, Josh Triplett wrote:
> > > > On Sun, Nov 23, 2014 at 01:46:23PM -0500, David Miller wrote:
> > > > > Truly removing sendfile/sendpage means that you can't even compile NFS
> > > > > into the tree.
> > > > 
> > > > If you mean the in-kernel nfsd (CONFIG_NFSD), that already has a large
> > > > stack of "select" and "depends on", both directly and indirectly; adding
> > > > a "select SPLICE_SYSCALL" to it seems fine.  (That select does need
> > > > adding, though.  Pieter, you need to test-compile more than just
> > > > tinyconfig and defconfig.  Try an allyesconfig with *just* splice turned
> > > > off, and make sure that compiles.)
> > > 
> > > Did exacly that. Took forever on my hardware, but no problems.
> > 
> > Ah, I see.  Looking more closely at nfsd, it looks like it already has a
> > code path for filesystems that don't do splice.  I think, rather than
> > making nfsd select SPLICE_SYSCALL, that it would suffice to change the
> > "rqstp->rq_splice_ok = true;" in svc_process_common (net/sunrpc/svc.c)
> > to:
> > 
> > rqstp->rq_splice_ok = IS_ENABLED(CONFIG_SPLICE_SYSCALL);
> > 
> > Then nfsd should simply *always* fall back to its non-splice support.
> > 
> 
> I'd probably prefer the above, actually. We have to keep supporting
> non-splice enabled fs' for the forseeable future, so we may as well
> allow people to run nfsd in such configurations. It could even be
> useful for testing the non-splice-enabled codepaths.

Good point!

- Josh Triplett

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [PATCH 0/6] kernel tinification: optionally compile out splice family of syscalls (splice, vmsplice, tee and sendfile)
@ 2014-11-24  0:32             ` Josh Triplett
  0 siblings, 0 replies; 58+ messages in thread
From: Josh Triplett @ 2014-11-24  0:32 UTC (permalink / raw)
  To: Jeff Layton
  Cc: Pieter Smith, David Miller,
	alexander.h.duyck-ral2JQCrhuEAvxtiuMwx3w,
	viro-RmSDqhL/yNMiFSDQTTA3OLVCufUGDwFn,
	ast-uqk4Ao+rVK5Wk0Htik3J/w,
	akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b,
	beber-2YnHqweIUXrk1uMJSBkQmQ,
	catalina.mocanu-Re5JQEeQqe8AvxtiuMwx3w,
	dborkman-H+wXaHxf7aLQT0dZR+AlfA, edumazet-hpIqsD4AKlfQT0dZR+AlfA,
	ebiederm-aS9lmoZGLiVWk0Htik3J/w, fabf-AgBVmzD5pcezQB+pC5nmwQ,
	fuse-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f,
	geert-Td1EMuHUCqxL1ZNQvxDV9g, hughd-hpIqsD4AKlfQT0dZR+AlfA,
	iulia.manda21-Re5JQEeQqe8AvxtiuMwx3w, JBeulich-IBi9RG/b67k,
	bfields-uC3wQj2KruNg9hUCZPvPmw, linux-api-u79uwXL29TY76Z2rM5mHXA,
	linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA, mcgrof-IBi9RG/b67k,
	mattst88-Re5JQEeQqe8AvxtiuMwx3w, mgorman-l3A5Bk7waGM,
	mst-H+wXaHxf7aLQT0dZR+AlfA, miklos-sUDqSbJrdHQHWmgEVkV9KA,
	netdev-u79uwXL29TY76Z2rM5mHXA, oleg-H+wXaHxf7aLQT0dZR+AlfA,
	Paul.Durrant-Sxgqhf6Nn4DQT0dZR+AlfA,
	paulmck-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8,
	pefoley2-lY0TAiDIAFlBDgjK7y7TUQ, tgraf-G/eBtMaohhA,
	therbert-hpIqsD4AKlfQT0dZR+AlfA, willemb-hpIqsD4AKlfQT0dZR+AlfA,
	xiaoguangrong-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8,
	zhenglong.cai-TJRtMXcVgQTM1kAEIRd3EQ

On Sun, Nov 23, 2014 at 07:28:10PM -0500, Jeff Layton wrote:
> On Sun, 23 Nov 2014 15:36:37 -0800
> Josh Triplett <josh-iaAMLnmF4UmaiuxdJuQwMA@public.gmane.org> wrote:
> 
> > On Sun, Nov 23, 2014 at 09:30:40PM +0100, Pieter Smith wrote:
> > > On Sun, Nov 23, 2014 at 11:43:26AM -0800, Josh Triplett wrote:
> > > > On Sun, Nov 23, 2014 at 01:46:23PM -0500, David Miller wrote:
> > > > > Truly removing sendfile/sendpage means that you can't even compile NFS
> > > > > into the tree.
> > > > 
> > > > If you mean the in-kernel nfsd (CONFIG_NFSD), that already has a large
> > > > stack of "select" and "depends on", both directly and indirectly; adding
> > > > a "select SPLICE_SYSCALL" to it seems fine.  (That select does need
> > > > adding, though.  Pieter, you need to test-compile more than just
> > > > tinyconfig and defconfig.  Try an allyesconfig with *just* splice turned
> > > > off, and make sure that compiles.)
> > > 
> > > Did exacly that. Took forever on my hardware, but no problems.
> > 
> > Ah, I see.  Looking more closely at nfsd, it looks like it already has a
> > code path for filesystems that don't do splice.  I think, rather than
> > making nfsd select SPLICE_SYSCALL, that it would suffice to change the
> > "rqstp->rq_splice_ok = true;" in svc_process_common (net/sunrpc/svc.c)
> > to:
> > 
> > rqstp->rq_splice_ok = IS_ENABLED(CONFIG_SPLICE_SYSCALL);
> > 
> > Then nfsd should simply *always* fall back to its non-splice support.
> > 
> 
> I'd probably prefer the above, actually. We have to keep supporting
> non-splice enabled fs' for the forseeable future, so we may as well
> allow people to run nfsd in such configurations. It could even be
> useful for testing the non-splice-enabled codepaths.

Good point!

- Josh Triplett

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [PATCH 0/6] kernel tinification: optionally compile out splice family of syscalls (splice, vmsplice, tee and sendfile)
  2014-11-23 23:36         ` Josh Triplett
  (?)
@ 2014-11-24  8:38           ` Geert Uytterhoeven
  -1 siblings, 0 replies; 58+ messages in thread
From: Geert Uytterhoeven @ 2014-11-24  8:38 UTC (permalink / raw)
  To: Josh Triplett
  Cc: Pieter Smith, David Miller, alexander.h.duyck, Al Viro,
	Alexei Starovoitov, Andrew Morton, beber, catalina.mocanu,
	Daniel Borkmann, Eric Dumazet, Eric W. Biederman,
	Fabian Frederick, fuse-devel, Hugh Dickins, iulia.manda21,
	Jan Beulich, bfields, jlayton, linux-api, Linux FS Devel,
	linux-kernel, Luis R. Rodriguez, Matt Turner, Mel Gorman,
	Michael S. Tsirkin, Miklos Szeredi, netdev, Oleg Nesterov,
	Paul.Durrant, Paul McKenney, Peter Foley, Thomas Graf,
	Tom Herbert, willemb, xiaoguangrong, zhenglong.cai

On Mon, Nov 24, 2014 at 12:36 AM, Josh Triplett <josh@joshtriplett.org> wrote:
> On Sun, Nov 23, 2014 at 09:30:40PM +0100, Pieter Smith wrote:
>> On Sun, Nov 23, 2014 at 11:43:26AM -0800, Josh Triplett wrote:
>> > On Sun, Nov 23, 2014 at 01:46:23PM -0500, David Miller wrote:
>> > > Truly removing sendfile/sendpage means that you can't even compile NFS
>> > > into the tree.
>> >
>> > If you mean the in-kernel nfsd (CONFIG_NFSD), that already has a large
>> > stack of "select" and "depends on", both directly and indirectly; adding
>> > a "select SPLICE_SYSCALL" to it seems fine.  (That select does need
>> > adding, though.  Pieter, you need to test-compile more than just
>> > tinyconfig and defconfig.  Try an allyesconfig with *just* splice turned
>> > off, and make sure that compiles.)
>>
>> Did exacly that. Took forever on my hardware, but no problems.
>
> Ah, I see.  Looking more closely at nfsd, it looks like it already has a
> code path for filesystems that don't do splice.  I think, rather than
> making nfsd select SPLICE_SYSCALL, that it would suffice to change the
> "rqstp->rq_splice_ok = true;" in svc_process_common (net/sunrpc/svc.c)
> to:
>
> rqstp->rq_splice_ok = IS_ENABLED(CONFIG_SPLICE_SYSCALL);
>
> Then nfsd should simply *always* fall back to its non-splice support.

Hence I suggest adding to the nfsd help text:

    While nfsd works without SPLICE_SYSCALL, you may want to enable
    SPLICE_SYSCALL for <...> (performance?) reasons.

(Hmm, does Kconfig need a "suggests", cfr. Debian package dependencies?)

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [PATCH 0/6] kernel tinification: optionally compile out splice family of syscalls (splice, vmsplice, tee and sendfile)
@ 2014-11-24  8:38           ` Geert Uytterhoeven
  0 siblings, 0 replies; 58+ messages in thread
From: Geert Uytterhoeven @ 2014-11-24  8:38 UTC (permalink / raw)
  To: Josh Triplett
  Cc: Pieter Smith, David Miller,
	alexander.h.duyck-ral2JQCrhuEAvxtiuMwx3w, Al Viro,
	Alexei Starovoitov, Andrew Morton, beber-2YnHqweIUXrk1uMJSBkQmQ,
	catalina.mocanu-Re5JQEeQqe8AvxtiuMwx3w, Daniel Borkmann,
	Eric Dumazet, Eric W. Biederman, Fabian Frederick,
	fuse-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f, Hugh Dickins,
	iulia.manda21-Re5JQEeQqe8AvxtiuMwx3w, Jan Beulich,
	bfields-uC3wQj2KruNg9hUCZPvPmw, jlayton-vpEMnDpepFuMZCB2o+C8xQ,
	linux-api-u79uwXL29TY76Z2rM5mHXA, Linux FS Devel,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA, Luis R. Rodriguez,
	Matt Turner, Mel Gorman, Michael S. Tsirkin, Miklos

On Mon, Nov 24, 2014 at 12:36 AM, Josh Triplett <josh-iaAMLnmF4UmaiuxdJuQwMA@public.gmane.org> wrote:
> On Sun, Nov 23, 2014 at 09:30:40PM +0100, Pieter Smith wrote:
>> On Sun, Nov 23, 2014 at 11:43:26AM -0800, Josh Triplett wrote:
>> > On Sun, Nov 23, 2014 at 01:46:23PM -0500, David Miller wrote:
>> > > Truly removing sendfile/sendpage means that you can't even compile NFS
>> > > into the tree.
>> >
>> > If you mean the in-kernel nfsd (CONFIG_NFSD), that already has a large
>> > stack of "select" and "depends on", both directly and indirectly; adding
>> > a "select SPLICE_SYSCALL" to it seems fine.  (That select does need
>> > adding, though.  Pieter, you need to test-compile more than just
>> > tinyconfig and defconfig.  Try an allyesconfig with *just* splice turned
>> > off, and make sure that compiles.)
>>
>> Did exacly that. Took forever on my hardware, but no problems.
>
> Ah, I see.  Looking more closely at nfsd, it looks like it already has a
> code path for filesystems that don't do splice.  I think, rather than
> making nfsd select SPLICE_SYSCALL, that it would suffice to change the
> "rqstp->rq_splice_ok = true;" in svc_process_common (net/sunrpc/svc.c)
> to:
>
> rqstp->rq_splice_ok = IS_ENABLED(CONFIG_SPLICE_SYSCALL);
>
> Then nfsd should simply *always* fall back to its non-splice support.

Hence I suggest adding to the nfsd help text:

    While nfsd works without SPLICE_SYSCALL, you may want to enable
    SPLICE_SYSCALL for <...> (performance?) reasons.

(Hmm, does Kconfig need a "suggests", cfr. Debian package dependencies?)

