1. 16 Nov, 2013 1 commit
  2. 19 Aug, 2013 1 commit
    • Linus Torvalds's avatar
      proc: more readdir conversion bug-fixes · fd3930f7
      Linus Torvalds authored
      In the previous commit, Richard Genoud fixed proc_root_readdir(), which
      had lost the check for whether all of the non-process /proc entries had
      been returned or not.
      
      But that in turn exposed _another_ bug, namely that the original readdir
      conversion patch had yet another problem: it had lost the return value
      of proc_readdir_de(), so now checking whether it had completed
      successfully or not didn't actually work right anyway.
      
      This reinstates the non-zero return for the "end of base entries" that
      had also gotten lost in commit f0c3b509 ("[readdir] convert
      procfs").  So now you get all the base entries *and* you get all the
      process entries, regardless of getdents buffer size.
      
      (Side note: the Linux "getdents" manual page actually has a nice example
      application for testing getdents, which can be easily modified to use
      different buffers.  Who knew? Man-pages can be useful)
      Reported-by: default avatarEmmanuel Benisty <benisty.e@gmail.com>
      Reported-by: default avatarMarc Dionne <marc.c.dionne@gmail.com>
      Cc: Richard Genoud <richard.genoud@gmail.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      fd3930f7
  3. 29 Jun, 2013 1 commit
  4. 01 May, 2013 5 commits
  5. 29 Apr, 2013 1 commit
  6. 09 Apr, 2013 7 commits
  7. 28 Feb, 2013 1 commit
  8. 26 Feb, 2013 1 commit
  9. 23 Feb, 2013 1 commit
  10. 26 Dec, 2012 1 commit
    • Eric W. Biederman's avatar
      proc: Allow proc_free_inum to be called from any context · dfb2ea45
      Eric W. Biederman authored
      While testing the pid namespace code I hit this nasty warning.
      
      [  176.262617] ------------[ cut here ]------------
      [  176.263388] WARNING: at /home/eric/projects/linux/linux-userns-devel/kernel/softirq.c:160 local_bh_enable_ip+0x7a/0xa0()
      [  176.265145] Hardware name: Bochs
      [  176.265677] Modules linked in:
      [  176.266341] Pid: 742, comm: bash Not tainted 3.7.0userns+ #18
      [  176.266564] Call Trace:
      [  176.266564]  [<ffffffff810a539f>] warn_slowpath_common+0x7f/0xc0
      [  176.266564]  [<ffffffff810a53fa>] warn_slowpath_null+0x1a/0x20
      [  176.266564]  [<ffffffff810ad9ea>] local_bh_enable_ip+0x7a/0xa0
      [  176.266564]  [<ffffffff819308c9>] _raw_spin_unlock_bh+0x19/0x20
      [  176.266564]  [<ffffffff8123dbda>] proc_free_inum+0x3a/0x50
      [  176.266564]  [<ffffffff8111d0dc>] free_pid_ns+0x1c/0x80
      [  176.266564]  [<ffffffff8111d195>] put_pid_ns+0x35/0x50
      [  176.266564]  [<ffffffff810c608a>] put_pid+0x4a/0x60
      [  176.266564]  [<ffffffff8146b177>] tty_ioctl+0x717/0xc10
      [  176.266564]  [<ffffffff810aa4d5>] ? wait_consider_task+0x855/0xb90
      [  176.266564]  [<ffffffff81086bf9>] ? default_spin_lock_flags+0x9/0x10
      [  176.266564]  [<ffffffff810cab0a>] ? remove_wait_queue+0x5a/0x70
      [  176.266564]  [<ffffffff811e37e8>] do_vfs_ioctl+0x98/0x550
      [  176.266564]  [<ffffffff810b8a0f>] ? recalc_sigpending+0x1f/0x60
      [  176.266564]  [<ffffffff810b9127>] ? __set_task_blocked+0x37/0x80
      [  176.266564]  [<ffffffff810ab95b>] ? sys_wait4+0xab/0xf0
      [  176.266564]  [<ffffffff811e3d31>] sys_ioctl+0x91/0xb0
      [  176.266564]  [<ffffffff810a95f0>] ? task_stopped_code+0x50/0x50
      [  176.266564]  [<ffffffff81939199>] system_call_fastpath+0x16/0x1b
      [  176.266564] ---[ end trace 387af88219ad6143 ]---
      
      It turns out that spin_unlock_bh(proc_inum_lock) is not safe when
      put_pid is called with another spinlock held and irqs disabled.
      
