From f97df70b1c879f764f88b25b0e67b03a5213968a Mon Sep 17 00:00:00 2001 From: Seth Forshee Date: Mon, 14 Nov 2016 11:12:56 +0000 Subject: [PATCH] xenfs: Use proc_create_mount_point() to create /proc/xen Mounting proc in user namespace containers fails if the xenbus filesystem is mounted on /proc/xen because this directory fails the "permanently empty" test. proc_create_mount_point() exists specifically to create such mountpoints in proc but is currently proc-internal. Export this interface to modules, then use it in xenbus when creating /proc/xen. Signed-off-by: Seth Forshee Signed-off-by: David Vrabel Signed-off-by: Juergen Gross --- drivers/xen/xenbus/xenbus_probe.c | 2 +- fs/proc/generic.c | 1 + fs/proc/internal.h | 1 - include/linux/proc_fs.h | 2 ++ 4 files changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c index 33a31cfef55d..b5c1dec4a7c2 100644 --- a/drivers/xen/xenbus/xenbus_probe.c +++ b/drivers/xen/xenbus/xenbus_probe.c @@ -826,7 +826,7 @@ static int __init xenbus_init(void) * Create xenfs mountpoint in /proc for compatibility with * utilities that expect to find "xenbus" under "/proc/xen". */ - proc_mkdir("xen", NULL); + proc_create_mount_point("xen"); #endif out_error: diff --git a/fs/proc/generic.c b/fs/proc/generic.c index 5f2dc2032c79..7eb3cefcf2a3 100644 --- a/fs/proc/generic.c +++ b/fs/proc/generic.c @@ -479,6 +479,7 @@ struct proc_dir_entry *proc_create_mount_point(const char *name) } return ent; } +EXPORT_SYMBOL(proc_create_mount_point); struct proc_dir_entry *proc_create_data(const char *name, umode_t mode, struct proc_dir_entry *parent, diff --git a/fs/proc/internal.h b/fs/proc/internal.h index 5378441ec1b7..7de679572111 100644 --- a/fs/proc/internal.h +++ b/fs/proc/internal.h @@ -195,7 +195,6 @@ static inline bool is_empty_pde(const struct proc_dir_entry *pde) { return S_ISDIR(pde->mode) && !pde->proc_iops; } -struct proc_dir_entry *proc_create_mount_point(const char *name); /* * inode.c diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h index b97bf2ef996e..8bd2f726436a 100644 --- a/include/linux/proc_fs.h +++ b/include/linux/proc_fs.h @@ -21,6 +21,7 @@ extern struct proc_dir_entry *proc_mkdir_data(const char *, umode_t, struct proc_dir_entry *, void *); extern struct proc_dir_entry *proc_mkdir_mode(const char *, umode_t, struct proc_dir_entry *); +struct proc_dir_entry *proc_create_mount_point(const char *name); extern struct proc_dir_entry *proc_create_data(const char *, umode_t, struct proc_dir_entry *, @@ -56,6 +57,7 @@ static inline struct proc_dir_entry *proc_symlink(const char *name, struct proc_dir_entry *parent,const char *dest) { return NULL;} static inline struct proc_dir_entry *proc_mkdir(const char *name, struct proc_dir_entry *parent) {return NULL;} +static inline struct proc_dir_entry *proc_create_mount_point(const char *name) { return NULL; } static inline struct proc_dir_entry *proc_mkdir_data(const char *name, umode_t mode, struct proc_dir_entry *parent, void *data) { return NULL; } static inline struct proc_dir_entry *proc_mkdir_mode(const char *name, -- 2.20.1