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, 742 insertions, 0 deletions

diff --git a/fs/jffs2/fs.c b/fs/jffs2/fs.c
new file mode 100644
index 000000000..6ada8369a
--- /dev/null
+++ b/fs/jffs2/fs.c
@@ -0,0 +1,742 @@
+/*
+ * JFFS2 -- Journalling Flash File System, Version 2.
+ *
+ * Copyright © 2001-2007 Red Hat, Inc.
+ * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
+ *
+ * Created by David Woodhouse <dwmw2@infradead.org>
+ *
+ * For licensing information, see the file 'LICENCE' in this directory.
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/capability.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/cred.h>
+#include <linux/fs.h>
+#include <linux/fs_context.h>
+#include <linux/list.h>
+#include <linux/mtd/mtd.h>
+#include <linux/pagemap.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/vfs.h>
+#include <linux/crc32.h>
+#include "nodelist.h"
+
+static int jffs2_flash_setup(struct jffs2_sb_info *c);
+
+int jffs2_do_setattr (struct inode *inode, struct iattr *iattr)
+{
+	struct jffs2_full_dnode *old_metadata, *new_metadata;
+	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
+	struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
+	struct jffs2_raw_inode *ri;
+	union jffs2_device_node dev;
+	unsigned char *mdata = NULL;
+	int mdatalen = 0;
+	unsigned int ivalid;
+	uint32_t alloclen;
+	int ret;
+	int alloc_type = ALLOC_NORMAL;
+
+	jffs2_dbg(1, "%s(): ino #%llu\n", __func__, inode->i_ino);
+
+	/* Special cases - we don't want more than one data node
+	   for these types on the medium at any time. So setattr
+	   must read the original data associated with the node
+	   (i.e. the device numbers or the target name) and write
+	   it out again with the appropriate data attached */
+	if (S_ISBLK(inode->i_mode) || S_ISCHR(inode->i_mode)) {
+		/* For these, we don't actually need to read the old node */
+		mdatalen = jffs2_encode_dev(&dev, inode->i_rdev);
+		mdata = (char *)&dev;
+		jffs2_dbg(1, "%s(): Writing %d bytes of kdev_t\n",
+			  __func__, mdatalen);
+	} else if (S_ISLNK(inode->i_mode)) {
+		mutex_lock(&f->sem);
+		mdatalen = f->metadata->size;
+		mdata = kmalloc(f->metadata->size, GFP_USER);
+		if (!mdata) {
+			mutex_unlock(&f->sem);
+			return -ENOMEM;
+		}
+		ret = jffs2_read_dnode(c, f, f->metadata, mdata, 0, mdatalen);
+		if (ret) {
+			mutex_unlock(&f->sem);
+			kfree(mdata);
+			return ret;
+		}
+		mutex_unlock(&f->sem);
+		jffs2_dbg(1, "%s(): Writing %d bytes of symlink target\n",
+			  __func__, mdatalen);
+	}
+
+	ri = jffs2_alloc_raw_inode();
+	if (!ri) {
+		if (S_ISLNK(inode->i_mode))
+			kfree(mdata);
+		return -ENOMEM;
+	}
+
+	ret = jffs2_reserve_space(c, sizeof(*ri) + mdatalen, &alloclen,
+				  ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
+	if (ret) {
+		jffs2_free_raw_inode(ri);
+		if (S_ISLNK(inode->i_mode))
+			 kfree(mdata);
+		return ret;
+	}
+	mutex_lock(&f->sem);
+	ivalid = iattr->ia_valid;
+
+	ri->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
+	ri->nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE);
+	ri->totlen = cpu_to_je32(sizeof(*ri) + mdatalen);
+	ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));
+
+	ri->ino = cpu_to_je32(inode->i_ino);
+	ri->version = cpu_to_je32(++f->highest_version);
+
+	ri->uid = cpu_to_je16((ivalid & ATTR_UID)?
+		from_kuid(&init_user_ns, iattr->ia_uid):i_uid_read(inode));
+	ri->gid = cpu_to_je16((ivalid & ATTR_GID)?
