1. 25 Aug, 2015 24 commits
  2. 20 Aug, 2015 11 commits
    • Takashi Iwai's avatar
      ALSA: hda - Apply fixup for another Toshiba Satellite S50D · a4f614d5
      Takashi Iwai authored
      commit b9d9c9ef upstream.
      
      Toshiba Satellite S50D has another model with a different PCI SSID
      (1179:fa93) while the previous fixup was for 1179:fa91.  Adjust the
      fixup entry with SND_PCI_QUIRK_MASK() to match with both devices.
      Reported-by: default avatarTim Sample <timsample@gmail.com>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      a4f614d5
    • Denis Carikli's avatar
      ARM: dts: i.MX35: Fix can support. · be3e10f8
      Denis Carikli authored
      commit e053f96b upstream.
      
      Since commit 3d42a379
      ("can: flexcan: add 2nd clock to support imx53 and newer")
      the can driver requires a dt nodes to have a second clock.
      Add them to imx35 to fix probing the flex can driver on the
      respective platforms.
      Signed-off-by: default avatarDenis Carikli <denis@eukrea.com>
      Signed-off-by: default avatarShawn Guo <shawnguo@kernel.org>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      be3e10f8
    • Nicholas Bellinger's avatar
      iscsi-target: Fix iser explicit logout TX kthread leak · abc10600
      Nicholas Bellinger authored
      commit 007d038b upstream.
      
      This patch fixes a regression introduced with the following commit
      in v4.0-rc1 code, where an explicit iser-target logout would result
      in ->tx_thread_active being incorrectly cleared by the logout post
      handler, and subsequent TX kthread leak:
      
          commit 88dcd2da
          Author: Nicholas Bellinger <nab@linux-iscsi.org>
          Date:   Thu Feb 26 22:19:15 2015 -0800
      
              iscsi-target: Convert iscsi_thread_set usage to kthread.h
      
      To address this bug, change iscsit_logout_post_handler_closesession()
      and iscsit_logout_post_handler_samecid() to only cmpxchg() on
      ->tx_thread_active for traditional iscsi/tcp connections.
      
      This is required because iscsi/tcp connections are invoking logout
      post handler logic directly from TX kthread context, while iser
      connections are invoking logout post handler logic from a seperate
      workqueue context.
      
      Cc: Sagi Grimberg <sagig@mellanox.com>
      Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      abc10600
    • Nicholas Bellinger's avatar
      iscsi-target: Fix iscsit_start_kthreads failure OOPs · e76230df
      Nicholas Bellinger authored
      commit e5419865 upstream.
      
      This patch fixes a regression introduced with the following commit
      in v4.0-rc1 code, where a iscsit_start_kthreads() failure triggers
      a NULL pointer dereference OOPs:
      
          commit 88dcd2da
          Author: Nicholas Bellinger <nab@linux-iscsi.org>
          Date:   Thu Feb 26 22:19:15 2015 -0800
      
              iscsi-target: Convert iscsi_thread_set usage to kthread.h
      
      To address this bug, move iscsit_start_kthreads() immediately
      preceeding the transmit of last login response, before signaling
      a successful transition into full-feature-phase within existing
      iscsi_target_do_tx_login_io() logic.
      
      This ensures that no target-side resource allocation failures can
      occur after the final login response has been successfully sent.
      
      Also, it adds a iscsi_conn->rx_login_comp to allow the RX thread
      to sleep to prevent other socket related failures until the final
      iscsi_post_login_handler() call is able to complete.
      
      Cc: Sagi Grimberg <sagig@mellanox.com>
      Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
      [ luis: backported to 3.16: adjusted context ]
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      e76230df
    • Nicholas Bellinger's avatar
      iscsi-target: Fix use-after-free during TPG session shutdown · a19a94df
      Nicholas Bellinger authored
      commit 417c20a9 upstream.
      
      This patch fixes a use-after-free bug in iscsit_release_sessions_for_tpg()
      where se_portal_group->session_lock was incorrectly released/re-acquired
      while walking the active se_portal_group->tpg_sess_list.
      
