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* fuse: writepages: update bdi writeout when deleting secondary requestMaxim Patlasov2013-11-051-1/+4
| | | | | | | | | | | | | | BDI_WRITTEN counter is used to estimate bdi bandwidth. It must be incremented every time as bdi ends page writeback. No matter whether it was fulfilled by actual write or by discarding the request (e.g. due to shrunk i_size). Note that even before writepages patches, the case "Got truncated off completely" was handled in fuse_send_writepage() by calling fuse_writepage_finish() which updated BDI_WRITTEN unconditionally. Signed-off-by: Maxim Patlasov <MPatlasov@parallels.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
* fuse: writepages: crop secondary requestsMaxim Patlasov2013-11-051-5/+31
| | | | | | | | | | | | | | | | | | | | | If writeback happens while fuse is in FUSE_NOWRITE condition, the request will be queued but not processed immediately (see fuse_flush_writepages()). Until FUSE_NOWRITE becomes relaxed, more writebacks can happen. They will be queued as "secondary" requests to that first ("primary") request. Existing implementation crops only primary request. This is not correct because a subsequent extending write(2) may increase i_size and then secondary requests won't be cropped properly. The result would be stale data written to the server to a file offset where zeros must be. Similar problem may happen if secondary requests are attached to an in-flight request that was already cropped. The patch solves the issue by cropping all secondary requests in fuse_writepage_end(). Thanks to Miklos for idea. Signed-off-by: Maxim Patlasov <MPatlasov@parallels.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
* fuse: writepages: roll back changes if request not foundMaxim Patlasov2013-11-051-2/+4
| | | | | | | | | | | fuse_writepage_in_flight() returns false if it fails to find request with given index in fi->writepages. Then the caller proceeds with populating data->orig_pages[] and incrementing req->num_pages. Hence, fuse_writepage_in_flight() must revert changes it made in request before returning false. Signed-off-by: Maxim Patlasov <MPatlasov@parallels.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
* cuse: add fix minor number to /dev/cuseTom Gundersen2013-10-011-1/+4
| | | | | | | | | | | | This allows udev (or more recently systemd-tmpfiles) to create /dev/cuse on boot, in the same way as /dev/fuse is currently created, and the corresponding module to be loaded on first access. The corresponding functionalty was introduced for fuse in commit 578454f. Signed-off-by: Tom Gundersen <teg@jklm.no> Cc: Kay Sievers <kay@vrfy.org> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
* fuse: writepage: skip already in flightMiklos Szeredi2013-10-011-0/+12
| | | | | | | | | | If ->writepage() tries to write back a page whose copy is still in flight, then just skip by calling redirty_page_for_writepage(). This is OK, since now ->writepage() should never be called for data integrity sync. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
* fuse: writepages: handle same page rewritesMiklos Szeredi2013-10-012-10/+91
| | | | | | | | | | | | | | | | | | | | | | | | | | | As Maxim Patlasov pointed out, it's possible to get a dirty page while it's copy is still under writeback, despite fuse_page_mkwrite() doing its thing (direct IO). This could result in two concurrent write request for the same offset, with data corruption if they get mixed up. To prevent this, fuse needs to check and delay such writes. This implementation does this by: 1. check if page is still under writeout, if so create a new, single page secondary request for it 2. chain this secondary request onto the in-flight request 2/a. if a seconday request for the same offset was already chained to the in-flight request, then just copy the contents of the page and discard the new secondary request. This makes sure that for each page will have at most two requests associated with it 3. when the in-flight request finished, send off all secondary requests chained onto it Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
* fuse: writepages: fix aggregationMiklos Szeredi2013-10-011-1/+1
| | | | | | | Checking against tmp-page indexes is not very useful, and results in one (or rarely two) page requests. Which is not much of an improvement... Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
