Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 587 insertions, 0 deletions

diff --git a/fs/orangefs/file.c b/fs/orangefs/file.c
new file mode 100644
index 000000000..42591252e
--- /dev/null
+++ b/fs/orangefs/file.c
@@ -0,0 +1,587 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * (C) 2001 Clemson University and The University of Chicago
+ * Copyright 2018 Omnibond Systems, L.L.C.
+ *
+ * See COPYING in top-level directory.
+ */
+
+/*
+ *  Linux VFS file operations.
+ */
+
+#include "protocol.h"
+#include "orangefs-kernel.h"
+#include "orangefs-bufmap.h"
+#include <linux/fs.h>
+#include <linux/filelock.h>
+#include <linux/pagemap.h>
+
+static int flush_racache(struct inode *inode)
+{
+	struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
+	struct orangefs_kernel_op_s *new_op;
+	int ret;
+
+	gossip_debug(GOSSIP_UTILS_DEBUG,
+	    "%s: %pU: Handle is %pU | fs_id %d\n", __func__,
+	    get_khandle_from_ino(inode), &orangefs_inode->refn.khandle,
+	    orangefs_inode->refn.fs_id);
+
+	new_op = op_alloc(ORANGEFS_VFS_OP_RA_FLUSH);
+	if (!new_op)
+		return -ENOMEM;
+	new_op->upcall.req.ra_cache_flush.refn = orangefs_inode->refn;
+
+	ret = service_operation(new_op, "orangefs_flush_racache",
+	    get_interruptible_flag(inode));
+
+	gossip_debug(GOSSIP_UTILS_DEBUG, "%s: got return value of %d\n",
+	    __func__, ret);
+
+	op_release(new_op);
+	return ret;
+}
+
+/*
+ * Post and wait for the I/O upcall to finish
+ */
+ssize_t wait_for_direct_io(enum ORANGEFS_io_type type, struct inode *inode,
+	loff_t *offset, struct iov_iter *iter, size_t total_size,
+	loff_t readahead_size, struct orangefs_write_range *wr,
+	int *index_return, struct file *file)
+{
+	struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
+	struct orangefs_khandle *handle = &orangefs_inode->refn.khandle;
+	struct orangefs_kernel_op_s *new_op = NULL;
+	int buffer_index;
+	ssize_t ret;
+	size_t copy_amount;
+	bool open_for_read;
+	bool open_for_write;
+
+	new_op = op_alloc(ORANGEFS_VFS_OP_FILE_IO);
+	if (!new_op)
+		return -ENOMEM;
+
+	/* synchronous I/O */
+	new_op->upcall.req.io.readahead_size = readahead_size;
+	new_op->upcall.req.io.io_type = type;
+	new_op->upcall.req.io.refn = orangefs_inode->refn;
+
+populate_shared_memory:
+	/* get a shared buffer index */
+	buffer_index = orangefs_bufmap_get();
+	if (buffer_index < 0) {
+		ret = buffer_index;
+		gossip_debug(GOSSIP_FILE_DEBUG,
+			     "%s: orangefs_bufmap_get failure (%zd)\n",
+			     __func__, ret);
+		goto out;
+	}
+	gossip_debug(GOSSIP_FILE_DEBUG,
+		     "%s(%pU): GET op %p -> buffer_index %d\n",
+		     __func__,
+		     handle,
+		     new_op,
+		     buffer_index);
+
+	new_op->uses_shared_memory = 1;
+	new_op->upcall.req.io.buf_index = buffer_index;
+	new_op->upcall.req.io.count = total_size;
+	new_op->upcall.req.io.offset = *offset;
+	if (type == ORANGEFS_IO_WRITE && wr) {
+		new_op->upcall.uid = from_kuid(&init_user_ns, wr->uid);
+		new_op->upcall.gid = from_kgid(&init_user_ns, wr->gid);
+	}
+	/*
+	 * Orangefs has no open, and orangefs checks file permissions
+	 * on each file access. Posix requires that file permissions
+	 * be checked on open and nowhere else. Orangefs-through-the-kernel
+	 * needs to seem posix compliant.
+	 *
+	 * The VFS opens files, even if the filesystem provides no
+	 * method. We can see if a file was successfully opened for
+	 * read and or for write by looking at file->f_mode.
