| 1 | |
| 2 | FUSE: Filesystem in Userspace
|
| 3 | Copyright (C) 2001-2008 Miklos Szeredi <[email protected]>
|
| 4 |
|
| 5 | This program can be distributed under the terms of the GNU GPL.
|
| 6 | See the file COPYING.
|
| 7 |
|
| 8 |
|
| 9 | #include "fuse_i.h"
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| 10 |
|
| 11 | #include <linux/init.h>
|
| 12 | #include <linux/module.h>
|
| 13 | #include <linux/poll.h>
|
| 14 | #include <linux/sched/signal.h>
|
| 15 | #include <linux/uio.h>
|
| 16 | #include <linux/miscdevice.h>
|
| 17 | #include <linux/pagemap.h>
|
| 18 | #include <linux/file.h>
|
| 19 | #include <linux/slab.h>
|
| 20 | #include <linux/pipe_fs_i.h>
|
| 21 | #include <linux/swap.h>
|
| 22 | #include <linux/splice.h>
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| 23 | #include <linux/sched.h>
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| 24 |
|
| 25 | #define CREATE_TRACE_POINTS
|
| 26 | #include "fuse_trace.h"
|
| 27 |
|
| 28 | MODULE_ALIAS_MISCDEV(FUSE_MINOR);
|
| 29 | MODULE_ALIAS("devname:fuse");
|
| 30 |
|
| 31 |
|
| 32 | #define FUSE_INT_REQ_BIT (1ULL << 0)
|
| 33 | #define FUSE_REQ_ID_STEP (1ULL << 1)
|
| 34 |
|
| 35 | static struct kmem_cache *fuse_req_cachep;
|
| 36 |
|
| 37 | static void end_requests(struct list_head *head);
|
| 38 |
|
| 39 | static struct fuse_dev *fuse_get_dev(struct file *file)
|
| 40 | {
|
| 41 | |
| 42 | * Lockless access is OK, because file->private data is set
|
| 43 | * once during mount and is valid until the file is released.
|
| 44 |
|
| 45 | return READ_ONCE(file->private_data);
|
| 46 | }
|
| 47 |
|
| 48 | static void fuse_request_init(struct fuse_mount *fm, struct fuse_req *req)
|
| 49 | {
|
| 50 | INIT_LIST_HEAD(&req->list);
|
| 51 | INIT_LIST_HEAD(&req->intr_entry);
|
| 52 | init_waitqueue_head(&req->waitq);
|
| 53 | refcount_set(&req->count, 1);
|
| 54 | __set_bit(FR_PENDING, &req->flags);
|
| 55 | req->fm = fm;
|
| 56 | }
|
| 57 |
|
| 58 | static struct fuse_req *fuse_request_alloc(struct fuse_mount *fm, gfp_t flags)
|
| 59 | {
|
| 60 | struct fuse_req *req = kmem_cache_zalloc(fuse_req_cachep, flags);
|
| 61 | if (req)
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| 62 | fuse_request_init(fm, req);
|
| 63 |
|
| 64 | return req;
|
| 65 | }
|
| 66 |
|
| 67 | static void fuse_request_free(struct fuse_req *req)
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| 68 | {
|
| 69 | kmem_cache_free(fuse_req_cachep, req);
|
| 70 | }
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| 71 |
|
| 72 | static void __fuse_get_request(struct fuse_req *req)
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| 73 | {
|
| 74 | refcount_inc(&req->count);
|
| 75 | }
|
| 76 |
|
| 77 |
|
| 78 | static void __fuse_put_request(struct fuse_req *req)
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| 79 | {
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| 80 | refcount_dec(&req->count);
|
| 81 | }
|
| 82 |
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| 83 | void fuse_set_initialized(struct fuse_conn *fc)
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| 84 | {
|
| 85 |
|
| 86 | smp_wmb();
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| 87 | fc->initialized = 1;
|
| 88 | }
|
| 89 |
|
| 90 | static bool fuse_block_alloc(struct fuse_conn *fc, bool for_background)
|
| 91 | {
|
| 92 | return !fc->initialized || (for_background && fc->blocked);
|
| 93 | }
|
| 94 |
|
| 95 | static void fuse_drop_waiting(struct fuse_conn *fc)
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| 96 | {
|
| 97 | |
| 98 | * lockess check of fc->connected is okay, because atomic_dec_and_test()
|
| 99 | * provides a memory barrier matched with the one in fuse_wait_aborted()
|
| 100 | * to ensure no wake-up is missed.
|
| 101 |
|
| 102 | if (atomic_dec_and_test(&fc->num_waiting) &&
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| 103 | !READ_ONCE(fc->connected)) {
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| 104 |
|
| 105 | wake_up_all(&fc->blocked_waitq);
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| 106 | }
|
| 107 | }
|
| 108 |
|
| 109 | static void fuse_put_request(struct fuse_req *req);
|
| 110 |
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| 111 | static struct fuse_req *fuse_get_req(struct mnt_idmap *idmap,
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| 112 | struct fuse_mount *fm,
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| 113 | bool for_background)
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| 114 | {
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| 115 | struct fuse_conn *fc = fm->fc;
|
| 116 | struct fuse_req *req;
|
| 117 | bool no_idmap = !fm->sb || (fm->sb->s_iflags & SB_I_NOIDMAP);
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| 118 | kuid_t fsuid;
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| 119 | kgid_t fsgid;
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| 120 | int err;
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| 121 |
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| 122 | atomic_inc(&fc->num_waiting);
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| 123 |
|
| 124 | if (fuse_block_alloc(fc, for_background)) {
|
| 125 | err = -EINTR;
|
| 126 | if (wait_event_killable_exclusive(fc->blocked_waitq,
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| 127 | !fuse_block_alloc(fc, for_background)))
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| 128 | goto out;
|
| 129 | }
|
| 130 |
|
| 131 | smp_rmb();
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| 132 |
|
| 133 | err = -ENOTCONN;
|
| 134 | if (!fc->connected)
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| 135 | goto out;
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| 136 |
|
| 137 | err = -ECONNREFUSED;
|
| 138 | if (fc->conn_error)
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| 139 | goto out;
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| 140 |
|
| 141 | req = fuse_request_alloc(fm, GFP_KERNEL);
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| 142 | err = -ENOMEM;
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| 143 | if (!req) {
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| 144 | if (for_background)
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| 145 | wake_up(&fc->blocked_waitq);
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| 146 | goto out;
|
| 147 | }
|
| 148 |
|
| 149 | req->in.h.pid = pid_nr_ns(task_pid(current), fc->pid_ns);
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| 150 |
|
| 151 | __set_bit(FR_WAITING, &req->flags);
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| 152 | if (for_background)
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| 153 | __set_bit(FR_BACKGROUND, &req->flags);
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| 154 |
|
| 155 | |
| 156 | * Keep the old behavior when idmappings support was not
|
| 157 | * declared by a FUSE server.
|
| 158 | *
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| 159 | * For those FUSE servers who support idmapped mounts,
|
| 160 | * we send UID/GID only along with "inode creation"
|
| 161 | * fuse requests, otherwise idmap == &invalid_mnt_idmap and
|
| 162 | * req->in.h.{u,g}id will be equal to FUSE_INVALID_UIDGID.
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| 163 |
|
| 164 | fsuid = no_idmap ? current_fsuid() : mapped_fsuid(idmap, fc->user_ns);
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| 165 | fsgid = no_idmap ? current_fsgid() : mapped_fsgid(idmap, fc->user_ns);
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| 166 | req->in.h.uid = from_kuid(fc->user_ns, fsuid);
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| 167 | req->in.h.gid = from_kgid(fc->user_ns, fsgid);
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| 168 |
|
| 169 | if (no_idmap && unlikely(req->in.h.uid == ((uid_t)-1) ||
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| 170 | req->in.h.gid == ((gid_t)-1))) {
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| 171 | fuse_put_request(req);
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| 172 | return ERR_PTR(-EOVERFLOW);
|
| 173 | }
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| 174 |
|
| 175 | return req;
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| 176 |
|
| 177 | out:
|
| 178 | fuse_drop_waiting(fc);
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| 179 | return ERR_PTR(err);
|
| 180 | }
|
| 181 |
|
| 182 | static void fuse_put_request(struct fuse_req *req)
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| 183 | {
|
| 184 | struct fuse_conn *fc = req->fm->fc;
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| 185 |
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| 186 | if (refcount_dec_and_test(&req->count)) {
|
| 187 | if (test_bit(FR_BACKGROUND, &req->flags)) {
|
| 188 | |
| 189 | * We get here in the unlikely case that a background
|
| 190 | * request was allocated but not sent
|
| 191 |
|
| 192 | spin_lock(&fc->bg_lock);
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| 193 | if (!fc->blocked)
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| 194 | wake_up(&fc->blocked_waitq);
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| 195 | spin_unlock(&fc->bg_lock);
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| 196 | }
|
| 197 |
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| 198 | if (test_bit(FR_WAITING, &req->flags)) {
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| 199 | __clear_bit(FR_WAITING, &req->flags);
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| 200 | fuse_drop_waiting(fc);
|
| 201 | }
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| 202 |
|
| 203 | fuse_request_free(req);
|
| 204 | }
|
| 205 | }
|
| 206 |
|
| 207 | unsigned int fuse_len_args(unsigned int numargs, struct fuse_arg *args)
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| 208 | {
|
| 209 | unsigned nbytes = 0;
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| 210 | unsigned i;
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| 211 |
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| 212 | for (i = 0; i < numargs; i++)
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| 213 | nbytes += args[i].size;
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| 214 |
|
| 215 | return nbytes;
|
| 216 | }
|
| 217 | EXPORT_SYMBOL_GPL(fuse_len_args);
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| 218 |
|
| 219 | static u64 fuse_get_unique_locked(struct fuse_iqueue *fiq)
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| 220 | {
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| 221 | fiq->reqctr += FUSE_REQ_ID_STEP;
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| 222 | return fiq->reqctr;
|
| 223 | }
|
| 224 |
|
| 225 | u64 fuse_get_unique(struct fuse_iqueue *fiq)
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| 226 | {
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| 227 | u64 ret;
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| 228 |
|
| 229 | spin_lock(&fiq->lock);
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| 230 | ret = fuse_get_unique_locked(fiq);
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| 231 | spin_unlock(&fiq->lock);
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| 232 |
|
| 233 | return ret;
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| 234 | }
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| 235 | EXPORT_SYMBOL_GPL(fuse_get_unique);
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| 236 |
|
| 237 | static unsigned int fuse_req_hash(u64 unique)
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| 238 | {
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| 239 | return hash_long(unique & ~FUSE_INT_REQ_BIT, FUSE_PQ_HASH_BITS);
|
| 240 | }
|
| 241 |
|
| 242 | |
| 243 | * A new request is available, wake fiq->waitq
|
| 244 |
|
| 245 | static void fuse_dev_wake_and_unlock(struct fuse_iqueue *fiq)
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| 246 | __releases(fiq->lock)
|
| 247 | {
|
| 248 | wake_up(&fiq->waitq);
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| 249 | kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
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| 250 | spin_unlock(&fiq->lock);
|
| 251 | }
|
| 252 |
|
| 253 | static void fuse_dev_queue_forget(struct fuse_iqueue *fiq, struct fuse_forget_link *forget)
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| 254 | {
|
| 255 | spin_lock(&fiq->lock);
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| 256 | if (fiq->connected) {
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| 257 | fiq->forget_list_tail->next = forget;
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| 258 | fiq->forget_list_tail = forget;
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| 259 | fuse_dev_wake_and_unlock(fiq);
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| 260 | } else {
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| 261 | kfree(forget);
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| 262 | spin_unlock(&fiq->lock);
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| 263 | }
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| 264 | }
|
| 265 |
|
| 266 | static void fuse_dev_queue_interrupt(struct fuse_iqueue *fiq, struct fuse_req *req)
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| 267 | {
|
| 268 | spin_lock(&fiq->lock);
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| 269 | if (list_empty(&req->intr_entry)) {
|
| 270 | list_add_tail(&req->intr_entry, &fiq->interrupts);
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| 271 | |
| 272 | * Pairs with smp_mb() implied by test_and_set_bit()
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| 273 | * from fuse_request_end().
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| 274 |
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| 275 | smp_mb();
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| 276 | if (test_bit(FR_FINISHED, &req->flags)) {
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| 277 | list_del_init(&req->intr_entry);
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| 278 | spin_unlock(&fiq->lock);
|
| 279 | } else {
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| 280 | fuse_dev_wake_and_unlock(fiq);
|
| 281 | }
|
| 282 | } else {
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| 283 | spin_unlock(&fiq->lock);
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| 284 | }
|
| 285 | }
|
| 286 |
|
| 287 | static void fuse_dev_queue_req(struct fuse_iqueue *fiq, struct fuse_req *req)
|
| 288 | {
|
| 289 | spin_lock(&fiq->lock);
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| 290 | if (fiq->connected) {
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| 291 | if (req->in.h.opcode != FUSE_NOTIFY_REPLY)
|
| 292 | req->in.h.unique = fuse_get_unique_locked(fiq);
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| 293 | list_add_tail(&req->list, &fiq->pending);
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| 294 | fuse_dev_wake_and_unlock(fiq);
|
| 295 | } else {
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| 296 | spin_unlock(&fiq->lock);
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| 297 | req->out.h.error = -ENOTCONN;
|
| 298 | clear_bit(FR_PENDING, &req->flags);
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| 299 | fuse_request_end(req);
|
| 300 | }
|
| 301 | }
|
| 302 |
|
| 303 | const struct fuse_iqueue_ops fuse_dev_fiq_ops = {
|
| 304 | .send_forget = fuse_dev_queue_forget,
|
| 305 | .send_interrupt = fuse_dev_queue_interrupt,
|
| 306 | .send_req = fuse_dev_queue_req,
|
| 307 | };
|
| 308 | EXPORT_SYMBOL_GPL(fuse_dev_fiq_ops);
|
| 309 |
|
| 310 | static void fuse_send_one(struct fuse_iqueue *fiq, struct fuse_req *req)
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| 311 | {
|
| 312 | req->in.h.len = sizeof(struct fuse_in_header) +
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| 313 | fuse_len_args(req->args->in_numargs,
|
| 314 | (struct fuse_arg *) req->args->in_args);
|
| 315 | trace_fuse_request_send(req);
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| 316 | fiq->ops->send_req(fiq, req);
|
| 317 | }
|
| 318 |
|
| 319 | void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
|
| 320 | u64 nodeid, u64 nlookup)
|
| 321 | {
|
| 322 | struct fuse_iqueue *fiq = &fc->iq;
|
| 323 |
|
| 324 | forget->forget_one.nodeid = nodeid;
|
| 325 | forget->forget_one.nlookup = nlookup;
|
| 326 |
|
| 327 | fiq->ops->send_forget(fiq, forget);
|
| 328 | }
|
| 329 |
|
| 330 | static void flush_bg_queue(struct fuse_conn *fc)
|
| 331 | {
|
| 332 | struct fuse_iqueue *fiq = &fc->iq;
|
| 333 |
|
| 334 | while (fc->active_background < fc->max_background &&
|
| 335 | !list_empty(&fc->bg_queue)) {
|
| 336 | struct fuse_req *req;
|
| 337 |
|
| 338 | req = list_first_entry(&fc->bg_queue, struct fuse_req, list);
|
| 339 | list_del(&req->list);
|
| 340 | fc->active_background++;
|
| 341 | fuse_send_one(fiq, req);
|
| 342 | }
|
| 343 | }
|
| 344 |
|
| 345 | |
| 346 | * This function is called when a request is finished. Either a reply
|
| 347 | * has arrived or it was aborted (and not yet sent) or some error
|
| 348 | * occurred during communication with userspace, or the device file
|
| 349 | * was closed. The requester thread is woken up (if still waiting),
|
| 350 | * the 'end' callback is called if given, else the reference to the
|
| 351 | * request is released
|
| 352 |
|
| 353 | void fuse_request_end(struct fuse_req *req)
|
| 354 | {
|
| 355 | struct fuse_mount *fm = req->fm;
|
| 356 | struct fuse_conn *fc = fm->fc;
|
| 357 | struct fuse_iqueue *fiq = &fc->iq;
|
| 358 |
|
| 359 | if (test_and_set_bit(FR_FINISHED, &req->flags))
|
| 360 | goto put_request;
|
| 361 |
|
| 362 | trace_fuse_request_end(req);
|
| 363 | |
| 364 | * test_and_set_bit() implies smp_mb() between bit
|
| 365 | * changing and below FR_INTERRUPTED check. Pairs with
|
| 366 | * smp_mb() from queue_interrupt().
