[PATCH 12/26] fuse-bpf: Add support for fallocate

[Daniel Rosenberg <drosen@xxxxxxxxxx>]

Signed-off-by: Daniel Rosenberg <drosen@xxxxxxxxxx>
Signed-off-by: Paul Lawrence <paullawrence@xxxxxxxxxx>
---
 fs/fuse/backing.c | 48 +++++++++++++++++++++++++++++++++++++++++++++++
 fs/fuse/file.c    | 10 ++++++++++
 fs/fuse/fuse_i.h  | 11 +++++++++++
 3 files changed, 69 insertions(+)

diff --git a/fs/fuse/backing.c b/fs/fuse/backing.c
index 97e92c633cfd..95c60d6d7597 100644
--- a/fs/fuse/backing.c
+++ b/fs/fuse/backing.c
@@ -188,6 +188,54 @@ ssize_t fuse_backing_mmap(struct file *file, struct vm_area_struct *vma)
 	return ret;
 }
 
+int fuse_file_fallocate_initialize_in(struct bpf_fuse_args *fa,
+				      struct fuse_fallocate_in *ffi,
+				      struct file *file, int mode, loff_t offset, loff_t length)
+{
+	struct fuse_file *ff = file->private_data;
+
+	*ffi = (struct fuse_fallocate_in) {
+		.fh = ff->fh,
+		.offset = offset,
+		.length = length,
+		.mode = mode,
+	};
+
+	*fa = (struct bpf_fuse_args) {
+		.opcode = FUSE_FALLOCATE,
+		.nodeid = ff->nodeid,
+		.in_numargs = 1,
+		.in_args[0].size = sizeof(*ffi),
+		.in_args[0].value = ffi,
+	};
+
+	return 0;
+}
+
+int fuse_file_fallocate_initialize_out(struct bpf_fuse_args *fa,
+				       struct fuse_fallocate_in *ffi,
+				       struct file *file, int mode, loff_t offset, loff_t length)
+{
+	return 0;
+}
+
+int fuse_file_fallocate_backing(struct bpf_fuse_args *fa, int *out,
+				struct file *file, int mode, loff_t offset, loff_t length)
+{
+	const struct fuse_fallocate_in *ffi = fa->in_args[0].value;
+	struct fuse_file *ff = file->private_data;
+
+	*out = vfs_fallocate(ff->backing_file, ffi->mode, ffi->offset,
+			     ffi->length);
+	return 0;
+}
+
+int fuse_file_fallocate_finalize(struct bpf_fuse_args *fa, int *out,
+				 struct file *file, int mode, loff_t offset, loff_t length)
+{
+	return 0;
+}
+
 /*******************************************************************************
  * Directory operations after here                                             *
  ******************************************************************************/
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index dd4485261cc7..ef6f6b0b3b59 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -3002,6 +3002,16 @@ static long fuse_file_fallocate(struct file *file, int mode, loff_t offset,
 
 	bool block_faults = FUSE_IS_DAX(inode) && lock_inode;
 
+#ifdef CONFIG_FUSE_BPF
+	if (fuse_bpf_backing(inode, struct fuse_fallocate_in, err,
+			       fuse_file_fallocate_initialize_in,
+			       fuse_file_fallocate_initialize_out,
+			       fuse_file_fallocate_backing,
+			       fuse_file_fallocate_finalize,
+			       file, mode, offset, length))
+		return err;
+#endif
+
 	if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
 		     FALLOC_FL_ZERO_RANGE))
 		return -EOPNOTSUPP;
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index fc3e8adf0422..0e4996766c6c 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -1422,6 +1422,17 @@ int fuse_lseek_finalize(struct bpf_fuse_args *fa, loff_t *out, struct file *file
 
 ssize_t fuse_backing_mmap(struct file *file, struct vm_area_struct *vma);
 
+int fuse_file_fallocate_initialize_in(struct bpf_fuse_args *fa,
+				      struct fuse_fallocate_in *ffi,
+				      struct file *file, int mode, loff_t offset, loff_t length);
+int fuse_file_fallocate_initialize_out(struct bpf_fuse_args *fa,
+				       struct fuse_fallocate_in *ffi,
+				       struct file *file, int mode, loff_t offset, loff_t length);
+int fuse_file_fallocate_backing(struct bpf_fuse_args *fa, int *out,
+				struct file *file, int mode, loff_t offset, loff_t length);
+int fuse_file_fallocate_finalize(struct bpf_fuse_args *fa, int *out,
+				 struct file *file, int mode, loff_t offset, loff_t length);
+
 struct fuse_lookup_io {
 	struct fuse_entry_out feo;
 	struct fuse_entry_bpf feb;
-- 
2.37.3.998.g577e59143f-goog