- 11 12月, 2008 40 次提交
-
-
由 Jarkko Nikula 提交于
Switch to gpio_request/free calls Cc: linux-usb@vger.kernel.org Acked-by: NDavid Brownell <dbrownell@users.sourceforge.net> Signed-off-by: NJarkko Nikula <jarkko.nikula@nokia.com> Signed-off-by: NTony Lindgren <tony@atomide.com>
-
由 Jarkko Nikula 提交于
Switch to gpio_request/free calls Signed-off-by: NJarkko Nikula <jarkko.nikula@nokia.com> Signed-off-by: NTony Lindgren <tony@atomide.com>
-
由 David Brownell 提交于
Minor GPIO fixes: - If get_gpio_bank() fails, then BUG() out. - In omap_set_gpio_debounce(): * protect the read/modify/write with the relevant spinlock * make the omap3 clock ops pass "sparse" checking Except for the spinlock problem, these were reported through "make". Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net> Signed-off-by: NTony Lindgren <tony@atomide.com>
-
由 Jarkko Nikula 提交于
Clean up OMAP GPIO request/free functions - Rename and declare static OMAP specific GPIO request/free functions - Register them into gpiolib as chip-specific hooks - Add omap_request_gpio/omap_free_gpio wrappers for existing code not converted yet to use gpiolib Signed-off-by: NJarkko Nikula <jarkko.nikula@nokia.com> [ dbrownell@users.sourceforge.net: remove needless check_gpio() calls ] Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net> Signed-off-by: NTony Lindgren <tony@atomide.com>
-
由 David Brownell 提交于
Have most uses of OMAP_GPIO_IRQ() use gpio_to_irq() instead. Calls used for table initialization are left alone, at least this time around. (This patch is for code in both the OMAP tree and mainline.) Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net> Signed-off-by: NTony Lindgren <tony@atomide.com>
-
由 David Brownell 提交于
More conversion to the standard GPIO interfaces: stop using omap_set_gpio_direction() entirely, and switch over to the gpio_direction_output() call. Note that because gpio_direction_output() includes the initial value, this change isn't quite transparent. - For the call sites which defined an initial value either before or after setting the direction, that value was used. When that value was previously assigned afterwards, this could eliminate a brief output glitch ... and possibly change behavior. In a few cases (LCDs) several values were assigned together ... those were re-arranged to match the explicit sequence provided. - Some call sites didn't define such a value; so I chose an initial "off/reset" value that seemed to default to "off". In short, files touched by this patch might notice some small changes in startup behavior (with trivial fixes). Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net> Signed-off-by: NTony Lindgren <tony@atomide.com>
-
由 David Brownell 提交于
More switchover to the cross-platform GPIO interface: use gpio_direction_input(), not an OMAP-specific call. Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net> Signed-off-by: NTony Lindgren <tony@atomide.com>
-
由 David Brownell 提交于
This patch replaces some legacy OMAP GPIO calls with the "new" (not really, any more!) calls that work on most platforms. The calls addressed by this patch are the simple ones to get and set values ... for code that's in mainline, including the implementations of those calls. Except for the declarations and definitions of those calls, all of these changes were performed by a simple SED script. Plus, a few "if() set() else set()" branches were merged by hand. Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net> Signed-off-by: NTony Lindgren <tony@atomide.com>
-
由 David Brownell 提交于
Make OMAP use the new __gpio_to_irq() hook, to make it easier to support IRQs coming in from off-chip gpio controllers like the TWL4030/TPS65930 chip used on OMAP3 boads like Beagleboard.org and the Gumstix Overo. Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net> Signed-off-by: NTony Lindgren <tony@atomide.com>
-
由 Jarkko Nikula 提交于
There are already various drivers having bigger label than 10 bytes. Most of them fit well under 20 bytes but make column width exact so that oversized labels don't mess up output alignment. Signed-off-by: NJarkko Nikula <jarkko.nikula@nokia.com> Acked-by: NDavid Brownell <dbrownell@users.sourceforge.net> Signed-off-by: NTony Lindgren <tony@atomide.com>
-
由 Jouni Hogander 提交于
