Merge branch 'for-linus' of git://git.kernel.dk/linux-block

* 'for-linus' of git://git.kernel.dk/linux-block:
  block: Use hlist_entry() for io_context.cic_list.first
  cfq-iosched: Remove bogus check in queue_fail path
  xen/blkback: potential null dereference in error handling
  xen/blkback: don't call vbd_size() if bd_disk is NULL
  block: blkdev_get() should access ->bd_disk only after success
  CFQ: Fix typo and remove unnecessary semicolon
  block: remove unwanted semicolons
  Revert "block: Remove extra discard_alignment from hd_struct."
  nbd: adjust 'max_part' according to part_shift
  nbd: limit module parameters to a sane value
  nbd: pass MSG_* flags to kernel_recvmsg()
  block: improve the bio_add_page() and bio_add_pc_page() descriptions

9 files changed, 41 insertions, 28 deletions

diff --git a/block/blk-ioc.c b/block/blk-ioc.c
index c898049dafd..342eae9b0d3 100644
--- a/block/blk-ioc.c
+++ b/block/blk-ioc.c
@@ -21,7 +21,7 @@ static void cfq_dtor(struct io_context *ioc)
         if (!hlist_empty(&ioc->cic_list)) {
                 struct cfq_io_context *cic;
 
-                cic = list_entry(ioc->cic_list.first, struct cfq_io_context,
+                cic = hlist_entry(ioc->cic_list.first, struct cfq_io_context,
                                                                 cic_list);
                 cic->dtor(ioc);
         }
@@ -57,7 +57,7 @@ static void cfq_exit(struct io_context *ioc)
         if (!hlist_empty(&ioc->cic_list)) {
                 struct cfq_io_context *cic;
 
-                cic = list_entry(ioc->cic_list.first, struct cfq_io_context,
+                cic = hlist_entry(ioc->cic_list.first, struct cfq_io_context,
                                                                 cic_list);
                 cic->exit(ioc);
         }
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 7c52d688892..3c7b537bf90 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -185,7 +185,7 @@ struct cfq_group {
         int nr_cfqq;
 
         /*
-         * Per group busy queus average. Useful for workload slice calc. We
+         * Per group busy queues average. Useful for workload slice calc. We
          * create the array for each prio class but at run time it is used
          * only for RT and BE class and slot for IDLE class remains unused.
          * This is primarily done to avoid confusion and a gcc warning.
@@ -369,16 +369,16 @@ CFQ_CFQQ_FNS(wait_busy);
 #define cfq_log_cfqq(cfqd, cfqq, fmt, args...)  \
         blk_add_trace_msg((cfqd)->queue, "cfq%d%c %s " fmt, (cfqq)->pid, \
                         cfq_cfqq_sync((cfqq)) ? 'S' : 'A', \
-                        blkg_path(&(cfqq)->cfqg->blkg), ##args);
+                        blkg_path(&(cfqq)->cfqg->blkg), ##args)
 
 #define cfq_log_cfqg(cfqd, cfqg, fmt, args...)                          \
         blk_add_trace_msg((cfqd)->queue, "%s " fmt,                     \
-                                blkg_path(&(cfqg)->blkg), ##args);      \
+                                blkg_path(&(cfqg)->blkg), ##args)       \
 
 #else
 #define cfq_log_cfqq(cfqd, cfqq, fmt, args...)  \
         blk_add_trace_msg((cfqd)->queue, "cfq%d " fmt, (cfqq)->pid, ##args)
-#define cfq_log_cfqg(cfqd, cfqg, fmt, args...)          do {} while (0);
+#define cfq_log_cfqg(cfqd, cfqg, fmt, args...)          do {} while (0)
 #endif
 #define cfq_log(cfqd, fmt, args...)     \
         blk_add_trace_msg((cfqd)->queue, "cfq " fmt, ##args)
@@ -3786,9 +3786,6 @@ new_queue:
         return 0;
 
 queue_fail:
-        if (cic)
-                put_io_context(cic->ioc);
-
         cfq_schedule_dispatch(cfqd);
         spin_unlock_irqrestore(q->queue_lock, flags);
         cfq_log(cfqd, "set_request fail");
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index e6fc716aca4..f533f3375e2 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -192,7 +192,8 @@ static int sock_xmit(struct nbd_device *lo, int send, void *buf, int size,
                         if (lo->xmit_timeout)
                                 del_timer_sync(&ti);
                 } else
-                        result = kernel_recvmsg(sock, &msg, &iov, 1, size, 0);
+                        result = kernel_recvmsg(sock, &msg, &iov, 1, size,
+                                                msg.msg_flags);
 
                 if (signal_pending(current)) {
                         siginfo_t info;
@@ -753,9 +754,26 @@ static int __init nbd_init(void)
                 return -ENOMEM;
 
         part_shift = 0;
-        if (max_part > 0)
+        if (max_part > 0) {
                 part_shift = fls(max_part);
 
