Merge http://linux-ntfs.bkbits.net/ntfs-2.6

into ppc970.osdl.org:/home/torvalds/v2.6/linux

Documentation/filesystems/ntfs.txt

@@ -272,6 +272,8 @@ ChangeLog
 
 Note, a technical ChangeLog aimed at kernel hackers is in fs/ntfs/ChangeLog.
 
+2.1.7:
+	- Enable NFS exporting of mounted NTFS volumes.
 2.1.6:
 	- Fix minor bug in handling of compressed directories that fixes the
 	  erroneous "du" and "stat" output people reported.

fs/ntfs/ChangeLog

 ToDo:
 	- Find and fix bugs.
-	- Enable NFS exporting of NTFS.
 	- Implement aops->set_page_dirty() in order to take control of buffer
 	  dirtying. Not having it means if page_has_buffers(), all buffers
 	  will be dirtied with the page. And if not they won't be. That is
@@ -20,6 +19,26 @@ ToDo:
 	  sufficient for synchronisation here. We then just need to make sure
 	  ntfs_readpage/writepage/truncate interoperate properly with us.
 
+2.1.7 - Enable NFS exporting of mounted NTFS volumes.
+
+	- Set i_generation in the VFS inode from the seq_no of the NTFS inode.
+	- Make ntfs_lookup() NFS export safe, i.e. use d_splice_alias(), etc.
+	- Implement ->get_dentry() in fs/ntfs/namei.c::ntfs_get_dentry() as the
+	  default doesn't allow inode number 0 which is a valid inode on NTFS
+	  and even if it did allow that it uses iget() instead of ntfs_iget()
+	  which makes it useless for us.
+	- Implement ->get_parent() in fs/ntfs/namei.c::ntfs_get_parent() as the
+	  default just returns -EACCES which is not very useful.
+	- Define export operations (->s_export_op) for NTFS (ntfs_export_ops)
+	  and set them up in the super block at mount time (super.c) this
+	  allows mounted NTFS volumes to be exported via NFS.
+	- Add missing return -EOPNOTSUPP; in
+	  fs/ntfs/aops.c::ntfs_commit_nonresident_write().
+	- Enforce no atime and no dir atime updates at mount/remount time as
+	  they are not implemented yet anyway.
+	- Move a few assignments in fs/ntfs/attrib.c::load_attribute_list() to
+	  after a NULL check.  Thanks to Dave Jones for pointing this out.
+
 2.1.6 - Fix minor bug in handling of compressed directories.
 
 	- Fix bug in handling of compressed directories.  A compressed
@@ -60,6 +79,10 @@ ToDo:
 	- Reduce function local stack usage from 0x3d4 bytes to just noise in
 	  fs/ntfs/upcase.c. (Randy Dunlap <rddunlap@osdl.ord>)
 	- Remove compiler warnings for newer gcc.
+	- Pages are no longer kmapped by mm/filemap.c::generic_file_write()
+	  around calls to ->{prepare,commit}_write.  Adapt NTFS appropriately
+	  in fs/ntfs/aops.c::ntfs_prepare_nonresident_write() by using
+	  kmap_atomic(KM_USER0).
 
 2.1.0 - First steps towards write support: implement file overwrite.
 

fs/ntfs/Makefile

@@ -5,7 +5,7 @@ obj-$(CONFIG_NTFS_FS) += ntfs.o
 ntfs-objs := aops.o attrib.o compress.o debug.o dir.o file.o inode.o mft.o \
 	     mst.o namei.o super.o sysctl.o time.o unistr.o upcase.o
 
-EXTRA_CFLAGS = -DNTFS_VERSION=\"2.1.6\"
+EXTRA_CFLAGS = -DNTFS_VERSION=\"2.1.7\"
 
