From: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Date: Fri, 20 Mar 2026 22:39:32 +0000 (+0000)
Subject: mm/vma: remove superfluous map->hold_file_rmap_lock
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=04501e759e789288ba8359e04f83bcc00269611e;p=thirdparty%2Fkernel%2Flinux.git

mm/vma: remove superfluous map->hold_file_rmap_lock

We don't need to reference this field, it's confusing as it duplicates
mmap_action->hide_from_rmap_until_complete, so thread the mmap_action
through to __mmap_new_vma() instead and use the same field consistently.

Link: https://lkml.kernel.org/r/42c3fbb701e361a17193ecda0d2dabcc326288a5.1774045440.git.ljs@kernel.org
Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexandre Torgue <alexandre.torgue@foss.st.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Bodo Stroesser <bostroesser@gmail.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Clemens Ladisch <clemens@ladisch.de>
Cc: David Hildenbrand <david@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Long Li <longli@microsoft.com>
Cc: Marc Dionne <marc.dionne@auristor.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Richard Weinberger <richard@nod.at>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vignesh Raghavendra <vigneshr@ti.com>
Cc: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/mm/vma.c b/mm/vma.c
index 4095834dce093..8ad24be1654e5 100644
--- a/mm/vma.c
+++ b/mm/vma.c
@@ -38,8 +38,6 @@ struct mmap_state {
 
 	/* Determine if we can check KSM flags early in mmap() logic. */
 	bool check_ksm_early :1;
-	/* If we map new, hold the file rmap lock on mapping. */
-	bool hold_file_rmap_lock :1;
 	/* If .mmap_prepare changed the file, we don't need to pin. */
 	bool file_doesnt_need_get :1;
 };
@@ -2530,10 +2528,12 @@ static int __mmap_new_file_vma(struct mmap_state *map,
  *
  * @map:  Mapping state.
  * @vmap: Output pointer for the new VMA.
+ * @action: Any mmap_prepare action that is still to complete.
  *
  * Returns: Zero on success, or an error.
  */
-static int __mmap_new_vma(struct mmap_state *map, struct vm_area_struct **vmap)
+static int __mmap_new_vma(struct mmap_state *map, struct vm_area_struct **vmap,
+	struct mmap_action *action)
 {
 	struct vma_iterator *vmi = map->vmi;
 	int error = 0;
@@ -2582,7 +2582,7 @@ static int __mmap_new_vma(struct mmap_state *map, struct vm_area_struct **vmap)
 	vma_start_write(vma);
 	vma_iter_store_new(vmi, vma);
 	map->mm->map_count++;
-	vma_link_file(vma, map->hold_file_rmap_lock);
+	vma_link_file(vma, action->hide_from_rmap_until_complete);
 
 	/*
 	 * vma_merge_new_range() calls khugepaged_enter_vma() too, the below
@@ -2649,8 +2649,6 @@ static int call_action_prepare(struct mmap_state *map,
 	if (err)
 		return err;
 
-	if (desc->action.hide_from_rmap_until_complete)
-		map->hold_file_rmap_lock = true;
 	return 0;
 }
 
@@ -2740,7 +2738,7 @@ static int call_action_complete(struct mmap_state *map,
 	err = mmap_action_complete(vma, action);
 
 	/* If we held the file rmap we need to release it. */
-	if (map->hold_file_rmap_lock) {
+	if (action->hide_from_rmap_until_complete) {
 		struct file *file = vma->vm_file;
 
 		i_mmap_unlock_write(file->f_mapping);
@@ -2794,7 +2792,7 @@ static unsigned long __mmap_region(struct file *file, unsigned long addr,
 
 	/* ...but if we can't, allocate a new VMA. */
 	if (!vma) {
-		error = __mmap_new_vma(&map, &vma);
+		error = __mmap_new_vma(&map, &vma, &desc.action);
 		if (error)
 			goto unacct_error;
 		allocated_new = true;