      The can result in a NULL pointer dereference when iscsit_close_session()
      shutdown happens in the normal path asynchronously to this code, causing
      a bogus dereference of an already freed list entry to occur.
      
      To address this bug, walk the session list checking for the same state
      as before, but move entries to a local list to avoid dropping the lock
      while walking the active list.
      
      As before, signal using iscsi_session->session_restatement=1 for those
      list entries to be released locally by iscsit_free_session() code.
      Reported-by: default avatarSunilkumar Nadumuttlu <sjn@datera.io>
      Cc: Sunilkumar Nadumuttlu <sjn@datera.io>
      Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      a19a94df
    • Axel Lin's avatar
      ASoC: pcm1681: Fix setting de-emphasis sampling rate selection · 809f410c
      Axel Lin authored
      commit fa8173a3 upstream.
      
      The de-emphasis sampling rate selection is controlled by BIT[3:4] of
      PCM1681_DEEMPH_CONTROL register. Do proper left shift to set it.
      Signed-off-by: default avatarAxel Lin <axel.lin@ingics.com>
      Acked-by: default avatarMarek Belisko <marek.belisko@streamunlimited.com>
      Signed-off-by: default avatarMark Brown <broonie@kernel.org>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      809f410c
    • Roger Quadros's avatar
      ARM: OMAP2+: hwmod: Fix _wait_target_ready() for hwmods without sysc · 02c82959
      Roger Quadros authored
      commit 9a258afa upstream.
      
      For hwmods without sysc, _init_mpu_rt_base(oh) won't be called and so
      _find_mpu_rt_port(oh) will return NULL thus preventing ready state check
      on those modules after the module is enabled.
      
      This can potentially cause a bus access error if the module is accessed
      before the module is ready.
      
      Fix this by unconditionally calling _init_mpu_rt_base() during hwmod
      _init(). Do ioremap only if we need SYSC access.
      
      Eventhough _wait_target_ready() check doesn't really need MPU RT port but
      just the PRCM registers, we still mandate that the hwmod must have an
      MPU RT port if ready state check needs to be done. Else it would mean that
      the module is not accessible by MPU so there is no point in waiting
      for target to be ready.
      
      e.g. this fixes the below DCAN bus access error on AM437x-gp-evm.
      