|
| 367 |
|
| 368 | if (test_bit(FR_INTERRUPTED, &req->flags)) {
|
| 369 | spin_lock(&fiq->lock);
|
| 370 | list_del_init(&req->intr_entry);
|
| 371 | spin_unlock(&fiq->lock);
|
| 372 | }
|
| 373 | WARN_ON(test_bit(FR_PENDING, &req->flags));
|
| 374 | WARN_ON(test_bit(FR_SENT, &req->flags));
|
| 375 | if (test_bit(FR_BACKGROUND, &req->flags)) {
|
| 376 | spin_lock(&fc->bg_lock);
|
| 377 | clear_bit(FR_BACKGROUND, &req->flags);
|
| 378 | if (fc->num_background == fc->max_background) {
|
| 379 | fc->blocked = 0;
|
| 380 | wake_up(&fc->blocked_waitq);
|
| 381 | } else if (!fc->blocked) {
|
| 382 | |
| 383 | * Wake up next waiter, if any. It's okay to use
|
| 384 | * waitqueue_active(), as we've already synced up
|
| 385 | * fc->blocked with waiters with the wake_up() call
|
| 386 | * above.
|
| 387 |
|
| 388 | if (waitqueue_active(&fc->blocked_waitq))
|
| 389 | wake_up(&fc->blocked_waitq);
|
| 390 | }
|
| 391 |
|
| 392 | fc->num_background--;
|
| 393 | fc->active_background--;
|
| 394 | flush_bg_queue(fc);
|
| 395 | spin_unlock(&fc->bg_lock);
|
| 396 | } else {
|
| 397 |
|
| 398 | wake_up(&req->waitq);
|
| 399 | }
|
| 400 |
|
| 401 | if (test_bit(FR_ASYNC, &req->flags))
|
| 402 | req->args->end(fm, req->args, req->out.h.error);
|
| 403 | put_request:
|
| 404 | fuse_put_request(req);
|
| 405 | }
|
| 406 | EXPORT_SYMBOL_GPL(fuse_request_end);
|
| 407 |
|
| 408 | static int queue_interrupt(struct fuse_req *req)
|
| 409 | {
|
| 410 | struct fuse_iqueue *fiq = &req->fm->fc->iq;
|
| 411 |
|
| 412 |
|
| 413 | if (unlikely(!test_bit(FR_INTERRUPTED, &req->flags)))
|
| 414 | return -EINVAL;
|
| 415 |
|
| 416 | fiq->ops->send_interrupt(fiq, req);
|
| 417 |
|
| 418 | return 0;
|
| 419 | }
|
| 420 |
|
| 421 | static void request_wait_answer(struct fuse_req *req)
|
| 422 | {
|
| 423 | struct fuse_conn *fc = req->fm->fc;
|
| 424 | struct fuse_iqueue *fiq = &fc->iq;
|
| 425 | int err;
|
| 426 |
|
| 427 | if (!fc->no_interrupt) {
|
| 428 |
|
| 429 | err = wait_event_interruptible(req->waitq,
|
| 430 | test_bit(FR_FINISHED, &req->flags));
|
| 431 | if (!err)
|
| 432 | return;
|
| 433 |
|
| 434 | set_bit(FR_INTERRUPTED, &req->flags);
|
| 435 |
|
| 436 | smp_mb__after_atomic();
|
| 437 | if (test_bit(FR_SENT, &req->flags))
|
| 438 | queue_interrupt(req);
|
| 439 | }
|
| 440 |
|
| 441 | if (!test_bit(FR_FORCE, &req->flags)) {
|
| 442 |
|
| 443 | err = wait_event_killable(req->waitq,
|
| 444 | test_bit(FR_FINISHED, &req->flags));
|
| 445 | if (!err)
|
| 446 | return;
|
| 447 |
|
| 448 | spin_lock(&fiq->lock);
|
| 449 |
|
| 450 | if (test_bit(FR_PENDING, &req->flags)) {
|
| 451 | list_del(&req->list);
|
| 452 | spin_unlock(&fiq->lock);
|
| 453 | __fuse_put_request(req);
|
| 454 | req->out.h.error = -EINTR;
|
| 455 | return;
|
| 456 | }
|
| 457 | spin_unlock(&fiq->lock);
|
| 458 | }
|
| 459 |
|
| 460 | |
| 461 | * Either request is already in userspace, or it was forced.
|
| 462 | * Wait it out.
|
| 463 |
|
| 464 | wait_event(req->waitq, test_bit(FR_FINISHED, &req->flags));
|
| 465 | }
|
| 466 |
|
| 467 | static void __fuse_request_send(struct fuse_req *req)
|
| 468 | {
|
| 469 | struct fuse_iqueue *fiq = &req->fm->fc->iq;
|
| 470 |
|
| 471 | BUG_ON(test_bit(FR_BACKGROUND, &req->flags));
|
| 472 |
|
| 473 | |
| 474 | fuse_request_end()
|
| 475 | __fuse_get_request(req);
|
| 476 | fuse_send_one(fiq, req);
|
| 477 |
|
| 478 | request_wait_answer(req);
|
| 479 |
|
| 480 | smp_rmb();
|
| 481 | }
|
| 482 |
|
| 483 | static void fuse_adjust_compat(struct fuse_conn *fc, struct fuse_args *args)
|
| 484 | {
|
| 485 | if (fc->minor < 4 && args->opcode == FUSE_STATFS)
|
| 486 | args->out_args[0].size = FUSE_COMPAT_STATFS_SIZE;
|
| 487 |
|
| 488 | if (fc->minor < 9) {
|
| 489 | switch (args->opcode) {
|
| 490 | case FUSE_LOOKUP:
|
| 491 | case FUSE_CREATE:
|
| 492 | case FUSE_MKNOD:
|
| 493 | case FUSE_MKDIR:
|
| 494 | case FUSE_SYMLINK:
|
| 495 | case FUSE_LINK:
|
| 496 | args->out_args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE;
|
| 497 | break;
|
| 498 | case FUSE_GETATTR:
|
| 499 | case FUSE_SETATTR:
|
| 500 | args->out_args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE;
|
| 501 | break;
|
| 502 | }
|
| 503 | }
|
| 504 | if (fc->minor < 12) {
|
| 505 | switch (args->opcode) {
|
| 506 | case FUSE_CREATE:
|
| 507 | args->in_args[0].size = sizeof(struct fuse_open_in);
|
| 508 | break;
|
| 509 | case FUSE_MKNOD:
|
| 510 | args->in_args[0].size = FUSE_COMPAT_MKNOD_IN_SIZE;
|
| 511 | break;
|
| 512 | }
|
| 513 | }
|
| 514 | }
|
| 515 |
|
| 516 | static void fuse_force_creds(struct fuse_req *req)
|
| 517 | {
|
| 518 | struct fuse_conn *fc = req->fm->fc;
|
| 519 |
|
| 520 | if (!req->fm->sb || req->fm->sb->s_iflags & SB_I_NOIDMAP) {
|
| 521 | req->in.h.uid = from_kuid_munged(fc->user_ns, current_fsuid());
|
| 522 | req->in.h.gid = from_kgid_munged(fc->user_ns, current_fsgid());
|
| 523 | } else {
|
| 524 | req->in.h.uid = FUSE_INVALID_UIDGID;
|
| 525 | req->in.h.gid = FUSE_INVALID_UIDGID;
|
| 526 | }
|
| 527 |
|
| 528 | req->in.h.pid = pid_nr_ns(task_pid(current), fc->pid_ns);
|
| 529 | }
|
| 530 |
|
| 531 | static void fuse_args_to_req(struct fuse_req *req, struct fuse_args *args)
|
| 532 | {
|
| 533 | req->in.h.opcode = args->opcode;
|
| 534 | req->in.h.nodeid = args->nodeid;
|
| 535 | req->args = args;
|
| 536 | if (args->is_ext)
|
| 537 | req->in.h.total_extlen = args->in_args[args->ext_idx].size / 8;
|
| 538 | if (args->end)
|
| 539 | __set_bit(FR_ASYNC, &req->flags);
|
| 540 | }
|
| 541 |
|
| 542 | ssize_t __fuse_simple_request(struct mnt_idmap *idmap,
|
| 543 | struct fuse_mount *fm,
|
| 544 | struct fuse_args *args)
|
| 545 | {
|
| 546 | struct fuse_conn *fc = fm->fc;
|
| 547 | struct fuse_req *req;
|
| 548 | ssize_t ret;
|
| 549 |
|
| 550 | if (args->force) {
|
| 551 | atomic_inc(&fc->num_waiting);
|
| 552 | req = fuse_request_alloc(fm, GFP_KERNEL | __GFP_NOFAIL);
|
| 553 |
|
| 554 | if (!args->nocreds)
|
| 555 | fuse_force_creds(req);
|
| 556 |
|
| 557 | __set_bit(FR_WAITING, &req->flags);
|
| 558 | __set_bit(FR_FORCE, &req->flags);
|
| 559 | } else {
|
| 560 | WARN_ON(args->nocreds);
|
| 561 | req = fuse_get_req(idmap, fm, false);
|
| 562 | if (IS_ERR(req))
|
| 563 | return PTR_ERR(req);
|
| 564 | }
|
| 565 |
|
| 566 |
|
| 567 | fuse_adjust_compat(fc, args);
|
| 568 | fuse_args_to_req(req, args);
|
| 569 |
|
| 570 | if (!args->noreply)
|
| 571 | __set_bit(FR_ISREPLY, &req->flags);
|
| 572 | __fuse_request_send(req);
|
| 573 | ret = req->out.h.error;
|
| 574 | if (!ret && args->out_argvar) {
|
| 575 | BUG_ON(args->out_numargs == 0);
|
| 576 | ret = args->out_args[args->out_numargs - 1].size;
|
| 577 | }
|
| 578 | fuse_put_request(req);
|
| 579 |
|
| 580 | return ret;
|
| 581 | }
|
| 582 |
|
| 583 | static bool fuse_request_queue_background(struct fuse_req *req)
|
| 584 | {
|
| 585 | struct fuse_mount *fm = req->fm;
|
| 586 | struct fuse_conn *fc = fm->fc;
|
| 587 | bool queued = false;
|
| 588 |
|
| 589 | WARN_ON(!test_bit(FR_BACKGROUND, &req->flags));
|
| 590 | if (!test_bit(FR_WAITING, &req->flags)) {
|
| 591 | __set_bit(FR_WAITING, &req->flags);
|
| 592 | atomic_inc(&fc->num_waiting);
|
| 593 | }
|
| 594 | __set_bit(FR_ISREPLY, &req->flags);
|
| 595 | spin_lock(&fc->bg_lock);
|
| 596 | if (likely(fc->connected)) {
|
| 597 | fc->num_background++;
|
| 598 | if (fc->num_background == fc->max_background)
|
| 599 | fc->blocked = 1;
|
| 600 | list_add_tail(&req->list, &fc->bg_queue);
|
| 601 | flush_bg_queue(fc);
|
| 602 | queued = true;
|
| 603 | }
|
| 604 | spin_unlock(&fc->bg_lock);
|
| 605 |
|
| 606 | return queued;
|
| 607 | }
|
| 608 |
|
| 609 | int fuse_simple_background(struct fuse_mount *fm, struct fuse_args *args,
|
| 610 | gfp_t gfp_flags)
|
| 611 | {
|
| 612 | struct fuse_req *req;
|
| 613 |
|
| 614 | if (args->force) {
|
| 615 | WARN_ON(!args->nocreds);
|
| 616 | req = fuse_request_alloc(fm, gfp_flags);
|
| 617 | if (!req)
|
| 618 | return -ENOMEM;
|
| 619 | __set_bit(FR_BACKGROUND, &req->flags);
|
| 620 | } else {
|
| 621 | WARN_ON(args->nocreds);
|
| 622 | req = fuse_get_req(&invalid_mnt_idmap, fm, true);
|
| 623 | if (IS_ERR(req))
|
| 624 | return PTR_ERR(req);
|
| 625 | }
|
| 626 |
|
| 627 | fuse_args_to_req(req, args);
|
| 628 |
|
| 629 | if (!fuse_request_queue_background(req)) {
|
| 630 | fuse_put_request(req);
|
| 631 | return -ENOTCONN;
|
| 632 | }
|
| 633 |
|
| 634 | return 0;
|
| 635 | }
|
| 636 | EXPORT_SYMBOL_GPL(fuse_simple_background);
|
| 637 |
|
| 638 | static int fuse_simple_notify_reply(struct fuse_mount *fm,
|
| 639 | struct fuse_args *args, u64 unique)
|
| 640 | {
|
| 641 | struct fuse_req *req;
|
| 642 | struct fuse_iqueue *fiq = &fm->fc->iq;
|
| 643 |
|
| 644 | req = fuse_get_req(&invalid_mnt_idmap, fm, false);
|
| 645 | if (IS_ERR(req))
|
| 646 | return PTR_ERR(req);
|
| 647 |
|
| 648 | __clear_bit(FR_ISREPLY, &req->flags);
|
| 649 | req->in.h.unique = unique;
|
| 650 |
|
| 651 | fuse_args_to_req(req, args);
|
| 652 |
|
| 653 | fuse_send_one(fiq, req);
|
| 654 |
|
| 655 | return 0;
|
| 656 | }
|
| 657 |
|
| 658 | |
| 659 | * Lock the request. Up to the next unlock_request() there mustn't be
|
| 660 | * anything that could cause a page-fault. If the request was already
|
| 661 | * aborted bail out.
