1. 08 5月, 2013 15 次提交
    • K
      aio: give shared kioctx fields their own cachelines · 4e23bcae
      Kent Overstreet 提交于
      [akpm@linux-foundation.org: make reqs_active __cacheline_aligned_in_smp]
      Signed-off-by: NKent Overstreet <koverstreet@google.com>
      Cc: Zach Brown <zab@redhat.com>
      Cc: Felipe Balbi <balbi@ti.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Mark Fasheh <mfasheh@suse.com>
      Cc: Joel Becker <jlbec@evilplan.org>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Jens Axboe <axboe@kernel.dk>
      Cc: Asai Thambi S P <asamymuthupa@micron.com>
      Cc: Selvan Mani <smani@micron.com>
      Cc: Sam Bradshaw <sbradshaw@micron.com>
      Cc: Jeff Moyer <jmoyer@redhat.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Benjamin LaHaise <bcrl@kvack.org>
      Reviewed-by: N"Theodore Ts'o" <tytso@mit.edu>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      4e23bcae
    • K
      aio: kill struct aio_ring_info · 58c85dc2
      Kent Overstreet 提交于
      struct aio_ring_info was kind of odd, the only place it's used is where
      it's embedded in struct kioctx - there's no real need for it.
      
      The next patch rearranges struct kioctx and puts various things on their
      own cachelines - getting rid of struct aio_ring_info now makes that
      reordering a bit clearer.
      Signed-off-by: NKent Overstreet <koverstreet@google.com>
      Cc: Zach Brown <zab@redhat.com>
      Cc: Felipe Balbi <balbi@ti.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Mark Fasheh <mfasheh@suse.com>
      Cc: Joel Becker <jlbec@evilplan.org>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Jens Axboe <axboe@kernel.dk>
      Cc: Asai Thambi S P <asamymuthupa@micron.com>
      Cc: Selvan Mani <smani@micron.com>
      Cc: Sam Bradshaw <sbradshaw@micron.com>
      Cc: Jeff Moyer <jmoyer@redhat.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Benjamin LaHaise <bcrl@kvack.org>
      Reviewed-by: N"Theodore Ts'o" <tytso@mit.edu>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      58c85dc2
    • K
      aio: kill batch allocation · a1c8eae7
      Kent Overstreet 提交于
      Previously, allocating a kiocb required touching quite a few global
      (well, per kioctx) cachelines...  so batching up allocation to amortize
      those was worthwhile.  But we've gotten rid of some of those, and in
      another couple of patches kiocb allocation won't require writing to any
      shared cachelines, so that means we can just rip this code out.
      Signed-off-by: NKent Overstreet <koverstreet@google.com>
      Cc: Zach Brown <zab@redhat.com>
      Cc: Felipe Balbi <balbi@ti.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Mark Fasheh <mfasheh@suse.com>
      Cc: Joel Becker <jlbec@evilplan.org>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Jens Axboe <axboe@kernel.dk>
      Cc: Asai Thambi S P <asamymuthupa@micron.com>
      Cc: Selvan Mani <smani@micron.com>
      Cc: Sam Bradshaw <sbradshaw@micron.com>
      Cc: Jeff Moyer <jmoyer@redhat.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Benjamin LaHaise <bcrl@kvack.org>
      Reviewed-by: N"Theodore Ts'o" <tytso@mit.edu>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      a1c8eae7
    • K
      aio: change reqs_active to include unreaped completions · 3e845ce0
      Kent Overstreet 提交于
      The aio code tries really hard to avoid having to deal with the
      completion ringbuffer overflowing.  To do that, it has to keep track of
      the number of outstanding kiocbs, and the number of completions
      currently in the ringbuffer - and it's got to check that every time we
      allocate a kiocb.  Ouch.
      