+	 *
+	 * When writes are flowing from the page cache, file is no
+	 * longer available. We can trust the VFS to have checked
+	 * file->f_mode before writing to the page cache.
+	 *
+	 * The mode of a file might change between when it is opened
+	 * and IO commences, or it might be created with an arbitrary mode.
+	 *
+	 * We'll make sure we don't hit EACCES during the IO stage by
+	 * using UID 0. Some of the time we have access without changing
+	 * to UID 0 - how to check?
+	 */
+	if (file) {
+		open_for_write = file->f_mode & FMODE_WRITE;
+		open_for_read = file->f_mode & FMODE_READ;
+	} else {
+		open_for_write = 1;
+		open_for_read = 0; /* not relevant? */
+	}
+	if ((type == ORANGEFS_IO_WRITE) && open_for_write)
+		new_op->upcall.uid = 0;
+	if ((type == ORANGEFS_IO_READ) && open_for_read)
+		new_op->upcall.uid = 0;
+
+	gossip_debug(GOSSIP_FILE_DEBUG,
+		     "%s(%pU): offset: %llu total_size: %zd\n",
+		     __func__,
+		     handle,
+		     llu(*offset),
+		     total_size);
+	/*
+	 * Stage 1: copy the buffers into client-core's address space
+	 */
+	if (type == ORANGEFS_IO_WRITE && total_size) {
+		ret = orangefs_bufmap_copy_from_iovec(iter, buffer_index,
+		    total_size);
+		if (ret < 0) {
+			gossip_err("%s: Failed to copy-in buffers. Please make sure that the pvfs2-client is running. %ld\n",
+			    __func__, (long)ret);
+			goto out;
+		}
+	}
+
+	gossip_debug(GOSSIP_FILE_DEBUG,
+		     "%s(%pU): Calling post_io_request with tag (%llu)\n",
+		     __func__,
+		     handle,
+		     llu(new_op->tag));
+
+	/* Stage 2: Service the I/O operation */
+	ret = service_operation(new_op,
+				type == ORANGEFS_IO_WRITE ?
+					"file_write" :
+					"file_read",
+				get_interruptible_flag(inode));
+
+	/*
+	 * If service_operation() returns -EAGAIN #and# the operation was
+	 * purged from orangefs_request_list or htable_ops_in_progress, then
+	 * we know that the client was restarted, causing the shared memory
+	 * area to be wiped clean.  To restart a  write operation in this
+	 * case, we must re-copy the data from the user's iovec to a NEW
+	 * shared memory location. To restart a read operation, we must get
+	 * a new shared memory location.
+	 */
+	if (ret == -EAGAIN && op_state_purged(new_op)) {
+		orangefs_bufmap_put(buffer_index);
+		if (type == ORANGEFS_IO_WRITE)
+			iov_iter_revert(iter, total_size);
+		gossip_debug(GOSSIP_FILE_DEBUG,
+			     "%s:going to repopulate_shared_memory.\n",
+			     __func__);
+		goto populate_shared_memory;
+	}
+
+	if (ret < 0) {
+		if (ret == -EINTR) {
+			/*
+			 * We can't return EINTR if any data was written,
+			 * it's not POSIX. It is minimally acceptable
+			 * to give a partial write, the way NFS does.
+			 *
+			 * It would be optimal to return all or nothing,
+			 * but if a userspace write is bigger than
+			 * an IO buffer, and the interrupt occurs
+			 * between buffer writes, that would not be
+			 * possible.
+			 */
+			switch (new_op->op_state - OP_VFS_STATE_GIVEN_UP) {
+			/*
+			 * If the op was waiting when the interrupt
+			 * occurred, then the client-core did not
+			 * trigger the write.
+			 */
+			case OP_VFS_STATE_WAITING:
+				if (*offset == 0)
+					ret = -EINTR;
+				else
+					ret = 0;
+				break;
+			/*
+			 * If the op was in progress when the interrupt
+			 * occurred, then the client-core was able to
+			 * trigger the write.
