Skip to content

K
Kernel

openeuler / Kernel
1 年多 前同步成功

通知 8
Star 0
Fork 0
K
Kernel
切换分支/标签
  1. 22 5月, 2019 5 次提交
  3. 14 5月, 2019 1 次提交
  5. 09 5月, 2019 4 次提交
  7. 24 4月, 2019 3 次提交
  9. 20 4月, 2019 3 次提交
  11. 17 4月, 2019 2 次提交
  13. 16 4月, 2019 1 次提交
  15. 15 4月, 2019 3 次提交
    • M
      fs: prevent page refcount overflow in pipe_buf_get · 15fab63e
      由 Matthew Wilcox 提交于 
      Change pipe_buf_get() to return a bool indicating whether it succeeded
in raising the refcount of the page (if the thing in the pipe is a page).
This removes another mechanism for overflowing the page refcount.  All
callers converted to handle a failure.
Reported-by: NJann Horn <jannh@google.com>
Signed-off-by: NMatthew Wilcox <willy@infradead.org>
Cc: stable@kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      15fab63e
    • L
      mm: add 'try_get_page()' helper function · 88b1a17d
      由 Linus Torvalds 提交于 
      This is the same as the traditional 'get_page()' function, but instead
of unconditionally incrementing the reference count of the page, it only
does so if the count was "safe".  It returns whether the reference count
was incremented (and is marked __must_check, since the caller obviously
has to be aware of it).

Also like 'get_page()', you can't use this function unless you already
had a reference to the page.  The intent is that you can use this
exactly like get_page(), but in situations where you want to limit the
maximum reference count.

The code currently does an unconditional WARN_ON_ONCE() if we ever hit
the reference count issues (either zero or negative), as a notification
that the conditional non-increment actually happened.

NOTE! The count access for the "safety" check is inherently racy, but
that doesn't matter since the buffer we use is basically half the range
of the reference count (ie we look at the sign of the count).
Acked-by: NMatthew Wilcox <willy@infradead.org>
Cc: Jann Horn <jannh@google.com>
Cc: stable@kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      88b1a17d
    • L
      mm: make page ref count overflow check tighter and more explicit · f958d7b5
      由 Linus Torvalds 提交于 
      We have a VM_BUG_ON() to check that the page reference count doesn't
underflow (or get close to overflow) by checking the sign of the count.

That's all fine, but we actually want to allow people to use a "get page
ref unless it's already very high" helper function, and we want that one
to use the sign of the page ref (without triggering this VM_BUG_ON).

Change the VM_BUG_ON to only check for small underflows (or _very_ close
to overflowing), and ignore overflows which have strayed into negative
territory.
Acked-by: NMatthew Wilcox <willy@infradead.org>
Cc: Jann Horn <jannh@google.com>
Cc: stable@kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      f958d7b5
  17. 13 4月, 2019 4 次提交
  19. 12 4月, 2019 1 次提交
  21. 11 4月, 2019 8 次提交
  23. 10 4月, 2019 1 次提交
    • M
      blk-mq: introduce blk_mq_complete_request_sync() · 1b8f21b7
      由 Ming Lei 提交于 
      In NVMe's error handler, follows the typical steps of tearing down
hardware for recovering controller:

1) stop blk_mq hw queues
2) stop the real hw queues
3) cancel in-flight requests via
	blk_mq_tagset_busy_iter(tags, cancel_request, ...)
cancel_request():
	mark the request as abort
	blk_mq_complete_request(req);
4) destroy real hw queues

However, there may be race between #3 and #4, because blk_mq_complete_request()
may run q->mq_ops->complete(rq) remotelly and asynchronously, and
->complete(rq) may be run after #4.

This patch introduces blk_mq_complete_request_sync() for fixing the
above race.

Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: James Smart <james.smart@broadcom.com>
Cc: linux-nvme@lists.infradead.org
Reviewed-by: NKeith Busch <keith.busch@intel.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NMing Lei <ming.lei@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      1b8f21b7
  25. 09 4月, 2019 3 次提交
  27. 08 4月, 2019 1 次提交