      But - we can improve this quite a bit if we just change reqs_active to
      mean "number of outstanding requests and unreaped completions" - that
      means kiocb allocation doesn't have to look at the ringbuffer, which is
      a fairly significant win.
      Signed-off-by: NKent Overstreet <koverstreet@google.com>
      Cc: Zach Brown <zab@redhat.com>
      Cc: Felipe Balbi <balbi@ti.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Mark Fasheh <mfasheh@suse.com>
      Cc: Joel Becker <jlbec@evilplan.org>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Jens Axboe <axboe@kernel.dk>
      Cc: Asai Thambi S P <asamymuthupa@micron.com>
      Cc: Selvan Mani <smani@micron.com>
      Cc: Sam Bradshaw <sbradshaw@micron.com>
      Cc: Jeff Moyer <jmoyer@redhat.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Benjamin LaHaise <bcrl@kvack.org>
      Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      3e845ce0
    • K
      aio: use cancellation list lazily · 0460fef2
      Kent Overstreet 提交于
      Cancelling kiocbs requires adding them to a per kioctx linked list,
      which is one of the few things we need to take the kioctx lock for in
      the fast path.  But most kiocbs can't be cancelled - so if we just do
      this lazily, we can avoid quite a bit of locking overhead.
      
      While we're at it, instead of using a flag bit switch to using ki_cancel
      itself to indicate that a kiocb has been cancelled/completed.  This lets
      us get rid of ki_flags entirely.
      
      [akpm@linux-foundation.org: remove buggy BUG()]
      Signed-off-by: NKent Overstreet <koverstreet@google.com>
      Cc: Zach Brown <zab@redhat.com>
      Cc: Felipe Balbi <balbi@ti.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Mark Fasheh <mfasheh@suse.com>
      Cc: Joel Becker <jlbec@evilplan.org>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Jens Axboe <axboe@kernel.dk>
      Cc: Asai Thambi S P <asamymuthupa@micron.com>
      Cc: Selvan Mani <smani@micron.com>
      Cc: Sam Bradshaw <sbradshaw@micron.com>
      Cc: Jeff Moyer <jmoyer@redhat.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Benjamin LaHaise <bcrl@kvack.org>
      Reviewed-by: N"Theodore Ts'o" <tytso@mit.edu>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      0460fef2
    • K
      aio: use flush_dcache_page() · 21b40200
      Kent Overstreet 提交于
      This wasn't causing problems before because it's not needed on x86, but
      it is needed on other architectures.
      Signed-off-by: NKent Overstreet <koverstreet@google.com>
      Cc: Zach Brown <zab@redhat.com>
      Cc: Felipe Balbi <balbi@ti.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Mark Fasheh <mfasheh@suse.com>
      Cc: Joel Becker <jlbec@evilplan.org>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Jens Axboe <axboe@kernel.dk>
      Cc: Asai Thambi S P <asamymuthupa@micron.com>
      Cc: Selvan Mani <smani@micron.com>
      Cc: Sam Bradshaw <sbradshaw@micron.com>
      Cc: Jeff Moyer <jmoyer@redhat.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Benjamin LaHaise <bcrl@kvack.org>
      Cc: Theodore Ts'o <tytso@mit.edu>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      21b40200
    • K
      aio: make aio_read_evt() more efficient, convert to hrtimers · a31ad380
      Kent Overstreet 提交于
      Previously, aio_read_event() pulled a single completion off the
      ringbuffer at a time, locking and unlocking each time.  Change it to
      pull off as many events as it can at a time, and copy them directly to
      userspace.
      
      This also fixes a bug where if copying the event to userspace failed,
      we'd lose the event.
      
      Also convert it to wait_event_interruptible_hrtimeout(), which
      simplifies it quite a bit.
      