This patch changes gpio "driver" to enable debounce clock for gpio-bank only when debounce is enabled for some gpio in that bank. Gpio functional clocks are also renamed in clock tree, gpioX_fck -> gpioX_dbck. This patch triggers problem with gpio wake-up and Omap3. Gpios in PER domain aren't capable to generate wake-up if PER domain is in sleep state. For this iopad wake-up should be used and needed pad configuration should be done. Enabling iopad wake-up for gpio pads is left for bootloader or omap mux configuration in kernel. Signed-off-by: NJouni Hogander <jouni.hogander@nokia.com> Acked-by: NPaul Walmsley <paul@pwsan.com> Signed-off-by: NTony Lindgren <tony@atomide.com>
-
由 Linus Torvalds 提交于
-
由 Linus Torvalds 提交于
Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: CPU remove deadlock fix
-
由 Hugh Dickins 提交于
Lee Schermerhorn noticed yesterday that I broke the mapping_writably_mapped test in 2.6.7! Bad bad bug, good good find. The i_mmap_writable count must be incremented for VM_SHARED (just as i_writecount is for VM_DENYWRITE, but while holding the i_mmap_lock) when dup_mmap() copies the vma for fork: it has its own more optimal version of __vma_link_file(), and I missed this out. So the count was later going down to 0 (dangerous) when one end unmapped, then wrapping negative (inefficient) when the other end unmapped. The only impact on x86 would have been that setting a mandatory lock on a file which has at some time been opened O_RDWR and mapped MAP_SHARED (but not necessarily PROT_WRITE) across a fork, might fail with -EAGAIN when it should succeed, or succeed when it should fail. But those architectures which rely on flush_dcache_page() to flush userspace modifications back into the page before the kernel reads it, may in some cases have skipped the flush after such a fork - though any repetitive test will soon wrap the count negative, in which case it will flush_dcache_page() unnecessarily. Fix would be a two-liner, but mapping variable added, and comment moved. Reported-by: NLee Schermerhorn <Lee.Schermerhorn@hp.com> Signed-off-by: NHugh Dickins <hugh@veritas.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
git://git.kernel.org/pub/scm/linux/kernel/git/frob/linux-2.6-roland由 Linus Torvalds 提交于
* 'to-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/frob/linux-2.6-roland: tracehook: exec double-reporting fix
-
由 Manfred Spraul 提交于
The last patch to lib/idr.c caused a bug if idr_get_new_above() was called on an empty idr. Usually, nodes stay on the same layer. New layers are added to the top of the tree. The exception is idr_get_new_above() on an empty tree: In this case, the new root node is first added on layer 0, then moved upwards. p->layer was not updated. As usual: You shall never rely on the source code comments, they will only mislead you. Signed-off-by: NManfred Spraul <manfred@colorfullife.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Akira Takeuchi 提交于
Give the correct size when reserving the interrupt vector table. It should be a page not a single byte. Signed-off-by: NAkira Takeuchi <takeuchi.akr@jp.panasonic.com> Signed-off-by: NDavid Howells <dhowells@redhat.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Akira Takeuchi 提交于
Fix __put_user_asm8() by jumping to the end label (3:) from the exception handler, rather than jumping back to retry the second store instruction (label 2:). Signed-off-by: NAkira Takeuchi <takeuchi.akr@jp.panasonic.com> Signed-off-by: NDavid Howells <dhowells@redhat.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Akira Takeuchi 提交于
Fix the preemption resume_kernel() routine by inverting the test to see whether interrupts are off (IM7 is all enabled, not all disabled). Furthermore, interrupts should be disabled on entry to resume_kernel() so that they're correctly set for jumping to restore_all() and doing the need reschedule test. Signed-off-by: NAkira Takeuchi <takeuchi.akr@jp.panasonic.com> Signed-off-by: NDavid Howells <dhowells@redhat.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Akira Takeuchi 提交于
