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* Merge tag 'gfs2-merge-window' of ↵Linus Torvalds2015-06-2711-145/+435
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org:/pub/scm/linux/kernel/git/gfs2/linux-gfs2 Pull GFS2 updates from Bob Peterson: "Here are the patches we've accumulated for GFS2 for the current upstream merge window. We have a good mixture this time. Here are some of the features: - Fix a problem with RO mounts writing to the journal. - Further improvements to quotas on GFS2. - Added support for rename2 and RENAME_EXCHANGE on GFS2. - Increase performance by making glock lru_list less of a bottleneck. - Increase performance by avoiding unnecessary buffer_head releases. - Increase performance by using average glock round trip time from all CPUs. - Fixes for some compiler warnings and minor white space issues. - Other misc bug fixes" * tag 'gfs2-merge-window' of git://git.kernel.org:/pub/scm/linux/kernel/git/gfs2/linux-gfs2: GFS2: Don't brelse rgrp buffer_heads every allocation GFS2: Don't add all glocks to the lru gfs2: Don't support fallocate on jdata files gfs2: s64 cast for negative quota value gfs2: limit quota log messages gfs2: fix quota updates on block boundaries gfs2: fix shadow warning in gfs2_rbm_find() gfs2: kerneldoc warning fixes gfs2: convert simple_str to kstr GFS2: make sure S_NOSEC flag isn't overwritten GFS2: add support for rename2 and RENAME_EXCHANGE gfs2: handle NULL rgd in set_rgrp_preferences GFS2: inode.c: indent with TABs, not spaces GFS2: mark the journal idle to fix ro mounts GFS2: Average in only non-zero round-trip times for congestion stats GFS2: Use average srttb value in congestion calculations
| * GFS2: Don't brelse rgrp buffer_heads every allocationBob Peterson2015-06-193-7/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch allows the block allocation code to retain the buffers for the resource groups so they don't need to be re-read from buffer cache with every request. This is a performance improvement that's especially noticeable when resource groups are very large. For example, with 2GB resource groups and 4K blocks, there can be 33 blocks for every resource group. This patch allows those 33 buffers to be kept around and not read in and thrown away with every operation. The buffers are released when the resource group is either synced or invalidated. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Reviewed-by: Steven Whitehouse <swhiteho@redhat.com> Reviewed-by: Benjamin Marzinski <bmarzins@redhat.com>
| * GFS2: Don't add all glocks to the lruBob Peterson2015-06-183-3/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The glocks used for resource groups often come and go hundreds of thousands of times per second. Adding them to the lru list just adds unnecessary contention for the lru_lock spin_lock, especially considering we're almost certainly going to re-use the glock and take it back off the lru microseconds later. We never want the glock shrinker to cull them anyway. This patch adds a new bit in the glops that determines which glock types get put onto the lru list and which ones don't. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Acked-by: Steven Whitehouse <swhiteho@redhat.com>
| * gfs2: Don't support fallocate on jdata filesAbhi Das2015-06-091-1/+1
| | | | | | | | | | | | | | | | We cannot provide an efficient implementation due to the headers on the data blocks, so there doesn't seem much point in having it. Signed-off-by: Abhi Das <adas@redhat.com> Signed-off-by: Bob Peterson <rpeterso@redhat.com>
| * gfs2: s64 cast for negative quota valueAbhi Das2015-06-081-1/+1
| | | | | | | | | | | | | | | | | | One-line fix to cast quota value to s64 before comparison. By default the quantity is treated as u64. Signed-off-by: Abhi Das <adas@redhat.com> Signed-off-by: Bob Peterson <rpeterso@redhat.com> Acked-by: Steven Whitehouse <swhiteho@redhat.com>
| * gfs2: limit quota log messagesAbhi Das2015-06-022-4/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch makes the quota subsystem only report once that a particular user/group has exceeded their allotted quota. Previously, it was possible for a program to continuously try exceeding quota (despite receiving EDQUOT) and in turn trigger gfs2 to issue a kernel log message about quota exceed. In theory, this could get out of hand and flood the log and the filesystem hosting the log files. Signed-off-by: Abhi Das <adas@redhat.com> Signed-off-by: Bob Peterson <rpeterso@redhat.com>
| * gfs2: fix quota updates on block boundariesAbhi Das2015-06-022-80/+119
