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2017-02-02scsi, block: fix duplicate bdi name registration crashesDan Williams1-0/+21
Warnings of the following form occur because scsi reuses a devt number while the block layer still has it referenced as the name of the bdi [1]: WARNING: CPU: 1 PID: 93 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x62/0x80 sysfs: cannot create duplicate filename '/devices/virtual/bdi/8:192' [..] Call Trace: dump_stack+0x86/0xc3 __warn+0xcb/0xf0 warn_slowpath_fmt+0x5f/0x80 ? kernfs_path_from_node+0x4f/0x60 sysfs_warn_dup+0x62/0x80 sysfs_create_dir_ns+0x77/0x90 kobject_add_internal+0xb2/0x350 kobject_add+0x75/0xd0 device_add+0x15a/0x650 device_create_groups_vargs+0xe0/0xf0 device_create_vargs+0x1c/0x20 bdi_register+0x90/0x240 ? lockdep_init_map+0x57/0x200 bdi_register_owner+0x36/0x60 device_add_disk+0x1bb/0x4e0 ? __pm_runtime_use_autosuspend+0x5c/0x70 sd_probe_async+0x10d/0x1c0 async_run_entry_fn+0x39/0x170 This is a brute-force fix to pass the devt release information from sd_probe() to the locations where we register the bdi, device_add_disk(), and unregister the bdi, blk_cleanup_queue(). Thanks to Omar for the quick reproducer script [2]. This patch survives where an unmodified kernel fails in a few seconds. [1]: https://marc.info/?l=linux-scsi&m=147116857810716&w=4 [2]: http://marc.info/?l=linux-block&m=148554717109098&w=2 Cc: James Bottomley <James.Bottomley@hansenpartnership.com> Cc: Bart Van Assche <bart.vanassche@sandisk.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Jan Kara <jack@suse.cz> Reported-by: Omar Sandoval <osandov@osandov.com> Tested-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-02-02block: Use pointer to backing_dev_info from request_queueJan Kara1-1/+1
We will want to have struct backing_dev_info allocated separately from struct request_queue. As the first step add pointer to backing_dev_info to request_queue and convert all users touching it. No functional changes in this patch. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-02-02block: Unhash block device inodes on gendisk destructionJan Kara1-0/+2
Currently, block device inodes stay around after corresponding gendisk hash died until memory reclaim finds them and frees them. Since we will make block device inode pin the bdi, we want to free the block device inode as soon as the device goes away so that bdi does not stay around unnecessarily. Furthermore we need to avoid issues when new device with the same major,minor pair gets created since reusing the bdi structure would be rather difficult in this case. Unhashing block device inode on gendisk destruction nicely deals with these problems. Once last block device inode reference is dropped (which may be directly in del_gendisk()), the inode gets evicted. Furthermore if the major,minor pair gets reallocated, we are guaranteed to get new block device inode even if old block device inode is not yet evicted and thus we avoid issues with possible reuse of bdi. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-04block: fix bdi vs gendisk lifetime mismatchDan Williams1-1/+1
The name for a bdi of a gendisk is derived from the gendisk's devt. However, since the gendisk is destroyed before the bdi it leaves a window where a new gendisk could dynamically reuse the same devt while a bdi with the same name is still live. Arrange for the bdi to hold a reference against its "owner" disk device while it is registered. Otherwise we can hit sysfs duplicate name collisions like the following: WARNING: CPU: 10 PID: 2078 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x64/0x80 sysfs: cannot create duplicate filename '/devices/virtual/bdi/259:1' Hardware name: HP ProLiant DL580 Gen8, BIOS P79 05/06/2015 0000000000000286 0000000002c04ad5 ffff88006f24f970 ffffffff8134caec ffff88006f24f9c0 0000000000000000 ffff88006f24f9b0 ffffffff8108c351 0000001f0000000c ffff88105d236000 ffff88105d1031e0 ffff8800357427f8 Call Trace: [<ffffffff8134caec>] dump_stack+0x63/0x87 [<ffffffff8108c351>] __warn+0xd1/0xf0 [<ffffffff8108c3cf>] warn_slowpath_fmt+0x5f/0x80 [<ffffffff812a0d34>] sysfs_warn_dup+0x64/0x80 [<ffffffff812a0e1e>] sysfs_create_dir_ns+0x7e/0x90 [<ffffffff8134faaa>] kobject_add_internal+0xaa/0x320 [<ffffffff81358d4e>] ? vsnprintf+0x34e/0x4d0 [<ffffffff8134ff55>] kobject_add+0x75/0xd0 [<ffffffff816e66b2>] ? mutex_lock+0x12/0x2f [<ffffffff8148b0a5>] device_add+0x125/0x610 [<ffffffff8148b788>] device_create_groups_vargs+0xd8/0x100 [<ffffffff8148b7cc>] device_create_vargs+0x1c/0x20 [<ffffffff811b775c>] bdi_register+0x8c/0x180 [<ffffffff811b7877>] bdi_register_dev+0x27/0x30 [<ffffffff813317f5>] add_disk+0x175/0x4a0 Cc: <stable@vger.kernel.org> Reported-by: Yi Zhang <yizhan@redhat.com> Tested-by: Yi Zhang <yizhan@redhat.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Fixed up missing 0 return in bdi_register_owner(). Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-04block: fix use-after-free in seq fileVegard Nossum1-0/+1
