1. 22 Dec, 2018 1 commit
  2. 03 Dec, 2018 2 commits
  3. 16 Nov, 2018 3 commits
  4. 15 Nov, 2018 1 commit
  5. 13 Nov, 2018 1 commit
  6. 10 Nov, 2018 2 commits
  7. 07 Nov, 2018 1 commit
  8. 28 Sep, 2018 1 commit
  9. 13 Aug, 2018 3 commits
  10. 02 Aug, 2018 3 commits
  11. 12 Jun, 2018 2 commits
    • Kees Cook's avatar
      treewide: kzalloc() -> kcalloc() · 6396bb22
      Kees Cook authored
      The kzalloc() function has a 2-factor argument form, kcalloc(). This
      patch replaces cases of:
      
              kzalloc(a * b, gfp)
      
      with:
              kcalloc(a * b, gfp)
      
      as well as handling cases of:
      
              kzalloc(a * b * c, gfp)
      
      with:
      
              kzalloc(array3_size(a, b, c), gfp)
      
      as it's slightly less ugly than:
      
              kzalloc_array(array_size(a, b), c, gfp)
      
      This does, however, attempt to ignore constant size factors like:
      
              kzalloc(4 * 1024, gfp)
      
      though any constants defined via macros get caught up in the conversion.
      
      Any factors with a sizeof() of "unsigned char", "char", and "u8" were
      dropped, since they're redundant.
      
      The Coccinelle script used for this was:
      
      // Fix redundant parens around sizeof().
      @@
      type TYPE;
      expression THING, E;
      @@
      
      (
        kzalloc(
      -	(sizeof(TYPE)) * E
      +	sizeof(TYPE) * E
        , ...)
      |
        kzalloc(
      -	(sizeof(THING)) * E
      +	sizeof(THING) * E
        , ...)
      )
      
      // Drop single-byte sizes and redundant parens.
      @@
      expression COUNT;
      typedef u8;
      typedef __u8;
      @@
      
      (
        kzalloc(
      -	sizeof(u8) * (COUNT)
      +	COUNT
        , ...)
      |
        kzalloc(
      -	sizeof(__u8) * (COUNT)
      +	COUNT
        , ...)
      |
        kzalloc(
      -	sizeof(char) * (COUNT)
      +	COUNT
        , ...)
      |
        kzalloc(
      -	sizeof(unsigned char) * (COUNT)
      +	COUNT
        , ...)
      |
        kzalloc(
      -	sizeof(u8) * COUNT
      +	COUNT
        , ...)
      |
        kzalloc(
      -	sizeof(__u8) * COUNT
      +	COUNT
        , ...)
      |
        kzalloc(
      -	sizeof(char) * COUNT
      +	COUNT
        , ...)
      |
        kzalloc(
      -	sizeof(unsigned char) * COUNT
      +	COUNT
        , ...)
      )
      
      // 2-factor product with sizeof(type/expression) and identifier or constant.
      @@
      type TYPE;
      expression THING;
      identifier COUNT_ID;
      constant COUNT_CONST;
      @@
      
      (
      - kzalloc
      + kcalloc
        (
      -	sizeof(TYPE) * (COUNT_ID)
      +	COUNT_ID, sizeof(TYPE)
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	sizeof(TYPE) * COUNT_ID
      +	COUNT_ID, sizeof(TYPE)
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	sizeof(TYPE) * (COUNT_CONST)
      +	COUNT_CONST, sizeof(TYPE)
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	sizeof(TYPE) * COUNT_CONST
      +	COUNT_CONST, sizeof(TYPE)
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	sizeof(THING) * (COUNT_ID)
      +	COUNT_ID, sizeof(THING)
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	sizeof(THING) * COUNT_ID
      +	COUNT_ID, sizeof(THING)
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	sizeof(THING) * (COUNT_CONST)
      +	COUNT_CONST, sizeof(THING)
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	sizeof(THING) * COUNT_CONST
      +	COUNT_CONST, sizeof(THING)
        , ...)
      )
      
      // 2-factor product, only identifiers.
      @@
      identifier SIZE, COUNT;
      @@
      
      - kzalloc
      + kcalloc
        (
      -	SIZE * COUNT
      +	COUNT, SIZE
        , ...)
      
