All of lore.kernel.org
 help / color / mirror / Atom feed
From: Christian Schoenebeck <linux_oss@crudebyte.com>
To: Tyler Hicks <tyhicks@linux.microsoft.com>,
	Eric Van Hensbergen <ericvh@gmail.com>,
	Latchesar Ionkov <lucho@ionkov.net>,
	Dominique Martinet <asmadeus@codewreck.org>,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	v9fs-developer@lists.sourceforge.net
Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org
Subject: Re: [PATCH v2 04/06] 9p fid refcount: add p9_fid_get/put wrappers
Date: Tue, 14 Jun 2022 15:55:39 +0200	[thread overview]
Message-ID: <7044959.MN0D2SvuAq@silver> (raw)
In-Reply-To: <20220612234557.1559736-1-asmadeus@codewreck.org>

On Montag, 13. Juni 2022 01:45:54 CEST Dominique Martinet wrote:
> I was recently reminded that it is not clear that p9_client_clunk()
> was actually just decrementing refcount and clunking only when that
> reaches zero: make it clear through a set of helpers.
> 
> This will also allow instrumenting refcounting better for debugging
> next patch, which is the reason these are not defined as static inline:
> we won't be able to add trace events there...

Looks like you forgot to adjust the commit log sentence here, ...

> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
> ---
> v1 -> v2: p9_fid_get/put are now static inline in .h

... as the two functions are in fact static inlined in this v2 now.

Some more below ...

>  fs/9p/fid.c             | 18 ++++++++--------
>  fs/9p/fid.h             |  2 +-
>  fs/9p/vfs_addr.c        |  4 ++--
>  fs/9p/vfs_dentry.c      |  4 ++--
>  fs/9p/vfs_dir.c         |  2 +-
>  fs/9p/vfs_file.c        |  4 ++--
>  fs/9p/vfs_inode.c       | 48 ++++++++++++++++++++---------------------
>  fs/9p/vfs_inode_dotl.c  | 42 ++++++++++++++++++------------------
>  fs/9p/vfs_super.c       |  6 +++---
>  fs/9p/xattr.c           |  8 +++----
>  include/net/9p/client.h | 18 ++++++++++++++++
>  net/9p/client.c         | 15 +++----------
>  12 files changed, 90 insertions(+), 81 deletions(-)
> 
> diff --git a/fs/9p/fid.c b/fs/9p/fid.c
> index e8fad28fc5bd..d792499349c4 100644
> --- a/fs/9p/fid.c
> +++ b/fs/9p/fid.c
> @@ -56,7 +56,7 @@ static struct p9_fid *v9fs_fid_find_inode(struct inode
> *inode, kuid_t uid) h = (struct hlist_head *)&inode->i_private;
>  	hlist_for_each_entry(fid, h, ilist) {
>  		if (uid_eq(fid->uid, uid)) {
> -			refcount_inc(&fid->count);
> +			p9_fid_get(fid);
>  			ret = fid;
>  			break;
>  		}
> @@ -104,7 +104,7 @@ static struct p9_fid *v9fs_fid_find(struct dentry
> *dentry, kuid_t uid, int any) hlist_for_each_entry(fid, h, dlist) {
>  			if (any || uid_eq(fid->uid, uid)) {
>  				ret = fid;
> -				refcount_inc(&ret->count);
> +				p9_fid_get(ret);
>  				break;
>  			}
>  		}
> @@ -172,7 +172,7 @@ static struct p9_fid *v9fs_fid_lookup_with_uid(struct
> dentry *dentry, old_fid = fid;
> 
>  		fid = p9_client_walk(old_fid, 1, &dentry->d_name.name, 1);
> -		p9_client_clunk(old_fid);
> +		p9_fid_put(old_fid);
>  		goto fid_out;
>  	}
>  	up_read(&v9ses->rename_sem);
