]> git.karo-electronics.de Git - karo-tx-linux.git/blobdiff - mm/shmem.c
ipv6: check for ip6_null_entry in __ip6_del_rt_siblings()
[karo-tx-linux.git] / mm / shmem.c
index 3a7587a0314dc73fb4929a824a74f9b8948ea502..a26649a6633fbfd8e81296d27bdfe8c812079cf1 100644 (file)
@@ -34,6 +34,8 @@
 #include <linux/uio.h>
 #include <linux/khugepaged.h>
 
+#include <asm/tlbflush.h> /* for arch/microblaze update_mmu_cache() */
+
 static struct vfsmount *shm_mnt;
 
 #ifdef CONFIG_SHMEM
@@ -70,6 +72,8 @@ static struct vfsmount *shm_mnt;
 #include <linux/syscalls.h>
 #include <linux/fcntl.h>
 #include <uapi/linux/memfd.h>
+#include <linux/userfaultfd_k.h>
+#include <linux/rmap.h>
 
 #include <linux/uaccess.h>
 #include <asm/pgtable.h>
@@ -115,13 +119,14 @@ static int shmem_replace_page(struct page **pagep, gfp_t gfp,
                                struct shmem_inode_info *info, pgoff_t index);
 static int shmem_getpage_gfp(struct inode *inode, pgoff_t index,
                struct page **pagep, enum sgp_type sgp,
-               gfp_t gfp, struct mm_struct *fault_mm, int *fault_type);
+               gfp_t gfp, struct vm_area_struct *vma,
+               struct vm_fault *vmf, int *fault_type);
 
 int shmem_getpage(struct inode *inode, pgoff_t index,
                struct page **pagep, enum sgp_type sgp)
 {
        return shmem_getpage_gfp(inode, index, pagep, sgp,
-               mapping_gfp_mask(inode->i_mapping), NULL, NULL);
+               mapping_gfp_mask(inode->i_mapping), NULL, NULL, NULL);
 }
 
 static inline struct shmem_sb_info *SHMEM_SB(struct super_block *sb)
@@ -190,6 +195,11 @@ static const struct inode_operations shmem_special_inode_operations;
 static const struct vm_operations_struct shmem_vm_ops;
 static struct file_system_type shmem_fs_type;
 
+bool vma_is_shmem(struct vm_area_struct *vma)
+{
+       return vma->vm_ops == &shmem_vm_ops;
+}
+
 static LIST_HEAD(shmem_swaplist);
 static DEFINE_MUTEX(shmem_swaplist_mutex);
 
@@ -1570,7 +1580,7 @@ static int shmem_replace_page(struct page **pagep, gfp_t gfp,
  */
 static int shmem_getpage_gfp(struct inode *inode, pgoff_t index,
        struct page **pagep, enum sgp_type sgp, gfp_t gfp,
-       struct mm_struct *fault_mm, int *fault_type)
+       struct vm_area_struct *vma, struct vm_fault *vmf, int *fault_type)
 {
        struct address_space *mapping = inode->i_mapping;
        struct shmem_inode_info *info = SHMEM_I(inode);
@@ -1624,7 +1634,7 @@ repeat:
         * bring it back from swap or allocate.
         */
        sbinfo = SHMEM_SB(inode->i_sb);
-       charge_mm = fault_mm ? : current->mm;
+       charge_mm = vma ? vma->vm_mm : current->mm;
 
        if (swap.val) {
                /* Look it up and read it in.. */
@@ -1634,7 +1644,8 @@ repeat:
                        if (fault_type) {
                                *fault_type |= VM_FAULT_MAJOR;
                                count_vm_event(PGMAJFAULT);
-                               mem_cgroup_count_vm_event(fault_mm, PGMAJFAULT);
+                               mem_cgroup_count_vm_event(charge_mm,
+                                                         PGMAJFAULT);
                        }
                        /* Here we actually start the io */
                        page = shmem_swapin(swap, gfp, info, index);
@@ -1703,6 +1714,11 @@ repeat:
                swap_free(swap);
 
        } else {
+               if (vma && userfaultfd_missing(vma)) {
+                       *fault_type = handle_userfault(vmf, VM_UFFD_MISSING);
+                       return 0;
+               }
+
                /* shmem_symlink() */
                if (mapping->a_ops != &shmem_aops)
                        goto alloc_nohuge;
@@ -1892,8 +1908,9 @@ static int synchronous_wake_function(wait_queue_t *wait, unsigned mode, int sync
        return ret;
 }
 
-static int shmem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+static int shmem_fault(struct vm_fault *vmf)
 {
+       struct vm_area_struct *vma = vmf->vma;
        struct inode *inode = file_inode(vma->vm_file);
        gfp_t gfp = mapping_gfp_mask(inode->i_mapping);
        enum sgp_type sgp;
@@ -1965,7 +1982,7 @@ static int shmem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
                sgp = SGP_NOHUGE;
 
        error = shmem_getpage_gfp(inode, vmf->pgoff, &vmf->page, sgp,
-                                 gfp, vma->vm_mm, &ret);
+                                 gfp, vma, vmf, &ret);
        if (error)
                return ((error == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS);
        return ret;
@@ -2175,10 +2192,123 @@ static struct inode *shmem_get_inode(struct super_block *sb, const struct inode
 
 bool shmem_mapping(struct address_space *mapping)
 {
-       if (!mapping->host)
-               return false;
+       return mapping->a_ops == &shmem_aops;
+}
 
