[PATCH] tcm: Convert UNMAP + WRITE_SAME_* to IBLOCK only support
From: Nicholas A. Bellinger
Date: Thu Oct 14 2010 - 02:28:04 EST
From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
This patch series converts the existing transport_generic_unmap() and
transport_generic_write_same() code to be called directly from TCM code
using transport_emulate_control_cdb(). It also converts the primary
struct se_subsystem_api->do_discard() to accept an 'sector_t lba' and
'u32 range' that is passed from SCSI UNMAP/WRITE_SAME emulation down
to generic block level discard logic in TCM/IBLOCK.
This patch also makes emulate_tpu and emulate_tpws now disabled by default,
even when the underlying struct block_device supports Discard during IBLOCK
device creation. This means that these two attrs will need to be enabled
on a per $HBA/$DEV/attrib/ basis to explictly activate SCSI UNMAP/WRITE_SAME
support.
Finally, this patch also drops the Generic Block Discard support in TCM/FILEIO
as there is really not a safe way to do this yet.
Thanks again to hch for his input on this item!
Signed-off-by: Nicholas A. Bellinger <nab@xxxxxxxxxxxxxxx>
Reported-by: Christoph Hellwig <hch@xxxxxx>
---
drivers/target/target_core_device.c | 18 +++++
drivers/target/target_core_file.c | 127 +-------------------------------
drivers/target/target_core_iblock.c | 41 ++---------
drivers/target/target_core_transport.c | 27 ++++---
include/target/target_core_transport.h | 9 +--
5 files changed, 43 insertions(+), 179 deletions(-)
diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c
index 070da98..5364259 100644
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -1231,6 +1231,15 @@ int se_dev_set_emulate_tpu(struct se_device *dev, int flag)
printk(KERN_ERR "Illegal value %d\n", flag);
return -1;
}
+ /*
+ * We expect this value to be non-zero when generic Block Layer
+ * Discard supported is detected iblock_create_virtdevice().
+ */
+ if (!(DEV_ATTRIB(dev)->max_unmap_block_desc_count)) {
+ printk(KERN_ERR "Generic Block Discard not supported\n");
+ return -ENOSYS;
+ }
+
DEV_ATTRIB(dev)->emulate_tpu = flag;
printk(KERN_INFO "dev[%p]: SE Device Thin Provisioning UNMAP bit: %d\n",
dev, flag);
@@ -1243,6 +1252,15 @@ int se_dev_set_emulate_tpws(struct se_device *dev, int flag)
printk(KERN_ERR "Illegal value %d\n", flag);
return -1;
}
+ /*
+ * We expect this value to be non-zero when generic Block Layer
+ * Discard supported is detected iblock_create_virtdevice().
+ */
+ if (!(DEV_ATTRIB(dev)->max_unmap_block_desc_count)) {
+ printk(KERN_ERR "Generic Block Discard not supported\n");
+ return -ENOSYS;
+ }
+
DEV_ATTRIB(dev)->emulate_tpws = flag;
printk(KERN_INFO "dev[%p]: SE Device Thin Provisioning WRITE_SAME: %d\n",
dev, flag);
diff --git a/drivers/target/target_core_file.c b/drivers/target/target_core_file.c
index 3a68932..6c3f9e5 100644
--- a/drivers/target/target_core_file.c
+++ b/drivers/target/target_core_file.c
@@ -235,32 +235,6 @@ static struct se_device *fd_create_virtdevice(
fd_dev->fd_dev_id = fd_host->fd_host_dev_id_count++;
fd_dev->fd_queue_depth = dev->queue_depth;
- /*
- * Check for QUEUE_FLAG_DISCARD and enable TCM TPE emulation
- * if present for struct block_device backend
- */
- if (S_ISBLK(inode->i_mode)) {
- if (blk_queue_discard(bdev_get_queue(inode->i_bdev))) {
- struct block_device *bd = inode->i_bdev;
- struct request_queue *q = bdev_get_queue(bd);
-
- DEV_ATTRIB(dev)->max_unmap_lba_count =
- q->limits.max_discard_sectors;
- /*
- * Currently hardcoded to 1 in Linux/SCSI code..