> @@ -194,7 +194,7 @@ static struct p9_fid *v9fs_fid_lookup_with_uid(struct
> dentry *dentry, if (IS_ERR(root_fid))
>  			return root_fid;
> 
> -		refcount_inc(&root_fid->count);
> +		p9_fid_get(root_fid);
>  		v9fs_fid_add(dentry->d_sb->s_root, root_fid);
>  	}
>  	/* If we are root ourself just return that */
> @@ -225,7 +225,7 @@ static struct p9_fid *v9fs_fid_lookup_with_uid(struct
> dentry *dentry, old_fid == root_fid /* clone */);
>  		/* non-cloning walk will return the same fid */
>  		if (fid != old_fid) {
> -			p9_client_clunk(old_fid);
> +			p9_fid_put(old_fid);
>  			old_fid = fid;
>  		}
>  		if (IS_ERR(fid)) {
> @@ -240,11 +240,11 @@ static struct p9_fid *v9fs_fid_lookup_with_uid(struct
> dentry *dentry, spin_lock(&dentry->d_lock);
>  		if (d_unhashed(dentry)) {
>  			spin_unlock(&dentry->d_lock);
> -			p9_client_clunk(fid);
> +			p9_fid_put(fid);
>  			fid = ERR_PTR(-ENOENT);
>  		} else {
>  			__add_fid(dentry, fid);
> -			refcount_inc(&fid->count);
> +			p9_fid_get(fid);
>  			spin_unlock(&dentry->d_lock);
>  		}
>  	}
> @@ -301,7 +301,7 @@ struct p9_fid *v9fs_writeback_fid(struct dentry *dentry)
> fid = clone_fid(ofid);
>  	if (IS_ERR(fid))
>  		goto error_out;
> -	p9_client_clunk(ofid);
> +	p9_fid_put(ofid);
>  	/*
>  	 * writeback fid will only be used to write back the
>  	 * dirty pages. We always request for the open fid in read-write
> @@ -310,7 +310,7 @@ struct p9_fid *v9fs_writeback_fid(struct dentry *dentry)
> */
>  	err = p9_client_open(fid, O_RDWR);
>  	if (err < 0) {
> -		p9_client_clunk(fid);
> +		p9_fid_put(fid);
>  		fid = ERR_PTR(err);
>  		goto error_out;
>  	}
> diff --git a/fs/9p/fid.h b/fs/9p/fid.h
> index f7f33509e169..3168dfad510e 100644
> --- a/fs/9p/fid.h
> +++ b/fs/9p/fid.h
> @@ -29,7 +29,7 @@ static inline struct p9_fid *v9fs_fid_clone(struct dentry
> *dentry) return fid;
> 
>  	nfid = clone_fid(fid);
> -	p9_client_clunk(fid);
> +	p9_fid_put(fid);
>  	return nfid;
>  }
>  #endif
> diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c
> index 8ce82ff1e40a..ed598160e0c6 100644
> --- a/fs/9p/vfs_addr.c
> +++ b/fs/9p/vfs_addr.c
> @@ -60,7 +60,7 @@ static int v9fs_init_request(struct netfs_io_request
> *rreq, struct file *file) {
>  	struct p9_fid *fid = file->private_data;
> 
> -	refcount_inc(&fid->count);
> +	p9_fid_get(fid);
>  	rreq->netfs_priv = fid;
>  	return 0;
>  }
> @@ -74,7 +74,7 @@ static void v9fs_req_cleanup(struct address_space
> *mapping, void *priv) {
>  	struct p9_fid *fid = priv;
> 
> -	p9_client_clunk(fid);
> +	p9_fid_put(fid);
>  }
> 
>  /**
> diff --git a/fs/9p/vfs_dentry.c b/fs/9p/vfs_dentry.c
> index 1c609e99d280..f89f01734587 100644
> --- a/fs/9p/vfs_dentry.c
> +++ b/fs/9p/vfs_dentry.c
> @@ -54,7 +54,7 @@ static void v9fs_dentry_release(struct dentry *dentry)
>  	p9_debug(P9_DEBUG_VFS, " dentry: %pd (%p)\n",
>  		 dentry, dentry);
>  	hlist_for_each_safe(p, n, (struct hlist_head *)&dentry->d_fsdata)
> -		p9_client_clunk(hlist_entry(p, struct p9_fid, dlist));
