Al Viro [Sun, 29 Apr 2012 08:11:34 +0000 (04:11 -0400)]
microblaze: fix the horror with restarts of sigreturn()
solution a-la arm one - pick a callee-saved register (r30), set it
non-zero when entering a syscall, have sigreturn wrapper zero it out
and pass the value in it to do_notify_resume() as "in_syscall" (actually,
"restarts allowed") argument.
Note that we don't give a damn about ret_from_fork() - return value
is not restart-worthy anyway.
Possible remaining bug: on !MMU we still have _debug_exception()
restartable. If it hits with -ERESTART_... accidentally in r3, fun happens.
MMU does _not_ have _debug_exception() restartable. If that's decided to
be a bug (as I strongly suspect it to be), we'll just need to replace
setting r30 to 1 with setting r30 to 0 in !MMU _debug_exception().
Up to microblaze maintainers...
Al Viro [Sun, 29 Apr 2012 07:35:29 +0000 (03:35 -0400)]
microblaze: evict the check for kernel_mode(regs) from do_notify_resume()
Only one caller hasn't done it in assembler - work_pending on !MMU.
Everything else can't reach do_notify_resume() if we are returning
to kernel mode, so move that check to that sole caller and make
do_notify_resume() reachable only when returning to userland.
Linus Torvalds [Fri, 1 Jun 2012 18:53:44 +0000 (11:53 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal
Pull third pile of signal handling patches from Al Viro:
"This time it's mostly helpers and conversions to them; there's a lot
of stuff remaining in the tree, but that'll either go in -rc2
(isolated bug fixes, ideally via arch maintainers' trees) or will sit
there until the next cycle."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal:
x86: get rid of calling do_notify_resume() when returning to kernel mode
blackfin: check __get_user() return value
whack-a-mole with TIF_FREEZE
FRV: Optimise the system call exit path in entry.S [ver #2]
FRV: Shrink TIF_WORK_MASK [ver #2]
FRV: Prevent syscall exit tracing and notify_resume at end of kernel exceptions
new helper: signal_delivered()
powerpc: get rid of restore_sigmask()
most of set_current_blocked() callers want SIGKILL/SIGSTOP removed from set
set_restore_sigmask() is never called without SIGPENDING (and never should be)
TIF_RESTORE_SIGMASK can be set only when TIF_SIGPENDING is set
don't call try_to_freeze() from do_signal()
pull clearing RESTORE_SIGMASK into block_sigmask()
sh64: failure to build sigframe != signal without handler
openrisc: tracehook_signal_handler() is supposed to be called on success
new helper: sigmask_to_save()
new helper: restore_saved_sigmask()
new helpers: {clear,test,test_and_clear}_restore_sigmask()
HAVE_RESTORE_SIGMASK is defined on all architectures now
Linus Torvalds [Fri, 1 Jun 2012 17:34:35 +0000 (10:34 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs changes from Al Viro.
"A lot of misc stuff. The obvious groups:
* Miklos' atomic_open series; kills the damn abuse of
->d_revalidate() by NFS, which was the major stumbling block for
all work in that area.
* ripping security_file_mmap() and dealing with deadlocks in the
area; sanitizing the neighborhood of vm_mmap()/vm_munmap() in
general.
* ->encode_fh() switched to saner API; insane fake dentry in
mm/cleancache.c gone.
* assorted annotations in fs (endianness, __user)
* parts of Artem's ->s_dirty work (jff2 and reiserfs parts)
* ->update_time() work from Josef.
* other bits and pieces all over the place.
Normally it would've been in two or three pull requests, but
signal.git stuff had eaten a lot of time during this cycle ;-/"
Fix up trivial conflicts in Documentation/filesystems/vfs.txt (the
'truncate_range' inode method was removed by the VM changes, the VFS
update adds an 'update_time()' method), and in fs/btrfs/ulist.[ch] (due
to sparse fix added twice, with other changes nearby).
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (95 commits)
nfs: don't open in ->d_revalidate
vfs: retry last component if opening stale dentry
vfs: nameidata_to_filp(): don't throw away file on error
vfs: nameidata_to_filp(): inline __dentry_open()
vfs: do_dentry_open(): don't put filp
vfs: split __dentry_open()
vfs: do_last() common post lookup
vfs: do_last(): add audit_inode before open
vfs: do_last(): only return EISDIR for O_CREAT
vfs: do_last(): check LOOKUP_DIRECTORY
vfs: do_last(): make ENOENT exit RCU safe
vfs: make follow_link check RCU safe
vfs: do_last(): use inode variable
vfs: do_last(): inline walk_component()
vfs: do_last(): make exit RCU safe
vfs: split do_lookup()
Btrfs: move over to use ->update_time
fs: introduce inode operation ->update_time
reiserfs: get rid of resierfs_sync_super
reiserfs: mark the superblock as dirty a bit later
...
Linus Torvalds [Fri, 1 Jun 2012 17:12:15 +0000 (10:12 -0700)]
Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull Ext4 updates from Theodore Ts'o:
"The major new feature added in this update is Darrick J Wong's
metadata checksum feature, which adds crc32 checksums to ext4's
metadata fields.
There is also the usual set of cleanups and bug fixes."
* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (44 commits)
ext4: hole-punch use truncate_pagecache_range
jbd2: use kmem_cache_zalloc wrapper instead of flag
ext4: remove mb_groups before tearing down the buddy_cache
ext4: add ext4_mb_unload_buddy in the error path
ext4: don't trash state flags in EXT4_IOC_SETFLAGS
ext4: let getattr report the right blocks in delalloc+bigalloc
ext4: add missing save_error_info() to ext4_error()
ext4: add debugging trigger for ext4_error()
ext4: protect group inode free counting with group lock
ext4: use consistent ssize_t type in ext4_file_write()
ext4: fix format flag in ext4_ext_binsearch_idx()
ext4: cleanup in ext4_discard_allocated_blocks()
ext4: return ENOMEM when mounts fail due to lack of memory
ext4: remove redundundant "(char *) bh->b_data" casts
ext4: disallow hard-linked directory in ext4_lookup
ext4: fix potential integer overflow in alloc_flex_gd()
ext4: remove needs_recovery in ext4_mb_init()
ext4: force ro mount if ext4_setup_super() fails
ext4: fix potential NULL dereference in ext4_free_inodes_counts()
ext4/jbd2: add metadata checksumming to the list of supported features
...
