Introduce btrfs_iget helper

Date: Mon, 21 Jul 2008 02:01:04 +0530
This patch introduces a btrfs_iget helper to be used in NFS support.

Signed-off-by: Balaji Rao <balajirrao@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

2 files changed, 39 insertions, 18 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 040213359393..cecf29e03630 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1700,6 +1700,8 @@ struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid,
                                 struct btrfs_root *root);
 struct inode *btrfs_ilookup(struct super_block *s, u64 objectid,
                             u64 root_objectid);
+struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
+                         struct btrfs_root *root, int *is_new);
 int btrfs_commit_write(struct file *file, struct page *page,
                        unsigned from, unsigned to);
 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 38d7a81763cd..266ca5514b33 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1840,6 +1840,33 @@ struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid,
         return inode;
 }
 
+/* Get an inode object given its location and corresponding root.
+ * Returns in *is_new if the inode was read from disk
+ */
+struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
+                         struct btrfs_root *root, int *is_new)
+{
+        struct inode *inode;
+
+        inode = btrfs_iget_locked(s, location->objectid, root);
+        if (!inode)
+                return ERR_PTR(-EACCES);
+
+        if (inode->i_state & I_NEW) {
+                BTRFS_I(inode)->root = root;
+                memcpy(&BTRFS_I(inode)->location, location, sizeof(*location));
+                btrfs_read_locked_inode(inode);
+                unlock_new_inode(inode);
+                if (is_new)
+                        *is_new = 1;
+        } else {
+                if (is_new)
+                        *is_new = 0;
+        }
+
+        return inode;
+}
+
 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
                                    struct nameidata *nd)
 {
@@ -1848,7 +1875,7 @@ static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
         struct btrfs_root *root = bi->root;
         struct btrfs_root *sub_root = root;
         struct btrfs_key location;
-        int ret, do_orphan = 0;
+        int ret, new, do_orphan = 0;
 
         if (dentry->d_name.len > BTRFS_NAME_LEN)
                 return ERR_PTR(-ENAMETOOLONG);
@@ -1866,23 +1893,15 @@ static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
                         return ERR_PTR(ret);
                 if (ret > 0)
                         return ERR_PTR(-ENOENT);
-
-                inode = btrfs_iget_locked(dir->i_sb, location.objectid,
-                                          sub_root);
-                if (!inode)
-                        return ERR_PTR(-EACCES);
-                if (inode->i_state & I_NEW) {
-                        /* the inode and parent dir are two different roots */
-                        if (sub_root != root) {
-                                igrab(inode);
-                                sub_root->inode = inode;
-                                do_orphan = 1;
-                        }
-                        BTRFS_I(inode)->root = sub_root;
-                        memcpy(&BTRFS_I(inode)->location, &location,
-                               sizeof(location));
-                        btrfs_read_locked_inode(inode);
-                        unlock_new_inode(inode);
+                inode = btrfs_iget(dir->i_sb, &location, sub_root, &new);
+                if (IS_ERR(inode))
+                        return ERR_CAST(inode);
+
+                /* the inode and parent dir are two different roots */
+                if (new && root != sub_root) {
+                        igrab(inode);
+                        sub_root->inode = inode;
+                        do_orphan = 1;
                 }
         }