target: clean up the backend interface to caching parameters

Remove the dpo_emulated, fua_write_emulated, fua_read_emulated and
write_cache_emulated methods, and replace them with a simple bitfields in
se_subsystem_api in those cases where they ever returned one.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

3 files changed, 19 insertions, 103 deletions

diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c
index ca6e4a4df134..81352b7f9130 100644
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -972,36 +972,24 @@ int se_dev_set_unmap_granularity_alignment(
 
 int se_dev_set_emulate_dpo(struct se_device *dev, int flag)
 {
-        if ((flag != 0) && (flag != 1)) {
+        if (flag != 0 && flag != 1) {
                 pr_err("Illegal value %d\n", flag);
                 return -EINVAL;
         }
-        if (dev->transport->dpo_emulated == NULL) {
-                pr_err("dev->transport->dpo_emulated is NULL\n");
-                return -EINVAL;
-        }
-        if (dev->transport->dpo_emulated(dev) == 0) {
-                pr_err("dev->transport->dpo_emulated not supported\n");
-                return -EINVAL;
-        }
-        dev->se_sub_dev->se_dev_attrib.emulate_dpo = flag;
-        pr_debug("dev[%p]: SE Device Page Out (DPO) Emulation"
-                        " bit: %d\n", dev, dev->se_sub_dev->se_dev_attrib.emulate_dpo);
-        return 0;
+
+        pr_err("dpo_emulated not supported\n");
+        return -EINVAL;
 }
 
 int se_dev_set_emulate_fua_write(struct se_device *dev, int flag)
 {
-        if ((flag != 0) && (flag != 1)) {
+        if (flag != 0 && flag != 1) {
                 pr_err("Illegal value %d\n", flag);
                 return -EINVAL;
         }
-        if (dev->transport->fua_write_emulated == NULL) {
-                pr_err("dev->transport->fua_write_emulated is NULL\n");
-                return -EINVAL;
-        }
-        if (dev->transport->fua_write_emulated(dev) == 0) {
-                pr_err("dev->transport->fua_write_emulated not supported\n");
+
+        if (dev->transport->fua_write_emulated == 0) {
+                pr_err("fua_write_emulated not supported\n");
                 return -EINVAL;
         }
         dev->se_sub_dev->se_dev_attrib.emulate_fua_write = flag;
@@ -1012,36 +1000,23 @@ int se_dev_set_emulate_fua_write(struct se_device *dev, int flag)
 
 int se_dev_set_emulate_fua_read(struct se_device *dev, int flag)
 {
-        if ((flag != 0) && (flag != 1)) {
+        if (flag != 0 && flag != 1) {
                 pr_err("Illegal value %d\n", flag);
                 return -EINVAL;
         }
-        if (dev->transport->fua_read_emulated == NULL) {
-                pr_err("dev->transport->fua_read_emulated is NULL\n");
-                return -EINVAL;
-        }
-        if (dev->transport->fua_read_emulated(dev) == 0) {
-                pr_err("dev->transport->fua_read_emulated not supported\n");
-                return -EINVAL;
-        }
-        dev->se_sub_dev->se_dev_attrib.emulate_fua_read = flag;
-        pr_debug("dev[%p]: SE Device Forced Unit Access READs: %d\n",
-                        dev, dev->se_sub_dev->se_dev_attrib.emulate_fua_read);
-        return 0;
+
+        pr_err("ua read emulated not supported\n");
+        return -EINVAL;
 }
 
 int se_dev_set_emulate_write_cache(struct se_device *dev, int flag)
 {
-        if ((flag != 0) && (flag != 1)) {
+        if (flag != 0 && flag != 1) {
                 pr_err("Illegal value %d\n", flag);
                 return -EINVAL;
         }
-        if (dev->transport->write_cache_emulated == NULL) {
-                pr_err("dev->transport->write_cache_emulated is NULL\n");
-                return -EINVAL;
-        }
-        if (dev->transport->write_cache_emulated(dev) == 0) {
-                pr_err("dev->transport->write_cache_emulated not supported\n");
+        if (dev->transport->write_cache_emulated == 0) {
+                pr_err("write_cache_emulated not supported\n");
                 return -EINVAL;
         }
         dev->se_sub_dev->se_dev_attrib.emulate_write_cache = flag;
diff --git a/drivers/target/target_core_file.c b/drivers/target/target_core_file.c
index 98aa5836448b..19a0be9c6570 100644
--- a/drivers/target/target_core_file.c
+++ b/drivers/target/target_core_file.c
@@ -400,33 +400,6 @@ static void fd_emulate_sync_cache(struct se_task *task)
 }
 
