mm: migration: avoid race between shift_arg_pages() and rmap_walk() during migration...

[safe/jmp/linux-2.6] / fs / isofs / export.c

diff --git a/fs/isofs/export.c b/fs/isofs/export.c
index 4af856a..ed752cb 100644 (file)
--- a/fs/isofs/export.c
+++ b/fs/isofs/export.c
@@ -9,7 +9,7 @@
  *
  * The following files are helpful:
  *
- *     Documentation/filesystems/Exporting
+ *     Documentation/filesystems/nfs/Exporting
  *     fs/exportfs/expfs.c.
  */
 
@@ -22,34 +22,17 @@ isofs_export_iget(struct super_block *sb,
                  __u32 generation)
 {
        struct inode *inode;
-       struct dentry *result;
+
        if (block == 0)
                return ERR_PTR(-ESTALE);
        inode = isofs_iget(sb, block, offset);
-       if (inode == NULL)
-               return ERR_PTR(-ENOMEM);
-       if (is_bad_inode(inode)
-           || (generation && inode->i_generation != generation))
-       {
+       if (IS_ERR(inode))
+               return ERR_CAST(inode);
+       if (generation && inode->i_generation != generation) {
                iput(inode);
                return ERR_PTR(-ESTALE);
        }
-       result = d_alloc_anon(inode);
-       if (!result) {
-               iput(inode);
-               return ERR_PTR(-ENOMEM);
-       }
-       return result;
-}
-
-static struct dentry *
-isofs_export_get_dentry(struct super_block *sb, void *vobjp)
-{
-       __u32 *objp = vobjp;
-       unsigned long block = objp[0];
-       unsigned long offset = objp[1];
-       __u32 generation = objp[2];
-       return isofs_export_iget(sb, block, offset, generation);
+       return d_obtain_alias(inode);
 }
 
 /* This function is surprisingly simple.  The trick is understanding
@@ -63,7 +46,6 @@ static struct dentry *isofs_export_get_parent(struct dentry *child)
        unsigned long parent_offset = 0;
        struct inode *child_inode = child->d_inode;
        struct iso_inode_info *e_child_inode = ISOFS_I(child_inode);
-       struct inode *parent_inode = NULL;
        struct iso_directory_record *de = NULL;
        struct buffer_head * bh = NULL;
        struct dentry *rv = NULL;
@@ -116,26 +98,11 @@ static struct dentry *isofs_export_get_parent(struct dentry *child)
        /* Normalize */
        isofs_normalize_block_and_offset(de, &parent_block, &parent_offset);
 
-       /* Get the inode. */
-       parent_inode = isofs_iget(child_inode->i_sb,
-                                 parent_block,
-                                 parent_offset);
-       if (parent_inode == NULL) {
-               rv = ERR_PTR(-EACCES);
-               goto out;
-       }
-
-       /* Allocate the dentry. */
-       rv = d_alloc_anon(parent_inode);
-       if (rv == NULL) {
-               rv = ERR_PTR(-ENOMEM);
-               goto out;
-       }
-
+       rv = d_obtain_alias(isofs_iget(child_inode->i_sb, parent_block,
+                                    parent_offset));
  out:
-       if (bh) {
+       if (bh)
                brelse(bh);
-       }
        return rv;
 }
 
@@ -182,43 +149,44 @@ isofs_export_encode_fh(struct dentry *dentry,
        return type;
 }
 
+struct isofs_fid {
+       u32 block;
+       u16 offset;
+       u16 parent_offset;
+       u32 generation;
+       u32 parent_block;
+       u32 parent_generation;
+};
 
-static struct dentry *
-isofs_export_decode_fh(struct super_block *sb,
-                      __u32 *fh32,
-                      int fh_len,
-                      int fileid_type,
-                      int (*acceptable)(void *context, struct dentry *de),
-                      void *context)
+static struct dentry *isofs_fh_to_dentry(struct super_block *sb,
+       struct fid *fid, int fh_len, int fh_type)
 {
-       __u16 *fh16 = (__u16*)fh32;
-       __u32 child[3];   /* The child is what triggered all this. */
-       __u32 parent[3];  /* The parent is just along for the ride. */
+       struct isofs_fid *ifid = (struct isofs_fid *)fid;
 
-       if (fh_len < 3 || fileid_type > 2)
+       if (fh_len < 3 || fh_type > 2)
                return NULL;
 
-       child[0] = fh32[0];
-       child[1] = fh16[2];  /* fh16 [sic] */
-       child[2] = fh32[2];
-
-       parent[0] = 0;
-       parent[1] = 0;
-       parent[2] = 0;
-       if (fileid_type == 2) {
-               if (fh_len > 2) parent[0] = fh32[3];
-               parent[1] = fh16[3];  /* fh16 [sic] */
-               if (fh_len > 4) parent[2] = fh32[4];
-       }
-
-       return sb->s_export_op->find_exported_dentry(sb, child, parent,
-                                                    acceptable, context);
+       return isofs_export_iget(sb, ifid->block, ifid->offset,
+                       ifid->generation);
 }
 
+static struct dentry *isofs_fh_to_parent(struct super_block *sb,
+               struct fid *fid, int fh_len, int fh_type)
+{
+       struct isofs_fid *ifid = (struct isofs_fid *)fid;
+
+       if (fh_type != 2)
+               return NULL;
+
+       return isofs_export_iget(sb,
+                       fh_len > 2 ? ifid->parent_block : 0,
+                       ifid->parent_offset,
+                       fh_len > 4 ? ifid->parent_generation : 0);
+}
 
-struct export_operations isofs_export_ops = {
-       .decode_fh      = isofs_export_decode_fh,
+const struct export_operations isofs_export_ops = {
        .encode_fh      = isofs_export_encode_fh,
-       .get_dentry     = isofs_export_get_dentry,
+       .fh_to_dentry   = isofs_fh_to_dentry,
+       .fh_to_parent   = isofs_fh_to_parent,
        .get_parent     = isofs_export_get_parent,
 };