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert-Td1EMuHUCqxL1ZNQvxDV9g@public.gmane.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [PATCH 0/6] kernel tinification: optionally compile out splice family of syscalls (splice, vmsplice, tee and sendfile)
@ 2014-11-24  8:38           ` Geert Uytterhoeven
  0 siblings, 0 replies; 58+ messages in thread
From: Geert Uytterhoeven @ 2014-11-24  8:38 UTC (permalink / raw)
  To: Josh Triplett
  Cc: Pieter Smith, David Miller,
	alexander.h.duyck-ral2JQCrhuEAvxtiuMwx3w, Al Viro,
	Alexei Starovoitov, Andrew Morton, beber-2YnHqweIUXrk1uMJSBkQmQ,
	catalina.mocanu-Re5JQEeQqe8AvxtiuMwx3w, Daniel Borkmann,
	Eric Dumazet, Eric W. Biederman, Fabian Frederick,
	fuse-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f, Hugh Dickins,
	iulia.manda21-Re5JQEeQqe8AvxtiuMwx3w, Jan Beulich,
	bfields-uC3wQj2KruNg9hUCZPvPmw, jlayton-vpEMnDpepFuMZCB2o+C8xQ,
	linux-api-u79uwXL29TY76Z2rM5mHXA, Linux FS Devel,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA, Luis R. Rodriguez,
	Matt Turner, Mel Gorman, Michael S. Tsirkin, Miklos

On Mon, Nov 24, 2014 at 12:36 AM, Josh Triplett <josh-iaAMLnmF4UmaiuxdJuQwMA@public.gmane.org> wrote:
> On Sun, Nov 23, 2014 at 09:30:40PM +0100, Pieter Smith wrote:
>> On Sun, Nov 23, 2014 at 11:43:26AM -0800, Josh Triplett wrote:
>> > On Sun, Nov 23, 2014 at 01:46:23PM -0500, David Miller wrote:
>> > > Truly removing sendfile/sendpage means that you can't even compile NFS
>> > > into the tree.
>> >
>> > If you mean the in-kernel nfsd (CONFIG_NFSD), that already has a large
>> > stack of "select" and "depends on", both directly and indirectly; adding
>> > a "select SPLICE_SYSCALL" to it seems fine.  (That select does need
>> > adding, though.  Pieter, you need to test-compile more than just
>> > tinyconfig and defconfig.  Try an allyesconfig with *just* splice turned
>> > off, and make sure that compiles.)
>>
>> Did exacly that. Took forever on my hardware, but no problems.
>
> Ah, I see.  Looking more closely at nfsd, it looks like it already has a
> code path for filesystems that don't do splice.  I think, rather than
> making nfsd select SPLICE_SYSCALL, that it would suffice to change the
> "rqstp->rq_splice_ok = true;" in svc_process_common (net/sunrpc/svc.c)
> to:
>
> rqstp->rq_splice_ok = IS_ENABLED(CONFIG_SPLICE_SYSCALL);
>
> Then nfsd should simply *always* fall back to its non-splice support.

Hence I suggest adding to the nfsd help text:

    While nfsd works without SPLICE_SYSCALL, you may want to enable
    SPLICE_SYSCALL for <...> (performance?) reasons.

(Hmm, does Kconfig need a "suggests", cfr. Debian package dependencies?)

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert-Td1EMuHUCqxL1ZNQvxDV9g@public.gmane.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [PATCH 0/6] kernel tinification: optionally compile out splice family of syscalls (splice, vmsplice, tee and sendfile)
@ 2014-11-24  9:00             ` Josh Triplett
  0 siblings, 0 replies; 58+ messages in thread
From: Josh Triplett @ 2014-11-24  9:00 UTC (permalink / raw)
  To: Geert Uytterhoeven
  Cc: Pieter Smith, David Miller, alexander.h.duyck, Al Viro,
	Alexei Starovoitov, Andrew Morton, beber, catalina.mocanu,
	Daniel Borkmann, Eric Dumazet, Eric W. Biederman,
	Fabian Frederick, fuse-devel, Hugh Dickins, iulia.manda21,
	Jan Beulich, bfields, jlayton, linux-api, Linux FS Devel,
	linux-kernel, Luis R. Rodriguez, Matt Turner, Mel Gorman,
	Michael S. Tsirkin, Miklos Szeredi, netdev, Oleg Nesterov,
	Paul.Durrant, Paul McKenney, Peter Foley, Thomas Graf,
	Tom Herbert, willemb, xiaoguangrong, zhenglong.cai

On Mon, Nov 24, 2014 at 09:38:20AM +0100, Geert Uytterhoeven wrote:
> On Mon, Nov 24, 2014 at 12:36 AM, Josh Triplett <josh@joshtriplett.org> wrote:
> > On Sun, Nov 23, 2014 at 09:30:40PM +0100, Pieter Smith wrote:
> >> On Sun, Nov 23, 2014 at 11:43:26AM -0800, Josh Triplett wrote:
> >> > On Sun, Nov 23, 2014 at 01:46:23PM -0500, David Miller wrote:
> >> > > Truly removing sendfile/sendpage means that you can't even compile NFS
> >> > > into the tree.
> >> >
> >> > If you mean the in-kernel nfsd (CONFIG_NFSD), that already has a large
> >> > stack of "select" and "depends on", both directly and indirectly; adding
> >> > a "select SPLICE_SYSCALL" to it seems fine.  (That select does need
> >> > adding, though.  Pieter, you need to test-compile more than just
> >> > tinyconfig and defconfig.  Try an allyesconfig with *just* splice turned
> >> > off, and make sure that compiles.)
> >>
> >> Did exacly that. Took forever on my hardware, but no problems.
> >
> > Ah, I see.  Looking more closely at nfsd, it looks like it already has a
> > code path for filesystems that don't do splice.  I think, rather than
> > making nfsd select SPLICE_SYSCALL, that it would suffice to change the
> > "rqstp->rq_splice_ok = true;" in svc_process_common (net/sunrpc/svc.c)
> > to:
> >
> > rqstp->rq_splice_ok = IS_ENABLED(CONFIG_SPLICE_SYSCALL);
> >
> > Then nfsd should simply *always* fall back to its non-splice support.
> 
> Hence I suggest adding to the nfsd help text:
> 
>     While nfsd works without SPLICE_SYSCALL, you may want to enable
>     SPLICE_SYSCALL for <...> (performance?) reasons.

It already seems sufficiently unlikely to enable NFSD while disabling
SPLICE_SYSCALL (in the latter case, turning on EXPERT to do so).  It
doesn't seem worth adding such a note to NFSD.  At most, I'd say that
NFSD might want a note somewhere in its documentation saying that it
takes advantage of filesystems with splice support if serving files from
one, and if running on a kernel that has splice.

> (Hmm, does Kconfig need a "suggests", cfr. Debian package dependencies?)

Perhaps, though that seems much lower priority than, for instance,
transitive "select".

- Josh Triplett

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [PATCH 0/6] kernel tinification: optionally compile out splice family of syscalls (splice, vmsplice, tee and sendfile)
@ 2014-11-24  9:00             ` Josh Triplett
  0 siblings, 0 replies; 58+ messages in thread
From: Josh Triplett @ 2014-11-24  9:00 UTC (permalink / raw)
  To: Geert Uytterhoeven
  Cc: Pieter Smith, David Miller,
	alexander.h.duyck-ral2JQCrhuEAvxtiuMwx3w, Al Viro,
	Alexei Starovoitov, Andrew Morton, beber-2YnHqweIUXrk1uMJSBkQmQ,
	catalina.mocanu-Re5JQEeQqe8AvxtiuMwx3w, Daniel Borkmann,
	Eric Dumazet, Eric W. Biederman, Fabian Frederick,
	fuse-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f, Hugh Dickins,
	iulia.manda21-Re5JQEeQqe8AvxtiuMwx3w, Jan Beulich,
	bfields-uC3wQj2KruNg9hUCZPvPmw, jlayton-vpEMnDpepFuMZCB2o+C8xQ,
	linux-api-u79uwXL29TY76Z2rM5mHXA, Linux FS Devel,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA, Luis R. Rodriguez,
	Matt Turner, Mel Gorman, Michael S. Tsirkin, Miklos

On Mon, Nov 24, 2014 at 09:38:20AM +0100, Geert Uytterhoeven wrote:
> On Mon, Nov 24, 2014 at 12:36 AM, Josh Triplett <josh-iaAMLnmF4UmaiuxdJuQwMA@public.gmane.org> wrote:
> > On Sun, Nov 23, 2014 at 09:30:40PM +0100, Pieter Smith wrote:
> >> On Sun, Nov 23, 2014 at 11:43:26AM -0800, Josh Triplett wrote:
> >> > On Sun, Nov 23, 2014 at 01:46:23PM -0500, David Miller wrote:
> >> > > Truly removing sendfile/sendpage means that you can't even compile NFS
> >> > > into the tree.
> >> >
> >> > If you mean the in-kernel nfsd (CONFIG_NFSD), that already has a large
> >> > stack of "select" and "depends on", both directly and indirectly; adding
> >> > a "select SPLICE_SYSCALL" to it seems fine.  (That select does need
> >> > adding, though.  Pieter, you need to test-compile more than just
> >> > tinyconfig and defconfig.  Try an allyesconfig with *just* splice turned
> >> > off, and make sure that compiles.)
> >>
> >> Did exacly that. Took forever on my hardware, but no problems.
> >
> > Ah, I see.  Looking more closely at nfsd, it looks like it already has a
> > code path for filesystems that don't do splice.  I think, rather than
> > making nfsd select SPLICE_SYSCALL, that it would suffice to change the
> > "rqstp->rq_splice_ok = true;" in svc_process_common (net/sunrpc/svc.c)
> > to:
> >
> > rqstp->rq_splice_ok = IS_ENABLED(CONFIG_SPLICE_SYSCALL);
> >
> > Then nfsd should simply *always* fall back to its non-splice support.
> 
> Hence I suggest adding to the nfsd help text:
> 
>     While nfsd works without SPLICE_SYSCALL, you may want to enable
>     SPLICE_SYSCALL for <...> (performance?) reasons.

It already seems sufficiently unlikely to enable NFSD while disabling
SPLICE_SYSCALL (in the latter case, turning on EXPERT to do so).  It
doesn't seem worth adding such a note to NFSD.  At most, I'd say that
NFSD might want a note somewhere in its documentation saying that it
takes advantage of filesystems with splice support if serving files from
one, and if running on a kernel that has splice.

> (Hmm, does Kconfig need a "suggests", cfr. Debian package dependencies?)

Perhaps, though that seems much lower priority than, for instance,
transitive "select".

- Josh Triplett

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [PATCH 0/6] kernel tinification: optionally compile out splice family of syscalls (splice, vmsplice, tee and sendfile)
@ 2014-11-24  9:00             ` Josh Triplett
  0 siblings, 0 replies; 58+ messages in thread
From: Josh Triplett @ 2014-11-24  9:00 UTC (permalink / raw)
  To: Geert Uytterhoeven
  Cc: Pieter Smith, David Miller,
	alexander.h.duyck-ral2JQCrhuEAvxtiuMwx3w, Al Viro,
	Alexei Starovoitov, Andrew Morton, beber-2YnHqweIUXrk1uMJSBkQmQ,
	catalina.mocanu-Re5JQEeQqe8AvxtiuMwx3w, Daniel Borkmann,
	Eric Dumazet, Eric W. Biederman, Fabian Frederick,
	fuse-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f, Hugh Dickins,
	iulia.manda21-Re5JQEeQqe8AvxtiuMwx3w, Jan Beulich,
	bfields-uC3wQj2KruNg9hUCZPvPmw, jlayton-vpEMnDpepFuMZCB2o+C8xQ,
	linux-api-u79uwXL29TY76Z2rM5mHXA, Linux FS Devel,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA, Luis R. Rodriguez,
	Matt Turner, Mel Gorman, Michael S. Tsirkin, Miklos

On Mon, Nov 24, 2014 at 09:38:20AM +0100, Geert Uytterhoeven wrote:
> On Mon, Nov 24, 2014 at 12:36 AM, Josh Triplett <josh-iaAMLnmF4UmaiuxdJuQwMA@public.gmane.org> wrote:
> > On Sun, Nov 23, 2014 at 09:30:40PM +0100, Pieter Smith wrote:
> >> On Sun, Nov 23, 2014 at 11:43:26AM -0800, Josh Triplett wrote:
> >> > On Sun, Nov 23, 2014 at 01:46:23PM -0500, David Miller wrote:
> >> > > Truly removing sendfile/sendpage means that you can't even compile NFS
> >> > > into the tree.
> >> >
> >> > If you mean the in-kernel nfsd (CONFIG_NFSD), that already has a large
> >> > stack of "select" and "depends on", both directly and indirectly; adding
> >> > a "select SPLICE_SYSCALL" to it seems fine.  (That select does need
> >> > adding, though.  Pieter, you need to test-compile more than just
> >> > tinyconfig and defconfig.  Try an allyesconfig with *just* splice turned
> >> > off, and make sure that compiles.)
> >>
> >> Did exacly that. Took forever on my hardware, but no problems.
> >
> > Ah, I see.  Looking more closely at nfsd, it looks like it already has a
> > code path for filesystems that don't do splice.  I think, rather than
> > making nfsd select SPLICE_SYSCALL, that it would suffice to change the
> > "rqstp->rq_splice_ok = true;" in svc_process_common (net/sunrpc/svc.c)
> > to:
> >
> > rqstp->rq_splice_ok = IS_ENABLED(CONFIG_SPLICE_SYSCALL);
> >
> > Then nfsd should simply *always* fall back to its non-splice support.
> 
> Hence I suggest adding to the nfsd help text:
> 
>     While nfsd works without SPLICE_SYSCALL, you may want to enable
>     SPLICE_SYSCALL for <...> (performance?) reasons.

It already seems sufficiently unlikely to enable NFSD while disabling
SPLICE_SYSCALL (in the latter case, turning on EXPERT to do so).  It
doesn't seem worth adding such a note to NFSD.  At most, I'd say that
NFSD might want a note somewhere in its documentation saying that it
takes advantage of filesystems with splice support if serving files from
one, and if running on a kernel that has splice.

> (Hmm, does Kconfig need a "suggests", cfr. Debian package dependencies?)

Perhaps, though that seems much lower priority than, for instance,
transitive "select".

