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;