fs: convert most other generic_file_*mmap() users to .mmap_prepare()

Update nearly all generic_file_mmap() and generic_file_readonly_mmap()
callers to use generic_file_mmap_prepare() and
generic_file_readonly_mmap_prepare() respectively.

We update blkdev, 9p, afs, erofs, ext2, nfs, ntfs3, smb, ubifs and vboxsf
file systems this way.

Remaining users we cannot yet update are ecryptfs, fuse and cramfs. The
former two are nested file systems that must support any underlying file
ssytem, and cramfs inserts a mixed mapping which currently requires a VMA.

Once all file systems have been converted to mmap_prepare(), we can then
update nested file systems.

Signed-off-by: Lorenzo Stoakes <[e-mail]>
Link: https://lore.kernel.org/08db859[e-mail]
Signed-off-by: Christian Brauner <[e-mail]>

block/fops.c

···
 	return error;
 }
 
-static int blkdev_mmap(struct file *file, struct vm_area_struct *vma)
+static int blkdev_mmap_prepare(struct vm_area_desc *desc)
 {
-	struct inode *bd_inode = bdev_file_inode(file);
+	struct file *file = desc->file;
 
-	if (bdev_read_only(I_BDEV(bd_inode)))
-		return generic_file_readonly_mmap(file, vma);
+	if (bdev_read_only(I_BDEV(bdev_file_inode(file))))
+		return generic_file_readonly_mmap_prepare(desc);
 
-	return generic_file_mmap(file, vma);
+	return generic_file_mmap_prepare(desc);
 }
 
 const struct file_operations def_blk_fops = {
···
 	.read_iter	= blkdev_read_iter,
 	.write_iter	= blkdev_write_iter,
 	.iopoll		= iocb_bio_iopoll,
-	.mmap		= blkdev_mmap,
+	.mmap_prepare	= blkdev_mmap_prepare,
 	.fsync		= blkdev_fsync,
 	.unlocked_ioctl	= blkdev_ioctl,
 #ifdef CONFIG_COMPAT

fs/9p/vfs_file.c

···
 }
 
 static int
-v9fs_file_mmap(struct file *filp, struct vm_area_struct *vma)
+v9fs_file_mmap_prepare(struct vm_area_desc *desc)
 {
 	int retval;
+	struct file *filp = desc->file;
 	struct inode *inode = file_inode(filp);
 	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
 
···
 
 	if (!(v9ses->cache & CACHE_WRITEBACK)) {
 		p9_debug(P9_DEBUG_CACHE, "(read-only mmap mode)");
-		return generic_file_readonly_mmap(filp, vma);
+		return generic_file_readonly_mmap_prepare(desc);
 	}
 
-	retval = generic_file_mmap(filp, vma);
+	retval = generic_file_mmap_prepare(desc);
 	if (!retval)
-		vma->vm_ops = &v9fs_mmap_file_vm_ops;
+		desc->vm_ops = &v9fs_mmap_file_vm_ops;
 
 	return retval;
 }
···
 	.release = v9fs_dir_release,
 	.lock = v9fs_file_lock_dotl,
 	.flock = v9fs_file_flock_dotl,
-	.mmap = v9fs_file_mmap,
+	.mmap_prepare = v9fs_file_mmap_prepare,
 	.splice_read = v9fs_file_splice_read,
 	.splice_write = iter_file_splice_write,
 	.fsync = v9fs_file_fsync_dotl,

fs/afs/file.c

···
 #include <trace/events/netfs.h>
 #include "internal.h"
 
-static int afs_file_mmap(struct file *file, struct vm_area_struct *vma);
+static int afs_file_mmap_prepare(struct vm_area_desc *desc);
 
 static ssize_t afs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter);
 static ssize_t afs_file_splice_read(struct file *in, loff_t *ppos,
···
 	.llseek		= generic_file_llseek,
 	.read_iter	= afs_file_read_iter,
 	.write_iter	= netfs_file_write_iter,
-	.mmap		= afs_file_mmap,
+	.mmap_prepare	= afs_file_mmap_prepare,
 	.splice_read	= afs_file_splice_read,
 	.splice_write	= iter_file_splice_write,
 	.fsync		= afs_fsync,
···
 /*
  * Handle setting up a memory mapping on an AFS file.
  */
-static int afs_file_mmap(struct file *file, struct vm_area_struct *vma)
+static int afs_file_mmap_prepare(struct vm_area_desc *desc)
 {
-	struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
+	struct afs_vnode *vnode = AFS_FS_I(file_inode(desc->file));
 	int ret;
 
 	afs_add_open_mmap(vnode);
 
