1 files changed, 91 insertions, 197 deletions

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index b45a95363a84..ac65bb5e38ac 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -244,16 +244,66 @@ struct file_region {
 	long to;
 };
 
+/* Must be called with resv->lock held. Calling this with count_only == true
+ * will count the number of pages to be added but will not modify the linked
+ * list.
+ */
+static long add_reservation_in_range(struct resv_map *resv, long f, long t,
+				     bool count_only)
+{
+	long chg = 0;
+	struct list_head *head = &resv->regions;
+	struct file_region *rg = NULL, *trg = NULL, *nrg = NULL;
+
+	/* Locate the region we are before or in. */
+	list_for_each_entry(rg, head, link)
+		if (f <= rg->to)
+			break;
+
+	/* Round our left edge to the current segment if it encloses us. */
+	if (f > rg->from)
+		f = rg->from;
+
+	chg = t - f;
+
+	/* Check for and consume any regions we now overlap with. */
+	nrg = rg;
+	list_for_each_entry_safe(rg, trg, rg->link.prev, link) {
+		if (&rg->link == head)
+			break;
+		if (rg->from > t)
+			break;
+
+		/* We overlap with this area, if it extends further than
+		 * us then we must extend ourselves.  Account for its
+		 * existing reservation.
+		 */
+		if (rg->to > t) {
+			chg += rg->to - t;
+			t = rg->to;
+		}
+		chg -= rg->to - rg->from;
+
+		if (!count_only && rg != nrg) {
+			list_del(&rg->link);
+			kfree(rg);
+		}
+	}
+
+	if (!count_only) {
+		nrg->from = f;
+		nrg->to = t;
+	}
+
+	return chg;
+}
+
 /*
  * Add the huge page range represented by [f, t) to the reserve
- * map.  In the normal case, existing regions will be expanded
- * to accommodate the specified range.  Sufficient regions should
- * exist for expansion due to the previous call to region_chg
- * with the same range.  However, it is possible that region_del
- * could have been called after region_chg and modifed the map
- * in such a way that no region exists to be expanded.  In this
- * case, pull a region descriptor from the cache associated with
- * the map and use that for the new range.
+ * map.  Existing regions will be expanded to accommodate the specified
+ * range, or a region will be taken from the cache.  Sufficient regions
+ * must exist in the cache due to the previous call to region_chg with
+ * the same range.
  *
  * Return the number of new huge pages added to the map.  This
  * number is greater than or equal to zero.
@@ -261,7 +311,7 @@ struct file_region {
 static long region_add(struct resv_map *resv, long f, long t)
 {
 	struct list_head *head = &resv->regions;
-	struct file_region *rg, *nrg, *trg;
+	struct file_region *rg, *nrg;
 	long add = 0;
 
 	spin_lock(&resv->lock);
@@ -272,9 +322,8 @@ static long region_add(struct resv_map *resv, long f, long t)
 
 	/*
 	 * If no region exists which can be expanded to include the
-	 * specified range, the list must have been modified by an
-	 * interleving call to region_del().  Pull a region descriptor
-	 * from the cache and use it for this range.
+	 * specified range, pull a region descriptor from the cache
+	 * and use it for this range.
 	 */
 	if (&rg->link == head || t < rg->from) {
 		VM_BUG_ON(resv->region_cache_count <= 0);
@@ -292,38 +341,7 @@ static long region_add(struct resv_map *resv, long f, long t)
 		goto out_locked;
 	}
 
-	/* Round our left edge to the current segment if it encloses us. */
-	if (f > rg->from)
-		f = rg->from;
-
-	/* Check for and consume any regions we now overlap with. */
-	nrg = rg;
-	list_for_each_entry_safe(rg, trg, rg->link.prev, link) {
-		if (&rg->link == head)
-			break;
-		if (rg->from > t)
-			break;
-
-		/* If this area reaches higher then extend our area to
-		 * include it completely.  If this is not the first area
-		 * which we intend to reuse, free it. */
-		if (rg->to > t)
-			t = rg->to;
-		if (rg != nrg) {
-			/* Decrement return value by the deleted range.
-			 * Another range will span this area so that by
-			 * end of routine add will be >= zero
-			 */
-			add -= (rg->to - rg->from);
-			list_del(&rg->link);
-			kfree(rg);
-		}
-	}
-
-	add += (nrg->from - f);		/* Added to beginning of region */
-	nrg->from = f;
-	add += t - nrg->to;		/* Added to end of region */
-	nrg->to = t;
+	add = add_reservation_in_range(resv, f, t, false);
 
 out_locked:
 	resv->adds_in_progress--;
@@ -339,15 +357,9 @@ out_locked:
  * call to region_add that will actually modify the reserve
  * map to add the specified range [f, t).  region_chg does
  * not change the number of huge pages represented by the
- * map.  However, if the existing regions in the map can not
- * be expanded to represent the new range, a new file_region
- * structure is added to the map as a placeholder.  This is
- * so that the subsequent region_add call will have all the
- * regions it needs and will not fail.
- *
- * Upon entry, region_chg will also examine the cache of region descriptors
- * associated with the map.  If there are not enough descriptors cached, one
- * will be allocated for the in progress add operation.
+ * map.  A new file_region structure is added to the cache
+ * as a placeholder, so that the subsequent region_add
+ * call will have all the regions it needs and will not fail.
  *
  * Returns the number of huge pages that need to be added to the existing
  * reservation map for the range [f, t).  This number is greater or equal to
@@ -356,11 +368,8 @@ out_locked:
  */
 static long region_chg(struct resv_map *resv, long f, long t)
 {
-	struct list_head *head = &resv->regions;
-	struct file_region *rg, *nrg = NULL;
 	long chg = 0;
 