* fuse: fix race in fuse_writepages()Maxim Patlasov2013-10-011-1/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | The patch fixes a race between ftruncate(2), mmap-ed write and write(2): 1) An user makes a page dirty via mmap-ed write. 2) The user performs shrinking truncate(2) intended to purge the page. 3) Before fuse_do_setattr calls truncate_pagecache, the page goes to writeback. fuse_writepages_fill attaches a new page to FUSE_WRITE request, then releases the original page by end_page_writeback and unlock it. 4) fuse_do_setattr completes and successfully returns. Since now, i_mutex is free. 5) Ordinary write(2) extends i_size back to cover the page. Note that fuse_send_write_pages do wait for fuse writeback, but for another page->index. 6) fuse_writepages_fill attaches more pages to the request (if any), then fuse_writepages_send is eventually called. It is supposed to crop inarg->size of the request, but it doesn't because i_size has already been extended back. Moving end_page_writeback behind fuse_writepages_send guarantees that __fuse_release_nowrite (called from fuse_do_setattr) will crop inarg->size of the request before write(2) gets the chance to extend i_size. Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
* fuse: Implement writepages callbackPavel Emelyanov2013-10-011-3/+147
| | | | | | | | | | | The .writepages one is required to make each writeback request carry more than one page on it. The patch enables optimized behaviour unconditionally, i.e. mmap-ed writes will benefit from the patch even if fc->writeback_cache=0. [SzM: simplify, add comments] Signed-off-by: Maxim Patlasov <MPatlasov@parallels.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
* fuse: don't BUG on no write fileMiklos Szeredi2013-10-011-5/+12
| | | | | | | Don't bug if there's no writable files found for page writeback. If ever this is triggered, a WARN_ON helps debugging it much better then a BUG_ON. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
* fuse: lock page in mkwriteMiklos Szeredi2013-10-011-6/+9
| | | | | | | | Lock the page in fuse_page_mkwrite() to protect against a race with fuse_writepage() where the page is redirtied before the actual writeback begins. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
* fuse: Prepare to handle multiple pages in writebackPavel Emelyanov2013-10-011-8/+16
| | | | | | | | The .writepages callback will issue writeback requests with more than one page aboard. Make existing end/check code be aware of this. Signed-off-by: Maxim Patlasov <MPatlasov@parallels.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
* fuse: Getting file for writeback helperPavel Emelyanov2013-10-011-8/+16
| | | | | | | | | There will be a .writepageS callback implementation which will need to get a fuse_file out of a fuse_inode, thus make a helper for this. Signed-off-by: Maxim Patlasov <MPatlasov@parallels.com> Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
* fuse: no RCU mode in fuse_access()Miklos Szeredi2013-10-011-3/+2
| | | | | | | fuse_access() is never called in RCU walk, only on the final component of access(2) and chdir(2)... Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
* fuse: readdirplus: fix RCU walkMiklos Szeredi2013-10-012-3/+11
| | | | | | | | | | | | | | | | | | Doing dput(parent) is not valid in RCU walk mode. In RCU mode it would probably be okay to update the parent flags, but it's actually not necessary most of the time... So only set the FUSE_I_ADVISE_RDPLUS flag on the parent when the entry was recently initialized by READDIRPLUS. This is achieved by setting FUSE_I_INIT_RDPLUS on entries added by READDIRPLUS and only dropping out of RCU mode if this flag is set. FUSE_I_INIT_RDPLUS is cleared once the FUSE_I_ADVISE_RDPLUS flag is set in the parent. Reported-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Cc: stable@vger.kernel.org
* fuse: don't check_submounts_and_drop() in RCU walkMiklos Szeredi2013-10-011-1/+2
| | | | | | | | | If revalidate finds an invalid dentry in RCU walk mode, let the VFS deal with it instead of calling check_submounts_and_drop() which is not prepared for being called from RCU walk. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Cc: stable@vger.kernel.org
* fuse: fix fallocate vs. ftruncate raceMaxim Patlasov2013-09-181-0/+7
| | | | | | | | | | | | | | | | | | | | | A former patch introducing FUSE_I_SIZE_UNSTABLE flag provided detailed description of races between ftruncate and anyone who can extend i_size: > 1. As in the previous scenario fuse_dentry_revalidate() discovered that i_size > changed (due to our own fuse_do_setattr()) and is going to call > truncate_pagecache() for some 'new_size' it believes valid right now. But by > the time that particular truncate_pagecache() is called ... > 2. fuse_do_setattr() returns (either having called truncate_pagecache() or > not -- it doesn't matter). > 3. The file is extended either by write(2) or ftruncate(2) or fallocate(2). > 4. mmap-ed write makes a page in the extended region dirty. This patch adds necessary bits to fuse_file_fallocate() to protect from that race. Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Cc: stable@vger.kernel.org
