[PATCH 01/10] mm: rename call_mmap/mmap_prepare to vfs_mmap/mmap_prepare

Lorenzo Stoakes
2025-06-16T19:34:29Z

The call_mmap() function violates the existing convention in
include/linux/fs.h whereby invocations of virtual file system hooks is
performed by functions prefixed with vfs_xxx().

Correct this by renaming call_mmap() to vfs_mmap(). This also avoids
confusion as to the fact that f_op->mmap_prepare may be invoked here.

Also rename __call_mmap_prepare() function to vfs_mmap_prepare() and adjust
to accept a file parameter, this is useful later for nested file systems.

Finally, fix up the VMA userland tests and ensure the mmap_prepare -> mmap
shim is implemented there.

Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
---
drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c | 2 +-
fs/backing-file.c | 2 +-
fs/coda/file.c | 4 +--
include/linux/fs.h | 5 ++--
ipc/shm.c | 2 +-
mm/internal.h | 2 +-
mm/vma.c | 2 +-
tools/testing/vma/vma_internal.h | 32 ++++++++++++++++++----
8 files changed, 35 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
index 05e440643aa2..f4f1c979d1b9 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
@@ -105,7 +105,7 @@ static int i915_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *
if (!obj->base.filp)
return -ENODEV;

- ret = call_mmap(obj->base.filp, vma);
+ ret = vfs_mmap(obj->base.filp, vma);
if (ret)
return ret;

diff --git a/fs/backing-file.c b/fs/backing-file.c
index 763fbe9b72b2..04018679bf69 100644
--- a/fs/backing-file.c
+++ b/fs/backing-file.c
@@ -339,7 +339,7 @@ int backing_file_mmap(struct file *file, struct vm_area_struct *vma,
vma_set_file(vma, file);

old_cred = override_creds(ctx->cred);
- ret = call_mmap(vma->vm_file, vma);
+ ret = vfs_mmap(vma->vm_file, vma);
revert_creds(old_cred);

if (ctx->accessed)
diff --git a/fs/coda/file.c b/fs/coda/file.c
index 148856a582a9..2e6ea9319b35 100644
--- a/fs/coda/file.c
+++ b/fs/coda/file.c
@@ -199,10 +199,10 @@ coda_file_mmap(struct file *coda_file, struct vm_area_struct *vma)
spin_unlock(&cii->c_lock);

vma->vm_file = get_file(host_file);
- ret = call_mmap(vma->vm_file, vma);
+ ret = vfs_mmap(vma->vm_file, vma);

if (ret) {
- /* if call_mmap fails, our caller will put host_file so we
+ /* if vfs_mmap fails, our caller will put host_file so we
* should drop the reference to the coda_file that we got.
*/
fput(coda_file);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 93ee0d2d6f1a..7120f80255b3 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2278,7 +2278,7 @@ static inline bool file_has_valid_mmap_hooks(struct file *file)

int compat_vma_mmap_prepare(struct file *file, struct vm_area_struct *vma);

-static inline int call_mmap(struct file *file, struct vm_area_struct *vma)
+static inline int vfs_mmap(struct file *file, struct vm_area_struct *vma)
{
if (file->f_op->mmap_prepare)
return compat_vma_mmap_prepare(file, vma);
@@ -2286,8 +2286,7 @@ static inline int call_mmap(struct file *file, struct vm_area_struct *vma)
return file->f_op->mmap(file, vma);
}

-static inline int __call_mmap_prepare(struct file *file,
- struct vm_area_desc *desc)
+static inline int vfs_mmap_prepare(struct file *file, struct vm_area_desc *desc)
{
return file->f_op->mmap_prepare(desc);
}
diff --git a/ipc/shm.c b/ipc/shm.c
index 492fcc699985..a9310b6dbbc3 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -602,7 +602,7 @@ static int shm_mmap(struct file *file, struct vm_area_struct *vma)
if (ret)
return ret;

- ret = call_mmap(sfd->file, vma);
+ ret = vfs_mmap(sfd->file, vma);
if (ret) {
__shm_close(sfd);
return ret;
diff --git a/mm/internal.h b/mm/internal.h
index 3823fb356d3b..a55c88afff6d 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -165,7 +165,7 @@ static inline void *folio_raw_mapping(const struct folio *folio)
*/
static inline int mmap_file(struct file *file, struct vm_area_struct *vma)
{
- int err = call_mmap(file, vma);
+ int err = vfs_mmap(file, vma);

if (likely(!err))
return 0;
diff --git a/mm/vma.c b/mm/vma.c
index 5d35adadf2b5..f548bede3bbe 100644
--- a/mm/vma.c
+++ b/mm/vma.c
@@ -2582,7 +2582,7 @@ static int call_mmap_prepare(struct mmap_state *map)
};

/* Invoke the hook. */
- err = __call_mmap_prepare(map->file, &desc);
+ err = vfs_mmap_prepare(map->file, &desc);
if (err)
return err;

diff --git a/tools/testing/vma/vma_internal.h b/tools/testing/vma/vma_internal.h
index d7fea56e3bb3..51dd122b8d50 100644
--- a/tools/testing/vma/vma_internal.h
+++ b/tools/testing/vma/vma_internal.h
@@ -1458,6 +1458,27 @@ static inline void free_anon_vma_name(struct vm_area_struct *vma)
(void)vma;
}

+/* Declared in vma.h. */
+static inline void set_vma_from_desc(struct vm_area_struct *vma,
+ struct vm_area_desc *desc);
+
+static inline struct vm_area_desc *vma_to_desc(struct vm_area_struct *vma,
+ struct vm_area_desc *desc);
+
+static int compat_vma_mmap_prepare(struct file *file,
+ struct vm_area_struct *vma)
+{
+ struct vm_area_desc desc;
+ int err;
+
+ err = file->f_op->mmap_prepare(vma_to_desc(vma, &desc));
+ if (err)
+ return err;
+ set_vma_from_desc(vma, &desc);
+
+ return 0;
+}
+
/* Did the driver provide valid mmap hook configuration? */
static inline bool file_has_valid_mmap_hooks(struct file *file)
{
@@ -1467,22 +1488,21 @@ static inline bool file_has_valid_mmap_hooks(struct file *file)
/* Hooks are mutually exclusive. */
if (WARN_ON_ONCE(has_mmap && has_mmap_prepare))
return false;
- if (WARN_ON_ONCE(!has_mmap && !has_mmap_prepare))
+ if (!has_mmap && !has_mmap_prepare)
return false;

return true;
}

-static inline int call_mmap(struct file *file, struct vm_area_struct *vma)
+static inline int vfs_mmap(struct file *file, struct vm_area_struct *vma)
{
- if (WARN_ON_ONCE(file->f_op->mmap_prepare))
- return -EINVAL;
+ if (file->f_op->mmap_prepare)
+ return compat_vma_mmap_prepare(file, vma);

return file->f_op->mmap(file, vma);
}

-static inline int __call_mmap_prepare(struct file *file,
- struct vm_area_desc *desc)
+static inline int vfs_mmap_prepare(struct file *file, struct vm_area_desc *desc)
{
return file->f_op->mmap_prepare(desc);
}
--
2.49.0