-	ret = generic_file_mmap(file, vma);
+	ret = generic_file_mmap_prepare(desc);
 	if (ret == 0)
-		vma->vm_ops = &afs_vm_ops;
+		desc->vm_ops = &afs_vm_ops;
 	else
 		afs_drop_open_mmap(vnode);
 	return ret;

fs/erofs/data.c

···
 	.huge_fault	= erofs_dax_huge_fault,
 };
 
-static int erofs_file_mmap(struct file *file, struct vm_area_struct *vma)
+static int erofs_file_mmap_prepare(struct vm_area_desc *desc)
 {
-	if (!IS_DAX(file_inode(file)))
-		return generic_file_readonly_mmap(file, vma);
+	if (!IS_DAX(file_inode(desc->file)))
+		return generic_file_readonly_mmap_prepare(desc);
 
-	if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE))
+	if ((desc->vm_flags & VM_SHARED) && (desc->vm_flags & VM_MAYWRITE))
 		return -EINVAL;
 
-	vma->vm_ops = &erofs_dax_vm_ops;
-	vm_flags_set(vma, VM_HUGEPAGE);
+	desc->vm_ops = &erofs_dax_vm_ops;
+	desc->vm_flags |= VM_HUGEPAGE;
 	return 0;
 }
 #else
-#define erofs_file_mmap	generic_file_readonly_mmap
+#define erofs_file_mmap_prepare	generic_file_readonly_mmap_prepare
 #endif
 
 static loff_t erofs_file_llseek(struct file *file, loff_t offset, int whence)
···
 const struct file_operations erofs_file_fops = {
 	.llseek		= erofs_file_llseek,
 	.read_iter	= erofs_file_read_iter,
-	.mmap		= erofs_file_mmap,
+	.mmap_prepare	= erofs_file_mmap_prepare,
 	.get_unmapped_area = thp_get_unmapped_area,
 	.splice_read	= filemap_splice_read,
 };

fs/ext2/file.c

···
 	.pfn_mkwrite	= ext2_dax_fault,
 };
 
-static int ext2_file_mmap(struct file *file, struct vm_area_struct *vma)
+static int ext2_file_mmap_prepare(struct vm_area_desc *desc)
 {
+	struct file *file = desc->file;
+
 	if (!IS_DAX(file_inode(file)))
-		return generic_file_mmap(file, vma);
+		return generic_file_mmap_prepare(desc);
 
 	file_accessed(file);
-	vma->vm_ops = &ext2_dax_vm_ops;
+	desc->vm_ops = &ext2_dax_vm_ops;
 	return 0;
 }
 #else
-#define ext2_file_mmap	generic_file_mmap
+#define ext2_file_mmap_prepare	generic_file_mmap_prepare
 #endif
 
 /*
···
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= ext2_compat_ioctl,
 #endif
-	.mmap		= ext2_file_mmap,
+	.mmap_prepare	= ext2_file_mmap_prepare,
 	.open		= ext2_file_open,
 	.release	= ext2_release_file,
 	.fsync		= ext2_fsync,

fs/nfs/file.c

···
 EXPORT_SYMBOL_GPL(nfs_file_splice_read);
 
 int
-nfs_file_mmap(struct file *file, struct vm_area_struct *vma)
+nfs_file_mmap_prepare(struct vm_area_desc *desc)
 {
+	struct file *file = desc->file;
 	struct inode *inode = file_inode(file);
 	int	status;
 
 	dprintk("NFS: mmap(%pD2)\n", file);
 
-	/* Note: generic_file_mmap() returns ENOSYS on nommu systems
+	/* Note: generic_file_mmap_prepare() returns ENOSYS on nommu systems
 	 *       so we call that before revalidating the mapping
 	 */
-	status = generic_file_mmap(file, vma);
+	status = generic_file_mmap_prepare(desc);
 	if (!status) {
-		vma->vm_ops = &nfs_file_vm_ops;
+		desc->vm_ops = &nfs_file_vm_ops;
 		status = nfs_revalidate_mapping(inode, file->f_mapping);
 	}
 	return status;
 }
-EXPORT_SYMBOL_GPL(nfs_file_mmap);
+EXPORT_SYMBOL_GPL(nfs_file_mmap_prepare);
 
