1. 29 11月, 2013 2 次提交
    • M
      efi-pstore: Make efi-pstore return a unique id · fdeadb43
      Madper Xie 提交于
      Pstore fs expects that backends provide a unique id which could avoid
      pstore making entries as duplication or denominating entries the same
      name. So I combine the timestamp, part and count into id.
      Signed-off-by: NMadper Xie <cxie@redhat.com>
      Cc: Seiji Aguchi <seiji.aguchi@hds.com>
      Cc: stable@vger.kernel.org
      Signed-off-by: NMatt Fleming <matt.fleming@intel.com>
      fdeadb43
    • S
      efivars, efi-pstore: Hold off deletion of sysfs entry until the scan is completed · e0d59733
      Seiji Aguchi 提交于
      Currently, when mounting pstore file system, a read callback of
      efi_pstore driver runs mutiple times as below.
      
      - In the first read callback, scan efivar_sysfs_list from head and pass
        a kmsg buffer of a entry to an upper pstore layer.
      - In the second read callback, rescan efivar_sysfs_list from the entry
        and pass another kmsg buffer to it.
      - Repeat the scan and pass until the end of efivar_sysfs_list.
      
      In this process, an entry is read across the multiple read function
      calls. To avoid race between the read and erasion, the whole process
      above is protected by a spinlock, holding in open() and releasing in
      close().
      
      At the same time, kmemdup() is called to pass the buffer to pstore
      filesystem during it. And then, it causes a following lockdep warning.
      
      To make the dynamic memory allocation runnable without taking spinlock,
      holding off a deletion of sysfs entry if it happens while scanning it
      via efi_pstore, and deleting it after the scan is completed.
      
      To implement it, this patch introduces two flags, scanning and deleting,
      to efivar_entry.
      
      On the code basis, it seems that all the scanning and deleting logic is
      not needed because __efivars->lock are not dropped when reading from the
      EFI variable store.
      
      But, the scanning and deleting logic is still needed because an
      efi-pstore and a pstore filesystem works as follows.
      
      In case an entry(A) is found, the pointer is saved to psi->data.  And
      efi_pstore_read() passes the entry(A) to a pstore filesystem by
      releasing  __efivars->lock.
      
      And then, the pstore filesystem calls efi_pstore_read() again and the
      same entry(A), which is saved to psi->data, is used for resuming to scan
      a sysfs-list.
      
      So, to protect the entry(A), the logic is needed.
      
