04 Jul, 2012
1 commit
-
In commit 070ad7e793dc ("floppy: convert to delayed work and
single-thread wq") the 'fd_timeout' timer was converted to a delayed
work. However, the "del_timer(&fd_timeout)" was lost in the process,
and any previous pending timeouts would stay active when we then
re-queued the timeout.This resulted in the floppy probe sequence having a (stale) 20s timeout
rather than the intended 3s timeout, and thus made booting with the
floppy driver (but no actual floppy controller) take much longer than it
should.Of course, there's little reason for most people to compile the floppy
driver into the kernel at all, which is why most people never noticed.Canceling the delayed work where we used to do the del_timer() fixes the
issue, and makes the floppy probing use the proper new timeout instead.
The three second timeout is still very wasteful, but better than the 20s
one.Reported-and-tested-by: Andi Kleen
Reported-and-tested-by: Calvin Walton
Cc: Jiri Kosina
Signed-off-by: Linus Torvalds
18 May, 2012
2 commits
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Block layer now handles O_EXCL in a generic way for block devices.
The semantics is however different for floppy and all other block devices,
as floppy driver contains its own O_EXCL handling.The semantics for all-but-floppy bdevs is "there can be at most one O_EXCL
open of this file", while for floppy bdev the semantics is "if someone has
the bdev open with O_EXCL, noone else can open it".There is actual userspace-observable change in behavior because of this
since commit e525fd89d380c ("block: make blkdev_get/put() handle exclusive
access") -- on kernels containing this commit, mount of /dev/fd0 causes
the fd0 block device be claimed with _EXCL, preventing subsequent
open(/dev/fd0).Bring things back into shape, i.e. make it possible, analogically to
other block devices, to mount the floppy and open() it afterwards --
remove the floppy-specific handling and let the generic bdev code O_EXCL
handling take over.Signed-off-by: Jiri Kosina
Acked-by: Tejun Heo
Acked-by: NeilBrown
Signed-off-by: Andrew Morton
Signed-off-by: Jiri Kosina -
There are several races in floppy driver between bottom half
(scheduled_work) and timers (fd_timeout, fd_timer). Due to slowness
of the actual floppy devices, those races are never (at least to my
knowledge) triggered on a bare floppy metal. However on virtualized
(emulated) floppy drives, which are of course magnitudes faster
than the real ones, these races trigger reliably. They usually exhibit
themselves as NULL pointer dereferences during DMA setup, such asBUG: unable to handle kernel NULL pointer dereference at 0000000a
[ ... snip ... ]
EIP: 0060:[] EFLAGS: 00010293 CPU: 0
EAX: ffffe000 EBX: 0000000a ECX: 00000000 EDX: 0000000a
ESI: c05d2718 EDI: 00000000 EBP: 00000000 ESP: f540fe44
DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
Process swapper (pid: 0, ti=f540e000 task=c082d5a0 task.ti=c0826000)
Stack:
ffffe000 00001ffc 00000000 00000000 00000000 c05d2718 c0708b40 f540fe80
c020470f c05d2718 c0708b40 00000000 f540fe80 0000000a f540fee4 00000000
c0708b40 f540fee4 00000000 00000000 c020526b 00000000 c05d2718 c0708b40
Call Trace:
[] dump_trace+0xaf/0x110
[] show_trace_log_lvl+0x4b/0x60
[] show_trace+0x18/0x20
[] dump_stack+0x6d/0x72
[] warn_slowpath_common+0x77/0xb0
[] warn_slowpath_fmt+0x33/0x40
[] setup_DMA+0x14c/0x210 [floppy]
[] setup_rw_floppy+0x105/0x190 [floppy]
[] run_timer_softirq+0x168/0x2a0
[] __do_softirq+0xc2/0x1c0
[] do_softirq+0x7d/0xb0
[] 0xf54d89ffbut other instances can be easily seen as well. This can be observed at least under
VMWare, VirtualBox and KVM.This patch converts all the timers and bottom halfs to be processed in a single
workqueue. This aproach has been already discussed back in 2010 if I remember
correctly, and Acked by Linus [1], but it then never made it to the tree.This all is based on original idea and code of Stephen Hemminger. I have
ported original Stepen's code to the current state of the floppy driver, and
performed quite some testing (on real hardware), which didn't reveal any issues
(this includes not only writing and reading data, but also formatting
(unfortunately I didn't find any Double-Density disks any more)). Ability to
handle errors properly (supplying known bad floppies) has also been verified.[1] http://kerneltrap.org/mailarchive/linux-kernel/2010/6/11/4582092
Based-on-patch-by: Stephen Hemminger
Acked-by: Linus Torvalds
Signed-off-by: Jiri Kosina
30 Mar, 2012
1 commit
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The X86_32-only disable_hlt/enable_hlt mechanism was used by the
32-bit floppy driver. Its effect was to replace the use of the
HLT instruction inside default_idle() with cpu_relax() - essentially
it turned off the use of HLT.This workaround was commented in the code as:
"disable hlt during certain critical i/o operations"
"This halt magic was a workaround for ancient floppy DMA
wreckage. It should be safe to remove."H. Peter Anvin additionally adds:
"To the best of my knowledge, no-hlt only existed because of
flaky power distributions on 386/486 systems which were sold to
run DOS. Since DOS did no power management of any kind,
including HLT, the power draw was fairly uniform; when exposed
to the much hhigher noise levels you got when Linux used HLT
caused some of these systems to fail.They were by far in the minority even back then."