      For now take the easy path and use spin_lock_irqsave(proc_inum_lock)
      in proc_free_inum and spin_loc_irq in proc_alloc_inum(proc_inum_lock).
      Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
      dfb2ea45
  11. 21 Dec, 2012 1 commit
    • Xiaotian Feng's avatar
      proc: fix inconsistent lock state · ee297209
      Xiaotian Feng authored
      Lockdep found an inconsistent lock state when rcu is processing delayed
      work in softirq.  Currently, kernel is using spin_lock/spin_unlock to
      protect proc_inum_ida, but proc_free_inum is called by rcu in softirq
      context.
      
      Use spin_lock_bh/spin_unlock_bh fix following lockdep warning.
      
        =================================
        [ INFO: inconsistent lock state ]
        3.7.0 #36 Not tainted
        ---------------------------------
        inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
        swapper/1/0 [HC0[0]:SC1[1]:HE1:SE0] takes:
         (proc_inum_lock){+.?...}, at: proc_free_inum+0x1c/0x50
        {SOFTIRQ-ON-W} state was registered at:
           __lock_acquire+0x8ae/0xca0
           lock_acquire+0x199/0x200
           _raw_spin_lock+0x41/0x50
           proc_alloc_inum+0x4c/0xd0
           alloc_mnt_ns+0x49/0xc0
           create_mnt_ns+0x25/0x70
           mnt_init+0x161/0x1c7
           vfs_caches_init+0x107/0x11a
           start_kernel+0x348/0x38c
           x86_64_start_reservations+0x131/0x136
           x86_64_start_kernel+0x103/0x112
        irq event stamp: 2993422
        hardirqs last  enabled at (2993422):  _raw_spin_unlock_irqrestore+0x55/0x80
        hardirqs last disabled at (2993421):  _raw_spin_lock_irqsave+0x29/0x70
        softirqs last  enabled at (2993394):  _local_bh_enable+0x13/0x20
        softirqs last disabled at (2993395):  call_softirq+0x1c/0x30
      
        other info that might help us debug this:
         Possible unsafe locking scenario:
      
               CPU0
               ----
          lock(proc_inum_lock);
          <Interrupt>
            lock(proc_inum_lock);
      
         *** DEADLOCK ***
      
        no locks held by swapper/1/0.
      
        stack backtrace:
        Pid: 0, comm: swapper/1 Not tainted 3.7.0 #36
        Call Trace:
         <IRQ>  [<ffffffff810a40f1>] ? vprintk_emit+0x471/0x510
          print_usage_bug+0x2a5/0x2c0
          mark_lock+0x33b/0x5e0
          __lock_acquire+0x813/0xca0
          lock_acquire+0x199/0x200
          _raw_spin_lock+0x41/0x50
          proc_free_inum+0x1c/0x50
          free_pid_ns+0x1c/0x50
          put_pid_ns+0x2e/0x50
          put_pid+0x4a/0x60
          delayed_put_pid+0x12/0x20
          rcu_process_callbacks+0x462/0x790
          __do_softirq+0x1b4/0x3b0
          call_softirq+0x1c/0x30
          do_softirq+0x59/0xd0
          irq_exit+0x54/0xd0
          smp_apic_timer_interrupt+0x95/0xa3
          apic_timer_interrupt+0x72/0x80
          cpuidle_enter_tk+0x10/0x20
          cpuidle_enter_state+0x17/0x50
          cpuidle_idle_call+0x287/0x520
          cpu_idle+0xba/0x130
          start_secondary+0x2b3/0x2bc
      Signed-off-by: default avatarXiaotian Feng <dannyfeng@tencent.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: "Eric W. Biederman" <ebiederm@xmission.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      ee297209
  12. 20 Dec, 2012 1 commit
  13. 20 Nov, 2012 1 commit
  14. 05 Oct, 2012 2 commits
  15. 14 Jul, 2012 1 commit
    • Al Viro's avatar
      stop passing nameidata to ->lookup() · 00cd8dd3
      Al Viro authored
      Just the flags; only NFS cares even about that, but there are
      legitimate uses for such argument.  And getting rid of that
      completely would require splitting ->lookup() into a couple
      of methods (at least), so let's leave that alone for now...
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      00cd8dd3
  16. 04 Jan, 2012 1 commit
  17. 02 Nov, 2011 1 commit
  18. 27 Jul, 2011 1 commit
    • David Howells's avatar
      proc: make struct proc_dir_entry::name a terminal array rather than a pointer · 09570f91
      David Howells authored
      Since __proc_create() appends the name it is given to the end of the PDE
      structure that it allocates, there isn't a need to store a name pointer.
      Instead we can just replace the name pointer with a terminal char array of
      _unspecified_ length.  The compiler will simply append the string to statically
      defined variables of PDE type overlapping any hole at the end of the structure
      and, unlike specifying an explicitly _zero_ length array, won't give a warning
      if you try to statically initialise it with a string of more than zero length.
      