> +		p9_fid_put(hlist_entry(p, struct p9_fid, dlist));
>  	dentry->d_fsdata = NULL;
>  }
> 
> @@ -85,7 +85,7 @@ static int v9fs_lookup_revalidate(struct dentry *dentry,
> unsigned int flags) retval = v9fs_refresh_inode_dotl(fid, inode);
>  		else
>  			retval = v9fs_refresh_inode(fid, inode);
> -		p9_client_clunk(fid);
> +		p9_fid_put(fid);
> 
>  		if (retval == -ENOENT)
>  			return 0;
> diff --git a/fs/9p/vfs_dir.c b/fs/9p/vfs_dir.c
> index 958680f7f23e..000fbaae9b18 100644
> --- a/fs/9p/vfs_dir.c
> +++ b/fs/9p/vfs_dir.c
> @@ -218,7 +218,7 @@ int v9fs_dir_release(struct inode *inode, struct file
> *filp) spin_lock(&inode->i_lock);
>  		hlist_del(&fid->ilist);
>  		spin_unlock(&inode->i_lock);
> -		p9_client_clunk(fid);
> +		p9_fid_put(fid);
>  	}
> 
>  	if ((filp->f_mode & FMODE_WRITE)) {
> diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
> index 2573c08f335c..8276f3af35d7 100644
> --- a/fs/9p/vfs_file.c
> +++ b/fs/9p/vfs_file.c
> @@ -63,7 +63,7 @@ int v9fs_file_open(struct inode *inode, struct file *file)
> 
>  		err = p9_client_open(fid, omode);
>  		if (err < 0) {
> -			p9_client_clunk(fid);
> +			p9_fid_put(fid);
>  			return err;
>  		}
>  		if ((file->f_flags & O_APPEND) &&
> @@ -98,7 +98,7 @@ int v9fs_file_open(struct inode *inode, struct file *file)
> v9fs_open_fid_add(inode, fid);
>  	return 0;
>  out_error:
> -	p9_client_clunk(file->private_data);
> +	p9_fid_put(file->private_data);
>  	file->private_data = NULL;
>  	return err;
>  }
> diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
> index 18c780ffd4b5..38186d1a1440 100644
> --- a/fs/9p/vfs_inode.c
> +++ b/fs/9p/vfs_inode.c
> @@ -399,7 +399,7 @@ void v9fs_evict_inode(struct inode *inode)
>  	fscache_relinquish_cookie(v9fs_inode_cookie(v9inode), false);
>  	/* clunk the fid stashed in writeback_fid */
>  	if (v9inode->writeback_fid) {
> -		p9_client_clunk(v9inode->writeback_fid);
> +		p9_fid_put(v9inode->writeback_fid);
>  		v9inode->writeback_fid = NULL;
>  	}
>  }
> @@ -568,7 +568,7 @@ static int v9fs_remove(struct inode *dir, struct dentry
> *dentry, int flags) if (v9fs_proto_dotl(v9ses))
>  		retval = p9_client_unlinkat(dfid, dentry->d_name.name,
>  					    v9fs_at_to_dotl_flags(flags));
> -	p9_client_clunk(dfid);
> +	p9_fid_put(dfid);
>  	if (retval == -EOPNOTSUPP) {
>  		/* Try the one based on path */
>  		v9fid = v9fs_fid_clone(dentry);
> @@ -632,14 +632,14 @@ v9fs_create(struct v9fs_session_info *v9ses, struct
> inode *dir, if (IS_ERR(ofid)) {
>  		err = PTR_ERR(ofid);
>  		p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
> -		p9_client_clunk(dfid);
> +		p9_fid_put(dfid);
>  		return ERR_PTR(err);
>  	}
> 
>  	err = p9_client_fcreate(ofid, name, perm, mode, extension);
>  	if (err < 0) {
>  		p9_debug(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err);
> -		p9_client_clunk(dfid);
> +		p9_fid_put(dfid);
>  		goto error;
>  	}
> 
> @@ -651,7 +651,7 @@ v9fs_create(struct v9fs_session_info *v9ses, struct
> inode *dir, p9_debug(P9_DEBUG_VFS,
>  				   "p9_client_walk failed %d\n", err);
