md/bitmap: separate bitmap file allocation to its own function.

This will allow allocation before swapping in a new bitmap.

Signed-off-by: NeilBrown <neilb@suse.de>

1 files changed, 67 insertions, 46 deletions

diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index 7a3be0d4103e..4ac60ed66c49 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -716,6 +716,58 @@ static inline struct page *filemap_get_page(struct bitmap_storage *store,
                               - file_page_index(store, 0)];
 }
 
+static int bitmap_storage_alloc(struct bitmap_storage *store,
+                                unsigned long chunks, int with_super)
+{
+        int pnum;
+        unsigned long num_pages;
+        unsigned long bytes;
+
+        bytes = DIV_ROUND_UP(chunks, 8);
+        if (with_super)
+                bytes += sizeof(bitmap_super_t);
+
+        num_pages = DIV_ROUND_UP(bytes, PAGE_SIZE);
+
+        store->filemap = kmalloc(sizeof(struct page *)
+                                 * num_pages, GFP_KERNEL);
+        if (!store->filemap)
+                return -ENOMEM;
+
+        if (with_super && !store->sb_page) {
+                store->sb_page = alloc_page(GFP_KERNEL);
+                if (store->sb_page == NULL)
+                        return -ENOMEM;
+                store->sb_page->index = 0;
+        }
+        pnum = 0;
+        if (store->sb_page) {
+                store->filemap[0] = store->sb_page;
+                pnum = 1;
+        }
+        for ( ; pnum < num_pages; pnum++) {
+                store->filemap[pnum] = alloc_page(GFP_KERNEL);
+                if (!store->filemap[pnum]) {
+                        store->file_pages = pnum;
+                        return -ENOMEM;
+                }
+                store->filemap[pnum]->index = pnum;
+        }
+        store->file_pages = pnum;
+
+        /* We need 4 bits per page, rounded up to a multiple
+         * of sizeof(unsigned long) */
+        store->filemap_attr = kzalloc(
+                roundup(DIV_ROUND_UP(num_pages*4, 8), sizeof(unsigned long)),
+                GFP_KERNEL);
+        if (!store->filemap_attr)
+                return -ENOMEM;
+
+        store->bytes = bytes;
+
+        return 0;
+}
+
 static void bitmap_file_unmap(struct bitmap *bitmap)
 {
         struct page **map, *sb_page;
@@ -940,11 +992,10 @@ static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int n
 static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
 {
         unsigned long i, chunks, index, oldindex, bit;
-        int pnum;
         struct page *page = NULL;
-        unsigned long num_pages, bit_cnt = 0;
+        unsigned long bit_cnt = 0;
         struct file *file;
-        unsigned long bytes, offset;
+        unsigned long offset;
         int outofdate;
         int ret = -ENOSPC;
         void *paddr;
@@ -973,53 +1024,23 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
                 printk(KERN_INFO "%s: bitmap file is out of date, doing full "
                         "recovery\n", bmname(bitmap));
 
-        bytes = DIV_ROUND_UP(bitmap->chunks, 8);
-        if (!bitmap->mddev->bitmap_info.external)
-                bytes += sizeof(bitmap_super_t);
-
-        store->bytes = bytes;
-
-        num_pages = DIV_ROUND_UP(bytes, PAGE_SIZE);
-
-        if (file && i_size_read(file->f_mapping->host) < bytes) {
+        if (file && i_size_read(file->f_mapping->host) < store->bytes) {
                 printk(KERN_INFO "%s: bitmap file too short %lu < %lu\n",
-                        bmname(bitmap),
-                        (unsigned long) i_size_read(file->f_mapping->host),
-                        bytes);
+                       bmname(bitmap),
+                       (unsigned long) i_size_read(file->f_mapping->host),
+                       store->bytes);
                 goto err;
         }
 
-        ret = -ENOMEM;
-
-        store->filemap = kmalloc(sizeof(struct page *)
-                                          * num_pages, GFP_KERNEL);
-        if (!store->filemap)
+        ret = bitmap_storage_alloc(&bitmap->storage, bitmap->chunks,
+                                   !bitmap->mddev->bitmap_info.external);
+        if (ret)
                 goto err;
 
-        pnum = 0;
+        oldindex = ~0L;
         offset = 0;
-        if (store->sb_page) {
-                store->filemap[0] = store->sb_page;
-                pnum = 1;
+        if (!bitmap->mddev->bitmap_info.external)
                 offset = sizeof(bitmap_super_t);
-        }
-        for ( ; pnum < num_pages; pnum++) {
-                store->filemap[pnum] = alloc_page(GFP_KERNEL);
-                if (!store->filemap[pnum]) {
-                        store->file_pages = pnum;
-                        goto err;
-                }
-        }
-        store->file_pages = pnum;
-
-        /* We need 4 bits per page, rounded up to a multiple of sizeof(unsigned long) */
-        store->filemap_attr = kzalloc(
-                roundup(DIV_ROUND_UP(num_pages*4, 8), sizeof(unsigned long)),
-                GFP_KERNEL);
-        if (!store->filemap_attr)
-                goto err;
-
-        oldindex = ~0L;
 
         for (i = 0; i < chunks; i++) {
                 int b;
@@ -1028,8 +1049,8 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
                 if (index != oldindex) { /* this is a new page, read it in */
                         int count;
                         /* unmap the old page, we're done with it */
-                        if (index == num_pages-1)
-                                count = bytes - index * PAGE_SIZE;
+                        if (index == store->file_pages-1)
+                                count = store->bytes - index * PAGE_SIZE;
                         else
                                 count = PAGE_SIZE;
                         page = store->filemap[index];
@@ -1083,9 +1104,9 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
         }
 
         printk(KERN_INFO "%s: bitmap initialized from disk: "
-               "read %lu/%lu pages, set %lu of %lu bits\n",
+               "read %lu pages, set %lu of %lu bits\n",
                bmname(bitmap), store->file_pages,
-               num_pages, bit_cnt, chunks);
+               bit_cnt, chunks);
 
         return 0;