- Josh Triplett

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [fuse-devel] [PATCH 4/6] fs/fuse: support compiling out splice
  2014-11-23 23:23       ` Josh Triplett
@ 2014-11-24  9:49         ` Pieter Smith
  -1 siblings, 0 replies; 58+ messages in thread
From: Pieter Smith @ 2014-11-24  9:49 UTC (permalink / raw)
  To: Josh Triplett
  Cc: Richard Weinberger, Michael S. Tsirkin, Bertrand Jacquin,
	Oleg Nesterov, J. Bruce Fields, Eric Dumazet,
	蔡正龙,
	Jeff Layton, Tom Herbert, Alexei Starovoitov, Miklos Szeredi,
	Peter Foley, Hugh Dickins, Xiao Guangrong, Geert Uytterhoeven,
	Mel Gorman, Matt Turner, Paul E. McKenney, Alexander Duyck,
	open list:FUSE: FILESYSTEM...,
	Luis R. Rodriguez, Catalina Mocanu, Fabian Frederick,
	Thomas Graf, Paul Durrant, Alexander Viro, Jan Beulich,
	Willem de Bruijn, Iulia Manda, open list:ABI/API, open list,
	Daniel Borkmann, Eric W. Biederman,
	open list:NETWORKING [GENERAL],
	linux-fsdevel, Andrew Morton, David S. Miller

On Sun, Nov 23, 2014 at 03:23:02PM -0800, Josh Triplett wrote:
> On Sun, Nov 23, 2014 at 11:29:08PM +0100, Richard Weinberger wrote:
> > On Sun, Nov 23, 2014 at 3:20 PM, Pieter Smith <pieter@boesman.nl> wrote:
> > > To implement splice support, fs/fuse makes use of nosteal_pipe_buf_ops. This
> > > struct is exported by fs/splice. The goal of the larger patch set is to
> > > completely compile out fs/splice, so uses of the exported struct need to be
> > > compiled out along with fs/splice.
> > >
> > > This patch therefore compiles out splice support in fs/fuse when
> > > CONFIG_SYSCALL_SPLICE is undefined.
> > >
> > > Signed-off-by: Pieter Smith <pieter@boesman.nl>
> > > ---
> > >  fs/fuse/dev.c      | 4 ++--
> > >  include/linux/fs.h | 6 ++++++
> > >  2 files changed, 8 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
> > > index ca88731..f8f92a4 100644
> > > --- a/fs/fuse/dev.c
> > > +++ b/fs/fuse/dev.c
> > > @@ -1291,7 +1291,7 @@ static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov,
> > >         return fuse_dev_do_read(fc, file, &cs, iov_length(iov, nr_segs));
> > >  }
> > >
> > > -static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
> > > +static ssize_t __maybe_unused fuse_dev_splice_read(struct file *in, loff_t *ppos,
> > >                                     struct pipe_inode_info *pipe,
> > >                                     size_t len, unsigned int flags)
> > >  {
> > > @@ -2144,7 +2144,7 @@ const struct file_operations fuse_dev_operations = {
> > >         .llseek         = no_llseek,
> > >         .read           = do_sync_read,
> > >         .aio_read       = fuse_dev_read,
> > > -       .splice_read    = fuse_dev_splice_read,
> > > +       .splice_read    = __splice_p(fuse_dev_splice_read),
> > >         .write          = do_sync_write,
> > >         .aio_write      = fuse_dev_write,
> > >         .splice_write   = fuse_dev_splice_write,
> > > diff --git a/include/linux/fs.h b/include/linux/fs.h
> > > index a957d43..04c0975 100644
> > > --- a/include/linux/fs.h
> > > +++ b/include/linux/fs.h
> > > @@ -2443,6 +2443,12 @@ extern int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
> > >                         int datasync);
> > >  extern void block_sync_page(struct page *page);
> > >
> > > +#ifdef CONFIG_SYSCALL_SPLICE
> > > +#define __splice_p(x) x
> > > +#else
> > > +#define __splice_p(x) NULL
> > > +#endif
> > > +
> > 
> > This needs to go into a different patch.
> > One logical change per patch please. :-)
> 
> Easy enough to merge this one into the patch introducing
> CONFIG_SYSCALL_SPLICE, then.
> 
> - Josh Triplett

The patch introducing CONFIG_SYSCALL_SPLICE (PATCH 3) only compiles out the
syscalls. PATCH 6 on the other hand, compiles out fs/splice.c. This patch
allows fs/fuse to be compiled when fs/splice.c is compiled out. If I am to
squash it, it would be logical to include it in PATCH 6, not 3.

Is this agreeable?

PATCH 5 does the same as this one for net/core. Should I still keep PATCH 5
separate from a maintainership perspective?

- Pieter Smith


^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [fuse-devel] [PATCH 4/6] fs/fuse: support compiling out splice
@ 2014-11-24  9:49         ` Pieter Smith
  0 siblings, 0 replies; 58+ messages in thread
From: Pieter Smith @ 2014-11-24  9:49 UTC (permalink / raw)
  To: Josh Triplett
  Cc: Richard Weinberger, Michael S. Tsirkin, Bertrand Jacquin,
	Oleg Nesterov, J. Bruce Fields, Eric Dumazet,
	蔡正龙,
	Jeff Layton, Tom Herbert, Alexei Starovoitov, Miklos Szeredi,
	Peter Foley, Hugh Dickins, Xiao Guangrong, Geert Uytterhoeven,
	Mel Gorman, Matt Turner, Paul E. McKenney, Alexander Duyck,
	open list:FUSE: FILESYSTEM...,
	Luis R. Rodriguez

On Sun, Nov 23, 2014 at 03:23:02PM -0800, Josh Triplett wrote:
> On Sun, Nov 23, 2014 at 11:29:08PM +0100, Richard Weinberger wrote:
> > On Sun, Nov 23, 2014 at 3:20 PM, Pieter Smith <pieter@boesman.nl> wrote:
> > > To implement splice support, fs/fuse makes use of nosteal_pipe_buf_ops. This
> > > struct is exported by fs/splice. The goal of the larger patch set is to
> > > completely compile out fs/splice, so uses of the exported struct need to be
> > > compiled out along with fs/splice.
> > >
> > > This patch therefore compiles out splice support in fs/fuse when
> > > CONFIG_SYSCALL_SPLICE is undefined.
> > >
> > > Signed-off-by: Pieter Smith <pieter@boesman.nl>
> > > ---
> > >  fs/fuse/dev.c      | 4 ++--
> > >  include/linux/fs.h | 6 ++++++
> > >  2 files changed, 8 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
> > > index ca88731..f8f92a4 100644
> > > --- a/fs/fuse/dev.c
> > > +++ b/fs/fuse/dev.c
> > > @@ -1291,7 +1291,7 @@ static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov,
> > >         return fuse_dev_do_read(fc, file, &cs, iov_length(iov, nr_segs));
> > >  }
> > >
> > > -static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
> > > +static ssize_t __maybe_unused fuse_dev_splice_read(struct file *in, loff_t *ppos,
> > >                                     struct pipe_inode_info *pipe,
> > >                                     size_t len, unsigned int flags)
> > >  {
> > > @@ -2144,7 +2144,7 @@ const struct file_operations fuse_dev_operations = {
> > >         .llseek         = no_llseek,
> > >         .read           = do_sync_read,
> > >         .aio_read       = fuse_dev_read,
> > > -       .splice_read    = fuse_dev_splice_read,
> > > +       .splice_read    = __splice_p(fuse_dev_splice_read),
> > >         .write          = do_sync_write,
> > >         .aio_write      = fuse_dev_write,
> > >         .splice_write   = fuse_dev_splice_write,
> > > diff --git a/include/linux/fs.h b/include/linux/fs.h
> > > index a957d43..04c0975 100644
> > > --- a/include/linux/fs.h
> > > +++ b/include/linux/fs.h
> > > @@ -2443,6 +2443,12 @@ extern int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
> > >                         int datasync);
> > >  extern void block_sync_page(struct page *page);
> > >
> > > +#ifdef CONFIG_SYSCALL_SPLICE
> > > +#define __splice_p(x) x
> > > +#else
> > > +#define __splice_p(x) NULL
> > > +#endif
> > > +
> > 
> > This needs to go into a different patch.
> > One logical change per patch please. :-)
> 
> Easy enough to merge this one into the patch introducing
> CONFIG_SYSCALL_SPLICE, then.
> 
> - Josh Triplett

The patch introducing CONFIG_SYSCALL_SPLICE (PATCH 3) only compiles out the
syscalls. PATCH 6 on the other hand, compiles out fs/splice.c. This patch
allows fs/fuse to be compiled when fs/splice.c is compiled out. If I am to
squash it, it would be logical to include it in PATCH 6, not 3.

Is this agreeable?

PATCH 5 does the same as this one for net/core. Should I still keep PATCH 5
separate from a maintainership perspective?

- Pieter Smith

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [PATCH 0/6] kernel tinification: optionally compile out splice family of syscalls (splice, vmsplice, tee and sendfile)
  2014-11-24  0:32             ` Josh Triplett
@ 2014-11-24 10:01               ` Pieter Smith
  -1 siblings, 0 replies; 58+ messages in thread
From: Pieter Smith @ 2014-11-24 10:01 UTC (permalink / raw)
  To: Josh Triplett
  Cc: Jeff Layton, David Miller, alexander.h.duyck, viro, ast, akpm,
	beber, catalina.mocanu, dborkman, edumazet, ebiederm, fabf,
	fuse-devel, geert, hughd, iulia.manda21, JBeulich, bfields,
	linux-api, linux-fsdevel, linux-kernel, mcgrof, mattst88,
	mgorman, mst, miklos, netdev, oleg, Paul.Durrant, paulmck,
	pefoley2, tgraf, therbert, willemb, xiaoguangrong, zhenglong.cai

On Sun, Nov 23, 2014 at 04:32:51PM -0800, Josh Triplett wrote:
> On Sun, Nov 23, 2014 at 07:28:10PM -0500, Jeff Layton wrote:
> > On Sun, 23 Nov 2014 15:36:37 -0800
> > Josh Triplett <josh@joshtriplett.org> wrote:
> > 
> > > On Sun, Nov 23, 2014 at 09:30:40PM +0100, Pieter Smith wrote:
> > > > On Sun, Nov 23, 2014 at 11:43:26AM -0800, Josh Triplett wrote:
> > > > > On Sun, Nov 23, 2014 at 01:46:23PM -0500, David Miller wrote:
> > > > > > Truly removing sendfile/sendpage means that you can't even compile NFS
> > > > > > into the tree.
> > > > > 
> > > > > If you mean the in-kernel nfsd (CONFIG_NFSD), that already has a large
> > > > > stack of "select" and "depends on", both directly and indirectly; adding
> > > > > a "select SPLICE_SYSCALL" to it seems fine.  (That select does need
> > > > > adding, though.  Pieter, you need to test-compile more than just
> > > > > tinyconfig and defconfig.  Try an allyesconfig with *just* splice turned
> > > > > off, and make sure that compiles.)
> > > > 
> > > > Did exacly that. Took forever on my hardware, but no problems.
> > > 
> > > Ah, I see.  Looking more closely at nfsd, it looks like it already has a
> > > code path for filesystems that don't do splice.  I think, rather than
> > > making nfsd select SPLICE_SYSCALL, that it would suffice to change the
> > > "rqstp->rq_splice_ok = true;" in svc_process_common (net/sunrpc/svc.c)
> > > to:
> > > 
> > > rqstp->rq_splice_ok = IS_ENABLED(CONFIG_SPLICE_SYSCALL);
> > > 
> > > Then nfsd should simply *always* fall back to its non-splice support.
> > > 
> > 
> > I'd probably prefer the above, actually. We have to keep supporting
> > non-splice enabled fs' for the forseeable future, so we may as well
> > allow people to run nfsd in such configurations. It could even be
> > useful for testing the non-splice-enabled codepaths.
> 
> Good point!
> 
> - Josh Triplett

I'll add this to svc_process_common. I can squash this into PATCH 3, which is
where the syscalls can be compiled out. The log entry may however get a little
crowded and multi-functional.

Should I keep this as a separate patch?