>  			fid = NULL;
> -			p9_client_clunk(dfid);
> +			p9_fid_put(dfid);
>  			goto error;
>  		}
>  		/*
> @@ -662,20 +662,20 @@ v9fs_create(struct v9fs_session_info *v9ses, struct
> inode *dir, err = PTR_ERR(inode);
>  			p9_debug(P9_DEBUG_VFS,
>  				   "inode creation failed %d\n", err);
> -			p9_client_clunk(dfid);
> +			p9_fid_put(dfid);
>  			goto error;
>  		}
>  		v9fs_fid_add(dentry, fid);
>  		d_instantiate(dentry, inode);
>  	}
> -	p9_client_clunk(dfid);
> +	p9_fid_put(dfid);
>  	return ofid;
>  error:
>  	if (ofid)
> -		p9_client_clunk(ofid);
> +		p9_fid_put(ofid);
> 
>  	if (fid)
> -		p9_client_clunk(fid);
> +		p9_fid_put(fid);
> 
>  	return ERR_PTR(err);
>  }
> @@ -707,7 +707,7 @@ v9fs_vfs_create(struct user_namespace *mnt_userns,
> struct inode *dir, return PTR_ERR(fid);
> 
>  	v9fs_invalidate_inode_attr(dir);
> -	p9_client_clunk(fid);
> +	p9_fid_put(fid);
> 
>  	return 0;
>  }
> @@ -743,7 +743,7 @@ static int v9fs_vfs_mkdir(struct user_namespace
> *mnt_userns, struct inode *dir, }
> 
>  	if (fid)
> -		p9_client_clunk(fid);
> +		p9_fid_put(fid);
> 
>  	return err;
>  }
> @@ -784,7 +784,7 @@ struct dentry *v9fs_vfs_lookup(struct inode *dir, struct
> dentry *dentry, */
>  	name = dentry->d_name.name;
>  	fid = p9_client_walk(dfid, 1, &name, 1);
> -	p9_client_clunk(dfid);
> +	p9_fid_put(dfid);
>  	if (fid == ERR_PTR(-ENOENT))
>  		inode = NULL;
>  	else if (IS_ERR(fid))
> @@ -807,7 +807,7 @@ struct dentry *v9fs_vfs_lookup(struct inode *dir, struct
> dentry *dentry, else if (!IS_ERR(res))
>  			v9fs_fid_add(res, fid);
>  		else
> -			p9_client_clunk(fid);
> +			p9_fid_put(fid);
>  	}
>  	return res;
>  }
> @@ -890,7 +890,7 @@ v9fs_vfs_atomic_open(struct inode *dir, struct dentry
> *dentry,
> 
>  error:
>  	if (fid)
> -		p9_client_clunk(fid);
> +		p9_fid_put(fid);
>  	goto out;
>  }
> 
> @@ -958,7 +958,7 @@ v9fs_vfs_rename(struct user_namespace *mnt_userns,
> struct inode *old_dir, dfid = v9fs_parent_fid(old_dentry);
>  	olddirfid = clone_fid(dfid);
>  	if (dfid && !IS_ERR(dfid))
> -		p9_client_clunk(dfid);
> +		p9_fid_put(dfid);
> 
>  	if (IS_ERR(olddirfid)) {
>  		retval = PTR_ERR(olddirfid);
> @@ -967,7 +967,7 @@ v9fs_vfs_rename(struct user_namespace *mnt_userns,
> struct inode *old_dir,
> 
>  	dfid = v9fs_parent_fid(new_dentry);
>  	newdirfid = clone_fid(dfid);
> -	p9_client_clunk(dfid);
> +	p9_fid_put(dfid);
> 
>  	if (IS_ERR(newdirfid)) {
>  		retval = PTR_ERR(newdirfid);
> @@ -1019,13 +1019,13 @@ v9fs_vfs_rename(struct user_namespace *mnt_userns,
> struct inode *old_dir, d_move(old_dentry, new_dentry);
>  	}
>  	up_write(&v9ses->rename_sem);
> -	p9_client_clunk(newdirfid);
> +	p9_fid_put(newdirfid);
> 
>  clunk_olddir:
> -	p9_client_clunk(olddirfid);
> +	p9_fid_put(olddirfid);
> 
>  done:
> -	p9_client_clunk(oldfid);
> +	p9_fid_put(oldfid);
>  	return retval;
>  }
> 
> @@ -1059,7 +1059,7 @@ v9fs_vfs_getattr(struct user_namespace *mnt_userns,
> const struct path *path, return PTR_ERR(fid);
> 
>  	st = p9_client_stat(fid);
> -	p9_client_clunk(fid);
