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2009-04-07hwmon: add support for GMT G760A fan speed PWM controllerHerbert Valerio Riedel
This controller can be found on the D-Link DNS-323 for instance, where it is to be configured via static i2c_board_info in the board-specific mach-orion/dns323-setup.c; this driver supports only the new-style driver model. Tested-by: Martin Michlmayr <tbm@cyrius.com> Signed-off-by: Herbert Valerio Riedel <hvr@gnu.org> Signed-off-by: Matthew Palmer <mpalmer@debian.org> Signed-off-by: Laurie Bradshaw <bradshaw.laurie@googlemail.com> Signed-off-by: Martin Michlmayr <tbm@cyrius.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-07mm: add /proc controls for pdflush threadsPeter W Morreale
Add /proc entries to give the admin the ability to control the minimum and maximum number of pdflush threads. This allows finer control of pdflush on both large and small machines. The rationale is simply one size does not fit all. Admins on large and/or small systems may want to tune the min/max pdflush thread count to best suit their needs. Right now the min/max is hardcoded to 2/8. While probably a fair estimate for smaller machines, large machines with large numbers of CPUs and large numbers of filesystems/block devices may benefit from larger numbers of threads working on different block devices. Even if the background flushing algorithm is radically changed, it is still likely that multiple threads will be involved and admins would still desire finer control on the min/max other than to have to recompile the kernel. The patch adds '/proc/sys/vm/nr_pdflush_threads_min' and '/proc/sys/vm/nr_pdflush_threads_max' with r/w permissions. The minimum value for nr_pdflush_threads_min is 1 and the maximum value is the current value of nr_pdflush_threads_max. This minimum is required since additional thread creation is performed in a pdflush thread itself. The minimum value for nr_pdflush_threads_max is the current value of nr_pdflush_threads_min and the maximum value can be 1000. Documentation/sysctl/vm.txt is also updated. [akpm@linux-foundation.org: fix comment, fix whitespace, use __read_mostly] Signed-off-by: Peter W Morreale <pmorreale@novell.com> Reviewed-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-06Merge branch 'for_linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6 * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6: (120 commits) cx231xx: Convert to snd_card_create() V4L/DVB (11440): PWC: fix build error when CONFIG_INPUT=m V4L/DVB (11439): UVC: uvc_status_cleanup(): undefined reference to `input_unregister_device' V4L/DVB (11438): au0828: fix Kconfig dependance V4L/DVB (11437): pvrusb2: Drop client_register/unregister stubs V4L/DVB (11436): radio-mr800: convert to to v4l2_device V4L/DVB (11435): dsbr100 radio: convert to to v4l2_device V4L/DVB: zr364xx: remove unused #include <version.h> V4L/DVB: usbvision: remove unused #include <version.h> V4L/DVB (11427): gspca - m5602: Minor cleanups V4L/DVB (11426): gspca - m5602: Don't touch hflip/vflip register on Read/Modify/Write V4L/DVB (11425): gspca - m5602: Move the vflip quirk to probe stage. V4L/DVB (11424): gspca - m5602-ov9650: Use the local ctrl cache. Adjust image on vflip. V4L/DVB (11423): gspca - m5602-ov9650: Add a disconnect hook, setup a ctrl cache ctrl. V4L/DVB (11422): gspca - m5602-ov9650: Replace a magic constant with a define V4L/DVB (11421): gspca - m5602-ov9650: Synthesize modesetting. V4L/DVB (11420): gspca - m5602: Improve error handling in the ov9650 driver V4L/DVB (11419): gspca - m5602-ov9650: Don't read exposure data from COM1. V4L/DVB (11418): gspca - m5602-ov9650: Auto white balancing is on by default V4L/DVB (11417): gspca - m5602-ov9650: Autogain is on by default ...
2009-04-06Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: b44: Use kernel DMA addresses for the kernel DMA API forcedeth: Fix resume from hibernation regression. xfrm: fix fragmentation on inter family tunnels ibm_newemac: Fix dangerous struct assumption gigaset: documentation update gigaset: in file ops, check for device disconnect before anything else bas_gigaset: use tasklet_hi_schedule for timing critical tasklets net/802/fddi.c: add MODULE_LICENSE smsc911x: remove unused #include <linux/version.h> axnet_cs: fix phy_id detection for bogus Asix chip. bnx2: Use request_firmware() b44: Fix sizes passed to b44_sync_dma_desc_for_{device,cpu}() socket: use percpu_add() while updating sockets_in_use virtio_net: Set the mac config only when VIRITO_NET_F_MAC myri_sbus: use request_firmware e1000: fix loss of multicast packets vxge: should include tcp.h Conflict in firmware/WHENCE (SCSI vs net firmware)
2009-04-06V4L/DVB (11373): v4l2-common: add explicit v4l2_device pointer as first arg ↵Hans Verkuil
to new_(probed)_subdev The functions v4l2_i2c_new_subdev and v4l2_i2c_new_probed_subdev relied on i2c_get_adapdata to return the v4l2_device. However, this is not always possible on embedded platforms. So modify the API to pass the v4l2_device pointer explicitly. Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2009-04-06V4L/DVB (11367): v4l2-common: remove legacy codeHans Verkuil
Now that all drivers are converted to v4l2_subdev we can remove legacy code in v4l2-common. Also move the documentation of the internal API to v4l2-subdev.h where it really belongs. Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2009-04-06V4L/DVB (11351): v4l: use usb_interface for v4l2_device_registerJanne Grunau
If usb_interface.dev is used as dev parameter for v4l2_device_register v4l2_dev.name contains the v4l driver/module name and usb device and interface instead of a simple "usb x-y". It also matches the recommendation to set the parent devices for usb drivers. Signed-off-by: Janne Grunau <j@jannau.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2009-04-06V4L/DVB (11321): pxa_camera: Redesign DMA handlingRobert Jarzmik