+                /*
+                 * Adjust max_part according to part_shift as it is exported
+                 * to user space so that user can know the max number of
+                 * partition kernel should be able to manage.
+                 *
+                 * Note that -1 is required because partition 0 is reserved
+                 * for the whole disk.
+                 */
+                max_part = (1UL << part_shift) - 1;
+        }
+
+        if ((1UL << part_shift) > DISK_MAX_PARTS)
+                return -EINVAL;
+
+        if (nbds_max > 1UL << (MINORBITS - part_shift))
+                return -EINVAL;
+
         for (i = 0; i < nbds_max; i++) {
                 struct gendisk *disk = alloc_disk(1 << part_shift);
                 if (!disk)
diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index c73910cc28c..5cf2993a833 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -809,11 +809,13 @@ static int __init xen_blkif_init(void)
  failed_init:
         kfree(blkbk->pending_reqs);
         kfree(blkbk->pending_grant_handles);
-        for (i = 0; i < mmap_pages; i++) {
-                if (blkbk->pending_pages[i])
-                        __free_page(blkbk->pending_pages[i]);
+        if (blkbk->pending_pages) {
+                for (i = 0; i < mmap_pages; i++) {
+                        if (blkbk->pending_pages[i])
+                                __free_page(blkbk->pending_pages[i]);
+                }
+                kfree(blkbk->pending_pages);
         }
-        kfree(blkbk->pending_pages);
         kfree(blkbk);
         blkbk = NULL;
         return rc;
diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c
index 34570823355..6cc0db1bf52 100644
--- a/drivers/block/xen-blkback/xenbus.c
+++ b/drivers/block/xen-blkback/xenbus.c
@@ -357,14 +357,13 @@ static int xen_vbd_create(struct xen_blkif *blkif, blkif_vdev_t handle,
         }
 
         vbd->bdev = bdev;
-        vbd->size = vbd_sz(vbd);
-
         if (vbd->bdev->bd_disk == NULL) {
                 DPRINTK("xen_vbd_create: device %08x doesn't exist.\n",
                         vbd->pdevice);
                 xen_vbd_free(vbd);
                 return -ENOENT;
         }
+        vbd->size = vbd_sz(vbd);
 
         if (vbd->bdev->bd_disk->flags & GENHD_FL_CD || cdrom)
                 vbd->type |= VDISK_CDROM;
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 1f2b1997833..1a2421f908f 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1272,8 +1272,8 @@ int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder)
                  * individual writeable reference is too fragile given the
                  * way @mode is used in blkdev_get/put().
                  */
-                if ((disk->flags & GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE) &&
-                    !res && (mode & FMODE_WRITE) && !bdev->bd_write_holder) {
+                if (!res && (mode & FMODE_WRITE) && !bdev->bd_write_holder &&
+                    (disk->flags & GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE)) {
                         bdev->bd_write_holder = true;
                         disk_block_events(disk);
                 }
diff --git a/fs/partitions/check.c b/fs/partitions/check.c
index f82e762eeca..d545e97d99c 100644
--- a/fs/partitions/check.c
+++ b/fs/partitions/check.c
@@ -255,13 +255,7 @@ ssize_t part_discard_alignment_show(struct device *dev,
                                    struct device_attribute *attr, char *buf)
 {
         struct hd_struct *p = dev_to_part(dev);
-        struct gendisk *disk = dev_to_disk(dev);
-        unsigned int alignment = 0;
-
-        if (disk->queue)
-                alignment = queue_limit_discard_alignment(&disk->queue->limits,
-                                                                p->start_sect);
-        return sprintf(buf, "%u\n", alignment);
+        return sprintf(buf, "%u\n", p->discard_alignment);
 }
 
 ssize_t part_stat_show(struct device *dev,
@@ -455,6 +449,8 @@ struct hd_struct *add_partition(struct gendisk *disk, int partno,
         p->start_sect = start;
         p->alignment_offset =
                 queue_limit_alignment_offset(&disk->queue->limits, start);
+        p->discard_alignment =
+                queue_limit_discard_alignment(&disk->queue->limits, start);
         p->nr_sects = len;
         p->partno = partno;
         p->policy = get_disk_ro(disk);
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index ae9091a6848..1a23722e887 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1282,8 +1282,8 @@ queue_max_integrity_segments(struct request_queue *q)
 #define blk_get_integrity(a)                    (0)
 #define blk_integrity_compare(a, b)             (0)
 #define blk_integrity_register(a, b)            (0)
-#define blk_integrity_unregister(a)             do { } while (0);
-#define blk_queue_max_integrity_segments(a, b)  do { } while (0);
+#define blk_integrity_unregister(a)             do { } while (0)
+#define blk_queue_max_integrity_segments(a, b)  do { } while (0)
 #define queue_max_integrity_segments(a)         (0)
 #define blk_integrity_merge_rq(a, b, c)         (0)
 #define blk_integrity_merge_bio(a, b, c)        (0)
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index b78956b3c2e..300d7582006 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -100,6 +100,7 @@ struct hd_struct {
         sector_t start_sect;
         sector_t nr_sects;
         sector_t alignment_offset;
+        unsigned int discard_alignment;
         struct device __dev;
         struct kobject *holder_dir;
         int policy, partno;