patch-2.1.82 linux/fs/nfs/inode.c

• Lines: 264
• Date: Sat Jan 24 10:53:00 1998
• Orig file: v2.1.81/linux/fs/nfs/inode.c
• Orig date: Fri Jan 16 11:24:09 1998

diff -u --recursive --new-file v2.1.81/linux/fs/nfs/inode.c linux/fs/nfs/inode.c
@@ -32,9 +32,12 @@
 #include <asm/system.h>
 #include <asm/uaccess.h>
 
+#define CONFIG_NFS_SNAPSHOT 1
 #define NFSDBG_FACILITY		NFSDBG_VFS
 #define NFS_PARANOIA 1
 
+static struct inode * __nfs_fhget(struct super_block *, struct nfs_fattr *);
+
 static void nfs_read_inode(struct inode *);
 static void nfs_put_inode(struct inode *);
 static void nfs_delete_inode(struct inode *);
@@ -190,6 +193,7 @@
 	int			tcp;
 	struct sockaddr_in	srvaddr;
 	struct rpc_timeout	timeparms;
+	struct nfs_fattr	fattr;
 
 	MOD_INC_USE_COUNT;
 	if (!data)
@@ -274,7 +278,10 @@
 		goto out_no_fh;
 	*root_fh = data->root;
 
-	root_inode = nfs_fhget(sb, &data->root, NULL);
+	if (nfs_proc_getattr(server, root_fh, &fattr) != 0)
+		goto out_no_fattr;
+
+	root_inode = __nfs_fhget(sb, &fattr);
 	if (!root_inode)
 		goto out_no_root;
 	sb->s_root = d_alloc_root(root_inode, NULL);
@@ -295,6 +302,11 @@
 out_no_root:
 	printk("nfs_read_super: get root inode failed\n");
 	iput(root_inode);
+	goto out_free_fh;
+
+out_no_fattr:
+	printk("nfs_read_super: get root fattr failed\n");
+out_free_fh:
 	kfree(root_fh);
 out_no_fh:
 	rpciod_down();
@@ -384,42 +396,110 @@
 }
 
 /*
+ * Fill in inode information from the fattr.
+ */
+static void
+nfs_fill_inode(struct inode *inode, struct nfs_fattr *fattr)
+{
+	/*
+	 * Check whether the mode has been set, as we only want to
+	 * do this once. (We don't allow inodes to change types.)
+	 */
+	if (inode->i_mode == 0) {
+		inode->i_mode = fattr->mode;
+		if (S_ISREG(inode->i_mode))
+			inode->i_op = &nfs_file_inode_operations;
+		else if (S_ISDIR(inode->i_mode))
+			inode->i_op = &nfs_dir_inode_operations;
+		else if (S_ISLNK(inode->i_mode))
+			inode->i_op = &nfs_symlink_inode_operations;
+		else if (S_ISCHR(inode->i_mode)) {
+			inode->i_op = &chrdev_inode_operations;
+			inode->i_rdev = to_kdev_t(fattr->rdev);
+		} else if (S_ISBLK(inode->i_mode)) {
+			inode->i_op = &blkdev_inode_operations;
+			inode->i_rdev = to_kdev_t(fattr->rdev);
+		} else if (S_ISFIFO(inode->i_mode))
+			init_fifo(inode);
+		else
+			inode->i_op = NULL;
+		/*
+		 * Preset the size and mtime, as there's no need
+		 * to invalidate the caches.
+		 */ 
+		inode->i_size  = fattr->size;
+		inode->i_mtime = fattr->mtime.seconds;
+		NFS_OLDMTIME(inode) = fattr->mtime.seconds;
+	}
+	nfs_refresh_inode(inode, fattr);
+}
+
+/*
  * This is our own version of iget that looks up inodes by file handle
  * instead of inode number.  We use this technique instead of using
  * the vfs read_inode function because there is no way to pass the
  * file handle or current attributes into the read_inode function.
  *
+ * We provide a special check for NetApp .snapshot directories to avoid
+ * inode aliasing problems. All snapshot inodes are anonymous (unhashed).
+ */
+struct inode *
+nfs_fhget(struct dentry *dentry, struct nfs_fh *fhandle,
+				 struct nfs_fattr *fattr)
+{
+	struct super_block *sb = dentry->d_sb;
+
+	dprintk("NFS: nfs_fhget(%s/%s fileid=%d)\n",
+		dentry->d_parent->d_name.name, dentry->d_name.name,
+		fattr->fileid);
+
+	/* Install the filehandle in the dentry */
+	*((struct nfs_fh *) dentry->d_fsdata) = *fhandle;
+
+#ifdef CONFIG_NFS_SNAPSHOT
+	/*
+	 * Check for NetApp snapshot dentries, and get an 
+	 * unhashed inode to avoid aliasing problems.
+	 */
+	if ((dentry->d_parent->d_inode->u.nfs_i.flags & NFS_IS_SNAPSHOT) ||
+	    (IS_ROOT(dentry->d_parent) && dentry->d_name.len == 9 &&
+	     memcmp(dentry->d_name.name, ".snapshot", 9) == 0)) {
+		struct inode *inode = get_empty_inode();
+		if (!inode)
+			goto out;	
+		inode->i_sb = sb;
+		inode->i_dev = sb->s_dev;
+		inode->i_ino = fattr->fileid;
+		nfs_read_inode(inode);
+		nfs_fill_inode(inode, fattr);
+		inode->u.nfs_i.flags |= NFS_IS_SNAPSHOT;
+		dprintk("NFS: nfs_fhget(snapshot ino=%ld)\n", inode->i_ino);
+	out:
+		return inode;
+	}
+#endif
+	return __nfs_fhget(sb, fattr);
+}
+
+/*
+ * Look up the inode by super block and fattr->fileid.
+ *
  * Note carefully the special handling of busy inodes (i_count > 1).
- * With the Linux 2.1.xx dcache all inodes except hard links must
+ * With the kernel 2.1.xx dcache all inodes except hard links must
  * have i_count == 1 after iget(). Otherwise, it indicates that the
  * server has reused a fileid (i_ino) and we have a stale inode.
  */
-struct inode *
-nfs_fhget(struct super_block *sb, struct nfs_fh *fhandle,
-				  struct nfs_fattr *fattr)
+static struct inode *
+__nfs_fhget(struct super_block *sb, struct nfs_fattr *fattr)
 {
-	int error, max_count;
-	struct inode *inode = NULL;
-	struct nfs_fattr newfattr;
-
-	if (!sb)
-		goto out_bad_args;
-	if (!fattr) {
-		fattr = &newfattr;
-		error = nfs_proc_getattr(&sb->u.nfs_sb.s_server, fhandle,fattr);
-		if (error)
-			goto out_bad_attr;
-	}
+	struct inode *inode;
+	int max_count;
 