I got a KASAN report of use-after-free: ================================================================== BUG: KASAN: use-after-free in klist_iter_exit+0x61/0x70 at addr ffff8800b6581508 Read of size 8 by task trinity-c1/315 ============================================================================= BUG kmalloc-32 (Not tainted): kasan: bad access detected ----------------------------------------------------------------------------- Disabling lock debugging due to kernel taint INFO: Allocated in disk_seqf_start+0x66/0x110 age=144 cpu=1 pid=315 ___slab_alloc+0x4f1/0x520 __slab_alloc.isra.58+0x56/0x80 kmem_cache_alloc_trace+0x260/0x2a0 disk_seqf_start+0x66/0x110 traverse+0x176/0x860 seq_read+0x7e3/0x11a0 proc_reg_read+0xbc/0x180 do_loop_readv_writev+0x134/0x210 do_readv_writev+0x565/0x660 vfs_readv+0x67/0xa0 do_preadv+0x126/0x170 SyS_preadv+0xc/0x10 do_syscall_64+0x1a1/0x460 return_from_SYSCALL_64+0x0/0x6a INFO: Freed in disk_seqf_stop+0x42/0x50 age=160 cpu=1 pid=315 __slab_free+0x17a/0x2c0 kfree+0x20a/0x220 disk_seqf_stop+0x42/0x50 traverse+0x3b5/0x860 seq_read+0x7e3/0x11a0 proc_reg_read+0xbc/0x180 do_loop_readv_writev+0x134/0x210 do_readv_writev+0x565/0x660 vfs_readv+0x67/0xa0 do_preadv+0x126/0x170 SyS_preadv+0xc/0x10 do_syscall_64+0x1a1/0x460 return_from_SYSCALL_64+0x0/0x6a CPU: 1 PID: 315 Comm: trinity-c1 Tainted: G B 4.7.0+ #62 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 ffffea0002d96000 ffff880119b9f918 ffffffff81d6ce81 ffff88011a804480 ffff8800b6581500 ffff880119b9f948 ffffffff8146c7bd ffff88011a804480 ffffea0002d96000 ffff8800b6581500 fffffffffffffff4 ffff880119b9f970 Call Trace: [<ffffffff81d6ce81>] dump_stack+0x65/0x84 [<ffffffff8146c7bd>] print_trailer+0x10d/0x1a0 [<ffffffff814704ff>] object_err+0x2f/0x40 [<ffffffff814754d1>] kasan_report_error+0x221/0x520 [<ffffffff8147590e>] __asan_report_load8_noabort+0x3e/0x40 [<ffffffff83888161>] klist_iter_exit+0x61/0x70 [<ffffffff82404389>] class_dev_iter_exit+0x9/0x10 [<ffffffff81d2e8ea>] disk_seqf_stop+0x3a/0x50 [<ffffffff8151f812>] seq_read+0x4b2/0x11a0 [<ffffffff815f8fdc>] proc_reg_read+0xbc/0x180 [<ffffffff814b24e4>] do_loop_readv_writev+0x134/0x210 [<ffffffff814b4c45>] do_readv_writev+0x565/0x660 [<ffffffff814b8a17>] vfs_readv+0x67/0xa0 [<ffffffff814b8de6>] do_preadv+0x126/0x170 [<ffffffff814b92ec>] SyS_preadv+0xc/0x10 This problem can occur in the following situation: open() - pread() - .seq_start() - iter = kmalloc() // succeeds - seqf->private = iter - .seq_stop() - kfree(seqf->private) - pread() - .seq_start() - iter = kmalloc() // fails - .seq_stop() - class_dev_iter_exit(seqf->private) // boom! old pointer As the comment in disk_seqf_stop() says, stop is called even if start failed, so we need to reinitialise the private pointer to NULL when seq iteration stops. An alternative would be to set the private pointer to NULL when the kmalloc() in disk_seqf_start() fails. Cc: stable@vger.kernel.org Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-07-26Merge branch 'for-4.8/drivers' of git://git.kernel.dk/linux-blockLinus Torvalds1-9/+9
Pull block driver updates from Jens Axboe: "This branch also contains core changes. I've come to the conclusion that from 4.9 and forward, I'll be doing just a single branch. We often have dependencies between core and drivers, and it's hard to always split them up appropriately without pulling core into drivers when that happens. That said, this contains: - separate secure erase type for the core block layer, from Christoph. - set of discard fixes, from Christoph. - bio shrinking fixes from Christoph, as a followup up to the op/flags change in the core branch. - map and append request fixes from Christoph. - NVMeF (NVMe over Fabrics) code from Christoph. This is pretty exciting! - nvme-loop fixes from Arnd. - removal of ->driverfs_dev from Dan, after providing a device_add_disk() helper. - bcache fixes from Bhaktipriya and Yijing. - cdrom subchannel read fix from Vchannaiah. - set of lightnvm updates from Wenwei, Matias, Johannes, and Javier. - set of drbd updates and fixes from Fabian, Lars, and Philipp. - mg_disk error path fix from Bart. - user notification for failed device add for loop, from Minfei. - NVMe in general: + NVMe delay quirk from Guilherme. + SR-IOV support and command retry limits from Keith. + fix for memory-less NUMA node from Masayoshi. + use UINT_MAX for discard sectors, from Minfei. + cancel IO fixes from Ming. + don't allocate unused major, from Neil. + error code fixup from Dan. + use constants for PSDT/FUSE from James. + variable init fix from Jay. + fabrics fixes from Ming, Sagi, and Wei. + various fixes" * 'for-4.8/drivers' of git://git.kernel.dk/linux-block: (115 commits) nvme/pci: Provide SR-IOV support nvme: initialize variable before logical OR'ing it block: unexport various bio mapping helpers scsi/osd: open code blk_make_request target: stop using blk_make_request block: simplify and export blk_rq_append_bio block: ensure bios return from blk_get_request are properly initialized virtio_blk: use blk_rq_map_kern memstick: don't allow REQ_TYPE_BLOCK_PC requests block: shrink bio size again block: simplify and cleanup bvec pool handling block: get rid of bio_rw and READA block: don't ignore -EOPNOTSUPP blkdev_issue_write_same block: introduce BLKDEV_DISCARD_ZERO to fix zeroout NVMe: don't allocate unused nvme_major nvme: avoid crashes when node 0 is memoryless node. nvme: Limit command retries loop: Make user notify for adding loop device failed nvme-loop: fix nvme-loop Kconfig dependencies nvmet: fix return value check in nvmet_subsys_alloc() ...
