/*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (c) 2007-2009 Google Inc. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are * met: * * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above * copyright notice, this list of conditions and the following disclaimer * in the documentation and/or other materials provided with the * distribution. * * Neither the name of Google Inc. nor the names of its * contributors may be used to endorse or promote products derived from * this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * * Copyright (C) 2005 Csaba Henk. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "fuse.h" #include "fuse_internal.h" #include "fuse_ipc.h" SDT_PROVIDER_DECLARE(fusefs); /* * Fuse trace probe: * arg0: verbosity. Higher numbers give more verbose messages * arg1: Textual message */ SDT_PROBE_DEFINE2(fusefs, , device, trace, "int", "char*"); static struct cdev *fuse_dev; static d_kqfilter_t fuse_device_filter; static d_open_t fuse_device_open; static d_poll_t fuse_device_poll; static d_read_t fuse_device_read; static d_write_t fuse_device_write; static struct cdevsw fuse_device_cdevsw = { .d_kqfilter = fuse_device_filter, .d_open = fuse_device_open, .d_name = "fuse", .d_poll = fuse_device_poll, .d_read = fuse_device_read, .d_write = fuse_device_write, .d_version = D_VERSION, }; static int fuse_device_filt_read(struct knote *kn, long hint); static void fuse_device_filt_detach(struct knote *kn); struct filterops fuse_device_rfiltops = { .f_isfd = 1, .f_detach = fuse_device_filt_detach, .f_event = fuse_device_filt_read, }; /**************************** * * >>> Fuse device op defs * ****************************/ static void fdata_dtor(void *arg) { struct fuse_data *fdata; struct fuse_ticket *tick; fdata = arg; if (fdata == NULL) return; fdata_set_dead(fdata); FUSE_LOCK(); fuse_lck_mtx_lock(fdata->aw_mtx); /* wakup poll()ers */ selwakeuppri(&fdata->ks_rsel, PZERO + 1); /* Don't let syscall handlers wait in vain */ while ((tick = fuse_aw_pop(fdata))) { fuse_lck_mtx_lock(tick->tk_aw_mtx); fticket_set_answered(tick); tick->tk_aw_errno = ENOTCONN; wakeup(tick); fuse_lck_mtx_unlock(tick->tk_aw_mtx); FUSE_ASSERT_AW_DONE(tick); fuse_ticket_drop(tick); } fuse_lck_mtx_unlock(fdata->aw_mtx); FUSE_UNLOCK(); fdata_trydestroy(fdata); } static int fuse_device_filter(struct cdev *dev, struct knote *kn) { struct fuse_data *data; int error; error = devfs_get_cdevpriv((void **)&data); /* EVFILT_WRITE is not supported; the device is always ready to write */ if (error == 0 && kn->kn_filter == EVFILT_READ) { kn->kn_fop = &fuse_device_rfiltops; kn->kn_hook = data; knlist_add(&data->ks_rsel.si_note, kn, 0); error = 0; } else if (error == 0) { error = EINVAL; kn->kn_data = error; } return (error); } static void fuse_device_filt_detach(struct knote *kn) { struct fuse_data *data; data = (struct fuse_data*)kn->kn_hook; MPASS(data != NULL); knlist_remove(&data->ks_rsel.si_note, kn, 0); kn->kn_hook = NULL; } static int fuse_device_filt_read(struct knote *kn, long hint) { struct fuse_data *data; int ready; data = (struct fuse_data*)kn->kn_hook; MPASS(data != NULL); mtx_assert(&data->ms_mtx, MA_OWNED); if (fdata_get_dead(data)) { kn->kn_flags |= EV_EOF; kn->kn_fflags = ENODEV; kn->kn_data = 1; ready = 1; } else if (STAILQ_FIRST(&data->ms_head)) { MPASS(data->ms_count >= 1); kn->kn_data = data->ms_count; ready = 1; } else { ready = 0; } return (ready); } /* * Resources are set up on a per-open basis */ static int fuse_device_open(struct cdev *dev, int oflags, int devtype, struct thread *td) { struct fuse_data *fdata; int error; SDT_PROBE2(fusefs, , device, trace, 1, "device open"); fdata = fdata_alloc(dev, td->td_ucred); error = devfs_set_cdevpriv(fdata, fdata_dtor); if (error != 0) fdata_trydestroy(fdata); else SDT_PROBE2(fusefs, , device, trace, 1, "device open success"); return (error); } int fuse_device_poll(struct cdev *dev, int events, struct thread *td) { struct fuse_data *data; int error, revents = 0; error = devfs_get_cdevpriv((void **)&data); if (error != 0) return (events & (POLLHUP|POLLIN|POLLRDNORM|POLLOUT|POLLWRNORM)); if (events & (POLLIN | POLLRDNORM)) { fuse_lck_mtx_lock(data->ms_mtx); if (fdata_get_dead(data) || STAILQ_FIRST(&data->ms_head)) revents |= events & (POLLIN | POLLRDNORM); else selrecord(td, &data->ks_rsel); fuse_lck_mtx_unlock(data->ms_mtx); } if (events & (POLLOUT | POLLWRNORM)) { revents |= events & (POLLOUT | POLLWRNORM); } return (revents); } /* * fuse_device_read hangs on the queue of VFS messages. * When it's notified that there is a new one, it picks that and * passes up to the daemon */ int fuse_device_read(struct cdev *dev, struct uio *uio, int ioflag) { int err; struct fuse_data *data; struct fuse_ticket *tick; void *buf[] = {NULL, NULL, NULL}; int buflen[3]; int i; SDT_PROBE2(fusefs, , device, trace, 1, "fuse device read"); err = devfs_get_cdevpriv((void **)&data); if (err != 0) return (err); fuse_lck_mtx_lock(data->ms_mtx); again: if (fdata_get_dead(data)) { SDT_PROBE2(fusefs, , device, trace, 2, "we know early on that reader should be kicked so we " "don't wait for news"); fuse_lck_mtx_unlock(data->ms_mtx); return (ENODEV); } if (!(tick = fuse_ms_pop(data))) { /* check if we may block */ if (ioflag & O_NONBLOCK) { /* get outa here soon */ fuse_lck_mtx_unlock(data->ms_mtx); return (EAGAIN); } else { err = msleep(data, &data->ms_mtx, PCATCH, "fu_msg", 0); if (err != 0) { fuse_lck_mtx_unlock(data->ms_mtx); return (fdata_get_dead(data) ? ENODEV : err); } tick = fuse_ms_pop(data); } } if (!tick) { /* * We can get here if fuse daemon suddenly terminates, * eg, by being hit by a SIGKILL * -- and some other cases, too, tho not totally clear, when * (cv_signal/wakeup_one signals the whole process ?) */ SDT_PROBE2(fusefs, , device, trace, 1, "no message on thread"); goto again; } fuse_lck_mtx_unlock(data->ms_mtx); if (fdata_get_dead(data)) { /* * somebody somewhere -- eg., umount routine -- * wants this liaison finished off */ SDT_PROBE2(fusefs, , device, trace, 2, "reader is to be sacked"); if (tick) { SDT_PROBE2(fusefs, , device, trace, 2, "weird -- " "\"kick\" is set tho there is message"); FUSE_ASSERT_MS_DONE(tick); fuse_ticket_drop(tick); } return (ENODEV); /* This should make the daemon get off * of us */ } SDT_PROBE2(fusefs, , device, trace, 1, "fuse device read message successfully"); KASSERT(tick->tk_ms_bufdata || tick->tk_ms_bufsize == 0, ("non-null buf pointer with positive size")); switch (tick->tk_ms_type) { case FT_M_FIOV: buf[0] = tick->tk_ms_fiov.base; buflen[0] = tick->tk_ms_fiov.len; break; case FT_M_BUF: buf[0] = tick->tk_ms_fiov.base; buflen[0] = tick->tk_ms_fiov.len; buf[1] = tick->tk_ms_bufdata; buflen[1] = tick->tk_ms_bufsize; break; default: panic("unknown message type for fuse_ticket %p", tick); } for (i = 0; buf[i]; i++) { /* * Why not ban mercilessly stupid daemons who can't keep up * with us? (There is no much use of a partial read here...) */ /* * XXX note that in such cases Linux FUSE throws EIO at the * syscall invoker and stands back to the message queue. The * rationale should be made clear (and possibly adopt that * behaviour). Keeping the current scheme at least makes * fallacy as loud as possible... */ if (uio->uio_resid < buflen[i]) { fdata_set_dead(data); SDT_PROBE2(fusefs, , device, trace, 2, "daemon is stupid, kick it off..."); err = ENODEV; break; } err = uiomove(buf[i], buflen[i], uio); if (err) break; } FUSE_ASSERT_MS_DONE(tick); fuse_ticket_drop(tick); return (err); } static inline int fuse_ohead_audit(struct fuse_out_header *ohead, struct uio *uio) { if (uio->uio_resid + sizeof(struct fuse_out_header) != ohead->len) { SDT_PROBE2(fusefs, , device, trace, 1, "Format error: body size " "differs from size claimed by header"); return (EINVAL); } if (uio->uio_resid && ohead->unique != 0 && ohead->error) { SDT_PROBE2(fusefs, , device, trace, 1, "Format error: non zero error but message had a body"); return (EINVAL); } return (0); } SDT_PROBE_DEFINE1(fusefs, , device, fuse_device_write_notify, "struct fuse_out_header*"); SDT_PROBE_DEFINE1(fusefs, , device, fuse_device_write_missing_ticket, "uint64_t"); SDT_PROBE_DEFINE1(fusefs, , device, fuse_device_write_found, "struct fuse_ticket*"); /* * fuse_device_write first reads the header sent by the daemon. * If that's OK, looks up ticket/callback node by the unique id seen in header. * If the callback node contains a handler function, the uio is passed