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2010-06-29workqueue: increase max_active of keventd and kill current_is_keventd()Tejun Heo
Define WQ_MAX_ACTIVE and create keventd with max_active set to half of it which means that keventd now can process upto WQ_MAX_ACTIVE / 2 - 1 works concurrently. Unless some combination can result in dependency loop longer than max_active, deadlock won't happen and thus it's unnecessary to check whether current_is_keventd() before trying to schedule a work. Kill current_is_keventd(). (Lockdep annotations are broken. We need lock_map_acquire_read_norecurse()) Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Oleg Nesterov <oleg@redhat.com>
2010-06-29workqueue: implement concurrency managed dynamic worker poolTejun Heo
Instead of creating a worker for each cwq and putting it into the shared pool, manage per-cpu workers dynamically. Works aren't supposed to be cpu cycle hogs and maintaining just enough concurrency to prevent work processing from stalling due to lack of processing context is optimal. gcwq keeps the number of concurrent active workers to minimum but no less. As long as there's one or more running workers on the cpu, no new worker is scheduled so that works can be processed in batch as much as possible but when the last running worker blocks, gcwq immediately schedules new worker so that the cpu doesn't sit idle while there are works to be processed. gcwq always keeps at least single idle worker around. When a new worker is necessary and the worker is the last idle one, the worker assumes the role of "manager" and manages the worker pool - ie. creates another worker. Forward-progress is guaranteed by having dedicated rescue workers for workqueues which may be necessary while creating a new worker. When the manager is having problem creating a new worker, mayday timer activates and rescue workers are summoned to the cpu and execute works which might be necessary to create new workers. Trustee is expanded to serve the role of manager while a CPU is being taken down and stays down. As no new works are supposed to be queued on a dead cpu, it just needs to drain all the existing ones. Trustee continues to try to create new workers and summon rescuers as long as there are pending works. If the CPU is brought back up while the trustee is still trying to drain the gcwq from the previous offlining, the trustee will kill all idles ones and tell workers which are still busy to rebind to the cpu, and pass control over to gcwq which assumes the manager role as necessary. Concurrency managed worker pool reduces the number of workers drastically. Only workers which are necessary to keep the processing going are created and kept. Also, it reduces cache footprint by avoiding unnecessarily switching contexts between different workers. Please note that this patch does not increase max_active of any workqueue. All workqueues can still only process one work per cpu. Signed-off-by: Tejun Heo <tj@kernel.org>
2010-06-29workqueue: implement worker_{set|clr}_flags()Tejun Heo
Implement worker_{set|clr}_flags() to manipulate worker flags. These are currently simple wrappers but logics to track the current worker state and the current level of concurrency will be added. Signed-off-by: Tejun Heo <tj@kernel.org>
2010-06-29workqueue: use shared worklist and pool all workers per cpuTejun Heo
Use gcwq->worklist instead of cwq->worklist and break the strict association between a cwq and its worker. All works queued on a cpu are queued on gcwq->worklist and processed by any available worker on the gcwq. As there no longer is strict association between a cwq and its worker, whether a work is executing can now only be determined by calling [__]find_worker_executing_work(). After this change, the only association between a cwq and its worker is that a cwq puts a worker into shared worker pool on creation and kills it on destruction. As all workqueues are still limited to max_active of one, this means that there are always at least as many workers as active works and thus there's no danger for deadlock. The break of strong association between cwqs and workers requires somewhat clumsy changes to current_is_keventd() and destroy_workqueue(). Dynamic worker pool management will remove both clumsy changes. current_is_keventd() won't be necessary at all as the only reason it exists is to avoid queueing a work from a work which will be allowed just fine. The clumsy part of destroy_workqueue() is added because a worker can only be destroyed while idle and there's no guarantee a worker is idle when its wq is going down. With dynamic pool management, workers are not associated with workqueues at all and only idle ones will be submitted to destroy_workqueue() so the code won't be necessary anymore. Signed-off-by: Tejun Heo <tj@kernel.org>
