dir.c 39.2 KB
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/*
  FUSE: Filesystem in Userspace
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  Copyright (C) 2001-2008  Miklos Szeredi <miklos@szeredi.hu>
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  This program can be distributed under the terms of the GNU GPL.
  See the file COPYING.
*/

#include "fuse_i.h"

#include <linux/pagemap.h>
#include <linux/file.h>
#include <linux/gfp.h>
#include <linux/sched.h>
#include <linux/namei.h>

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#if BITS_PER_LONG >= 64
static inline void fuse_dentry_settime(struct dentry *entry, u64 time)
{
	entry->d_time = time;
}

static inline u64 fuse_dentry_time(struct dentry *entry)
{
	return entry->d_time;
}
#else
/*
 * On 32 bit archs store the high 32 bits of time in d_fsdata
 */
static void fuse_dentry_settime(struct dentry *entry, u64 time)
{
	entry->d_time = time;
	entry->d_fsdata = (void *) (unsigned long) (time >> 32);
}

static u64 fuse_dentry_time(struct dentry *entry)
{
	return (u64) entry->d_time +
		((u64) (unsigned long) entry->d_fsdata << 32);
}
#endif

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/*
 * FUSE caches dentries and attributes with separate timeout.  The
 * time in jiffies until the dentry/attributes are valid is stored in
 * dentry->d_time and fuse_inode->i_time respectively.
 */

/*
 * Calculate the time in jiffies until a dentry/attributes are valid
 */
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static u64 time_to_jiffies(unsigned long sec, unsigned long nsec)
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{
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	if (sec || nsec) {
		struct timespec ts = {sec, nsec};
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		return get_jiffies_64() + timespec_to_jiffies(&ts);
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	} else
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		return 0;
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}

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/*
 * Set dentry and possibly attribute timeouts from the lookup/mk*
 * replies
 */
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static void fuse_change_entry_timeout(struct dentry *entry,
				      struct fuse_entry_out *o)
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{
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	fuse_dentry_settime(entry,
		time_to_jiffies(o->entry_valid, o->entry_valid_nsec));
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}

static u64 attr_timeout(struct fuse_attr_out *o)
{
	return time_to_jiffies(o->attr_valid, o->attr_valid_nsec);
}

static u64 entry_attr_timeout(struct fuse_entry_out *o)
{
	return time_to_jiffies(o->attr_valid, o->attr_valid_nsec);
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}

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/*
 * Mark the attributes as stale, so that at the next call to
 * ->getattr() they will be fetched from userspace
 */
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void fuse_invalidate_attr(struct inode *inode)
{
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	get_fuse_inode(inode)->i_time = 0;
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}

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/*
 * Just mark the entry as stale, so that a next attempt to look it up
 * will result in a new lookup call to userspace
 *
 * This is called when a dentry is about to become negative and the
 * timeout is unknown (unlink, rmdir, rename and in some cases
 * lookup)
 */
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void fuse_invalidate_entry_cache(struct dentry *entry)
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{
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	fuse_dentry_settime(entry, 0);
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}

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/*
 * Same as fuse_invalidate_entry_cache(), but also try to remove the
 * dentry from the hash
 */
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static void fuse_invalidate_entry(struct dentry *entry)
{
	d_invalidate(entry);
	fuse_invalidate_entry_cache(entry);
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}

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static void fuse_lookup_init(struct fuse_conn *fc, struct fuse_req *req,
			     u64 nodeid, struct qstr *name,
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			     struct fuse_entry_out *outarg)
{
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	memset(outarg, 0, sizeof(struct fuse_entry_out));
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	req->in.h.opcode = FUSE_LOOKUP;
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	req->in.h.nodeid = nodeid;
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	req->in.numargs = 1;
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	req->in.args[0].size = name->len + 1;
	req->in.args[0].value = name->name;
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	req->out.numargs = 1;
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	if (fc->minor < 9)
		req->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE;
	else
		req->out.args[0].size = sizeof(struct fuse_entry_out);
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	req->out.args[0].value = outarg;
}

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u64 fuse_get_attr_version(struct fuse_conn *fc)
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{
	u64 curr_version;

	/*
	 * The spin lock isn't actually needed on 64bit archs, but we
	 * don't yet care too much about such optimizations.
	 */
	spin_lock(&fc->lock);
	curr_version = fc->attr_version;
	spin_unlock(&fc->lock);

	return curr_version;
}

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/*
 * Check whether the dentry is still valid
 *
 * If the entry validity timeout has expired and the dentry is
 * positive, try to redo the lookup.  If the lookup results in a
 * different inode, then let the VFS invalidate the dentry and redo
 * the lookup once more.  If the lookup results in the same inode,
 * then refresh the attributes, timeouts and mark the dentry valid.
 */
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static int fuse_dentry_revalidate(struct dentry *entry, struct nameidata *nd)
{
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	struct inode *inode = entry->d_inode;

	if (inode && is_bad_inode(inode))
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		return 0;
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	else if (fuse_dentry_time(entry) < get_jiffies_64()) {
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		int err;
		struct fuse_entry_out outarg;
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		struct fuse_conn *fc;
		struct fuse_req *req;
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		struct fuse_req *forget_req;
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		struct dentry *parent;
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		u64 attr_version;
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		/* For negative dentries, always do a fresh lookup */
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		if (!inode)
			return 0;

		fc = get_fuse_conn(inode);
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		req = fuse_get_req(fc);
		if (IS_ERR(req))
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			return 0;

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		forget_req = fuse_get_req(fc);
		if (IS_ERR(forget_req)) {
			fuse_put_request(fc, req);
			return 0;
		}

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		attr_version = fuse_get_attr_version(fc);
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		parent = dget_parent(entry);
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		fuse_lookup_init(fc, req, get_node_id(parent->d_inode),
				 &entry->d_name, &outarg);
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		fuse_request_send(fc, req);
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		dput(parent);
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		err = req->out.h.error;
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		fuse_put_request(fc, req);
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		/* Zero nodeid is same as -ENOENT */
		if (!err && !outarg.nodeid)
			err = -ENOENT;
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		if (!err) {
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			struct fuse_inode *fi = get_fuse_inode(inode);
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			if (outarg.nodeid != get_node_id(inode)) {
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				fuse_send_forget(fc, forget_req,
						 outarg.nodeid, 1);
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				return 0;
			}
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			spin_lock(&fc->lock);
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			fi->nlookup++;
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			spin_unlock(&fc->lock);
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		}
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		fuse_put_request(fc, forget_req);
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		if (err || (outarg.attr.mode ^ inode->i_mode) & S_IFMT)
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			return 0;

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		fuse_change_attributes(inode, &outarg.attr,
				       entry_attr_timeout(&outarg),
				       attr_version);
		fuse_change_entry_timeout(entry, &outarg);
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	}
	return 1;
}

