pm24.git/kernel/exit.c, branch v3.7-rc3

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

2012-10-03T03:25:04Z

Pull vfs update from Al Viro: - big one - consolidation of descriptor-related logics; almost all of that is moved to fs/file.c (BTW, I'm seriously tempted to rename the result to fd.c. As it is, we have a situation when file_table.c is about handling of struct file and file.c is about handling of descriptor tables; the reasons are historical - file_table.c used to be about a static array of struct file we used to have way back). A lot of stray ends got cleaned up and converted to saner primitives, disgusting mess in android/binder.c is still disgusting, but at least doesn't poke so much in descriptor table guts anymore. A bunch of relatively minor races got fixed in process, plus an ext4 struct file leak. - related thing - fget_light() partially unuglified; see fdget() in there (and yes, it generates the code as good as we used to have). - also related - bits of Cyrill's procfs stuff that got entangled into that work; _not_ all of it, just the initial move to fs/proc/fd.c and switch of fdinfo to seq_file. - Alex's fs/coredump.c spiltoff - the same story, had been easier to take that commit than mess with conflicts. The rest is a separate pile, this was just a mechanical code movement. - a few misc patches all over the place. Not all for this cycle, there'll be more (and quite a few currently sit in akpm's tree)." Fix up trivial conflicts in the android binder driver, and some fairly simple conflicts due to two different changes to the sock_alloc_file() interface ("take descriptor handling from sock_alloc_file() to callers" vs "net: Providing protocol type via system.sockprotoname xattr of /proc/PID/fd entries" adding a dentry name to the socket) * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (72 commits) MAX_LFS_FILESIZE should be a loff_t compat: fs: Generic compat_sys_sendfile implementation fs: push rcu_barrier() from deactivate_locked_super() to filesystems btrfs: reada_extent doesn't need kref for refcount coredump: move core dump functionality into its own file coredump: prevent double-free on an error path in core dumper usb/gadget: fix misannotations fcntl: fix misannotations ceph: don't abuse d_delete() on failure exits hypfs: ->d_parent is never NULL or negative vfs: delete surplus inode NULL check switch simple cases of fget_light to fdget new helpers: fdget()/fdput() switch o2hb_region_dev_write() to fget_light() proc_map_files_readdir(): don't bother with grabbing files make get_file() return its argument vhost_set_vring(): turn pollstart/pollstop into bool switch prctl_set_mm_exe_file() to fget_light() switch xfs_find_handle() to fget_light() switch xfs_swapext() to fget_light() ...

new helper: daemonize_descriptors()

2012-09-27T01:10:00Z

descriptor-related parts of daemonize, done right. As the result we simplify the locking rules for ->files - we hold task_lock in *all* cases when we modify ->files. Signed-off-by: Al Viro

move files_struct-related bits from kernel/exit.c to fs/file.c

2012-09-27T01:08:54Z

Signed-off-by: Al Viro

net: use a per task frag allocator

2012-09-24T20:31:37Z

We currently use a per socket order-0 page cache for tcp_sendmsg() operations. This page is used to build fragments for skbs. Its done to increase probability of coalescing small write() into single segments in skbs still in write queue (not yet sent) But it wastes a lot of memory for applications handling many mostly idle sockets, since each socket holds one page in sk->sk_sndmsg_page Its also quite inefficient to build TSO 64KB packets, because we need about 16 pages per skb on arches where PAGE_SIZE = 4096, so we hit page allocator more than wanted. This patch adds a per task frag allocator and uses bigger pages, if available. An automatic fallback is done in case of memory pressure. (up to 32768 bytes per frag, thats order-3 pages on x86) This increases TCP stream performance by 20% on loopback device, but also benefits on other network devices, since 8x less frags are mapped on transmit and unmapped on tx completion. Alexander Duyck mentioned a probable performance win on systems with IOMMU enabled. Its possible some SG enabled hardware cant cope with bigger fragments, but their ndo_start_xmit() should already handle this, splitting a fragment in sub fragments, since some arches have PAGE_SIZE=65536 Successfully tested on various ethernet devices. (ixgbe, igb, bnx2x, tg3, mellanox mlx4) Signed-off-by: Eric Dumazet Cc: Ben Hutchings Cc: Vijay Subramanian Cc: Alexander Duyck Tested-by: Vijay Subramanian Signed-off-by: David S. Miller