2016-07-07timers: Remove set_timer_slack() leftoversThomas Gleixner1-5/+0
We now have implicit batching in the timer wheel. The slack API is no longer used, so remove it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Andrew F. Davis <afd@ti.com> Cc: Arjan van de Ven <arjan@infradead.org> Cc: Chris Mason <clm@fb.com> Cc: David S. Miller <davem@davemloft.net> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: George Spelvin <linux@sciencehorizons.net> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jaehoon Chung <jh80.chung@samsung.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: John Stultz <john.stultz@linaro.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Len Brown <lenb@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathias Nyman <mathias.nyman@intel.com> Cc: Pali Rohár <pali.rohar@gmail.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Sebastian Reichel <sre@kernel.org> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: linux-block@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-mmc@vger.kernel.org Cc: linux-pm@vger.kernel.org Cc: linux-usb@vger.kernel.org Cc: netdev@vger.kernel.org Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160704094342.189813118@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-27block: remove ->driverfs_devDan Williams1-7/+2
Now that all drivers that specify a ->driverfs_dev have been converted to device_add_disk(), the pointer can be removed from struct gendisk. Cc: Jens Axboe <axboe@fb.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-06-15block: introduce device_add_disk()Dan Williams1-6/+11
In preparation for removing the ->driverfs_dev member of a gendisk, add an api that takes the parent device as a parameter to add_disk(). For now this maintains the status quo of WARN()ing on failure, but not return a error code. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-19Merge branch 'for-4.5/core' of git://git.kernel.dk/linux-blockLinus Torvalds1-1/+1
Pull core block updates from Jens Axboe: "We don't have a lot of core changes this time around, it's mostly in drivers, which will come in a subsequent pull. The cores changes include: - blk-mq - Prep patch from Christoph, changing blk_mq_alloc_request() to take flags instead of just using gfp_t for sleep/nosleep. - Doc patch from me, clarifying the difference between legacy and blk-mq for timer usage. - Fixes from Raghavendra for memory-less numa nodes, and a reuse of CPU masks. - Cleanup from Geliang Tang, using offset_in_page() instead of open coding it. - From Ilya, rename request_queue slab to it reflects what it holds, and a fix for proper use of bdgrab/put. - A real fix for the split across stripe boundaries from Keith. We yanked a broken version of this from 4.4-rc final, this one works. - From Mike Krinkin, emit a trace message when we split. - From Wei Tang, two small cleanups, not explicitly clearing memory that is already cleared" * 'for-4.5/core' of git://git.kernel.dk/linux-block: block: use bd{grab,put}() instead of open-coding block: split bios to max possible length block: add call to split trace point blk-mq: Avoid memoryless numa node encoded in hctx numa_node blk-mq: Reuse hardware context cpumask for tags blk-mq: add a flags parameter to blk_mq_alloc_request Revert "blk-flush: Queue through IO scheduler when flush not required" block: clarify blk_add_timer() use case for blk-mq bio: use offset_in_page macro block: do not initialise statics to 0 or NULL block: do not initialise globals to 0 or NULL block: rename request_queue slab cache
2016-01-09block: kill disk_{check|set|clear|alloc}_badblocksDan Williams1-42/+0
These actions are completely managed by a block driver or can use the badblocks api directly. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-09block: clarify badblocks lifetimeDan Williams1-5/+0
The badblocks list attached to a gendisk is allocated by the driver which equates to the driver owning the lifetime of the object. Do not automatically free it in del_gendisk(). This is in preparation for expanding the use of badblocks in libnvdimm drivers and introducing devm_init_badblocks(). Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-09badblocks: rename badblocks_free to badblocks_exitDan Williams1-1/+1
For symmetry with badblocks_init() make it clear that this path only destroys incremental allocations of a badblocks instance, and does not free the badblocks instance itself. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-09block: Add badblock management for gendisksVishal Verma1-0/+76
NVDIMM devices, which can behave more like DRAM rather than block devices, may develop bad cache lines, or 'poison'. A block device exposed by the pmem driver can then consume poison via a read (or write), and cause a machine check. On platforms without machine check recovery features, this would mean a crash. The block device maintaining a runtime list of all known sectors that have poison can directly avoid this, and also provide a path forward to enable proper handling/recovery for DAX faults on such a device. Use the new badblock management interfaces to add a badblocks list to gendisks. Signed-off-by: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-09block: fix del_gendisk() vs blkdev_ioctl crashDan Williams1-1/+0
When tearing down a block device early in its lifetime, userspace may still be performing discovery actions like blkdev_ioctl() to re-read partitions. The nvdimm_revalidate_disk() implementation depends on disk->driverfs_dev to be valid at entry. However, it is set to NULL in del_gendisk() and fatally this is happening *before* the disk device is deleted from userspace view. There's no reason for del_gendisk() to clear ->driverfs_dev. That device is the parent of the disk. It is guaranteed to not be freed until the disk, as a child, drops its ->parent reference. We could also fix this issue locally in nvdimm_revalidate_disk() by using disk_to_dev(disk)->parent, but lets fix it globally since ->driverfs_dev follows the lifetime of the parent. Longer term we should probably just add a @parent parameter to add_disk(), and stop carrying this pointer in the gendisk. BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<ffffffffa00340a8>] nvdimm_revalidate_disk+0x18/0x90 [libnvdimm] CPU: 2 PID: 538 Comm: systemd-udevd Tainted: G O 4.4.0-rc5 #2257 [..] Call Trace: [<ffffffff8143e5c7>] rescan_partitions+0x87/0x2c0 [<ffffffff810f37f9>] ? __lock_is_held+0x49/0x70 [<ffffffff81438c62>] __blkdev_reread_part+0x72/0xb0 [<ffffffff81438cc5>] blkdev_reread_part+0x25/0x40 [<ffffffff8143982d>] blkdev_ioctl+0x4fd/0x9c0 [<ffffffff811246c9>] ? current_kernel_time64+0x69/0xd0 [<ffffffff812916dd>] block_ioctl+0x3d/0x50 [<ffffffff81264c38>] do_vfs_ioctl+0x308/0x560 [<ffffffff8115dbd1>] ? __audit_syscall_entry+0xb1/0x100 [<ffffffff810031d6>] ? do_audit_syscall_entry+0x66/0x70 [<ffffffff81264f09>] SyS_ioctl+0x79/0x90 [<ffffffff81902672>] entry_SYSCALL_64_fastpath+0x12/0x76 Reported-by: Robert Hu <robert.hu@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-11-24block: do not initialise statics to 0 or NULLWei Tang1-1/+1