 /*
  * Flush any dirty pages for this process, and check for write errors.
···
 	.llseek		= nfs_file_llseek,
 	.read_iter	= nfs_file_read,
 	.write_iter	= nfs_file_write,
-	.mmap		= nfs_file_mmap,
+	.mmap_prepare	= nfs_file_mmap_prepare,
 	.open		= nfs_file_open,
 	.flush		= nfs_file_flush,
 	.release	= nfs_file_release,

fs/nfs/internal.h

···
 ssize_t nfs_file_read(struct kiocb *, struct iov_iter *);
 ssize_t nfs_file_splice_read(struct file *in, loff_t *ppos, struct pipe_inode_info *pipe,
 			     size_t len, unsigned int flags);
-int nfs_file_mmap(struct file *, struct vm_area_struct *);
+int nfs_file_mmap_prepare(struct vm_area_desc *);
 ssize_t nfs_file_write(struct kiocb *, struct iov_iter *);
 int nfs_file_release(struct inode *, struct file *);
 int nfs_lock(struct file *, int, struct file_lock *);

fs/nfs/nfs4file.c

···
 const struct file_operations nfs4_file_operations = {
 	.read_iter	= nfs_file_read,
 	.write_iter	= nfs_file_write,
-	.mmap		= nfs_file_mmap,
+	.mmap_prepare	= nfs_file_mmap_prepare,
 	.open		= nfs4_file_open,
 	.flush		= nfs4_file_flush,
 	.release	= nfs_file_release,

fs/ntfs3/file.c

···
 }
 
 /*
- * ntfs_file_mmap - file_operations::mmap
+ * ntfs_file_mmap_prepare - file_operations::mmap_prepare
  */
-static int ntfs_file_mmap(struct file *file, struct vm_area_struct *vma)
+static int ntfs_file_mmap_prepare(struct vm_area_desc *desc)
 {
+	struct file *file = desc->file;
 	struct inode *inode = file_inode(file);
 	struct ntfs_inode *ni = ntfs_i(inode);
-	u64 from = ((u64)vma->vm_pgoff << PAGE_SHIFT);
-	bool rw = vma->vm_flags & VM_WRITE;
+	u64 from = ((u64)desc->pgoff << PAGE_SHIFT);
+	bool rw = desc->vm_flags & VM_WRITE;
 	int err;
 
 	if (unlikely(ntfs3_forced_shutdown(inode->i_sb)))
···
 
 	if (rw) {
 		u64 to = min_t(loff_t, i_size_read(inode),
-			       from + vma->vm_end - vma->vm_start);
+			       from + desc->end - desc->start);
 
 		if (is_sparsed(ni)) {
 			/* Allocate clusters for rw map. */
···
 		}
 	}
 
-	err = generic_file_mmap(file, vma);
+	err = generic_file_mmap_prepare(desc);
 out:
 	return err;
 }
···
 #endif
 	.splice_read	= ntfs_file_splice_read,
 	.splice_write	= ntfs_file_splice_write,
-	.mmap		= ntfs_file_mmap,
+	.mmap_prepare	= ntfs_file_mmap_prepare,
 	.open		= ntfs_file_open,
 	.fsync		= generic_file_fsync,
 	.fallocate	= ntfs_fallocate,

fs/smb/client/cifsfs.c

···
 	.flock = cifs_flock,
 	.fsync = cifs_fsync,
 	.flush = cifs_flush,
-	.mmap  = cifs_file_mmap,
+	.mmap_prepare = cifs_file_mmap_prepare,
 	.splice_read = filemap_splice_read,
 	.splice_write = iter_file_splice_write,
 	.llseek = cifs_llseek,
···
 	.flock = cifs_flock,
 	.fsync = cifs_strict_fsync,
 	.flush = cifs_flush,
-	.mmap = cifs_file_strict_mmap,
+	.mmap_prepare = cifs_file_strict_mmap_prepare,
 	.splice_read = filemap_splice_read,
 	.splice_write = iter_file_splice_write,
 	.llseek = cifs_llseek,
···
 	.flock = cifs_flock,
 	.fsync = cifs_fsync,
 	.flush = cifs_flush,
-	.mmap = cifs_file_mmap,
+	.mmap_prepare = cifs_file_mmap_prepare,
 	.splice_read = copy_splice_read,
 	.splice_write = iter_file_splice_write,
 	.unlocked_ioctl  = cifs_ioctl,
···
 	.release = cifs_close,
 	.fsync = cifs_fsync,
 	.flush = cifs_flush,
-	.mmap  = cifs_file_mmap,
+	.mmap_prepare = cifs_file_mmap_prepare,
 	.splice_read = filemap_splice_read,
 	.splice_write = iter_file_splice_write,
 	.llseek = cifs_llseek,
···
 	.release = cifs_close,
 	.fsync = cifs_strict_fsync,
 	.flush = cifs_flush,
-	.mmap = cifs_file_strict_mmap,
+	.mmap_prepare = cifs_file_strict_mmap_prepare,
 	.splice_read = filemap_splice_read,
 	.splice_write = iter_file_splice_write,
 	.llseek = cifs_llseek,
···
 	.release = cifs_close,
 	.fsync = cifs_fsync,
 	.flush = cifs_flush,
-	.mmap = cifs_file_mmap,
+	.mmap_prepare = cifs_file_mmap_prepare,
 	.splice_read = copy_splice_read,
 	.splice_write = iter_file_splice_write,
 	.unlocked_ioctl  = cifs_ioctl,

