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2008-02-05uml: fix hostfs tv_usec calculationsDominique Quatravaux1-4/+4
To convert from tv_nsec to tv_usec, one needs to divide by 1000, not multiply. Signed-off-by: Dominique Quatravaux <dominique@quatravaux.org> Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05Add 64-bit capability support to the kernelAndrew Morgan2-11/+20
The patch supports legacy (32-bit) capability userspace, and where possible translates 32-bit capabilities to/from userspace and the VFS to 64-bit kernel space capabilities. If a capability set cannot be compressed into 32-bits for consumption by user space, the system call fails, with -ERANGE. FWIW libcap-2.00 supports this change (and earlier capability formats) http://www.kernel.org/pub/linux/libs/security/linux-privs/kernel-2.6/ [akpm@linux-foundation.org: coding-syle fixes] [akpm@linux-foundation.org: use get_task_comm()] [ezk@cs.sunysb.edu: build fix] [akpm@linux-foundation.org: do not initialise statics to 0 or NULL] [akpm@linux-foundation.org: unused var] [serue@us.ibm.com: export __cap_ symbols] Signed-off-by: Andrew G. Morgan <morgan@kernel.org> Cc: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Chris Wright <chrisw@sous-sol.org> Cc: James Morris <jmorris@namei.org> Cc: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Erez Zadok <ezk@cs.sunysb.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05VFS: Reorder vfs_getxattr to avoid unnecessary calls to the LSMDavid P. Quigley1-7/+8
Originally vfs_getxattr would pull the security xattr variable using the inode getxattr handle and then proceed to clobber it with a subsequent call to the LSM. This patch reorders the two operations such that when the xattr requested is in the security namespace it first attempts to grab the value from the LSM directly. If it fails to obtain the value because there is no module present or the module does not support the operation it will fall back to using the inode getxattr operation. In the event that both are inaccessible it returns EOPNOTSUPP. Signed-off-by: David P. Quigley <dpquigl@tycho.nsa.gov> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Chris Wright <chrisw@sous-sol.org> Acked-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Casey Schaufler <casey@schaufler-ca.com> 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>
2008-02-05VFS/Security: Rework inode_getsecurity and callers to return resulting bufferDavid P. Quigley1-2/+28
This patch modifies the interface to inode_getsecurity to have the function return a buffer containing the security blob and its length via parameters instead of relying on the calling function to give it an appropriately sized buffer. Security blobs obtained with this function should be freed using the release_secctx LSM hook. This alleviates the problem of the caller having to guess a length and preallocate a buffer for this function allowing it to be used elsewhere for Labeled NFS. The patch also removed the unused err parameter. The conversion is similar to the one performed by Al Viro for the security_getprocattr hook. Signed-off-by: David P. Quigley <dpquigl@tycho.nsa.gov> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Chris Wright <chrisw@sous-sol.org> Acked-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Casey Schaufler <casey@schaufler-ca.com> 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>
2008-02-05writeback: speed up writeback of big dirty filesFengguang Wu1-2/+16
After making dirty a 100M file, the normal behavior is to start the writeback for all data after 30s delays. But sometimes the following happens instead: - after 30s: ~4M - after 5s: ~4M - after 5s: all remaining 92M Some analyze shows that the internal io dispatch queues goes like this: s_io s_more_io ------------------------- 1) 100M,1K 0 2) 1K 96M 3) 0 96M 1) initial state with a 100M file and a 1K file 2) 4M written, nr_to_write <= 0, so write more 3) 1K written, nr_to_write > 0, no more writes(BUG) nr_to_write > 0 in (3) fools the upper layer to think that data have all been written out. The big dirty file is actually still sitting in s_more_io. We cannot simply splice s_more_io back to s_io as soon as s_io becomes empty, and let the loop in generic_sync_sb_inodes() continue: this may starve newly expired inodes in s_dirty. It is also not an option to draw inodes from both s_more_io and s_dirty, an let the loop go on: this might lead to live locks, and might also starve other