+		from_kgid(&init_user_ns, iattr->ia_gid):i_gid_read(inode));
+
+	if (ivalid & ATTR_MODE)
+		ri->mode = cpu_to_jemode(iattr->ia_mode);
+	else
+		ri->mode = cpu_to_jemode(inode->i_mode);
+
+
+	ri->isize = cpu_to_je32((ivalid & ATTR_SIZE)?iattr->ia_size:inode->i_size);
+	ri->atime = cpu_to_je32(I_SEC((ivalid & ATTR_ATIME)?iattr->ia_atime:inode_get_atime(inode)));
+	ri->mtime = cpu_to_je32(I_SEC((ivalid & ATTR_MTIME)?iattr->ia_mtime:inode_get_mtime(inode)));
+	ri->ctime = cpu_to_je32(I_SEC((ivalid & ATTR_CTIME)?iattr->ia_ctime:inode_get_ctime(inode)));
+
+	ri->offset = cpu_to_je32(0);
+	ri->csize = ri->dsize = cpu_to_je32(mdatalen);
+	ri->compr = JFFS2_COMPR_NONE;
+	if (ivalid & ATTR_SIZE && inode->i_size < iattr->ia_size) {
+		/* It's an extension. Make it a hole node */
+		ri->compr = JFFS2_COMPR_ZERO;
+		ri->dsize = cpu_to_je32(iattr->ia_size - inode->i_size);
+		ri->offset = cpu_to_je32(inode->i_size);
+	} else if (ivalid & ATTR_SIZE && !iattr->ia_size) {
+		/* For truncate-to-zero, treat it as deletion because
+		   it'll always be obsoleting all previous nodes */
+		alloc_type = ALLOC_DELETION;
+	}
+	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
+	if (mdatalen)
+		ri->data_crc = cpu_to_je32(crc32(0, mdata, mdatalen));
+	else
+		ri->data_crc = cpu_to_je32(0);
+
+	new_metadata = jffs2_write_dnode(c, f, ri, mdata, mdatalen, alloc_type);
+	if (S_ISLNK(inode->i_mode))
+		kfree(mdata);
+
+	if (IS_ERR(new_metadata)) {
+		jffs2_complete_reservation(c);
+		jffs2_free_raw_inode(ri);
+		mutex_unlock(&f->sem);
+		return PTR_ERR(new_metadata);
+	}
+	/* It worked. Update the inode */
+	inode_set_atime_to_ts(inode, ITIME(je32_to_cpu(ri->atime)));
+	inode_set_ctime_to_ts(inode, ITIME(je32_to_cpu(ri->ctime)));
+	inode_set_mtime_to_ts(inode, ITIME(je32_to_cpu(ri->mtime)));
+	inode->i_mode = jemode_to_cpu(ri->mode);
+	i_uid_write(inode, je16_to_cpu(ri->uid));
+	i_gid_write(inode, je16_to_cpu(ri->gid));
+
+
+	old_metadata = f->metadata;
+
+	if (ivalid & ATTR_SIZE && inode->i_size > iattr->ia_size)
+		jffs2_truncate_fragtree (c, &f->fragtree, iattr->ia_size);
+
+	if (ivalid & ATTR_SIZE && inode->i_size < iattr->ia_size) {
+		jffs2_add_full_dnode_to_inode(c, f, new_metadata);
+		inode->i_size = iattr->ia_size;
+		inode->i_blocks = (inode->i_size + 511) >> 9;
+		f->metadata = NULL;
+	} else {
+		f->metadata = new_metadata;
+	}
+	if (old_metadata) {
+		jffs2_mark_node_obsolete(c, old_metadata->raw);
+		jffs2_free_full_dnode(old_metadata);
+	}
+	jffs2_free_raw_inode(ri);
+
+	mutex_unlock(&f->sem);
+	jffs2_complete_reservation(c);
+
+	/* We have to do the truncate_setsize() without f->sem held, since
+	   some pages may be locked and waiting for it in read_folio().
