1. 08 2月, 2014 1 次提交
  2. 23 2月, 2013 1 次提交
  3. 30 11月, 2012 1 次提交
  4. 26 9月, 2012 1 次提交
    • M
      Fix a crash when block device is read and block size is changed at the same time · b87570f5
      Mikulas Patocka 提交于
      The kernel may crash when block size is changed and I/O is issued
      simultaneously.
      
      Because some subsystems (udev or lvm) may read any block device anytime,
      the bug actually puts any code that changes a block device size in
      jeopardy.
      
      The crash can be reproduced if you place "msleep(1000)" to
      blkdev_get_blocks just before "bh->b_size = max_blocks <<
      inode->i_blkbits;".
      Then, run "dd if=/dev/ram0 of=/dev/null bs=4k count=1 iflag=direct"
      While it is waiting in msleep, run "blockdev --setbsz 2048 /dev/ram0"
      You get a BUG.
      
      The direct and non-direct I/O is written with the assumption that block
      size does not change. It doesn't seem practical to fix these crashes
      one-by-one there may be many crash possibilities when block size changes
      at a certain place and it is impossible to find them all and verify the
      code.
      
      This patch introduces a new rw-lock bd_block_size_semaphore. The lock is
      taken for read during I/O. It is taken for write when changing block
      size. Consequently, block size can't be changed while I/O is being
      submitted.
      
      For asynchronous I/O, the patch only prevents block size change while
      the I/O is being submitted. The block size can change when the I/O is in
      progress or when the I/O is being finished. This is acceptable because
      there are no accesses to block size when asynchronous I/O is being
      finished.
      
      The patch prevents block size changing while the device is mapped with
      mmap.
      Signed-off-by: NMikulas Patocka <mpatocka@redhat.com>
      Signed-off-by: NJens Axboe <axboe@kernel.dk>
      b87570f5
  5. 04 1月, 2012 1 次提交
  6. 15 9月, 2011 1 次提交
  7. 07 5月, 2011 2 次提交
  8. 13 11月, 2010 1 次提交
    • T
      block: make blkdev_get/put() handle exclusive access · e525fd89
      Tejun Heo 提交于
      Over time, block layer has accumulated a set of APIs dealing with bdev
      open, close, claim and release.
      
      * blkdev_get/put() are the primary open and close functions.
      
      * bd_claim/release() deal with exclusive open.
      
      * open/close_bdev_exclusive() are combination of open and claim and
        the other way around, respectively.
      
      * bd_link/unlink_disk_holder() to create and remove holder/slave
        symlinks.
      
      * open_by_devnum() wraps bdget() + blkdev_get().
      
      The interface is a bit confusing and the decoupling of open and claim
      makes it impossible to properly guarantee exclusive access as
      in-kernel open + claim sequence can disturb the existing exclusive
      open even before the block layer knows the current open if for another
      exclusive access.  Reorganize the interface such that,
      
      * blkdev_get() is extended to include exclusive access management.
        @holder argument is added and, if is @FMODE_EXCL specified, it will
        gain exclusive access atomically w.r.t. other exclusive accesses.
      
      * blkdev_put() is similarly extended.  It now takes @mode argument and
        if @FMODE_EXCL is set, it releases an exclusive access.  Also, when
        the last exclusive claim is released, the holder/slave symlinks are
        removed automatically.
      
      * bd_claim/release() and close_bdev_exclusive() are no longer
        necessary and either made static or removed.
      
      * bd_link_disk_holder() remains the same but bd_unlink_disk_holder()
        is no longer necessary and removed.
      
      * open_bdev_exclusive() becomes a simple wrapper around lookup_bdev()
        and blkdev_get().  It also has an unexpected extra bdev_read_only()
        test which probably should be moved into blkdev_get().
      
      * open_by_devnum() is modified to take @holder argument and pass it to
        blkdev_get().
      
      Most of bdev open/close operations are unified into blkdev_get/put()
      and most exclusive accesses are tested atomically at the open time (as
      it should).  This cleans up code and removes some, both valid and
      invalid, but unnecessary all the same, corner cases.
      
      open_bdev_exclusive() and open_by_devnum() can use further cleanup -
      rename to blkdev_get_by_path() and blkdev_get_by_devt() and drop
      special features.  Well, let's leave them for another day.
      
