f2fs: large volume support

f2fs's cp has one page which consists of struct f2fs_checkpoint and
version bitmap of sit and nat. To support lots of segments, we need more
blocks for sit bitmap. So let's arrange sit bitmap as following:
+-----------------+------------+
| f2fs_checkpoint | sit bitmap |
| + nat bitmap    |            |
+-----------------+------------+
0                 4k        N blocks

Signed-off-by: Changman Lee <cm224.lee@samsung.com>
[Jaegeuk Kim: simple code change for readability]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

3 files changed, 53 insertions, 7 deletions

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index fe968c7bfc90..ecba8da3308b 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -371,7 +371,9 @@ void recover_orphan_inodes(struct f2fs_sb_info *sbi)
                 return;
 
         sbi->por_doing = true;
-        start_blk = __start_cp_addr(sbi) + 1;
+
+        start_blk = __start_cp_addr(sbi) + 1 +
+                le32_to_cpu(F2FS_RAW_SUPER(sbi)->cp_payload);
         orphan_blkaddr = __start_sum_addr(sbi) - 1;
 
         ra_meta_pages(sbi, start_blk, orphan_blkaddr, META_CP);
@@ -512,8 +514,11 @@ int get_valid_checkpoint(struct f2fs_sb_info *sbi)
         unsigned long blk_size = sbi->blocksize;
         unsigned long long cp1_version = 0, cp2_version = 0;
         unsigned long long cp_start_blk_no;
+        unsigned int cp_blks = 1 + le32_to_cpu(F2FS_RAW_SUPER(sbi)->cp_payload);
+        block_t cp_blk_no;
+        int i;
 
-        sbi->ckpt = kzalloc(blk_size, GFP_KERNEL);
+        sbi->ckpt = kzalloc(cp_blks * blk_size, GFP_KERNEL);
         if (!sbi->ckpt)
                 return -ENOMEM;
         /*
@@ -544,6 +549,23 @@ int get_valid_checkpoint(struct f2fs_sb_info *sbi)
         cp_block = (struct f2fs_checkpoint *)page_address(cur_page);
         memcpy(sbi->ckpt, cp_block, blk_size);
 
+        if (cp_blks <= 1)
+                goto done;
+
+        cp_blk_no = le32_to_cpu(fsb->cp_blkaddr);
+        if (cur_page == cp2)
+                cp_blk_no += 1 << le32_to_cpu(fsb->log_blocks_per_seg);
+
+        for (i = 1; i < cp_blks; i++) {
+                void *sit_bitmap_ptr;
+                unsigned char *ckpt = (unsigned char *)sbi->ckpt;
+
+                cur_page = get_meta_page(sbi, cp_blk_no + i);
+                sit_bitmap_ptr = page_address(cur_page);
+                memcpy(ckpt + i * blk_size, sit_bitmap_ptr, blk_size);
+                f2fs_put_page(cur_page, 1);
+        }
+done:
         f2fs_put_page(cp1, 1);
         f2fs_put_page(cp2, 1);
         return 0;
@@ -736,6 +758,7 @@ static void do_checkpoint(struct f2fs_sb_info *sbi, bool is_umount)
         __u32 crc32 = 0;
         void *kaddr;
         int i;
+        int cp_payload_blks = le32_to_cpu(F2FS_RAW_SUPER(sbi)->cp_payload);
 
         /*
          * This avoids to conduct wrong roll-forward operations and uses
@@ -786,16 +809,19 @@ static void do_checkpoint(struct f2fs_sb_info *sbi, bool is_umount)
 
         orphan_blocks = (sbi->n_orphans + F2FS_ORPHANS_PER_BLOCK - 1)
                                         / F2FS_ORPHANS_PER_BLOCK;
-        ckpt->cp_pack_start_sum = cpu_to_le32(1 + orphan_blocks);
+        ckpt->cp_pack_start_sum = cpu_to_le32(1 + cp_payload_blks +
+                        orphan_blocks);
 
         if (is_umount) {
                 set_ckpt_flags(ckpt, CP_UMOUNT_FLAG);
                 ckpt->cp_pack_total_block_count = cpu_to_le32(2 +
-                        data_sum_blocks + orphan_blocks + NR_CURSEG_NODE_TYPE);
+                                cp_payload_blks + data_sum_blocks +
+                                orphan_blocks + NR_CURSEG_NODE_TYPE);
         } else {
                 clear_ckpt_flags(ckpt, CP_UMOUNT_FLAG);
                 ckpt->cp_pack_total_block_count = cpu_to_le32(2 +
-                        data_sum_blocks + orphan_blocks);
+                                cp_payload_blks + data_sum_blocks +
+                                orphan_blocks);
         }
 
         if (sbi->n_orphans)
@@ -821,6 +847,15 @@ static void do_checkpoint(struct f2fs_sb_info *sbi, bool is_umount)
         set_page_dirty(cp_page);
         f2fs_put_page(cp_page, 1);
 
+        for (i = 1; i < 1 + cp_payload_blks; i++) {
+                cp_page = grab_meta_page(sbi, start_blk++);
+                kaddr = page_address(cp_page);
+                memcpy(kaddr, (char *)ckpt + i * F2FS_BLKSIZE,
+                                (1 << sbi->log_blocksize));
+                set_page_dirty(cp_page);
+                f2fs_put_page(cp_page, 1);
+        }
+
         if (sbi->n_orphans) {
                 write_orphan_inodes(sbi, start_blk);
                 start_blk += orphan_blocks;
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 676a2c6ccec7..9684b1f77a7d 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -764,9 +764,18 @@ static inline unsigned long __bitmap_size(struct f2fs_sb_info *sbi, int flag)
 static inline void *__bitmap_ptr(struct f2fs_sb_info *sbi, int flag)
 {
         struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
-        int offset = (flag == NAT_BITMAP) ?
+        int offset;
+
+        if (le32_to_cpu(F2FS_RAW_SUPER(sbi)->cp_payload) > 0) {
+                if (flag == NAT_BITMAP)
+                        return &ckpt->sit_nat_version_bitmap;
+                else
+                        return ((unsigned char *)ckpt + F2FS_BLKSIZE);
+        } else {
+                offset = (flag == NAT_BITMAP) ?
                         le32_to_cpu(ckpt->sit_ver_bitmap_bytesize) : 0;
-        return &ckpt->sit_nat_version_bitmap + offset;
+                return &ckpt->sit_nat_version_bitmap + offset;
+        }
 }
 
 static inline block_t __start_cp_addr(struct f2fs_sb_info *sbi)
diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h
index ba6f3127738f..6ff0b0b42d47 100644
--- a/include/linux/f2fs_fs.h
+++ b/include/linux/f2fs_fs.h
@@ -19,6 +19,7 @@
 #define F2FS_LOG_SECTORS_PER_BLOCK      3       /* 4KB: F2FS_BLKSIZE */
 #define F2FS_BLKSIZE                    4096    /* support only 4KB block */
 #define F2FS_MAX_EXTENSION              64      /* # of extension entries */
+#define F2FS_BLK_ALIGN(x)       (((x) + F2FS_BLKSIZE - 1) / F2FS_BLKSIZE)
 
 #define NULL_ADDR               ((block_t)0)    /* used as block_t addresses */
 #define NEW_ADDR                ((block_t)-1)   /* used as block_t addresses */
@@ -75,6 +76,7 @@ struct f2fs_super_block {
         __le16 volume_name[512];        /* volume name */
         __le32 extension_count;         /* # of extensions below */
         __u8 extension_list[F2FS_MAX_EXTENSION][8];     /* extension array */
+        __le32 cp_payload;
 } __packed;
 
 /*