| | | | | | | | | | | | | | | | | | | | | | | | | | | | For smaller block sizes (512B, 1K, 2K), some quotas straddle block boundaries such that the usage value is on one block and the rest of the quota is on the previous block. In such cases, the value does not get updated correctly. This patch fixes that by addressing the boundary conditions correctly. This patch also adds a (s64) cast that was missing in a call to gfs2_quota_change() in inode.c Signed-off-by: Abhi Das <adas@redhat.com> Signed-off-by: Bob Peterson <rpeterso@redhat.com>
| * gfs2: fix shadow warning in gfs2_rbm_find()Fabian Frederick2015-05-181-3/+1
| | | | | | | | | | | | | | bi was already declared and initialized globally in gfs2_rbm_find() Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: Bob Peterson <rpeterso@redhat.com>
| * gfs2: kerneldoc warning fixesFabian Frederick2015-05-051-4/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fixes the following kernel-doc warnings: Warning(fs/gfs2/aops.c:180): No description found for parameter 'wbc' Warning(fs/gfs2/aops.c:236): No description found for parameter 'end' Warning(fs/gfs2/aops.c:236): No description found for parameter 'done_index' Warning(fs/gfs2/aops.c:236): Excess function parameter 'writepage' description in 'gfs2_write_jdata_pagevec' Warning(fs/gfs2/aops.c:346): Excess function parameter 'writepage' description in 'gfs2_write_cache_jdata' Warning(fs/gfs2/aops.c:346): Excess function parameter 'data' description in 'gfs2_write_cache_jdata' Warning(fs/gfs2/aops.c:605): No description found for parameter 'file' Warning(fs/gfs2/aops.c:605): No description found for parameter 'mapping' Warning(fs/gfs2/aops.c:605): No description found for parameter 'pages' Warning(fs/gfs2/aops.c:605): No description found for parameter 'nr_pages' Warning(fs/gfs2/aops.c:870): No description found for parameter 'copied' Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: Bob Peterson <rpeterso@redhat.com>
| * gfs2: convert simple_str to kstrFabian Frederick2015-05-051-18/+48
| | | | | | | | | | | | | | | | | | | | | | | | -Remove obsolete simple_str functions. -Return error code when kstr failed. -This patch also calls functions corresponding to destination type. Thanks to Alexey Dobriyan for suggesting improvements in block_store() and wdack_store() Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: Bob Peterson <rpeterso@redhat.com>
| * GFS2: make sure S_NOSEC flag isn't overwrittenBenjamin Marzinski2015-05-051-1/+1
| | | | | | | | | | | | | | | | | | At the end of gfs2_set_inode_flags inode->i_flags is set to flags, so we should be modifying flags instead of inode->i_flags, so it isn't overwritten. Signed-off-by: Benjamin Marzinski <bmarzins redhat com> Signed-off-by: Bob Peterson <rpeterso@redhat.com>
| * GFS2: add support for rename2 and RENAME_EXCHANGEBenjamin Marzinski2015-05-051-16/+189
| | | | | | | | | | | | | | | | | | gfs2 now uses the rename2 directory iop, and supports the RENAME_EXCHANGE flag (as well as RENAME_NOREPLACE, which the vfs takes care of). Signed-off-by: Benjamin Marzinski <bmarzins redhat com> Signed-off-by: Bob Peterson <rpeterso@redhat.com>
| * gfs2: handle NULL rgd in set_rgrp_preferencesAbhi Das2015-05-051-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The function set_rgrp_preferences() does not handle the (rarely returned) NULL value from gfs2_rgrpd_get_next() and this patch fixes that. The fs image in question is only 150MB in size which allows for only 1 rgrp to be created. The in-memory rb tree has only 1 node and when gfs2_rgrpd_get_next() is called on this sole rgrp, it returns NULL. (Default behavior is to wrap around the rb tree and return the first node to give the illusion of a circular linked list. In the case of only 1 rgrp, we can't have gfs2_rgrpd_get_next() return the same rgrp (first, last, next all point to the same rgrp)... that would cause unintended consequences and infinite loops.) Signed-off-by: Abhi Das <adas@redhat.com> Signed-off-by: Bob Peterson <rpeterso@redhat.com>
| * GFS2: inode.c: indent with TABs, not spacesAntonio Ospite2015-05-011-2/+2
| | | | | | | | | | | | | | Follow the same style used for the other functions in the same file. Signed-off-by: Antonio Ospite <ao2@ao2.it> Signed-off-by: Bob Peterson <rpeterso@redhat.com>
