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authorLinus Torvalds <torvalds@linux-foundation.org>2013-02-07 08:38:33 +1100
committerLinus Torvalds <torvalds@linux-foundation.org>2013-02-07 08:38:33 +1100
commit2110cf029a67237db572299bb51e0de9e3e3d4dd (patch)
tree6837ff139a807037f06952c3eb72c3e350bc05c8
parent1589a3e7777631ff56dd58cd7dcdf275185e62b5 (diff)
parent1383923d1985cef2bceb8128094fbe5e05de7435 (diff)
downloadlinux-stericsson-2110cf029a67237db572299bb51e0de9e3e3d4dd.tar.gz
Merge branch 'for-linus' of git://git.kernel.dk/linux-block
Pull block layer updates from Jens Axboe: "I've got a few bits pending for 3.8 final, that I better get sent out. It's all been sitting for a while, I consider it safe. It contains: - Two bug fixes for mtip32xx, fixing a driver hang and a crash. - A few-liner protocol error fix for drbd. - A few fixes for the xen block front/back driver, fixing a potential data corruption issue. - A race fix for disk_clear_events(), causing spurious warnings. Out of the Chrome OS base. - A deadlock fix for disk_clear_events(), moving it to the a unfreezable workqueue. Also from the Chrome OS base." * 'for-linus' of git://git.kernel.dk/linux-block: drbd: fix potential protocol error and resulting disconnect/reconnect mtip32xx: fix for crash when the device surprise removed during rebuild mtip32xx: fix for driver hang after a command timeout block: prevent race/cleanup block: remove deadlock in disk_clear_events xen-blkfront: handle bvecs with partial data llist/xen-blkfront: implement safe version of llist_for_each_entry xen-blkback: implement safe iterator for the list of persistent grants
-rw-r--r--block/genhd.c42
-rw-r--r--drivers/block/drbd/drbd_req.c2
-rw-r--r--drivers/block/drbd/drbd_req.h1
-rw-r--r--drivers/block/drbd/drbd_state.c7
-rw-r--r--drivers/block/mtip32xx/mtip32xx.c24
-rw-r--r--drivers/block/xen-blkback/blkback.c18
-rw-r--r--drivers/block/xen-blkfront.c10
-rw-r--r--include/linux/llist.h25
8 files changed, 101 insertions, 28 deletions
diff --git a/block/genhd.c b/block/genhd.c
index 9a289d7c84bb..3993ebf4135f 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -35,6 +35,8 @@ static DEFINE_IDR(ext_devt_idr);
static struct device_type disk_type;
+static void disk_check_events(struct disk_events *ev,
+ unsigned int *clearing_ptr);
static void disk_alloc_events(struct gendisk *disk);
static void disk_add_events(struct gendisk *disk);
static void disk_del_events(struct gendisk *disk);
@@ -1549,6 +1551,7 @@ unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask)
const struct block_device_operations *bdops = disk->fops;
struct disk_events *ev = disk->ev;
unsigned int pending;
+ unsigned int clearing = mask;
if (!ev) {
/* for drivers still using the old ->media_changed method */
@@ -1558,34 +1561,53 @@ unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask)
return 0;
}
- /* tell the workfn about the events being cleared */
+ disk_block_events(disk);
+
+ /*
+ * store the union of mask and ev->clearing on the stack so that the
+ * race with disk_flush_events does not cause ambiguity (ev->clearing
+ * can still be modified even if events are blocked).
+ */
spin_lock_irq(&ev->lock);
- ev->clearing |= mask;
+ clearing |= ev->clearing;
+ ev->clearing = 0;
spin_unlock_irq(&ev->lock);
- /* uncondtionally schedule event check and wait for it to finish */
- disk_block_events(disk);
- queue_delayed_work(system_freezable_wq, &ev->dwork, 0);
- flush_delayed_work(&ev->dwork);
- __disk_unblock_events(disk, false);
+ disk_check_events(ev, &clearing);
+ /*
+ * if ev->clearing is not 0, the disk_flush_events got called in the
+ * middle of this function, so we want to run the workfn without delay.
+ */
+ __disk_unblock_events(disk, ev->clearing ? true : false);
/* then, fetch and clear pending events */
spin_lock_irq(&ev->lock);
- WARN_ON_ONCE(ev->clearing & mask); /* cleared by workfn */
pending = ev->pending & mask;
ev->pending &= ~mask;
spin_unlock_irq(&ev->lock);
+ WARN_ON_ONCE(clearing & mask);
return pending;
}
+/*
+ * Separate this part out so that a different pointer for clearing_ptr can be
+ * passed in for disk_clear_events.