|
| 662 |
|
| 663 | static int lock_request(struct fuse_req *req)
|
| 664 | {
|
| 665 | int err = 0;
|
| 666 | if (req) {
|
| 667 | spin_lock(&req->waitq.lock);
|
| 668 | if (test_bit(FR_ABORTED, &req->flags))
|
| 669 | err = -ENOENT;
|
| 670 | else
|
| 671 | set_bit(FR_LOCKED, &req->flags);
|
| 672 | spin_unlock(&req->waitq.lock);
|
| 673 | }
|
| 674 | return err;
|
| 675 | }
|
| 676 |
|
| 677 | |
| 678 | * Unlock request. If it was aborted while locked, caller is responsible
|
| 679 | * for unlocking and ending the request.
|
| 680 |
|
| 681 | static int unlock_request(struct fuse_req *req)
|
| 682 | {
|
| 683 | int err = 0;
|
| 684 | if (req) {
|
| 685 | spin_lock(&req->waitq.lock);
|
| 686 | if (test_bit(FR_ABORTED, &req->flags))
|
| 687 | err = -ENOENT;
|
| 688 | else
|
| 689 | clear_bit(FR_LOCKED, &req->flags);
|
| 690 | spin_unlock(&req->waitq.lock);
|
| 691 | }
|
| 692 | return err;
|
| 693 | }
|
| 694 |
|
| 695 | struct fuse_copy_state {
|
| 696 | int write;
|
| 697 | struct fuse_req *req;
|
| 698 | struct iov_iter *iter;
|
| 699 | struct pipe_buffer *pipebufs;
|
| 700 | struct pipe_buffer *currbuf;
|
| 701 | struct pipe_inode_info *pipe;
|
| 702 | unsigned long nr_segs;
|
| 703 | struct page *pg;
|
| 704 | unsigned len;
|
| 705 | unsigned offset;
|
| 706 | unsigned move_pages:1;
|
| 707 | };
|
| 708 |
|
| 709 | static void fuse_copy_init(struct fuse_copy_state *cs, int write,
|
| 710 | struct iov_iter *iter)
|
| 711 | {
|
| 712 | memset(cs, 0, sizeof(*cs));
|
| 713 | cs->write = write;
|
| 714 | cs->iter = iter;
|
| 715 | }
|
| 716 |
|
| 717 |
|
| 718 | static void fuse_copy_finish(struct fuse_copy_state *cs)
|
| 719 | {
|
| 720 | if (cs->currbuf) {
|
| 721 | struct pipe_buffer *buf = cs->currbuf;
|
| 722 |
|
| 723 | if (cs->write)
|
| 724 | buf->len = PAGE_SIZE - cs->len;
|
| 725 | cs->currbuf = NULL;
|
| 726 | } else if (cs->pg) {
|
| 727 | if (cs->write) {
|
| 728 | flush_dcache_page(cs->pg);
|
| 729 | set_page_dirty_lock(cs->pg);
|
| 730 | }
|
| 731 | put_page(cs->pg);
|
| 732 | }
|
| 733 | cs->pg = NULL;
|
| 734 | }
|
| 735 |
|
| 736 | |
| 737 | * Get another pagefull of userspace buffer, and map it to kernel
|
| 738 | * address space, and lock request
|
| 739 |
|
| 740 | static int fuse_copy_fill(struct fuse_copy_state *cs)
|
| 741 | {
|
| 742 | struct page *page;
|
| 743 | int err;
|
| 744 |
|
| 745 | err = unlock_request(cs->req);
|
| 746 | if (err)
|
| 747 | return err;
|
| 748 |
|
| 749 | fuse_copy_finish(cs);
|
| 750 | if (cs->pipebufs) {
|
| 751 | struct pipe_buffer *buf = cs->pipebufs;
|
| 752 |
|
| 753 | if (!cs->write) {
|
| 754 | err = pipe_buf_confirm(cs->pipe, buf);
|
| 755 | if (err)
|
| 756 | return err;
|
| 757 |
|
| 758 | BUG_ON(!cs->nr_segs);
|
| 759 | cs->currbuf = buf;
|
| 760 | cs->pg = buf->page;
|
| 761 | cs->offset = buf->offset;
|
| 762 | cs->len = buf->len;
|
| 763 | cs->pipebufs++;
|
| 764 | cs->nr_segs--;
|
| 765 | } else {
|
| 766 | if (cs->nr_segs >= cs->pipe->max_usage)
|
| 767 | return -EIO;
|
| 768 |
|
| 769 | page = alloc_page(GFP_HIGHUSER);
|
| 770 | if (!page)
|
| 771 | return -ENOMEM;
|
| 772 |
|
| 773 | buf->page = page;
|
| 774 | buf->offset = 0;
|
| 775 | buf->len = 0;
|
| 776 |
|
| 777 | cs->currbuf = buf;
|
| 778 | cs->pg = page;
|
| 779 | cs->offset = 0;
|
| 780 | cs->len = PAGE_SIZE;
|
| 781 | cs->pipebufs++;
|
| 782 | cs->nr_segs++;
|
| 783 | }
|
| 784 | } else {
|
| 785 | size_t off;
|
| 786 | err = iov_iter_get_pages2(cs->iter, &page, PAGE_SIZE, 1, &off);
|
| 787 | if (err < 0)
|
| 788 | return err;
|
| 789 | BUG_ON(!err);
|
| 790 | cs->len = err;
|
| 791 | cs->offset = off;
|
| 792 | cs->pg = page;
|
| 793 | }
|
| 794 |
|
| 795 | return lock_request(cs->req);
|
| 796 | }
|
| 797 |
|
| 798 |
|
| 799 | static int fuse_copy_do(struct fuse_copy_state *cs, void **val, unsigned *size)
|
| 800 | {
|
| 801 | unsigned ncpy = min(*size, cs->len);
|
| 802 | if (val) {
|
| 803 | void *pgaddr = kmap_local_page(cs->pg);
|
| 804 | void *buf = pgaddr + cs->offset;
|
| 805 |
|
| 806 | if (cs->write)
|
| 807 | memcpy(buf, *val, ncpy);
|
| 808 | else
|
| 809 | memcpy(*val, buf, ncpy);
|
| 810 |
|
| 811 | kunmap_local(pgaddr);
|
| 812 | *val += ncpy;
|
| 813 | }
|
| 814 | *size -= ncpy;
|
| 815 | cs->len -= ncpy;
|
| 816 | cs->offset += ncpy;
|
| 817 | return ncpy;
|
| 818 | }
|
| 819 |
|
| 820 | static int fuse_check_folio(struct folio *folio)
|
| 821 | {
|
| 822 | if (folio_mapped(folio) ||
|
| 823 | folio->mapping != NULL ||
|
| 824 | (folio->flags & PAGE_FLAGS_CHECK_AT_PREP &
|
| 825 | ~(1 << PG_locked |
|
| 826 | 1 << PG_referenced |
|
| 827 | 1 << PG_lru |
|
| 828 | 1 << PG_active |
|
| 829 | 1 << PG_workingset |
|
| 830 | 1 << PG_reclaim |
|
| 831 | 1 << PG_waiters |
|
| 832 | LRU_GEN_MASK | LRU_REFS_MASK))) {
|
| 833 | dump_page(&folio->page, "fuse: trying to steal weird page");
|
| 834 | return 1;
|
| 835 | }
|
| 836 | return 0;
|
| 837 | }
|
| 838 |
|
| 839 | static int fuse_try_move_page(struct fuse_copy_state *cs, struct page **pagep)
|
| 840 | {
|
| 841 | int err;
|
| 842 | struct folio *oldfolio = page_folio(*pagep);
|
| 843 | struct folio *newfolio;
|
| 844 | struct pipe_buffer *buf = cs->pipebufs;
|
| 845 |
|
| 846 | folio_get(oldfolio);
|
| 847 | err = unlock_request(cs->req);
|
| 848 | if (err)
|
| 849 | goto out_put_old;
|
| 850 |
|
| 851 | fuse_copy_finish(cs);
|
| 852 |
|
| 853 | err = pipe_buf_confirm(cs->pipe, buf);
|
| 854 | if (err)
|
| 855 | goto out_put_old;
|
| 856 |
|
| 857 | BUG_ON(!cs->nr_segs);
|
| 858 | cs->currbuf = buf;
|
| 859 | cs->len = buf->len;
|
| 860 | cs->pipebufs++;
|
| 861 | cs->nr_segs--;
|
| 862 |
|
| 863 | if (cs->len != PAGE_SIZE)
|
| 864 | goto out_fallback;
|
| 865 |
|
| 866 | if (!pipe_buf_try_steal(cs->pipe, buf))
|
| 867 | goto out_fallback;
|
| 868 |
|
| 869 | newfolio = page_folio(buf->page);
|
| 870 |
|
| 871 | folio_clear_uptodate(newfolio);
|
| 872 | folio_clear_mappedtodisk(newfolio);
|
| 873 |
|
| 874 | if (fuse_check_folio(newfolio) != 0)
|
| 875 | goto out_fallback_unlock;
|
| 876 |
|
| 877 | |
| 878 | * This is a new and locked page, it shouldn't be mapped or
|
| 879 | * have any special flags on it
|
| 880 |
|
| 881 | if (WARN_ON(folio_mapped(oldfolio)))
|
| 882 | goto out_fallback_unlock;
|
| 883 | if (WARN_ON(folio_has_private(oldfolio)))
|
| 884 | goto out_fallback_unlock;
|
| 885 | if (WARN_ON(folio_test_dirty(oldfolio) ||
|
| 886 | folio_test_writeback(oldfolio)))
|
| 887 | goto out_fallback_unlock;
|
| 888 | if (WARN_ON(folio_test_mlocked(oldfolio)))
|
| 889 | goto out_fallback_unlock;
|
| 890 |
|
| 891 | replace_page_cache_folio(oldfolio, newfolio);
|
| 892 |
|
| 893 | folio_get(newfolio);
|
| 894 |
|
| 895 | if (!(buf->flags & PIPE_BUF_FLAG_LRU))
|
| 896 | folio_add_lru(newfolio);
|
| 897 |
|
| 898 | |
| 899 | * Release while we have extra ref on stolen page. Otherwise
|
| 900 | * anon_pipe_buf_release() might think the page can be reused.
|
| 901 |
|
| 902 | pipe_buf_release(cs->pipe, buf);
|
| 903 |
|
| 904 | err = 0;
|
| 905 | spin_lock(&cs->req->waitq.lock);
|
| 906 | if (test_bit(FR_ABORTED, &cs->req->flags))
|
| 907 | err = -ENOENT;
|
| 908 | else
|
| 909 | *pagep = &newfolio->page;
|
| 910 | spin_unlock(&cs->req->waitq.lock);
|
| 911 |
|
| 912 | if (err) {
|
| 913 | folio_unlock(newfolio);
|
| 914 | folio_put(newfolio);
|
| 915 | goto out_put_old;
|
| 916 | }
|
| 917 |
|
| 918 | folio_unlock(oldfolio);
|
| 919 |
|
| 920 | folio_put(oldfolio);
|
| 921 | cs->len = 0;
|
| 922 |
|
| 923 | err = 0;
|
| 924 | out_put_old:
|
| 925 |
|
| 926 | folio_put(oldfolio);
|
| 927 | return err;
|
| 928 |
|
| 929 | out_fallback_unlock:
|
| 930 | folio_unlock(newfolio);
|
| 931 | out_fallback:
|
| 932 | cs->pg = buf->page;
|
| 933 | cs->offset = buf->offset;
|
| 934 |
|
| 935 | err = lock_request(cs->req);
|
| 936 | if (!err)
|
| 937 | err = 1;
|
| 938 |
|
| 939 | goto out_put_old;
|
| 940 | }
|
| 941 |
|
| 942 | static int fuse_ref_page(struct fuse_copy_state *cs, struct page *page,
|
| 943 | unsigned offset, unsigned count)
|
| 944 | {
|
| 945 | struct pipe_buffer *buf;
|
| 946 | int err;
|
| 947 |
|
| 948 | if (cs->nr_segs >= cs->pipe->max_usage)
|
| 949 | return -EIO;
|
| 950 |
|
| 951 | get_page(page);
|
| 952 | err = unlock_request(cs->req);
|
| 953 | if (err) {
|
| 954 | put_page(page);
|
| 955 | return err;
|
| 956 | }
|
| 957 |
|
| 958 | fuse_copy_finish(cs);
|
| 959 |
|
| 960 | buf = cs->pipebufs;
|
| 961 | buf->page = page;
|
| 962 | buf->offset = offset;
|
| 963 | buf->len = count;
|
| 964 |
|
| 965 | cs->pipebufs++;
|
| 966 | cs->nr_segs++;
|
| 967 | cs->len = 0;
|
| 968 |
|
| 969 | return 0;
|
| 970 | }
|
| 971 |
|
| 972 | |
| 973 | * Copy a page in the request to/from the userspace buffer. Must be
|
| 974 | * done atomically
|
| 975 |
|
| 976 | static int fuse_copy_page(struct fuse_copy_state *cs, struct page **pagep,
|
| 977 | unsigned offset, unsigned count, int zeroing)
|
| 978 | {
|
| 979 | int err;
|
| 980 | struct page *page = *pagep;
|
| 981 |
|
| 982 | if (page && zeroing && count < PAGE_SIZE)
|
| 983 | clear_highpage(page);
|
| 984 |
|
| 985 | while (count) {
|
| 986 | if (cs->write && cs->pipebufs && page) {
|
| 987 | |
| 988 | * Can't control lifetime of pipe buffers, so always
|
| 989 | * copy user pages.