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [PATCH 0/6] kernel tinification: optionally compile out splice family of syscalls (splice, vmsplice, tee and sendfile)
@ 2014-11-24 10:01               ` Pieter Smith
  0 siblings, 0 replies; 58+ messages in thread
From: Pieter Smith @ 2014-11-24 10:01 UTC (permalink / raw)
  To: Josh Triplett
  Cc: Jeff Layton, David Miller,
	alexander.h.duyck-ral2JQCrhuEAvxtiuMwx3w,
	viro-RmSDqhL/yNMiFSDQTTA3OLVCufUGDwFn,
	ast-uqk4Ao+rVK5Wk0Htik3J/w,
	akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b,
	beber-2YnHqweIUXrk1uMJSBkQmQ,
	catalina.mocanu-Re5JQEeQqe8AvxtiuMwx3w,
	dborkman-H+wXaHxf7aLQT0dZR+AlfA, edumazet-hpIqsD4AKlfQT0dZR+AlfA,
	ebiederm-aS9lmoZGLiVWk0Htik3J/w, fabf-AgBVmzD5pcezQB+pC5nmwQ,
	fuse-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f,
	geert-Td1EMuHUCqxL1ZNQvxDV9g, hughd-hpIqsD4AKlfQT0dZR+AlfA,
	iulia.manda21-Re5JQEeQqe8AvxtiuMwx3w, JBeulich-IBi9RG/b67k,
	bfields-uC3wQj2KruNg9hUCZPvPmw, linux-api-u79uwXL29TY76Z2rM5mHXA,
	linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA, mcgrof-IBi9RG/b67k,
	mattst88-Re5JQEeQqe8AvxtiuMwx3w, mgorman-l3A5Bk7waGM,
	mst-H+wXaHxf7aLQT0dZR+AlfA, miklos-sUDqSbJrdHQHWmgEVkV9KA,
	netdev-u79uwXL29TY76Z2rM5mHXA, oleg-H+wXaHxf7aLQT0dZR+AlfA,
	Paul.Durrant-Sxgqhf6Nn4DQT0dZR+AlfA,
	paulmck-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8,
	pefoley2-lY0TAiDIAFlBDgjK7y7TUQ, tgraf-G/eBtMaohhA,
	therbert-hpIqsD4AKlfQT0dZR+AlfA, willemb-hpIqsD4AKlfQT0dZR+AlfA,
	xiaoguangrong-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8,
	zhenglong.cai-TJRtMXcVgQTM1kAEIRd3EQ

On Sun, Nov 23, 2014 at 04:32:51PM -0800, Josh Triplett wrote:
> On Sun, Nov 23, 2014 at 07:28:10PM -0500, Jeff Layton wrote:
> > On Sun, 23 Nov 2014 15:36:37 -0800
> > Josh Triplett <josh-iaAMLnmF4UmaiuxdJuQwMA@public.gmane.org> wrote:
> > 
> > > On Sun, Nov 23, 2014 at 09:30:40PM +0100, Pieter Smith wrote:
> > > > On Sun, Nov 23, 2014 at 11:43:26AM -0800, Josh Triplett wrote:
> > > > > On Sun, Nov 23, 2014 at 01:46:23PM -0500, David Miller wrote:
> > > > > > Truly removing sendfile/sendpage means that you can't even compile NFS
> > > > > > into the tree.
> > > > > 
> > > > > If you mean the in-kernel nfsd (CONFIG_NFSD), that already has a large
> > > > > stack of "select" and "depends on", both directly and indirectly; adding
> > > > > a "select SPLICE_SYSCALL" to it seems fine.  (That select does need
> > > > > adding, though.  Pieter, you need to test-compile more than just
> > > > > tinyconfig and defconfig.  Try an allyesconfig with *just* splice turned
> > > > > off, and make sure that compiles.)
> > > > 
> > > > Did exacly that. Took forever on my hardware, but no problems.
> > > 
> > > Ah, I see.  Looking more closely at nfsd, it looks like it already has a
> > > code path for filesystems that don't do splice.  I think, rather than
> > > making nfsd select SPLICE_SYSCALL, that it would suffice to change the
> > > "rqstp->rq_splice_ok = true;" in svc_process_common (net/sunrpc/svc.c)
> > > to:
> > > 
> > > rqstp->rq_splice_ok = IS_ENABLED(CONFIG_SPLICE_SYSCALL);
> > > 
> > > Then nfsd should simply *always* fall back to its non-splice support.
> > > 
> > 
> > I'd probably prefer the above, actually. We have to keep supporting
> > non-splice enabled fs' for the forseeable future, so we may as well
> > allow people to run nfsd in such configurations. It could even be
> > useful for testing the non-splice-enabled codepaths.
> 
> Good point!
> 
> - Josh Triplett

I'll add this to svc_process_common. I can squash this into PATCH 3, which is
where the syscalls can be compiled out. The log entry may however get a little
crowded and multi-functional.

Should I keep this as a separate patch?

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [PATCH 0/6] kernel tinification: optionally compile out splice family of syscalls (splice, vmsplice, tee and sendfile)
  2014-11-24 10:01               ` Pieter Smith
@ 2014-11-24 14:54                 ` Josh Triplett
  -1 siblings, 0 replies; 58+ messages in thread
From: Josh Triplett @ 2014-11-24 14:54 UTC (permalink / raw)
  To: Pieter Smith
  Cc: Jeff Layton, David Miller, alexander.h.duyck, viro, ast, akpm,
	beber, catalina.mocanu, dborkman, edumazet, ebiederm, fabf,
	fuse-devel, geert, hughd, iulia.manda21, JBeulich, bfields,
	linux-api, linux-fsdevel, linux-kernel, mcgrof, mattst88,
	mgorman, mst, miklos, netdev, oleg, Paul.Durrant, paulmck,
	pefoley2, tgraf, therbert, willemb, xiaoguangrong, zhenglong.cai

On Mon, Nov 24, 2014 at 11:01:38AM +0100, Pieter Smith wrote:
> On Sun, Nov 23, 2014 at 04:32:51PM -0800, Josh Triplett wrote:
> > On Sun, Nov 23, 2014 at 07:28:10PM -0500, Jeff Layton wrote:
> > > On Sun, 23 Nov 2014 15:36:37 -0800
> > > Josh Triplett <josh@joshtriplett.org> wrote:
> > > 
> > > > On Sun, Nov 23, 2014 at 09:30:40PM +0100, Pieter Smith wrote:
> > > > > On Sun, Nov 23, 2014 at 11:43:26AM -0800, Josh Triplett wrote:
> > > > > > On Sun, Nov 23, 2014 at 01:46:23PM -0500, David Miller wrote:
> > > > > > > Truly removing sendfile/sendpage means that you can't even compile NFS
> > > > > > > into the tree.
> > > > > > 
> > > > > > If you mean the in-kernel nfsd (CONFIG_NFSD), that already has a large
> > > > > > stack of "select" and "depends on", both directly and indirectly; adding
> > > > > > a "select SPLICE_SYSCALL" to it seems fine.  (That select does need
> > > > > > adding, though.  Pieter, you need to test-compile more than just
> > > > > > tinyconfig and defconfig.  Try an allyesconfig with *just* splice turned
> > > > > > off, and make sure that compiles.)
> > > > > 
> > > > > Did exacly that. Took forever on my hardware, but no problems.
> > > > 
> > > > Ah, I see.  Looking more closely at nfsd, it looks like it already has a
> > > > code path for filesystems that don't do splice.  I think, rather than
> > > > making nfsd select SPLICE_SYSCALL, that it would suffice to change the
> > > > "rqstp->rq_splice_ok = true;" in svc_process_common (net/sunrpc/svc.c)
> > > > to:
> > > > 
> > > > rqstp->rq_splice_ok = IS_ENABLED(CONFIG_SPLICE_SYSCALL);
> > > > 
> > > > Then nfsd should simply *always* fall back to its non-splice support.
> > > > 
> > > 
> > > I'd probably prefer the above, actually. We have to keep supporting
> > > non-splice enabled fs' for the forseeable future, so we may as well
> > > allow people to run nfsd in such configurations. It could even be
> > > useful for testing the non-splice-enabled codepaths.
> > 
> > Good point!
> > 
> > - Josh Triplett
> 
> I'll add this to svc_process_common. I can squash this into PATCH 3, which is
> where the syscalls can be compiled out. The log entry may however get a little
> crowded and multi-functional.
> 
> Should I keep this as a separate patch?

I'd keep it as a separate patch, yes.  It doesn't become necessary until
patch 6, so you can add it as a new patch between patches 3 and 6.

- Josh Triplett

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [PATCH 0/6] kernel tinification: optionally compile out splice family of syscalls (splice, vmsplice, tee and sendfile)
@ 2014-11-24 14:54                 ` Josh Triplett
  0 siblings, 0 replies; 58+ messages in thread
From: Josh Triplett @ 2014-11-24 14:54 UTC (permalink / raw)
  To: Pieter Smith
  Cc: Jeff Layton, David Miller,
	alexander.h.duyck-ral2JQCrhuEAvxtiuMwx3w,
	viro-RmSDqhL/yNMiFSDQTTA3OLVCufUGDwFn,
	ast-uqk4Ao+rVK5Wk0Htik3J/w,
	akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b,
	beber-2YnHqweIUXrk1uMJSBkQmQ,
	catalina.mocanu-Re5JQEeQqe8AvxtiuMwx3w,
	dborkman-H+wXaHxf7aLQT0dZR+AlfA, edumazet-hpIqsD4AKlfQT0dZR+AlfA,
	ebiederm-aS9lmoZGLiVWk0Htik3J/w, fabf-AgBVmzD5pcezQB+pC5nmwQ,
	fuse-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f,
	geert-Td1EMuHUCqxL1ZNQvxDV9g, hughd-hpIqsD4AKlfQT0dZR+AlfA,
	iulia.manda21-Re5JQEeQqe8AvxtiuMwx3w, JBeulich-IBi9RG/b67k,
	bfields-uC3wQj2KruNg9hUCZPvPmw, linux-api-u79uwXL29TY76Z2rM5mHXA,
	linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA, mcgrof-IBi9RG/b67k,
	mattst88-Re5JQEeQqe8AvxtiuMwx3w, mgorman-l3A5Bk7waGM,
	mst-H+wXaHxf7aLQT0dZR+AlfA, miklos-sUDqSbJrdHQHWmgEVkV9KA,
	netdev-u79uwXL29TY76Z2rM5mHXA, oleg-H+wXaHxf7aLQT0dZR+AlfA,
	Paul.Durrant-Sxgqhf6Nn4DQT0dZR+AlfA,
	paulmck-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8,
	pefoley2-lY0TAiDIAFlBDgjK7y7TUQ, tgraf-G/eBtMaohhA,
	therbert-hpIqsD4AKlfQT0dZR+AlfA, willemb-hpIqsD4AKlfQT0dZR+AlfA,
	xiaoguangrong-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8,
	zhenglong.cai-TJRtMXcVgQTM1kAEIRd3EQ

On Mon, Nov 24, 2014 at 11:01:38AM +0100, Pieter Smith wrote:
> On Sun, Nov 23, 2014 at 04:32:51PM -0800, Josh Triplett wrote:
> > On Sun, Nov 23, 2014 at 07:28:10PM -0500, Jeff Layton wrote:
> > > On Sun, 23 Nov 2014 15:36:37 -0800
> > > Josh Triplett <josh-iaAMLnmF4UmaiuxdJuQwMA@public.gmane.org> wrote:
> > > 
> > > > On Sun, Nov 23, 2014 at 09:30:40PM +0100, Pieter Smith wrote:
> > > > > On Sun, Nov 23, 2014 at 11:43:26AM -0800, Josh Triplett wrote:
> > > > > > On Sun, Nov 23, 2014 at 01:46:23PM -0500, David Miller wrote:
> > > > > > > Truly removing sendfile/sendpage means that you can't even compile NFS
> > > > > > > into the tree.
> > > > > > 
> > > > > > If you mean the in-kernel nfsd (CONFIG_NFSD), that already has a large
> > > > > > stack of "select" and "depends on", both directly and indirectly; adding
> > > > > > a "select SPLICE_SYSCALL" to it seems fine.  (That select does need
> > > > > > adding, though.  Pieter, you need to test-compile more than just
> > > > > > tinyconfig and defconfig.  Try an allyesconfig with *just* splice turned
> > > > > > off, and make sure that compiles.)
> > > > > 
> > > > > Did exacly that. Took forever on my hardware, but no problems.
> > > > 
> > > > Ah, I see.  Looking more closely at nfsd, it looks like it already has a
> > > > code path for filesystems that don't do splice.  I think, rather than
> > > > making nfsd select SPLICE_SYSCALL, that it would suffice to change the
> > > > "rqstp->rq_splice_ok = true;" in svc_process_common (net/sunrpc/svc.c)
> > > > to:
> > > > 
> > > > rqstp->rq_splice_ok = IS_ENABLED(CONFIG_SPLICE_SYSCALL);
> > > > 
> > > > Then nfsd should simply *always* fall back to its non-splice support.
> > > > 
> > > 
> > > I'd probably prefer the above, actually. We have to keep supporting
> > > non-splice enabled fs' for the forseeable future, so we may as well
> > > allow people to run nfsd in such configurations. It could even be
> > > useful for testing the non-splice-enabled codepaths.
> > 
> > Good point!
> > 
> > - Josh Triplett
> 
> I'll add this to svc_process_common. I can squash this into PATCH 3, which is
> where the syscalls can be compiled out. The log entry may however get a little
> crowded and multi-functional.
> 
> Should I keep this as a separate patch?

I'd keep it as a separate patch, yes.  It doesn't become necessary until
patch 6, so you can add it as a new patch between patches 3 and 6.

