The patch titled
lockdep: floppy.c irq release fix
has been added to the -mm tree. Its filename is
lockdep-floppyc-irq-release-fix.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: lockdep: floppy.c irq release fix
From: Ingo Molnar <mingo@xxxxxxx>
The lock validator triggered a number of bugs in the floppy driver, all
related to the floppy driver allocating and freeing irq and dma resources from
interrupt context. The initial solution was to use schedule_work() to push
this into process context, but this caused further problems: for example the
current floppy driver in -mm2 is totally broken and all floppy commands time
out with an error. (as reported by Barry K. Nathan)
This patch tries another solution: simply get rid of all that dynamic IRQ and
DMA allocation/freeing. I doubt it made much sense back in the heydays of
floppies (if two devices raced for DMA or IRQ resources then we didnt handle
those cases too gracefully anyway), and today it makes near zero sense.
So the new code does the simplest and most straightforward thing: allocate IRQ
and DMA resources at module init time, and free them at module removal time.
Dont try to release while the driver is operational. This, besides making the
floppy driver functional again has an added bonus, floppy IRQ stats are
finally persistent and visible in /proc/interrupts:
6: 63 XT-PIC-level floppy
Besides normal floppy IO i have also tested IO error handling, motor-off
timeouts, etc. - and everything seems to be working fine.
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
drivers/block/floppy.c | 42 +++------------------------------------
1 file changed, 4 insertions(+), 38 deletions(-)
diff -puN drivers/block/floppy.c~lockdep-floppyc-irq-release-fix drivers/block/floppy.c
--- a/drivers/block/floppy.c~lockdep-floppyc-irq-release-fix
+++ a/drivers/block/floppy.c
@@ -251,18 +251,6 @@ static int irqdma_allocated;
#include <linux/cdrom.h> /* for the compatibility eject ioctl */
#include <linux/completion.h>
-/*
- * Interrupt freeing also means /proc VFS work - dont do it
- * from interrupt context. We push this work into keventd:
- */
-static void fd_free_irq_fn(void *data)
-{
- fd_free_irq();
-}
-
-static DECLARE_WORK(fd_free_irq_work, fd_free_irq_fn, NULL);
-
-
static struct request *current_req;
static struct request_queue *floppy_queue;
static void do_fd_request(request_queue_t * q);
@@ -828,15 +816,6 @@ static int set_dor(int fdc, char mask, c
UDRS->select_date = jiffies;
}
}
- /*
- * We should propagate failures to grab the resources back
- * nicely from here. Actually we ought to rewrite the fd
- * driver some day too.
- */
- if (newdor & FLOPPY_MOTOR_MASK)
- floppy_grab_irq_and_dma();
- if (olddor & FLOPPY_MOTOR_MASK)
- floppy_release_irq_and_dma();
return olddor;
}
@@ -894,8 +873,6 @@ static int _lock_fdc(int drive, int inte
line);
return -1;
}
- if (floppy_grab_irq_and_dma() == -1)
- return -EBUSY;
if (test_and_set_bit(0, &fdc_busy)) {
DECLARE_WAITQUEUE(wait, current);
@@ -917,6 +894,8 @@ static int _lock_fdc(int drive, int inte
set_current_state(TASK_RUNNING);
remove_wait_queue(&fdc_wait, &wait);
+
+ flush_scheduled_work();
}
command_status = FD_COMMAND_NONE;
@@ -950,7 +929,6 @@ static inline void unlock_fdc(void)
if (elv_next_request(floppy_queue))
do_fd_request(floppy_queue);
spin_unlock_irqrestore(&floppy_lock, flags);
- floppy_release_irq_and_dma();
wake_up(&fdc_wait);
}
@@ -3697,8 +3675,8 @@ static int floppy_release(struct inode *
}
if (!UDRS->fd_ref)
opened_bdev[drive] = NULL;
- floppy_release_irq_and_dma();
