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Commit 0f5e2ec4 authored by Nicholas Bellinger's avatar Nicholas Bellinger
Browse files

target/file: Add DIF protection init/format support 



This patch adds support for DIF protection init/format support into
the FILEIO backend.

It involves using a seperate $FILE.protection for storing PI that is
opened via fd_init_prot() using the common pi_prot_type attribute.
The actual formatting of the protection is done via fd_format_prot()
using the common pi_prot_format attribute, that will populate the
initial PI data based upon the currently configured pi_prot_type.

Based on original FILEIO code from Sagi.

v1 changes:
  - Fix sparse warnings in fd_init_format_buf (Fengguang)

Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent ecebbf6c

drivers/target/target_core_file.c

+137 −0
Original line number Diff line number Diff line
@@ -700,6 +700,140 @@ static sector_t fd_get_blocks(struct se_device *dev) 
		       dev->dev_attrib.block_size);

}



static int fd_init_prot(struct se_device *dev)

{

	struct fd_dev *fd_dev = FD_DEV(dev);

	struct file *prot_file, *file = fd_dev->fd_file;

	struct inode *inode;

	int ret, flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;

	char buf[FD_MAX_DEV_PROT_NAME];



	if (!file) {

		pr_err("Unable to locate fd_dev->fd_file\n");

		return -ENODEV;

	}



	inode = file->f_mapping->host;

	if (S_ISBLK(inode->i_mode)) {

		pr_err("FILEIO Protection emulation only supported on"

		       " !S_ISBLK\n");

		return -ENOSYS;

	}



	if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE)

		flags &= ~O_DSYNC;



	snprintf(buf, FD_MAX_DEV_PROT_NAME, "%s.protection",

		 fd_dev->fd_dev_name);



	prot_file = filp_open(buf, flags, 0600);

	if (IS_ERR(prot_file)) {

		pr_err("filp_open(%s) failed\n", buf);

		ret = PTR_ERR(prot_file);

		return ret;

	}

	fd_dev->fd_prot_file = prot_file;



	return 0;

}



static void fd_init_format_buf(struct se_device *dev, unsigned char *buf,

			       u32 unit_size, u32 *ref_tag, u16 app_tag,

			       bool inc_reftag)

{

	unsigned char *p = buf;

	int i;



	for (i = 0; i < unit_size; i += dev->prot_length) {

		*((u16 *)&p[0]) = 0xffff;

		*((__be16 *)&p[2]) = cpu_to_be16(app_tag);

		*((__be32 *)&p[4]) = cpu_to_be32(*ref_tag);



		if (inc_reftag)

			(*ref_tag)++;



		p += dev->prot_length;

	}

}



static int fd_format_prot(struct se_device *dev)

{

	struct fd_dev *fd_dev = FD_DEV(dev);

	struct file *prot_fd = fd_dev->fd_prot_file;

	sector_t prot_length, prot;

	unsigned char *buf;

	loff_t pos = 0;

	u32 ref_tag = 0;

	int unit_size = FDBD_FORMAT_UNIT_SIZE * dev->dev_attrib.block_size;

	int rc, ret = 0, size, len;

	bool inc_reftag = false;



	if (!dev->dev_attrib.pi_prot_type) {

		pr_err("Unable to format_prot while pi_prot_type == 0\n");

		return -ENODEV;

	}

	if (!prot_fd) {

		pr_err("Unable to locate fd_dev->fd_prot_file\n");

		return -ENODEV;

	}



	switch (dev->dev_attrib.pi_prot_type) {

	case TARGET_DIF_TYPE3_PROT:

		ref_tag = 0xffffffff;

		break;

	case TARGET_DIF_TYPE2_PROT:

	case TARGET_DIF_TYPE1_PROT:

		inc_reftag = true;

		break;

	default:

		break;

	}



	buf = vzalloc(unit_size);

	if (!buf) {

		pr_err("Unable to allocate FILEIO prot buf\n");

		return -ENOMEM;

	}



	prot_length = (dev->transport->get_blocks(dev) + 1) * dev->prot_length;

	size = prot_length;



	pr_debug("Using FILEIO prot_length: %llu\n",

		 (unsigned long long)prot_length);



	for (prot = 0; prot < prot_length; prot += unit_size) {



		fd_init_format_buf(dev, buf, unit_size, &ref_tag, 0xffff,

				   inc_reftag);



		len = min(unit_size, size);



		rc = kernel_write(prot_fd, buf, len, pos);

		if (rc != len) {

			pr_err("vfs_write to prot file failed: %d\n", rc);

			ret = -ENODEV;

			goto out;

		}

		pos += len;

		size -= len;

	}



out:

	vfree(buf);

	return ret;

}



static void fd_free_prot(struct se_device *dev)

{

	struct fd_dev *fd_dev = FD_DEV(dev);



	if (!fd_dev->fd_prot_file)

		return;



	filp_close(fd_dev->fd_prot_file, NULL);

	fd_dev->fd_prot_file = NULL;

}



static struct sbc_ops fd_sbc_ops = {

	.execute_rw		= fd_execute_rw,

	.execute_sync_cache	= fd_execute_sync_cache,
@@ -730,6 +864,9 @@ static struct se_subsystem_api fileio_template = { 
	.show_configfs_dev_params = fd_show_configfs_dev_params,

	.get_device_type	= sbc_get_device_type,

	.get_blocks		= fd_get_blocks,

	.init_prot		= fd_init_prot,

	.format_prot		= fd_format_prot,

	.free_prot		= fd_free_prot,

};



static int __init fileio_module_init(void)

drivers/target/target_core_file.h

+4 −0
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ 
#define FD_VERSION		"4.0"



#define FD_MAX_DEV_NAME		256

#define FD_MAX_DEV_PROT_NAME	FD_MAX_DEV_NAME + 16

#define FD_DEVICE_QUEUE_DEPTH	32

#define FD_MAX_DEVICE_QUEUE_DEPTH 128

#define FD_BLOCKSIZE		512
@@ -15,6 +16,8 @@ 
#define FBDF_HAS_PATH		0x01

#define FBDF_HAS_SIZE		0x02

#define FDBD_HAS_BUFFERED_IO_WCE 0x04

#define FDBD_FORMAT_UNIT_SIZE	2048





struct fd_dev {

	struct se_device dev;
@@ -29,6 +32,7 @@ struct fd_dev { 
	u32		fd_block_size;

	unsigned long long fd_dev_size;

	struct file	*fd_file;

	struct file	*fd_prot_file;

	/* FILEIO HBA device is connected to */

	struct fd_host *fd_host;

} ____cacheline_aligned;