* fuse: wait for writeback in fuse_file_fallocate()Maxim Patlasov2013-09-181-6/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | The patch fixes a race between mmap-ed write and fallocate(PUNCH_HOLE): 1) An user makes a page dirty via mmap-ed write. 2) The user performs fallocate(2) with mode == PUNCH_HOLE|KEEP_SIZE and <offset, size> covering the page. 3) Before truncate_pagecache_range call from fuse_file_fallocate, the page goes to write-back. The page is fully processed by fuse_writepage (including end_page_writeback on the page), but fuse_flush_writepages did nothing because fi->writectr < 0. 4) truncate_pagecache_range is called and fuse_file_fallocate is finishing by calling fuse_release_nowrite. The latter triggers processing queued write-back request which will write stale data to the hole soon. Changed in v2 (thanks to Brian for suggestion): - Do not truncate page cache until FUSE_FALLOCATE succeeded. Otherwise, we can end up in returning -ENOTSUPP while user data is already punched from page cache. Use filemap_write_and_wait_range() instead. Changed in v3 (thanks to Miklos for suggestion): - fuse_wait_on_writeback() is prone to livelocks; use fuse_set_nowrite() instead. So far as we need a dirty-page barrier only, fuse_sync_writes() should be enough. - rebased to for-linus branch of fuse.git Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Cc: stable@vger.kernel.org
* Merge branch 'for-next' of git://git.samba.org/sfrench/cifs-2.6Linus Torvalds2013-09-161-5/+10
|\ | | | | | | | | | | | | | | | | | | Pull CIFS fixes from Steve French: "Two minor cifs fixes and a minor documentation cleanup for cifs.txt" * 'for-next' of git://git.samba.org/sfrench/cifs-2.6: cifs: update cifs.txt and remove some outdated infos cifs: Avoid calling unlock_page() twice in cifs_readpage() when using fscache cifs: Do not take a reference to the page in cifs_readpage_worker()
| * cifs: Avoid calling unlock_page() twice in cifs_readpage() when using fscacheSachin Prabhu2013-09-131-3/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When reading a single page with cifs_readpage(), we make a call to fscache_read_or_alloc_page() which once done, asynchronously calls the completion function cifs_readpage_from_fscache_complete(). This completion function unlocks the page once it has been populated from cache. The module then attempts to unlock the page a second time in cifs_readpage() which leads to warning messages. In case of a successful call to fscache_read_or_alloc_page() we should skip the second unlock_page() since this will be called by the cifs_readpage_from_fscache_complete() once the page has been populated by fscache. With the modifications to cifs_readpage_worker(), we will need to re-grab the page lock in cifs_write_begin(). The problem was first noticed when testing new fscache patches for cifs. https://bugzilla.redhat.com/show_bug.cgi?id=1005737 Signed-off-by: Sachin Prabhu <sprabhu@redhat.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com>
| * cifs: Do not take a reference to the page in cifs_readpage_worker()Sachin Prabhu2013-09-131-2/+3
| | | | | | | | | | | | | | | | | | | | | | We do not need to take a reference to the pagecache in cifs_readpage_worker() since the calling function will have already taken one before passing the pointer to the page as an argument to the function. Signed-off-by: Sachin Prabhu <sprabhu@redhat.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com>
* | Merge tag 'upstream-3.12-rc1' of git://git.infradead.org/linux-ubifsLinus Torvalds2013-09-161-3/+4
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull ubifs fix from Artem Bityutskiy: "Just one patch which fixes the power-cut recovery testing mode. I'll start using a single UBI/UBIFS tree instead of 2 trees from now on. So in the future you'll get 1 small pull request instead of 2 tiny ones" * tag 'upstream-3.12-rc1' of git://git.infradead.org/linux-ubifs: UBIFS: remove invalid warn msg with tst_recovery enabled
| * | UBIFS: remove invalid warn msg with tst_recovery enabledMats Kärrman2013-08-161-3/+4
| | | | | | | | | | | | | | | Signed-off-by: Mats Karrman <mats.karrman@tritech.se> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
* | | vfs: fix typo in comment in recent dentry workLinus Torvalds2013-09-151-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | Sedat points out that I transposed some letters in "LRU" and wrote "RLU" instead in one of the new comments explaining the flow. Let's just fix it. Reported-by: Sedat Dilek <sedat.dilek@jpberlin.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Merge tag 'writeback-fixes' of ↵Linus Torvalds2013-09-132-4/+6
