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, 706 insertions, 0 deletions

diff --git a/fs/squashfs/super.c b/fs/squashfs/super.c
new file mode 100644
index 000000000..5dabc5770
--- /dev/null
+++ b/fs/squashfs/super.c
@@ -0,0 +1,706 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Squashfs - a compressed read only filesystem for Linux
+ *
+ * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008
+ * Phillip Lougher <phillip@squashfs.org.uk>
+ *
+ * super.c
+ */
+
+/*
+ * This file implements code to read the superblock, read and initialise
+ * in-memory structures at mount time, and all the VFS glue code to register
+ * the filesystem.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/blkdev.h>
+#include <linux/fs.h>
+#include <linux/fs_context.h>
+#include <linux/fs_parser.h>
+#include <linux/vfs.h>
+#include <linux/slab.h>
+#include <linux/mutex.h>
+#include <linux/seq_file.h>
+#include <linux/pagemap.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/magic.h>
+#include <linux/xattr.h>
+
+#include "squashfs_fs.h"
+#include "squashfs_fs_sb.h"
+#include "squashfs_fs_i.h"
+#include "squashfs.h"
+#include "decompressor.h"
+#include "xattr.h"
+
+static struct file_system_type squashfs_fs_type;
+static const struct super_operations squashfs_super_ops;
+
+enum Opt_errors {
+	Opt_errors_continue,
+	Opt_errors_panic,
+};
+
+enum squashfs_param {
+	Opt_errors,
+	Opt_threads,
+};
+
+struct squashfs_mount_opts {
+	enum Opt_errors errors;
+	const struct squashfs_decompressor_thread_ops *thread_ops;
+	int thread_num;
+};
+
+static const struct constant_table squashfs_param_errors[] = {
+	{"continue",   Opt_errors_continue },
+	{"panic",      Opt_errors_panic },
+	{}
+};
+
+static const struct fs_parameter_spec squashfs_fs_parameters[] = {
+	fsparam_enum("errors", Opt_errors, squashfs_param_errors),
+	fsparam_string("threads", Opt_threads),
+	{}
+};
+
+
+static int squashfs_parse_param_threads_str(const char *str, struct squashfs_mount_opts *opts)
+{
+#ifdef CONFIG_SQUASHFS_CHOICE_DECOMP_BY_MOUNT
+	if (strcmp(str, "single") == 0) {
+		opts->thread_ops = &squashfs_decompressor_single;
+		return 0;
+	}
+	if (strcmp(str, "multi") == 0) {
+		opts->thread_ops = &squashfs_decompressor_multi;
+		return 0;
+	}
+	if (strcmp(str, "percpu") == 0) {
+		opts->thread_ops = &squashfs_decompressor_percpu;
+		return 0;
+	}
+#endif
+	return -EINVAL;
+}
+
+static int squashfs_parse_param_threads_num(const char *str, struct squashfs_mount_opts *opts)
+{
+#ifdef CONFIG_SQUASHFS_MOUNT_DECOMP_THREADS
+	int ret;
+	unsigned long num;
+
+	ret = kstrtoul(str, 0, &num);
+	if (ret != 0)
+		return -EINVAL;
+	if (num > 1) {
+		opts->thread_ops = &squashfs_decompressor_multi;
+		if (num > opts->thread_ops->max_decompressors())
+			return -EINVAL;
+		opts->thread_num = (int)num;
+		return 0;
+	}
+#ifdef CONFIG_SQUASHFS_DECOMP_SINGLE
+	if (num == 1) {
+		opts->thread_ops = &squashfs_decompressor_single;
+		opts->thread_num = 1;
+		return 0;
+	}
+#endif
+#endif /* !CONFIG_SQUASHFS_MOUNT_DECOMP_THREADS */
+	return -EINVAL;
+}
+
+static int squashfs_parse_param_threads(const char *str, struct squashfs_mount_opts *opts)
+{
+	int ret = squashfs_parse_param_threads_str(str, opts);
+
+	if (ret == 0)
+		return ret;
+	return squashfs_parse_param_threads_num(str, opts);
+}
+
+static int squashfs_parse_param(struct fs_context *fc, struct fs_parameter *param)
+{
+	struct squashfs_mount_opts *opts = fc->fs_private;
+	struct fs_parse_result result;
+	int opt;
+
+	opt = fs_parse(fc, squashfs_fs_parameters, param, &result);
+	if (opt < 0)
+		return opt;
+
+	switch (opt) {
+	case Opt_errors:
+		opts->errors = result.uint_32;
+		break;
+	case Opt_threads:
+		if (squashfs_parse_param_threads(param->string, opts) != 0)
