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-rw-r--r--include/linux/mm.h4
-rw-r--r--mm/filemap.c9
-rw-r--r--mm/memory.c17
3 files changed, 25 insertions, 5 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h
index d396753c0577..ec9d4559514d 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -236,10 +236,14 @@ extern pgprot_t protection_map[16];
* ->fault function. The vma's ->fault is responsible for returning a bitmask
* of VM_FAULT_xxx flags that give details about how the fault was handled.
*
+ * MM layer fills up gfp_mask for page allocations but fault handler might
+ * alter it if its implementation requires a different allocation context.
+ *
* pgoff should be used in favour of virtual_address, if possible.
*/
struct vm_fault {
unsigned int flags; /* FAULT_FLAG_xxx flags */
+ gfp_t gfp_mask; /* gfp mask to be used for allocations */
pgoff_t pgoff; /* Logical page offset based on vma */
void __user *virtual_address; /* Faulting virtual address */
diff --git a/mm/filemap.c b/mm/filemap.c
index 1bb007624b53..ff42d31c891a 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1812,19 +1812,18 @@ EXPORT_SYMBOL(generic_file_read_iter);
* This adds the requested page to the page cache if it isn't already there,
* and schedules an I/O to read in its contents from disk.
*/
-static int page_cache_read(struct file *file, pgoff_t offset)
+static int page_cache_read(struct file *file, pgoff_t offset, gfp_t gfp_mask)
{
struct address_space *mapping = file->f_mapping;
struct page *page;
int ret;
do {
- page = page_cache_alloc_cold(mapping);
+ page = __page_cache_alloc(gfp_mask|__GFP_COLD);
if (!page)
return -ENOMEM;
- ret = add_to_page_cache_lru(page, mapping, offset,
- mapping_gfp_constraint(mapping, GFP_KERNEL));
+ ret = add_to_page_cache_lru(page, mapping, offset, gfp_mask & GFP_KERNEL);
if (ret == 0)
ret = mapping->a_ops->readpage(file, page);
else if (ret == -EEXIST)
@@ -2005,7 +2004,7 @@ no_cached_page:
* We're only likely to ever get here if MADV_RANDOM is in
* effect.
*/
- error = page_cache_read(file, offset);
+ error = page_cache_read(file, offset, vmf->gfp_mask);
/*
* The page we want has now been added to the page cache.
diff --git a/mm/memory.c b/mm/memory.c
index f7026c035940..d4e4d37c1989 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1938,6 +1938,20 @@ static inline void cow_user_page(struct page *dst, struct page *src, unsigned lo
copy_user_highpage(dst, src, va, vma);
}
+static gfp_t __get_fault_gfp_mask(struct vm_area_struct *vma)
+{
+ struct file *vm_file = vma->vm_file;
+
+ if (vm_file)
+ return mapping_gfp_mask(vm_file->f_mapping) | __GFP_FS | __GFP_IO;
+
+ /*
+ * Special mappings (e.g. VDSO) do not have any file so fake
+ * a default GFP_KERNEL for them.
+ */
+ return GFP_KERNEL;
+}
+
/*
* Notify the address space that the page is about to become writable so that
* it can prohibit this or wait for the page to get into an appropriate state.
@@ -1953,6 +1967,7 @@ static int do_page_mkwrite(struct vm_area_struct *vma, struct page *page,
vmf.virtual_address = (void __user *)(address & PAGE_MASK);
vmf.pgoff = page->index;
vmf.flags = FAULT_FLAG_WRITE|FAULT_FLAG_MKWRITE;
+ vmf.gfp_mask = __get_fault_gfp_mask(vma);
vmf.page = page;
vmf.cow_page = NULL;
@@ -2757,6 +2772,7 @@ static int __do_fault(struct vm_area_struct *vma, unsigned long address,
vmf.pgoff = pgoff;
vmf.flags = flags;
vmf.page = NULL;
+ vmf.gfp_mask = __get_fault_gfp_mask(vma);
vmf.cow_page = cow_page;
ret = vma->vm_ops->fault(vma, &vmf);
@@ -2923,6 +2939,7 @@ static void do_fault_around(struct vm_area_struct *vma, unsigned long address,
vmf.pgoff = pgoff;
vmf.max_pgoff = max_pgoff;
vmf.flags = flags;
+ vmf.gfp_mask = __get_fault_gfp_mask(vma);
vma->vm_ops->map_pages(vma, &vmf);
}