This patch added a function tcmu_pr_info_encode() which can
encode Persistent Reservation info, from a struct tcmu_pr_info
to a string, so that we can store this string on a TCMU device.
This function will call the pervious added encoder like
tcmu_pr_info_reg_encode() to do it's work.
Signed-off-by: Zhu Lingshan <lszhu@xxxxxxxx>
---
drivers/target/target_core_user.c | 133 ++++++++++++++++++++++++++++++
1 file changed, 133 insertions(+)
diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
index 0f8eeed61c60..957e444d853b 100644
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -107,6 +107,31 @@
#define TCMU_PR_INFO_XATTR_FIELD_NUM_REGS 5
#define TCMU_PR_INFO_XATTR_FIELD_REGS_START 6
+/* don't allow encoded PR info to exceed 8K */
+#define TCMU_PR_INFO_XATTR_MAX_SIZE 8192
+
+#define TCMU_PR_INFO_XATTR_ENCODED_SCSI2_RSV_MAXLEN \
+ (TCMU_PR_IT_NEXUS_MAXLEN + sizeof("\n"))
+
+#define TCMU_PR_INFO_XATTR_ENCODED_PR_RSV_MAXLEN \
+ ((sizeof("0x") + sizeof(u64) * 2) + sizeof(" ") + \
+ TCMU_PR_IT_NEXUS_MAXLEN + sizeof(" ") + \
+ (sizeof("0x") + sizeof(u64) * 2) + sizeof("\n"))
+
+#define TCMU_PR_INFO_XATTR_ENCODED_PR_REG_MAXLEN \
+ ((sizeof("0x") + sizeof(u64) * 2) + sizeof(" ") + \
+ TCMU_PR_IT_NEXUS_MAXLEN + sizeof("\n"))
+
+#define TCMU_PR_INFO_XATTR_ENCODED_MAXLEN(_num_regs) \
+ ((sizeof("0x") + sizeof(u32) * 2) + sizeof("\n") + \
+ (sizeof("0x") + sizeof(u32) * 2) + sizeof("\n") + \
+ TCMU_PR_INFO_XATTR_ENCODED_SCSI2_RSV_MAXLEN + \
+ (sizeof("0x") + sizeof(u32) * 2) + sizeof("\n") + \
+ TCMU_PR_INFO_XATTR_ENCODED_PR_RSV_MAXLEN + \
+ (sizeof("0x") + sizeof(u32) * 2) + sizeof("\n") + \
+ (TCMU_PR_INFO_XATTR_ENCODED_PR_REG_MAXLEN * _num_regs) + \
+ sizeof("\0"))
+
static u8 tcmu_kern_cmd_reply_supported;
static struct device *tcmu_root_device;
@@ -2304,6 +2329,114 @@ static int tcmu_pr_info_get(struct tcmu_dev *udev,
return rc;
}
+static int tcmu_pr_info_encode(struct tcmu_pr_info *pr_info,
+ char **_pr_xattr, int *pr_xattr_len)
+{
+ struct tcmu_pr_reg *reg;
+ char *pr_xattr;
+ char *p;
+ size_t buf_remain;
+ int rc;
+ int i;
+
+ if (pr_info->vers != TCMU_PR_INFO_XATTR_VERS) {
+ pr_err("unsupported PR info version: %u\n", pr_info->vers);
+ return -EINVAL;
+ }
+
+ buf_remain = TCMU_PR_INFO_XATTR_ENCODED_MAXLEN(pr_info->num_regs);
+ if (buf_remain > TCMU_PR_INFO_XATTR_MAX_SIZE) {
+ pr_err("PR info too large for encoding: %zd\n", buf_remain);
+ return -EINVAL;
+ }
+ pr_debug("encoding PR info: vers=%u, seq=%u, gen=%u, num regs=%u ",
+ pr_info->vers, pr_info->seq, pr_info->gen, pr_info->num_regs);
+ pr_debug("into %zd bytes\n", buf_remain);
+
+ pr_xattr = kmalloc(buf_remain, GFP_KERNEL);
+ if (!pr_xattr)
+ return -ENOMEM;
+
+ p = pr_xattr;
+ rc = tcmu_pr_info_vers_seq_encode(p, buf_remain, pr_info->vers,
+ pr_info->seq);
+ if (rc < 0) {
+ rc = -EINVAL;
+ goto err_xattr_free;
+ }
+
+ p += rc;
+ buf_remain -= rc;
+
+ rc = tcmu_pr_info_scsi2_rsv_encode(p, buf_remain, pr_info->scsi2_rsv);
+ if (rc < 0) {
+ rc = -EINVAL;
+ goto err_xattr_free;
+ }
+
+ p += rc;
+ buf_remain -= rc;
+
+ rc = tcmu_pr_info_gen_encode(p, buf_remain, pr_info->gen);
+ if (rc < 0) {
+ rc = -EINVAL;
+ goto err_xattr_free;
+ }
+
+ p += rc;
+ buf_remain -= rc;
+
+ rc = tcmu_pr_info_rsv_encode(p, buf_remain, pr_info->rsv);
+ if (rc < 0) {
+ rc = -EINVAL;
+ goto err_xattr_free;
+ }
+
+ p += rc;
+ buf_remain -= rc;
+
+ rc = tcmu_pr_info_num_regs_encode(p, buf_remain, pr_info->num_regs);
+ if (rc < 0) {
+ rc = -EINVAL;
+ goto err_xattr_free;
+ }
+
+ p += rc;
+ buf_remain -= rc;
+
+ i = 0;
+ list_for_each_entry(reg, &pr_info->regs, regs_node) {
+ rc = tcmu_pr_info_reg_encode(p, buf_remain, reg);
+ if (rc < 0) {
+ rc = -EINVAL;
+ goto err_xattr_free;
+ }
+
+ p += rc;
+ buf_remain -= rc;
+ i++;
+ }
+
+ if (i != pr_info->num_regs) {
+ pr_err("mismatch between PR num_regs and list entries!\n");
+ rc = -EINVAL;
+ goto err_xattr_free;
+ }
+
+ *_pr_xattr = pr_xattr;
+ /* +1 to include null term */
+ *pr_xattr_len = (p - pr_xattr) + 1;
+
+ pr_err("successfully encoded all %d PR regs into %d bytes: %s\n",
+ pr_info->num_regs, *pr_xattr_len, pr_xattr);
+
+ return 0;
+
+err_xattr_free:
+ kfree(pr_xattr);
+ return rc;
+}
+
static int tcmu_configure_device(struct se_device *dev)
{
struct tcmu_dev *udev = TCMU_DEV(dev);
--
2.17.1
--
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