+			return -EINVAL;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static const struct squashfs_decompressor *supported_squashfs_filesystem(
+	struct fs_context *fc,
+	short major, short minor, short id)
+{
+	const struct squashfs_decompressor *decompressor;
+
+	if (major < SQUASHFS_MAJOR) {
+		errorf(fc, "Major/Minor mismatch, older Squashfs %d.%d "
+		       "filesystems are unsupported", major, minor);
+		return NULL;
+	} else if (major > SQUASHFS_MAJOR || minor > SQUASHFS_MINOR) {
+		errorf(fc, "Major/Minor mismatch, trying to mount newer "
+		       "%d.%d filesystem", major, minor);
+		errorf(fc, "Please update your kernel");
+		return NULL;
+	}
+
+	decompressor = squashfs_lookup_decompressor(id);
+	if (!decompressor->supported) {
+		errorf(fc, "Filesystem uses \"%s\" compression. This is not supported",
+		       decompressor->name);
+		return NULL;
+	}
+
+	return decompressor;
+}
+
+
+static int squashfs_fill_super(struct super_block *sb, struct fs_context *fc)
+{
+	struct squashfs_mount_opts *opts = fc->fs_private;
+	struct squashfs_sb_info *msblk;
+	struct squashfs_super_block *sblk = NULL;
+	struct inode *root;
+	long long root_inode;
+	unsigned short flags;
+	unsigned int fragments;
+	u64 lookup_table_start, xattr_id_table_start, next_table;
+	int err, devblksize = sb_min_blocksize(sb, SQUASHFS_DEVBLK_SIZE);
+
+	TRACE("Entered squashfs_fill_superblock\n");
+
+	if (!devblksize) {
+		errorf(fc, "squashfs: unable to set blocksize\n");
+		return -EINVAL;
+	}
+
+	sb->s_fs_info = kzalloc_obj(*msblk);
+	if (sb->s_fs_info == NULL) {
+		ERROR("Failed to allocate squashfs_sb_info\n");
+		return -ENOMEM;
+	}
+	msblk = sb->s_fs_info;
+	msblk->thread_ops = opts->thread_ops;
+
+	msblk->panic_on_errors = (opts->errors == Opt_errors_panic);
+
+	msblk->devblksize = devblksize;
+	msblk->devblksize_log2 = ffz(~msblk->devblksize);
+
+	mutex_init(&msblk->meta_index_mutex);
+
+	/*
+	 * msblk->bytes_used is checked in squashfs_read_table to ensure reads
+	 * are not beyond filesystem end.  But as we're using
+	 * squashfs_read_table here to read the superblock (including the value
+	 * of bytes_used) we need to set it to an initial sensible dummy value
+	 */
+	msblk->bytes_used = sizeof(*sblk);
+	sblk = squashfs_read_table(sb, SQUASHFS_START, sizeof(*sblk));
+
+	if (IS_ERR(sblk)) {
+		errorf(fc, "unable to read squashfs_super_block");
+		err = PTR_ERR(sblk);
+		sblk = NULL;
+		goto failed_mount;
+	}
+
+	err = -EINVAL;
+
+	/* Check it is a SQUASHFS superblock */
+	sb->s_magic = le32_to_cpu(sblk->s_magic);
+	if (sb->s_magic != SQUASHFS_MAGIC) {
+		if (!(fc->sb_flags & SB_SILENT))
+			errorf(fc, "Can't find a SQUASHFS superblock on %pg",
+			       sb->s_bdev);
+		goto failed_mount;
+	}
+
+	if (opts->thread_num == 0) {
+		msblk->max_thread_num = msblk->thread_ops->max_decompressors();
+	} else {
+		msblk->max_thread_num = opts->thread_num;
+	}
+
+	/* Check the MAJOR & MINOR versions and lookup compression type */
+	msblk->decompressor = supported_squashfs_filesystem(
+			fc,
+			le16_to_cpu(sblk->s_major),
+			le16_to_cpu(sblk->s_minor),
+			le16_to_cpu(sblk->compression));
+	if (msblk->decompressor == NULL)
+		goto failed_mount;
+
+	/* Check the filesystem does not extend beyond the end of the
+	   block device */
+	msblk->bytes_used = le64_to_cpu(sblk->bytes_used);
+	if (msblk->bytes_used < 0 ||
+	    msblk->bytes_used > bdev_nr_bytes(sb->s_bdev))
+		goto failed_mount;
+
+	/* Check block size for sanity */
+	msblk->block_size = le32_to_cpu(sblk->block_size);
+	if (msblk->block_size > SQUASHFS_FILE_MAX_SIZE)
+		goto insanity;
+
+	/*
+	 * Check the system page size is not larger than the filesystem
+	 * block size (by default 128K).  This is currently not supported.