> +	p9_fid_put(fid);
>  	if (IS_ERR(st))
>  		return PTR_ERR(st);
> 
> @@ -1135,7 +1135,7 @@ static int v9fs_vfs_setattr(struct user_namespace
> *mnt_userns, retval = p9_client_wstat(fid, &wstat);
> 
>  	if (use_dentry)
> -		p9_client_clunk(fid);
> +		p9_fid_put(fid);
> 
>  	if (retval < 0)
>  		return retval;
> @@ -1260,7 +1260,7 @@ static const char *v9fs_vfs_get_link(struct dentry
> *dentry, return ERR_CAST(fid);
> 
>  	st = p9_client_stat(fid);
> -	p9_client_clunk(fid);
> +	p9_fid_put(fid);
>  	if (IS_ERR(st))
>  		return ERR_CAST(st);
> 
> @@ -1307,7 +1307,7 @@ static int v9fs_vfs_mkspecial(struct inode *dir,
> struct dentry *dentry, return PTR_ERR(fid);
> 
>  	v9fs_invalidate_inode_attr(dir);
> -	p9_client_clunk(fid);
> +	p9_fid_put(fid);
>  	return 0;
>  }
> 
> @@ -1363,7 +1363,7 @@ v9fs_vfs_link(struct dentry *old_dentry, struct inode
> *dir, v9fs_refresh_inode(oldfid, d_inode(old_dentry));
>  		v9fs_invalidate_inode_attr(dir);
>  	}
> -	p9_client_clunk(oldfid);
> +	p9_fid_put(oldfid);
>  	return retval;
>  }
> 
> diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c
> index b6eb1160296c..09b124fe349c 100644
> --- a/fs/9p/vfs_inode_dotl.c
> +++ b/fs/9p/vfs_inode_dotl.c
> @@ -274,7 +274,7 @@ v9fs_vfs_atomic_open_dotl(struct inode *dir, struct
> dentry *dentry, if (IS_ERR(ofid)) {
>  		err = PTR_ERR(ofid);
>  		p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
> -		p9_client_clunk(dfid);
> +		p9_fid_put(dfid);
>  		goto out;
>  	}
> 
> @@ -286,7 +286,7 @@ v9fs_vfs_atomic_open_dotl(struct inode *dir, struct
> dentry *dentry, if (err) {
>  		p9_debug(P9_DEBUG_VFS, "Failed to get acl values in creat %d\n",
>  			 err);
> -		p9_client_clunk(dfid);
> +		p9_fid_put(dfid);
>  		goto error;
>  	}
>  	err = p9_client_create_dotl(ofid, name, v9fs_open_to_dotl_flags(flags),
> @@ -294,14 +294,14 @@ v9fs_vfs_atomic_open_dotl(struct inode *dir, struct
> dentry *dentry, if (err < 0) {
>  		p9_debug(P9_DEBUG_VFS, "p9_client_open_dotl failed in creat %d\n",
>  			 err);
> -		p9_client_clunk(dfid);
> +		p9_fid_put(dfid);
>  		goto error;
>  	}
>  	v9fs_invalidate_inode_attr(dir);
> 
>  	/* instantiate inode and assign the unopened fid to the dentry */
>  	fid = p9_client_walk(dfid, 1, &name, 1);
> -	p9_client_clunk(dfid);
> +	p9_fid_put(dfid);
>  	if (IS_ERR(fid)) {
>  		err = PTR_ERR(fid);
>  		p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
> @@ -358,10 +358,10 @@ v9fs_vfs_atomic_open_dotl(struct inode *dir, struct
> dentry *dentry,
> 
>  error:
>  	if (fid)
> -		p9_client_clunk(fid);
> +		p9_fid_put(fid);
>  err_clunk_old_fid:
>  	if (ofid)
> -		p9_client_clunk(ofid);
> +		p9_fid_put(ofid);
>  	goto out;
>  }
> 
> @@ -458,9 +458,9 @@ static int v9fs_vfs_mkdir_dotl(struct user_namespace
> *mnt_userns, v9fs_invalidate_inode_attr(dir);
>  error:
>  	if (fid)
> -		p9_client_clunk(fid);
> +		p9_fid_put(fid);
>  	v9fs_put_acl(dacl, pacl);
> -	p9_client_clunk(dfid);
> +	p9_fid_put(dfid);
>  	return err;
>  }
> 
> @@ -489,7 +489,7 @@ v9fs_vfs_getattr_dotl(struct user_namespace *mnt_userns,
