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* hlist: drop the node parameter from iteratorsSasha Levin2013-02-271-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I'm not sure why, but the hlist for each entry iterators were conceived list_for_each_entry(pos, head, member) The hlist ones were greedy and wanted an extra parameter: hlist_for_each_entry(tpos, pos, head, member) Why did they need an extra pos parameter? I'm not quite sure. Not only they don't really need it, it also prevents the iterator from looking exactly like the list iterator, which is unfortunate. Besides the semantic patch, there was some manual work required: - Fix up the actual hlist iterators in linux/list.h - Fix up the declaration of other iterators based on the hlist ones. - A very small amount of places were using the 'node' parameter, this was modified to use 'obj->member' instead. - Coccinelle didn't handle the hlist_for_each_entry_safe iterator properly, so those had to be fixed up manually. The semantic patch which is mostly the work of Peter Senna Tschudin is here: @@ iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host; type T; expression a,c,d,e; identifier b; statement S; @@ -T b; <+... when != b ( hlist_for_each_entry(a, - b, c, d) S | hlist_for_each_entry_continue(a, - b, c) S | hlist_for_each_entry_from(a, - b, c) S | hlist_for_each_entry_rcu(a, - b, c, d) S | hlist_for_each_entry_rcu_bh(a, - b, c, d) S | hlist_for_each_entry_continue_rcu_bh(a, - b, c) S | for_each_busy_worker(a, c, - b, d) S | ax25_uid_for_each(a, - b, c) S | ax25_for_each(a, - b, c) S | inet_bind_bucket_for_each(a, - b, c) S | sctp_for_each_hentry(a, - b, c) S | sk_for_each(a, - b, c) S | sk_for_each_rcu(a, - b, c) S | sk_for_each_from -(a, b) +(a) S + sk_for_each_from(a) S | sk_for_each_safe(a, - b, c, d) S | sk_for_each_bound(a, - b, c) S | hlist_for_each_entry_safe(a, - b, c, d, e) S | hlist_for_each_entry_continue_rcu(a, - b, c) S | nr_neigh_for_each(a, - b, c) S | nr_neigh_for_each_safe(a, - b, c, d) S | nr_node_for_each(a, - b, c) S | nr_node_for_each_safe(a, - b, c, d) S | - for_each_gfn_sp(a, c, d, b) S + for_each_gfn_sp(a, c, d) S | - for_each_gfn_indirect_valid_sp(a, c, d, b) S + for_each_gfn_indirect_valid_sp(a, c, d) S | for_each_host(a, - b, c) S | for_each_host_safe(a, - b, c, d) S | for_each_mesh_entry(a, - b, c, d) S ) ...+> [akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c] [akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c] [akpm@linux-foundation.org: checkpatch fixes] [akpm@linux-foundation.org: fix warnings] [akpm@linux-foudnation.org: redo intrusive kvm changes] Tested-by: Peter Senna Tschudin <peter.senna@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: make do_mmap_pgoff return populate as a size in bytes, not as a boolMichel Lespinasse2013-02-231-3/+2
| | | | | | | | | | | | | | | | | | | do_mmap_pgoff() rounds up the desired size to the next PAGE_SIZE multiple, however there was no equivalent code in mm_populate(), which caused issues. This could be fixed by introduced the same rounding in mm_populate(), however I think it's preferable to make do_mmap_pgoff() return populate as a size rather than as a boolean, so we don't have to duplicate the size rounding logic in mm_populate(). Signed-off-by: Michel Lespinasse <walken@google.com> Acked-by: Rik van Riel <riel@redhat.com> Tested-by: Andy Lutomirski <luto@amacapital.net> Cc: Greg Ungerer <gregungerer@westnet.com.au> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: introduce mm_populate() for populating new vmasMichel Lespinasse2013-02-231-1/+5
| | | | | | | | | | | | | | | | | | | | | | | When creating new mappings using the MAP_POPULATE / MAP_LOCKED flags (or with MCL_FUTURE in effect), we want to populate the pages within the newly created vmas. This may take a while as we may have to read pages from disk, so ideally we want to do this outside of the write-locked mmap_sem region. This change introduces mm_populate(), which is used to defer populating such mappings until after the mmap_sem write lock has been released. This is implemented as a generalization of the former do_mlock_pages(), which accomplished the same task but was using during mlock() / mlockall(). Signed-off-by: Michel Lespinasse <walken@google.com> Reported-by: Andy Lutomirski <luto@amacapital.net> Acked-by: Rik van Riel <riel@redhat.com> Tested-by: Andy Lutomirski <luto@amacapital.net> Cc: Greg Ungerer <gregungerer@westnet.com.au> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* aio: now fput() is OK from interrupt context; get rid of manual delayed __fput()Al Viro2012-07-221-70/+3
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge branch 'for-linus' of ↵Linus Torvalds2012-06-011-3/+3
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 ...