+	   We are protected from a simultaneous write() extending i_size
+	   back past iattr->ia_size, because do_truncate() holds the
+	   generic inode semaphore. */
+	if (ivalid & ATTR_SIZE && inode->i_size > iattr->ia_size) {
+		truncate_setsize(inode, iattr->ia_size);
+		inode->i_blocks = (inode->i_size + 511) >> 9;
+	}
+
+	return 0;
+}
+
+int jffs2_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
+		  struct iattr *iattr)
+{
+	struct inode *inode = d_inode(dentry);
+	int rc;
+
+	rc = setattr_prepare(&nop_mnt_idmap, dentry, iattr);
+	if (rc)
+		return rc;
+
+	rc = jffs2_do_setattr(inode, iattr);
+	if (!rc && (iattr->ia_valid & ATTR_MODE))
+		rc = posix_acl_chmod(&nop_mnt_idmap, dentry, inode->i_mode);
+
+	return rc;
+}
+
+int jffs2_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+	struct jffs2_sb_info *c = JFFS2_SB_INFO(dentry->d_sb);
+	unsigned long avail;
+
+	buf->f_type = JFFS2_SUPER_MAGIC;
+	buf->f_bsize = 1 << PAGE_SHIFT;
+	buf->f_blocks = c->flash_size >> PAGE_SHIFT;
+	buf->f_files = 0;
+	buf->f_ffree = 0;
+	buf->f_namelen = JFFS2_MAX_NAME_LEN;
+	buf->f_fsid.val[0] = JFFS2_SUPER_MAGIC;
+	buf->f_fsid.val[1] = c->mtd->index;
+
+	spin_lock(&c->erase_completion_lock);
+	avail = c->dirty_size + c->free_size;
+	if (avail > c->sector_size * c->resv_blocks_write)
+		avail -= c->sector_size * c->resv_blocks_write;
+	else
+		avail = 0;
+	spin_unlock(&c->erase_completion_lock);
+
+	buf->f_bavail = buf->f_bfree = avail >> PAGE_SHIFT;
+
+	return 0;
+}
+
+
+void jffs2_evict_inode (struct inode *inode)
+{
+	/* We can forget about this inode for now - drop all
+	 *  the nodelists associated with it, etc.
+	 */
+	struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
+	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
+
+	jffs2_dbg(1, "%s(): ino #%llu mode %o\n",
+		  __func__, inode->i_ino, inode->i_mode);
+	truncate_inode_pages_final(&inode->i_data);
+	clear_inode(inode);
+	jffs2_do_clear_inode(c, f);
+}
+
+struct inode *jffs2_iget(struct super_block *sb, unsigned long ino)
+{
+	struct jffs2_inode_info *f;
+	struct jffs2_sb_info *c;
+	struct jffs2_raw_inode latest_node;
+	union jffs2_device_node jdev;
+	struct inode *inode;
+	dev_t rdev = 0;
+	int ret;
+
+	jffs2_dbg(1, "%s(): ino == %lu\n", __func__, ino);
+
+	inode = iget_locked(sb, ino);
+	if (!inode)
+		return ERR_PTR(-ENOMEM);
+	if (!(inode_state_read_once(inode) & I_NEW))
+		return inode;
+
+	f = JFFS2_INODE_INFO(inode);
+	c = JFFS2_SB_INFO(inode->i_sb);
+
+	jffs2_init_inode_info(f);
+	mutex_lock(&f->sem);
+
+	ret = jffs2_do_read_inode(c, f, inode->i_ino, &latest_node);
+	if (ret)
+		goto error;
+
+	inode->i_mode = jemode_to_cpu(latest_node.mode);
+	i_uid_write(inode, je16_to_cpu(latest_node.uid));
+	i_gid_write(inode, je16_to_cpu(latest_node.gid));
+	inode->i_size = je32_to_cpu(latest_node.isize);
+	inode_set_atime_to_ts(inode, ITIME(je32_to_cpu(latest_node.atime)));
+	inode_set_mtime_to_ts(inode, ITIME(je32_to_cpu(latest_node.mtime)));
+	inode_set_ctime_to_ts(inode, ITIME(je32_to_cpu(latest_node.ctime)));
+