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux Pull writeback fix from Wu Fengguang: "A trivial writeback fix" * tag 'writeback-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux: writeback: Do not sort b_io list only because of block device inode
| * | | writeback: Do not sort b_io list only because of block device inodeJan Kara2013-07-092-4/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It is very likely that block device inode will be part of BDI dirty list as well. However it doesn't make sence to sort inodes on the b_io list just because of this inode (as it contains buffers all over the device anyway). So save some CPU cycles which is valuable since we hold relatively contented wb->list_lock. Signed-off-by: Jan Kara <jack@suse.cz>
* | | | vfs: fix dentry LRU list handling and nr_dentry_unused accountingLinus Torvalds2013-09-131-27/+101
| |_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The LRU list changes interacted badly with our nr_dentry_unused accounting, and even worse with the new DCACHE_LRU_LIST bit logic. This introduces helper functions to make sure everything follows the proper dcache d_lru list rules: the dentry cache is complicated by the fact that some of the hotpaths don't even want to look at the LRU list at all, and the fact that we use the same list entry in the dentry for both the LRU list and for our temporary shrinking lists when removing things from the LRU. The helper functions temporarily have some extra sanity checking for the flag bits that have to match the current LRU state of the dentry. We'll remove that before the final 3.12 release, but considering how easy it is to get wrong, this first cleanup version has some very particular sanity checking. Acked-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Merge git://git.kvack.org/~bcrl/aio-nextLinus Torvalds2013-09-137-269/+537
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull aio changes from Ben LaHaise: "First off, sorry for this pull request being late in the merge window. Al had raised a couple of concerns about 2 items in the series below. I addressed the first issue (the race introduced by Gu's use of mm_populate()), but he has not provided any further details on how he wants to rework the anon_inode.c changes (which were sent out months ago but have yet to be commented on). The bulk of the changes have been sitting in the -next tree for a few months, with all the issues raised being addressed" * git://git.kvack.org/~bcrl/aio-next: (22 commits) aio: rcu_read_lock protection for new rcu_dereference calls aio: fix race in ring buffer page lookup introduced by page migration support aio: fix rcu sparse warnings introduced by ioctx table lookup patch aio: remove unnecessary debugging from aio_free_ring() aio: table lookup: verify ctx pointer staging/lustre: kiocb->ki_left is removed aio: fix error handling and rcu usage in "convert the ioctx list to table lookup v3" aio: be defensive to ensure request batching is non-zero instead of BUG_ON() aio: convert the ioctx list to table lookup v3 aio: double aio_max_nr in calculations aio: Kill ki_dtor aio: Kill ki_users aio: Kill unneeded kiocb members aio: Kill aio_rw_vect_retry() aio: Don't use ctx->tail unnecessarily aio: io_cancel() no longer returns the io_event aio: percpu ioctx refcount aio: percpu reqs_available aio: reqs_active -> reqs_available aio: fix build when migration is disabled ...
| * | | aio: rcu_read_lock protection for new rcu_dereference callsArtem Savkov2013-09-091-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch "aio: fix rcu sparse warnings introduced by ioctx table lookup patch" (77d30b14d24e557f89c41980011d72428514d729 in linux-next.git) introduced a couple of new rcu_dereference calls which are not protected by rcu_read_lock and result in following warnings during syscall fuzzing(trinity): [ 471.646379] =============================== [ 471.649727] [ INFO: suspicious RCU usage. ] [ 471.653919] 3.11.0-next-20130906+ #496 Not tainted [ 471.657792] ------------------------------- [ 471.661235] fs/aio.c:503 suspicious rcu_dereference_check() usage! [ 471.665968] [ 471.665968] other info that might help us debug this: [ 471.665968] [ 471.672141] [ 471.672141] rcu_scheduler_active = 1, debug_locks = 1 [ 471.677549] 1 lock held by trinity-child0/3774: [ 471.681675] #0: (&(&mm->ioctx_lock)->rlock){+.+...