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| author |   Omar Sandoval <osandov@fb.com> | 2017-01-31 14:53:17 -0800 |
|---|---|---|
| committer |   Jens Axboe <axboe@fb.com> | 2017-02-02 10:20:16 -0700 |
| commit | a7c5437b0bbec5165df6eb1efc5e37dc40b9e05d (patch) | |
| tree | d37659f3ab5b8baccafe06442ca3fa6a1048503c /include/linux/debugfs.h | |
| parent | scsi, block: fix duplicate bdi name registration crashes (diff) | |
| download | wireguard-linux-a7c5437b0bbec5165df6eb1efc5e37dc40b9e05d.tar.xz wireguard-linux-a7c5437b0bbec5165df6eb1efc5e37dc40b9e05d.zip | |
debugfs: add debugfs_lookup()
We don't always have easy access to the dentry of a file or directory we
created in debugfs. Add a helper which allows us to get a dentry we
previously created.
The motivation for this change is a problem with blktrace and the blk-mq
debugfs entries introduced in 07e4fead45e6 ("blk-mq: create debugfs
directory tree"). Namely, in some cases, the directory that blktrace
needs to create may already exist, but in other cases, it may not. We
_could_ rely on a bunch of implied knowledge to decide whether to create
the directory or not, but it's much cleaner on our end to just look it
up.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'include/linux/debugfs.h')
| -rw-r--r-- | include/linux/debugfs.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/include/linux/debugfs.h b/include/linux/debugfs.h index 014cc564d1c4..c0befcf41b58 100644 --- a/include/linux/debugfs.h +++ b/include/linux/debugfs.h @@ -80,6 +80,8 @@ static const struct file_operations __fops = { \ #if defined(CONFIG_DEBUG_FS) +struct dentry *debugfs_lookup(const char *name, struct dentry *parent); + struct dentry *debugfs_create_file(const char *name, umode_t mode, struct dentry *parent, void *data, const struct file_operations *fops); @@ -181,6 +183,12 @@ ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf, * want to duplicate the design decision mistakes of procfs and devfs again. */ +static inline struct dentry *debugfs_lookup(const char *name, + struct dentry *parent) +{ + return ERR_PTR(-ENODEV); +} + static inline struct dentry *debugfs_create_file(const char *name, umode_t mode, struct dentry *parent, void *data, const struct file_operations *fops) |