Al Viro [Mon, 30 Apr 2012 22:24:46 +0000 (18:24 -0400)]
x86: get rid of calling do_notify_resume() when returning to kernel mode
If we end up calling do_notify_resume() with !user_mode(refs), it
does nothing (do_signal() explicitly bails out and we can't get there
with TIF_NOTIFY_RESUME in such situations). Then we jump to
resume_userspace_sig, which rechecks the same thing and bails out
to resume_kernel, thus breaking the loop.
It's easier and cheaper to check *before* calling do_notify_resume()
and bail out to resume_kernel immediately. And kill the check in
do_signal()...
Note that on amd64 we can't get there with !user_mode() at all - asm
glue takes care of that.
Acked-and-reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
David Howells [Tue, 1 May 2012 18:44:14 +0000 (19:44 +0100)]
FRV: Prevent syscall exit tracing and notify_resume at end of kernel exceptions
Move the test for kernel mode processing from do_signal() into entry.S to also
prevent system call exit tracing and userspace resumption notification handling
happening when returning from kernel exceptions.
Reported-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Al Viro [Sat, 28 Apr 2012 06:04:15 +0000 (02:04 -0400)]
new helper: signal_delivered()
Does block_sigmask() + tracehook_signal_handler(); called when
sigframe has been successfully built. All architectures converted
to it; block_sigmask() itself is gone now (merged into this one).
I'm still not too happy with the signature, but that's a separate
story (IMO we need a structure that would contain signal number +
siginfo + k_sigaction, so that get_signal_to_deliver() would fill one,
signal_delivered(), handle_signal() and probably setup...frame() -
take one).
Al Viro [Fri, 27 Apr 2012 17:58:59 +0000 (13:58 -0400)]
most of set_current_blocked() callers want SIGKILL/SIGSTOP removed from set
Only 3 out of 63 do not. Renamed the current variant to __set_current_blocked(),
added set_current_blocked() that will exclude unblockable signals, switched
open-coded instances to it.
Al Viro [Tue, 22 May 2012 03:33:55 +0000 (23:33 -0400)]
new helper: restore_saved_sigmask()
first fruits of ..._restore_sigmask() helpers: now we can take
boilerplate "signal didn't have a handler, clear RESTORE_SIGMASK
and restore the blocked mask from ->saved_mask" into a common
helper. Open-coded instances switched...
Al Viro [Thu, 26 Apr 2012 22:31:00 +0000 (18:31 -0400)]
HAVE_RESTORE_SIGMASK is defined on all architectures now
Everyone either defines it in arch thread_info.h or has TIF_RESTORE_SIGMASK
and picks default set_restore_sigmask() in linux/thread_info.h. Kill the
ifdefs, slap #error in linux/thread_info.h to catch breakage when new ones
get merged.
Miklos Szeredi [Mon, 21 May 2012 15:30:20 +0000 (17:30 +0200)]
nfs: don't open in ->d_revalidate
NFSv4 can't do reliable opens in d_revalidate, since it cannot know whether a
mount needs to be followed or not. It does check d_mountpoint() on the dentry,
which can result in a weird error if the VFS found that the mount does not in
fact need to be followed, e.g.:
# mount --bind /mnt/nfs /mnt/nfs-clone
# echo something > /mnt/nfs/tmp/bar
# echo x > /tmp/file
# mount --bind /tmp/file /mnt/nfs-clone/tmp/bar
# cat /mnt/nfs/tmp/bar
cat: /mnt/nfs/tmp/bar: Not a directory
Which should, by any sane filesystem, result in "something" being printed.
So instead do the open in f_op->open() and in the unlikely case that the cached
dentry turned out to be invalid, drop the dentry and return EOPENSTALE to let
the VFS retry.
Miklos Szeredi [Mon, 21 May 2012 15:30:19 +0000 (17:30 +0200)]
vfs: retry last component if opening stale dentry
NFS optimizes away d_revalidates for last component of open. This means that
open itself can find the dentry stale.
This patch allows the filesystem to return EOPENSTALE and the VFS will retry the
lookup on just the last component if possible.
If the lookup was done using RCU mode, including the last component, then this
is not possible since the parent dentry is lost. In this case fall back to
non-RCU lookup. Currently this is not used since NFS will always leave RCU
mode.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Josef Bacik [Mon, 26 Mar 2012 13:46:47 +0000 (09:46 -0400)]
Btrfs: move over to use ->update_time
Btrfs had been doing it's own file_update_time so we could catch ENOSPC
properly, so just update our btrfs_update_time to work with the new stuff and
then we'll be fancy later. Thanks,
Josef Bacik [Mon, 26 Mar 2012 13:59:21 +0000 (09:59 -0400)]
fs: introduce inode operation ->update_time
Btrfs has to make sure we have space to allocate new blocks in order to modify
the inode, so updating time can fail. We've gotten around this by having our
own file_update_time but this is kind of a pain, and Christoph has indicated he
would like to make xfs do something different with atime updates. So introduce
->update_time, where we will deal with i_version an a/m/c time updates and
indicate which changes need to be made. The normal version just does what it
has always done, updates the time and marks the inode dirty, and then
filesystems can choose to do something different.
I've gone through all of the users of file_update_time and made them check for
errors with the exception of the fault code since it's complicated and I wasn't
quite sure what to do there, also Jan is going to be pushing the file time
updates into page_mkwrite for those who have it so that should satisfy btrfs and
make it not a big deal to check the file_update_time() return code in the
generic fault path. Thanks,
Linus Torvalds [Fri, 1 Jun 2012 15:37:31 +0000 (08:37 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs updates from Chris Mason:
"This includes a fairly large change from Josef around data writeback
completion. Before, the writeback wasn't completed until the metadata
insertions for the extent were done, and this made for fairly large
latency spikes on the last page of each ordered extent.
We already had a separate mechanism for tracking pending metadata
insertions, so Josef just needed to tweak things a little to end
writeback earlier on the page. Overall it makes us much friendly to
memory reclaim and lowers latencies quite a lot for synchronous IO.
Jan Schmidt has finished some background work required to track btree
blocks as they go through changes in ownership. It's the missing
piece he needed for both btrfs send/receive and subvolume quotas.
Neither of those are ready yet, but the new tracking code is included
here. Most of the time, the new code is off. It is only used by
scrub and other backref walkers.
Stefan Behrens has added io failure tracking. This includes counters
for which drives are causing the most trouble so the admin (or an
automated tool) can choose to kick them out. We're tracking IO
errors, crc errors, and generation checks we do on each metadata
block.