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static int invalid_nodeid(u64 nodeid)
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{
	return !nodeid || nodeid == FUSE_ROOT_ID;
}

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struct dentry_operations fuse_dentry_operations = {
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	.d_revalidate	= fuse_dentry_revalidate,
};

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int fuse_valid_type(int m)
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{
	return S_ISREG(m) || S_ISDIR(m) || S_ISLNK(m) || S_ISCHR(m) ||
		S_ISBLK(m) || S_ISFIFO(m) || S_ISSOCK(m);
}

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/*
 * Add a directory inode to a dentry, ensuring that no other dentry
 * refers to this inode.  Called with fc->inst_mutex.
 */
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static struct dentry *fuse_d_add_directory(struct dentry *entry,
					   struct inode *inode)
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{
	struct dentry *alias = d_find_alias(inode);
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	if (alias && !(alias->d_flags & DCACHE_DISCONNECTED)) {
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		/* This tries to shrink the subtree below alias */
		fuse_invalidate_entry(alias);
		dput(alias);
		if (!list_empty(&inode->i_dentry))
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			return ERR_PTR(-EBUSY);
	} else {
		dput(alias);
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	}
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	return d_splice_alias(inode, entry);
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}

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int fuse_lookup_name(struct super_block *sb, u64 nodeid, struct qstr *name,
		     struct fuse_entry_out *outarg, struct inode **inode)
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{
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	struct fuse_conn *fc = get_fuse_conn_super(sb);
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	struct fuse_req *req;
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	struct fuse_req *forget_req;
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	u64 attr_version;
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	int err;
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	*inode = NULL;
	err = -ENAMETOOLONG;
	if (name->len > FUSE_NAME_MAX)
		goto out;
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	req = fuse_get_req(fc);
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	err = PTR_ERR(req);
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	if (IS_ERR(req))
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		goto out;
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	forget_req = fuse_get_req(fc);
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	err = PTR_ERR(forget_req);
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	if (IS_ERR(forget_req)) {
		fuse_put_request(fc, req);
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		goto out;
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	}

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	attr_version = fuse_get_attr_version(fc);
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	fuse_lookup_init(fc, req, nodeid, name, outarg);
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	fuse_request_send(fc, req);
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	err = req->out.h.error;
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	fuse_put_request(fc, req);
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	/* Zero nodeid is same as -ENOENT, but with valid timeout */
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	if (err || !outarg->nodeid)
		goto out_put_forget;

	err = -EIO;
	if (!outarg->nodeid)
		goto out_put_forget;
	if (!fuse_valid_type(outarg->attr.mode))
		goto out_put_forget;

	*inode = fuse_iget(sb, outarg->nodeid, outarg->generation,
			   &outarg->attr, entry_attr_timeout(outarg),
			   attr_version);
	err = -ENOMEM;
	if (!*inode) {
		fuse_send_forget(fc, forget_req, outarg->nodeid, 1);
		goto out;
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	}
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	err = 0;

 out_put_forget:
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	fuse_put_request(fc, forget_req);
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 out:
	return err;
}

static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry,
				  struct nameidata *nd)
{
	int err;
	struct fuse_entry_out outarg;
	struct inode *inode;
	struct dentry *newent;
	struct fuse_conn *fc = get_fuse_conn(dir);
	bool outarg_valid = true;

	err = fuse_lookup_name(dir->i_sb, get_node_id(dir), &entry->d_name,
			       &outarg, &inode);
	if (err == -ENOENT) {
		outarg_valid = false;
		err = 0;
	}
	if (err)
		goto out_err;

	err = -EIO;
	if (inode && get_node_id(inode) == FUSE_ROOT_ID)
		goto out_iput;
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	if (inode && S_ISDIR(inode->i_mode)) {
		mutex_lock(&fc->inst_mutex);
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		newent = fuse_d_add_directory(entry, inode);
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		mutex_unlock(&fc->inst_mutex);
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		err = PTR_ERR(newent);
		if (IS_ERR(newent))
			goto out_iput;
	} else {
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		newent = d_splice_alias(inode, entry);
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	}
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	entry = newent ? newent : entry;
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	entry->d_op = &fuse_dentry_operations;
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	if (outarg_valid)
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		fuse_change_entry_timeout(entry, &outarg);
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	else
		fuse_invalidate_entry_cache(entry);
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	return newent;
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 out_iput:
	iput(inode);
 out_err:
	return ERR_PTR(err);
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}

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/*
 * Synchronous release for the case when something goes wrong in CREATE_OPEN
 */
static void fuse_sync_release(struct fuse_conn *fc, struct fuse_file *ff,
			      u64 nodeid, int flags)
{
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	fuse_release_fill(ff, nodeid, flags, FUSE_RELEASE);
	ff->reserved_req->force = 1;
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	fuse_request_send(fc, ff->reserved_req);
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	fuse_put_request(fc, ff->reserved_req);
	kfree(ff);
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}

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/*
 * Atomic create+open operation
 *
 * If the filesystem doesn't support this, then fall back to separate
 * 'mknod' + 'open' requests.
 */
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static int fuse_create_open(struct inode *dir, struct dentry *entry, int mode,
			    struct nameidata *nd)
{
	int err;
	struct inode *inode;
	struct fuse_conn *fc = get_fuse_conn(dir);
	struct fuse_req *req;
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	struct fuse_req *forget_req;
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	struct fuse_open_in inarg;
	struct fuse_open_out outopen;
	struct fuse_entry_out outentry;
	struct fuse_file *ff;
	struct file *file;
	int flags = nd->intent.open.flags - 1;

	if (fc->no_create)
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		return -ENOSYS;
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	forget_req = fuse_get_req(fc);
	if (IS_ERR(forget_req))
		return PTR_ERR(forget_req);

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	req = fuse_get_req(fc);
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	err = PTR_ERR(req);
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	if (IS_ERR(req))
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		goto out_put_forget_req;
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	err = -ENOMEM;
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	ff = fuse_file_alloc(fc);
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	if (!ff)
		goto out_put_request;

	flags &= ~O_NOCTTY;
	memset(&inarg, 0, sizeof(inarg));
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	memset(&outentry, 0, sizeof(outentry));
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	inarg.flags = flags;
	inarg.mode = mode;
	req->in.h.opcode = FUSE_CREATE;
	req->in.h.nodeid = get_node_id(dir);
	req->in.numargs = 2;
	req->in.args[0].size = sizeof(inarg);
	req->in.args[0].value = &inarg;
	req->in.args[1].size = entry->d_name.len + 1;
	req->in.args[1].value = entry->d_name.name;
	req->out.numargs = 2;
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	if (fc->minor < 9)
		req->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE;
	else
		req->out.args[0].size = sizeof(outentry);
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	req->out.args[0].value = &outentry;
	req->out.args[1].size = sizeof(outopen);
	req->out.args[1].value = &outopen;
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	fuse_request_send(fc, req);
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	err = req->out.h.error;
	if (err) {
		if (err == -ENOSYS)
			fc->no_create = 1;
		goto out_free_ff;
	}

	err = -EIO;
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	if (!S_ISREG(outentry.attr.mode) || invalid_nodeid(outentry.nodeid))
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		goto out_free_ff;