+	 */
+	if (PAGE_SIZE > msblk->block_size) {
+		errorf(fc, "Page size > filesystem block size (%d).  This is "
+		       "currently not supported!", msblk->block_size);
+		goto failed_mount;
+	}
+
+	/* Check block log for sanity */
+	msblk->block_log = le16_to_cpu(sblk->block_log);
+	if (msblk->block_log > SQUASHFS_FILE_MAX_LOG)
+		goto failed_mount;
+
+	/* Check that block_size and block_log match */
+	if (msblk->block_size != (1 << msblk->block_log))
+		goto insanity;
+
+	/* Check the root inode for sanity */
+	root_inode = le64_to_cpu(sblk->root_inode);
+	if (SQUASHFS_INODE_OFFSET(root_inode) > SQUASHFS_METADATA_SIZE)
+		goto insanity;
+
+	msblk->inode_table = le64_to_cpu(sblk->inode_table_start);
+	msblk->directory_table = le64_to_cpu(sblk->directory_table_start);
+	msblk->inodes = le32_to_cpu(sblk->inodes);
+	msblk->fragments = le32_to_cpu(sblk->fragments);
+	msblk->ids = le16_to_cpu(sblk->no_ids);
+	flags = le16_to_cpu(sblk->flags);
+
+	TRACE("Found valid superblock on %pg\n", sb->s_bdev);
+	TRACE("Inodes are %scompressed\n", SQUASHFS_UNCOMPRESSED_INODES(flags)
+				? "un" : "");
+	TRACE("Data is %scompressed\n", SQUASHFS_UNCOMPRESSED_DATA(flags)
+				? "un" : "");
+	TRACE("Filesystem size %lld bytes\n", msblk->bytes_used);
+	TRACE("Block size %d\n", msblk->block_size);
+	TRACE("Number of inodes %d\n", msblk->inodes);
+	TRACE("Number of fragments %d\n", msblk->fragments);
+	TRACE("Number of ids %d\n", msblk->ids);
+	TRACE("sblk->inode_table_start %llx\n", msblk->inode_table);
+	TRACE("sblk->directory_table_start %llx\n", msblk->directory_table);
+	TRACE("sblk->fragment_table_start %llx\n",
+		(u64) le64_to_cpu(sblk->fragment_table_start));
+	TRACE("sblk->id_table_start %llx\n",
+		(u64) le64_to_cpu(sblk->id_table_start));
+
+	sb->s_maxbytes = MAX_LFS_FILESIZE;
+	sb->s_time_min = 0;
+	sb->s_time_max = U32_MAX;
+	sb->s_flags |= SB_RDONLY;
+	sb->s_op = &squashfs_super_ops;
+
+	msblk->block_cache = squashfs_cache_init("metadata",
+			SQUASHFS_CACHED_BLKS, SQUASHFS_METADATA_SIZE);
+	if (IS_ERR(msblk->block_cache)) {
+		err = PTR_ERR(msblk->block_cache);
+		goto failed_mount;
+	}
+
+	/* Allocate read_page block */
+	msblk->read_page = squashfs_cache_init("data",
+		SQUASHFS_READ_PAGES, msblk->block_size);
+	if (IS_ERR(msblk->read_page)) {
+		errorf(fc, "Failed to allocate read_page block");
+		err = PTR_ERR(msblk->read_page);
+		goto failed_mount;
+	}
+
+	if (msblk->devblksize == PAGE_SIZE) {
+		struct inode *cache = new_inode(sb);
+
+		if (cache == NULL) {
+			err = -ENOMEM;
+			goto failed_mount;
+		}
+
+		set_nlink(cache, 1);
+		cache->i_size = OFFSET_MAX;
+		mapping_set_gfp_mask(cache->i_mapping, GFP_NOFS);
+
+		msblk->cache_mapping = cache->i_mapping;
+	}
+
+	msblk->stream = squashfs_decompressor_setup(sb, flags);
+	if (IS_ERR(msblk->stream)) {
+		err = PTR_ERR(msblk->stream);
+		msblk->stream = NULL;
+		goto insanity;
+	}
+