      [akpm@linux-foundation.org: coding-style fixes]
      Signed-off-by: NKent Overstreet <koverstreet@google.com>
      Cc: Zach Brown <zab@redhat.com>
      Cc: Felipe Balbi <balbi@ti.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Mark Fasheh <mfasheh@suse.com>
      Cc: Joel Becker <jlbec@evilplan.org>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Jens Axboe <axboe@kernel.dk>
      Cc: Asai Thambi S P <asamymuthupa@micron.com>
      Cc: Selvan Mani <smani@micron.com>
      Cc: Sam Bradshaw <sbradshaw@micron.com>
      Cc: Jeff Moyer <jmoyer@redhat.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Benjamin LaHaise <bcrl@kvack.org>
      Reviewed-by: N"Theodore Ts'o" <tytso@mit.edu>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      a31ad380
    • K
      aio: refcounting cleanup · 36f55889
      Kent Overstreet 提交于
      The usage of ctx->dead was fubar - it makes no sense to explicitly check
      it all over the place, especially when we're already using RCU.
      
      Now, ctx->dead only indicates whether we've dropped the initial
      refcount. The new teardown sequence is:
      
        set ctx->dead
        hlist_del_rcu();
        synchronize_rcu();
      
      Now we know no system calls can take a new ref, and it's safe to drop
      the initial ref:
      
        put_ioctx();
      
      We also need to ensure there are no more outstanding kiocbs.  This was
      done incorrectly - it was being done in kill_ctx(), and before dropping
      the initial refcount.  At this point, other syscalls may still be
      submitting kiocbs!
      
      Now, we cancel and wait for outstanding kiocbs in free_ioctx(), after
      kioctx->users has dropped to 0 and we know no more iocbs could be
      submitted.
      
      [akpm@linux-foundation.org: coding-style fixes]
      Signed-off-by: NKent Overstreet <koverstreet@google.com>
      Cc: Zach Brown <zab@redhat.com>
      Cc: Felipe Balbi <balbi@ti.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Mark Fasheh <mfasheh@suse.com>
      Cc: Joel Becker <jlbec@evilplan.org>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Jens Axboe <axboe@kernel.dk>
      Cc: Asai Thambi S P <asamymuthupa@micron.com>
      Cc: Selvan Mani <smani@micron.com>
      Cc: Sam Bradshaw <sbradshaw@micron.com>
      Cc: Jeff Moyer <jmoyer@redhat.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Benjamin LaHaise <bcrl@kvack.org>
      Reviewed-by: N"Theodore Ts'o" <tytso@mit.edu>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      36f55889
    • K
      aio: make aio_put_req() lockless · 11599eba
      Kent Overstreet 提交于
      Freeing a kiocb needed to touch the kioctx for three things:
      
       * Pull it off the reqs_active list
       * Decrementing reqs_active
       * Issuing a wakeup, if the kioctx was in the process of being freed.
      
      This patch moves these to aio_complete(), for a couple reasons:
      
       * aio_complete() already has to issue the wakeup, so if we drop the
         kioctx refcount before aio_complete does its wakeup we don't have to
         do it twice.
       * aio_complete currently has to take the kioctx lock, so it makes sense
         for it to pull the kiocb off the reqs_active list too.
       * A later patch is going to change reqs_active to include unreaped
         completions - this will mean allocating a kiocb doesn't have to look
         at the ringbuffer. So taking the decrement of reqs_active out of
         kiocb_free() is useful prep work for that patch.
      
      This doesn't really affect cancellation, since existing (usb) code that
      implements a cancel function still calls aio_complete() - we just have
      to make sure that aio_complete does the necessary teardown for cancelled
      kiocbs.
      
      It does affect code paths where we free kiocbs that were never
      submitted; they need to decrement reqs_active and pull the kiocb off the
      reqs_active list.  This occurs in two places: kiocb_batch_free(), which
      is going away in a later patch, and the error path in io_submit_one.
      