The DMA transfers in pxa_camera showed some weaknesses in multiple queued buffers context : - poll/select problem The bug shows up with capture_example tool from v4l2 hg tree. The process just "stalls" on a "select timeout". - multiple buffers DMA starting When multiple buffers were queued, the DMA channels were always started right away. This is not optimal, as a special case appears when the first EOF was not yet reached, and the DMA channels were prematurely started. - Maintainability DMA code was a bit obfuscated. Rationalize the code to be easily maintainable by anyone. - DMA hot chaining DMA is not stopped anymore to queue a buffer, the buffer is queued with DMA running. As a tribute, a corner case exists where chaining happens while DMA finishes the chain, and the capture is restarted to deal with the missed link buffer. This patch attemps to address these issues / improvements. create mode 100644 Documentation/video4linux/pxa_camera.txt Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2009-04-06gigaset: documentation updateTilman Schmidt
Update, correct and clarify instructions for loading the driver and for setting the UNDOCREQ kernel configuration option. Impact: documentation Signed-off-by: Tilman Schmidt <tilman@imap.cc> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-06Merge git://git.infradead.org/mtd-2.6Linus Torvalds
* git://git.infradead.org/mtd-2.6: (53 commits) [MTD] struct device - replace bus_id with dev_name(), dev_set_name() [MTD] [NOR] Fixup for Numonyx M29W128 chips [MTD] mtdpart: Make ecc_stats more realistic. powerpc/85xx: TQM8548: Update DTS file for multi-chip support powerpc: NAND: FSL UPM: document new bindings [MTD] [NAND] FSL-UPM: Add wait flags to support board/chip specific delays [MTD] [NAND] FSL-UPM: add multi chip support [MTD] [NOR] Add device parent info to physmap_of [MTD] [NAND] Add support for NAND on the Socrates board [MTD] [NAND] Add support for 4KiB pages. [MTD] sysfs support should not depend on CONFIG_PROC_FS [MTD] [NAND] Add parent info for CAFÉ controller [MTD] support driver model updates [MTD] driver model updates (part 2) [MTD] driver model updates [MTD] [NAND] move gen_nand's probe function to .devinit.text [MTD] [MAPS] move sa1100 flash's probe function to .devinit.text [MTD] fix use after free in register_mtd_blktrans [MTD] [MAPS] Drop now unused sharpsl-flash map [MTD] ofpart: Check name property to determine partition nodes. ... Manually fix trivial conflict in drivers/mtd/maps/Makefile
2009-04-06LANANA: Fix datesAlan Cox
As noted by Janne Grunau it would be good if the date was also right. (Web site also resynched) Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-06docs: alphabetize entries in kernel-parameters.txtRandy Dunlap
Move entries to be in alpha order as specified near the beginning of this file. Clean up some whitespace and line-length miscues. Add '=' to "selinux" option syntax. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-06docbook: fix fatal filename errorRandy Dunlap
Fix docbook fatal error: docproc: block/blktrace.c: No such file or directory Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-06Merge branch 'for-2.6.30' of git://linux-nfs.org/~bfields/linuxLinus Torvalds
* 'for-2.6.30' of git://linux-nfs.org/~bfields/linux: (81 commits) nfsd41: define nfsd4_set_statp as noop for !CONFIG_NFSD_V4 nfsd41: define NFSD_DRC_SIZE_SHIFT in set_max_drc nfsd41: Documentation/filesystems/nfs41-server.txt nfsd41: CREATE_EXCLUSIVE4_1 nfsd41: SUPPATTR_EXCLCREAT attribute nfsd41: support for 3-word long attribute bitmask nfsd: dynamically skip encoded fattr bitmap in _nfsd4_verify nfsd41: pass writable attrs mask to nfsd4_decode_fattr nfsd41: provide support for minor version 1 at rpc level nfsd41: control nfsv4.1 svc via /proc/fs/nfsd/versions nfsd41: add OPEN4_SHARE_ACCESS_WANT nfs4_stateid bmap nfsd41: access_valid nfsd41: clientid handling nfsd41: check encode size for sessions maxresponse cached nfsd41: stateid handling nfsd: pass nfsd4_compound_state* to nfs4_preprocess_{state,seq}id_op nfsd41: destroy_session operation nfsd41: non-page DRC for solo sequence responses nfsd41: Add a create session replay cache nfsd41: create_session operation ...
2009-04-06Merge branch 'i2c-for-linus' of git://jdelvare.pck.nerim.net/jdelvare-2.6Linus Torvalds
* 'i2c-for-linus' of git://jdelvare.pck.nerim.net/jdelvare-2.6: i2c: Delete unused i2c-algo-sgi helper module i2c: Delete many unused driver IDs i2c: Deprecate client_register and client_unregister methods
2009-04-06Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (74 commits) [SCSI] sg: fix q->queue_lock on scsi_error_handler path [SCSI] replace __inline with inline [SCSI] a2091: make 2 functions static [SCSI] a3000: make 2 functions static [SCSI] ses: #if 0 the unused ses_match_host() [SCSI] use kmem_cache_zalloc instead of kmem_cache_alloc/memset [SCSI] sg: fix iovec bugs introduced by the block layer conversion [SCSI] qlogicpti: use request_firmware [SCSI] advansys: use request_firmware [SCSI] qla1280: use request_firmware [SCSI] libiscsi: fix iscsi pool error path [SCSI] cxgb3i: call ddp release function directly [SCSI] cxgb3i: merge cxgb3i_ddp into cxgb3i module [SCSI] cxgb3i: close all tcp connections upon chip reset [SCSI] cxgb3i: re-read ddp settings information after chip reset [SCSI] cxgb3i: re-initialize ddp settings after chip reset [SCSI] cxgb3i: subscribe to error notification from cxgb3 driver [SCSI] aacraid driver update [SCSI] mptsas: remove unneeded check [SCSI] config: Make need for SCSI_CDROM clearer ...