superblocks in sync time(well kupdate may still starve some superblocks, that's another bug). We have to return when a full scan of s_io completes. So nr_to_write > 0 does not necessarily mean that "all data are written". This patch introduces a flag writeback_control.more_io to indicate that more io should be done. With it the big dirty file no longer has to wait for the next kupdate invokation 5s later. In sync_sb_inodes() we only set more_io on super_blocks we actually visited. This avoids the interaction between two pdflush deamons. Also in __sync_single_inode() we don't blindly keep requeuing the io if the filesystem cannot progress. Failing to do so may lead to 100% iowait. Tested-by: Mike Snitzer <snitzer@gmail.com> Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn> Cc: Michael Rubin <mrubin@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05skip writing data pages when inode is under I_SYNCQi Yong1-12/+1
Since I_SYNC was split out from I_LOCK, the concern in commit 4b89eed93e0fa40a63e3d7b1796ec1337ea7a3aa ("Write back inode data pages even when the inode itself is locked") is not longer valid. We should revert to the original behavior: in __writeback_single_inode(), when we find an I_SYNC-ed inode and we're not doing a data-integrity sync, skip writing entirely. Otherwise, we are double calling do_writepages() Signed-off-by: Qi Yong <qiyong@fc-cn.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hugh@veritas.com> Cc: Joern Engel <joern@wohnheim.fh-wedel.de> Cc: WU Fengguang <wfg@mail.ustc.edu.cn> Cc: Michael Rubin <mrubin@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05Fix /proc dcache deadlock in do_exitAndrea Arcangeli1-1/+2
This patch fixes a sles9 system hang in start_this_handle from a customer with some heavy workload where all tasks are waiting on kjournald to commit the transaction, but kjournald waits on t_updates to go down to zero (it never does). This was reported as a lowmem shortage deadlock but when checking the debug data I noticed the VM wasn't under pressure at all (well it was really under vm pressure, because lots of tasks hanged in the VM prune_dcache methods trying to flush dirty inodes, but no task was hanging in GFP_NOFS mode, the holder of the journal handle should have if this was a vm issue in the first place). No task was apparently holding the leftover handle in the committing transaction, so I deduced t_updates was stuck to 1 because a journal_stop was never run by some path (this turned out to be correct). With a debug patch adding proper reverse links and stack trace logging in ext3 deployed in production, I found journal_stop is never run because mark_inode_dirty_sync is called inside release_task called by do_exit. (that was quite fun because I would have never thought about this subtleness, I thought a regular path in ext3 had a bug and it forgot to call journal_stop) do_exit->release_task->mark_inode_dirty_sync->schedule() (will never come back to run journal_stop) The reason is that shrink_dcache_parent is racy by design (feature not a bug) and it can do blocking I/O in some case, but the point is that calling shrink_dcache_parent at the last stage of do_exit isn't safe for self-reaping tasks. I guess the memory pressure of the unbalanced highmem system allowed to trigger this more easily. Now mainline doesn't have this line in iput (like sles9 has): if (inode->i_state & I_DIRTY_DELAYED) mark_inode_dirty_sync(inode); so it will probably not crash with ext3, but for example ext2 implements an I/O-blocking ext2_put_inode that will lead to similar screwups with ext2_free_blocks never coming back and it's definitely wrong to call blocking-IO paths inside do_exit. So this should fix a subtle bug in mainline too (not verified in practice though). The equivalent fix for ext3 is also not verified yet to fix the problem in sles9 but I don't have doubt it will (it usually takes days to crash, so it'll take weeks to be sure). An alternate fix would be to offload that work to a kernel thread, but I don't think a reschedule for this is worth it, the vm should be able to collect those entries for the synchronous release_task. Signed-off-by: Andrea Arcangeli <andrea@suse.de> Cc: Jan Kara <jack@ucw.cz> Cc: Ingo Molnar <mingo@elte.hu> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05maps4: make page monitoring /proc file optionalMatt Mackall3-2/+8