| * GFS2: mark the journal idle to fix ro mountsBenjamin Marzinski2015-05-011-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When gfs2 was mounted read-only and then unmounted, it was writing a header block to the journal in the syncing gfs2_log_flush() call from kill_sb(). This is because the journal was not being marked as idle until the first log header was written out, and on a read-only mount there never was a log header written out. Since the journal was not marked idle, gfs2_log_flush() was writing out a header lock to make sure it was empty during the sync. Not only did this cause IO to a read-only filesystem, but the journalling isn't completely initialized on read-only mounts, and so gfs2 was writing out the wrong sequence number in the log header. Now, the journal is marked idle on mount, and gfs2_log_flush() won't write out anything until there starts being transactions to flush. Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> Signed-off-by: Bob Peterson <rpeterso@redhat.com> Acked-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: Average in only non-zero round-trip times for congestion statsBob Peterson2015-04-241-3/+7
| | | | | | | | | | | | | | | | | | | | | | | | This patch changes function gfs2_rgrp_congested so that it only factors in non-zero values into its average round trip time. If the round-trip time is zero for a particular cpu, that cpu has obviously never dealt with bouncing the resource group in question, so factoring in a zero value will only skew the numbers. It also fixes a compile error on some arches related to division. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Acked-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: Use average srttb value in congestion calculationsBob Peterson2015-04-241-4/+9
| | | | | | | | | | | | | | | | | | | | | | This patch changes function gfs2_rgrp_congested so that it uses an average srttb (smoothed round trip time for blocking rgrp glocks) rather than the CPU-specific value. If we use the CPU-specific value it can incorrectly report no contention when there really is contention due to the glock processing occurring on a different CPU. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Acked-by: Steven Whitehouse <swhiteho@redhat.com>
* | Revert "jbd2: speedup jbd2_journal_dirty_metadata()"Linus Torvalds2015-06-271-27/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit 2143c1965a761332ae417b22fd477b636e4f54ec. This commit seems to be the cause of the following jbd2 assertion failure: ------------[ cut here ]------------ kernel BUG at fs/jbd2/transaction.c:1325! invalid opcode: 0000 [#1] SMP Modules linked in: bnep bluetooth fuse ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 ... CPU: 7 PID: 5509 Comm: gcc Not tainted 4.1.0-10944-g2a298679b411 #1 Hardware name: /DH87RL, BIOS RLH8710H.86A.0327.2014.0924.1645 09/24/2014 task: ffff8803bf866040 ti: ffff880308528000 task.ti: ffff880308528000 RIP: jbd2_journal_dirty_metadata+0x237/0x290 Call Trace: __ext4_handle_dirty_metadata+0x43/0x1f0 ext4_handle_dirty_dirent_node+0xde/0x160 ? jbd2_journal_get_write_access+0x36/0x50 ext4_delete_entry+0x112/0x160 ? __ext4_journal_start_sb+0x52/0xb0 ext4_unlink+0xfa/0x260 vfs_unlink+0xec/0x190 do_unlinkat+0x24a/0x270 SyS_unlink+0x11/0x20 entry_SYSCALL_64_fastpath+0x12/0x6a ---[ end trace ae033ebde8d080b4 ]--- which is not easily reproducible (I've seen it just once, and then Ted was able to reproduce it once). Revert it while Ted and Jan try to figure out what is wrong. Cc: Jan Kara <jack@suse.cz> Acked-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge branch 'for-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds2015-06-263-164/+353
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull workqueue updates from Tejun Heo: "Most of the changes are around implementing and fixing fallouts from sysfs and internal interface to limit the CPUs available to all unbound workqueues to help isolating CPUs. It needs more work as ordered workqueues can roam unrestricted but still is a significant improvement" * 'for-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: fix typos in comments workqueue: move flush_scheduled_work() to workqueue.h workqueue: remove the lock from wq_sysfs_prep_attrs() workqueue: remove the declaration of copy_workqueue_attrs() workqueue: ensure attrs changes are properly synchronized workqueue: separate out and refactor the locking of applying attrs workqueue: simplify wq_update_unbound_numa() workqueue: wq_pool_mutex protects the attrs-installation workqueue: fix a typo workqueue: function name in the comment differs from the real function name workqueue: fix trivial typo in Documentation/workqueue.txt workqueue: Allow modifying low level unbound workqueue cpumask workqueue: Create low-level unbound workqueues cpumask workqueue: split apply_workqueue_attrs() into 3 stages