2009-04-06i2c: Deprecate client_register and client_unregister methodsJean Delvare
The new i2c binding model makes the client_register and client_unregister methods of struct i2c_adapter useless, so we can remove them with the rest of the legacy model. Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-04-06leds: Add openfirmware platform device supportTrent Piepho
Add bindings to support LEDs defined as of_platform devices in addition to the existing bindings for platform devices. New options in Kconfig allow the platform binding code and/or the of_platform code to be turned on. The of_platform code is of course only available on archs that have OF support. The existing probe and remove methods are refactored to use new functions create_gpio_led(), to create and register one led, and delete_gpio_led(), to unregister and free one led. The new probe and remove methods for the of_platform driver can then share most of the common probe and remove code with the platform driver. The suspend and resume methods aren't shared, but they are very short. The actual led driving code is the same for LEDs created by either binding. The OF bindings are based on patch by Anton Vorontsov <avorontsov@ru.mvista.com>. They have been extended to allow multiple LEDs per device. Signed-off-by: Trent Piepho <tpiepho@freescale.com> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Sean MacLennan <smaclennan@pikatech.com> Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
2009-04-06powerpc: NAND: FSL UPM: document new bindingsWolfgang Grandegger
This patch adds documentation for the new NAND FSL UPM bindings for: NAND: FSL-UPM: add multi chip support NAND: FSL-UPM: Add wait flags to support board/chip specific delays It also documents the old binding for "chip-delay". Signed-off-by: Wolfgang Grandegger <wg@grandegger.com> Acked-by: Anton Vorontsov <avorontsov@ru.mvista.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-04-05Merge branch 'release' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6 * 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6: (140 commits) ACPI: processor: use .notify method instead of installing handler directly ACPI: button: use .notify method instead of installing handler directly ACPI: support acpi_device_ops .notify methods toshiba-acpi: remove MAINTAINERS entry ACPI: battery: asynchronous init acer-wmi: Update copyright notice & documentation acer-wmi: Cleanup the failure cleanup handling acer-wmi: Blacklist Acer Aspire One video: build fix thinkpad-acpi: rework brightness support thinkpad-acpi: enhanced debugging messages for the fan subdriver thinkpad-acpi: enhanced debugging messages for the hotkey subdriver thinkpad-acpi: enhanced debugging messages for rfkill subdrivers thinkpad-acpi: restrict access to some firmware LEDs thinkpad-acpi: remove HKEY disable functionality thinkpad-acpi: add new debug helpers and warn of deprecated atts thinkpad-acpi: add missing log levels thinkpad-acpi: cleanup debug helpers thinkpad-acpi: documentation cleanup thinkpad-acpi: drop ibm-acpi alias ...
2009-04-05Merge git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6: (23 commits) sh: sh7785lcr: Map whole PCI address space. sh: Fix up DSP context save/restore. sh: Fix up number of on-chip DMA channels on SH7091. sh: update defconfigs. sh: Kill off broken direct-mapped cache mode. sh: Wire up ARCH_HAS_DEFAULT_IDLE for cpuidle. sh: Add a command line option for disabling I/O trapping. sh: Select ARCH_HIBERNATION_POSSIBLE. sh: migor: Fix up CEU use flags. input: migor_ts: add wakeup support rtc: rtc-sh: use set_irq_wake() input: sh_keysc: use enable/disable_irq_wake() sh: intc: set_irq_wake() support sh: intc: install enable, disable and shutdown callbacks clocksource: sh_cmt: use remove_irq() and remove clockevent workaround sh: ap325 and Migo-R use new sh_mobile_ceu_info flags sh: Fix up -Wformat-security whining. sh: ap325rxa: Add ov772x support, again. sh: Sanitize asm/mmu.h for assembly use. sh: Tidy up sh7786 pinmux table. ...
2009-04-05Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging-2.6: (714 commits) Staging: sxg: slicoss: Specify the license for Sahara SXG and Slicoss drivers Staging: serqt_usb: fix build due to proc tty changes Staging: serqt_usb: fix checkpatch errors Staging: serqt_usb: add TODO file Staging: serqt_usb: Lindent the code Staging: add USB serial Quatech driver staging: document that the wifi staging drivers a bit better Staging: echo cleanup Staging: BUG to BUG_ON changes Staging: remove some pointless conditionals before kfree_skb() Staging: line6: fix build error, select SND_RAWMIDI Staging: line6: fix checkpatch errors in variax.c Staging: line6: fix checkpatch errors in toneport.c Staging: line6: fix checkpatch errors in pcm.c Staging: line6: fix checkpatch errors in midibuf.c Staging: line6: fix checkpatch errors in midi.c Staging: line6: fix checkpatch errors in dumprequest.c Staging: line6: fix checkpatch errors in driver.c Staging: line6: fix checkpatch errors in audio.c Staging: line6: fix checkpatch errors in pod.c ...
2009-04-05Merge branch 'tracing-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (413 commits) tracing, net: fix net tree and tracing tree merge interaction tracing, powerpc: fix powerpc tree and tracing tree interaction ring-buffer: do not remove reader page from list on ring buffer free function-graph: allow unregistering twice trace: make argument 'mem' of trace_seq_putmem() const tracing: add missing 'extern' keywords to trace_output.h tracing: provide trace_seq_reserve() blktrace: print out BLK_TN_MESSAGE properly blktrace: extract duplidate code blktrace: fix memory leak when freeing struct blk_io_trace blktrace: fix blk_probes_ref chaos blktrace: make classic output more classic blktrace: fix off-by-one bug blktrace: fix the original blktrace blktrace: fix a race when creating blk_tree_root in debugfs blktrace: fix timestamp in binary output tracing, Text Edit Lock: cleanup tracing: filter fix for TRACE_EVENT_FORMAT events ftrace: Using FTRACE_WARN_ON() to check "freed record" in ftrace_release() x86: kretprobe-booster interrupt emulation code fix ... Fix up trivial conflicts in arch/parisc/include/asm/ftrace.h include/linux/memory.h kernel/extable.c kernel/module.c
2009-04-05Merge branch 'core/debugobjects' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core/debugobjects' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: debugobjects: delay free of internal objects debugobjects: replace static objects when slab cache becomes available debug_objects: add boot-parameter toggle to turn object debugging off again
2009-04-05Merge branch 'linus' into releaseLen Brown
Conflicts: arch/x86/kernel/cpu/cpufreq/longhaul.c Signed-off-by: Len Brown <len.brown@intel.com>
2009-04-05Merge branch 'acpi_enforce_resources' into releaseLen Brown
2009-04-05Merge branch 'thinkpad-acpi' into releaseLen Brown
2009-04-04acer-wmi: Update copyright notice & documentationCarlos Corbacho
Explicitly note in the documentation that the Acer Aspire One is not supported. Signed-off-by: Carlos Corbacho <carlos@strangeworlds.co.uk> Signed-off-by: Len Brown <len.brown@intel.com>
2009-04-04thinkpad-acpi: rework brightness supportHenrique de Moraes Holschuh
Refactor and redesign the brightness control backend... In order to fix bugzilla #11750... Add a new brightness control mode: support direct NVRAM checkpointing of the backlight level (i.e. store directly to NVRAM without the need for UCMS calls), and use that together with the EC-based control. Disallow UCMS+EC, thus avoiding races with the SMM firmware. Switch the models that define HBRV (EC Brightness Value) in the DSDT to the new mode. These are: T40-T43, R50-R52, R50e, R51e, X31-X41. Change the default for all other IBM ThinkPads to UCMS-only. The Lenovo models already default to UCMS-only. Reported-by: Alexey Fisher <bug-track@fisher-privat.net> Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Signed-off-by: Len Brown <len.brown@intel.com>
2009-04-04thinkpad-acpi: enhanced debugging messages for the fan subdriverHenrique de Moraes Holschuh
Enhance debugging messages for the fan subdriver. Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Signed-off-by: Len Brown <len.brown@intel.com>
2009-04-04thinkpad-acpi: enhanced debugging messages for the hotkey subdriverHenrique de Moraes Holschuh
Enhance debugging messages for the hotkey subdriver. Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Signed-off-by: Len Brown <len.brown@intel.com>
2009-04-04thinkpad-acpi: enhanced debugging messages for rfkill subdriversHenrique de Moraes Holschuh
Enhance debugging messages for all rfkill subdrivers in thinkpad-acpi. Also, log a warning if the deprecated sysfs attributes are in use. These attributes are going to be removed sometime in 2010. There is an user-visible side-effect: we now coalesce attempts to enable/disable bluetooth or WWAN in the procfs interface, instead of hammering the firmware with multiple requests. Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Signed-off-by: Len Brown <len.brown@intel.com>
2009-04-04thinkpad-acpi: restrict access to some firmware LEDsHenrique de Moraes Holschuh
Some of the ThinkPad LEDs indicate critical conditions that can cause data loss or cause hardware damage when ignored (e.g. force-ejecting a powered up bay; ignoring a failing battery, or empty battery; force- undocking with the dock buses still active, etc). On almost all ThinkPads, LED access is write-only, and the firmware usually does fire-and-forget signaling on them, so you effectively lose whatever message the firmware was trying to convey to the user when you override the LED state, without any chance to restore it. Restrict access to all LEDs that can convey important alarms, or that could mislead the user into incorrectly operating the hardware. This will make the Lenovo engineers less unhappy about the whole issue. Allow users that really want it to still control all LEDs, it is the unaware user that we have to worry about. Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Signed-off-by: Len Brown <len.brown@intel.com>
2009-04-04thinkpad-acpi: remove HKEY disable functionalityHenrique de Moraes Holschuh
The HKEY disable functionality basically cripples the entire event model of the ThinkPad firmware and of the thinkpad-acpi driver. Remove this functionality from the driver. HKEY must be enabled at all times while thinkpad-acpi is loaded, and disabled otherwise. For sysfs, according to the sysfs ABI and the thinkpad-acpi sysfs rules of engagement, we will just remove the attributes. This will be done in two stages: disable their function now, after two kernel releases, remove the attributes. For procfs, we call WARN(). If nothing triggers it, I will simply remove the enable/disable commands entirely in the future along with the sysfs attributes. I don't expect much, if any fallout from this. There really isn't any reason to mess with hotkey_enable or with the enable/disable commands to /proc/acpi/ibm/hotkey, and this has been true for years... Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Signed-off-by: Len Brown <len.brown@intel.com>
2009-04-04thinkpad-acpi: add new debug helpers and warn of deprecated attsHenrique de Moraes Holschuh
Add a debug helper that discloses the TGID of the userspace task attempting to access the driver. This is highly useful when dealing with bug reports, since often the user has no idea that some userspace application is accessing thinkpad-acpi... Also add a helper to log warnings about sysfs attributes that are deprecated. Use the new helpers to issue deprecation warnings for bluetooth_enable and wwan_enabled, that have been deprecated for a while, now. Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Signed-off-by: Len Brown <len.brown@intel.com>
2009-04-04thinkpad-acpi: documentation cleanupHenrique de Moraes Holschuh
Some cleanups to the documentation of the driver. Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Signed-off-by: Len Brown <len.brown@intel.com>
2009-04-03nfsd41: Documentation/filesystems/nfs41-server.txtBenny Halevy
Initial nfs41 server write up describing the status of the linux server implementation. [nfsd41: document unenforced nfs41 compound ordering rules.] [get rid of CONFIG_NFSD_V4_1] Signed-off-by: Benny Halevy <bhalevy@panasas.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-04-03LANANA: Change of management and resyncAlan Cox
Bring the devices.txt back into some relationship with reality. Update the documentation a bit. Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-03Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid: HID: remove compat stuff HID: constify arrays of struct apple_key_translation HID: add support for Kye/Genius Ergo 525V HID: Support Apple mini aluminum keyboard HID: support for Kensington slimblade device HID: DragonRise game controller force feedback driver HID: add support for another version of 0e8f:0003 device in hid-pl HID: fix race between usb_register_dev() and hiddev_open() HID: bring back possibility to specify vid/pid ignore on module load HID: make HID_DEBUG defaults consistent HID: autosuspend -- fix lockup of hid on reset HID: hid_reset_resume() needs to be defined only when CONFIG_PM is set HID: fix USB HID devices after STD with autosuspend HID: do not try to compile PM code with CONFIG_PM unset HID: autosuspend support for USB HID
2009-04-03Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (28 commits) trivial: Update my email address trivial: NULL noise: drivers/mtd/tests/mtd_*test.c trivial: NULL noise: drivers/media/dvb/frontends/drx397xD_fw.h trivial: Fix misspelling of "Celsius". trivial: remove unused variable 'path' in alloc_file() trivial: fix a pdlfush -> pdflush typo in comment trivial: jbd header comment typo fix for JBD_PARANOID_IOFAIL trivial: wusb: Storage class should be before const qualifier trivial: drivers/char/bsr.c: Storage class should be before const qualifier trivial: h8300: Storage class should be before const qualifier trivial: fix where cgroup documentation is not correctly referred to trivial: Give the right path in Documentation example trivial: MTD: remove EOL from MODULE_DESCRIPTION trivial: Fix typo in bio_split()'s documentation trivial: PWM: fix of #endif comment trivial: fix typos/grammar errors in Kconfig texts trivial: Fix misspelling of firmware trivial: cgroups: documentation typo and spelling corrections trivial: Update contact info for Jochen Hein trivial: fix typo "resgister" -> "register" ...
