fs/proc/base: use maple tree iterators in place of linked list

Use mas_for_each to iterate the list of VMAs instead of a for loop
across the linked list.

Link: https://lkml.kernel.org/r/20220822150128.1562046-43-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/fs/proc/base.c b/fs/proc/base.c
index 93f7e3d971e4bbc758165ac09710945a50975af3..0b72a6d8aac3a8b494c3fb88e5d6a847b86aee7f 100644 (file)
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -2350,6 +2350,7 @@ proc_map_files_readdir(struct file *file, struct dir_context *ctx)
        GENRADIX(struct map_files_info) fa;
        struct map_files_info *p;
        int ret;
+       MA_STATE(mas, NULL, 0, 0);
 
        genradix_init(&fa);
 
@@ -2377,6 +2378,7 @@ proc_map_files_readdir(struct file *file, struct dir_context *ctx)
        }
 
        nr_files = 0;
+       mas.tree = &mm->mm_mt;
 
        /*
         * We need two passes here:
@@ -2388,7 +2390,8 @@ proc_map_files_readdir(struct file *file, struct dir_context *ctx)
         * routine might require mmap_lock taken in might_fault().
         */
 
-       for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
+       pos = 2;
+       mas_for_each(&mas, vma, ULONG_MAX) {
                if (!vma->vm_file)
                        continue;
                if (++pos <= ctx->pos)