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	fuse_put_request(fc, req);
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	inode = fuse_iget(dir->i_sb, outentry.nodeid, outentry.generation,
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			  &outentry.attr, entry_attr_timeout(&outentry), 0);
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	if (!inode) {
		flags &= ~(O_CREAT | O_EXCL | O_TRUNC);
		ff->fh = outopen.fh;
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		fuse_sync_release(fc, ff, outentry.nodeid, flags);
		fuse_send_forget(fc, forget_req, outentry.nodeid, 1);
		return -ENOMEM;
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	}
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	fuse_put_request(fc, forget_req);
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	d_instantiate(entry, inode);
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	fuse_change_entry_timeout(entry, &outentry);
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	fuse_invalidate_attr(dir);
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	file = lookup_instantiate_filp(nd, entry, generic_file_open);
	if (IS_ERR(file)) {
		ff->fh = outopen.fh;
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		fuse_sync_release(fc, ff, outentry.nodeid, flags);
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		return PTR_ERR(file);
	}
	fuse_finish_open(inode, file, ff, &outopen);
	return 0;

 out_free_ff:
	fuse_file_free(ff);
 out_put_request:
	fuse_put_request(fc, req);
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 out_put_forget_req:
	fuse_put_request(fc, forget_req);
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	return err;
}

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/*
 * Code shared between mknod, mkdir, symlink and link
 */
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static int create_new_entry(struct fuse_conn *fc, struct fuse_req *req,
			    struct inode *dir, struct dentry *entry,
			    int mode)
{
	struct fuse_entry_out outarg;
	struct inode *inode;
	int err;
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	struct fuse_req *forget_req;

	forget_req = fuse_get_req(fc);
	if (IS_ERR(forget_req)) {
		fuse_put_request(fc, req);
		return PTR_ERR(forget_req);
	}
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	memset(&outarg, 0, sizeof(outarg));
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	req->in.h.nodeid = get_node_id(dir);
	req->out.numargs = 1;
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	if (fc->minor < 9)
		req->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE;
	else
		req->out.args[0].size = sizeof(outarg);
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	req->out.args[0].value = &outarg;
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	fuse_request_send(fc, req);
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	err = req->out.h.error;
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	fuse_put_request(fc, req);
	if (err)
		goto out_put_forget_req;

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	err = -EIO;
	if (invalid_nodeid(outarg.nodeid))
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		goto out_put_forget_req;
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	if ((outarg.attr.mode ^ mode) & S_IFMT)
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		goto out_put_forget_req;
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	inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation,
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			  &outarg.attr, entry_attr_timeout(&outarg), 0);
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	if (!inode) {
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		fuse_send_forget(fc, forget_req, outarg.nodeid, 1);
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		return -ENOMEM;
	}
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	fuse_put_request(fc, forget_req);
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	if (S_ISDIR(inode->i_mode)) {
		struct dentry *alias;
		mutex_lock(&fc->inst_mutex);
		alias = d_find_alias(inode);
		if (alias) {
			/* New directory must have moved since mkdir */
			mutex_unlock(&fc->inst_mutex);
			dput(alias);
			iput(inode);
			return -EBUSY;
		}
		d_instantiate(entry, inode);
		mutex_unlock(&fc->inst_mutex);
	} else
		d_instantiate(entry, inode);
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	fuse_change_entry_timeout(entry, &outarg);
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	fuse_invalidate_attr(dir);
	return 0;
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 out_put_forget_req:
	fuse_put_request(fc, forget_req);
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	return err;
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}

static int fuse_mknod(struct inode *dir, struct dentry *entry, int mode,
		      dev_t rdev)
{
	struct fuse_mknod_in inarg;
	struct fuse_conn *fc = get_fuse_conn(dir);
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	struct fuse_req *req = fuse_get_req(fc);
	if (IS_ERR(req))
		return PTR_ERR(req);
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	memset(&inarg, 0, sizeof(inarg));
	inarg.mode = mode;
	inarg.rdev = new_encode_dev(rdev);
	req->in.h.opcode = FUSE_MKNOD;
	req->in.numargs = 2;
	req->in.args[0].size = sizeof(inarg);
	req->in.args[0].value = &inarg;
	req->in.args[1].size = entry->d_name.len + 1;
	req->in.args[1].value = entry->d_name.name;
	return create_new_entry(fc, req, dir, entry, mode);
}

static int fuse_create(struct inode *dir, struct dentry *entry, int mode,
		       struct nameidata *nd)
{
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	if (nd && (nd->flags & LOOKUP_OPEN)) {
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		int err = fuse_create_open(dir, entry, mode, nd);
		if (err != -ENOSYS)
			return err;
		/* Fall back on mknod */
	}
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	return fuse_mknod(dir, entry, mode, 0);
}

static int fuse_mkdir(struct inode *dir, struct dentry *entry, int mode)
{
	struct fuse_mkdir_in inarg;
	struct fuse_conn *fc = get_fuse_conn(dir);
588 589 590
	struct fuse_req *req = fuse_get_req(fc);
	if (IS_ERR(req))
		return PTR_ERR(req);
591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607

	memset(&inarg, 0, sizeof(inarg));
	inarg.mode = mode;
	req->in.h.opcode = FUSE_MKDIR;
	req->in.numargs = 2;
	req->in.args[0].size = sizeof(inarg);
	req->in.args[0].value = &inarg;
	req->in.args[1].size = entry->d_name.len + 1;
	req->in.args[1].value = entry->d_name.name;
	return create_new_entry(fc, req, dir, entry, S_IFDIR);
}

static int fuse_symlink(struct inode *dir, struct dentry *entry,
			const char *link)
{
	struct fuse_conn *fc = get_fuse_conn(dir);
	unsigned len = strlen(link) + 1;
608 609 610
	struct fuse_req *req = fuse_get_req(fc);
	if (IS_ERR(req))
		return PTR_ERR(req);
611 612 613 614 615 616 617 618 619 620 621 622 623 624

	req->in.h.opcode = FUSE_SYMLINK;
	req->in.numargs = 2;
	req->in.args[0].size = entry->d_name.len + 1;
	req->in.args[0].value = entry->d_name.name;
	req->in.args[1].size = len;
	req->in.args[1].value = link;
	return create_new_entry(fc, req, dir, entry, S_IFLNK);
}

static int fuse_unlink(struct inode *dir, struct dentry *entry)
{
	int err;
	struct fuse_conn *fc = get_fuse_conn(dir);
625 626 627
	struct fuse_req *req = fuse_get_req(fc);
	if (IS_ERR(req))
		return PTR_ERR(req);
628 629 630 631 632 633

	req->in.h.opcode = FUSE_UNLINK;
	req->in.h.nodeid = get_node_id(dir);
	req->in.numargs = 1;
	req->in.args[0].size = entry->d_name.len + 1;
	req->in.args[0].value = entry->d_name.name;
634
	fuse_request_send(fc, req);
635 636 637 638 639
	err = req->out.h.error;
	fuse_put_request(fc, req);
	if (!err) {
		struct inode *inode = entry->d_inode;

