static int nilfs_sync_fs(struct super_block *sb, int wait)
{
struct the_nilfs *nilfs = sb->s_fs_info;
struct nilfs_super_block **sbp;
int err = 0;
/* This function is called when super block should be written back */
if (wait)
err = nilfs_construct_segment(sb);
down_write(&nilfs->ns_sem);
if (nilfs_sb_dirty(nilfs)) {
sbp = nilfs_prepare_super(sb, nilfs_sb_will_flip(nilfs));
if (likely(sbp)) {
nilfs_set_log_cursor(sbp[0], nilfs);
nilfs_commit_super(sb, NILFS_SB_COMMIT);
}
}
up_write(&nilfs->ns_sem);
if (!err)
err = nilfs_flush_device(nilfs);
return err;
}
/**
* nilfs_cleanup_super() - write filesystem state for cleanup
* @sbi: nilfs_sb_info to be unmounted or degraded to read-only
*
* This function restores state flags in the on-disk super block.
* This will set "clean" flag (i.e. NILFS_VALID_FS) unless the
* filesystem was not clean previously.
*/
int nilfs_cleanup_super(struct nilfs_sb_info *sbi)
{
struct nilfs_super_block **sbp;
int flag = NILFS_SB_COMMIT;
int ret = -EIO;
sbp = nilfs_prepare_super(sbi, 0);
if (sbp) {
sbp[0]->s_state = cpu_to_le16(sbi->s_nilfs->ns_mount_state);
nilfs_set_log_cursor(sbp[0], sbi->s_nilfs);
if (sbp[1] && sbp[0]->s_last_cno == sbp[1]->s_last_cno) {
/*
* make the "clean" flag also to the opposite
* super block if both super blocks point to
* the same checkpoint.
*/
sbp[1]->s_state = sbp[0]->s_state;
flag = NILFS_SB_COMMIT_ALL;
}
ret = nilfs_commit_super(sbi, flag);
}
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;
}
