Quoting Vitaliy Gusev (vgusev@xxxxxxxxxx):
> fcntl(F_GETLK,..) can return pid of process for not current pid namespace (if
> process is belonged to the several namespaces). It is true also for pids
> in /proc/locks. So correct behavior is saving pointer to the struct pid of
> the process lock owner.
>
> Assigned-off-by: Vitaliy Gusev <vgusev@xxxxxxxxxx>
> Acked-by: Serge Hallyn <serue@xxxxxxxxxx>
Thanks, Vitaliy.
-serge
> fs/locks.c | 26 +++++++++++++++++++++-----
> include/linux/fs.h | 3 ++-
> 2 files changed, 23 insertions(+), 6 deletions(-)
>
> diff --git a/fs/locks.c b/fs/locks.c
> index 8b8388e..14989fa 100644
> --- a/fs/locks.c
> +++ b/fs/locks.c
> @@ -125,6 +125,7 @@
> #include <linux/syscalls.h>
> #include <linux/time.h>
> #include <linux/rcupdate.h>
> +#include <linux/pid_namespace.h>
>
> #include <asm/semaphore.h>
> #include <asm/uaccess.h>
> @@ -185,6 +186,7 @@ void locks_init_lock(struct file_lock *fl)
> fl->fl_fasync = NULL;
> fl->fl_owner = NULL;
> fl->fl_pid = 0;
> + fl->fl_nspid = NULL;
> fl->fl_file = NULL;
> fl->fl_flags = 0;
> fl->fl_type = 0;
> @@ -553,6 +555,8 @@ static void locks_insert_lock(struct file_lock **pos, struct file_lock *fl)
> {
> list_add(&fl->fl_link, &file_lock_list);
>
> + fl->fl_nspid = get_pid(task_tgid(current));
> +
> /* insert into file's list */
> fl->fl_next = *pos;
> *pos = fl;
> @@ -584,6 +588,9 @@ static void locks_delete_lock(struct file_lock **thisfl_p)
> if (fl->fl_ops && fl->fl_ops->fl_remove)
> fl->fl_ops->fl_remove(fl);
>
> + put_pid(fl->fl_nspid);
> + fl->fl_nspid = NULL;
> +
> locks_wake_up_blocks(fl);
> locks_free_lock(fl);
> }
> @@ -673,9 +680,12 @@ posix_test_lock(struct file *filp, struct file_lock *fl)
> if (posix_locks_conflict(fl, cfl))
> break;
> }
> - if (cfl)
> + if (cfl) {
> __locks_copy_lock(fl, cfl);
> - else
> + if (cfl->fl_nspid)
> + fl->fl_pid = pid_nr_ns(cfl->fl_nspid,
> + task_active_pid_ns(current));
> + } else
> fl->fl_type = F_UNLCK;
> unlock_kernel();
> return;
> @@ -2084,6 +2094,12 @@ static void lock_get_status(struct seq_file *f, struct file_lock *fl,
> int id, char *pfx)
> {
> struct inode *inode = NULL;
> + unsigned int fl_pid;
> +
> + if (fl->fl_nspid)
> + fl_pid = pid_nr_ns(fl->fl_nspid, task_active_pid_ns(current));
> + else
> + fl_pid = fl->fl_pid;
>
> if (fl->fl_file != NULL)
> inode = fl->fl_file->f_path.dentry->d_inode;
> @@ -2124,16 +2140,16 @@ static void lock_get_status(struct seq_file *f, struct file_lock *fl,
> }
> if (inode) {
> #ifdef WE_CAN_BREAK_LSLK_NOW
> - seq_printf(f, "%d %s:%ld ", fl->fl_pid,
> + seq_printf(f, "%d %s:%ld ", fl_pid,
> inode->i_sb->s_id, inode->i_ino);
> #else
> /* userspace relies on this representation of dev_t ;-( */
> - seq_printf(f, "%d %02x:%02x:%ld ", fl->fl_pid,
> + seq_printf(f, "%d %02x:%02x:%ld ", fl_pid,
> MAJOR(inode->i_sb->s_dev),
> MINOR(inode->i_sb->s_dev), inode->i_ino);
> #endif
> } else {
> - seq_printf(f, "%d <none>:0 ", fl->fl_pid);
> + seq_printf(f, "%d <none>:0 ", fl_pid);
> }
> if (IS_POSIX(fl)) {
> if (fl->fl_end == OFFSET_MAX)
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index b3ec4a4..1fb952f 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -869,7 +869,8 @@ struct file_lock {
> struct list_head fl_link; /* doubly linked list of all locks */
> struct list_head fl_block; /* circular list of blocked processes */