2009-04-03Staging: pohmelfs: documentation.Evgeniy Polyakov
This patch includes POHMELFS design and implementation description. Separate file includes mount options, default parameters and usage examples. Signed-off-by: Eveniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-04-03Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/lrg/voltage-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lrg/voltage-2.6: (32 commits) regulator: twl4030 VAUX3 supports 3.0V regulator: Support disabling of unused regulators by machines regulator: Don't increment use_count for boot_on regulators twl4030-regulator: expose VPLL2 regulator: refcount fixes regulator: Don't warn if we failed to get a regulator regulator: Allow boot_on regulators to be disabled by clients regulator: Implement list_voltage for WM835x LDOs and DCDCs twl4030-regulator: list more VAUX4 voltages regulator: Don't warn on omitted voltage constraints regulator: Implement list_voltage() for WM8400 DCDCs and LDOs MMC: regulator utilities regulator: twl4030 voltage enumeration (v2) regulator: twl4030 regulators regulator: get_status() grows kerneldoc regulator: enumerate voltages (v2) regulator: Fix get_mode() for WM835x DCDCs regulator: Allow regulators to set the initial operating mode regulator: Suggest use of datasheet supply or pin names for consumers regulator: email - update email address and regulator webpage. ...
2009-04-03Merge git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-2.6-fscacheLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-2.6-fscache: (41 commits) NFS: Add mount options to enable local caching on NFS NFS: Display local caching state NFS: Store pages from an NFS inode into a local cache NFS: Read pages from FS-Cache into an NFS inode NFS: nfs_readpage_async() needs to be accessible as a fallback for local caching NFS: Add read context retention for FS-Cache to call back with NFS: FS-Cache page management NFS: Add some new I/O counters for FS-Cache doing things for NFS NFS: Invalidate FsCache page flags when cache removed NFS: Use local disk inode cache NFS: Define and create inode-level cache objects NFS: Define and create superblock-level objects NFS: Define and create server-level objects NFS: Register NFS for caching and retrieve the top-level index NFS: Permit local filesystem caching to be enabled for NFS NFS: Add FS-Cache option bit and debug bit NFS: Add comment banners to some NFS functions FS-Cache: Make kAFS use FS-Cache CacheFiles: A cache that backs onto a mounted filesystem CacheFiles: Export things for CacheFiles ...
2009-04-03Merge branch 'for-linus' of git://git.open-osd.org/linux-open-osdLinus Torvalds
* 'for-linus' of git://git.open-osd.org/linux-open-osd: fs: Add exofs to Kernel build exofs: Documentation exofs: export_operations exofs: super_operations and file_system_type exofs: dir_inode and directory operations exofs: address_space_operations exofs: symlink_inode and fast_symlink_inode operations exofs: file and file_inode operations exofs: Kbuild, Headers and osd utils
2009-04-03Merge branch 'for_linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-udf-2.6 * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-udf-2.6: udf: Don't write integrity descriptor too often udf: Try anchor in block 256 first udf: Some type fixes and cleanups udf: use hardware sector size udf: fix novrs mount option udf: Fix oops when invalid character in filename occurs udf: return f_fsid for statfs(2) udf: Add checks to not underflow sector_t udf: fix default mode and dmode options handling udf: fix sparse warnings: udf: unsigned last[i] cannot be less than 0 udf: implement mode and dmode mounting options udf: reduce stack usage of udf_get_filename udf: reduce stack usage of udf_load_pvoldesc Fix the udf code not to pass structs on stack where possible. Remove struct typedefs from fs/udf/ecma_167.h et al.
2009-04-03Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/rcu-doc-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/rcu-doc-2.6: Doc: Fix spelling in RCU/rculist_nulls.txt. Doc: Fix wrong API example usage of call_rcu(). Doc: Fix missing whitespaces in RCU documentation.
2009-04-03Merge branch 'for-linus' of git://neil.brown.name/mdLinus Torvalds
* 'for-linus' of git://neil.brown.name/md: (53 commits) md/raid5 revise rules for when to update metadata during reshape md/raid5: minor code cleanups in make_request. md: remove CONFIG_MD_RAID_RESHAPE config option. md/raid5: be more careful about write ordering when reshaping. md: don't display meaningless values in sysfs files resync_start and sync_speed md/raid5: allow layout and chunksize to be changed on active array. md/raid5: reshape using largest of old and new chunk size md/raid5: prepare for allowing reshape to change layout md/raid5: prepare for allowing reshape to change chunksize. md/raid5: clearly differentiate 'before' and 'after' stripes during reshape. Documentation/md.txt update md: allow number of drives in raid5 to be reduced md/raid5: change reshape-progress measurement to cope with reshaping backwards. md: add explicit method to signal the end of a reshape. md/raid5: enhance raid5_size to work correctly with negative delta_disks md/raid5: drop qd_idx from r6_state md/raid6: move raid6 data processing to raid6_pq.ko md: raid5 run(): Fix max_degraded for raid level 4. md: 'array_size' sysfs attribute md: centralize ->array_sectors modifications ...
