rbd: more cleanup in rbd_header_from_disk()
This just rearranges things a bit more in rbd_header_from_disk()
so that the snapshot sizes are initialized right after the buffer
to hold them is allocated and doing a little further consolidation
that follows from that. Also adds a few simple comments.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 163fd85..145fbf6 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -520,6 +520,7 @@
u32 snap_count;
size_t len;
size_t size;
+ u32 i;
memset(header, 0, sizeof (*header));
@@ -535,6 +536,8 @@
if (snap_count) {
u64 snap_names_len = le64_to_cpu(ondisk->snap_names_len);
+ /* Save a copy of the snapshot names */
+
if (snap_names_len > (u64) SIZE_MAX)
return -EIO;
header->snap_names = kmalloc(snap_names_len, GFP_KERNEL);
@@ -549,10 +552,15 @@
memcpy(header->snap_names, &ondisk->snaps[snap_count],
snap_names_len);
+ /* Record each snapshot's size */
+
size = snap_count * sizeof (*header->snap_sizes);
header->snap_sizes = kmalloc(size, GFP_KERNEL);
if (!header->snap_sizes)
goto out_err;
+ for (i = 0; i < snap_count; i++)
+ header->snap_sizes[i] =
+ le64_to_cpu(ondisk->snaps[i].image_size);
} else {
WARN_ON(ondisk->snap_names_len);
header->snap_names = NULL;
@@ -565,6 +573,8 @@
header->comp_type = ondisk->options.comp_type;
header->total_snaps = snap_count;
+ /* Allocate and fill in the snapshot context */
+
size = sizeof (struct ceph_snap_context);
size += snap_count * sizeof (header->snapc->snaps[0]);
header->snapc = kzalloc(size, GFP_KERNEL);
@@ -574,19 +584,9 @@
atomic_set(&header->snapc->nref, 1);
header->snapc->seq = le64_to_cpu(ondisk->snap_seq);
header->snapc->num_snaps = snap_count;
-
- /* Fill in the snapshot information */
-
- if (snap_count) {
- u32 i;
-
- for (i = 0; i < snap_count; i++) {
- header->snapc->snaps[i] =
- le64_to_cpu(ondisk->snaps[i].id);
- header->snap_sizes[i] =
- le64_to_cpu(ondisk->snaps[i].image_size);
- }
- }
+ for (i = 0; i < snap_count; i++)
+ header->snapc->snaps[i] =
+ le64_to_cpu(ondisk->snaps[i].id);
return 0;