      [    1.143710] ------------[ cut here ]------------
      [    1.144058] WARNING: CPU: 1 PID: 1 at kernel/lockdep.c:2740 lockdep_trace_alloc+0x104/0x110()
      [    1.144058] DEBUG_LOCKS_WARN_ON(irqs_disabled_flags(flags))
      [    1.144058] Modules linked in:
      [    1.144058] CPU: 1 PID: 1 Comm: systemd Not tainted 3.11.0-rc5 #2
      [    1.144058]  0000000000000009 ffff8800797e9ae0 ffffffff816614a5 ffff8800797e9b28
      [    1.144058]  ffff8800797e9b18 ffffffff8105510d 0000000000000080 0000000000000046
      [    1.144058]  00000000000000d0 00000000000003af ffffffff81ccd0c0 ffff8800797e9b78
      [    1.144058] Call Trace:
      [    1.144058]  [<ffffffff816614a5>] dump_stack+0x54/0x74
      [    1.144058]  [<ffffffff8105510d>] warn_slowpath_common+0x7d/0xa0
      [    1.144058]  [<ffffffff8105517c>] warn_slowpath_fmt+0x4c/0x50
      [    1.144058]  [<ffffffff8131290f>] ? vsscanf+0x57f/0x7b0
      [    1.144058]  [<ffffffff810bbd74>] lockdep_trace_alloc+0x104/0x110
      [    1.144058]  [<ffffffff81192da0>] __kmalloc_track_caller+0x50/0x280
      [    1.144058]  [<ffffffff815147bb>] ? efi_pstore_read_func.part.1+0x12b/0x170
      [    1.144058]  [<ffffffff8115b260>] kmemdup+0x20/0x50
      [    1.144058]  [<ffffffff815147bb>] efi_pstore_read_func.part.1+0x12b/0x170
      [    1.144058]  [<ffffffff81514800>] ? efi_pstore_read_func.part.1+0x170/0x170
      [    1.144058]  [<ffffffff815148b4>] efi_pstore_read_func+0xb4/0xe0
      [    1.144058]  [<ffffffff81512b7b>] __efivar_entry_iter+0xfb/0x120
      [    1.144058]  [<ffffffff8151428f>] efi_pstore_read+0x3f/0x50
      [    1.144058]  [<ffffffff8128d7ba>] pstore_get_records+0x9a/0x150
      [    1.158207]  [<ffffffff812af25c>] ? selinux_d_instantiate+0x1c/0x20
      [    1.158207]  [<ffffffff8128ce30>] ? parse_options+0x80/0x80
      [    1.158207]  [<ffffffff8128ced5>] pstore_fill_super+0xa5/0xc0
      [    1.158207]  [<ffffffff811ae7d2>] mount_single+0xa2/0xd0
      [    1.158207]  [<ffffffff8128ccf8>] pstore_mount+0x18/0x20
      [    1.158207]  [<ffffffff811ae8b9>] mount_fs+0x39/0x1b0
      [    1.158207]  [<ffffffff81160550>] ? __alloc_percpu+0x10/0x20
      [    1.158207]  [<ffffffff811c9493>] vfs_kern_mount+0x63/0xf0
      [    1.158207]  [<ffffffff811cbb0e>] do_mount+0x23e/0xa20
      [    1.158207]  [<ffffffff8115b51b>] ? strndup_user+0x4b/0xf0
      [    1.158207]  [<ffffffff811cc373>] SyS_mount+0x83/0xc0
      [    1.158207]  [<ffffffff81673cc2>] system_call_fastpath+0x16/0x1b
      [    1.158207] ---[ end trace 61981bc62de9f6f4 ]---
      Signed-off-by: NSeiji Aguchi <seiji.aguchi@hds.com>
      Tested-by: NMadper Xie <cxie@redhat.com>
      Cc: stable@kernel.org
      Signed-off-by: NMatt Fleming <matt.fleming@intel.com>
      e0d59733
  2. 03 11月, 2013 1 次提交
  3. 01 11月, 2013 1 次提交
  4. 31 10月, 2013 2 次提交
  5. 24 10月, 2013 1 次提交
  6. 05 10月, 2013 1 次提交
  7. 25 9月, 2013 14 次提交
  8. 12 9月, 2013 5 次提交
  9. 05 9月, 2013 3 次提交
  10. 28 8月, 2013 1 次提交
    • G
      firmware: dcdbas: use binary attribute groups · 4c33dea7
      Greg KH 提交于
      The dcdbas code was "hand rolling" a binary attribute group, which the
      driver core now supports automatically.  So remove the "create the files
      by hand" logic, and just set the proper field in the attribute group
      structure, saving lots of code and headache.
      
      Cc: Doug Warzecha <Douglas_Warzecha@dell.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      
      --
      
       Doug, I can take this through my driver-core tree if you don't object.
      
       drivers/firmware/dcdbas.c |   19 ++-----------------
       1 file changed, 2 insertions(+), 17 deletions(-)
      4c33dea7
  11. 20 8月, 2013 3 次提交
  12. 01 8月, 2013 1 次提交
  13. 11 7月, 2013 1 次提交
  14. 04 7月, 2013 1 次提交
  15. 01 7月, 2013 1 次提交
  16. 29 6月, 2013 1 次提交
  17. 04 6月, 2013 1 次提交