      // 3-factor product with 1 sizeof(type) or sizeof(expression), with
      // redundant parens removed.
      @@
      expression THING;
      identifier STRIDE, COUNT;
      type TYPE;
      @@
      
      (
        kzalloc(
      -	sizeof(TYPE) * (COUNT) * (STRIDE)
      +	array3_size(COUNT, STRIDE, sizeof(TYPE))
        , ...)
      |
        kzalloc(
      -	sizeof(TYPE) * (COUNT) * STRIDE
      +	array3_size(COUNT, STRIDE, sizeof(TYPE))
        , ...)
      |
        kzalloc(
      -	sizeof(TYPE) * COUNT * (STRIDE)
      +	array3_size(COUNT, STRIDE, sizeof(TYPE))
        , ...)
      |
        kzalloc(
      -	sizeof(TYPE) * COUNT * STRIDE
      +	array3_size(COUNT, STRIDE, sizeof(TYPE))
        , ...)
      |
        kzalloc(
      -	sizeof(THING) * (COUNT) * (STRIDE)
      +	array3_size(COUNT, STRIDE, sizeof(THING))
        , ...)
      |
        kzalloc(
      -	sizeof(THING) * (COUNT) * STRIDE
      +	array3_size(COUNT, STRIDE, sizeof(THING))
        , ...)
      |
        kzalloc(
      -	sizeof(THING) * COUNT * (STRIDE)
      +	array3_size(COUNT, STRIDE, sizeof(THING))
        , ...)
      |
        kzalloc(
      -	sizeof(THING) * COUNT * STRIDE
      +	array3_size(COUNT, STRIDE, sizeof(THING))
        , ...)
      )
      
      // 3-factor product with 2 sizeof(variable), with redundant parens removed.
      @@
      expression THING1, THING2;
      identifier COUNT;
      type TYPE1, TYPE2;
      @@
      
      (
        kzalloc(
      -	sizeof(TYPE1) * sizeof(TYPE2) * COUNT
      +	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
        , ...)
      |
        kzalloc(
      -	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
      +	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
        , ...)
      |
        kzalloc(
      -	sizeof(THING1) * sizeof(THING2) * COUNT
      +	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
        , ...)
      |
        kzalloc(
      -	sizeof(THING1) * sizeof(THING2) * (COUNT)
      +	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
        , ...)
      |
        kzalloc(
      -	sizeof(TYPE1) * sizeof(THING2) * COUNT
      +	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
        , ...)
      |
        kzalloc(
      -	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
      +	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
        , ...)
      )
      
      // 3-factor product, only identifiers, with redundant parens removed.
      @@
      identifier STRIDE, SIZE, COUNT;
      @@
      
      (
        kzalloc(
      -	(COUNT) * STRIDE * SIZE
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kzalloc(
      -	COUNT * (STRIDE) * SIZE
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kzalloc(
      -	COUNT * STRIDE * (SIZE)
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kzalloc(
      -	(COUNT) * (STRIDE) * SIZE
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kzalloc(
      -	COUNT * (STRIDE) * (SIZE)
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kzalloc(
      -	(COUNT) * STRIDE * (SIZE)
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kzalloc(
      -	(COUNT) * (STRIDE) * (SIZE)
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kzalloc(
      -	COUNT * STRIDE * SIZE
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      )
      
      // Any remaining multi-factor products, first at least 3-factor products,
      // when they're not all constants...
      @@
      expression E1, E2, E3;
      constant C1, C2, C3;
      @@
      
