fuse update for 4.19

This contains various bug fixes and cleanups.
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Merge tag 'fuse-update-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse

Pull fuse update from Miklos Szeredi:
 "Various bug fixes and cleanups"

* tag 'fuse-update-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: reduce allocation size for splice_write
  fuse: use kvmalloc to allocate array of pipe_buffer structs.
  fuse: convert last timespec use to timespec64
  fs: fuse: Adding new return type vm_fault_t
  fuse: simplify fuse_abort_conn()
  fuse: Add missed unlock_page() to fuse_readpages_fill()
  fuse: Don't access pipe->buffers without pipe_lock()
  fuse: fix initial parallel dirops
  fuse: Fix oops at process_init_reply()
  fuse: umount should wait for all requests
  fuse: fix unlocked access to processing queue
  fuse: fix double request_end()

fs/fuse/dev.c

@@ -127,6 +127,16 @@ static bool fuse_block_alloc(struct fuse_conn *fc, bool for_background)
 	return !fc->initialized || (for_background && fc->blocked);
 }
 
+static void fuse_drop_waiting(struct fuse_conn *fc)
+{
+	if (fc->connected) {
+		atomic_dec(&fc->num_waiting);
+	} else if (atomic_dec_and_test(&fc->num_waiting)) {
+		/* wake up aborters */
+		wake_up_all(&fc->blocked_waitq);
+	}
+}
+
 static struct fuse_req *__fuse_get_req(struct fuse_conn *fc, unsigned npages,
 				       bool for_background)
 {
@@ -175,7 +185,7 @@ static struct fuse_req *__fuse_get_req(struct fuse_conn *fc, unsigned npages,
 	return req;
 
  out:
-	atomic_dec(&fc->num_waiting);
+	fuse_drop_waiting(fc);
 	return ERR_PTR(err);
 }
 
@@ -285,7 +295,7 @@ void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req)
 
 		if (test_bit(FR_WAITING, &req->flags)) {
 			__clear_bit(FR_WAITING, &req->flags);
-			atomic_dec(&fc->num_waiting);
+			fuse_drop_waiting(fc);
 		}
 
 		if (req->stolen_file)
@@ -371,7 +381,7 @@ static void request_end(struct fuse_conn *fc, struct fuse_req *req)
 	struct fuse_iqueue *fiq = &fc->iq;
 
 	if (test_and_set_bit(FR_FINISHED, &req->flags))
-		return;
+		goto put_request;
 
 	spin_lock(&fiq->waitq.lock);
 	list_del_init(&req->intr_entry);
@@ -400,6 +410,7 @@ static void request_end(struct fuse_conn *fc, struct fuse_req *req)
 	wake_up(&req->waitq);
 	if (req->end)
 		req->end(fc, req);
+put_request:
 	fuse_put_request(fc, req);
 }
 
@@ -1362,8 +1373,8 @@ static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
 	if (!fud)
 		return -EPERM;
 
-	bufs = kmalloc_array(pipe->buffers, sizeof(struct pipe_buffer),
+	bufs = kvmalloc_array(pipe->buffers, sizeof(struct pipe_buffer),
-			     GFP_KERNEL);
+			      GFP_KERNEL);
 	if (!bufs)
 		return -ENOMEM;
 
@@ -1396,7 +1407,7 @@ out:
 	for (; page_nr < cs.nr_segs; page_nr++)
 		put_page(bufs[page_nr].page);
 
-	kfree(bufs);
+	kvfree(bufs);
 	return ret;
 }
 
@@ -1944,12 +1955,15 @@ static ssize_t fuse_dev_splice_write(struct pipe_inode_info *pipe,
 	if (!fud)
 		return -EPERM;
 
-	bufs = kmalloc_array(pipe->buffers, sizeof(struct pipe_buffer),
-			     GFP_KERNEL);
-	if (!bufs)
-		return -ENOMEM;
-
 	pipe_lock(pipe);
+
+	bufs = kvmalloc_array(pipe->nrbufs, sizeof(struct pipe_buffer),
+			      GFP_KERNEL);
+	if (!bufs) {
+		pipe_unlock(pipe);
+		return -ENOMEM;
+	}
+
 	nbuf = 0;
 	rem = 0;
 	for (idx = 0; idx < pipe->nrbufs && rem < len; idx++)
@@ -2003,7 +2017,7 @@ static ssize_t fuse_dev_splice_write(struct pipe_inode_info *pipe,
 		pipe_buf_release(pipe, &bufs[idx]);
 
 out:
-	kfree(bufs);
+	kvfree(bufs);
 	return ret;
 }
 
@@ -2087,8 +2101,7 @@ void fuse_abort_conn(struct fuse_conn *fc, bool is_abort)
 	if (fc->connected) {
 		struct fuse_dev *fud;
 		struct fuse_req *req, *next;
-		LIST_HEAD(to_end1);
+		LIST_HEAD(to_end);
-		LIST_HEAD(to_end2);
 