RAID5/6 did miss the cut this time because I'm having trouble with
corruptions. I'll nail it down next week and post as a beta testing
before 3.6"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (58 commits)
Btrfs: fix tree mod log rewinded level and rewinding of moved keys
Btrfs: fix tree mod log del_ptr
Btrfs: add tree_mod_dont_log helper
Btrfs: add missing spin_lock for insertion into tree mod log
Btrfs: add inodes before dropping the extent lock in find_all_leafs
Btrfs: use delayed ref sequence numbers for all fs-tree updates
Btrfs: fix false positive in check-integrity on unmount
Btrfs: fix runtime warning in check-integrity check data mode
Btrfs: set ioprio of scrub readahead to idle
Btrfs: fix return code in drop_objectid_items
Btrfs: check to see if the inode is in the log before fsyncing
Btrfs: return value of btrfs_read_buffer is checked correctly
Btrfs: read device stats on mount, write modified ones during commit
Btrfs: add ioctl to get and reset the device stats
Btrfs: add device counters for detected IO and checksum errors
btrfs: Drop unused function btrfs_abort_devices()
Btrfs: fix the same inode id problem when doing auto defragment
Btrfs: fall back to non-inline if we don't have enough space
Btrfs: fix how we deal with the orphan block rsv
Btrfs: convert the inode bit field to use the actual bit operations
...
Linus Torvalds [Fri, 1 Jun 2012 15:32:58 +0000 (08:32 -0700)]
Merge branch 'for-3.5' of git://linux-nfs.org/~bfields/linux
Pull the rest of the nfsd commits from Bruce Fields:
"... and then I cherry-picked the remainder of the patches from the
head of my previous branch"
This is the rest of the original nfsd branch, rebased without the
delegation stuff that I thought really needed to be redone.
I don't like rebasing things like this in general, but in this situation
this was the lesser of two evils.
* 'for-3.5' of git://linux-nfs.org/~bfields/linux: (50 commits)
nfsd4: fix, consolidate client_has_state
nfsd4: don't remove rebooted client record until confirmation
nfsd4: remove some dprintk's and a comment
nfsd4: return "real" sequence id in confirmed case
nfsd4: fix exchange_id to return confirm flag
nfsd4: clarify that renewing expired client is a bug
nfsd4: simpler ordering of setclientid_confirm checks
nfsd4: setclientid: remove pointless assignment
nfsd4: fix error return in non-matching-creds case
nfsd4: fix setclientid_confirm same_cred check
nfsd4: merge 3 setclientid cases to 2
nfsd4: pull out common code from setclientid cases
nfsd4: merge last two setclientid cases
nfsd4: setclientid/confirm comment cleanup
nfsd4: setclientid remove unnecessary terms from a logical expression
nfsd4: move rq_flavor into svc_cred
nfsd4: stricter cred comparison for setclientid/exchange_id
nfsd4: move principal name into svc_cred
nfsd4: allow removing clients not holding state
nfsd4: rearrange exchange_id logic to simplify
...
This patch stops reiserfs using the VFS 'write_super()' method along with the
s_dirt flag, because they are on their way out.
The whole "superblock write-out" VFS infrastructure is served by the
'sync_supers()' kernel thread, which wakes up every 5 (by default) seconds and
writes out all dirty superblock using the '->write_super()' call-back. But the
problem with this thread is that it wastes power by waking up the system every
5 seconds, even if there are no diry superblocks, or there are no client
file-systems which would need this (e.g., btrfs does not use
'->write_super()'). So we want to kill it completely and thus, we need to make
file-systems to stop using the '->write_super()' VFS service, and then remove
it together with the kernel thread.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
reiserfs: mark the superblock as dirty a bit later
The 'journal_mark_dirty()' function currently first marks the superblock as
dirty by setting 's_dirt' to 1, then does various sanity checks and returns,
then actuall does all the magic with the journal.
This is not an ideal order, though. It makes more sense to first do all the
checks, then do all the internal stuff, and at the end notify the VFS that the
superblock is now dirty.
This patch moves the 's_dirt = 1' assignment from the very beginning of this
function to the very end.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The 'reiserfs_resize()' function marks the superblock as dirty by assigning 1
to 's_dirt' and then calls 'journal_mark_dirty()' which does the same. Thus,
we can remove the assignment from 'reiserfs_resize()'.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
We have the reiserfs superblock pointer in the 'sbi' variable in this
function, no need to use the 'REISERFS_SB(s)' macro which is the same.
This is jut a small clean-up.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Hugh Dickins [Fri, 1 Jun 2012 04:15:28 +0000 (00:15 -0400)]
ext4: hole-punch use truncate_pagecache_range
When truncating a file, we unmap pages from userspace first, as that's
usually more efficient than relying, page by page, on the fallback in
truncate_inode_page() - particularly if the file is mapped many times.
Do the same when punching a hole: 3.4 added truncate_pagecache_range()
to do the unmap and trunc, so use it in ext4_ext_punch_hole(), instead
of calling truncate_inode_pages_range() directly.
Salman Qazi [Fri, 1 Jun 2012 03:52:14 +0000 (23:52 -0400)]
ext4: remove mb_groups before tearing down the buddy_cache
We can't have references held on pages in the s_buddy_cache while we are
trying to truncate its pages and put the inode. All the pages must be
gone before we reach clear_inode. This can only be gauranteed if we
can prevent new users from grabbing references to s_buddy_cache's pages.
The original bug can be reproduced and the bug fix can be verified by:
while true; do mount -t ext4 /dev/ram0 /export/hda3/ram0; \
umount /export/hda3/ram0; done &
while true; do cat /proc/fs/ext4/ram0/mb_groups; done
Theodore Ts'o [Fri, 1 Jun 2012 03:46:01 +0000 (23:46 -0400)]
ext4: don't trash state flags in EXT4_IOC_SETFLAGS
In commit 353eb83c we removed i_state_flags with 64-bit longs, But
when handling the EXT4_IOC_SETFLAGS ioctl, we replace i_flags
directly, which trashes the state flags which are stored in the high
32-bits of i_flags on 64-bit platforms. So use the the
ext4_{set,clear}_inode_flags() functions which use atomic bit
manipulation functions instead.
Reported-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: stable@kernel.org
Linus Torvalds [Fri, 1 Jun 2012 01:47:30 +0000 (18:47 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal
Pull second pile of signal handling patches from Al Viro:
"This one is just task_work_add() series + remaining prereqs for it.