- */
- DEV_ATTRIB(dev)->max_unmap_block_desc_count = 1;
- DEV_ATTRIB(dev)->unmap_granularity =
- q->limits.discard_granularity;
- DEV_ATTRIB(dev)->unmap_granularity_alignment =
- q->limits.discard_alignment;
-
- DEV_ATTRIB(dev)->emulate_tpu = 1;
- DEV_ATTRIB(dev)->emulate_tpws = 1;
- printk(KERN_INFO "FILEIO: Enabling BLOCK Discard"
- " for TPU=1 and TPWS=1 emulation\n");
- }
- }
printk(KERN_INFO "CORE_FILE[%u] - Added TCM FILEIO Device ID: %u at %s,"
" %llu total bytes\n", fd_host->fd_host_id, fd_dev->fd_dev_id,
@@ -358,91 +332,6 @@ static void *fd_allocate_request(
return (void *)fd_req;
}
-static int fd_emulate_unmap(struct se_task *task)
-{
- struct se_cmd *cmd = TASK_CMD(task);
- struct fd_dev *fd_dev = task->se_dev->dev_ptr;
- struct file *f = fd_dev->fd_file;
- struct inode *i;
- struct block_device *bd;
- int ret;
-
- i = igrab(f->f_mapping->host);
- if (!(i)) {
- printk(KERN_ERR "FILEIO: Unable to locate inode for"
- " backend for UNMAP\n");
- return PYX_TRANSPORT_LU_COMM_FAILURE;
- }
- /*
- * Currently for struct file w/o a struct block_device
- * backend we return a success..
- */
- if (!(S_ISBLK(i->i_mode))) {
- printk(KERN_WARNING "Ignoring UNMAP for non BD"
- " backend for struct file\n");
- iput(i);
- return PYX_TRANSPORT_LU_COMM_FAILURE;
- }
- bd = I_BDEV(f->f_mapping->host);
- if (!(bd)) {
- printk(KERN_ERR "FILEIO: Unable to locate struct"
- " block_device for UNMAP\n");
- iput(i);
- return PYX_TRANSPORT_LU_COMM_FAILURE;
- }
- /*
- * Now call the transport_generic_unmap() -> blkdev_issue_discard()
- * wrapper to translate SCSI UNMAP into Linux/BLOCK discards on
- * LBA+Range descriptors in the UNMAP write paylaod.
- */
- ret = transport_generic_unmap(cmd, bd);
- iput(i);
-
- return ret;
-}
-
-static int fd_emulate_write_same_unmap(struct se_task *task)
-{
- struct se_cmd *cmd = TASK_CMD(task);
- struct fd_dev *fd_dev = task->se_dev->dev_ptr;
- struct file *f = fd_dev->fd_file;
- struct inode *i;
- struct block_device *bd;
- int ret;
-
- i = igrab(f->f_mapping->host);
- if (!(i)) {
- printk(KERN_ERR "FILEIO: Unable to locate inode for"
- " backend for WRITE_SAME\n");
- return PYX_TRANSPORT_LU_COMM_FAILURE;
- }
- /*
- * Currently for struct file w/o a struct block_device
- * backend we return a success..
- */
- if (!(S_ISBLK(i->i_mode))) {
- printk(KERN_WARNING "Ignoring WRITE_SAME for non BD"
- " backend for struct file\n");
- iput(i);
- return PYX_TRANSPORT_LU_COMM_FAILURE;
- }
- bd = I_BDEV(f->f_mapping->host);
- if (!(bd)) {
- printk(KERN_ERR "FILEIO: Unable to locate struct"
- " block_device for WRITE_SAME\n");
- iput(i);
- return PYX_TRANSPORT_LU_COMM_FAILURE;
- }
- ret = transport_generic_write_same(cmd, bd);
- iput(i);
- if (ret < 0)
- return ret;
-
- task->task_scsi_status = GOOD;
- transport_complete_task(task, 1);
- return PYX_TRANSPORT_SENT_TO_TRANSPORT;
-}
-
static inline int fd_iovec_alloc(struct fd_request *req)
{
req->fd_iovs = kzalloc(sizeof(struct iovec) * req->fd_sg_count,
@@ -774,20 +663,6 @@ static int fd_do_task(struct se_task *task)
return PYX_TRANSPORT_SENT_TO_TRANSPORT;
}
-static int fd_do_discard(struct se_task *task, enum blk_discard_type type)
-{
- if (type == DISCARD_UNMAP)
- return fd_emulate_unmap(task);
- else if (type == DISCARD_WRITE_SAME_UNMAP)
- return fd_emulate_write_same_unmap(task);
- else {
- printk(KERN_ERR "Unsupported discard_type_t: %d\n", type);
- return -ENOSYS;
- }
-
- return -ENOSYS;
-}
-
/* fd_free_task(): (Part of se_subsystem_api_t template)
*
*
@@ -1172,7 +1047,7 @@ static struct se_subsystem_api fileio_template = {
.transport_complete = fd_transport_complete,
.allocate_request = fd_allocate_request,
.do_task = fd_do_task,
- .do_discard = fd_do_discard,
+ .do_discard = NULL,
.do_sync_cache = fd_emulate_sync_cache,
.free_task = fd_free_task,