Make /proc/ page monitoring configurable This puts the following files under an embedded config option: /proc/pid/clear_refs /proc/pid/smaps /proc/pid/pagemap /proc/kpagecount /proc/kpageflags [akpm@linux-foundation.org: Kconfig fix] Signed-off-by: Matt Mackall <mpm@selenic.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>
2008-02-05maps4: add /proc/kpageflags interfaceMatt Mackall1-1/+83
This makes a subset of physical page flags available to userspace. Together with /proc/pid/kpagemap, this allows tracking of a wide variety of VM behaviors. Exported flags are decoupled from the kernel's internal flags. This allows us to reorder flag bits, and synthesize any bits that get redefined in terms of other bits. [akpm@linux-foundation.org: remove unneeded access_ok()] [akpm@linux-foundation.org: s/0/NULL/] Signed-off-by: Matt Mackall <mpm@selenic.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>
2008-02-05maps4: add /proc/kpagecount interfaceMatt Mackall1-0/+50
This makes physical page map counts available to userspace. Together with /proc/pid/pagemap and /proc/pid/clear_refs, this can be used to monitor memory usage on a per-page basis. [akpm@linux-foundation.org: remove unneeded access_ok()] [bunk@stusta.de: make struct proc_kpagemap static] Signed-off-by: Matt Mackall <mpm@selenic.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Adrian Bunk <bunk@stusta.de> 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>
2008-02-05maps4: add /proc/pid/pagemap interfaceMatt Mackall3-2/+204
This interface provides a mapping for each page in an address space to its physical page frame number, allowing precise determination of what pages are mapped and what pages are shared between processes. New in this version: - headers gone again (as recommended by Dave Hansen and Alan Cox) - 64-bit entries (as per discussion with Andi Kleen) - swap pte information exported (from Dave Hansen) - page walker callback for holes (from Dave Hansen) - direct put_user I/O (as suggested by Rusty Russell) This patch folds in cleanups and swap PTE support from Dave Hansen <haveblue@us.ibm.com>. Signed-off-by: Matt Mackall <mpm@selenic.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>
2008-02-05maps4: regroup task_mmu by interfaceMatt Mackall1-207/+210
Reorder source so that all the code and data for each interface is together. Signed-off-by: Matt Mackall <mpm@selenic.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: David Rientjes <rientjes@google.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>
2008-02-05maps4: move clear_refs code to task_mmu.cMatt Mackall3-53/+37
This puts all the clear_refs code where it belongs and probably lets things compile on MMU-less systems as well. Signed-off-by: Matt Mackall <mpm@selenic.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: David Rientjes <rientjes@google.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>
2008-02-05maps4: simplify interdependence of maps and smapsMatt Mackall1-26/+26
This pulls the shared map display code out of show_map and puts it in show_smap where it belongs. Signed-off-by: Matt Mackall <mpm@selenic.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Acked-by: David Rientjes <rientjes@google.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>
2008-02-05maps4: use pagewalker in clear_refs and smapsMatt Mackall1-78/+17
Use the generic pagewalker for smaps and clear_refs Signed-off-by: Matt Mackall <mpm@selenic.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>
2008-02-05maps4: add proportional set size accounting in smapsFengguang Wu1-1/+27
The "proportional set size" (PSS) of a process is the count of pages it has in memory, where each page is divided by the number of processes sharing it. So if a process has 1000 pages all to itself, and 1000 shared with one other process, its PSS will be 1500. - lwn.net: "ELC: How much memory are applications really using?" The PSS proposed by Matt Mackall is a very nice metic for measuring an process's memory footprint. So collect and export it via /proc/<pid>/smaps. Matt Mackall's pagemap/kpagemap and John Berthels's exmap can also do the job. They are comprehensive tools. But for PSS, let's do it in the simple way. Cc: John Berthels <jjberthels@gmail.com> Cc: Bernardo Innocenti <bernie@codewiz.org> Cc: Padraig Brady <P@draigBrady.com> Cc: Denys Vlasenko <vda.linux@googlemail.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn> Cc: Hugh Dickins <hugh@veritas.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>
2008-02-05hugetlb: allow sticky directory mount optionKen Chen1-1/+1
