2021-12-08 15:31:01

by Steven Rostedt

Subject: [PATCH] tracefs: Use d_inode() helper function to get the dentry inode

From: "Steven Rostedt (VMware)" <[email protected]>

Instead of referencing the inode from a dentry via dentry->d_inode, use
the helper function d_inode(dentry) instead. This is the considered the
correct way to access it.

Reported-by: Christian Brauner <[email protected]>
Reported: https://lore.kernel.org/all/20211208104454.nhxyvmmn6d2qhpwl@wittgenstein/
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
---
fs/tracefs/inode.c | 24 ++++++++++++------------
1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c
index 925a621b432e..9899c6078c95 100644
--- a/fs/tracefs/inode.c
+++ b/fs/tracefs/inode.c
@@ -109,12 +109,12 @@ static int tracefs_syscall_rmdir(struct inode *inode, struct dentry *dentry)
* also the directory that is being deleted.
*/
inode_unlock(inode);
- inode_unlock(dentry->d_inode);
+ inode_unlock(d_inode(dentry));

ret = tracefs_ops.rmdir(name);

inode_lock_nested(inode, I_MUTEX_PARENT);
- inode_lock(dentry->d_inode);
+ inode_lock(d_inode(dentry));

kfree(name);

@@ -212,7 +212,7 @@ static int tracefs_parse_options(char *data, struct tracefs_mount_opts *opts)
static int tracefs_apply_options(struct super_block *sb)
{
struct tracefs_fs_info *fsi = sb->s_fs_info;
- struct inode *inode = sb->s_root->d_inode;
+ struct inode *inode = d_inode(sb->s_root);
struct tracefs_mount_opts *opts = &fsi->mount_opts;

inode->i_mode &= ~S_IALLUGO;
@@ -331,18 +331,18 @@ static struct dentry *start_creating(const char *name, struct dentry *parent)
if (!parent)
parent = tracefs_mount->mnt_root;

- inode_lock(parent->d_inode);
- if (unlikely(IS_DEADDIR(parent->d_inode)))
+ inode_lock(d_inode(parent));
+ if (unlikely(IS_DEADDIR(d_inode(parent))))
dentry = ERR_PTR(-ENOENT);
else
dentry = lookup_one_len(name, parent, strlen(name));
- if (!IS_ERR(dentry) && dentry->d_inode) {
+ if (!IS_ERR(dentry) && d_inode(dentry)) {
dput(dentry);
dentry = ERR_PTR(-EEXIST);
}

if (IS_ERR(dentry)) {
- inode_unlock(parent->d_inode);
+ inode_unlock(d_inode(parent));
simple_release_fs(&tracefs_mount, &tracefs_mount_count);
}

@@ -351,7 +351,7 @@ static struct dentry *start_creating(const char *name, struct dentry *parent)

static struct dentry *failed_creating(struct dentry *dentry)
{
- inode_unlock(dentry->d_parent->d_inode);
+ inode_unlock(d_inode(dentry->d_parent));
dput(dentry);
simple_release_fs(&tracefs_mount, &tracefs_mount_count);
return NULL;
@@ -359,7 +359,7 @@ static struct dentry *failed_creating(struct dentry *dentry)

static struct dentry *end_creating(struct dentry *dentry)
{
- inode_unlock(dentry->d_parent->d_inode);
+ inode_unlock(d_inode(dentry->d_parent));
return dentry;
}

@@ -415,7 +415,7 @@ struct dentry *tracefs_create_file(const char *name, umode_t mode,
inode->i_fop = fops ? fops : &tracefs_file_operations;
inode->i_private = data;
d_instantiate(dentry, inode);
- fsnotify_create(dentry->d_parent->d_inode, dentry);
+ fsnotify_create(d_inode(dentry->d_parent), dentry);
return end_creating(dentry);
}

@@ -440,8 +440,8 @@ static struct dentry *__create_dir(const char *name, struct dentry *parent,
/* directory inodes start off with i_nlink == 2 (for "." entry) */
inc_nlink(inode);
d_instantiate(dentry, inode);
- inc_nlink(dentry->d_parent->d_inode);
- fsnotify_mkdir(dentry->d_parent->d_inode, dentry);
+ inc_nlink(d_inode(dentry->d_parent));
+ fsnotify_mkdir(d_inode(dentry->d_parent), dentry);
return end_creating(dentry);
}

--
2.31.1

2021-12-08 15:33:22

by Christian Brauner

Subject: Re: [PATCH] tracefs: Use d_inode() helper function to get the dentry inode

On Wed, Dec 08, 2021 at 10:30:52AM -0500, Steven Rostedt wrote:
> From: "Steven Rostedt (VMware)" <[email protected]>
>
> Instead of referencing the inode from a dentry via dentry->d_inode, use
> the helper function d_inode(dentry) instead. This is the considered the
> correct way to access it.
>
> Reported-by: Christian Brauner <[email protected]>
> Reported: https://lore.kernel.org/all/20211208104454.nhxyvmmn6d2qhpwl@wittgenstein/
> Signed-off-by: Steven Rostedt (VMware) <[email protected]>
> ---

It's honestly not that big of a deal but yeah, looks good! :)
Acked-by: Christian Brauner <[email protected]>

2021-12-08 15:41:55

by Steven Rostedt

Subject: Re: [PATCH] tracefs: Use d_inode() helper function to get the dentry inode

On Wed, 8 Dec 2021 16:33:09 +0100
Christian Brauner <[email protected]> wrote:

> It's honestly not that big of a deal but yeah, looks good! :)

That's why I didn't add a Fixes tag ;-)

> Acked-by: Christian Brauner <[email protected]>

Thanks!

-- Steve