> */
> 
>  	st = p9_client_getattr_dotl(fid, P9_STATS_ALL);
> -	p9_client_clunk(fid);
> +	p9_fid_put(fid);
>  	if (IS_ERR(st))
>  		return PTR_ERR(st);
> 
> @@ -603,7 +603,7 @@ int v9fs_vfs_setattr_dotl(struct user_namespace
> *mnt_userns, retval = p9_client_setattr(fid, &p9attr);
>  	if (retval < 0) {
>  		if (use_dentry)
> -			p9_client_clunk(fid);
> +			p9_fid_put(fid);
>  		return retval;
>  	}
> 
> @@ -619,12 +619,12 @@ int v9fs_vfs_setattr_dotl(struct user_namespace
> *mnt_userns, retval = v9fs_acl_chmod(inode, fid);
>  		if (retval < 0) {
>  			if (use_dentry)
> -				p9_client_clunk(fid);
> +				p9_fid_put(fid);
>  			return retval;
>  		}
>  	}
>  	if (use_dentry)
> -		p9_client_clunk(fid);
> +		p9_fid_put(fid);
> 
>  	return 0;
>  }
> @@ -771,9 +771,9 @@ v9fs_vfs_symlink_dotl(struct user_namespace *mnt_userns,
> struct inode *dir,
> 
>  error:
>  	if (fid)
> -		p9_client_clunk(fid);
> +		p9_fid_put(fid);
> 
> -	p9_client_clunk(dfid);
> +	p9_fid_put(dfid);
>  	return err;
>  }
> 
> @@ -803,14 +803,14 @@ v9fs_vfs_link_dotl(struct dentry *old_dentry, struct
> inode *dir,
> 
>  	oldfid = v9fs_fid_lookup(old_dentry);
>  	if (IS_ERR(oldfid)) {
> -		p9_client_clunk(dfid);
> +		p9_fid_put(dfid);
>  		return PTR_ERR(oldfid);
>  	}
> 
>  	err = p9_client_link(dfid, oldfid, dentry->d_name.name);
> 
> -	p9_client_clunk(dfid);
> -	p9_client_clunk(oldfid);
> +	p9_fid_put(dfid);
> +	p9_fid_put(oldfid);
>  	if (err < 0) {
>  		p9_debug(P9_DEBUG_VFS, "p9_client_link failed %d\n", err);
>  		return err;
> @@ -826,7 +826,7 @@ v9fs_vfs_link_dotl(struct dentry *old_dentry, struct
> inode *dir, return PTR_ERR(fid);
> 
>  		v9fs_refresh_inode_dotl(fid, d_inode(old_dentry));
> -		p9_client_clunk(fid);
> +		p9_fid_put(fid);
>  	}
>  	ihold(d_inode(old_dentry));
>  	d_instantiate(dentry, d_inode(old_dentry));
> @@ -924,9 +924,9 @@ v9fs_vfs_mknod_dotl(struct user_namespace *mnt_userns,
> struct inode *dir, }
>  error:
>  	if (fid)
> -		p9_client_clunk(fid);
> +		p9_fid_put(fid);
>  	v9fs_put_acl(dacl, pacl);
> -	p9_client_clunk(dfid);
> +	p9_fid_put(dfid);
> 
>  	return err;
>  }
> @@ -956,7 +956,7 @@ v9fs_vfs_get_link_dotl(struct dentry *dentry,
>  	if (IS_ERR(fid))
>  		return ERR_CAST(fid);
>  	retval = p9_client_readlink(fid, &target);
> -	p9_client_clunk(fid);
> +	p9_fid_put(fid);
>  	if (retval)
>  		return ERR_PTR(retval);
>  	set_delayed_call(done, kfree_link, target);
> diff --git a/fs/9p/vfs_super.c b/fs/9p/vfs_super.c
> index 97e23b4e6982..bf350fad9500 100644
> --- a/fs/9p/vfs_super.c
> +++ b/fs/9p/vfs_super.c
> @@ -190,7 +190,7 @@ static struct dentry *v9fs_mount(struct file_system_type
> *fs_type, int flags, return dget(sb->s_root);
> 
>  clunk_fid:
> -	p9_client_clunk(fid);
> +	p9_fid_put(fid);
>  	v9fs_session_close(v9ses);
>  free_session:
>  	kfree(v9ses);
> @@ -203,7 +203,7 @@ static struct dentry *v9fs_mount(struct file_system_type
> *fs_type, int flags, * attached the fid to dentry so it won't get clunked
>  	 * automatically.