| * switch aio and shm to do_mmap_pgoff(), make do_mmap() staticAl Viro2012-06-011-3/+3
| | | | | | | | | | | | after all, 0 bytes and 0 pages is the same thing... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | aio/vfs: cleanup of rw_copy_check_uvector() and compat_rw_copy_check_uvector()Christopher Yeoh2012-05-311-2/+2
|/ | | | | | | | | | | | | | | | | | 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>
* vfs: make AIO use the proper rw_verify_area() area helpersLinus Torvalds2012-05-211-16/+14
| | | | | | | | | | | | | | | | | | We had for some reason overlooked the AIO interface, and it didn't use the proper rw_verify_area() helper function that checks (for example) mandatory locking on the file, and that the size of the access doesn't cause us to overflow the provided offset limits etc. Instead, AIO did just the security_file_permission() thing (that rw_verify_area() also does) directly. This fixes it to do all the proper helper functions, which not only means that now mandatory file locking works with AIO too, we can actually remove lines of code. Reported-by: Manish Honap <manish_honap_vit@yahoo.co.in> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kill mm argument of vm_munmap()Al Viro2012-04-211-1/+1
| | | | | | it's always current->mm Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* aio: don't bother with unmapping when aio_free_ring() is coming from exit_aio()Al Viro2012-04-211-1/+14
| | | | | | | | | ... since exit_mmap() is coming and it will munmap() everything anyway. In all other cases aio_free_ring() has ctx->mm == current->mm; moreover, all other callers of vm_munmap() have mm == current->mm, so this will allow us to get rid of mm argument of vm_munmap(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* VM: add "vm_munmap()" helper functionLinus Torvalds2012-04-201-5/+2
| | | | | | | Like the vm_brk() function, this is the same as "do_munmap()", except it does the VM locking for the caller. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* aio: take final put_ioctx() into callers of io_destroy()Al Viro2012-03-311-6/+4
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* aio: merge aio_cancel_all() with wait_for_all_aios()Al Viro2012-03-311-15/+7
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge tag 'module-for-3.4' of ↵Linus Torvalds2012-03-241-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux Pull cleanup of fs/ and lib/ users of module.h from Paul Gortmaker: "Fix up files in fs/ and lib/ dirs to only use module.h if they really need it. These are trivial in scope vs the work done previously. We now have things where any few remaining cleanups can be farmed out to arch or subsystem maintainers, and I have done so when possible. What is remaining here represents the bits that don't clearly lie within a single arch/subsystem boundary, like the fs dir and the lib dir. Some duplicate includes arising from overlapping fixes from independent subsystem maintainer submissions are also quashed." Fix up trivial conflicts due to clashes with other include file cleanups (including some due to the previous bug.h cleanup pull). * tag 'module-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: lib: reduce the use of module.h wherever possible fs: reduce the use of module.h wherever possible includecheck: delete any duplicate instances of module.h
| * fs: reduce the use of module.h wherever possiblePaul Gortmaker2012-02-281-1/+1
| | | | | | | | | | | | | | | | | | | | For files only using THIS_MODULE and/or EXPORT_SYMBOL, map them onto including export.h -- or if the file isn't even using those, then just delete the include. Fix up any implicit include dependencies that were being masked by module.h along the way. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* | Merge branch 'for-linus' of ↵Linus Torvalds2012-03-211-43/+22
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs pile 1 from Al Viro: "This is _not_ all; in particular, Miklos' and Jan's stuff is not there yet." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (64 commits) ext4: initialization of ext4_li_mtx needs to be done earlier debugfs-related mode_t whack-a-mole hfsplus: add an ioctl to bless files hfsplus: change finder_info to u32 hfsplus: initialise userflags qnx4: new helper - try_extent() qnx4: get rid of qnx4_bread/qnx4_getblk take removal of PF_FORKNOEXEC to flush_old_exec() trim includes in inode.c um: uml_dup_mmap() relies on ->mmap_sem being held, but activate_mm() doesn't hold it um: embed ->stub_pages[] into mmu_context gadgetfs: list_for_each_safe() misuse ocfs2: fix leaks on failure exits in module_init ecryptfs: make register_filesystem() the last potential failure exit ntfs: forgets to unregister sysctls on register_filesystem() failure logfs: missing cleanup on register_filesystem() failure jfs: mising cleanup on register_filesystem() failure make configfs_pin_fs() return root dentry on success configfs: configfs_create_dir() has parent dentry in dentry->d_parent configfs: sanitize configfs_create() ...
