Staging: zram: Remove need for explicit device initialization

[firefly-linux-kernel-4.4.55.git] / drivers / staging / zram / zram_drv.c

diff --git a/drivers/staging/zram/zram_drv.c b/drivers/staging/zram/zram_drv.c
index 3f698a5fc68210fb672f0f01a97acfaf7a1a3af5..c5f84ee3d28a9c4b425b2adfcbdc228351dafaa6 100644 (file)
--- a/drivers/staging/zram/zram_drv.c
+++ b/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 @@ out:
 
 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 */
@@ -490,6 +495,7 @@ 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)
@@ -497,9 +503,11 @@ 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);