      [   16.672978] ------------[ cut here ]------------
      [   16.677885] WARNING: CPU: 0 PID: 1580 at drivers/bus/omap_l3_noc.c:147 l3_interrupt_handler+0x234/0x35c()
      [   16.687946] 44000000.ocp:L3 Custom Error: MASTER M2 (64-bit) TARGET L4_PER_0 (Read): Data Access in User mode during Functional access
      [   16.700654] Modules linked in: xhci_hcd btwilink ti_vpfe dwc3 videobuf2_core ov2659 bluetooth v4l2_common videodev ti_am335x_adc kfifo_buf industrialio c_can_platform videobuf2_dma_contig media snd_soc_tlv320aic3x pixcir_i2c_ts c_can dc
      [   16.731144] CPU: 0 PID: 1580 Comm: rpc.statd Not tainted 3.14.26-02561-gf733aa036398 #180
      [   16.739747] Backtrace:
      [   16.742336] [<c0011108>] (dump_backtrace) from [<c00112a4>] (show_stack+0x18/0x1c)
      [   16.750285]  r6:00000093 r5:00000009 r4:eab5b8a8 r3:00000000
      [   16.756252] [<c001128c>] (show_stack) from [<c05a4418>] (dump_stack+0x20/0x28)
      [   16.763870] [<c05a43f8>] (dump_stack) from [<c0037120>] (warn_slowpath_common+0x6c/0x8c)
      [   16.772408] [<c00370b4>] (warn_slowpath_common) from [<c00371e4>] (warn_slowpath_fmt+0x38/0x40)
      [   16.781550]  r8:c05d1f90 r7:c0730844 r6:c0730448 r5:80080003 r4:ed0cd210
      [   16.788626] [<c00371b0>] (warn_slowpath_fmt) from [<c027fa94>] (l3_interrupt_handler+0x234/0x35c)
      [   16.797968]  r3:ed0cd480 r2:c0730508
      [   16.801747] [<c027f860>] (l3_interrupt_handler) from [<c0063758>] (handle_irq_event_percpu+0x54/0x1bc)
      [   16.811533]  r10:ed005600 r9:c084855b r8:0000002a r7:00000000 r6:00000000 r5:0000002a
      [   16.819780]  r4:ed0e6d80
      [   16.822453] [<c0063704>] (handle_irq_event_percpu) from [<c00638f0>] (handle_irq_event+0x30/0x40)
      [   16.831789]  r10:eb2b6938 r9:eb2b6960 r8:bf011420 r7:fa240100 r6:00000000 r5:0000002a
      [   16.840052]  r4:ed005600
      [   16.842744] [<c00638c0>] (handle_irq_event) from [<c00661d8>] (handle_fasteoi_irq+0x74/0x128)
      [   16.851702]  r4:ed005600 r3:00000000
      [   16.855479] [<c0066164>] (handle_fasteoi_irq) from [<c0063068>] (generic_handle_irq+0x28/0x38)
      [   16.864523]  r4:0000002a r3:c0066164
      [   16.868294] [<c0063040>] (generic_handle_irq) from [<c000ef60>] (handle_IRQ+0x38/0x8c)
      [   16.876612]  r4:c081c640 r3:00000202
      [   16.880380] [<c000ef28>] (handle_IRQ) from [<c00084f0>] (gic_handle_irq+0x30/0x5c)
      [   16.888328]  r6:eab5ba38 r5:c0804460 r4:fa24010c r3:00000100
      [   16.894303] [<c00084c0>] (gic_handle_irq) from [<c05a8d80>] (__irq_svc+0x40/0x50)
      [   16.902193] Exception stack(0xeab5ba38 to 0xeab5ba80)
      [   16.907499] ba20:                                                       00000000 00000006
      [   16.916108] ba40: fa1d0000 fa1d0008 ed3d3000 eab5bab4 ed3d3460 c0842af4 bf011420 eb2b6960
      [   16.924716] ba60: eb2b6938 eab5ba8c eab5ba90 eab5ba80 bf035220 bf07702c 600f0013 ffffffff
      [   16.933317]  r7:eab5ba6c r6:ffffffff r5:600f0013 r4:bf07702c
      [   16.939317] [<bf077000>] (c_can_plat_read_reg_aligned_to_16bit [c_can_platform]) from [<bf035220>] (c_can_get_berr_counter+0x38/0x64 [c_can])
      [   16.952696] [<bf0351e8>] (c_can_get_berr_counter [c_can]) from [<bf010294>] (can_fill_info+0x124/0x15c [can_dev])
      [   16.963480]  r5:ec8c9740 r4:ed3d3000
      [   16.967253] [<bf010170>] (can_fill_info [can_dev]) from [<c0502fa8>] (rtnl_fill_ifinfo+0x58c/0x8fc)
      [   16.976749]  r6:ec8c9740 r5:ed3d3000 r4:eb2b6780
      [   16.981613] [<c0502a1c>] (rtnl_fill_ifinfo) from [<c0503408>] (rtnl_dump_ifinfo+0xf0/0x1dc)
      [   16.990401]  r10:ec8c9740 r9:00000000 r8:00000000 r7:00000000 r6:ebd4d1b4 r5:ed3d3000
      [   16.998671]  r4:00000000
      [   17.001342] [<c0503318>] (rtnl_dump_ifinfo) from [<c050e6e4>] (netlink_dump+0xa8/0x1e0)
      [   17.009772]  r10:00000000 r9:00000000 r8:c0503318 r7:ebf3e6c0 r6:ebd4d1b4 r5:ec8c9740
      [   17.018050]  r4:ebd4d000
      [   17.020714] [<c050e63c>] (netlink_dump) from [<c050ec10>] (__netlink_dump_start+0x104/0x154)
      [   17.029591]  r6:eab5bd34 r5:ec8c9980 r4:ebd4d000
      [   17.034454] [<c050eb0c>] (__netlink_dump_start) from [<c0505604>] (rtnetlink_rcv_msg+0x110/0x1f4)
      [   17.043778]  r7:00000000 r6:ec8c9980 r5:00000f40 r4:ebf3e6c0
      [   17.049743] [<c05054f4>] (rtnetlink_rcv_msg) from [<c05108e8>] (netlink_rcv_skb+0xb4/0xc8)
      [   17.058449]  r8:eab5bdac r7:ec8c9980 r6:c05054f4 r5:ec8c9980 r4:ebf3e6c0
      [   17.065534] [<c0510834>] (netlink_rcv_skb) from [<c0504134>] (rtnetlink_rcv+0x24/0x2c)
      [   17.073854]  r6:ebd4d000 r5:00000014 r4:ec8c9980 r3:c0504110
      [   17.079846] [<c0504110>] (rtnetlink_rcv) from [<c05102ac>] (netlink_unicast+0x180/0x1ec)
      [   17.088363]  r4:ed0c6800 r3:c0504110
      [   17.092113] [<c051012c>] (netlink_unicast) from [<c0510670>] (netlink_sendmsg+0x2ac/0x380)
      [   17.100813]  r10:00000000 r8:00000008 r7:ec8c9980 r6:ebd4d000 r5:eab5be70 r4:eab5bee4
      [   17.109083] [<c05103c4>] (netlink_sendmsg) from [<c04dfdb4>] (sock_sendmsg+0x90/0xb0)
      [   17.117305]  r10:00000000 r9:eab5a000 r8:becdda3c r7:0000000c r6:ea978400 r5:eab5be70
      [   17.125563]  r4:c05103c4
      [   17.128225] [<c04dfd24>] (sock_sendmsg) from [<c04e1c28>] (SyS_sendto+0xb8/0xdc)
      [   17.136001]  r6:becdda5c r5:00000014 r4:ecd37040
      [   17.140876] [<c04e1b70>] (SyS_sendto) from [<c000e680>] (ret_fast_syscall+0x0/0x30)
      [   17.148923]  r10:00000000 r8:c000e804 r7:00000122 r6:becdda5c r5:0000000c r4:becdda5c
      [   17.157169] ---[ end trace 2b71e15b38f58bad ]---
      