      [akpm@linux-foundation.org: coding-style fixes]
      Signed-off-by: NKent Overstreet <koverstreet@google.com>
      Cc: Zach Brown <zab@redhat.com>
      Cc: Felipe Balbi <balbi@ti.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Mark Fasheh <mfasheh@suse.com>
      Cc: Joel Becker <jlbec@evilplan.org>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Jens Axboe <axboe@kernel.dk>
      Cc: Asai Thambi S P <asamymuthupa@micron.com>
      Cc: Selvan Mani <smani@micron.com>
      Cc: Sam Bradshaw <sbradshaw@micron.com>
      Acked-by: NJeff Moyer <jmoyer@redhat.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Benjamin LaHaise <bcrl@kvack.org>
      Reviewed-by: N"Theodore Ts'o" <tytso@mit.edu>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      11599eba
    • K
      aio: do fget() after aio_get_req() · 1d98ebfc
      Kent Overstreet 提交于
      aio_get_req() will fail if we have the maximum number of requests
      outstanding, which depending on the application may not be uncommon.  So
      avoid doing an unnecessary fget().
      Signed-off-by: NKent Overstreet <koverstreet@google.com>
      Cc: Zach Brown <zab@redhat.com>
      Cc: Felipe Balbi <balbi@ti.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Mark Fasheh <mfasheh@suse.com>
      Cc: Joel Becker <jlbec@evilplan.org>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Jens Axboe <axboe@kernel.dk>
      Cc: Asai Thambi S P <asamymuthupa@micron.com>
      Cc: Selvan Mani <smani@micron.com>
      Cc: Sam Bradshaw <sbradshaw@micron.com>
      Acked-by: NJeff Moyer <jmoyer@redhat.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Benjamin LaHaise <bcrl@kvack.org>
      Reviewed-by: N"Theodore Ts'o" <tytso@mit.edu>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      1d98ebfc
    • K
      aio: dprintk() -> pr_debug() · caf4167a
      Kent Overstreet 提交于
      Signed-off-by: NKent Overstreet <koverstreet@google.com>
      Cc: Zach Brown <zab@redhat.com>
      Cc: Felipe Balbi <balbi@ti.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Mark Fasheh <mfasheh@suse.com>
      Cc: Joel Becker <jlbec@evilplan.org>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Jens Axboe <axboe@kernel.dk>
      Cc: Asai Thambi S P <asamymuthupa@micron.com>
      Cc: Selvan Mani <smani@micron.com>
      Cc: Sam Bradshaw <sbradshaw@micron.com>
      Acked-by: NJeff Moyer <jmoyer@redhat.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Benjamin LaHaise <bcrl@kvack.org>
      Cc: Theodore Ts'o <tytso@mit.edu>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      caf4167a
    • K
      aio: move private stuff out of aio.h · 4e179bca
      Kent Overstreet 提交于
      Signed-off-by: NKent Overstreet <koverstreet@google.com>
      Cc: Zach Brown <zab@redhat.com>
      Cc: Felipe Balbi <balbi@ti.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Mark Fasheh <mfasheh@suse.com>
      Cc: Joel Becker <jlbec@evilplan.org>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Jens Axboe <axboe@kernel.dk>
      Cc: Asai Thambi S P <asamymuthupa@micron.com>
      Cc: Selvan Mani <smani@micron.com>
      Cc: Sam Bradshaw <sbradshaw@micron.com>
      Acked-by: NJeff Moyer <jmoyer@redhat.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Benjamin LaHaise <bcrl@kvack.org>
      Cc: Theodore Ts'o <tytso@mit.edu>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      4e179bca
    • K
      aio: add kiocb_cancel() · 906b973c
      Kent Overstreet 提交于
      Minor refactoring, to get rid of some duplicated code
      