|
| 990 |
|
| 991 | if (cs->req->args->user_pages) {
|
| 992 | err = fuse_copy_fill(cs);
|
| 993 | if (err)
|
| 994 | return err;
|
| 995 | } else {
|
| 996 | return fuse_ref_page(cs, page, offset, count);
|
| 997 | }
|
| 998 | } else if (!cs->len) {
|
| 999 | if (cs->move_pages && page &&
|
| 1000 | offset == 0 && count == PAGE_SIZE) {
|
| 1001 | err = fuse_try_move_page(cs, pagep);
|
| 1002 | if (err <= 0)
|
| 1003 | return err;
|
| 1004 | } else {
|
| 1005 | err = fuse_copy_fill(cs);
|
| 1006 | if (err)
|
| 1007 | return err;
|
| 1008 | }
|
| 1009 | }
|
| 1010 | if (page) {
|
| 1011 | void *mapaddr = kmap_local_page(page);
|
| 1012 | void *buf = mapaddr + offset;
|
| 1013 | offset += fuse_copy_do(cs, &buf, &count);
|
| 1014 | kunmap_local(mapaddr);
|
| 1015 | } else
|
| 1016 | offset += fuse_copy_do(cs, NULL, &count);
|
| 1017 | }
|
| 1018 | if (page && !cs->write)
|
| 1019 | flush_dcache_page(page);
|
| 1020 | return 0;
|
| 1021 | }
|
| 1022 |
|
| 1023 |
|
| 1024 | static int fuse_copy_pages(struct fuse_copy_state *cs, unsigned nbytes,
|
| 1025 | int zeroing)
|
| 1026 | {
|
| 1027 | unsigned i;
|
| 1028 | struct fuse_req *req = cs->req;
|
| 1029 | struct fuse_args_pages *ap = container_of(req->args, typeof(*ap), args);
|
| 1030 |
|
| 1031 | for (i = 0; i < ap->num_folios && (nbytes || zeroing); i++) {
|
| 1032 | int err;
|
| 1033 | unsigned int offset = ap->descs[i].offset;
|
| 1034 | unsigned int count = min(nbytes, ap->descs[i].length);
|
| 1035 | struct page *orig, *pagep;
|
| 1036 |
|
| 1037 | orig = pagep = &ap->folios[i]->page;
|
| 1038 |
|
| 1039 | err = fuse_copy_page(cs, &pagep, offset, count, zeroing);
|
| 1040 | if (err)
|
| 1041 | return err;
|
| 1042 |
|
| 1043 | nbytes -= count;
|
| 1044 |
|
| 1045 | |
| 1046 | * fuse_copy_page may have moved a page from a pipe instead of
|
| 1047 | * copying into our given page, so update the folios if it was
|
| 1048 | * replaced.
|
| 1049 |
|
| 1050 | if (pagep != orig)
|
| 1051 | ap->folios[i] = page_folio(pagep);
|
| 1052 | }
|
| 1053 | return 0;
|
| 1054 | }
|
| 1055 |
|
| 1056 |
|
| 1057 | static int fuse_copy_one(struct fuse_copy_state *cs, void *val, unsigned size)
|
| 1058 | {
|
| 1059 | while (size) {
|
| 1060 | if (!cs->len) {
|
| 1061 | int err = fuse_copy_fill(cs);
|
| 1062 | if (err)
|
| 1063 | return err;
|
| 1064 | }
|
| 1065 | fuse_copy_do(cs, &val, &size);
|
| 1066 | }
|
| 1067 | return 0;
|
| 1068 | }
|
| 1069 |
|
| 1070 |
|
| 1071 | static int fuse_copy_args(struct fuse_copy_state *cs, unsigned numargs,
|
| 1072 | unsigned argpages, struct fuse_arg *args,
|
| 1073 | int zeroing)
|
| 1074 | {
|
| 1075 | int err = 0;
|
| 1076 | unsigned i;
|
| 1077 |
|
| 1078 | for (i = 0; !err && i < numargs; i++) {
|
| 1079 | struct fuse_arg *arg = &args[i];
|
| 1080 | if (i == numargs - 1 && argpages)
|
| 1081 | err = fuse_copy_pages(cs, arg->size, zeroing);
|
| 1082 | else
|
| 1083 | err = fuse_copy_one(cs, arg->value, arg->size);
|
| 1084 | }
|
| 1085 | return err;
|
| 1086 | }
|
| 1087 |
|
| 1088 | static int forget_pending(struct fuse_iqueue *fiq)
|
| 1089 | {
|
| 1090 | return fiq->forget_list_head.next != NULL;
|
| 1091 | }
|
| 1092 |
|
| 1093 | static int request_pending(struct fuse_iqueue *fiq)
|
| 1094 | {
|
| 1095 | return !list_empty(&fiq->pending) || !list_empty(&fiq->interrupts) ||
|
| 1096 | forget_pending(fiq);
|
| 1097 | }
|
| 1098 |
|
| 1099 | |
| 1100 | * Transfer an interrupt request to userspace
|
| 1101 | *
|
| 1102 | * Unlike other requests this is assembled on demand, without a need
|
| 1103 | * to allocate a separate fuse_req structure.
|
| 1104 | *
|
| 1105 | * Called with fiq->lock held, releases it
|
| 1106 |
|
| 1107 | static int fuse_read_interrupt(struct fuse_iqueue *fiq,
|
| 1108 | struct fuse_copy_state *cs,
|
| 1109 | size_t nbytes, struct fuse_req *req)
|
| 1110 | __releases(fiq->lock)
|
| 1111 | {
|
| 1112 | struct fuse_in_header ih;
|
| 1113 | struct fuse_interrupt_in arg;
|
| 1114 | unsigned reqsize = sizeof(ih) + sizeof(arg);
|
| 1115 | int err;
|
| 1116 |
|
| 1117 | list_del_init(&req->intr_entry);
|
| 1118 | memset(&ih, 0, sizeof(ih));
|
| 1119 | memset(&arg, 0, sizeof(arg));
|
| 1120 | ih.len = reqsize;
|
| 1121 | ih.opcode = FUSE_INTERRUPT;
|
| 1122 | ih.unique = (req->in.h.unique | FUSE_INT_REQ_BIT);
|
| 1123 | arg.unique = req->in.h.unique;
|
| 1124 |
|
| 1125 | spin_unlock(&fiq->lock);
|
| 1126 | if (nbytes < reqsize)
|
| 1127 | return -EINVAL;
|
| 1128 |
|
| 1129 | err = fuse_copy_one(cs, &ih, sizeof(ih));
|
| 1130 | if (!err)
|
| 1131 | err = fuse_copy_one(cs, &arg, sizeof(arg));
|
| 1132 | fuse_copy_finish(cs);
|
| 1133 |
|
| 1134 | return err ? err : reqsize;
|
| 1135 | }
|
| 1136 |
|
| 1137 | static struct fuse_forget_link *fuse_dequeue_forget(struct fuse_iqueue *fiq,
|
| 1138 | unsigned int max,
|
| 1139 | unsigned int *countp)
|
| 1140 | {
|
| 1141 | struct fuse_forget_link *head = fiq->forget_list_head.next;
|
| 1142 | struct fuse_forget_link **newhead = &head;
|
| 1143 | unsigned count;
|
| 1144 |
|
| 1145 | for (count = 0; *newhead != NULL && count < max; count++)
|
| 1146 | newhead = &(*newhead)->next;
|
| 1147 |
|
| 1148 | fiq->forget_list_head.next = *newhead;
|
| 1149 | *newhead = NULL;
|
| 1150 | if (fiq->forget_list_head.next == NULL)
|
| 1151 | fiq->forget_list_tail = &fiq->forget_list_head;
|
| 1152 |
|
| 1153 | if (countp != NULL)
|
| 1154 | *countp = count;
|
| 1155 |
|
| 1156 | return head;
|
| 1157 | }
|
| 1158 |
|
| 1159 | static int fuse_read_single_forget(struct fuse_iqueue *fiq,
|
| 1160 | struct fuse_copy_state *cs,
|
| 1161 | size_t nbytes)
|
| 1162 | __releases(fiq->lock)
|
| 1163 | {
|
| 1164 | int err;
|
| 1165 | struct fuse_forget_link *forget = fuse_dequeue_forget(fiq, 1, NULL);
|
| 1166 | struct fuse_forget_in arg = {
|
| 1167 | .nlookup = forget->forget_one.nlookup,
|
| 1168 | };
|
| 1169 | struct fuse_in_header ih = {
|
| 1170 | .opcode = FUSE_FORGET,
|
| 1171 | .nodeid = forget->forget_one.nodeid,
|
| 1172 | .unique = fuse_get_unique_locked(fiq),
|
| 1173 | .len = sizeof(ih) + sizeof(arg),
|
| 1174 | };
|
| 1175 |
|
| 1176 | spin_unlock(&fiq->lock);
|
| 1177 | kfree(forget);
|
| 1178 | if (nbytes < ih.len)
|
| 1179 | return -EINVAL;
|
| 1180 |
|
| 1181 | err = fuse_copy_one(cs, &ih, sizeof(ih));
|
| 1182 | if (!err)
|
| 1183 | err = fuse_copy_one(cs, &arg, sizeof(arg));
|
| 1184 | fuse_copy_finish(cs);
|
| 1185 |
|
| 1186 | if (err)
|
| 1187 | return err;
|
| 1188 |
|
| 1189 | return ih.len;
|
| 1190 | }
|
| 1191 |
|
| 1192 | static int fuse_read_batch_forget(struct fuse_iqueue *fiq,
|
| 1193 | struct fuse_copy_state *cs, size_t nbytes)
|
| 1194 | __releases(fiq->lock)
|
| 1195 | {
|
| 1196 | int err;
|
| 1197 | unsigned max_forgets;
|
| 1198 | unsigned count;
|
| 1199 | struct fuse_forget_link *head;
|
| 1200 | struct fuse_batch_forget_in arg = { .count = 0 };
|
| 1201 | struct fuse_in_header ih = {
|
| 1202 | .opcode = FUSE_BATCH_FORGET,
|
| 1203 | .unique = fuse_get_unique_locked(fiq),
|
| 1204 | .len = sizeof(ih) + sizeof(arg),
|
| 1205 | };
|
| 1206 |
|
| 1207 | if (nbytes < ih.len) {
|
| 1208 | spin_unlock(&fiq->lock);
|
| 1209 | return -EINVAL;
|
| 1210 | }
|
| 1211 |
|
| 1212 | max_forgets = (nbytes - ih.len) / sizeof(struct fuse_forget_one);
|
| 1213 | head = fuse_dequeue_forget(fiq, max_forgets, &count);
|
| 1214 | spin_unlock(&fiq->lock);
|
| 1215 |
|
| 1216 | arg.count = count;
|
| 1217 | ih.len += count * sizeof(struct fuse_forget_one);
|
| 1218 | err = fuse_copy_one(cs, &ih, sizeof(ih));
|
| 1219 | if (!err)
|
| 1220 | err = fuse_copy_one(cs, &arg, sizeof(arg));
|
| 1221 |
|
| 1222 | while (head) {
|
| 1223 | struct fuse_forget_link *forget = head;
|
| 1224 |
|
| 1225 | if (!err) {
|
| 1226 | err = fuse_copy_one(cs, &forget->forget_one,
|
| 1227 | sizeof(forget->forget_one));
|
| 1228 | }
|
| 1229 | head = forget->next;
|
| 1230 | kfree(forget);
|
| 1231 | }
|
| 1232 |
|
| 1233 | fuse_copy_finish(cs);
|
| 1234 |
|
| 1235 | if (err)
|
| 1236 | return err;
|
| 1237 |
|
| 1238 | return ih.len;
|
| 1239 | }
|
| 1240 |
|
| 1241 | static int fuse_read_forget(struct fuse_conn *fc, struct fuse_iqueue *fiq,
|
| 1242 | struct fuse_copy_state *cs,
|
| 1243 | size_t nbytes)
|
| 1244 | __releases(fiq->lock)
|
| 1245 | {
|
| 1246 | if (fc->minor < 16 || fiq->forget_list_head.next->next == NULL)
|
| 1247 | return fuse_read_single_forget(fiq, cs, nbytes);
|
| 1248 | else
|
| 1249 | return fuse_read_batch_forget(fiq, cs, nbytes);
|
| 1250 | }
|
| 1251 |
|
| 1252 | |
| 1253 | * Read a single request into the userspace filesystem's buffer. This
|
| 1254 | * function waits until a request is available, then removes it from
|
| 1255 | * the pending list and copies request data to userspace buffer. If
|
| 1256 | * no reply is needed (FORGET) or request has been aborted or there
|
| 1257 | * was an error during the copying then it's finished by calling
|
| 1258 | * fuse_request_end(). Otherwise add it to the processing list, and set
|
| 1259 | * the 'sent' flag.
|
| 1260 |
|
| 1261 | static ssize_t fuse_dev_do_read(struct fuse_dev *fud, struct file *file,
|
| 1262 | struct fuse_copy_state *cs, size_t nbytes)
|
| 1263 | {
|
| 1264 | ssize_t err;
|
| 1265 | struct fuse_conn *fc = fud->fc;
|
| 1266 | struct fuse_iqueue *fiq = &fc->iq;
|
| 1267 | struct fuse_pqueue *fpq = &fud->pq;
|
| 1268 | struct fuse_req *req;
|
| 1269 | struct fuse_args *args;
|
| 1270 | unsigned reqsize;
|
| 1271 | unsigned int hash;
|
| 1272 |
|
| 1273 | |
| 1274 | * Require sane minimum read buffer - that has capacity for fixed part
|
| 1275 | * of any request header + negotiated max_write room for data.
|
| 1276 | *
|
| 1277 | * Historically libfuse reserves 4K for fixed header room, but e.g.
|
| 1278 | * GlusterFS reserves only 80 bytes
|
| 1279 | *
|
| 1280 | * = `sizeof(fuse_in_header) + sizeof(fuse_write_in)`
|
| 1281 | *
|
| 1282 | * which is the absolute minimum any sane filesystem should be using
|
| 1283 | * for header room.
