pavel@suse.cz no longer works, replace it with working address.
Signed-off-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
The pktcdvd driver uses proper locking and does not need the BKL in the
ioctl and llseek functions of the character device, so kill both.
Moving the compat_ioctl handling from common code into the driver itself
fixes build problems when CONFIG_BLOCK is disabled.
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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 <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
fs/compat_ioctl.c: In function 'do_ioctl_trans':
fs/compat_ioctl.c:534: warning: 'karg' may be used uninitialized in this function
fs/compat_ioctl.c:533: warning: 'kcmd' may be used uninitialized in this function
fs/compat_ioctl.c:656: warning: 'ret' may be used uninitialized in this function
Reduces text size by 44 bytes.
If someone calls one of these functions with an unexpected argument, the
code's buggy as-is.
Amerigo Wang <amwang@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-rc-fixes-2.6:
[SCSI] qla2xxx: Obtain proper host structure during response-queue processing.
[SCSI] compat_ioct: fix bsg SG_IO
[SCSI] qla2xxx: make msix interrupt handler safe for irq
[SCSI] zfcp: Report FC BSG errors in correct field
[SCSI] mptfusion : mptscsih_abort return value should be SUCCESS instead of value 0.
This is used by tcgetsid(3).
Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
md ioctls are now handled by the md driver itself, but mdadm
may call RAID_VERSION on other devices as well. Mark the command
as IGNORE_IOCTL so this fails silently rather than printing
an annoying message.
Reported-by: "Michael S. Tsirkin" <m.s.tsirkin@gmail.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
bsg's SG_IO doesn't work on 32-bit userspace and 64-bit kernelspace.
The problem is that both sg and bsg drivers use SG_IO
ioctl. sg_ioctl_trans() does 32/64-bit conversion even against bsg
header. It messes up bsg header. bsg driver gets garbage.
This patch fixes sg_ioctl_trans to handle only sg header (struct
sg_io_hdr).
Reported-by: Giridhar Malavali <giridhar.malavali@qlogic.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
After the commit fb07a5f8 ("compat_ioctl: remove all VT ioctl
handling"), I got this error message on 64-bit mips kernel with 32-bit
busybox userland:
ioctl32(init:1): Unknown cmd fd(0) cmd(00005600){t:'V';sz:0} arg(7fd76480) on /dev/console
The cmd 5600 is VT_OPENQRY. The busybox's init issues this ioctl to
know vt-console or serial-console. If the console was serial console,
VT ioctls are not handled by the serial driver.
And by quick search, I found some programs using VT_GETMODE to check
vt-console is available or not.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
No driver uses SG_SET_TRANSFORM any more in Linux, since the ide-scsi
driver was removed in 2.6.29. The compat-ioctl cleanup series moved
the handling for this around, which broke building without CONFIG_BLOCK.
Just remove the code handling it for compat mode.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The RAID ioctls are only implemented in md.c, so the
handling for them should also be moved there from
fs/compat_ioctl.c.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Neil Brown <neilb@suse.de>
Cc: Andre Noll <maan@systemlinux.org>
Cc: linux-raid@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
Half the compat_ioctl handling is in devio.c, the other
half is in fs/compat_ioctl.c. This moves everything into
one place for consistency.
As a positive side-effect, push down the BKL into the
ioctl methods.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Oliver Neukum <oliver@neukum.org>
Cc: Alon Bar-Lev <alon.barlev@gmail.com>
Cc: David Vrabel <david.vrabel@csr.com>
Cc: linux-usb@vger.kernel.org
Handling for LPSETTIMEOUT can easily be done in lp_ioctl, which
is the only user. As a positive side-effect, push the BKL
into the ioctl methods.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Instead of having each handler call compat_ptr, we can now
convert the pointer once and pass that to each handler.
This saves a little bit of both source and object code size.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
The compat_ioctl table now only contains entries for
COMPATIBLE_IOCTL, so we only need to know if a number
is listed in it or now.
As an optimization, we hash the table entries with a
reversible transformation to get a more uniform distribution
over it, sort the table at startup and then guess the
position in the table when an ioctl number gets called
to do a linear search from there.
With the current set of ioctl numbers and the chosen
transformation function, we need an average of four
steps to find if a number is in the set, all of the
accesses within one or two cache lines.