There probably will be another pull request from that tree this
cycle - at least for helpers, to get them out of the way for per-arch
fixes remaining in the tree."
Fix trivial conflict in kernel/irq/manage.c: the merge of Andrew's pile
had brought in commit 97fd75b7b8e0 ("kernel/irq/manage.c: use the
pr_foo() infrastructure to prefix printks") which changed one of the
pr_err() calls that this merge moves around.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal:
keys: kill task_struct->replacement_session_keyring
keys: kill the dummy key_replace_session_keyring()
keys: change keyctl_session_to_parent() to use task_work_add()
genirq: reimplement exit_irq_thread() hook via task_work_add()
task_work_add: generic process-context callbacks
avr32: missed _TIF_NOTIFY_RESUME on one of do_notify_resume callers
parisc: need to check NOTIFY_RESUME when exiting from syscall
move key_repace_session_keyring() into tracehook_notify_resume()
TIF_NOTIFY_RESUME is defined on all targets now
Linus Torvalds [Fri, 1 Jun 2012 01:18:11 +0000 (18:18 -0700)]
Merge branch 'for-3.5-take-2' of git://linux-nfs.org/~bfields/linux
Pull nfsd update from Bruce Fields.
* 'for-3.5-take-2' of git://linux-nfs.org/~bfields/linux: (23 commits)
nfsd: trivial: use SEEK_SET instead of 0 in vfs_llseek
SUNRPC: split upcall function to extract reusable parts
nfsd: allocate id-to-name and name-to-id caches in per-net operations.
nfsd: make name-to-id cache allocated per network namespace context
nfsd: make id-to-name cache allocated per network namespace context
nfsd: pass network context to idmap init/exit functions
nfsd: allocate export and expkey caches in per-net operations.
nfsd: make expkey cache allocated per network namespace context
nfsd: make export cache allocated per network namespace context
nfsd: pass pointer to export cache down to stack wherever possible.
nfsd: pass network context to export caches init/shutdown routines
Lockd: pass network namespace to creation and destruction routines
NFSd: remove hard-coded dereferences to name-to-id and id-to-name caches
nfsd: pass pointer to expkey cache down to stack wherever possible.
nfsd: use hash table from cache detail in nfsd export seq ops
nfsd: pass svc_export_cache pointer as private data to "exports" seq file ops
nfsd: use exp_put() for svc_export_cache put
nfsd: use cache detail pointer from svc_export structure on cache put
nfsd: add link to owner cache detail to svc_export structure
nfsd: use passed cache_detail pointer expkey_parse()
...
Linus Torvalds [Fri, 1 Jun 2012 01:10:18 +0000 (18:10 -0700)]
Merge branch 'akpm' (Andrew's patch-bomb)
Merge misc patches from Andrew Morton:
- the "misc" tree - stuff from all over the map
- checkpatch updates
- fatfs
- kmod changes
- procfs
- cpumask
- UML
- kexec
- mqueue
- rapidio
- pidns
- some checkpoint-restore feature work. Reluctantly. Most of it
delayed a release. I'm still rather worried that we don't have a
clear roadmap to completion for this work.
* emailed from Andrew Morton <akpm@linux-foundation.org>: (78 patches)
kconfig: update compression algorithm info
c/r: prctl: add ability to set new mm_struct::exe_file
c/r: prctl: extend PR_SET_MM to set up more mm_struct entries
c/r: procfs: add arg_start/end, env_start/end and exit_code members to /proc/$pid/stat
syscalls, x86: add __NR_kcmp syscall
fs, proc: introduce /proc/<pid>/task/<tid>/children entry
sysctl: make kernel.ns_last_pid control dependent on CHECKPOINT_RESTORE
aio/vfs: cleanup of rw_copy_check_uvector() and compat_rw_copy_check_uvector()
eventfd: change int to __u64 in eventfd_signal()
fs/nls: add Apple NLS
pidns: make killed children autoreap
pidns: use task_active_pid_ns in do_notify_parent
rapidio/tsi721: add DMA engine support
rapidio: add DMA engine support for RIO data transfers
ipc/mqueue: add rbtree node caching support
tools/selftests: add mq_perf_tests
ipc/mqueue: strengthen checks on mqueue creation
ipc/mqueue: correct mq_attr_ok test
ipc/mqueue: improve performance of send/recv
selftests: add mq_open_tests
...
Linus Torvalds [Fri, 1 Jun 2012 01:01:18 +0000 (18:01 -0700)]
Merge branch 'drm-prime-vmap' of git://people.freedesktop.org/~airlied/linux
Pull drm prime mmap/vmap code from Dave Airlie:
"As mentioned previously these are the extra bits of drm that relied on
the dma-buf pull to work, the first three just stub out the mmap
interface, and the next set provide vmap export to i915/radeon/nouveau
and vmap import to udl."
* 'drm-prime-vmap' of git://people.freedesktop.org/~airlied/linux:
radeon: add radeon prime vmap support.
nouveau: add vmap support to nouveau prime support
udl: support vmapping imported dma-bufs
i915: add dma-buf vmap support for exporting vmapped buffer
radeon: add stub dma-buf mmap functionality
nouveau: add stub dma-buf mmap functionality.
i915: add stub dma-buf mmap callback.
Randy Dunlap [Thu, 31 May 2012 23:26:46 +0000 (16:26 -0700)]
kconfig: update compression algorithm info
There have been new compression algorithms added without updating nearby
relevant descriptive text that refers to (a) the number of compression
algorithms and (b) the most recent one. Fix these inconsistencies.
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Reported-by: <qasdfgtyuiop@gmail.com> Cc: Lasse Collin <lasse.collin@tukaani.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Markus Trippelsdorf <markus@trippelsdorf.de> Cc: Alain Knaff <alain@knaff.lu> Cc: Albin Tonnerre <albin.tonnerre@free-electrons.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cyrill Gorcunov [Thu, 31 May 2012 23:26:46 +0000 (16:26 -0700)]
c/r: prctl: add ability to set new mm_struct::exe_file
When we do restore we would like to have a way to setup a former
mm_struct::exe_file so that /proc/pid/exe would point to the original
executable file a process had at checkpoint time.
For this the PR_SET_MM_EXE_FILE code is introduced. This option takes a
file descriptor which will be set as a source for new /proc/$pid/exe
symlink.
Note it allows to change /proc/$pid/exe if there are no VM_EXECUTABLE
vmas present for current process, simply because this feature is a special
to C/R and mm::num_exe_file_vmas become meaningless after that.