Allow sticky directory mount option for hugetlbfs. This allows admin to create a shared hugetlbfs mount point for multiple users, while prevent accidental file deletion that users may step on each other. It is similiar to default tmpfs mount option, or typical option used on /tmp. Signed-off-by: Ken Chen <kenchen@google.com> Cc: Badari Pulavarty <pbadari@us.ibm.com> Cc: Adam Litke <agl@us.ibm.com> Cc: David Gibson <hermes@gibson.dropbear.id.au> Cc: William Lee Irwin III <wli@holomorphy.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05bufferhead: revert constructor removalChristoph Lameter1-3/+15
The constructor for buffer_head slabs was removed recently. We need the constructor back in slab defrag in order to insure that slab objects always have a definite state even before we allocated them. I think we mistakenly merged the removal of the constuctor into a cleanup patch. You (ie: akpm) had a test that showed that the removal of the constructor led to a small regression. The prior state makes things easier for slab defrag. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05is_vmalloc_addr(): Check if an address is within the vmalloc boundariesChristoph Lameter4-7/+4
Checking if an address is a vmalloc address is done in a couple of places. Define a common version in mm.h and replace the other checks. Again the include structures suck. The definition of VMALLOC_START and VMALLOC_END is not available in vmalloc.h since highmem.c cannot be included there. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05Pagecache zeroing: zero_user_segment, zero_user_segments and zero_userChristoph Lameter19-96/+71
Simplify page cache zeroing of segments of pages through 3 functions zero_user_segments(page, start1, end1, start2, end2) Zeros two segments of the page. It takes the position where to start and end the zeroing which avoids length calculations and makes code clearer. zero_user_segment(page, start, end) Same for a single segment. zero_user(page, start, length) Length variant for the case where we know the length. We remove the zero_user_page macro. Issues: 1. Its a macro. Inline functions are preferable. 2. The KM_USER0 macro is only defined for HIGHMEM. Having to treat this special case everywhere makes the code needlessly complex. The parameter for zeroing is always KM_USER0 except in one single case that we open code. Avoiding KM_USER0 makes a lot of code not having to be dealing with the special casing for HIGHMEM anymore. Dealing with kmap is only necessary for HIGHMEM configurations. In those configurations we use KM_USER0 like we do for a series of other functions defined in highmem.h. Since KM_USER0 is depends on HIGHMEM the existing zero_user_page function could not be a macro. zero_user_* functions introduced here can be be inline because that constant is not used when these functions are called. Also extract the flushing of the caches to be outside of the kmap. [akpm@linux-foundation.org: fix nfs and ntfs build] [akpm@linux-foundation.org: fix ntfs build some more] Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Steven French <sfrench@us.ibm.com> Cc: Michael Halcrow <mhalcrow@us.ibm.com> Cc: <linux-ext4@vger.kernel.org> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Anton Altaparmakov <aia21@cantab.net> Cc: Mark Fasheh <mark.fasheh@oracle.com> Cc: David Chinner <dgc@sgi.com> Cc: Michael Halcrow <mhalcrow@us.ibm.com> Cc: Steven French <sfrench@us.ibm.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05timerfd: new timerfd APIDavide Libenzi2-74/+165
This is the new timerfd API as it is implemented by the following patch: int timerfd_create(int clockid, int flags); int timerfd_settime(int ufd, int flags, const struct itimerspec *utmr, struct itimerspec *otmr); int timerfd_gettime(int ufd, struct itimerspec *otmr); The timerfd_create() API creates an un-programmed timerfd fd. The "clockid" parameter can be either CLOCK_MONOTONIC or CLOCK_REALTIME. The timerfd_settime() API give new settings by the timerfd fd, by optionally retrieving the previous expiration time (in case the "otmr" parameter is not NULL). The time value specified in "utmr" is absolute, if the TFD_TIMER_ABSTIME bit is set in the "flags" parameter. Otherwise it's a relative time. The timerfd_gettime() API returns the next expiration time of the timer, or {0, 0} if the timerfd has not been set yet. Like the previous timerfd API implementation, read(2) and poll(2) are supported (with the same interface). Here's a simple test program I used to exercise the new timerfd APIs: http://www.xmailserver.org/timerfd-test2.c [akpm@linux-foundation.org: coding-style cleanups] [akpm@linux-foundation.org: fix ia64 build] [akpm@linux-foundation.org: fix m68k build] [akpm@linux-foundation.org: fix mips build] [akpm@linux-foundation.org: fix alpha, arm, blackfin, cris, m68k, s390, sparc and sparc64 builds] [heiko.carstens@de.ibm.com: fix s390] [akpm@linux-foundation.org: fix powerpc build] [akpm@linux-foundation.org: fix sparc64 more] Signed-off-by: Davide Libenzi <davidel@xmailserver.org> Cc: Michael Kerrisk <mtk-manpages@gmx.