M
Miklos Szeredi 已提交
640 641 642 643 644
		/*
		 * Set nlink to zero so the inode can be cleared, if the inode
		 * does have more links this will be discovered at the next
		 * lookup/getattr.
		 */
645
		clear_nlink(inode);
646 647
		fuse_invalidate_attr(inode);
		fuse_invalidate_attr(dir);
648
		fuse_invalidate_entry_cache(entry);
649 650 651 652 653 654 655 656 657
	} else if (err == -EINTR)
		fuse_invalidate_entry(entry);
	return err;
}

static int fuse_rmdir(struct inode *dir, struct dentry *entry)
{
	int err;
	struct fuse_conn *fc = get_fuse_conn(dir);
658 659 660
	struct fuse_req *req = fuse_get_req(fc);
	if (IS_ERR(req))
		return PTR_ERR(req);
661 662 663 664 665 666

	req->in.h.opcode = FUSE_RMDIR;
	req->in.h.nodeid = get_node_id(dir);
	req->in.numargs = 1;
	req->in.args[0].size = entry->d_name.len + 1;
	req->in.args[0].value = entry->d_name.name;
667
	fuse_request_send(fc, req);
668 669 670
	err = req->out.h.error;
	fuse_put_request(fc, req);
	if (!err) {
671
		clear_nlink(entry->d_inode);
672
		fuse_invalidate_attr(dir);
673
		fuse_invalidate_entry_cache(entry);
674 675 676 677 678 679 680 681 682 683 684
	} else if (err == -EINTR)
		fuse_invalidate_entry(entry);
	return err;
}

static int fuse_rename(struct inode *olddir, struct dentry *oldent,
		       struct inode *newdir, struct dentry *newent)
{
	int err;
	struct fuse_rename_in inarg;
	struct fuse_conn *fc = get_fuse_conn(olddir);
685 686 687
	struct fuse_req *req = fuse_get_req(fc);
	if (IS_ERR(req))
		return PTR_ERR(req);
688 689 690 691 692 693 694 695 696 697 698 699

	memset(&inarg, 0, sizeof(inarg));
	inarg.newdir = get_node_id(newdir);
	req->in.h.opcode = FUSE_RENAME;
	req->in.h.nodeid = get_node_id(olddir);
	req->in.numargs = 3;
	req->in.args[0].size = sizeof(inarg);
	req->in.args[0].value = &inarg;
	req->in.args[1].size = oldent->d_name.len + 1;
	req->in.args[1].value = oldent->d_name.name;
	req->in.args[2].size = newent->d_name.len + 1;
	req->in.args[2].value = newent->d_name.name;
700
	fuse_request_send(fc, req);
701 702 703
	err = req->out.h.error;
	fuse_put_request(fc, req);
	if (!err) {
704 705 706
		/* ctime changes */
		fuse_invalidate_attr(oldent->d_inode);

707 708 709
		fuse_invalidate_attr(olddir);
		if (olddir != newdir)
			fuse_invalidate_attr(newdir);
710 711 712 713

		/* newent will end up negative */
		if (newent->d_inode)
			fuse_invalidate_entry_cache(newent);
714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734
	} else if (err == -EINTR) {
		/* If request was interrupted, DEITY only knows if the
		   rename actually took place.  If the invalidation
		   fails (e.g. some process has CWD under the renamed
		   directory), then there can be inconsistency between
		   the dcache and the real filesystem.  Tough luck. */
		fuse_invalidate_entry(oldent);
		if (newent->d_inode)
			fuse_invalidate_entry(newent);
	}

	return err;
}

static int fuse_link(struct dentry *entry, struct inode *newdir,
		     struct dentry *newent)
{
	int err;
	struct fuse_link_in inarg;
	struct inode *inode = entry->d_inode;
	struct fuse_conn *fc = get_fuse_conn(inode);
735 736 737
	struct fuse_req *req = fuse_get_req(fc);
	if (IS_ERR(req))
		return PTR_ERR(req);
738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758

	memset(&inarg, 0, sizeof(inarg));
	inarg.oldnodeid = get_node_id(inode);
	req->in.h.opcode = FUSE_LINK;
	req->in.numargs = 2;
	req->in.args[0].size = sizeof(inarg);
	req->in.args[0].value = &inarg;
	req->in.args[1].size = newent->d_name.len + 1;
	req->in.args[1].value = newent->d_name.name;
	err = create_new_entry(fc, req, newdir, newent, inode->i_mode);
	/* Contrary to "normal" filesystems it can happen that link
	   makes two "logical" inodes point to the same "physical"
	   inode.  We invalidate the attributes of the old one, so it
	   will reflect changes in the backing inode (link count,
	   etc.)
	*/
	if (!err || err == -EINTR)
		fuse_invalidate_attr(inode);
	return err;
}

759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779
static void fuse_fillattr(struct inode *inode, struct fuse_attr *attr,
			  struct kstat *stat)
{
	stat->dev = inode->i_sb->s_dev;
	stat->ino = attr->ino;
	stat->mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
	stat->nlink = attr->nlink;
	stat->uid = attr->uid;
	stat->gid = attr->gid;
	stat->rdev = inode->i_rdev;
	stat->atime.tv_sec = attr->atime;
	stat->atime.tv_nsec = attr->atimensec;
	stat->mtime.tv_sec = attr->mtime;
	stat->mtime.tv_nsec = attr->mtimensec;
	stat->ctime.tv_sec = attr->ctime;
	stat->ctime.tv_nsec = attr->ctimensec;
	stat->size = attr->size;
	stat->blocks = attr->blocks;
	stat->blksize = (1 << inode->i_blkbits);
}