To minimize the amount of transition the /proc/pid/exe symlink might have,
this feature is implemented in one-shot manner. Thus once changed the
symlink can't be changed again. This should help sysadmins to monitor the
symlinks over all process running in a system.
In particular one could make a snapshot of processes and ring alarm if
there unexpected changes of /proc/pid/exe's in a system.
Note -- this feature is available iif CONFIG_CHECKPOINT_RESTORE is set and
the caller must have CAP_SYS_RESOURCE capability granted, otherwise the
request to change symlink will be rejected.
Cyrill Gorcunov [Thu, 31 May 2012 23:26:45 +0000 (16:26 -0700)]
c/r: prctl: extend PR_SET_MM to set up more mm_struct entries
During checkpoint we dump whole process memory to a file and the dump
includes process stack memory. But among stack data itself, the stack
carries additional parameters such as command line arguments, environment
data and auxiliary vector.
So when we do restore procedure and once we've restored stack data itself
we need to setup mm_struct::arg_start/end, env_start/end, so restored
process would be able to find command line arguments and environment data
it had at checkpoint time. The same applies to auxiliary vector.
For this reason additional PR_SET_MM_(ARG_START | ARG_END | ENV_START |
ENV_END | AUXV) codes are introduced.
Cyrill Gorcunov [Thu, 31 May 2012 23:26:44 +0000 (16:26 -0700)]
c/r: procfs: add arg_start/end, env_start/end and exit_code members to /proc/$pid/stat
We would like to have an ability to restore command line arguments and
program environment pointers but first we need to obtain them somehow.
Thus we put these values into /proc/$pid/stat. The exit_code is needed to
restore zombie tasks.
Cyrill Gorcunov [Thu, 31 May 2012 23:26:44 +0000 (16:26 -0700)]
syscalls, x86: add __NR_kcmp syscall
While doing the checkpoint-restore in the user space one need to determine
whether various kernel objects (like mm_struct-s of file_struct-s) are
shared between tasks and restore this state.
The 2nd step can be solved by using appropriate CLONE_ flags and the
unshare syscall, while there's currently no ways for solving the 1st one.
One of the ways for checking whether two tasks share e.g. mm_struct is to
provide some mm_struct ID of a task to its proc file, but showing such
info considered to be not that good for security reasons.
Thus after some debates we end up in conclusion that using that named
'comparison' syscall might be the best candidate. So here is it --
__NR_kcmp.
It takes up to 5 arguments - the pids of the two tasks (which
characteristics should be compared), the comparison type and (in case of
comparison of files) two file descriptors.
Lookups for pids are done in the caller's PID namespace only.
At moment only x86 is supported and tested.
[akpm@linux-foundation.org: fix up selftests, warnings]
[akpm@linux-foundation.org: include errno.h]
[akpm@linux-foundation.org: tweak comment text] Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Andrey Vagin <avagin@openvz.org> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Glauber Costa <glommer@parallels.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Tejun Heo <tj@kernel.org> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Vasiliy Kulikov <segoon@openwall.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Valdis.Kletnieks@vt.edu Cc: Michal Marek <mmarek@suse.cz> Cc: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When we do checkpoint of a task we need to know the list of children the
task, has but there is no easy and fast way to generate reverse
parent->children chain from arbitrary <pid> (while a parent pid is
provided in "PPid" field of /proc/<pid>/status).
So instead of walking over all pids in the system (creating one big
process tree in memory, just to figure out which children a task has) --
we add explicit /proc/<pid>/task/<tid>/children entry, because the kernel
already has this kind of information but it is not yet exported.
This is a first level children, not the whole process tree.
Christopher Yeoh [Thu, 31 May 2012 23:26:42 +0000 (16:26 -0700)]
aio/vfs: cleanup of rw_copy_check_uvector() and compat_rw_copy_check_uvector()
A cleanup of rw_copy_check_uvector and compat_rw_copy_check_uvector after
changes made to support CMA in an earlier patch.
Rather than having an additional check_access parameter to these
functions, the first paramater type is overloaded to allow the caller to
specify CHECK_IOVEC_ONLY which means check that the contents of the iovec
are valid, but do not check the memory that they point to. This is used
by process_vm_readv/writev where we need to validate that a iovec passed
to the syscall is valid but do not want to check the memory that it points
to at this point because it refers to an address space in another process.
Signed-off-by: Chris Yeoh <yeohc@au1.ibm.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sha Zhengju [Thu, 31 May 2012 23:26:41 +0000 (16:26 -0700)]
eventfd: change int to __u64 in eventfd_signal()
eventfd_ctx->count is an __u64 counter which is allowed to reach
ULLONG_MAX. eventfd_write() adds a __u64 value to "count", but the kernel
side eventfd_signal() only adds an int value to it. Make them consistent.
HFS has support for NLS. However the relevant NLS tables are missing.
Here they are automatically transformed from the tables at unicode.org.
Codepages requiring special handling like CJK, RTL or Brahmic ones are not
included in this patch.
[akpm@linux-foundation.org: add unicode.org copyright and permission notices] Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Cc: Clemens Ladisch <clemens@ladisch.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Force SIGCHLD handling to SIG_IGN so that signals are not generated and so
that the children autoreap. This increases the parallelize and in general
the speed of network namespace shutdown.
Note self reaping childrean can exist past zap_pid_ns_processess but they
will all be reaped before we allow the pid namespace init task with pid ==
1 to be reaped.
[akpm@linux-foundation.org: checkpatch fixes] Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Louis Rilling <louis.rilling@kerlabs.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Using task_active_pid_ns is more robust because it works even after we
have called exit_namespaces. This change allows us to have parent
processes that are zombies. Normally a zombie parent processes is crazy
and the last thing you would want to have but in the case of not letting
the init process of a pid namespace be reaped until all of it's children
are dead and reaped a zombie parent process is exactly what we want.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Louis Rilling <louis.rilling@kerlabs.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Adds support for DMA Engine API into Tsi721 mport driver.
Includes following changes for Tsi721 driver:
- Modifies BDMA register offset definitions to support per-channel handling
- Separates BDMA channel reserved for RIO Maintenance requests
- Adds DMA Engine callback routines
Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Vinod Koul <vinod.koul@intel.com> Cc: Li Yang <leoli@freescale.com> Cc: Matt Porter <mporter@kernel.crashing.org> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
rapidio: add DMA engine support for RIO data transfers
Adds DMA Engine framework support into RapidIO subsystem.
