ocfs2: Read from an unwritten extent returns zeros
Return an optional extent flags field from our lookup functions and wire up
callers to treat unwritten regions as holes for the purpose of returning
zeros to the user.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index 3617601..f516619 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -1127,6 +1127,7 @@
size_t count)
{
int ret = 0;
+ unsigned int extent_flags;
u32 cpos, clusters, extent_len, phys_cpos;
struct super_block *sb = inode->i_sb;
@@ -1134,13 +1135,14 @@
clusters = ocfs2_clusters_for_bytes(sb, pos + count) - cpos;
while (clusters) {
- ret = ocfs2_get_clusters(inode, cpos, &phys_cpos, &extent_len);
+ ret = ocfs2_get_clusters(inode, cpos, &phys_cpos, &extent_len,
+ &extent_flags);
if (ret < 0) {
mlog_errno(ret);
goto out;
}
- if (phys_cpos == 0) {
+ if (phys_cpos == 0 || (extent_flags & OCFS2_EXT_UNWRITTEN)) {
ret = 1;
break;
}