Discard low-prioriy Tx interrupts when closing an MN10300 on-chip serial port. The MN10300 on-chip serial port uses three interrupts to manage its serial ports: (1) A very high priority interrupt that drives virtual DMA for Rx. (2) A very high priority interrupt that drives virtual DMA for Tx. (3) A normal priority virtual interrupt that does the normal UART interrupt stuff and is shared between Rx and Tx. mn10300_serial_stop_tx() only disables the high priority Tx interrupt. It doesn't also disable the normal priority one because it is shared with Rx. However, the high priority interrupt may interrupt local_irq_disabled() sections, and so may have queued up a low priority virtual interrupt whilst the UART driver is asking for the Tx interrupt to be disabled. The result of this can be an oops when we try to process the interrupt in mn10300_serial_transmit_interrupt() as port->uart.info and port->uart.info->tty may have gone away. To deal with this, if either of those pointers is NULL, we make sure the high-priority Tx interrupt is disabled and discard the interrupt. The low priority interrupt is disabled by the mn10300_serial_pic irq_chip table. Signed-off-by: NAkira Takeuchi <takeuchi.akr@jp.panasonic.com> Signed-off-by: NDavid Howells <dhowells@redhat.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Cyrill Gorcunov 提交于
Include the linux/page.h header into the MN10300 kernel linker script thus allowing us to use PAGE_SIZE macro instead of a numeric constant. Also use the PERCPU macro instead of an explicit section definition. Signed-off-by: NCyrill Gorcunov <gorcunov@gmail.com> Signed-off-by: NDavid Howells <dhowells@redhat.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6由 Linus Torvalds 提交于
* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: crypto: api - Disallow cryptomgr as a module if algorithms are built-in
-
git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6由 Linus Torvalds 提交于
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6: PCIe: ASPM: Break out of endless loop waiting for PCI config bits to switch PCI: stop leaking 'slot_name' in pci_create_slot
-
git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6由 Linus Torvalds 提交于
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6: [IA64] SN: prevent IRQ retargetting in request_irq() [IA64] Fix section mismatch ioc3uart_init()/ioc3uart_submodule [IA64] Clear up section mismatch for ioc4_ide_attach_one. [IA64] Clear up section mismatch with arch_unregister_cpu() [IA64] Clear up section mismatch for sn_check_wars. [IA64] Updated the generic_defconfig to work with the 2.6.28-rc7 kernel. [IA64] Fix GRU compile error w/o CONFIG_HUGETLB_PAGE [IA64] eliminate NULL test and memset after alloc_bootmem [IA64] remove BUILD_BUG_ON from paravirt_getreg()
-
git://ftp.linux-mips.org/pub/scm/upstream-linus由 Linus Torvalds 提交于
* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus: MIPS: Better than nothing implementation of PCI mmap to fix X.
-
由 Kay Sievers 提交于
The pktcdvd created class devices only export some sysfs files, but have no char dev_t registered in the driver. At class device creation time they copy the dev_t value of the block device to the char device, wich will register a new char device in the driver core and userspace, with a conflicting dev_t value. In many cases the class devices dev_t just points to a random USB device. This fixes the sysfs "duplicate entry" errors. Signed-off-by: NKay Sievers <kay.sievers@vrfy.org> Acked-by: NPeter Osterlund <petero2@telia.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6由 Linus Torvalds 提交于
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6: firewire: fw-ohci: fix IOMMU resource exhaustion ieee1394: node manager causes up to ~3.25s delay in freezing tasks
-
由 Andrew Morton 提交于
sparc64: drivers/video/mb862xx/mb862xxfb.c:929: warning: long long unsigned int format, resource_size_t arg (arg 4) drivers/video/mb862xx/mb862xxfb.c:931: warning: long long unsigned int format, resource_size_t arg (arg 4) We don't know what type the architecture uses to implement u64, hence they cannot be printed. Cc: Anatolij Gustschin <agust@denx.de> Cc: Dmitry Baryshkov <dbaryshkov@gmail.com> Cc: Anton Vorontsov <avorontsov@ru.mvista.com> Cc: Matteo Fortini <m.fortini@selcomgroup.com> Cc: Krzysztof Helt <krzysztof.h1@poczta.fm> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Hugh Dickins 提交于