-retry:
 	spin_lock(&resv->lock);
 retry_locked:
 	resv->adds_in_progress++;
@@ -378,10 +387,8 @@ retry_locked:
 		spin_unlock(&resv->lock);
 
 		trg = kmalloc(sizeof(*trg), GFP_KERNEL);
-		if (!trg) {
-			kfree(nrg);
+		if (!trg)
 			return -ENOMEM;
-		}
 
 		spin_lock(&resv->lock);
 		list_add(&trg->link, &resv->region_cache);
@@ -389,61 +396,8 @@ retry_locked:
 		goto retry_locked;
 	}
 
-	/* Locate the region we are before or in. */
-	list_for_each_entry(rg, head, link)
-		if (f <= rg->to)
-			break;
+	chg = add_reservation_in_range(resv, f, t, true);
 
-	/* If we are below the current region then a new region is required.
-	 * Subtle, allocate a new region at the position but make it zero
-	 * size such that we can guarantee to record the reservation. */
-	if (&rg->link == head || t < rg->from) {
-		if (!nrg) {
-			resv->adds_in_progress--;
-			spin_unlock(&resv->lock);
-			nrg = kmalloc(sizeof(*nrg), GFP_KERNEL);
-			if (!nrg)
-				return -ENOMEM;
-
-			nrg->from = f;
-			nrg->to   = f;
-			INIT_LIST_HEAD(&nrg->link);
-			goto retry;
-		}
-
-		list_add(&nrg->link, rg->link.prev);
-		chg = t - f;
-		goto out_nrg;
-	}
-
-	/* Round our left edge to the current segment if it encloses us. */
-	if (f > rg->from)
-		f = rg->from;
-	chg = t - f;
-
-	/* Check for and consume any regions we now overlap with. */
-	list_for_each_entry(rg, rg->link.prev, link) {
-		if (&rg->link == head)
-			break;
-		if (rg->from > t)
-			goto out;
-
-		/* We overlap with this area, if it extends further than
-		 * us then we must extend ourselves.  Account for its
-		 * existing reservation. */
-		if (rg->to > t) {
-			chg += rg->to - t;
-			t = rg->to;
-		}
-		chg -= rg->to - rg->from;
-	}
-
-out:
-	spin_unlock(&resv->lock);
-	/*  We already know we raced and no longer need the new region */
-	kfree(nrg);
-	return chg;
-out_nrg:
 	spin_unlock(&resv->lock);
 	return chg;
 }
@@ -1069,85 +1023,12 @@ static void free_gigantic_page(struct page *page, unsigned int order)
 }
 
 #ifdef CONFIG_CONTIG_ALLOC
-static int __alloc_gigantic_page(unsigned long start_pfn,
-				unsigned long nr_pages, gfp_t gfp_mask)
-{
-	unsigned long end_pfn = start_pfn + nr_pages;
-	return alloc_contig_range(start_pfn, end_pfn, MIGRATE_MOVABLE,
-				  gfp_mask);
-}
-
-static bool pfn_range_valid_gigantic(struct zone *z,
-			unsigned long start_pfn, unsigned long nr_pages)
-{
-	unsigned long i, end_pfn = start_pfn + nr_pages;
-	struct page *page;
-
-	for (i = start_pfn; i < end_pfn; i++) {
-		page = pfn_to_online_page(i);
-		if (!page)
-			return false;
-
-		if (page_zone(page) != z)
-			return false;
-
-		if (PageReserved(page))
-			return false;
-
-		if (page_count(page) > 0)
-			return false;
-
-		if (PageHuge(page))
-			return false;
-	}
-
-	return true;
-}
-
-static bool zone_spans_last_pfn(const struct zone *zone,
-			unsigned long start_pfn, unsigned long nr_pages)
-{
-	unsigned long last_pfn = start_pfn + nr_pages - 1;
-	return zone_spans_pfn(zone, last_pfn);
-}
-
 static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask,
 		int nid, nodemask_t *nodemask)
 {
-	unsigned int order = huge_page_order(h);
-	unsigned long nr_pages = 1 << order;
-	unsigned long ret, pfn, flags;
-	struct zonelist *zonelist;
-	struct zone *zone;
-	struct zoneref *z;
+	unsigned long nr_pages = 1UL << huge_page_order(h);
 