780 781
static int fuse_do_getattr(struct inode *inode, struct kstat *stat,
			   struct file *file)
782 783
{
	int err;
784 785
	struct fuse_getattr_in inarg;
	struct fuse_attr_out outarg;
786
	struct fuse_conn *fc = get_fuse_conn(inode);
787 788 789 790
	struct fuse_req *req;
	u64 attr_version;

	req = fuse_get_req(fc);
791 792
	if (IS_ERR(req))
		return PTR_ERR(req);
793

794
	attr_version = fuse_get_attr_version(fc);
795

796
	memset(&inarg, 0, sizeof(inarg));
797
	memset(&outarg, 0, sizeof(outarg));
798 799 800 801 802 803 804
	/* Directories have separate file-handle space */
	if (file && S_ISREG(inode->i_mode)) {
		struct fuse_file *ff = file->private_data;

		inarg.getattr_flags |= FUSE_GETATTR_FH;
		inarg.fh = ff->fh;
	}
805 806
	req->in.h.opcode = FUSE_GETATTR;
	req->in.h.nodeid = get_node_id(inode);
807 808 809
	req->in.numargs = 1;
	req->in.args[0].size = sizeof(inarg);
	req->in.args[0].value = &inarg;
810
	req->out.numargs = 1;
811 812 813 814
	if (fc->minor < 9)
		req->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE;
	else
		req->out.args[0].size = sizeof(outarg);
815
	req->out.args[0].value = &outarg;
816
	fuse_request_send(fc, req);
817 818 819
	err = req->out.h.error;
	fuse_put_request(fc, req);
	if (!err) {
820
		if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) {
821 822 823
			make_bad_inode(inode);
			err = -EIO;
		} else {
824 825
			fuse_change_attributes(inode, &outarg.attr,
					       attr_timeout(&outarg),
826 827
					       attr_version);
			if (stat)
828
				fuse_fillattr(inode, &outarg.attr, stat);
829 830 831 832 833
		}
	}
	return err;
}

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Miklos Szeredi 已提交
834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858
int fuse_update_attributes(struct inode *inode, struct kstat *stat,
			   struct file *file, bool *refreshed)
{
	struct fuse_inode *fi = get_fuse_inode(inode);
	int err;
	bool r;

	if (fi->i_time < get_jiffies_64()) {
		r = true;
		err = fuse_do_getattr(inode, stat, file);
	} else {
		r = false;
		err = 0;
		if (stat) {
			generic_fillattr(inode, stat);
			stat->mode = fi->orig_i_mode;
		}
	}

	if (refreshed != NULL)
		*refreshed = r;

	return err;
}

859 860 861 862 863 864 865 866 867 868 869 870 871
/*
 * Calling into a user-controlled filesystem gives the filesystem
 * daemon ptrace-like capabilities over the requester process.  This
 * means, that the filesystem daemon is able to record the exact
 * filesystem operations performed, and can also control the behavior
 * of the requester process in otherwise impossible ways.  For example
 * it can delay the operation for arbitrary length of time allowing
 * DoS against the requester.
 *
 * For this reason only those processes can call into the filesystem,
 * for which the owner of the mount has ptrace privilege.  This
 * excludes processes started by other users, suid or sgid processes.
 */
M
Miklos Szeredi 已提交
872
int fuse_allow_task(struct fuse_conn *fc, struct task_struct *task)
873
{
874 875
	const struct cred *cred;
	int ret;
876

877
	if (fc->flags & FUSE_ALLOW_OTHER)
878 879
		return 1;

880 881 882 883 884 885 886 887 888 889 890 891 892
	rcu_read_lock();
	ret = 0;
	cred = __task_cred(task);
	if (cred->euid == fc->user_id &&
	    cred->suid == fc->user_id &&
	    cred->uid  == fc->user_id &&
	    cred->egid == fc->group_id &&
	    cred->sgid == fc->group_id &&
	    cred->gid  == fc->group_id)
		ret = 1;
	rcu_read_unlock();

	return ret;
893 894
}

M
Miklos Szeredi 已提交
895 896 897 898 899 900 901 902 903 904
static int fuse_access(struct inode *inode, int mask)
{
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_req *req;
	struct fuse_access_in inarg;
	int err;

	if (fc->no_access)
		return 0;

905 906 907
	req = fuse_get_req(fc);
	if (IS_ERR(req))
		return PTR_ERR(req);
M
Miklos Szeredi 已提交
908 909

	memset(&inarg, 0, sizeof(inarg));
910
	inarg.mask = mask & (MAY_READ | MAY_WRITE | MAY_EXEC);
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Miklos Szeredi 已提交
911 912 913 914 915
	req->in.h.opcode = FUSE_ACCESS;
	req->in.h.nodeid = get_node_id(inode);
	req->in.numargs = 1;
	req->in.args[0].size = sizeof(inarg);
	req->in.args[0].value = &inarg;
916
	fuse_request_send(fc, req);
M
Miklos Szeredi 已提交
917 918 919 920 921 922 923 924 925
	err = req->out.h.error;
	fuse_put_request(fc, req);
	if (err == -ENOSYS) {
		fc->no_access = 1;
		err = 0;
	}
	return err;
}

926 927 928 929 930 931 932 933 934 935 936 937 938
/*
 * Check permission.  The two basic access models of FUSE are:
 *
 * 1) Local access checking ('default_permissions' mount option) based
 * on file mode.  This is the plain old disk filesystem permission
 * modell.
 *
 * 2) "Remote" access checking, where server is responsible for
 * checking permission in each inode operation.  An exception to this
 * is if ->permission() was invoked from sys_access() in which case an
 * access request is sent.  Execute permission is still checked
 * locally based on file mode.
 */
939
static int fuse_permission(struct inode *inode, int mask)
940 941
{
	struct fuse_conn *fc = get_fuse_conn(inode);
942 943
	bool refreshed = false;
	int err = 0;
944

945
	if (!fuse_allow_task(fc, current))
946
		return -EACCES;
947 948

	/*
949
	 * If attributes are needed, refresh them before proceeding
950
	 */
951 952
	if ((fc->flags & FUSE_DEFAULT_PERMISSIONS) ||
	    ((mask & MAY_EXEC) && S_ISREG(inode->i_mode))) {
M
Miklos Szeredi 已提交
953 954 955
		err = fuse_update_attributes(inode, NULL, NULL, &refreshed);
		if (err)
			return err;
956 957 958
	}

	if (fc->flags & FUSE_DEFAULT_PERMISSIONS) {
M
Miklos Szeredi 已提交
959
		err = generic_permission(inode, mask, NULL);
M
Miklos Szeredi 已提交
960 961 962 963

		/* If permission is denied, try to refresh file
		   attributes.  This is also needed, because the root
		   node will at first have no permissions */
964
		if (err == -EACCES && !refreshed) {
965
			err = fuse_do_getattr(inode, NULL, NULL);
M
Miklos Szeredi 已提交
966 967 968 969
			if (!err)
				err = generic_permission(inode, mask, NULL);
		}

970 971 972 973
		/* Note: the opposite of the above test does not
		   exist.  So if permissions are revoked this won't be
		   noticed immediately, only after the attribute
		   timeout has expired */
974
	} else if (mask & MAY_ACCESS) {
975 976 977 978 979 980
		err = fuse_access(inode, mask);
	} else if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) {
		if (!(inode->i_mode & S_IXUGO)) {
			if (refreshed)
				return -EACCES;