      Fixes: 6423d6df ("ARM: OMAP2+: hwmod: check for module address space during init")
      Signed-off-by: default avatarRoger Quadros <rogerq@ti.com>
      Signed-off-by: default avatarPaul Walmsley <paul@pwsan.com>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      02c82959
    • Eric W. Biederman's avatar
      sysfs: Create mountpoints with sysfs_create_mount_point · b8ad501a
      Eric W. Biederman authored
      commit f9bb4882 upstream.
      
      This allows for better documentation in the code and
      it allows for a simpler and fully correct version of
      fs_fully_visible to be written.
      
      The mount points converted and their filesystems are:
      /sys/hypervisor/s390/       s390_hypfs
      /sys/kernel/config/         configfs
      /sys/kernel/debug/          debugfs
      /sys/firmware/efi/efivars/  efivarfs
      /sys/fs/fuse/connections/   fusectl
      /sys/fs/pstore/             pstore
      /sys/kernel/tracing/        tracefs
      /sys/fs/cgroup/             cgroup
      /sys/kernel/security/       securityfs
      /sys/fs/selinux/            selinuxfs
      /sys/fs/smackfs/            smackfs
      Acked-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
      Signed-off-by: default avatarSeth Forshee <seth.forshee@canonical.com>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      b8ad501a
    • David S. Miller's avatar
      sparc64: Fix userspace FPU register corruptions. · 3b9378cc
      David S. Miller authored
      commit 44922150 upstream.
      
      If we have a series of events from userpsace, with %fprs=FPRS_FEF,
      like follows:
      
      ETRAP
      	ETRAP
      		VIS_ENTRY(fprs=0x4)
      		VIS_EXIT
      		RTRAP (kernel FPU restore with fpu_saved=0x4)
      	RTRAP
      
      We will not restore the user registers that were clobbered by the FPU
      using kernel code in the inner-most trap.
      
