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Commit 6f6b5d1e authored by Kent Overstreet's avatar Kent Overstreet Committed by Nicholas Bellinger
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percpu_ida: Make percpu_ida_alloc + callers accept task state bitmask 



This patch changes percpu_ida_alloc() + callers to accept task state
bitmask for prepare_to_wait() for code like target/iscsi that needs
it for interruptible sleep, that is provided in a subsequent patch.

It now expects TASK_UNINTERRUPTIBLE when the caller is able to sleep
waiting for a new tag, or TASK_RUNNING when the caller cannot sleep,
and is forced to return a negative value when no tags are available.

v2 changes:
  - Include blk-mq + tcm_fc + vhost/scsi + target/iscsi changes
  - Drop signal_pending_state() call
v3 changes:
  - Only call prepare_to_wait() + finish_wait() when != TASK_RUNNING
    (PeterZ)

Reported-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: default avatarKent Overstreet <kmo@daterainc.com>
Cc: <stable@vger.kernel.org> #3.12+
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent 4a4caa29

block/blk-mq-tag.c

+4 −2
Original line number Diff line number Diff line
@@ -36,7 +36,8 @@ static unsigned int __blk_mq_get_tag(struct blk_mq_tags *tags, gfp_t gfp) 
{

	int tag;



	tag = percpu_ida_alloc(&tags->free_tags, gfp);

	tag = percpu_ida_alloc(&tags->free_tags, (gfp & __GFP_WAIT) ?

			       TASK_UNINTERRUPTIBLE : TASK_RUNNING);

	if (tag < 0)

		return BLK_MQ_TAG_FAIL;

	return tag + tags->nr_reserved_tags;
@@ -52,7 +53,8 @@ static unsigned int __blk_mq_get_reserved_tag(struct blk_mq_tags *tags, 
		return BLK_MQ_TAG_FAIL;

	}



	tag = percpu_ida_alloc(&tags->reserved_tags, gfp);

	tag = percpu_ida_alloc(&tags->reserved_tags, (gfp & __GFP_WAIT) ?

			       TASK_UNINTERRUPTIBLE : TASK_RUNNING);

	if (tag < 0)

		return BLK_MQ_TAG_FAIL;

	return tag;

drivers/target/iscsi/iscsi_target_util.c

+6 −2
Original line number Diff line number Diff line
@@ -156,9 +156,13 @@ 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;

	int size, tag, state = (gfp_mask & __GFP_WAIT) ? TASK_UNINTERRUPTIBLE :

				TASK_RUNNING;



	tag = percpu_ida_alloc(&se_sess->sess_tag_pool, state);

	if (tag < 0)

		return NULL;



	tag = percpu_ida_alloc(&se_sess->sess_tag_pool, gfp_mask);

	size = sizeof(struct iscsi_cmd) + conn->conn_transport->priv_size;

	cmd = (struct iscsi_cmd *)(se_sess->sess_cmd_map + (tag * size));

	memset(cmd, 0, size);

drivers/target/tcm_fc/tfc_cmd.c

+1 −1
Original line number Diff line number Diff line
@@ -438,7 +438,7 @@ static void ft_recv_cmd(struct ft_sess *sess, struct fc_frame *fp) 
	struct se_session *se_sess = sess->se_sess;

	int tag;



	tag = percpu_ida_alloc(&se_sess->sess_tag_pool, GFP_ATOMIC);

	tag = percpu_ida_alloc(&se_sess->sess_tag_pool, TASK_RUNNING);

	if (tag < 0)

		goto busy;

drivers/vhost/scsi.c

+1 −1
Original line number Diff line number Diff line
@@ -728,7 +728,7 @@ vhost_scsi_get_tag(struct vhost_virtqueue *vq, 
	}

	se_sess = tv_nexus->tvn_se_sess;



	tag = percpu_ida_alloc(&se_sess->sess_tag_pool, GFP_ATOMIC);

	tag = percpu_ida_alloc(&se_sess->sess_tag_pool, TASK_RUNNING);

	if (tag < 0) {

		pr_err("Unable to obtain tag for tcm_vhost_cmd\n");

		return ERR_PTR(-ENOMEM);

include/linux/percpu_ida.h

+2 −1
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ 
#include <linux/types.h>

#include <linux/bitops.h>

#include <linux/init.h>

#include <linux/sched.h>

#include <linux/spinlock_types.h>

#include <linux/wait.h>

#include <linux/cpumask.h>
@@ -61,7 +62,7 @@ struct percpu_ida { 
/* Max size of percpu freelist, */

#define IDA_DEFAULT_PCPU_SIZE	((IDA_DEFAULT_PCPU_BATCH_MOVE * 3) / 2)



int percpu_ida_alloc(struct percpu_ida *pool, gfp_t gfp);

int percpu_ida_alloc(struct percpu_ida *pool, int state);

void percpu_ida_free(struct percpu_ida *pool, unsigned tag);



void percpu_ida_destroy(struct percpu_ida *pool);