This patch fixes the checkpatch.pl error to genhd.c: ERROR: do not initialise statics to 0 or NULL Signed-off-by: Wei Tang <tangwei@cmss.chinamobile.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-21block: Inline blk_integrity in struct gendiskMartin K. Petersen1-0/+2
Up until now the_integrity profile has been dynamically allocated and attached to struct gendisk after the disk has been made active. This causes problems because NVMe devices need to register the profile prior to the partition table being read due to a mandatory metadata buffer requirement. In addition, DM goes through hoops to deal with preallocating, but not initializing integrity profiles. Since the integrity profile is small (4 bytes + a pointer), Christoph suggested moving it to struct gendisk proper. This requires several changes: - Moving the blk_integrity definition to genhd.h. - Inlining blk_integrity in struct gendisk. - Removing the dynamic allocation code. - Adding helper functions which allow gendisk to set up and tear down the integrity sysfs dir when a disk is added/deleted. - Adding a blk_integrity_revalidate() callback for updating the stable pages bdi setting. - The calls that depend on whether a device has an integrity profile or not now key off of the bi->profile pointer. - Simplifying the integrity support routines in DM (Mike Snitzer). Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Reported-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-07-17block: partition: convert percpu refMing Lei1-1/+5
Percpu refcount is the perfect match for partition's case, and the conversion is quite straight. With the convertion, one pair of atomic inc/dec can be saved for accounting block I/O, which is run in hot path of block I/O. Signed-off-by: Ming Lei <tom.leiming@gmail.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-07-17block: partition: introduce hd_free_part()Ming Lei1-2/+1
So the helper can be used in both generic partition case and part0 case. Signed-off-by: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-25Merge branch 'for-4.2/writeback' of git://git.kernel.dk/linux-blockLinus Torvalds1-0/+1
Pull cgroup writeback support from Jens Axboe: "This is the big pull request for adding cgroup writeback support. This code has been in development for a long time, and it has been simmering in for-next for a good chunk of this cycle too. This is one of those problems that has been talked about for at least half a decade, finally there's a solution and code to go with it. Also see last weeks writeup on LWN: http://lwn.net/Articles/648292/" * 'for-4.2/writeback' of git://git.kernel.dk/linux-block: (85 commits) writeback, blkio: add documentation for cgroup writeback support vfs, writeback: replace FS_CGROUP_WRITEBACK with SB_I_CGROUPWB writeback: do foreign inode detection iff cgroup writeback is enabled v9fs: fix error handling in v9fs_session_init() bdi: fix wrong error return value in cgwb_create() buffer: remove unusued 'ret' variable writeback: disassociate inodes from dying bdi_writebacks writeback: implement foreign cgroup inode bdi_writeback switching writeback: add lockdep annotation to inode_to_wb() writeback: use unlocked_inode_to_wb transaction in inode_congested() writeback: implement unlocked_inode_to_wb transaction and use it for stat updates writeback: implement [locked_]inode_to_wb_and_lock_list() writeback: implement foreign cgroup inode detection writeback: make writeback_control track the inode being written back writeback: relocate wb[_try]_get(), wb_put(), inode_{attach|detach}_wb() mm: vmscan: disable memcg direct reclaim stalling if cgroup writeback support is in use writeback: implement memcg writeback domain based throttling writeback: reset wb_domain->dirty_limit[_tstmp] when memcg domain size changes writeback: implement memcg wb_domain writeback: update wb_over_bg_thresh() to use wb_domain aware operations ...
2015-06-11block: fix ext_dev_lock lockdep reportDan Williams1-6/+6
================================= [ INFO: inconsistent lock state ] 4.1.0-rc7+ #217 Tainted: G O --------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. swapper/6/0 [HC0[0]:SC1[1]:HE1:SE0] takes: (ext_devt_lock){+.?...}, at: [<ffffffff8143a60c>] blk_free_devt+0x3c/0x70 {SOFTIRQ-ON-W} state was registered at: [<ffffffff810bf6b1>] __lock_acquire+0x461/0x1e70 [<ffffffff810c1947>] lock_acquire+0xb7/0x290 [<ffffffff818ac3a8>] _raw_spin_lock+0x38/0x50 [<ffffffff8143a07d>] blk_alloc_devt+0x6d/0xd0 <-- take the lock in process context [..] [<ffffffff810bf64e>] __lock_acquire+0x3fe/0x1e70 [<ffffffff810c00ad>] ? __lock_acquire+0xe5d/0x1e70 [<ffffffff810c1947>] lock_acquire+0xb7/0x290 [<ffffffff8143a60c>] ? blk_free_devt+0x3c/0x70 [<ffffffff818ac3a8>] _raw_spin_lock+0x38/0x50 [<ffffffff8143a60c>] ? blk_free_devt+0x3c/0x70 [<ffffffff8143a60c>] blk_free_devt+0x3c/0x70 <-- take the lock in softirq [<ffffffff8143bfec>] part_release+0x1c/0x50 [<ffffffff8158edf6>] device_release+0x36/0xb0 [<ffffffff8145ac2b>] kobject_cleanup+0x7b/0x1a0 [<ffffffff8145aad0>] kobject_put+0x30/0x70 [<ffffffff8158f147>] put_device+0x17/0x20 [<ffffffff8143c29c>] delete_partition_rcu_cb+0x16c/0x180 [<ffffffff8143c130>] ? read_dev_sector+0xa0/0xa0 [<ffffffff810e0e0f>] rcu_process_callbacks+0x2ff/0xa90 [<ffffffff810e0dcf>] ? rcu_process_callbacks+0x2bf/0xa90 [<ffffffff81067e2e>] __do_softirq+0xde/0x600 Neil sees this in his tests and it also triggers on pmem driver unbind for the libnvdimm tests. This fix is on top of an initial fix by Keith for incorrect usage of mutex_lock() in this path: 2da78092dda1 "block: Fix dev_t minor allocation lifetime". Both this and 2da78092dda1 are candidates for -stable. Fixes: 2da78092dda1 ("block: Fix dev_t minor allocation lifetime") Cc: <stable@vger.kernel.org> Cc: Keith Busch <keith.busch@intel.com> Reported-by: NeilBrown <neilb@suse.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02writeback: separate out include/linux/backing-dev-defs.hTejun Heo1-0/+1