Miles Lane tailing /sys files hit a BUG which Pekka Enberg has tracked to my 966c8c12 sprint_symbol(): use less stack exposing a bug in slub's list_locations() - kallsyms_lookup() writes a 0 to namebuf[KSYM_NAME_LEN-1], but that was beyond the end of page provided. The 100 slop which list_locations() allows at end of page looks roughly enough for all the other stuff it might print after the symbol before it checks again: break out KSYM_SYMBOL_LEN earlier than before. Latencytop and ftrace and are using KSYM_NAME_LEN buffers where they need KSYM_SYMBOL_LEN buffers, and vmallocinfo a 2*KSYM_NAME_LEN buffer where it wants a KSYM_SYMBOL_LEN buffer: fix those before anyone copies them. [akpm@linux-foundation.org: ftrace.h needs module.h] Signed-off-by: NHugh Dickins <hugh@veritas.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc Miles Lane <miles.lane@gmail.com> Acked-by: NPekka Enberg <penberg@cs.helsinki.fi> Acked-by: NSteven Rostedt <srostedt@redhat.com> Acked-by: NFrederic Weisbecker <fweisbec@gmail.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Dmitri Monakhov 提交于
On umount two event will be dispatched to watcher: 1: inotify_dev_queue_event(.., IN_UNMOUNT,..) 2: remove_watch(watch, dev) ->inotify_dev_queue_event(.., IN_IGNORED, ..) But if watcher has IN_ONESHOT bit set then the watcher will be released inside first event. Which result in accessing invalid object later. IMHO it is not pure regression. This bug wasn't triggered while initial inotify interface testing phase because of another bug in IN_ONESHOT handling logic :) commit ac74c00e Author: Ulisses Furquim <ulissesf@gmail.com> Date: Fri Feb 8 04:18:16 2008 -0800 inotify: fix check for one-shot watches before destroying them As the IN_ONESHOT bit is never set when an event is sent we must check it in the watch's mask and not in the event's mask. TESTCASE: mkdir mnt mount -ttmpfs none mnt mkdir mnt/d ./inotify mnt/d& umount mnt ## << lockup or crash here TESTSOURCE: /* gcc -oinotify inotify.c */ #include <stdio.h> #include <stdlib.h> #include <sys/inotify.h> int main(int argc, char **argv) { char buf[1024]; struct inotify_event *ie; char *p; int i; ssize_t l; p = argv[1]; i = inotify_init(); inotify_add_watch(i, p, ~0); l = read(i, buf, sizeof(buf)); printf("read %d bytes\n", l); ie = (struct inotify_event *) buf; printf("event mask: %d\n", ie->mask); return 0; } Signed-off-by: NDmitri Monakhov <dmonakhov@openvz.org> Cc: John McCutchan <ttb@tentacle.dhs.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Robert Love <rlove@google.com> Cc: Ulisses Furquim <ulissesf@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Eric Dumazet 提交于
atomic_long_xchg() is not correctly defined for 32bit arches. Signed-off-by: NEric Dumazet <dada1@cosmosbay.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Brice Goglin 提交于
Since commit 2f007e74, do_pages_stat() gets the page address from user-space and puts the corresponding status back while holding the mmap_sem for read. There is no need to hold mmap_sem there while some page-faults may occur. This patch adds a temporary address and status buffer so as to only hold mmap_sem while working on these kernel buffers. This is implemented by extracting do_pages_stat_array() out of do_pages_stat(). Signed-off-by: NBrice Goglin <Brice.Goglin@inria.fr> Cc: Christoph Lameter <clameter@sgi.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Balaji Rao 提交于
Signed-off-by: NBalaji Rao <balajirrao@gmail.com> Acked-by: NBen Dooks <ben-linux@fluff.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Matt Mackall 提交于
The large pages fix from bcf8039e broke 32-bit pagemap by pulling the pagemap entry code out into a function with the wrong return type. Pagemap entries are 64 bits on all systems and unsigned long is only 32 bits on 32-bit systems. Signed-off-by: NMatt Mackall <mpm@selenic.com> Reported-by: NDoug Graham <dgraham@nortel.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Cc: <stable@kernel.org> [2.6.26.x, 2.6.27.x] Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 KAMEZAWA Hiroyuki 提交于
Fix a total bootup freeze on ia64. Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Tested-by: NLi Zefan <lizf@cn.fujitsu.com> Reported-by: NLi Zefan <lizf@cn.fujitsu.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Randy Dunlap 提交于
Fix build error when RTC_INTF_DEV=n: drivers/rtc/rtc-twl4030.c:402: error: 'twl4030_rtc_ioctl' undeclared here (not in a function) make[3]: *** [drivers/rtc/rtc-twl4030.o] Error 1 Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com> Cc: David Brownell <dbrownell@users.sourceforge.net> Cc: Tony Lindgren <tony@atomide.com> Cc: Samuel Ortiz <sameo@openedhand.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Geoff Levand 提交于
