Janos Haar of First NetCenter Bt. reported numerous crashes involving the
NBD driver. With his help, this was tracked down to bogus bio vectors
which in turn was the result of a race condition between the
receive/transmit routines in the NBD driver.
The bug manifests itself like this:
CPU0 CPU1
do_nbd_request
add req to queuelist
nbd_send_request
send req head
for each bio
kmap
send
nbd_read_stat
nbd_find_request
nbd_end_request
kunmap
When CPU1 finishes nbd_end_request, the request and all its associated
bio's are freed. So when CPU0 calls kunmap whose argument is derived from
the last bio, it may crash.
Under normal circumstances, the race occurs only on the last bio. However,
if an error is encountered on the remote NBD server (such as an incorrect
magic number in the request), or if there were a bug in the server, it is
possible for the nbd_end_request to occur any time after the request's
addition to the queuelist.
The following patch fixes this problem by making sure that requests are not
added to the queuelist until after they have been completed transmission.
In order for the receiving side to be ready for responses involving
requests still being transmitted, the patch introduces the concept of the
active request.
When a response matches the current active request, its processing is
delayed until after the tranmission has come to a stop.
This has been tested by Janos and it has been successful in curing this
race condition.
From: Herbert Xu <herbert@gondor.apana.org.au>
Here is an updated patch which removes the active_req wait in
nbd_clear_queue and the associated memory barrier.
I've also clarified this in the comment.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Cc: <djani22@dynamicweb.hu>
Cc: Paul Clements <Paul.Clements@SteelEye.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
nls_utf8 is available, and the check in hfsplus_fill_super checks the wrong
pointer for NULLness (it checks the saved nls, not the new one that it
needs to use.)
Signed-off-by: Joshua Kwan <joshk@triplehelix.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Update IDE to use new blk_ordered. This change makes the
following behavior changes.
* Partial completion of the barrier request is handled as
failure of the whole ordered sequence. No more partial
completion for barrier requests.
* Any failure of pre or post flush request results in failure
of the whole ordered sequence.
So, successfully completed ordered sequence guarantees that
all requests prior to the barrier made to physical medium and,
then, the while barrier request made to the physical medium.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jens Axboe <axboe@suse.de>
Reflect changes in SCSI midlayer and updated to use new
ordered request implementation
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jens Axboe <axboe@suse.de>
All ordered request related stuff delegated to HLD. Midlayer
now doens't deal with ordered setting or prepare_flush
callback. sd.c updated to deal with blk_queue_ordered
setting. Currently, ordered tag isn't used as SCSI midlayer
cannot guarantee request ordering.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jens Axboe <axboe@suse.de>
Reimplement handling of barrier requests.
* Flexible handling to deal with various capabilities of
target devices.
* Retry support for falling back.
* Tagged queues which don't support ordered tag can do ordered.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jens Axboe <axboe@suse.de>
Separate out bio initialization part from __make_request. It
will be used by the following blk_ordered_reimpl.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jens Axboe <axboe@suse.de>
add @uptodate argument to end_that_request_last() and @error
to rq_end_io_fn(). there's no generic way to pass error code
to request completion function, making generic error handling
of non-fs request difficult (rq->errors is driver-specific and
each driver uses it differently). this patch adds @uptodate
to end_that_request_last() and @error to rq_end_io_fn().
for fs requests, this doesn't really matter, so just using the
same uptodate argument used in the last call to
end_that_request_first() should suffice. imho, this can also
help the generic command-carrying request jens is working on.
Signed-off-by: tejun heo <htejun@gmail.com>
Signed-Off-By: Jens Axboe <axboe@suse.de>
the patch below marks various read-only variables in block/* as const,
so that gcc can optimize the use of them; eg gcc will replace the use by
the value directly now and will even remove the memory usage of these.
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Jens Axboe <axboe@suse.de>
For filesystems with a blocksize < page size, we can merge same page
calls into the bio_vec at the end of the bio. This saves segments
on systems with a page size > the "normal" 4kb fs block size.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@suse.de>
Originally from: Nick Piggin <nickpiggin@yahoo.com.au>
Move current_io_context out of the get_request fastpth. Also try to
streamline a few other things in this area.
Signed-off-by: Jens Axboe <axboe@suse.de>
Unlike other ioscheds, as-iosched handles alias by chaing them using
rq->queuelist. As aliased requests are very rare in the first place,
this complicates merge/dispatch handling without meaningful
performance improvement. This patch updates as-iosched to dump
aliased requests into dispatch queue as other ioscheds do.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jens Axboe <axboe@suse.de>
Setting RF (resume flag) allows a debugger to resume execution after a
code breakpoint without tripping the breakpoint again. It is reset by
the CPU after execution of one instruction.
