ocfs2: support writing of unwritten extents
Update the write code to detect when the user is asking to write to an
unwritten extent. Like writing to a hole, we must zero the region between
the write and the cluster boundaries. Most of the existing cluster zeroing
logic can be re-used with some additional checks for the unwritten flag on
extent records.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index a80f317..6745086 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -527,20 +527,21 @@
* understand sparse inodes.
*/
int ocfs2_lock_allocators(struct inode *inode, struct ocfs2_dinode *di,
- u32 clusters_to_add,
+ u32 clusters_to_add, u32 extents_to_split,
struct ocfs2_alloc_context **data_ac,
struct ocfs2_alloc_context **meta_ac)
{
int ret, num_free_extents;
+ unsigned int max_recs_needed = clusters_to_add + 2 * extents_to_split;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
*meta_ac = NULL;
*data_ac = NULL;
mlog(0, "extend inode %llu, i_size = %lld, di->i_clusters = %u, "
- "clusters_to_add = %u\n",
+ "clusters_to_add = %u, extents_to_split = %u\n",
(unsigned long long)OCFS2_I(inode)->ip_blkno, i_size_read(inode),
- le32_to_cpu(di->i_clusters), clusters_to_add);
+ le32_to_cpu(di->i_clusters), clusters_to_add, extents_to_split);
num_free_extents = ocfs2_num_free_extents(osb, inode, di);
if (num_free_extents < 0) {
@@ -558,9 +559,12 @@
*
* Most of the time we'll only be seeing this 1 cluster at a time
* anyway.
+ *
+ * Always lock for any unwritten extents - we might want to
+ * add blocks during a split.
*/
if (!num_free_extents ||
- (ocfs2_sparse_alloc(osb) && num_free_extents < clusters_to_add)) {
+ (ocfs2_sparse_alloc(osb) && num_free_extents < max_recs_needed)) {
ret = ocfs2_reserve_new_metadata(osb, di, meta_ac);
if (ret < 0) {
if (ret != -ENOSPC)
@@ -641,7 +645,7 @@
down_write(&OCFS2_I(inode)->ip_alloc_sem);
drop_alloc_sem = 1;
- status = ocfs2_lock_allocators(inode, fe, clusters_to_add, &data_ac,
+ status = ocfs2_lock_allocators(inode, fe, clusters_to_add, 0, &data_ac,
&meta_ac);
if (status) {
mlog_errno(status);