 		fc->connected = 0;
 		fc->blocked = 0;
@@ -2105,11 +2118,12 @@ void fuse_abort_conn(struct fuse_conn *fc, bool is_abort)
 				set_bit(FR_ABORTED, &req->flags);
 				if (!test_bit(FR_LOCKED, &req->flags)) {
 					set_bit(FR_PRIVATE, &req->flags);
-					list_move(&req->list, &to_end1);
+					__fuse_get_request(req);
+					list_move(&req->list, &to_end);
 				}
 				spin_unlock(&req->waitq.lock);
 			}
-			list_splice_init(&fpq->processing, &to_end2);
+			list_splice_tail_init(&fpq->processing, &to_end);
 			spin_unlock(&fpq->lock);
 		}
 		fc->max_background = UINT_MAX;
@@ -2117,9 +2131,9 @@ void fuse_abort_conn(struct fuse_conn *fc, bool is_abort)
 
 		spin_lock(&fiq->waitq.lock);
 		fiq->connected = 0;
-		list_splice_init(&fiq->pending, &to_end2);
+		list_for_each_entry(req, &fiq->pending, list)
-		list_for_each_entry(req, &to_end2, list)
 			clear_bit(FR_PENDING, &req->flags);
+		list_splice_tail_init(&fiq->pending, &to_end);
 		while (forget_pending(fiq))
 			kfree(dequeue_forget(fiq, 1, NULL));
 		wake_up_all_locked(&fiq->waitq);
@@ -2129,19 +2143,18 @@ void fuse_abort_conn(struct fuse_conn *fc, bool is_abort)
 		wake_up_all(&fc->blocked_waitq);
 		spin_unlock(&fc->lock);
 
-		while (!list_empty(&to_end1)) {
+		end_requests(fc, &to_end);
-			req = list_first_entry(&to_end1, struct fuse_req, list);
-			__fuse_get_request(req);
-			list_del_init(&req->list);
-			request_end(fc, req);
-		}
-		end_requests(fc, &to_end2);
 	} else {
 		spin_unlock(&fc->lock);
 	}
 }
 EXPORT_SYMBOL_GPL(fuse_abort_conn);
 
+void fuse_wait_aborted(struct fuse_conn *fc)
+{
+	wait_event(fc->blocked_waitq, atomic_read(&fc->num_waiting) == 0);
+}
+
 int fuse_dev_release(struct inode *inode, struct file *file)
 {
 	struct fuse_dev *fud = fuse_get_dev(file);
@@ -2149,9 +2162,15 @@ int fuse_dev_release(struct inode *inode, struct file *file)
 	if (fud) {
 		struct fuse_conn *fc = fud->fc;
 		struct fuse_pqueue *fpq = &fud->pq;
+		LIST_HEAD(to_end);
 
+		spin_lock(&fpq->lock);
 		WARN_ON(!list_empty(&fpq->io));
-		end_requests(fc, &fpq->processing);
+		list_splice_init(&fpq->processing, &to_end);
+		spin_unlock(&fpq->lock);
+
+		end_requests(fc, &to_end);
+
 		/* Are we the last open device? */
 		if (atomic_dec_and_test(&fc->dev_count)) {
 			WARN_ON(fc->iq.fasync != NULL);

fs/fuse/dir.c

@@ -355,11 +355,12 @@ static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry,
 	struct inode *inode;
 	struct dentry *newent;
 	bool outarg_valid = true;
+	bool locked;
 
-	fuse_lock_inode(dir);
+	locked = fuse_lock_inode(dir);
 	err = fuse_lookup_name(dir->i_sb, get_node_id(dir), &entry->d_name,
 			       &outarg, &inode);
-	fuse_unlock_inode(dir);
+	fuse_unlock_inode(dir, locked);
 	if (err == -ENOENT) {
 		outarg_valid = false;
 		err = 0;
@@ -1347,6 +1348,7 @@ static int fuse_readdir(struct file *file, struct dir_context *ctx)
 	struct fuse_conn *fc = get_fuse_conn(inode);
 	struct fuse_req *req;
 	u64 attr_version = 0;
+	bool locked;
 
 	if (is_bad_inode(inode))
 		return -EIO;
@@ -1374,9 +1376,9 @@ static int fuse_readdir(struct file *file, struct dir_context *ctx)
 		fuse_read_fill(req, file, ctx->pos, PAGE_SIZE,
 			       FUSE_READDIR);
 	}
-	fuse_lock_inode(inode);
+	locked = fuse_lock_inode(inode);
 	fuse_request_send(fc, req);
-	fuse_unlock_inode(inode);
+	fuse_unlock_inode(inode, locked);
 	nbytes = req->out.args[0].size;
 	err = req->out.h.error;
 	fuse_put_request(fc, req);

fs/fuse/file.c

@@ -867,6 +867,7 @@ static int fuse_readpages_fill(void *_data, struct page *page)
 	}
 
 	if (WARN_ON(req->num_pages >= req->max_pages)) {
+		unlock_page(page);
 		fuse_put_request(fc, req);
 		return -EIO;
 	}
@@ -2049,7 +2050,7 @@ static void fuse_vma_close(struct vm_area_struct *vma)
  * - sync(2)
  * - try_to_free_pages() with order > PAGE_ALLOC_COSTLY_ORDER
  */
-static int fuse_page_mkwrite(struct vm_fault *vmf)
+static vm_fault_t fuse_page_mkwrite(struct vm_fault *vmf)
 {
 	struct page *page = vmf->page;
 	struct inode *inode = file_inode(vmf->vma->vm_file);

fs/fuse/fuse_i.h

@@ -862,6 +862,7 @@ void fuse_request_send_background_locked(struct fuse_conn *fc,
 
