From 0f5e2ec46dd64579c0770f3822764f94db4fa465 Mon Sep 17 00:00:00 2001 From: Nicholas Bellinger Date: Sat, 18 Jan 2014 09:32:56 +0000 Subject: [PATCH] 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 Cc: Christoph Hellwig Cc: Hannes Reinecke Cc: Sagi Grimberg Cc: Or Gerlitz Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_file.c | 137 ++++++++++++++++++++++++++++++++++++++ drivers/target/target_core_file.h | 4 ++ 2 files changed, 141 insertions(+) diff --git a/drivers/target/target_core_file.c b/drivers/target/target_core_file.c index 0e34cda..119d519 100644 --- a/drivers/target/target_core_file.c +++ b/drivers/target/target_core_file.c @@ -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) diff --git a/drivers/target/target_core_file.h b/drivers/target/target_core_file.h index 37ffc5b..583691e 100644 --- a/drivers/target/target_core_file.h +++ b/drivers/target/target_core_file.h @@ -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; -- 2.7.4