1. 20 Feb, 2015 1 commit
    • David Howells's avatar
      configfs: Fix potential NULL d_inode dereference · 112fc894
      David Howells authored
      
      
      Code that does this:
      
      		if (!(d_unhashed(dentry) && dentry->d_inode)) {
      			...
      			simple_unlink(parent->d_inode, dentry);
      		}
      
      is broken because:
      
          !(d_unhashed(dentry) && dentry->d_inode)
      
      is equivalent to:
      
          !d_unhashed(dentry) || !dentry->d_inode
      
      so it is possible to get into simple_unlink() with dentry->d_inode == NULL.
      
      simple_unlink(), however, assumes dentry->d_inode cannot be NULL.
      
      I think that what was meant is this:
      
          !d_unhashed(dentry) && dentry->d_inode
      
      and that the logical-not operator or the final close-bracket was misplaced.
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      cc: Joel Becker <joel.becker@oracle.com>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      112fc894
  2. 18 Feb, 2015 1 commit
  3. 20 Jan, 2015 2 commits
  4. 04 Jun, 2014 2 commits
  5. 18 Sep, 2012 1 commit
  6. 21 Mar, 2012 2 commits
  7. 04 Jan, 2012 1 commit
  8. 13 Dec, 2011 1 commit
  9. 27 Sep, 2011 1 commit
    • Paul Bolle's avatar
      doc: fix broken references · 395cf969
      Paul Bolle authored
      
      
      There are numerous broken references to Documentation files (in other
      Documentation files, in comments, etc.). These broken references are
      caused by typo's in the references, and by renames or removals of the
      Documentation files. Some broken references are simply odd.
      
      Fix these broken references, sometimes by dropping the irrelevant text
      they were part of.
      Signed-off-by: default avatarPaul Bolle <pebolle@tiscali.nl>
      Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
      395cf969
  10. 07 Jan, 2011 3 commits
  11. 26 Oct, 2010 1 commit
    • Christoph Hellwig's avatar
      fs: do not assign default i_ino in new_inode · 85fe4025
      Christoph Hellwig authored
      
      
      Instead of always assigning an increasing inode number in new_inode
      move the call to assign it into those callers that actually need it.
      For now callers that need it is estimated conservatively, that is
      the call is added to all filesystems that do not assign an i_ino
      by themselves.  For a few more filesystems we can avoid assigning
      any inode number given that they aren't user visible, and for others
      it could be done lazily when an inode number is actually needed,
      but that's left for later patches.
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      85fe4025
  12. 04 Jun, 2010 2 commits
  13. 28 May, 2010 1 commit
  14. 30 Mar, 2010 1 commit
    • Tejun Heo's avatar
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      Tejun Heo authored
      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: default avatarTejun Heo <tj@kernel.org>
      Guess-its-ok-by: default avatarChristoph Lameter <cl@linux-foundation.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6
  15. 11 Sep, 2009 1 commit
  16. 30 Apr, 2009 1 commit
    • Louis Rilling's avatar
      configfs: Silence lockdep on mkdir() and rmdir() · e74cc06d
      Louis Rilling authored
      
      
      When attaching default groups (subdirs) of a new group (in mkdir() or
      in configfs_register()), configfs recursively takes inode's mutexes
      along the path from the parent of the new group to the default
      subdirs. This is needed to ensure that the VFS will not race with
      operations on these sub-dirs. This is safe for the following reasons:
      
      - the VFS allows one to lock first an inode and second one of its
        children (The lock subclasses for this pattern are respectively
        I_MUTEX_PARENT and I_MUTEX_CHILD);
      - from this rule any inode path can be recursively locked in
        descending order as long as it stays under a single mountpoint and
        does not follow symlinks.
      
      Unfortunately lockdep does not know (yet?) how to handle such
      recursion.
      
      I've tried to use Peter Zijlstra's lock_set_subclass() helper to
      upgrade i_mutexes from I_MUTEX_CHILD to I_MUTEX_PARENT when we know
      that we might recursively lock some of their descendant, but this
      usage does not seem to fit the purpose of lock_set_subclass() because
      it leads to several i_mutex locked with subclass I_MUTEX_PARENT by
      the same task.
      
      >From inside configfs it is not possible to serialize those recursive
      locking with a top-level one, because mkdir() and rmdir() are already
      called with inodes locked by the VFS. So using some
      mutex_lock_nest_lock() is not an option.
      