+ */
static void disk_events_workfn(struct work_struct *work)
{
struct delayed_work *dwork = to_delayed_work(work);
struct disk_events *ev = container_of(dwork, struct disk_events, dwork);
+
+ disk_check_events(ev, &ev->clearing);
+}
+
+static void disk_check_events(struct disk_events *ev,
+ unsigned int *clearing_ptr)
+{
struct gendisk *disk = ev->disk;
char *envp[ARRAY_SIZE(disk_uevents) + 1] = { };
- unsigned int clearing = ev->clearing;
+ unsigned int clearing = *clearing_ptr;
unsigned int events;
unsigned long intv;
int nr_events = 0, i;
@@ -1598,7 +1620,7 @@ static void disk_events_workfn(struct work_struct *work)
events &= ~ev->pending;
ev->pending |= events;
- ev->clearing &= ~clearing;
+ *clearing_ptr &= ~clearing;
intv = disk_events_poll_jiffies(disk);
if (!ev->block && intv)
diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c
index f58a4a4b4dfb..2b8303ad63c9 100644
--- a/drivers/block/drbd/drbd_req.c
+++ b/drivers/block/drbd/drbd_req.c
@@ -168,7 +168,7 @@ static void wake_all_senders(struct drbd_tconn *tconn) {
}
/* must hold resource->req_lock */
-static void start_new_tl_epoch(struct drbd_tconn *tconn)
+void start_new_tl_epoch(struct drbd_tconn *tconn)
{
/* no point closing an epoch, if it is empty, anyways. */
if (tconn->current_tle_writes == 0)
diff --git a/drivers/block/drbd/drbd_req.h b/drivers/block/drbd/drbd_req.h
index 016de6b8bb57..c08d22964d06 100644
--- a/drivers/block/drbd/drbd_req.h
+++ b/drivers/block/drbd/drbd_req.h
@@ -267,6 +267,7 @@ struct bio_and_error {
int error;
};
+extern void start_new_tl_epoch(struct drbd_tconn *tconn);
extern void drbd_req_destroy(struct kref *kref);
extern void _req_may_be_done(struct drbd_request *req,
struct bio_and_error *m);
diff --git a/drivers/block/drbd/drbd_state.c b/drivers/block/drbd/drbd_state.c
index 53bf6182bac4..0fe220cfb9e9 100644
--- a/drivers/block/drbd/drbd_state.c
+++ b/drivers/block/drbd/drbd_state.c
@@ -931,6 +931,7 @@ __drbd_set_state(struct drbd_conf *mdev, union drbd_state ns,
enum drbd_state_rv rv = SS_SUCCESS;
enum sanitize_state_warnings ssw;
struct after_state_chg_work *ascw;
+ bool did_remote, should_do_remote;
os = drbd_read_state(mdev);
@@ -981,11 +982,17 @@ __drbd_set_state(struct drbd_conf *mdev, union drbd_state ns,
(os.disk != D_DISKLESS && ns.disk == D_DISKLESS))
atomic_inc(&mdev->local_cnt);
+ did_remote = drbd_should_do_remote(mdev->state);
mdev->state.i = ns.i;
+ should_do_remote = drbd_should_do_remote(mdev->state);
mdev->tconn->susp = ns.susp;
mdev->tconn->susp_nod = ns.susp_nod;
mdev->tconn->susp_fen = ns.susp_fen;
+ /* put replicated vs not-replicated requests in seperate epochs */
+ if (did_remote != should_do_remote)
+ start_new_tl_epoch(mdev->tconn);
+
if (os.disk == D_ATTACHING && ns.disk >= D_NEGOTIATING)
drbd_print_uuids(mdev, "attached to UUIDs");
diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c
index 9694dd99bbbc..3fd100990453 100644
--- a/drivers/block/mtip32xx/mtip32xx.c
+++ b/drivers/block/mtip32xx/mtip32xx.c
@@ -626,12 +626,13 @@ static void mtip_timeout_function(unsigned long int data)
}
}
- if (cmdto_cnt && !test_bit(MTIP_PF_IC_ACTIVE_BIT, &port->flags)) {
+ if (cmdto_cnt) {
print_tags(port->dd, "timed out", tagaccum, cmdto_cnt);
-
- mtip_restart_port(port);
+ if (!test_bit(MTIP_PF_IC_ACTIVE_BIT, &port->flags)) {
+ mtip_restart_port(port);
+ wake_up_interruptible(&port->svc_wait);
+ }
clear_bit(MTIP_PF_EH_ACTIVE_BIT, &port->flags);
- wake_up_interruptible(&port->svc_wait);
}
if (port->ic_pause_timer) {
@@ -3887,7 +3888,12 @@ static int mtip_block_remove(struct driver_data *dd)
* Delete our gendisk structure. This also removes the device
* from /dev
*/
- del_gendisk(dd->disk);
+ if (dd->disk) {
+ if (dd->disk->queue)
+ del_gendisk(dd->disk);
+ else
+ put_disk(dd->disk);
+ }
spin_lock(&rssd_index_lock);
ida_remove(&rssd_index_ida, dd->index);
@@ -3921,7 +3927,13 @@ static int mtip_block_shutdown(struct driver_data *dd)
"Shutting down %s ...\n", dd->disk->disk_name);
/* Delete our gendisk structure, and cleanup the blk queue. */
- del_gendisk(dd->disk);
+ if (dd->disk) {
+ if (dd->disk->queue)
+ del_gendisk(dd->disk);
+ else
+ put_disk(dd->disk);
+ }
+
spin_lock(&rssd_index_lock);
ida_remove(&rssd_index_ida, dd->index);
diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index 74374fb762aa..5ac841ff6cc7 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -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);
}
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 96e9b00db081..11043c18ac5a 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -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 */
diff --git a/include/linux/llist.h b/include/linux/llist.h
index a5199f6d0e82..d0ab98f73d38 100644
--- a/include/linux/llist.h
+++ b/include/linux/llist.h
@@ -125,6 +125,31 @@ static inline void init_llist_head(struct llist_head *list)
(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
*