}, at: [<c119ba1a>] SyS_io_setup+0x63a/0xc70 [ 471.688721] [ 471.688721] stack backtrace: [ 471.692488] CPU: 1 PID: 3774 Comm: trinity-child0 Not tainted 3.11.0-next-20130906+ #496 [ 471.698437] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 471.703151] 00000000 00000000 c58bbf30 c18a814b de2234c0 c58bbf58 c10a4ec6 c1b0d824 [ 471.709544] c1b0f60e 00000001 00000001 c1af61b0 00000000 cb670ac0 c3aca000 c58bbfac [ 471.716251] c119bc7c 00000002 00000001 00000000 c119b8dd 00000000 c10cf684 c58bbfb4 [ 471.722902] Call Trace: [ 471.724859] [<c18a814b>] dump_stack+0x4b/0x66 [ 471.728772] [<c10a4ec6>] lockdep_rcu_suspicious+0xc6/0x100 [ 471.733716] [<c119bc7c>] SyS_io_setup+0x89c/0xc70 [ 471.737806] [<c119b8dd>] ? SyS_io_setup+0x4fd/0xc70 [ 471.741689] [<c10cf684>] ? __audit_syscall_entry+0x94/0xe0 [ 471.746080] [<c18b1fcc>] syscall_call+0x7/0xb [ 471.749723] [<c1080000>] ? task_fork_fair+0x240/0x260 Signed-off-by: Artem Savkov <artem.savkov@gmail.com> Reviewed-by: Gu Zheng <guz.fnst@cn.fujitsu.com> Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
| * | | aio: fix race in ring buffer page lookup introduced by page migration supportBenjamin LaHaise2013-09-091-3/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Prior to the introduction of page migration support in "fs/aio: Add support to aio ring pages migration" / 36bc08cc01709b4a9bb563b35aa530241ddc63e3, mapping of the ring buffer pages was done via get_user_pages() while retaining mmap_sem held for write. This avoided possible races with userland racing an munmap() or mremap(). The page migration patch, however, switched to using mm_populate() to prime the page mapping. mm_populate() cannot be called with mmap_sem held. Instead of dropping the mmap_sem, revert to the old behaviour and simply drop the use of mm_populate() since get_user_pages() will cause the pages to get mapped anyways. Thanks to Al Viro for spotting this issue. Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
| * | | aio: fix rcu sparse warnings introduced by ioctx table lookup patchBenjamin LaHaise2013-08-301-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Sseveral sparse warnings were caused by missing rcu_dereference() annotations for dereferencing mm->ioctx_table. Thankfully, none of those were actual bugs as the deref was protected by a spin lock in all instances. Signed-off-by: Benjamin LaHaise <bcrl@kvack.org> Reported-by: Fengguang Wu <fengguang.wu@intel.com>
| * | | aio: remove unnecessary debugging from aio_free_ring()Benjamin LaHaise2013-08-301-5/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The commit 36bc08cc0170 ("fs/aio: Add support to aio ring pages migration") added some debugging code that is not required and resulted in a build error when 98474236f72e ("vfs: make the dentry cache use the lockref infrastructure") was added to the tree. The code is not required, so just delete it. Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
| * | | aio: table lookup: verify ctx pointerBenjamin LaHaise2013-08-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Another shortcoming of the table lookup patch was revealed where the pointer was not being tested before being dereferenced. Verify this to avoid the NULL pointer dereference. Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
| * | | aio: fix error handling and rcu usage in "convert the ioctx list to table ↵Benjamin LaHaise2013-08-051-8/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | lookup v3" In the patch "aio: convert the ioctx list to table lookup v3", incorrect handling in the ioctx_alloc() error path was introduced that lead to an ioctx being added via ioctx_add_table() while freed when the ioctx_alloc() call returned -EAGAIN due to hitting the aio_max_nr limit. Fix this by only calling ioctx_add_table() as the last step in ioctx_alloc(). Also, several unnecessary rcu_dereference() calls were added that lead to RCU warnings where the system was already protected by a spin lock for accessing mm->ioctx_table. Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
| * | | aio: be defensive to ensure request batching is non-zero instead of BUG_ON()Benjamin LaHaise2013-07-311-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | In the event that an overflow/underflow occurs while calculating req_batch, clamp the minimum at 1 request instead of doing a BUG_ON(). Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
| * | | aio: convert the ioctx list to table lookup v3Benjamin LaHaise2013-07-301-22/+114