> fl_owner_t fl_owner;
> - unsigned int fl_pid;
> + unsigned int fl_pid; /* unique id and sometimes global pid */
> + struct pid *fl_nspid; /* to calculate owner pid_nr for userspace */
> wait_queue_head_t fl_wait;
> struct file *fl_file;
> unsigned char fl_flags;
>
> diff --git a/fs/locks.c b/fs/locks.c
> index 8b8388e..d2d3d75 100644
> --- a/fs/locks.c
> +++ b/fs/locks.c
> @@ -125,6 +125,7 @@
> #include <linux/syscalls.h>
> #include <linux/time.h>
> #include <linux/rcupdate.h>
> +#include <linux/pid_namespace.h>
>
> #include <asm/semaphore.h>
> #include <asm/uaccess.h>
> @@ -185,6 +186,7 @@ void locks_init_lock(struct file_lock *fl)
> fl->fl_fasync = NULL;
> fl->fl_owner = NULL;
> fl->fl_pid = 0;
> + fl->fl_nspid = NULL;
> fl->fl_file = NULL;
> fl->fl_flags = 0;
> fl->fl_type = 0;
> @@ -553,6 +555,8 @@ static void locks_insert_lock(struct file_lock **pos, struct file_lock *fl)
> {
> list_add(&fl->fl_link, &file_lock_list);
>
> + fl->fl_nspid = get_pid(task_tgid(current));
> +
> /* insert into file's list */
> fl->fl_next = *pos;
> *pos = fl;
> @@ -584,6 +588,11 @@ static void locks_delete_lock(struct file_lock **thisfl_p)
> if (fl->fl_ops && fl->fl_ops->fl_remove)
> fl->fl_ops->fl_remove(fl);
>
> + if (fl->fl_nspid) {
> + put_pid(fl->fl_nspid);
> + fl->fl_nspid = NULL;
> + }
> +
> locks_wake_up_blocks(fl);
> locks_free_lock(fl);
> }
> @@ -673,14 +682,16 @@ posix_test_lock(struct file *filp, struct file_lock *fl)
> if (posix_locks_conflict(fl, cfl))
> break;
> }
> - if (cfl)
> + if (cfl) {
> __locks_copy_lock(fl, cfl);
> - else
> + if (cfl->fl_nspid)
> + fl->fl_pid = pid_nr_ns(cfl->fl_nspid,
> + task_active_pid_ns(current));
> + } else
> fl->fl_type = F_UNLCK;
> unlock_kernel();
> return;
> }
> -
> EXPORT_SYMBOL(posix_test_lock);
>
> /* This function tests for deadlock condition before putting a process to
> @@ -2084,6 +2095,12 @@ static void lock_get_status(struct seq_file *f, struct file_lock *fl,
> int id, char *pfx)
> {
> struct inode *inode = NULL;
> + unsigned int fl_pid;
> +
> + if (fl->fl_nspid)
> + fl_pid = pid_nr_ns(fl->fl_nspid, task_active_pid_ns(current));
> + else
> + fl_pid = fl->fl_pid;
>
> if (fl->fl_file != NULL)
> inode = fl->fl_file->f_path.dentry->d_inode;
> @@ -2124,16 +2141,16 @@ static void lock_get_status(struct seq_file *f, struct file_lock *fl,
> }
> if (inode) {
> #ifdef WE_CAN_BREAK_LSLK_NOW
> - seq_printf(f, "%d %s:%ld ", fl->fl_pid,
> + seq_printf(f, "%d %s:%ld ", fl_pid,
> inode->i_sb->s_id, inode->i_ino);
> #else
> /* userspace relies on this representation of dev_t ;-( */
> - seq_printf(f, "%d %02x:%02x:%ld ", fl->fl_pid,
> + seq_printf(f, "%d %02x:%02x:%ld ", fl_pid,
> MAJOR(inode->i_sb->s_dev),
> MINOR(inode->i_sb->s_dev), inode->i_ino);
> #endif
> } else {
> - seq_printf(f, "%d <none>:0 ", fl->fl_pid);
> + seq_printf(f, "%d <none>:0 ", fl_pid);
> }
> if (IS_POSIX(fl)) {
> if (fl->fl_end == OFFSET_MAX)
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index b3ec4a4..5876f68 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -870,6 +870,7 @@ struct file_lock {
> struct list_head fl_block; /* circular list of blocked processes */
> fl_owner_t fl_owner;
> unsigned int fl_pid;
> + struct pid *fl_nspid;
> wait_queue_head_t fl_wait;
> struct file *fl_file;
> unsigned char fl_flags;
-
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