      Traps allocate FPU save slots in the thread struct, and FPU using
      sequences save the "dirty" FPU registers only.
      
      This works at the initial trap level because all of the registers
      get recorded into the top-level FPU save area, and we'll return
      to userspace with the FPU disabled so that any FPU use by the user
      will take an FPU disabled trap wherein we'll load the registers
      back up properly.
      
      But this is not how trap returns from kernel to kernel operate.
      
      The simplest fix for this bug is to always save all FPU register state
      for anything other than the top-most FPU save area.
      
      Getting rid of the optimized inner-slot FPU saving code ends up
      making VISEntryHalf degenerate into plain VISEntry.
      
      Longer term we need to do something smarter to reinstate the partial
      save optimizations.  Perhaps the fundament error is having trap entry
      and exit allocate FPU save slots and restore register state.  Instead,
      the VISEntry et al. calls should be doing that work.
      
      This bug is about two decades old.
      Reported-by: default avatarJames Y Knight <jyknight@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      3b9378cc
    • Benjamin Randazzo's avatar
      md: use kzalloc() when bitmap is disabled · 0624b99b
      Benjamin Randazzo authored
      commit b6878d9e upstream.
      
      In drivers/md/md.c get_bitmap_file() uses kmalloc() for creating a
      mdu_bitmap_file_t called "file".
      
      5769         file = kmalloc(sizeof(*file), GFP_NOIO);
      5770         if (!file)
      5771                 return -ENOMEM;
      
      This structure is copied to user space at the end of the function.
      
      5786         if (err == 0 &&
      5787             copy_to_user(arg, file, sizeof(*file)))
      5788                 err = -EFAULT
      
      But if bitmap is disabled only the first byte of "file" is initialized
      with zero, so it's possible to read some bytes (up to 4095) of kernel
      space memory from user space. This is an information leak.
      
      5775         /* bitmap disabled, zero the first byte and copy out */
      5776         if (!mddev->bitmap_info.file)
      5777                 file->pathname[0] = '\0';
      Signed-off-by: default avatarBenjamin Randazzo <benjamin@randazzo.fr>
      Signed-off-by: default avatarNeilBrown <neilb@suse.com>
      Cc: Moritz Mühlenhoff <jmm@inutil.org>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      0624b99b
    • Luis Henriques's avatar
      Linux 3.16.7-ckt16 · 72388a13
      Luis Henriques authored
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      72388a13
  3. 12 Aug, 2015 5 commits
    • Firo Yang's avatar
      md: fix a build warning · aac281ee
      Firo Yang authored
      commit 4e023612 upstream.
      
      Warning like this:
      
      drivers/md/md.c: In function "update_array_info":
      drivers/md/md.c:6394:26: warning: logical not is only applied
      to the left hand side of comparison [-Wlogical-not-parentheses]
            !mddev->persistent  != info->not_persistent||
      
      Fix it as Neil Brown said:
      mddev->persistent != !info->not_persistent ||
      Signed-off-by: default avatarFiro Yang <firogm@gmail.com>
      Signed-off-by: default avatarNeilBrown <neilb@suse.de>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      aac281ee
    • Alessio Igor Bogani's avatar
      mmc: sdhci: Fix FSL ESDHC reset handling quirk · 725614a0
      Alessio Igor Bogani authored
      commit 304f0a98 upstream.
      
      The commit 0718e59a ("mmc: sdhci: move FSL ESDHC reset handling quirk into
      esdhc code") states that Freescale esdhc is the only controller which needs
      the interrupt registers restored after a reset. So it moves
      SDHCI_QUIRK_RESTORE_IRQS_AFTER_RESET quirk handling code into the
      esdhc-imx driver only. Unfortunately the same controller is used in
      other boards which use the of-esdhc driver instead (like powerpc P2020).
      
