mmap: change do_mas_munmap and do_mas_aligned_munmap() to use vma iterator

Start passing the vma iterator through the mm code.  This will allow for
reuse of the state and cleaner invalidation if necessary.

Link: https://lkml.kernel.org/r/20230120162650.984577-13-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/include/linux/mm.h b/include/linux/mm.h
index b977a90..152a136 100644 (file)
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2905,7 +2905,7 @@ extern unsigned long mmap_region(struct file *file, unsigned long addr,
 extern unsigned long do_mmap(struct file *file, unsigned long addr,
        unsigned long len, unsigned long prot, unsigned long flags,
        unsigned long pgoff, unsigned long *populate, struct list_head *uf);
-extern int do_mas_munmap(struct ma_state *mas, struct mm_struct *mm,
+extern int do_vmi_munmap(struct vma_iterator *vmi, struct mm_struct *mm,
                         unsigned long start, size_t len, struct list_head *uf,
                         bool downgrade);
 extern int do_munmap(struct mm_struct *, unsigned long, size_t,

diff --git a/mm/mmap.c b/mm/mmap.c
index d46a798..5b83023 100644 (file)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2305,8 +2305,8 @@ static inline int munmap_sidetree(struct vm_area_struct *vma,
 }
 
 /*
- * do_mas_align_munmap() - munmap the aligned region from @start to @end.
- * @mas: The maple_state, ideally set up to alter the correct tree location.
+ * do_vmi_align_munmap() - munmap the aligned region from @start to @end.
+ * @vmi: The vma iterator
  * @vma: The starting vm_area_struct
  * @mm: The mm_struct
  * @start: The aligned start address to munmap.
@@ -2317,7 +2317,7 @@ static inline int munmap_sidetree(struct vm_area_struct *vma,
  * If @downgrade is true, check return code for potential release of the lock.
  */
 static int
-do_mas_align_munmap(struct ma_state *mas, struct vm_area_struct *vma,
+do_vmi_align_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma,
                    struct mm_struct *mm, unsigned long start,
                    unsigned long end, struct list_head *uf, bool downgrade)
 {
@@ -2329,7 +2329,6 @@ do_mas_align_munmap(struct ma_state *mas, struct vm_area_struct *vma,
        mt_init_flags(&mt_detach, MT_FLAGS_LOCK_EXTERN);
        mt_set_external_lock(&mt_detach, &mm->mmap_lock);
 
-       mas->last = end - 1;
        /*
         * If we need to split any vma, do it now to save pain later.
         *
@@ -2349,27 +2348,23 @@ do_mas_align_munmap(struct ma_state *mas, struct vm_area_struct *vma,
                if (end < vma->vm_end && mm->map_count >= sysctl_max_map_count)
                        goto map_count_exceeded;
 
-               /*
-                * mas_pause() is not needed since mas->index needs to be set
-                * differently than vma->vm_end anyways.
-                */
                error = __split_vma(mm, vma, start, 0);
                if (error)
                        goto start_split_failed;
 
-               mas_set(mas, start);
-               vma = mas_walk(mas);
+               vma_iter_set(vmi, start);
+               vma = vma_find(vmi, end);
        }
 
-       prev = mas_prev(mas, 0);
+       prev = vma_prev(vmi);
        if (unlikely((!prev)))
-               mas_set(mas, start);
+               vma_iter_set(vmi, start);
 
        /*
         * Detach a range of VMAs from the mm. Using next as a temp variable as
         * it is always overwritten.
         */
-       mas_for_each(mas, next, end - 1) {
+       for_each_vma_range(*vmi, next, end) {
                /* Does it split the end? */
                if (next->vm_end > end) {
                        struct vm_area_struct *split;
@@ -2378,8 +2373,8 @@ do_mas_align_munmap(struct ma_state *mas, struct vm_area_struct *vma,
                        if (error)
                                goto end_split_failed;
 
-                       mas_set(mas, end);
-                       split = mas_prev(mas, 0);
+                       vma_iter_set(vmi, end);
+                       split = vma_prev(vmi);
                        error = munmap_sidetree(split, &mas_detach);
                        if (error)
                                goto munmap_sidetree_failed;
@@ -2401,7 +2396,7 @@ do_mas_align_munmap(struct ma_state *mas, struct vm_area_struct *vma,
        }
 
        if (!next)
-               next = mas_next(mas, ULONG_MAX);
+               next = vma_next(vmi);
 
        if (unlikely(uf)) {
                /*
@@ -2426,10 +2421,10 @@ do_mas_align_munmap(struct ma_state *mas, struct vm_area_struct *vma,
                struct vm_area_struct *vma_mas, *vma_test;
                int test_count = 0;
 