mutex_unlock(&open_lock);
+
return 0;
}
@@ -3729,9 +3707,6 @@ static int floppy_open(struct inode *ino
if (UDRS->fd_ref == -1 || (UDRS->fd_ref && (filp->f_flags & O_EXCL)))
goto out2;
- if (floppy_grab_irq_and_dma())
- goto out2;
-
if (filp->f_flags & O_EXCL)
UDRS->fd_ref = -1;
else
@@ -3808,7 +3783,6 @@ out:
UDRS->fd_ref--;
if (!UDRS->fd_ref)
opened_bdev[drive] = NULL;
- floppy_release_irq_and_dma();
out2:
mutex_unlock(&open_lock);
return res;
@@ -3825,14 +3799,9 @@ static int check_floppy_change(struct ge
return 1;
if (time_after(jiffies, UDRS->last_checked + UDP->checkfreq)) {
- if (floppy_grab_irq_and_dma()) {
- return 1;
- }
-
lock_fdc(drive, 0);
poll_drive(0, 0);
process_fd_request();
- floppy_release_irq_and_dma();
}
if (UTESTF(FD_DISK_CHANGED) ||
@@ -4382,7 +4351,6 @@ static int __init floppy_init(void)
fdc = 0;
del_timer(&fd_timeout);
current_drive = 0;
- floppy_release_irq_and_dma();
initialising = 0;
if (have_no_fdc) {
DPRINT("no floppy controllers found\n");
@@ -4542,7 +4510,7 @@ static void floppy_release_irq_and_dma(v
if (irqdma_allocated) {
fd_disable_dma();
fd_free_dma();
- schedule_work(&fd_free_irq_work);
+ fd_free_irq();
irqdma_allocated = 0;
}
set_dor(0, ~0, 8);
@@ -4653,8 +4621,6 @@ void cleanup_module(void)
/* eject disk, if any */
fd_eject(0);
- flush_scheduled_work(); /* fd_free_irq() might be pending */
-
wait_for_completion(&device_release);
}
_
Patches currently in -mm which might be from mingo@xxxxxxx are
origin.patch
define-__raw_get_cpu_var-and-use-it.patch
ide-cd-end-of-media-error-fix.patch
lock-validator-introduce-warn_on_oncecond.patch
emu10k1-mark-midi_spinlock-as-used.patch
epoll-use-unlocked-wqueue-operations.patch
pacct-none-delayed-process-accounting-accumulation.patch
disable-debugging-version-of-write_lock.patch
fix-drivers-mfd-ucb1x00-corec-irq-probing-bug.patch
cifs-remove-f_ownerlock-use.patch
lock-validator-fix-ns83820c-irq-flags-bug.patch
revert-gregkh-pci-pci-test-that-drivers-properly-call-pci_set_master.patch
x86-re-enable-generic-numa.patch
i386-fix-softirq-accounting-with-4k-stacks.patch
vdso-randomize-the-i386-vdso-by-moving-it-into-a-vma.patch
vdso-randomize-the-i386-vdso-by-moving-it-into-a-vma-tidy.patch
vdso-randomize-the-i386-vdso-by-moving-it-into-a-vma-arch_vma_name-fix.patch
vdso-randomize-the-i386-vdso-by-moving-it-into-a-vma-vs-x86_64-mm-reliable-stack-trace-support-i386.patch
vdso-randomize-the-i386-vdso-by-moving-it-into-a-vma-vs-x86_64-mm-reliable-stack-trace-support-i386-2.patch
vdso-randomize-the-i386-vdso-by-moving-it-into-a-vma-vs-x86_64-mm-reliable-stack-trace-support-i386-2-revert-maxmem-change.patch
work-around-ppc64-bootup-bug-by-making-mutex-debugging-save-restore-irqs.patch
kernel-kernel-cpuc-to-mutexes.patch
spin-rwlock-init-cleanups.patch
time-clocksource-infrastructure.patch
sched-fix-smt-nice-lock-contention-and-optimization.patch
sched-fix-smt-nice-lock-contention-and-optimization-tidy.patch
sched-comment-bitmap-size-accounting.patch
sched-fix-interactive-ceiling-code.patch
sched-cpu-hotplug-race-vs-set_cpus_allowed.patch
sched-implement-smpnice.patch
sched-protect-calculation-of-max_pull-from-integer-wrap.patch
sched-store-weighted-load-on-up.patch
sched-add-discrete-weighted-cpu-load-function.patch
sched-prevent-high-load-weight-tasks-suppressing-balancing.patch
sched-improve-stability-of-smpnice-load-balancing.patch
sched-improve-smpnice-load-balancing-when-load-per-task.patch
smpnice-dont-consider-sched-groups-which-are-lightly-loaded-for-balancing.patch