      [akpm@linux-foundation.org: fix warning]
      Signed-off-by: NKent Overstreet <koverstreet@google.com>
      Cc: Zach Brown <zab@redhat.com>
      Cc: Felipe Balbi <balbi@ti.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Mark Fasheh <mfasheh@suse.com>
      Cc: Joel Becker <jlbec@evilplan.org>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Jens Axboe <axboe@kernel.dk>
      Cc: Asai Thambi S P <asamymuthupa@micron.com>
      Cc: Selvan Mani <smani@micron.com>
      Cc: Sam Bradshaw <sbradshaw@micron.com>
      Acked-by: NJeff Moyer <jmoyer@redhat.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Benjamin LaHaise <bcrl@kvack.org>
      Reviewed-by: N"Theodore Ts'o" <tytso@mit.edu>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      906b973c
    • K
      aio: kill return value of aio_complete() · 2d68449e
      Kent Overstreet 提交于
      Nothing used the return value, and it probably wasn't possible to use it
      safely for the locked versions (aio_complete(), aio_put_req()).  Just
      kill it.
      Signed-off-by: NKent Overstreet <koverstreet@google.com>
      Acked-by: NZach Brown <zab@redhat.com>
      Cc: Felipe Balbi <balbi@ti.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Mark Fasheh <mfasheh@suse.com>
      Cc: Joel Becker <jlbec@evilplan.org>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Jens Axboe <axboe@kernel.dk>
      Cc: Asai Thambi S P <asamymuthupa@micron.com>
      Cc: Selvan Mani <smani@micron.com>
      Cc: Sam Bradshaw <sbradshaw@micron.com>
      Acked-by: NJeff Moyer <jmoyer@redhat.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Benjamin LaHaise <bcrl@kvack.org>
      Reviewed-by: N"Theodore Ts'o" <tytso@mit.edu>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      2d68449e
    • Z
      aio: remove retry-based AIO · 41003a7b
      Zach Brown 提交于
      This removes the retry-based AIO infrastructure now that nothing in tree
      is using it.
      
      We want to remove retry-based AIO because it is fundemantally unsafe.
      It retries IO submission from a kernel thread that has only assumed the
      mm of the submitting task.  All other task_struct references in the IO
      submission path will see the kernel thread, not the submitting task.
      This design flaw means that nothing of any meaningful complexity can use
      retry-based AIO.
      
      This removes all the code and data associated with the retry machinery.
      The most significant benefit of this is the removal of the locking
      around the unused run list in the submission path.
      
      [akpm@linux-foundation.org: coding-style fixes]
      Signed-off-by: NKent Overstreet <koverstreet@google.com>
      Signed-off-by: NZach Brown <zab@redhat.com>
      Cc: Zach Brown <zab@redhat.com>
      Cc: Felipe Balbi <balbi@ti.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Mark Fasheh <mfasheh@suse.com>
      Cc: Joel Becker <jlbec@evilplan.org>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Jens Axboe <axboe@kernel.dk>
      Cc: Asai Thambi S P <asamymuthupa@micron.com>
      Cc: Selvan Mani <smani@micron.com>
      Cc: Sam Bradshaw <sbradshaw@micron.com>
      Acked-by: NJeff Moyer <jmoyer@redhat.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Benjamin LaHaise <bcrl@kvack.org>
      Reviewed-by: N"Theodore Ts'o" <tytso@mit.edu>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      41003a7b
  2. 26 4月, 2013 1 次提交
  3. 10 4月, 2013 1 次提交
  4. 04 3月, 2013 1 次提交
  5. 28 2月, 2013 1 次提交
    • S
      hlist: drop the node parameter from iterators · b67bfe0d
      Sasha Levin 提交于
      I'm not sure why, but the hlist for each entry iterators were conceived
      
              list_for_each_entry(pos, head, member)
      
      The hlist ones were greedy and wanted an extra parameter:
      
              hlist_for_each_entry(tpos, pos, head, member)
      
      Why did they need an extra pos parameter? I'm not quite sure. Not only
      they don't really need it, it also prevents the iterator from looking
      exactly like the list iterator, which is unfortunate.
      
      Besides the semantic patch, there was some manual work required:
      
       - Fix up the actual hlist iterators in linux/list.h
       - Fix up the declaration of other iterators based on the hlist ones.
       - A very small amount of places were using the 'node' parameter, this
       was modified to use 'obj->member' instead.
       - Coccinelle didn't handle the hlist_for_each_entry_safe iterator
       properly, so those had to be fixed up manually.
      
