1 files changed, 130 insertions, 1 deletions

diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index 062cca065195..8351c44a7320 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -56,6 +56,7 @@
 #include "btnode.h"
 #include "page.h"
 #include "cpfile.h"
+#include "sufile.h" /* nilfs_sufile_resize(), nilfs_sufile_set_alloc_range() */
 #include "ifile.h"
 #include "dat.h"
 #include "segment.h"
@@ -165,7 +166,7 @@ struct inode *nilfs_alloc_inode(struct super_block *sb)
         ii->i_state = 0;
         ii->i_cno = 0;
         ii->vfs_inode.i_version = 1;
-        nilfs_btnode_cache_init(&ii->i_btnode_cache, sb->s_bdi);
+        nilfs_mapping_init(&ii->i_btnode_cache, &ii->vfs_inode, sb->s_bdi);
         return &ii->vfs_inode;
 }
 
@@ -347,6 +348,134 @@ int nilfs_cleanup_super(struct super_block *sb)
         return ret;
 }
 
+/**
+ * nilfs_move_2nd_super - relocate secondary super block
+ * @sb: super block instance
+ * @sb2off: new offset of the secondary super block (in bytes)
+ */
+static int nilfs_move_2nd_super(struct super_block *sb, loff_t sb2off)
+{
+        struct the_nilfs *nilfs = sb->s_fs_info;
+        struct buffer_head *nsbh;
+        struct nilfs_super_block *nsbp;
+        sector_t blocknr, newblocknr;
+        unsigned long offset;
+        int sb2i = -1;  /* array index of the secondary superblock */
+        int ret = 0;
+
+        /* nilfs->ns_sem must be locked by the caller. */
+        if (nilfs->ns_sbh[1] &&
+            nilfs->ns_sbh[1]->b_blocknr > nilfs->ns_first_data_block) {
+                sb2i = 1;
+                blocknr = nilfs->ns_sbh[1]->b_blocknr;
+        } else if (nilfs->ns_sbh[0]->b_blocknr > nilfs->ns_first_data_block) {
+                sb2i = 0;
+                blocknr = nilfs->ns_sbh[0]->b_blocknr;
+        }
+        if (sb2i >= 0 && (u64)blocknr << nilfs->ns_blocksize_bits == sb2off)
+                goto out;  /* super block location is unchanged */
+
+        /* Get new super block buffer */
+        newblocknr = sb2off >> nilfs->ns_blocksize_bits;
+        offset = sb2off & (nilfs->ns_blocksize - 1);
+        nsbh = sb_getblk(sb, newblocknr);
+        if (!nsbh) {
+                printk(KERN_WARNING
+                       "NILFS warning: unable to move secondary superblock "
+                       "to block %llu\n", (unsigned long long)newblocknr);
+                ret = -EIO;
+                goto out;
+        }
+        nsbp = (void *)nsbh->b_data + offset;
+        memset(nsbp, 0, nilfs->ns_blocksize);
+
+        if (sb2i >= 0) {
+                memcpy(nsbp, nilfs->ns_sbp[sb2i], nilfs->ns_sbsize);
+                brelse(nilfs->ns_sbh[sb2i]);
+                nilfs->ns_sbh[sb2i] = nsbh;
+                nilfs->ns_sbp[sb2i] = nsbp;
+        } else if (nilfs->ns_sbh[0]->b_blocknr < nilfs->ns_first_data_block) {
+                /* secondary super block will be restored to index 1 */
+                nilfs->ns_sbh[1] = nsbh;
+                nilfs->ns_sbp[1] = nsbp;
+        } else {
+                brelse(nsbh);
+        }
+out:
+        return ret;
+}
+
+/**
+ * nilfs_resize_fs - resize the filesystem
+ * @sb: super block instance
+ * @newsize: new size of the filesystem (in bytes)
+ */
+int nilfs_resize_fs(struct super_block *sb, __u64 newsize)
+{
+        struct the_nilfs *nilfs = sb->s_fs_info;
+        struct nilfs_super_block **sbp;
+        __u64 devsize, newnsegs;
+        loff_t sb2off;
+        int ret;
+
+        ret = -ERANGE;
+        devsize = i_size_read(sb->s_bdev->bd_inode);
+        if (newsize > devsize)
+                goto out;
+
+        /*
+         * Write lock is required to protect some functions depending
+         * on the number of segments, the number of reserved segments,
+         * and so forth.
+         */
+        down_write(&nilfs->ns_segctor_sem);
+
+        sb2off = NILFS_SB2_OFFSET_BYTES(newsize);
+        newnsegs = sb2off >> nilfs->ns_blocksize_bits;
+        do_div(newnsegs, nilfs->ns_blocks_per_segment);
+
+        ret = nilfs_sufile_resize(nilfs->ns_sufile, newnsegs);
+        up_write(&nilfs->ns_segctor_sem);
+        if (ret < 0)
+                goto out;
+
+        ret = nilfs_construct_segment(sb);
+        if (ret < 0)
+                goto out;
+
+        down_write(&nilfs->ns_sem);
+        nilfs_move_2nd_super(sb, sb2off);
+        ret = -EIO;
+        sbp = nilfs_prepare_super(sb, 0);
+        if (likely(sbp)) {
+                nilfs_set_log_cursor(sbp[0], nilfs);
+                /*
+                 * Drop NILFS_RESIZE_FS flag for compatibility with
+                 * mount-time resize which may be implemented in a
+                 * future release.
+                 */
+                sbp[0]->s_state = cpu_to_le16(le16_to_cpu(sbp[0]->s_state) &
+                                              ~NILFS_RESIZE_FS);
+                sbp[0]->s_dev_size = cpu_to_le64(newsize);
+                sbp[0]->s_nsegments = cpu_to_le64(nilfs->ns_nsegments);
+                if (sbp[1])
+                        memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
+                ret = nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL);
+        }
+        up_write(&nilfs->ns_sem);
+
+        /*
+         * Reset the range of allocatable segments last.  This order
+         * is important in the case of expansion because the secondary
+         * superblock must be protected from log write until migration
+         * completes.
+         */
+        if (!ret)
+                nilfs_sufile_set_alloc_range(nilfs->ns_sufile, 0, newnsegs - 1);
+out:
+        return ret;
+}
+
 static void nilfs_put_super(struct super_block *sb)
 {
         struct the_nilfs *nilfs = sb->s_fs_info;