+	/* Handle xattrs */
+	sb->s_xattr = squashfs_xattr_handlers;
+	xattr_id_table_start = le64_to_cpu(sblk->xattr_id_table_start);
+	if (xattr_id_table_start == SQUASHFS_INVALID_BLK) {
+		next_table = msblk->bytes_used;
+		goto allocate_id_index_table;
+	}
+
+	/* Allocate and read xattr id lookup table */
+	msblk->xattr_id_table = squashfs_read_xattr_id_table(sb,
+		xattr_id_table_start, &msblk->xattr_table, &msblk->xattr_ids);
+	if (IS_ERR(msblk->xattr_id_table)) {
+		errorf(fc, "unable to read xattr id index table");
+		err = PTR_ERR(msblk->xattr_id_table);
+		msblk->xattr_id_table = NULL;
+		if (err != -ENOTSUPP)
+			goto failed_mount;
+	}
+	next_table = msblk->xattr_table;
+
+allocate_id_index_table:
+	/* Allocate and read id index table */
+	msblk->id_table = squashfs_read_id_index_table(sb,
+		le64_to_cpu(sblk->id_table_start), next_table, msblk->ids);
+	if (IS_ERR(msblk->id_table)) {
+		errorf(fc, "unable to read id index table");
+		err = PTR_ERR(msblk->id_table);
+		msblk->id_table = NULL;
+		goto failed_mount;
+	}
+	next_table = le64_to_cpu(msblk->id_table[0]);
+
+	/* Handle inode lookup table */
+	lookup_table_start = le64_to_cpu(sblk->lookup_table_start);
+	if (lookup_table_start == SQUASHFS_INVALID_BLK)
+		goto handle_fragments;
+
+	/* Allocate and read inode lookup table */
+	msblk->inode_lookup_table = squashfs_read_inode_lookup_table(sb,
+		lookup_table_start, next_table, msblk->inodes);
+	if (IS_ERR(msblk->inode_lookup_table)) {
+		errorf(fc, "unable to read inode lookup table");
+		err = PTR_ERR(msblk->inode_lookup_table);
+		msblk->inode_lookup_table = NULL;
+		goto failed_mount;
+	}
+	next_table = le64_to_cpu(msblk->inode_lookup_table[0]);
+
+	sb->s_export_op = &squashfs_export_ops;
+
+handle_fragments:
+	fragments = msblk->fragments;
+	if (fragments == 0)
+		goto check_directory_table;
+
+	msblk->fragment_cache = squashfs_cache_init("fragment",
+		min(SQUASHFS_CACHED_FRAGMENTS, fragments), msblk->block_size);
+	if (IS_ERR(msblk->fragment_cache)) {
+		err = PTR_ERR(msblk->fragment_cache);
+		goto failed_mount;
+	}
+
+	/* Allocate and read fragment index table */
+	msblk->fragment_index = squashfs_read_fragment_index_table(sb,
+		le64_to_cpu(sblk->fragment_table_start), next_table, fragments);
+	if (IS_ERR(msblk->fragment_index)) {
+		errorf(fc, "unable to read fragment index table");
+		err = PTR_ERR(msblk->fragment_index);
+		msblk->fragment_index = NULL;
+		goto failed_mount;
+	}
+	next_table = le64_to_cpu(msblk->fragment_index[0]);
+
+check_directory_table:
+	/* Sanity check directory_table */
+	if (msblk->directory_table > next_table) {
+		err = -EINVAL;
+		goto insanity;
+	}
+
+	/* Sanity check inode_table */
+	if (msblk->inode_table >= msblk->directory_table) {
+		err = -EINVAL;
+		goto insanity;
+	}
+
+	/* allocate root */
+	root = new_inode(sb);
+	if (!root) {
+		err = -ENOMEM;
+		goto failed_mount;
+	}