-               mas_set_range(mas, start, end - 1);
+               vma_iter_set(vmi, start);
                rcu_read_lock();
                vma_test = mas_find(&test, end - 1);
-               mas_for_each(mas, vma_mas, end - 1) {
+               for_each_vma_range(*vmi, vma_mas, end) {
                        BUG_ON(vma_mas != vma_test);
                        test_count++;
                        vma_test = mas_next(&test, end - 1);
@@ -2439,8 +2434,8 @@ do_mas_align_munmap(struct ma_state *mas, struct vm_area_struct *vma,
        }
 #endif
        /* Point of no return */
-       mas_set_range(mas, start, end - 1);
-       if (mas_store_gfp(mas, NULL, GFP_KERNEL))
+       vma_iter_set(vmi, start);
+       if (vma_iter_clear_gfp(vmi, start, end, GFP_KERNEL))
                return -ENOMEM;
 
        mm->map_count -= count;
@@ -2478,8 +2473,8 @@ map_count_exceeded:
 }
 
 /*
- * do_mas_munmap() - munmap a given range.
- * @mas: The maple state
+ * do_vmi_munmap() - munmap a given range.
+ * @vmi: The vma iterator
  * @mm: The mm_struct
  * @start: The start address to munmap
  * @len: The length of the range to munmap
@@ -2493,7 +2488,7 @@ map_count_exceeded:
  *
  * Returns: -EINVAL on failure, 1 on success and unlock, 0 otherwise.
  */
-int do_mas_munmap(struct ma_state *mas, struct mm_struct *mm,
+int do_vmi_munmap(struct vma_iterator *vmi, struct mm_struct *mm,
                  unsigned long start, size_t len, struct list_head *uf,
                  bool downgrade)
 {
@@ -2511,11 +2506,11 @@ int do_mas_munmap(struct ma_state *mas, struct mm_struct *mm,
        arch_unmap(mm, start, end);
 
        /* Find the first overlapping VMA */
-       vma = mas_find(mas, end - 1);
+       vma = vma_find(vmi, end);
        if (!vma)
                return 0;
 
-       return do_mas_align_munmap(mas, vma, mm, start, end, uf, downgrade);
+       return do_vmi_align_munmap(vmi, vma, mm, start, end, uf, downgrade);
 }
 
 /* do_munmap() - Wrapper function for non-maple tree aware do_munmap() calls.
@@ -2527,9 +2522,9 @@ int do_mas_munmap(struct ma_state *mas, struct mm_struct *mm,
 int do_munmap(struct mm_struct *mm, unsigned long start, size_t len,
              struct list_head *uf)
 {
-       MA_STATE(mas, &mm->mm_mt, start, start);
+       VMA_ITERATOR(vmi, mm, start);
 
-       return do_mas_munmap(&mas, mm, start, len, uf, false);
+       return do_vmi_munmap(&vmi, mm, start, len, uf, false);
 }
 
 unsigned long mmap_region(struct file *file, unsigned long addr,
@@ -2545,7 +2540,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
        unsigned long merge_start = addr, merge_end = end;
        pgoff_t vm_pgoff;
        int error;
-       MA_STATE(mas, &mm->mm_mt, addr, end - 1);
+       VMA_ITERATOR(vmi, mm, addr);
 
        /* Check against address space limit. */
        if (!may_expand_vm(mm, vm_flags, len >> PAGE_SHIFT)) {
@@ -2563,7 +2558,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
        }
 
        /* Unmap any existing mapping in the area */
-       if (do_mas_munmap(&mas, mm, addr, len, uf, false))
+       if (do_vmi_munmap(&vmi, mm, addr, len, uf, false))
                return -ENOMEM;
 
        /*
@@ -2576,8 +2571,8 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
                vm_flags |= VM_ACCOUNT;
        }
 
-       next = mas_next(&mas, ULONG_MAX);
-       prev = mas_prev(&mas, 0);
+       next = vma_next(&vmi);
+       prev = vma_prev(&vmi);
        if (vm_flags & VM_SPECIAL)
                goto cannot_expand;
 