| * | workqueue: fix typos in commentsShailendra Verma2015-05-291-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | tj: dropped iff -> if, iff is if and only if not a typo. Spotted by Randy Dunlap. Signed-off-by: Shailendra Verma <shailendra.capricorn@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Randy Dunlap <rdunlap@infradead.org>
| * | workqueue: move flush_scheduled_work() to workqueue.hLai Jiangshan2015-05-212-31/+29
| | | | | | | | | | | | | | | | | | | | | flush_scheduled_work() is just a simple call to flush_work(). Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * | workqueue: remove the lock from wq_sysfs_prep_attrs()Lai Jiangshan2015-05-211-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | Reading to wq->unbound_attrs requires protection of either wq_pool_mutex or wq->mutex, and wq_sysfs_prep_attrs() is called with wq_pool_mutex held, so we don't need to grab wq->mutex here. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * | workqueue: remove the declaration of copy_workqueue_attrs()Lai Jiangshan2015-05-211-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | This pre-declaration was unneeded since a previous refactor patch 6ba94429c8e7 ("workqueue: Reorder sysfs code"). Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * | workqueue: ensure attrs changes are properly synchronizedLai Jiangshan2015-05-191-9/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Current modification to attrs via sysfs is not fully synchronized. Process A (change cpumask) | Process B (change numa affinity) wq_cpumask_store() | wq_sysfs_prep_attrs() | | apply_workqueue_attrs() apply_workqueue_attrs() | It results that the Process B's operation is totally reverted without any notification, it is a buggy behavior. So this patch moves wq_sysfs_prep_attrs() into the protection under wq_pool_mutex to ensure attrs changes are properly synchronized. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * | workqueue: separate out and refactor the locking of applying attrsLai Jiangshan2015-05-191-33/+45
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Applying attrs requires two locks: get_online_cpus() and wq_pool_mutex, and this code is duplicated at two places (apply_workqueue_attrs() and workqueue_set_unbound_cpumask()). So we separate out this locking code into apply_wqattrs_[un]lock() and do a minor refactor on apply_workqueue_attrs(). The apply_wqattrs_[un]lock() will be also used on later patch for ensuring attrs changes are properly synchronized. tj: minor updates to comments Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * | workqueue: simplify wq_update_unbound_numa()Lai Jiangshan2015-05-181-15/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | wq_update_unbound_numa() is known be called with wq_pool_mutex held. But wq_update_unbound_numa() requests wq->mutex before reading wq->unbound_attrs, wq->numa_pwq_tbl[] and wq->dfl_pwq. But these fields were changed to be allowed being read with wq_pool_mutex held. So we simply remove the mutex_lock(&wq->mutex). Without the dependence on the the mutex_lock(&wq->mutex), the test of wq->unbound_attrs->no_numa can also be moved upward. The old code need a long comment to describe the stableness of @wq->unbound_attrs which is also guaranteed by wq_pool_mutex now, so we don't need this such comment. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * | workqueue: wq_pool_mutex protects the attrs-installationLai Jiangshan2015-05-181-7/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Current wq_pool_mutex doesn't proctect the attrs-installation, it results that ->unbound_attrs, ->numa_pwq_tbl[] and ->dfl_pwq can only be accessed under wq->mutex and causes some inconveniences. Example, wq_update_unbound_numa() has to acquire wq->mutex before fetching the wq->unbound_attrs->no_numa and the old_pwq. attrs-installation is a short operation, so this change will no cause any latency for other operations which also acquire the wq_pool_mutex. The only unprotected attrs-installation code is in apply_workqueue_attrs(), so this patch touches code less than comments. It is also a preparation patch for next several patches which read wq->unbound_attrs, wq->numa_pwq_tbl[] and wq->dfl_pwq with only wq_pool_mutex held. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * | workqueue: fix a typoChen Hanxiao2015-05-131-1/+1