|
| 1284 |
|
| 1285 | if (nbytes < max_t(size_t, FUSE_MIN_READ_BUFFER,
|
| 1286 | sizeof(struct fuse_in_header) +
|
| 1287 | sizeof(struct fuse_write_in) +
|
| 1288 | fc->max_write))
|
| 1289 | return -EINVAL;
|
| 1290 |
|
| 1291 | restart:
|
| 1292 | for (;;) {
|
| 1293 | spin_lock(&fiq->lock);
|
| 1294 | if (!fiq->connected || request_pending(fiq))
|
| 1295 | break;
|
| 1296 | spin_unlock(&fiq->lock);
|
| 1297 |
|
| 1298 | if (file->f_flags & O_NONBLOCK)
|
| 1299 | return -EAGAIN;
|
| 1300 | err = wait_event_interruptible_exclusive(fiq->waitq,
|
| 1301 | !fiq->connected || request_pending(fiq));
|
| 1302 | if (err)
|
| 1303 | return err;
|
| 1304 | }
|
| 1305 |
|
| 1306 | if (!fiq->connected) {
|
| 1307 | err = fc->aborted ? -ECONNABORTED : -ENODEV;
|
| 1308 | goto err_unlock;
|
| 1309 | }
|
| 1310 |
|
| 1311 | if (!list_empty(&fiq->interrupts)) {
|
| 1312 | req = list_entry(fiq->interrupts.next, struct fuse_req,
|
| 1313 | intr_entry);
|
| 1314 | return fuse_read_interrupt(fiq, cs, nbytes, req);
|
| 1315 | }
|
| 1316 |
|
| 1317 | if (forget_pending(fiq)) {
|
| 1318 | if (list_empty(&fiq->pending) || fiq->forget_batch-- > 0)
|
| 1319 | return fuse_read_forget(fc, fiq, cs, nbytes);
|
| 1320 |
|
| 1321 | if (fiq->forget_batch <= -8)
|
| 1322 | fiq->forget_batch = 16;
|
| 1323 | }
|
| 1324 |
|
| 1325 | req = list_entry(fiq->pending.next, struct fuse_req, list);
|
| 1326 | clear_bit(FR_PENDING, &req->flags);
|
| 1327 | list_del_init(&req->list);
|
| 1328 | spin_unlock(&fiq->lock);
|
| 1329 |
|
| 1330 | args = req->args;
|
| 1331 | reqsize = req->in.h.len;
|
| 1332 |
|
| 1333 |
|
| 1334 | if (nbytes < reqsize) {
|
| 1335 | req->out.h.error = -EIO;
|
| 1336 |
|
| 1337 | if (args->opcode == FUSE_SETXATTR)
|
| 1338 | req->out.h.error = -E2BIG;
|
| 1339 | fuse_request_end(req);
|
| 1340 | goto restart;
|
| 1341 | }
|
| 1342 | spin_lock(&fpq->lock);
|
| 1343 | |
| 1344 | * Must not put request on fpq->io queue after having been shut down by
|
| 1345 | * fuse_abort_conn()
|
| 1346 |
|
| 1347 | if (!fpq->connected) {
|
| 1348 | req->out.h.error = err = -ECONNABORTED;
|
| 1349 | goto out_end;
|
| 1350 |
|
| 1351 | }
|
| 1352 | list_add(&req->list, &fpq->io);
|
| 1353 | spin_unlock(&fpq->lock);
|
| 1354 | cs->req = req;
|
| 1355 | err = fuse_copy_one(cs, &req->in.h, sizeof(req->in.h));
|
| 1356 | if (!err)
|
| 1357 | err = fuse_copy_args(cs, args->in_numargs, args->in_pages,
|
| 1358 | (struct fuse_arg *) args->in_args, 0);
|
| 1359 | fuse_copy_finish(cs);
|
| 1360 | spin_lock(&fpq->lock);
|
| 1361 | clear_bit(FR_LOCKED, &req->flags);
|
| 1362 | if (!fpq->connected) {
|
| 1363 | err = fc->aborted ? -ECONNABORTED : -ENODEV;
|
| 1364 | goto out_end;
|
| 1365 | }
|
| 1366 | if (err) {
|
| 1367 | req->out.h.error = -EIO;
|
| 1368 | goto out_end;
|
| 1369 | }
|
| 1370 | if (!test_bit(FR_ISREPLY, &req->flags)) {
|
| 1371 | err = reqsize;
|
| 1372 | goto out_end;
|
| 1373 | }
|
| 1374 | hash = fuse_req_hash(req->in.h.unique);
|
| 1375 | list_move_tail(&req->list, &fpq->processing[hash]);
|
| 1376 | __fuse_get_request(req);
|
| 1377 | set_bit(FR_SENT, &req->flags);
|
| 1378 | spin_unlock(&fpq->lock);
|
| 1379 |
|
| 1380 | smp_mb__after_atomic();
|
| 1381 | if (test_bit(FR_INTERRUPTED, &req->flags))
|
| 1382 | queue_interrupt(req);
|
| 1383 | fuse_put_request(req);
|
| 1384 |
|
| 1385 | return reqsize;
|
| 1386 |
|
| 1387 | out_end:
|
| 1388 | if (!test_bit(FR_PRIVATE, &req->flags))
|
| 1389 | list_del_init(&req->list);
|
| 1390 | spin_unlock(&fpq->lock);
|
| 1391 | fuse_request_end(req);
|
| 1392 | return err;
|
| 1393 |
|
| 1394 | err_unlock:
|
| 1395 | spin_unlock(&fiq->lock);
|
| 1396 | return err;
|
| 1397 | }
|
| 1398 |
|
| 1399 | static int fuse_dev_open(struct inode *inode, struct file *file)
|
| 1400 | {
|
| 1401 | |
| 1402 | * The fuse device's file's private_data is used to hold
|
| 1403 | * the fuse_conn(ection) when it is mounted, and is used to
|
| 1404 | * keep track of whether the file has been mounted already.
|
| 1405 |
|
| 1406 | file->private_data = NULL;
|
| 1407 | return 0;
|
| 1408 | }
|
| 1409 |
|
| 1410 | static ssize_t fuse_dev_read(struct kiocb *iocb, struct iov_iter *to)
|
| 1411 | {
|
| 1412 | struct fuse_copy_state cs;
|
| 1413 | struct file *file = iocb->ki_filp;
|
| 1414 | struct fuse_dev *fud = fuse_get_dev(file);
|
| 1415 |
|
| 1416 | if (!fud)
|
| 1417 | return -EPERM;
|
| 1418 |
|
| 1419 | if (!user_backed_iter(to))
|
| 1420 | return -EINVAL;
|
| 1421 |
|
| 1422 | fuse_copy_init(&cs, 1, to);
|
| 1423 |
|
| 1424 | return fuse_dev_do_read(fud, file, &cs, iov_iter_count(to));
|
| 1425 | }
|
| 1426 |
|
| 1427 | static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
|
| 1428 | struct pipe_inode_info *pipe,
|
| 1429 | size_t len, unsigned int flags)
|
| 1430 | {
|
| 1431 | int total, ret;
|
| 1432 | int page_nr = 0;
|
| 1433 | struct pipe_buffer *bufs;
|
| 1434 | struct fuse_copy_state cs;
|
| 1435 | struct fuse_dev *fud = fuse_get_dev(in);
|
| 1436 |
|
| 1437 | if (!fud)
|
| 1438 | return -EPERM;
|
| 1439 |
|
| 1440 | bufs = kvmalloc_array(pipe->max_usage, sizeof(struct pipe_buffer),
|
| 1441 | GFP_KERNEL);
|
| 1442 | if (!bufs)
|
| 1443 | return -ENOMEM;
|
| 1444 |
|
| 1445 | fuse_copy_init(&cs, 1, NULL);
|
| 1446 | cs.pipebufs = bufs;
|
| 1447 | cs.pipe = pipe;
|
| 1448 | ret = fuse_dev_do_read(fud, in, &cs, len);
|
| 1449 | if (ret < 0)
|
| 1450 | goto out;
|
| 1451 |
|
| 1452 | if (pipe_occupancy(pipe->head, pipe->tail) + cs.nr_segs > pipe->max_usage) {
|
| 1453 | ret = -EIO;
|
| 1454 | goto out;
|
| 1455 | }
|
| 1456 |
|
| 1457 | for (ret = total = 0; page_nr < cs.nr_segs; total += ret) {
|
| 1458 | |
| 1459 | * Need to be careful about this. Having buf->ops in module
|
| 1460 | * code can Oops if the buffer persists after module unload.
|
| 1461 |
|
| 1462 | bufs[page_nr].ops = &nosteal_pipe_buf_ops;
|
| 1463 | bufs[page_nr].flags = 0;
|
| 1464 | ret = add_to_pipe(pipe, &bufs[page_nr++]);
|
| 1465 | if (unlikely(ret < 0))
|
| 1466 | break;
|
| 1467 | }
|
| 1468 | if (total)
|
| 1469 | ret = total;
|
| 1470 | out:
|
| 1471 | for (; page_nr < cs.nr_segs; page_nr++)
|
| 1472 | put_page(bufs[page_nr].page);
|
| 1473 |
|
| 1474 | kvfree(bufs);
|
| 1475 | return ret;
|
| 1476 | }
|
| 1477 |
|
| 1478 | static int fuse_notify_poll(struct fuse_conn *fc, unsigned int size,
|
| 1479 | struct fuse_copy_state *cs)
|
| 1480 | {
|
| 1481 | struct fuse_notify_poll_wakeup_out outarg;
|
| 1482 | int err = -EINVAL;
|
| 1483 |
|
| 1484 | if (size != sizeof(outarg))
|
| 1485 | goto err;
|
| 1486 |
|
| 1487 | err = fuse_copy_one(cs, &outarg, sizeof(outarg));
|
| 1488 | if (err)
|
| 1489 | goto err;
|
| 1490 |
|
| 1491 | fuse_copy_finish(cs);
|
| 1492 | return fuse_notify_poll_wakeup(fc, &outarg);
|
| 1493 |
|
| 1494 | err:
|
| 1495 | fuse_copy_finish(cs);
|
| 1496 | return err;
|
| 1497 | }
|
| 1498 |
|
| 1499 | static int fuse_notify_inval_inode(struct fuse_conn *fc, unsigned int size,
|
| 1500 | struct fuse_copy_state *cs)
|
| 1501 | {
|
| 1502 | struct fuse_notify_inval_inode_out outarg;
|
| 1503 | int err = -EINVAL;
|
| 1504 |
|
| 1505 | if (size != sizeof(outarg))
|
| 1506 | goto err;
|
| 1507 |
|
| 1508 | err = fuse_copy_one(cs, &outarg, sizeof(outarg));
|
| 1509 | if (err)
|
| 1510 | goto err;
|
| 1511 | fuse_copy_finish(cs);
|
| 1512 |
|
| 1513 | down_read(&fc->killsb);
|
| 1514 | err = fuse_reverse_inval_inode(fc, outarg.ino,
|
| 1515 | outarg.off, outarg.len);
|
| 1516 | up_read(&fc->killsb);
|
| 1517 | return err;
|
| 1518 |
|
| 1519 | err:
|
| 1520 | fuse_copy_finish(cs);
|
| 1521 | return err;
|
| 1522 | }
|
| 1523 |
|
| 1524 | static int fuse_notify_inval_entry(struct fuse_conn *fc, unsigned int size,
|
| 1525 | struct fuse_copy_state *cs)
|
| 1526 | {
|
| 1527 | struct fuse_notify_inval_entry_out outarg;
|
| 1528 | int err = -ENOMEM;
|
| 1529 | char *buf;
|
| 1530 | struct qstr name;
|
| 1531 |
|
| 1532 | buf = kzalloc(FUSE_NAME_MAX + 1, GFP_KERNEL);
|
| 1533 | if (!buf)
|
| 1534 | goto err;
|
| 1535 |
|
| 1536 | err = -EINVAL;
|
| 1537 | if (size < sizeof(outarg))
|
| 1538 | goto err;
|
| 1539 |
|
| 1540 | err = fuse_copy_one(cs, &outarg, sizeof(outarg));
|
| 1541 | if (err)
|
| 1542 | goto err;
|
| 1543 |
|
| 1544 | err = -ENAMETOOLONG;
|
| 1545 | if (outarg.namelen > FUSE_NAME_MAX)
|
| 1546 | goto err;
|
| 1547 |
|
| 1548 | err = -EINVAL;
|
| 1549 | if (size != sizeof(outarg) + outarg.namelen + 1)
|
| 1550 | goto err;
|
| 1551 |
|
| 1552 | name.name = buf;
|
| 1553 | name.len = outarg.namelen;
|
| 1554 | err = fuse_copy_one(cs, buf, outarg.namelen + 1);
|
| 1555 | if (err)
|
| 1556 | goto err;
|
| 1557 | fuse_copy_finish(cs);
|
| 1558 | buf[outarg.namelen] = 0;
|
| 1559 |
|
| 1560 | down_read(&fc->killsb);
|
| 1561 | err = fuse_reverse_inval_entry(fc, outarg.parent, 0, &name, outarg.flags);
|
| 1562 | up_read(&fc->killsb);
|
| 1563 | kfree(buf);
|
| 1564 | return err;
|
| 1565 |
|
| 1566 | err:
|
| 1567 | kfree(buf);
|
| 1568 | fuse_copy_finish(cs);
|
| 1569 | return err;
|
| 1570 | }
|
| 1571 |
|