Alan Cox further says:
"Also for the Cyrix 5510 which tended to go castors up if a HLT
occurred during a DMA cycle and on a few other boxes HLT during
DMA tended to go astray.Do we care ? I doubt it. The 5510 was pretty obscure, the 5520
fixed it, the 5530 is probably the oldest still in any kind of
use."So, let's finally drop this.
Signed-off-by: Len Brown
Signed-off-by: Josh Boyer
Signed-off-by: Andrew Morton
Acked-by: "H. Peter Anvin"
Acked-by: Alan Cox
Cc: Stephen Hemminger
Cc:
Link: http://lkml.kernel.org/n/tip-3rhk9bzf0x9rljkv488tloib@git.kernel.org
[ If anyone cares then alternative instruction patching could be
used to replace HLT with a one-byte NOP instruction. Much simpler. ]
Signed-off-by: Ingo Molnar
29 Mar, 2012
1 commit
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Remove all #inclusions of asm/system.h preparatory to splitting and killing
it. Performed with the following command:perl -p -i -e 's!^#\s*include\s*.*\n!!' `grep -Irl '^#\s*include\s*' *`
Signed-off-by: David Howells
06 Mar, 2012
1 commit
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Fix setting bio flags in drivers (sd_dif/floppy).
Signed-off-by: Muthukumar R
Cc: Jens Axboe
Cc: James Bottomley
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
09 Feb, 2012
2 commits
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floppy driver does not call add_disk() on all the drives hence we don't take
gendisk reference on request queue for these drives. Don't call put_disk()
with disk->queue set, otherwise we try to put the reference we never took.Reported-and-tested-by: Dirk Gouders
Signed-off-by: Vivek Goyal
Acked-by: Tejun Heo
Signed-off-by: Jens Axboe -
add_disk() takes gendisk reference on request queue. If driver failed during
initialization and never called add_disk() then that extra reference is not
taken. That reference is put in put_disk(). floppy driver allocates the
disk, allocates queue, sets disk->queue and then relizes that floppy
controller is not present. It tries to tear down everything and tries to
put a reference down in put_disk() which was never taken.In such error cases cleanup disk->queue before calling put_disk() so that
we never try to put down a reference which was never taken in first place.Reported-and-tested-by: Suresh Jayaraman
Tested-by: Dirk Gouders
Signed-off-by: Vivek Goyal
Acked-by: Tejun Heo
Signed-off-by: Jens Axboe
04 Jan, 2012
1 commit
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Move invalidate_bdev, block_sync_page into fs/block_dev.c. Export
kill_bdev as well, so brd doesn't have to open code it. Reduce
buffer_head.h requirement accordingly.Removed a rather large comment from invalidate_bdev, as it looked a bit
obsolete to bother moving. The small comment replacing it says enough.Signed-off-by: Nick Piggin
Cc: Al Viro
Cc: Christoph Hellwig
Signed-off-by: Andrew Morton
Signed-off-by: Al Viro
21 Sep, 2011
1 commit
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When no floppy is found the module code can be released while a timer
function is pending or about to be executed.CPU0 CPU1
floppy_init()
timer_softirq()
spin_lock_irq(&base->lock);
detach_timer();
spin_unlock_irq(&base->lock);
-> Interrupt
del_timer();
return -ENODEV;
module_cleanup();
Signed-off-by: Thomas Gleixner
Cc: Jens Axboe
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Jens Axboe
30 May, 2011
1 commit
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* 'idle-release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-idle-2.6:
x86 idle: deprecate mwait_idle() and "idle=mwait" cmdline param
x86 idle: deprecate "no-hlt" cmdline param
x86 idle APM: deprecate CONFIG_APM_CPU_IDLE
x86 idle floppy: deprecate disable_hlt()
x86 idle: EXPORT_SYMBOL(default_idle, pm_idle) only when APM demands it
x86 idle: clarify AMD erratum 400 workaround
idle governor: Avoid lock acquisition to read pm_qos before entering idle
cpuidle: menu: fixed wrapping timers at 4.294 seconds
29 May, 2011
1 commit
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Plan to remove floppy_disable_hlt in 2012, an ancient
workaround with comments that it should be removed.This allows us to remove clutter and a run-time branch
from the idle code.WARN_ONCE() on invocation until it is removed.