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Davide Libenzi <davidel@xmailserver.org> Cc: Michael Kerrisk <mtk-manpages@gmx.net> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05exec: rework the group exit and fix the race with killOleg Nesterov1-9/+4
As Roland pointed out, we have the very old problem with exec. de_thread() sets SIGNAL_GROUP_EXIT, kills other threads, changes ->group_leader and then clears signal->flags. All signals (even fatal ones) sent in this window (which is not too small) will be lost. With this patch exec doesn't abuse SIGNAL_GROUP_EXIT. signal_group_exit(), the new helper, should be used to detect exit_group() or exec() in progress. It can have more users, but this patch does only strictly necessary changes. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Davide Libenzi <davidel@xmailserver.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Robin Holt <holt@sgi.com> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05get_task_comm(): return the resultAndrew Morton1-1/+2
It was dumb to make get_task_comm() return void. Change it to return a pointer to the resulting output for caller convenience. Cc: Ulrich Drepper <drepper@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05lockdep: annotate epollPeter Zijlstra1-1/+1
On Sat, 2008-01-05 at 13:35 -0800, Davide Libenzi wrote: > I remember I talked with Arjan about this time ago. Basically, since 1) > you can drop an epoll fd inside another epoll fd 2) callback-based wakeups > are used, you can see a wake_up() from inside another wake_up(), but they > will never refer to the same lock instance. > Think about: > > dfd = socket(...); > efd1 = epoll_create(); > efd2 = epoll_create(); > epoll_ctl(efd1, EPOLL_CTL_ADD, dfd, ...); > epoll_ctl(efd2, EPOLL_CTL_ADD, efd1, ...); > > When a packet arrives to the device underneath "dfd", the net code will > issue a wake_up() on its poll wake list. Epoll (efd1) has installed a > callback wakeup entry on that queue, and the wake_up() performed by the > "dfd" net code will end up in ep_poll_callback(). At this point epoll > (efd1) notices that it may have some event ready, so it needs to wake up > the waiters on its poll wait list (efd2). So it calls ep_poll_safewake() > that ends up in another wake_up(), after having checked about the > recursion constraints. That are, no more than EP_MAX_POLLWAKE_NESTS, to > avoid stack blasting. Never hit the same queue, to avoid loops like: > > epoll_ctl(efd2, EPOLL_CTL_ADD, efd1, ...); > epoll_ctl(efd3, EPOLL_CTL_ADD, efd2, ...); > epoll_ctl(efd4, EPOLL_CTL_ADD, efd3, ...); > epoll_ctl(efd1, EPOLL_CTL_ADD, efd4, ...); > > The code "if (tncur->wq == wq || ..." prevents re-entering the same > queue/lock. Since the epoll code is very careful to not nest same instance locks allow the recursion. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Stefan Richter <stefanr@s5r6.in-berlin.de> Acked-by: Davide Libenzi <davidel@xmailserver.org> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-04Merge git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivialLinus Torvalds14-16/+16
* git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial: (79 commits) Jesper Juhl is the new trivial patches maintainer Documentation: mention email-clients.txt in SubmittingPatches fs/binfmt_elf.c: spello fix do_invalidatepage() comment typo fix Documentation/filesystems/porting fixes typo fixes in net/core/net_namespace.c typo fix in net/rfkill/rfkill.c typo fixes in net/sctp/sm_statefuns.c lib/: Spelling fixes kernel/: Spelling fixes include/scsi/: Spelling fixes include/linux/: Spelling fixes include/asm-m68knommu/: Spelling fixes include/asm-frv/: Spelling fixes fs/: Spelling fixes drivers/watchdog/: Spelling fixes drivers/video/: Spelling fixes drivers/ssb/: Spelling fixes drivers/serial/: Spelling fixes drivers/scsi/: Spelling fixes ...
