linux.git/fs/splice.c, branch v2.6.37

Export 'get_pipe_info()' to other users

2010-11-28T22:09:57+00:00

And in particular, use it in 'pipe_fcntl()'.

The other pipe functions do not need to use the 'careful' version, since
they are only ever called for things that are already known to be pipes.

The normal read/write/ioctl functions are called through the file
operations structures, so if a file isn't a pipe, they'd never get
called.  But pipe_fcntl() is special, and called directly from the
generic fcntl code, and needs to use the same careful function that the
splice code is using.

Cc: Jens Axboe 
Cc: Andrew Morton 
Cc: Al Viro 
Cc: Dave Jones 
Signed-off-by: Linus Torvalds

Rename 'pipe_info()' to 'get_pipe_info()'

2010-11-28T21:56:09+00:00

.. and change it to take the 'file' pointer instead of an inode, since
that's what all users want anyway.

The renaming is preparatory to exporting it to other users.  The old
'pipe_info()' name was too generic and is already used elsewhere, so
before making the function public we need to use a more specific name.

Cc: Jens Axboe 
Cc: Andrew Morton 
Cc: Al Viro 
Cc: Dave Jones 
Signed-off-by: Linus Torvalds

splice: fix misuse of SPLICE_F_NONBLOCK

2010-08-07T16:52:56+00:00

SPLICE_F_NONBLOCK is clearly documented to only affect blocking on the
pipe.  In __generic_file_splice_read(), however, it causes an EAGAIN
if the page is currently being read.

This makes it impossible to write an application that only wants
failure if the pipe is full.  For example if the same process is
handling both ends of a pipe and isn't otherwise able to determine
whether a splice to the pipe will fill it or not.

We could make the read non-blocking on O_NONBLOCK or some other splice
flag, but for now this is the simplest fix.

Signed-off-by: Miklos Szeredi 
CC: stable@kernel.org
Signed-off-by: Jens Axboe

gcc-4.6: fs: fix unused but set warnings

2010-08-07T16:23:12+00:00

No real bugs I believe, just some dead code, and some
shut up code.

Signed-off-by: Andi Kleen 
Cc: Eric Paris 
Signed-off-by: Andrew Morton 
Signed-off-by: Jens Axboe

splice: check f_mode for seekable file

2010-06-30T06:12:37+00:00

check f_mode for seekable file

As a seekable file is allowed without a llseek function, so the old way isn't
work any more.

Signed-off-by: Changli Gao 
Signed-off-by: Miklos Szeredi 
----
 fs/splice.c |    6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)
Signed-off-by: Jens Axboe

splice: direct_splice_actor() should not use pos in sd

2010-06-30T06:12:37+00:00

direct_splice_actor() shouldn't use sd->pos, as sd->pos is for file reading,
file->f_pos should be used instead.

Signed-off-by: Changli Gao 
Signed-off-by: Miklos Szeredi 
----
 fs/splice.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
Signed-off-by: Jens Axboe

fs/splice.c: fix mapping_gfp_mask usage

2010-05-25T08:25:26+00:00

mapping_gfp_mask() is not supposed to store allocation contex details,
only page location details.  So mapping_gfp_mask should be applied to the
pagecache page allocation, wheras normal (kernel mapped) memory should be
used for surrounding allocations such as radix-tree nodes allocated by
add_to_page_cache.  Context modifiers should be applied on a per-callsite
basis.

So change splice to follow this convention (which is followed in similar
code patterns in core code).

Signed-off-by: Nick Piggin 
Signed-off-by: Andrew Morton 
Signed-off-by: Jens Axboe

pipe: add support for shrinking and growing pipes

2010-05-21T19:12:40+00:00

This patch adds F_GETPIPE_SZ and F_SETPIPE_SZ fcntl() actions for
growing and shrinking the size of a pipe and adjusts pipe.c and splice.c
(and relay and network splice) usage to work with these larger (or smaller)
pipes.

Signed-off-by: Jens Axboe

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

2010-03-30T13:02:32+00:00

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo 
Guess-its-ok-by: Christoph Lameter 
Cc: Ingo Molnar 
Cc: Lee Schermerhorn

sendfile(): check f_op.splice_write() rather than f_op.sendpage()

2009-11-04T08:09:52+00:00

sendfile(2) was reworked with the splice infrastructure, but it still
checks f_op.sendpage() instead of f_op.splice_write() wrongly.  Although
if f_op.sendpage() exists, f_op.splice_write() always exists at the same
time currently, the assumption will be broken in future silently.  This
patch also brings a side effect: sendfile(2) can work with any output
file.  Some security checks related to f_op are added too.

Signed-off-by: Changli Gao 
Signed-off-by: Jens Axboe