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authorNicholas Bellinger <nab@linux-iscsi.org>2014-01-20 03:36:24 +0000
committerNicholas Bellinger <nab@linux-iscsi.org>2014-01-25 06:58:52 +0000
commit555b270e25b0279b98083518a85f4b1da144a181 (patch)
tree01cb1c9e3c65deb02c41ed45fa9ad69902274e2c
parent6f6b5d1ec56acdeab0503d2b823f6f88a0af493e (diff)
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>
-rw-r--r--drivers/target/iscsi/iscsi_target_util.c2
-rw-r--r--lib/percpu_ida.c9
2 files changed, 8 insertions, 3 deletions
diff --git a/drivers/target/iscsi/iscsi_target_util.c b/drivers/target/iscsi/iscsi_target_util.c
index 9b8e1db1257b..5477ecabc00e 100644
--- a/drivers/target/iscsi/iscsi_target_util.c
+++ b/drivers/target/iscsi/iscsi_target_util.c
@@ -156,7 +156,7 @@ struct iscsi_cmd *iscsit_allocate_cmd(struct iscsi_conn *conn, gfp_t gfp_mask)
{
struct iscsi_cmd *cmd;
struct se_session *se_sess = conn->sess->se_sess;
- int size, tag, state = (gfp_mask & __GFP_WAIT) ? TASK_UNINTERRUPTIBLE :
+ int size, tag, state = (gfp_mask & __GFP_WAIT) ? TASK_INTERRUPTIBLE :
TASK_RUNNING;
tag = percpu_ida_alloc(&se_sess->sess_tag_pool, state);
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);