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mm: switch vma_merge(), split_vma(), and __split_vma to vma iterator
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Drop the vmi_* functions and transition all users to use the vma iterator
directly.

Link: https://lkml.kernel.org/r/20230120162650.984577-30-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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@howlett @akpm00
howlett authored and akpm00 committed Feb 10, 2023
1 parent 07f1bc5 commit 9760ebf
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Showing 9 changed files with 55 additions and 98 deletions.
14 changes: 7 additions & 7 deletions fs/userfaultfd.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -909,7 +909,7 @@ static int userfaultfd_release(struct inode *inode, struct file *file)
continue;
}
new_flags = vma->vm_flags & ~__VM_UFFD_FLAGS;
prev = vmi_vma_merge(&vmi, mm, prev, vma->vm_start, vma->vm_end,
prev = vma_merge(&vmi, mm, prev, vma->vm_start, vma->vm_end,
new_flags, vma->anon_vma,
vma->vm_file, vma->vm_pgoff,
vma_policy(vma),
Expand Down Expand Up @@ -1452,7 +1452,7 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx,
vma_end = min(end, vma->vm_end);

new_flags = (vma->vm_flags & ~__VM_UFFD_FLAGS) | vm_flags;
prev = vmi_vma_merge(&vmi, mm, prev, start, vma_end, new_flags,
prev = vma_merge(&vmi, mm, prev, start, vma_end, new_flags,
vma->anon_vma, vma->vm_file, vma->vm_pgoff,
vma_policy(vma),
((struct vm_userfaultfd_ctx){ ctx }),
Expand All @@ -1463,12 +1463,12 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx,
goto next;
}
if (vma->vm_start < start) {
ret = vmi_split_vma(&vmi, mm, vma, start, 1);
ret = split_vma(&vmi, vma, start, 1);
if (ret)
break;
}
if (vma->vm_end > end) {
ret = vmi_split_vma(&vmi, mm, vma, end, 0);
ret = split_vma(&vmi, vma, end, 0);
if (ret)
break;
}
Expand Down Expand Up @@ -1632,7 +1632,7 @@ static int userfaultfd_unregister(struct userfaultfd_ctx *ctx,
uffd_wp_range(mm, vma, start, vma_end - start, false);

new_flags = vma->vm_flags & ~__VM_UFFD_FLAGS;
prev = vmi_vma_merge(&vmi, mm, prev, start, vma_end, new_flags,
prev = vma_merge(&vmi, mm, prev, start, vma_end, new_flags,
vma->anon_vma, vma->vm_file, vma->vm_pgoff,
vma_policy(vma),
NULL_VM_UFFD_CTX, anon_vma_name(vma));
Expand All @@ -1641,12 +1641,12 @@ static int userfaultfd_unregister(struct userfaultfd_ctx *ctx,
goto next;
}
if (vma->vm_start < start) {
ret = vmi_split_vma(&vmi, mm, vma, start, 1);
ret = split_vma(&vmi, vma, start, 1);
if (ret)
break;
}
if (vma->vm_end > end) {
ret = vmi_split_vma(&vmi, mm, vma, end, 0);
ret = split_vma(&vmi, vma, end, 0);
if (ret)
break;
}
Expand Down
18 changes: 5 additions & 13 deletions include/linux/mm.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2839,24 +2839,16 @@ static inline int vma_adjust(struct vm_area_struct *vma, unsigned long start,
{
return __vma_adjust(vma, start, end, pgoff, insert, NULL);
}
extern struct vm_area_struct *vma_merge(struct mm_struct *,
struct vm_area_struct *prev, unsigned long addr, unsigned long end,
unsigned long vm_flags, struct anon_vma *, struct file *, pgoff_t,
struct mempolicy *, struct vm_userfaultfd_ctx, struct anon_vma_name *);
extern struct vm_area_struct *vmi_vma_merge(struct vma_iterator *vmi,
extern struct vm_area_struct *vma_merge(struct vma_iterator *vmi,
struct mm_struct *, struct vm_area_struct *prev, unsigned long addr,
unsigned long end, unsigned long vm_flags, struct anon_vma *,
struct file *, pgoff_t, struct mempolicy *, struct vm_userfaultfd_ctx,
struct anon_vma_name *);
extern struct anon_vma *find_mergeable_anon_vma(struct vm_area_struct *);
extern int __split_vma(struct mm_struct *, struct vm_area_struct *,
unsigned long addr, int new_below);
extern int vmi__split_vma(struct vma_iterator *vmi, struct mm_struct *,
struct vm_area_struct *, unsigned long addr, int new_below);
extern int split_vma(struct mm_struct *, struct vm_area_struct *,
unsigned long addr, int new_below);
extern int vmi_split_vma(struct vma_iterator *vmi, struct mm_struct *,
struct vm_area_struct *, unsigned long addr, int new_below);
extern int __split_vma(struct vma_iterator *vmi, struct vm_area_struct *,
unsigned long addr, int new_below);
extern int split_vma(struct vma_iterator *vmi, struct vm_area_struct *,
unsigned long addr, int new_below);
extern int insert_vm_struct(struct mm_struct *, struct vm_area_struct *);
extern void unlink_file_vma(struct vm_area_struct *);
extern struct vm_area_struct *copy_vma(struct vm_area_struct **,
Expand Down
6 changes: 3 additions & 3 deletions mm/madvise.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -150,7 +150,7 @@ static int madvise_update_vma(struct vm_area_struct *vma,
}

pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
*prev = vmi_vma_merge(&vmi, mm, *prev, start, end, new_flags,
*prev = vma_merge(&vmi, mm, *prev, start, end, new_flags,
vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma),
vma->vm_userfaultfd_ctx, anon_name);
if (*prev) {
Expand All @@ -163,15 +163,15 @@ static int madvise_update_vma(struct vm_area_struct *vma,
if (start != vma->vm_start) {
if (unlikely(mm->map_count >= sysctl_max_map_count))
return -ENOMEM;
error = vmi__split_vma(&vmi, mm, vma, start, 1);
error = __split_vma(&vmi, vma, start, 1);
if (error)
return error;
}

if (end != vma->vm_end) {
if (unlikely(mm->map_count >= sysctl_max_map_count))
return -ENOMEM;
error = vmi__split_vma(&vmi, mm, vma, end, 0);
error = __split_vma(&vmi, vma, end, 0);
if (error)
return error;
}
Expand Down
6 changes: 3 additions & 3 deletions mm/mempolicy.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -810,7 +810,7 @@ static int mbind_range(struct mm_struct *mm, unsigned long start,

pgoff = vma->vm_pgoff +
((vmstart - vma->vm_start) >> PAGE_SHIFT);
prev = vmi_vma_merge(&vmi, mm, prev, vmstart, vmend, vma->vm_flags,
prev = vma_merge(&vmi, mm, prev, vmstart, vmend, vma->vm_flags,
vma->anon_vma, vma->vm_file, pgoff,
new_pol, vma->vm_userfaultfd_ctx,
anon_vma_name(vma));
Expand All @@ -819,12 +819,12 @@ static int mbind_range(struct mm_struct *mm, unsigned long start,
goto replace;
}
if (vma->vm_start != vmstart) {
err = vmi_split_vma(&vmi, vma->vm_mm, vma, vmstart, 1);
err = split_vma(&vmi, vma, vmstart, 1);
if (err)
goto out;
}
if (vma->vm_end != vmend) {
err = vmi_split_vma(&vmi, vma->vm_mm, vma, vmend, 0);
err = split_vma(&vmi, vma, vmend, 0);
if (err)
goto out;
}
Expand Down
6 changes: 3 additions & 3 deletions mm/mlock.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -418,7 +418,7 @@ static int mlock_fixup(struct vma_iterator *vmi, struct vm_area_struct *vma,
goto out;

pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
*prev = vmi_vma_merge(vmi, mm, *prev, start, end, newflags,
*prev = vma_merge(vmi, mm, *prev, start, end, newflags,
vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma),
vma->vm_userfaultfd_ctx, anon_vma_name(vma));
if (*prev) {
Expand All @@ -427,13 +427,13 @@ static int mlock_fixup(struct vma_iterator *vmi, struct vm_area_struct *vma,
}

if (start != vma->vm_start) {
ret = vmi_split_vma(vmi, mm, vma, start, 1);
ret = split_vma(vmi, vma, start, 1);
if (ret)
goto out;
}