With the planned cgroup writeback support, backing-dev related declarations will be more widely used across block and cgroup; unfortunately, including backing-dev.h from include/linux/blkdev.h makes cyclic include dependency quite likely. This patch separates out backing-dev-defs.h which only has the essential definitions and updates blkdev.h to include it. c files which need access to more backing-dev details now include backing-dev.h directly. This takes backing-dev.h off the common include dependency chain making it a lot easier to use it across block and cgroup. v2: fs/fat build failure fixed. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-28block: discard bdi_unregister() in favour of bdi_destroy()NeilBrown1-1/+0
bdi_unregister() now contains very little functionality. It contains a "WARN_ON" if bdi->dev is NULL. This warning is of no real consequence as bdi->dev isn't needed by anything else in the function, and it triggers if blk_cleanup_queue() -> bdi_destroy() is called before bdi_unregister, which happens since Commit: 6cd18e711dd8 ("block: destroy bdi before blockdev is unregistered.") So this isn't wanted. It also calls bdi_set_min_ratio(). This needs to be called after writes through the bdi have all been flushed, and before the bdi is destroyed. Calling it early is better than calling it late as it frees up a global resource. Calling it immediately after bdi_wb_shutdown() in bdi_destroy() perfectly fits these requirements. So bdi_unregister() can be discarded with the important content moved to bdi_destroy(), as can the writeback_bdi_unregister event which is already not used. Reported-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org (v4.0) Fixes: c4db59d31e39 ("fs: don't reassign dirty inodes to default_backing_dev_info") Fixes: 6cd18e711dd8 ("block: destroy bdi before blockdev is unregistered.") Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Dan Williams <dan.j.williams@intel.com> Tested-by: Nicholas Moulin <nicholas.w.moulin@linux.intel.com> Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2014-11-19genhd: check for int overflow in disk_expand_part_tbl()Jens Axboe1-2/+9
We can get here from blkdev_ioctl() -> blkpg_ioctl() -> add_partition() with a user passed in partno value. If we pass in 0x7fffffff, the new target in disk_expand_part_tbl() overflows the 'int' and we access beyond the end of ptbl->part[] and even write to it when we do the rcu_assign_pointer() to assign the new partition. Reported-by: David Ramos <daramos@stanford.edu> Cc: stable@kernel.org Signed-off-by: Jens Axboe <axboe@fb.com>
2014-10-07Merge branch 'for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial Pull "trivial tree" updates from Jiri Kosina: "Usual pile from trivial tree everyone is so eagerly waiting for" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits) Remove MN10300_PROC_MN2WS0038 mei: fix comments treewide: Fix typos in Kconfig kprobes: update jprobe_example.c for do_fork() change Documentation: change "&" to "and" in Documentation/applying-patches.txt Documentation: remove obsolete pcmcia-cs from Changes Documentation: update links in Changes Documentation: Docbook: Fix generated DocBook/kernel-api.xml score: Remove GENERIC_HAS_IOMAP gpio: fix 'CONFIG_GPIO_IRQCHIP' comments tty: doc: Fix grammar in serial/tty dma-debug: modify check_for_stack output treewide: fix errors in printk genirq: fix reference in devm_request_threaded_irq comment treewide: fix synchronize_rcu() in comments checkstack.pl: port to AArch64 doc: queue-sysfs: minor fixes init/do_mounts: better syntax description MIPS: fix comment spelling powerpc/simpleboot: fix comment ...
2014-09-22genhd: fix leftover might_sleep() in blk_free_devt()Jens Axboe1-2/+0
Commit 2da78092 changed the locking from a mutex to a spinlock, so we now longer sleep in this context. But there was a leftover might_sleep() in there, which now triggers since we do the final free from an RCU callback. Get rid of it. Reported-by: Pontus Fuchs <pontus.fuchs@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2014-09-09Documentation: Docbook: Fix generated DocBook/kernel-api.xmlMasanari Iida1-1/+1
This patch fix spelling typo found in DocBook/kernel-api.xml. It is because the file is generated from the source comments, I have to fix the comments in source codes. Signed-off-by: Masanari Iida <standby24x7@gmail.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-09-03block: Fix dev_t minor allocation lifetimeKeith Busch1-10/+14
Releases the dev_t minor when all references are closed to prevent another device from acquiring the same major/minor. Since the partition's release may be invoked from call_rcu's soft-irq context, the ext_dev_idr's mutex had to be replaced with a spinlock so as not so sleep. Signed-off-by: Keith Busch <keith.busch@intel.com> Cc: stable@kernel.org Signed-off-by: Jens Axboe <axboe@fb.com>
2013-09-11block: Convert kmalloc_node(...GFP_ZERO...) to kzalloc_node(...)Joe Perches1-2/+1
Use the helper function instead of __GFP_ZERO. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-07-03block: do not pass disk names as format stringsKees Cook1-1/+1
Disk names may contain arbitrary strings, so they must not be interpreted as format strings. It seems that only md allows arbitrary strings to be used for disk names, but this could allow for a local memory corruption from uid 0 into ring 0. CVE-2013-2851 Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-05-14block: queue work on power efficient wqViresh Kumar1-4/+8
Block layer uses workqueues for multiple purposes. There is no real dependency of scheduling these on the cpu which scheduled them. On a idle system, it is observed that and idle cpu wakes up many times just to service this work. It would be better if we can schedule it on a cpu which the scheduler believes to be the most appropriate one. This patch replaces normal workqueues with power efficient versions. Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2013-04-11driver core: handle user namespaces properly with the uid/gid devtmpfs changeGreg Kroah-Hartman1-1/+1
