blk-mq-debug: Make show() operations interruptible
Allow users to interrupt show operations instead of making a user
space process unkillable if ownership of q->sysfs_lock cannot be
obtained.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
index 0119ec5..54b2f48 100644
--- a/block/blk-mq-debugfs.c
+++ b/block/blk-mq-debugfs.c
@@ -178,13 +178,17 @@
{
struct blk_mq_hw_ctx *hctx = m->private;
struct request_queue *q = hctx->queue;
+ int res;
- mutex_lock(&q->sysfs_lock);
+ res = mutex_lock_interruptible(&q->sysfs_lock);
+ if (res)
+ goto out;
if (hctx->tags)
blk_mq_debugfs_tags_show(m, hctx->tags);
mutex_unlock(&q->sysfs_lock);
- return 0;
+out:
+ return res;
}
static int hctx_tags_open(struct inode *inode, struct file *file)
@@ -203,12 +207,17 @@
{
struct blk_mq_hw_ctx *hctx = m->private;
struct request_queue *q = hctx->queue;
+ int res;
- mutex_lock(&q->sysfs_lock);
+ res = mutex_lock_interruptible(&q->sysfs_lock);
+ if (res)
+ goto out;
if (hctx->tags)
sbitmap_bitmap_show(&hctx->tags->bitmap_tags.sb, m);
mutex_unlock(&q->sysfs_lock);
- return 0;
+
+out:
+ return res;
}
static int hctx_tags_bitmap_open(struct inode *inode, struct file *file)
@@ -227,13 +236,17 @@
{
struct blk_mq_hw_ctx *hctx = m->private;
struct request_queue *q = hctx->queue;
+ int res;
- mutex_lock(&q->sysfs_lock);
+ res = mutex_lock_interruptible(&q->sysfs_lock);
+ if (res)
+ goto out;
if (hctx->sched_tags)
blk_mq_debugfs_tags_show(m, hctx->sched_tags);
mutex_unlock(&q->sysfs_lock);
- return 0;
+out:
+ return res;
}
static int hctx_sched_tags_open(struct inode *inode, struct file *file)
@@ -252,12 +265,17 @@
{
struct blk_mq_hw_ctx *hctx = m->private;
struct request_queue *q = hctx->queue;
+ int res;
- mutex_lock(&q->sysfs_lock);
+ res = mutex_lock_interruptible(&q->sysfs_lock);
+ if (res)
+ goto out;
if (hctx->sched_tags)
sbitmap_bitmap_show(&hctx->sched_tags->bitmap_tags.sb, m);
mutex_unlock(&q->sysfs_lock);
- return 0;
+
+out:
+ return res;
}
static int hctx_sched_tags_bitmap_open(struct inode *inode, struct file *file)