From 9ac29fd3f87ffdd993505d75e89714ab931cdedb Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Wed, 7 Apr 2021 14:36:45 +0200 Subject: [PATCH] fuse: move ioctl to separate source file Next patch will expand ioctl code and fuse/file.c is large enough as it is. Signed-off-by: Miklos Szeredi --- fs/fuse/Makefile | 2 +- fs/fuse/file.c | 380 ----------------------------------------------- fs/fuse/fuse_i.h | 27 ++++ fs/fuse/ioctl.c | 366 +++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 394 insertions(+), 381 deletions(-) create mode 100644 fs/fuse/ioctl.c diff --git a/fs/fuse/Makefile b/fs/fuse/Makefile index 8c7021fb2cd4..0c48b35c058d 100644 --- a/fs/fuse/Makefile +++ b/fs/fuse/Makefile @@ -7,7 +7,7 @@ obj-$(CONFIG_FUSE_FS) += fuse.o obj-$(CONFIG_CUSE) += cuse.o obj-$(CONFIG_VIRTIO_FS) += virtiofs.o -fuse-y := dev.o dir.o file.o inode.o control.o xattr.o acl.o readdir.o +fuse-y := dev.o dir.o file.o inode.o control.o xattr.o acl.o readdir.o ioctl.o fuse-$(CONFIG_FUSE_DAX) += dax.o virtiofs-y := virtio_fs.o diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 8cccecb55fb8..c549850089bb 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -14,24 +14,11 @@ #include #include #include -#include #include #include #include #include -static struct page **fuse_pages_alloc(unsigned int npages, gfp_t flags, - struct fuse_page_desc **desc) -{ - struct page **pages; - - pages = kzalloc(npages * (sizeof(struct page *) + - sizeof(struct fuse_page_desc)), flags); - *desc = (void *) (pages + npages); - - return pages; -} - static int fuse_send_open(struct fuse_mount *fm, u64 nodeid, struct file *file, int opcode, struct fuse_open_out *outargp) { @@ -1346,16 +1333,6 @@ out: return written ? written : err; } -static inline void fuse_page_descs_length_init(struct fuse_page_desc *descs, - unsigned int index, - unsigned int nr_pages) -{ - int i; - - for (i = index; i < index + nr_pages; i++) - descs[i].length = PAGE_SIZE - descs[i].offset; -} - static inline unsigned long fuse_get_user_addr(const struct iov_iter *ii) { return (unsigned long)ii->iov->iov_base + ii->iov_offset; @@ -2636,363 +2613,6 @@ static loff_t fuse_file_llseek(struct file *file, loff_t offset, int whence) return retval; } -/* - * CUSE servers compiled on 32bit broke on 64bit kernels because the - * ABI was defined to be 'struct iovec' which is different on 32bit - * and 64bit. Fortunately we can determine which structure the server - * used from the size of the reply. - */ -static int fuse_copy_ioctl_iovec_old(struct iovec *dst, void *src, - size_t transferred, unsigned count, - bool is_compat) -{ -#ifdef CONFIG_COMPAT - if (count * sizeof(struct compat_iovec) == transferred) { - struct compat_iovec *ciov = src; - unsigned i; - - /* - * With this interface a 32bit server cannot support - * non-compat (i.e. ones coming from 64bit apps) ioctl - * requests - */ - if (!is_compat) - return -EINVAL; - - for (i = 0; i < count; i++) { - dst[i].iov_base = compat_ptr(ciov[i].iov_base); - dst[i].iov_len = ciov[i].iov_len; - } - return 0; - } -#endif - - if (count * sizeof(struct iovec) != transferred) - return -EIO; - - memcpy(dst, src, transferred); - return 0; -} - -/* Make sure iov_length() won't overflow */ -static int fuse_verify_ioctl_iov(struct fuse_conn *fc, struct iovec *iov, - size_t count) -{ - size_t n; - u32 max = fc->max_pages << PAGE_SHIFT; - - for (n = 0; n < count; n++, iov++) { - if (iov->iov_len > (size_t) max) - return -ENOMEM; - max -= iov->iov_len; - } - return 0; -} - -static int fuse_copy_ioctl_iovec(struct fuse_conn *fc, struct iovec *dst, - void *src, size_t transferred, unsigned count, - bool is_compat) -{ - unsigned i; - struct fuse_ioctl_iovec *fiov = src; - - if (fc->minor < 16) { - return fuse_copy_ioctl_iovec_old(dst, src, transferred, - count, is_compat); - } - - if (count * sizeof(struct fuse_ioctl_iovec) != transferred) - return -EIO; - - for (i = 0; i < count; i++) { - /* Did the server supply an inappropriate value? */ - if (fiov[i].base != (unsigned long) fiov[i].base || - fiov[i].len != (unsigned long) fiov[i].len) - return -EIO; - - dst[i].iov_base = (void __user *) (unsigned long) fiov[i].base; - dst[i].iov_len = (size_t) fiov[i].len; - -#ifdef CONFIG_COMPAT - if (is_compat && - (ptr_to_compat(dst[i].iov_base) != fiov[i].base || - (compat_size_t) dst[i].iov_len != fiov[i].len)) - return -EIO; -#endif - } - - return 0; -} - - -/* - * For ioctls, there is no generic way to determine how much memory - * needs to be read and/or written. Furthermore, ioctls are allowed - * to dereference the passed pointer, so the parameter requires deep - * copying but FUSE has no idea whatsoever about what to copy in or - * out. - * - * This is solved by allowing FUSE server to retry ioctl with - * necessary in/out iovecs. Let's assume the ioctl implementation - * needs to read in the following structure. - * - * struct a { - * char *buf; - * size_t buflen; - * } - * - * On the first callout to FUSE server, inarg->in_size and - * inarg->out_size will be NULL; then, the server completes the ioctl - * with FUSE_IOCTL_RETRY set in out->flags, out->in_iovs set to 1 and - * the actual iov array to - * - * { { .iov_base = inarg.arg, .iov_len = sizeof(struct a) } } - * - * which tells FUSE to copy in the requested area and retry the ioctl. - * On the second round, the server has access to the structure and - * from that it can tell what to look for next, so on the invocation, - * it sets FUSE_IOCTL_RETRY, out->in_iovs to 2 and iov array to - * - * { { .iov_base = inarg.arg, .iov_len = sizeof(struct a) }, - * { .iov_base = a.buf, .iov_len = a.buflen } } - * - * FUSE will copy both struct a and the pointed buffer from the - * process doing the ioctl and retry ioctl with both struct a and the - * buffer. - * - * This time, FUSE server has everything it needs and completes ioctl - * without FUSE_IOCTL_RETRY which finishes the ioctl call. - * - * Copying data out works the same way. - * - * Note that if FUSE_IOCTL_UNRESTRICTED is clear, the kernel - * automatically initializes in and out iovs by decoding @cmd with - * _IOC_* macros and the server is not allowed to request RETRY. This - * limits ioctl data transfers to well-formed ioctls and is the forced - * behavior for all FUSE servers. - */ -long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg, - unsigned int flags) -{ - struct fuse_file *ff = file->private_data; - struct fuse_mount *fm = ff->fm; - struct fuse_ioctl_in inarg = { - .fh = ff->fh, - .cmd = cmd, - .arg = arg, - .flags = flags - }; - struct fuse_ioctl_out outarg; - struct