1. 13 Jun, 2012 4 commits
    • Hans de Goede's avatar
      usb-storage: Add 090c:1000 to unusal-devs · afff07e6
      Hans de Goede authored
      This device gives a bogus answer to get_capacity(16):
      [ 8628.278614] scsi 8:0:0:0: Direct-Access     USB 2.0  USB Flash Drive  1100 PQ: 0 ANSI: 4
      [ 8628.279452] sd 8:0:0:0: Attached scsi generic sg4 type 0
      [ 8628.280338] sd 8:0:0:0: [sdd] 35747322042253313 512-byte logical blocks: (18.3 EB/15.8 EiB)
      
      So set the quirk flag to avoid using get_capacity(16) with it:
      [11731.386014] usb-storage 2-1.6:1.0: Quirks match for vid 090c pid 1000: 80000
      [11731.386075] scsi9 : usb-storage 2-1.6:1.0
      [11731.386172] usbcore: registered new interface driver usb-storage
      [11731.386175] USB Mass Storage support registered.
      [11732.387394] scsi 9:0:0:0: Direct-Access     USB 2.0  USB Flash Drive  1100 PQ: 0 ANSI: 4
      [11732.388462] sd 9:0:0:0: Attached scsi generic sg3 type 0
      [11732.389432] sd 9:0:0:0: [sdc] 7975296 512-byte logical blocks: (4.08 GB/3.80 GiB)
      
      Which makes the capacity look a lot more sane :)
      Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
      Tested-by: default avatarSimon Raffeiner <sturmflut@lieberbiber.de>
      Cc: stable <stable@vger.kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      afff07e6
    • Alan Stern's avatar
      USB: serial-generic: use a single set of device IDs · 0b84704a
      Alan Stern authored
      The usb-serial-generic driver uses different device IDs for its USB
      matching and its serial matching.  This can lead to problems: The
      driver can end up getting bound to a USB interface without being
      allowed to bind to the corresponding serial port.
      
      This patch (as1557) fixes the problem by using the same device ID
      table (the one that can be altered by the "vendor=" and "product="
      module parameters) for both purposes.  The unused table is removed.
      Now the driver will bind only to the intended devices.
      Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
      CC: Bjørn Mork <bjorn@mork.no>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      0b84704a
    • Bjørn Mork's avatar
      USB: serial: Enforce USB driver and USB serial driver match · 954c3f8a
      Bjørn Mork authored
      We need to make sure that the USB serial driver we find
      matches the USB driver whose probe we are currently
      executing. Otherwise we will end up with USB serial
      devices bound to the correct serial driver but wrong
      USB driver.
      
      An example of such cross-probing, where the usbserial_generic
      USB driver has found the sierra serial driver:
      
      May 29 18:26:15 nemi kernel: [ 4442.559246] usbserial_generic 4-4:1.0: Sierra USB modem converter detected
      May 29 18:26:20 nemi kernel: [ 4447.556747] usbserial_generic 4-4:1.2: Sierra USB modem converter detected
      May 29 18:26:25 nemi kernel: [ 4452.557288] usbserial_generic 4-4:1.3: Sierra USB modem converter detected
      
      sysfs view of the same problem:
      
      bjorn@nemi:~$ ls -l /sys/bus/usb/drivers/sierra/
      total 0
      --w------- 1 root root 4096 May 29 18:23 bind
      lrwxrwxrwx 1 root root    0 May 29 18:23 module -> ../../../../module/usbserial
      --w------- 1 root root 4096 May 29 18:23 uevent
      --w------- 1 root root 4096 May 29 18:23 unbind
      bjorn@nemi:~$ ls -l /sys/bus/usb-serial/drivers/sierra/
      total 0
      --w------- 1 root root 4096 May 29 18:23 bind
      lrwxrwxrwx 1 root root    0 May 29 18:23 module -> ../../../../module/sierra
      -rw-r--r-- 1 root root 4096 May 29 18:23 new_id
      lrwxrwxrwx 1 root root    0 May 29 18:32 ttyUSB0 -> ../../../../devices/pci0000:00/0000:00:1d.7/usb4/4-4/4-4:1.0/ttyUSB0
      lrwxrwxrwx 1 root root    0 May 29 18:32 ttyUSB1 -> ../../../../devices/pci0000:00/0000:00:1d.7/usb4/4-4/4-4:1.2/ttyUSB1
      lrwxrwxrwx 1 root root    0 May 29 18:32 ttyUSB2 -> ../../../../devices/pci0000:00/0000:00:1d.7/usb4/4-4/4-4:1.3/ttyUSB2
      --w------- 1 root root 4096 May 29 18:23 uevent
      --w------- 1 root root 4096 May 29 18:23 unbind
      