| 1572 | static int fuse_notify_delete(struct fuse_conn *fc, unsigned int size,
|
| 1573 | struct fuse_copy_state *cs)
|
| 1574 | {
|
| 1575 | struct fuse_notify_delete_out outarg;
|
| 1576 | int err = -ENOMEM;
|
| 1577 | char *buf;
|
| 1578 | struct qstr name;
|
| 1579 |
|
| 1580 | buf = kzalloc(FUSE_NAME_MAX + 1, GFP_KERNEL);
|
| 1581 | if (!buf)
|
| 1582 | goto err;
|
| 1583 |
|
| 1584 | err = -EINVAL;
|
| 1585 | if (size < sizeof(outarg))
|
| 1586 | goto err;
|
| 1587 |
|
| 1588 | err = fuse_copy_one(cs, &outarg, sizeof(outarg));
|
| 1589 | if (err)
|
| 1590 | goto err;
|
| 1591 |
|
| 1592 | err = -ENAMETOOLONG;
|
| 1593 | if (outarg.namelen > FUSE_NAME_MAX)
|
| 1594 | goto err;
|
| 1595 |
|
| 1596 | err = -EINVAL;
|
| 1597 | if (size != sizeof(outarg) + outarg.namelen + 1)
|
| 1598 | goto err;
|
| 1599 |
|
| 1600 | name.name = buf;
|
| 1601 | name.len = outarg.namelen;
|
| 1602 | err = fuse_copy_one(cs, buf, outarg.namelen + 1);
|
| 1603 | if (err)
|
| 1604 | goto err;
|
| 1605 | fuse_copy_finish(cs);
|
| 1606 | buf[outarg.namelen] = 0;
|
| 1607 |
|
| 1608 | down_read(&fc->killsb);
|
| 1609 | err = fuse_reverse_inval_entry(fc, outarg.parent, outarg.child, &name, 0);
|
| 1610 | up_read(&fc->killsb);
|
| 1611 | kfree(buf);
|
| 1612 | return err;
|
| 1613 |
|
| 1614 | err:
|
| 1615 | kfree(buf);
|
| 1616 | fuse_copy_finish(cs);
|
| 1617 | return err;
|
| 1618 | }
|
| 1619 |
|
| 1620 | static int fuse_notify_store(struct fuse_conn *fc, unsigned int size,
|
| 1621 | struct fuse_copy_state *cs)
|
| 1622 | {
|
| 1623 | struct fuse_notify_store_out outarg;
|
| 1624 | struct inode *inode;
|
| 1625 | struct address_space *mapping;
|
| 1626 | u64 nodeid;
|
| 1627 | int err;
|
| 1628 | pgoff_t index;
|
| 1629 | unsigned int offset;
|
| 1630 | unsigned int num;
|
| 1631 | loff_t file_size;
|
| 1632 | loff_t end;
|
| 1633 |
|
| 1634 | err = -EINVAL;
|
| 1635 | if (size < sizeof(outarg))
|
| 1636 | goto out_finish;
|
| 1637 |
|
| 1638 | err = fuse_copy_one(cs, &outarg, sizeof(outarg));
|
| 1639 | if (err)
|
| 1640 | goto out_finish;
|
| 1641 |
|
| 1642 | err = -EINVAL;
|
| 1643 | if (size - sizeof(outarg) != outarg.size)
|
| 1644 | goto out_finish;
|
| 1645 |
|
| 1646 | nodeid = outarg.nodeid;
|
| 1647 |
|
| 1648 | down_read(&fc->killsb);
|
| 1649 |
|
| 1650 | err = -ENOENT;
|
| 1651 | inode = fuse_ilookup(fc, nodeid, NULL);
|
| 1652 | if (!inode)
|
| 1653 | goto out_up_killsb;
|
| 1654 |
|
| 1655 | mapping = inode->i_mapping;
|
| 1656 | index = outarg.offset >> PAGE_SHIFT;
|
| 1657 | offset = outarg.offset & ~PAGE_MASK;
|
| 1658 | file_size = i_size_read(inode);
|
| 1659 | end = outarg.offset + outarg.size;
|
| 1660 | if (end > file_size) {
|
| 1661 | file_size = end;
|
| 1662 | fuse_write_update_attr(inode, file_size, outarg.size);
|
| 1663 | }
|
| 1664 |
|
| 1665 | num = outarg.size;
|
| 1666 | while (num) {
|
| 1667 | struct folio *folio;
|
| 1668 | struct page *page;
|
| 1669 | unsigned int this_num;
|
| 1670 |
|
| 1671 | folio = filemap_grab_folio(mapping, index);
|
| 1672 | err = PTR_ERR(folio);
|
| 1673 | if (IS_ERR(folio))
|
| 1674 | goto out_iput;
|
| 1675 |
|
| 1676 | page = &folio->page;
|
| 1677 | this_num = min_t(unsigned, num, folio_size(folio) - offset);
|
| 1678 | err = fuse_copy_page(cs, &page, offset, this_num, 0);
|
| 1679 | if (!folio_test_uptodate(folio) && !err && offset == 0 &&
|
| 1680 | (this_num == folio_size(folio) || file_size == end)) {
|
| 1681 | folio_zero_segment(folio, this_num, folio_size(folio));
|
| 1682 | folio_mark_uptodate(folio);
|
| 1683 | }
|
| 1684 | folio_unlock(folio);
|
| 1685 | folio_put(folio);
|
| 1686 |
|
| 1687 | if (err)
|
| 1688 | goto out_iput;
|
| 1689 |
|
| 1690 | num -= this_num;
|
| 1691 | offset = 0;
|
| 1692 | index++;
|
| 1693 | }
|
| 1694 |
|
| 1695 | err = 0;
|
| 1696 |
|
| 1697 | out_iput:
|
| 1698 | iput(inode);
|
| 1699 | out_up_killsb:
|
| 1700 | up_read(&fc->killsb);
|
| 1701 | out_finish:
|
| 1702 | fuse_copy_finish(cs);
|
| 1703 | return err;
|
| 1704 | }
|
| 1705 |
|
| 1706 | struct fuse_retrieve_args {
|
| 1707 | struct fuse_args_pages ap;
|
| 1708 | struct fuse_notify_retrieve_in inarg;
|
| 1709 | };
|
| 1710 |
|
| 1711 | static void fuse_retrieve_end(struct fuse_mount *fm, struct fuse_args *args,
|
| 1712 | int error)
|
| 1713 | {
|
| 1714 | struct fuse_retrieve_args *ra =
|
| 1715 | container_of(args, typeof(*ra), ap.args);
|
| 1716 |
|
| 1717 | release_pages(ra->ap.folios, ra->ap.num_folios);
|
| 1718 | kfree(ra);
|
| 1719 | }
|
| 1720 |
|
| 1721 | static int fuse_retrieve(struct fuse_mount *fm, struct inode *inode,
|
| 1722 | struct fuse_notify_retrieve_out *outarg)
|
| 1723 | {
|
| 1724 | int err;
|
| 1725 | struct address_space *mapping = inode->i_mapping;
|
| 1726 | pgoff_t index;
|
| 1727 | loff_t file_size;
|
| 1728 | unsigned int num;
|
| 1729 | unsigned int offset;
|
| 1730 | size_t total_len = 0;
|
| 1731 | unsigned int num_pages, cur_pages = 0;
|
| 1732 | struct fuse_conn *fc = fm->fc;
|
| 1733 | struct fuse_retrieve_args *ra;
|
| 1734 | size_t args_size = sizeof(*ra);
|
| 1735 | struct fuse_args_pages *ap;
|
| 1736 | struct fuse_args *args;
|
| 1737 |
|
| 1738 | offset = outarg->offset & ~PAGE_MASK;
|
| 1739 | file_size = i_size_read(inode);
|
| 1740 |
|
| 1741 | num = min(outarg->size, fc->max_write);
|
| 1742 | if (outarg->offset > file_size)
|
| 1743 | num = 0;
|
| 1744 | else if (outarg->offset + num > file_size)
|
| 1745 | num = file_size - outarg->offset;
|
| 1746 |
|
| 1747 | num_pages = (num + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
|
| 1748 | num_pages = min(num_pages, fc->max_pages);
|
| 1749 |
|
| 1750 | args_size += num_pages * (sizeof(ap->folios[0]) + sizeof(ap->descs[0]));
|
| 1751 |
|
| 1752 | ra = kzalloc(args_size, GFP_KERNEL);
|
| 1753 | if (!ra)
|
| 1754 | return -ENOMEM;
|
| 1755 |
|
| 1756 | ap = &ra->ap;
|
| 1757 | ap->folios = (void *) (ra + 1);
|
| 1758 | ap->descs = (void *) (ap->folios + num_pages);
|
| 1759 |
|
| 1760 | args = &ap->args;
|
| 1761 | args->nodeid = outarg->nodeid;
|
| 1762 | args->opcode = FUSE_NOTIFY_REPLY;
|
| 1763 | args->in_numargs = 2;
|
| 1764 | args->in_pages = true;
|
| 1765 | args->end = fuse_retrieve_end;
|
| 1766 |
|
| 1767 | index = outarg->offset >> PAGE_SHIFT;
|
| 1768 |
|
| 1769 | while (num && cur_pages < num_pages) {
|
| 1770 | struct folio *folio;
|
| 1771 | unsigned int this_num;
|
| 1772 |
|
| 1773 | folio = filemap_get_folio(mapping, index);
|
| 1774 | if (IS_ERR(folio))
|
| 1775 | break;
|
| 1776 |
|
| 1777 | this_num = min_t(unsigned, num, PAGE_SIZE - offset);
|
| 1778 | ap->folios[ap->num_folios] = folio;
|
| 1779 | ap->descs[ap->num_folios].offset = offset;
|
| 1780 | ap->descs[ap->num_folios].length = this_num;
|
| 1781 | ap->num_folios++;
|
| 1782 | cur_pages++;
|
| 1783 |
|
| 1784 | offset = 0;
|
| 1785 | num -= this_num;
|
| 1786 | total_len += this_num;
|
| 1787 | index++;
|
| 1788 | }
|
| 1789 | ra->inarg.offset = outarg->offset;
|
| 1790 | ra->inarg.size = total_len;
|
| 1791 | args->in_args[0].size = sizeof(ra->inarg);
|
| 1792 | args->in_args[0].value = &ra->inarg;
|
| 1793 | args->in_args[1].size = total_len;
|
| 1794 |
|
| 1795 | err = fuse_simple_notify_reply(fm, args, outarg->notify_unique);
|
| 1796 | if (err)
|
| 1797 | fuse_retrieve_end(fm, args, err);
|
| 1798 |
|
| 1799 | return err;
|
| 1800 | }
|
| 1801 |
|
| 1802 | static int fuse_notify_retrieve(struct fuse_conn *fc, unsigned int size,
|
| 1803 | struct fuse_copy_state *cs)
|
| 1804 | {
|
| 1805 | struct fuse_notify_retrieve_out outarg;
|
| 1806 | struct fuse_mount *fm;
|
| 1807 | struct inode *inode;
|
| 1808 | u64 nodeid;
|
| 1809 | int err;
|
| 1810 |
|
| 1811 | err = -EINVAL;
|
| 1812 | if (size != sizeof(outarg))
|
| 1813 | goto copy_finish;
|
| 1814 |
|
| 1815 | err = fuse_copy_one(cs, &outarg, sizeof(outarg));
|
| 1816 | if (err)
|
| 1817 | goto copy_finish;
|
| 1818 |
|
| 1819 | fuse_copy_finish(cs);
|
| 1820 |
|
| 1821 | down_read(&fc->killsb);
|
| 1822 | err = -ENOENT;
|
| 1823 | nodeid = outarg.nodeid;
|
| 1824 |
|
| 1825 | inode = fuse_ilookup(fc, nodeid, &fm);
|
| 1826 | if (inode) {
|
| 1827 | err = fuse_retrieve(fm, inode, &outarg);
|
| 1828 | iput(inode);
|
| 1829 | }
|
| 1830 | up_read(&fc->killsb);
|
| 1831 |
|
| 1832 | return err;
|
| 1833 |
|
| 1834 | copy_finish:
|
| 1835 | fuse_copy_finish(cs);
|
| 1836 | return err;
|
| 1837 | }
|
| 1838 |
|
| 1839 | |
| 1840 | * Resending all processing queue requests.
|
| 1841 | *
|
| 1842 | * During a FUSE daemon panics and failover, it is possible for some inflight
|
| 1843 | * requests to be lost and never returned. As a result, applications awaiting
|
| 1844 | * replies would become stuck forever. To address this, we can use notification
|
| 1845 | * to trigger resending of these pending requests to the FUSE daemon, ensuring
|
| 1846 | * they are properly processed again.
|
| 1847 | *
|
| 1848 | * Please note that this strategy is applicable only to idempotent requests or
|
| 1849 | * if the FUSE daemon takes careful measures to avoid processing duplicated
|
| 1850 | * non-idempotent requests.
