11 files changed, 85 insertions, 78 deletions

diff --git a/mm/fremap.c b/mm/fremap.c
index 736ba7f3306a..b6ec85abbb39 100644
--- a/mm/fremap.c
+++ b/mm/fremap.c
@@ -198,7 +198,7 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
                         flags &= MAP_NONBLOCK;
                         get_file(file);
                         addr = mmap_region(file, start, size,
-                                        flags, vma->vm_flags, pgoff, 1);
+                                        flags, vma->vm_flags, pgoff);
                         fput(file);
                         if (IS_ERR_VALUE(addr)) {
                                 err = addr;
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 618e98304080..107da3d809a8 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2269,12 +2269,18 @@ void hugetlb_change_protection(struct vm_area_struct *vma,
 
 int hugetlb_reserve_pages(struct inode *inode,
                                         long from, long to,
-                                        struct vm_area_struct *vma)
+                                        struct vm_area_struct *vma,
+                                        int acctflag)
 {
         long ret, chg;
         struct hstate *h = hstate_inode(inode);
 
-        if (vma && vma->vm_flags & VM_NORESERVE)
+        /*
+         * Only apply hugepage reservation if asked. At fault time, an
+         * attempt will be made for VM_NORESERVE to allocate a page
+         * and filesystem quota without using reserves
+         */
+        if (acctflag & VM_NORESERVE)
                 return 0;
 
         /*
@@ -2299,13 +2305,31 @@ int hugetlb_reserve_pages(struct inode *inode,
         if (chg < 0)
                 return chg;
 
+        /* There must be enough filesystem quota for the mapping */
         if (hugetlb_get_quota(inode->i_mapping, chg))
                 return -ENOSPC;
+
+        /*
+         * Check enough hugepages are available for the reservation.
+         * Hand back the quota if there are not
+         */
         ret = hugetlb_acct_memory(h, chg);
         if (ret < 0) {
                 hugetlb_put_quota(inode->i_mapping, chg);
                 return ret;
         }
+
+        /*
+         * Account for the reservations made. Shared mappings record regions
+         * that have reservations as they are shared by multiple VMAs.
+         * When the last VMA disappears, the region map says how much
+         * the reservation was and the page cache tells how much of
+         * the reservation was consumed. Private mappings are per-VMA and
+         * only the consumed reservations are tracked. When the VMA
+         * disappears, the original reservation is the VMA size and the
+         * consumed reservations are stored in the map. Hence, nothing
+         * else has to be done for private mappings here
+         */
         if (!vma || vma->vm_flags & VM_SHARED)
                 region_add(&inode->i_mapping->private_list, from, to);
         return 0;
diff --git a/mm/memory.c b/mm/memory.c
index 22bfa7a47a0b..baa999e87cd2 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1999,7 +1999,7 @@ gotten:
          * Don't let another task, with possibly unlocked vma,
          * keep the mlocked page.
          */
-        if (vma->vm_flags & VM_LOCKED) {
+        if ((vma->vm_flags & VM_LOCKED) && old_page) {
                 lock_page(old_page);    /* for LRU manipulation */
                 clear_page_mlock(old_page);
                 unlock_page(old_page);
diff --git a/mm/migrate.c b/mm/migrate.c
index 2bb4e1d63520..a9eff3f092f6 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1129,7 +1129,7 @@ int migrate_vmas(struct mm_struct *mm, const nodemask_t *to,
         struct vm_area_struct *vma;
         int err = 0;
 
