linux/ipc/mqueue.c, branch v2.6.30

namespaces: mqueue namespace: adapt sysctl

2009-04-07T15:31:09Z

Largely inspired from ipc/ipc_sysctl.c. This patch isolates the mqueue sysctl stuff in its own file. [akpm@linux-foundation.org: build fix] Signed-off-by: Cedric Le Goater Signed-off-by: Nadia Derbey Signed-off-by: Serge E. Hallyn Cc: Alexey Dobriyan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

namespaces: ipc namespaces: implement support for posix msqueues

2009-04-07T15:31:09Z

Implement multiple mounts of the mqueue file system, and link it to usage of CLONE_NEWIPC. Each ipc ns has a corresponding mqueuefs superblock. When a user does clone(CLONE_NEWIPC) or unshare(CLONE_NEWIPC), the unshare will cause an internal mount of a new mqueuefs sb linked to the new ipc ns. When a user does 'mount -t mqueue mqueue /dev/mqueue', he mounts the mqueuefs superblock. Posix message queues can be worked with both through the mq_* system calls (see mq_overview(7)), and through the VFS through the mqueue mount. Any usage of mq_open() and friends will work with the acting task's ipc namespace. Any actions through the VFS will work with the mqueuefs in which the file was created. So if a user doesn't remount mqueuefs after unshare(CLONE_NEWIPC), mq_open("/ab") will not be reflected in "ls /dev/mqueue". If task a mounts mqueue for ipc_ns:1, then clones task b with a new ipcns, ipcns:2, and then task a is the last task in ipc_ns:1 to exit, then (1) ipc_ns:1 will be freed, (2) it's superblock will live on until task b umounts the corresponding mqueuefs, and vfs actions will continue to succeed, but (3) sb->s_fs_info will be NULL for the sb corresponding to the deceased ipc_ns:1. To make this happen, we must protect the ipc reference count when a) a task exits and drops its ipcns->count, since it might be dropping it to 0 and freeing the ipcns b) a task accesses the ipcns through its mqueuefs interface, since it bumps the ipcns refcount and might race with the last task in the ipcns exiting. So the kref is changed to an atomic_t so we can use atomic_dec_and_lock(&ns->count,mq_lock), and every access to the ipcns through ns = mqueuefs_sb->s_fs_info is protected by the same lock. Signed-off-by: Cedric Le Goater Signed-off-by: Serge E. Hallyn Cc: Alexey Dobriyan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

namespaces: mqueue ns: move mqueue_mnt into struct ipc_namespace

2009-04-07T15:31:09Z

Move mqueue vfsmount plus a few tunables into the ipc_namespace struct. The CONFIG_IPC_NS boolean and the ipc_namespace struct will serve both the posix message queue namespaces and the SYSV ipc namespaces. The sysctl code will be fixed separately in patch 3. After just this patch, making a change to posix mqueue tunables always changes the values in the initial ipc namespace. Signed-off-by: Cedric Le Goater Signed-off-by: Serge E. Hallyn Cc: Alexey Dobriyan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

New helper - current_umask()

2009-04-01T03:00:26Z

current->fs->umask is what most of fs_struct users are doing. Put that into a helper function. Signed-off-by: Al Viro

Use f_lock to protect f_flags

2009-03-16T14:32:27Z

Traditionally, changes to struct file->f_flags have been done under BKL protection, or with no protection at all. This patch causes all f_flags changes after file open/creation time to be done under protection of f_lock. This allows the removal of some BKL usage and fixes a number of longstanding (if microscopic) races. Reviewed-by: Christoph Hellwig Cc: Al Viro Signed-off-by: Jonathan Corbet

[CVE-2009-0029] System call wrappers part 26

2009-01-14T13:15:29Z

Signed-off-by: Heiko Carstens

[CVE-2009-0029] System call wrappers part 25

2009-01-14T13:15:28Z

Signed-off-by: Heiko Carstens

[CVE-2009-0029] Convert all system calls to return a long

2009-01-14T13:15:14Z

Convert all system calls to return a long. This should be a NOP since all converted types should have the same size anyway. With the exception of sys_exit_group which returned void. But that doesn't matter since the system call doesn't return. Signed-off-by: Heiko Carstens

mqueue: fix si_pid value in mqueue do_notify()

2009-01-08T16:31:12Z

If a process registers for asynchronous notification on a POSIX message queue, it gets a signal and a siginfo_t structure when a message arrives on the message queue. The si_pid in the siginfo_t structure is set to the PID of the process that sent the message to the message queue. The principle is the following: . when mq_notify(SIGEV_SIGNAL) is called, the caller registers for notification when a msg arrives. The associated pid structure is stroed into inode_info->notify_owner. Let's call this process P1. . when mq_send() is called by say P2, P2 sends a signal to P1 to notify him about msg arrival. The way .si_pid is set today is not correct, since it doesn't take into account the fact that the process that is sending the message might not be in the same namespace as the notified one. This patch proposes to set si_pid to the sender's pid into the notify_owner namespace. Signed-off-by: Nadia Derbey Signed-off-by: Sukadev Bhattiprolu Acked-by: Oleg Nesterov Cc: Roland McGrath Cc: Bastian Blank Cc: Pavel Emelyanov Cc: Eric W. Biederman Acked-by: Serge Hallyn Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6

2009-01-06T02:32:06Z

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: inotify: fix type errors in interfaces fix breakage in reiserfs_new_inode() fix the treatment of jfs special inodes vfs: remove duplicate code in get_fs_type() add a vfs_fsync helper sys_execve and sys_uselib do not call into fsnotify zero i_uid/i_gid on inode allocation inode->i_op is never NULL ntfs: don't NULL i_op isofs check for NULL ->i_op in root directory is dead code affs: do not zero ->i_op kill suid bit only for regular files vfs: lseek(fd, 0, SEEK_CUR) race condition