- Josh Triplett

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [fuse-devel] [PATCH 4/6] fs/fuse: support compiling out splice
  2014-11-24  9:49         ` Pieter Smith
@ 2014-11-24 16:05           ` Josh Triplett
  -1 siblings, 0 replies; 58+ messages in thread
From: Josh Triplett @ 2014-11-24 16:05 UTC (permalink / raw)
  To: Pieter Smith
  Cc: Richard Weinberger, Michael S. Tsirkin, Bertrand Jacquin,
	Oleg Nesterov, J. Bruce Fields, Eric Dumazet,
	蔡正龙,
	Jeff Layton, Tom Herbert, Alexei Starovoitov, Miklos Szeredi,
	Peter Foley, Hugh Dickins, Xiao Guangrong, Geert Uytterhoeven,
	Mel Gorman, Matt Turner, Paul E. McKenney, Alexander Duyck,
	open list:FUSE: FILESYSTEM...,
	Luis R. Rodriguez, Catalina Mocanu, Fabian Frederick,
	Thomas Graf, Paul Durrant, Alexander Viro, Jan Beulich,
	Willem de Bruijn, Iulia Manda, open list:ABI/API, open list,
	Daniel Borkmann, Eric W. Biederman,
	open list:NETWORKING [GENERAL],
	linux-fsdevel, Andrew Morton, David S. Miller

On Mon, Nov 24, 2014 at 10:49:31AM +0100, Pieter Smith wrote:
> On Sun, Nov 23, 2014 at 03:23:02PM -0800, Josh Triplett wrote:
> > On Sun, Nov 23, 2014 at 11:29:08PM +0100, Richard Weinberger wrote:
> > > On Sun, Nov 23, 2014 at 3:20 PM, Pieter Smith <pieter@boesman.nl> wrote:
> > > > To implement splice support, fs/fuse makes use of nosteal_pipe_buf_ops. This
> > > > struct is exported by fs/splice. The goal of the larger patch set is to
> > > > completely compile out fs/splice, so uses of the exported struct need to be
> > > > compiled out along with fs/splice.
> > > >
> > > > This patch therefore compiles out splice support in fs/fuse when
> > > > CONFIG_SYSCALL_SPLICE is undefined.
> > > >
> > > > Signed-off-by: Pieter Smith <pieter@boesman.nl>
> > > > ---
> > > >  fs/fuse/dev.c      | 4 ++--
> > > >  include/linux/fs.h | 6 ++++++
> > > >  2 files changed, 8 insertions(+), 2 deletions(-)
> > > >
> > > > diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
> > > > index ca88731..f8f92a4 100644
> > > > --- a/fs/fuse/dev.c
> > > > +++ b/fs/fuse/dev.c
> > > > @@ -1291,7 +1291,7 @@ static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov,
> > > >         return fuse_dev_do_read(fc, file, &cs, iov_length(iov, nr_segs));
> > > >  }
> > > >
> > > > -static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
> > > > +static ssize_t __maybe_unused fuse_dev_splice_read(struct file *in, loff_t *ppos,
> > > >                                     struct pipe_inode_info *pipe,
> > > >                                     size_t len, unsigned int flags)
> > > >  {
> > > > @@ -2144,7 +2144,7 @@ const struct file_operations fuse_dev_operations = {
> > > >         .llseek         = no_llseek,
> > > >         .read           = do_sync_read,
> > > >         .aio_read       = fuse_dev_read,
> > > > -       .splice_read    = fuse_dev_splice_read,
> > > > +       .splice_read    = __splice_p(fuse_dev_splice_read),
> > > >         .write          = do_sync_write,
> > > >         .aio_write      = fuse_dev_write,
> > > >         .splice_write   = fuse_dev_splice_write,
> > > > diff --git a/include/linux/fs.h b/include/linux/fs.h
> > > > index a957d43..04c0975 100644
> > > > --- a/include/linux/fs.h
> > > > +++ b/include/linux/fs.h
> > > > @@ -2443,6 +2443,12 @@ extern int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
> > > >                         int datasync);
> > > >  extern void block_sync_page(struct page *page);
> > > >
> > > > +#ifdef CONFIG_SYSCALL_SPLICE
> > > > +#define __splice_p(x) x
> > > > +#else
> > > > +#define __splice_p(x) NULL
> > > > +#endif
> > > > +
> > > 
> > > This needs to go into a different patch.
> > > One logical change per patch please. :-)
> > 
> > Easy enough to merge this one into the patch introducing
> > CONFIG_SYSCALL_SPLICE, then.
> > 
> > - Josh Triplett
> 
> The patch introducing CONFIG_SYSCALL_SPLICE (PATCH 3) only compiles out the
> syscalls. PATCH 6 on the other hand, compiles out fs/splice.c. This patch
> allows fs/fuse to be compiled when fs/splice.c is compiled out. If I am to
> squash it, it would be logical to include it in PATCH 6, not 3.

The suggestion wasn't to move the fs/fuse/dev.c bits; those should
definitely stay in this patch.  The suggestion was just to move the bit
of the patch defining __splice_p from this patch to patch 3.  (Note that
you need to define it before you use it, so it can't go in patch 6.)

- Josh Triplett

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [fuse-devel] [PATCH 4/6] fs/fuse: support compiling out splice
@ 2014-11-24 16:05           ` Josh Triplett
  0 siblings, 0 replies; 58+ messages in thread
From: Josh Triplett @ 2014-11-24 16:05 UTC (permalink / raw)
  To: Pieter Smith
  Cc: Richard Weinberger, Michael S. Tsirkin, Bertrand Jacquin,
	Oleg Nesterov, J. Bruce Fields, Eric Dumazet,
	蔡正龙,
	Jeff Layton, Tom Herbert, Alexei Starovoitov, Miklos Szeredi,
	Peter Foley, Hugh Dickins, Xiao Guangrong, Geert Uytterhoeven,
	Mel Gorman, Matt Turner, Paul E. McKenney, Alexander Duyck,
	open list:FUSE: FILESYSTEM...,
	Luis R. Rodriguez

On Mon, Nov 24, 2014 at 10:49:31AM +0100, Pieter Smith wrote:
> On Sun, Nov 23, 2014 at 03:23:02PM -0800, Josh Triplett wrote:
> > On Sun, Nov 23, 2014 at 11:29:08PM +0100, Richard Weinberger wrote:
> > > On Sun, Nov 23, 2014 at 3:20 PM, Pieter Smith <pieter@boesman.nl> wrote:
> > > > To implement splice support, fs/fuse makes use of nosteal_pipe_buf_ops. This
> > > > struct is exported by fs/splice. The goal of the larger patch set is to
> > > > completely compile out fs/splice, so uses of the exported struct need to be
> > > > compiled out along with fs/splice.
> > > >
> > > > This patch therefore compiles out splice support in fs/fuse when
> > > > CONFIG_SYSCALL_SPLICE is undefined.
> > > >
> > > > Signed-off-by: Pieter Smith <pieter@boesman.nl>
> > > > ---
> > > >  fs/fuse/dev.c      | 4 ++--
> > > >  include/linux/fs.h | 6 ++++++
> > > >  2 files changed, 8 insertions(+), 2 deletions(-)
> > > >
> > > > diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
> > > > index ca88731..f8f92a4 100644
> > > > --- a/fs/fuse/dev.c
> > > > +++ b/fs/fuse/dev.c
> > > > @@ -1291,7 +1291,7 @@ static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov,
> > > >         return fuse_dev_do_read(fc, file, &cs, iov_length(iov, nr_segs));
> > > >  }
> > > >
> > > > -static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
> > > > +static ssize_t __maybe_unused fuse_dev_splice_read(struct file *in, loff_t *ppos,
> > > >                                     struct pipe_inode_info *pipe,
> > > >                                     size_t len, unsigned int flags)
> > > >  {
> > > > @@ -2144,7 +2144,7 @@ const struct file_operations fuse_dev_operations = {
> > > >         .llseek         = no_llseek,
> > > >         .read           = do_sync_read,
> > > >         .aio_read       = fuse_dev_read,
> > > > -       .splice_read    = fuse_dev_splice_read,
> > > > +       .splice_read    = __splice_p(fuse_dev_splice_read),
> > > >         .write          = do_sync_write,
> > > >         .aio_write      = fuse_dev_write,
> > > >         .splice_write   = fuse_dev_splice_write,
> > > > diff --git a/include/linux/fs.h b/include/linux/fs.h
> > > > index a957d43..04c0975 100644
> > > > --- a/include/linux/fs.h
> > > > +++ b/include/linux/fs.h
> > > > @@ -2443,6 +2443,12 @@ extern int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
> > > >                         int datasync);
> > > >  extern void block_sync_page(struct page *page);
> > > >
> > > > +#ifdef CONFIG_SYSCALL_SPLICE
> > > > +#define __splice_p(x) x
> > > > +#else
> > > > +#define __splice_p(x) NULL
> > > > +#endif
> > > > +
> > > 
> > > This needs to go into a different patch.
> > > One logical change per patch please. :-)
> > 
> > Easy enough to merge this one into the patch introducing
> > CONFIG_SYSCALL_SPLICE, then.
> > 
> > - Josh Triplett
> 
> The patch introducing CONFIG_SYSCALL_SPLICE (PATCH 3) only compiles out the
> syscalls. PATCH 6 on the other hand, compiles out fs/splice.c. This patch
> allows fs/fuse to be compiled when fs/splice.c is compiled out. If I am to
> squash it, it would be logical to include it in PATCH 6, not 3.

The suggestion wasn't to move the fs/fuse/dev.c bits; those should
definitely stay in this patch.  The suggestion was just to move the bit
of the patch defining __splice_p from this patch to patch 3.  (Note that
you need to define it before you use it, so it can't go in patch 6.)

- Josh Triplett

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [fuse-devel] [PATCH 4/6] fs/fuse: support compiling out splice
  2014-11-24 16:05           ` Josh Triplett
@ 2014-11-24 19:34             ` Greg KH
  -1 siblings, 0 replies; 58+ messages in thread
From: Greg KH @ 2014-11-24 19:34 UTC (permalink / raw)
  To: Josh Triplett
  Cc: Pieter Smith, Richard Weinberger, Michael S. Tsirkin,
	Bertrand Jacquin, Oleg Nesterov, J. Bruce Fields, Eric Dumazet,
	蔡正龙,
	Jeff Layton, Tom Herbert, Alexei Starovoitov, Miklos Szeredi,
	Peter Foley, Hugh Dickins, Xiao Guangrong, Geert Uytterhoeven,
	Mel Gorman, Matt Turner, Paul E. McKenney, Alexander Duyck,
	open list:FUSE: FILESYSTEM...,
	Luis R. Rodriguez, Catalina Mocanu, Fabian Frederick,
	Thomas Graf, Paul Durrant, Alexander Viro, Jan Beulich,
	Willem de Bruijn, Iulia Manda, open list:ABI/API, open list,
	Daniel Borkmann, Eric W. Biederman,
	open list:NETWORKING [GENERAL],
	linux-fsdevel, Andrew Morton, David S. Miller

On Mon, Nov 24, 2014 at 08:05:10AM -0800, Josh Triplett wrote:
> On Mon, Nov 24, 2014 at 10:49:31AM +0100, Pieter Smith wrote:
> > On Sun, Nov 23, 2014 at 03:23:02PM -0800, Josh Triplett wrote:
> > > On Sun, Nov 23, 2014 at 11:29:08PM +0100, Richard Weinberger wrote:
> > > > On Sun, Nov 23, 2014 at 3:20 PM, Pieter Smith <pieter@boesman.nl> wrote:
> > > > > To implement splice support, fs/fuse makes use of nosteal_pipe_buf_ops. This
> > > > > struct is exported by fs/splice. The goal of the larger patch set is to
> > > > > completely compile out fs/splice, so uses of the exported struct need to be
> > > > > compiled out along with fs/splice.
> > > > >
> > > > > This patch therefore compiles out splice support in fs/fuse when
> > > > > CONFIG_SYSCALL_SPLICE is undefined.
> > > > >
> > > > > Signed-off-by: Pieter Smith <pieter@boesman.nl>
> > > > > ---
> > > > >  fs/fuse/dev.c      | 4 ++--
> > > > >  include/linux/fs.h | 6 ++++++
> > > > >  2 files changed, 8 insertions(+), 2 deletions(-)
> > > > >
> > > > > diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
> > > > > index ca88731..f8f92a4 100644
> > > > > --- a/fs/fuse/dev.c
> > > > > +++ b/fs/fuse/dev.c
> > > > > @@ -1291,7 +1291,7 @@ static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov,
> > > > >         return fuse_dev_do_read(fc, file, &cs, iov_length(iov, nr_segs));
> > > > >  }
> > > > >
> > > > > -static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
> > > > > +static ssize_t __maybe_unused fuse_dev_splice_read(struct file *in, loff_t *ppos,
> > > > >                                     struct pipe_inode_info *pipe,
> > > > >                                     size_t len, unsigned int flags)
> > > > >  {
> > > > > @@ -2144,7 +2144,7 @@ const struct file_operations fuse_dev_operations = {
> > > > >         .llseek         = no_llseek,
> > > > >         .read           = do_sync_read,
> > > > >         .aio_read       = fuse_dev_read,
> > > > > -       .splice_read    = fuse_dev_splice_read,
> > > > > +       .splice_read    = __splice_p(fuse_dev_splice_read),
> > > > >         .write          = do_sync_write,
> > > > >         .aio_write      = fuse_dev_write,
> > > > >         .splice_write   = fuse_dev_splice_write,
> > > > > diff --git a/include/linux/fs.h b/include/linux/fs.h
> > > > > index a957d43..04c0975 100644
> > > > > --- a/include/linux/fs.h
> > > > > +++ b/include/linux/fs.h
> > > > > @@ -2443,6 +2443,12 @@ extern int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
> > > > >                         int datasync);
> > > > >  extern void block_sync_page(struct page *page);
> > > > >
> > > > > +#ifdef CONFIG_SYSCALL_SPLICE
> > > > > +#define __splice_p(x) x
> > > > > +#else
> > > > > +#define __splice_p(x) NULL
> > > > > +#endif
> > > > > +
> > > > 
> > > > This needs to go into a different patch.
> > > > One logical change per patch please. :-)
> > > 
> > > Easy enough to merge this one into the patch introducing
> > > CONFIG_SYSCALL_SPLICE, then.
> > > 
> > > - Josh Triplett
> > 
> > The patch introducing CONFIG_SYSCALL_SPLICE (PATCH 3) only compiles out the
> > syscalls. PATCH 6 on the other hand, compiles out fs/splice.c. This patch
> > allows fs/fuse to be compiled when fs/splice.c is compiled out. If I am to
> > squash it, it would be logical to include it in PATCH 6, not 3.
> 
> The suggestion wasn't to move the fs/fuse/dev.c bits; those should
> definitely stay in this patch.  The suggestion was just to move the bit
> of the patch defining __splice_p from this patch to patch 3.  (Note that
> you need to define it before you use it, so it can't go in patch 6.)