      Most conversions are straight-forward.  drbd conversion is a bit more
      involved as there was some reordering, but the logic should stay the
      same.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Acked-by: NNeil Brown <neilb@suse.de>
      Acked-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
      Acked-by: NMike Snitzer <snitzer@redhat.com>
      Acked-by: NPhilipp Reisner <philipp.reisner@linbit.com>
      Cc: Peter Osterlund <petero2@telia.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Jan Kara <jack@suse.cz>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Andreas Dilger <adilger.kernel@dilger.ca>
      Cc: "Theodore Ts'o" <tytso@mit.edu>
      Cc: Mark Fasheh <mfasheh@suse.com>
      Cc: Joel Becker <joel.becker@oracle.com>
      Cc: Alex Elder <aelder@sgi.com>
      Cc: Christoph Hellwig <hch@infradead.org>
      Cc: dm-devel@redhat.com
      Cc: drbd-dev@lists.linbit.com
      Cc: Leo Chen <leochen@broadcom.com>
      Cc: Scott Branden <sbranden@broadcom.com>
      Cc: Chris Mason <chris.mason@oracle.com>
      Cc: Steven Whitehouse <swhiteho@redhat.com>
      Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
      Cc: Joern Engel <joern@logfs.org>
      Cc: reiserfs-devel@vger.kernel.org
      Cc: Alexander Viro <viro@zeniv.linux.org.uk>
      e525fd89
  9. 19 10月, 2010 1 次提交
    • A
      fix rawctl compat ioctls breakage on amd64 and itanic · c4a04727
      Al Viro 提交于
      RAW_SETBIND and RAW_GETBIND 32bit versions are fscked in interesting ways.
      
      1) fs/compat_ioctl.c has COMPATIBLE_IOCTL(RAW_SETBIND) followed by
      HANDLE_IOCTL(RAW_SETBIND, raw_ioctl).  The latter is ignored.
      
      2) on amd64 (and itanic) the damn thing is broken - we have int + u64 + u64
      and layouts on i386 and amd64 are _not_ the same.  raw_ioctl() would
      work there, but it's never called due to (1).  As it is, i386 /sbin/raw
      definitely doesn't work on amd64 boxen.
      
      3) switching to raw_ioctl() as is would *not* work on e.g. sparc64 and ppc64,
      which would be rather sad, seeing that normal userland there is 32bit.
      The thing is, slapping __packed on the struct in question does not DTRT -
      it eliminates *all* padding.  The real solution is to use compat_u64.
      
      4) of course, all that stuff has no business being outside of raw.c in the
      first place - there should be ->compat_ioctl() for /dev/rawctl instead of
      messing with compat_ioctl.c.
      
      [akpm@linux-foundation.org: coding-style fixes]
      [arnd@arndb.de: port to 2.6.36]
      Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NArnd Bergmann <arnd@arndb.de>
      c4a04727
  10. 16 9月, 2010 1 次提交
  11. 17 5月, 2010 1 次提交
  12. 07 4月, 2010 2 次提交
  13. 30 3月, 2010 1 次提交
    • T
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      Tejun Heo 提交于
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
      
      percpu.h is included by sched.h and module.h and thus ends up being
      included when building most .c files.  percpu.h includes slab.h which
      in turn includes gfp.h making everything defined by the two files
      universally available and complicating inclusion dependencies.
      
      percpu.h -> slab.h dependency is about to be removed.  Prepare for
      this change by updating users of gfp and slab facilities include those
      headers directly instead of assuming availability.  As this conversion
      needs to touch large number of source files, the following script is
      used as the basis of conversion.
      
        http://userweb.kernel.org/~tj/misc/slabh-sweep.py
      
      The script does the followings.
      
      * Scan files for gfp and slab usages and update includes such that
        only the necessary includes are there.  ie. if only gfp is used,
        gfp.h, if slab is used, slab.h.
      
      * When the script inserts a new include, it looks at the include
        blocks and try to put the new include such that its order conforms
        to its surrounding.  It's put in the include block which contains
        core kernel includes, in the same order that the rest are ordered -
        alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
        doesn't seem to be any matching order.
      