posix_types.h: Cleanup stale __NFDBITS and related definitions

2012-07-26T20:36:43Z

Recently, glibc made a change to suppress sign-conversion warnings in FD_SET (glibc commit ceb9e56b3d1). This uncovered an issue with the kernel's definition of __NFDBITS if applications #include after including . A build failure would be seen when passing the -Werror=sign-compare and -D_FORTIFY_SOURCE=2 flags to gcc. It was suggested that the kernel should either match the glibc definition of __NFDBITS or remove that entirely. The current in-kernel uses of __NFDBITS can be replaced with BITS_PER_LONG, and there are no uses of the related __FDELT and __FDMASK defines. Given that, we'll continue the cleanup that was started with commit 8b3d1cda4f5f ("posix_types: Remove fd_set macros") and drop the remaining unused macros. Additionally, linux/time.h has similar macros defined that expand to nothing so we'll remove those at the same time. Reported-by: Jeff Law Suggested-by: Linus Torvalds CC: Signed-off-by: Josh Boyer [ .. and fix up whitespace as per akpm ] Signed-off-by: Linus Torvalds

move exit_task_work() past exit_files() et.al.

2012-07-22T19:57:57Z

... and get rid of PF_EXITING check in task_work_add(). Signed-off-by: Al Viro

pidns: find_new_reaper() can no longer switch to init_pid_ns.child_reaper

2012-06-20T21:39:36Z

find_new_reaper() changes pid_ns->child_reaper, see add0d4df ("pid_ns: zap_pid_ns_processes: fix the ->child_reaper changing"). The original reason has gone away after the previous patch, ->children list must be empty after zap_pid_ns_processes(). However now we can not switch to init_pid_ns.child_reaper. __unhash_process() relies on the "->child_reaper == parent" check, but this check does not work if the last exiting task is also the child reaper. As Eric sugested, we can change __unhash_process() to use the parent's pid_ns and remove this code. Also, with this change we can move detach_pid(PIDTYPE_PID) back, where it was before the previous fix. Signed-off-by: Oleg Nesterov Acked-by: "Eric W. Biederman" Cc: Louis Rilling Cc: Mike Galbraith Acked-by: Pavel Emelyanov Tested-by: Andrew Wagin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

pidns: guarantee that the pidns init will be the last pidns process reaped

2012-06-20T21:39:36Z

Today we have a twofold bug. Sometimes release_task on pid == 1 in a pid namespace can run before other processes in a pid namespace have had release task called. With the result that pid_ns_release_proc can be called before the last proc_flus_task() is done using upid->ns->proc_mnt, resulting in the use of a stale pointer. This same set of circumstances can lead to waitpid(...) returning for a processes started with clone(CLONE_NEWPID) before the every process in the pid namespace has actually exited. To fix this modify zap_pid_ns_processess wait until all other processes in the pid namespace have exited, even EXIT_DEAD zombies. The delay_group_leader and related tests ensure that the thread gruop leader will be the last thread of a process group to be reaped, or to become EXIT_DEAD and self reap. With the change to zap_pid_ns_processes we get the guarantee that pid == 1 in a pid namespace will be the last task that release_task is called on. With pid == 1 being the last task to pass through release_task pid_ns_release_proc can no longer be called too early nor can wait return before all of the EXIT_DEAD tasks in a pid namespace have exited. Signed-off-by: Eric W. Biederman Signed-off-by: Oleg Nesterov Cc: Louis Rilling Cc: Mike Galbraith Acked-by: Pavel Emelyanov Tested-by: Andrew Wagin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: correctly synchronize rss-counters at exit/exec

2012-06-20T21:39:36Z

do_exit() and exec_mmap() call sync_mm_rss() before mm_release() does put_user(clear_child_tid) which can update task->rss_stat and thus make mm->rss_stat inconsistent. This triggers the "BUG:" printk in check_mm(). Let's fix this bug in the safest way, and optimize/cleanup this later. Reported-by: Markus Trippelsdorf Signed-off-by: Konstantin Khlebnikov Cc: Oleg Nesterov Cc: KAMEZAWA Hiroyuki Cc: Hugh Dickins Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Revert "mm: correctly synchronize rss-counters at exit/exec"

2012-06-08T00:54:07Z

This reverts commit 40af1bbdca47e5c8a2044039bb78ca8fd8b20f94. It's horribly and utterly broken for at least the following reasons: - calling sync_mm_rss() from mmput() is fundamentally wrong, because there's absolutely no reason to believe that the task that does the mmput() always does it on its own VM. Example: fork, ptrace, /proc - you name it. - calling it *after* having done mmdrop() on it is doubly insane, since the mm struct may well be gone now. - testing mm against NULL before you call it is insane too, since a NULL mm there would have caused oopses long before. .. and those are just the three bugs I found before I decided to give up looking for me and revert it asap. I should have caught it before I even took it, but I trusted Andrew too much. Cc: Konstantin Khlebnikov Cc: Markus Trippelsdorf Cc: Hugh Dickins Cc: KAMEZAWA Hiroyuki Cc: Oleg Nesterov Cc: Andrew Morton Signed-off-by: Linus Torvalds