-        for(vma = mm->mmap; vma->vm_next && !err; vma = vma->vm_next) {
+        for (vma = mm->mmap; vma && !err; vma = vma->vm_next) {
                 if (vma->vm_ops && vma->vm_ops->migrate) {
                         err = vma->vm_ops->migrate(vma, to, from, flags);
                         if (err)
diff --git a/mm/mlock.c b/mm/mlock.c
index 2904a347e476..037161d61b4e 100644
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -294,14 +294,10 @@ static inline int __mlock_posix_error_return(long retval)
  *
  * return number of pages [> 0] to be removed from locked_vm on success
  * of "special" vmas.
- *
- * return negative error if vma spanning @start-@range disappears while
- * mmap semaphore is dropped.  Unlikely?
  */
 long mlock_vma_pages_range(struct vm_area_struct *vma,
                         unsigned long start, unsigned long end)
 {
-        struct mm_struct *mm = vma->vm_mm;
         int nr_pages = (end - start) / PAGE_SIZE;
         BUG_ON(!(vma->vm_flags & VM_LOCKED));
 
@@ -314,20 +310,11 @@ long mlock_vma_pages_range(struct vm_area_struct *vma,
         if (!((vma->vm_flags & (VM_DONTEXPAND | VM_RESERVED)) ||
                         is_vm_hugetlb_page(vma) ||
                         vma == get_gate_vma(current))) {
-                long error;
-                downgrade_write(&mm->mmap_sem);
-
-                error = __mlock_vma_pages_range(vma, start, end, 1);
 
-                up_read(&mm->mmap_sem);
-                /* vma can change or disappear */
-                down_write(&mm->mmap_sem);
-                vma = find_vma(mm, start);
-                /* non-NULL vma must contain @start, but need to check @end */
-                if (!vma ||  end > vma->vm_end)
-                        return -ENOMEM;
+                __mlock_vma_pages_range(vma, start, end, 1);
 
-                return 0;       /* hide other errors from mmap(), et al */
+                /* Hide errors from mmap() and other callers */
+                return 0;
         }
 
         /*
@@ -438,41 +425,14 @@ success:
         vma->vm_flags = newflags;
 
         if (lock) {
-                /*
-                 * mmap_sem is currently held for write.  Downgrade the write
-                 * lock to a read lock so that other faults, mmap scans, ...
-                 * while we fault in all pages.
-                 */
-                downgrade_write(&mm->mmap_sem);
-
                 ret = __mlock_vma_pages_range(vma, start, end, 1);
 
-                /*
-                 * Need to reacquire mmap sem in write mode, as our callers
-                 * expect this.  We have no support for atomically upgrading
-                 * a sem to write, so we need to check for ranges while sem
-                 * is unlocked.
-                 */
-                up_read(&mm->mmap_sem);
-                /* vma can change or disappear */
-                down_write(&mm->mmap_sem);
-                *prev = find_vma(mm, start);
-                /* non-NULL *prev must contain @start, but need to check @end */
-                if (!(*prev) || end > (*prev)->vm_end)
-                        ret = -ENOMEM;
-                else if (ret > 0) {
+                if (ret > 0) {
                         mm->locked_vm -= ret;
                         ret = 0;
                 } else
                         ret = __mlock_posix_error_return(ret); /* translate if needed */
         } else {
-                /*
-                 * TODO:  for unlocking, pages will already be resident, so
-                 * we don't need to wait for allocations/reclaim/pagein, ...
-                 * However, unlocking a very large region can still take a
-                 * while.  Should we downgrade the semaphore for both lock
-                 * AND unlock ?
-                 */
                 __mlock_vma_pages_range(vma, start, end, 0);
         }
 
diff --git a/mm/mmap.c b/mm/mmap.c
index 214b6a258eeb..00ced3ee49a8 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -918,7 +918,6 @@ unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
         struct inode *inode;
         unsigned int vm_flags;
         int error;
-        int accountable = 1;
         unsigned long reqprot = prot;
 
         /*
@@ -1019,8 +1018,6 @@ unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
                                         return -EPERM;
                                 vm_flags &= ~VM_MAYEXEC;
                         }
-                        if (is_file_hugepages(file))
-                                accountable = 0;
 
                         if (!file->f_op || !file->f_op->mmap)
                                 return -ENODEV;
@@ -1053,8 +1050,7 @@ unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
         if (error)
                 return error;
 