| * | aio: fix the comment in aio_kick_handler()Al Viro2012-03-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | It should've been changed when queue_work() became queue_delayed_work(..., 0) in there. It's always had been about not needing a delay, not about not using specific function... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | aio: don't bother with cancel_delayed_work() in exit_aio()Al Viro2012-03-201-4/+0
| | | | | | | | | | | | | | | | | | __put_ioctx() will cover it anyway. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | aio: use cancel_delayed_work_sync()Al Viro2012-03-201-2/+1
| | | | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | aio: aio_nr_lock is taken only synchronously nowAl Viro2012-03-201-3/+3
| | | | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | aio: aio_nr decrements don't need to be delayedAl Viro2012-03-201-28/+14
| | | | | | | | | | | | | | | | | | | | | we can do that right in __put_ioctx(); as the result, the loop in ioctx_alloc() can be killed. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | aio: don't bother with async freeing on failure in ioctx_alloc()Al Viro2012-03-201-7/+5
| | | | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | | fs: remove the second argument of k[un]map_atomic()Cong Wang2012-03-201-15/+15
|/ / | | | | | | | | Acked-by: Benjamin LaHaise <bcrl@kvack.org> Signed-off-by: Cong Wang <amwang@redhat.com>
* | aio: fix the "too late munmap()" raceAl Viro2012-03-091-8/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Current code has put_ioctx() called asynchronously from aio_fput_routine(); that's done *after* we have killed the request that used to pin ioctx, so there's nothing to stop io_destroy() waiting in wait_for_all_aios() from progressing. As the result, we can end up with async call of put_ioctx() being the last one and possibly happening during exit_mmap() or elf_core_dump(), neither of which expects stray munmap() being done to them... We do need to prevent _freeing_ ioctx until aio_fput_routine() is done with that, but that's all we care about - neither io_destroy() nor exit_aio() will progress past wait_for_all_aios() until aio_fput_routine() does really_put_req(), so the ioctx teardown won't be done until then and we don't care about the contents of ioctx past that point. Since actual freeing of these suckers is RCU-delayed, we don't need to bump ioctx refcount when request goes into list for async removal. All we need is rcu_read_lock held just over the ->ctx_lock-protected area in aio_fput_routine(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Acked-by: Benjamin LaHaise <bcrl@kvack.org> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | aio: fix io_setup/io_destroy raceAl Viro2012-03-091-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Have ioctx_alloc() return an extra reference, so that caller would drop it on success and not bother with re-grabbing it on failure exit. The current code is obviously broken - io_destroy() from another thread that managed to guess the address io_setup() would've returned would free ioctx right under us; gets especially interesting if aio_context_t * we pass to io_setup() points to PROT_READ mapping, so put_user() fails and we end up doing io_destroy() on kioctx another thread has just got freed... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Acked-by: Benjamin LaHaise <bcrl@kvack.org> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | aio: wake up waiters when freeing unused kiocbsJeff Moyer2012-03-051-0/+2
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Bart Van Assche reported a hung fio process when either hot-removing storage or when interrupting the fio process itself. The (pruned) call trace for the latter looks like so: fio D 0000000000000001 0 6849 6848 0x00000004 ffff880092541b88 0000000000000046 ffff880000000000 ffff88012fa11dc0 ffff88012404be70 ffff880092541fd8 ffff880092541fd8 ffff880092541fd8 ffff880128b894d0 ffff88012404be70 ffff880092541b88 000000018106f24d Call Trace: schedule+0x3f/0x60 io_schedule+0x8f/0xd0 wait_for_all_aios+0xc0/0x100 exit_aio+0x55/0xc0 mmput+0x2d/0x110 exit_mm+0x10d/0x130 do_exit+0x671/0x860 do_group_exit+0x44/0xb0 get_signal_to_deliver+0x218/0x5a0 do_signal+0x65/0x700 do_notify_resume+0x65/0x80 int_signal+0x12/0x17 The problem lies with the allocation batching code. It will opportunistically allocate kiocbs, and then trim back the list of iocbs when there is not enough room in the completion ring to hold all of the events. In the case above, what happens is that the pruning back of events ends up freeing up the last active request and the context is marked as dead, so it is thus responsible for waking up waiters. Unfortunately, the code does not check for this condition, so we end up with a hung task. Signed-off-by: Jeff Moyer <jmoyer@redhat.com> Reported-by: Bart Van Assche <bvanassche@acm.org> Tested-by: Bart Van Assche <bvanassche@acm.org> Cc: <stable@kernel.org> [3.2.x only] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Unused iocbs in a batch should not be accounted as active.Gleb Natapov2012-01-131-2/+9