iovec *iov_page = NULL; - struct iovec *in_iov = NULL, *out_iov = NULL; - unsigned int in_iovs = 0, out_iovs = 0, max_pages; - size_t in_size, out_size, c; - ssize_t transferred; - int err, i; - struct iov_iter ii; - struct fuse_args_pages ap = {}; - -#if BITS_PER_LONG == 32 - inarg.flags |= FUSE_IOCTL_32BIT; -#else - if (flags & FUSE_IOCTL_COMPAT) { - inarg.flags |= FUSE_IOCTL_32BIT; -#ifdef CONFIG_X86_X32 - if (in_x32_syscall()) - inarg.flags |= FUSE_IOCTL_COMPAT_X32; -#endif - } -#endif - - /* assume all the iovs returned by client always fits in a page */ - BUILD_BUG_ON(sizeof(struct fuse_ioctl_iovec) * FUSE_IOCTL_MAX_IOV > PAGE_SIZE); - - err = -ENOMEM; - ap.pages = fuse_pages_alloc(fm->fc->max_pages, GFP_KERNEL, &ap.descs); - iov_page = (struct iovec *) __get_free_page(GFP_KERNEL); - if (!ap.pages || !iov_page) - goto out; - - fuse_page_descs_length_init(ap.descs, 0, fm->fc->max_pages); - - /* - * If restricted, initialize IO parameters as encoded in @cmd. - * RETRY from server is not allowed. - */ - if (!(flags & FUSE_IOCTL_UNRESTRICTED)) { - struct iovec *iov = iov_page; - - iov->iov_base = (void __user *)arg; - - switch (cmd) { - case FS_IOC_GETFLAGS: - case FS_IOC_SETFLAGS: - iov->iov_len = sizeof(int); - break; - default: - iov->iov_len = _IOC_SIZE(cmd); - break; - } - - if (_IOC_DIR(cmd) & _IOC_WRITE) { - in_iov = iov; - in_iovs = 1; - } - - if (_IOC_DIR(cmd) & _IOC_READ) { - out_iov = iov; - out_iovs = 1; - } - } - - retry: - inarg.in_size = in_size = iov_length(in_iov, in_iovs); - inarg.out_size = out_size = iov_length(out_iov, out_iovs); - - /* - * Out data can be used either for actual out data or iovs, - * make sure there always is at least one page. - */ - out_size = max_t(size_t, out_size, PAGE_SIZE); - max_pages = DIV_ROUND_UP(max(in_size, out_size), PAGE_SIZE); - - /* make sure there are enough buffer pages and init request with them */ - err = -ENOMEM; - if (max_pages > fm->fc->max_pages) - goto out; - while (ap.num_pages < max_pages) { - ap.pages[ap.num_pages] = alloc_page(GFP_KERNEL | __GFP_HIGHMEM); - if (!ap.pages[ap.num_pages]) - goto out; - ap.num_pages++; - } - - - /* okay, let's send it to the client */ - ap.args.opcode = FUSE_IOCTL; - ap.args.nodeid = ff->nodeid; - ap.args.in_numargs = 1; - ap.args.in_args[0].size = sizeof(inarg); - ap.args.in_args[0].value = &inarg; - if (in_size) { - ap.args.in_numargs++; - ap.args.in_args[1].size = in_size; - ap.args.in_pages = true; - - err = -EFAULT; - iov_iter_init(&ii, WRITE, in_iov, in_iovs, in_size); - for (i = 0; iov_iter_count(&ii) && !WARN_ON(i >= ap.num_pages); i++) { - c = copy_page_from_iter(ap.pages[i], 0, PAGE_SIZE, &ii); - if (c != PAGE_SIZE && iov_iter_count(&ii)) - goto out; - } - } - - ap.args.out_numargs = 2; - ap.args.out_args[0].size = sizeof(outarg); - ap.args.out_args[0].value = &outarg; - ap.args.out_args[1].size = out_size; - ap.args.out_pages = true; - ap.args.out_argvar = true; - - transferred = fuse_simple_request(fm, &ap.args); - err = transferred; - if (transferred < 0) - goto out; - - /* did it ask for retry? */ - if (outarg.flags & FUSE_IOCTL_RETRY) { - void *vaddr; - - /* no retry if in restricted mode */ - err = -EIO; - if (!