-        return mmap_region(file, addr, len, flags, vm_flags, pgoff,
-                           accountable);
+        return mmap_region(file, addr, len, flags, vm_flags, pgoff);
 }
 EXPORT_SYMBOL(do_mmap_pgoff);
 
@@ -1092,17 +1088,23 @@ int vma_wants_writenotify(struct vm_area_struct *vma)
 
 /*
  * We account for memory if it's a private writeable mapping,
- * and VM_NORESERVE wasn't set.
+ * not hugepages and VM_NORESERVE wasn't set.
  */
-static inline int accountable_mapping(unsigned int vm_flags)
+static inline int accountable_mapping(struct file *file, unsigned int vm_flags)
 {
+        /*
+         * hugetlb has its own accounting separate from the core VM
+         * VM_HUGETLB may not be set yet so we cannot check for that flag.
+         */
+        if (file && is_file_hugepages(file))
+                return 0;
+
         return (vm_flags & (VM_NORESERVE | VM_SHARED | VM_WRITE)) == VM_WRITE;
 }
 
 unsigned long mmap_region(struct file *file, unsigned long addr,
                           unsigned long len, unsigned long flags,
-                          unsigned int vm_flags, unsigned long pgoff,
-                          int accountable)
+                          unsigned int vm_flags, unsigned long pgoff)
 {
         struct mm_struct *mm = current->mm;
         struct vm_area_struct *vma, *prev;
@@ -1128,18 +1130,22 @@ munmap_back:
 
         /*
          * Set 'VM_NORESERVE' if we should not account for the
-         * memory use of this mapping. We only honor MAP_NORESERVE
-         * if we're allowed to overcommit memory.
+         * memory use of this mapping.
          */
-        if ((flags & MAP_NORESERVE) && sysctl_overcommit_memory != OVERCOMMIT_NEVER)
-                vm_flags |= VM_NORESERVE;
-        if (!accountable)
-                vm_flags |= VM_NORESERVE;
+        if ((flags & MAP_NORESERVE)) {
+                /* We honor MAP_NORESERVE if allowed to overcommit */
+                if (sysctl_overcommit_memory != OVERCOMMIT_NEVER)
+                        vm_flags |= VM_NORESERVE;
+
+                /* hugetlb applies strict overcommit unless MAP_NORESERVE */
+                if (file && is_file_hugepages(file))
+                        vm_flags |= VM_NORESERVE;
+        }
 
         /*
          * Private writable mapping: check memory availability
          */
-        if (accountable_mapping(vm_flags)) {
+        if (accountable_mapping(file, vm_flags)) {
                 charged = len >> PAGE_SHIFT;
                 if (security_vm_enough_memory(charged))
                         return -ENOMEM;
@@ -2078,12 +2084,8 @@ void exit_mmap(struct mm_struct *mm)
         unsigned long end;
 
         /* mm's last user has gone, and its about to be pulled down */
-        arch_exit_mmap(mm);
         mmu_notifier_release(mm);
 
-        if (!mm->mmap)  /* Can happen if dup_mmap() received an OOM */
-                return;
-
         if (mm->locked_vm) {
                 vma = mm->mmap;
                 while (vma) {
@@ -2092,7 +2094,13 @@ void exit_mmap(struct mm_struct *mm)
                         vma = vma->vm_next;
                 }
         }
+
+        arch_exit_mmap(mm);
+
         vma = mm->mmap;
+        if (!vma)       /* Can happen if dup_mmap() received an OOM */
+                return;
+
         lru_add_drain();
         flush_cache_mm(mm);
         tlb = tlb_gather_mmu(mm, 1);
diff --git a/mm/mprotect.c b/mm/mprotect.c
index abe2694e13f4..258197b76fb4 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -151,10 +151,11 @@ mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev,
         /*
          * If we make a private mapping writable we increase our commit;
          * but (without finer accounting) cannot reduce our commit if we
-         * make it unwritable again.
+         * make it unwritable again. hugetlb mapping were accounted for
+         * even if read-only so there is no need to account for them here
          */
         if (newflags & VM_WRITE) {
-                if (!(oldflags & (VM_ACCOUNT|VM_WRITE|
+                if (!(oldflags & (VM_ACCOUNT|VM_WRITE|VM_HUGETLB|
                                                 VM_SHARED|VM_NORESERVE))) {
                         charged = nrpages;
                         if (security_vm_enough_memory(charged))
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index b493db7841dc..6106a5c7ed44 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -209,7 +209,7 @@ int dirty_bytes_handler(struct ctl_table *table, int write,
                 struct file *filp, void __user *buffer, size_t *lenp,
                 loff_t *ppos)
 {
-        int old_bytes = vm_dirty_bytes;
+        unsigned long old_bytes = vm_dirty_bytes;
         int ret;
 