Now that devtmpfs is caring about uid/gid, we need to use the correct internal types so users who have USER_NS enabled will have things work properly for them. Thanks to Eric for pointing this out, and the patch review. Reported-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Kay Sievers <kay@vrfy.org> Cc: Ming Lei <ming.lei@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-08driver core: add uid and gid to devtmpfsKay Sievers1-1/+2
Some drivers want to tell userspace what uid and gid should be used for their device nodes, so allow that information to percolate through the driver core to userspace in order to make this happen. This means that some systems (i.e. Android and friends) will not need to even run a udev-like daemon for their device node manager and can just rely in devtmpfs fully, reducing their footprint even more. Signed-off-by: Kay Sievers <kay@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-27block: convert to idr_alloc()Tejun Heo1-15/+6
Convert to the much saner new idr interface. Both bsg and genhd protect idr w/ mutex making preloading unnecessary. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27block: fix synchronization and limit check in blk_alloc_devt()Tejun Heo1-8/+5
idr allocation in blk_alloc_devt() wasn't synchronized against lookup and removal, and its limit check was off by one - 1 << MINORBITS is the number of minors allowed, not the maximum allowed minor. Add locking and rename MAX_EXT_DEVT to NR_EXT_DEVT and fix limit checking. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Jens Axboe <axboe@kernel.dk> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27block: fix ext_devt_idr handlingTomas Henzl1-1/+5
While adding and removing a lot of disks disks and partitions this sometimes shows up: WARNING: at fs/sysfs/dir.c:512 sysfs_add_one+0xc9/0x130() (Not tainted) Hardware name: sysfs: cannot create duplicate filename '/dev/block/259:751' Modules linked in: raid1 autofs4 bnx2fc cnic uio fcoe libfcoe libfc 8021q scsi_transport_fc scsi_tgt garp stp llc sunrpc cpufreq_ondemand powernow_k8 freq_table mperf ipv6 dm_mirror dm_region_hash dm_log power_meter microcode dcdbas serio_raw amd64_edac_mod edac_core edac_mce_amd i2c_piix4 i2c_core k10temp bnx2 sg ixgbe dca mdio ext4 mbcache jbd2 dm_round_robin sr_mod cdrom sd_mod crc_t10dif ata_generic pata_acpi pata_atiixp ahci mptsas mptscsih mptbase scsi_transport_sas dm_multipath dm_mod [last unloaded: scsi_wait_scan] Pid: 44103, comm: async/16 Not tainted 2.6.32-195.el6.x86_64 #1 Call Trace: warn_slowpath_common+0x87/0xc0 warn_slowpath_fmt+0x46/0x50 sysfs_add_one+0xc9/0x130 sysfs_do_create_link+0x12b/0x170 sysfs_create_link+0x13/0x20 device_add+0x317/0x650 idr_get_new+0x13/0x50 add_partition+0x21c/0x390 rescan_partitions+0x32b/0x470 sd_open+0x81/0x1f0 [sd_mod] __blkdev_get+0x1b6/0x3c0 blkdev_get+0x10/0x20 register_disk+0x155/0x170 add_disk+0xa6/0x160 sd_probe_async+0x13b/0x210 [sd_mod] add_wait_queue+0x46/0x60 async_thread+0x102/0x250 default_wake_function+0x0/0x20 async_thread+0x0/0x250 kthread+0x96/0xa0 child_rip+0xa/0x20 kthread+0x0/0xa0 child_rip+0x0/0x20 This most likely happens because dev_t is freed while the number is still used and idr_get_new() is not protected on every use. The fix adds a mutex where it wasn't before and moves the dev_t free function so it is called after device del. Signed-off-by: Tomas Henzl <thenzl@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-23block/genhd.c: apply pm_runtime_set_memalloc_noio on block devicesMing Lei1-0/+10
Apply the introduced pm_runtime_set_memalloc_noio on block device so that PM core will teach mm to not allocate memory with GFP_IOFS when calling the runtime_resume and runtime_suspend callback for block devices and its ancestors. Signed-off-by: Ming Lei <ming.lei@canonical.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Minchan Kim <minchan@kernel.org> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Oliver Neukum <oneukum@suse.de> Cc: Jiri Kosina <jiri.kosina@suse.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Greg KH <greg@kroah.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: David Decotigny <david.decotigny@google.com> Cc: Tom Herbert <therbert@google.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-19block: prevent race/cleanupDerek Basehore1-15/+30
Remove a race condition which causes a warning in disk_clear_events. This is a race between disk_clear_events() and disk_flush_events(). ev->clearing will be altered by disk_flush_events() even though we are blocking event checking through disk_flush_events(). If this happens after ev->clearing was cleared for disk_clear_events(), this can cause the WARN_ON_ONCE() in that function to be triggered. This change also has disk_clear_events() not go through a workqueue. Since we have to wait for the work to complete, we should just call the function directly. Also, since this work cannot be put on a freezable workqueue, it will have to contend with increased demand, so calling the function directly avoids this. [akpm@linux-foundation.org: fix spello in comment] Signed-off-by: Derek Basehore <dbasehore@chromium.org> Cc: Mandeep Singh Baines <msb@chromium.org> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-12-19block: remove deadlock in disk_clear_eventsDerek Basehore1-1/+8
In disk_clear_events, do not put work on system_nrt_freezable_wq. Instead, put it on system_nrt_wq. There is a race between probing a usb and suspending the device. Since probing a usb calls disk_clear_events, which puts work on a frozen workqueue, probing cannot finish after the workqueue is frozen. However, suspending cannot finish until the usb probe is finished, so we get a deadlock, causing the system to reboot. The way to reproduce this bug is to wake up from suspend with a usb storage device plugged in, or plugging in a usb storage device right before suspend. The window of time is on the order of time it takes to probe the usb device. As long as the workqueues are frozen before the call to add_disk within sd_probe_async finishes, there will be a deadlock (which calls blkdev_get, sd_open, check_disk_change, then disk_clear_events). This is not difficult to reproduce after figuring out the timings. [akpm@linux-foundation.org: fix up comment] Signed-off-by: Derek Basehore <dbasehore@chromium.org> Reviewed-by: Mandeep Singh Baines <msb@chromium.org> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-12-17Merge branch 'for-3.8/drivers' of git://git.kernel.dk/linux-blockLinus Torvalds1-7/+1