>  	 */
> -	p9_client_clunk(fid);
> +	p9_fid_put(fid);
>  	deactivate_locked_super(sb);
>  	return ERR_PTR(retval);
>  }
> @@ -270,7 +270,7 @@ static int v9fs_statfs(struct dentry *dentry, struct
> kstatfs *buf) }
>  	res = simple_statfs(dentry, buf);
>  done:
> -	p9_client_clunk(fid);
> +	p9_fid_put(fid);
>  	return res;
>  }
> 
> diff --git a/fs/9p/xattr.c b/fs/9p/xattr.c
> index a824441b95a2..1f9298a4bd42 100644
> --- a/fs/9p/xattr.c
> +++ b/fs/9p/xattr.c
> @@ -44,7 +44,7 @@ ssize_t v9fs_fid_xattr_get(struct p9_fid *fid, const char
> *name, if (err)
>  			retval = err;
>  	}
> -	p9_client_clunk(attr_fid);
> +	p9_fid_put(attr_fid);
>  	return retval;
>  }
> 
> @@ -71,7 +71,7 @@ ssize_t v9fs_xattr_get(struct dentry *dentry, const char
> *name, if (IS_ERR(fid))
>  		return PTR_ERR(fid);
>  	ret = v9fs_fid_xattr_get(fid, name, buffer, buffer_size);
> -	p9_client_clunk(fid);
> +	p9_fid_put(fid);
> 
>  	return ret;
>  }
> @@ -98,7 +98,7 @@ int v9fs_xattr_set(struct dentry *dentry, const char
> *name, if (IS_ERR(fid))
>  		return PTR_ERR(fid);
>  	ret = v9fs_fid_xattr_set(fid, name, value, value_len, flags);
> -	p9_client_clunk(fid);
> +	p9_fid_put(fid);
>  	return ret;
>  }
> 
> @@ -128,7 +128,7 @@ int v9fs_fid_xattr_set(struct p9_fid *fid, const char
> *name, retval);
>  	else
>  		p9_client_write(fid, 0, &from, &retval);
> -	err = p9_client_clunk(fid);
> +	err = p9_fid_put(fid);
>  	if (!retval && err)
>  		retval = err;
>  	return retval;
> diff --git a/include/net/9p/client.h b/include/net/9p/client.h
> index ec1d1706f43c..9fd38d674057 100644
> --- a/include/net/9p/client.h
> +++ b/include/net/9p/client.h
> @@ -237,6 +237,24 @@ static inline int p9_req_try_get(struct p9_req_t *r)
> 
>  int p9_req_put(struct p9_req_t *r);
> 
> +static inline struct p9_fid *p9_fid_get(struct p9_fid *fid)
> +{

Isn't this missing a check here?

    if (!fid)
        return NULL;

> +	refcount_inc(&fid->count);
> +
> +	return fid;
> +}
> +
> +static inline int p9_fid_put(struct p9_fid *fid)
> +{
> +	if (!fid || IS_ERR(fid))
> +		return 0;
> +
> +	if (!refcount_dec_and_test(&fid->count))
> +		return 0;
> +
> +	return p9_client_clunk(fid);
> +}
> +

I don't know the common symbol name patterns in the Linux kernel for acquiring
and releasing counted references are (if there is a common one at all), but I
think those two functions deserve a short API comment to make it clear they
belong together, i.e. that a p9_fid_get() call should be paired with
subsequent p9_fid_put(). It's maybe just nitpicking, as the code is quite
short and probably already speaks for itself.

On the long-term I could imagine using automated, destructor based
p9_fid_put() calls when leaving a block/function scope. That would simplify
code a load and avoid leaks in future.