|
| 1851 |
|
| 1852 | static void fuse_resend(struct fuse_conn *fc)
|
| 1853 | {
|
| 1854 | struct fuse_dev *fud;
|
| 1855 | struct fuse_req *req, *next;
|
| 1856 | struct fuse_iqueue *fiq = &fc->iq;
|
| 1857 | LIST_HEAD(to_queue);
|
| 1858 | unsigned int i;
|
| 1859 |
|
| 1860 | spin_lock(&fc->lock);
|
| 1861 | if (!fc->connected) {
|
| 1862 | spin_unlock(&fc->lock);
|
| 1863 | return;
|
| 1864 | }
|
| 1865 |
|
| 1866 | list_for_each_entry(fud, &fc->devices, entry) {
|
| 1867 | struct fuse_pqueue *fpq = &fud->pq;
|
| 1868 |
|
| 1869 | spin_lock(&fpq->lock);
|
| 1870 | for (i = 0; i < FUSE_PQ_HASH_SIZE; i++)
|
| 1871 | list_splice_tail_init(&fpq->processing[i], &to_queue);
|
| 1872 | spin_unlock(&fpq->lock);
|
| 1873 | }
|
| 1874 | spin_unlock(&fc->lock);
|
| 1875 |
|
| 1876 | list_for_each_entry_safe(req, next, &to_queue, list) {
|
| 1877 | set_bit(FR_PENDING, &req->flags);
|
| 1878 | clear_bit(FR_SENT, &req->flags);
|
| 1879 |
|
| 1880 | req->in.h.unique |= FUSE_UNIQUE_RESEND;
|
| 1881 | }
|
| 1882 |
|
| 1883 | spin_lock(&fiq->lock);
|
| 1884 | if (!fiq->connected) {
|
| 1885 | spin_unlock(&fiq->lock);
|
| 1886 | list_for_each_entry(req, &to_queue, list)
|
| 1887 | clear_bit(FR_PENDING, &req->flags);
|
| 1888 | end_requests(&to_queue);
|
| 1889 | return;
|
| 1890 | }
|
| 1891 |
|
| 1892 | list_splice(&to_queue, &fiq->pending);
|
| 1893 | fuse_dev_wake_and_unlock(fiq);
|
| 1894 | }
|
| 1895 |
|
| 1896 | static int fuse_notify_resend(struct fuse_conn *fc)
|
| 1897 | {
|
| 1898 | fuse_resend(fc);
|
| 1899 | return 0;
|
| 1900 | }
|
| 1901 |
|
| 1902 | static int fuse_notify(struct fuse_conn *fc, enum fuse_notify_code code,
|
| 1903 | unsigned int size, struct fuse_copy_state *cs)
|
| 1904 | {
|
| 1905 |
|
| 1906 | cs->move_pages = 0;
|
| 1907 |
|
| 1908 | switch (code) {
|
| 1909 | case FUSE_NOTIFY_POLL:
|
| 1910 | return fuse_notify_poll(fc, size, cs);
|
| 1911 |
|
| 1912 | case FUSE_NOTIFY_INVAL_INODE:
|
| 1913 | return fuse_notify_inval_inode(fc, size, cs);
|
| 1914 |
|
| 1915 | case FUSE_NOTIFY_INVAL_ENTRY:
|
| 1916 | return fuse_notify_inval_entry(fc, size, cs);
|
| 1917 |
|
| 1918 | case FUSE_NOTIFY_STORE:
|
| 1919 | return fuse_notify_store(fc, size, cs);
|
| 1920 |
|
| 1921 | case FUSE_NOTIFY_RETRIEVE:
|
| 1922 | return fuse_notify_retrieve(fc, size, cs);
|
| 1923 |
|
| 1924 | case FUSE_NOTIFY_DELETE:
|
| 1925 | return fuse_notify_delete(fc, size, cs);
|
| 1926 |
|
| 1927 | case FUSE_NOTIFY_RESEND:
|
| 1928 | return fuse_notify_resend(fc);
|
| 1929 |
|
| 1930 | default:
|
| 1931 | fuse_copy_finish(cs);
|
| 1932 | return -EINVAL;
|
| 1933 | }
|
| 1934 | }
|
| 1935 |
|
| 1936 |
|
| 1937 | static struct fuse_req *request_find(struct fuse_pqueue *fpq, u64 unique)
|
| 1938 | {
|
| 1939 | unsigned int hash = fuse_req_hash(unique);
|
| 1940 | struct fuse_req *req;
|
| 1941 |
|
| 1942 | list_for_each_entry(req, &fpq->processing[hash], list) {
|
| 1943 | if (req->in.h.unique == unique)
|
| 1944 | return req;
|
| 1945 | }
|
| 1946 | return NULL;
|
| 1947 | }
|
| 1948 |
|
| 1949 | static int copy_out_args(struct fuse_copy_state *cs, struct fuse_args *args,
|
| 1950 | unsigned nbytes)
|
| 1951 | {
|
| 1952 | unsigned reqsize = sizeof(struct fuse_out_header);
|
| 1953 |
|
| 1954 | reqsize += fuse_len_args(args->out_numargs, args->out_args);
|
| 1955 |
|
| 1956 | if (reqsize < nbytes || (reqsize > nbytes && !args->out_argvar))
|
| 1957 | return -EINVAL;
|
| 1958 | else if (reqsize > nbytes) {
|
| 1959 | struct fuse_arg *lastarg = &args->out_args[args->out_numargs-1];
|
| 1960 | unsigned diffsize = reqsize - nbytes;
|
| 1961 |
|
| 1962 | if (diffsize > lastarg->size)
|
| 1963 | return -EINVAL;
|
| 1964 | lastarg->size -= diffsize;
|
| 1965 | }
|
| 1966 | return fuse_copy_args(cs, args->out_numargs, args->out_pages,
|
| 1967 | args->out_args, args->page_zeroing);
|
| 1968 | }
|
| 1969 |
|
| 1970 | |
| 1971 | * Write a single reply to a request. First the header is copied from
|
| 1972 | * the write buffer. The request is then searched on the processing
|
| 1973 | * list by the unique ID found in the header. If found, then remove
|
| 1974 | * it from the list and copy the rest of the buffer to the request.
|
| 1975 | * The request is finished by calling fuse_request_end().
|
| 1976 |
|
| 1977 | static ssize_t fuse_dev_do_write(struct fuse_dev *fud,
|
| 1978 | struct fuse_copy_state *cs, size_t nbytes)
|
| 1979 | {
|
| 1980 | int err;
|
| 1981 | struct fuse_conn *fc = fud->fc;
|
| 1982 | struct fuse_pqueue *fpq = &fud->pq;
|
| 1983 | struct fuse_req *req;
|
| 1984 | struct fuse_out_header oh;
|
| 1985 |
|
| 1986 | err = -EINVAL;
|
| 1987 | if (nbytes < sizeof(struct fuse_out_header))
|
| 1988 | goto out;
|
| 1989 |
|
| 1990 | err = fuse_copy_one(cs, &oh, sizeof(oh));
|
| 1991 | if (err)
|
| 1992 | goto copy_finish;
|
| 1993 |
|
| 1994 | err = -EINVAL;
|
| 1995 | if (oh.len != nbytes)
|
| 1996 | goto copy_finish;
|
| 1997 |
|
| 1998 | |
| 1999 | * Zero oh.unique indicates unsolicited notification message
|
| 2000 | * and error contains notification code.
|
| 2001 |
|
| 2002 | if (!oh.unique) {
|
| 2003 | err = fuse_notify(fc, oh.error, nbytes - sizeof(oh), cs);
|
| 2004 | goto out;
|
| 2005 | }
|
| 2006 |
|
| 2007 | err = -EINVAL;
|
| 2008 | if (oh.error <= -512 || oh.error > 0)
|
| 2009 | goto copy_finish;
|
| 2010 |
|
| 2011 | spin_lock(&fpq->lock);
|
| 2012 | req = NULL;
|
| 2013 | if (fpq->connected)
|
| 2014 | req = request_find(fpq, oh.unique & ~FUSE_INT_REQ_BIT);
|
| 2015 |
|
| 2016 | err = -ENOENT;
|
| 2017 | if (!req) {
|
| 2018 | spin_unlock(&fpq->lock);
|
| 2019 | goto copy_finish;
|
| 2020 | }
|
| 2021 |
|
| 2022 |
|
| 2023 | if (oh.unique & FUSE_INT_REQ_BIT) {
|
| 2024 | __fuse_get_request(req);
|
| 2025 | spin_unlock(&fpq->lock);
|
| 2026 |
|
| 2027 | err = 0;
|
| 2028 | if (nbytes != sizeof(struct fuse_out_header))
|
| 2029 | err = -EINVAL;
|
| 2030 | else if (oh.error == -ENOSYS)
|
| 2031 | fc->no_interrupt = 1;
|
| 2032 | else if (oh.error == -EAGAIN)
|
| 2033 | err = queue_interrupt(req);
|
| 2034 |
|
| 2035 | fuse_put_request(req);
|
| 2036 |
|
| 2037 | goto copy_finish;
|
| 2038 | }
|
| 2039 |
|
| 2040 | clear_bit(FR_SENT, &req->flags);
|
| 2041 | list_move(&req->list, &fpq->io);
|
| 2042 | req->out.h = oh;
|
| 2043 | set_bit(FR_LOCKED, &req->flags);
|
| 2044 | spin_unlock(&fpq->lock);
|
| 2045 | cs->req = req;
|
| 2046 | if (!req->args->page_replace)
|
| 2047 | cs->move_pages = 0;
|
| 2048 |
|
| 2049 | if (oh.error)
|
| 2050 | err = nbytes != sizeof(oh) ? -EINVAL : 0;
|
| 2051 | else
|
| 2052 | err = copy_out_args(cs, req->args, nbytes);
|
| 2053 | fuse_copy_finish(cs);
|
| 2054 |
|
| 2055 | spin_lock(&fpq->lock);
|
| 2056 | clear_bit(FR_LOCKED, &req->flags);
|
| 2057 | if (!fpq->connected)
|
| 2058 | err = -ENOENT;
|
| 2059 | else if (err)
|
| 2060 | req->out.h.error = -EIO;
|
| 2061 | if (!test_bit(FR_PRIVATE, &req->flags))
|
| 2062 | list_del_init(&req->list);
|
| 2063 | spin_unlock(&fpq->lock);
|
| 2064 |
|
| 2065 | fuse_request_end(req);
|
| 2066 | out:
|
| 2067 | return err ? err : nbytes;
|
| 2068 |
|
| 2069 | copy_finish:
|
| 2070 | fuse_copy_finish(cs);
|
| 2071 | goto out;
|
| 2072 | }
|
| 2073 |
|
| 2074 | static ssize_t fuse_dev_write(struct kiocb *iocb, struct iov_iter *from)
|
| 2075 | {
|
| 2076 | struct fuse_copy_state cs;
|
| 2077 | struct fuse_dev *fud = fuse_get_dev(iocb->ki_filp);
|
| 2078 |
|
| 2079 | if (!fud)
|
| 2080 | return -EPERM;
|
| 2081 |
|
| 2082 | if (!user_backed_iter(from))
|
| 2083 | return -EINVAL;
|
| 2084 |
|
| 2085 | fuse_copy_init(&cs, 0, from);
|
| 2086 |
|
| 2087 | return fuse_dev_do_write(fud, &cs, iov_iter_count(from));
|
| 2088 | }
|
| 2089 |
|
| 2090 | static ssize_t fuse_dev_splice_write(struct pipe_inode_info *pipe,
|
| 2091 | struct file *out, loff_t *ppos,
|
| 2092 | size_t len, unsigned int flags)
|
| 2093 | {
|
| 2094 | unsigned int head, tail, mask, count;
|
| 2095 | unsigned nbuf;
|
| 2096 | unsigned idx;
|
| 2097 | struct pipe_buffer *bufs;
|
| 2098 | struct fuse_copy_state cs;
|
| 2099 | struct fuse_dev *fud;
|
| 2100 | size_t rem;
|
| 2101 | ssize_t ret;
|
| 2102 |
|
| 2103 | fud = fuse_get_dev(out);
|
| 2104 | if (!fud)
|
| 2105 | return -EPERM;
|
| 2106 |
|
| 2107 | pipe_lock(pipe);
|
| 2108 |
|
| 2109 | head = pipe->head;
|
| 2110 | tail = pipe->tail;
|
| 2111 | mask = pipe->ring_size - 1;
|
| 2112 | count = head - tail;
|
| 2113 |
|
| 2114 | bufs = kvmalloc_array(count, sizeof(struct pipe_buffer), GFP_KERNEL);
|
| 2115 | if (!bufs) {
|
| 2116 | pipe_unlock(pipe);
|
| 2117 | return -ENOMEM;
|
| 2118 | }
|
| 2119 |
|
| 2120 | nbuf = 0;
|
| 2121 | rem = 0;
|
| 2122 | for (idx = tail; idx != head && rem < len; idx++)
|
| 2123 | rem += pipe->bufs[idx & mask].len;
|
| 2124 |
|
| 2125 | ret = -EINVAL;
|
| 2126 | if (rem < len)
|
| 2127 | goto out_free;
|
| 2128 |
|
| 2129 | rem = len;
|
| 2130 | while (rem) {
|
| 2131 | struct pipe_buffer *ibuf;
|
| 2132 | struct pipe_buffer *obuf;
|
| 2133 |
|
| 2134 | if (WARN_ON(nbuf >= count || tail == head))
|
| 2135 | goto out_free;
|
| 2136 |
|
| 2137 | ibuf = &pipe->bufs[tail & mask];
|
| 2138 | obuf = &bufs[nbuf];
|
| 2139 |
|
| 2140 | if (rem >= ibuf->len) {
|
| 2141 | *obuf = *ibuf;
|
| 2142 | ibuf->ops = NULL;
|
| 2143 | tail++;
|
| 2144 | pipe->tail = tail;
|
| 2145 | } else {
|
| 2146 | if (!pipe_buf_get(pipe, ibuf))
|
| 2147 | goto out_free;
|
| 2148 |
|
| 2149 | *obuf = *ibuf;
|
| 2150 | obuf->flags &= ~PIPE_BUF_FLAG_GIFT;
|
| 2151 | obuf->len = rem;
|
| 2152 | ibuf->offset += obuf->len;
|
| 2153 | ibuf->len -= obuf->len;
|
| 2154 | }
|
| 2155 | nbuf++;
|
| 2156 | rem -= obuf->len;
|
| 2157 | }
|
| 2158 | pipe_unlock(pipe);
|
| 2159 |
|
| 2160 | fuse_copy_init(&cs, 0, NULL);
|
| 2161 | cs.pipebufs = bufs;
|
| 2162 | cs.nr_segs = nbuf;
|
| 2163 | cs.pipe = pipe;
|
| 2164 |
|
| 2165 | if (flags & SPLICE_F_MOVE)
|
| 2166 | cs.move_pages = 1;
|
| 2167 |
|
| 2168 | ret = fuse_dev_do_write(fud, &cs, len);
|
| 2169 |
|
| 2170 | pipe_lock(pipe);
|
| 2171 | out_free:
|
| 2172 | for (idx = 0; idx < nbuf; idx++) {
|
| 2173 | struct pipe_buffer *buf = &bufs[idx];
|
| 2174 |
|
| 2175 | if (buf->ops)
|
| 2176 | pipe_buf_release(pipe, buf);
|
| 2177 | }
|
| 2178 | pipe_unlock(pipe);
|
| 2179 |
|
| 2180 | kvfree(bufs);
|
| 2181 | return ret;
|
| 2182 | }
|
| 2183 |
|
| 2184 | static __poll_t fuse_dev_poll(struct file *file, poll_table *wait)
|
| 2185 | {
|
| 2186 | __poll_t mask = EPOLLOUT | EPOLLWRNORM;
|
| 2187 | struct fuse_iqueue *fiq;
|
| 2188 | struct fuse_dev *fud = fuse_get_dev(file);
|
| 2189 |
|
| 2190 | if (!fud)
|
| 2191 | return EPOLLERR;
|
| 2192 |
|
| 2193 | fiq = &fud->fc->iq;
|
| 2194 | poll_wait(file, &fiq->waitq, wait);
|
| 2195 |
|
| 2196 | spin_lock(&fiq->lock);
|
| 2197 | if (!fiq->connected)
|
| 2198 | mask = EPOLLERR;
|
| 2199 | else if (request_pending(fiq))
|
| 2200 | mask |= EPOLLIN | EPOLLRDNORM;
|
| 2201 | spin_unlock(&fiq->lock);
|
| 2202 |
|
| 2203 | return mask;
|
| 2204 | }
|
| 2205 |
|
| 2206 |
|
| 2207 | static void end_requests(struct list_head *head)
|
| 2208 | {
|
| 2209 | while (!list_empty(head)) {
|
| 2210 | struct fuse_req *req;
|
| 2211 | req = list_entry(head->next, struct fuse_req, list);
|
| 2212 | req->out.h.error = -ECONNABORTED;
|
| 2213 | clear_bit(FR_SENT, &req->flags);
|
| 2214 | list_del_init(&req->list);
|
| 2215 | fuse_request_end(req);
|
| 2216 | }
|
| 2217 | }
|
| 2218 |
|
| 2219 | static void end_polls(struct fuse_conn *fc)
|
| 2220 | {
|
| 2221 | struct rb_node *p;
|
| 2222 |
|
| 2223 | p = rb_first(&fc->polled_files);
|
| 2224 |
|
| 2225 | while (p) {
|
| 2226 | struct fuse_file *ff;
|
| 2227 | ff = rb_entry(p, struct fuse_file, polled_node);
|
| 2228 | wake_up_interruptible_all(&ff->poll_wait);
|
| 2229 |
|
| 2230 | p = rb_next(p);
|
| 2231 | }
|
| 2232 | }
|
| 2233 |
|
| 2234 | |
| 2235 | * Abort all requests.