Uses DMA Engine DMA_SLAVE interface to generate data transfers to/from
remote RapidIO target devices.
Introduces RapidIO-specific wrapper for prep_slave_sg() interface with an
extra parameter to pass target specific information.
Uses scatterlist to describe local data buffer. Address flat data buffer
on a remote side.
Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com> Cc: Dan Williams <dan.j.williams@intel.com> Acked-by: Vinod Koul <vinod.koul@linux.intel.com> Cc: Li Yang <leoli@freescale.com> Cc: Matt Porter <mporter@kernel.crashing.org> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Doug Ledford [Thu, 31 May 2012 23:26:38 +0000 (16:26 -0700)]
ipc/mqueue: add rbtree node caching support
When I wrote the first patch that added the rbtree support for message
queue insertion, it sped up the case where the queue was very full
drastically from the original code. It, however, slowed down the case
where the queue was empty (not drastically though).
This patch caches the last freed rbtree node struct so we can quickly
reuse it when we get a new message. This is the common path for any queue
that very frequently goes from 0 to 1 then back to 0 messages in queue.
Andrew Morton didn't like that we were doing a GFP_ATOMIC allocation in
msg_insert, so this patch attempts to speculatively allocate a new node
struct outside of the spin lock when we know we need it, but will still
fall back to a GFP_ATOMIC allocation if it has to.
Once I added the caching, the necessary various ret = ; spin_unlock
gyrations in mq_timedsend were getting pretty ugly, so this also slightly
refactors that function to streamline the flow of the code and the
function exit.
Finally, while working on getting performance back I made sure that all of
the node structs were always fully initialized when they were first used,
rendering the use of kzalloc unnecessary and a waste of CPU cycles.
The net result of all of this is:
1) We will avoid a GFP_ATOMIC allocation when possible, but fall back
on it when necessary.
2) We will speculatively allocate a node struct using GFP_KERNEL if our
cache is empty (and save the struct to our cache if it's still empty
after we have obtained the spin lock).
3) The performance of the common queue empty case has significantly
improved and is now much more in line with the older performance for
this case.
The performance changes are:
Old mqueue new mqueue new mqueue + caching
queue empty
send/recv 305/288ns 349/318ns 310/322ns
I don't think we'll ever be able to get the recv performance back, but
that's because the old recv performance was a direct result and
consequence of the old methods abysmal send performance. The recv path
simply must do more so that the send path does not incur such a penalty
under higher queue depths.
As it turns out, the new caching code also sped up the various queue full
cases relative to my last patch. That could be because of the difference
between the syscall path in 3.3.4-rc5 and 3.3.4-rc6, or because of the
change in code flow in the mq_timedsend routine. Regardless, I'll take
it. It wasn't huge, and I *would* say it was within the margin for error,
but after many repeated runs what I'm seeing is that the old numbers trend
slightly higher (about 10 to 20ns depending on which test is the one
running).
Doug Ledford [Thu, 31 May 2012 23:26:37 +0000 (16:26 -0700)]
tools/selftests: add mq_perf_tests
Add the mq_perf_tests tool I used when creating my mq performance patch.
Also add a local .gitignore to keep the binaries from showing up in git
status output.
Doug Ledford [Thu, 31 May 2012 23:26:36 +0000 (16:26 -0700)]
ipc/mqueue: strengthen checks on mqueue creation
We already check the mq attr struct if it's passed in, but now that the
admin can set system wide defaults separate from maximums, it's actually
possible to set the defaults to something that would overflow. So, if
there is no attr struct passed in to the open call, check the default
values.
While we are at it, simplify mq_attr_ok() by making it return 0 or an
error condition, so that way if we add more tests to it later, we have the
option of what error should be returned instead of the calling location
having to pick a possibly inaccurate error code.
Doug Ledford [Thu, 31 May 2012 23:26:36 +0000 (16:26 -0700)]
ipc/mqueue: correct mq_attr_ok test
While working on the other parts of the mqueue stuff, I noticed that the
calculation for overflow in mq_attr_ok didn't actually match reality (this
is especially true since my last patch which changed how we account memory
slightly).
In particular, we used to test for overflow using:
msgs * msgsize + msgs * sizeof(struct msg_msg *)
That was never really correct because each message we allocate via
load_msg() is actually a struct msg_msg followed by the data for the
message (and if struct msg_msg + data exceeds PAGE_SIZE we end up
allocating struct msg_msgseg structs too, but accounting for them would
get really tedious, so let's ignore those...they're only a pointer in size
anyway). This patch updates the calculation to be more accurate in
regards to maximum possible memory consumption by the mqueue.
[akpm@linux-foundation.org: add a local to simplify overflow-checking expression] Signed-off-by: Doug Ledford <dledford@redhat.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Manfred Spraul <manfred@colorfullife.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Doug Ledford [Thu, 31 May 2012 23:26:35 +0000 (16:26 -0700)]
ipc/mqueue: improve performance of send/recv
The existing implementation of the POSIX message queue send and recv
functions is, well, abysmal. Even worse than abysmal. I submitted a
patch to increase the maximum POSIX message queue limit to 65536 due to
customer needs, however, upon looking over the send/recv implementation, I
realized that my customer needs help with that too even if they don't know
it. The basic problem is that, given the fairly typical use case scenario
for a large queue of queueing lots of messages all at the same priority (I
verified with my customer that this is indeed what their app does), the
msg_insert routine is basically a frikkin' bubble sort. I mean, whoa,
that's *so* middle school.
OK, OK, to not slam the original author too much, I'm sure they didn't
envision a queue depth of 50,000+ messages. No one would think that
moving elements in an array, one at a time, and dereferencing each pointer
in that array to check priority of the message being pointed too, again
one at a time, for 50,000+ times would be good. So let's assume that, as
is typical, the users have found a way to break our code simply by using
it in a way we didn't envision. Fair enough.
"So, just how broken is it?", you ask. I wondered the same thing, so I
wrote an app to let me know. It's my next patch. It gave me some
interesting results. Here's what it tested:
Interference with other apps - In continuous mode, the app just sits there
and hits a message queue forever, while you go do something productive on
another terminal using other CPUs. You then measure how long it takes you
to do that something productive. Then you restart the app in fake
continuous mode, and it sits in a tight loop on a CPU while you repeat
your tests. The whole point of this is to keep one CPU tied up (so it
can't be used in your other work) but in one case tied up hitting the
mqueue code so we can see the effect of walking that 65,528 element array
one pointer at a time on the global CPU cache. If it's bad, then it will
slow down your app on the other CPUs just by polluting cache mercilessly.