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On Wed, Jun 12, 2013 at 11:14:40AM -0700, Kent Overstreet wrote: > On Mon, Apr 15, 2013 at 02:40:55PM +0300, Octavian Purdila wrote: > > When using a large number of threads performing AIO operations the > > IOCTX list may get a significant number of entries which will cause > > significant overhead. For example, when running this fio script: > > > > rw=randrw; size=256k ;directory=/mnt/fio; ioengine=libaio; iodepth=1 > > blocksize=1024; numjobs=512; thread; loops=100 > > > > on an EXT2 filesystem mounted on top of a ramdisk we can observe up to > > 30% CPU time spent by lookup_ioctx: > > > > 32.51% [guest.kernel] [g] lookup_ioctx > > 9.19% [guest.kernel] [g] __lock_acquire.isra.28 > > 4.40% [guest.kernel] [g] lock_release > > 4.19% [guest.kernel] [g] sched_clock_local > > 3.86% [guest.kernel] [g] local_clock > > 3.68% [guest.kernel] [g] native_sched_clock > > 3.08% [guest.kernel] [g] sched_clock_cpu > > 2.64% [guest.kernel] [g] lock_release_holdtime.part.11 > > 2.60% [guest.kernel] [g] memcpy > > 2.33% [guest.kernel] [g] lock_acquired > > 2.25% [guest.kernel] [g] lock_acquire > > 1.84% [guest.kernel] [g] do_io_submit > > > > This patchs converts the ioctx list to a radix tree. For a performance > > comparison the above FIO script was run on a 2 sockets 8 core > > machine. This are the results (average and %rsd of 10 runs) for the > > original list based implementation and for the radix tree based > > implementation: > > > > cores 1 2 4 8 16 32 > > list 109376 ms 69119 ms 35682 ms 22671 ms 19724 ms 16408 ms > > %rsd 0.69% 1.15% 1.17% 1.21% 1.71% 1.43% > > radix 73651 ms 41748 ms 23028 ms 16766 ms 15232 ms 13787 ms > > %rsd 1.19% 0.98% 0.69% 1.13% 0.72% 0.75% > > % of radix > > relative 66.12% 65.59% 66.63% 72.31% 77.26% 83.66% > > to list > > > > To consider the impact of the patch on the typical case of having > > only one ctx per process the following FIO script was run: > > > > rw=randrw; size=100m ;directory=/mnt/fio; ioengine=libaio; iodepth=1 > > blocksize=1024; numjobs=1; thread; loops=100 > > > > on the same system and the results are the following: > > > > list 58892 ms > > %rsd 0.91% > > radix 59404 ms > > %rsd 0.81% > > % of radix > > relative 100.87% > > to list > > So, I was just doing some benchmarking/profiling to get ready to send > out the aio patches I've got for 3.11 - and it looks like your patch is > causing a ~1.5% throughput regression in my testing :/ ... <snip> I've got an alternate approach for fixing this wart in lookup_ioctx()... Instead of using an rbtree, just use the reserved id in the ring buffer header to index an array pointing the ioctx. It's not finished yet, and it needs to be tidied up, but is most of the way there. -ben -- "Thought is the essence of where you are now." -- kmo> And, a rework of Ben's code, but this was entirely his idea kmo> -Kent bcrl> And fix the code to use the right mm_struct in kill_ioctx(), actually free memory. Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
| * | | aio: double aio_max_nr in calculationsBenjamin LaHaise2013-07-301-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the changes to use percpu counters for aio event ring size calculation, existing increases to aio_max_nr are now insufficient to allow for the allocation of enough events. Double the value used for aio_max_nr to account for the doubling introduced by the percpu slack. Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
| * | | aio: Kill ki_dtorKent Overstreet2013-07-301-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | sock_aio_dtor() is dead code - and stuff that does need to do cleanup can simply do it before calling aio_complete(). Signed-off-by: Kent Overstreet <koverstreet@google.com> Cc: Zach Brown <zab@redhat.com> Cc: Felipe Balbi <balbi@ti.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jens Axboe <axboe@kernel.dk> Cc: Asai Thambi S P <asamymuthupa@micron.com> Cc: Selvan Mani <smani@micron.com> Cc: Sam Bradshaw <sbradshaw@micron.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
| * | | aio: Kill ki_usersKent Overstreet2013-07-301-35/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The kiocb refcount is only needed for cancellation - to ensure a kiocb isn't freed while a ki_cancel callback is running. But if we restrict ki_cancel callbacks to not block (which they currently don't), we can simply drop the refcount. Signed-off-by: Kent Overstreet <koverstreet@google.com> Cc: Zach Brown <zab@redhat.com> Cc: Felipe Balbi <balbi@ti.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jens Axboe <axboe@kernel.dk> Cc: Asai Thambi S P <asamymuthupa@micron.com> Cc: Selvan Mani <smani@micron.com> Cc: Sam Bradshaw <sbradshaw@micron.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
| * | | aio: Kill unneeded kiocb membersKent Overstreet2013-07-301-29/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The old aio retry infrastucture needed to save the various arguments to to aio operations. But with the retry infrastructure gone, we can trim struct kiocb quite a bit. Signed-off-by: Kent Overstreet <koverstreet@google.com> Cc: Zach Brown <zab@redhat.com> Cc: Felipe Balbi <balbi@ti.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jens Axboe <axboe@kernel.dk> Cc: Asai Thambi S P <asamymuthupa@micron.com> Cc: Selvan Mani <smani@micron.com> Cc: Sam Bradshaw <sbradshaw@micron.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