| | | | | | | | | | | | | | | | | | | | | s/detemined/determined Signed-off-by: Chen Hanxiao <chenhanxiao@cn.fujitsu.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * | workqueue: function name in the comment differs from the real function nameGong Zhaogang2015-05-111-1/+1
| | | | | | | | | | | | | | | | | | | | | modify wq_calc_node_mask to wq_calc_node_cpumask Signed-off-by: Gong Zhaogang <gongzhaogang@inspur.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * | workqueue: fix trivial typo in Documentation/workqueue.txtChris Bainbridge2015-05-051-1/+1
| | | | | | | | | | | | | | | Signed-off-by: Chris Bainbridge <chris.bainbridge@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * | workqueue: Allow modifying low level unbound workqueue cpumaskLai Jiangshan2015-04-302-9/+119
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allow to modify the low-level unbound workqueues cpumask through sysfs. This is performed by traversing the entire workqueue list and calling apply_wqattrs_prepare() on the unbound workqueues with the new low level mask. Only after all the preparation are done, we commit them all together. Ordered workqueues are ignored from the low level unbound workqueue cpumask, it will be handled in near future. All the (default & per-node) pwqs are mandatorily controlled by the low level cpumask. If the user configured cpumask doesn't overlap with the low level cpumask, the low level cpumask will be used for the wq instead. The comment of wq_calc_node_cpumask() is updated and explicitly requires that its first argument should be the attrs of the default pwq. The default wq_unbound_cpumask is cpu_possible_mask. The workqueue subsystem doesn't know its best default value, let the system manager or the other subsystem set it when needed. Changed from V8: merge the calculating code for the attrs of the default pwq together. minor change the code&comments for saving the user configured attrs. remove unnecessary list_del(). minor update the comment of wq_calc_node_cpumask(). update the comment of workqueue_set_unbound_cpumask(); Cc: Christoph Lameter <cl@linux.com> Cc: Kevin Hilman <khilman@linaro.org> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Mike Galbraith <bitbucket@online.de> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Tejun Heo <tj@kernel.org> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Original-patch-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * | workqueue: Create low-level unbound workqueues cpumaskFrederic Weisbecker2015-04-271-2/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Create a cpumask that limits the affinity of all unbound workqueues. This cpumask is controlled through a file at the root of the workqueue sysfs directory. It works on a lower-level than the per WQ_SYSFS workqueues cpumask files such that the effective cpumask applied for a given unbound workqueue is the intersection of /sys/devices/virtual/workqueue/$WORKQUEUE/cpumask and the new /sys/devices/virtual/workqueue/cpumask file. This patch implements the basic infrastructure and the read interface. wq_unbound_cpumask is initially set to cpu_possible_mask. Cc: Christoph Lameter <cl@linux.com> Cc: Kevin Hilman <khilman@linaro.org> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Mike Galbraith <bitbucket@online.de> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Tejun Heo <tj@kernel.org> Cc: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * | workqueue: split apply_workqueue_attrs() into 3 stagesLai Jiangshan2015-04-271-84/+115
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Current apply_workqueue_attrs() includes pwqs-allocation and pwqs-installation, so when we batch multiple apply_workqueue_attrs()s as a transaction, we can't ensure the transaction must succeed or fail as a complete unit. To solve this, we split apply_workqueue_attrs() into three stages. The first stage does the preparation: allocation memory, pwqs. The second stage does the attrs-installaion and pwqs-installation. The third stage frees the allocated memory and (old or unused) pwqs. As the result, batching multiple apply_workqueue_attrs()s can succeed or fail as a complete unit: 1) batch do all the first stage for all the workqueues 2) only commit all when all the above succeed. This patch is a preparation for the next patch ("Allow modifying low level unbound workqueue cpumask") which will do a multiple apply_workqueue_attrs(). The patch doesn't have functionality changed except two minor adjustment: 1) free_unbound_pwq() for the error path is removed, we use the heavier version put_pwq_unlocked() instead since the error path is rare. this adjustment simplifies the code. 2) the memory-allocation is also moved into wq_pool_mutex. this is needed to avoid to do the further splitting. tj: minor updates to comments. Suggested-by: Tejun Heo <tj@kernel.org> Cc: Christoph Lameter <cl@linux.com> Cc: Kevin Hilman <khilman@linaro.org> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Mike Galbraith <bitbucket@online.de> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Tejun Heo <tj@kernel.org> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* | | Merge branch 'for-4.2' of ↵Linus Torvalds2015-06-2611-940/+1028