2010-06-29workqueue: implement WQ_NON_REENTRANTTejun Heo
With gcwq managing all the workers and work->data pointing to the last gcwq it was on, non-reentrance can be easily implemented by checking whether the work is still running on the previous gcwq on queueing. Implement it. Signed-off-by: Tejun Heo <tj@kernel.org>
2010-06-29workqueue: carry cpu number in work data once execution startsTejun Heo
To implement non-reentrant workqueue, the last gcwq a work was executed on must be reliably obtainable as long as the work structure is valid even if the previous workqueue has been destroyed. To achieve this, work->data will be overloaded to carry the last cpu number once execution starts so that the previous gcwq can be located reliably. This means that cwq can't be obtained from work after execution starts but only gcwq. Implement set_work_{cwq|cpu}(), get_work_[g]cwq() and clear_work_data() to set work data to the cpu number when starting execution, access the overloaded work data and clear it after cancellation. queue_delayed_work_on() is updated to preserve the last cpu while in-flight in timer and other callers which depended on getting cwq from work after execution starts are converted to depend on gcwq instead. * Anton Blanchard fixed compile error on powerpc due to missing linux/threads.h include. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Anton Blanchard <anton@samba.org>
2010-06-29workqueue: add find_worker_executing_work() and track current_cwqTejun Heo
Now that all the workers are tracked by gcwq, we can find which worker is executing a work from gcwq. Implement find_worker_executing_work() and make worker track its current_cwq so that we can find things the other way around. This will be used to implement non-reentrant wqs. Signed-off-by: Tejun Heo <tj@kernel.org>
2010-06-29workqueue: make single thread workqueue shared worker pool friendlyTejun Heo
Reimplement st (single thread) workqueue so that it's friendly to shared worker pool. It was originally implemented by confining st workqueues to use cwq of a fixed cpu and always having a worker for the cpu. This implementation isn't very friendly to shared worker pool and suboptimal in that it ends up crossing cpu boundaries often. Reimplement st workqueue using dynamic single cpu binding and cwq->limit. WQ_SINGLE_THREAD is replaced with WQ_SINGLE_CPU. In a single cpu workqueue, at most single cwq is bound to the wq at any given time. Arbitration is done using atomic accesses to wq->single_cpu when queueing a work. Once bound, the binding stays till the workqueue is drained. Note that the binding is never broken while a workqueue is frozen. This is because idle cwqs may have works waiting in delayed_works queue while frozen. On thaw, the cwq is restarted if there are any delayed works or unbound otherwise. When combined with max_active limit of 1, single cpu workqueue has exactly the same execution properties as the original single thread workqueue while allowing sharing of per-cpu workers. Signed-off-by: Tejun Heo <tj@kernel.org>
2010-06-29workqueue: reimplement CPU hotplugging support using trusteeTejun Heo
Reimplement CPU hotplugging support using trustee thread. On CPU down, a trustee thread is created and each step of CPU down is executed by the trustee and workqueue_cpu_callback() simply drives and waits for trustee state transitions. CPU down operation no longer waits for works to be drained but trustee sticks around till all pending works have been completed. If CPU is brought back up while works are still draining, workqueue_cpu_callback() tells trustee to step down and tell workers to rebind to the cpu. As it's difficult to tell whether cwqs are empty if it's freezing or frozen, trustee doesn't consider draining to be complete while a gcwq is freezing or frozen (tracked by new GCWQ_FREEZING flag). Also, workers which get unbound from their cpu are marked with WORKER_ROGUE. Trustee based implementation doesn't bring any new feature at this point but it will be used to manage worker pool when dynamic shared worker pool is implemented. Signed-off-by: Tejun Heo <tj@kernel.org>