| | | | | | | | | | | | | | | | | | | | | | | Since commit 080d676de095 ("aio: allocate kiocbs in batches") iocbs are allocated in a batch during processing of first iocbs. All iocbs in a batch are automatically added to ctx->active_reqs list and accounted in ctx->reqs_active. If one (not the last one) of iocbs submitted by an user fails, further iocbs are not processed, but they are still present in ctx->active_reqs and accounted in ctx->reqs_active. This causes process to stuck in a D state in wait_for_all_aios() on exit since ctx->reqs_active will never go down to zero. Furthermore since kiocb_batch_free() frees iocb without removing it from active_reqs list the list become corrupted which may cause oops. Fix this by removing iocb from ctx->active_reqs and updating ctx->reqs_active in kiocb_batch_free(). Signed-off-by: Gleb Natapov <gleb@redhat.com> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Cc: stable@kernel.org # 3.2 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* aio: allocate kiocbs in batchesJeff Moyer2011-11-021-29/+107
| | | | | | | | | | | | | | | | | | | | | | | In testing aio on a fast storage device, I found that the context lock takes up a fair amount of cpu time in the I/O submission path. The reason is that we take it for every I/O submitted (see __aio_get_req). Since we know how many I/Os are passed to io_submit, we can preallocate the kiocbs in batches, reducing the number of times we take and release the lock. In my testing, I was able to reduce the amount of time spent in _raw_spin_lock_irq by .56% (average of 3 runs). The command I used to test this was: aio-stress -O -o 2 -o 3 -r 8 -d 128 -b 32 -i 32 -s 16384 <dev> I also tested the patch with various numbers of events passed to io_submit, and I ran the xfstests aio group of tests to ensure I didn't break anything. Signed-off-by: Jeff Moyer <jmoyer@redhat.com> Cc: Daniel Ehrenberg <dehrenberg@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Cross Memory AttachChristopher Yeoh2011-10-311-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The basic idea behind cross memory attach is to allow MPI programs doing intra-node communication to do a single copy of the message rather than a double copy of the message via shared memory. The following patch attempts to achieve this by allowing a destination process, given an address and size from a source process, to copy memory directly from the source process into its own address space via a system call. There is also a symmetrical ability to copy from the current process's address space into a destination process's address space. - Use of /proc/pid/mem has been considered, but there are issues with using it: - Does not allow for specifying iovecs for both src and dest, assuming preadv or pwritev was implemented either the area read from or written to would need to be contiguous. - Currently mem_read allows only processes who are currently ptrace'ing the target and are still able to ptrace the target to read from the target. This check could possibly be moved to the open call, but its not clear exactly what race this restriction is stopping (reason appears to have been lost) - Having to send the fd of /proc/self/mem via SCM_RIGHTS on unix domain socket is a bit ugly from a userspace point of view, especially when you may have hundreds if not (eventually) thousands of processes that all need to do this with each other - Doesn't allow for some future use of the interface we would like to consider adding in the future (see below) - Interestingly reading from /proc/pid/mem currently actually involves two copies! (But this could be fixed pretty easily) As mentioned previously use of vmsplice instead was considered, but has problems. Since you need the reader and writer working co-operatively if the pipe is not drained then you block. Which requires some wrapping to do non blocking on the send side or polling on the receive. In all to all communication it requires ordering otherwise you can deadlock. And in the example of many MPI tasks writing to one MPI task vmsplice serialises the copying. There are some cases of MPI collectives where even a single copy interface does not get us the performance gain we could. For example in an MPI_Reduce rather than copy the data from the source we would like to instead use it directly in a mathops (say the reduce is doing a sum) as this would save us doing a copy. We don't need to keep a copy of the data from the source. I haven't implemented this, but I