From: Fred Isaman <iisaman@xxxxxxxxxxxxxx>
Signed-off-by: Fred Isaman <iisaman@xxxxxxxxxxxxxx>
Signed-off-by: Benny Halevy <bhalevy@xxxxxxxxxxx>
---
fs/nfs/blocklayout/extents.c | 48 ++++++++++++++++++++++++++++++++++++++---
1 files changed, 44 insertions(+), 4 deletions(-)
diff --git a/fs/nfs/blocklayout/extents.c b/fs/nfs/blocklayout/extents.c
index 1719a67..a05ee2a 100644
--- a/fs/nfs/blocklayout/extents.c
+++ b/fs/nfs/blocklayout/extents.c
@@ -773,12 +773,43 @@ _prep_new_extent(struct pnfs_block_extent *new,
new->be_inval = orig->be_inval;
}
+/* Tries to merge be with extent in front of it in list.
+ * Frees storage if not used.
+ */
+static struct pnfs_block_extent *
+_front_merge(struct pnfs_block_extent *be, struct list_head *head,
+ struct pnfs_block_extent *storage)
+{
+ struct pnfs_block_extent *prev;
+
+ if (!storage)
+ goto no_merge;
+ if (&be->be_node == head || be->be_node.prev == head)
+ goto no_merge;
+ prev = list_entry(be->be_node.prev, struct pnfs_block_extent, be_node);
+ if ((prev->be_f_offset + prev->be_length != be->be_f_offset) ||
+ !extents_consistent(prev, be))
+ goto no_merge;
+ _prep_new_extent(storage, prev, prev->be_f_offset,
+ prev->be_length + be->be_length, prev->be_state);
+ list_replace(&prev->be_node, &storage->be_node);
+ put_extent(prev);
+ list_del(&be->be_node);
+ put_extent(be);
+ return storage;
+
+ no_merge:
+ kfree(storage);
+ return be;
+}
+
static u64
set_to_rw(struct pnfs_block_layout *bl, u64 offset, u64 length)
{
- u64 rv = 0;
+ u64 rv = offset + length;
struct pnfs_block_extent *be, *e1, *e2, *e3, *new, *old;
struct pnfs_block_extent *children[3];
+ struct pnfs_block_extent *merge1 = NULL, *merge2 = NULL;
int i = 0, j;
dprintk("%s(%llu, %llu)\n", __func__, offset, length);
@@ -792,7 +823,6 @@ set_to_rw(struct pnfs_block_layout *bl, u64 offset, u64 length)
spin_lock(&bl->bl_ext_lock);
be = find_get_extent_locked(bl, offset);
- print_bl_extent(be);
rv = be->be_f_offset + be->be_length;
if (be->be_state != PNFS_BLOCK_INVALID_DATA) {
spin_unlock(&bl->bl_ext_lock);
@@ -805,13 +835,15 @@ set_to_rw(struct pnfs_block_layout *bl, u64 offset, u64 length)
PNFS_BLOCK_INVALID_DATA);
children[i++] = e1;
kref_get(&e1->be_refcnt);
+ print_bl_extent(e1);
} else
- kfree(e1);
+ merge1 = e1;
_prep_new_extent(e2, be, offset,
min(length, be->be_f_offset + be->be_length - offset),
PNFS_BLOCK_READWRITE_DATA);
children[i++] = e2;
kref_get(&e2->be_refcnt);
+ print_bl_extent(e2);
if (offset + length < be->be_f_offset + be->be_length) {
_prep_new_extent(e3, be, e2->be_f_offset + e2->be_length,
be->be_f_offset + be->be_length -
@@ -819,8 +851,9 @@ set_to_rw(struct pnfs_block_layout *bl, u64 offset, u64 length)
PNFS_BLOCK_INVALID_DATA);
children[i++] = e3;
kref_get(&e3->be_refcnt);
+ print_bl_extent(e3);
} else
- kfree(e3);
+ merge2 = e3;
/* Remove be from list, and insert the e* */
/* We don't get refs on e*, since this list is the base reference
@@ -831,11 +864,18 @@ set_to_rw(struct pnfs_block_layout *bl, u64 offset, u64 length)
new = children[0];
list_replace(&be->be_node, &new->be_node);
put_extent(be);
+ new = _front_merge(new, &bl->bl_extents[RW_EXTENT], merge1);
for (j = 1; j < i; j++) {
old = new;
new = children[j];
list_add(&new->be_node, &old->be_node);
}
+ if (merge2) {
+ /* This is a HACK, should just create a _back_merge function */
+ new = list_entry(new->be_node.next,
+ struct pnfs_block_extent, be_node);
+ new = _front_merge(new, &bl->bl_extents[RW_EXTENT], merge2);
+ }
spin_unlock(&bl->bl_ext_lock);
/* Since we removed the base reference above, be is now scheduled for
--
1.7.4.1
--
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