2010-06-29workqueue: implement worker statesTejun Heo
Implement worker states. After created, a worker is STARTED. While a worker isn't processing a work, it's IDLE and chained on gcwq->idle_list. While processing a work, a worker is BUSY and chained on gcwq->busy_hash. Also, gcwq now counts the number of all workers and idle ones. worker_thread() is restructured to reflect state transitions. cwq->more_work is removed and waking up a worker makes it check for events. A worker is killed by setting DIE flag while it's IDLE and waking it up. This gives gcwq better visibility of what's going on and allows it to find out whether a work is executing quickly which is necessary to have multiple workers processing the same cwq. Signed-off-by: Tejun Heo <tj@kernel.org>
2010-06-29workqueue: introduce global cwq and unify cwq locksTejun Heo
There is one gcwq (global cwq) per each cpu and all cwqs on an cpu point to it. A gcwq contains a lock to be used by all cwqs on the cpu and an ida to give IDs to workers belonging to the cpu. This patch introduces gcwq, moves worker_ida into gcwq and make all cwqs on the same cpu use the cpu's gcwq->lock instead of separate locks. gcwq->ida is now protected by gcwq->lock too. Signed-off-by: Tejun Heo <tj@kernel.org>
2010-06-29workqueue: reimplement workqueue freeze using max_activeTejun Heo
Currently, workqueue freezing is implemented by marking the worker freezeable and calling try_to_freeze() from dispatch loop. Reimplement it using cwq->limit so that the workqueue is frozen instead of the worker. * workqueue_struct->saved_max_active is added which stores the specified max_active on initialization. * On freeze, all cwq->max_active's are quenched to zero. Freezing is complete when nr_active on all cwqs reach zero. * On thaw, all cwq->max_active's are restored to wq->saved_max_active and the worklist is repopulated. This new implementation allows having single shared pool of workers per cpu. Signed-off-by: Tejun Heo <tj@kernel.org>
2010-06-29workqueue: implement per-cwq active work limitTejun Heo
Add cwq->nr_active, cwq->max_active and cwq->delayed_work. nr_active counts the number of active works per cwq. A work is active if it's flushable (colored) and is on cwq's worklist. If nr_active reaches max_active, new works are queued on cwq->delayed_work and activated later as works on the cwq complete and decrement nr_active. cwq->max_active can be specified via the new @max_active parameter to __create_workqueue() and is set to 1 for all workqueues for now. As each cwq has only single worker now, this double queueing doesn't cause any behavior difference visible to its users. This will be used to reimplement freeze/thaw and implement shared worker pool. Signed-off-by: Tejun Heo <tj@kernel.org>
2010-06-29workqueue: reimplement work flushing using linked worksTejun Heo
A work is linked to the next one by having WORK_STRUCT_LINKED bit set and these links can be chained. When a linked work is dispatched to a worker, all linked works are dispatched to the worker's newly added ->scheduled queue and processed back-to-back. Currently, as there's only single worker per cwq, having linked works doesn't make any visible behavior difference. This change is to prepare for multiple shared workers per cpu. Signed-off-by: Tejun Heo <tj@kernel.org>
2010-06-29workqueue: introduce workerTejun Heo
Separate out worker thread related information to struct worker from struct cpu_workqueue_struct and implement helper functions to deal with the new struct worker. The only change which is visible outside is that now workqueue worker are all named "kworker/CPUID:WORKERID" where WORKERID is allocated from per-cpu ida. This is in preparation of concurrency managed workqueue where shared multiple workers would be available per cpu. Signed-off-by: Tejun Heo <tj@kernel.org>