+	set_nlink(inode, f->inocache->pino_nlink);
+
+	inode->i_blocks = (inode->i_size + 511) >> 9;
+
+	switch (inode->i_mode & S_IFMT) {
+
+	case S_IFLNK:
+		inode->i_op = &jffs2_symlink_inode_operations;
+		inode->i_link = f->target;
+		break;
+
+	case S_IFDIR:
+	{
+		struct jffs2_full_dirent *fd;
+		set_nlink(inode, 2); /* parent and '.' */
+
+		for (fd=f->dents; fd; fd = fd->next) {
+			if (fd->type == DT_DIR && fd->ino)
+				inc_nlink(inode);
+		}
+		/* Root dir gets i_nlink 3 for some reason */
+		if (inode->i_ino == 1)
+			inc_nlink(inode);
+
+		inode->i_op = &jffs2_dir_inode_operations;
+		inode->i_fop = &jffs2_dir_operations;
+		break;
+	}
+	case S_IFREG:
+		inode->i_op = &jffs2_file_inode_operations;
+		inode->i_fop = &jffs2_file_operations;
+		inode->i_mapping->a_ops = &jffs2_file_address_operations;
+		inode->i_mapping->nrpages = 0;
+		break;
+
+	case S_IFBLK:
+	case S_IFCHR:
+		/* Read the device numbers from the media */
+		if (f->metadata->size != sizeof(jdev.old_id) &&
+		    f->metadata->size != sizeof(jdev.new_id)) {
+			pr_notice("Device node has strange size %d\n",
+				  f->metadata->size);
+			goto error_io;
+		}
+		jffs2_dbg(1, "Reading device numbers from flash\n");
+		ret = jffs2_read_dnode(c, f, f->metadata, (char *)&jdev, 0, f->metadata->size);
+		if (ret < 0) {
+			/* Eep */
+			pr_notice("Read device numbers for inode %llu failed\n",
+				  inode->i_ino);
+			goto error;
+		}
+		if (f->metadata->size == sizeof(jdev.old_id))
+			rdev = old_decode_dev(je16_to_cpu(jdev.old_id));
+		else
+			rdev = new_decode_dev(je32_to_cpu(jdev.new_id));
+		fallthrough;
+
+	case S_IFSOCK:
+	case S_IFIFO:
+		inode->i_op = &jffs2_file_inode_operations;
+		init_special_inode(inode, inode->i_mode, rdev);
+		break;
+
+	default:
+		pr_warn("%s(): Bogus i_mode %o for ino %llu\n",
+			__func__, inode->i_mode, inode->i_ino);
+	}
+
+	mutex_unlock(&f->sem);
+
+	jffs2_dbg(1, "jffs2_read_inode() returning\n");
+	unlock_new_inode(inode);
+	return inode;
+
+error_io:
+	ret = -EIO;
+error:
+	mutex_unlock(&f->sem);
+	iget_failed(inode);
+	return ERR_PTR(ret);
+}
+
+void jffs2_dirty_inode(struct inode *inode, int flags)
+{
+	struct iattr iattr;
+
+	if (!(inode_state_read_once(inode) & I_DIRTY_DATASYNC)) {
+		jffs2_dbg(2, "%s(): not calling setattr() for ino #%llu\n",
+			  __func__, inode->i_ino);
+		return;
+	}
+
+	jffs2_dbg(1, "%s(): calling setattr() for ino #%llu\n",
+		  __func__, inode->i_ino);
+
+	iattr.ia_valid = ATTR_MODE|ATTR_UID|ATTR_GID|ATTR_ATIME|ATTR_MTIME|ATTR_CTIME;
+	iattr.ia_mode = inode->i_mode;
+	iattr.ia_uid = inode->i_uid;
+	iattr.ia_gid = inode->i_gid;
+	iattr.ia_atime = inode_get_atime(inode);
+	iattr.ia_mtime = inode_get_mtime(inode);
+	iattr.ia_ctime = inode_get_ctime(inode);
+
+	jffs2_do_setattr(inode, &iattr);
+}
+
+int jffs2_do_remount_fs(struct super_block *sb, struct fs_context *fc)
+{
+	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
+
+	if (c->flags & JFFS2_SB_FLAG_RO && !sb_rdonly(sb))
+		return -EROFS;
+
+	/* We stop if it was running, then restart if it needs to.