      (
        kzalloc(C1 * C2 * C3, ...)
      |
        kzalloc(
      -	(E1) * E2 * E3
      +	array3_size(E1, E2, E3)
        , ...)
      |
        kzalloc(
      -	(E1) * (E2) * E3
      +	array3_size(E1, E2, E3)
        , ...)
      |
        kzalloc(
      -	(E1) * (E2) * (E3)
      +	array3_size(E1, E2, E3)
        , ...)
      |
        kzalloc(
      -	E1 * E2 * E3
      +	array3_size(E1, E2, E3)
        , ...)
      )
      
      // And then all remaining 2 factors products when they're not all constants,
      // keeping sizeof() as the second factor argument.
      @@
      expression THING, E1, E2;
      type TYPE;
      constant C1, C2, C3;
      @@
      
      (
        kzalloc(sizeof(THING) * C2, ...)
      |
        kzalloc(sizeof(TYPE) * C2, ...)
      |
        kzalloc(C1 * C2 * C3, ...)
      |
        kzalloc(C1 * C2, ...)
      |
      - kzalloc
      + kcalloc
        (
      -	sizeof(TYPE) * (E2)
      +	E2, sizeof(TYPE)
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	sizeof(TYPE) * E2
      +	E2, sizeof(TYPE)
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	sizeof(THING) * (E2)
      +	E2, sizeof(THING)
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	sizeof(THING) * E2
      +	E2, sizeof(THING)
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	(E1) * E2
      +	E1, E2
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	(E1) * (E2)
      +	E1, E2
        , ...)
      |
      - kzalloc
      + kcalloc
        (
      -	E1 * E2
      +	E1, E2
        , ...)
      )
      Signed-off-by: default avatarKees Cook <keescook@chromium.org>
      6396bb22
    • Kees Cook's avatar
      treewide: kmalloc() -> kmalloc_array() · 6da2ec56
      Kees Cook authored
      The kmalloc() function has a 2-factor argument form, kmalloc_array(). This
      patch replaces cases of:
      
              kmalloc(a * b, gfp)
      
      with:
              kmalloc_array(a * b, gfp)
      
      as well as handling cases of:
      
              kmalloc(a * b * c, gfp)
      
      with:
      
              kmalloc(array3_size(a, b, c), gfp)
      
      as it's slightly less ugly than:
      
              kmalloc_array(array_size(a, b), c, gfp)
      
      This does, however, attempt to ignore constant size factors like:
      
              kmalloc(4 * 1024, gfp)
      
      though any constants defined via macros get caught up in the conversion.
      
      Any factors with a sizeof() of "unsigned char", "char", and "u8" were
      dropped, since they're redundant.
      
      The tools/ directory was manually excluded, since it has its own
      implementation of kmalloc().
      
      The Coccinelle script used for this was:
      
      // Fix redundant parens around sizeof().
      @@
      type TYPE;
      expression THING, E;
      @@
      
      (
        kmalloc(
      -	(sizeof(TYPE)) * E
      +	sizeof(TYPE) * E
        , ...)
      |
        kmalloc(
      -	(sizeof(THING)) * E
      +	sizeof(THING) * E
        , ...)
      )
      
      // Drop single-byte sizes and redundant parens.
      @@
      expression COUNT;
      typedef u8;
      typedef __u8;
      @@
      
      (
        kmalloc(
      -	sizeof(u8) * (COUNT)
      +	COUNT
        , ...)
      |
        kmalloc(
      -	sizeof(__u8) * (COUNT)
      +	COUNT
        , ...)
      |
        kmalloc(
      -	sizeof(char) * (COUNT)
      +	COUNT
        , ...)
      |
        kmalloc(
      -	sizeof(unsigned char) * (COUNT)
      +	COUNT
        , ...)
      |
        kmalloc(
      -	sizeof(u8) * COUNT
      +	COUNT
        , ...)
      |
        kmalloc(
      -	sizeof(__u8) * COUNT
      +	COUNT
        , ...)
      |
        kmalloc(
      -	sizeof(char) * COUNT
      +	COUNT
        , ...)
      |
        kmalloc(
      -	sizeof(unsigned char) * COUNT
      +	COUNT
        , ...)
      )
      