 ifeq ($(CONFIG_NTFS_DEBUG),y)
 EXTRA_CFLAGS += -DDEBUG

fs/ntfs/aops.c

 /**
  * aops.c - NTFS kernel address space operations and page cache handling.
- * 	    Part of the Linux-NTFS project.
+ *	    Part of the Linux-NTFS project.
  *
- * Copyright (c) 2001-2003 Anton Altaparmakov
+ * Copyright (c) 2001-2004 Anton Altaparmakov
  * Copyright (c) 2002 Richard Russon
  *
  * This program/include file is free software; you can redistribute it and/or
@@ -10,13 +10,13 @@
  * by the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
- * This program/include file is distributed in the hope that it will be 
- * useful, but WITHOUT ANY WARRANTY; without even the implied warranty 
+ * This program/include file is distributed in the hope that it will be
+ * useful, but WITHOUT ANY WARRANTY; without even the implied warranty
  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
- * along with this program (in the main directory of the Linux-NTFS 
+ * along with this program (in the main directory of the Linux-NTFS
  * distribution in the file COPYING); if not, write to the Free Software
  * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
@@ -572,11 +572,11 @@ static int ntfs_write_block(struct writeback_control *wbc, struct page *page)
 				// Again for each page do:
 				// - wait_on_page_locked()
 				// - Check (PageUptodate(page) &&
-				// 			!PageError(page))
+				//			!PageError(page))
 				// Update initialized size in the attribute and
 				// in the inode.
 				// Again, for each page do:
-				// 	__set_page_dirty_buffers();
+				//	__set_page_dirty_buffers();
 				// page_cache_release()
 				// We don't need to wait on the writes.
 				// Update iblock.
@@ -1112,11 +1112,11 @@ static int ntfs_prepare_nonresident_write(struct page *page,
 				// Again for each page do:
 				// - wait_on_page_locked()
 				// - Check (PageUptodate(page) &&
-				// 			!PageError(page))
+				//			!PageError(page))
 				// Update initialized size in the attribute and
 				// in the inode.
 				// Again, for each page do:
-				// 	__set_page_dirty_buffers();
+				//	__set_page_dirty_buffers();
 				// page_cache_release()
 				// We don't need to wait on the writes.
 				// Update iblock.
@@ -1188,7 +1188,7 @@ static int ntfs_prepare_nonresident_write(struct page *page,
 					// TODO: Instantiate the hole.
 					// clear_buffer_new(bh);
 					// unmap_underlying_metadata(bh->b_bdev,
-					// 		bh->b_blocknr);
+					//		bh->b_blocknr);
 					// For non-uptodate buffers, need to
 					// zero out the region outside the
 					// request in this bh or all bhs,
@@ -1279,7 +1279,7 @@ static int ntfs_prepare_nonresident_write(struct page *page,
 		if (PageUptodate(page)) {
 			if (!buffer_uptodate(bh))
 				set_buffer_uptodate(bh);
-			continue; 
+			continue;
 		}
 		/*
 		 * The page is not uptodate. The buffer is mapped. If it is not
@@ -1525,6 +1525,7 @@ static int ntfs_commit_nonresident_write(struct page *page,
 	if (pos > vi->i_size) {
 		ntfs_error(vi->i_sb, "Writing beyond the existing file size is "
 				"not supported yet. Sorry.");
+		return -EOPNOTSUPP;
 		// vi->i_size = pos;
 		// mark_inode_dirty(vi);
 	}
@@ -1708,7 +1709,7 @@ static int ntfs_commit_write(struct file *file, struct page *page,
 		/*
 		 * Bring the out of bounds area(s) uptodate by copying data
 		 * from the mft record to the page.
-	 	 */
+		 */
 		if (from > 0)
 			memcpy(kaddr, kattr, from);
 		if (to < bytes)

fs/ntfs/attrib.c

@@ -1235,11 +1235,11 @@ int load_attribute_list(ntfs_volume *vol, run_list *run_list, u8 *al_start,
 	u8 *al_end = al + initialized_size;
 	run_list_element *rl;
 	struct buffer_head *bh;
-	struct super_block *sb = vol->sb;
-	unsigned long block_size = sb->s_blocksize;
+	struct super_block *sb;
+	unsigned long block_size;
 	unsigned long block, max_block;
 	int err = 0;
-	unsigned char block_size_bits = sb->s_blocksize_bits;
+	unsigned char block_size_bits;
 
 	ntfs_debug("Entering.");
 	if (!vol || !run_list || !al || size <= 0 || initialized_size < 0 ||
@@ -1249,6 +1249,9 @@ int load_attribute_list(ntfs_volume *vol, run_list *run_list, u8 *al_start,
 		memset(al, 0, size);
 		return 0;
 	}
+	sb = vol->sb;
+	block_size = sb->s_blocksize;
+	block_size_bits = sb->s_blocksize_bits;
 	down_read(&run_list->lock);
 	rl = run_list->rl;
 	/* Read all clusters specified by the run list one run at a time. */

fs/ntfs/dir.c

 /**
  * dir.c - NTFS kernel directory operations. Part of the Linux-NTFS project.
  *
- * Copyright (c) 2001-2003 Anton Altaparmakov
+ * Copyright (c) 2001-2004 Anton Altaparmakov
  * Copyright (c) 2002 Richard Russon
  *
  * This program/include file is free software; you can redistribute it and/or
@@ -200,7 +200,8 @@ MFT_REF ntfs_lookup_inode_by_name(ntfs_inode *dir_ni, const uchar_t *uname,
 						"and if that doesn't find any "
 						"errors please report you saw "
 						"this message to "
-						"linux-ntfs-dev@lists.sf.net.");
+						"linux-ntfs-dev@lists."
+						"sourceforge.net.");
 				goto dir_err_out;
 			}
 