smpnice-dont-consider-sched-groups-which-are-lightly-loaded-for-balancing-fix.patch
sched-modify-move_tasks-to-improve-load-balancing-outcomes.patch
sched-avoid-unnecessarily-moving-highest-priority-task-move_tasks.patch
sched-avoid-unnecessarily-moving-highest-priority-task-move_tasks-fix-2.patch
sched_domain-handle-kmalloc-failure.patch
sched_domain-handle-kmalloc-failure-fix.patch
sched_domain-dont-use-gfp_atomic.patch
sched_domain-use-kmalloc_node.patch
sched_domain-allocate-sched_group-structures-dynamically.patch
sched-mc-smt-power-savings-sched-policy.patch
sched-uninline-task_rq_lock.patch
bug-if-setscheduler-is-called-from-interrupt-context.patch
sched-add-above-background-load-function.patch
mm-implement-swap-prefetching.patch
pi-futex-futex-code-cleanups.patch
pi-futex-robust-futex-docs-fix.patch
pi-futex-introduce-debug_check_no_locks_freed.patch
pi-futex-introduce-warn_on_smp.patch
pi-futex-add-plist-implementation.patch
pi-futex-scheduler-support-for-pi.patch
pi-futex-rt-mutex-core.patch
pi-futex-rt-mutex-docs.patch
pi-futex-rt-mutex-docs-update.patch
pi-futex-rt-mutex-debug.patch
pi-futex-rt-mutex-tester.patch
pi-futex-rt-mutex-tester-fix.patch
pi-futex-rt-mutex-futex-api.patch
pi-futex-futex_lock_pi-futex_unlock_pi-support.patch
pi-futex-futex_lock_pi-futex_unlock_pi-support-fix.patch
fix-rt-mutex-defaults-and-dependencies.patch
drop-tasklist-lock-in-do_sched_setscheduler.patch
rtmutex-modify-rtmutex-tester-to-test-the-setscheduler.patch
rtmutex-propagate-priority-settings-into-pi-lock-chains.patch
rtmutex-propagate-priority-settings-into-pi-lock-chains-fix.patch
futex_requeue-optimization.patch
fix-ide-deadlock-in-error-reporting-code.patch
genirq-rename-desc-handler-to-desc-chip.patch
genirq-rename-desc-handler-to-desc-chip-power-fix.patch
genirq-rename-desc-handler-to-desc-chip-ia64-fix.patch
genirq-rename-desc-handler-to-desc-chip-ia64-fix-2.patch
genirq-rename-desc-handler-to-desc-chip-terminate_irqs-fix.patch
genirq-sem2mutex-probe_sem-probing_active.patch
genirq-cleanup-merge-irq_affinity-into-irq_desc.patch
genirq-cleanup-remove-irq_descp.patch
genirq-cleanup-remove-irq_descp-fix.patch
genirq-cleanup-remove-fastcall.patch
genirq-cleanup-misc-code-cleanups.patch
genirq-cleanup-reduce-irq_desc_t-use-mark-it-obsolete.patch
genirq-cleanup-include-linux-irqh.patch
genirq-cleanup-merge-irq_dir-smp_affinity_entry-into-irq_desc.patch
genirq-cleanup-merge-pending_irq_cpumask-into-irq_desc.patch
genirq-cleanup-turn-arch_has_irq_per_cpu-into-config_irq_per_cpu.patch
genirq-debug-better-debug-printout-in-enable_irq.patch
genirq-add-retrigger-irq-op-to-consolidate-hw_irq_resend.patch
genirq-doc-comment-include-linux-irqh-structures.patch
genirq-doc-handle_irq_event-and-__do_irq-comments.patch
genirq-cleanup-no_irq_type-cleanups.patch
genirq-doc-add-design-documentation.patch
genirq-add-genirq-sw-irq-retrigger.patch
genirq-add-irq_noprobe-support.patch
genirq-add-irq_norequest-support.patch
genirq-add-irq_noautoen-support.patch
genirq-update-copyrights.patch
genirq-core.patch
genirq-msi-fixes-2.patch
genirq-add-irq-chip-support.patch
genirq-add-irq-chip-support-fix.patch
genirq-add-irq-chip-support-misroute-irq-dont-call-desc-chip-end.patch
genirq-add-handle_bad_irq.patch
genirq-add-irq-wake-power-management-support.patch
genirq-add-sa_trigger-support.patch
genirq-cleanup-no_irq_type-no_irq_chip-rename.patch
genirq-more-verbose-debugging-on-unexpected-irq-vectors.patch
genirq-ia64-build-fix.patch
genirq-add-irq_type_sense_mask.patch
genirq-add-irq-chip-support-fasteoi-handler-handle-interrupt-disabling.patch