fs/smb/client/cifsfs.h

···
 extern int cifs_fsync(struct file *, loff_t, loff_t, int);
 extern int cifs_strict_fsync(struct file *, loff_t, loff_t, int);
 extern int cifs_flush(struct file *, fl_owner_t id);
-extern int cifs_file_mmap(struct file *file, struct vm_area_struct *vma);
-extern int cifs_file_strict_mmap(struct file *file, struct vm_area_struct *vma);
+int cifs_file_mmap_prepare(struct vm_area_desc *desc);
+int cifs_file_strict_mmap_prepare(struct vm_area_desc *desc);
 extern const struct file_operations cifs_dir_ops;
 extern int cifs_readdir(struct file *file, struct dir_context *ctx);
 

fs/smb/client/file.c

···
 	.page_mkwrite = cifs_page_mkwrite,
 };
 
-int cifs_file_strict_mmap(struct file *file, struct vm_area_struct *vma)
+int cifs_file_strict_mmap_prepare(struct vm_area_desc *desc)
 {
 	int xid, rc = 0;
-	struct inode *inode = file_inode(file);
+	struct inode *inode = file_inode(desc->file);
 
 	xid = get_xid();
 
 	if (!CIFS_CACHE_READ(CIFS_I(inode)))
 		rc = cifs_zap_mapping(inode);
 	if (!rc)
-		rc = generic_file_mmap(file, vma);
+		rc = generic_file_mmap_prepare(desc);
 	if (!rc)
-		vma->vm_ops = &cifs_file_vm_ops;
+		desc->vm_ops = &cifs_file_vm_ops;
 
 	free_xid(xid);
 	return rc;
 }
 
-int cifs_file_mmap(struct file *file, struct vm_area_struct *vma)
+int cifs_file_mmap_prepare(struct vm_area_desc *desc)
 {
 	int rc, xid;
 
 	xid = get_xid();
 
-	rc = cifs_revalidate_file(file);
+	rc = cifs_revalidate_file(desc->file);
 	if (rc)
 		cifs_dbg(FYI, "Validation prior to mmap failed, error=%d\n",
 			 rc);
 	if (!rc)
-		rc = generic_file_mmap(file, vma);
+		rc = generic_file_mmap_prepare(desc);
 	if (!rc)
-		vma->vm_ops = &cifs_file_vm_ops;
+		desc->vm_ops = &cifs_file_vm_ops;
 
 	free_xid(xid);
 	return rc;

fs/ubifs/file.c

···
 	.page_mkwrite = ubifs_vm_page_mkwrite,
 };
 
-static int ubifs_file_mmap(struct file *file, struct vm_area_struct *vma)
+static int ubifs_file_mmap_prepare(struct vm_area_desc *desc)
 {
 	int err;
 
-	err = generic_file_mmap(file, vma);
+	err = generic_file_mmap_prepare(desc);
 	if (err)
 		return err;
-	vma->vm_ops = &ubifs_file_vm_ops;
+	desc->vm_ops = &ubifs_file_vm_ops;
 
 	if (IS_ENABLED(CONFIG_UBIFS_ATIME_SUPPORT))
-		file_accessed(file);
+		file_accessed(desc->file);
 
 	return 0;
 }
···
 	.llseek         = generic_file_llseek,
 	.read_iter      = generic_file_read_iter,
 	.write_iter     = ubifs_write_iter,
-	.mmap           = ubifs_file_mmap,
+	.mmap_prepare   = ubifs_file_mmap_prepare,
 	.fsync          = ubifs_fsync,
 	.unlocked_ioctl = ubifs_ioctl,
 	.splice_read	= filemap_splice_read,

fs/vboxsf/file.c

···
 	.map_pages	= filemap_map_pages,
 };
 
-static int vboxsf_file_mmap(struct file *file, struct vm_area_struct *vma)
+static int vboxsf_file_mmap_prepare(struct vm_area_desc *desc)
 {
 	int err;
 
-	err = generic_file_mmap(file, vma);
+	err = generic_file_mmap_prepare(desc);
 	if (!err)
-		vma->vm_ops = &vboxsf_file_vm_ops;
+		desc->vm_ops = &vboxsf_file_vm_ops;
 
 	return err;
 }
···
 	.llseek = generic_file_llseek,
 	.read_iter = generic_file_read_iter,
 	.write_iter = generic_file_write_iter,
-	.mmap = vboxsf_file_mmap,
+	.mmap_prepare = vboxsf_file_mmap_prepare,
 	.open = vboxsf_file_open,
 	.release = vboxsf_file_release,
 	.fsync = noop_fsync,