ocfs2: teach extend/truncate about sparse files
For ocfs2_truncate_file(), we eliminate the "simple" truncate case which no
longer exists since i_size is not tied to i_clusters. In
ocfs2_extend_file(), we skip the allocation / page zeroing code for file
systems which understand sparse files.
The core truncate code is changed to do a bottom up tree traversal. This
gets abstracted out into it's own function. To make things more readable,
most of the special case handling for in-inode extents from
ocfs2_do_truncate() is also removed.
Though write support for sparse files comes in a later patch, we at least
update ocfs2_prepare_inode_for_write() to skip allocation for sparse files.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index 8c97fa1..edc0b61 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -344,18 +344,6 @@
}
ocfs2_data_unlock(inode, 1);
- if (le32_to_cpu(fe->i_clusters) ==
- ocfs2_clusters_for_bytes(osb->sb, new_i_size)) {
- mlog(0, "fe->i_clusters = %u, so we do a simple truncate\n",
- fe->i_clusters);
- /* No allocation change is required, so lets fast path
- * this truncate. */
- status = ocfs2_simple_size_update(inode, di_bh, new_i_size);
- if (status < 0)
- mlog_errno(status);
- goto bail;
- }
-
/* alright, we're going to need to do a full blown alloc size
* change. Orphan the inode so that recovery can complete the
* truncate if necessary. This does the task of marking
@@ -785,7 +773,7 @@
size_t tail_to_skip)
{
int ret = 0;
- u32 clusters_to_add;
+ u32 clusters_to_add = 0;
BUG_ON(!tail_to_skip && !di_bh);
@@ -797,6 +785,11 @@
goto out;
BUG_ON(new_i_size < i_size_read(inode));
+ if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb))) {
+ BUG_ON(tail_to_skip != 0);
+ goto out_update_size;
+ }
+
clusters_to_add = ocfs2_clusters_for_bytes(inode->i_sb, new_i_size) -
OCFS2_I(inode)->ip_clusters;
@@ -832,6 +825,7 @@
goto out_unlock;
}
+out_update_size:
if (!tail_to_skip) {
/* We're being called from ocfs2_setattr() which wants
* us to update i_size */
@@ -841,7 +835,8 @@
}
out_unlock:
- ocfs2_data_unlock(inode, 1);
+ if (!ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)))
+ ocfs2_data_unlock(inode, 1);
out:
return ret;
@@ -1097,6 +1092,14 @@
} else {
saved_pos = *ppos;
}
+
+ /*
+ * The rest of this loop is concerned with legacy file
+ * systems which don't support sparse files.
+ */
+ if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)))
+ break;
+
newsize = count + saved_pos;
mlog(0, "pos=%lld newsize=%lld cursize=%lld\n",