@@ -457,7 +458,8 @@ MFT_REF ntfs_lookup_inode_by_name(ntfs_inode *dir_ni, const uchar_t *uname,
 						"and if that doesn't find any "
 						"errors please report you saw "
 						"this message to "
-						"linux-ntfs-dev@lists.sf.net.");
+						"linux-ntfs-dev@lists."
+						"sourceforge.net.");
 				ntfs_unmap_page(page);
 				goto dir_err_out;
 			}

fs/ntfs/inode.c

@@ -196,7 +196,7 @@ struct inode *ntfs_iget(struct super_block *sb, unsigned long mft_no)
 	}
 	/*
 	 * There is no point in keeping bad inodes around if the failure was
-	 * due to ENOMEM. We want to be able to retry again layer.
+	 * due to ENOMEM. We want to be able to retry again later.
 	 */
 	if (err == -ENOMEM) {
 		iput(vi);
@@ -533,7 +533,7 @@ static int ntfs_read_locked_inode(struct inode *vi)
 	}
 
 	/* Transfer information from mft record into vfs and ntfs inodes. */
-	ni->seq_no = le16_to_cpu(m->sequence_number);
+	vi->i_generation = ni->seq_no = le16_to_cpu(m->sequence_number);
 
 	/*
 	 * FIXME: Keep in mind that link_count is two for files which have both
@@ -1109,7 +1109,7 @@ static int ntfs_read_locked_attr_inode(struct inode *base_vi, struct inode *vi)
 	vi->i_mtime	= base_vi->i_mtime;
 	vi->i_ctime	= base_vi->i_ctime;
 	vi->i_atime	= base_vi->i_atime;
-	ni->seq_no	= base_ni->seq_no;
+	vi->i_generation = ni->seq_no = base_ni->seq_no;
 
 	/* Set inode type to zero but preserve permissions. */
 	vi->i_mode	= base_vi->i_mode & ~S_IFMT;
@@ -1137,7 +1137,8 @@ static int ntfs_read_locked_attr_inode(struct inode *base_vi, struct inode *vi)
 					"the attribute is resident (mft_no "
 					"0x%lx, type 0x%x, name_len %i). "
 					"Please report you saw this message "
-					"to linux-ntfs-dev@lists.sf.net",
+					"to linux-ntfs-dev@lists."
+					"sourceforge.net",
 					vi->i_ino, ni->type, ni->name_len);
 			goto unm_err_out;
 		}
@@ -1157,8 +1158,9 @@ static int ntfs_read_locked_attr_inode(struct inode *base_vi, struct inode *vi)
 						"type 0x%x, name_len %i). "
 						"Please report you saw this "
 						"message to linux-ntfs-dev@"
-						"lists.sf.net", vi->i_ino,
-						ni->type, ni->name_len);
+						"lists.sourceforge.net",
+						vi->i_ino, ni->type,
+						ni->name_len);
 				goto unm_err_out;
 			}
 			NInoSetCompressed(ni);
@@ -1169,7 +1171,8 @@ static int ntfs_read_locked_attr_inode(struct inode *base_vi, struct inode *vi)
 						"(mft_no 0x%lx, type 0x%x, "
 						"name_len %i). Please report "
 						"you saw this message to "
-						"linux-ntfs-dev@lists.sf.net",
+						"linux-ntfs-dev@lists."
+						"sourceforge.net",
 						vi->i_ino, ni->type,
 						ni->name_len);
 				goto unm_err_out;
@@ -1224,8 +1227,9 @@ static int ntfs_read_locked_attr_inode(struct inode *base_vi, struct inode *vi)
 						"type 0x%x, name_len %i). "
 						"Please report you saw this "
 						"message to linux-ntfs-dev@"
-						"lists.sf.net", vi->i_ino,
-						ni->type, ni->name_len);
+						"lists.sourceforge.net",
+						vi->i_ino, ni->type,
+						ni->name_len);
 				goto unm_err_out;
 			}
 			NInoSetEncrypted(ni);
@@ -1238,8 +1242,9 @@ static int ntfs_read_locked_attr_inode(struct inode *base_vi, struct inode *vi)
 						"type 0x%x, name_len %i). "
 						"Please report you saw this "
 						"message to linux-ntfs-dev@"
-						"lists.sf.net", vi->i_ino,
-						ni->type, ni->name_len);
+						"lists.sourceforge.net",
+						vi->i_ino, ni->type,
+						ni->name_len);
 				goto unm_err_out;
 			}
 			NInoSetSparse(ni);
@@ -1414,7 +1419,7 @@ void ntfs_read_inode_mount(struct inode *vi)
 	}
 