      Restore interrupts after reset in the sdhci-of-esdhc driver also.
      Signed-off-by: default avatarAlessio Igor Bogani <alessio.bogani@elettra.eu>
      Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
      Cc: Jakub Kicinski <kubakici@wp.pl>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      725614a0
    • Heiko Carstens's avatar
      s390/process: fix sfpc inline assembly · 4a957da5
      Heiko Carstens authored
      commit e47994dd upstream.
      
      The sfpc inline assembly within execve_tail() may incorrectly set bits
      28-31 of the sfpc instruction to a value which is not zero.
      These bits however are currently unused and therefore should be zero
      so we won't get surprised if these bits will be used in the future.
      
      Therefore remove the second operand from the inline assembly.
      Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
      Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
      Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      4a957da5
    • Martin Schwidefsky's avatar
      s390/sclp: clear upper register halves in _sclp_print_early · 65f9f71d
      Martin Schwidefsky authored
      commit f9c87a6f upstream.
      
      If the kernel is compiled with gcc 5.1 and the XZ compression option
      the decompress_kernel function calls _sclp_print_early in 64-bit mode
      while the content of the upper register half of %r6 is non-zero.
      This causes a specification exception on the servc instruction in
      _sclp_servc.
      
      The _sclp_print_early function saves and restores the upper registers
      halves but it fails to clear them for the 31-bit code of the mini sclp
      driver.
      Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      65f9f71d
    • Al Viro's avatar
      freeing unlinked file indefinitely delayed · e2f9d514
      Al Viro authored
      commit 75a6f82a upstream.
      
      	Normally opening a file, unlinking it and then closing will have
      the inode freed upon close() (provided that it's not otherwise busy and
      has no remaining links, of course).  However, there's one case where that
      does *not* happen.  Namely, if you open it by fhandle with cold dcache,
      then unlink() and close().
      
      	In normal case you get d_delete() in unlink(2) notice that dentry
      is busy and unhash it; on the final dput() it will be forcibly evicted from
      dcache, triggering iput() and inode removal.  In this case, though, we end
      up with *two* dentries - disconnected (created by open-by-fhandle) and
      regular one (used by unlink()).  The latter will have its reference to inode
      dropped just fine, but the former will not - it's considered hashed (it
      is on the ->s_anon list), so it will stay around until the memory pressure
      will finally do it in.  As the result, we have the final iput() delayed
      indefinitely.  It's trivial to reproduce -
      
      void flush_dcache(void)
      {
              system("mount -o remount,rw /");
      }
      
      static char buf[20 * 1024 * 1024];
      
      main()
      {
              int fd;
              union {
                      struct file_handle f;
                      char buf[MAX_HANDLE_SZ];
              } x;
              int m;
      
              x.f.handle_bytes = sizeof(x);
              chdir("/root");
              mkdir("foo", 0700);
              fd = open("foo/bar", O_CREAT | O_RDWR, 0600);
              close(fd);
              name_to_handle_at(AT_FDCWD, "foo/bar", &x.f, &m, 0);
              flush_dcache();
              fd = open_by_handle_at(AT_FDCWD, &x.f, O_RDWR);
              unlink("foo/bar");
              write(fd, buf, sizeof(buf));
              system("df .");			/* 20Mb eaten */
              close(fd);
              system("df .");			/* should've freed those 20Mb */
              flush_dcache();
              system("df .");			/* should be the same as #2 */
      }
      
      will spit out something like
      Filesystem     1K-blocks   Used Available Use% Mounted on
      /dev/root         322023 303843      1131 100% /
      Filesystem     1K-blocks   Used Available Use% Mounted on
      /dev/root         322023 303843      1131 100% /
      Filesystem     1K-blocks   Used Available Use% Mounted on
      /dev/root         322023 283282     21692  93% /
      - inode gets freed only when dentry is finally evicted (here we trigger
      than by remount; normally it would've happened in response to memory
      pressure hell knows when).
      Acked-by: default avatarJ. Bruce Fields <bfields@fieldses.org>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      [ kamal: backport to 3.19-stable: no fast_dput() ]
      Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      e2f9d514