I would, again, argue that stuff like __splice_p() not be implemented at
all please.  It will only cause a huge proliferation of stuff like this
that will not make any sense, and only cause a trivial, if any, amount
of code savings.

I thought you were going to not do this type of thing until you got the
gcc optimizer working for function callbacks.

Again, don't do this please.

thanks,

greg k-h

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [fuse-devel] [PATCH 4/6] fs/fuse: support compiling out splice
@ 2014-11-24 19:34             ` Greg KH
  0 siblings, 0 replies; 58+ messages in thread
From: Greg KH @ 2014-11-24 19:34 UTC (permalink / raw)
  To: Josh Triplett
  Cc: Pieter Smith, Richard Weinberger, Michael S. Tsirkin,
	Bertrand Jacquin, Oleg Nesterov, J. Bruce Fields, Eric Dumazet,
	蔡正龙,
	Jeff Layton, Tom Herbert, Alexei Starovoitov, Miklos Szeredi,
	Peter Foley, Hugh Dickins, Xiao Guangrong, Geert Uytterhoeven,
	Mel Gorman, Matt Turner, Paul E. McKenney, Alexander Duyck,
	open list:FUSE: FILESYSTEM...

On Mon, Nov 24, 2014 at 08:05:10AM -0800, Josh Triplett wrote:
> On Mon, Nov 24, 2014 at 10:49:31AM +0100, Pieter Smith wrote:
> > On Sun, Nov 23, 2014 at 03:23:02PM -0800, Josh Triplett wrote:
> > > On Sun, Nov 23, 2014 at 11:29:08PM +0100, Richard Weinberger wrote:
> > > > On Sun, Nov 23, 2014 at 3:20 PM, Pieter Smith <pieter@boesman.nl> wrote:
> > > > > To implement splice support, fs/fuse makes use of nosteal_pipe_buf_ops. This
> > > > > struct is exported by fs/splice. The goal of the larger patch set is to
> > > > > completely compile out fs/splice, so uses of the exported struct need to be
> > > > > compiled out along with fs/splice.
> > > > >
> > > > > This patch therefore compiles out splice support in fs/fuse when
> > > > > CONFIG_SYSCALL_SPLICE is undefined.
> > > > >
> > > > > Signed-off-by: Pieter Smith <pieter@boesman.nl>
> > > > > ---
> > > > >  fs/fuse/dev.c      | 4 ++--
> > > > >  include/linux/fs.h | 6 ++++++
> > > > >  2 files changed, 8 insertions(+), 2 deletions(-)
> > > > >
> > > > > diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
> > > > > index ca88731..f8f92a4 100644
> > > > > --- a/fs/fuse/dev.c
> > > > > +++ b/fs/fuse/dev.c
> > > > > @@ -1291,7 +1291,7 @@ static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov,
> > > > >         return fuse_dev_do_read(fc, file, &cs, iov_length(iov, nr_segs));
> > > > >  }
> > > > >
> > > > > -static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
> > > > > +static ssize_t __maybe_unused fuse_dev_splice_read(struct file *in, loff_t *ppos,
> > > > >                                     struct pipe_inode_info *pipe,
> > > > >                                     size_t len, unsigned int flags)
> > > > >  {
> > > > > @@ -2144,7 +2144,7 @@ const struct file_operations fuse_dev_operations = {
> > > > >         .llseek         = no_llseek,
> > > > >         .read           = do_sync_read,
> > > > >         .aio_read       = fuse_dev_read,
> > > > > -       .splice_read    = fuse_dev_splice_read,
> > > > > +       .splice_read    = __splice_p(fuse_dev_splice_read),
> > > > >         .write          = do_sync_write,
> > > > >         .aio_write      = fuse_dev_write,
> > > > >         .splice_write   = fuse_dev_splice_write,
> > > > > diff --git a/include/linux/fs.h b/include/linux/fs.h
> > > > > index a957d43..04c0975 100644
> > > > > --- a/include/linux/fs.h
> > > > > +++ b/include/linux/fs.h
> > > > > @@ -2443,6 +2443,12 @@ extern int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
> > > > >                         int datasync);
> > > > >  extern void block_sync_page(struct page *page);
> > > > >
> > > > > +#ifdef CONFIG_SYSCALL_SPLICE
> > > > > +#define __splice_p(x) x
> > > > > +#else
> > > > > +#define __splice_p(x) NULL
> > > > > +#endif
> > > > > +
> > > > 
> > > > This needs to go into a different patch.
> > > > One logical change per patch please. :-)
> > > 
> > > Easy enough to merge this one into the patch introducing
> > > CONFIG_SYSCALL_SPLICE, then.
> > > 
> > > - Josh Triplett
> > 
> > The patch introducing CONFIG_SYSCALL_SPLICE (PATCH 3) only compiles out the
> > syscalls. PATCH 6 on the other hand, compiles out fs/splice.c. This patch
> > allows fs/fuse to be compiled when fs/splice.c is compiled out. If I am to
> > squash it, it would be logical to include it in PATCH 6, not 3.
> 
> The suggestion wasn't to move the fs/fuse/dev.c bits; those should
> definitely stay in this patch.  The suggestion was just to move the bit
> of the patch defining __splice_p from this patch to patch 3.  (Note that
> you need to define it before you use it, so it can't go in patch 6.)

I would, again, argue that stuff like __splice_p() not be implemented at
all please.  It will only cause a huge proliferation of stuff like this
that will not make any sense, and only cause a trivial, if any, amount
of code savings.

I thought you were going to not do this type of thing until you got the
gcc optimizer working for function callbacks.

Again, don't do this please.

thanks,

greg k-h

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [fuse-devel] [PATCH 4/6] fs/fuse: support compiling out splice
@ 2014-11-24 20:14               ` josh-iaAMLnmF4UmaiuxdJuQwMA
  0 siblings, 0 replies; 58+ messages in thread
From: josh @ 2014-11-24 20:14 UTC (permalink / raw)
  To: Greg KH
  Cc: Pieter Smith, Richard Weinberger, Michael S. Tsirkin,
	Bertrand Jacquin, Oleg Nesterov, J. Bruce Fields, Eric Dumazet,
	蔡正龙,
	Jeff Layton, Tom Herbert, Alexei Starovoitov, Miklos Szeredi,
	Peter Foley, Hugh Dickins, Xiao Guangrong, Geert Uytterhoeven,
	Mel Gorman, Matt Turner, Paul E. McKenney, Alexander Duyck,
	open list:FUSE: FILESYSTEM...,
	Luis R. Rodriguez, Catalina Mocanu, Fabian Frederick,
	Thomas Graf, Paul Durrant, Alexander Viro, Jan Beulich,
	Willem de Bruijn, Iulia Manda, open list:ABI/API, open list,
	Daniel Borkmann, Eric W. Biederman,
	open list:NETWORKING [GENERAL],
	linux-fsdevel, Andrew Morton, David S. Miller

On Mon, Nov 24, 2014 at 11:34:12AM -0800, Greg KH wrote:
> On Mon, Nov 24, 2014 at 08:05:10AM -0800, Josh Triplett wrote:
> > On Mon, Nov 24, 2014 at 10:49:31AM +0100, Pieter Smith wrote:
> > > On Sun, Nov 23, 2014 at 03:23:02PM -0800, Josh Triplett wrote:
> > > > On Sun, Nov 23, 2014 at 11:29:08PM +0100, Richard Weinberger wrote:
> > > > > On Sun, Nov 23, 2014 at 3:20 PM, Pieter Smith <pieter@boesman.nl> wrote:
> > > > > > To implement splice support, fs/fuse makes use of nosteal_pipe_buf_ops. This
> > > > > > struct is exported by fs/splice. The goal of the larger patch set is to
> > > > > > completely compile out fs/splice, so uses of the exported struct need to be
> > > > > > compiled out along with fs/splice.
> > > > > >
> > > > > > This patch therefore compiles out splice support in fs/fuse when
> > > > > > CONFIG_SYSCALL_SPLICE is undefined.
> > > > > >
> > > > > > Signed-off-by: Pieter Smith <pieter@boesman.nl>
> > > > > > ---
> > > > > >  fs/fuse/dev.c      | 4 ++--
> > > > > >  include/linux/fs.h | 6 ++++++
> > > > > >  2 files changed, 8 insertions(+), 2 deletions(-)
> > > > > >
> > > > > > diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
> > > > > > index ca88731..f8f92a4 100644
> > > > > > --- a/fs/fuse/dev.c
> > > > > > +++ b/fs/fuse/dev.c
> > > > > > @@ -1291,7 +1291,7 @@ static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov,
> > > > > >         return fuse_dev_do_read(fc, file, &cs, iov_length(iov, nr_segs));
> > > > > >  }
> > > > > >
> > > > > > -static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
> > > > > > +static ssize_t __maybe_unused fuse_dev_splice_read(struct file *in, loff_t *ppos,
> > > > > >                                     struct pipe_inode_info *pipe,
> > > > > >                                     size_t len, unsigned int flags)
> > > > > >  {
> > > > > > @@ -2144,7 +2144,7 @@ const struct file_operations fuse_dev_operations = {
> > > > > >         .llseek         = no_llseek,
> > > > > >         .read           = do_sync_read,
> > > > > >         .aio_read       = fuse_dev_read,
> > > > > > -       .splice_read    = fuse_dev_splice_read,
> > > > > > +       .splice_read    = __splice_p(fuse_dev_splice_read),
> > > > > >         .write          = do_sync_write,
> > > > > >         .aio_write      = fuse_dev_write,
> > > > > >         .splice_write   = fuse_dev_splice_write,
> > > > > > diff --git a/include/linux/fs.h b/include/linux/fs.h
> > > > > > index a957d43..04c0975 100644
> > > > > > --- a/include/linux/fs.h
> > > > > > +++ b/include/linux/fs.h
> > > > > > @@ -2443,6 +2443,12 @@ extern int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
> > > > > >                         int datasync);
> > > > > >  extern void block_sync_page(struct page *page);
> > > > > >
> > > > > > +#ifdef CONFIG_SYSCALL_SPLICE
> > > > > > +#define __splice_p(x) x
> > > > > > +#else
> > > > > > +#define __splice_p(x) NULL
> > > > > > +#endif
> > > > > > +
> > > > > 
> > > > > This needs to go into a different patch.
> > > > > One logical change per patch please. :-)
> > > > 
> > > > Easy enough to merge this one into the patch introducing
> > > > CONFIG_SYSCALL_SPLICE, then.
> > > > 
> > > > - Josh Triplett
> > > 
> > > The patch introducing CONFIG_SYSCALL_SPLICE (PATCH 3) only compiles out the
> > > syscalls. PATCH 6 on the other hand, compiles out fs/splice.c. This patch
> > > allows fs/fuse to be compiled when fs/splice.c is compiled out. If I am to
> > > squash it, it would be logical to include it in PATCH 6, not 3.
> > 
> > The suggestion wasn't to move the fs/fuse/dev.c bits; those should
> > definitely stay in this patch.  The suggestion was just to move the bit
> > of the patch defining __splice_p from this patch to patch 3.  (Note that
> > you need to define it before you use it, so it can't go in patch 6.)
> 
> I would, again, argue that stuff like __splice_p() not be implemented at
> all please.  It will only cause a huge proliferation of stuff like this
> that will not make any sense, and only cause a trivial, if any, amount
> of code savings.
> 
> I thought you were going to not do this type of thing until you got the
> gcc optimizer working for function callbacks.

Compared to the previous patchset, there are now only two instances of
ifdefs outside of the splice code for this, and this is one of them.  In
this case, the issue is no longer about making the code for this
splice_read function disappear, but rather to eliminate a reference to a
bit of splice functionality (used *inside* the FUSE splice code) that
will not work without SPLICE_SYSCALL.

Would you prefer to see this specific case handled via an #ifdef in
fs/fuse/dev.c rather than introducing a __splice_p that people might be
inclined to propagate?  That'd be fine; the code could simply wrap
fuse_dev_splice_read in an #ifdef and have the #else define a NULL
fuse_dev_splice_read.

- Josh Triplett

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [fuse-devel] [PATCH 4/6] fs/fuse: support compiling out splice
@ 2014-11-24 20:14               ` josh-iaAMLnmF4UmaiuxdJuQwMA
  0 siblings, 0 replies; 58+ messages in thread
From: josh-iaAMLnmF4UmaiuxdJuQwMA @ 2014-11-24 20:14 UTC (permalink / raw)
  To: Greg KH
  Cc: Pieter Smith, Richard Weinberger, Michael S. Tsirkin,
	Bertrand Jacquin, Oleg Nesterov, J. Bruce Fields, Eric Dumazet,
	蔡正龙,
	Jeff Layton, Tom Herbert, Alexei Starovoitov, Miklos Szeredi,
	Peter Foley, Hugh Dickins, Xiao Guangrong, Geert Uytterhoeven,
	Mel Gorman, Matt Turner, Paul E. McKenney, Alexander Duyck,
	open list:FUSE: FILESYSTEM...