(flags & FUSE_IOCTL_UNRESTRICTED)) - goto out; - - in_iovs = outarg.in_iovs; - out_iovs = outarg.out_iovs; - - /* - * Make sure things are in boundary, separate checks - * are to protect against overflow. - */ - err = -ENOMEM; - if (in_iovs > FUSE_IOCTL_MAX_IOV || - out_iovs > FUSE_IOCTL_MAX_IOV || - in_iovs + out_iovs > FUSE_IOCTL_MAX_IOV) - goto out; - - vaddr = kmap_atomic(ap.pages[0]); - err = fuse_copy_ioctl_iovec(fm->fc, iov_page, vaddr, - transferred, in_iovs + out_iovs, - (flags & FUSE_IOCTL_COMPAT) != 0); - kunmap_atomic(vaddr); - if (err) - goto out; - - in_iov = iov_page; - out_iov = in_iov + in_iovs; - - err = fuse_verify_ioctl_iov(fm->fc, in_iov, in_iovs); - if (err) - goto out; - - err = fuse_verify_ioctl_iov(fm->fc, out_iov, out_iovs); - if (err) - goto out; - - goto retry; - } - - err = -EIO; - if (transferred > inarg.out_size) - goto out; - - err = -EFAULT; - iov_iter_init(&ii, READ, out_iov, out_iovs, transferred); - for (i = 0; iov_iter_count(&ii) && !WARN_ON(i >= ap.num_pages); i++) { - c = copy_page_to_iter(ap.pages[i], 0, PAGE_SIZE, &ii); - if (c != PAGE_SIZE && iov_iter_count(&ii)) - goto out; - } - err = 0; - out: - free_page((unsigned long) iov_page); - while (ap.num_pages) - __free_page(ap.pages[--ap.num_pages]); - kfree(ap.pages); - - return err ? err : outarg.result; -} -EXPORT_SYMBOL_GPL(fuse_do_ioctl); - -long fuse_ioctl_common(struct file *file, unsigned int cmd, - unsigned long arg, unsigned int flags) -{ - struct inode *inode = file_inode(file); - struct fuse_conn *fc = get_fuse_conn(inode); - - if (!fuse_allow_current_process(fc)) - return -EACCES; - - if (fuse_is_bad(inode)) - return -EIO; - - return fuse_do_ioctl(file, cmd, arg, flags); -} - -static long fuse_file_ioctl(struct file *file, unsigned int cmd, - unsigned long arg) -{ - return fuse_ioctl_common(file, cmd, arg, 0); -} - -static long fuse_file_compat_ioctl(struct file *file, unsigned int cmd, - unsigned long arg) -{ - return fuse_ioctl_common(file, cmd, arg, FUSE_IOCTL_COMPAT); -} - /* * All files which have been polled are linked to RB tree * fuse_conn->polled_files which is indexed by kh. Walk the tree and diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index 63d97a15ffde..ad7e629f3903 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -872,6 +872,28 @@ static inline bool fuse_is_bad(struct inode *inode) return unlikely(test_bit(FUSE_I_BAD, &get_fuse_inode(inode)->state)); } +static inline struct page **fuse_pages_alloc(unsigned int npages, gfp_t flags, + struct fuse_page_desc **desc) +{ + struct page **pages; + + pages = kzalloc(npages * (sizeof(struct page *) + + sizeof(struct fuse_page_desc)), flags); + *desc = (void *) (pages + npages); + + return pages; +} + +static inline void fuse_page_descs_length_init(struct fuse_page_desc *descs, + unsigned int index, + unsigned int nr_pages) +{ + int i; + + for (i = index; i < index + nr_pages; i++) + descs[i].length = PAGE_SIZE - descs[i].offset; +} + /** Device operations */ extern const struct file_operations fuse_dev_operations; @@ -1214,4 +1236,9 @@ void fuse_dax_inode_cleanup(struct inode *inode); bool fuse_dax_check_alignment(struct fuse_conn *fc, unsigned int map_alignment); void fuse_dax_cancel_work(struct fuse_conn *fc); +/* ioctl.c */ +long fuse_file_ioctl(struct file *file, unsigned int cmd, unsigned long arg); +long fuse_file_compat_ioctl(struct file *file, unsigned