981
			err = fuse_do_getattr(inode, NULL, NULL);
982 983 984
			if (!err && !(inode->i_mode & S_IXUGO))
				return -EACCES;
		}
985
	}
986
	return err;
987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013
}

static int parse_dirfile(char *buf, size_t nbytes, struct file *file,
			 void *dstbuf, filldir_t filldir)
{
	while (nbytes >= FUSE_NAME_OFFSET) {
		struct fuse_dirent *dirent = (struct fuse_dirent *) buf;
		size_t reclen = FUSE_DIRENT_SIZE(dirent);
		int over;
		if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX)
			return -EIO;
		if (reclen > nbytes)
			break;

		over = filldir(dstbuf, dirent->name, dirent->namelen,
			       file->f_pos, dirent->ino, dirent->type);
		if (over)
			break;

		buf += reclen;
		nbytes -= reclen;
		file->f_pos = dirent->off;
	}

	return 0;
}

1014
static int fuse_readdir(struct file *file, void *dstbuf, filldir_t filldir)
1015
{
1016 1017 1018
	int err;
	size_t nbytes;
	struct page *page;
J
Josef Sipek 已提交
1019
	struct inode *inode = file->f_path.dentry->d_inode;
1020
	struct fuse_conn *fc = get_fuse_conn(inode);
1021 1022 1023 1024 1025
	struct fuse_req *req;

	if (is_bad_inode(inode))
		return -EIO;

1026 1027 1028
	req = fuse_get_req(fc);
	if (IS_ERR(req))
		return PTR_ERR(req);
1029

1030 1031 1032 1033 1034 1035 1036
	page = alloc_page(GFP_KERNEL);
	if (!page) {
		fuse_put_request(fc, req);
		return -ENOMEM;
	}
	req->num_pages = 1;
	req->pages[0] = page;
1037
	fuse_read_fill(req, file, inode, file->f_pos, PAGE_SIZE, FUSE_READDIR);
1038
	fuse_request_send(fc, req);
1039
	nbytes = req->out.args[0].size;
1040 1041 1042
	err = req->out.h.error;
	fuse_put_request(fc, req);
	if (!err)
1043 1044
		err = parse_dirfile(page_address(page), nbytes, file, dstbuf,
				    filldir);
1045

1046
	__free_page(page);
1047
	fuse_invalidate_attr(inode); /* atime changed */
1048
	return err;
1049 1050 1051 1052 1053 1054
}

static char *read_link(struct dentry *dentry)
{
	struct inode *inode = dentry->d_inode;
	struct fuse_conn *fc = get_fuse_conn(inode);
1055
	struct fuse_req *req = fuse_get_req(fc);
1056 1057
	char *link;

1058
	if (IS_ERR(req))
1059
		return ERR_CAST(req);
1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071

	link = (char *) __get_free_page(GFP_KERNEL);
	if (!link) {
		link = ERR_PTR(-ENOMEM);
		goto out;
	}
	req->in.h.opcode = FUSE_READLINK;
	req->in.h.nodeid = get_node_id(inode);
	req->out.argvar = 1;
	req->out.numargs = 1;
	req->out.args[0].size = PAGE_SIZE - 1;
	req->out.args[0].value = link;
1072
	fuse_request_send(fc, req);
1073 1074 1075 1076 1077 1078 1079
	if (req->out.h.error) {
		free_page((unsigned long) link);
		link = ERR_PTR(req->out.h.error);
	} else
		link[req->out.args[0].size] = '\0';
 out:
	fuse_put_request(fc, req);
1080
	fuse_invalidate_attr(inode); /* atime changed */
1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102
	return link;
}

static void free_link(char *link)
{
	if (!IS_ERR(link))
		free_page((unsigned long) link);
}

static void *fuse_follow_link(struct dentry *dentry, struct nameidata *nd)
{
	nd_set_link(nd, read_link(dentry));
	return NULL;
}

static void fuse_put_link(struct dentry *dentry, struct nameidata *nd, void *c)
{
	free_link(nd_get_link(nd));
}

static int fuse_dir_open(struct inode *inode, struct file *file)
{
1103
	return fuse_open_common(inode, file, 1);
1104 1105 1106 1107
}

static int fuse_dir_release(struct inode *inode, struct file *file)
{
1108
	return fuse_release_common(inode, file, 1);
1109 1110
}

1111 1112 1113 1114 1115 1116
static int fuse_dir_fsync(struct file *file, struct dentry *de, int datasync)
{
	/* nfsd can call this with no file */
	return file ? fuse_fsync_common(file, de, datasync, 1) : 0;
}

M
Miklos Szeredi 已提交
1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130
static bool update_mtime(unsigned ivalid)
{
	/* Always update if mtime is explicitly set  */
	if (ivalid & ATTR_MTIME_SET)
		return true;

	/* If it's an open(O_TRUNC) or an ftruncate(), don't update */
	if ((ivalid & ATTR_SIZE) && (ivalid & (ATTR_OPEN | ATTR_FILE)))
		return false;

	/* In all other cases update */
	return true;
}

1131
static void iattr_to_fattr(struct iattr *iattr, struct fuse_setattr_in *arg)
1132 1133 1134 1135
{
	unsigned ivalid = iattr->ia_valid;

	if (ivalid & ATTR_MODE)
1136
		arg->valid |= FATTR_MODE,   arg->mode = iattr->ia_mode;
1137
	if (ivalid & ATTR_UID)
1138
		arg->valid |= FATTR_UID,    arg->uid = iattr->ia_uid;
1139
	if (ivalid & ATTR_GID)
1140
		arg->valid |= FATTR_GID,    arg->gid = iattr->ia_gid;
1141
	if (ivalid & ATTR_SIZE)
1142
		arg->valid |= FATTR_SIZE,   arg->size = iattr->ia_size;
M
Miklos Szeredi 已提交
1143 1144
	if (ivalid & ATTR_ATIME) {
		arg->valid |= FATTR_ATIME;
1145
		arg->atime = iattr->ia_atime.tv_sec;
M
Miklos Szeredi 已提交
1146 1147 1148 1149 1150 1151
		arg->atimensec = iattr->ia_atime.tv_nsec;
		if (!(ivalid & ATTR_ATIME_SET))
			arg->valid |= FATTR_ATIME_NOW;
	}
	if ((ivalid & ATTR_MTIME) && update_mtime(ivalid)) {
		arg->valid |= FATTR_MTIME;
1152
		arg->mtime = iattr->ia_mtime.tv_sec;
M
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		arg->mtimensec = iattr->ia_mtime.tv_nsec;
		if (!(ivalid & ATTR_MTIME_SET))
			arg->valid |= FATTR_MTIME_NOW;
1156
	}
1157 1158
}

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/*
 * Prevent concurrent writepages on inode
 *
 * This is done by adding a negative bias to the inode write counter
 * and waiting for all pending writes to finish.
 */
void fuse_set_nowrite(struct inode *inode)
{
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_inode *fi = get_fuse_inode(inode);