      // 2-factor product with sizeof(type/expression) and identifier or constant.
      @@
      type TYPE;
      expression THING;
      identifier COUNT_ID;
      constant COUNT_CONST;
      @@
      
      (
      - kmalloc
      + kmalloc_array
        (
      -	sizeof(TYPE) * (COUNT_ID)
      +	COUNT_ID, sizeof(TYPE)
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	sizeof(TYPE) * COUNT_ID
      +	COUNT_ID, sizeof(TYPE)
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	sizeof(TYPE) * (COUNT_CONST)
      +	COUNT_CONST, sizeof(TYPE)
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	sizeof(TYPE) * COUNT_CONST
      +	COUNT_CONST, sizeof(TYPE)
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	sizeof(THING) * (COUNT_ID)
      +	COUNT_ID, sizeof(THING)
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	sizeof(THING) * COUNT_ID
      +	COUNT_ID, sizeof(THING)
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	sizeof(THING) * (COUNT_CONST)
      +	COUNT_CONST, sizeof(THING)
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	sizeof(THING) * COUNT_CONST
      +	COUNT_CONST, sizeof(THING)
        , ...)
      )
      
      // 2-factor product, only identifiers.
      @@
      identifier SIZE, COUNT;
      @@
      
      - kmalloc
      + kmalloc_array
        (
      -	SIZE * COUNT
      +	COUNT, SIZE
        , ...)
      
      // 3-factor product with 1 sizeof(type) or sizeof(expression), with
      // redundant parens removed.
      @@
      expression THING;
      identifier STRIDE, COUNT;
      type TYPE;
      @@
      
      (
        kmalloc(
      -	sizeof(TYPE) * (COUNT) * (STRIDE)
      +	array3_size(COUNT, STRIDE, sizeof(TYPE))
        , ...)
      |
        kmalloc(
      -	sizeof(TYPE) * (COUNT) * STRIDE
      +	array3_size(COUNT, STRIDE, sizeof(TYPE))
        , ...)
      |
        kmalloc(
      -	sizeof(TYPE) * COUNT * (STRIDE)
      +	array3_size(COUNT, STRIDE, sizeof(TYPE))
        , ...)
      |
        kmalloc(
      -	sizeof(TYPE) * COUNT * STRIDE
      +	array3_size(COUNT, STRIDE, sizeof(TYPE))
        , ...)
      |
        kmalloc(
      -	sizeof(THING) * (COUNT) * (STRIDE)
      +	array3_size(COUNT, STRIDE, sizeof(THING))
        , ...)
      |
        kmalloc(
      -	sizeof(THING) * (COUNT) * STRIDE
      +	array3_size(COUNT, STRIDE, sizeof(THING))
        , ...)
      |
        kmalloc(
      -	sizeof(THING) * COUNT * (STRIDE)
      +	array3_size(COUNT, STRIDE, sizeof(THING))
        , ...)
      |
        kmalloc(
      -	sizeof(THING) * COUNT * STRIDE
      +	array3_size(COUNT, STRIDE, sizeof(THING))
        , ...)
      )
      
      // 3-factor product with 2 sizeof(variable), with redundant parens removed.
      @@
      expression THING1, THING2;
      identifier COUNT;
      type TYPE1, TYPE2;
      @@
      
      (
        kmalloc(
      -	sizeof(TYPE1) * sizeof(TYPE2) * COUNT
      +	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
        , ...)
      |
        kmalloc(
      -	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
      +	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
        , ...)
      |
        kmalloc(
      -	sizeof(THING1) * sizeof(THING2) * COUNT
      +	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
        , ...)
      |
        kmalloc(
      -	sizeof(THING1) * sizeof(THING2) * (COUNT)
      +	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
        , ...)
      |
        kmalloc(
      -	sizeof(TYPE1) * sizeof(THING2) * COUNT
      +	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
        , ...)
      |
        kmalloc(
      -	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
      +	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
        , ...)
      )
      
      // 3-factor product, only identifiers, with redundant parens removed.
      @@
      identifier STRIDE, SIZE, COUNT;
      @@
      
