libnvdimm/pfn_dev: Add page size and struct page size to pfn superblock

This is needed so that pmem probe don't wrongly initialize a namespace
which doesn't have enough space reserved for holding struct pages
with the current kernel.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Link: https://lore.kernel.org/r/20190905154603.10349-5-aneesh.kumar@linux.ibm.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

diff --git a/drivers/nvdimm/pfn.h b/drivers/nvdimm/pfn.h
index 7381673b7b70b9804b00ed982ddac2153d44f305..acb19517f678b05020fdb3e5af0d5c04d4bb8eae 100644 (file)
--- a/drivers/nvdimm/pfn.h
+++ b/drivers/nvdimm/pfn.h
@@ -29,7 +29,10 @@ struct nd_pfn_sb {
        /* minor-version-2 record the base alignment of the mapping */
        __le32 align;
        /* minor-version-3 guarantee the padding and flags are zero */
-       u8 padding[4000];
+       /* minor-version-4 record the page size and struct page size */
+       __le32 page_size;
+       __le16 page_struct_size;
+       u8 padding[3994];
        __le64 checksum;
 };
 

diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
index cd120feb9213bddab8a08ca0f91af958ae5cb6ee..ce9ef18282dd0491a21a273e5bd20fe5967bf04f 100644 (file)
--- a/drivers/nvdimm/pfn_devs.c
+++ b/drivers/nvdimm/pfn_devs.c
@@ -460,6 +460,11 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn, const char *sig)
        if (__le16_to_cpu(pfn_sb->version_minor) < 2)
                pfn_sb->align = 0;
 
+       if (__le16_to_cpu(pfn_sb->version_minor) < 4) {
+               pfn_sb->page_struct_size = cpu_to_le16(64);
+               pfn_sb->page_size = cpu_to_le32(PAGE_SIZE);
+       }
+
        switch (le32_to_cpu(pfn_sb->mode)) {
        case PFN_MODE_RAM:
        case PFN_MODE_PMEM:
@@ -475,6 +480,22 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn, const char *sig)
                align = 1UL << ilog2(offset);
        mode = le32_to_cpu(pfn_sb->mode);
 
+       if ((le32_to_cpu(pfn_sb->page_size) > PAGE_SIZE) &&
+                       (mode == PFN_MODE_PMEM)) {
+               dev_err(&nd_pfn->dev,
+                               "init failed, page size mismatch %d\n",
+                               le32_to_cpu(pfn_sb->page_size));
+               return -EOPNOTSUPP;
+       }
+
+       if ((le16_to_cpu(pfn_sb->page_struct_size) < sizeof(struct page)) &&
+                       (mode == PFN_MODE_PMEM)) {
+               dev_err(&nd_pfn->dev,
+                               "init failed, struct page size mismatch %d\n",
+                               le16_to_cpu(pfn_sb->page_struct_size));
+               return -EOPNOTSUPP;
+       }
+
        if (!nd_pfn->uuid) {
                /*
                 * When probing a namepace via nd_pfn_probe() the uuid
@@ -730,8 +751,10 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn)
        memcpy(pfn_sb->uuid, nd_pfn->uuid, 16);
        memcpy(pfn_sb->parent_uuid, nd_dev_to_uuid(&ndns->dev), 16);
        pfn_sb->version_major = cpu_to_le16(1);
-       pfn_sb->version_minor = cpu_to_le16(3);
+       pfn_sb->version_minor = cpu_to_le16(4);
        pfn_sb->align = cpu_to_le32(nd_pfn->align);
+       pfn_sb->page_struct_size = cpu_to_le16(MAX_STRUCT_PAGE_SIZE);
+       pfn_sb->page_size = cpu_to_le32(PAGE_SIZE);
        checksum = nd_sb_checksum((struct nd_gen_sb *) pfn_sb);
        pfn_sb->checksum = cpu_to_le64(checksum);