think this interface could in the future do all this through the use of the flags - eg could specify the math operation and type and the kernel rather than just copying the data would apply the specified operation between the source and destination and store it in the destination. Although we don't have a "second user" of the interface (though I've had some nibbles from people who may be interested in using it for intra process messaging which is not MPI). This interface is something which hardware vendors are already doing for their custom drivers to implement fast local communication. And so in addition to this being useful for OpenMPI it would mean the driver maintainers don't have to fix things up when the mm changes. There was some discussion about how much faster a true zero copy would go. Here's a link back to the email with some testing I did on that: http://marc.info/?l=linux-mm&m=130105930902915&w=2 There is a basic man page for the proposed interface here: http://ozlabs.org/~cyeoh/cma/process_vm_readv.txt This has been implemented for x86 and powerpc, other architecture should mainly (I think) just need to add syscall numbers for the process_vm_readv and process_vm_writev. There are 32 bit compatibility versions for 64-bit kernels. For arch maintainers there are some simple tests to be able to quickly verify that the syscalls are working correctly here: http://ozlabs.org/~cyeoh/cma/cma-test-20110718.tgz Signed-off-by: Chris Yeoh <yeohc@au1.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Howells <dhowells@redhat.com> Cc: James Morris <jmorris@namei.org> Cc: <linux-man@vger.kernel.org> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds2011-03-241-70/+7
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block: (65 commits) Documentation/iostats.txt: bit-size reference etc. cfq-iosched: removing unnecessary think time checking cfq-iosched: Don't clear queue stats when preempt. blk-throttle: Reset group slice when limits are changed blk-cgroup: Only give unaccounted_time under debug cfq-iosched: Don't set active queue in preempt block: fix non-atomic access to genhd inflight structures block: attempt to merge with existing requests on plug flush block: NULL dereference on error path in __blkdev_get() cfq-iosched: Don't update group weights when on service tree fs: assign sb->s_bdi to default_backing_dev_info if the bdi is going away block: Require subsystems to explicitly allocate bio_set integrity mempool jbd2: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging jbd: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging fs: make fsync_buffers_list() plug mm: make generic_writepages() use plugging blk-cgroup: Add unaccounted time to timeslice_used. block: fixup plugging stubs for !CONFIG_BLOCK block: remove obsolete comments for blkdev_issue_zeroout. blktrace: Use rq->cmd_flags directly in blk_add_trace_rq. ... Fix up conflicts in fs/{aio.c,super.c}
| * Merge branch 'for-2.6.39/stack-plug' into for-2.6.39/coreJens Axboe2011-03-101-70/+7
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: block/blk-core.c block/blk-flush.c drivers/md/raid1.c drivers/md/raid10.c drivers/md/raid5.c fs/nilfs2/btnode.c fs/nilfs2/mdt.c Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
| | * aio: remove request submission batchingJens Axboe2011-03-101-72/+3
| | | | | | | | | | | | | | | | | | | | | This should be useless now that we have on-stack plugging. So lets just kill it. Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
| | * fs: make aio plugShaohua Li2011-03-101-0/+4
| | | | | | | | | | | | | | | Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
| | * block: remove per-queue pluggingJens Axboe2011-03-101-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | Code has been converted over to the new explicit on-stack plugging, and delay users have been converted to use the new API for that. So lets kill off the old plugging along with aops->sync_page(). Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
* | | aio: wake all waiters when destroying ctxRoland Dreier2011-03-221-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The test program below will hang because io_getevents() uses add_wait_queue_exclusive(), which means the wake_up() in io_destroy() only wakes up one of the threads. Fix this by using wake_up_all() in the aio code paths where we want to make sure no one gets stuck. // t.c -- compile with gcc -lpthread -laio t.c #include <libaio.h> #include <pthread.h> #include <stdio.h> #include <unistd.h> static const int nthr = 2; void *getev(void *ctx) { struct io_event ev; io_getevents(ctx, 1, 1, &ev, NULL); printf("io_getevents returned\n"); return NULL; } int main(int argc, char *argv[]) { io_context_t ctx = 0; pthread_t thread[nthr]; int i; io_setup(1024, &ctx); for (i = 0; i < nthr; ++i) pthread_create(&thread[i], NULL, getev, ctx); sleep(1); io_destroy(ctx); for (i = 0; i < nthr; ++i) pthread_join(thread[i], NULL); return 0; } Signed-off-by: Roland Dreier <roland@purestorage.com> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Merge branch 'for-2.6.39' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds2011-03-161-2/+2