	BUG_ON(!mutex_is_locked(&inode->i_mutex));

	spin_lock(&fc->lock);
	BUG_ON(fi->writectr < 0);
	fi->writectr += FUSE_NOWRITE;
	spin_unlock(&fc->lock);
	wait_event(fi->page_waitq, fi->writectr == FUSE_NOWRITE);
}

/*
 * Allow writepages on inode
 *
 * Remove the bias from the writecounter and send any queued
 * writepages.
 */
static void __fuse_release_nowrite(struct inode *inode)
{
	struct fuse_inode *fi = get_fuse_inode(inode);

	BUG_ON(fi->writectr != FUSE_NOWRITE);
	fi->writectr = 0;
	fuse_flush_writepages(inode);
}

void fuse_release_nowrite(struct inode *inode)
{
	struct fuse_conn *fc = get_fuse_conn(inode);

	spin_lock(&fc->lock);
	__fuse_release_nowrite(inode);
	spin_unlock(&fc->lock);
}

1203 1204 1205 1206 1207
/*
 * Set attributes, and at the same time refresh them.
 *
 * Truncation is slightly complicated, because the 'truncate' request
 * may fail, in which case we don't want to touch the mapping.
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 * vmtruncate() doesn't allow for this case, so do the rlimit checking
 * and the actual truncation by hand.
1210
 */
1211 1212
static int fuse_do_setattr(struct dentry *entry, struct iattr *attr,
			   struct file *file)
1213 1214 1215 1216 1217 1218
{
	struct inode *inode = entry->d_inode;
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_req *req;
	struct fuse_setattr_in inarg;
	struct fuse_attr_out outarg;
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	bool is_truncate = false;
	loff_t oldsize;
1221 1222
	int err;

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	if (!fuse_allow_task(fc, current))
		return -EACCES;

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	if (fc->flags & FUSE_DEFAULT_PERMISSIONS) {
		err = inode_change_ok(inode, attr);
		if (err)
			return err;
	}

1232 1233 1234
	if ((attr->ia_valid & ATTR_OPEN) && fc->atomic_o_trunc)
		return 0;

1235 1236
	if (attr->ia_valid & ATTR_SIZE) {
		unsigned long limit;
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		if (IS_SWAPFILE(inode))
			return -ETXTBSY;
1239 1240 1241 1242 1243
		limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
		if (limit != RLIM_INFINITY && attr->ia_size > (loff_t) limit) {
			send_sig(SIGXFSZ, current, 0);
			return -EFBIG;
		}
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		is_truncate = true;
1245 1246
	}

1247 1248 1249
	req = fuse_get_req(fc);
	if (IS_ERR(req))
		return PTR_ERR(req);
1250

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	if (is_truncate)
		fuse_set_nowrite(inode);

1254
	memset(&inarg, 0, sizeof(inarg));
1255
	memset(&outarg, 0, sizeof(outarg));
1256
	iattr_to_fattr(attr, &inarg);
1257 1258 1259 1260 1261
	if (file) {
		struct fuse_file *ff = file->private_data;
		inarg.valid |= FATTR_FH;
		inarg.fh = ff->fh;
	}
1262 1263 1264 1265 1266
	if (attr->ia_valid & ATTR_SIZE) {
		/* For mandatory locking in truncate */
		inarg.valid |= FATTR_LOCKOWNER;
		inarg.lock_owner = fuse_lock_owner_id(fc, current->files);
	}
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	req->in.h.opcode = FUSE_SETATTR;
	req->in.h.nodeid = get_node_id(inode);
	req->in.numargs = 1;
	req->in.args[0].size = sizeof(inarg);
	req->in.args[0].value = &inarg;
	req->out.numargs = 1;
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	if (fc->minor < 9)
		req->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE;
	else
		req->out.args[0].size = sizeof(outarg);
1277
	req->out.args[0].value = &outarg;
1278
	fuse_request_send(fc, req);
1279 1280
	err = req->out.h.error;
	fuse_put_request(fc, req);
1281 1282 1283
	if (err) {
		if (err == -EINTR)
			fuse_invalidate_attr(inode);
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		goto error;
1285
	}
1286

1287 1288
	if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) {
		make_bad_inode(inode);
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		err = -EIO;
		goto error;
	}

	spin_lock(&fc->lock);
	fuse_change_attributes_common(inode, &outarg.attr,
				      attr_timeout(&outarg));
	oldsize = inode->i_size;
	i_size_write(inode, outarg.attr.size);

	if (is_truncate) {
		/* NOTE: this may release/reacquire fc->lock */
		__fuse_release_nowrite(inode);
	}
	spin_unlock(&fc->lock);

	/*
	 * Only call invalidate_inode_pages2() after removing
	 * FUSE_NOWRITE, otherwise fuse_launder_page() would deadlock.
	 */
	if (S_ISREG(inode->i_mode) && oldsize != outarg.attr.size) {
		if (outarg.attr.size < oldsize)
			fuse_truncate(inode->i_mapping, outarg.attr.size);
		invalidate_inode_pages2(inode->i_mapping);
1313 1314 1315
	}

	return 0;
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error:
	if (is_truncate)
		fuse_release_nowrite(inode);

	return err;
1322 1323
}

1324 1325 1326 1327 1328 1329 1330 1331
static int fuse_setattr(struct dentry *entry, struct iattr *attr)
{
	if (attr->ia_valid & ATTR_FILE)
		return fuse_do_setattr(entry, attr, attr->ia_file);
	else
		return fuse_do_setattr(entry, attr, NULL);
}

1332 1333 1334 1335
static int fuse_getattr(struct vfsmount *mnt, struct dentry *entry,
			struct kstat *stat)
{
	struct inode *inode = entry->d_inode;
1336 1337 1338 1339 1340
	struct fuse_conn *fc = get_fuse_conn(inode);

	if (!fuse_allow_task(fc, current))
		return -EACCES;

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	return fuse_update_attributes(inode, stat, NULL, NULL);
1342 1343
}

1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355
static int fuse_setxattr(struct dentry *entry, const char *name,
			 const void *value, size_t size, int flags)
{
	struct inode *inode = entry->d_inode;
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_req *req;
	struct fuse_setxattr_in inarg;
	int err;

	if (fc->no_setxattr)
		return -EOPNOTSUPP;

1356 1357 1358
	req = fuse_get_req(fc);
	if (IS_ERR(req))
		return PTR_ERR(req);
1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371

	memset(&inarg, 0, sizeof(inarg));
	inarg.size = size;
	inarg.flags = flags;
	req->in.h.opcode = FUSE_SETXATTR;
	req->in.h.nodeid = get_node_id(inode);
	req->in.numargs = 3;
	req->in.args[0].size = sizeof(inarg);
	req->in.args[0].value = &inarg;
	req->in.args[1].size = strlen(name) + 1;
	req->in.args[1].value = name;
	req->in.args[2].size = size;
	req->in.args[2].value = value;
1372
	fuse_request_send(fc, req);
1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394
	err = req->out.h.error;
	fuse_put_request(fc, req);
	if (err == -ENOSYS) {
		fc->no_setxattr = 1;
		err = -EOPNOTSUPP;
	}
	return err;
}

static ssize_t fuse_getxattr(struct dentry *entry, const char *name,
			     void *value, size_t size)
{
	struct inode *inode = entry->d_inode;
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_req *req;
	struct fuse_getxattr_in inarg;
	struct fuse_getxattr_out outarg;
	ssize_t ret;

	if (fc->no_getxattr)
		return -EOPNOTSUPP;

