NTFS: writev() fix and maintenance/contact details update

Fix writev() to not keep writing the first segment over and over again
instead of moving onto subsequent segments and update the NTFS entry in
MAINTAINERS to reflect that Tuxera Inc. now supports the NTFS driver.

Signed-off-by: Anton Altaparmakov <anton@tuxera.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 17 insertions, 18 deletions

diff --git a/fs/ntfs/file.c b/fs/ntfs/file.c
index 113ebd9f25a..f4b1057abdd 100644
--- a/fs/ntfs/file.c
+++ b/fs/ntfs/file.c
@@ -1,7 +1,7 @@
 /*
  * file.c - NTFS kernel file operations.  Part of the Linux-NTFS project.
  *
- * Copyright (c) 2001-2007 Anton Altaparmakov
+ * Copyright (c) 2001-2011 Anton Altaparmakov and Tuxera Inc.
  *
  * 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
@@ -1380,15 +1380,14 @@ static inline void ntfs_set_next_iovec(const struct iovec **iovp,
  * pages (out to offset + bytes), to emulate ntfs_copy_from_user()'s
  * single-segment behaviour.
  *
- * We call the same helper (__ntfs_copy_from_user_iovec_inatomic()) both
- * when atomic and when not atomic.  This is ok because
- * __ntfs_copy_from_user_iovec_inatomic() calls __copy_from_user_inatomic()
- * and it is ok to call this when non-atomic.
- * Infact, the only difference between __copy_from_user_inatomic() and
+ * We call the same helper (__ntfs_copy_from_user_iovec_inatomic()) both when
+ * atomic and when not atomic.  This is ok because it calls
+ * __copy_from_user_inatomic() and it is ok to call this when non-atomic.  In
+ * fact, the only difference between __copy_from_user_inatomic() and
  * __copy_from_user() is that the latter calls might_sleep() and the former
- * should not zero the tail of the buffer on error.  And on many
- * architectures __copy_from_user_inatomic() is just defined to
- * __copy_from_user() so it makes no difference at all on those architectures.
+ * should not zero the tail of the buffer on error.  And on many architectures
+ * __copy_from_user_inatomic() is just defined to __copy_from_user() so it
+ * makes no difference at all on those architectures.
  */
 static inline size_t ntfs_copy_from_user_iovec(struct page **pages,
 		unsigned nr_pages, unsigned ofs, const struct iovec **iov,
@@ -1409,28 +1408,28 @@ static inline size_t ntfs_copy_from_user_iovec(struct page **pages,
 		if (unlikely(copied != len)) {
 			/* Do it the slow way. */
 			addr = kmap(*pages);
-			copied = __ntfs_copy_from_user_iovec_inatomic(addr + ofs,
-					*iov, *iov_ofs, len);
-			/*
-			 * Zero the rest of the target like __copy_from_user().
-			 */
-			memset(addr + ofs + copied, 0, len - copied);
-			kunmap(*pages);
+			copied = __ntfs_copy_from_user_iovec_inatomic(addr +
+					ofs, *iov, *iov_ofs, len);
 			if (unlikely(copied != len))
 				goto err_out;
+			kunmap(*pages);
 		}
 		total += len;
+		ntfs_set_next_iovec(iov, iov_ofs, len);
 		bytes -= len;
 		if (!bytes)
 			break;
-		ntfs_set_next_iovec(iov, iov_ofs, len);
 		ofs = 0;
 	} while (++pages < last_page);
 out:
 	return total;
 err_out:
-	total += copied;
+	BUG_ON(copied > len);
 	/* Zero the rest of the target like __copy_from_user(). */
+	memset(addr + ofs + copied, 0, len - copied);
+	kunmap(*pages);
+	total += copied;
+	ntfs_set_next_iovec(iov, iov_ofs, copied);
 	while (++pages < last_page) {
 		bytes -= len;
 		if (!bytes)