 	/* Need this to sanity check attribute list references to $MFT. */
-	ni->seq_no = le16_to_cpu(m->sequence_number);
+	vi->i_generation = ni->seq_no = le16_to_cpu(m->sequence_number);
 
 	/* Provides readpage() and sync_page() for map_mft_record(). */
 	vi->i_mapping->a_ops = &ntfs_mft_aops;
@@ -1541,7 +1546,8 @@ void ntfs_read_inode_mount(struct inode *vi)
 						"of $MFT is not in the base "
 						"mft record. Please report "
 						"you saw this message to "
-						"linux-ntfs-dev@lists.sf.net");
+						"linux-ntfs-dev@lists."
+						"sourceforge.net");
 				goto put_err_out;
 			} else {
 				/* Sequence numbers must match. */
@@ -1662,7 +1668,8 @@ void ntfs_read_inode_mount(struct inode *vi)
 						"Run chkdsk and if no errors "
 						"are found, please report you "
 						"saw this message to "
-						"linux-ntfs-dev@lists.sf.net");
+						"linux-ntfs-dev@lists."
+						"sourceforge.net");
 				put_attr_search_ctx(ctx);
 				/* Revert to the safe super operations. */
 				sb->s_op = &ntfs_mount_sops;

fs/ntfs/layout.h

@@ -2,7 +2,7 @@
  * layout.h - All NTFS associated on-disk structures. Part of the Linux-NTFS
  *	      project.
  *
- * Copyright (c) 2001-2003 Anton Altaparmakov
+ * Copyright (c) 2001-2004 Anton Altaparmakov
  * Copyright (c) 2002 Richard Russon
  *
  * This program/include file is free software; you can redistribute it and/or
@@ -941,7 +941,7 @@ typedef struct {
 					   modified. */
 /* 18*/	s64 last_mft_change_time;	/* Time this mft record was last
 					   modified. */
-/* 20*/	s64 last_access_time;		/* Last time this mft record was
+/* 20*/	s64 last_access_time;		/* Time this mft record was last
 					   accessed. */
 /* 28*/	s64 allocated_size;		/* Byte size of allocated space for the
 					   data attribute. NOTE: Is a multiple

fs/ntfs/namei.c

@@ -2,7 +2,7 @@
  * namei.c - NTFS kernel directory inode operations. Part of the Linux-NTFS
  * 	     project.
  *
- * Copyright (c) 2001-2003 Anton Altaparmakov
+ * Copyright (c) 2001-2004 Anton Altaparmakov
  *
  * This program/include file is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as published
@@ -21,6 +21,7 @@
  */
 