On Mon, Nov 24, 2014 at 11:34:12AM -0800, Greg KH wrote:
> On Mon, Nov 24, 2014 at 08:05:10AM -0800, Josh Triplett wrote:
> > On Mon, Nov 24, 2014 at 10:49:31AM +0100, Pieter Smith wrote:
> > > On Sun, Nov 23, 2014 at 03:23:02PM -0800, Josh Triplett wrote:
> > > > On Sun, Nov 23, 2014 at 11:29:08PM +0100, Richard Weinberger wrote:
> > > > > On Sun, Nov 23, 2014 at 3:20 PM, Pieter Smith <pieter-qeJ+1H9vRZbz+pZb47iToQ@public.gmane.org> wrote:
> > > > > > To implement splice support, fs/fuse makes use of nosteal_pipe_buf_ops. This
> > > > > > struct is exported by fs/splice. The goal of the larger patch set is to
> > > > > > completely compile out fs/splice, so uses of the exported struct need to be
> > > > > > compiled out along with fs/splice.
> > > > > >
> > > > > > This patch therefore compiles out splice support in fs/fuse when
> > > > > > CONFIG_SYSCALL_SPLICE is undefined.
> > > > > >
> > > > > > Signed-off-by: Pieter Smith <pieter-qeJ+1H9vRZbz+pZb47iToQ@public.gmane.org>
> > > > > > ---
> > > > > >  fs/fuse/dev.c      | 4 ++--
> > > > > >  include/linux/fs.h | 6 ++++++
> > > > > >  2 files changed, 8 insertions(+), 2 deletions(-)
> > > > > >
> > > > > > diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
> > > > > > index ca88731..f8f92a4 100644
> > > > > > --- a/fs/fuse/dev.c
> > > > > > +++ b/fs/fuse/dev.c
> > > > > > @@ -1291,7 +1291,7 @@ static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov,
> > > > > >         return fuse_dev_do_read(fc, file, &cs, iov_length(iov, nr_segs));
> > > > > >  }
> > > > > >
> > > > > > -static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
> > > > > > +static ssize_t __maybe_unused fuse_dev_splice_read(struct file *in, loff_t *ppos,
> > > > > >                                     struct pipe_inode_info *pipe,
> > > > > >                                     size_t len, unsigned int flags)
> > > > > >  {
> > > > > > @@ -2144,7 +2144,7 @@ const struct file_operations fuse_dev_operations = {
> > > > > >         .llseek         = no_llseek,
> > > > > >         .read           = do_sync_read,
> > > > > >         .aio_read       = fuse_dev_read,
> > > > > > -       .splice_read    = fuse_dev_splice_read,
> > > > > > +       .splice_read    = __splice_p(fuse_dev_splice_read),
> > > > > >         .write          = do_sync_write,
> > > > > >         .aio_write      = fuse_dev_write,
> > > > > >         .splice_write   = fuse_dev_splice_write,
> > > > > > diff --git a/include/linux/fs.h b/include/linux/fs.h
> > > > > > index a957d43..04c0975 100644
> > > > > > --- a/include/linux/fs.h
> > > > > > +++ b/include/linux/fs.h
> > > > > > @@ -2443,6 +2443,12 @@ extern int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
> > > > > >                         int datasync);
> > > > > >  extern void block_sync_page(struct page *page);
> > > > > >
> > > > > > +#ifdef CONFIG_SYSCALL_SPLICE
> > > > > > +#define __splice_p(x) x
> > > > > > +#else
> > > > > > +#define __splice_p(x) NULL
> > > > > > +#endif
> > > > > > +
> > > > > 
> > > > > This needs to go into a different patch.
> > > > > One logical change per patch please. :-)
> > > > 
> > > > Easy enough to merge this one into the patch introducing
> > > > CONFIG_SYSCALL_SPLICE, then.
> > > > 
> > > > - Josh Triplett
> > > 
> > > The patch introducing CONFIG_SYSCALL_SPLICE (PATCH 3) only compiles out the
> > > syscalls. PATCH 6 on the other hand, compiles out fs/splice.c. This patch
> > > allows fs/fuse to be compiled when fs/splice.c is compiled out. If I am to
> > > squash it, it would be logical to include it in PATCH 6, not 3.
> > 
> > The suggestion wasn't to move the fs/fuse/dev.c bits; those should
> > definitely stay in this patch.  The suggestion was just to move the bit
> > of the patch defining __splice_p from this patch to patch 3.  (Note that
> > you need to define it before you use it, so it can't go in patch 6.)
> 
> I would, again, argue that stuff like __splice_p() not be implemented at
> all please.  It will only cause a huge proliferation of stuff like this
> that will not make any sense, and only cause a trivial, if any, amount
> of code savings.
> 
> I thought you were going to not do this type of thing until you got the
> gcc optimizer working for function callbacks.

Compared to the previous patchset, there are now only two instances of
ifdefs outside of the splice code for this, and this is one of them.  In
this case, the issue is no longer about making the code for this
splice_read function disappear, but rather to eliminate a reference to a
bit of splice functionality (used *inside* the FUSE splice code) that
will not work without SPLICE_SYSCALL.

Would you prefer to see this specific case handled via an #ifdef in
fs/fuse/dev.c rather than introducing a __splice_p that people might be
inclined to propagate?  That'd be fine; the code could simply wrap
fuse_dev_splice_read in an #ifdef and have the #else define a NULL
fuse_dev_splice_read.

- Josh Triplett

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [fuse-devel] [PATCH 4/6] fs/fuse: support compiling out splice
  2014-11-24 20:14               ` josh-iaAMLnmF4UmaiuxdJuQwMA
@ 2014-11-24 20:22                 ` Greg KH
  -1 siblings, 0 replies; 58+ messages in thread
From: Greg KH @ 2014-11-24 20:22 UTC (permalink / raw)
  To: josh
  Cc: Pieter Smith, Richard Weinberger, Michael S. Tsirkin,
	Bertrand Jacquin, Oleg Nesterov, J. Bruce Fields, Eric Dumazet,
	蔡正龙,
	Jeff Layton, Tom Herbert, Alexei Starovoitov, Miklos Szeredi,
	Peter Foley, Hugh Dickins, Xiao Guangrong, Geert Uytterhoeven,
	Mel Gorman, Matt Turner, Paul E. McKenney, Alexander Duyck,
	open list:FUSE: FILESYSTEM...,
	Luis R. Rodriguez, Catalina Mocanu, Fabian Frederick,
	Thomas Graf, Paul Durrant, Alexander Viro, Jan Beulich,
	Willem de Bruijn, Iulia Manda, open list:ABI/API, open list,
	Daniel Borkmann, Eric W. Biederman,
	open list:NETWORKING [GENERAL],
	linux-fsdevel, Andrew Morton, David S. Miller

On Mon, Nov 24, 2014 at 12:14:50PM -0800, josh@joshtriplett.org wrote:
> > I would, again, argue that stuff like __splice_p() not be implemented at
> > all please.  It will only cause a huge proliferation of stuff like this
> > that will not make any sense, and only cause a trivial, if any, amount
> > of code savings.
> > 
> > I thought you were going to not do this type of thing until you got the
> > gcc optimizer working for function callbacks.
> 
> Compared to the previous patchset, there are now only two instances of
> ifdefs outside of the splice code for this, and this is one of them.  In
> this case, the issue is no longer about making the code for this
> splice_read function disappear, but rather to eliminate a reference to a
> bit of splice functionality (used *inside* the FUSE splice code) that
> will not work without SPLICE_SYSCALL.
> 
> Would you prefer to see this specific case handled via an #ifdef in
> fs/fuse/dev.c rather than introducing a __splice_p that people might be
> inclined to propagate?  That'd be fine; the code could simply wrap
> fuse_dev_splice_read in an #ifdef and have the #else define a NULL
> fuse_dev_splice_read.

Yes, I would prefer that, but I'm not the fuse maintainer.

thanks,

greg k-h

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [fuse-devel] [PATCH 4/6] fs/fuse: support compiling out splice
@ 2014-11-24 20:22                 ` Greg KH
  0 siblings, 0 replies; 58+ messages in thread
From: Greg KH @ 2014-11-24 20:22 UTC (permalink / raw)
  To: josh
  Cc: Pieter Smith, Richard Weinberger, Michael S. Tsirkin,
	Bertrand Jacquin, Oleg Nesterov, J. Bruce Fields, Eric Dumazet,
	蔡正龙,
	Jeff Layton, Tom Herbert, Alexei Starovoitov, Miklos Szeredi,
	Peter Foley, Hugh Dickins, Xiao Guangrong, Geert Uytterhoeven,
	Mel Gorman, Matt Turner, Paul E. McKenney, Alexander Duyck,
	open list:FUSE: FILESYSTEM...

On Mon, Nov 24, 2014 at 12:14:50PM -0800, josh@joshtriplett.org wrote:
> > I would, again, argue that stuff like __splice_p() not be implemented at
> > all please.  It will only cause a huge proliferation of stuff like this
> > that will not make any sense, and only cause a trivial, if any, amount
> > of code savings.
> > 
> > I thought you were going to not do this type of thing until you got the
> > gcc optimizer working for function callbacks.
> 
> Compared to the previous patchset, there are now only two instances of
> ifdefs outside of the splice code for this, and this is one of them.  In
> this case, the issue is no longer about making the code for this
> splice_read function disappear, but rather to eliminate a reference to a
> bit of splice functionality (used *inside* the FUSE splice code) that
> will not work without SPLICE_SYSCALL.
> 
> Would you prefer to see this specific case handled via an #ifdef in
> fs/fuse/dev.c rather than introducing a __splice_p that people might be
> inclined to propagate?  That'd be fine; the code could simply wrap
> fuse_dev_splice_read in an #ifdef and have the #else define a NULL
> fuse_dev_splice_read.

Yes, I would prefer that, but I'm not the fuse maintainer.

thanks,

greg k-h

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [fuse-devel] [PATCH 4/6] fs/fuse: support compiling out splice
@ 2014-11-24 21:49                   ` Pieter Smith
  0 siblings, 0 replies; 58+ messages in thread
From: Pieter Smith @ 2014-11-24 21:49 UTC (permalink / raw)
  To: Greg KH
  Cc: josh, Richard Weinberger, Michael S. Tsirkin, Bertrand Jacquin,
	Oleg Nesterov, J. Bruce Fields, Eric Dumazet,
	蔡正龙,
	Jeff Layton, Tom Herbert, Alexei Starovoitov, Miklos Szeredi,
	Peter Foley, Hugh Dickins, Xiao Guangrong, Geert Uytterhoeven,
	Mel Gorman, Matt Turner, Paul E. McKenney, Alexander Duyck,
	open list:FUSE: FILESYSTEM...,
	Luis R. Rodriguez, Catalina Mocanu, Fabian Frederick,
	Thomas Graf, Paul Durrant, Alexander Viro, Jan Beulich,
	Willem de Bruijn, Iulia Manda, open list:ABI/API, open list,
	Daniel Borkmann, Eric W. Biederman,
	open list:NETWORKING [GENERAL],
	linux-fsdevel, Andrew Morton, David S. Miller

On Mon, Nov 24, 2014 at 12:22:14PM -0800, Greg KH wrote:
> On Mon, Nov 24, 2014 at 12:14:50PM -0800, josh@joshtriplett.org wrote:
> > > I would, again, argue that stuff like __splice_p() not be implemented at
> > > all please.  It will only cause a huge proliferation of stuff like this
> > > that will not make any sense, and only cause a trivial, if any, amount
> > > of code savings.
> > > 
> > > I thought you were going to not do this type of thing until you got the
> > > gcc optimizer working for function callbacks.
> > 
> > Compared to the previous patchset, there are now only two instances of
> > ifdefs outside of the splice code for this, and this is one of them.  In
> > this case, the issue is no longer about making the code for this
> > splice_read function disappear, but rather to eliminate a reference to a
> > bit of splice functionality (used *inside* the FUSE splice code) that
> > will not work without SPLICE_SYSCALL.
> > 
> > Would you prefer to see this specific case handled via an #ifdef in
> > fs/fuse/dev.c rather than introducing a __splice_p that people might be
> > inclined to propagate?  That'd be fine; the code could simply wrap
> > fuse_dev_splice_read in an #ifdef and have the #else define a NULL
> > fuse_dev_splice_read.
> 
> Yes, I would prefer that, but I'm not the fuse maintainer.
> 
> thanks,
> 
> greg k-h

Okay. I'll do my part to prevent the type of proliferation guaranteed to rate
high on the respected K-H icky-scale. __splice_p() goes the way of the dodo
in favor of the solution presented by Josh.

I pray that the Gods of fuse maintenance will look favorable upon the result.

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [fuse-devel] [PATCH 4/6] fs/fuse: support compiling out splice
@ 2014-11-24 21:49                   ` Pieter Smith
  0 siblings, 0 replies; 58+ messages in thread
From: Pieter Smith @ 2014-11-24 21:49 UTC (permalink / raw)
  To: Greg KH
  Cc: josh-iaAMLnmF4UmaiuxdJuQwMA, Richard Weinberger,
	Michael S. Tsirkin, Bertrand Jacquin, Oleg Nesterov,
	J. Bruce Fields, Eric Dumazet, 蔡正龙,
	Jeff Layton, Tom Herbert, Alexei Starovoitov, Miklos Szeredi,
	Peter Foley, Hugh Dickins, Xiao Guangrong, Geert Uytterhoeven,
	Mel Gorman, Matt Turner, Paul E. McKenney, Alexander Duyck,
	open list:FUSE: FILESYSTEM...