 /* Abort all requests */
 void fuse_abort_conn(struct fuse_conn *fc, bool is_abort);
+void fuse_wait_aborted(struct fuse_conn *fc);
 
 /**
  * Invalidate inode attributes
@@ -974,8 +975,8 @@ int fuse_do_setattr(struct dentry *dentry, struct iattr *attr,
 
 void fuse_set_initialized(struct fuse_conn *fc);
 
-void fuse_unlock_inode(struct inode *inode);
+void fuse_unlock_inode(struct inode *inode, bool locked);
-void fuse_lock_inode(struct inode *inode);
+bool fuse_lock_inode(struct inode *inode);
 
 int fuse_setxattr(struct inode *inode, const char *name, const void *value,
 		  size_t size, int flags);

fs/fuse/inode.c

@@ -208,7 +208,7 @@ void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
 	struct fuse_inode *fi = get_fuse_inode(inode);
 	bool is_wb = fc->writeback_cache;
 	loff_t oldsize;
-	struct timespec old_mtime;
+	struct timespec64 old_mtime;
 
 	spin_lock(&fc->lock);
 	if ((attr_version != 0 && fi->attr_version > attr_version) ||
@@ -217,7 +217,7 @@ void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
 		return;
 	}
 
-	old_mtime = timespec64_to_timespec(inode->i_mtime);
+	old_mtime = inode->i_mtime;
 	fuse_change_attributes_common(inode, attr, attr_valid);
 
 	oldsize = inode->i_size;
@@ -237,7 +237,7 @@ void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
 			truncate_pagecache(inode, attr->size);
 			inval = true;
 		} else if (fc->auto_inval_data) {
-			struct timespec new_mtime = {
+			struct timespec64 new_mtime = {
 				.tv_sec = attr->mtime,
 				.tv_nsec = attr->mtimensec,
 			};
@@ -246,7 +246,7 @@ void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
 			 * Auto inval mode also checks and invalidates if mtime
 			 * has changed.
 			 */
-			if (!timespec_equal(&old_mtime, &new_mtime))
+			if (!timespec64_equal(&old_mtime, &new_mtime))
 				inval = true;
 		}
 
@@ -357,15 +357,21 @@ int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
 	return 0;
 }
 
-void fuse_lock_inode(struct inode *inode)
+bool fuse_lock_inode(struct inode *inode)
 {
-	if (!get_fuse_conn(inode)->parallel_dirops)
+	bool locked = false;
+
+	if (!get_fuse_conn(inode)->parallel_dirops) {
 		mutex_lock(&get_fuse_inode(inode)->mutex);
+		locked = true;
+	}
+
+	return locked;
 }
 
-void fuse_unlock_inode(struct inode *inode)
+void fuse_unlock_inode(struct inode *inode, bool locked)
 {
-	if (!get_fuse_conn(inode)->parallel_dirops)
+	if (locked)
 		mutex_unlock(&get_fuse_inode(inode)->mutex);
 }
 
@@ -391,9 +397,6 @@ static void fuse_put_super(struct super_block *sb)
 {
 	struct fuse_conn *fc = get_fuse_conn_super(sb);
 
-	fuse_send_destroy(fc);
-
-	fuse_abort_conn(fc, false);
 	mutex_lock(&fuse_mutex);
 	list_del(&fc->entry);
 	fuse_ctl_remove_conn(fc);
@@ -1210,16 +1213,25 @@ static struct dentry *fuse_mount(struct file_system_type *fs_type,
 	return mount_nodev(fs_type, flags, raw_data, fuse_fill_super);
 }
 
-static void fuse_kill_sb_anon(struct super_block *sb)
+static void fuse_sb_destroy(struct super_block *sb)
 {
 	struct fuse_conn *fc = get_fuse_conn_super(sb);
 
 	if (fc) {
+		fuse_send_destroy(fc);
+
+		fuse_abort_conn(fc, false);
+		fuse_wait_aborted(fc);
+
 		down_write(&fc->killsb);
 		fc->sb = NULL;
 		up_write(&fc->killsb);
 	}
+}
 
+static void fuse_kill_sb_anon(struct super_block *sb)
+{
+	fuse_sb_destroy(sb);
 	kill_anon_super(sb);
 }
 
@@ -1242,14 +1254,7 @@ static struct dentry *fuse_mount_blk(struct file_system_type *fs_type,
 
 static void fuse_kill_sb_blk(struct super_block *sb)
 {
-	struct fuse_conn *fc = get_fuse_conn_super(sb);
+	fuse_sb_destroy(sb);
-
-	if (fc) {
-		down_write(&fc->killsb);
-		fc->sb = NULL;
-		up_write(&fc->killsb);
-	}
-
 	kill_block_super(sb);
 }