2009-04-03Merge master.kernel.org:/home/rmk/linux-2.6-armLinus Torvalds
* master.kernel.org:/home/rmk/linux-2.6-arm: [ARM] fix build-breaking 7a192ec commit ARM: Add SMSC911X support to Overo platform (V2) arm: update omap_ldp defconfig to use smsc911x arm: update realview defconfigs to use smsc911x arm: update pcm037 defconfig to use smsc911x arm: convert omap ldp platform to use smsc911x arm: convert realview platform to use smsc911x arm: convert pcm037 platform to use smsc911x [ARM] 5444/1: ARM: Realview: Fix event-device multiplicators in localtimer.c [ARM] 5442/1: pxa/cm-x255: fix reverse RDY gpios in PCMCIA driver [ARM] 5441/1: Use pr_err on error paths in at91 pm [ARM] 5440/1: Fix VFP state corruption due to preemption during VFP exceptions [ARM] 5439/1: Do not clear bit 10 of DFSR during abort handling on ARMv6 [ARM] 5437/1: Add documentation for "nohlt" kernel parameter [ARM] 5436/1: ARM: OMAP: Fix compile for rx51 [ARM] arch_reset() now takes a second parameter [ARM] Kirkwood: small L2 code cleanup [ARM] Kirkwood: invalidate L2 cache before enabling it
2009-04-03CacheFiles: A cache that backs onto a mounted filesystemDavid Howells
Add an FS-Cache cache-backend that permits a mounted filesystem to be used as a backing store for the cache. CacheFiles uses a userspace daemon to do some of the cache management - such as reaping stale nodes and culling. This is called cachefilesd and lives in /sbin. The source for the daemon can be downloaded from: http://people.redhat.com/~dhowells/cachefs/cachefilesd.c And an example configuration from: http://people.redhat.com/~dhowells/cachefs/cachefilesd.conf The filesystem and data integrity of the cache are only as good as those of the filesystem providing the backing services. Note that CacheFiles does not attempt to journal anything since the journalling interfaces of the various filesystems are very specific in nature. CacheFiles creates a misc character device - "/dev/cachefiles" - that is used to communication with the daemon. Only one thing may have this open at once, and whilst it is open, a cache is at least partially in existence. The daemon opens this and sends commands down it to control the cache. CacheFiles is currently limited to a single cache. CacheFiles attempts to maintain at least a certain percentage of free space on the filesystem, shrinking the cache by culling the objects it contains to make space if necessary - see the "Cache Culling" section. This means it can be placed on the same medium as a live set of data, and will expand to make use of spare space and automatically contract when the set of data requires more space. ============ REQUIREMENTS ============ The use of CacheFiles and its daemon requires the following features to be available in the system and in the cache filesystem: - dnotify. - extended attributes (xattrs). - openat() and friends. - bmap() support on files in the filesystem (FIBMAP ioctl). - The use of bmap() to detect a partial page at the end of the file. It is strongly recommended that the "dir_index" option is enabled on Ext3 filesystems being used as a cache. ============= CONFIGURATION ============= The cache is configured by a script in /etc/cachefilesd.conf. These commands set up cache ready for use. The following script commands are available: (*) brun <N>% (*) bcull <N>% (*) bstop <N>% (*) frun <N>% (*) fcull <N>% (*) fstop <N>% Configure the culling limits. Optional. See the section on culling The defaults are 7% (run), 5% (cull) and 1% (stop) respectively. The commands beginning with a 'b' are file space (block) limits, those beginning with an 'f' are file count limits. (*) dir <path> Specify the directory containing the root of the cache. Mandatory. (*) tag <name> Specify a tag to FS-Cache to use in distinguishing multiple caches. Optional. The default is "CacheFiles". (*) debug <mask> Specify a numeric bitmask to control debugging in the kernel module. Optional. The default is zero (all off). The following values can be OR'd into the mask to collect various information: 1 Turn on trace of function entry (_enter() macros) 2 Turn on trace of function exit (_leave() macros) 4 Turn on trace of internal debug points (_debug()) This mask can also be set through sysfs, eg: echo 5 >/sys/modules/cachefiles/parameters/debug ================== STARTING THE CACHE ================== The cache is started by running the daemon. The daemon opens the cache device, configures the cache and tells it to begin caching. At that point the cache binds to fscache and the cache becomes live. The daemon is run as follows: /sbin/cachefilesd [-d]* [-s] [-n] [-f <configfile>] The flags are: (*) -d Increase the debugging level. This can be specified multiple times and is cumulative with itself. (*) -s Send messages to stderr instead of syslog. (*) -n Don't daemonise and go into background. (*) -f <configfile> Use an alternative configuration file rather than the default one. =============== THINGS TO AVOID =============== Do not mount other things within the cache as this will cause problems. The kernel module contains its own very cut-down path walking facility that ignores mountpoints, but the daemon can't avoid them. Do not create, rename or unlink files and directories in the cache whilst the cache is active, as this may cause the state to become uncertain. Renaming files in the cache might make objects appear to be other objects (the filename is part of the lookup key). Do not change or remove the extended attributes attached to cache files by the cache as this will cause the cache state management to get confused. Do not create files or directories in the cache, lest the cache get confused or serve incorrect data. Do not chmod files in the cache. The module creates things with minimal permissions to prevent random users being able to access them directly. ============= CACHE CULLING ============= The cache may need culling occasionally to make space. This involves discarding objects from the cache that have been used less recently than anything else. Culling is based on the access time of data objects. Empty directories are culled if not in use. Cache culling is done on the basis of the percentage of blocks and the percentage of files available in the underlying filesystem. There are six "limits": (*) brun (*) frun If the amount of free space and the number of available files in the cache rises above both these limits, then culling is turned off. (*) bcull (*) fcull If the amount of available space or the number of available files in the cache falls below either of these limits, then culling is started. (*) bstop (*) fstop If the amount of available space or the number of available files in the cache falls below either of these limits, then no further allocation of disk space or files is permitted until culling has raised things above these limits again. These must be configured thusly: 0 <= bstop < bcull < brun < 100 0 <= fstop < fcull < frun < 100 Note that these are percentages of available space and available files, and do _not_ appear as 100 minus the percentage displayed by the "df" program. The userspace daemon scans the cache to build up a table of cullable objects. These are then culled in least recently used order. A new scan of the cache is started as soon as space is made in the table. Objects will be skipped if their atimes have changed or if the kernel module says it is still using them. =============== CACHE STRUCTURE =============== The CacheFiles module will create two directories in the directory it was given: (*) cache/ (*) graveyard/ The active cache objects all reside in the first directory. The CacheFiles kernel module moves any retired or culled objects that it can't simply unlink to the graveyard from which the daemon will actually