      (
        kmalloc(
      -	(COUNT) * STRIDE * SIZE
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kmalloc(
      -	COUNT * (STRIDE) * SIZE
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kmalloc(
      -	COUNT * STRIDE * (SIZE)
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kmalloc(
      -	(COUNT) * (STRIDE) * SIZE
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kmalloc(
      -	COUNT * (STRIDE) * (SIZE)
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kmalloc(
      -	(COUNT) * STRIDE * (SIZE)
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kmalloc(
      -	(COUNT) * (STRIDE) * (SIZE)
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      |
        kmalloc(
      -	COUNT * STRIDE * SIZE
      +	array3_size(COUNT, STRIDE, SIZE)
        , ...)
      )
      
      // Any remaining multi-factor products, first at least 3-factor products,
      // when they're not all constants...
      @@
      expression E1, E2, E3;
      constant C1, C2, C3;
      @@
      
      (
        kmalloc(C1 * C2 * C3, ...)
      |
        kmalloc(
      -	(E1) * E2 * E3
      +	array3_size(E1, E2, E3)
        , ...)
      |
        kmalloc(
      -	(E1) * (E2) * E3
      +	array3_size(E1, E2, E3)
        , ...)
      |
        kmalloc(
      -	(E1) * (E2) * (E3)
      +	array3_size(E1, E2, E3)
        , ...)
      |
        kmalloc(
      -	E1 * E2 * E3
      +	array3_size(E1, E2, E3)
        , ...)
      )
      
      // And then all remaining 2 factors products when they're not all constants,
      // keeping sizeof() as the second factor argument.
      @@
      expression THING, E1, E2;
      type TYPE;
      constant C1, C2, C3;
      @@
      
      (
        kmalloc(sizeof(THING) * C2, ...)
      |
        kmalloc(sizeof(TYPE) * C2, ...)
      |
        kmalloc(C1 * C2 * C3, ...)
      |
        kmalloc(C1 * C2, ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	sizeof(TYPE) * (E2)
      +	E2, sizeof(TYPE)
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	sizeof(TYPE) * E2
      +	E2, sizeof(TYPE)
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	sizeof(THING) * (E2)
      +	E2, sizeof(THING)
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	sizeof(THING) * E2
      +	E2, sizeof(THING)
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	(E1) * E2
      +	E1, E2
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	(E1) * (E2)
      +	E1, E2
        , ...)
      |
      - kmalloc
      + kmalloc_array
        (
      -	E1 * E2
      +	E1, E2
        , ...)
      )
      Signed-off-by: default avatarKees Cook <keescook@chromium.org>
      6da2ec56
  12. 05 Jun, 2018 4 commits
  13. 16 May, 2018 2 commits
  14. 14 May, 2018 2 commits
  15. 07 May, 2018 2 commits
    • Christoph Hellwig's avatar
      ide: remove the PCI_DMA_BUS_IS_PHYS check · 164c3d09
      Christoph Hellwig authored
      We now have ways to deal with drainage in the block layer, and libata has
      been using it for ages.  We also want to get rid of PCI_DMA_BUS_IS_PHYS
      now, so just reduce the PCI transfer size for ide - anyone who cares for
      performance on PCI controllers should have switched to libata long ago.
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      Reviewed-by: default avatarJens Axboe <axboe@kernel.dk>
      164c3d09
    • Christoph Hellwig's avatar
      ide: kill ide_toggle_bounce · 1d3b9917
      Christoph Hellwig authored
      ide_toggle_bounce did select various strange block bounce limits, including
      not bouncing at all as soon as an iommu is present in the system.  Given
      that the dma_map routines now handle any required bounce buffering except
      for ISA DMA, and the ide code already must handle either ISA DMA or highmem
      at least for iommu equipped systems we can get rid of the block layer
      bounce limit setting entirely.
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      Reviewed-by: default avatarJens Axboe <axboe@kernel.dk>
      1d3b9917
  16. 26 Mar, 2018 1 commit
  17. 17 Mar, 2018 1 commit
    • Bart Van Assche's avatar
      block: Move SECTOR_SIZE and SECTOR_SHIFT definitions into <linux/blkdev.h> · 233bde21
      Bart Van Assche authored
      It happens often while I'm preparing a patch for a block driver that
      I'm wondering: is a definition of SECTOR_SIZE and/or SECTOR_SHIFT
      available for this driver? Do I have to introduce definitions of these
      constants before I can use these constants? To avoid this confusion,
      move the existing definitions of SECTOR_SIZE and SECTOR_SHIFT into the
      <linux/blkdev.h> header file such that these become available for all
      block drivers. Make the SECTOR_SIZE definition in the uapi msdos_fs.h
      header file conditional to avoid that including that header file after
      <linux/blkdev.h> causes the compiler to complain about a SECTOR_SIZE
      redefinition.
      