      bjorn@nemi:~$ ls -l /sys/bus/usb/drivers/usbserial_generic/
      total 0
      lrwxrwxrwx 1 root root    0 May 29 18:33 4-4:1.0 -> ../../../../devices/pci0000:00/0000:00:1d.7/usb4/4-4/4-4:1.0
      lrwxrwxrwx 1 root root    0 May 29 18:33 4-4:1.2 -> ../../../../devices/pci0000:00/0000:00:1d.7/usb4/4-4/4-4:1.2
      lrwxrwxrwx 1 root root    0 May 29 18:33 4-4:1.3 -> ../../../../devices/pci0000:00/0000:00:1d.7/usb4/4-4/4-4:1.3
      --w------- 1 root root 4096 May 29 18:33 bind
      lrwxrwxrwx 1 root root    0 May 29 18:33 module -> ../../../../module/usbserial
      --w------- 1 root root 4096 May 29 18:22 uevent
      --w------- 1 root root 4096 May 29 18:33 unbind
      bjorn@nemi:~$ ls -l /sys/bus/usb-serial/drivers/generic/
      total 0
      --w------- 1 root root 4096 May 29 18:33 bind
      lrwxrwxrwx 1 root root    0 May 29 18:33 module -> ../../../../module/usbserial
      -rw-r--r-- 1 root root 4096 May 29 18:33 new_id
      --w------- 1 root root 4096 May 29 18:22 uevent
      --w------- 1 root root 4096 May 29 18:33 unbind
      
      So we end up with a mismatch between the USB driver and the
      USB serial driver.  The reason for the above is simple: The
      USB driver probe will succeed if *any* registered serial
      driver matches, and will use that serial driver for all
      serial driver functions.
      
      This makes ref counting go wrong. We count the USB driver
      as used, but not the USB serial driver.  This may result
      in Oops'es as demonstrated by Johan Hovold <jhovold@gmail.com>:
      