|\ \ \ | |/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'for-2.6.39' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: fix build failure introduced by s/freezeable/freezable/ workqueue: add system_freezeable_wq rds/ib: use system_wq instead of rds_ib_fmr_wq net/9p: replace p9_poll_task with a work net/9p: use system_wq instead of p9_mux_wq xfs: convert to alloc_workqueue() reiserfs: make commit_wq use the default concurrency level ocfs2: use system_wq instead of ocfs2_quota_wq ext4: convert to alloc_workqueue() scsi/scsi_tgt_lib: scsi_tgtd isn't used in memory reclaim path scsi/be2iscsi,qla2xxx: convert to alloc_workqueue() misc/iwmc3200top: use system_wq instead of dedicated workqueues i2o: use alloc_workqueue() instead of create_workqueue() acpi: kacpi*_wq don't need WQ_MEM_RECLAIM fs/aio: aio_wq isn't used in memory reclaim path input/tps6507x-ts: use system_wq instead of dedicated workqueue cpufreq: use system_wq instead of dedicated workqueues wireless/ipw2x00: use system_wq instead of dedicated workqueues arm/omap: use system_wq in mailbox workqueue: use WQ_MEM_RECLAIM instead of WQ_RESCUER
| * | fs/aio: aio_wq isn't used in memory reclaim pathTejun Heo2011-01-261-2/+2
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | aio_wq isn't used during memory reclaim. Convert to alloc_workqueue() without WQ_MEM_RECLAIM. It's possible to use system_wq but given that the number of work items is determined from userland and the work item may block, enforcing strict concurrency limit would be a good idea. Also, move fput_work to system_wq so that aio_wq is used soley to throttle the max concurrency of aio work items and fput_work doesn't interact with other work items. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Jeff Moyer <jmoyer@redhat.com> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: linux-aio@kvack.org
* | aio: fix race between io_destroy() and io_submit()Jan Kara2011-02-251-0/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A race can occur when io_submit() races with io_destroy(): CPU1 CPU2 io_submit() do_io_submit() ... ctx = lookup_ioctx(ctx_id); io_destroy() Now do_io_submit() holds the last reference to ctx. ... queue new AIO put_ioctx(ctx) - frees ctx with active AIOs We solve this issue by checking whether ctx is being destroyed in AIO submission path after adding new AIO to ctx. Then we are guaranteed that either io_destroy() waits for new AIO or we see that ctx is being destroyed and bail out. Cc: Nick Piggin <npiggin@kernel.dk> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | aio: fix rcu ioctx lookupNick Piggin2011-02-251-11/+24
|/ | | | | | | | | | | | | | | | | aio-dio-invalidate-failure GPFs in aio_put_req from io_submit. lookup_ioctx doesn't implement the rcu lookup pattern properly. rcu_read_lock does not prevent refcount going to zero, so we might take a refcount on a zero count ioctx. Fix the bug by atomically testing for zero refcount before incrementing. [jack@suse.cz: added comment into the code] Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Nick Piggin <npiggin@kernel.dk> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* aio: check return value of create_workqueue()Namhyung Kim2011-01-171-1/+1
| | | | | Signed-off-by: Namhyung Kim <namhyung@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* aio: remove unused aio_run_iocbs()Jeff Moyer2011-01-131-22/+5
| | | | | | | | | aio_run_iocbs() is not used at all, so get rid of it. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* aio: remove unnecessary checkNamhyung Kim2011-01-131-1/+1
| | | | | | | | | 'nr >= min_nr >= 0' always satisfies 'nr >= 0' so the check is unnecesary. Signed-off-by: Namhyung Kim <namhyung@gmail.com> Acked-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* new helper: ihold()Al Viro2010-10-251-3/+2
| | | | | | Clones an existing reference to inode; caller must already hold one. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* aio: bump i_count instead of using igrabChris Mason2010-10-251-1/+14
| | | | | | | | | | | | | | | | The aio batching code is using igrab to get an extra reference on the inode so it can safely batch. igrab will go ahead and take the global inode spinlock, which can be a bottleneck on large machines doing lots of AIO. In this case, igrab isn't required because we already have a reference on the file handle. It is safe to just bump the i_count directly on the inode. Benchmarking shows this patch brings IOP/s on tons of flash up by about 2.5X. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* aio: do not return ERESTARTSYS as a result of AIOJan Kara2010-09-221-1/+9