 /*
- * Tell TCM Core that we are capable of WriteCache emulation for
- * an underlying struct se_device.
- */
-static int fd_emulated_write_cache(struct se_device *dev)
-{
-        return 1;
-}
-
-static int fd_emulated_dpo(struct se_device *dev)
-{
-        return 0;
-}
-/*
- * Tell TCM Core that we will be emulating Forced Unit Access (FUA) for WRITEs
- * for TYPE_DISK.
- */
-static int fd_emulated_fua_write(struct se_device *dev)
-{
-        return 1;
-}
-
-static int fd_emulated_fua_read(struct se_device *dev)
-{
-        return 0;
-}
-
-/*
  * WRITE Force Unit Access (FUA) emulation on a per struct se_task
  * LBA range basis..
  */
@@ -640,15 +613,13 @@ static struct se_subsystem_api fileio_template = {
         .name                   = "fileio",
         .owner                  = THIS_MODULE,
         .transport_type         = TRANSPORT_PLUGIN_VHBA_PDEV,
+        .write_cache_emulated   = 1,
+        .fua_write_emulated     = 1,
         .attach_hba             = fd_attach_hba,
         .detach_hba             = fd_detach_hba,
         .allocate_virtdevice    = fd_allocate_virtdevice,
         .create_virtdevice      = fd_create_virtdevice,
         .free_device            = fd_free_device,
-        .dpo_emulated           = fd_emulated_dpo,
-        .fua_write_emulated     = fd_emulated_fua_write,
-        .fua_read_emulated      = fd_emulated_fua_read,
-        .write_cache_emulated   = fd_emulated_write_cache,
         .alloc_task             = fd_alloc_task,
         .do_task                = fd_do_task,
         .do_sync_cache          = fd_emulate_sync_cache,
diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c
index d9ad2a216eaa..41ad02b5fb87 100644
--- a/drivers/target/target_core_iblock.c
+++ b/drivers/target/target_core_iblock.c
@@ -351,34 +351,6 @@ static void iblock_emulate_sync_cache(struct se_task *task)
         submit_bio(WRITE_FLUSH, bio);
 }
 
-/*
- * Tell TCM Core that we are capable of WriteCache emulation for
- * an underlying struct se_device.
- */
-static int iblock_emulated_write_cache(struct se_device *dev)
-{
-        return 1;
-}
-
-static int iblock_emulated_dpo(struct se_device *dev)
-{
-        return 0;
-}
-
-/*
- * Tell TCM Core that we will be emulating Forced Unit Access (FUA) for WRITEs
- * for TYPE_DISK.
- */
-static int iblock_emulated_fua_write(struct se_device *dev)
-{
-        return 1;
-}
-
-static int iblock_emulated_fua_read(struct se_device *dev)
-{
-        return 0;
-}
-
 static int iblock_do_discard(struct se_device *dev, sector_t lba, u32 range)
 {
         struct iblock_dev *ibd = dev->dev_ptr;
@@ -679,15 +651,13 @@ static struct se_subsystem_api iblock_template = {
         .name                   = "iblock",
         .owner                  = THIS_MODULE,
         .transport_type         = TRANSPORT_PLUGIN_VHBA_PDEV,
+        .write_cache_emulated   = 1,
+        .fua_write_emulated     = 1,
         .attach_hba             = iblock_attach_hba,
         .detach_hba             = iblock_detach_hba,
         .allocate_virtdevice    = iblock_allocate_virtdevice,
         .create_virtdevice      = iblock_create_virtdevice,
         .free_device            = iblock_free_device,
-        .dpo_emulated           = iblock_emulated_dpo,
-        .fua_write_emulated     = iblock_emulated_fua_write,
-        .fua_read_emulated      = iblock_emulated_fua_read,
-        .write_cache_emulated   = iblock_emulated_write_cache,
         .alloc_task             = iblock_alloc_task,
         .do_task                = iblock_do_task,
         .do_discard             = iblock_do_discard,