      [11811.646396] drivers/usb/serial/usb-serial.c: get_free_serial 1
      [11811.646443] drivers/usb/serial/usb-serial.c: get_free_serial - minor base = 0
      [11811.646460] drivers/usb/serial/usb-serial.c: usb_serial_probe - registering ttyUSB0
      [11811.646766] usb 6-1: pl2303 converter now attached to ttyUSB0
      [11812.264197] USB Serial deregistering driver FTDI USB Serial Device
      [11812.264865] usbcore: deregistering interface driver ftdi_sio
      [11812.282180] USB Serial deregistering driver pl2303
      [11812.283141] pl2303 ttyUSB0: pl2303 converter now disconnected from ttyUSB0
      [11812.283272] usbcore: deregistering interface driver pl2303
      [11812.301056] USB Serial deregistering driver generic
      [11812.301186] usbcore: deregistering interface driver usbserial_generic
      [11812.301259] drivers/usb/serial/usb-serial.c: usb_serial_disconnect
      [11812.301823] BUG: unable to handle kernel paging request at f8e7438c
      [11812.301845] IP: [<f8e38445>] usb_serial_disconnect+0xb5/0x100 [usbserial]
      [11812.301871] *pde = 357ef067 *pte = 00000000
      [11812.301957] Oops: 0000 [#1] PREEMPT SMP
      [11812.301983] Modules linked in: usbserial(-) [last unloaded: pl2303]
      [11812.302008]
      [11812.302019] Pid: 1323, comm: modprobe Tainted: G        W    3.4.0-rc7+ #101 Dell Inc. Vostro 1520/0T816J
      [11812.302115] EIP: 0060:[<f8e38445>] EFLAGS: 00010246 CPU: 1
      [11812.302130] EIP is at usb_serial_disconnect+0xb5/0x100 [usbserial]
      [11812.302141] EAX: f508a180 EBX: f508a180 ECX: 00000000 EDX: f8e74300
      [11812.302151] ESI: f5050800 EDI: 00000001 EBP: f5141e78 ESP: f5141e58
      [11812.302160]  DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
      [11812.302170] CR0: 8005003b CR2: f8e7438c CR3: 34848000 CR4: 000007d0
      [11812.302180] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
      [11812.302189] DR6: ffff0ff0 DR7: 00000400
      [11812.302199] Process modprobe (pid: 1323, ti=f5140000 task=f61e2bc0 task.ti=f5140000)
      [11812.302209] Stack:
      [11812.302216]  f8e3be0f f8e3b29c f8e3ae00 00000000 f513641c f5136400 f513641c f507a540
      [11812.302325]  f5141e98 c133d2c1 00000000 00000000 f509c400 f513641c f507a590 f5136450
      [11812.302372]  f5141ea8 c12f0344 f513641c f507a590 f5141ebc c12f0c67 00000000 f507a590
      [11812.302419] Call Trace:
      [11812.302439]  [<c133d2c1>] usb_unbind_interface+0x51/0x190
      [11812.302456]  [<c12f0344>] __device_release_driver+0x64/0xb0
      [11812.302469]  [<c12f0c67>] driver_detach+0x97/0xa0
      [11812.302483]  [<c12f001c>] bus_remove_driver+0x6c/0xe0
      [11812.302500]  [<c145938d>] ? __mutex_unlock_slowpath+0xcd/0x140
      [11812.302514]  [<c12f0ff9>] driver_unregister+0x49/0x80
      [11812.302528]  [<c1457df6>] ? printk+0x1d/0x1f
      [11812.302540]  [<c133c50d>] usb_deregister+0x5d/0xb0
      [11812.302557]  [<f8e37c55>] ? usb_serial_deregister+0x45/0x50 [usbserial]
      [11812.302575]  [<f8e37c8d>] usb_serial_deregister_drivers+0x2d/0x40 [usbserial]
      [11812.302593]  [<f8e3a6e2>] usb_serial_generic_deregister+0x12/0x20 [usbserial]
      [11812.302611]  [<f8e3acf0>] usb_serial_exit+0x8/0x32 [usbserial]
      [11812.302716]  [<c1080b48>] sys_delete_module+0x158/0x260
      [11812.302730]  [<c110594e>] ? mntput+0x1e/0x30
      [11812.302746]  [<c145c3c3>] ? sysenter_exit+0xf/0x18
      [11812.302746]  [<c107777c>] ? trace_hardirqs_on_caller+0xec/0x170
      [11812.302746]  [<c145c390>] sysenter_do_call+0x12/0x36
      [11812.302746] Code: 24 02 00 00 e8 dd f3 20 c8 f6 86 74 02 00 00 02 74 b4 8d 86 4c 02 00 00 47 e8 78 55 4b c8 0f b6 43 0e 39 f8 7f a9 8b 53 04 89 d8 <ff> 92 8c 00 00 00 89 d8 e8 0e ff ff ff 8b 45 f0 c7 44 24 04 2f
      [11812.302746] EIP: [<f8e38445>] usb_serial_disconnect+0xb5/0x100 [usbserial] SS:ESP 0068:f5141e58
      [11812.302746] CR2: 00000000f8e7438c
      
      Fix by only evaluating serial drivers pointing back to the
      USB driver we are currently probing.  This still allows two
      or more drivers to match the same device, running their
      serial driver probes to sort out which one to use.
      