         ret = proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos);
@@ -1051,13 +1051,25 @@ continue_unlock:
                                 }
                         }
 
-                        if (wbc->sync_mode == WB_SYNC_NONE) {
-                                wbc->nr_to_write--;
-                                if (wbc->nr_to_write <= 0) {
+                        if (nr_to_write > 0) {
+                                nr_to_write--;
+                                if (nr_to_write == 0 &&
+                                    wbc->sync_mode == WB_SYNC_NONE) {
+                                        /*
+                                         * We stop writing back only if we are
+                                         * not doing integrity sync. In case of
+                                         * integrity sync we have to keep going
+                                         * because someone may be concurrently
+                                         * dirtying pages, and we might have
+                                         * synced a lot of newly appeared dirty
+                                         * pages, but have not synced all of the
+                                         * old dirty pages.
+                                         */
                                         done = 1;
                                         break;
                                 }
                         }
+
                         if (wbc->nonblocking && bdi_write_congested(bdi)) {
                                 wbc->encountered_congestion = 1;
                                 done = 1;
diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c
index 7006a11350c8..ceecfbb143fa 100644
--- a/mm/page_cgroup.c
+++ b/mm/page_cgroup.c
@@ -114,7 +114,8 @@ static int __init_refok init_section_page_cgroup(unsigned long pfn)
                 nid = page_to_nid(pfn_to_page(pfn));
                 table_size = sizeof(struct page_cgroup) * PAGES_PER_SECTION;
                 if (slab_is_available()) {
-                        base = kmalloc_node(table_size, GFP_KERNEL, nid);
+                        base = kmalloc_node(table_size,
+                                        GFP_KERNEL | __GFP_NOWARN, nid);
                         if (!base)
                                 base = vmalloc_node(table_size, nid);
                 } else {
diff --git a/mm/rmap.c b/mm/rmap.c
index ac4af8cffbf9..16521664010d 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1072,7 +1072,8 @@ static int try_to_unmap_file(struct page *page, int unlock, int migration)
         spin_lock(&mapping->i_mmap_lock);
         vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
                 if (MLOCK_PAGES && unlikely(unlock)) {
-                        if (!(vma->vm_flags & VM_LOCKED))
+                        if (!((vma->vm_flags & VM_LOCKED) &&
+                                                page_mapped_in_vma(page, vma)))
                                 continue;       /* must visit all vmas */
                         ret = SWAP_MLOCK;
                 } else {
diff --git a/mm/slub.c b/mm/slub.c
index 6392ae5cc6b1..bdc9abb08a23 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1996,7 +1996,7 @@ static struct kmem_cache_cpu *alloc_kmem_cache_cpu(struct kmem_cache *s,
 static void free_kmem_cache_cpu(struct kmem_cache_cpu *c, int cpu)
 {
         if (c < per_cpu(kmem_cache_cpu, cpu) ||
-                        c > per_cpu(kmem_cache_cpu, cpu) + NR_KMEM_CACHE_CPU) {
+                        c >= per_cpu(kmem_cache_cpu, cpu) + NR_KMEM_CACHE_CPU) {
                 kfree(c);
                 return;
         }