int cmd, + unsigned long arg); + #endif /* _FS_FUSE_I_H */ diff --git a/fs/fuse/ioctl.c b/fs/fuse/ioctl.c new file mode 100644 index 000000000000..c2f3ba162ecb --- /dev/null +++ b/fs/fuse/ioctl.c @@ -0,0 +1,366 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2017 Red Hat, Inc. + */ + +#include "fuse_i.h" + +#include +#include +#include + +/* + * CUSE servers compiled on 32bit broke on 64bit kernels because the + * ABI was defined to be 'struct iovec' which is different on 32bit + * and 64bit. Fortunately we can determine which structure the server + * used from the size of the reply. + */ +static int fuse_copy_ioctl_iovec_old(struct iovec *dst, void *src, + size_t transferred, unsigned count, + bool is_compat) +{ +#ifdef CONFIG_COMPAT + if (count * sizeof(struct compat_iovec) == transferred) { + struct compat_iovec *ciov = src; + unsigned i; + + /* + * With this interface a 32bit server cannot support + * non-compat (i.e. ones coming from 64bit apps) ioctl + * requests + */ + if (!is_compat) + return -EINVAL; + + for (i = 0; i < count; i++) { + dst[i].iov_base = compat_ptr(ciov[i].iov_base); + dst[i].iov_len = ciov[i].iov_len; + } + return 0; + } +#endif + + if (count * sizeof(struct iovec) != transferred) + return -EIO; + + memcpy(dst, src, transferred); + return 0; +} + +/* Make sure iov_length() won't overflow */ +static int fuse_verify_ioctl_iov(struct fuse_conn *fc, struct iovec *iov, + size_t count) +{ + size_t n; + u32 max = fc->max_pages << PAGE_SHIFT; + + for (n = 0; n < count; n++, iov++) { + if (iov->iov_len > (size_t) max) + return -ENOMEM; + max -= iov->iov_len; + } + return 0; +} + +static int fuse_copy_ioctl_iovec(struct fuse_conn *fc, struct iovec *dst, + void *src, size_t transferred, unsigned count, + bool is_compat) +{ + unsigned i; + struct fuse_ioctl_iovec *fiov = src; + + if (fc->minor < 16) { + return fuse_copy_ioctl_iovec_old(dst, src, transferred, + count, is_compat); + } + + if (count * sizeof(struct fuse_ioctl_iovec) != transferred) + return -EIO; + + for (i = 0; i < count; i++) { + /* Did the server supply an inappropriate value? */ + if (fiov[i].base != (unsigned long) fiov[i].base || + fiov[i].len != (unsigned long) fiov[i].len) + return -EIO; + + dst[i].iov_base = (void __user *) (unsigned long) fiov[i].base; + dst[i].iov_len = (size_t) fiov[i].len; + +#ifdef CONFIG_COMPAT + if (is_compat && + (ptr_to_compat(dst[i].iov_base) != fiov[i].base || + (compat_size_t) dst[i].iov_len != fiov[i].len)) + return -EIO; +#endif + } + + return 0; +} + + +/* + * For ioctls, there is no generic way to determine how much memory + * needs to be read and/or written. Furthermore, ioctls are allowed + * to dereference the passed pointer, so the parameter requires deep + * copying but FUSE has no idea whatsoever about what to copy in or + * out. + * + * This is solved by allowing FUSE server to retry ioctl with + * necessary in/out iovecs. Let's assume the ioctl implementation + * needs to read in the following structure. + * + * struct a { + * char *buf; + * size_t buflen; + * } + * + * On the first callout to FUSE server, inarg->in_size and + * inarg->out_size will be NULL; then, the server completes the ioctl + * with FUSE_IOCTL_RETRY set in out->flags, out->in_iovs set to 1 and + * the actual iov array to + * + * { { .iov_base = inarg.arg, .iov_len = sizeof(struct a) } } + * + * which tells FUSE to copy in the requested area and retry the ioctl. + * On the second round, the server has access to the structure and + * from that it can tell what to look for next, so on the invocation, + * it sets FUSE_IOCTL_RETRY, out->in_iovs to 2 and iov array to + * + * { { .iov_base = inarg.arg, .iov_len = sizeof(struct a) }, + * { .iov_base = a.buf, .iov_len = a.buflen } } + * + * FUSE will copy both struct a and the pointed buffer from the + * process doing the ioctl and retry ioctl with both struct a and the + * buffer. + * + * This time, FUSE server has everything it needs and completes ioctl + * without FUSE_IOCTL_RETRY which finishes the ioctl call. + * + * Copying data out works the same way. + * + * Note that if FUSE_IOCTL_UNRESTRICTED is clear, the kernel + * automatically initializes in and out iovs by decoding @cmd with + * _IOC_* macros and the server is not allowed to request RETRY. This + * limits ioctl data transfers to well-formed ioctls and is the forced + * behavior for all FUSE servers. + */ +long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg, + unsigned int flags) +{ + struct fuse_file *ff = file->private_data; + struct fuse_mount *fm = ff->fm; + struct fuse_ioctl_in inarg = { + .fh = ff->fh, + .cmd = cmd, + .arg = arg, + .flags = flags + }; + struct fuse_ioctl_out outarg; + struct iovec *iov_page = NULL; + struct iovec *in_iov = NULL, *out_iov = NULL; + unsigned int in_iovs = 0, out_iovs = 0, max_pages; + size_t in_size, out_size, c; + ssize_t transferred; + int err, i; + struct iov_iter ii; + struct fuse_args_pages ap = {}; + +#if BITS_PER_LONG == 32 + inarg.flags |= FUSE_IOCTL_32BIT; +#else + if (flags & FUSE_IOCTL_COMPAT) { + inarg.flags |= FUSE_IOCTL_32BIT; +#ifdef CONFIG_X86_X32 + if (in_x32_syscall()) + inarg.flags |= FUSE_IOCTL_COMPAT_X32; +#endif + } +#endif + + /* assume all the iovs returned by client always fits in a page */ + BUILD_BUG_ON(sizeof(struct fuse_ioctl_iovec) * FUSE_IOCTL_MAX_IOV > PAGE_SIZE); + + err = -ENOMEM; + ap.pages = fuse_pages_alloc(fm->fc->max_pages, GFP_KERNEL, &ap.descs); + iov_page = (struct iovec *) __get_free_page(GFP_KERNEL); + if (!ap.pages || !iov_page) + goto out; + + fuse_page_descs_length_init(ap.descs, 0, fm->fc->max_pages); + + /* + * If restricted, initialize IO parameters as encoded in @cmd. + * RETRY from server is not allowed. + */ + if (!(flags & FUSE_IOCTL_UNRESTRICTED)) { + struct iovec *iov = iov_page; + + iov->iov_base = (void __user *)arg; + + switch (cmd) { + case FS_IOC_GETFLAGS: + case FS_IOC_SETFLAGS: + iov->iov_len = sizeof(int); + break; + default: + iov->iov_len = _IOC_SIZE(cmd); + break; + } + + if (_IOC_DIR(cmd) & _IOC_WRITE) { + in_iov = iov; + in_iovs = 1; + } + + if (_IOC_DIR(cmd) & _IOC_READ) { + out_iov = iov; + out_iovs = 1; + } + } + + retry: + inarg.in_size = in_size = iov_length(in_iov, in_iovs); + inarg.out_size = out_size = iov_length(out_iov, out_iovs); + + /* + * Out data can be used either for actual out data or iovs, + * make sure there always is at least one page. + */ + out_size = max_t(size_t, out_size, PAGE_SIZE); + max_pages = DIV_ROUND_UP(max(in_size, out_size), PAGE_SIZE); + + /* make sure there are enough buffer pages and init request