This at least as good as the previous hash table
approach but saves 8.5 kb of kernel memory.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
The compat_ioctl array now contains only entries for ioctl numbers
that do not require a separate handler. By special-casing the
ULONG_IOCTL case in the do_ioctl_trans function, we can kill the
final use of a function pointer in the array.
text data bss dec hex filename
7539 13352 2080 22971 59bb before/fs/compat_ioctl.o
7910 8552 2080 18542 486e after/fs/compat_ioctl.o
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
This makes all ioctl conversion handlers called from
a single switch statement, leaving only COMPATIBLE_IOCTL
and ULONG_IOCTL statements in the table. This is somewhat
more space efficient and also lets us simplify the
handling of the lookup table significantly.
before:
text data bss dec hex filename
7619 14024 2080 23723 5cab obj/fs/compat_ioctl.o
after:
7567 13352 2080 22999 59d7 obj/fs/compat_ioctl.o
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
We have always called ioctl conversion handlers under the big kernel lock,
although that is generally not necessary. In particular it is not needed
for conversion of data structures and for calling sys_ioctl or
do_vfs_ioctl, which will get the BKL again if needed.
Handlers doing more than those two have been moved out, so we can kill off
the BKL from compat_sys_ioctl. This may significantly improve latencies
with 32 bit applications, and it avoids a common scenario where a thread
acquires the BKL twice.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The VT driver now handles all of these ioctls directly, so we can remove
the handlers from common code.
These are the only handlers that require the BKL because they directly
perform the ioctl action rather than just converting the data structures.
Once they are gone, we can remove the BKL from the remaining ioctl
conversion handlers.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
"Definition" is misspelled "defintion" in several comments; this
patch fixes them. No code changes.
Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
For FS_IOC_RESVSP and FS_IOC_RESVSP64 compat_sys_ioctl() uses its
arg argument as a pointer to userspace. However it is missing a
a call to compat_ptr() which will do a proper pointer conversion.
This was introduced with 3e63cbb1 "fs: Add new pre-allocation ioctls
to vfs for compatibility with legacy xfs ioctls".
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ankit Jain <me@ankitjain.org>
Acked-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Arnd Bergmann <arndbergmann@googlemail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: <stable@kernel.org> [2.6.31.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This removes the original socket compat_ioctl code
from fs/compat_ioctl.c and converts the code from the copy
in net/socket.c into a single function. We add a few cycles
of runtime to compat_sock_ioctl() with the long switch()
statement, but gain some cycles in return by simplifying
the call chain to get there.
Due to better inlining, save 1.5kb of object size in the
process, and enable further savings:
before:
text data bss dec hex filename
13540 18008 2080 33628 835c obj/fs/compat_ioctl.o
14565 636 40 15241 3b89 obj/net/socket.o
after:
text data bss dec hex filename
8916 15176 2080 26172 663c obj/fs/compat_ioctl.o
20725 636 40 21401 5399 obj/net/socket.o
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
We must not have a compat ioctl handler for SIOCATALKDIFADDR
in common code, because the same number is used in other protocols
with different data structures.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Slip and a few other drivers use the same ioctl numbers on
tty devices that are normally meant for sockets. This causes
problems with our compat_ioctl handling that tries to convert
the data structures in a different format.
Fortunately, these five drivers all use 32 bit compatible
data structures in the ioctl numbers, so we can just add
a trivial compat_ioctl conversion function to each of them.
SIOCSIFENCAP and SIOCGIFENCAP do not need to live in
fs/compat_ioctl.c after this any more, and they are not
used on any sockets.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
The tun driver is the only code in the kernel that operates
on a character device with struct ifreq. Change the driver
to handle the conversion itself so we can contain the
remaining ifreq handling in the socket layer.
This also fixes a bug in the handling of invalid ioctl
numbers on an unbound tun device. The driver treats this
as a TUNSETIFF in native mode, but there is no way for
the generic compat_ioctl() function to emulate this
behaviour. Possibly the driver was only doing this
accidentally anyway, but if any code relies on this
misfeature, it now also works in compat mode.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
The FIEMAP_IOC_FIEMAP mapping ioctl was missing a 32-bit compat handler,
which means that 32-bit suerspace on 64-bit kernels cannot use this ioctl
command.