In the fake case, it will be in a tight loop, but not polluting cache.
Testing the mqueue subsystem directly - Here we just run a number of tests
to see how the mqueue subsystem performs under different conditions. A
couple conditions are known to be worst case for the old system, and some
routines, so this tests all of them.
So, on to the results already:
Subsystem/Test Old New
Time to compile linux
kernel (make -j12 on a
6 core CPU)
Running mqueue test user 49m10.744s user 45m26.294s
sys 5m51.924s sys 4m59.894s
total 55m02.668s total 50m26.188s
Running fake test user 45m32.686s user 45m18.552s
sys 5m12.465s sys 4m56.468s
total 50m45.151s total 50m15.020s
% slowdown from mqueue
cache thrashing ~8% ~.5%
Avg time to send/recv (in nanoseconds per message)
when queue empty 305/288 349/318
when queue full (65528 messages)
constant priority 526589/823 362/314
increasing priority 403105/916 495/445
decreasing priority 73420/594 482/409
random priority 280147/920 546/436
Time to fill/drain queue (65528 messages, in seconds)
constant priority 17.37/.12 .13/.12
increasing priority 4.14/.14 .21/.18
decreasing priority 12.93/.13 .21/.18
random priority 8.88/.16 .22/.17
So, I think the results speak for themselves. It's possible this
implementation could be improved by cacheing at least one priority level
in the node tree (that would bring the queue empty performance more in
line with the old implementation), but this works and is *so* much better
than what we had, especially for the common case of a single priority in
use, that further refinements can be in follow on patches.
[akpm@linux-foundation.org: fix typo in comment, remove stray semicolon]
[levinsasha928@gmail.com: use correct gfp flags in msg_insert] Signed-off-by: Doug Ledford <dledford@redhat.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Manfred Spraul <manfred@colorfullife.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Sasha Levin <levinsasha928@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Doug Ledford [Thu, 31 May 2012 23:26:34 +0000 (16:26 -0700)]
selftests: add mq_open_tests
Add a directory to house POSIX message queue subsystem specific tests.
Add first test which checks the operation of mq_open() under various
corner conditions.
KOSAKI Motohiro [Thu, 31 May 2012 23:26:33 +0000 (16:26 -0700)]
mqueue: separate mqueue default value from maximum value
Commit b231cca4381e ("message queues: increase range limits") changed
mqueue default value when attr parameter is specified NULL from hard
coded value to fs.mqueue.{msg,msgsize}_max sysctl value.
This made large side effect. When user need to use two mqueue
applications 1) using !NULL attr parameter and it require big message
size and 2) using NULL attr parameter and only need small size message,
app (1) require to raise fs.mqueue.msgsize_max and app (2) consume large
memory size even though it doesn't need.
Doug Ledford propsed to switch back it to static hard coded value.
However it also has a compatibility problem. Some applications might
started depend on the default value is tunable.
The solution is to separate default value from maximum value.
KOSAKI Motohiro [Thu, 31 May 2012 23:26:31 +0000 (16:26 -0700)]
mqueue: don't use kmalloc with KMALLOC_MAX_SIZE
KMALLOC_MAX_SIZE is not a good threshold. It is extremely high and
problematic. Unfortunately, some silly drivers depend on this and we
can't change it. But any new code needn't use such extreme ugly high
order allocations. It brings us awful fragmentation issues and system
slowdown.
Signed-off-by: KOSAKI Motohiro <mkosaki@jp.fujitsu.com> Acked-by: Doug Ledford <dledford@redhat.com> Acked-by: Joe Korty <joe.korty@ccur.com> Cc: Amerigo Wang <amwang@redhat.com> Cc: Serge E. Hallyn <serue@us.ibm.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Joe Korty <joe.korty@ccur.com> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
KOSAKI Motohiro [Thu, 31 May 2012 23:26:31 +0000 (16:26 -0700)]
mqueue: revert bump up DFLT_*MAX
Mqueue limitation is slightly naieve parameter likes other ipcs because
unprivileged user can consume kernel memory by using ipcs.
Thus, too aggressive raise bring us security issue. Example, current
setting allow evil unprivileged user use 256GB (= 256 * 1024 * 1024*1024)
and it's enough large to system will belome unresponsive. Don't do that.
Instead, every admin should adjust the knobs for their own systems.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Doug Ledford <dledford@redhat.com> Acked-by: Joe Korty <joe.korty@ccur.com> Cc: Amerigo Wang <amwang@redhat.com> Acked-by: Serge E. Hallyn <serue@us.ibm.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Doug Ledford [Thu, 31 May 2012 23:26:30 +0000 (16:26 -0700)]
ipc/mqueue: update maximums for the mqueue subsystem
Commit b231cca4381e ("message queues: increase range limits") changed the
maximum size of a message in a message queue from INT_MAX to 8192*128.
Unfortunately, we had customers that relied on a size much larger than
8192*128 on their production systems. After reviewing POSIX, we found
that it is silent on the maximum message size. We did find a couple other
areas in which it was not silent. Fix up the mqueue maximums so that the
customer's system can continue to work, and document both the POSIX and
real world requirements in ipc_namespace.h so that we don't have this
issue crop back up.
Also, commit 9cf18e1dd74cd0 ("ipc: HARD_MSGMAX should be higher not lower
on 64bit") fiddled with HARD_MSGMAX without realizing that the number was
intentionally in place to limit the msg queue depth to one that was small
enough to kmalloc an array of pointers (hence why we divided 128k by
sizeof(long)). If we wish to meet POSIX requirements, we have no choice
but to change our allocation to a vmalloc instead (at least for the large
queue size case). With that, it's possible to increase our allowed
maximum to the POSIX requirements (or more if we choose).
[sfr@canb.auug.org.au: using vmalloc requires including vmalloc.h] Signed-off-by: Doug Ledford <dledford@redhat.com> Cc: Serge E. Hallyn <serue@us.ibm.com> Cc: Amerigo Wang <amwang@redhat.com> Cc: Joe Korty <joe.korty@ccur.com> Cc: Jiri Slaby <jslaby@suse.cz> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Doug Ledford [Thu, 31 May 2012 23:26:29 +0000 (16:26 -0700)]
ipc/mqueue: enforce hard limits
In two places we don't enforce the hard limits for CAP_SYS_RESOURCE apps.