      I am proposing two solutions:
      1) one that wraps recursive mutex_lock()s with
         lockdep_off()/lockdep_on().
      2) (as suggested earlier by Peter Zijlstra) one that puts the
         i_mutexes recursively locked in different classes based on their
         depth from the top-level config_group created. This
         induces an arbitrary limit (MAX_LOCK_DEPTH - 2 == 46) on the
         nesting of configfs default groups whenever lockdep is activated
         but this limit looks reasonably high. Unfortunately, this also
         isolates VFS operations on configfs default groups from the others
         and thus lowers the chances to detect locking issues.
      
      Nobody likes solution 1), which I can understand.
      
      This patch implements solution 2). However lockdep is still not happy with
      configfs_depend_item(). Next patch reworks the locking of
      configfs_depend_item() and finally makes lockdep happy.
      
      [ Note: This hides a few locking interactions with the VFS from lockdep.
        That was my big concern, because we like lockdep's protection.  However,
        the current state always dumps a spurious warning.  The locking is
        correct, so I tell people to ignore the warning and that we'll keep
        our eyes on the locking to make sure it stays correct.  With this patch,
        we eliminate the warning.  We do lose some of the lockdep protections,
        but this only means that we still have to keep our eyes on the locking.
        We're going to do that anyway.  -- Joel ]
      Signed-off-by: default avatarLouis Rilling <louis.rilling@kerlabs.com>
      Signed-off-by: default avatarJoel Becker <joel.becker@oracle.com>
      e74cc06d
  17. 05 Jan, 2009 1 commit
  18. 14 Jul, 2008 1 commit
    • Louis Rilling's avatar
      configfs: Introduce configfs_dirent_lock · 6f610764
      Louis Rilling authored
      
      
      This patch introduces configfs_dirent_lock spinlock to protect configfs_dirent
      traversals against linkage mutations (add/del/move). This will allow
      configfs_detach_prep() to avoid locking i_mutexes.
      
      Locking rules for configfs_dirent linkage mutations are the same plus the
      requirement of taking configfs_dirent_lock. For configfs_dirent walking, one can
      either take appropriate i_mutex as before, or take configfs_dirent_lock.
      
      The spinlock could actually be a mutex, but the critical sections are either
      O(1) or should not be too long (default groups walking in last patch).
      
      ChangeLog:
        - Clarify the comment on configfs_dirent_lock usage
        - Move sd->s_element init before linking the new dirent
        - In lseek(), do not release configfs_dirent_lock before the dirent is
          relinked.
      Signed-off-by: default avatarLouis Rilling <Louis.Rilling@kerlabs.com>
      Signed-off-by: default avatarJoel Becker <joel.becker@oracle.com>
      6f610764
  19. 30 Apr, 2008 1 commit
  20. 17 Oct, 2007 1 commit
  21. 16 Oct, 2007 1 commit
  22. 21 May, 2007 1 commit
    • Alexey Dobriyan's avatar
      Detach sched.h from mm.h · e8edc6e0
      Alexey Dobriyan authored
      
      
      First thing mm.h does is including sched.h solely for can_do_mlock() inline
      function which has "current" dereference inside. By dealing with can_do_mlock()
      mm.h can be detached from sched.h which is good. See below, why.
      
      This patch
      a) removes unconditional inclusion of sched.h from mm.h
      b) makes can_do_mlock() normal function in mm/mlock.c
      c) exports can_do_mlock() to not break compilation
      d) adds sched.h inclusions back to files that were getting it indirectly.
      e) adds less bloated headers to some files (asm/signal.h, jiffies.h) that were
         getting them indirectly
      
      Net result is:
      a) mm.h users would get less code to open, read, preprocess, parse, ... if
         they don't need sched.h
      b) sched.h stops being dependency for significant number of files:
         on x86_64 allmodconfig touching sched.h results in recompile of 4083 files,
         after patch it's only 3744 (-8.3%).
      
      Cross-compile tested on
      
      	all arm defconfigs, all mips defconfigs, all powerpc defconfigs,
      	alpha alpha-up
      	arm
      	i386 i386-up i386-defconfig i386-allnoconfig
      	ia64 ia64-up
      	m68k
      	mips
      	parisc parisc-up
      	powerpc powerpc-up
      	s390 s390-up
      	sparc sparc-up
      	sparc64 sparc64-up
      	um-x86_64
      	x86_64 x86_64-up x86_64-defconfig x86_64-allnoconfig
      
      as well as my two usual configs.
      Signed-off-by: default avatarAlexey Dobriyan <adobriyan@gmail.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      e8edc6e0
  23. 12 Feb, 2007 1 commit
  24. 27 Sep, 2006 2 commits
  25. 28 Jun, 2006 1 commit
  26. 03 Feb, 2006 2 commits
  27. 09 Jan, 2006 1 commit
  28. 03 Jan, 2006 1 commit