>  void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status);
> 
>  int p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type,
> diff --git a/net/9p/client.c b/net/9p/client.c
> index 8bba0d9cf975..f3eb280c7d9d 100644
> --- a/net/9p/client.c
> +++ b/net/9p/client.c
> @@ -1228,7 +1228,7 @@ struct p9_fid *p9_client_walk(struct p9_fid *oldfid,
> uint16_t nwname,
> 
>  clunk_fid:
>  	kfree(wqids);
> -	p9_client_clunk(fid);
> +	p9_fid_put(fid);
>  	fid = NULL;
> 
>  error:
> @@ -1459,15 +1459,6 @@ int p9_client_clunk(struct p9_fid *fid)
>  	struct p9_req_t *req;
>  	int retries = 0;
> 
> -	if (!fid || IS_ERR(fid)) {
> -		pr_warn("%s (%d): Trying to clunk with invalid fid\n",
> -			__func__, task_pid_nr(current));
> -		dump_stack();
> -		return 0;
> -	}
> -	if (!refcount_dec_and_test(&fid->count))
> -		return 0;
> -
>  again:
>  	p9_debug(P9_DEBUG_9P, ">>> TCLUNK fid %d (try %d)\n",
>  		 fid->fid, retries);
> @@ -1519,7 +1510,7 @@ int p9_client_remove(struct p9_fid *fid)
>  	p9_tag_remove(clnt, req);
>  error:
>  	if (err == -ERESTARTSYS)
> -		p9_client_clunk(fid);
> +		p9_fid_put(fid);
>  	else
>  		p9_fid_destroy(fid);
>  	return err;
> @@ -2042,7 +2033,7 @@ struct p9_fid *p9_client_xattrwalk(struct p9_fid
> *file_fid, attr_fid->fid, *attr_size);
>  	return attr_fid;
>  clunk_fid:
> -	p9_client_clunk(attr_fid);
> +	p9_fid_put(attr_fid);
>  	attr_fid = NULL;
>  error:
>  	if (attr_fid && attr_fid != file_fid)





  parent reply	other threads:[~2022-06-14 13:56 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-06-12  8:53 [PATCH 00/06] fid refcounting improvements and fixes Dominique Martinet
2022-06-12  8:53 ` [PATCH 01/06] 9p: fix fid refcount leak in v9fs_vfs_atomic_open_dotl Dominique Martinet
2022-06-13 16:27   ` Tyler Hicks
2022-06-14 13:17   ` Christian Schoenebeck
2022-06-12  8:53 ` [PATCH 02/06] 9p: fix fid refcount leak in v9fs_vfs_get_link Dominique Martinet
2022-06-13 16:29   ` Tyler Hicks
2022-06-14 13:19   ` Christian Schoenebeck
2022-06-12  8:53 ` [PATCH 03/06] 9p: v9fs_fid_lookup_with_uid fix's fix suggestion Dominique Martinet
2022-06-13 20:08   ` Tyler Hicks
2022-06-12  8:53 ` [PATCH 04/06] 9p fid refcount: add p9_fid_get/put wrappers Dominique Martinet
2022-06-12 23:45   ` [PATCH v2 " Dominique Martinet
2022-06-13 17:31     ` Tyler Hicks
2022-06-14 13:55     ` Christian Schoenebeck [this message]
2022-06-14 14:27       ` Dominique Martinet
2022-06-15  3:16       ` [PATCH v3 " Dominique Martinet
2022-06-15 13:00         ` Christian Schoenebeck
2022-06-15 13:47           ` Dominique Martinet
2022-06-12  8:53 ` [PATCH 05/06] 9p fid refcount: add a 9p_fid_ref tracepoint Dominique Martinet
2022-06-12 22:46   ` Steven Rostedt
2022-06-12 23:46     ` [PATCH v2 " Dominique Martinet
2022-06-13  7:00       ` Dominique Martinet
2022-06-12  8:53 ` [PATCH 06/06] 9p fid refcount: cleanup p9_fid_put calls Dominique Martinet
2022-06-13 17:55   ` Tyler Hicks
2022-06-13 19:50     ` Dominique Martinet
2022-06-13 20:12       ` Tyler Hicks
2022-06-13 20:20 ` [PATCH 00/06] fid refcounting improvements and fixes Tyler Hicks
2022-06-13 21:00   ` Dominique Martinet
2022-06-14  1:14     ` Tyler Hicks

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=7044959.MN0D2SvuAq@silver \
    --to=linux_oss@crudebyte.com \
    --cc=asmadeus@codewreck.org \
    --cc=davem@davemloft.net \
    --cc=ericvh@gmail.com \
    --cc=kuba@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=lucho@ionkov.net \
    --cc=netdev@vger.kernel.org \
    --cc=pabeni@redhat.com \
    --cc=tyhicks@linux.microsoft.com \
    --cc=v9fs-developer@lists.sourceforge.net \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.