2008-02-04Merge branch 'locks' of git://linux-nfs.org/~bfields/linuxLinus Torvalds1-61/+64
* 'locks' of git://linux-nfs.org/~bfields/linux: pid-namespaces-vs-locks-interaction file locks: Use wait_event_interruptible_timeout() locks: clarify posix_locks_deadlock
2008-02-04vm audit: add VM_DONTEXPAND to mmap for drivers that need itNick Piggin1-4/+0
Drivers that register a ->fault handler, but do not range-check the offset argument, must set VM_DONTEXPAND in the vm_flags in order to prevent an expanding mremap from overflowing the resource. I've audited the tree and attempted to fix these problems (usually by adding VM_DONTEXPAND where it is not obvious). Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-03pid-namespaces-vs-locks-interactionVitaliy Gusev1-6/+23
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 <vgusev@openvz.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2008-02-03file locks: Use wait_event_interruptible_timeout()Matthew Wilcox1-28/+4
interruptible_sleep_on_locked() is just an open-coded wait_event_interruptible_timeout(), with the one difference that interruptible_sleep_on_locked() doesn't bother to check the condition on which it is waiting, depending instead on the BKL to avoid the case where it blocks after the wakeup has already been called. locks_block_on_timeout() is only used in one place, so it's actually simpler to inline it into its caller. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2008-02-03locks: clarify posix_locks_deadlockJ. Bruce Fields1-30/+40
For such a short function (with such a long comment), posix_locks_deadlock() seems to cause a lot of confusion. Attempt to make it a bit clearer: - Remove the initial posix_same_owner() check, which can never pass (since this is only called in the case that block_fl and caller_fl conflict) - Use an explicit loop (and a helper function) instead of a goto. - Rewrite the comment, attempting a clearer explanation, and removing some uninteresting historical detail. Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2008-02-03fs/binfmt_elf.c: spello fixOhad Ben-Cohen1-1/+1
s/litle/little Signed-off-by: Ohad Ben-Cohen <ohad@bencohen.org> Signed-off-by: Adrian Bunk <bunk@kernel.org>
2008-02-03fs/: Spelling fixesJoe Perches9-11/+11
Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Adrian Bunk <bunk@kernel.org>
2008-02-03Spelling fixes: lenght->lengthPaulius Zaleckas2-2/+2
Signed-off-by: Paulius Zaleckas <pauliusz@yahoo.com> Signed-off-by: Adrian Bunk <bunk@kernel.org>
2008-02-03Typoes: "whith" -> "with"Robert P. J. Day1-1/+1
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca> Signed-off-by: Adrian Bunk <bunk@kernel.org>
2008-02-03Fix a small number of "memeber" typoes.Robert P. J. Day1-1/+1
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca> Signed-off-by: Adrian Bunk <bunk@kernel.org>
2008-02-02Merge branch 'for-linus' of git://linux-nfs.org/~bfields/linuxLinus Torvalds23-375/+466
* 'for-linus' of git://linux-nfs.org/~bfields/linux: (100 commits) SUNRPC: RPC program information is stored in unsigned integers SUNRPC: Move exported symbol definitions after function declaration part 2 NLM: tear down RPC clients in nlm_shutdown_hosts SUNRPC: spin svc_rqst initialization to its own function nfsd: more careful input validation in nfsctl write methods lockd: minor log message fix knfsd: don't bother mapping putrootfh enoent to eperm rdma: makefile rdma: ONCRPC RDMA protocol marshalling rdma: SVCRDMA sendto rdma: SVCRDMA recvfrom rdma: SVCRDMA Core Transport Services rdma: SVCRDMA Transport Module rdma: SVCRMDA Header File svc: Add svc_xprt_names service to replace svc_sock_names knfsd: Support adding transports by writing portlist file svc: Add svc API that queries for a transport instance svc: Add /proc/sys/sunrpc/transport files svc: Add transport hdr size for defer/revisit svc: Move the xprt independent code to the svc_xprt.c file ...