-       return mapping->host->i_sb->s_op == &shmem_ops;
+int shmem_mcopy_atomic_pte(struct mm_struct *dst_mm,
+                          pmd_t *dst_pmd,
+                          struct vm_area_struct *dst_vma,
+                          unsigned long dst_addr,
+                          unsigned long src_addr,
+                          struct page **pagep)
+{
+       struct inode *inode = file_inode(dst_vma->vm_file);
+       struct shmem_inode_info *info = SHMEM_I(inode);
+       struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb);
+       struct address_space *mapping = inode->i_mapping;
+       gfp_t gfp = mapping_gfp_mask(mapping);
+       pgoff_t pgoff = linear_page_index(dst_vma, dst_addr);
+       struct mem_cgroup *memcg;
+       spinlock_t *ptl;
+       void *page_kaddr;
+       struct page *page;
+       pte_t _dst_pte, *dst_pte;
+       int ret;
+
+       ret = -ENOMEM;
+       if (shmem_acct_block(info->flags, 1))
+               goto out;
+       if (sbinfo->max_blocks) {
+               if (percpu_counter_compare(&sbinfo->used_blocks,
+                                          sbinfo->max_blocks) >= 0)
+                       goto out_unacct_blocks;
+               percpu_counter_inc(&sbinfo->used_blocks);
+       }
+
+       if (!*pagep) {
+               page = shmem_alloc_page(gfp, info, pgoff);
+               if (!page)
+                       goto out_dec_used_blocks;
+
+               page_kaddr = kmap_atomic(page);
+               ret = copy_from_user(page_kaddr, (const void __user *)src_addr,
+                                    PAGE_SIZE);
+               kunmap_atomic(page_kaddr);
+
+               /* fallback to copy_from_user outside mmap_sem */
+               if (unlikely(ret)) {
+                       *pagep = page;
+                       if (sbinfo->max_blocks)
+                               percpu_counter_add(&sbinfo->used_blocks, -1);
+                       shmem_unacct_blocks(info->flags, 1);
+                       /* don't free the page */
+                       return -EFAULT;
+               }
+       } else {
+               page = *pagep;
+               *pagep = NULL;
+       }
+
+       VM_BUG_ON(PageLocked(page) || PageSwapBacked(page));
+       __SetPageLocked(page);
+       __SetPageSwapBacked(page);
+       __SetPageUptodate(page);
+
+       ret = mem_cgroup_try_charge(page, dst_mm, gfp, &memcg, false);
+       if (ret)
+               goto out_release;
+
+       ret = radix_tree_maybe_preload(gfp & GFP_RECLAIM_MASK);
+       if (!ret) {
+               ret = shmem_add_to_page_cache(page, mapping, pgoff, NULL);
+               radix_tree_preload_end();
+       }
+       if (ret)
+               goto out_release_uncharge;
+
+       mem_cgroup_commit_charge(page, memcg, false, false);
+
+       _dst_pte = mk_pte(page, dst_vma->vm_page_prot);
+       if (dst_vma->vm_flags & VM_WRITE)
+               _dst_pte = pte_mkwrite(pte_mkdirty(_dst_pte));
+
+       ret = -EEXIST;
+       dst_pte = pte_offset_map_lock(dst_mm, dst_pmd, dst_addr, &ptl);
+       if (!pte_none(*dst_pte))
+               goto out_release_uncharge_unlock;
+
+       lru_cache_add_anon(page);
+
+       spin_lock(&info->lock);
+       info->alloced++;
+       inode->i_blocks += BLOCKS_PER_PAGE;
+       shmem_recalc_inode(inode);
+       spin_unlock(&info->lock);
+
+       inc_mm_counter(dst_mm, mm_counter_file(page));
+       page_add_file_rmap(page, false);
+       set_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte);
+
+       /* No need to invalidate - it was non-present before */
+       update_mmu_cache(dst_vma, dst_addr, dst_pte);
+       unlock_page(page);
+       pte_unmap_unlock(dst_pte, ptl);
+       ret = 0;
+out:
+       return ret;
+out_release_uncharge_unlock:
+       pte_unmap_unlock(dst_pte, ptl);
+out_release_uncharge:
+       mem_cgroup_cancel_charge(page, memcg, false);
+out_release:
+       unlock_page(page);
+       put_page(page);
+out_dec_used_blocks:
+       if (sbinfo->max_blocks)
+               percpu_counter_add(&sbinfo->used_blocks, -1);
+out_unacct_blocks:
+       shmem_unacct_blocks(info->flags, 1);
+       goto out;
 }
 
 #ifdef CONFIG_TMPFS
@@ -2201,7 +2331,7 @@ shmem_write_begin(struct file *file, struct address_space *mapping,
        pgoff_t index = pos >> PAGE_SHIFT;
 
        /* i_mutex is held by caller */
-       if (unlikely(info->seals)) {
+       if (unlikely(info->seals & (F_SEAL_WRITE | F_SEAL_GROW))) {
                if (info->seals & F_SEAL_WRITE)
                        return -EPERM;
                if ((info->seals & F_SEAL_GROW) && pos + len > inode->i_size)
@@ -4140,7 +4270,7 @@ struct page *shmem_read_mapping_page_gfp(struct address_space *mapping,
 
        BUG_ON(mapping->a_ops != &shmem_aops);
        error = shmem_getpage_gfp(inode, index, &page, SGP_CACHE,
-                                 gfp, NULL, NULL);
+                                 gfp, NULL, NULL, NULL);
        if (error)
                page = ERR_PTR(error);
        else