delete them. The daemon uses dnotify to monitor the graveyard directory, and will delete anything that appears therein. The module represents index objects as directories with the filename "I..." or "J...". Note that the "cache/" directory is itself a special index. Data objects are represented as files if they have no children, or directories if they do. Their filenames all begin "D..." or "E...". If represented as a directory, data objects will have a file in the directory called "data" that actually holds the data. Special objects are similar to data objects, except their filenames begin "S..." or "T...". If an object has children, then it will be represented as a directory. Immediately in the representative directory are a collection of directories named for hash values of the child object keys with an '@' prepended. Into this directory, if possible, will be placed the representations of the child objects: INDEX INDEX INDEX DATA FILES ========= ========== ================================= ================ cache/@4a/I03nfs/@30/Ji000000000000000--fHg8hi8400 cache/@4a/I03nfs/@30/Ji000000000000000--fHg8hi8400/@75/Es0g000w...DB1ry cache/@4a/I03nfs/@30/Ji000000000000000--fHg8hi8400/@75/Es0g000w...N22ry cache/@4a/I03nfs/@30/Ji000000000000000--fHg8hi8400/@75/Es0g000w...FP1ry If the key is so long that it exceeds NAME_MAX with the decorations added on to it, then it will be cut into pieces, the first few of which will be used to make a nest of directories, and the last one of which will be the objects inside the last directory. The names of the intermediate directories will have '+' prepended: J1223/@23/+xy...z/+kl...m/Epqr Note that keys are raw data, and not only may they exceed NAME_MAX in size, they may also contain things like '/' and NUL characters, and so they may not be suitable for turning directly into a filename. To handle this, CacheFiles will use a suitably printable filename directly and "base-64" encode ones that aren't directly suitable. The two versions of object filenames indicate the encoding: OBJECT TYPE PRINTABLE ENCODED =============== =============== =============== Index "I..." "J..." Data "D..." "E..." Special "S..." "T..." Intermediate directories are always "@" or "+" as appropriate. Each object in the cache has an extended attribute label that holds the object type ID (required to distinguish special objects) and the auxiliary data from the netfs. The latter is used to detect stale objects in the cache and update or retire them. Note that CacheFiles will erase from the cache any file it doesn't recognise or any file of an incorrect type (such as a FIFO file or a device file). ========================== SECURITY MODEL AND SELINUX ========================== CacheFiles is implemented to deal properly with the LSM security features of the Linux kernel and the SELinux facility. One of the problems that CacheFiles faces is that it is generally acting on behalf of a process, and running in that process's context, and that includes a security context that is not appropriate for accessing the cache - either because the files in the cache are inaccessible to that process, or because if the process creates a file in the cache, that file may be inaccessible to other processes. The way CacheFiles works is to temporarily change the security context (fsuid, fsgid and actor security label) that the process acts as - without changing the security context of the process when it the target of an operation performed by some other process (so signalling and suchlike still work correctly). When the CacheFiles module is asked to bind to its cache, it: (1) Finds the security label attached to the root cache directory and uses that as the security label with which it will create files. By default, this is: cachefiles_var_t (2) Finds the security label of the process which issued the bind request (presumed to be the cachefilesd daemon), which by default will be: cachefilesd_t and asks LSM to supply a security ID as which it should act given the daemon's label. By default, this will be: cachefiles_kernel_t SELinux transitions the daemon's security ID to the module's security ID based on a rule of this form in the policy. type_transition <daemon's-ID> kernel_t : process <module's-ID>; For instance: type_transition cachefilesd_t kernel_t : process cachefiles_kernel_t; The module's security ID gives it permission to create, move and remove files and directories in the cache, to find and access directories and files in the cache, to set and access extended attributes on cache objects, and to read and write files in the cache. The daemon's security ID gives it only a very restricted set of permissions: it may scan directories, stat files and erase files and directories. It may not read or write files in the cache, and so it is precluded from accessing the data cached therein; nor is it permitted to create new files in the cache. There are policy source files available in: http://people.redhat.com/~dhowells/fscache/cachefilesd-0.8.tar.bz2 and later versions. In that tarball, see the files: cachefilesd.te cachefilesd.fc cachefilesd.if They are built and installed directly by the RPM. If a non-RPM based system is being used, then copy the above files to their own directory and run: make -f /usr/share/selinux/devel/Makefile semodule -i cachefilesd.pp You will need checkpolicy and selinux-policy-devel installed prior to the build. By default, the cache is located in /var/fscache, but if it is desirable that it should be elsewhere, than either the above policy files must be altered, or an auxiliary policy must be installed to label the alternate location of the cache. For instructions on how to add an auxiliary policy to enable the cache to be located elsewhere when SELinux is in enforcing mode, please see: /usr/share/doc/cachefilesd-*/move-cache.txt When the cachefilesd rpm is installed; alternatively, the document can be found in the sources. ================== A NOTE ON SECURITY ================== CacheFiles makes use of the split security in the task_struct. It allocates its own task_security structure, and redirects current->act_as to point to it when it acts on behalf of another process, in that process's context. The reason it does this is that it calls vfs_mkdir() and suchlike rather than bypassing security and calling inode ops directly. Therefore the VFS and LSM may deny the CacheFiles access to the cache data because under some circumstances the caching code is running in the security context of whatever process issued the original syscall on the netfs. Furthermore, should CacheFiles create a file or directory, the security parameters with that object is created (UID, GID, security label) would be derived from that process that issued the system call, thus potentially preventing other processes from accessing the cache - including CacheFiles's cache management daemon (cachefilesd). What is required is to temporarily override the security of the process that issued the system call. We can't, however, just do an in-place change of the security data as that affects the process as an object, not just as a subject. This means it may lose signals or ptrace events for example, and affects what the process looks like in /proc. So CacheFiles makes use of a logical split in the security between the objective security (task->sec) and the subjective security (task->act_as). The objective security holds the intrinsic security properties of a process and is never overridden. This is what appears in /proc, and is what is used when a process is the target of an operation by some other process (SIGKILL for example). The subjective security holds the active security properties of a process, and may be overridden. This is not seen externally, and is used whan a process acts upon another object, for example SIGKILLing another process or opening a file. LSM hooks exist that allow SELinux (or Smack or whatever) to reject a request for CacheFiles to run in a context of a specific security label, or to create files and directories with another security label. This documentation is added by the patch to: Documentation/filesystems/caching/cachefiles.txt Signed-Off-By: David Howells <dhowells@redhat.com> Acked-by: Steve Dickson <steved@redhat.com> Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Tested-by: Daire Byrne <Daire.Byrne@framestore.com>