      * If the script can't find a place to put a new include (mostly
        because the file doesn't have fitting include block), it prints out
        an error message indicating which .h file needs to be added to the
        file.
      
      The conversion was done in the following steps.
      
      1. The initial automatic conversion of all .c files updated slightly
         over 4000 files, deleting around 700 includes and adding ~480 gfp.h
         and ~3000 slab.h inclusions.  The script emitted errors for ~400
         files.
      
      2. Each error was manually checked.  Some didn't need the inclusion,
         some needed manual addition while adding it to implementation .h or
         embedding .c file was more appropriate for others.  This step added
         inclusions to around 150 files.
      
      3. The script was run again and the output was compared to the edits
         from #2 to make sure no file was left behind.
      
      4. Several build tests were done and a couple of problems were fixed.
         e.g. lib/decompress_*.c used malloc/free() wrappers around slab
         APIs requiring slab.h to be added manually.
      
      5. The script was run on all .h files but without automatically
         editing them as sprinkling gfp.h and slab.h inclusions around .h
         files could easily lead to inclusion dependency hell.  Most gfp.h
         inclusion directives were ignored as stuff from gfp.h was usually
         wildly available and often used in preprocessor macros.  Each
         slab.h inclusion directive was examined and added manually as
         necessary.
      
      6. percpu.h was updated not to include slab.h.
      
      7. Build test were done on the following configurations and failures
         were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
         distributed build env didn't work with gcov compiles) and a few
         more options had to be turned off depending on archs to make things
         build (like ipr on powerpc/64 which failed due to missing writeq).
      
         * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
         * powerpc and powerpc64 SMP allmodconfig
         * sparc and sparc64 SMP allmodconfig
         * ia64 SMP allmodconfig
         * s390 SMP allmodconfig
         * alpha SMP allmodconfig
         * um on x86_64 SMP allmodconfig
      
      8. percpu.h modifications were reverted so that it could be applied as
         a separate patch and serve as bisection point.
      
      Given the fact that I had only a couple of failures from tests on step
      6, I'm fairly confident about the coverage of this conversion patch.
      If there is a breakage, it's likely to be something in one of the arch
      headers which should be easily discoverable easily on most builds of
      the specific arch.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6
  14. 20 9月, 2009 1 次提交
  15. 14 9月, 2009 1 次提交
  16. 16 6月, 2009 1 次提交
  17. 23 5月, 2009 1 次提交
  18. 28 3月, 2009 1 次提交
  19. 21 10月, 2008 3 次提交
  20. 17 10月, 2008 1 次提交
  21. 22 7月, 2008 1 次提交
  22. 21 6月, 2008 1 次提交
  23. 13 10月, 2007 1 次提交
  24. 12 2月, 2007 1 次提交
    • J
      [PATCH] raw: don't allow the creation of a raw device with minor number 0 · 38584c14
      Jeff Moyer 提交于
      Minor number 0 (under the raw major) is reserved for the rawctl device
      file, which is used to query, set, and unset raw device bindings.  However,
      the ioctl interface does not protect the user from specifying a raw device
      with minor number 0:
      
      $ sudo ./raw /dev/raw/raw0 /dev/VolGroup00/swap
      /dev/raw/raw0:  bound to major 253, minor 2
      $ ls -l /dev/rawctl
      ls: /dev/rawctl: No such file or directory
      $ ls -l /dev/raw/raw0
      crw------- 1 root root 162, 0 Jan 12 10:51 /dev/raw/raw0
      $ sudo ./raw -qa
      Cannot open master raw device '/dev/rawctl' (No such file or directory)
      
      As you can see, this prevents any further raw operations from
      succeeding.  The fix (from Steve Fernandez) is quite simple--do not
      allow the allocation of minor number 0.
      Signed-off-by: NJeff Moyer <jmoyer@redhat.com>
      Cc: Steven Fernandez <sfernand@redhat.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      38584c14
  25. 09 12月, 2006 1 次提交
  26. 02 12月, 2006 1 次提交
  27. 01 10月, 2006 3 次提交
  28. 30 9月, 2006 1 次提交
  29. 04 7月, 2006 1 次提交
  30. 27 6月, 2006 3 次提交
  31. 23 3月, 2006 1 次提交
  32. 29 10月, 2005 1 次提交