Split out the madvise behavior applying logic from do_madvise() to make
it easier to reuse from the following change.

Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: SeongJae Park <sj@kernel.org>
---
 mm/madvise.c | 53 +++++++++++++++++++++++++++++-----------------------
 1 file changed, 30 insertions(+), 23 deletions(-)

diff --git a/mm/madvise.c b/mm/madvise.c
index efab2878be7c..31e5df75b926 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -1615,6 +1615,35 @@ static bool is_valid_madvise(unsigned long start, size_t len_in, int behavior)
 	return true;
 }
 
+static int madvise_do_behavior(struct mm_struct *mm,
+		unsigned long start, size_t len_in, size_t len, int behavior)
+{
+	struct blk_plug plug;
+	unsigned long end;
+	int error;
+
+#ifdef CONFIG_MEMORY_FAILURE
+	if (behavior == MADV_HWPOISON || behavior == MADV_SOFT_OFFLINE)
+		return madvise_inject_error(behavior, start, start + len_in);
+#endif
+	start = untagged_addr_remote(mm, start);
+	end = start + len;
+
+	blk_start_plug(&plug);
+	switch (behavior) {
+	case MADV_POPULATE_READ:
+	case MADV_POPULATE_WRITE:
+		error = madvise_populate(mm, start, end, behavior);
+		break;
+	default:
+		error = madvise_walk_vmas(mm, start, end, behavior,
+					  madvise_vma_behavior);
+		break;
+	}
+	blk_finish_plug(&plug);
+	return error;
+}
+
 /*
  * The madvise(2) system call.
  *
@@ -1692,7 +1721,6 @@ int do_madvise(struct mm_struct *mm, unsigned long start, size_t len_in, int beh
 	unsigned long end;
 	int error;
 	size_t len;
-	struct blk_plug plug;
 
 	if (!is_valid_madvise(start, len_in, behavior))
 		return -EINVAL;
@@ -1706,28 +1734,7 @@ int do_madvise(struct mm_struct *mm, unsigned long start, size_t len_in, int beh
 	error = madvise_lock(mm, behavior);
 	if (error)
 		return error;
-
-#ifdef CONFIG_MEMORY_FAILURE
-	if (behavior == MADV_HWPOISON || behavior == MADV_SOFT_OFFLINE)
-		return madvise_inject_error(behavior, start, start + len_in);
-#endif
-
-	start = untagged_addr_remote(mm, start);
-	end = start + len;
-
-	blk_start_plug(&plug);
-	switch (behavior) {
-	case MADV_POPULATE_READ:
-	case MADV_POPULATE_WRITE:
-		error = madvise_populate(mm, start, end, behavior);
-		break;
-	default:
-		error = madvise_walk_vmas(mm, start, end, behavior,
-					  madvise_vma_behavior);
-		break;
-	}
-	blk_finish_plug(&plug);
-
+	error = madvise_do_behavior(mm, start, len_in, len, behavior);
 	madvise_unlock(mm, behavior);
 
 	return error;
-- 
2.39.5

* SeongJae Park <sj@kernel.org> [250206 01:15]:
> Split out the madvise behavior applying logic from do_madvise() to make
> it easier to reuse from the following change.
> 
> Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
> Signed-off-by: SeongJae Park <sj@kernel.org>

Reviewed-by: Liam R. Howlett <howlett@gmail.com>

> ---
>  mm/madvise.c | 53 +++++++++++++++++++++++++++++-----------------------
>  1 file changed, 30 insertions(+), 23 deletions(-)
> 
> diff --git a/mm/madvise.c b/mm/madvise.c
> index efab2878be7c..31e5df75b926 100644
> --- a/mm/madvise.c
> +++ b/mm/madvise.c
> @@ -1615,6 +1615,35 @@ static bool is_valid_madvise(unsigned long start, size_t len_in, int behavior)
>  	return true;
>  }
>  
> +static int madvise_do_behavior(struct mm_struct *mm,
> +		unsigned long start, size_t len_in, size_t len, int behavior)
> +{
> +	struct blk_plug plug;
> +	unsigned long end;
> +	int error;
> +
> +#ifdef CONFIG_MEMORY_FAILURE
> +	if (behavior == MADV_HWPOISON || behavior == MADV_SOFT_OFFLINE)
> +		return madvise_inject_error(behavior, start, start + len_in);
> +#endif
> +	start = untagged_addr_remote(mm, start);
> +	end = start + len;
> +
> +	blk_start_plug(&plug);
> +	switch (behavior) {
> +	case MADV_POPULATE_READ:
> +	case MADV_POPULATE_WRITE:
> +		error = madvise_populate(mm, start, end, behavior);
> +		break;
> +	default:
> +		error = madvise_walk_vmas(mm, start, end, behavior,
> +					  madvise_vma_behavior);
> +		break;
> +	}
> +	blk_finish_plug(&plug);
> +	return error;
> +}
> +
>  /*
>   * The madvise(2) system call.
>   *
> @@ -1692,7 +1721,6 @@ int do_madvise(struct mm_struct *mm, unsigned long start, size_t len_in, int beh
>  	unsigned long end;
>  	int error;
>  	size_t len;
> -	struct blk_plug plug;
>  
>  	if (!is_valid_madvise(start, len_in, behavior))
>  		return -EINVAL;
> @@ -1706,28 +1734,7 @@ int do_madvise(struct mm_struct *mm, unsigned long start, size_t len_in, int beh
>  	error = madvise_lock(mm, behavior);
>  	if (error)
>  		return error;
> -
> -#ifdef CONFIG_MEMORY_FAILURE
> -	if (behavior == MADV_HWPOISON || behavior == MADV_SOFT_OFFLINE)
> -		return madvise_inject_error(behavior, start, start + len_in);
> -#endif
> -
> -	start = untagged_addr_remote(mm, start);
> -	end = start + len;
> -
> -	blk_start_plug(&plug);
> -	switch (behavior) {
> -	case MADV_POPULATE_READ:
> -	case MADV_POPULATE_WRITE:
> -		error = madvise_populate(mm, start, end, behavior);
> -		break;
> -	default:
> -		error = madvise_walk_vmas(mm, start, end, behavior,
> -					  madvise_vma_behavior);
> -		break;
> -	}
> -	blk_finish_plug(&plug);
> -
> +	error = madvise_do_behavior(mm, start, len_in, len, behavior);
>  	madvise_unlock(mm, behavior);
>  
>  	return error;
> -- 
> 2.39.5