The structure is nicely aligned, padded, and sized, so it is just this
simple.
Tested w/ 32-bit ioctl tester (from Josef) on a 64-bit kernel on ext4.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Cc: <linux-ext4@vger.kernel.org>
Cc: Mark Lord <lkml@rtr.ca>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Josef Bacik <josef@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Remove smp_lock.h from files which don't need it (including some headers!)
* Add smp_lock.h to files which do need it
* Make smp_lock.h include conditional in hardirq.h
It's needed only for one kernel_locked() usage which is under CONFIG_PREEMPT
This will make hardirq.h inclusion cheaper for every PREEMPT=n config
(which includes allmodconfig/allyesconfig, BTW)
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch adds ioctls to vfs for compatibility with legacy XFS
pre-allocation ioctls (XFS_IOC_*RESVP*). The implementation
effectively invokes sys_fallocate for the new ioctls.
Also handles the compat_ioctl case.
Note: These legacy ioctls are also implemented by OCFS2.
[AV: folded fixes from hch]
Signed-off-by: Ankit Jain <me@ankitjain.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* git://git.infradead.org/mtd-2.6: (63 commits)
mtd: OneNAND: Allow setting of boundary information when built as module
jffs2: leaking jffs2_summary in function jffs2_scan_medium
mtd: nand: Fix memory leak on txx9ndfmc probe failure.
mtd: orion_nand: use burst reads with double word accesses
mtd/nand: s3c6400 support for s3c2410 driver
[MTD] [NAND] S3C2410: Use DIV_ROUND_UP
[MTD] [NAND] S3C2410: Deal with unaligned lengths in S3C2440 buffer read/write
[MTD] [NAND] S3C2410: Allow the machine code to get the BBT table from NAND
[MTD] [NAND] S3C2410: Added a kerneldoc for s3c2410_nand_set
mtd: physmap_of: Add multiple regions and concatenation support
mtd: nand: max_retries off by one in mxc_nand
mtd: nand: s3c2410_nand_setrate(): use correct macros for 2412/2440
mtd: onenand: add bbt_wait & unlock_all as replaceable for some platform
mtd: Flex-OneNAND support
mtd: nand: add OMAP2/OMAP3 NAND driver
mtd: maps: Blackfin async: fix memory leaks in probe/remove funcs
mtd: uclinux: mark local stuff static
mtd: uclinux: do not allow to be built as a module
mtd: uclinux: allow systems to override map addr/size
mtd: blackfin NFC: fix hang when using NAND on BF527-EZKITs
...
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6:
[SCSI] aic79xx: make driver respect nvram for IU and QAS settings
[SCSI] don't attach ULD to Dell Universal Xport
[SCSI] lpfc 8.3.3 : Update driver version to 8.3.3
[SCSI] lpfc 8.3.3 : Add support for Target Reset handler entrypoint
[SCSI] lpfc 8.3.3 : Fix a couple of spin_lock and memory issues and a crash
[SCSI] lpfc 8.3.3 : FC/FCOE discovery fixes
[SCSI] lpfc 8.3.3 : Fix various SLI-3 vs SLI-4 differences
[SCSI] qla2xxx: Resolve a performance issue in interrupt
[SCSI] cnic, bnx2i: Fix build failure when CONFIG_PCI is not set.
[SCSI] nsp_cs: time_out reaches -1
[SCSI] qla2xxx: fix printk format warnings
[SCSI] ncr53c8xx: div reaches -1
[SCSI] compat: don't perform unneeded copy in sg_io code
[SCSI] zfcp: Update FC pass-through support
[SCSI] zfcp: Add FC pass-through support
[SCSI] FC Pass Thru support
The members from 'status' in struct sg_io_hdr to the last are used to
transfer information from kernel to user space. The values that user
space sets are just ignored.
Signed-off-by: Alexey Zaytsev <alexey.zaytsev@gmail.com>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Remove all references to MTD ioctls from fs/compat_ioctl.c and let
them all be handled by mtd_compat_ioctl().
