nilfs2: implement resize ioctl
This adds resize ioctl which makes online resize possible.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index eba5b53..2846491 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"
@@ -404,6 +405,77 @@
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;