cc: x86@kernel.org
cc: stable@kernel.org # .39.x
Signed-off-by: Len Brown
22 Apr, 2011
1 commit
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In-kernel disk event polling doesn't matter for legacy/fringe drivers
and may lead to infinite event loop if ->check_events() implementation
generates events on level condition instead of edge.Now that block layer supports suppressing exporting unlisted events,
simply leaving disk->events cleared allows these drivers to keep the
internal revalidation behavior intact while avoiding weird
interactions with userland event handler.Signed-off-by: Tejun Heo
Cc: Kay Sievers
Signed-off-by: Jens Axboe
10 Mar, 2011
3 commits
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Conflicts:
block/blk-core.c
block/blk-flush.c
drivers/md/raid1.c
drivers/md/raid10.c
drivers/md/raid5.c
fs/nilfs2/btnode.c
fs/nilfs2/mdt.cSigned-off-by: Jens Axboe
-
Code has been converted over to the new explicit on-stack plugging,
and delay users have been converted to use the new API for that.
So lets kill off the old plugging along with aops->sync_page().Signed-off-by: Jens Axboe
-
Convert the floppy drivers from ->media_changed() to ->check_events().
Both floppy and ataflop buffer media changed state bit and clear them
on revalidation and will behave correctly with kernel event polling.I can't tell how amiflop clears its event and it's possible that it
may generate spurious events when polled.Signed-off-by: Tejun Heo
Cc: Jens Axboe
Cc: Kay Sievers
24 Feb, 2011
1 commit
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There are two cases when we call flush_disk.
In one, the device has disappeared (check_disk_change) so any
data will hold becomes irrelevant.
In the oter, the device has changed size (check_disk_size_change)
so data we hold may be irrelevant.In both cases it makes sense to discard any 'clean' buffers,
so they will be read back from the device if needed.In the former case it makes sense to discard 'dirty' buffers
as there will never be anywhere safe to write the data. In the
second case it *does*not* make sense to discard dirty buffers
as that will lead to file system corruption when you simply enlarge
the containing devices.flush_disk calls __invalidate_devices.
__invalidate_device calls both invalidate_inodes and invalidate_bdev.invalidate_inodes *does* discard I_DIRTY inodes and this does lead
to fs corruption.invalidate_bev *does*not* discard dirty pages, but I don't really care
about that at present.So this patch adds a flag to __invalidate_device (calling it
__invalidate_device2) to indicate whether dirty buffers should be
killed, and this is passed to invalidate_inodes which can choose to
skip dirty inodes.flusk_disk then passes true from check_disk_change and false from
check_disk_size_change.dm avoids tripping over this problem by calling i_size_write directly
rathher than using check_disk_size_change.md does use check_disk_size_change and so is affected.
