ocfs2: properly update i_mtime on buffered write

We weren't always updating i_mtime on writes, so fix ocfs2_commit_write() to
handle this.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Acked-by: Zach Brown <zach.brown@oracle.com>

fs/ocfs2/aops.c

@@ -391,31 +391,28 @@ struct ocfs2_journal_handle *ocfs2_start_walk_page_trans(struct inode *inode,
 static int ocfs2_commit_write(struct file *file, struct page *page,
 			      unsigned from, unsigned to)
 {
-	int ret, extending = 0, locklevel = 0;
-	loff_t new_i_size;
+	int ret;
 	struct buffer_head *di_bh = NULL;
 	struct inode *inode = page->mapping->host;
 	struct ocfs2_journal_handle *handle = NULL;
+	struct ocfs2_dinode *di;
 
 	mlog_entry("(0x%p, 0x%p, %u, %u)\n", file, page, from, to);
 
 	/* NOTE: ocfs2_file_aio_write has ensured that it's safe for
-	 * us to sample inode->i_size here without the metadata lock:
+	 * us to continue here without rechecking the I/O against
+	 * changed inode values.
 	 *
 	 * 1) We're currently holding the inode alloc lock, so no
 	 *    nodes can change it underneath us.
 	 *
 	 * 2) We've had to take the metadata lock at least once
-	 *    already to check for extending writes, hence insuring
-	 *    that our current copy is also up to date.
+	 *    already to check for extending writes, suid removal, etc.
+	 *    The meta data update code then ensures that we don't get a
+	 *    stale inode allocation image (i_size, i_clusters, etc).
 	 */
-	new_i_size = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
-	if (new_i_size > i_size_read(inode)) {
-		extending = 1;
-		locklevel = 1;
-	}
 
-	ret = ocfs2_meta_lock_with_page(inode, NULL, &di_bh, locklevel, page);
+	ret = ocfs2_meta_lock_with_page(inode, NULL, &di_bh, 1, page);
 	if (ret != 0) {
 		mlog_errno(ret);
 		goto out;
@@ -427,23 +424,20 @@ static int ocfs2_commit_write(struct file *file, struct page *page,
 		goto out_unlock_meta;
 	}
 
-	if (extending) {
-		handle = ocfs2_start_walk_page_trans(inode, page, from, to);
-		if (IS_ERR(handle)) {
-			ret = PTR_ERR(handle);
-			handle = NULL;
-			goto out_unlock_data;
-		}
+	handle = ocfs2_start_walk_page_trans(inode, page, from, to);
+	if (IS_ERR(handle)) {
+		ret = PTR_ERR(handle);
+		goto out_unlock_data;
+	}
 
-		/* Mark our buffer early. We'd rather catch this error up here
-		 * as opposed to after a successful commit_write which would
-		 * require us to set back inode->i_size. */
-		ret = ocfs2_journal_access(handle, inode, di_bh,
-					   OCFS2_JOURNAL_ACCESS_WRITE);
-		if (ret < 0) {
-			mlog_errno(ret);
-			goto out_commit;
-		}
+	/* Mark our buffer early. We'd rather catch this error up here
+	 * as opposed to after a successful commit_write which would
+	 * require us to set back inode->i_size. */
+	ret = ocfs2_journal_access(handle, inode, di_bh,
+				   OCFS2_JOURNAL_ACCESS_WRITE);
+	if (ret < 0) {
+		mlog_errno(ret);
+		goto out_commit;
 	}
 
 	/* might update i_size */
@@ -453,37 +447,28 @@ static int ocfs2_commit_write(struct file *file, struct page *page,
 		goto out_commit;
 	}
 
-	if (extending) {
-		loff_t size = (u64) i_size_read(inode);
-		struct ocfs2_dinode *di =
-			(struct ocfs2_dinode *)di_bh->b_data;
+	di = (struct ocfs2_dinode *)di_bh->b_data;
 
-		/* ocfs2_mark_inode_dirty is too heavy to use here. */
-		inode->i_blocks = ocfs2_align_bytes_to_sectors(size);
-		inode->i_ctime = inode->i_mtime = CURRENT_TIME;
+	/* ocfs2_mark_inode_dirty() is too heavy to use here. */
+	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+	di->i_mtime = di->i_ctime = cpu_to_le64(inode->i_mtime.tv_sec);
+	di->i_mtime_nsec = di->i_ctime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
 
-		di->i_size = cpu_to_le64(size);
-		di->i_ctime = di->i_mtime = 
-				cpu_to_le64(inode->i_mtime.tv_sec);
-		di->i_ctime_nsec = di->i_mtime_nsec = 
-				cpu_to_le32(inode->i_mtime.tv_nsec);
+	inode->i_blocks = ocfs2_align_bytes_to_sectors((u64)(i_size_read(inode)));
+	di->i_size = cpu_to_le64((u64)i_size_read(inode));
 
-		ret = ocfs2_journal_dirty(handle, di_bh);
-		if (ret < 0) {
-			mlog_errno(ret);
-			goto out_commit;
-		}
+	ret = ocfs2_journal_dirty(handle, di_bh);
+	if (ret < 0) {
+		mlog_errno(ret);
+		goto out_commit;
 	}
 
-	BUG_ON(extending && (i_size_read(inode) != new_i_size));
-
 out_commit:
-	if (handle)
-		ocfs2_commit_trans(handle);
+	ocfs2_commit_trans(handle);
 out_unlock_data:
 	ocfs2_data_unlock(inode, 1);
 out_unlock_meta:
-	ocfs2_meta_unlock(inode, locklevel);
+	ocfs2_meta_unlock(inode, 1);
 out:
 	if (di_bh)
 		brelse(di_bh);