diff options
| author | Nicholas Bellinger <nab@linux-iscsi.org> | 2014-01-20 03:36:24 +0000 |
|---|---|---|
| committer | Nicholas Bellinger <nab@linux-iscsi.org> | 2014-01-25 06:58:52 +0000 |
| commit | 555b270e25b0279b98083518a85f4b1da144a181 (patch) | |
| tree | 01cb1c9e3c65deb02c41ed45fa9ad69902274e2c /lib | |
| parent | 6f6b5d1ec56acdeab0503d2b823f6f88a0af493e (diff) | |
| download | lwn-555b270e25b0279b98083518a85f4b1da144a181.tar.gz lwn-555b270e25b0279b98083518a85f4b1da144a181.zip | |
iscsi-target: Fix connection reset hang with percpu_ida_alloc
This patch addresses a bug where connection reset would hang
indefinately once percpu_ida_alloc() was starved for tags, due
to the fact that it always assumed uninterruptible sleep mode.
So now make percpu_ida_alloc() check for signal_pending_state() for
making interruptible sleep optional, and convert iscsit_allocate_cmd()
to set TASK_INTERRUPTIBLE for GFP_KERNEL, or TASK_RUNNING for
GFP_ATOMIC.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Kent Overstreet <kmo@daterainc.com>
Cc: <stable@vger.kernel.org> #3.12+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/percpu_ida.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/lib/percpu_ida.c b/lib/percpu_ida.c index 58b671484ac2..7be235f1a70b 100644 --- a/lib/percpu_ida.c +++ b/lib/percpu_ida.c @@ -138,14 +138,14 @@ static inline unsigned alloc_local_tag(struct percpu_ida_cpu *tags) * tag_pool_init()), or otherwise -ENOSPC on allocation failure. * * Safe to be called from interrupt context (assuming it isn't passed - * TASK_UNINTERRUPTIBLE, of course). + * TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, of course). * * @gfp indicates whether or not to wait until a free id is available (it's not * used for internal memory allocations); thus if passed __GFP_WAIT we may sleep * however long it takes until another thread frees an id (same semantics as a * mempool). * - * Will not fail if passed TASK_UNINTERRUPTIBLE. + * Will not fail if passed TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE. */ int percpu_ida_alloc(struct percpu_ida *pool, int state) { @@ -195,6 +195,11 @@ int percpu_ida_alloc(struct percpu_ida *pool, int state) if (tag >= 0 || state == TASK_RUNNING) break; + if (signal_pending_state(state, current)) { + tag = -ERESTARTSYS; + break; + } + schedule(); local_irq_save(flags); |