.check_configfs_dev_params = fd_check_configfs_dev_params,
diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c
index e740265..463f992 100644
--- a/drivers/target/target_core_iblock.c
+++ b/drivers/target/target_core_iblock.c
@@ -213,10 +213,8 @@ static struct se_device *iblock_create_virtdevice(
DEV_ATTRIB(dev)->unmap_granularity_alignment =
q->limits.discard_alignment;
- DEV_ATTRIB(dev)->emulate_tpu = 1;
- DEV_ATTRIB(dev)->emulate_tpws = 1;
- printk(KERN_INFO "IBLOCK: Enabling BLOCK Discard support"
- " for TPU=1 and TPWS=1 emulation\n");
+ printk(KERN_INFO "IBLOCK: BLOCK Discard support available,"
+ " disabled by default\n");
}
return dev;
@@ -392,22 +390,6 @@ static unsigned long long iblock_emulate_read_cap_with_block_size(
return blocks_long;
}
-static int iblock_emulate_write_same_unmap(struct se_task *task)
-{
- struct iblock_dev *ibd = task->se_dev->dev_ptr;
- struct block_device *bd = ibd->ibd_bd;
- struct se_cmd *cmd = TASK_CMD(task);
- int ret;
-
- ret = transport_generic_write_same(cmd, bd);
- if (ret < 0)
- return ret;
-
- task->task_scsi_status = GOOD;
- transport_complete_task(task, 1);
- return PYX_TRANSPORT_SENT_TO_TRANSPORT;
-}
-
static int __iblock_do_sync_cache(struct se_device *dev)
{
struct iblock_dev *ib_dev = (struct iblock_dev *)dev->dev_ptr;
@@ -532,22 +514,13 @@ static int iblock_do_task(struct se_task *task)
return PYX_TRANSPORT_SENT_TO_TRANSPORT;
}
-static int iblock_do_discard(struct se_task *task, enum blk_discard_type type)
+static int iblock_do_discard(struct se_device *dev, sector_t lba, u32 range)
{
- struct iblock_dev *ibd = task->se_dev->dev_ptr;
+ struct iblock_dev *ibd = dev->dev_ptr;
struct block_device *bd = ibd->ibd_bd;
- struct se_cmd *cmd = TASK_CMD(task);
-
- if (type == DISCARD_UNMAP)
- return transport_generic_unmap(cmd, bd);
- else if (type == DISCARD_WRITE_SAME_UNMAP)
- return iblock_emulate_write_same_unmap(task);
- else {
- printk(KERN_ERR "Unsupported discard_type_t: %d\n", type);
- return -ENOSYS;
- }
-
- return -ENOSYS;
+ int barrier = 0;
+
+ return blkdev_issue_discard(bd, lba, range, GFP_KERNEL, barrier);
}
static void iblock_free_task(struct se_task *task)
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 4a30fb9..44376a3 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -5475,14 +5475,15 @@ int transport_get_sense_data(struct se_cmd *cmd)
* Used for TCM/IBLOCK and TCM/FILEIO for block/blk-lib.c level discard support.
* Note this is not used for TCM/pSCSI passthrough
*/
-int transport_generic_unmap(struct se_cmd *cmd, struct block_device *bdev)
+static int transport_generic_unmap(struct se_task *task)
{
+ struct se_cmd *cmd = TASK_CMD(task);
struct se_device *dev = SE_DEV(cmd);
unsigned char *buf = T_TASK(cmd)->t_task_buf, *ptr = NULL;
unsigned char *cdb = &T_TASK(cmd)->t_task_cdb[0];
sector_t lba;
unsigned int size = cmd->data_length, range;
- int barrier = 0, ret, offset = 8; /* First UNMAP block descriptor starts at 8 byte offset */
+ int ret, offset = 8; /* First UNMAP block descriptor starts at 8 byte offset */
unsigned short dl, bd_dl;
/* Skip over UNMAP header */
@@ -5499,7 +5500,7 @@ int transport_generic_unmap(struct se_cmd *cmd, struct block_device *bdev)
printk(KERN_INFO "UNMAP: Using lba: %llu and range: %u\n",
(unsigned long long)lba, range);
- ret = blkdev_issue_discard(bdev, lba, range, GFP_KERNEL, barrier);
+ ret = TRANSPORT(dev)->do_discard(dev, lba, range);
if (ret < 0) {
printk(KERN_ERR "blkdev_issue_discard() failed: %d\n", ret);
return -1;
@@ -5509,20 +5510,22 @@ int transport_generic_unmap(struct se_cmd *cmd, struct block_device *bdev)
size -= 16;
}
+ task->task_scsi_status = GOOD;
+ transport_complete_task(task, 1);
return 0;
}
-EXPORT_SYMBOL(transport_generic_unmap);
/*
* Used for TCM/IBLOCK and TCM/FILEIO for block/blk-lib.c level discard support.