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: - threadgroup_lock got reorganized so that its users can pick the actual locking mechanism to use. Its only user - cgroups - is updated to use a percpu_rwsem instead of per-process rwsem. This makes things a bit lighter on hot paths and allows cgroups to perform and fail multi-task (a process) migrations atomically. Multi-task migrations are used in several places including the unified hierarchy. - Delegation rule and documentation added to unified hierarchy. This will likely be the last interface update from the cgroup core side for unified hierarchy before lifting the devel mask. - Some groundwork for the pids controller which is scheduled to be merged in the coming devel cycle. * 'for-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: add delegation section to unified hierarchy documentation cgroup: require write perm on common ancestor when moving processes on the default hierarchy cgroup: separate out cgroup_procs_write_permission() from __cgroup_procs_write() kernfs: make kernfs_get_inode() public MAINTAINERS: add a cgroup core co-maintainer cgroup: fix uninitialised iterator in for_each_subsys_which cgroup: replace explicit ss_mask checking with for_each_subsys_which cgroup: use bitmask to filter for_each_subsys cgroup: add seq_file forward declaration for struct cftype cgroup: simplify threadgroup locking sched, cgroup: replace signal_struct->group_rwsem with a global percpu_rwsem sched, cgroup: reorganize threadgroup locking cgroup: switch to unsigned long for bitmasks cgroup: reorganize include/linux/cgroup.h cgroup: separate out include/linux/cgroup-defs.h cgroup: fix some comment typos
| * | | cgroup: add delegation section to unified hierarchy documentationTejun Heo2015-06-181-18/+84
| | | | | | | | | | | | | | | | | | | | | | | | | | | | v2: Rearranged paragraphs as suggested by Johannes Weiner. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org>
| * | | cgroup: require write perm on common ancestor when moving processes on the ↵Tejun Heo2015-06-182-3/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | default hierarchy On traditional hierarchies, if a task has write access to "tasks" or "cgroup.procs" file of a cgroup and its euid agrees with the target, it can move the target to the cgroup; however, consider the following scenario. The owner of each cgroup is in the parentheses. R (root) - 0 (root) - 00 (user1) - 000 (user1) | \ 001 (user1) \ 1 (root) - 10 (user1) The subtrees of 00 and 10 are delegated to user1; however, while both subtrees may belong to the same user, it is clear that the two subtrees are to be isolated - they're under completely separate resource limits imposed by 0 and 1, respectively. Note that 0 and 1 aren't strictly necessary but added to ease illustrating the issue. If user1 is allowed to move processes between the two subtrees, the intention of the hierarchy - keeping a given group of processes under a subtree with certain resource restrictions while delegating management of the subtree - can be circumvented by user1. This happens because migration permission check doesn't consider the hierarchical nature of cgroups. To fix the issue, this patch adds an extra permission requirement when userland tries to migrate a process in the default hierarchy - the issuing task must have write access to the common ancestor of "cgroup.procs" file of the ancestor in addition to the destination's. Conceptually, the issuer must be able to move the target process from the source cgroup to the common ancestor of source and destination cgroups and then to the destination. As long as delegation is done in a proper top-down way, this guarantees that a delegatee can't smuggle processes across disjoint delegation domains. The next patch will add documentation on the delegation model on the default hierarchy. v2: Fixed missing !ret test. Spotted by Li Zefan. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Li Zefan <lizefan@huawei.com>