over * that. */ static int fuse_device_write(struct cdev *dev, struct uio *uio, int ioflag) { struct fuse_out_header ohead; int err = 0; struct fuse_data *data; struct mount *mp; struct fuse_ticket *tick, *itick, *x_tick; int found = 0; err = devfs_get_cdevpriv((void **)&data); if (err != 0) return (err); mp = data->mp; if (uio->uio_resid < sizeof(struct fuse_out_header)) { SDT_PROBE2(fusefs, , device, trace, 1, "fuse_device_write got less than a header!"); fdata_set_dead(data); return (EINVAL); } if ((err = uiomove(&ohead, sizeof(struct fuse_out_header), uio)) != 0) return (err); /* * We check header information (which is redundant) and compare it * with what we see. If we see some inconsistency we discard the * whole answer and proceed on as if it had never existed. In * particular, no pretender will be woken up, regardless the * "unique" value in the header. */ if ((err = fuse_ohead_audit(&ohead, uio))) { fdata_set_dead(data); return (err); } /* Pass stuff over to callback if there is one installed */ /* Looking for ticket with the unique id of header */ fuse_lck_mtx_lock(data->aw_mtx); TAILQ_FOREACH_SAFE(tick, &data->aw_head, tk_aw_link, x_tick) { if (tick->tk_unique == ohead.unique) { SDT_PROBE1(fusefs, , device, fuse_device_write_found, tick); found = 1; fuse_aw_remove(tick); break; } } if (found && tick->irq_unique > 0) { /* * Discard the FUSE_INTERRUPT ticket that tried to interrupt * this operation */ TAILQ_FOREACH_SAFE(itick, &data->aw_head, tk_aw_link, x_tick) { if (itick->tk_unique == tick->irq_unique) { fuse_aw_remove(itick); break; } } tick->irq_unique = 0; } fuse_lck_mtx_unlock(data->aw_mtx); if (found) { if (tick->tk_aw_handler) { /* * We found a callback with proper handler. In this * case the out header will be 0wnd by the callback, * so the fun of freeing that is left for her. * (Then, by all chance, she'll just get that's done * via ticket_drop(), so no manual mucking * around...) */ SDT_PROBE2(fusefs, , device, trace, 1, "pass ticket to a callback"); /* Sanitize the linuxism of negative errnos */ ohead.error *= -1; memcpy(&tick->tk_aw_ohead, &ohead, sizeof(ohead)); err = tick->tk_aw_handler(tick, uio); } else { /* pretender doesn't wanna do anything with answer */ SDT_PROBE2(fusefs, , device, trace, 1, "stuff devalidated, so we drop it"); } /* * As aw_mtx was not held during the callback execution the * ticket may have been inserted again. However, this is safe * because fuse_ticket_drop() will deal with refcount anyway. */ fuse_ticket_drop(tick); } else if (ohead.unique == 0){ /* unique == 0 means asynchronous notification */ SDT_PROBE1(fusefs, , device, fuse_device_write_notify, &ohead); switch (ohead.error) { case FUSE_NOTIFY_INVAL_ENTRY: err = fuse_internal_invalidate_entry(mp, uio); break; case FUSE_NOTIFY_INVAL_INODE: err = fuse_internal_invalidate_inode(mp, uio); break; case FUSE_NOTIFY_RETRIEVE: case FUSE_NOTIFY_STORE: /* * Unimplemented. I don't know of any file systems * that use them, and the protocol isn't sound anyway, * since the notification messages don't include the * inode's generation number. Without that, it's * possible to manipulate the cache of the wrong vnode. * Finally, it's not defined what this message should * do for a file with dirty cache. */ case FUSE_NOTIFY_POLL: /* Unimplemented. See comments in fuse_vnops */ default: /* Not implemented */ err = ENOSYS; } } else { /* no callback at all! */ SDT_PROBE1(fusefs, , device, fuse_device_write_missing_ticket, ohead.unique); if (ohead.error == -EAGAIN) { /* * This was probably a response to a FUSE_INTERRUPT * operation whose original operation is already * complete. We can't store FUSE_INTERRUPT tickets * indefinitely because their responses are optional. * So we delete them when the original operation * completes. And sadly the fuse_header_out doesn't * identify the opcode, so we have to guess. */ err = 0; } else { err = EINVAL; } } return (err); } int fuse_device_init(void) { fuse_dev = make_dev(&fuse_device_cdevsw, 0, UID_ROOT, GID_OPERATOR, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH, "fuse"); if (fuse_dev == NULL) return (ENOMEM); return (0); } void fuse_device_destroy(void) { MPASS(fuse_dev != NULL); destroy_dev(fuse_dev); }