+	   This also catches the case where it was stopped and this
+	   is just a remount to restart it.
+	   Flush the writebuffer, if necessary, else we loose it */
+	if (!sb_rdonly(sb)) {
+		jffs2_stop_garbage_collect_thread(c);
+		mutex_lock(&c->alloc_sem);
+		jffs2_flush_wbuf_pad(c);
+		mutex_unlock(&c->alloc_sem);
+	}
+
+	if (!(fc->sb_flags & SB_RDONLY))
+		jffs2_start_garbage_collect_thread(c);
+
+	fc->sb_flags |= SB_NOATIME;
+	return 0;
+}
+
+/* jffs2_new_inode: allocate a new inode and inocache, add it to the hash,
+   fill in the raw_inode while you're at it. */
+struct inode *jffs2_new_inode (struct inode *dir_i, umode_t mode, struct jffs2_raw_inode *ri)
+{
+	struct inode *inode;
+	struct super_block *sb = dir_i->i_sb;
+	struct jffs2_sb_info *c;
+	struct jffs2_inode_info *f;
+	int ret;
+
+	jffs2_dbg(1, "%s(): dir_i %llu, mode 0x%x\n",
+		  __func__, dir_i->i_ino, mode);
+
+	c = JFFS2_SB_INFO(sb);
+
+	inode = new_inode(sb);
+
+	if (!inode)
+		return ERR_PTR(-ENOMEM);
+
+	f = JFFS2_INODE_INFO(inode);
+	jffs2_init_inode_info(f);
+	mutex_lock(&f->sem);
+
+	memset(ri, 0, sizeof(*ri));
+	/* Set OS-specific defaults for new inodes */
+	ri->uid = cpu_to_je16(from_kuid(&init_user_ns, current_fsuid()));
+
+	if (dir_i->i_mode & S_ISGID) {
+		ri->gid = cpu_to_je16(i_gid_read(dir_i));
+		if (S_ISDIR(mode))
+			mode |= S_ISGID;
+	} else {
+		ri->gid = cpu_to_je16(from_kgid(&init_user_ns, current_fsgid()));
+	}
+
+	/* POSIX ACLs have to be processed now, at least partly.
+	   The umask is only applied if there's no default ACL */
+	ret = jffs2_init_acl_pre(dir_i, inode, &mode);
+	if (ret) {
+		mutex_unlock(&f->sem);
+		make_bad_inode(inode);
+		iput(inode);
+		return ERR_PTR(ret);
+	}
+	ret = jffs2_do_new_inode (c, f, mode, ri);
+	if (ret) {
+		mutex_unlock(&f->sem);
+		make_bad_inode(inode);
+		iput(inode);
+		return ERR_PTR(ret);
+	}
+	set_nlink(inode, 1);
+	inode->i_ino = je32_to_cpu(ri->ino);
+	inode->i_mode = jemode_to_cpu(ri->mode);
+	i_gid_write(inode, je16_to_cpu(ri->gid));
+	i_uid_write(inode, je16_to_cpu(ri->uid));
+	simple_inode_init_ts(inode);
+	ri->atime = ri->mtime = ri->ctime = cpu_to_je32(I_SEC(inode_get_mtime(inode)));
+
+	inode->i_blocks = 0;
+	inode->i_size = 0;
+
+	if (insert_inode_locked(inode) < 0) {
+		mutex_unlock(&f->sem);
+		make_bad_inode(inode);
+		iput(inode);
+		return ERR_PTR(-EINVAL);
+	}
+
+	return inode;
+}
+
+static int calculate_inocache_hashsize(uint32_t flash_size)
+{
+	/*
+	 * Pick a inocache hash size based on the size of the medium.
+	 * Count how many megabytes we're dealing with, apply a hashsize twice
+	 * that size, but rounding down to the usual big powers of 2. And keep
+	 * to sensible bounds.
