From: Vitaliy Gusev Date: Thu, 17 Jan 2008 00:07:08 +0000 (+0000) Subject: pid-namespaces-vs-locks-interaction X-Git-Tag: v2.6.25-rc1~1060^2 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ab1f16116527e42dec8aee176d673a41a881b809;p=linux-2.6 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: Vitaliy Gusev Acked-by: Serge Hallyn Cc: "Eric W. Biederman" Signed-off-by: Andrew Morton Signed-off-by: J. Bruce Fields --- diff --git a/fs/locks.c b/fs/locks.c index faddccb633..49354b9c7d 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -125,6 +125,7 @@ #include #include #include +#include #include #include @@ -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); } @@ -646,14 +655,16 @@ 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); /* @@ -2070,6 +2081,12 @@ 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; @@ -2110,16 +2127,16 @@ 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 :0 ", fl->fl_pid); + seq_printf(f, "%d :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 a516b67168..b7736ab8bb 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -872,6 +872,7 @@ 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;