if (end != vma->vm_end) {
ret = vmi_split_vma(vmi, mm, vma, end, 0);
ret = split_vma(vmi, vma, end, 0);
if (ret)
goto out;
}
Expand Down
79 changes: 22 additions & 57 deletions mm/mmap.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1010,7 +1010,7 @@ can_vma_merge_after(struct vm_area_struct *vma, unsigned long vm_flags,
* parameter) may establish ptes with the wrong permissions of NNNN
* instead of the right permissions of XXXX.
*/
struct vm_area_struct *vma_merge(struct mm_struct *mm,
struct vm_area_struct *vma_merge(struct vma_iterator *vmi, struct mm_struct *mm,
struct vm_area_struct *prev, unsigned long addr,
unsigned long end, unsigned long vm_flags,
struct anon_vma *anon_vma, struct file *file,
Expand All @@ -1019,7 +1019,7 @@ struct vm_area_struct *vma_merge(struct mm_struct *mm,
struct anon_vma_name *anon_name)
{
pgoff_t pglen = (end - addr) >> PAGE_SHIFT;
struct vm_area_struct *mid, *next, *res;
struct vm_area_struct *mid, *next, *res = NULL;
int err = -1;
bool merge_prev = false;
bool merge_next = false;
Expand Down Expand Up @@ -1085,26 +1085,11 @@ struct vm_area_struct *vma_merge(struct mm_struct *mm,
if (err)
return NULL;
khugepaged_enter_vma(res, vm_flags);
return res;
}

struct vm_area_struct *vmi_vma_merge(struct vma_iterator *vmi,
struct mm_struct *mm,
struct vm_area_struct *prev, unsigned long addr,
unsigned long end, unsigned long vm_flags,
struct anon_vma *anon_vma, struct file *file,
pgoff_t pgoff, struct mempolicy *policy,
struct vm_userfaultfd_ctx vm_userfaultfd_ctx,
struct anon_vma_name *anon_name)
{
struct vm_area_struct *tmp;

tmp = vma_merge(mm, prev, addr, end, vm_flags, anon_vma, file, pgoff,
policy, vm_userfaultfd_ctx, anon_name);
if (tmp)
if (res)
vma_iter_set(vmi, end);

return tmp;
return res;
}

/*
Expand Down Expand Up @@ -2228,12 +2213,14 @@ static void unmap_region(struct mm_struct *mm, struct maple_tree *mt,
* __split_vma() bypasses sysctl_max_map_count checking. We use this where it
* has already been checked or doesn't make sense to fail.
*/
int __split_vma(struct mm_struct *mm, struct vm_area_struct *vma,
int __split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma,
unsigned long addr, int new_below)
{
struct vm_area_struct *new;
int err;
validate_mm_mt(mm);
unsigned long end = vma->vm_end;

validate_mm_mt(vma->vm_mm);

if (vma->vm_ops && vma->vm_ops->may_split) {
err = vma->vm_ops->may_split(vma, addr);
Expand Down Expand Up @@ -2273,8 +2260,10 @@ int __split_vma(struct mm_struct *mm, struct vm_area_struct *vma,
err = vma_adjust(vma, vma->vm_start, addr, vma->vm_pgoff, new);

/* Success. */
if (!err)
if (!err) {
vma_iter_set(vmi, end);
return 0;
}

/* Avoid vm accounting in close() operation */
new->vm_start = new->vm_end;
Expand All @@ -2289,46 +2278,21 @@ int __split_vma(struct mm_struct *mm, struct vm_area_struct *vma,
mpol_put(vma_policy(new));
out_free_vma:
vm_area_free(new);
validate_mm_mt(mm);
validate_mm_mt(vma->vm_mm);
return err;
}
int vmi__split_vma(struct vma_iterator *vmi, struct mm_struct *mm,
struct vm_area_struct *vma, unsigned long addr, int new_below)
{
int ret;
unsigned long end = vma->vm_end;

ret = __split_vma(mm, vma, addr, new_below);
if (!ret)
vma_iter_set(vmi, end);

return ret;
}

/*
* Split a vma into two pieces at address 'addr', a new vma is allocated
* either for the first part or the tail.
*/
int split_vma(struct mm_struct *mm, struct vm_area_struct *vma,
int split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma,
unsigned long addr, int new_below)
{
if (mm->map_count >= sysctl_max_map_count)
if (vma->vm_mm->map_count >= sysctl_max_map_count)
return -ENOMEM;

return __split_vma(mm, vma, addr, new_below);
}

int vmi_split_vma(struct vma_iterator *vmi, struct mm_struct *mm,
struct vm_area_struct *vma, unsigned long addr, int new_below)
{
int ret;
unsigned long end = vma->vm_end;

ret = split_vma(mm, vma, addr, new_below);
if (!ret)
vma_iter_set(vmi, end);

return ret;
return __split_vma(vmi, vma, addr, new_below);
}

static inline int munmap_sidetree(struct vm_area_struct *vma,
Expand Down Expand Up @@ -2388,7 +2352,7 @@ do_vmi_align_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma,
if (end < vma->vm_end && mm->map_count >= sysctl_max_map_count)
goto map_count_exceeded;

error = vmi__split_vma(vmi, mm, vma, start, 0);
error = __split_vma(vmi, vma, start, 0);
if (error)
goto start_split_failed;

Expand All @@ -2409,7 +2373,7 @@ do_vmi_align_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma,
if (next->vm_end > end) {
struct vm_area_struct *split;

error = vmi__split_vma(vmi, mm, next, end, 1);
error = __split_vma(vmi, next, end, 1);
if (error)
goto end_split_failed;

Expand Down Expand Up @@ -2690,9 +2654,10 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
* vma again as we may succeed this time.
*/
if (unlikely(vm_flags != vma->vm_flags && prev)) {
merge = vmi_vma_merge(&vmi, mm, prev, vma->vm_start,
vma->vm_end, vma->vm_flags, NULL, vma->vm_file,
vma->vm_pgoff, NULL, NULL_VM_UFFD_CTX, NULL);
merge = vma_merge(&vmi, mm, prev, vma->vm_start,
vma->vm_end, vma->vm_flags, NULL,
vma->vm_file, vma->vm_pgoff, NULL,
NULL_VM_UFFD_CTX, NULL);
if (merge) {
/*
* ->mmap() can change vma->vm_file and fput
Expand Down Expand Up @@ -3249,7 +3214,7 @@ struct vm_area_struct *copy_vma(struct vm_area_struct **vmap,
if (new_vma && new_vma->vm_start < addr + len)
return NULL; /* should never get here */

new_vma = vmi_vma_merge(&vmi, mm, prev, addr, addr + len, vma->vm_flags,
new_vma = vma_merge(&vmi, mm, prev, addr, addr + len, vma->vm_flags,
vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma),
vma->vm_userfaultfd_ctx, anon_vma_name(vma));
if (new_vma) {
Expand Down
6 changes: 3 additions & 3 deletions mm/mprotect.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -642,7 +642,7 @@ mprotect_fixup(struct vma_iterator *vmi, struct mmu_gather *tlb,
* First try to merge with previous and/or next vma.
*/
pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
*pprev = vmi_vma_merge(vmi, mm, *pprev, start, end, newflags,
*pprev = vma_merge(vmi, mm, *pprev, start, end, newflags,
vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma),
vma->vm_userfaultfd_ctx, anon_vma_name(vma));
if (*pprev) {
Expand All @@ -654,13 +654,13 @@ mprotect_fixup(struct vma_iterator *vmi, struct mmu_gather *tlb,
*pprev = vma;

if (start != vma->vm_start) {
error = vmi_split_vma(vmi, mm, vma, start, 1);
error = split_vma(vmi, vma, start, 1);
if (error)
goto fail;
}

if (end != vma->vm_end) {
error = vmi_split_vma(vmi, mm, vma, end, 0);
error = split_vma(vmi, vma, end, 0);
if (error)
goto fail;
}
Expand Down
10 changes: 4 additions & 6 deletions mm/mremap.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1043,12 +1043,10 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
* when a vma would be actually removed due to a merge.
*/
if (!vma->vm_ops || !vma->vm_ops->close) {
vma = vmi_vma_merge(&vmi, mm, vma,
extension_start, extension_end,
vma->vm_flags, vma->anon_vma,
vma->vm_file, extension_pgoff,
vma_policy(vma), vma->vm_userfaultfd_ctx,
anon_vma_name(vma));
vma = vma_merge(&vmi, mm, vma, extension_start,
extension_end, vma->vm_flags, vma->anon_vma,
vma->vm_file, extension_pgoff, vma_policy(vma),
vma->vm_userfaultfd_ctx, anon_vma_name(vma));
} else if (vma_adjust(vma, vma->vm_start, addr + new_len,
vma->vm_pgoff, NULL)) {
vma = NULL;
Expand Down
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