+	 */
+
+	int size_mb = flash_size / 1024 / 1024;
+	int hashsize = (size_mb * 2) & ~0x3f;
+
+	if (hashsize < INOCACHE_HASHSIZE_MIN)
+		return INOCACHE_HASHSIZE_MIN;
+	if (hashsize > INOCACHE_HASHSIZE_MAX)
+		return INOCACHE_HASHSIZE_MAX;
+
+	return hashsize;
+}
+
+int jffs2_do_fill_super(struct super_block *sb, struct fs_context *fc)
+{
+	struct jffs2_sb_info *c;
+	struct inode *root_i;
+	int ret;
+	size_t blocks;
+
+	c = JFFS2_SB_INFO(sb);
+
+	/* Do not support the MLC nand */
+	if (c->mtd->type == MTD_MLCNANDFLASH)
+		return -EINVAL;
+
+#ifndef CONFIG_JFFS2_FS_WRITEBUFFER
+	if (c->mtd->type == MTD_NANDFLASH) {
+		errorf(fc, "Cannot operate on NAND flash unless jffs2 NAND support is compiled in");
+		return -EINVAL;
+	}
+	if (c->mtd->type == MTD_DATAFLASH) {
+		errorf(fc, "Cannot operate on DataFlash unless jffs2 DataFlash support is compiled in");
+		return -EINVAL;
+	}
+#endif
+
+	c->flash_size = c->mtd->size;
+	c->sector_size = c->mtd->erasesize;
+	blocks = c->flash_size / c->sector_size;
+
+	/*
+	 * Size alignment check
+	 */
+	if ((c->sector_size * blocks) != c->flash_size) {
+		c->flash_size = c->sector_size * blocks;
+		infof(fc, "Flash size not aligned to erasesize, reducing to %dKiB",
+		      c->flash_size / 1024);
+	}
+
+	if (c->flash_size < 5*c->sector_size) {
+		errorf(fc, "Too few erase blocks (%d)",
+		       c->flash_size / c->sector_size);
+		return -EINVAL;
+	}
+
+	c->cleanmarker_size = sizeof(struct jffs2_unknown_node);
+
+	/* NAND (or other bizarre) flash... do setup accordingly */
+	ret = jffs2_flash_setup(c);
+	if (ret)
+		return ret;
+
+	c->inocache_hashsize = calculate_inocache_hashsize(c->flash_size);
+	c->inocache_list = kzalloc_objs(struct jffs2_inode_cache *,
+					c->inocache_hashsize);
+	if (!c->inocache_list) {
+		ret = -ENOMEM;
+		goto out_wbuf;
+	}
+
+	jffs2_init_xattr_subsystem(c);
+
+	if ((ret = jffs2_do_mount_fs(c)))
+		goto out_inohash;
+
+	jffs2_dbg(1, "%s(): Getting root inode\n", __func__);
+	root_i = jffs2_iget(sb, 1);
+	if (IS_ERR(root_i)) {
+		jffs2_dbg(1, "get root inode failed\n");
+		ret = PTR_ERR(root_i);
+		goto out_root;
+	}
+
+	ret = -ENOMEM;
+
+	jffs2_dbg(1, "%s(): d_make_root()\n", __func__);
+	sb->s_root = d_make_root(root_i);
+	if (!sb->s_root)
+		goto out_root;
+
+	sb->s_maxbytes = 0xFFFFFFFF;
+	sb->s_blocksize = PAGE_SIZE;
+	sb->s_blocksize_bits = PAGE_SHIFT;
+	sb->s_magic = JFFS2_SUPER_MAGIC;
+	sb->s_time_min = 0;
+	sb->s_time_max = U32_MAX;
+
+	if (!sb_rdonly(sb))
+		jffs2_start_garbage_collect_thread(c);
+	return 0;
+
+out_root:
+	jffs2_free_ino_caches(c);
+	jffs2_free_raw_node_refs(c);
+	kvfree(c->blocks);
+	jffs2_clear_xattr_subsystem(c);
+	jffs2_sum_exit(c);
+ out_inohash:
+	kfree(c->inocache_list);
+ out_wbuf:
+	jffs2_flash_cleanup(c);
+
+	return ret;
+}
+
+void jffs2_gc_release_inode(struct jffs2_sb_info *c,
+				   struct jffs2_inode_info *f)
+{
+	iput(OFNI_EDONI_2SFFJ(f));
+}
+
+struct jffs2_inode_info *jffs2_gc_fetch_inode(struct jffs2_sb_info *c,
+					      int inum, int unlinked)
+{
+	struct inode *inode;
+	struct jffs2_inode_cache *ic;
+
+	if (unlinked) {
+		/* The inode has zero nlink but its nodes weren't yet marked
+		   obsolete. This has to be because we're still waiting for
+		   the final (close() and) iput() to happen.
