nilfs2: set pointer to root object in inodes

This puts a pointer to nilfs_root object in the private part of
on-memory inode, and makes nilfs_iget function pick up the inode with
the same root object.

Non-root inodes inherit its nilfs_root object from parent inode.  That
of the root inode is allocated through nilfs_attach_checkpoint()
function.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

1 files changed, 22 insertions, 5 deletions

diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c
index 82cfdbc43e1c..7306fc7c4962 100644
--- a/fs/nilfs2/inode.c
+++ b/fs/nilfs2/inode.c
@@ -37,6 +37,7 @@
 struct nilfs_iget_args {
         u64 ino;
         __u64 cno;
+        struct nilfs_root *root;
         int for_gc;
 };
 
@@ -284,6 +285,7 @@ struct inode *nilfs_new_inode(struct inode *dir, int mode)
         struct nilfs_sb_info *sbi = NILFS_SB(sb);
         struct inode *inode;
         struct nilfs_inode_info *ii;
+        struct nilfs_root *root;
         int err = -ENOMEM;
         ino_t ino;
 
@@ -294,8 +296,10 @@ struct inode *nilfs_new_inode(struct inode *dir, int mode)
         mapping_set_gfp_mask(inode->i_mapping,
                              mapping_gfp_mask(inode->i_mapping) & ~__GFP_FS);
 
+        root = NILFS_I(dir)->i_root;
         ii = NILFS_I(inode);
         ii->i_state = 1 << NILFS_I_NEW;
+        ii->i_root = root;
 
         err = nilfs_ifile_create_inode(sbi->s_ifile, &ino, &ii->i_bh);
         if (unlikely(err))
@@ -484,7 +488,7 @@ static int nilfs_iget_test(struct inode *inode, void *opaque)
         struct nilfs_iget_args *args = opaque;
         struct nilfs_inode_info *ii;
 
-        if (args->ino != inode->i_ino)
+        if (args->ino != inode->i_ino || args->root != NILFS_I(inode)->i_root)
                 return 0;
 
         ii = NILFS_I(inode);
@@ -502,13 +506,21 @@ static int nilfs_iget_set(struct inode *inode, void *opaque)
         if (args->for_gc) {
                 NILFS_I(inode)->i_state = 1 << NILFS_I_GCINODE;
                 NILFS_I(inode)->i_cno = args->cno;
+                NILFS_I(inode)->i_root = NULL;
+        } else {
+                if (args->root && args->ino == NILFS_ROOT_INO)
+                        nilfs_get_root(args->root);
+                NILFS_I(inode)->i_root = args->root;
         }
         return 0;
 }
 
-struct inode *nilfs_iget(struct super_block *sb, unsigned long ino)
+struct inode *nilfs_iget(struct super_block *sb, struct nilfs_root *root,
+                         unsigned long ino)
 {
-        struct nilfs_iget_args args = { .ino = ino, .cno = 0, .for_gc = 0 };
+        struct nilfs_iget_args args = {
+                .ino = ino, .root = root, .cno = 0, .for_gc = 0
+        };
         struct inode *inode;
         int err;
 
@@ -530,7 +542,9 @@ struct inode *nilfs_iget(struct super_block *sb, unsigned long ino)
 struct inode *nilfs_iget_for_gc(struct super_block *sb, unsigned long ino,
                                 __u64 cno)
 {
-        struct nilfs_iget_args args = { .ino = ino, .cno = cno, .for_gc = 1 };
+        struct nilfs_iget_args args = {
+                .ino = ino, .root = NULL, .cno = cno, .for_gc = 1
+        };
         struct inode *inode;
         int err;
 
@@ -682,6 +696,9 @@ static void nilfs_clear_inode(struct inode *inode)
                 nilfs_bmap_clear(ii->i_bmap);
 
         nilfs_btnode_cache_clear(&ii->i_btnode_cache);
+
+        if (ii->i_root && inode->i_ino == NILFS_ROOT_INO)
+                nilfs_put_root(ii->i_root);
 }
 
 void nilfs_evict_inode(struct inode *inode)
@@ -690,7 +707,7 @@ void nilfs_evict_inode(struct inode *inode)
         struct super_block *sb = inode->i_sb;
         struct nilfs_inode_info *ii = NILFS_I(inode);
 
-        if (inode->i_nlink || unlikely(is_bad_inode(inode))) {
+        if (inode->i_nlink || !ii->i_root || unlikely(is_bad_inode(inode))) {
                 if (inode->i_data.nrpages)
                         truncate_inode_pages(&inode->i_data, 0);
                 end_writeback(inode);