2010-06-29workqueue: reimplement workqueue flushing using color coded worksTejun Heo
Reimplement workqueue flushing using color coded works. wq has the current work color which is painted on the works being issued via cwqs. Flushing a workqueue is achieved by advancing the current work colors of cwqs and waiting for all the works which have any of the previous colors to drain. Currently there are 16 possible colors, one is reserved for no color and 15 colors are useable allowing 14 concurrent flushes. When color space gets full, flush attempts are batched up and processed together when color frees up, so even with many concurrent flushers, the new implementation won't build up huge queue of flushers which has to be processed one after another. Only works which are queued via __queue_work() are colored. Works which are directly put on queue using insert_work() use NO_COLOR and don't participate in workqueue flushing. Currently only works used for work-specific flush fall in this category. This new implementation leaves only cleanup_workqueue_thread() as the user of flush_cpu_workqueue(). Just make its users use flush_workqueue() and kthread_stop() directly and kill cleanup_workqueue_thread(). As workqueue flushing doesn't use barrier request anymore, the comment describing the complex synchronization around it in cleanup_workqueue_thread() is removed together with the function. This new implementation is to allow having and sharing multiple workers per cpu. Please note that one more bit is reserved for a future work flag by this patch. This is to avoid shifting bits and updating comments later. Signed-off-by: Tejun Heo <tj@kernel.org>
2010-06-29workqueue: update cwq alignementTejun Heo
work->data field is used for two purposes. It points to cwq it's queued on and the lower bits are used for flags. Currently, two bits are reserved which is always safe as 4 byte alignment is guaranteed on every architecture. However, future changes will need more flag bits. On SMP, the percpu allocator is capable of honoring larger alignment (there are other users which depend on it) and larger alignment works just fine. On UP, percpu allocator is a thin wrapper around kzalloc/kfree() and don't honor alignment request. This patch introduces WORK_STRUCT_FLAG_BITS and implements alloc/free_cwqs() which guarantees max(1 << WORK_STRUCT_FLAG_BITS, __alignof__(unsigned long long) alignment both on SMP and UP. On SMP, simply wrapping percpu allocator is enough. On UP, extra space is allocated so that cwq can be aligned and the original pointer can be stored after it which is used in the free path. * Alignment problem on UP is reported by Michal Simek. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Frederic Weisbecker <fweisbec@gmail.com> Reported-by: Michal Simek <michal.simek@petalogix.com>
2010-06-29workqueue: kill cpu_populated_mapTejun Heo
Worker management is about to be overhauled. Simplify things by removing cpu_populated_map, creating workers for all possible cpus and making single threaded workqueues behave more like multi threaded ones. After this patch, all cwqs are always initialized, all workqueues are linked on the workqueues list and workers for all possibles cpus always exist. This also makes CPU hotplug support simpler - checking ->cpus_allowed before processing works in worker_thread() and flushing cwqs on CPU_POST_DEAD are enough. While at it, make get_cwq() always return the cwq for the specified cpu, add target_cwq() for cases where single thread distinction is necessary and drop all direct usage of per_cpu_ptr() on wq->cpu_wq. Signed-off-by: Tejun Heo <tj@kernel.org>
2010-06-29workqueue: temporarily remove workqueue tracingTejun Heo
Strip tracing code from workqueue and remove workqueue tracing. This is temporary measure till concurrency managed workqueue is complete. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Frederic Weisbecker <fweisbec@gmail.com>
2010-06-29workqueue: separate out process_one_work()Tejun Heo
Separate out process_one_work() out of run_workqueue(). This patch doesn't cause any behavior change. Signed-off-by: Tejun Heo <tj@kernel.org>