Pull block driver update from Jens Axboe: "Now that the core bits are in, here are the driver bits for 3.8. The branch contains: - A huge pile of drbd bits that were dumped from the 3.7 merge window. Following that, it was both made perfectly clear that there is going to be no more over-the-wall pulls and how the situation on individual pulls can be improved. - A few cleanups from Akinobu Mita for drbd and cciss. - Queue improvement for loop from Lukas. This grew into adding a generic interface for waiting/checking an even with a specific lock, allowing this to be pulled out of md and now loop and drbd is also using it. - A few fixes for xen back/front block driver from Roger Pau Monne. - Partition improvements from Stephen Warren, allowing partiion UUID to be used as an identifier." * 'for-3.8/drivers' of git://git.kernel.dk/linux-block: (609 commits) drbd: update Kconfig to match current dependencies drbd: Fix drbdsetup wait-connect, wait-sync etc... commands drbd: close race between drbd_set_role and drbd_connect drbd: respect no-md-barriers setting also when changed online via disk-options drbd: Remove obsolete check drbd: fixup after wait_even_lock_irq() addition to generic code loop: Limit the number of requests in the bio list wait: add wait_event_lock_irq() interface xen-blkfront: free allocated page xen-blkback: move free persistent grants code block: partition: msdos: provide UUIDs for partitions init: reduce PARTUUID min length to 1 from 36 block: store partition_meta_info.uuid as a string cciss: use check_signature() cciss: cleanup bitops usage drbd: use copy_highpage drbd: if the replication link breaks during handshake, keep retrying drbd: check return of kmalloc in receive_uuids drbd: Broadcast sync progress no more often than once per second drbd: don't try to clear bits once the disk has failed ...
2012-11-23block: store partition_meta_info.uuid as a stringStephen Warren1-7/+1
This will allow other types of UUID to be stored here, aside from true UUIDs. This also simplifies code that uses this field, since it's usually constructed from a, used as a, or compared to other, strings. Note: A simplistic approach here would be to set uuid_str[36]=0 whenever a /PARTNROFF option was found to be present. However, this modifies the input string, and causes subsequent calls to devt_from_partuuid() not to see the /PARTNROFF option, which causes different results. In order to avoid misleading future maintainers, this parameter is marked const. Signed-off-by: Stephen Warren <swarren@nvidia.com> Cc: Tejun Heo <tj@kernel.org> Cc: Will Drewry <wad@chromium.org> Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-11-10block: use NUMA_NO_NODE instead of -1Ezequiel Garcia1-1/+1
Signed-off-by: Ezequiel Garcia <elezegarcia@gmail.com> Modified by me to cover blk_init_queue() as well. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-10-02Merge branch 'for-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds1-8/+6
Pull workqueue changes from Tejun Heo: "This is workqueue updates for v3.7-rc1. A lot of activities this round including considerable API and behavior cleanups. * delayed_work combines a timer and a work item. The handling of the timer part has always been a bit clunky leading to confusing cancelation API with weird corner-case behaviors. delayed_work is updated to use new IRQ safe timer and cancelation now works as expected. * Another deficiency of delayed_work was lack of the counterpart of mod_timer() which led to cancel+queue combinations or open-coded timer+work usages. mod_delayed_work[_on]() are added. These two delayed_work changes make delayed_work provide interface and behave like timer which is executed with process context. * A work item could be executed concurrently on multiple CPUs, which is rather unintuitive and made flush_work() behavior confusing and half-broken under certain circumstances. This problem doesn't exist for non-reentrant workqueues. While non-reentrancy check isn't free, the overhead is incurred only when a work item bounces across different CPUs and even in simulated pathological scenario the overhead isn't too high. All workqueues are made non-reentrant. This removes the distinction between flush_[delayed_]work() and flush_[delayed_]_work_sync(). The former is now as strong as the latter and the specified work item is guaranteed to have finished execution of any previous queueing on return. * In addition to the various bug fixes, Lai redid and simplified CPU hotplug handling significantly. * Joonsoo introduced system_highpri_wq and used it during CPU hotplug. There are two merge commits - one to pull in IRQ safe timer from tip/timers/core and the other to pull in CPU hotplug fixes from wq/for-3.6-fixes as Lai's hotplug restructuring depended on them." Fixed a number of trivial conflicts, but the more interesting conflicts were silent ones where the deprecated interfaces had been used by new code in the merge window, and thus didn't cause any real data conflicts. Tejun pointed out a few of them, I fixed a couple more. * 'for-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (46 commits) workqueue: remove spurious WARN_ON_ONCE(in_irq()) from try_to_grab_pending() workqueue: use cwq_set_max_active() helper for workqueue_set_max_active() workqueue: introduce cwq_set_max_active() helper for thaw_workqueues() workqueue: remove @delayed from cwq_dec_nr_in_flight() workqueue: fix possible stall on try_to_grab_pending() of a delayed work item workqueue: use hotcpu_notifier() for workqueue_cpu_down_callback() workqueue: use __cpuinit instead of __devinit for cpu callbacks workqueue: rename manager_mutex to assoc_mutex workqueue: WORKER_REBIND is no longer necessary for idle rebinding workqueue: WORKER_REBIND is no longer necessary for busy rebinding workqueue: reimplement idle worker rebinding workqueue: deprecate __cancel_delayed_work() workqueue: reimplement cancel_delayed_work() using try_to_grab_pending() workqueue: use mod_delayed_work() instead of __cancel + queue workqueue: use irqsafe timer for delayed_work workqueue: clean up delayed_work initializers and add missing one workqueue: make deferrable delayed_work initializer names consistent workqueue: cosmetic whitespace updates for macro definitions workqueue: deprecate system_nrt[_freezable]_wq workqueue: deprecate flush[_delayed]_work_sync() ...
