mm/mmap.c: pass in mapping to __vma_link_file()

__vma_link_file() resolves the mapping from the file, if there is one.
Pass through the mapping and check the vm_file externally since most
places already have the required information and check of vm_file.

Link: https://lkml.kernel.org/r/20220504011345.662299-54-Liam.Howlett@oracle.com
Link: https://lkml.kernel.org/r/20220621204632.3370049-70-Liam.Howlett@oracle.com
Link: https://lkml.kernel.org/r/20220720021727.17018-70-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Howells <dhowells@redhat.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hulk Robot <hulkci@huawei.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/mmap.c b/mm/mmap.c
index 8070792525e5a122a82bf52435b5f436d6832626..8fa9465f3999b4b029429719436fa40f8ca3d38a 100644 (file)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -199,6 +199,7 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)
        if (brk < min_brk)
                goto out;
 
+
        /*
         * Check against rlimit here. If this check is done later after the test
         * of oldbrk with newbrk then it can escape the test and let the data
@@ -275,7 +276,6 @@ success:
        if (populate)
                mm_populate(oldbrk, newbrk - oldbrk);
        return brk;
-
 out:
        mmap_write_unlock(mm);
        return origbrk;
@@ -407,21 +407,15 @@ static unsigned long count_vma_pages_range(struct mm_struct *mm,
        return nr_pages;
 }
 
-static void __vma_link_file(struct vm_area_struct *vma)
+static void __vma_link_file(struct vm_area_struct *vma,
+                           struct address_space *mapping)
 {
-       struct file *file;
-
-       file = vma->vm_file;
-       if (file) {
-               struct address_space *mapping = file->f_mapping;
-
-               if (vma->vm_flags & VM_SHARED)
-                       mapping_allow_writable(mapping);
+       if (vma->vm_flags & VM_SHARED)
+               mapping_allow_writable(mapping);
 
-               flush_dcache_mmap_lock(mapping);
-               vma_interval_tree_insert(vma, &mapping->i_mmap);
-               flush_dcache_mmap_unlock(mapping);
-       }
+       flush_dcache_mmap_lock(mapping);
+       vma_interval_tree_insert(vma, &mapping->i_mmap);
+       flush_dcache_mmap_unlock(mapping);
 }
 
 /*
@@ -488,10 +482,11 @@ static int vma_link(struct mm_struct *mm, struct vm_area_struct *vma)
        }
 
        vma_mas_store(vma, &mas);
-       __vma_link_file(vma);
 
-       if (mapping)
+       if (mapping) {
+               __vma_link_file(vma, mapping);
                i_mmap_unlock_write(mapping);
+       }
 
        mm->map_count++;
        validate_mm(mm);
@@ -730,14 +725,14 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start,
                        uprobe_munmap(next, next->vm_start, next->vm_end);
 
                i_mmap_lock_write(mapping);
-               if (insert) {
+               if (insert && insert->vm_file) {
                        /*
                         * Put into interval tree now, so instantiated pages
                         * are visible to arm/parisc __flush_dcache_page
                         * throughout; but we cannot insert into address
                         * space until vma start or end is updated.
                         */
-                       __vma_link_file(insert);
+                       __vma_link_file(insert, insert->vm_file->f_mapping);
                }
        }
 
@@ -2933,6 +2928,7 @@ static int do_brk_flags(struct ma_state *mas, struct vm_area_struct *vma,
        struct mm_struct *mm = current->mm;
 
        validate_mm_mt(mm);
+
        /*
         * Check against address space limits by the changed size
         * Note: This happens *after* clearing old mappings in some code paths.
@@ -2990,6 +2986,7 @@ static int do_brk_flags(struct ma_state *mas, struct vm_area_struct *vma,
                goto mas_store_fail;
 
        mm->map_count++;
+
 out:
        perf_event_mmap(vma);
        mm->total_vm += len >> PAGE_SHIFT;