 #include <linux/dcache.h>
+#include <linux/security.h>
 
 #include "ntfs.h"
 #include "dir.h"
@@ -41,16 +42,17 @@
  * @dir_ino looking for the converted Unicode name. If the name is found in the
  * directory, the corresponding inode is loaded by calling ntfs_iget() on its
  * inode number and the inode is associated with the dentry @dent via a call to
- * d_add().
+ * d_splice_alias().
  *
  * If the name is not found in the directory, a NULL inode is inserted into the
- * dentry @dent. The dentry is then termed a negative dentry.
+ * dentry @dent via a call to d_add(). The dentry is then termed a negative
+ * dentry.
  *
  * Only if an actual error occurs, do we return an error via ERR_PTR().
  *
  * In order to handle the case insensitivity issues of NTFS with regards to the
  * dcache and the dcache requiring only one dentry per directory, we deal with
- * dentry aliases that only differ in case in ->ntfs_lookup() while maintining
+ * dentry aliases that only differ in case in ->ntfs_lookup() while maintaining
  * a case sensitive dcache. This means that we get the full benefit of dcache
  * speed when the file/directory is looked up with the same case as returned by
  * ->ntfs_readdir() but that a lookup for any other case (or for the short file
@@ -70,15 +72,18 @@
  * 1) @dent perfectly matches (i.e. including case) a directory entry with a
  *    file name in the WIN32 or POSIX namespaces. In this case
  *    ntfs_lookup_inode_by_name() will return with name set to NULL and we
- *    just d_add() @dent.
+ *    just d_splice_alias() @dent.
  * 2) @dent matches (not including case) a directory entry with a file name in
  *    the WIN32 namespace. In this case ntfs_lookup_inode_by_name() will return
  *    with name set to point to a kmalloc()ed ntfs_name structure containing
  *    the properly cased little endian Unicode name. We convert the name to the
  *    current NLS code page, search if a dentry with this name already exists
- *    and if so return that instead of @dent. The VFS will then destroy the old
- *    @dent and use the one we returned. If a dentry is not found, we allocate
- *    a new one, d_add() it, and return it as above.
+ *    and if so return that instead of @dent.  At this point things are
+ *    complicated by the possibility of 'disconnected' dentries due to NFS
+ *    which we deal with appropriately (see the code comments).  The VFS will
+ *    then destroy the old @dent and use the one we returned.  If a dentry is
+ *    not found, we allocate a new one, d_splice_alias() it, and return it as
+ *    above.
  * 3) @dent matches either perfectly or not (i.e. we don't care about case) a
  *    directory entry with a file name in the DOS namespace. In this case
  *    ntfs_lookup_inode_by_name() will return with name set to point to a
@@ -88,7 +93,8 @@
  *    name. We then convert the name to the current NLS code page, and proceed
  *    searching for a dentry with this name, etc, as in case 2), above.
  */
-static struct dentry *ntfs_lookup(struct inode *dir_ino, struct dentry *dent, struct nameidata *nd)
+static struct dentry *ntfs_lookup(struct inode *dir_ino, struct dentry *dent,
+		struct nameidata *nd)
 {
 	ntfs_volume *vol = NTFS_SB(dir_ino->i_sb);
 	struct inode *dent_inode;
@@ -120,9 +126,8 @@ static struct dentry *ntfs_lookup(struct inode *dir_ino, struct dentry *dent, st
 					dent_ino == FILE_MFT) {
 				/* Perfect WIN32/POSIX match. -- Case 1. */
 				if (!name) {
-					d_add(dent, dent_inode);
 					ntfs_debug("Done.");
-					return NULL;
+					return d_splice_alias(dent_inode, dent);
 				}
 				/*
 				 * We are too indented. Handle imperfect
@@ -132,7 +137,7 @@ static struct dentry *ntfs_lookup(struct inode *dir_ino, struct dentry *dent, st
 			}
 			ntfs_error(vol->sb, "Found stale reference to inode "
 					"0x%lx (reference sequence number = "
-					"0x%x, inode sequence number = 0x%x, "
+					"0x%x, inode sequence number = 0x%x), "
 					"returning -EIO. Run chkdsk.",
 					dent_ino, MSEQNO(mref),
 					NTFS_I(dent_inode)->seq_no);
@@ -162,7 +167,7 @@ static struct dentry *ntfs_lookup(struct inode *dir_ino, struct dentry *dent, st
 	// TODO: Consider moving this lot to a separate function! (AIA)
 handle_name:
    {
-	struct dentry *real_dent;
+	struct dentry *real_dent, *new_dent;
 	MFT_RECORD *m;
 	attr_search_context *ctx;
 	ntfs_inode *ni = NTFS_I(dent_inode);
@@ -173,8 +178,7 @@ static struct dentry *ntfs_lookup(struct inode *dir_ino, struct dentry *dent, st
 	if (name->type != FILE_NAME_DOS) {			/* Case 2. */
 		nls_name.len = (unsigned)ntfs_ucstonls(vol,
 				(uchar_t*)&name->name, name->len,
-				(unsigned char**)&nls_name.name,
-				name->len * 3 + 1);
+				(unsigned char**)&nls_name.name, 0);
 		kfree(name);
 	} else /* if (name->type == FILE_NAME_DOS) */ {		/* Case 3. */
 		FILE_NAME_ATTR *fn;
@@ -225,8 +229,7 @@ static struct dentry *ntfs_lookup(struct inode *dir_ino, struct dentry *dent, st
 		/* Convert the found WIN32 name to current NLS code page. */
 		nls_name.len = (unsigned)ntfs_ucstonls(vol,
 				(uchar_t*)&fn->file_name, fn->file_name_length,
-				(unsigned char**)&nls_name.name,
-				fn->file_name_length * 3 + 1);
+				(unsigned char**)&nls_name.name, 0);
 
