Create a new helper out of the code in chrdev_open() which looks up a struct cdev from a struct inode.
This will be necessary to create a cdev_get_by_path() which is similar to blkdev_get_by_path() and is required to allow NVMe-OF passthru to lookup an NVMe controller cdev from a path. Signed-off-by: Logan Gunthorpe <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> Cc: Alexander Viro <[email protected]> --- fs/char_dev.c | 26 +++++++++++++++++++------- 1 file changed, 19 insertions(+), 7 deletions(-) diff --git a/fs/char_dev.c b/fs/char_dev.c index 00dfe17871ac..5cc53bd5f654 100644 --- a/fs/char_dev.c +++ b/fs/char_dev.c @@ -367,12 +367,8 @@ void cdev_put(struct cdev *p) } } -/* - * Called every time a character special file is opened - */ -static int chrdev_open(struct inode *inode, struct file *filp) +static struct cdev *cdev_lookup(struct inode *inode) { - const struct file_operations *fops; struct cdev *p; struct cdev *new = NULL; int ret = 0; @@ -385,7 +381,7 @@ static int chrdev_open(struct inode *inode, struct file *filp) spin_unlock(&cdev_lock); kobj = kobj_lookup(cdev_map, inode->i_rdev, &idx); if (!kobj) - return -ENXIO; + return ERR_PTR(-ENXIO); new = container_of(kobj, struct cdev, kobj); spin_lock(&cdev_lock); /* Check i_cdev again in case somebody beat us to it while @@ -402,7 +398,23 @@ static int chrdev_open(struct inode *inode, struct file *filp) spin_unlock(&cdev_lock); cdev_put(new); if (ret) - return ret; + return ERR_PTR(ret); + + return p; +} + +/* + * Called every time a character special file is opened + */ +static int chrdev_open(struct inode *inode, struct file *filp) +{ + const struct file_operations *fops; + struct cdev *p; + int ret = 0; + + p = cdev_lookup(inode); + if (IS_ERR(p)) + return PTR_ERR(p); ret = -ENXIO; fops = fops_get(p->ops); -- 2.20.1
