target: break up free_device callback

[linux.git] / drivers / target / target_core_iblock.c

diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c
index d316ed537d59132a3fde2dfd11eba3194d899bec..a5e16f715392031712027e08b7a2aeaef31e6a97 100644 (file)
--- a/drivers/target/target_core_iblock.c
+++ b/drivers/target/target_core_iblock.c
@@ -86,6 +86,7 @@ static int iblock_configure_device(struct se_device *dev)
        struct block_device *bd = NULL;
        struct blk_integrity *bi;
        fmode_t mode;
+       unsigned int max_write_zeroes_sectors;
        int ret = -ENOMEM;
 
        if (!(ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)) {
@@ -129,7 +130,11 @@ static int iblock_configure_device(struct se_device *dev)
         * Enable write same emulation for IBLOCK and use 0xFFFF as
         * the smaller WRITE_SAME(10) only has a two-byte block count.
         */
-       dev->dev_attrib.max_write_same_len = 0xFFFF;
+       max_write_zeroes_sectors = bdev_write_zeroes_sectors(bd);
+       if (max_write_zeroes_sectors)
+               dev->dev_attrib.max_write_same_len = max_write_zeroes_sectors;
+       else
+               dev->dev_attrib.max_write_same_len = 0xFFFF;
 
        if (blk_queue_nonrot(q))
                dev->dev_attrib.is_nonrot = 1;
@@ -184,6 +189,11 @@ static void iblock_dev_call_rcu(struct rcu_head *p)
 }
 
 static void iblock_free_device(struct se_device *dev)
+{
+       call_rcu(&dev->rcu_head, iblock_dev_call_rcu);
+}
+
+static void iblock_destroy_device(struct se_device *dev)
 {
        struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 
@@ -191,8 +201,6 @@ static void iblock_free_device(struct se_device *dev)
                blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
        if (ib_dev->ibd_bio_set != NULL)
                bioset_free(ib_dev->ibd_bio_set);
-
-       call_rcu(&dev->rcu_head, iblock_dev_call_rcu);
 }
 
 static unsigned long long iblock_emulate_read_cap_with_block_size(
@@ -279,7 +287,7 @@ static void iblock_complete_cmd(struct se_cmd *cmd)
        struct iblock_req *ibr = cmd->priv;
        u8 status;
 
-       if (!atomic_dec_and_test(&ibr->pending))
+       if (!refcount_dec_and_test(&ibr->pending))
                return;
 
        if (atomic_read(&ibr->ib_bio_err_cnt))
@@ -415,28 +423,31 @@ iblock_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
 }
 
 static sense_reason_t
-iblock_execute_write_same_direct(struct block_device *bdev, struct se_cmd *cmd)
+iblock_execute_zero_out(struct block_device *bdev, struct se_cmd *cmd)
 {
        struct se_device *dev = cmd->se_dev;
        struct scatterlist *sg = &cmd->t_data_sg[0];
-       struct page *page = NULL;
-       int ret;
+       unsigned char *buf, zero = 0x00, *p = &zero;
+       int rc, ret;
 
-       if (sg->offset) {
-               page = alloc_page(GFP_KERNEL);
-               if (!page)
-                       return TCM_OUT_OF_RESOURCES;
-               sg_copy_to_buffer(sg, cmd->t_data_nents, page_address(page),
-                                 dev->dev_attrib.block_size);
-       }
+       buf = kmap(sg_page(sg)) + sg->offset;
+       if (!buf)
+               return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+       /*
+        * Fall back to block_execute_write_same() slow-path if
+        * incoming WRITE_SAME payload does not contain zeros.
+        */
+       rc = memcmp(buf, p, cmd->data_length);
+       kunmap(sg_page(sg));
 
-       ret = blkdev_issue_write_same(bdev,
+       if (rc)
+               return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+
+       ret = blkdev_issue_zeroout(bdev,
                                target_to_linux_sector(dev, cmd->t_task_lba),
                                target_to_linux_sector(dev,
                                        sbc_get_write_same_sectors(cmd)),
-                               GFP_KERNEL, page ? page : sg_page(sg));
-       if (page)
-               __free_page(page);
+                               GFP_KERNEL, false);
        if (ret)
                return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 
@@ -472,8 +483,10 @@ iblock_execute_write_same(struct se_cmd *cmd)
                return TCM_INVALID_CDB_FIELD;
        }
 
-       if (bdev_write_same(bdev))
-               return iblock_execute_write_same_direct(bdev, cmd);
+       if (bdev_write_zeroes_sectors(bdev)) {
+               if (!iblock_execute_zero_out(bdev, cmd))
+                       return 0;
+       }
 
        ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
        if (!ibr)
@@ -487,7 +500,7 @@ iblock_execute_write_same(struct se_cmd *cmd)
        bio_list_init(&list);
        bio_list_add(&list, bio);
 
-       atomic_set(&ibr->pending, 1);
+       refcount_set(&ibr->pending, 1);
 
        while (sectors) {
                while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
@@ -498,7 +511,7 @@ iblock_execute_write_same(struct se_cmd *cmd)
                        if (!bio)
                                goto fail_put_bios;
 
-                       atomic_inc(&ibr->pending);
+                       refcount_inc(&ibr->pending);
                        bio_list_add(&list, bio);
                }
 
@@ -706,7 +719,7 @@ iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
        cmd->priv = ibr;
 
        if (!sgl_nents) {
-               atomic_set(&ibr->pending, 1);
+               refcount_set(&ibr->pending, 1);
                iblock_complete_cmd(cmd);
                return 0;
        }
@@ -719,7 +732,7 @@ iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
        bio_list_init(&list);
        bio_list_add(&list, bio);
 
-       atomic_set(&ibr->pending, 2);
+       refcount_set(&ibr->pending, 2);
        bio_cnt = 1;
 
        for_each_sg(sgl, sg, sgl_nents, i) {
@@ -740,7 +753,7 @@ iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
                        if (!bio)
                                goto fail_put_bios;
 
-                       atomic_inc(&ibr->pending);
+                       refcount_inc(&ibr->pending);
                        bio_list_add(&list, bio);
                        bio_cnt++;
                }
@@ -848,6 +861,7 @@ static const struct target_backend_ops iblock_ops = {
        .detach_hba             = iblock_detach_hba,
        .alloc_device           = iblock_alloc_device,
        .configure_device       = iblock_configure_device,
+       .destroy_device         = iblock_destroy_device,
        .free_device            = iblock_free_device,
        .parse_cdb              = iblock_parse_cdb,
        .set_configfs_dev_params = iblock_set_configfs_dev_params,