Requested by Stephane Eranian:
"I am trying to the user HW debug registers on i386 and I am running
into a problem with ptrace() not allowing access to EFLAGS_RF for
POKEUSER (see FLAG_MASK). [ ... ] It avoids the need to remove the
breakpoint, single step, and reinstall. The equivalent functionality
exists on IA-64 and is allowed by ptrace()"
Cc: Stephane Eranian <eranian@hpl.hp.com>
Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
These patches add the header linux/if_ether.h and change 1500 to
ETH_DATA_LEN in some files.
Signed-off-by: Kris Katterjohn <kjak@users.sourceforge.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add some PCMCIA device IDs for the microdrive found in the Sharp Zaurus
and a different revision of the Socket CF+ Bluetooth card.
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
kill the socket_shutdown()/shutdown_socket() confusion by making it
one single function. move cs_socket_put() in there. nicer to read and
smaller:
original:
text data bss dec hex filename
25181 1076 32 26289 66b1 drivers/pcmcia/pcmcia_core.ko
patched:
text data bss dec hex filename
24973 1076 32 26081 65e1 drivers/pcmcia/pcmcia_core.ko
Signed-off-by: Daniel Ritz <daniel.ritz@gmx.ch>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Export the stored values instead of re-reading everything in the socket
information sysfs files, and make them accessible to all users, not only
to root.
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
This adds PCMCIA support for both MPC885ADS and MPC866ADS.
This is established not together with FADS, because 885 does not have
io_block_mapping() for BCSR area.
Also, some cleanups done both for 885ADS and MBX.
Signed-off-by: Vitaly Bordug <vbordug@ru.mvista.com>
Signed-off-by: Marcelo Tosatti <marcelo.tosatti@cyclades.com>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Some PCMCIA sockets have statically mapped memory windows, but dynamically
mapped IO windows. Using the "nonstatic" socket library is inpractical for
them, as they do neither need a resource database (as we can trust the
kernel resource database on m68k and ppc) nor lots of other features of that
library. Let them get a small "iodyn" socket library (105 lines of code)
instead.
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Update the PCMCIA sound drivers to handle the recent changes to the PCMCIA
core. A part of this merge was done by Takashi Iwai <tiwai@suse.de>.
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Unify the EVENT_CARD_INSERTION and "attach" callbacks to one unified
probe() callback. As all in-kernel drivers are changed to this new
callback, there will be no temporary backwards-compatibility. Inside a
probe() function, each driver _must_ set struct pcmcia_device
*p_dev->instance and instance->handle correctly.
With these patches, the basic driver interface for 16-bit PCMCIA drivers
now has the classic four callbacks known also from other buses:
int (*probe) (struct pcmcia_device *dev);
void (*remove) (struct pcmcia_device *dev);
int (*suspend) (struct pcmcia_device *dev);
int (*resume) (struct pcmcia_device *dev);
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
The linked list of devices managed by each PCMCIA driver is, in very most
cases, unused. Therefore, remove it from many drivers.
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Unify the "detach" and REMOVAL_EVENT handlers to one "remove" function.
Old functionality is preserved, for the moment.
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Merge the suspend and resume methods for 16-bit PCMCIA cards into the
device model -- for both runtime power management and suspend to ram/disk.
Bugfix in ds.c by Richard Purdie
Signed-Off-By: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Move the suspend and resume methods out of the event handler, and into
special functions. Also use these functions for pre- and post-reset, as
almost all drivers already do, and the remaining ones can easily be
converted.
Bugfix to include/pcmcia/ds.c
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Make the bridge specific initialization code config options depending on
CONFIG_EMBEDDED. Config options for TI/EnE, Toshiba, Ricoh and O2Micro are
available. Disabling all of the specific tweaks cuts off more than half
of yenta_socket.ko.
Signed-off-by: Daniel Ritz <daniel.ritz@gmx.ch>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Also return a value if CONFIG_PCMCIA_PROBE is not set.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Add a return value to pcmcia_validate_mem. Only if we have enough memory
available to map the CIS, we should proceed in trying to determine information
about the device.
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Don't waste cpu time in yenta interrupt handler when the interrupt was for
another device.
Signed-off-by: Daniel Ritz <daniel.ritz@gmx.ch>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
arch/ia64/kernel/setup.c: In function `show_cpuinfo':
arch/ia64/kernel/setup.c:576: warning: long unsigned int format, different type arg (arg 12)
arch/ia64/kernel/setup.c:576: warning: long unsigned int format, different type arg (arg 13)
Introduced by 95235ca2c2
Signed-off-by: Tony Luck <tony.luck@intel.com>
