1. 30 Jan, 2016 3 commits
    • Dan Williams's avatar
      fs, block: force direct-I/O for dax-enabled block devices · 65f87ee7
      Dan Williams authored
      Similar to the file I/O path, re-direct all I/O to the DAX path for I/O
      to a block-device special file.  Both regular files and device special
      files can use the common filp->f_mapping->host lookup to determing is
      DAX is enabled.
      
      Otherwise, we confuse the DAX code that does not expect to find live
      data in the page cache:
      
          ------------[ cut here ]------------
          WARNING: CPU: 0 PID: 7676 at mm/filemap.c:217
          __delete_from_page_cache+0x9f6/0xb60()
          Modules linked in:
          CPU: 0 PID: 7676 Comm: a.out Not tainted 4.4.0+ #276
          Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
           00000000ffffffff ffff88006d3f7738 ffffffff82999e2d 0000000000000000
           ffff8800620a0000 ffffffff86473d20 ffff88006d3f7778 ffffffff81352089
           ffffffff81658d36 ffffffff86473d20 00000000000000d9 ffffea0000009d60
          Call Trace:
           [<     inline     >] __dump_stack lib/dump_stack.c:15
           [<ffffffff82999e2d>] dump_stack+0x6f/0xa2 lib/dump_stack.c:50
           [<ffffffff81352089>] warn_slowpath_common+0xd9/0x140 kernel/panic.c:482
           [<ffffffff813522b9>] warn_slowpath_null+0x29/0x30 kernel/panic.c:515
           [<ffffffff81658d36>] __delete_from_page_cache+0x9f6/0xb60 mm/filemap.c:217
           [<ffffffff81658fb2>] delete_from_page_cache+0x112/0x200 mm/filemap.c:244
           [<ffffffff818af369>] __dax_fault+0x859/0x1800 fs/dax.c:487
           [<ffffffff8186f4f6>] blkdev_dax_fault+0x26/0x30 fs/block_dev.c:1730
           [<     inline     >] wp_pfn_shared mm/memory.c:2208
           [<ffffffff816e9145>] do_wp_page+0xc85/0x14f0 mm/memory.c:2307
           [<     inline     >] handle_pte_fault mm/memory.c:3323
           [<     inline     >] __handle_mm_fault mm/memory.c:3417
           [<ffffffff816ecec3>] handle_mm_fault+0x2483/0x4640 mm/memory.c:3446
           [<ffffffff8127eff6>] __do_page_fault+0x376/0x960 arch/x86/mm/fault.c:1238
           [<ffffffff8127f738>] trace_do_page_fault+0xe8/0x420 arch/x86/mm/fault.c:1331
           [<ffffffff812705c4>] do_async_page_fault+0x14/0xd0 arch/x86/kernel/kvm.c:264
           [<ffffffff86338f78>] async_page_fault+0x28/0x30 arch/x86/entry/entry_64.S:986
           [<ffffffff86336c36>] entry_SYSCALL_64_fastpath+0x16/0x7a
          arch/x86/entry/entry_64.S:185
          ---[ end trace dae21e0f85f1f98c ]---
      
      Fixes: 5a023cdb ("block: enable dax for raw block devices")
      Reported-by: default avatarDmitry Vyukov <dvyukov@google.com>
      Reported-by: default avatarKirill A. Shutemov <kirill@shutemov.name>
      Suggested-by: default avatarJan Kara <jack@suse.cz>
      Reviewed-by: default avatarJan Kara <jack@suse.cz>
      Suggested-by: default avatarMatthew Wilcox <willy@linux.intel.com>
      Tested-by: default avatarRoss Zwisler <ross.zwisler@linux.intel.com>
      Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
      65f87ee7
    • Dan Williams's avatar
      devm_memremap_pages: fix vmem_altmap lifetime + alignment handling · eb7d78c9
      Dan Williams authored
      to_vmem_altmap() needs to return valid results until
      arch_remove_memory() completes.  It also needs to be valid for any pfn
      in a section regardless of whether that pfn maps to data.  This escape
      was a result of a bug in the unit test.
      
      The signature of this bug is that free_pagetable() fails to retrieve a
      vmem_altmap and goes off into the weeds:
      
       BUG: unable to handle kernel NULL pointer dereference at           (null)
       IP: [<ffffffff811d2629>] get_pfnblock_flags_mask+0x49/0x60
       [..]
       Call Trace:
        [<ffffffff811d3477>] free_hot_cold_page+0x97/0x1d0
        [<ffffffff811d367a>] __free_pages+0x2a/0x40
        [<ffffffff8191e669>] free_pagetable+0x8c/0xd4
        [<ffffffff8191ef4e>] remove_pagetable+0x37a/0x808
        [<ffffffff8191b210>] vmemmap_free+0x10/0x20
      
      Fixes: 4b94ffdc ("x86, mm: introduce vmem_altmap to augment vmemmap_populate()")
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Reported-by: default avatarJeff Moyer <jmoyer@redhat.com>
      Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
      eb7d78c9
    • Dan Williams's avatar
      libnvdimm, pfn: fix restoring memmap location · 45eb570a
      Dan Williams authored
      This path was missed when turning on the memmap in pmem support.  Permit
      'pmem' as a valid location for the map.
      Reported-by: default avatarJeff Moyer <jmoyer@redhat.com>
      Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
      45eb570a
  2. 26 Jan, 2016 1 commit
  3. 24 Jan, 2016 36 commits