genirq-irq-document-what-an-irq-is.patch
genirq-add-chip-eoi-fastack-fasteoi-core.patch
genirq-add-chip-eoi-fastack-fasteoi-fix.patch
lockdep-floppyc-irq-release-fix.patch
lockdep-acpi-locking-fix.patch
lockdep-console_init-after-local_irq_enable.patch
lockdep-add-is_module_address.patch
lockdep-add-print_ip_sym.patch
lockdep-add-per_cpu_offset.patch
lockdep-add-disable-enable_irq_lockdep-api.patch
lockdep-add-local_irq_enable_in_hardirq-api.patch
lockdep-add-declare_completion_onstack-api.patch
lockdep-clean-up-rwsems.patch
lockdep-rename-debug_warn_on.patch
lockdep-remove-debug_bug_on.patch
lockdep-remove-mutex-deadlock-checking-code.patch
lockdep-better-lock-debugging.patch
lockdep-mutex-section-binutils-workaround.patch
lockdep-locking-init-debugging-improvement.patch
lockdep-beautify-x86_64-stacktraces.patch
lockdep-x86_64-document-stack-frame-internals.patch
lockdep-i386-remove-multi-entry-backtraces.patch
lockdep-stacktrace-subsystem-core.patch
lockdep-s390-config_frame_pointer-support.patch
lockdep-stacktrace-subsystem-i386-support.patch
lockdep-stacktrace-subsystem-x86_64-support.patch
lockdep-stacktrace-subsystem-s390-support.patch
lockdep-irqtrace-subsystem-core.patch
lockdep-irqtrace-subsystem-docs.patch
lockdep-irqtrace-subsystem-i386-support.patch
lockdep-irqtrace-subsystem-x86_64-support.patch
lockdep-irqtrace-subsystem-s390-support.patch
lockdep-locking-api-self-tests.patch
lockdep-irqtrace-cleanup-of-include-asm-i386-irqflagsh.patch
lockdep-irqtrace-cleanup-of-include-asm-x86_64-irqflagsh.patch
lockdep-core.patch
lockdep-design-docs.patch
lockdep-procfs.patch
lockdep-prove-rwsem-locking-correctness.patch
lockdep-prove-spinlock-rwlock-locking-correctness.patch
lockdep-prove-mutex-locking-correctness.patch
lockdep-kconfig.patch
lockdep-print-all-lock-classes-on-sysrq-d.patch
lockdep-x86_64-early-init.patch
lockdep-x86-smp-alternatives-workaround.patch
lockdep-do-not-recurse-in-printk.patch
lockdep-fix-rt_hash_lock_sz.patch
lockdep-s390-turn-validator-off-in-machine-check-handler.patch
lockdep-enable-on-i386.patch
lockdep-enable-on-x86_64.patch
lockdep-enable-on-s390.patch
lockdep-annotate-direct-io.patch
lockdep-annotate-serial.patch
lockdep-annotate-dcache.patch
lockdep-annotate-i_mutex.patch
lockdep-annotate-futex.patch
lockdep-annotate-genirq.patch
lockdep-annotate-waitqueues.patch
lockdep-annotate-mm.patch
lockdep-annotate-serio.patch
lockdep-annotate-skb_queue_head_init.patch
lockdep-annotate-timer-base-locks.patch
lockdep-annotate-scheduler-runqueue-locks.patch
lockdep-annotate-hrtimer-base-locks.patch
lockdep-annotate-sock_lock_init.patch
lockdep-annotate-af_unix-locking.patch
lockdep-annotate-bh_lock_sock.patch
lockdep-annotate-ieee1394-skb-queue-head-locking.patch
lockdep-annotate-mmap_sem.patch
lockdep-annotate-sunrpc-code.patch
lockdep-annotate-ntfs-locking-rules.patch
lockdep-annotate-the-quota-code.patch
lockdep-annotate-usbfs.patch
lockdep-annotate-sound-core-seq-seq_portsc.patch
lockdep-annotate-sound-core-seq-seq_devicec.patch
lockdep-annotate-8390c-disable_irq.patch
lockdep-annotate-3c59xc-disable_irq.patch
lockdep-annotate-forcedethc-disable_irq.patch
lockdep-annotate-enable_in_hardirq.patch
lockdep-annotate-on-stack-completions.patch
lockdep-annotate-qeth-driver.patch
lockdep-annotate-s_lock.patch
lockdep-annotate-sb-s_umount.patch
lockdep-annotate-slab-code.patch
lockdep-annotate-blkdev-nesting.patch
acpi-reduce-code-size-clean-up-fix-validator-message.patch
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