 		put_attr_search_ctx(ctx);
 		unmap_mft_record(ni);
@@ -256,8 +259,12 @@ static struct dentry *ntfs_lookup(struct inode *dir_ino, struct dentry *dent, st
 			err = -ENOMEM;
 			goto err_out;
 		}
-		d_add(real_dent, dent_inode);
-		return real_dent;
+		new_dent = d_splice_alias(dent_inode, real_dent);
+		if (new_dent)
+			dput(real_dent);
+		else
+			new_dent = real_dent;
+		return new_dent;
 	}
 	kfree(nls_name.name);
 	/* Matching dentry exists, check if it is negative. */
@@ -266,14 +273,54 @@ static struct dentry *ntfs_lookup(struct inode *dir_ino, struct dentry *dent, st
 		/*
 		 * Already have the inode and the dentry attached, decrement
 		 * the reference count to balance the ntfs_iget() we did
-		 * earlier on.
+		 * earlier on.  We found the dentry using d_lookup() so it
+		 * cannot be disconnected and thus we do not need to worry
+		 * about any NFS/disconnectedness issues here.
 		 */
 		iput(dent_inode);
 		return real_dent;
 	}
-	/* Negative dentry: instantiate it. */
-	d_instantiate(real_dent, dent_inode);
-	return real_dent;
+	/*
+	 * Negative dentry: instantiate it unless the inode is a directory and
+	 * has a 'disconnected' dentry (i.e. IS_ROOT and DCACHE_DISCONNECTED),
+	 * in which case d_move() that in place of the found dentry.
+	 */
+	if (!S_ISDIR(dent_inode->i_mode)) {
+		/* Not a directory; everything is easy. */
+		d_instantiate(real_dent, dent_inode);
+		return real_dent;
+	}
+	spin_lock(&dcache_lock);
+	if (list_empty(&dent_inode->i_dentry)) {
+		/*
+		 * Directory without a 'disconnected' dentry; we need to do
+		 * d_instantiate() by hand because it takes dcache_lock which
+		 * we already hold.
+		 */
+		list_add(&real_dent->d_alias, &dent_inode->i_dentry);
+		real_dent->d_inode = dent_inode;
+		spin_unlock(&dcache_lock);
+		security_d_instantiate(real_dent, dent_inode);
+		return real_dent;
+	}
+	/*
+	 * Directory with a 'disconnected' dentry; get a reference to the
+	 * 'disconnected' dentry.
+	 */
+	new_dent = list_entry(dent_inode->i_dentry.next, struct dentry,
+			d_alias);
+	dget_locked(new_dent);
+	spin_unlock(&dcache_lock);
+	/* Do security vodoo. */
+	security_d_instantiate(real_dent, dent_inode);
+	/* Move new_dent in place of real_dent. */
+	d_move(new_dent, real_dent);
+	/* Balance the ntfs_iget() we did above. */
+	iput(dent_inode);
+	/* Throw away real_dent. */
+	dput(real_dent);
+	/* Use new_dent as the actual dentry. */
+	return new_dent;
 
 eio_err_out:
 	ntfs_error(vol->sb, "Illegal file name attribute. Run chkdsk.");
@@ -288,10 +335,139 @@ static struct dentry *ntfs_lookup(struct inode *dir_ino, struct dentry *dent, st
    }
 }
 
-/*
+/**
  * Inode operations for directories.
  */
 struct inode_operations ntfs_dir_inode_ops = {
 	.lookup	= ntfs_lookup,	/* VFS: Lookup directory. */
 };
 