+			 */
+			case OP_VFS_STATE_INPROGR:
+				if (type == ORANGEFS_IO_READ)
+					ret = -EINTR;
+				else
+					ret = total_size;
+				break;
+			default:
+				gossip_err("%s: unexpected op state :%d:.\n",
+					   __func__,
+					   new_op->op_state);
+				ret = 0;
+				break;
+			}
+			gossip_debug(GOSSIP_FILE_DEBUG,
+				     "%s: got EINTR, state:%d: %p\n",
+				     __func__,
+				     new_op->op_state,
+				     new_op);
+		} else {
+			gossip_err("%s: error in %s handle %pU, returning %zd\n",
+				__func__,
+				type == ORANGEFS_IO_READ ?
+					"read from" : "write to",
+				handle, ret);
+		}
+		if (orangefs_cancel_op_in_progress(new_op))
+			return ret;
+
+		goto out;
+	}
+
+	/*
+	 * Stage 3: Post copy buffers from client-core's address space
+	 */
+	if (type == ORANGEFS_IO_READ && new_op->downcall.resp.io.amt_complete) {
+		/*
+		 * NOTE: the iovector can either contain addresses which
+		 *       can futher be kernel-space or user-space addresses.
+		 *       or it can pointers to struct page's
+		 */
+
+		copy_amount = new_op->downcall.resp.io.amt_complete;
+
+		ret = orangefs_bufmap_copy_to_iovec(iter, buffer_index,
+			copy_amount);
+		if (ret < 0) {
+			gossip_err("%s: Failed to copy-out buffers. Please make sure that the pvfs2-client is running (%ld)\n",
+			    __func__, (long)ret);
+			goto out;
+		}
+	}
+	gossip_debug(GOSSIP_FILE_DEBUG,
+	    "%s(%pU): Amount %s, returned by the sys-io call:%d\n",
+	    __func__,
+	    handle,
+	    type == ORANGEFS_IO_READ ?  "read" : "written",
+	    (int)new_op->downcall.resp.io.amt_complete);
+
+	ret = new_op->downcall.resp.io.amt_complete;
+
+out:
+	if (buffer_index >= 0) {
+		orangefs_bufmap_put(buffer_index);
+		gossip_debug(GOSSIP_FILE_DEBUG,
+			"%s(%pU): PUT buffer_index %d\n",
+			__func__, handle, buffer_index);
+	}
+	op_release(new_op);
+	return ret;
+}
+
+int orangefs_revalidate_mapping(struct inode *inode)
+{
+	struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
+	struct address_space *mapping = inode->i_mapping;
+	unsigned long *bitlock = &orangefs_inode->bitlock;
+	int ret;
+
+	while (1) {
+		ret = wait_on_bit(bitlock, 1, TASK_KILLABLE);
+		if (ret)
+			return ret;
+		spin_lock(&inode->i_lock);
+		if (test_bit(1, bitlock)) {
+			spin_unlock(&inode->i_lock);
+			continue;
+		}
+		if (!time_before(jiffies, orangefs_inode->mapping_time))
+			break;
+		spin_unlock(&inode->i_lock);
+		return 0;
+	}
+
+	set_bit(1, bitlock);
+	smp_wmb();
+	spin_unlock(&inode->i_lock);
+
+	unmap_mapping_range(mapping, 0, 0, 0);
+	ret = filemap_write_and_wait(mapping);
+	if (!ret)
+		ret = invalidate_inode_pages2(mapping);
+
+	orangefs_inode->mapping_time = jiffies +
+	    orangefs_cache_timeout_msecs*HZ/1000;
+
+	clear_bit(1, bitlock);
+	smp_mb__after_atomic();
+	wake_up_bit(bitlock, 1);
+
+	return ret;
+}
+
+static ssize_t orangefs_file_read_iter(struct kiocb *iocb,
+    struct iov_iter *iter)
+{
+	int ret;
+	orangefs_stats.reads++;
+
+	down_read(&file_inode(iocb->ki_filp)->i_rwsem);
+	ret = orangefs_revalidate_mapping(file_inode(iocb->ki_filp));
+	if (ret)
+		goto out;