|
| 2236 | *
|
| 2237 | * Emergency exit in case of a malicious or accidental deadlock, or just a hung
|
| 2238 | * filesystem.
|
| 2239 | *
|
| 2240 | * The same effect is usually achievable through killing the filesystem daemon
|
| 2241 | * and all users of the filesystem. The exception is the combination of an
|
| 2242 | * asynchronous request and the tricky deadlock (see
|
| 2243 | * Documentation/filesystems/fuse.rst).
|
| 2244 | *
|
| 2245 | * Aborting requests under I/O goes as follows: 1: Separate out unlocked
|
| 2246 | * requests, they should be finished off immediately. Locked requests will be
|
| 2247 | * finished after unlock; see unlock_request(). 2: Finish off the unlocked
|
| 2248 | * requests. It is possible that some request will finish before we can. This
|
| 2249 | * is OK, the request will in that case be removed from the list before we touch
|
| 2250 | * it.
|
| 2251 |
|
| 2252 | void fuse_abort_conn(struct fuse_conn *fc)
|
| 2253 | {
|
| 2254 | struct fuse_iqueue *fiq = &fc->iq;
|
| 2255 |
|
| 2256 | spin_lock(&fc->lock);
|
| 2257 | if (fc->connected) {
|
| 2258 | struct fuse_dev *fud;
|
| 2259 | struct fuse_req *req, *next;
|
| 2260 | LIST_HEAD(to_end);
|
| 2261 | unsigned int i;
|
| 2262 |
|
| 2263 |
|
| 2264 | spin_lock(&fc->bg_lock);
|
| 2265 | fc->connected = 0;
|
| 2266 | spin_unlock(&fc->bg_lock);
|
| 2267 |
|
| 2268 | fuse_set_initialized(fc);
|
| 2269 | list_for_each_entry(fud, &fc->devices, entry) {
|
| 2270 | struct fuse_pqueue *fpq = &fud->pq;
|
| 2271 |
|
| 2272 | spin_lock(&fpq->lock);
|
| 2273 | fpq->connected = 0;
|
| 2274 | list_for_each_entry_safe(req, next, &fpq->io, list) {
|
| 2275 | req->out.h.error = -ECONNABORTED;
|
| 2276 | spin_lock(&req->waitq.lock);
|
| 2277 | set_bit(FR_ABORTED, &req->flags);
|
| 2278 | if (!test_bit(FR_LOCKED, &req->flags)) {
|
| 2279 | set_bit(FR_PRIVATE, &req->flags);
|
| 2280 | __fuse_get_request(req);
|
| 2281 | list_move(&req->list, &to_end);
|
| 2282 | }
|
| 2283 | spin_unlock(&req->waitq.lock);
|
| 2284 | }
|
| 2285 | for (i = 0; i < FUSE_PQ_HASH_SIZE; i++)
|
| 2286 | list_splice_tail_init(&fpq->processing[i],
|
| 2287 | &to_end);
|
| 2288 | spin_unlock(&fpq->lock);
|
| 2289 | }
|
| 2290 | spin_lock(&fc->bg_lock);
|
| 2291 | fc->blocked = 0;
|
| 2292 | fc->max_background = UINT_MAX;
|
| 2293 | flush_bg_queue(fc);
|
| 2294 | spin_unlock(&fc->bg_lock);
|
| 2295 |
|
| 2296 | spin_lock(&fiq->lock);
|
| 2297 | fiq->connected = 0;
|
| 2298 | list_for_each_entry(req, &fiq->pending, list)
|
| 2299 | clear_bit(FR_PENDING, &req->flags);
|
| 2300 | list_splice_tail_init(&fiq->pending, &to_end);
|
| 2301 | while (forget_pending(fiq))
|
| 2302 | kfree(fuse_dequeue_forget(fiq, 1, NULL));
|
| 2303 | wake_up_all(&fiq->waitq);
|
| 2304 | spin_unlock(&fiq->lock);
|
| 2305 | kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
|
| 2306 | end_polls(fc);
|
| 2307 | wake_up_all(&fc->blocked_waitq);
|
| 2308 | spin_unlock(&fc->lock);
|
| 2309 |
|
| 2310 | end_requests(&to_end);
|
| 2311 | } else {
|
| 2312 | spin_unlock(&fc->lock);
|
| 2313 | }
|
| 2314 | }
|
| 2315 | EXPORT_SYMBOL_GPL(fuse_abort_conn);
|
| 2316 |
|
| 2317 | void fuse_wait_aborted(struct fuse_conn *fc)
|
| 2318 | {
|
| 2319 |
|
| 2320 | smp_mb();
|
| 2321 | wait_event(fc->blocked_waitq, atomic_read(&fc->num_waiting) == 0);
|
| 2322 | }
|
| 2323 |
|
| 2324 | int fuse_dev_release(struct inode *inode, struct file *file)
|
| 2325 | {
|
| 2326 | struct fuse_dev *fud = fuse_get_dev(file);
|
| 2327 |
|
| 2328 | if (fud) {
|
| 2329 | struct fuse_conn *fc = fud->fc;
|
| 2330 | struct fuse_pqueue *fpq = &fud->pq;
|
| 2331 | LIST_HEAD(to_end);
|
| 2332 | unsigned int i;
|
| 2333 |
|
| 2334 | spin_lock(&fpq->lock);
|
| 2335 | WARN_ON(!list_empty(&fpq->io));
|
| 2336 | for (i = 0; i < FUSE_PQ_HASH_SIZE; i++)
|
| 2337 | list_splice_init(&fpq->processing[i], &to_end);
|
| 2338 | spin_unlock(&fpq->lock);
|
| 2339 |
|
| 2340 | end_requests(&to_end);
|
| 2341 |
|
| 2342 |
|
| 2343 | if (atomic_dec_and_test(&fc->dev_count)) {
|
| 2344 | WARN_ON(fc->iq.fasync != NULL);
|
| 2345 | fuse_abort_conn(fc);
|
| 2346 | }
|
| 2347 | fuse_dev_free(fud);
|
| 2348 | }
|
| 2349 | return 0;
|
| 2350 | }
|
| 2351 | EXPORT_SYMBOL_GPL(fuse_dev_release);
|
| 2352 |
|
| 2353 | static int fuse_dev_fasync(int fd, struct file *file, int on)
|
| 2354 | {
|
| 2355 | struct fuse_dev *fud = fuse_get_dev(file);
|
| 2356 |
|
| 2357 | if (!fud)
|
| 2358 | return -EPERM;
|
| 2359 |
|
| 2360 |
|
| 2361 | return fasync_helper(fd, file, on, &fud->fc->iq.fasync);
|
| 2362 | }
|
| 2363 |
|
| 2364 | static int fuse_device_clone(struct fuse_conn *fc, struct file *new)
|
| 2365 | {
|
| 2366 | struct fuse_dev *fud;
|
| 2367 |
|
| 2368 | if (new->private_data)
|
| 2369 | return -EINVAL;
|
| 2370 |
|
| 2371 | fud = fuse_dev_alloc_install(fc);
|
| 2372 | if (!fud)
|
| 2373 | return -ENOMEM;
|
| 2374 |
|
| 2375 | new->private_data = fud;
|
| 2376 | atomic_inc(&fc->dev_count);
|
| 2377 |
|
| 2378 | return 0;
|
| 2379 | }
|
| 2380 |
|
| 2381 | static long fuse_dev_ioctl_clone(struct file *file, __u32 __user *argp)
|
| 2382 | {
|
| 2383 | int res;
|
| 2384 | int oldfd;
|
| 2385 | struct fuse_dev *fud = NULL;
|
| 2386 |
|
| 2387 | if (get_user(oldfd, argp))
|
| 2388 | return -EFAULT;
|
| 2389 |
|
| 2390 | CLASS(fd, f)(oldfd);
|
| 2391 | if (fd_empty(f))
|
| 2392 | return -EINVAL;
|
| 2393 |
|
| 2394 | |
| 2395 | * Check against file->f_op because CUSE
|
| 2396 | * uses the same ioctl handler.
|
| 2397 |
|
| 2398 | if (fd_file(f)->f_op == file->f_op)
|
| 2399 | fud = fuse_get_dev(fd_file(f));
|
| 2400 |
|
| 2401 | res = -EINVAL;
|
| 2402 | if (fud) {
|
| 2403 | mutex_lock(&fuse_mutex);
|
| 2404 | res = fuse_device_clone(fud->fc, file);
|
| 2405 | mutex_unlock(&fuse_mutex);
|
| 2406 | }
|
| 2407 |
|
| 2408 | return res;
|
| 2409 | }
|
| 2410 |
|
| 2411 | static long fuse_dev_ioctl_backing_open(struct file *file,
|
| 2412 | struct fuse_backing_map __user *argp)
|
| 2413 | {
|
| 2414 | struct fuse_dev *fud = fuse_get_dev(file);
|
| 2415 | struct fuse_backing_map map;
|
| 2416 |
|
| 2417 | if (!fud)
|
| 2418 | return -EPERM;
|
| 2419 |
|
| 2420 | if (!IS_ENABLED(CONFIG_FUSE_PASSTHROUGH))
|
| 2421 | return -EOPNOTSUPP;
|
| 2422 |
|
| 2423 | if (copy_from_user(&map, argp, sizeof(map)))
|
| 2424 | return -EFAULT;
|
| 2425 |
|
| 2426 | return fuse_backing_open(fud->fc, &map);
|
| 2427 | }
|
| 2428 |
|
| 2429 | static long fuse_dev_ioctl_backing_close(struct file *file, __u32 __user *argp)
|
| 2430 | {
|
| 2431 | struct fuse_dev *fud = fuse_get_dev(file);
|
| 2432 | int backing_id;
|
| 2433 |
|
| 2434 | if (!fud)
|
| 2435 | return -EPERM;
|
| 2436 |
|
| 2437 | if (!IS_ENABLED(CONFIG_FUSE_PASSTHROUGH))
|
| 2438 | return -EOPNOTSUPP;
|
| 2439 |
|
| 2440 | if (get_user(backing_id, argp))
|
| 2441 | return -EFAULT;
|
| 2442 |
|
| 2443 | return fuse_backing_close(fud->fc, backing_id);
|
| 2444 | }
|
| 2445 |
|
| 2446 | static long fuse_dev_ioctl(struct file *file, unsigned int cmd,
|
| 2447 | unsigned long arg)
|
| 2448 | {
|
| 2449 | void __user *argp = (void __user *)arg;
|
| 2450 |
|
| 2451 | switch (cmd) {
|
| 2452 | case FUSE_DEV_IOC_CLONE:
|
| 2453 | return fuse_dev_ioctl_clone(file, argp);
|
| 2454 |
|
| 2455 | case FUSE_DEV_IOC_BACKING_OPEN:
|
| 2456 | return fuse_dev_ioctl_backing_open(file, argp);
|
| 2457 |
|
| 2458 | case FUSE_DEV_IOC_BACKING_CLOSE:
|
| 2459 | return fuse_dev_ioctl_backing_close(file, argp);
|
| 2460 |
|
| 2461 | default:
|
| 2462 | return -ENOTTY;
|
| 2463 | }
|
| 2464 | }
|
| 2465 |
|
| 2466 | const struct file_operations fuse_dev_operations = {
|
| 2467 | .owner = THIS_MODULE,
|
| 2468 | .open = fuse_dev_open,
|
| 2469 | .read_iter = fuse_dev_read,
|
| 2470 | .splice_read = fuse_dev_splice_read,
|
| 2471 | .write_iter = fuse_dev_write,
|
| 2472 | .splice_write = fuse_dev_splice_write,
|
| 2473 | .poll = fuse_dev_poll,
|
| 2474 | .release = fuse_dev_release,
|
| 2475 | .fasync = fuse_dev_fasync,
|
| 2476 | .unlocked_ioctl = fuse_dev_ioctl,
|
| 2477 | .compat_ioctl = compat_ptr_ioctl,
|
| 2478 | };
|
| 2479 | EXPORT_SYMBOL_GPL(fuse_dev_operations);
|
| 2480 |
|
| 2481 | static struct miscdevice fuse_miscdevice = {
|
| 2482 | .minor = FUSE_MINOR,
|
| 2483 | .name = "fuse",
|
| 2484 | .fops = &fuse_dev_operations,
|
| 2485 | };
|
| 2486 |
|
| 2487 | int __init fuse_dev_init(void)
|
| 2488 | {
|
| 2489 | int err = -ENOMEM;
|
| 2490 | fuse_req_cachep = kmem_cache_create("fuse_request",
|
| 2491 | sizeof(struct fuse_req),
|
| 2492 | 0, 0, NULL);
|
| 2493 | if (!fuse_req_cachep)
|
| 2494 | goto out;
|
| 2495 |
|
| 2496 | err = misc_register(&fuse_miscdevice);
|
| 2497 | if (err)
|
| 2498 | goto out_cache_clean;
|
| 2499 |
|
| 2500 | return 0;
|
| 2501 |
|
| 2502 | out_cache_clean:
|
| 2503 | kmem_cache_destroy(fuse_req_cachep);
|
| 2504 | out:
|
| 2505 | return err;
|
| 2506 | }
|
| 2507 |
|
| 2508 | void fuse_dev_cleanup(void)
|
| 2509 | {
|
| 2510 | misc_deregister(&fuse_miscdevice);
|
| 2511 | kmem_cache_destroy(fuse_req_cachep);
|
| 2512 | }
|