      The semantic patch which is mostly the work of Peter Senna Tschudin is here:
      
      @@
      iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host;
      
      type T;
      expression a,c,d,e;
      identifier b;
      statement S;
      @@
      
      -T b;
          <+... when != b
      (
      hlist_for_each_entry(a,
      - b,
      c, d) S
      |
      hlist_for_each_entry_continue(a,
      - b,
      c) S
      |
      hlist_for_each_entry_from(a,
      - b,
      c) S
      |
      hlist_for_each_entry_rcu(a,
      - b,
      c, d) S
      |
      hlist_for_each_entry_rcu_bh(a,
      - b,
      c, d) S
      |
      hlist_for_each_entry_continue_rcu_bh(a,
      - b,
      c) S
      |
      for_each_busy_worker(a, c,
      - b,
      d) S
      |
      ax25_uid_for_each(a,
      - b,
      c) S
      |
      ax25_for_each(a,
      - b,
      c) S
      |
      inet_bind_bucket_for_each(a,
      - b,
      c) S
      |
      sctp_for_each_hentry(a,
      - b,
      c) S
      |
      sk_for_each(a,
      - b,
      c) S
      |
      sk_for_each_rcu(a,
      - b,
      c) S
      |
      sk_for_each_from
      -(a, b)
      +(a)
      S
      + sk_for_each_from(a) S
      |
      sk_for_each_safe(a,
      - b,
      c, d) S
      |
      sk_for_each_bound(a,
      - b,
      c) S
      |
      hlist_for_each_entry_safe(a,
      - b,
      c, d, e) S
      |
      hlist_for_each_entry_continue_rcu(a,
      - b,
      c) S
      |
      nr_neigh_for_each(a,
      - b,
      c) S
      |
      nr_neigh_for_each_safe(a,
      - b,
      c, d) S
      |
      nr_node_for_each(a,
      - b,
      c) S
      |
      nr_node_for_each_safe(a,
      - b,
      c, d) S
      |
      - for_each_gfn_sp(a, c, d, b) S
      + for_each_gfn_sp(a, c, d) S
      |
      - for_each_gfn_indirect_valid_sp(a, c, d, b) S
      + for_each_gfn_indirect_valid_sp(a, c, d) S
      |
      for_each_host(a,
      - b,
      c) S
      |
      for_each_host_safe(a,
      - b,
      c, d) S
      |
      for_each_mesh_entry(a,
      - b,
      c, d) S
      )
          ...+>
      
      [akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c]
      [akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c]
      [akpm@linux-foundation.org: checkpatch fixes]
      [akpm@linux-foundation.org: fix warnings]
      [akpm@linux-foudnation.org: redo intrusive kvm changes]
      Tested-by: NPeter Senna Tschudin <peter.senna@gmail.com>
      Acked-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      Signed-off-by: NSasha Levin <sasha.levin@oracle.com>
      Cc: Wu Fengguang <fengguang.wu@intel.com>
      Cc: Marcelo Tosatti <mtosatti@redhat.com>
      Cc: Gleb Natapov <gleb@redhat.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      b67bfe0d
  6. 24 2月, 2013 2 次提交
  7. 23 7月, 2012 1 次提交
  8. 01 6月, 2012 2 次提交
  9. 22 5月, 2012 1 次提交
    • L
      vfs: make AIO use the proper rw_verify_area() area helpers · a70b52ec
      Linus Torvalds 提交于
      We had for some reason overlooked the AIO interface, and it didn't use
      the proper rw_verify_area() helper function that checks (for example)
      mandatory locking on the file, and that the size of the access doesn't
      cause us to overflow the provided offset limits etc.
      
      Instead, AIO did just the security_file_permission() thing (that
      rw_verify_area() also does) directly.
      
