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 4095834dce093066eb7c466a97ee99637a6e9298..8ad24be1654e582469ce3b9fb4a7741f7b92496a 100644 (file)
--- 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;