elevator_ops->elevator_init_fn() has a weird return value. It returns
a void * which the caller should assign to q->elevator->elevator_data
and %NULL return denotes init failure.
Update such that it returns integer 0/-errno and sets elevator_data
directly as necessary.
This makes the interface more conventional and eases further cleanup.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Elevator switch tries hard to keep as much as context until new
elevator is ready so that it can revert to the original state if
initializing the new elevator fails for some reason. Unfortunately,
with more auxiliary contexts to manage, this makes elevator init and
exit paths too complex and fragile.
This patch makes elevator_switch() unregister the current elevator and
flush icq's before start initializing the new one. As we still keep
the old elevator itself, the only difference is that we lose icq's on
rare occassions of switching failure, which isn't critical at all.
Note that this makes explicit elevator parameter to
elevator_init_queue() and __elv_register_queue() unnecessary as they
always can use the current elevator.
This patch enables block cgroup cleanups.
-v2: blk_add_trace_msg() prints elevator name from @new_e instead of
@e->type as the local variable no longer exists. This caused
build failure on CONFIG_BLK_DEV_IO_TRACE.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
cfq has been registering zeroed blkio_poilcy_cfq if CFQ_GROUP_IOSCHED
is disabled. This fortunately doesn't collide with blk-throtl as
BLKIO_POLICY_PROP is zero but is unnecessary and risky. Just don't
register it if not enabled.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Block cgroup core can be built as module; however, it isn't too useful
as blk-throttle can only be built-in and cfq-iosched is usually the
default built-in scheduler. Scheduled blkcg cleanup requires calling
into blkcg from block core. To simplify that, disallow building blkcg
as module by making CONFIG_BLK_CGROUP bool.
If building blkcg core as module really matters, which I doubt, we can
revisit it after blkcg API cleanup.
-v2: Vivek pointed out that IOSCHED_CFQ was incorrectly updated to
depend on BLK_CGROUP. Fixed.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Currently, blk_cleanup_queue() doesn't call elv_drain_elevator() if
q->elevator doesn't exist; however, bio based drivers don't have
elevator initialized but can still use blk-throttle. This patch moves
q->elevator test inside blk_drain_queue() such that only
elv_drain_elevator() is skipped if !q->elevator.
-v2: loop can have registered queue which has NULL request_fn. Make
sure we don't call into __blk_run_queue() in such cases.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Vivek Goyal <vgoyal@redhat.com>
Fold in bug fix from Vivek.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This patch (as1519) fixes a bug in the block layer's disk-events
polling. The polling is done by a work routine queued on the
system_nrt_wq workqueue. Since that workqueue isn't freezable, the
polling continues even in the middle of a system sleep transition.
Obviously, polling a suspended drive for media changes and such isn't
a good thing to do; in the case of USB mass-storage devices it can
lead to real problems requiring device resets and even re-enumeration.
The patch fixes things by creating a new system-wide, non-reentrant,
freezable workqueue and using it for disk-events polling.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: <stable@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Set CommandMailbox with memset before use it. Fix for:
drivers/block/DAC960.c: In function ‘DAC960_V1_EnableMemoryMailboxInterface’:
arch/x86/include/asm/io.h:61:1: warning: ‘CommandMailbox.Bytes[12]’
may be used uninitialized in this function [-Wuninitialized]
drivers/block/DAC960.c:1175:30: note: ‘CommandMailbox.Bytes[12]’
was declared here
Signed-off-by: Danny Kukawka <danny.kukawka@bisect.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Fixed compiler warning:
comparison between ‘DAC960_V2_IOCTL_Opcode_T’ and ‘enum <anonymous>’
Renamed enum, added a new enum for SCSI_10.CommandOpcode in
DAC960_V2_ProcessCompletedCommand().
Signed-off-by: Danny Kukawka <danny.kukawka@bisect.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The following situation might occur:
__blkdev_get: add_disk:
register_disk()
get_gendisk()
disk_block_events()
disk->ev == NULL
disk_add_events()
__disk_unblock_events()
disk->ev != NULL
--ev->block
Then we unblock events, when they are suppose to be blocked. This can
trigger events related block/genhd.c warnings, but also can crash in
sd_check_events() or other places.
I'm able to reproduce crashes with the following scripts (with
connected usb dongle as sdb disk).