      This fixes it to do all the proper helper functions, which not only
      means that now mandatory file locking works with AIO too, we can
      actually remove lines of code.
      Reported-by: NManish Honap <manish_honap_vit@yahoo.co.in>
      Cc: stable@vger.kernel.org
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      a70b52ec
  10. 21 4月, 2012 3 次提交
  11. 01 4月, 2012 2 次提交
  12. 21 3月, 2012 6 次提交
  13. 20 3月, 2012 1 次提交
  14. 10 3月, 2012 2 次提交
    • A
      aio: fix the "too late munmap()" race · c7b28555
      Al Viro 提交于
      Current code has put_ioctx() called asynchronously from aio_fput_routine();
      that's done *after* we have killed the request that used to pin ioctx,
      so there's nothing to stop io_destroy() waiting in wait_for_all_aios()
      from progressing.  As the result, we can end up with async call of
      put_ioctx() being the last one and possibly happening during exit_mmap()
      or elf_core_dump(), neither of which expects stray munmap() being done
      to them...
      
      We do need to prevent _freeing_ ioctx until aio_fput_routine() is done
      with that, but that's all we care about - neither io_destroy() nor
      exit_aio() will progress past wait_for_all_aios() until aio_fput_routine()
      does really_put_req(), so the ioctx teardown won't be done until then
      and we don't care about the contents of ioctx past that point.
      
      Since actual freeing of these suckers is RCU-delayed, we don't need to
      bump ioctx refcount when request goes into list for async removal.
      All we need is rcu_read_lock held just over the ->ctx_lock-protected
      area in aio_fput_routine().
      Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      Reviewed-by: NJeff Moyer <jmoyer@redhat.com>
      Acked-by: NBenjamin LaHaise <bcrl@kvack.org>
      Cc: stable@vger.kernel.org
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      c7b28555
    • A
      aio: fix io_setup/io_destroy race · 86b62a2c
      Al Viro 提交于
      Have ioctx_alloc() return an extra reference, so that caller would drop it
      on success and not bother with re-grabbing it on failure exit.  The current
      code is obviously broken - io_destroy() from another thread that managed
      to guess the address io_setup() would've returned would free ioctx right
      under us; gets especially interesting if aio_context_t * we pass to
      io_setup() points to PROT_READ mapping, so put_user() fails and we end
      up doing io_destroy() on kioctx another thread has just got freed...
      Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      Acked-by: NBenjamin LaHaise <bcrl@kvack.org>
      Reviewed-by: NJeff Moyer <jmoyer@redhat.com>
      Cc: stable@vger.kernel.org
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      86b62a2c
  15. 06 3月, 2012 1 次提交
    • J
      aio: wake up waiters when freeing unused kiocbs · 880641bb
      Jeff Moyer 提交于
      Bart Van Assche reported a hung fio process when either hot-removing
      storage or when interrupting the fio process itself.  The (pruned) call
      trace for the latter looks like so:
      
        fio             D 0000000000000001     0  6849   6848 0x00000004
         ffff880092541b88 0000000000000046 ffff880000000000 ffff88012fa11dc0
         ffff88012404be70 ffff880092541fd8 ffff880092541fd8 ffff880092541fd8
         ffff880128b894d0 ffff88012404be70 ffff880092541b88 000000018106f24d
        Call Trace:
          schedule+0x3f/0x60
          io_schedule+0x8f/0xd0
          wait_for_all_aios+0xc0/0x100
          exit_aio+0x55/0xc0
          mmput+0x2d/0x110
          exit_mm+0x10d/0x130
          do_exit+0x671/0x860
          do_group_exit+0x44/0xb0
          get_signal_to_deliver+0x218/0x5a0
          do_signal+0x65/0x700
          do_notify_resume+0x65/0x80
          int_signal+0x12/0x17
      
      The problem lies with the allocation batching code.  It will
      opportunistically allocate kiocbs, and then trim back the list of iocbs
      when there is not enough room in the completion ring to hold all of the
      events.
      
      In the case above, what happens is that the pruning back of events ends
      up freeing up the last active request and the context is marked as dead,
      so it is thus responsible for waking up waiters.  Unfortunately, the
      code does not check for this condition, so we end up with a hung task.
      Signed-off-by: NJeff Moyer <jmoyer@redhat.com>
      Reported-by: NBart Van Assche <bvanassche@acm.org>
      Tested-by: NBart Van Assche <bvanassche@acm.org>
      Cc: <stable@kernel.org>		[3.2.x only]
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      880641bb