2010-06-29workqueue: define masks for work flags and conditionalize STATIC flagsTejun Heo
Work flags are about to see more traditional mask handling. Define WORK_STRUCT_*_BIT as the bit position constant and redefine WORK_STRUCT_* as bit masks. Also, make WORK_STRUCT_STATIC_* flags conditional While at it, re-define these constants as enums and use WORK_STRUCT_STATIC instead of hard-coding 2 in WORK_DATA_STATIC_INIT(). Signed-off-by: Tejun Heo <tj@kernel.org>
2010-06-29workqueue: merge feature parameters into flagsTejun Heo
Currently, __create_workqueue_key() takes @singlethread and @freezeable paramters and store them separately in workqueue_struct. Merge them into a single flags parameter and field and use WQ_FREEZEABLE and WQ_SINGLE_THREAD. Signed-off-by: Tejun Heo <tj@kernel.org>
2010-06-29workqueue: misc/cosmetic updatesTejun Heo
Make the following updates in preparation of concurrency managed workqueue. None of these changes causes any visible behavior difference. * Add comments and adjust indentations to data structures and several functions. * Rename wq_per_cpu() to get_cwq() and swap the position of two parameters for consistency. Convert a direct per_cpu_ptr() access to wq->cpu_wq to get_cwq(). * Add work_static() and Update set_wq_data() such that it sets the flags part to WORK_STRUCT_PENDING | WORK_STRUCT_STATIC if static | @extra_flags. * Move santiy check on work->entry emptiness from queue_work_on() to __queue_work() which all queueing paths share. * Make __queue_work() take @cpu and @wq instead of @cwq. * Restructure flush_work() and __create_workqueue_key() to make them easier to modify. Signed-off-by: Tejun Heo <tj@kernel.org>
2010-06-29workqueue: kill RT workqueueTejun Heo
With stop_machine() converted to use cpu_stop, RT workqueue doesn't have any user left. Kill RT workqueue support. Signed-off-by: Tejun Heo <tj@kernel.org>
2010-06-29acpi: use queue_work_on() instead of binding workqueue worker to cpu0Tejun Heo
ACPI works need to be executed on cpu0 and acpi/osl.c achieves this by creating singlethread workqueue and then binding it to cpu0 from a work which is quite unorthodox. Make it create regular workqueues and use queue_work_on() instead. This is in preparation of concurrency managed workqueue and the extra workers won't be a problem after it's implemented. Signed-off-by: Tejun Heo <tj@kernel.org>
2010-06-29kthread: implement kthread_data()Tejun Heo
Implement kthread_data() which takes @task pointing to a kthread and returns @data specified when creating the kthread. The caller is responsible for ensuring the validity of @task when calling this function. Signed-off-by: Tejun Heo <tj@kernel.org>
2010-06-29ivtv: use kthread_worker instead of workqueueTejun Heo
Upcoming workqueue updates will no longer guarantee fixed workqueue to worker kthread association, so giving RT priority to the irq worker won't work. Use kthread_worker which guarantees specific kthread association instead. This also makes setting the priority cleaner. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Andy Walls <awalls@md.metrocast.net> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: ivtv-devel@ivtvdriver.org Cc: linux-media@vger.kernel.org
2010-06-29kthread: implement kthread_workerTejun Heo
Implement simple work processor for kthread. This is to ease using kthread. Single thread workqueue used to be used for things like this but workqueue won't guarantee fixed kthread association anymore to enable worker sharing. This can be used in cases where specific kthread association is necessary, for example, when it should have RT priority or be assigned to certain cgroup. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org>
2010-06-13Merge branch 'sched-wq' of ../wq into cmwq-baseTejun Heo
2010-06-11Linux 2.6.35-rc3v2.6.35-rc3Linus Torvalds
2010-06-11Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: wimax/i2400m: fix missing endian correction read in fw loader net8139: fix a race at the end of NAPI pktgen: Fix accuracy of inter-packet delay. pkt_sched: gen_estimator: add a new lock net: deliver skbs on inactive slaves to exact matches ipv6: fix ICMP6_MIB_OUTERRORS r8169: fix mdio_read and update mdio_write according to hw specs gianfar: Revive the driver for eTSEC devices (disable timestamping) caif: fix a couple range checks phylib: Add support for the LXT973 phy. net: Print num_rx_queues imbalance warning only when there are allocated queues
