1 /* SPDX-License-Identifier: GPL-2.0 2 * 3 * FUSE: Filesystem in Userspace 4 * Copyright (C) 2001-2008 Miklos Szeredi <miklos@szeredi.hu> 5 */ 6 #ifndef _FS_FUSE_DEV_I_H 7 #define _FS_FUSE_DEV_I_H 8 9 #include <linux/types.h> 10 11 /* Ordinary requests have even IDs, while interrupts IDs are odd */ 12 #define FUSE_INT_REQ_BIT (1ULL << 0) 13 #define FUSE_REQ_ID_STEP (1ULL << 1) 14 15 extern struct wait_queue_head fuse_dev_waitq; 16 17 struct fuse_arg; 18 struct fuse_args; 19 struct fuse_pqueue; 20 struct fuse_req; 21 struct fuse_iqueue; 22 struct fuse_forget_link; 23 24 struct fuse_copy_state { 25 struct fuse_req *req; 26 struct iov_iter *iter; 27 struct pipe_buffer *pipebufs; 28 struct pipe_buffer *currbuf; 29 struct pipe_inode_info *pipe; 30 unsigned long nr_segs; 31 struct page *pg; 32 unsigned int len; 33 unsigned int offset; 34 bool write:1; 35 bool move_folios:1; 36 bool is_uring:1; 37 struct { 38 unsigned int copied_sz; /* copied size into the user buffer */ 39 } ring; 40 }; 41 42 /* fud->fc gets assigned to this value when /dev/fuse is closed */ 43 #define FUSE_DEV_FC_DISCONNECTED ((struct fuse_conn *) 1) 44 45 /* 46 * Lockless access is OK, because fud->fc is set once during mount and is valid 47 * until the file is released. 48 * 49 * fud->fc is set to FUSE_DEV_FC_DISCONNECTED only after the containing file is 50 * released, so result is safe to dereference in most cases. Exceptions are: 51 * fuse_dev_put() and fuse_fill_super_common(). 52 */ 53 static inline struct fuse_conn *fuse_dev_fc_get(struct fuse_dev *fud) 54 { 55 /* Pairs with xchg() in fuse_dev_install() */ 56 return smp_load_acquire(&fud->fc); 57 } 58 59 static inline struct fuse_dev *fuse_file_to_fud(struct file *file) 60 { 61 return file->private_data; 62 } 63 64 static inline struct fuse_dev *__fuse_get_dev(struct file *file) 65 { 66 struct fuse_dev *fud = fuse_file_to_fud(file); 67 68 if (!fuse_dev_fc_get(fud)) 69 return NULL; 70 71 return fud; 72 } 73 74 struct fuse_dev *fuse_get_dev(struct file *file); 75 76 unsigned int fuse_req_hash(u64 unique); 77 struct fuse_req *fuse_request_find(struct fuse_pqueue *fpq, u64 unique); 78 79 void fuse_dev_end_requests(struct list_head *head); 80 81 void fuse_copy_init(struct fuse_copy_state *cs, bool write, 82 struct iov_iter *iter); 83 void fuse_copy_finish(struct fuse_copy_state *cs); 84 int fuse_copy_args(struct fuse_copy_state *cs, unsigned int numargs, 85 unsigned int argpages, struct fuse_arg *args, 86 int zeroing); 87 int fuse_copy_out_args(struct fuse_copy_state *cs, struct fuse_args *args, 88 unsigned int nbytes); 89 void fuse_dev_queue_forget(struct fuse_iqueue *fiq, 90 struct fuse_forget_link *forget); 91 void fuse_dev_queue_interrupt(struct fuse_iqueue *fiq, struct fuse_req *req); 92 bool fuse_remove_pending_req(struct fuse_req *req, spinlock_t *lock); 93 94 bool fuse_request_expired(struct fuse_conn *fc, struct list_head *list); 95 96 #endif 97 98