+/**
+ * ntfs_get_parent - find the dentry of the parent of a given directory dentry
+ * @child_dent:		dentry of the directory whose parent directory to find
+ *
+ * Find the dentry for the parent directory of the directory specified by the
+ * dentry @child_dent.  This function is called from
+ * fs/exportfs/expfs.c::find_exported_dentry() which in turn is called from the
+ * default ->decode_fh() which is export_decode_fh() in the same file.
+ *
+ * The code is based on the ext3 ->get_parent() implementation found in
+ * fs/ext3/namei.c::ext3_get_parent().
+ *
+ * Note: ntfs_get_parent() is called with @child_dent->d_inode->i_sem down.
+ *
+ * Return the dentry of the parent directory on success or the error code on
+ * error (IS_ERR() is true).
+ */
+struct dentry *ntfs_get_parent(struct dentry *child_dent)
+{
+	struct inode *vi = child_dent->d_inode;
+	ntfs_inode *ni = NTFS_I(vi);
+	MFT_RECORD *mrec;
+	attr_search_context *ctx;
+	ATTR_RECORD *attr;
+	FILE_NAME_ATTR *fn;
+	struct inode *parent_vi;
+	struct dentry *parent_dent;
+	unsigned long parent_ino;
+
+	ntfs_debug("Entering for inode 0x%lx.", vi->i_ino);
+	/* Get the mft record of the inode belonging to the child dentry. */
+	mrec = map_mft_record(ni);
+	if (unlikely(IS_ERR(mrec)))
+		return (struct dentry *)mrec;
+	/* Find the first file name attribute in the mft record. */
+	ctx = get_attr_search_ctx(ni, mrec);
+	if (unlikely(!ctx)) {
+		unmap_mft_record(ni);
+		return ERR_PTR(-ENOMEM);
+	}
+try_next:
+	if (unlikely(!lookup_attr(AT_FILE_NAME, NULL, 0, IGNORE_CASE, 0,
+			NULL, 0, ctx))) {
+		put_attr_search_ctx(ctx);
+		unmap_mft_record(ni);
+		ntfs_error(vi->i_sb, "Inode 0x%lx does not have a file name "
+				"attribute. Run chkdsk.", vi->i_ino);
+		return ERR_PTR(-ENOENT);
+	}
+	attr = ctx->attr;
+	if (unlikely(attr->non_resident))
+		goto try_next;
+	fn = (FILE_NAME_ATTR *)((u8 *)attr +
+			le16_to_cpu(attr->data.resident.value_offset));
+	if (unlikely((u8 *)fn + le32_to_cpu(attr->data.resident.value_length) >
+			(u8*)attr + le32_to_cpu(attr->length)))
+		goto try_next;
+	/* Get the inode number of the parent directory. */
+	parent_ino = MREF_LE(fn->parent_directory);
+	/* Release the search context and the mft record of the child. */
+	put_attr_search_ctx(ctx);
+	unmap_mft_record(ni);
+	/* Get the inode of the parent directory. */
+	parent_vi = ntfs_iget(vi->i_sb, parent_ino);
+	if (unlikely(IS_ERR(parent_vi) || is_bad_inode(parent_vi))) {
+		if (!IS_ERR(parent_vi))
+			iput(parent_vi);
+		ntfs_error(vi->i_sb, "Failed to get parent directory inode "
+				"0x%lx of child inode 0x%lx.", parent_ino,
+				vi->i_ino);
+		return ERR_PTR(-EACCES);
+	}
+	/* Finally get a dentry for the parent directory and return it. */
+	parent_dent = d_alloc_anon(parent_vi);
+	if (unlikely(!parent_dent)) {
+		iput(parent_vi);
+		return ERR_PTR(-ENOMEM);
+	}
+	ntfs_debug("Done for inode 0x%lx.", vi->i_ino);
+	return parent_dent;
+}
+
+/**
+ * ntfs_get_dentry - find a dentry for the inode from a file handle sub-fragment
+ * @sb:		super block identifying the mounted ntfs volume
+ * @fh:		the file handle sub-fragment
+ *
+ * Find a dentry for the inode given a file handle sub-fragment.  This function
+ * is called from fs/exportfs/expfs.c::find_exported_dentry() which in turn is
+ * called from the default ->decode_fh() which is export_decode_fh() in the
+ * same file.  The code is closely based on the default ->get_dentry() helper
+ * fs/exportfs/expfs.c::get_object().
+ *
+ * The @fh contains two 32-bit unsigned values, the first one is the inode
+ * number and the second one is the inode generation.
+ *
+ * Return the dentry on success or the error code on error (IS_ERR() is true).
+ */
+struct dentry *ntfs_get_dentry(struct super_block *sb, void *fh)
+{
+	struct inode *vi;
+	struct dentry *dent;
+	unsigned long ino = ((u32 *)fh)[0];
+	u32 gen = ((u32 *)fh)[1];
+
+	ntfs_debug("Entering for inode 0x%lx, generation 0x%x.", ino, gen);
+	vi = ntfs_iget(sb, ino);
+	if (unlikely(IS_ERR(vi))) {
+		ntfs_error(sb, "Failed to get inode 0x%lx.", ino);
+		return (struct dentry *)vi;
+	}
+	if (unlikely(is_bad_inode(vi) || vi->i_generation != gen)) {
+		/* We didn't find the right inode. */
+		ntfs_error(sb, "Inode 0x%lx, bad count: %d %d or version 0x%x "
+				"0x%x.", vi->i_ino, vi->i_nlink,
+				atomic_read(&vi->i_count), vi->i_generation,
+				gen);
+		iput(vi);
+		return ERR_PTR(-ESTALE);
+	}
+	/* Now find a dentry.  If possible, get a well-connected one. */
+	dent = d_alloc_anon(vi);
+	if (unlikely(!dent)) {
+		iput(vi);
+		return ERR_PTR(-ENOMEM);
+	}
+	ntfs_debug("Done for inode 0x%lx, generation 0x%x.", ino, gen);
+	return dent;
+}

fs/ntfs/super.c

 /*
  * super.c - NTFS kernel super block handling. Part of the Linux-NTFS project.
  *
- * Copyright (c) 2001-2003 Anton Altaparmakov
+ * Copyright (c) 2001-2004 Anton Altaparmakov
  * Copyright (c) 2001,2002 Richard Russon
  *
  * This program/include file is free software; you can redistribute it and/or
@@ -323,6 +323,9 @@ static int ntfs_remount(struct super_block *sb, int *flags, char *opt)
 			return -EROFS;
 		}
 	}
+	// TODO:  For now we enforce no atime and dir atime updates as they are
+	// not implemented.
+	*flags |= MS_NOATIME | MS_NODIRATIME;
 #endif
 
 	// FIXME/TODO: If left like this we will have problems with rw->ro and
@@ -1338,6 +1341,40 @@ struct super_operations ntfs_sops = {
 	.show_options	= ntfs_show_options, /* Show mount options in proc. */
 };
 