2010-06-11Merge branch 'pm-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6 * 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6: PM / x86: Save/restore MISC_ENABLE register
2010-06-11Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: Btrfs: The file argument for fsync() is never null Btrfs: handle ERR_PTR from posix_acl_from_xattr() Btrfs: avoid BUG when dropping root and reference in same transaction Btrfs: prohibit a operation of changing acl's mask when noacl mount option used Btrfs: should add a permission check for setfacl Btrfs: btrfs_lookup_dir_item() can return ERR_PTR Btrfs: btrfs_read_fs_root_no_name() returns ERR_PTRs Btrfs: unwind after btrfs_start_transaction() errors Btrfs: btrfs_iget() returns ERR_PTR Btrfs: handle kzalloc() failure in open_ctree() Btrfs: handle error returns from btrfs_lookup_dir_item() Btrfs: Fix BUG_ON for fs converted from extN Btrfs: Fix null dereference in relocation.c Btrfs: fix remap_file_pages error Btrfs: uninitialized data is check_path_shared() Btrfs: fix fallocate regression Btrfs: fix loop device on top of btrfs
2010-06-11Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6: PCI: clear bridge resource range if BIOS assigned bad one PCI: hotplug/cpqphp, fix NULL dereference Revert "PCI: create function symlinks in /sys/bus/pci/slots/N/" PCI: change resource collision messages from KERN_ERR to KERN_INFO
2010-06-11PCI: clear bridge resource range if BIOS assigned bad oneYinghai Lu
Yannick found that video does not work with 2.6.34. The cause of this bug was that the BIOS had assigned the wrong range to the PCI bridge above the video device. Before 2.6.34 the kernel would have shrunk the size of the bridge window, but since d65245c PCI: don't shrink bridge resources the kernel will avoid shrinking BIOS ranges. So zero out the old range if we fail to claim it at boot time; this will cause us to allocate a new range at startup, restoring the 2.6.34 behavior. Fixes regression https://bugzilla.kernel.org/show_bug.cgi?id=16009. Reported-by: Yannick <yannick.roehlly@free.fr> Acked-by: Bjorn Helgaas <bjorn.helgaas@hp.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-06-11PCI: hotplug/cpqphp, fix NULL dereferenceJiri Slaby
There are devices out there which are PCI Hot-plug controllers with compaq PCI IDs, but are not bridges, hence have pdev->subordinate NULL. But cpqphp expects the pointer to be non-NULL. Add a check to the probe function to avoid oopses like: BUG: unable to handle kernel NULL pointer dereference at 00000050 IP: [<f82e3c41>] cpqhpc_probe+0x951/0x1120 [cpqphp] *pdpt = 0000000033779001 *pde = 0000000000000000 ... The device here was: 00:0b.0 PCI Hot-plug controller [0804]: Compaq Computer Corporation PCI Hotplug Controller [0e11:a0f7] (rev 11) Subsystem: Compaq Computer Corporation Device [0e11:a2f8] Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Greg KH <greg@kroah.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-06-11Revert "PCI: create function symlinks in /sys/bus/pci/slots/N/"Jesse Barnes
This reverts commit 75568f8094eb0333e9c2109b23cbc8b82d318a3c. Since they're just a convenience anyway, remove these symlinks since they're causing duplicate filename errors in the wild. Acked-by: Alex Chiang <achiang@canonical.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-06-11PCI: change resource collision messages from KERN_ERR to KERN_INFOBjorn Helgaas
We can often deal with PCI resource issues by moving devices around. In that case, there's no point in alarming the user with messages like these. There are many bug reports where the message itself is the only problem, e.g., https://bugs.launchpad.net/ubuntu/+source/linux/+bug/413419 . Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-06-11Btrfs: The file argument for fsync() is never nullDan Carpenter
The "file" argument for fsync is never null so we can remove this check. What drew my attention here is that 7ea8085910e: "drop unused dentry argument to ->fsync" introduced an unconditional dereference at the start of the function and that generated a smatch warning. Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-06-11Btrfs: handle ERR_PTR from posix_acl_from_xattr()Dan Carpenter
