target/rd: Refactor rd_build_device_space + rd_release_device_space

This patch refactors rd_build_device_space() + rd_release_device_space()
into rd_allocate_sgl_table() + rd_release_device_space() so that they
may be used seperatly for setup + release of protection information
scatterlists.

Also add explicit memset of pages within rd_allocate_sgl_table() based
upon passed 'init_payload' value.

v2 changes:
  - Drop unused sg_table from rd_release_device_space (Wei)

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: Nicholas Bellinger <nab@linux-iscsi.org>

diff --git a/drivers/target/target_core_rd.c b/drivers/target/target_core_rd.c
index 4ffe5f2..e9fa879 100644 (file)
--- a/drivers/target/target_core_rd.c
+++ b/drivers/target/target_core_rd.c
@@ -78,23 +78,14 @@ static void rd_detach_hba(struct se_hba *hba)
        hba->hba_ptr = NULL;
 }
 
-/*     rd_release_device_space():
- *
- *
- */
-static void rd_release_device_space(struct rd_dev *rd_dev)
+static u32 rd_release_sgl_table(struct rd_dev *rd_dev, struct rd_dev_sg_table *sg_table,
+                                u32 sg_table_count)
 {
-       u32 i, j, page_count = 0, sg_per_table;
-       struct rd_dev_sg_table *sg_table;
        struct page *pg;
        struct scatterlist *sg;
+       u32 i, j, page_count = 0, sg_per_table;
 
-       if (!rd_dev->sg_table_array || !rd_dev->sg_table_count)
-               return;
-
-       sg_table = rd_dev->sg_table_array;
-
-       for (i = 0; i < rd_dev->sg_table_count; i++) {
+       for (i = 0; i < sg_table_count; i++) {
                sg = sg_table[i].sg_table;
                sg_per_table = sg_table[i].rd_sg_count;
 
@@ -105,16 +96,28 @@ static void rd_release_device_space(struct rd_dev *rd_dev)
                                page_count++;
                        }
                }
-
                kfree(sg);
        }
 
+       kfree(sg_table);
+       return page_count;
+}
+
+static void rd_release_device_space(struct rd_dev *rd_dev)
+{
+       u32 page_count;
+
+       if (!rd_dev->sg_table_array || !rd_dev->sg_table_count)
+               return;
+
+       page_count = rd_release_sgl_table(rd_dev, rd_dev->sg_table_array,
+                                         rd_dev->sg_table_count);
+
        pr_debug("CORE_RD[%u] - Released device space for Ramdisk"
                " Device ID: %u, pages %u in %u tables total bytes %lu\n",
                rd_dev->rd_host->rd_host_id, rd_dev->rd_dev_id, page_count,
                rd_dev->sg_table_count, (unsigned long)page_count * PAGE_SIZE);
 
-       kfree(sg_table);
        rd_dev->sg_table_array = NULL;
        rd_dev->sg_table_count = 0;
 }
@@ -124,38 +127,15 @@ static void rd_release_device_space(struct rd_dev *rd_dev)
  *
  *
  */
-static int rd_build_device_space(struct rd_dev *rd_dev)
+static int rd_allocate_sgl_table(struct rd_dev *rd_dev, struct rd_dev_sg_table *sg_table,
+                                u32 total_sg_needed, unsigned char init_payload)
 {
-       u32 i = 0, j, page_offset = 0, sg_per_table, sg_tables, total_sg_needed;
+       u32 i = 0, j, page_offset = 0, sg_per_table;
        u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
                                sizeof(struct scatterlist));
-       struct rd_dev_sg_table *sg_table;
        struct page *pg;
        struct scatterlist *sg;
-
-       if (rd_dev->rd_page_count <= 0) {
-               pr_err("Illegal page count: %u for Ramdisk device\n",
-                       rd_dev->rd_page_count);
-               return -EINVAL;
-       }
-
-       /* Don't need backing pages for NULLIO */
-       if (rd_dev->rd_flags & RDF_NULLIO)
-               return 0;
-
-       total_sg_needed = rd_dev->rd_page_count;
-
-       sg_tables = (total_sg_needed / max_sg_per_table) + 1;
-
-       sg_table = kzalloc(sg_tables * sizeof(struct rd_dev_sg_table), GFP_KERNEL);
-       if (!sg_table) {
-               pr_err("Unable to allocate memory for Ramdisk"
-                       " scatterlist tables\n");
-               return -ENOMEM;
-       }
-
-       rd_dev->sg_table_array = sg_table;
-       rd_dev->sg_table_count = sg_tables;
+       unsigned char *p;
 
        while (total_sg_needed) {
                sg_per_table = (total_sg_needed > max_sg_per_table) ?
@@ -186,16 +166,59 @@ static int rd_build_device_space(struct rd_dev *rd_dev)
                        }
                        sg_assign_page(&sg[j], pg);
                        sg[j].length = PAGE_SIZE;
+
+                       p = kmap(pg);
+                       memset(p, init_payload, PAGE_SIZE);
+                       kunmap(pg);
                }
 
                page_offset += sg_per_table;
                total_sg_needed -= sg_per_table;
        }
 
+       return 0;
+}
+
+static int rd_build_device_space(struct rd_dev *rd_dev)
+{
+       struct rd_dev_sg_table *sg_table;
+       u32 sg_tables, total_sg_needed;
+       u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
+                               sizeof(struct scatterlist));
+       int rc;
+
+       if (rd_dev->rd_page_count <= 0) {
+               pr_err("Illegal page count: %u for Ramdisk device\n",
+                      rd_dev->rd_page_count);
+               return -EINVAL;
+       }
+
+       /* Don't need backing pages for NULLIO */
+       if (rd_dev->rd_flags & RDF_NULLIO)
+               return 0;
+
+       total_sg_needed = rd_dev->rd_page_count;
+
+       sg_tables = (total_sg_needed / max_sg_per_table) + 1;
+
+       sg_table = kzalloc(sg_tables * sizeof(struct rd_dev_sg_table), GFP_KERNEL);
+       if (!sg_table) {
+               pr_err("Unable to allocate memory for Ramdisk"
+                      " scatterlist tables\n");
+               return -ENOMEM;
+       }
+
+       rd_dev->sg_table_array = sg_table;
+       rd_dev->sg_table_count = sg_tables;
+
+       rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0x00);
+       if (rc)
+               return rc;
+
        pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u space of"
-               " %u pages in %u tables\n", rd_dev->rd_host->rd_host_id,
-               rd_dev->rd_dev_id, rd_dev->rd_page_count,
-               rd_dev->sg_table_count);
+                " %u pages in %u tables\n", rd_dev->rd_host->rd_host_id,
+                rd_dev->rd_dev_id, rd_dev->rd_page_count,
+                rd_dev->sg_table_count);
 
        return 0;
 }