      Note: the SECTOR_SIZE / SECTOR_SHIFT / SECTOR_BITS definitions have
      not been removed from uapi header files nor from NAND drivers in
      which these constants are used for another purpose than converting
      block layer offsets and sizes into a number of sectors.
      
      Cc: David S. Miller <davem@davemloft.net>
      Cc: Mike Snitzer <snitzer@redhat.com>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Minchan Kim <minchan@kernel.org>
      Cc: Nitin Gupta <ngupta@vflare.org>
      Reviewed-by: default avatarSergey Senozhatsky <sergey.senozhatsky@gmail.com>
      Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
      Reviewed-by: default avatarJohannes Thumshirn <jthumshirn@suse.de>
      Reviewed-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      Signed-off-by: default avatarBart Van Assche <bart.vanassche@wdc.com>
      Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      233bde21
  18. 11 Mar, 2018 1 commit
  19. 09 Mar, 2018 1 commit
    • Maurizio Lombardi's avatar
      cdrom: do not call check_disk_change() inside cdrom_open() · 2bbea6e1
      Maurizio Lombardi authored
      when mounting an ISO filesystem sometimes (very rarely)
      the system hangs because of a race condition between two tasks.
      
      PID: 6766   TASK: ffff88007b2a6dd0  CPU: 0   COMMAND: "mount"
       #0 [ffff880078447ae0] __schedule at ffffffff8168d605
       #1 [ffff880078447b48] schedule_preempt_disabled at ffffffff8168ed49
       #2 [ffff880078447b58] __mutex_lock_slowpath at ffffffff8168c995
       #3 [ffff880078447bb8] mutex_lock at ffffffff8168bdef
       #4 [ffff880078447bd0] sr_block_ioctl at ffffffffa00b6818 [sr_mod]
       #5 [ffff880078447c10] blkdev_ioctl at ffffffff812fea50
       #6 [ffff880078447c70] ioctl_by_bdev at ffffffff8123a8b3
       #7 [ffff880078447c90] isofs_fill_super at ffffffffa04fb1e1 [isofs]
       #8 [ffff880078447da8] mount_bdev at ffffffff81202570
       #9 [ffff880078447e18] isofs_mount at ffffffffa04f9828 [isofs]
      #10 [ffff880078447e28] mount_fs at ffffffff81202d09
      #11 [ffff880078447e70] vfs_kern_mount at ffffffff8121ea8f
      #12 [ffff880078447ea8] do_mount at ffffffff81220fee
      #13 [ffff880078447f28] sys_mount at ffffffff812218d6
      #14 [ffff880078447f80] system_call_fastpath at ffffffff81698c49
          RIP: 00007fd9ea914e9a  RSP: 00007ffd5d9bf648  RFLAGS: 00010246
          RAX: 00000000000000a5  RBX: ffffffff81698c49  RCX: 0000000000000010
          RDX: 00007fd9ec2bc210  RSI: 00007fd9ec2bc290  RDI: 00007fd9ec2bcf30
          RBP: 0000000000000000   R8: 0000000000000000   R9: 0000000000000010
          R10: 00000000c0ed0001  R11: 0000000000000206  R12: 00007fd9ec2bc040
          R13: 00007fd9eb6b2380  R14: 00007fd9ec2bc210  R15: 00007fd9ec2bcf30
          ORIG_RAX: 00000000000000a5  CS: 0033  SS: 002b
      
      This task was trying to mount the cdrom.  It allocated and configured a
      super_block struct and owned the write-lock for the super_block->s_umount
      rwsem. While exclusively owning the s_umount lock, it called
      sr_block_ioctl and waited to acquire the global sr_mutex lock.
      
