Commit ab1f1611 authored by Vitaliy Gusev's avatar Vitaliy Gusev Committed by J. Bruce Fields

pid-namespaces-vs-locks-interaction

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.
Signed-off-by: default avatarVitaliy Gusev <vgusev@openvz.org>
Acked-by: default avatarSerge Hallyn <serue@us.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarJ. Bruce Fields <bfields@citi.umich.edu>
parent 4321e01e
...@@ -125,6 +125,7 @@ ...@@ -125,6 +125,7 @@
#include <linux/syscalls.h> #include <linux/syscalls.h>
#include <linux/time.h> #include <linux/time.h>
#include <linux/rcupdate.h> #include <linux/rcupdate.h>
#include <linux/pid_namespace.h>
#include <asm/semaphore.h> #include <asm/semaphore.h>
#include <asm/uaccess.h> #include <asm/uaccess.h>
...@@ -185,6 +186,7 @@ void locks_init_lock(struct file_lock *fl) ...@@ -185,6 +186,7 @@ void locks_init_lock(struct file_lock *fl)
fl->fl_fasync = NULL; fl->fl_fasync = NULL;
fl->fl_owner = NULL; fl->fl_owner = NULL;
fl->fl_pid = 0; fl->fl_pid = 0;
fl->fl_nspid = NULL;
fl->fl_file = NULL; fl->fl_file = NULL;
fl->fl_flags = 0; fl->fl_flags = 0;
fl->fl_type = 0; fl->fl_type = 0;
...@@ -553,6 +555,8 @@ static void locks_insert_lock(struct file_lock **pos, struct file_lock *fl) ...@@ -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); list_add(&fl->fl_link, &file_lock_list);
fl->fl_nspid = get_pid(task_tgid(current));
/* insert into file's list */ /* insert into file's list */
fl->fl_next = *pos; fl->fl_next = *pos;
*pos = fl; *pos = fl;
...@@ -584,6 +588,11 @@ static void locks_delete_lock(struct file_lock **thisfl_p) ...@@ -584,6 +588,11 @@ static void locks_delete_lock(struct file_lock **thisfl_p)
if (fl->fl_ops && fl->fl_ops->fl_remove) if (fl->fl_ops && fl->fl_ops->fl_remove)
fl->fl_ops->fl_remove(fl); 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_wake_up_blocks(fl);
locks_free_lock(fl); locks_free_lock(fl);
} }
...@@ -646,14 +655,16 @@ posix_test_lock(struct file *filp, struct file_lock *fl) ...@@ -646,14 +655,16 @@ posix_test_lock(struct file *filp, struct file_lock *fl)
if (posix_locks_conflict(fl, cfl)) if (posix_locks_conflict(fl, cfl))
break; break;
} }
if (cfl) if (cfl) {
__locks_copy_lock(fl, 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; fl->fl_type = F_UNLCK;
unlock_kernel(); unlock_kernel();
return; return;
} }
EXPORT_SYMBOL(posix_test_lock); EXPORT_SYMBOL(posix_test_lock);
/* /*
...@@ -2070,6 +2081,12 @@ static void lock_get_status(struct seq_file *f, struct file_lock *fl, ...@@ -2070,6 +2081,12 @@ static void lock_get_status(struct seq_file *f, struct file_lock *fl,
int id, char *pfx) int id, char *pfx)
{ {
struct inode *inode = NULL; 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) if (fl->fl_file != NULL)
inode = fl->fl_file->f_path.dentry->d_inode; inode = fl->fl_file->f_path.dentry->d_inode;
...@@ -2110,16 +2127,16 @@ static void lock_get_status(struct seq_file *f, struct file_lock *fl, ...@@ -2110,16 +2127,16 @@ static void lock_get_status(struct seq_file *f, struct file_lock *fl,
} }
if (inode) { if (inode) {
#ifdef WE_CAN_BREAK_LSLK_NOW #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); inode->i_sb->s_id, inode->i_ino);
#else #else
/* userspace relies on this representation of dev_t ;-( */ /* 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), MAJOR(inode->i_sb->s_dev),
MINOR(inode->i_sb->s_dev), inode->i_ino); MINOR(inode->i_sb->s_dev), inode->i_ino);
#endif #endif
} else { } else {
seq_printf(f, "%d <none>:0 ", fl->fl_pid); seq_printf(f, "%d <none>:0 ", fl_pid);
} }
if (IS_POSIX(fl)) { if (IS_POSIX(fl)) {
if (fl->fl_end == OFFSET_MAX) if (fl->fl_end == OFFSET_MAX)
......
...@@ -872,6 +872,7 @@ struct file_lock { ...@@ -872,6 +872,7 @@ struct file_lock {
struct list_head fl_block; /* circular list of blocked processes */ struct list_head fl_block; /* circular list of blocked processes */
fl_owner_t fl_owner; fl_owner_t fl_owner;
unsigned int fl_pid; unsigned int fl_pid;
struct pid *fl_nspid;
wait_queue_head_t fl_wait; wait_queue_head_t fl_wait;
struct file *fl_file; struct file *fl_file;
unsigned char fl_flags; unsigned char fl_flags;
......
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