@@ -2605,13 +2600,11 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
 
        /* Actually expand, if possible */
        if (vma &&
-           !vma_expand(&mas, vma, merge_start, merge_end, vm_pgoff, next)) {
+           !vma_expand(&vmi.mas, vma, merge_start, merge_end, vm_pgoff, next)) {
                khugepaged_enter_vma(vma, vm_flags);
                goto expanded;
        }
 
-       mas.index = addr;
-       mas.last = end - 1;
 cannot_expand:
        /*
         * Determine the object being mapped and call the appropriate
@@ -2650,7 +2643,7 @@ cannot_expand:
                        error = -EINVAL;
                        goto close_and_free_vma;
                }
-               mas_reset(&mas);
+               vma_iter_set(&vmi, addr);
 
                /*
                 * If vm_flags changed after call_mmap(), we should try merge
@@ -2706,7 +2699,7 @@ cannot_expand:
                        goto free_vma;
        }
 
-       if (mas_preallocate(&mas, GFP_KERNEL)) {
+       if (vma_iter_prealloc(&vmi)) {
                error = -ENOMEM;
                if (file)
                        goto close_and_free_vma;
@@ -2719,7 +2712,7 @@ cannot_expand:
        if (vma->vm_file)
                i_mmap_lock_write(vma->vm_file->f_mapping);
 
-       vma_mas_store(vma, &mas);
+       vma_iter_store(&vmi, vma);
        mm->map_count++;
        if (vma->vm_file) {
                if (vma->vm_flags & VM_SHARED)
@@ -2780,7 +2773,7 @@ unmap_and_free_vma:
        vma->vm_file = NULL;
 
        /* Undo any partial mapping done by a device driver. */
-       unmap_region(mm, mas.tree, vma, prev, next, vma->vm_start, vma->vm_end);
+       unmap_region(mm, &mm->mm_mt, vma, prev, next, vma->vm_start, vma->vm_end);
        if (file && (vm_flags & VM_SHARED))
                mapping_unmap_writable(file->f_mapping);
 free_vma:
@@ -2797,12 +2790,12 @@ static int __vm_munmap(unsigned long start, size_t len, bool downgrade)
        int ret;
        struct mm_struct *mm = current->mm;
        LIST_HEAD(uf);
-       MA_STATE(mas, &mm->mm_mt, start, start);
+       VMA_ITERATOR(vmi, mm, start);
 
        if (mmap_write_lock_killable(mm))
                return -EINTR;
 
-       ret = do_mas_munmap(&mas, mm, start, len, &uf, downgrade);
+       ret = do_vmi_munmap(&vmi, mm, start, len, &uf, downgrade);
        /*
         * Returning 1 indicates mmap_lock is downgraded.
         * But 1 is not legal return value of vm_munmap() and munmap(), reset
@@ -2934,7 +2927,7 @@ static int do_brk_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma,
        int ret;
 
        arch_unmap(mm, newbrk, oldbrk);
-       ret = do_mas_align_munmap(&vmi->mas, vma, mm, newbrk, oldbrk, uf, true);
+       ret = do_vmi_align_munmap(vmi, vma, mm, newbrk, oldbrk, uf, true);
        validate_mm_mt(mm);
        return ret;
 }
@@ -3057,7 +3050,7 @@ int vm_brk_flags(unsigned long addr, unsigned long request, unsigned long flags)
        if (ret)
                goto limits_failed;
 
-       ret = do_mas_munmap(&vmi.mas, mm, addr, len, &uf, 0);
+       ret = do_vmi_munmap(&vmi, mm, addr, len, &uf, 0);
        if (ret)
                goto munmap_failed;
 

diff --git a/mm/mremap.c b/mm/mremap.c
index 05f90f4..3cc64c3 100644 (file)
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -978,14 +978,14 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
        /*
         * Always allow a shrinking remap: that just unmaps
         * the unnecessary pages..
-        * do_mas_munmap does all the needed commit accounting, and
+        * do_vmi_munmap does all the needed commit accounting, and
         * downgrades mmap_lock to read if so directed.
         */
        if (old_len >= new_len) {
                int retval;
-               MA_STATE(mas, &mm->mm_mt, addr + new_len, addr + new_len);
+               VMA_ITERATOR(vmi, mm, addr + new_len);
 
-               retval = do_mas_munmap(&mas, mm, addr + new_len,
+               retval = do_vmi_munmap(&vmi, mm, addr + new_len,
                                       old_len - new_len, &uf_unmap, true);
                /* Returning 1 indicates mmap_lock is downgraded to read. */
                if (retval == 1) {