1395 1396 1397
	req = fuse_get_req(fc);
	if (IS_ERR(req))
		return PTR_ERR(req);
1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417

	memset(&inarg, 0, sizeof(inarg));
	inarg.size = size;
	req->in.h.opcode = FUSE_GETXATTR;
	req->in.h.nodeid = get_node_id(inode);
	req->in.numargs = 2;
	req->in.args[0].size = sizeof(inarg);
	req->in.args[0].value = &inarg;
	req->in.args[1].size = strlen(name) + 1;
	req->in.args[1].value = name;
	/* This is really two different operations rolled into one */
	req->out.numargs = 1;
	if (size) {
		req->out.argvar = 1;
		req->out.args[0].size = size;
		req->out.args[0].value = value;
	} else {
		req->out.args[0].size = sizeof(outarg);
		req->out.args[0].value = &outarg;
	}
1418
	fuse_request_send(fc, req);
1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440
	ret = req->out.h.error;
	if (!ret)
		ret = size ? req->out.args[0].size : outarg.size;
	else {
		if (ret == -ENOSYS) {
			fc->no_getxattr = 1;
			ret = -EOPNOTSUPP;
		}
	}
	fuse_put_request(fc, req);
	return ret;
}

static ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size)
{
	struct inode *inode = entry->d_inode;
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_req *req;
	struct fuse_getxattr_in inarg;
	struct fuse_getxattr_out outarg;
	ssize_t ret;

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	if (!fuse_allow_task(fc, current))
		return -EACCES;

1444 1445 1446
	if (fc->no_listxattr)
		return -EOPNOTSUPP;

1447 1448 1449
	req = fuse_get_req(fc);
	if (IS_ERR(req))
		return PTR_ERR(req);
1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467

	memset(&inarg, 0, sizeof(inarg));
	inarg.size = size;
	req->in.h.opcode = FUSE_LISTXATTR;
	req->in.h.nodeid = get_node_id(inode);
	req->in.numargs = 1;
	req->in.args[0].size = sizeof(inarg);
	req->in.args[0].value = &inarg;
	/* This is really two different operations rolled into one */
	req->out.numargs = 1;
	if (size) {
		req->out.argvar = 1;
		req->out.args[0].size = size;
		req->out.args[0].value = list;
	} else {
		req->out.args[0].size = sizeof(outarg);
		req->out.args[0].value = &outarg;
	}
1468
	fuse_request_send(fc, req);
1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491
	ret = req->out.h.error;
	if (!ret)
		ret = size ? req->out.args[0].size : outarg.size;
	else {
		if (ret == -ENOSYS) {
			fc->no_listxattr = 1;
			ret = -EOPNOTSUPP;
		}
	}
	fuse_put_request(fc, req);
	return ret;
}

static int fuse_removexattr(struct dentry *entry, const char *name)
{
	struct inode *inode = entry->d_inode;
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_req *req;
	int err;

	if (fc->no_removexattr)
		return -EOPNOTSUPP;

1492 1493 1494
	req = fuse_get_req(fc);
	if (IS_ERR(req))
		return PTR_ERR(req);
1495 1496 1497 1498 1499 1500

	req->in.h.opcode = FUSE_REMOVEXATTR;
	req->in.h.nodeid = get_node_id(inode);
	req->in.numargs = 1;
	req->in.args[0].size = strlen(name) + 1;
	req->in.args[0].value = name;
1501
	fuse_request_send(fc, req);
1502 1503 1504 1505 1506 1507 1508 1509 1510
	err = req->out.h.error;
	fuse_put_request(fc, req);
	if (err == -ENOSYS) {
		fc->no_removexattr = 1;
		err = -EOPNOTSUPP;
	}
	return err;
}

1511
static const struct inode_operations fuse_dir_inode_operations = {
1512
	.lookup		= fuse_lookup,
1513 1514 1515 1516 1517 1518 1519 1520 1521
	.mkdir		= fuse_mkdir,
	.symlink	= fuse_symlink,
	.unlink		= fuse_unlink,
	.rmdir		= fuse_rmdir,
	.rename		= fuse_rename,
	.link		= fuse_link,
	.setattr	= fuse_setattr,
	.create		= fuse_create,
	.mknod		= fuse_mknod,
1522 1523
	.permission	= fuse_permission,
	.getattr	= fuse_getattr,
1524 1525 1526 1527
	.setxattr	= fuse_setxattr,
	.getxattr	= fuse_getxattr,
	.listxattr	= fuse_listxattr,
	.removexattr	= fuse_removexattr,
1528 1529
};

1530
static const struct file_operations fuse_dir_operations = {
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	.llseek		= generic_file_llseek,
1532 1533 1534 1535
	.read		= generic_read_dir,
	.readdir	= fuse_readdir,
	.open		= fuse_dir_open,
	.release	= fuse_dir_release,
1536
	.fsync		= fuse_dir_fsync,
1537 1538
};

1539
static const struct inode_operations fuse_common_inode_operations = {
1540
	.setattr	= fuse_setattr,
1541 1542
	.permission	= fuse_permission,
	.getattr	= fuse_getattr,
1543 1544 1545 1546
	.setxattr	= fuse_setxattr,
	.getxattr	= fuse_getxattr,
	.listxattr	= fuse_listxattr,
	.removexattr	= fuse_removexattr,
1547 1548
};

1549
static const struct inode_operations fuse_symlink_inode_operations = {
1550
	.setattr	= fuse_setattr,
1551 1552 1553 1554
	.follow_link	= fuse_follow_link,
	.put_link	= fuse_put_link,
	.readlink	= generic_readlink,
	.getattr	= fuse_getattr,
1555 1556 1557 1558
	.setxattr	= fuse_setxattr,
	.getxattr	= fuse_getxattr,
	.listxattr	= fuse_listxattr,
	.removexattr	= fuse_removexattr,
1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575
};

void fuse_init_common(struct inode *inode)
{
	inode->i_op = &fuse_common_inode_operations;
}

void fuse_init_dir(struct inode *inode)
{
	inode->i_op = &fuse_dir_inode_operations;
	inode->i_fop = &fuse_dir_operations;
}

void fuse_init_symlink(struct inode *inode)
{
	inode->i_op = &fuse_symlink_inode_operations;
}