2008-02-01NLM: tear down RPC clients in nlm_shutdown_hostsJeff Layton1-1/+6
It's possible for a RPC to outlive the lockd daemon that created it, so we need to make sure that all RPC's are killed when lockd is coming down. When nlm_shutdown_hosts is called, kill off all RPC tasks associated with the host. Since we need to wait until they have all gone away, we might as well just shut down the RPC client altogether. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2008-02-01nfsd: more careful input validation in nfsctl write methodsJ. Bruce Fields1-1/+4
Neil Brown points out that we're checking buf[size-1] in a couple places without first checking whether size is zero. Actually, given the implementation of simple_transaction_get(), buf[-1] is zero, so in both of these cases the subsequent check of the value of buf[size-1] will catch this case. But it seems fragile to depend on that, so add explicit checks for this case. Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu> Acked-by: NeilBrown <neilb@suse.de>
2008-02-01lockd: minor log message fixJ. Bruce Fields1-1/+1
Wendy Cheng noticed that function name doesn't agree here. Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu> Cc: Wendy Cheng <wcheng@redhat.com>
2008-02-01knfsd: don't bother mapping putrootfh enoent to epermJ. Bruce Fields1-2/+0
Neither EPERM and ENOENT map to valid errors for PUTROOTFH according to rfc 3530, and, if anything, ENOENT is likely to be slightly more informative; so don't bother mapping ENOENT to EPERM. (Probably this was originally done because one likely cause was that there is an fsid=0 export but that it isn't permitted to this particular client. Now that we allow WRONGSEC returns, this is somewhat less likely.) In the long term we should work to make this situation less likely, perhaps by turning off nfsv4 service entirely in the absence of the pseudofs root, or constructing a pseudofilesystem root ourselves in the kernel as necessary. Thanks to Benny Halevy <bhalevy@panasas.com> for pointing out this problem. Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu> Cc: Benny Halevy <bhalevy@panasas.com>
2008-02-01svc: Add svc_xprt_names service to replace svc_sock_namesTom Tucker1-1/+1
Create a transport independent version of the svc_sock_names function. The toclose capability of the svc_sock_names service can be implemented using the svc_xprt_find and svc_xprt_close services. Signed-off-by: Tom Tucker <tom@opengridcomputing.com> Acked-by: Neil Brown <neilb@suse.de> Reviewed-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Greg Banks <gnb@sgi.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2008-02-01knfsd: Support adding transports by writing portlist fileTom Tucker2-6/+61
Update the write handler for the portlist file to allow creating new listening endpoints on a transport. The general form of the string is: <transport_name><space><port number> For example: echo "tcp 2049" > /proc/fs/nfsd/portlist This is intended to support the creation of a listening endpoint for RDMA transports without adding #ifdef code to the nfssvc.c file. Transports can also be removed as follows: '-'<transport_name><space><port number> For example: echo "-tcp 2049" > /proc/fs/nfsd/portlist Attempting to add a listener with an invalid transport string results in EPROTONOSUPPORT and a perror string of "Protocol not supported". Attempting to remove an non-existent listener (.e.g. bad proto or port) results in ENOTCONN and a perror string of "Transport endpoint is not connected" Signed-off-by: Tom Tucker <tom@opengridcomputing.com> Acked-by: Neil Brown <neilb@suse.de> Reviewed-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Greg Banks <gnb@sgi.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2008-02-01svc: Add svc API that queries for a transport instanceTom Tucker1-14/+2
Add a new svc function that allows a service to query whether a transport instance has already been created. This is used in lockd to determine whether or not a transport needs to be created when a lockd instance is brought up. Specifying 0 for the address family or port is effectively a wild-card, and will result in matching the first transport in the service's list that has a matching class name. Signed-off-by: Tom Tucker <tom@opengridcomputing.com> Acked-by: Neil Brown <neilb@suse.de> Reviewed-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Greg Banks <gnb@sgi.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2008-02-01svc: Make close transport independentTom Tucker2-5/+5