-	zonelist = node_zonelist(nid, gfp_mask);
-	for_each_zone_zonelist_nodemask(zone, z, zonelist, gfp_zone(gfp_mask), nodemask) {
-		spin_lock_irqsave(&zone->lock, flags);
-
-		pfn = ALIGN(zone->zone_start_pfn, nr_pages);
-		while (zone_spans_last_pfn(zone, pfn, nr_pages)) {
-			if (pfn_range_valid_gigantic(zone, pfn, nr_pages)) {
-				/*
-				 * We release the zone lock here because
-				 * alloc_contig_range() will also lock the zone
-				 * at some point. If there's an allocation
-				 * spinning on this lock, it may win the race
-				 * and cause alloc_contig_range() to fail...
-				 */
-				spin_unlock_irqrestore(&zone->lock, flags);
-				ret = __alloc_gigantic_page(pfn, nr_pages, gfp_mask);
-				if (!ret)
-					return pfn_to_page(pfn);
-				spin_lock_irqsave(&zone->lock, flags);
-			}
-			pfn += nr_pages;
-		}
-
-		spin_unlock_irqrestore(&zone->lock, flags);
-	}
-
-	return NULL;
+	return alloc_contig_pages(nr_pages, gfp_mask, nid, nodemask);
 }
 
 static void prep_new_huge_page(struct hstate *h, struct page *page, int nid);
@@ -3915,7 +3796,7 @@ retry:
 			 * handling userfault.  Reacquire after handling
 			 * fault to make calling code simpler.
 			 */
-			hash = hugetlb_fault_mutex_hash(h, mapping, idx, haddr);
+			hash = hugetlb_fault_mutex_hash(mapping, idx);
 			mutex_unlock(&hugetlb_fault_mutex_table[hash]);
 			ret = handle_userfault(&vmf, VM_UFFD_MISSING);
 			mutex_lock(&hugetlb_fault_mutex_table[hash]);
@@ -4042,8 +3923,7 @@ backout_unlocked:
 }
 
 #ifdef CONFIG_SMP
-u32 hugetlb_fault_mutex_hash(struct hstate *h, struct address_space *mapping,
-			    pgoff_t idx, unsigned long address)
+u32 hugetlb_fault_mutex_hash(struct address_space *mapping, pgoff_t idx)
 {
 	unsigned long key[2];
 	u32 hash;
@@ -4051,7 +3931,7 @@ u32 hugetlb_fault_mutex_hash(struct hstate *h, struct address_space *mapping,
 	key[0] = (unsigned long) mapping;
 	key[1] = idx;
 
-	hash = jhash2((u32 *)&key, sizeof(key)/sizeof(u32), 0);
+	hash = jhash2((u32 *)&key, sizeof(key)/(sizeof(u32)), 0);
 
 	return hash & (num_fault_mutexes - 1);
 }
@@ -4060,8 +3940,7 @@ u32 hugetlb_fault_mutex_hash(struct hstate *h, struct address_space *mapping,
  * For uniprocesor systems we always use a single mutex, so just
  * return 0 and avoid the hashing overhead.
  */
-u32 hugetlb_fault_mutex_hash(struct hstate *h, struct address_space *mapping,
-			    pgoff_t idx, unsigned long address)
+u32 hugetlb_fault_mutex_hash(struct address_space *mapping, pgoff_t idx)
 {
 	return 0;
 }
@@ -4105,7 +3984,7 @@ vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 	 * get spurious allocation failures if two CPUs race to instantiate
 	 * the same page in the page cache.
 	 */
-	hash = hugetlb_fault_mutex_hash(h, mapping, idx, haddr);
+	hash = hugetlb_fault_mutex_hash(mapping, idx);
 	mutex_lock(&hugetlb_fault_mutex_table[hash]);
 
 	entry = huge_ptep_get(ptep);
@@ -4459,6 +4338,21 @@ long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
 				break;
 			}
 		}
+
+		/*
+		 * If subpage information not requested, update counters
+		 * and skip the same_page loop below.
+		 */
+		if (!pages && !vmas && !pfn_offset &&
+		    (vaddr + huge_page_size(h) < vma->vm_end) &&
+		    (remainder >= pages_per_huge_page(h))) {
+			vaddr += huge_page_size(h);
+			remainder -= pages_per_huge_page(h);
+			i += pages_per_huge_page(h);
+			spin_unlock(ptl);
+			continue;
+		}
+
 same_page:
 		if (pages) {
 			pages[i] = mem_map_offset(page, pfn_offset);
@@ -4842,7 +4736,7 @@ pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
 	if (!vma_shareable(vma, addr))
 		return (pte_t *)pmd_alloc(mm, pud, addr);
 
-	i_mmap_lock_write(mapping);
+	i_mmap_lock_read(mapping);
 	vma_interval_tree_foreach(svma, &mapping->i_mmap, idx, idx) {
 		if (svma == vma)
 			continue;
@@ -4872,7 +4766,7 @@ pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
 	spin_unlock(ptl);
 out:
 	pte = (pte_t *)pmd_alloc(mm, pud, addr);
-	i_mmap_unlock_write(mapping);
+	i_mmap_unlock_read(mapping);
 	return pte;
 }