+
+/**
+ * Declarations for NTFS specific export operations (fs/ntfs/namei.c).
+ */
+extern struct dentry *ntfs_get_parent(struct dentry *child_dent);
+extern struct dentry *ntfs_get_dentry(struct super_block *sb, void *fh);
+
+/**
+ * Export operations allowing NFS exporting of mounted NTFS partitions.
+ *
+ * We use the default ->decode_fh() and ->encode_fh() for now.  Note that they
+ * use 32 bits to store the inode number which is an unsigned long so on 64-bit
+ * architectures is usually 64 bits so it would all fail horribly on huge
+ * volumes.  I guess we need to define our own encode and decode fh functions
+ * that store 64-bit inode numbers at some point but for now we will ignore the
+ * problem...
+ *
+ * We also use the default ->get_name() helper (used by ->decode_fh() via
+ * fs/exportfs/expfs.c::find_exported_dentry()) as that is completely fs
+ * independent.
+ *
+ * The default ->get_parent() just returns -EACCES so we have to provide our
+ * own and the default ->get_dentry() is incompatible with NTFS due to not
+ * allowing the inode number 0 which is used in NTFS for the system file $MFT
+ * and due to using iget() whereas NTFS needs ntfs_iget().
+ */
+static struct export_operations ntfs_export_ops = {
+	.get_parent	= ntfs_get_parent,	/* Find the parent of a given
+						   directory. */
+	.get_dentry	= ntfs_get_dentry,	/* Find a dentry for the inode
+						   given a file handle
+						   sub-fragment. */
+};
+
 /**
  * ntfs_fill_super - mount an ntfs files system
  * @sb:		super block of ntfs file system to mount
@@ -1366,6 +1403,10 @@ static int ntfs_fill_super(struct super_block *sb, void *opt, const int silent)
 	ntfs_debug("Entering.");
 #ifndef NTFS_RW
 	sb->s_flags |= MS_RDONLY | MS_NOATIME | MS_NODIRATIME;
+#else
+	// TODO:  For now we enforce no atime and dir atime updates as they are
+	// not implemented.
+	sb->s_flags |= MS_NOATIME | MS_NODIRATIME;
 #endif
 	/* Allocate a new ntfs_volume and place it in sb->s_fs_info. */
 	sb->s_fs_info = kmalloc(sizeof(ntfs_volume), GFP_NOFS);
@@ -1544,6 +1585,7 @@ static int ntfs_fill_super(struct super_block *sb, void *opt, const int silent)
 			default_upcase = NULL;
 		}
 		up(&ntfs_lock);
+		sb->s_export_op = &ntfs_export_ops;
 		return 0;
 	}
 	ntfs_error(sb, "Failed to allocate root directory.");
@@ -1788,13 +1830,13 @@ static void __exit exit_ntfs_fs(void)
 		printk(KERN_CRIT "NTFS: This causes memory to leak! There is "
 				"probably a BUG in the driver! Please report "
 				"you saw this message to "
-				"linux-ntfs-dev@lists.sf.net\n");
+				"linux-ntfs-dev@lists.sourceforge.net\n");
 	/* Unregister the ntfs sysctls. */
 	ntfs_sysctl(0);
 }
 
 MODULE_AUTHOR("Anton Altaparmakov <aia21@cantab.net>");
-MODULE_DESCRIPTION("NTFS 1.2/3.x driver - Copyright (c) 2001-2003 Anton Altaparmakov");
+MODULE_DESCRIPTION("NTFS 1.2/3.x driver - Copyright (c) 2001-2004 Anton Altaparmakov");
 MODULE_LICENSE("GPL");
 #ifdef DEBUG
 MODULE_PARM(debug_msgs, "i");

fs/ntfs/unistr.c

 /*
  * unistr.c - NTFS Unicode string handling. Part of the Linux-NTFS project.
  *
- * Copyright (c) 2001-2003 Anton Altaparmakov
+ * Copyright (c) 2001-2004 Anton Altaparmakov
  *
  * This program/include file is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as published
@@ -305,8 +305,9 @@ int ntfs_nlstoucs(const ntfs_volume *vol, const char *ins,
  * Convert the input little endian, 2-byte Unicode string @ins, of length
  * @ins_len into the string format dictated by the loaded NLS.
  *
- * If @outs is NULL, this function allocates the string and the caller is
- * responsible for calling kfree(@outs); when finished with it.
+ * If *@outs is NULL, this function allocates the string and the caller is
+ * responsible for calling kfree(*@outs); when finished with it. In this case
+ * @outs_len is ignored and can be 0.
  *
  * On success the function returns the number of bytes written to the output
  * string *@outs (>= 0), not counting the terminating NULL byte. If the output