In preparation for making more reasonable hard limits, start enforcing
them even on CAP_SYS_RESOURCE.
Signed-off-by: Doug Ledford <dledford@redhat.com> Cc: Serge E. Hallyn <serue@us.ibm.com> Cc: Amerigo Wang <amwang@redhat.com> Cc: Joe Korty <joe.korty@ccur.com> Cc: Jiri Slaby <jslaby@suse.cz> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Doug Ledford [Thu, 31 May 2012 23:26:29 +0000 (16:26 -0700)]
ipc/mqueue: switch back to using non-max values on create
Commit b231cca4381e ("message queues: increase range limits") changed
how we create a queue that does not include an attr struct passed to
open so that it creates the queue with whatever the maximum values are.
However, if the admin has set the maximums to allow flexibility in
creating a queue (aka, both a large size and large queue are allowed,
but combined they create a queue too large for the RLIMIT_MSGQUEUE of
the user), then attempts to create a queue without an attr struct will
fail. Switch back to using acceptable defaults regardless of what the
maximums are.
Note: so far, we only know of a few applications that rely on this
behavior (specifically, set the maximums in /proc, then run the
application which calls mq_open() without passing in an attr struct, and
the application expects the newly created message queue to have the
maximum sizes that were set in /proc used on the mq_open() call, and all
of those applications that we know of are actually part of regression
test suites that were coded to do something like this:
for size in 4096 65536 $((1024 * 1024)) $((16 * 1024 * 1024)); do
echo $size > /proc/sys/fs/mqueue/msgsize_max
mq_open || echo "Error opening mq with size $size"
done
These test suites that depend on any behavior like this are broken. The
concept that programs should rely upon the system wide maximum in order
to get their desired results instead of simply using a attr struct to
specify what they want is fundamentally unfriendly programming practice
for any multi-tasking OS.
Fixing this will break those few apps that we know of (and those app
authors recognize the brokenness of their code and the need to fix it).
However, the following patch "mqueue: separate mqueue default value"
allows a workaround in the form of new knobs for the default msg queue
creation parameters for any software out there that we don't already
know about that might rely on this behavior at the moment.
Signed-off-by: Doug Ledford <dledford@redhat.com> Cc: Serge E. Hallyn <serue@us.ibm.com> Cc: Amerigo Wang <amwang@redhat.com> Cc: Joe Korty <joe.korty@ccur.com> Cc: Jiri Slaby <jslaby@suse.cz> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Doug Ledford [Thu, 31 May 2012 23:26:28 +0000 (16:26 -0700)]
ipc/mqueue: cleanup definition names and locations
Since commit b231cca4381e ("message queues: increase range limits") on
Oct 18, 2008, calls to mq_open() that did not pass in an attribute
struct and expected to get default values for the size of the queue and
the max message size now get the system wide maximums instead of
hardwired defaults like they used to get.
This was uncovered when one of the earlier patches in this patch set
increased the default system wide maximums at the same time it increased
the hard ceiling on the system wide maximums (a customer specifically
needed the hard ceiling brought back up, the new ceiling that commit b231cca4381e introduced was too low for their production systems). By
increasing the default maximums and not realising they were tied to any
attempt to create a message queue without an attribute struct, I had
inadvertently made it such that all message queue creation attempts
without an attribute struct were failing because the new default
maximums would create a queue that exceeded the default rlimit for
message queue bytes.
As a result, the system wide defaults were brought back down to their
previous levels, and the system wide ceilings on the maximums were
raised to meet the customer's needs. However, the fact that the no
attribute struct behavior of mq_open() could be broken by changing the
system wide maximums for message queues was seen as fundamentally broken
itself. So we hardwired the no attribute case back like it used to be.
But, then we realized that on the very off chance that some piece of
software in the wild depended on that behavior, we could work around
that issue by adding two new knobs to /proc that allowed setting the
defaults for message queues created without an attr struct separately
from the system wide maximums.
What is not an option IMO is to leave the current behavior in place. No
piece of software should ever rely on setting the system wide maximums
in order to get a desired message queue. Such a reliance would be so
fundamentally multitasking OS unfriendly as to not really be tolerable.
Fortunately, we don't know of any software in the wild that uses this
except for a regression test program that caught the issue in the first
place. If there is though, we have made accommodations with the two new
/proc knobs (and that's all the accommodations such fundamentally broken
software can be allowed)..
This patch:
The various defines for minimums and maximums of the sysctl controllable
mqueue values are scattered amongst different files and named
inconsistently. Move them all into ipc_namespace.h and make them have
consistent names. Additionally, make the number of queues per namespace
also have a minimum and maximum and use the same sysctl function as the
other two settable variables.
Signed-off-by: Doug Ledford <dledford@redhat.com> Acked-by: Serge E. Hallyn <serue@us.ibm.com> Cc: Amerigo Wang <amwang@redhat.com> Cc: Joe Korty <joe.korty@ccur.com> Cc: Jiri Slaby <jslaby@suse.cz> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add userspace definitions, guard all relevant kernel structures. While at
it document stuff and remove now useless userspace hint.
It is easy to add the relevant system call to respective libc's, but it
seems pointless to have to duplicate the data structures.
This is based on the kexec-tools headers, with the exception of just using
int on return (succes or failure) and using size_t instead of 'unsigned
long int' for the number of segments argument of kexec_load().
Signed-off-by: maximilian attems <max@stro.at> Cc: Simon Horman <horms@verge.net.au> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Haren Myneni <hbabu@us.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Anton Vorontsov [Thu, 31 May 2012 23:26:26 +0000 (16:26 -0700)]
kernel/cpu.c: document clear_tasks_mm_cpumask()
Add more comments on clear_tasks_mm_cpumask, plus adds a runtime check:
the function is only suitable for offlined CPUs, and if called
inappropriately, the kernel should scream aloud.
[akpm@linux-foundation.org: tweak comment: s/walks up/walks/, use 80 cols] Suggested-by: Andrew Morton <akpm@linux-foundation.org> Suggested-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Anton Vorontsov [Thu, 31 May 2012 23:26:26 +0000 (16:26 -0700)]
um: properly check all process' threads for a live mm
kill_off_processes() might miss a valid process, this is because checking
for process->mm is not enough. Process' main thread may exit or detach
its mm via use_mm(), but other threads may still have a valid mm.
To catch this we use find_lock_task_mm(), which walks up all threads and
returns an appropriate task (with task lock held).
Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Cc: Richard Weinberger <richard@nod.at> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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