posix_acl_from_xattr() returns both ERR_PTRs and null, but it's OK to pass null values to set_cached_acl() Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-06-11Btrfs: avoid BUG when dropping root and reference in same transactionSage Weil
If btrfs_ioctl_snap_destroy() deletes a snapshot but finishes with end_transaction(), the cleaner kthread may come in and drop the root in the same transaction. If that's the case, the root's refs still == 1 in the tree when btrfs_del_root() deletes the item, because commit_fs_roots() hasn't updated it yet (that happens during the commit). This wasn't a problem before only because btrfs_ioctl_snap_destroy() would commit the transaction before dropping the dentry reference, so the dead root wouldn't get queued up until after the fs root item was updated in the btree. Since it is not an error to drop the root reference and the root in the same transaction, just drop the BUG_ON() in btrfs_del_root(). Signed-off-by: Sage Weil <sage@newdream.net> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-06-11Btrfs: prohibit a operation of changing acl's mask when noacl mount option usedShi Weihua
when used Posix File System Test Suite(pjd-fstest) to test btrfs, some cases about setfacl failed when noacl mount option used. I simplified used commands in pjd-fstest, and the following steps can reproduce it. ------------------------ # cd btrfs-part/ # mkdir aaa # setfacl -m m::rw aaa <- successed, but not expected by pjd-fstest. ------------------------ I checked ext3, a warning message occured, like as: setfacl: aaa/: Operation not supported Certainly, it's expected by pjd-fstest. So, i compared acl.c of btrfs and ext3. Based on that, a patch created. Fortunately, it works. Signed-off-by: Shi Weihua <shiwh@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-06-11Btrfs: should add a permission check for setfaclShi Weihua
On btrfs, do the following ------------------ # su user1 # cd btrfs-part/ # touch aaa # getfacl aaa # file: aaa # owner: user1 # group: user1 user::rw- group::rw- other::r-- # su user2 # cd btrfs-part/ # setfacl -m u::rwx aaa # getfacl aaa # file: aaa # owner: user1 # group: user1 user::rwx <- successed to setfacl group::rw- other::r-- ------------------ but we should prohibit it that user2 changing user1's acl. In fact, on ext3 and other fs, a message occurs: setfacl: aaa: Operation not permitted This patch fixed it. Signed-off-by: Shi Weihua <shiwh@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-06-11Btrfs: btrfs_lookup_dir_item() can return ERR_PTRDan Carpenter
btrfs_lookup_dir_item() can return either ERR_PTRs or null. Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-06-11Btrfs: btrfs_read_fs_root_no_name() returns ERR_PTRsDan Carpenter
btrfs_read_fs_root_no_name() returns ERR_PTRs on error so I added a check for that. It's not clear to me if it can also return NULL pointers or not so I left the original NULL pointer check as is. Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-06-11Btrfs: unwind after btrfs_start_transaction() errorsDan Carpenter
This was added by a22285a6a3: "Btrfs: Integrate metadata reservation with start_transaction". If we goto out here then we skip all the unwinding and there are locks still held etc. Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-06-11Btrfs: btrfs_iget() returns ERR_PTRDan Carpenter
btrfs_iget() returns an ERR_PTR() on failure and not null. Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-06-11Btrfs: handle kzalloc() failure in open_ctree()Dan Carpenter
Unwind and return -ENOMEM if the allocation fails here. Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-06-11Btrfs: handle error returns from btrfs_lookup_dir_item()Dan Carpenter
If btrfs_lookup_dir_item() fails, we should can just let the mount fail with an error. Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-06-11Btrfs: Fix BUG_ON for fs converted from extNYan, Zheng
Tree blocks can live in data block groups in FS converted from extN. So it's easy to trigger the BUG_ON. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>