dect
/
linux-2.6
Archived
13
0
Fork 0
Code Releases Activity

Merge branch 'stable/for-jens-3.8' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen into for-linus 

Konrad writes:

Please git pull the following branch:

 git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen.git stable/for-jens-3.8

which has a bug-fix to the xen-blkfront and xen-blkback driver
when using the persistent mode. An issue was discovered where LVM
disks could not be read correctly and this fixes it. There
is also a change in llist.h which has been blessed by akpm.
This commit is contained in:
Jens Axboe 2012-12-19 20:37:10 +01:00
parent 12c2bdb232 d62f691858
commit b6c46cfa31
3 changed files with 42 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
drivers/block/xen-blkback/blkback.c
View File

@ -161,10 +161,12 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif,
static void make_response(struct xen_blkif *blkif, u64 id,
unsigned short op, int st);
#define foreach_grant(pos, rbtree, node) \
for ((pos) = container_of(rb_first((rbtree)), typeof(*(pos)), node); \
#define foreach_grant_safe(pos, n, rbtree, node) \
for ((pos) = container_of(rb_first((rbtree)), typeof(*(pos)), node), \
(n) = rb_next(&(pos)->node); \
&(pos)->node != NULL; \
(pos) = container_of(rb_next(&(pos)->node), typeof(*(pos)), node))
(pos) = container_of(n, typeof(*(pos)), node), \
(n) = (&(pos)->node != NULL) ? rb_next(&(pos)->node) : NULL)
static void add_persistent_gnt(struct rb_root *root,
@ -217,10 +219,11 @@ static void free_persistent_gnts(struct rb_root *root, unsigned int num)
struct gnttab_unmap_grant_ref unmap[BLKIF_MAX_SEGMENTS_PER_REQUEST];
struct page *pages[BLKIF_MAX_SEGMENTS_PER_REQUEST];
struct persistent_gnt *persistent_gnt;
struct rb_node *n;
int ret = 0;
int segs_to_unmap = 0;
foreach_grant(persistent_gnt, root, node) {
foreach_grant_safe(persistent_gnt, n, root, node) {
BUG_ON(persistent_gnt->handle ==
BLKBACK_INVALID_HANDLE);
gnttab_set_unmap_op(&unmap[segs_to_unmap],
@ -230,9 +233,6 @@ static void free_persistent_gnts(struct rb_root *root, unsigned int num)
persistent_gnt->handle);
pages[segs_to_unmap] = persistent_gnt->page;
rb_erase(&persistent_gnt->node, root);
kfree(persistent_gnt);
num--;
if (++segs_to_unmap == BLKIF_MAX_SEGMENTS_PER_REQUEST ||
!rb_next(&persistent_gnt->node)) {
@ -241,6 +241,10 @@ static void free_persistent_gnts(struct rb_root *root, unsigned int num)
BUG_ON(ret);
segs_to_unmap = 0;
}
rb_erase(&persistent_gnt->node, root);
kfree(persistent_gnt);
num--;
}
BUG_ON(num != 0);
}

10
drivers/block/xen-blkfront.c
View File

@ -792,6 +792,7 @@ static void blkif_free(struct blkfront_info *info, int suspend)
{
struct llist_node *all_gnts;
struct grant *persistent_gnt;
struct llist_node *n;
/* Prevent new requests being issued until we fix things up. */
spin_lock_irq(&info->io_lock);
@ -804,7 +805,7 @@ static void blkif_free(struct blkfront_info *info, int suspend)
/* Remove all persistent grants */
if (info->persistent_gnts_c) {
all_gnts = llist_del_all(&info->persistent_gnts);
llist_for_each_entry(persistent_gnt, all_gnts, node) {
llist_for_each_entry_safe(persistent_gnt, n, all_gnts, node) {
gnttab_end_foreign_access(persistent_gnt->gref, 0, 0UL);
__free_page(pfn_to_page(persistent_gnt->pfn));
kfree(persistent_gnt);
@ -835,7 +836,7 @@ static void blkif_free(struct blkfront_info *info, int suspend)
static void blkif_completion(struct blk_shadow *s, struct blkfront_info *info,
struct blkif_response *bret)
{
int i;
int i = 0;
struct bio_vec *bvec;
struct req_iterator iter;
unsigned long flags;
@ -852,7 +853,8 @@ static void blkif_completion(struct blk_shadow *s, struct blkfront_info *info,
*/
rq_for_each_segment(bvec, s->request, iter) {
BUG_ON((bvec->bv_offset + bvec->bv_len) > PAGE_SIZE);
i = offset >> PAGE_SHIFT;
if (bvec->bv_offset < offset)
i++;
BUG_ON(i >= s->req.u.rw.nr_segments);
shared_data = kmap_atomic(
pfn_to_page(s->grants_used[i]->pfn));
@ -861,7 +863,7 @@ static void blkif_completion(struct blk_shadow *s, struct blkfront_info *info,
bvec->bv_len);
bvec_kunmap_irq(bvec_data, &flags);
kunmap_atomic(shared_data);
offset += bvec->bv_len;
offset = bvec->bv_offset + bvec->bv_len;
}
}
/* Add the persistent grant into the list of free grants */

25
include/linux/llist.h
View File

@ -124,6 +124,31 @@ static inline void init_llist_head(struct llist_head *list)
&(pos)->member != NULL; \
(pos) = llist_entry((pos)->member.next, typeof(*(pos)), member))
/**
* llist_for_each_entry_safe - iterate safely against remove over some entries
* of lock-less list of given type.
* @pos: the type * to use as a loop cursor.
* @n: another type * to use as a temporary storage.
* @node: the fist entry of deleted list entries.
* @member: the name of the llist_node with the struct.
*
* In general, some entries of the lock-less list can be traversed
* safely only after being removed from list, so start with an entry
* instead of list head. This variant allows removal of entries
* as we iterate.
*
* If being used on entries deleted from lock-less list directly, the
* traverse order is from the newest to the oldest added entry. If
* you want to traverse from the oldest to the newest, you must
* reverse the order by yourself before traversing.
*/
#define llist_for_each_entry_safe(pos, n, node, member) \
for ((pos) = llist_entry((node), typeof(*(pos)), member), \
(n) = (pos)->member.next; \
&(pos)->member != NULL; \
(pos) = llist_entry(n, typeof(*(pos)), member), \
(n) = (&(pos)->member != NULL) ? (pos)->member.next : NULL)
/**
* llist_empty - tests whether a lock-less list is empty
* @head: the list to test