| * | | aio: Kill aio_rw_vect_retry()Kent Overstreet2013-07-306-82/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This code doesn't serve any purpose anymore, since the aio retry infrastructure has been removed. This change should be safe because aio_read/write are also used for synchronous IO, and called from do_sync_read()/do_sync_write() - and there's no looping done in the sync case (the read and write syscalls). Signed-off-by: Kent Overstreet <koverstreet@google.com> Cc: Zach Brown <zab@redhat.com> Cc: Felipe Balbi <balbi@ti.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jens Axboe <axboe@kernel.dk> Cc: Asai Thambi S P <asamymuthupa@micron.com> Cc: Selvan Mani <smani@micron.com> Cc: Sam Bradshaw <sbradshaw@micron.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Benjamin LaHaise <bcrl@kvack.org> Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
| * | | aio: Don't use ctx->tail unnecessarilyKent Overstreet2013-07-301-19/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | aio_complete() (arguably) needs to keep its own trusted copy of the tail pointer, but io_getevents() doesn't have to use it - it's already using the head pointer from the ring buffer. So convert it to use the tail from the ring buffer so it touches fewer cachelines and doesn't contend with the cacheline aio_complete() needs. Signed-off-by: Kent Overstreet <koverstreet@google.com> Cc: Zach Brown <zab@redhat.com> Cc: Felipe Balbi <balbi@ti.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jens Axboe <axboe@kernel.dk> Cc: Asai Thambi S P <asamymuthupa@micron.com> Cc: Selvan Mani <smani@micron.com> Cc: Sam Bradshaw <sbradshaw@micron.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Benjamin LaHaise <bcrl@kvack.org> Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
| * | | aio: io_cancel() no longer returns the io_eventKent Overstreet2013-07-301-30/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Originally, io_event() was documented to return the io_event if cancellation succeeded - the io_event wouldn't be delivered via the ring buffer like it normally would. But this isn't what the implementation was actually doing; the only driver implementing cancellation, the usb gadget code, never returned an io_event in its cancel function. And aio_complete() was recently changed to no longer suppress event delivery if the kiocb had been cancelled. This gets rid of the unused io_event argument to kiocb_cancel() and kiocb->ki_cancel(), and changes io_cancel() to return -EINPROGRESS if kiocb->ki_cancel() returned success. Also tweak the refcounting in kiocb_cancel() to make more sense. Signed-off-by: Kent Overstreet <koverstreet@google.com> Cc: Zach Brown <zab@redhat.com> Cc: Felipe Balbi <balbi@ti.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jens Axboe <axboe@kernel.dk> Cc: Asai Thambi S P <asamymuthupa@micron.com> Cc: Selvan Mani <smani@micron.com> Cc: Sam Bradshaw <sbradshaw@micron.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Benjamin LaHaise <bcrl@kvack.org> Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
| * | | aio: percpu ioctx refcountKent Overstreet2013-07-301-39/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This just converts the ioctx refcount to the new generic dynamic percpu refcount code. Signed-off-by: Kent Overstreet <koverstreet@google.com> Cc: Zach Brown <zab@redhat.com> Cc: Felipe Balbi <balbi@ti.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jens Axboe <axboe@kernel.dk> Cc: Asai Thambi S P <asamymuthupa@micron.com> Cc: Selvan Mani <smani@micron.com> Cc: Sam Bradshaw <sbradshaw@micron.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Benjamin LaHaise <bcrl@kvack.org> Reviewed-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
| * | | aio: percpu reqs_availableKent Overstreet2013-07-301-7/+99
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | See the previous patch ("aio: reqs_active -> reqs_available") for why we want to do this - this basically implements a per cpu allocator for reqs_available that doesn't actually allocate anything. Note that we need to increase the size of the ringbuffer we allocate, since a single thread won't necessarily be able to use all the reqs_available slots - some (up to about half) might be on other per cpu lists, unavailable for the current thread. We size the ringbuffer based on the nr_events userspace passed to io_setup(), so this is a slight behaviour change - but nr_events wasn't being used as a hard limit before, it was being rounded up to the next page before so this doesn't change the actual semantics. Signed-off-by: Kent Overstreet <koverstreet@google.com> Cc: Zach Brown <zab@redhat.com> Cc: Felipe Balbi <balbi@ti.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jens Axboe <axboe@kernel.dk> Cc: Asai Thambi S P <asamymuthupa@micron.com> Cc: Selvan Mani <smani@micron.com> Cc: Sam Bradshaw <sbradshaw@micron.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Benjamin LaHaise <bcrl@kvack.org> Reviewed-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
