From: Andrew Morton <akpm@osdl.org>
Date: Tue, 16 Oct 2007 08:24:54 +0000 (-0700)
Subject: Revert "[PATCH] generic_file_buffered_write(): handle zero-length iovec segments"
X-Git-Tag: v2.6.24-rc1~1209
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4b49643fbb3fa8bf4910f82be02d45e94e8972a4;p=linux-2.6

Revert "[PATCH] generic_file_buffered_write(): handle zero-length iovec segments"

This reverts commit 81b0c8713385ce1b1b9058e916edcf9561ad76d6, which was
a bugfix against 6527c2bdf1f833cc18e8f42bd97973d583e4aa83 ("[PATCH]
generic_file_buffered_write(): deadlock on vectored write"), which we
also revert.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/mm/filemap.c b/mm/filemap.c
index c504db18ac..caaaa7adfd 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1895,12 +1895,6 @@ generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov,
 			break;
 		}
 
-		if (unlikely(bytes == 0)) {
-			status = 0;
-			copied = 0;
-			goto zero_length_segment;
-		}
-
 		status = a_ops->prepare_write(file, page, offset, offset+bytes);
 		if (unlikely(status)) {
 			loff_t isize = i_size_read(inode);
@@ -1930,8 +1924,7 @@ generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov,
 			page_cache_release(page);
 			continue;
 		}
-zero_length_segment:
-		if (likely(copied >= 0)) {
+		if (likely(copied > 0)) {
 			if (!status)
 				status = copied;
 
diff --git a/mm/filemap.h b/mm/filemap.h
index c2bff04c84..a1e10a232e 100644
--- a/mm/filemap.h
+++ b/mm/filemap.h
@@ -87,7 +87,7 @@ filemap_set_next_iovec(const struct iovec **iovp, size_t *basep, size_t bytes)
 	const struct iovec *iov = *iovp;
 	size_t base = *basep;
 
-	do {
+	while (bytes) {
 		int copy = min(bytes, iov->iov_len - base);
 
 		bytes -= copy;
@@ -96,7 +96,7 @@ filemap_set_next_iovec(const struct iovec **iovp, size_t *basep, size_t bytes)
 			iov++;
 			base = 0;
 		}
-	} while (bytes);
+	}
 	*iovp = iov;
 	*basep = base;
 }