The patch titled
lock validator: drivers/block/floppy.c fixes
has been removed from the -mm tree. Its filename is
lock-validator-floppyc-irq-release-fix-fix.patch
This patch was dropped because lockdep is being redone
------------------------------------------------------
Subject: lock validator: drivers/block/floppy.c fixes
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: Andrew Morton <akpm@xxxxxxxx>
---
drivers/block/floppy.c | 61 +--------------------------------------
1 file changed, 2 insertions(+), 59 deletions(-)
diff -puN drivers/block/floppy.c~lock-validator-floppyc-irq-release-fix-fix drivers/block/floppy.c
--- devel/drivers/block/floppy.c~lock-validator-floppyc-irq-release-fix-fix 2006-06-03 16:39:50.000000000 -0700
+++ devel-akpm/drivers/block/floppy.c 2006-06-03 16:39:50.000000000 -0700
@@ -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);
@@ -573,21 +561,6 @@ static int floppy_grab_irq_and_dma(void)
static void floppy_release_irq_and_dma(void);
/*
- * Interrupt, DMA and region freeing must not be done from IRQ
- * context - e.g. irq-unregistration means /proc VFS work, region
- * release takes an irq-unsafe lock, etc. So we push this work
- * into keventd:
- */
-static void fd_release_fn(void *data)
-{
- mutex_lock(&open_lock);
- floppy_release_irq_and_dma();
- mutex_unlock(&open_lock);
-}
-
-static DECLARE_WORK(floppy_release_irq_and_dma_work, fd_release_fn, NULL);
-
-/*
* The "reset" variable should be tested whenever an interrupt is scheduled,
* after the commands have been sent. This is to ensure that the driver doesn't
* get wedged when the interrupt doesn't come because of a failed command.
@@ -843,15 +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)
- schedule_work(&floppy_release_irq_and_dma_work);
return olddor;
}
@@ -909,8 +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);
@@ -967,7 +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);
- schedule_work(&floppy_release_irq_and_dma_work);
wake_up(&fdc_wait);
}
@@ -3714,8 +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;
}
@@ -3746,9 +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
@@ -3825,7 +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;
@@ -3842,14 +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) ||
@@ -4399,7 +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");
@@ -4559,7 +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);
@@ -4664,20 +4615,12 @@ void cleanup_module(void)
del_timer_sync(&fd_timer);
blk_cleanup_queue(floppy_queue);
- /*
- * Wait for any asynchronous floppy_release_irq_and_dma()
- * calls to finish first:
- */
- flush_scheduled_work();
-
if (usage_count)
floppy_release_irq_and_dma();
/* 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
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
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
define-__raw_get_cpu_var-and-use-it.patch
ide-cd-end-of-media-error-fix.patch
spin-rwlock-init-cleanups.patch
lock-validator-introduce-warn_on_oncecond.patch
lock-validator-introduce-warn_on_oncecond-speedup.patch
emu10k1-mark-midi_spinlock-as-used.patch
epoll-use-unlocked-wqueue-operations.patch
reintegrate-irqreturnh-into-hardirqh.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_exit-fix-parent-time_slice-calculation.patch
sched_exit-move-the-callsite-to-do_exit.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
rtmutex-modify-rtmutex-tester-to-test-the-setscheduler.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
acpi-reduce-code-size-clean-up-fix-validator-message.patch
lock-validator-special-locking-kgdb.patch
detect-atomic-counter-underflows.patch
debug-shared-irqs.patch
make-frame_pointer-default=y.patch
mutex-subsystem-synchro-test-module.patch
vdso-print-fatal-signals.patch
vdso-improve-print_fatal_signals-support-by-adding-memory-maps.patch
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