---

yaml
---
r: 219715
b: refs/heads/master
c: 484875a
h: refs/heads/master
i:
  219713: 360b3a2
  219711: eccc417
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: e98419c23b1a189c932775f7833e94cb5230a16b
+refs/heads/master: 484875adbc473041b7cf4ef0cb3f56a2ae44a448

trunk/drivers/staging/zram/zram_drv.c

@@ -207,9 +207,15 @@ static int zram_read(struct zram *zram, struct bio *bio)
 	u32 index;
 	struct bio_vec *bvec;
 
-	zram_stat64_inc(zram, &zram->stats.num_reads);
+	if (unlikely(!zram->init_done)) {
+		set_bit(BIO_UPTODATE, &bio->bi_flags);
+		bio_endio(bio, 0);
+		return 0;
+	}
 
+	zram_stat64_inc(zram, &zram->stats.num_reads);
 	index = bio->bi_sector >> SECTORS_PER_PAGE_SHIFT;
+
 	bio_for_each_segment(bvec, bio, i) {
 		int ret;
 		size_t clen;
@@ -275,16 +281,20 @@ static int zram_read(struct zram *zram, struct bio *bio)
 
 static int zram_write(struct zram *zram, struct bio *bio)
 {
-	int i;
+	int i, ret;
 	u32 index;
 	struct bio_vec *bvec;
 
-	zram_stat64_inc(zram, &zram->stats.num_writes);
+	if (unlikely(!zram->init_done)) {
+		ret = zram_init_device(zram);
+		if (ret)
+			goto out;
+	}
 
+	zram_stat64_inc(zram, &zram->stats.num_writes);
 	index = bio->bi_sector >> SECTORS_PER_PAGE_SHIFT;
 
 	bio_for_each_segment(bvec, bio, i) {
-		int ret;
 		u32 offset;
 		size_t clen;
 		struct zobj_header *zheader;
@@ -425,11 +435,6 @@ static int zram_make_request(struct request_queue *queue, struct bio *bio)
 	int ret = 0;
 	struct zram *zram = queue->queuedata;
 
-	if (unlikely(!zram->init_done)) {
-		bio_io_error(bio);
-		return 0;
-	}
-
 	if (!valid_io_request(zram, bio)) {
 		zram_stat64_inc(zram, &zram->stats.invalid_io);
 		bio_io_error(bio);
@@ -453,7 +458,7 @@ void zram_reset_device(struct zram *zram)
 {
 	size_t index;
 
-	/* Do not accept any new I/O request */
+	mutex_lock(&zram->init_lock);
 	zram->init_done = 0;
 
 	/* Free various per-device buffers */
@@ -490,16 +495,19 @@ void zram_reset_device(struct zram *zram)
 	memset(&zram->stats, 0, sizeof(zram->stats));
 
 	zram->disksize = 0;
+	mutex_unlock(&zram->init_lock);
 }
 
 int zram_init_device(struct zram *zram)
 {
 	int ret;
 	size_t num_pages;
 
+	mutex_lock(&zram->init_lock);
+
 	if (zram->init_done) {
-		pr_info("Device already initialized!\n");
-		return -EBUSY;
+		mutex_unlock(&zram->init_lock);
+		return 0;
 	}
 
 	zram_set_disksize(zram, totalram_pages << PAGE_SHIFT);
@@ -542,11 +550,13 @@ int zram_init_device(struct zram *zram)
 	}
 
 	zram->init_done = 1;
+	mutex_unlock(&zram->init_lock);
 
 	pr_debug("Initialization done!\n");
 	return 0;
 
 fail:
+	mutex_unlock(&zram->init_lock);
 	zram_reset_device(zram);
 
 	pr_err("Initialization failed: err=%d\n", ret);
@@ -572,6 +582,7 @@ static int create_device(struct zram *zram, int device_id)
 	int ret = 0;
 
 	mutex_init(&zram->lock);
+	mutex_init(&zram->init_lock);
 	spin_lock_init(&zram->stat64_lock);
 
 	zram->queue = blk_alloc_queue(GFP_KERNEL);

trunk/drivers/staging/zram/zram_drv.h

@@ -108,6 +108,8 @@ struct zram {
 	struct request_queue *queue;
 	struct gendisk *disk;
 	int init_done;
+	/* Prevent concurrent execution of device init and reset */
+	struct mutex init_lock;
 	/*
 	 * This is the limit on amount of *uncompressed* worth of data
 	 * we can store in a disk.

trunk/drivers/staging/zram/zram_sysfs.c

@@ -58,8 +58,10 @@ static ssize_t disksize_store(struct device *dev,
 	int ret;
 	struct zram *zram = dev_to_zram(dev);
 
-	if (zram->init_done)
+	if (zram->init_done) {
+		pr_info("Cannot change disksize for initialized device\n");
 		return -EBUSY;
+	}
 
 	ret = strict_strtoull(buf, 10, &zram->disksize);
 	if (ret)
@@ -79,25 +81,6 @@ static ssize_t initstate_show(struct device *dev,
 	return sprintf(buf, "%u\n", zram->init_done);
 }
 
-static ssize_t initstate_store(struct device *dev,
-		struct device_attribute *attr, const char *buf, size_t len)
-{
-	int ret;
-	unsigned long do_init;
-	struct zram *zram = dev_to_zram(dev);
-
-	ret = strict_strtoul(buf, 10, &do_init);
-	if (ret)
-		return ret;
-
-	if (!do_init)
-		return -EINVAL;
-
-	zram_init_device(zram);
-
-	return len;
-}
-
 static ssize_t reset_store(struct device *dev,
 		struct device_attribute *attr, const char *buf, size_t len)
 {
@@ -208,8 +191,7 @@ static ssize_t mem_used_total_show(struct device *dev,
 
 static DEVICE_ATTR(disksize, S_IRUGO | S_IWUGO,
 		disksize_show, disksize_store);
-static DEVICE_ATTR(initstate, S_IRUGO | S_IWUGO,
-		initstate_show, initstate_store);
+static DEVICE_ATTR(initstate, S_IRUGO, initstate_show, NULL);
 static DEVICE_ATTR(reset, S_IWUGO, NULL, reset_store);
 static DEVICE_ATTR(num_reads, S_IRUGO, num_reads_show, NULL);
 static DEVICE_ATTR(num_writes, S_IRUGO, num_writes_show, NULL);