6 files changed, 53 insertions, 37 deletions

diff --git a/fs/nilfs2/cpfile.c b/fs/nilfs2/cpfile.c
index 03de1da8795b..5ff15a8a1024 100644
--- a/fs/nilfs2/cpfile.c
+++ b/fs/nilfs2/cpfile.c
@@ -863,26 +863,19 @@ int nilfs_cpfile_is_snapshot(struct inode *cpfile, __u64 cno)
  */
 int nilfs_cpfile_change_cpmode(struct inode *cpfile, __u64 cno, int mode)
 {
-        struct the_nilfs *nilfs;
         int ret;
 
-        nilfs = NILFS_MDT(cpfile)->mi_nilfs;
-
         switch (mode) {
         case NILFS_CHECKPOINT:
-                /*
-                 * Check for protecting existing snapshot mounts:
-                 * ns_mount_mutex is used to make this operation atomic and
-                 * exclusive with a new mount job.  Though it doesn't cover
-                 * umount, it's enough for the purpose.
-                 */
-                if (nilfs_checkpoint_is_mounted(nilfs, cno, 1)) {
-                        /* Current implementation does not have to protect
-                           plain read-only mounts since they are exclusive
-                           with a read/write mount and are protected from the
-                           cleaner. */
+                if (nilfs_checkpoint_is_mounted(cpfile->i_sb, cno))
+                        /*
+                         * Current implementation does not have to protect
+                         * plain read-only mounts since they are exclusive
+                         * with a read/write mount and are protected from the
+                         * cleaner.
+                         */
                         ret = -EBUSY;
-                } else
+                else
                         ret = nilfs_cpfile_clear_snapshot(cpfile, cno);
                 return ret;
         case NILFS_SNAPSHOT:
diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c
index 5b3d43fb4e12..71d4bc8464e0 100644
--- a/fs/nilfs2/inode.c
+++ b/fs/nilfs2/inode.c
@@ -506,6 +506,16 @@ static int nilfs_iget_set(struct inode *inode, void *opaque)
         return 0;
 }
 
+struct inode *nilfs_ilookup(struct super_block *sb, struct nilfs_root *root,
+                            unsigned long ino)
+{
+        struct nilfs_iget_args args = {
+                .ino = ino, .root = root, .cno = 0, .for_gc = 0
+        };
+
+        return ilookup5(sb, ino, nilfs_iget_test, &args);
+}
+
 struct inode *nilfs_iget_locked(struct super_block *sb, struct nilfs_root *root,
                                 unsigned long ino)
 {
diff --git a/fs/nilfs2/nilfs.h b/fs/nilfs2/nilfs.h
index 2ca2ca5ca848..f6e276eaaf6f 100644
--- a/fs/nilfs2/nilfs.h
+++ b/fs/nilfs2/nilfs.h
@@ -244,6 +244,8 @@ extern int nilfs_get_block(struct inode *, sector_t, struct buffer_head *, int);
 extern void nilfs_set_inode_flags(struct inode *);
 extern int nilfs_read_inode_common(struct inode *, struct nilfs_inode *);
 extern void nilfs_write_inode_common(struct inode *, struct nilfs_inode *, int);
+struct inode *nilfs_ilookup(struct super_block *sb, struct nilfs_root *root,
+                            unsigned long ino);
 struct inode *nilfs_iget_locked(struct super_block *sb, struct nilfs_root *root,
                                 unsigned long ino);
 struct inode *nilfs_iget(struct super_block *sb, struct nilfs_root *root,
@@ -285,6 +287,7 @@ extern int nilfs_commit_super(struct nilfs_sb_info *, int);
 extern int nilfs_cleanup_super(struct nilfs_sb_info *);
 int nilfs_attach_checkpoint(struct nilfs_sb_info *sbi, __u64 cno, int curr_mnt,
                             struct nilfs_root **root);
+int nilfs_checkpoint_is_mounted(struct super_block *sb, __u64 cno);
 
 /* gcinode.c */
 int nilfs_gccache_submit_read_data(struct inode *, sector_t, sector_t, __u64,
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index 39e7d7f8eda0..ab96d26bf7e9 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -833,6 +833,38 @@ static int nilfs_try_to_shrink_tree(struct dentry *root_dentry)
         return nilfs_tree_was_touched(root_dentry);
 }
 
+int nilfs_checkpoint_is_mounted(struct super_block *sb, __u64 cno)
+{
+        struct the_nilfs *nilfs = NILFS_SB(sb)->s_nilfs;
+        struct nilfs_root *root;
+        struct inode *inode;
+        struct dentry *dentry;
+        int ret;
+
+        if (cno < 0 || cno > nilfs->ns_cno)
+                return false;
+
+        if (cno >= nilfs_last_cno(nilfs))
+                return true;    /* protect recent checkpoints */
+
+        ret = false;
+        root = nilfs_lookup_root(NILFS_SB(sb)->s_nilfs, cno);
+        if (root) {
+                inode = nilfs_ilookup(sb, root, NILFS_ROOT_INO);
+                if (inode) {
+                        dentry = d_find_alias(inode);
+                        if (dentry) {
+                                if (nilfs_tree_was_touched(dentry))
+                                        ret = nilfs_try_to_shrink_tree(dentry);
+                                dput(dentry);
+                        }
+                        iput(inode);
+                }
+                nilfs_put_root(root);
+        }
+        return ret;
+}
+
 /**
  * nilfs_fill_super() - initialize a super block instance
  * @sb: super_block
diff --git a/fs/nilfs2/the_nilfs.c b/fs/nilfs2/the_nilfs.c
index 4d6763e28eb5..4cc705a1d135 100644
--- a/fs/nilfs2/the_nilfs.c
+++ b/fs/nilfs2/the_nilfs.c
@@ -769,24 +769,3 @@ void nilfs_put_root(struct nilfs_root *root)
                 kfree(root);
         }
 }
-
-int nilfs_checkpoint_is_mounted(struct the_nilfs *nilfs, __u64 cno,
-                                int snapshot_mount)
-{
-        struct nilfs_root *root;
-        int ret;
-
-        if (cno < 0 || cno > nilfs->ns_cno)
-                return false;
-
-        if (cno >= nilfs_last_cno(nilfs))
-                return true;    /* protect recent checkpoints */
-
-        ret = false;
-        root = nilfs_lookup_root(nilfs, cno);
-        if (root) {
-                ret = true;
-                nilfs_put_root(root);
-        }
-        return ret;
-}
diff --git a/fs/nilfs2/the_nilfs.h b/fs/nilfs2/the_nilfs.h
index a5178dc43dfd..cae56f338b64 100644
--- a/fs/nilfs2/the_nilfs.h
+++ b/fs/nilfs2/the_nilfs.h
@@ -242,7 +242,6 @@ struct nilfs_root *nilfs_find_or_create_root(struct the_nilfs *nilfs,
                                              __u64 cno);
 void nilfs_put_root(struct nilfs_root *root);
 struct nilfs_sb_info *nilfs_find_sbinfo(struct the_nilfs *, int, __u64);
-int nilfs_checkpoint_is_mounted(struct the_nilfs *, __u64, int);
 int nilfs_near_disk_full(struct the_nilfs *);
 void nilfs_fall_back_super_block(struct the_nilfs *);
 void nilfs_swap_super_block(struct the_nilfs *);