<snip>
DEV=/dev/sdb
ENABLE=/sys/bus/usb/devices/1-2/bConfigurationValue
function stop_me()
{
for i in `jobs -p` ; do kill $i 2> /dev/null ; done
exit
}
trap stop_me SIGHUP SIGINT SIGTERM
for ((i = 0; i < 10; i++)) ; do
while true; do fdisk -l $DEV 2>&1 > /dev/null ; done &
done
while true ; do
echo 1 > $ENABLE
sleep 1
echo 0 > $ENABLE
done
</snip>
I use the script to verify patch fixing oops in sd_revalidate_disk
http://marc.info/?l=linux-scsi&m=132935572512352&w=2
Without Jun'ichi Nomura patch titled "Fix NULL pointer dereference in
sd_revalidate_disk" or this one, script easily crash kernel within
a few seconds. With both patches applied I do not observe crash.
Unfortunately after some time (dozen of minutes), script will hung in:
[ 1563.906432] [<c08354f5>] schedule_timeout_uninterruptible+0x15/0x20
[ 1563.906437] [<c04532d5>] msleep+0x15/0x20
[ 1563.906443] [<c05d60b2>] blk_drain_queue+0x32/0xd0
[ 1563.906447] [<c05d6e00>] blk_cleanup_queue+0xd0/0x170
[ 1563.906454] [<c06d278f>] scsi_free_queue+0x3f/0x60
[ 1563.906459] [<c06d7e6e>] __scsi_remove_device+0x6e/0xb0
[ 1563.906463] [<c06d4aff>] scsi_forget_host+0x4f/0x60
[ 1563.906468] [<c06cd84a>] scsi_remove_host+0x5a/0xf0
[ 1563.906482] [<f7f030fb>] quiesce_and_remove_host+0x5b/0xa0 [usb_storage]
[ 1563.906490] [<f7f03203>] usb_stor_disconnect+0x13/0x20 [usb_storage]
Anyway I think this patch is some step forward.
As drawback, I do not teardown on sysfs file create error, because I do
not know how to nullify disk->ev (since it can be used). However add_disk
error handling practically does not exist too, and things will work
without this sysfs file, except events will not be exported to user
space.
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Since 2.6.39 (1196f8b), when a driver returns -ENOMEDIUM for open(),
__blkdev_get() calls rescan_partitions() to remove
in-kernel partition structures and raise KOBJ_CHANGE uevent.
However it ends up calling driver's revalidate_disk without open
and could cause oops.
In the case of SCSI:
process A process B
----------------------------------------------
sys_open
__blkdev_get
sd_open
returns -ENOMEDIUM
scsi_remove_device
<scsi_device torn down>
rescan_partitions
sd_revalidate_disk
<oops>
Oopses are reported here:
http://marc.info/?l=linux-scsi&m=132388619710052
This patch separates the partition invalidation from rescan_partitions()
and use it for -ENOMEDIUM case.
Reported-by: Huajun Li <huajun.li.lee@gmail.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
While updating locking, b2efa05265 "block, cfq: unlink
cfq_io_context's immediately" moved elevator_exit_icq_fn() invocation
from exit_io_context() to the final ioc put. While this doesn't cause
catastrophic failure, it effectively removes task exit notification to
elevator and cause noticeable IO performance degradation with CFQ.
On task exit, CFQ used to immediately expire the slice if it was being
used by the exiting task as no more IO would be issued by the task;
however, after b2efa05265, the notification is lost and disk could sit
idle needlessly, leading to noticeable IO performance degradation for
certain workloads.
This patch renames ioc_exit_icq() to ioc_destroy_icq(), separates
elevator_exit_icq_fn() invocation into ioc_exit_icq() and invokes it
from exit_io_context(). ICQ_EXITED flag is added to avoid invoking
the callback more than once for the same icq.
Walking icq_list from ioc side and invoking elevator callback requires
reverse double locking. This may be better implemented using RCU;
unfortunately, using RCU isn't trivial. e.g. RCU protection would
need to cover request_queue and queue_lock switch on cleanup makes
grabbing queue_lock from RCU unsafe. Reverse double locking should
do, at least for now.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-and-bisected-by: Shaohua Li <shli@kernel.org>
LKML-Reference: <CANejiEVzs=pUhQSTvUppkDcc2TNZyfohBRLygW5zFmXyk5A-xQ@mail.gmail.com>
Tested-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Reverse double lock dancing in ioc_release_fn() can be simplified by
just using trylock on the queue_lock and back out from ioc lock on
trylock failure. Simplify it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Tested-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
icq->changed was used for ICQ_*_CHANGED bits. Rename it to flags and
access it under ioc->lock instead of using atomic bitops.
ioc_get_changed() is added so that the changed part can be fetched and
cleared as before.
icq->flags will be used to carry other flags.
Signed-off-by: Tejun Heo <tj@kernel.org>
Tested-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
One small bug fix from Axel plus a fix for a build failure in unrealistic
but commonly built configs which for some reason manage to survive for
an awfully long time in -next without any reports.
* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
regulator: Fix getting voltage in max8649_enable_time()
regulator: Fix mc13xxx regulator modular build (again)
Quoth BenH:
"Here are a few powerpc fixes for 3.3, all pretty trivial. I also
added the patch to define GET_IP/SET_IP so we can use some more
asm-generic goodness."
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
powerpc/pseries/eeh: Fix crash when error happens during device probe
powerpc/pseries: Fix partition migration hang in stop_topology_update
powerpc/powernv: Disable interrupts while taking phb->lock
powerpc: Fix WARN_ON in decrementer_check_overflow
powerpc/wsp: Fix IRQ affinity setting
powerpc: Implement GET_IP/SET_IP
powerpc/wsp: Permanently enable PCI class code workaround
MMC fixes for 3.3-rc4:
* The most visible fix here is against a regression introduced in 3.3-rc1
that ran cards in Ultra High Speed mode even when they failed to initialize
in that mode, leading to lower-speed cards failing to mount.
* A lockdep warning introduced in 3.3-rc1 is fixed.
* Various other small driver fixes, most notably for a NULL dereference
when using highmem with dw_mmc.
* tag 'mmc-fixes-for-3.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/cjb/mmc:
mmc: dw_mmc: Fix PIO mode with support of highmem
mmc: atmel-mci: save and restore sdioirq when soft reset is performed
mmc: block: Init ro_lock sysfs attr to fix lockdep warnings
mmc: sh_mmcif: fix late delayed work initialisation
mmc: tmio_mmc: fix card eject during IO with DMA
mmc: core: Fix comparison issue in mmc_compare_ext_csds
mmc: core: Fix PowerOff Notify suspend/resume
mmc: sdhci-pci: set Medfield SDIO as non-removable
mmc: core: add the capability for broken voltage
mmc: core: Fix low speed mmc card detection failure
mmc: esdhc: set the timeout to the max value
mmc: esdhc: add PIO mode support
mmc: core: Ensure clocks are always enabled before host interaction
mmc: of_mmc_spi: fix little endian support
mmc: core: UHS sdio card that fails should not exceed 50MHz
mmc: esdhc: fix errors when booting kernel on Freescale eSDHC version 2.3
Two fixes for VCPU offlining; One to fix the string format exposed
by the xen-pci[front|back] to conform to the one used in majority of
PCI drivers; Two fixes to make the code more resilient to invalid
configurations.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* tag 'stable/for-linus-fixes-3.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
xenbus_dev: add missing error check to watch handling
xen/pci[front|back]: Use %d instead of %1x for displaying PCI devfn.
xen pvhvm: do not remap pirqs onto evtchns if !xen_have_vector_callback
xen/smp: Fix CPU online/offline bug triggering a BUG: scheduling while atomic.
xen/bootup: During bootup suppress XENBUS: Unable to read cpu state
sound fixes for 3.3-rc4
Basically all small fixes suited as rc4: a few HD-audio regression fixes,
a stable fix for an old Dell laptop with intel8x0, and a simple fix for
ASoC fsi.
* tag 'sound-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
ALSA: intel8x0: Fix default inaudible sound on Gateway M520
ALSA: hda - Fix silent speaker output on Acer Aspire 6935
ALSA: hda - Fix initialization of secondary capture source on VT1705
ASoC: fsi: fixup fsi_pointer() calculation method
ALSA: hda - Fix mute-LED VREF value for new HP laptops
* git://git.samba.org/sfrench/cifs-2.6:
cifs: don't return error from standard_receive3 after marking response malformed
cifs: request oplock when doing open on lookup
cifs: fix error handling when cifscreds key payload is an error
This updates the sha512 fix so that it doesn't cause excessive stack
usage on i386. This is done by reverting to the original code, and
avoiding the W duplication by moving its initialisation into the loop.
As the underlying code is in fact the one that we have used for years,
I'm pushing this now instead of postponing to the next cycle.
* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
crypto: sha512 - Avoid stack bloat on i386
crypto: sha512 - Use binary and instead of modulus
EEH may happen during a PCI driver probe. If the driver is trying to
access some register in a loop, the EEH code will try to print the
driver name. But the driver pointer in struct pci_dev is not set until
probe returns successfully.
Use a function to test if the device and the driver pointer is NULL
before accessing the driver's name.
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tejun Heo
Dan Carpenter
Alan Stern
Danny Kukawka
Stanislaw Gruszka
Muthukumar R
Jun'ichi Nomura
Linus Torvalds
Daniel T Chen
Takashi Iwai
Thadeu Lima de Souza Cascardo