[PATCH] md/bitmap: fix online removal of file-backed bitmaps

[linux-2.6-block.git] / mm / sparse.c

diff --git a/mm/sparse.c b/mm/sparse.c
index 100040c0dfb6c8e674dada0ed8eb471820e2f75b..e0a3fe48aa3745bebd710ff80d8cad6215dd244d 100644 (file)
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -99,6 +99,22 @@ int __section_nr(struct mem_section* ms)
        return (root_nr * SECTIONS_PER_ROOT) + (ms - root);
 }
 
+/*
+ * During early boot, before section_mem_map is used for an actual
+ * mem_map, we use section_mem_map to store the section's NUMA
+ * node.  This keeps us from having to use another data structure.  The
+ * node information is cleared just before we store the real mem_map.
+ */
+static inline unsigned long sparse_encode_early_nid(int nid)
+{
+       return (nid << SECTION_NID_SHIFT);
+}
+
+static inline int sparse_early_nid(struct mem_section *section)
+{
+       return (section->section_mem_map >> SECTION_NID_SHIFT);
+}
+
 /* Record a memory area against a node. */
 void memory_present(int nid, unsigned long start, unsigned long end)
 {
@@ -113,7 +129,8 @@ void memory_present(int nid, unsigned long start, unsigned long end)
 
                ms = __nr_to_section(section);
                if (!ms->section_mem_map)
-                       ms->section_mem_map = SECTION_MARKED_PRESENT;
+                       ms->section_mem_map = sparse_encode_early_nid(nid) |
+                                                       SECTION_MARKED_PRESENT;
        }
 }
 
@@ -164,6 +181,7 @@ static int sparse_init_one_section(struct mem_section *ms,
        if (!valid_section(ms))
                return -EINVAL;
 
+       ms->section_mem_map &= ~SECTION_MAP_MASK;
        ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum);
 
        return 1;
@@ -172,8 +190,8 @@ static int sparse_init_one_section(struct mem_section *ms,
 static struct page *sparse_early_mem_map_alloc(unsigned long pnum)
 {
        struct page *map;
-       int nid = early_pfn_to_nid(section_nr_to_pfn(pnum));
        struct mem_section *ms = __nr_to_section(pnum);
+       int nid = sparse_early_nid(ms);
 
        map = alloc_remap(nid, sizeof(struct page) * PAGES_PER_SECTION);
        if (map)