| | | | | | | | | | | | | | | | | | | OCFS2 can return ERESTARTSYS from its write function when the process is signalled while waiting for a cluster lock (and the filesystem is mounted with intr mount option). Generally, it seems reasonable to allow filesystems to return this error code from its IO functions. As we must not leak ERESTARTSYS (and similar error codes) to userspace as a result of an AIO operation, we have to properly convert it to EINTR inside AIO code (restarting the syscall isn't really an option because other AIO could have been already submitted by the same io_submit syscall). Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Zach Brown <zach.brown@oracle.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* aio: check for multiplication overflow in do_io_submitJeff Moyer2010-09-141-0/+3
| | | | | | | | | | | | | | | | | | | | | Tavis Ormandy pointed out that do_io_submit does not do proper bounds checking on the passed-in iocb array:        if (unlikely(nr < 0))                return -EINVAL;        if (unlikely(!access_ok(VERIFY_READ, iocbpp, (nr*sizeof(iocbpp)))))                return -EFAULT;                      ^^^^^^^^^^^^^^^^^^ The attached patch checks for overflow, and if it is detected, the number of iocbs submitted is scaled down to a number that will fit in the long.  This is an ok thing to do, as sys_io_submit is documented as returning the number of iocbs submitted, so callers should handle a return value of less than the 'nr' argument passed in. Reported-by: Tavis Ormandy <taviso@cmpxchg8b.com> Signed-off-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* aio: fix wrong subsystem commentsSatoru Takeuchi2010-08-051-10/+11
| | | | | | | | | | | | | | - sys_io_destroy(): acutually return -EINVAL if the context pointed to is invalidIndex: linux-2.6.33-rc4/fs/aio.c - sys_io_getevents(): An argument specifying timeout is not `when', but `timeout'. - sys_io_getevents(): Should describe what is returned if this syscall succeeds. Signed-off-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* get rid of the magic around f_count in aioAl Viro2010-05-271-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | __aio_put_req() plays sick games with file refcount. What it wants is fput() from atomic context; it's almost always done with f_count > 1, so they only have to deal with delayed work in rare cases when their reference happens to be the last one. Current code decrements f_count and if it hasn't hit 0, everything is fine. Otherwise it keeps a pointer to struct file (with zero f_count!) around and has delayed work do __fput() on it. Better way to do it: use atomic_long_add_unless( , -1, 1) instead of !atomic_long_dec_and_test(). IOW, decrement it only if it's not the last reference, leave refcount alone if it was. And use normal fput() in delayed work. I've made that atomic_long_add_unless call a new helper - fput_atomic(). Drops a reference to file if it's safe to do in atomic (i.e. if that's not the last one), tells if it had been able to do that. aio.c converted to it, __fput() use is gone. req->ki_file *always* contributes to refcount now. And __fput() became static. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* aio: fix the compat vectored operationsJeff Moyer2010-05-271-24/+41
| | | | | | | | | | | | | | | | | | | | | | | | The aio compat code was not converting the struct iovecs from 32bit to 64bit pointers, causing either EINVAL to be returned from io_getevents, or EFAULT as the result of the I/O. This patch passes a compat flag to io_submit to signal that pointer conversion is necessary for a given iocb array. A variant of this was tested by Michael Tokarev. I have also updated the libaio test harness to exercise this code path with good success. Further, I grabbed a copy of ltp and ran the testcases/kernel/syscall/readv and writev tests there (compiled with -m32 on my 64bit system). All seems happy, but extra eyes on this would be welcome. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: fix CONFIG_COMPAT=n build] Signed-off-by: Jeff Moyer <jmoyer@redhat.com> Reported-by: Michael Tokarev <mjt@tls.msk.ru> Cc: Zach Brown <zach.brown@oracle.com> Cc: <stable@kernel.org> [2.6.35.1] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* aio: remove unused fieldShaohua Li2009-12-161-38/+2
| | | | | | | | | | | Don't know the reason, but it appears ki_wait field of iocb never gets used. Signed-off-by: Shaohua Li <shaohua.li@intel.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Zach Brown <zach.brown@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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