+
+	err = squashfs_read_inode(root, root_inode);
+	if (err) {
+		make_bad_inode(root);
+		iput(root);
+		goto failed_mount;
+	}
+	insert_inode_hash(root);
+
+	sb->s_root = d_make_root(root);
+	if (sb->s_root == NULL) {
+		ERROR("Root inode create failed\n");
+		err = -ENOMEM;
+		goto failed_mount;
+	}
+
+	TRACE("Leaving squashfs_fill_super\n");
+	kfree(sblk);
+	return 0;
+
+insanity:
+	errorf(fc, "squashfs image failed sanity check");
+failed_mount:
+	squashfs_cache_delete(msblk->block_cache);
+	squashfs_cache_delete(msblk->fragment_cache);
+	squashfs_cache_delete(msblk->read_page);
+	if (msblk->cache_mapping)
+		iput(msblk->cache_mapping->host);
+	msblk->thread_ops->destroy(msblk);
+	kfree(msblk->inode_lookup_table);
+	kfree(msblk->fragment_index);
+	kfree(msblk->id_table);
+	kfree(msblk->xattr_id_table);
+	kfree(sb->s_fs_info);
+	sb->s_fs_info = NULL;
+	kfree(sblk);
+	return err;
+}
+
+static int squashfs_get_tree(struct fs_context *fc)
+{
+	return get_tree_bdev(fc, squashfs_fill_super);
+}
+
+static int squashfs_reconfigure(struct fs_context *fc)
+{
+	struct super_block *sb = fc->root->d_sb;
+	struct squashfs_sb_info *msblk = sb->s_fs_info;
+	struct squashfs_mount_opts *opts = fc->fs_private;
+
+	sync_filesystem(fc->root->d_sb);
+	fc->sb_flags |= SB_RDONLY;
+
+	msblk->panic_on_errors = (opts->errors == Opt_errors_panic);
+
+	return 0;
+}
+
+static void squashfs_free_fs_context(struct fs_context *fc)
+{
+	kfree(fc->fs_private);
+}
+
+static const struct fs_context_operations squashfs_context_ops = {
+	.get_tree	= squashfs_get_tree,
+	.free		= squashfs_free_fs_context,
+	.parse_param	= squashfs_parse_param,
+	.reconfigure	= squashfs_reconfigure,
+};
+
+static int squashfs_show_options(struct seq_file *s, struct dentry *root)
+{
+	struct super_block *sb = root->d_sb;
+	struct squashfs_sb_info *msblk = sb->s_fs_info;
+
+	if (msblk->panic_on_errors)
+		seq_puts(s, ",errors=panic");
+	else
+		seq_puts(s, ",errors=continue");
+
+#ifdef CONFIG_SQUASHFS_CHOICE_DECOMP_BY_MOUNT
+	if (msblk->thread_ops == &squashfs_decompressor_single) {
+		seq_puts(s, ",threads=single");
+		return 0;
+	}
+	if (msblk->thread_ops == &squashfs_decompressor_percpu) {
+		seq_puts(s, ",threads=percpu");
+		return 0;
+	}
+#endif
+#ifdef CONFIG_SQUASHFS_MOUNT_DECOMP_THREADS
+	seq_printf(s, ",threads=%d", msblk->max_thread_num);
+#endif
+	return 0;
+}
+
+static int squashfs_init_fs_context(struct fs_context *fc)
+{
+	struct squashfs_mount_opts *opts;
+
+	opts = kzalloc_obj(*opts);
+	if (!opts)
+		return -ENOMEM;
+
+#ifdef CONFIG_SQUASHFS_DECOMP_SINGLE
+	opts->thread_ops = &squashfs_decompressor_single;
+#elif defined(CONFIG_SQUASHFS_DECOMP_MULTI)
+	opts->thread_ops = &squashfs_decompressor_multi;
+#elif defined(CONFIG_SQUASHFS_DECOMP_MULTI_PERCPU)
+	opts->thread_ops = &squashfs_decompressor_percpu;
+#else
+#error "fail: unknown squashfs decompression thread mode?"