+
+	ret = generic_file_read_iter(iocb, iter);
+out:
+	up_read(&file_inode(iocb->ki_filp)->i_rwsem);
+	return ret;
+}
+
+static ssize_t orangefs_file_splice_read(struct file *in, loff_t *ppos,
+					 struct pipe_inode_info *pipe,
+					 size_t len, unsigned int flags)
+{
+	struct inode *inode = file_inode(in);
+	ssize_t ret;
+
+	orangefs_stats.reads++;
+
+	down_read(&inode->i_rwsem);
+	ret = orangefs_revalidate_mapping(inode);
+	if (ret)
+		goto out;
+
+	ret = filemap_splice_read(in, ppos, pipe, len, flags);
+out:
+	up_read(&inode->i_rwsem);
+	return ret;
+}
+
+static ssize_t orangefs_file_write_iter(struct kiocb *iocb,
+    struct iov_iter *iter)
+{
+	int ret;
+	orangefs_stats.writes++;
+
+	if (iocb->ki_pos > i_size_read(file_inode(iocb->ki_filp))) {
+		ret = orangefs_revalidate_mapping(file_inode(iocb->ki_filp));
+		if (ret)
+			return ret;
+	}
+
+	ret = generic_file_write_iter(iocb, iter);
+	return ret;
+}
+
+static vm_fault_t orangefs_fault(struct vm_fault *vmf)
+{
+	struct file *file = vmf->vma->vm_file;
+	int ret;
+	ret = orangefs_inode_getattr(file->f_mapping->host,
+	    ORANGEFS_GETATTR_SIZE);
+	if (ret == -ESTALE)
+		ret = -EIO;
+	if (ret) {
+		gossip_err("%s: orangefs_inode_getattr failed, "
+		    "ret:%d:.\n", __func__, ret);
+		return VM_FAULT_SIGBUS;
+	}
+	return filemap_fault(vmf);
+}
+
+static const struct vm_operations_struct orangefs_file_vm_ops = {
+	.fault = orangefs_fault,
+	.map_pages = filemap_map_pages,
+	.page_mkwrite = orangefs_page_mkwrite,
+};
+
+/*
+ * Memory map a region of a file.
+ */
+static int orangefs_file_mmap_prepare(struct vm_area_desc *desc)
+{
+	struct file *file = desc->file;
+	int ret;
+
+	ret = orangefs_revalidate_mapping(file_inode(file));
+	if (ret)
+		return ret;
+
+	gossip_debug(GOSSIP_FILE_DEBUG,
+		     "orangefs_file_mmap: called on %pD\n", file);
+
+	/* set the sequential readahead hint */
+	vma_desc_set_flags(desc, VMA_SEQ_READ_BIT);
+	vma_desc_clear_flags(desc, VMA_RAND_READ_BIT);
+
+	file_accessed(file);
+	desc->vm_ops = &orangefs_file_vm_ops;
+	return 0;
+}
+
+#define mapping_nrpages(idata) ((idata)->nrpages)
+
+/*
+ * Called to notify the module that there are no more references to
+ * this file (i.e. no processes have it open).
+ *
+ * \note Not called when each file is closed.
+ */
+static int orangefs_file_release(struct inode *inode, struct file *file)
+{
+	gossip_debug(GOSSIP_FILE_DEBUG,
+		     "orangefs_file_release: called on %pD\n",
+		     file);
+
+	/*
+	 * remove all associated inode pages from the page cache and
+	 * readahead cache (if any); this forces an expensive refresh of
+	 * data for the next caller of mmap (or 'get_block' accesses)
+	 */
+	if (mapping_nrpages(file->f_mapping)) {
+		if (orangefs_features & ORANGEFS_FEATURE_READAHEAD) {
+			gossip_debug(GOSSIP_INODE_DEBUG,
+			    "calling flush_racache on %pU\n",
+			    get_khandle_from_ino(inode));
+			flush_racache(inode);
+			gossip_debug(GOSSIP_INODE_DEBUG,
+			    "flush_racache finished\n");
+		}
+
+	}
+	return 0;
+}
+
+/*
+ * Push all data for a specific file onto permanent storage.