Move sk_list and sk_ready to svc_xprt. This involves close because these lists are walked by svcs when closing all their transports. So I combined the moving of these lists to svc_xprt with making close transport independent. The svc_force_sock_close has been changed to svc_close_all and takes a list as an argument. This removes some svc internals knowledge from the svcs. This code races with module removal and transport addition. Thanks to Simon Holm Thøgersen for a compile fix. Signed-off-by: Tom Tucker <tom@opengridcomputing.com> Acked-by: Neil Brown <neilb@suse.de> Reviewed-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Greg Banks <gnb@sgi.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu> Cc: Simon Holm Thøgersen <odie@cs.aau.dk>
2008-02-01svc: Change services to use new svc_create_xprt serviceTom Tucker3-13/+12
Modify the various kernel RPC svcs to use the svc_create_xprt service. Signed-off-by: Tom Tucker <tom@opengridcomputing.com> Acked-by: Neil Brown <neilb@suse.de> Reviewed-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Greg Banks <gnb@sgi.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2008-02-01Leak in nlmsvc_testlock for async GETFL caseOleg Drokin1-1/+1
Fix nlm_block leak for the case of supplied blocking lock info. Signed-off-by: Oleg Drokin <green@linuxhacker.ru> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2008-02-01nfsd4: clean up access_valid, deny_valid checks.J. Bruce Fields1-4/+9
Document these checks a little better and inline, as suggested by Neil Brown (note both functions have two callers). Remove an obviously bogus check while we're there (checking whether unsigned value is negative). Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu> Cc: Neil Brown <neilb@suse.de>
2008-02-01nfsd: allow root to set uid and gid on createJ. Bruce Fields1-19/+28
The server silently ignores attempts to set the uid and gid on create. Based on the comment, this appears to have been done to prevent some overly-clever IRIX client from causing itself problems. Perhaps we should remove that hack completely. For now, at least, it makes sense to allow root (when no_root_squash is set) to set uid and gid. While we're there, since nfsd_create and nfsd_create_v3 share the same logic, pull that out into a separate function. And spell out the individual modifications of ia_valid instead of doing them both at once inside a conditional. Thanks to Roger Willcocks <roger@filmlight.ltd.uk> for the bug report and original patch on which this is based. Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2008-02-01lockd: fix a leak in nlmsvc_testlock asynchronous request handlingOleg Drokin1-7/+11
Without the patch, there is a leakage of nlmblock structure refcount that holds a reference nlmfile structure, that holds a reference to struct file, when async GETFL is used (-EINPROGRESS return from file_ops->lock()), and also in some error cases. Fix up a style nit while we're here. Signed-off-by: Oleg Drokin <green@linuxhacker.ru> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2008-02-01nfsd: Allow AIX client to read dir containing mountpointsFrank Filz2-6/+23
This patch addresses a compatibility issue with a Linux NFS server and AIX NFS client. I have exported /export as fsid=0 with sec=krb5:krb5i I have mount --bind /home onto /export/home I have exported /export/home with sec=krb5i The AIX client mounts / -o sec=krb5:krb5i onto /mnt If I do an ls /mnt, the AIX client gets a permission error. Looking at the network traceIwe see a READDIR looking for attributes FATTR4_RDATTR_ERROR and FATTR4_MOUNTED_ON_FILEID. The response gives a NFS4ERR_WRONGSEC which the AIX client is not expecting. Since the AIX client is only asking for an attribute that is an attribute of the parent file system (pseudo root in my example), it seems reasonable that there should not be an error. In discussing this issue with Bruce Fields, I initially proposed ignoring the error in nfsd4_encode_dirent_fattr() if all that was being asked for was FATTR4_RDATTR_ERROR and FATTR4_MOUNTED_ON_FILEID, however, Bruce suggested that we avoid calling cross_mnt() if only these attributes are requested. The following patch implements bypassing cross_mnt() if only FATTR4_RDATTR_ERROR and FATTR4_MOUNTED_ON_FILEID are called. Since there is some complexity in the code in nfsd4_encode_fattr(), I didn't want to duplicate code (and introduce a maintenance nightmare), so I added a parameter to nfsd4_encode_fattr() that indicates whether it should ignore cross mounts and simply fill in the attribute using the passed in dentry as opposed to it's parent. Signed-off-by: Frank Filz <ffilzlnx@us.ibm.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>