      Also, whilst we're at it:
      
       (1) Move namelen to end just prior to name and reduce it to a single byte
           (name shouldn't be longer than NAME_MAX).
      
       (2) Move pde_unload_lock two places further on so that if it's four bytes in
           size on a 64-bit machine, it won't cause an unused hole in the PDE struct.
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Signed-off-by: default avatarAlexey Dobriyan <adobriyan@gmail.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      09570f91
  19. 16 May, 2011 1 commit
  20. 24 Mar, 2011 1 commit
  21. 13 Jan, 2011 2 commits
  22. 07 Jan, 2011 2 commits
    • Nick Piggin's avatar
      fs: dcache reduce branches in lookup path · fb045adb
      Nick Piggin authored
      Reduce some branches and memory accesses in dcache lookup by adding dentry
      flags to indicate common d_ops are set, rather than having to check them.
      This saves a pointer memory access (dentry->d_op) in common path lookup
      situations, and saves another pointer load and branch in cases where we
      have d_op but not the particular operation.
      
      Patched with:
      
      git grep -E '[.>]([[:space:]])*d_op([[:space:]])*=' | xargs sed -e 's/\([^\t ]*\)->d_op = \(.*\);/d_set_d_op(\1, \2);/' -e 's/\([^\t ]*\)\.d_op = \(.*\);/d_set_d_op(\&\1, \2);/' -i
      Signed-off-by: default avatarNick Piggin <npiggin@kernel.dk>
      fb045adb
    • Nick Piggin's avatar
      fs: change d_delete semantics · fe15ce44
      Nick Piggin authored
      Change d_delete from a dentry deletion notification to a dentry caching
      advise, more like ->drop_inode. Require it to be constant and idempotent,
      and not take d_lock. This is how all existing filesystems use the callback
      anyway.
      
      This makes fine grained dentry locking of dput and dentry lru scanning
      much simpler.
      Signed-off-by: default avatarNick Piggin <npiggin@kernel.dk>
      fe15ce44
  23. 09 Aug, 2010 1 commit
    • Christoph Hellwig's avatar
      remove inode_setattr · 1025774c
      Christoph Hellwig authored
      Replace inode_setattr with opencoded variants of it in all callers.  This
      moves the remaining call to vmtruncate into the filesystem methods where it
      can be replaced with the proper truncate sequence.
      
      In a few cases it was obvious that we would never end up calling vmtruncate
      so it was left out in the opencoded variant:
      
       spufs: explicitly checks for ATTR_SIZE earlier
       btrfs,hugetlbfs,logfs,dlmfs: explicitly clears ATTR_SIZE earlier
       ufs: contains an opencoded simple_seattr + truncate that sets the filesize just above
      
      In addition to that ncpfs called inode_setattr with handcrafted iattrs,
      which allowed to trim down the opencoded variant.
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      1025774c
  24. 27 May, 2010 1 commit
  25. 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
  26. 06 Mar, 2010 2 commits