+ */
+static int orangefs_fsync(struct file *file,
+		       loff_t start,
+		       loff_t end,
+		       int datasync)
+{
+	int ret;
+	struct orangefs_inode_s *orangefs_inode =
+		ORANGEFS_I(file_inode(file));
+	struct orangefs_kernel_op_s *new_op = NULL;
+
+	ret = filemap_write_and_wait_range(file_inode(file)->i_mapping,
+	    start, end);
+	if (ret < 0)
+		return ret;
+
+	new_op = op_alloc(ORANGEFS_VFS_OP_FSYNC);
+	if (!new_op)
+		return -ENOMEM;
+	new_op->upcall.req.fsync.refn = orangefs_inode->refn;
+
+	ret = service_operation(new_op,
+			"orangefs_fsync",
+			get_interruptible_flag(file_inode(file)));
+
+	gossip_debug(GOSSIP_FILE_DEBUG,
+		     "orangefs_fsync got return value of %d\n",
+		     ret);
+
+	op_release(new_op);
+	return ret;
+}
+
+/*
+ * Change the file pointer position for an instance of an open file.
+ *
+ * \note If .llseek is overriden, we must acquire lock as described in
+ *       Documentation/filesystems/locking.rst.
+ *
+ * Future upgrade could support SEEK_DATA and SEEK_HOLE but would
+ * require much changes to the FS
+ */
+static loff_t orangefs_file_llseek(struct file *file, loff_t offset, int origin)
+{
+	int ret = -EINVAL;
+	struct inode *inode = file_inode(file);
+
+	if (origin == SEEK_END) {
+		/*
+		 * revalidate the inode's file size.
+		 * NOTE: We are only interested in file size here,
+		 * so we set mask accordingly.
+		 */
+		ret = orangefs_inode_getattr(file->f_mapping->host,
+		    ORANGEFS_GETATTR_SIZE);
+		if (ret == -ESTALE)
+			ret = -EIO;
+		if (ret) {
+			gossip_debug(GOSSIP_FILE_DEBUG,
+				     "%s:%s:%d calling make bad inode\n",
+				     __FILE__,
+				     __func__,
+				     __LINE__);
+			return ret;
+		}
+	}
+
+	gossip_debug(GOSSIP_FILE_DEBUG,
+		     "orangefs_file_llseek: offset is %ld | origin is %d"
+		     " | inode size is %lu\n",
+		     (long)offset,
+		     origin,
+		     (unsigned long)i_size_read(inode));
+
+	return generic_file_llseek(file, offset, origin);
+}
+
+/*
+ * Support local locks (locks that only this kernel knows about)
+ * if Orangefs was mounted -o local_lock.
+ */
+static int orangefs_lock(struct file *filp, int cmd, struct file_lock *fl)
+{
+	int rc = -EINVAL;
+
+	if (ORANGEFS_SB(file_inode(filp)->i_sb)->flags & ORANGEFS_OPT_LOCAL_LOCK) {
+		if (cmd == F_GETLK) {
+			rc = 0;
+			posix_test_lock(filp, fl);
+		} else {
+			rc = posix_lock_file(filp, fl, NULL);
+		}
+	}
+
+	return rc;
+}
+
+static int orangefs_flush(struct file *file, fl_owner_t id)
+{
+	/*
+	 * This is vfs_fsync_range(file, 0, LLONG_MAX, 0) without the
+	 * service_operation in orangefs_fsync.
+	 *
+	 * Do not send fsync to OrangeFS server on a close.  Do send fsync
+	 * on an explicit fsync call.  This duplicates historical OrangeFS
+	 * behavior.
+	 */
+	int r;
+
+	r = filemap_write_and_wait_range(file->f_mapping, 0, LLONG_MAX);
+	if (r > 0)
+		return 0;
+	else
+		return r;
+}
+
+/** ORANGEFS implementation of VFS file operations */
+const struct file_operations orangefs_file_operations = {
+	.llseek		= orangefs_file_llseek,
+	.read_iter	= orangefs_file_read_iter,
+	.write_iter	= orangefs_file_write_iter,
+	.lock		= orangefs_lock,
+	.mmap_prepare	= orangefs_file_mmap_prepare,
+	.open		= generic_file_open,
+	.splice_read    = orangefs_file_splice_read,
+	.splice_write   = iter_file_splice_write,
+	.flush		= orangefs_flush,
+	.release	= orangefs_file_release,
+	.fsync		= orangefs_fsync,
+	.setlease	= generic_setlease,
+};