1 files changed, 173 insertions, 23 deletions

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index c8224587123f..82a66466a24c 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -13,6 +13,7 @@
 #include <linux/kernel.h>
 #include <linux/sched.h>
 #include <linux/module.h>
+#include <linux/compat.h>
 
 static const struct file_operations fuse_direct_io_file_operations;
 
@@ -85,18 +86,52 @@ struct fuse_file *fuse_file_get(struct fuse_file *ff)
         return ff;
 }
 
+static void fuse_release_async(struct work_struct *work)
+{
+        struct fuse_req *req;
+        struct fuse_conn *fc;
+        struct path path;
+
+        req = container_of(work, struct fuse_req, misc.release.work);
+        path = req->misc.release.path;
+        fc = get_fuse_conn(path.dentry->d_inode);
+
+        fuse_put_request(fc, req);
+        path_put(&path);
+}
+
 static void fuse_release_end(struct fuse_conn *fc, struct fuse_req *req)
 {
-        path_put(&req->misc.release.path);
+        if (fc->destroy_req) {
+                /*
+                 * If this is a fuseblk mount, then it's possible that
+                 * releasing the path will result in releasing the
+                 * super block and sending the DESTROY request.  If
+                 * the server is single threaded, this would hang.
+                 * For this reason do the path_put() in a separate
+                 * thread.
+                 */
+                atomic_inc(&req->count);
+                INIT_WORK(&req->misc.release.work, fuse_release_async);
+                schedule_work(&req->misc.release.work);
+        } else {
+                path_put(&req->misc.release.path);
+        }
 }
 
-static void fuse_file_put(struct fuse_file *ff)
+static void fuse_file_put(struct fuse_file *ff, bool sync)
 {
         if (atomic_dec_and_test(&ff->count)) {
                 struct fuse_req *req = ff->reserved_req;
 
-                req->end = fuse_release_end;
-                fuse_request_send_background(ff->fc, req);
+                if (sync) {
+                        fuse_request_send(ff->fc, req);
+                        path_put(&req->misc.release.path);
+                        fuse_put_request(ff->fc, req);
+                } else {
+                        req->end = fuse_release_end;
+                        fuse_request_send_background(ff->fc, req);
+                }
                 kfree(ff);
         }
 }
@@ -134,6 +169,7 @@ EXPORT_SYMBOL_GPL(fuse_do_open);
 void fuse_finish_open(struct inode *inode, struct file *file)
 {
         struct fuse_file *ff = file->private_data;
+        struct fuse_conn *fc = get_fuse_conn(inode);
 
         if (ff->open_flags & FOPEN_DIRECT_IO)
                 file->f_op = &fuse_direct_io_file_operations;
@@ -141,6 +177,15 @@ void fuse_finish_open(struct inode *inode, struct file *file)
                 invalidate_inode_pages2(inode->i_mapping);
         if (ff->open_flags & FOPEN_NONSEEKABLE)
                 nonseekable_open(inode, file);
+        if (fc->atomic_o_trunc && (file->f_flags & O_TRUNC)) {
+                struct fuse_inode *fi = get_fuse_inode(inode);
+
+                spin_lock(&fc->lock);
+                fi->attr_version = ++fc->attr_version;
+                i_size_write(inode, 0);
+                spin_unlock(&fc->lock);
+                fuse_invalidate_attr(inode);
+        }
 }
 
 int fuse_open_common(struct inode *inode, struct file *file, bool isdir)
@@ -177,7 +222,7 @@ static void fuse_prepare_release(struct fuse_file *ff, int flags, int opcode)
                 rb_erase(&ff->polled_node, &fc->polled_files);
         spin_unlock(&fc->lock);
 
-        wake_up_interruptible_sync(&ff->poll_wait);
+        wake_up_interruptible_all(&ff->poll_wait);
 
         inarg->fh = ff->fh;
         inarg->flags = flags;
@@ -208,8 +253,12 @@ void fuse_release_common(struct file *file, int opcode)
          * Normally this will send the RELEASE request, however if
          * some asynchronous READ or WRITE requests are outstanding,
          * the sending will be delayed.
+         *
+         * Make the release synchronous if this is a fuseblk mount,
+         * synchronous RELEASE is allowed (and desirable) in this case
+         * because the server can be trusted not to screw up.
          */
-        fuse_file_put(ff);
+        fuse_file_put(ff, ff->fc->destroy_req != NULL);
 }
 
 static int fuse_open(struct inode *inode, struct file *file)
@@ -474,7 +523,7 @@ static int fuse_readpage(struct file *file, struct page *page)
                 goto out;
 