 retry:
 	inode = iget(sb, fattr->fileid);
 	if (!inode)
 		goto out_no_inode;
-#ifdef NFS_PARANOIA
-if (inode->i_dev != sb->s_dev)
-printk("nfs_fhget: impossible\n");
-#endif
-
+	/* N.B. This should be impossible ... */
 	if (inode->i_ino != fattr->fileid)
 		goto out_bad_id;
 
@@ -434,19 +514,20 @@
 	 */
 	max_count = S_ISDIR(fattr->mode) ? 1 : fattr->nlink;
 	if (inode->i_count > max_count) {
-printk("nfs_fhget: inode %ld busy, i_count=%d, i_nlink=%d\n",
+printk("__nfs_fhget: inode %ld busy, i_count=%d, i_nlink=%d\n",
 inode->i_ino, inode->i_count, inode->i_nlink);
 		nfs_free_dentries(inode);
 		if (inode->i_count > max_count) {
-printk("nfs_fhget: inode %ld still busy, i_count=%d\n",
+printk("__nfs_fhget: inode %ld still busy, i_count=%d\n",
 inode->i_ino, inode->i_count);
 			if (!list_empty(&inode->i_dentry)) {
 				struct dentry *dentry;
 				dentry = list_entry(inode->i_dentry.next,
 						 struct dentry, d_alias);
-printk("nfs_fhget: killing %s/%s filehandle\n",
+printk("__nfs_fhget: killing %s/%s filehandle\n",
 dentry->d_parent->d_name.name, dentry->d_name.name);
-				memset(dentry->d_fsdata, 0, sizeof(*fhandle));
+				memset(dentry->d_fsdata, 0, 
+					sizeof(struct nfs_fh));
 			} else
 				printk("NFS: inode %ld busy, no aliases?\n",
 					inode->i_ino);
@@ -456,56 +537,18 @@
 		iput(inode);
 		goto retry;
 	}
-
-	/*
-	 * Check whether the mode has been set, as we only want to
-	 * do this once. (We don't allow inodes to change types.)
-	 */
-	if (inode->i_mode == 0) {
-		inode->i_mode = fattr->mode;
-		if (S_ISREG(inode->i_mode))
-			inode->i_op = &nfs_file_inode_operations;
-		else if (S_ISDIR(inode->i_mode))
-			inode->i_op = &nfs_dir_inode_operations;
-		else if (S_ISLNK(inode->i_mode))
-			inode->i_op = &nfs_symlink_inode_operations;
-		else if (S_ISCHR(inode->i_mode)) {
-			inode->i_op = &chrdev_inode_operations;
-			inode->i_rdev = to_kdev_t(fattr->rdev);
-		} else if (S_ISBLK(inode->i_mode)) {
-			inode->i_op = &blkdev_inode_operations;
-			inode->i_rdev = to_kdev_t(fattr->rdev);
-		} else if (S_ISFIFO(inode->i_mode))
-			init_fifo(inode);
-		else
-			inode->i_op = NULL;
-		/*
-		 * Preset the size and mtime, as there's no need
-		 * to invalidate the caches.
-		 */ 
-		inode->i_size  = fattr->size;
-		inode->i_mtime = fattr->mtime.seconds;
-		NFS_OLDMTIME(inode) = fattr->mtime.seconds;
-	}
-	nfs_refresh_inode(inode, fattr);
-	dprintk("NFS: fhget(%x/%ld ct=%d)\n",
-		inode->i_dev, inode->i_ino,
-		inode->i_count);
+	nfs_fill_inode(inode, fattr);
+	dprintk("NFS: __nfs_fhget(%x/%ld ct=%d)\n",
+		inode->i_dev, inode->i_ino, inode->i_count);
 
 out:
 	return inode;
 
-out_bad_args:
-	printk("nfs_fhget: super block is NULL\n");
-	goto out;
-out_bad_attr:
-	printk("nfs_fhget: getattr error = %d\n", -error);
-	goto out;
 out_no_inode:
-	printk("nfs_fhget: iget failed\n");
+	printk("__nfs_fhget: iget failed\n");
 	goto out;
 out_bad_id:
-	printk("nfs_fhget: unexpected inode from iget\n");
+	printk("__nfs_fhget: unexpected inode from iget\n");
 	goto out;
 }