This regression was introduced by commit 608aeef17a which causes
check_disk_size_change to call flush_disk, so it is suitable for any
kernel since 2.6.27.Cc: stable@kernel.org
Acked-by: Jeff Moyer
Cc: Andrew Patterson
Cc: Jens Axboe
Signed-off-by: NeilBrown
14 Jan, 2011
1 commit
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* 'for-2.6.38/drivers' of git://git.kernel.dk/linux-2.6-block:
cciss: reinstate proper FIFO order of command queue list
floppy: replace NO_GEOM macro with a function
24 Dec, 2010
1 commit
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flush_scheduled_work() is deprecated and scheduled to be removed.
Directly flush floppy_work instead.Signed-off-by: Tejun Heo
Cc: Jens Axboe
08 Nov, 2010
1 commit
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This patch replaces the NO_GEOM macro with a proper static inline function and
converts an open-coded caller in check_floppy_change() to use it.Cc: Stephen Hemminger
Cc: Andrew Morton
Signed-off-by: Pekka Enberg
Signed-off-by: Jens Axboe
06 Nov, 2010
2 commits
-
While scanning the floopy code due to c093ee4f07f4 ("floppy: fix
use-after-free in module load failure path"), I found one more instance
of trying to access disk->queue pointer after doing put_disk() on
gendisk. For some reason , floppy moule still loads/unloads fine. The
object is probably still around with right pointer values.o There seems to be one more instance of trying to cleanup the request
queue after we have called put_disk() on associated gendisk.o This fix is more out of code inspection. Even without this fix for
some reason I am able to load/unload floppy module without any
issues.o Floppy module loads/unloads fine after the fix.
Signed-off-by: Vivek Goyal
Signed-off-by: Linus Torvalds -
Commit 488211844e0c ("floppy: switch to one queue per drive instead of
sharing a queue") introduced a use-after-free. We do "put_disk()" on
the disk device _before_ we then clean up the queue associated with that
disk.Move the put_disk() down to avoid dereferencing a free'd data structure.
Cc: Jens Axboe
Cc: Vivek Goyal
Reported-and-tested-by: Randy Dunlap
Signed-off-by: Linus Torvalds
23 Oct, 2010
1 commit
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* 'for-2.6.37/drivers' of git://git.kernel.dk/linux-2.6-block: (95 commits)
cciss: fix PCI IDs for new Smart Array controllers
drbd: add race-breaker to drbd_go_diskless
drbd: use dynamic_dev_dbg to optionally log uuid changes
dynamic_debug.h: Fix dynamic_dev_dbg() macro if CONFIG_DYNAMIC_DEBUG not set
drbd: cleanup: change "s
drbd: add explicit drbd_md_sync to drbd_resync_finished
drbd: Do not log an ASSERT for P_OV_REQUEST packets while C_CONNECTED
drbd: fix for possible deadlock on IO error during resync
drbd: fix unlikely access after free and list corruption
drbd: fix for spurious fullsync (uuids rotated too fast)
drbd: allow for explicit resync-finished notifications
drbd: preparation commit, using full state in receive_state()
drbd: drbd_send_ack_dp must not rely on header information
drbd: Fix regression in recv_bm_rle_bits (compressed bitmap)
drbd: Fixed a stupid copy and paste error
drbd: Allow larger values for c-fill-target.
...Fix up trivial conflict in drivers/block/ataflop.c due to BKL removal
05 Oct, 2010
1 commit
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The block device drivers have all gained new lock_kernel
calls from a recent pushdown, and some of the drivers
were already using the BKL before.This turns the BKL into a set of per-driver mutexes.
Still need to check whether this is safe to do.file=$1
name=$2
if grep -q lock_kernel ${file} ; then
if grep -q 'include.*linux.mutex.h' ${file} ; then
sed -i '/include.*/d' ${file}
else
sed -i 's/include.*.*$/include /g' ${file}
fi
sed -i ${file} \
-e "/^#include.*linux.mutex.h/,$ {
1,/^\(static\|int\|long\)/ {
/^\(static\|int\|long\)/istatic DEFINE_MUTEX(${name}_mutex);} }" \
-e "s/\(un\)*lock_kernel\>[ ]*()/mutex_\1lock(\&${name}_mutex)/g" \
-e '/[ ]*cycle_kernel_lock();/d'
else
sed -i -e '/include.*\/d' ${file} \
-e '/cycle_kernel_lock()/d'
fiSigned-off-by: Arnd Bergmann
22 Sep, 2010
1 commit
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Pretty straight forward conversion. Note that we do round-robin
between the drives that have available requests, before we simply
used the drive that the IO scheduler told us to. Since the IO
scheduler doesn't care about multiple devices per queue, the resulting
sort would not have made sense.Fixed by Vivek to get rid of a double lock problem in set_next_request()
Signed-off-by: Jens Axboe
Signed-off-by: Vivek Goyal
08 Aug, 2010
11 commits
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The struct cont_t is just a set of virtual function pointers.