         /*
-         * Page writeback can extend beyond the liftime of the
+         * Page writeback can extend beyond the lifetime of the
          * page-cache page, so make sure we read a properly synced
          * page.
          */
@@ -547,7 +596,7 @@ static void fuse_readpages_end(struct fuse_conn *fc, struct fuse_req *req)
                 page_cache_release(page);
         }
         if (req->ff)
-                fuse_file_put(req->ff);
+                fuse_file_put(req->ff, false);
 }
 
 static void fuse_send_readpages(struct fuse_req *req, struct file *file)
@@ -1126,7 +1175,7 @@ static ssize_t fuse_direct_write(struct file *file, const char __user *buf,
 static void fuse_writepage_free(struct fuse_conn *fc, struct fuse_req *req)
 {
         __free_page(req->pages[0]);
-        fuse_file_put(req->ff);
+        fuse_file_put(req->ff, false);
 }
 
 static void fuse_writepage_finish(struct fuse_conn *fc, struct fuse_req *req)
@@ -1618,6 +1667,94 @@ static int fuse_ioctl_copy_user(struct page **pages, struct iovec *iov,
 }
 
 /*
+ * 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 iovec *iov, size_t count)
+{
+        size_t n;
+        u32 max = FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT;
+
+        for (n = 0; n < count; n++) {
+                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
@@ -1677,18 +1814,25 @@ long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
         struct fuse_ioctl_out outarg;
         struct fuse_req *req = NULL;
         struct page **pages = NULL;
-        struct page *iov_page = NULL;
+        struct iovec *iov_page = NULL;
         struct iovec *in_iov = NULL, *out_iov = NULL;
         unsigned int in_iovs = 0, out_iovs = 0, num_pages = 0, max_pages;
         size_t in_size, out_size, transferred;
         int err;
 
+#if BITS_PER_LONG == 32
+        inarg.flags |= FUSE_IOCTL_32BIT;
+#else
+        if (flags & FUSE_IOCTL_COMPAT)
+                inarg.flags |= FUSE_IOCTL_32BIT;
+#endif
+
         /* assume all the iovs returned by client always fits in a page */
-        BUILD_BUG_ON(sizeof(struct iovec) * FUSE_IOCTL_MAX_IOV > PAGE_SIZE);
+        BUILD_BUG_ON(sizeof(struct fuse_ioctl_iovec) * FUSE_IOCTL_MAX_IOV > PAGE_SIZE);
 
         err = -ENOMEM;
         pages = kzalloc(sizeof(pages[0]) * FUSE_MAX_PAGES_PER_REQ, GFP_KERNEL);
-        iov_page = alloc_page(GFP_KERNEL);
+        iov_page = (struct iovec *) __get_free_page(GFP_KERNEL);
         if (!pages || !iov_page)
                 goto out;
 
@@ -1697,7 +1841,7 @@ long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
          * RETRY from server is not allowed.
          */
         if (!(flags & FUSE_IOCTL_UNRESTRICTED)) {
-                struct iovec *iov = page_address(iov_page);
+                struct iovec *iov = iov_page;
 
                 iov->iov_base = (void __user *)arg;
                 iov->iov_len = _IOC_SIZE(cmd);
@@ -1778,7 +1922,7 @@ long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
 
         /* did it ask for retry? */
         if (outarg.flags & FUSE_IOCTL_RETRY) {
-                char *vaddr;
+                void *vaddr;
 
                 /* no retry if in restricted mode */
                 err = -EIO;
@@ -1798,18 +1942,25 @@ long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
                     in_iovs + out_iovs > FUSE_IOCTL_MAX_IOV)
                         goto out;
 
-                err = -EIO;
-                if ((in_iovs + out_iovs) * sizeof(struct iovec) != transferred)
-                        goto out;
-
-                /* okay, copy in iovs and retry */
                 vaddr = kmap_atomic(pages[0], KM_USER0);
-                memcpy(page_address(iov_page), vaddr, transferred);
+                err = fuse_copy_ioctl_iovec(fc, iov_page, vaddr,
+                                            transferred, in_iovs + out_iovs,
+                                            (flags & FUSE_IOCTL_COMPAT) != 0);
                 kunmap_atomic(vaddr, KM_USER0);
+                if (err)
+                        goto out;
 
-                in_iov = page_address(iov_page);
+                in_iov = iov_page;
                 out_iov = in_iov + in_iovs;
 
+                err = fuse_verify_ioctl_iov(in_iov, in_iovs);
+                if (err)
+                        goto out;
+
+                err = fuse_verify_ioctl_iov(out_iov, out_iovs);
+                if (err)
+                        goto out;
+
                 goto retry;
         }
 
@@ -1821,8 +1972,7 @@ long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
  out:
         if (req)
                 fuse_put_request(fc, req);
-        if (iov_page)
-                __free_page(iov_page);
+        free_page((unsigned long) iov_page);
         while (num_pages)
                 __free_page(pages[--num_pages]);
         kfree(pages);