diff options
Diffstat (limited to 'fs/fuse/file.c')
-rw-r--r-- | fs/fuse/file.c | 435 |
1 files changed, 36 insertions, 399 deletions
diff --git a/fs/fuse/file.c b/fs/fuse/file.c index df769f55f205..09ef2a4d25ed 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -14,32 +14,20 @@ #include <linux/sched.h> #include <linux/sched/signal.h> #include <linux/module.h> -#include <linux/compat.h> #include <linux/swap.h> #include <linux/falloc.h> #include <linux/uio.h> #include <linux/fs.h> -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) +static int fuse_send_open(struct fuse_mount *fm, u64 nodeid, + unsigned int open_flags, int opcode, + struct fuse_open_out *outargp) { struct fuse_open_in inarg; FUSE_ARGS(args); memset(&inarg, 0, sizeof(inarg)); - inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY); + inarg.flags = open_flags & ~(O_CREAT | O_EXCL | O_NOCTTY); if (!fm->fc->atomic_o_trunc) inarg.flags &= ~O_TRUNC; @@ -136,8 +124,8 @@ static void fuse_file_put(struct fuse_file *ff, bool sync, bool isdir) } } -int fuse_do_open(struct fuse_mount *fm, u64 nodeid, struct file *file, - bool isdir) +struct fuse_file *fuse_file_open(struct fuse_mount *fm, u64 nodeid, + unsigned int open_flags, bool isdir) { struct fuse_conn *fc = fm->fc; struct fuse_file *ff; @@ -145,7 +133,7 @@ int fuse_do_open(struct fuse_mount *fm, u64 nodeid, struct file *file, ff = fuse_file_alloc(fm); if (!ff) - return -ENOMEM; + return ERR_PTR(-ENOMEM); ff->fh = 0; /* Default for no-open */ @@ -154,14 +142,14 @@ int fuse_do_open(struct fuse_mount *fm, u64 nodeid, struct file *file, struct fuse_open_out outarg; int err; - err = fuse_send_open(fm, nodeid, file, opcode, &outarg); + err = fuse_send_open(fm, nodeid, open_flags, opcode, &outarg); if (!err) { ff->fh = outarg.fh; ff->open_flags = outarg.open_flags; } else if (err != -ENOSYS) { fuse_file_free(ff); - return err; + return ERR_PTR(err); } else { if (isdir) fc->no_opendir = 1; @@ -174,9 +162,19 @@ int fuse_do_open(struct fuse_mount *fm, u64 nodeid, struct file *file, ff->open_flags &= ~FOPEN_DIRECT_IO; ff->nodeid = nodeid; - file->private_data = ff; - return 0; + return ff; +} + +int fuse_do_open(struct fuse_mount *fm, u64 nodeid, struct file *file, + bool isdir) +{ + struct fuse_file *ff = fuse_file_open(fm, nodeid, file->f_flags, isdir); + + if (!IS_ERR(ff)) + file->private_data = ff; + + return PTR_ERR_OR_ZERO(ff); } EXPORT_SYMBOL_GPL(fuse_do_open); @@ -268,7 +266,7 @@ out: } static void fuse_prepare_release(struct fuse_inode *fi, struct fuse_file *ff, - int flags, int opcode) + unsigned int flags, int opcode) { struct fuse_conn *fc = ff->fm->fc; struct fuse_release_args *ra = ff->release_args; @@ -297,22 +295,21 @@ static void fuse_prepare_release(struct fuse_inode *fi, struct fuse_file *ff, ra->args.nocreds = true; } -void fuse_release_common(struct file *file, bool isdir) +void fuse_file_release(struct inode *inode, struct fuse_file *ff, + unsigned int open_flags, fl_owner_t id, bool isdir) { - struct fuse_inode *fi = get_fuse_inode(file_inode(file)); - struct fuse_file *ff = file->private_data; + struct fuse_inode *fi = get_fuse_inode(inode); struct fuse_release_args *ra = ff->release_args; int opcode = isdir ? FUSE_RELEASEDIR : FUSE_RELEASE; - fuse_prepare_release(fi, ff, file->f_flags, opcode); + fuse_prepare_release(fi, ff, open_flags, opcode); if (ff->flock) { ra->inarg.release_flags |= FUSE_RELEASE_FLOCK_UNLOCK; - ra->inarg.lock_owner = fuse_lock_owner_id(ff->fm->fc, - (fl_owner_t) file); + ra->inarg.lock_owner = fuse_lock_owner_id(ff->fm->fc, id); } /* Hold inode until release is finished */ - ra->inode = igrab(file_inode(file)); + ra->inode = igrab(inode); /* * Normally this will send the RELEASE request, however if @@ -326,6 +323,12 @@ void fuse_release_common(struct file *file, bool isdir) fuse_file_put(ff, ff->fm->fc->destroy, isdir); } +void fuse_release_common(struct file *file, bool isdir) +{ + fuse_file_release(file_inode(file), file->private_data, file->f_flags, + (fl_owner_t) file, isdir); +} + static int fuse_open(struct inode *inode, struct file *file) { return fuse_open_common(inode, file, false); @@ -345,7 +348,8 @@ static int fuse_release(struct inode *inode, struct file *file) return 0; } -void fuse_sync_release(struct fuse_inode *fi, struct fuse_file *ff, int flags) +void fuse_sync_release(struct fuse_inode *fi, struct fuse_file *ff, + unsigned int flags) { WARN_ON(refcount_read(&ff->count) > 1); fuse_prepare_release(fi, ff, flags, FUSE_RELEASE); @@ -1354,16 +1358,6 @@ 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; @@ -2654,363 +2648,6 @@ static loff_t fuse_file_llseek(struct file *file, loff_t offset, int whence) } /* - * 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 * find the matching one. |