linux.git/drivers/char/raw.c, branch v3.0

RAW driver: Remove call to kobject_put().

2011-05-07T00:52:32+00:00

If cdev_add() fails, there is no justification for subsequently
calling kobject_put().

Signed-off-by: Robert P. J. Day 
Signed-off-by: Greg Kroah-Hartman

Allow setting of number of raw devices as a module parameter

2011-05-07T00:52:31+00:00

Allow setting of maximal number of raw devices as a module parameter. This
requires changing of static array into a vmalloced one (the array is going to
be too large for kmalloc).

Signed-off-by: Jan Kara 
Signed-off-by: Greg Kroah-Hartman

block: make blkdev_get/put() handle exclusive access

2010-11-13T10:55:17+00:00

Over time, block layer has accumulated a set of APIs dealing with bdev
open, close, claim and release.

* blkdev_get/put() are the primary open and close functions.

* bd_claim/release() deal with exclusive open.

* open/close_bdev_exclusive() are combination of open and claim and
  the other way around, respectively.

* bd_link/unlink_disk_holder() to create and remove holder/slave
  symlinks.

* open_by_devnum() wraps bdget() + blkdev_get().

The interface is a bit confusing and the decoupling of open and claim
makes it impossible to properly guarantee exclusive access as
in-kernel open + claim sequence can disturb the existing exclusive
open even before the block layer knows the current open if for another
exclusive access.  Reorganize the interface such that,

* blkdev_get() is extended to include exclusive access management.
  @holder argument is added and, if is @FMODE_EXCL specified, it will
  gain exclusive access atomically w.r.t. other exclusive accesses.

* blkdev_put() is similarly extended.  It now takes @mode argument and
  if @FMODE_EXCL is set, it releases an exclusive access.  Also, when
  the last exclusive claim is released, the holder/slave symlinks are
  removed automatically.

* bd_claim/release() and close_bdev_exclusive() are no longer
  necessary and either made static or removed.

* bd_link_disk_holder() remains the same but bd_unlink_disk_holder()
  is no longer necessary and removed.

* open_bdev_exclusive() becomes a simple wrapper around lookup_bdev()
  and blkdev_get().  It also has an unexpected extra bdev_read_only()
  test which probably should be moved into blkdev_get().

* open_by_devnum() is modified to take @holder argument and pass it to
  blkdev_get().

Most of bdev open/close operations are unified into blkdev_get/put()
and most exclusive accesses are tested atomically at the open time (as
it should).  This cleans up code and removes some, both valid and
invalid, but unnecessary all the same, corner cases.

open_bdev_exclusive() and open_by_devnum() can use further cleanup -
rename to blkdev_get_by_path() and blkdev_get_by_devt() and drop
special features.  Well, let's leave them for another day.

Most conversions are straight-forward.  drbd conversion is a bit more
involved as there was some reordering, but the logic should stay the
same.

Signed-off-by: Tejun Heo 
Acked-by: Neil Brown 
Acked-by: Ryusuke Konishi 
Acked-by: Mike Snitzer 
Acked-by: Philipp Reisner 
Cc: Peter Osterlund 
Cc: Martin Schwidefsky 
Cc: Heiko Carstens 
Cc: Jan Kara 
Cc: Andrew Morton 
Cc: Andreas Dilger 
Cc: "Theodore Ts'o" 
Cc: Mark Fasheh 
Cc: Joel Becker 
Cc: Alex Elder 
Cc: Christoph Hellwig 
Cc: dm-devel@redhat.com
Cc: drbd-dev@lists.linbit.com
Cc: Leo Chen 
Cc: Scott Branden 
Cc: Chris Mason 
Cc: Steven Whitehouse 
Cc: Dave Kleikamp 
Cc: Joern Engel 
Cc: reiserfs-devel@vger.kernel.org
Cc: Alexander Viro

Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl

2010-10-22T17:52:56+00:00

* 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
  vfs: make no_llseek the default
  vfs: don't use BKL in default_llseek
  llseek: automatically add .llseek fop
  libfs: use generic_file_llseek for simple_attr
  mac80211: disallow seeks in minstrel debug code
  lirc: make chardev nonseekable
  viotape: use noop_llseek
  raw: use explicit llseek file operations
  ibmasmfs: use generic_file_llseek
  spufs: use llseek in all file operations
  arm/omap: use generic_file_llseek in iommu_debug
  lkdtm: use generic_file_llseek in debugfs
  net/wireless: use generic_file_llseek in debugfs
  drm: use noop_llseek

fix rawctl compat ioctls breakage on amd64 and itanic

2010-10-19T09:29:54+00:00

RAW_SETBIND and RAW_GETBIND 32bit versions are fscked in interesting ways.

1) fs/compat_ioctl.c has COMPATIBLE_IOCTL(RAW_SETBIND) followed by
HANDLE_IOCTL(RAW_SETBIND, raw_ioctl).  The latter is ignored.

2) on amd64 (and itanic) the damn thing is broken - we have int + u64 + u64
and layouts on i386 and amd64 are _not_ the same.  raw_ioctl() would
work there, but it's never called due to (1).  As it is, i386 /sbin/raw
definitely doesn't work on amd64 boxen.

3) switching to raw_ioctl() as is would *not* work on e.g. sparc64 and ppc64,
which would be rather sad, seeing that normal userland there is 32bit.
The thing is, slapping __packed on the struct in question does not DTRT -
it eliminates *all* padding.  The real solution is to use compat_u64.

4) of course, all that stuff has no business being outside of raw.c in the
first place - there should be ->compat_ioctl() for /dev/rawctl instead of
messing with compat_ioctl.c.

[akpm@linux-foundation.org: coding-style fixes]
[arnd@arndb.de: port to 2.6.36]
Signed-off-by: Al Viro 
Signed-off-by: Andrew Morton 
Signed-off-by: Arnd Bergmann

raw: use explicit llseek file operations

2010-09-16T08:33:14+00:00

The raw_fops may need to seek, so there should
be an explicit reference to default_llseek.
raw_ctl_fops does not contain a read or write
method, so we use noop_llseek to ignore seeking
requests without an error.

Signed-off-by: Arnd Bergmann

drivers: Push down BKL into various drivers

2010-05-17T03:27:41+00:00

These are the last remaining device drivers using
the ->ioctl file operation in the drivers directory
(except from v4l drivers).

[fweisbec: drop i8k pushdown as it has been done from
procfs pushdown branch already]

Signed-off-by: Arnd Bergmann 
Signed-off-by: Frederic Weisbecker

vfs: rename block_fsync() to blkdev_fsync()

2010-04-07T15:38:04+00:00

Requested by hch, for consistency now it is exported.

Cc: Alexander Viro 
Cc: Anton Blanchard 
Cc: Christoph Hellwig 
Cc: Jan Kara 
Cc: Jeff Moyer 
Cc: Jens Axboe 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

raw: fsync method is now required

2010-04-07T15:38:04+00:00

Commit 148f948ba877f4d3cdef036b1ff6d9f68986706a (vfs: Introduce new
helpers for syncing after writing to O_SYNC file or IS_SYNC inode) broke
the raw driver.

We now call through generic_file_aio_write -> generic_write_sync ->
vfs_fsync_range.  vfs_fsync_range has:

        if (!fop || !fop->fsync) {
                ret = -EINVAL;
                goto out;
        }

But drivers/char/raw.c doesn't set an fsync method.

We have two options: fix it or remove the raw driver completely.  I'm
happy to do either, the fact this has been broken for so long suggests it
is rarely used.

The patch below adds an fsync method to the raw driver.  My knowledge of
the block layer is pretty sketchy so this could do with a once over.

If we instead decide to remove the raw driver, this patch might still be
useful as a backport to 2.6.33 and 2.6.32.

Signed-off-by: Anton Blanchard 
Reviewed-by: Jan Kara 
Cc: Christoph Hellwig 
Cc: Alexander Viro 
Cc: Jens Axboe 
Reviewed-by: Jeff Moyer 
Tested-by: Jeff Moyer 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

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