On Mon, Nov 24, 2014 at 12:22:14PM -0800, Greg KH wrote:
> On Mon, Nov 24, 2014 at 12:14:50PM -0800, josh-iaAMLnmF4UmaiuxdJuQwMA@public.gmane.org wrote:
> > > I would, again, argue that stuff like __splice_p() not be implemented at
> > > all please.  It will only cause a huge proliferation of stuff like this
> > > that will not make any sense, and only cause a trivial, if any, amount
> > > of code savings.
> > > 
> > > I thought you were going to not do this type of thing until you got the
> > > gcc optimizer working for function callbacks.
> > 
> > Compared to the previous patchset, there are now only two instances of
> > ifdefs outside of the splice code for this, and this is one of them.  In
> > this case, the issue is no longer about making the code for this
> > splice_read function disappear, but rather to eliminate a reference to a
> > bit of splice functionality (used *inside* the FUSE splice code) that
> > will not work without SPLICE_SYSCALL.
> > 
> > Would you prefer to see this specific case handled via an #ifdef in
> > fs/fuse/dev.c rather than introducing a __splice_p that people might be
> > inclined to propagate?  That'd be fine; the code could simply wrap
> > fuse_dev_splice_read in an #ifdef and have the #else define a NULL
> > fuse_dev_splice_read.
> 
> Yes, I would prefer that, but I'm not the fuse maintainer.
> 
> thanks,
> 
> greg k-h

Okay. I'll do my part to prevent the type of proliferation guaranteed to rate
high on the respected K-H icky-scale. __splice_p() goes the way of the dodo
in favor of the solution presented by Josh.

I pray that the Gods of fuse maintenance will look favorable upon the result.

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [PATCH 4/6] fs/fuse: support compiling out splice
  2014-11-22 20:59   ` Pieter Smith
  (?)
@ 2014-11-22 21:44   ` Josh Triplett
  -1 siblings, 0 replies; 58+ messages in thread
From: Josh Triplett @ 2014-11-22 21:44 UTC (permalink / raw)
  To: Pieter Smith
  Cc: Miklos Szeredi, Jeff Layton, J. Bruce Fields,
	open list:FUSE: FILESYSTEM...,
	open list, linux-fsdevel

On Sat, Nov 22, 2014 at 09:59:59PM +0100, Pieter Smith wrote:
> Compile out splice support from fuse when the splice-family of syscalls is not
> supported by the system (i.e. CONFIG_SYSCALL_SPLICE is undefined).

This patch needs some additional explanation.  Could you explain in the
commit message why this particular splice_read function (and only the
splice_read function, not the splice_write function) needs compiling
out, when others do not?

- Josh Triplett

> Signed-off-by: Pieter Smith <pieter@boesman.nl>
> ---
>  fs/fuse/dev.c      | 4 ++--
>  include/linux/fs.h | 6 ++++++
>  2 files changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
> index ca88731..f8f92a4 100644
> --- a/fs/fuse/dev.c
> +++ b/fs/fuse/dev.c
> @@ -1291,7 +1291,7 @@ static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov,
>  	return fuse_dev_do_read(fc, file, &cs, iov_length(iov, nr_segs));
>  }
>  
> -static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
> +static ssize_t __maybe_unused fuse_dev_splice_read(struct file *in, loff_t *ppos,
>  				    struct pipe_inode_info *pipe,
>  				    size_t len, unsigned int flags)
>  {
> @@ -2144,7 +2144,7 @@ const struct file_operations fuse_dev_operations = {
>  	.llseek		= no_llseek,
>  	.read		= do_sync_read,
>  	.aio_read	= fuse_dev_read,
> -	.splice_read	= fuse_dev_splice_read,
> +	.splice_read	= __splice_p(fuse_dev_splice_read),
>  	.write		= do_sync_write,
>  	.aio_write	= fuse_dev_write,
>  	.splice_write	= fuse_dev_splice_write,
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index a957d43..04c0975 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -2443,6 +2443,12 @@ extern int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
>  			int datasync);
>  extern void block_sync_page(struct page *page);
>  
> +#ifdef CONFIG_SYSCALL_SPLICE
> +#define __splice_p(x) x
> +#else
> +#define __splice_p(x) NULL
> +#endif
> +
>  /* fs/splice.c */
>  extern ssize_t generic_file_splice_read(struct file *, loff_t *,
>  		struct pipe_inode_info *, size_t, unsigned int);
> -- 
> 1.9.1
> 

^ permalink raw reply	[flat|nested] 58+ messages in thread

* [PATCH 4/6] fs/fuse: support compiling out splice
@ 2014-11-22 20:59   ` Pieter Smith
  0 siblings, 0 replies; 58+ messages in thread
From: Pieter Smith @ 2014-11-22 20:59 UTC (permalink / raw)
  To: pieter
  Cc: Josh Triplett, Miklos Szeredi, Jeff Layton, J. Bruce Fields,
	open list:FUSE: FILESYSTEM...,
	open list, linux-fsdevel

Compile out splice support from fuse when the splice-family of syscalls is not
supported by the system (i.e. CONFIG_SYSCALL_SPLICE is undefined).

Signed-off-by: Pieter Smith <pieter@boesman.nl>
---
 fs/fuse/dev.c      | 4 ++--
 include/linux/fs.h | 6 ++++++
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index ca88731..f8f92a4 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -1291,7 +1291,7 @@ static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov,
 	return fuse_dev_do_read(fc, file, &cs, iov_length(iov, nr_segs));
 }
 
-static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
+static ssize_t __maybe_unused fuse_dev_splice_read(struct file *in, loff_t *ppos,
 				    struct pipe_inode_info *pipe,
 				    size_t len, unsigned int flags)
 {
@@ -2144,7 +2144,7 @@ const struct file_operations fuse_dev_operations = {
 	.llseek		= no_llseek,
 	.read		= do_sync_read,
 	.aio_read	= fuse_dev_read,
-	.splice_read	= fuse_dev_splice_read,
+	.splice_read	= __splice_p(fuse_dev_splice_read),
 	.write		= do_sync_write,
 	.aio_write	= fuse_dev_write,
 	.splice_write	= fuse_dev_splice_write,
diff --git a/include/linux/fs.h b/include/linux/fs.h
index a957d43..04c0975 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2443,6 +2443,12 @@ extern int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
 			int datasync);
 extern void block_sync_page(struct page *page);
 
+#ifdef CONFIG_SYSCALL_SPLICE
+#define __splice_p(x) x
+#else
+#define __splice_p(x) NULL
+#endif
+
 /* fs/splice.c */
 extern ssize_t generic_file_splice_read(struct file *, loff_t *,
 		struct pipe_inode_info *, size_t, unsigned int);
-- 
1.9.1


^ permalink raw reply related	[flat|nested] 58+ messages in thread

* [PATCH 4/6] fs/fuse: support compiling out splice
@ 2014-11-22 20:59   ` Pieter Smith
  0 siblings, 0 replies; 58+ messages in thread
From: Pieter Smith @ 2014-11-22 20:59 UTC (permalink / raw)
  To: pieter-qeJ+1H9vRZbz+pZb47iToQ
  Cc: Miklos Szeredi, open list:FUSE: FILESYSTEM...,
	Josh Triplett, open list, J. Bruce Fields,
	linux-fsdevel-u79uwXL29TY76Z2rM5mHXA, Jeff Layton

Compile out splice support from fuse when the splice-family of syscalls is not
supported by the system (i.e. CONFIG_SYSCALL_SPLICE is undefined).

Signed-off-by: Pieter Smith <pieter-qeJ+1H9vRZbz+pZb47iToQ@public.gmane.org>
---
 fs/fuse/dev.c      | 4 ++--
 include/linux/fs.h | 6 ++++++
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index ca88731..f8f92a4 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -1291,7 +1291,7 @@ static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov,
 	return fuse_dev_do_read(fc, file, &cs, iov_length(iov, nr_segs));
 }
 
-static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
+static ssize_t __maybe_unused fuse_dev_splice_read(struct file *in, loff_t *ppos,
 				    struct pipe_inode_info *pipe,
 				    size_t len, unsigned int flags)
 {
@@ -2144,7 +2144,7 @@ const struct file_operations fuse_dev_operations = {
 	.llseek		= no_llseek,
 	.read		= do_sync_read,
 	.aio_read	= fuse_dev_read,
-	.splice_read	= fuse_dev_splice_read,
+	.splice_read	= __splice_p(fuse_dev_splice_read),
 	.write		= do_sync_write,
 	.aio_write	= fuse_dev_write,
 	.splice_write	= fuse_dev_splice_write,
diff --git a/include/linux/fs.h b/include/linux/fs.h
index a957d43..04c0975 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2443,6 +2443,12 @@ extern int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
 			int datasync);
 extern void block_sync_page(struct page *page);
 
+#ifdef CONFIG_SYSCALL_SPLICE
+#define __splice_p(x) x
+#else
+#define __splice_p(x) NULL
+#endif
+
 /* fs/splice.c */
 extern ssize_t generic_file_splice_read(struct file *, loff_t *,
 		struct pipe_inode_info *, size_t, unsigned int);
-- 
1.9.1


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^ permalink raw reply related	[flat|nested] 58+ messages in thread

end of thread, other threads:[~2014-11-24 21:49 UTC | newest]

Thread overview: 58+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2014-11-23 14:20 [PATCH 0/6] kernel tinification: optionally compile out splice family of syscalls (splice, vmsplice, tee and sendfile) Pieter Smith
2014-11-23 14:20 ` Pieter Smith
2014-11-23 14:20 ` Pieter Smith
2014-11-23 14:20 ` [PATCH 1/6] fs: move sendfile syscall into fs/splice Pieter Smith
2014-11-23 14:20   ` Pieter Smith
2014-11-23 14:20   ` Pieter Smith
2014-11-23 14:20 ` [PATCH 2/6] fs: moved kernel_write to fs/read_write Pieter Smith
2014-11-23 14:20   ` Pieter Smith
2014-11-23 14:20   ` Pieter Smith
2014-11-23 14:20 ` [PATCH 3/6] fs/splice: support compiling out splice-family syscalls Pieter Smith
2014-11-23 14:20   ` Pieter Smith
2014-11-23 14:20   ` Pieter Smith
2014-11-23 14:20 ` [PATCH 4/6] fs/fuse: support compiling out splice Pieter Smith
2014-11-23 14:20   ` Pieter Smith
2014-11-23 14:20   ` Pieter Smith
2014-11-23 22:29   ` [fuse-devel] " Richard Weinberger
2014-11-23 22:29     ` Richard Weinberger
2014-11-23 23:23     ` Josh Triplett
2014-11-23 23:23       ` Josh Triplett
2014-11-24  9:49       ` Pieter Smith
2014-11-24  9:49         ` Pieter Smith
2014-11-24 16:05         ` Josh Triplett
2014-11-24 16:05           ` Josh Triplett
2014-11-24 19:34           ` Greg KH
2014-11-24 19:34             ` Greg KH
2014-11-24 20:14             ` josh
2014-11-24 20:14               ` josh-iaAMLnmF4UmaiuxdJuQwMA
2014-11-24 20:22               ` Greg KH
2014-11-24 20:22                 ` Greg KH
2014-11-24 21:49                 ` Pieter Smith
2014-11-24 21:49                   ` Pieter Smith
2014-11-23 14:20 ` [PATCH 5/6] net/core: " Pieter Smith
2014-11-23 14:20   ` Pieter Smith
2014-11-23 14:20 ` [PATCH 6/6] fs/splice: full support for " Pieter Smith
2014-11-23 14:20   ` Pieter Smith
2014-11-23 18:46 ` [PATCH 0/6] kernel tinification: optionally compile out splice family of syscalls (splice, vmsplice, tee and sendfile) David Miller
2014-11-23 18:46   ` David Miller
2014-11-23 19:43   ` Josh Triplett
2014-11-23 19:43     ` Josh Triplett
2014-11-23 20:30     ` Pieter Smith
2014-11-23 23:36       ` Josh Triplett
2014-11-23 23:36         ` Josh Triplett
2014-11-24  0:28         ` Jeff Layton
2014-11-24  0:32           ` Josh Triplett
2014-11-24  0:32             ` Josh Triplett
2014-11-24 10:01             ` Pieter Smith
2014-11-24 10:01               ` Pieter Smith
2014-11-24 14:54               ` Josh Triplett
2014-11-24 14:54                 ` Josh Triplett
2014-11-24  8:38         ` Geert Uytterhoeven
2014-11-24  8:38           ` Geert Uytterhoeven
2014-11-24  8:38           ` Geert Uytterhoeven
2014-11-24  9:00           ` Josh Triplett
2014-11-24  9:00             ` Josh Triplett
2014-11-24  9:00             ` Josh Triplett
     [not found] <1416690001-20817-1-git-send-email-pieter@boesman.nl>
2014-11-22 20:59 ` [PATCH 4/6] fs/fuse: support compiling out splice Pieter Smith
2014-11-22 20:59   ` Pieter Smith
2014-11-22 21:44   ` Josh Triplett

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