* Note this is not used for TCM/pSCSI passthrough
*/
-int transport_generic_write_same(struct se_cmd *cmd, struct block_device *bdev)
+static int transport_generic_write_same(struct se_task *task)
{
+ struct se_cmd *cmd = TASK_CMD(task);
struct se_device *dev = SE_DEV(cmd);
sector_t lba;
unsigned int range;
- int barrier = 0, ret;
+ int ret;
lba = T_TASK(cmd)->t_task_lba;
range = (cmd->data_length / TRANSPORT(dev)->get_blocksize(dev));
@@ -5530,14 +5533,16 @@ int transport_generic_write_same(struct se_cmd *cmd, struct block_device *bdev)
printk(KERN_INFO "WRITE_SAME UNMAP: LBA: %llu Range: %u\n",
(unsigned long long)lba, range);
- ret = blkdev_issue_discard(bdev, lba, range, GFP_KERNEL, barrier);
+ ret = TRANSPORT(dev)->do_discard(dev, lba, range);
if (ret < 0) {
printk(KERN_INFO "blkdev_issue_discard() failed for WRITE_SAME\n");
return -1;
}
+
+ task->task_scsi_status = GOOD;
+ transport_complete_task(task, 1);
return 0;
}
-EXPORT_SYMBOL(transport_generic_write_same);
/*
* Used by TCM subsystem plugins IBLOCK, FILEIO, and RAMDISK as a
@@ -5610,7 +5615,7 @@ int transport_emulate_control_cdb(struct se_task *task)
TRANSPORT(dev)->name);
return PYX_TRANSPORT_UNKNOWN_SAM_OPCODE;
}
- ret = TRANSPORT(dev)->do_discard(task, DISCARD_UNMAP);
+ ret = transport_generic_unmap(task);
if (ret < 0)
return ret;
break;
@@ -5620,7 +5625,7 @@ int transport_emulate_control_cdb(struct se_task *task)
" for: %s\n", TRANSPORT(dev)->name);
return PYX_TRANSPORT_UNKNOWN_SAM_OPCODE;
}
- ret = TRANSPORT(dev)->do_discard(task, DISCARD_WRITE_SAME_UNMAP);
+ ret = transport_generic_write_same(task);
if (ret < 0)
return ret;
break;
@@ -5633,7 +5638,7 @@ int transport_emulate_control_cdb(struct se_task *task)
" supported for: %s\n", TRANSPORT(dev)->name);
return PYX_TRANSPORT_UNKNOWN_SAM_OPCODE;
}
- ret = TRANSPORT(dev)->do_discard(task, DISCARD_WRITE_SAME_UNMAP);
+ ret = transport_generic_write_same(task);
if (ret < 0)
return ret;
break;
diff --git a/include/target/target_core_transport.h b/include/target/target_core_transport.h
index 1f29cf3..c156098 100644
--- a/include/target/target_core_transport.h
+++ b/include/target/target_core_transport.h
@@ -127,11 +127,6 @@
#define MOD_MAX_SECTORS(ms, bs) (ms % (PAGE_SIZE / bs))
-enum blk_discard_type {
- DISCARD_UNMAP,
- DISCARD_WRITE_SAME_UNMAP,
-};
-
struct se_mem;
struct se_subsystem_api;
@@ -243,8 +238,6 @@ extern int transport_generic_emulate_modesense(struct se_cmd *,
extern int transport_generic_emulate_request_sense(struct se_cmd *,
unsigned char *);
extern int transport_get_sense_data(struct se_cmd *);
-extern int transport_generic_unmap(struct se_cmd *, struct block_device *);
-extern int transport_generic_write_same(struct se_cmd *, struct block_device *);
extern int transport_emulate_control_cdb(struct se_task *);
extern struct se_cmd *transport_allocate_passthrough(unsigned char *, int, u32,
void *, u32, u32, void *);
@@ -471,7 +464,7 @@ struct se_subsystem_api {
* Used by virtual subsystem plugins IBLOCK and FILEIO to emulate
* UNMAP and WRITE_SAME_* w/ UNMAP=1 <-> Linux/Block Discard
*/
- int (*do_discard)(struct se_task *, enum blk_discard_type);
+ int (*do_discard)(struct se_device *, sector_t, u32);
/*
* Used by virtual subsystem plugins IBLOCK and FILEIO to emulate
* SYNCHRONIZE_CACHE_* <-> Linux/Block blkdev_issue_flush()
--
1.5.6.5
--
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