| * | | cgroup: separate out cgroup_procs_write_permission() from __cgroup_procs_write()Tejun Heo2015-06-181-14/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Separate out task / process migration permission check from __cgroup_procs_write() into cgroup_procs_write_permission(). * Permission check is moved right above the actual migration and no longer performed while holding rcu_read_lock(). cgroup_procs_write_permission() uses get_task_cred() / put_cred() instead of __task_cred(). Also, !root trying to migrate kthreadd or PF_NO_SETAFFINITY tasks will now fail with -EINVAL rather than -EACCES which should be fine. * The same permission check is now performed even when moving self by specifying 0 as pid. This always succeeds so there's no functional difference. We'll add more permission checks later and the benefits of keeping both cases consistent outweigh the minute overhead of doing perm checks on pid 0 case. Signed-off-by: Tejun Heo <tj@kernel.org>
| * | | kernfs: make kernfs_get_inode() publicTejun Heo2015-06-182-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move kernfs_get_inode() prototype from fs/kernfs/kernfs-internal.h to include/linux/kernfs.h. It obtains the matching inode for a kernfs_node. It will be used by cgroup for inode based permission checks for now but is generally useful. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | MAINTAINERS: add a cgroup core co-maintainerTejun Heo2015-06-141-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add Johannes Weiner as a co-maintainer of cgroup core. Johannes has been heavily involved with the design of the v2 interface and is familiar with design and implementation of cgroup core. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com> Cc: Johannes Weiner <hannes@cmpxchg.org>
| * | | cgroup: fix uninitialised iterator in for_each_subsys_whichAleksa Sarai2015-06-101-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix the fact that @ssid is uninitialised in the case where CGROUP_SUBSYS_COUNT = 0 by setting ssid to 0. Fixes: cb4a31675270 ("cgroup: use bitmask to filter for_each_subsys") Signed-off-by: Aleksa Sarai <cyphar@cyphar.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * | | cgroup: replace explicit ss_mask checking with for_each_subsys_whichAleksa Sarai2015-06-081-28/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Replace the explicit checking against ss_masks inside a for_each_subsys block with for_each_subsys_which(..., ss_mask), to take advantage of the more readable (and more efficient) macro. Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
| * | | cgroup: use bitmask to filter for_each_subsysAleksa Sarai2015-06-082-20/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a new macro for_each_subsys_which that allows all enabled cgroup subsystems to be filtered by a bitmask, such that mask & (1 << ssid) determines if the subsystem is to be processed in the loop body (where ssid is the unique id of the subsystem). Also replace the need_forkexit_callback with two separate bitmasks for each callback to make (ss->{fork,exit}) checks unnecessary. tj: add a short comment for "if (!CGROUP_SUBSYS_COUNT)". Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
| * | | cgroup: add seq_file forward declaration for struct cftypeArnd Bergmann2015-05-291-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Recent header file changes for cgroup caused lots of warnings about a missing struct seq_file form declaration for every inclusion of include/linux/cgroup-defs.h. As some files are built with -Werror, this leads to build failure like: from /git/arm-soc/drivers/gpu/drm/tilcdc/tilcdc_crtc.c:18: /git/arm-soc/include/linux/cgroup-defs.h:354:25: error: 'struct seq_file' declared inside parameter list [-Werror] cc1: all warnings being treated as errors make[6]: *** [drivers/gpu/drm/tilcdc/tilcdc_crtc.o] Error 1 This patch adds the declaration, which resolves both the warnings and the drm failure. tj: Moved it where other type declarations are. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Fixes: b4a04ab7a37b ("cgroup: separate out include/linux/cgroup-defs.h") Signed-off-by: Tejun Heo <tj@kernel.org>
| * | | cgroup: simplify threadgroup lockingTejun Heo2015-05-261-35/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that threadgroup locking is made global, code paths around it can be simplified. * lock-verify-unlock-retry dancing removed from __cgroup_procs_write(). * Race protection against de_thread() removed from cgroup_update_dfl_csses(). Signed-off-by: Tejun Heo <tj@kernel.org>