| * | | aio: reqs_active -> reqs_availableKent Overstreet2013-07-301-16/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The number of outstanding kiocbs is one of the few shared things left that has to be touched for every kiocb - it'd be nice to make it percpu. We can make it per cpu by treating it like an allocation problem: we have a maximum number of kiocbs that can be outstanding (i.e. slots) - then we just allocate and free slots, and we know how to write per cpu allocators. So as prep work for that, we convert reqs_active to reqs_available. Signed-off-by: Kent Overstreet <koverstreet@google.com> Cc: Zach Brown <zab@redhat.com> Cc: Felipe Balbi <balbi@ti.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jens Axboe <axboe@kernel.dk> Cc: Asai Thambi S P <asamymuthupa@micron.com> Cc: Selvan Mani <smani@micron.com> Cc: Sam Bradshaw <sbradshaw@micron.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Benjamin LaHaise <bcrl@kvack.org> Reviewed-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
| * | | aio: fix build when migration is disabledBenjamin LaHaise2013-07-171-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When "fs/aio: Add support to aio ring pages migration" was applied, it broke the build when CONFIG_MIGRATION was disabled. Wrap the migration code with a test for CONFIG_MIGRATION to fix this and save a few bytes when migration is disabled. Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
| * | | fs/aio: Add support to aio ring pages migrationGu Zheng2013-07-161-11/+108
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As the aio job will pin the ring pages, that will lead to mem migrated failed. In order to fix this problem we use an anon inode to manage the aio ring pages, and setup the migratepage callback in the anon inode's address space, so that when mem migrating the aio ring pages will be moved to other mem node safely. Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com> Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
| * | | fs/anon_inode: Introduce a new lib function anon_inode_getfile_private()Gu Zheng2013-07-161-0/+66
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce a new lib function anon_inode_getfile_private(), it creates a new file instance by hooking it up to an anonymous inode, and a dentry that describe the "class" of the file, similar to anon_inode_getfile(), but each file holds a single inode. Furthermore, anyone who wants to create a private anon file will benefit from this change. Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com> Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
* | | | Merge tag 'xfs-for-linus-v3.12-rc1-2' of git://oss.sgi.com/xfs/xfsLinus Torvalds2013-09-1225-166/+461
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull xfs update #2 from Ben Myers: "Here we have defrag support for v5 superblock, a number of bugfixes and a cleanup or two. - defrag support for CRC filesystems - fix endian worning in xlog_recover_get_buf_lsn - fixes for sparse warnings - fix for assert in xfs_dir3_leaf_hdr_from_disk - fix for log recovery of remote symlinks - fix for log recovery of btree root splits - fixes formemory allocation failures with ACLs - fix for assert in xfs_buf_item_relse - fix for assert in xfs_inode_buf_verify - fix an assignment in an assert that should be a test in xfs_bmbt_change_owner - remove dead code in xlog_recover_inode_pass2" * tag 'xfs-for-linus-v3.12-rc1-2' of git://oss.sgi.com/xfs/xfs: xfs: remove dead code from xlog_recover_inode_pass2 xfs: = vs == typo in ASSERT() xfs: don't assert fail on bad inode numbers xfs: aborted buf items can be in the AIL. xfs: factor all the kmalloc-or-vmalloc fallback allocations xfs: fix memory allocation failures with ACLs xfs: ensure we copy buffer type in da btree root splits xfs: set remote symlink buffer type for recovery xfs: recovery of swap extents operations for CRC filesystems xfs: swap extents operations for CRC filesystems xfs: check magic numbers in dir3 leaf verifier first xfs: fix some minor sparse warnings xfs: fix endian warning in xlog_recover_get_buf_lsn()
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