      PID: 6785   TASK: ffff880078720fb0  CPU: 0   COMMAND: "systemd-udevd"
       #0 [ffff880078417898] __schedule at ffffffff8168d605
       #1 [ffff880078417900] schedule at ffffffff8168dc59
       #2 [ffff880078417910] rwsem_down_read_failed at ffffffff8168f605
       #3 [ffff880078417980] call_rwsem_down_read_failed at ffffffff81328838
       #4 [ffff8800784179d0] down_read at ffffffff8168cde0
       #5 [ffff8800784179e8] get_super at ffffffff81201cc7
       #6 [ffff880078417a10] __invalidate_device at ffffffff8123a8de
       #7 [ffff880078417a40] flush_disk at ffffffff8123a94b
       #8 [ffff880078417a88] check_disk_change at ffffffff8123ab50
       #9 [ffff880078417ab0] cdrom_open at ffffffffa00a29e1 [cdrom]
      #10 [ffff880078417b68] sr_block_open at ffffffffa00b6f9b [sr_mod]
      #11 [ffff880078417b98] __blkdev_get at ffffffff8123ba86
      #12 [ffff880078417bf0] blkdev_get at ffffffff8123bd65
      #13 [ffff880078417c78] blkdev_open at ffffffff8123bf9b
      #14 [ffff880078417c90] do_dentry_open at ffffffff811fc7f7
      #15 [ffff880078417cd8] vfs_open at ffffffff811fc9cf
      #16 [ffff880078417d00] do_last at ffffffff8120d53d
      #17 [ffff880078417db0] path_openat at ffffffff8120e6b2
      #18 [ffff880078417e48] do_filp_open at ffffffff8121082b
      #19 [ffff880078417f18] do_sys_open at ffffffff811fdd33
      #20 [ffff880078417f70] sys_open at ffffffff811fde4e
      #21 [ffff880078417f80] system_call_fastpath at ffffffff81698c49
          RIP: 00007f29438b0c20  RSP: 00007ffc76624b78  RFLAGS: 00010246
          RAX: 0000000000000002  RBX: ffffffff81698c49  RCX: 0000000000000000
          RDX: 00007f2944a5fa70  RSI: 00000000000a0800  RDI: 00007f2944a5fa70
          RBP: 00007f2944a5f540   R8: 0000000000000000   R9: 0000000000000020
          R10: 00007f2943614c40  R11: 0000000000000246  R12: ffffffff811fde4e
          R13: ffff880078417f78  R14: 000000000000000c  R15: 00007f2944a4b010
          ORIG_RAX: 0000000000000002  CS: 0033  SS: 002b
      
      This task tried to open the cdrom device, the sr_block_open function
      acquired the global sr_mutex lock. The call to check_disk_change()
      then saw an event flag indicating a possible media change and tried
      to flush any cached data for the device.
      As part of the flush, it tried to acquire the super_block->s_umount
      lock associated with the cdrom device.
      This was the same super_block as created and locked by the previous task.
      
      The first task acquires the s_umount lock and then the sr_mutex_lock;
      the second task acquires the sr_mutex_lock and then the s_umount lock.
      
      This patch fixes the issue by moving check_disk_change() out of
      cdrom_open() and let the caller take care of it.
      Signed-off-by: default avatarMaurizio Lombardi <mlombard@redhat.com>
      Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      2bbea6e1
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  25. 15 Nov, 2017 1 commit