Add a call to cancel_work_sync() in fbcon_exit() to cancel any pending work in the fbcon workqueue. The current implementation of fbcon_exit() sets the fbcon workqueue function info->queue.func to NULL, but does not assure that there is no work pending when it does so. On occasion, depending on system timing, there will still be pending work in the queue when fbcon_exit() is called. This results in a null pointer deference when run_workqueue() tries to call the queue's work function. Fixes errors on shutdown similar to these: Console: switching to colour dummy device 80x25 Unable to handle kernel paging request for data at address 0x00000000 Signed-off-by: NGeoff Levand <geoffrey.levand@am.sony.com> Cc: Krzysztof Helt <krzysztof.h1@poczta.fm> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 KOSAKI Motohiro 提交于
Currently, lru_add_drain_all() has two version. (1) use schedule_on_each_cpu() (2) don't use schedule_on_each_cpu() Gerald Schaefer reported it doesn't work well on SMP (not NUMA) S390 machine. offline_pages() calls lru_add_drain_all() followed by drain_all_pages(). While drain_all_pages() works on each cpu, lru_add_drain_all() only runs on the current cpu for architectures w/o CONFIG_NUMA. This let us run into the BUG_ON(!PageBuddy(page)) in __offline_isolated_pages() during memory hotplug stress test on s390. The page in question was still on the pcp list, because of a race with lru_add_drain_all() and drain_all_pages() on different cpus. Actually, Almost machine has CONFIG_UNEVICTABLE_LRU=y. Then almost machine use (1) version lru_add_drain_all although the machine is UP. Then this ifdef is not valueable. simple removing is better. Signed-off-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com> Acked-by: NGerald Schaefer <gerald.schaefer@de.ibm.com> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Andrew Morton 提交于
Revert commit e8ced39d Author: Mingming Cao <cmm@us.ibm.com> Date: Fri Jul 11 19:27:31 2008 -0400 percpu_counter: new function percpu_counter_sum_and_set As described in revert "percpu counter: clean up percpu_counter_sum_and_set()" the new percpu_counter_sum_and_set() is racy against updates to the cpu-local accumulators on other CPUs. Revert that change. This means that ext4 will be slow again. But correct. Reported-by: NEric Dumazet <dada1@cosmosbay.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mingming Cao <cmm@us.ibm.com> Cc: <linux-ext4@vger.kernel.org> Cc: <stable@kernel.org> [2.6.27.x] Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Andrew Morton 提交于
Revert commit 1f7c14c6 Author: Mingming Cao <cmm@us.ibm.com> Date: Thu Oct 9 12:50:59 2008 -0400 percpu counter: clean up percpu_counter_sum_and_set() Before this patch we had the following: percpu_counter_sum(): return the percpu_counter's value percpu_counter_sum_and_set(): return the percpu_counter's value, copying that value into the central value and zeroing the per-cpu counters before returning. After this patch, percpu_counter_sum_and_set() has gone, and percpu_counter_sum() gets the old percpu_counter_sum_and_set() functionality. Problem is, as Eric points out, the old percpu_counter_sum_and_set() functionality was racy and wrong. It zeroes out counters on "other" cpus, without holding any locks which will prevent races agaist updates from those other CPUS. This patch reverts 1f7c14c6. This means that percpu_counter_sum_and_set() still has the race, but percpu_counter_sum() does not. Note that this is not a simple revert - ext4 has since started using percpu_counter_sum() for its dirty_blocks counter as well. Note that this revert patch changes percpu_counter_sum() semantics. Before the patch, a call to percpu_counter_sum() will bring the counter's central counter mostly up-to-date, so a following percpu_counter_read() will return a close value. After this patch, a call to percpu_counter_sum() will leave the counter's central accumulator unaltered, so a subsequent call to percpu_counter_read() can now return a significantly inaccurate result. If there is any code in the tree which was introduced after e8ced39d was merged, and which depends upon the new percpu_counter_sum() semantics, that code will break. Reported-by: NEric Dumazet <dada1@cosmosbay.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mingming Cao <cmm@us.ibm.com> Cc: <linux-ext4@vger.kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-