      Cc: stable@vger.kernel.org # 3.0, 3.2, 3.3, 3.4
      Signed-off-by: default avatarBjørn Mork <bjorn@mork.no>
      Reviewed-by: default avatarFelipe Balbi <balbi@ti.com>
      Tested-by: default avatarJohan Hovold <jhovold@gmail.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      954c3f8a
    • Alan Stern's avatar
      USB: add NO_D3_DURING_SLEEP flag and revert 151b6128 · c2fb8a3f
      Alan Stern authored
      This patch (as1558) fixes a problem affecting several ASUS computers:
      The machine crashes or corrupts memory when going into suspend if the
      ehci-hcd driver is bound to any controllers.  Users have been forced
      to unbind or unload ehci-hcd before putting their systems to sleep.
      
      After extensive testing, it was determined that the machines don't
      like going into suspend when any EHCI controllers are in the PCI D3
      power state.  Presumably this is a firmware bug, but there's nothing
      we can do about it except to avoid putting the controllers in D3
      during system sleep.
      
      The patch adds a new flag to indicate whether the problem is present,
      and avoids changing the controller's power state if the flag is set.
      Runtime suspend is unaffected; this matters only for system suspend.
      However as a side effect, the controller will not respond to remote
      wakeup requests while the system is asleep.  Hence USB wakeup is not
      functional -- but of course, this is already true in the current state
      of affairs.
      
      A similar patch has already been applied as commit
      151b6128 (USB: EHCI: fix crash during
      suspend on ASUS computers).  The patch supersedes that one and reverts
      it.  There are two differences:
      
      	The old patch added the flag at the USB level; this patch
      	adds it at the PCI level.
      
      	The old patch applied to all chipsets with the same vendor,
      	subsystem vendor, and product IDs; this patch makes an
      	exception for a known-good system (based on DMI information).
      Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
      Tested-by: default avatarDâniel Fraga <fragabr@gmail.com>
      Tested-by: default avatarAndrey Rahmatullin <wrar@wrar.name>
      Tested-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      Cc: stable <stable@vger.kernel.org>
      Reviewed-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      c2fb8a3f
  2. 12 Jun, 2012 12 commits
  3. 05 Jun, 2012 1 commit
  4. 04 Jun, 2012 12 commits
  5. 03 Jun, 2012 2 commits
  6. 02 Jun, 2012 9 commits
    • Joe Thornber's avatar
      dm thin: provide userspace access to pool metadata · cc8394d8
      Joe Thornber authored
      This patch implements two new messages that can be sent to the thin
      pool target allowing it to take a snapshot of the _metadata_.  This,
      read-only snapshot can be accessed by userland, concurrently with the
      live target.
      
      Only one metadata snapshot can be held at a time.  The pool's status
      line will give the block location for the current msnap.
      
      Since version 0.1.5 of the userland thin provisioning tools, the
      thin_dump program displays the msnap as follows:
      
          thin_dump -m <msnap root> <metadata dev>
      
      Available here: https://github.com/jthornber/thin-provisioning-tools
      
      Now that userland can access the metadata we can do various things
      that have traditionally been kernel side tasks:
      
           i) Incremental backups.
      
           By using metadata snapshots we can work out what blocks have
           changed over time.  Combined with data snapshots we can ensure
           the data doesn't change while we back it up.
      