with them */ + err = -ENOMEM; + if (max_pages > fm->fc->max_pages) + goto out; + while (ap.num_pages < max_pages) { + ap.pages[ap.num_pages] = alloc_page(GFP_KERNEL | __GFP_HIGHMEM); + if (!ap.pages[ap.num_pages]) + goto out; + ap.num_pages++; + } + + + /* okay, let's send it to the client */ + ap.args.opcode = FUSE_IOCTL; + ap.args.nodeid = ff->nodeid; + ap.args.in_numargs = 1; + ap.args.in_args[0].size = sizeof(inarg); + ap.args.in_args[0].value = &inarg; + if (in_size) { + ap.args.in_numargs++; + ap.args.in_args[1].size = in_size; + ap.args.in_pages = true; + + err = -EFAULT; + iov_iter_init(&ii, WRITE, in_iov, in_iovs, in_size); + for (i = 0; iov_iter_count(&ii) && !WARN_ON(i >= ap.num_pages); i++) { + c = copy_page_from_iter(ap.pages[i], 0, PAGE_SIZE, &ii); + if (c != PAGE_SIZE && iov_iter_count(&ii)) + goto out; + } + } + + ap.args.out_numargs = 2; + ap.args.out_args[0].size = sizeof(outarg); + ap.args.out_args[0].value = &outarg; + ap.args.out_args[1].size = out_size; + ap.args.out_pages = true; + ap.args.out_argvar = true; + + transferred = fuse_simple_request(fm, &ap.args); + err = transferred; + if (transferred < 0) + goto out; + + /* did it ask for retry? */ + if (outarg.flags & FUSE_IOCTL_RETRY) { + void *vaddr; + + /* no retry if in restricted mode */ + err = -EIO; + if (!(flags & FUSE_IOCTL_UNRESTRICTED)) + goto out; + + in_iovs = outarg.in_iovs; + out_iovs = outarg.out_iovs; + + /* + * Make sure things are in boundary, separate checks + * are to protect against overflow. + */ + err = -ENOMEM; + if (in_iovs > FUSE_IOCTL_MAX_IOV || + out_iovs > FUSE_IOCTL_MAX_IOV || + in_iovs + out_iovs > FUSE_IOCTL_MAX_IOV) + goto out; + + vaddr = kmap_atomic(ap.pages[0]); + err = fuse_copy_ioctl_iovec(fm->fc, iov_page, vaddr, + transferred, in_iovs + out_iovs, + (flags & FUSE_IOCTL_COMPAT) != 0); + kunmap_atomic(vaddr); + if (err) + goto out; + + in_iov = iov_page; + out_iov = in_iov + in_iovs; + + err = fuse_verify_ioctl_iov(fm->fc, in_iov, in_iovs); + if (err) + goto out; + + err = fuse_verify_ioctl_iov(fm->fc, out_iov, out_iovs); + if (err) + goto out; + + goto retry; + } + + err = -EIO; + if (transferred > inarg.out_size) + goto out; + + err = -EFAULT; + iov_iter_init(&ii, READ, out_iov, out_iovs, transferred); + for (i = 0; iov_iter_count(&ii) && !WARN_ON(i >= ap.num_pages); i++) { + c = copy_page_to_iter(ap.pages[i], 0, PAGE_SIZE, &ii); + if (c != PAGE_SIZE && iov_iter_count(&ii)) + goto out; + } + err = 0; + out: + free_page((unsigned long) iov_page); + while (ap.num_pages) + __free_page(ap.pages[--ap.num_pages]); + kfree(ap.pages); + + return err ? err : outarg.result; +} +EXPORT_SYMBOL_GPL(fuse_do_ioctl); + +long fuse_ioctl_common(struct file *file, unsigned int cmd, + unsigned long arg, unsigned int flags) +{ + struct inode *inode = file_inode(file); + struct fuse_conn *fc = get_fuse_conn(inode); + + if (!fuse_allow_current_process(fc)) + return -EACCES; + + if (fuse_is_bad(inode)) + return -EIO; + + return fuse_do_ioctl(file, cmd, arg, flags); +} + +long fuse_file_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + return fuse_ioctl_common(file, cmd, arg, 0); +} + +long fuse_file_compat_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + return fuse_ioctl_common(file, cmd, arg, FUSE_IOCTL_COMPAT); +} -- 2.20.1