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authorRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>2010-09-20 18:19:06 +0900
committerRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>2010-10-23 09:24:39 +0900
commit5beb6e0b2008386571fd342d0a4a14f5c8c0baf8 (patch)
treeb5b86e48c3fe5041ce495ca9bee2e5f93f788293 /fs/nilfs2/super.c
parentc05dbfc2609993ccc067879579e2a7726e12b3f1 (diff)
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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 <konishi.ryusuke@lab.ntt.co.jp>
Diffstat (limited to 'fs/nilfs2/super.c')
-rw-r--r--fs/nilfs2/super.c58
1 files changed, 54 insertions, 4 deletions
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index a1cd444103f..92e8c769584 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;