           A short proof of concept script can be found here:
      
           https://github.com/jthornber/thinp-test-suite/blob/master/incremental_backup_example.rb
      
           ii) Migration of thin devices from one pool to another.
      
           iii) Merging snapshots back into an external origin.
      
           iv) Asyncronous replication.
      Signed-off-by: default avatarJoe Thornber <ejt@redhat.com>
      Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
      cc8394d8
    • Mike Snitzer's avatar
      dm thin: use slab mempools · a24c2569
      Mike Snitzer authored
      Use dedicated caches prefixed with a "dm_" name rather than relying on
      kmalloc mempools backed by generic slab caches so the memory usage of
      thin provisioning (and any leaks) can be accounted for independently.
      Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
      Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
      a24c2569
    • Mikulas Patocka's avatar
      dm mpath: allow ioctls to trigger pg init · 35991652
      Mikulas Patocka authored
      After the failure of a group of paths, any alternative paths that
      need initialising do not become available until further I/O is sent to
      the device.  Until this has happened, ioctls return -EAGAIN.
      
      With this patch, new paths are made available in response to an ioctl
      too.  The processing of the ioctl gets delayed until this has happened.
      
      Instead of returning an error, we submit a work item to kmultipathd
      (that will potentially activate the new path) and retry in ten
      milliseconds.
      
      Note that the patch doesn't retry an ioctl if the ioctl itself fails due
      to a path failure.  Such retries should be handled intelligently by the
      code that generated the ioctl in the first place, noting that some SCSI
      commands should not be retried because they are not idempotent (XOR write
      commands).  For commands that could be retried, there is a danger that
      if the device rejected the SCSI command, the path could be errorneously
      marked as failed, and the request would be retried on another path which
      might fail too.  It can be determined if the failure happens on the
      device or on the SCSI controller, but there is no guarantee that all
      SCSI drivers set these flags correctly.
      Signed-off-by: default avatarMikulas Patocka <mpatocka@redhat.com>
      Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
      35991652
    • Mike Christie's avatar
      dm mpath: delay retry of bypassed pg · f220fd4e
      Mike Christie authored
      If I/O needs retrying and only bypassed priority groups are available,
      set the pg_init_delay_retry flag to wait before retrying.
      
      If, for example, the reason for the bypass is that the controller is
      getting reset or there is a firmware upgrade happening, retrying right
      away would cause a flood of log messages and retries for what could be a
      few seconds or even several minutes.
      Signed-off-by: default avatarMike Christie <michaelc@cs.wisc.edu>
      Acked-by: default avatarMike Snitzer <snitzer@redhat.com>
      Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
      f220fd4e
    • Mike Snitzer's avatar
      dm mpath: reduce size of struct multipath · 1fbdd2b3
      Mike Snitzer authored
      Move multipath structure's 'lock' and 'queue_size' members to eliminate
      two 4-byte holes.  Also use a bit within a single unsigned int for each
      existing flag (saves 8-bytes).  This allows future flags to be added
      without each consuming an unsigned int.
      Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
      Acked-by: default avatarHannes Reinecke <hare@suse.de>
      Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
      1fbdd2b3
    • Linus Torvalds's avatar
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net · 4fc3acf2
      Linus Torvalds authored
      Pull networking updates from David Miller:
      
       1) Make syn floods consume significantly less resources by
      
          a) Not pre-COW'ing routing metrics for SYN/ACKs
          b) Mirroring the device queue mapping of the SYN for the SYN/ACK
             reply.
      
          Both from Eric Dumazet.
      
       2) Fix calculation errors in Byte Queue Limiting, from Hiroaki SHIMODA.
      
       3) Validate the length requested when building a paged SKB for a
          socket, so we don't overrun the page vector accidently.  From Jason
          Wang.
      
       4) When netlabel is disabled, we abort all IP option processing when we
          see a CIPSO option.  This isn't the right thing to do, we should
          simply skip over it and continue processing the remaining options
          (if any).  Fix from Paul Moore.
      
       5) SRIOV fixes for the mellanox driver from Jack orgenstein and Marcel
          Apfelbaum.
      
       6) 8139cp enables the receiver before the ring address is properly
          programmed, which potentially lets the device crap over random
          memory.  Fix from Jason Wang.
      
       7) e1000/e1000e fixes for i217 RST handling, and an improper buffer
          address reference in jumbo RX frame processing from Bruce Allan and
          Sebastian Andrzej Siewior, respectively.
      
      * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
        fec_mpc52xx: fix timestamp filtering
        mcs7830: Implement link state detection
        e1000e: fix Rapid Start Technology support for i217
        e1000: look into the page instead of skb->data for e1000_tbi_adjust_stats()
        r8169: call netif_napi_del at errpaths and at driver unload
        tcp: reflect SYN queue_mapping into SYNACK packets
        tcp: do not create inetpeer on SYNACK message
        8139cp/8139too: terminate the eeprom access with the right opmode
        8139cp: set ring address before enabling receiver
        cipso: handle CIPSO options correctly when NetLabel is disabled
        net: sock: validate data_len before allocating skb in sock_alloc_send_pskb()
        bql: Avoid possible inconsistent calculation.
        bql: Avoid unneeded limit decrement.
        bql: Fix POSDIFF() to integer overflow aware.
        net/mlx4_core: Fix obscure mlx4_cmd_box parameter in QUERY_DEV_CAP
        net/mlx4_core: Check port out-of-range before using in mlx4_slave_cap
        net/mlx4_core: Fixes for VF / Guest startup flow
        net/mlx4_en: Fix improper use of "port" parameter in mlx4_en_event
        net/mlx4_core: Fix number of EQs used in ICM initialisation
        net/mlx4_core: Fix the slave_id out-of-range test in mlx4_eq_int
      4fc3acf2
    • Linus Torvalds's avatar
      Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 63004afa
      Linus Torvalds authored
      Pull straggler x86 fixes from Peter Anvin:
       "Three groups of patches:
      
        - EFI boot stub documentation and the ability to print error messages;
        - Removal for PTRACE_ARCH_PRCTL for x32 (obsolete interface which
          should never have been ported, and the port is broken and
          potentially dangerous.)
        - ftrace stack corruption fixes.  I'm not super-happy about the
          technical implementation, but it is probably the least invasive in
          the short term.  In the future I would like a single method for
          nesting the debug stack, however."
      
      * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        x86, x32, ptrace: Remove PTRACE_ARCH_PRCTL for x32
        x86, efi: Add EFI boot stub documentation
        x86, efi; Add EFI boot stub console support
        x86, efi: Only close open files in error path
        ftrace/x86: Do not change stacks in DEBUG when calling lockdep
        x86: Allow nesting of the debug stack IDT setting
        x86: Reset the debug_stack update counter
        ftrace: Use breakpoint method to update ftrace caller
        ftrace: Synchronize variable setting with breakpoints
      63004afa
    • Linus Torvalds's avatar
      tty: Revert the tty locking series, it needs more work · f309532b
      Linus Torvalds authored
      This reverts the tty layer change to use per-tty locking, because it's
      not correct yet, and fixing it will require some more deep surgery.
      
      The main revert is d29f3ef3 ("tty_lock: Localise the lock"), but
      there are several smaller commits that built upon it, they also get
      reverted here. The list of reverted commits is:
      
        fde86d31 - tty: add lockdep annotations
        8f6576ad - tty: fix ldisc lock inversion trace
        d3ca8b64 - pty: Fix lock inversion
        b1d679af - tty: drop the pty lock during hangup
        abcefe5f - tty/amiserial: Add missing argument for tty_unlock()
        fd11b42e - cris: fix missing tty arg in wait_event_interruptible_tty call
        d29f3ef3 - tty_lock: Localise the lock
      
      The revert had a trivial conflict in the 68360serial.c staging driver
      that got removed in the meantime.
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      f309532b
    • Stephan Gatzka's avatar
      fec_mpc52xx: fix timestamp filtering · 9ca3cc6f
      Stephan Gatzka authored
      skb_defer_rx_timestamp was called with a freshly allocated skb but must
      be called with rskb instead.
      Signed-off-by: default avatarStephan Gatzka <stephan@gatzka.org>
      Cc: stable <stable@vger.kernel.org>
      Acked-by: default avatarRichard Cochran <richardcochran@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      9ca3cc6f