Signed-off-by: Stephen Hemminger
Signed-off-by: Andrew Morton
Signed-off-by: Jens Axboe -
The open and release block_device_operations are currently
called with the BKL held. In order to change that, we must
first make sure that all drivers that currently rely
on this have no regressions.This blindly pushes the BKL into all .open and .release
operations for all block drivers to prepare for the
next step. The drivers can subsequently replace the BKL
with their own locks or remove it completely when it can
be shown that it is not needed.The functions blkdev_get and blkdev_put are the only
remaining users of the big kernel lock in the block
layer, besides a few uses in the ioctl code, none
of which need to serialize with blkdev_{get,put}.Most of these two functions is also under the protection
of bdev->bd_mutex, including the actual calls to
->open and ->release, and the common code does not
access any global data structures that need the BKL.Signed-off-by: Arnd Bergmann
Acked-by: Christoph Hellwig
Signed-off-by: Jens Axboe -
As a preparation for the removal of the big kernel
lock in the block layer, this removes the BKL
from the common ioctl handling code, moving it
into every single driver still using it.Signed-off-by: Arnd Bergmann
Acked-by: Christoph Hellwig
Signed-off-by: Jens Axboe -
Convert assertions to use WARN(). There are several error checks in the
code for things that should never happen. Convert them to standard
warnings so kerneloops.org will see them.Signed-off-by: Stephen Hemminger
Signed-off-by: Andrew Morton
Signed-off-by: Jens Axboe -
Convert wait loops to use wait_event_ macros.
Signed-off-by: Stephen Hemminger
Signed-off-by: Andrew Morton
Signed-off-by: Jens Axboe -
Ioctl cmd value is unsigned, so change normalize_ioctl
Signed-off-by: Stephen Hemminger
Signed-off-by: Andrew Morton
Signed-off-by: Jens Axboe -
As reported by sparse, cmos attribute is local.
Signed-off-by: Stephen Hemminger
Signed-off-by: Andrew Morton
Signed-off-by: Jens Axboe -
The usage_count was being protected by a lock which was only there to
create an atomic counter.Signed-off-by: Stephen Hemminger
Signed-off-by: Andrew Morton
Signed-off-by: Jens Axboe -
The first thing the floppy does is read block 0 to test geometry and to
test for disk presence. If disk is not present this causes a console
warning message about failed I/O. Set flag to silence.Signed-off-by: Stephen Hemminger
Signed-off-by: Andrew Morton
Signed-off-by: Jens Axboe -
These routines are all big enough that is better to let the compiler
decide to inline or not.Signed-off-by: Stephen Hemminger
Signed-off-by: Andrew Morton
Signed-off-by: Jens Axboe -
Set debug jiffies offset at initialization. Avoids wierd values showing
up if debugging enabled.Signed-off-by: Stephen Hemminger
Signed-off-by: Andrew Morton
Signed-off-by: Jens Axboe
13 Mar, 2010
4 commits
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Convert outparam to const void *.
Cast outparam to const char * for strlen().Signed-off-by: Joe Perches
Cc: Stephen Hemminger
Cc: Jens Axboe
Cc: Marcin Slusarz
Cc: Bartlomiej Zolnierkiewicz
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Just code the test directly
Signed-off-by: Joe Perches
Cc: Stephen Hemminger
Cc: Jens Axboe
Cc: Marcin Slusarz
Cc: Bartlomiej Zolnierkiewicz
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Signed-off-by: Joe Perches
Cc: Stephen Hemminger
Cc: Jens Axboe
Cc: Marcin Slusarz
Cc: Bartlomiej Zolnierkiewicz
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Make debugt messages a little neater.
Signed-off-by: Joe Perches
Cc: Stephen Hemminger
Cc: Jens Axboe
Cc: Marcin Slusarz
Cc: Bartlomiej Zolnierkiewicz
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