+
+		   There's a possibility that the final iput() could have
+		   happened while we were contemplating. In order to ensure
+		   that we don't cause a new read_inode() (which would fail)
+		   for the inode in question, we use ilookup() in this case
+		   instead of iget().
+
+		   The nlink can't _become_ zero at this point because we're
+		   holding the alloc_sem, and jffs2_do_unlink() would also
+		   need that while decrementing nlink on any inode.
+		*/
+		inode = ilookup(OFNI_BS_2SFFJ(c), inum);
+		if (!inode) {
+			jffs2_dbg(1, "ilookup() failed for ino #%u; inode is probably deleted.\n",
+				  inum);
+
+			spin_lock(&c->inocache_lock);
+			ic = jffs2_get_ino_cache(c, inum);
+			if (!ic) {
+				jffs2_dbg(1, "Inode cache for ino #%u is gone\n",
+					  inum);
+				spin_unlock(&c->inocache_lock);
+				return NULL;
+			}
+			if (ic->state != INO_STATE_CHECKEDABSENT) {
+				/* Wait for progress. Don't just loop */
+				jffs2_dbg(1, "Waiting for ino #%u in state %d\n",
+					  ic->ino, ic->state);
+				sleep_on_spinunlock(&c->inocache_wq, &c->inocache_lock);
+			} else {
+				spin_unlock(&c->inocache_lock);
+			}
+
+			return NULL;
+		}
+	} else {
+		/* Inode has links to it still; they're not going away because
+		   jffs2_do_unlink() would need the alloc_sem and we have it.
+		   Just iget() it, and if read_inode() is necessary that's OK.
+		*/
+		inode = jffs2_iget(OFNI_BS_2SFFJ(c), inum);
+		if (IS_ERR(inode))
+			return ERR_CAST(inode);
+	}
+	if (is_bad_inode(inode)) {
+		pr_notice("Eep. read_inode() failed for ino #%u. unlinked %d\n",
+			  inum, unlinked);
+		/* NB. This will happen again. We need to do something appropriate here. */
+		iput(inode);
+		return ERR_PTR(-EIO);
+	}
+
+	return JFFS2_INODE_INFO(inode);
+}
+
+static int jffs2_flash_setup(struct jffs2_sb_info *c) {
+	int ret = 0;
+
+	if (jffs2_cleanmarker_oob(c)) {
+		/* NAND flash... do setup accordingly */
+		ret = jffs2_nand_flash_setup(c);
+		if (ret)
+			return ret;
+	}
+
+	/* and Dataflash */
+	if (jffs2_dataflash(c)) {
+		ret = jffs2_dataflash_setup(c);
+		if (ret)
+			return ret;
+	}
+
+	/* and Intel "Sibley" flash */
+	if (jffs2_nor_wbuf_flash(c)) {
+		ret = jffs2_nor_wbuf_flash_setup(c);
+		if (ret)
+			return ret;
+	}
+
+	/* and an UBI volume */
+	if (jffs2_ubivol(c)) {
+		ret = jffs2_ubivol_setup(c);
+		if (ret)
+			return ret;
+	}
+
+	return ret;
+}
+
+void jffs2_flash_cleanup(struct jffs2_sb_info *c) {
+
+	if (jffs2_cleanmarker_oob(c)) {
+		jffs2_nand_flash_cleanup(c);
+	}
+
+	/* and DataFlash */
+	if (jffs2_dataflash(c)) {
+		jffs2_dataflash_cleanup(c);
+	}
+
+	/* and Intel "Sibley" flash */
+	if (jffs2_nor_wbuf_flash(c)) {
+		jffs2_nor_wbuf_flash_cleanup(c);
+	}
+
+	/* and an UBI volume */
+	if (jffs2_ubivol(c)) {
+		jffs2_ubivol_cleanup(c);
+	}
+}