linux/ipc/util.c, branch v2.6.28

sysvipc: fix the ipc structures initialization

2008-11-20T02:49:57Z

A problem was found while reviewing the code after Bugzilla bug http://bugzilla.kernel.org/show_bug.cgi?id=11796. In ipc_addid(), the newly allocated ipc structure is inserted into the ipcs tree (i.e made visible to readers) without locking it. This is not correct since its initialization continues after it has been inserted in the tree. This patch moves the ipc structure lock initialization + locking before the actual insertion. Signed-off-by: Nadia Derbey Reported-by: Clement Calmels Cc: Manfred Spraul Cc: [2.6.27.x] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ipc: get rid of ipc_lock_down()

2008-07-25T17:53:42Z

Remove the ipc_lock_down() routines: they used to call idr_find() locklessly (given that the ipc ids lock was already held), so they are not needed anymore. Signed-off-by: Nadia Derbey Acked-by: "Paul E. McKenney" Cc: Manfred Spraul Cc: Jim Houston Cc: Pierre Peiffer Acked-by: Rik van Riel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ipc: call idr_find() without locking in ipc_lock()

2008-07-25T17:53:42Z

Call idr_find() locklessly from ipc_lock(), since the idr tree is now RCU protected. Signed-off-by: Nadia Derbey Acked-by: "Paul E. McKenney" Cc: Manfred Spraul Cc: Jim Houston Cc: Pierre Peiffer Acked-by: Rik van Riel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

sysvipc: use non-racy method for proc entries creation

2008-04-29T15:06:20Z

Use proc_create_data() to make sure that ->proc_fops and ->data be setup before gluing PDE to main tree. Signed-off-by: Denis V. Lunev Cc: Alexey Dobriyan Cc: "Eric W. Biederman" Cc: Nadia Derbey Cc: Pierre Peiffer Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ipc: add definitions of USHORT_MAX and others

2008-04-29T15:06:14Z

Add definitions of USHORT_MAX and others into kernel. ipc uses it and slub implementation might also use it. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Zhang Yanmin Reviewed-by: Christoph Lameter Cc: Nadia Derbey Cc: "Pierre Peiffer" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

IPC: consolidate all xxxctl_down() functions

2008-04-29T15:06:14Z

semctl_down(), msgctl_down() and shmctl_down() are used to handle the same set of commands for each kind of IPC. They all start to do the same job (they retrieve the ipc and do some permission checks) before handling the commands on their own. This patch proposes to consolidate this by moving these same pieces of code into one common function called ipcctl_pre_down(). It simplifies a little these xxxctl_down() functions and increases a little the maintainability. Signed-off-by: Pierre Peiffer Acked-by: Serge Hallyn Cc: Nadia Derbey Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

IPC: introduce ipc_update_perm()

2008-04-29T15:06:13Z

The IPC_SET command performs the same permission setting for all IPCs. This patch introduces a common ipc_update_perm() function to update these permissions and makes use of it for all IPCs. Signed-off-by: Pierre Peiffer Acked-by: Serge Hallyn Cc: Nadia Derbey Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ipc: invoke the ipcns notifier chain as a work item

2008-04-29T15:06:12Z

Make the memory hotplug chain's mutex held for a shorter time: when memory is offlined or onlined a work item is added to the global workqueue. When the work item is run, it notifies the ipcns notifier chain with the IPCNS_MEMCHANGED event. Signed-off-by: Nadia Derbey Cc: Yasunori Goto Cc: Matt Helsley Cc: Mingming Cao Cc: Pierre Peiffer Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ipc: recompute msgmni on memory add / remove

2008-04-29T15:06:12Z

Introduce the registration of a callback routine that recomputes msg_ctlmni upon memory add / remove. A single notifier block is registered in the hotplug memory chain for all the ipc namespaces. Since the ipc namespaces are not linked together, they have their own notification chain: one notifier_block is defined per ipc namespace. Each time an ipc namespace is created (removed) it registers (unregisters) its notifier block in (from) the ipcns chain. The callback routine registered in the memory chain invokes the ipcns notifier chain with the IPCNS_LOWMEM event. Each callback routine registered in the ipcns namespace, in turn, recomputes msgmni for the owning namespace. Signed-off-by: Nadia Derbey Cc: Yasunori Goto Cc: Matt Helsley Cc: Mingming Cao Cc: Pierre Peiffer Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ipc: scale msgmni to the number of ipc namespaces

2008-04-29T15:06:12Z

Since all the namespaces see the same amount of memory (the total one) this patch introduces a new variable that counts the ipc namespaces and divides msg_ctlmni by this counter. Signed-off-by: Nadia Derbey Cc: Yasunori Goto Cc: Matt Helsley Cc: Mingming Cao Cc: Pierre Peiffer Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds