From 5beb6e0b2008386571fd342d0a4a14f5c8c0baf8 Mon Sep 17 00:00:00 2001 From: Ryusuke Konishi Date: Mon, 20 Sep 2010 18:19:06 +0900 Subject: [PATCH] nilfs2: add bdev freeze/thaw support Nilfs hasn't supported the freeze/thaw feature because it didn't work due to the peculiar design that multiple super block instances could be allocated for a device. This limitation was removed by the patch "nilfs2: do not allocate multiple super block instances for a device". So now this adds the freeze/thaw support to nilfs. Signed-off-by: Ryusuke Konishi --- fs/nilfs2/ioctl.c | 2 ++ fs/nilfs2/segment.c | 2 ++ fs/nilfs2/super.c | 58 +++++++++++++++++++++++++++++++++++++++++---- 3 files changed, 58 insertions(+), 4 deletions(-) diff --git a/fs/nilfs2/ioctl.c b/fs/nilfs2/ioctl.c index 338858fc907c..3e90f86d5bfe 100644 --- a/fs/nilfs2/ioctl.c +++ b/fs/nilfs2/ioctl.c @@ -580,6 +580,8 @@ static int nilfs_ioctl_clean_segments(struct inode *inode, struct file *filp, goto out_free; } + vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE); + ret = nilfs_ioctl_move_blocks(inode->i_sb, &argv[0], kbufs[0]); if (ret < 0) printk(KERN_ERR "NILFS: GC failed during preparation: " diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c index 56350bf1f79f..172ad4257494 100644 --- a/fs/nilfs2/segment.c +++ b/fs/nilfs2/segment.c @@ -191,6 +191,8 @@ int nilfs_transaction_begin(struct super_block *sb, if (ret > 0) return 0; + vfs_check_frozen(sb, SB_FREEZE_WRITE); + sbi = NILFS_SB(sb); nilfs = sbi->s_nilfs; down_read(&nilfs->ns_segctor_sem); diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c index a1cd444103ff..92e8c769584c 100644 --- a/fs/nilfs2/super.c +++ b/fs/nilfs2/super.c @@ -73,6 +73,7 @@ struct kmem_cache *nilfs_transaction_cachep; struct kmem_cache *nilfs_segbuf_cachep; struct kmem_cache *nilfs_btree_path_cache; +static int nilfs_setup_super(struct nilfs_sb_info *sbi, int is_mount); static int nilfs_remount(struct super_block *sb, int *flags, char *data); static void nilfs_set_error(struct nilfs_sb_info *sbi) @@ -439,6 +440,36 @@ int nilfs_attach_checkpoint(struct nilfs_sb_info *sbi, __u64 cno, int curr_mnt, return err; } +static int nilfs_freeze(struct super_block *sb) +{ + struct nilfs_sb_info *sbi = NILFS_SB(sb); + struct the_nilfs *nilfs = sbi->s_nilfs; + int err; + + if (sb->s_flags & MS_RDONLY) + return 0; + + /* Mark super block clean */ + down_write(&nilfs->ns_sem); + err = nilfs_cleanup_super(sbi); + up_write(&nilfs->ns_sem); + return err; +} + +static int nilfs_unfreeze(struct super_block *sb) +{ + struct nilfs_sb_info *sbi = NILFS_SB(sb); + struct the_nilfs *nilfs = sbi->s_nilfs; + + if (sb->s_flags & MS_RDONLY) + return 0; + + down_write(&nilfs->ns_sem); + nilfs_setup_super(sbi, false); + up_write(&nilfs->ns_sem); + return 0; +} + static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf) { struct super_block *sb = dentry->d_sb; @@ -523,6 +554,8 @@ static const struct super_operations nilfs_sops = { .put_super = nilfs_put_super, /* .write_super = nilfs_write_super, */ .sync_fs = nilfs_sync_fs, + .freeze_fs = nilfs_freeze, + .unfreeze_fs = nilfs_unfreeze, /* .write_super_lockfs */ /* .unlockfs */ .statfs = nilfs_statfs, @@ -626,7 +659,7 @@ nilfs_set_default_options(struct nilfs_sb_info *sbi, NILFS_MOUNT_ERRORS_RO | NILFS_MOUNT_BARRIER; } -static int nilfs_setup_super(struct nilfs_sb_info *sbi) +static int nilfs_setup_super(struct nilfs_sb_info *sbi, int is_mount) { struct the_nilfs *nilfs = sbi->s_nilfs; struct nilfs_super_block **sbp; @@ -638,6 +671,9 @@ static int nilfs_setup_super(struct nilfs_sb_info *sbi) if (!sbp) return -EIO; + if (!is_mount) + goto skip_mount_setup; + max_mnt_count = le16_to_cpu(sbp[0]->s_max_mnt_count); mnt_count = le16_to_cpu(sbp[0]->s_mnt_count); @@ -654,9 +690,11 @@ static int nilfs_setup_super(struct nilfs_sb_info *sbi) sbp[0]->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT); sbp[0]->s_mnt_count = cpu_to_le16(mnt_count + 1); + sbp[0]->s_mtime = cpu_to_le64(get_seconds()); + +skip_mount_setup: sbp[0]->s_state = cpu_to_le16(le16_to_cpu(sbp[0]->s_state) & ~NILFS_VALID_FS); - sbp[0]->s_mtime = cpu_to_le64(get_seconds()); /* synchronize sbp[1] with sbp[0] */ memcpy(sbp[1], sbp[0], nilfs->ns_sbsize); return nilfs_commit_super(sbi, NILFS_SB_COMMIT_ALL); @@ -938,7 +976,7 @@ nilfs_fill_super(struct super_block *sb, void *data, int silent) if (!(sb->s_flags & MS_RDONLY)) { down_write(&nilfs->ns_sem); - nilfs_setup_super(sbi); + nilfs_setup_super(sbi, true); up_write(&nilfs->ns_sem); } @@ -1034,7 +1072,7 @@ static int nilfs_remount(struct super_block *sb, int *flags, char *data) goto restore_opts; down_write(&nilfs->ns_sem); - nilfs_setup_super(sbi); + nilfs_setup_super(sbi, true); up_write(&nilfs->ns_sem); } out: @@ -1132,7 +1170,19 @@ nilfs_get_sb(struct file_system_type *fs_type, int flags, goto failed; } + /* + * once the super is inserted into the list by sget, s_umount + * will protect the lockfs code from trying to start a snapshot + * while we are mounting + */ + mutex_lock(&sd.bdev->bd_fsfreeze_mutex); + if (sd.bdev->bd_fsfreeze_count > 0) { + mutex_unlock(&sd.bdev->bd_fsfreeze_mutex); + err = -EBUSY; + goto failed; + } s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, sd.bdev); + mutex_unlock(&sd.bdev->bd_fsfreeze_mutex); if (IS_ERR(s)) { err = PTR_ERR(s); goto failed; -- 2.20.1