2009-04-03FS-Cache: Add and document asynchronous operation handlingDavid Howells
Add and document asynchronous operation handling for use by FS-Cache's data storage and retrieval routines. The following documentation is added to: Documentation/filesystems/caching/operations.txt ================================ ASYNCHRONOUS OPERATIONS HANDLING ================================ ======== OVERVIEW ======== FS-Cache has an asynchronous operations handling facility that it uses for its data storage and retrieval routines. Its operations are represented by fscache_operation structs, though these are usually embedded into some other structure. This facility is available to and expected to be be used by the cache backends, and FS-Cache will create operations and pass them off to the appropriate cache backend for completion. To make use of this facility, <linux/fscache-cache.h> should be #included. =============================== OPERATION RECORD INITIALISATION =============================== An operation is recorded in an fscache_operation struct: struct fscache_operation { union { struct work_struct fast_work; struct slow_work slow_work; }; unsigned long flags; fscache_operation_processor_t processor; ... }; Someone wanting to issue an operation should allocate something with this struct embedded in it. They should initialise it by calling: void fscache_operation_init(struct fscache_operation *op, fscache_operation_release_t release); with the operation to be initialised and the release function to use. The op->flags parameter should be set to indicate the CPU time provision and the exclusivity (see the Parameters section). The op->fast_work, op->slow_work and op->processor flags should be set as appropriate for the CPU time provision (see the Parameters section). FSCACHE_OP_WAITING may be set in op->flags prior to each submission of the operation and waited for afterwards. ========== PARAMETERS ========== There are a number of parameters that can be set in the operation record's flag parameter. There are three options for the provision of CPU time in these operations: (1) The operation may be done synchronously (FSCACHE_OP_MYTHREAD). A thread may decide it wants to handle an operation itself without deferring it to another thread. This is, for example, used in read operations for calling readpages() on the backing filesystem in CacheFiles. Although readpages() does an asynchronous data fetch, the determination of whether pages exist is done synchronously - and the netfs does not proceed until this has been determined. If this option is to be used, FSCACHE_OP_WAITING must be set in op->flags before submitting the operation, and the operating thread must wait for it to be cleared before proceeding: wait_on_bit(&op->flags, FSCACHE_OP_WAITING, fscache_wait_bit, TASK_UNINTERRUPTIBLE); (2) The operation may be fast asynchronous (FSCACHE_OP_FAST), in which case it will be given to keventd to process. Such an operation is not permitted to sleep on I/O. This is, for example, used by CacheFiles to copy data from a backing fs page to a netfs page after the backing fs has read the page in. If this option is used, op->fast_work and op->processor must be initialised before submitting the operation: INIT_WORK(&op->fast_work, do_some_work); (3) The operation may be slow asynchronous (FSCACHE_OP_SLOW), in which case it will be given to the slow work facility to process. Such an operation is permitted to sleep on I/O. This is, for example, used by FS-Cache to handle background writes of pages that have just been fetched from a remote server. If this option is used, op->slow_work and op->processor must be initialised before submitting the operation: fscache_operation_init_slow(op, processor) Furthermore, operations may be one of two types: (1) Exclusive (FSCACHE_OP_EXCLUSIVE). Operations of this type may not run in conjunction with any other operation on the object being operated upon. An example of this is the attribute change operation, in which the file being written to may need truncation. (2) Shareable. Operations of this type may be running simultaneously. It's up to the operation implementation to prevent interference between other operations running at the same time. ========= PROCEDURE ========= Operations are used through the following procedure: (1) The submitting thread must allocate the operation and initialise it itself. Normally this would be part of a more specific structure with the generic op embedded within. (2) The submitting thread must then submit the operation for processing using one of the following two functions: int fscache_submit_op(struct fscache_object *object, struct fscache_operation *op); int fscache_submit_exclusive_op(struct fscache_object *object, struct fscache_operation *op); The first function should be used to submit non-exclusive ops and the second to submit exclusive ones. The caller must still set the FSCACHE_OP_EXCLUSIVE flag. If successful, both functions will assign the operation to the specified object and return 0. -ENOBUFS will be returned if the object specified is permanently unavailable. The operation manager will defer operations on an object that is still undergoing lookup or creation. The operation will also be deferred if an operation of conflicting exclusivity is in progress on the object. If the operation is asynchronous, the manager will retain a reference to it, so the caller should put their reference to it by passing it to: void fscache_put_operation(struct fscache_operation *op); (3) If the submitting thread wants to do the work itself, and has marked the operation with FSCACHE_OP_MYTHREAD, then it should monitor FSCACHE_OP_WAITING as described above and check the state of the object if necessary (the object might have died whilst the thread was waiting). When it has finished doing its processing, it should call fscache_put_operation() on it. (4) The operation holds an effective lock upon the object, preventing other exclusive ops conflicting until it is released. The operation can be enqueued for further immediate asynchronous processing by adjusting the CPU time provisioning option if necessary, eg: op->flags &= ~FSCACHE_OP_TYPE; op->flags |= ~FSCACHE_OP_FAST; and calling: void fscache_enqueue_operation(struct fscache_operation *op) This can be used to allow other things to have use of the worker thread pools. ===================== ASYNCHRONOUS CALLBACK ===================== When used in asynchronous mode, the worker thread pool will invoke the processor method with a pointer to the operation. This should then get at the container struct by using container_of(): static void fscache_write_op(struct fscache_operation *_op) { struct fscache_storage *op = container_of(_op, struct fscache_storage, op); ... } The caller holds a reference on the operation, and will invoke fscache_put_operation() when the processor function returns. The processor function is at liberty to call fscache_enqueue_operation() or to take extra references. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Steve Dickson <steved@redhat.com> Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Tested-by: Daire Byrne <Daire.Byrne@framestore.com>