+#endif
+	opts->thread_num = 0;
+	fc->fs_private = opts;
+	fc->ops = &squashfs_context_ops;
+	return 0;
+}
+
+static int squashfs_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+	struct squashfs_sb_info *msblk = dentry->d_sb->s_fs_info;
+	u64 id = huge_encode_dev(dentry->d_sb->s_bdev->bd_dev);
+
+	TRACE("Entered squashfs_statfs\n");
+
+	buf->f_type = SQUASHFS_MAGIC;
+	buf->f_bsize = msblk->block_size;
+	buf->f_blocks = ((msblk->bytes_used - 1) >> msblk->block_log) + 1;
+	buf->f_bfree = buf->f_bavail = 0;
+	buf->f_files = msblk->inodes;
+	buf->f_ffree = 0;
+	buf->f_namelen = SQUASHFS_NAME_LEN;
+	buf->f_fsid = u64_to_fsid(id);
+
+	return 0;
+}
+
+
+static void squashfs_put_super(struct super_block *sb)
+{
+	if (sb->s_fs_info) {
+		struct squashfs_sb_info *sbi = sb->s_fs_info;
+		squashfs_cache_delete(sbi->block_cache);
+		squashfs_cache_delete(sbi->fragment_cache);
+		squashfs_cache_delete(sbi->read_page);
+		if (sbi->cache_mapping)
+			iput(sbi->cache_mapping->host);
+		sbi->thread_ops->destroy(sbi);
+		kfree(sbi->id_table);
+		kfree(sbi->fragment_index);
+		kfree(sbi->meta_index);
+		kfree(sbi->inode_lookup_table);
+		kfree(sbi->xattr_id_table);
+		kfree(sb->s_fs_info);
+		sb->s_fs_info = NULL;
+	}
+}
+
+static struct kmem_cache *squashfs_inode_cachep;
+
+
+static void init_once(void *foo)
+{
+	struct squashfs_inode_info *ei = foo;
+
+	inode_init_once(&ei->vfs_inode);
+}
+
+
+static int __init init_inodecache(void)
+{
+	squashfs_inode_cachep = kmem_cache_create("squashfs_inode_cache",
+		sizeof(struct squashfs_inode_info), 0,
+		SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|SLAB_ACCOUNT,
+		init_once);
+
+	return squashfs_inode_cachep ? 0 : -ENOMEM;
+}
+
+
+static void destroy_inodecache(void)
+{
+	/*
+	 * Make sure all delayed rcu free inodes are flushed before we
+	 * destroy cache.
+	 */
+	rcu_barrier();
+	kmem_cache_destroy(squashfs_inode_cachep);
+}
+
+
+static int __init init_squashfs_fs(void)
+{
+	int err = init_inodecache();
+
+	if (err)
+		return err;
+
+	err = register_filesystem(&squashfs_fs_type);
+	if (err) {
+		destroy_inodecache();
+		return err;
+	}
+
+	pr_info("version 4.0 (2009/01/31) Phillip Lougher\n");
+
+	return 0;
+}
+
+
+static void __exit exit_squashfs_fs(void)
+{
+	unregister_filesystem(&squashfs_fs_type);
+	destroy_inodecache();
+}
+
+
+static struct inode *squashfs_alloc_inode(struct super_block *sb)
+{
+	struct squashfs_inode_info *ei =
+		alloc_inode_sb(sb, squashfs_inode_cachep, GFP_KERNEL);
+
+	return ei ? &ei->vfs_inode : NULL;
+}
+
+
+static void squashfs_free_inode(struct inode *inode)
+{
+	kmem_cache_free(squashfs_inode_cachep, squashfs_i(inode));
+}
+
+static struct file_system_type squashfs_fs_type = {
+	.owner = THIS_MODULE,
+	.name = "squashfs",
+	.init_fs_context = squashfs_init_fs_context,
+	.parameters = squashfs_fs_parameters,
+	.kill_sb = kill_block_super,
+	.fs_flags = FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
+};
+MODULE_ALIAS_FS("squashfs");
+
+static const struct super_operations squashfs_super_ops = {
+	.alloc_inode = squashfs_alloc_inode,
+	.free_inode = squashfs_free_inode,
+	.statfs = squashfs_statfs,
+	.put_super = squashfs_put_super,
+	.show_options = squashfs_show_options,
+};
+
+module_init(init_squashfs_fs);
+module_exit(exit_squashfs_fs);
+MODULE_DESCRIPTION("squashfs 4.0, a compressed read-only filesystem");
+MODULE_AUTHOR("Phillip Lougher <phillip@squashfs.org.uk>");
+MODULE_LICENSE("GPL");