Signed-off-by: Kevin Cernekee <kpc.mtd@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
1) Move the MEMREADOOB/MEMWRITEOOB compat_ioctl wrappers from
fs/compat_ioctl.c into mtdchar.c . Original request was here:
http://lkml.org/lkml/2009/4/1/295
2) Add missing COMPATIBLE_IOCTL lines, so that mtd-utils does not error
out when running in 64/32 compatibility mode.
LKML-Reference: <200904011650.22928.arnd@arndb.de>
Signed-off-by: Kevin Cernekee <kpc.mtd@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
New MEMERASE/MEMREADOOB/MEMWRITEOOB ioctls are needed in order to support
64-bit offsets into large NAND flash devices.
Signed-off-by: Kevin Cernekee <kpc.mtd@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
In file included from fs/compat_ioctl.c:61:
include/linux/loop.h:59: error: field 'lo_bio_list' has incomplete type
Signed-off-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* 'for-linus' of git://neil.brown.name/md: (53 commits)
md/raid5 revise rules for when to update metadata during reshape
md/raid5: minor code cleanups in make_request.
md: remove CONFIG_MD_RAID_RESHAPE config option.
md/raid5: be more careful about write ordering when reshaping.
md: don't display meaningless values in sysfs files resync_start and sync_speed
md/raid5: allow layout and chunksize to be changed on active array.
md/raid5: reshape using largest of old and new chunk size
md/raid5: prepare for allowing reshape to change layout
md/raid5: prepare for allowing reshape to change chunksize.
md/raid5: clearly differentiate 'before' and 'after' stripes during reshape.
Documentation/md.txt update
md: allow number of drives in raid5 to be reduced
md/raid5: change reshape-progress measurement to cope with reshaping backwards.
md: add explicit method to signal the end of a reshape.
md/raid5: enhance raid5_size to work correctly with negative delta_disks
md/raid5: drop qd_idx from r6_state
md/raid6: move raid6 data processing to raid6_pq.ko
md: raid5 run(): Fix max_degraded for raid level 4.
md: 'array_size' sysfs attribute
md: centralize ->array_sectors modifications
...
This makes the includes more explicit, and is preparation for moving
md_k.h to drivers/md/md.h
Remove include/raid/md.h as its only remaining use was to #include
other files.
Signed-off-by: NeilBrown <neilb@suse.de>
Commit 8e961870bb removed the FREEZE/THAW
handling in xfs_compat_ioctl but never added any compat handler back, so
now any freeze/thaw request from a 32-bit binary ond 64-bit userspace
will fail.
As these ioctls are 32/64-bit compatible two simple COMPATIBLE_IOCTL
entries in fs/compat_ioctl.c will do the job.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Otherwise, these don't work when called from 32-bit userspace on 64-bit
kernels.
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: <stable@kernel.org> [2.6.25.x, 2.6.26.x, 2.6.27.x, 2.6.28.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Unlike a normal socket path, the tuntap device send path does
not have any accounting. This means that the user-space sender
may be able to pin down arbitrary amounts of kernel memory by
continuing to send data to an end-point that is congested.
Even when this isn't an issue because of limited queueing at
most end points, this can also be a problem because its only
response to congestion is packet loss. That is, when those
local queues at the end-point fills up, the tuntap device will
start wasting system time because it will continue to send
data there which simply gets dropped straight away.
Of course one could argue that everybody should do congestion
control end-to-end, unfortunately there are people in this world
still hooked on UDP, and they don't appear to be going away
anywhere fast. In fact, we've always helped them by performing
accounting in our UDP code, the sole purpose of which is to
provide congestion feedback other than through packet loss.
This patch attempts to apply the same bandaid to the tuntap device.
It creates a pseudo-socket object which is used to account our
packets just as a normal socket does for UDP. Of course things
are a little complex because we're actually reinjecting traffic
back into the stack rather than out of the stack.
The stack complexities however should have been resolved by preceding
patches. So this one can simply start using skb_set_owner_w.
For now the accounting is essentially disabled by default for
backwards compatibility. In particular, we set the cap to INT_MAX.
This is so that existing applications don't get confused by the
sudden arrival EAGAIN errors.
In future we may wish (or be forced to) do this by default.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
... and yes, gcc is insane enough to eat that without complaint.
We probably want sparse to scream on those...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pavel Machek