| * | | sched, cgroup: replace signal_struct->group_rwsem with a global percpu_rwsemTejun Heo2015-05-266-83/+46
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The cgroup side of threadgroup locking uses signal_struct->group_rwsem to synchronize against threadgroup changes. This per-process rwsem adds small overhead to thread creation, exit and exec paths, forces cgroup code paths to do lock-verify-unlock-retry dance in a couple places and makes it impossible to atomically perform operations across multiple processes. This patch replaces signal_struct->group_rwsem with a global percpu_rwsem cgroup_threadgroup_rwsem which is cheaper on the reader side and contained in cgroups proper. This patch converts one-to-one. This does make writer side heavier and lower the granularity; however, cgroup process migration is a fairly cold path, we do want to optimize thread operations over it and cgroup migration operations don't take enough time for the lower granularity to matter. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org>
| * | | sched, cgroup: reorganize threadgroup lockingTejun Heo2015-05-263-36/+69
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | threadgroup_change_begin/end() are used to mark the beginning and end of threadgroup modifying operations to allow code paths which require a threadgroup to stay stable across blocking operations to synchronize against those sections using threadgroup_lock/unlock(). It's currently implemented as a general mechanism in sched.h using per-signal_struct rwsem; however, this never grew non-cgroup use cases and becomes noop if !CONFIG_CGROUPS. It turns out that cgroups is gonna be better served with a different sycnrhonization scheme and is a bit silly to keep cgroups specific details as a general mechanism. What's general here is identifying the places where threadgroups are modified. This patch restructures threadgroup locking so that threadgroup_change_begin/end() become a place where subsystems which need to sycnhronize against threadgroup changes can hook into. cgroup_threadgroup_change_begin/end() which operate on the per-signal_struct rwsem are created and threadgroup_lock/unlock() are moved to cgroup.c and made static. This is pure reorganization which doesn't cause any functional changes. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org>
| * | | cgroup: switch to unsigned long for bitmasksAleksa Sarai2015-05-181-19/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Switch the type of all internal cgroup masks to (unsigned long), which is the correct type for bitmasks. This is in preparation for the for_each_subsys_which patch. Signed-off-by: Aleksa Sarai <cyphar@cyphar.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * | | cgroup: reorganize include/linux/cgroup.hTejun Heo2015-05-181-281/+271
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | From c4d440938b5e2015c70594fe6666a099c844f929 Mon Sep 17 00:00:00 2001 From: Tejun Heo <tj@kernel.org> Date: Wed, 13 May 2015 16:21:40 -0400 Over time, cgroup.h grew organically and doesn't have much logical structure at this point. Separation of cgroup-defs.h in the previous patch gives us a good chance for reorganizing cgroup.h as changes to the header are likely to cause conflicts anyway. This patch reorganizes cgroup.h so that it has consistent logical grouping. This is pure reorganization. v2: Relocating #ifdef CONFIG_CGROUPS caused build failure when cgroup is disabled. Dropped. Signed-off-by: Tejun Heo <tj@kernel.org>
| * | | cgroup: separate out include/linux/cgroup-defs.hTejun Heo2015-05-182-453/+466
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | From 2d728f74bfc071df06773e2fd7577dd5dab6425d Mon Sep 17 00:00:00 2001 From: Tejun Heo <tj@kernel.org> Date: Wed, 13 May 2015 15:37:01 -0400 This patch separates out cgroup-defs.h from cgroup.h which has grown a lot of dependencies. cgroup-defs.h currently only contains constant and type definitions and can be used to break circular include dependency. While moving, definitions are reordered so that cgroup-defs.h has consistent logical structure. This patch is pure reorganization. Signed-off-by: Tejun Heo <tj@kernel.org>
| * | | cgroup: fix some comment typosChen Hanxiao2015-04-231-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | s/effctive/effective s/hierarhcy/hierarchy s/shoulid/should Signed-off-by: Chen Hanxiao <chenhanxiao@cn.fujitsu.com> Signed-off-by: Tejun Heo <tj@kernel.org>