2012-08-20workqueue: deprecate system_nrt[_freezable]_wqTejun Heo1-5/+5
system_nrt[_freezable]_wq are now spurious. Mark them deprecated and convert all users to system[_freezable]_wq. If you're cc'd and wondering what's going on: Now all workqueues are non-reentrant, so there's no reason to use system_nrt[_freezable]_wq. Please use system[_freezable]_wq instead. This patch doesn't make any functional difference. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-By: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: David Airlie <airlied@linux.ie> Cc: Jiri Kosina <jkosina@suse.cz> Cc: "David S. Miller" <davem@davemloft.net> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: David Howells <dhowells@redhat.com>
2012-08-13workqueue: use mod_delayed_work() instead of cancel + queueTejun Heo1-4/+2
Convert delayed_work users doing cancel_delayed_work() followed by queue_delayed_work() to mod_delayed_work(). Most conversions are straight-forward. Ones worth mentioning are, * drivers/edac/edac_mc.c: edac_mc_workq_setup() converted to always use mod_delayed_work() and cancel loop in edac_mc_reset_delay_period() is dropped. * drivers/platform/x86/thinkpad_acpi.c: No need to remember whether watchdog is active or not. @fan_watchdog_active and related code dropped. * drivers/power/charger-manager.c: Seemingly a lot of delayed_work_pending() abuse going on here. [delayed_]work_pending() are unsynchronized and racy when used like this. I converted one instance in fullbatt_handler(). Please conver the rest so that it invokes workqueue APIs for the intended target state rather than trying to game work item pending state transitions. e.g. if timer should be modified - call mod_delayed_work(), canceled - call cancel_delayed_work[_sync](). * drivers/thermal/thermal_sys.c: thermal_zone_device_set_polling() simplified. Note that round_jiffies() calls in this function are meaningless. round_jiffies() work on absolute jiffies not delta delay used by delayed_work. v2: Tomi pointed out that __cancel_delayed_work() users can't be safely converted to mod_delayed_work(). They could be calling it from irq context and if that happens while delayed_work_timer_fn() is running, it could deadlock. __cancel_delayed_work() users are dropped. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Acked-by: Anton Vorontsov <cbouatmailru@gmail.com> Acked-by: David Howells <dhowells@redhat.com> Cc: Tomi Valkeinen <tomi.valkeinen@ti.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Doug Thompson <dougthompson@xmission.com> Cc: David Airlie <airlied@linux.ie> Cc: Roland Dreier <roland@kernel.org> Cc: "John W. Linville" <linville@tuxdriver.com> Cc: Zhang Rui <rui.zhang@intel.com> Cc: Len Brown <len.brown@intel.com> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Johannes Berg <johannes@sipsolutions.net>
2012-08-03block: Don't use static to define "void *p" in show_partition_start()Jianpeng Ma1-1/+1
I met a odd prblem:read /proc/partitions may return zero. I wrote a file test.c: int main() { char buff[4096]; int ret; int fd; printf("pid=%d\n",getpid()); while (1) { fd = open("/proc/partitions", O_RDONLY); if (fd < 0) { printf("open error %s\n", strerror(errno)); return 0; } ret = read(fd, buff, 4096); if (ret <= 0) printf("ret=%d, %s, %ld\n", ret, strerror(errno), lseek(fd,0,SEEK_CUR)); close(fd); } exit(0); } You can reproduce by: 1:while true;do cat /proc/partitions > /dev/null ;done 2:./test I reviewed the code and found: >> static void *show_partition_start(struct seq_file *seqf, loff_t *pos) >> { >> static void *p; >> >> p = disk_seqf_start(seqf, pos); >> if (!IS_ERR_OR_NULL(p) && !*pos) >> seq_puts(seqf, "major minor #blocks name\n\n"); >> return p; >> } test cat /proc/partitions p = disk_seqf_start()(Not NULL) p = disk_seqf_start()(NULL because pos) if (!IS_ERR_OR_NULL(p) && !*pos) Signed-off-by: Jianpeng Ma <majianpeng@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-08-01block: add partition resize function to blkpg ioctlVivek Goyal1-5/+15
Add a new operation code (BLKPG_RESIZE_PARTITION) to the BLKPG ioctl that allows altering the size of an existing partition, even if it is currently in use. This patch converts hd_struct->nr_sects into sequence counter because One might extend a partition while IO is happening to it and update of nr_sects can be non-atomic on 32bit machines with 64bit sector_t. This can lead to issues like reading inconsistent size of a partition. Sequence counter have been used so that readers don't have to take bdev mutex lock as we call sector_in_part() very frequently. Now all the access to hd_struct->nr_sects should happen using sequence counter read/update helper functions part_nr_sects_read/part_nr_sects_write. There is one exception though, set_capacity()/get_capacity(). I think theoritically race should exist there too but this patch does not modify set_capacity()/get_capacity() due to sheer number of call sites and I am afraid that change might break something. I have left that as a TODO item. We can handle it later if need be. This patch does not introduce any new races as such w.r.t set_capacity()/get_capacity(). v2: Add CONFIG_LBDAF test to UP preempt case as suggested by Phillip. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Phillip Susi <psusi@ubuntu.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-05-15block: fix buffer overflow when printing partition UUIDsTejun Heo1-4/+6
6d1d8050b4bc8 "block, partition: add partition_meta_info to hd_struct" added part_unpack_uuid() which assumes that the passed in buffer has enough space for sprintfing "%pU" - 37 characters including '\0'. Unfortunately, b5af921ec0233 "init: add support for root devices specified by partition UUID" supplied 33 bytes buffer to the function leading to the following panic with stackprotector enabled. Kernel panic - not syncing: stack-protector: Kernel stack corrupted in: ffffffff81b14c7e [<ffffffff815e226b>] panic+0xba/0x1c6 [<ffffffff81b14c7e>] ? printk_all_partitions+0x259/0x26xb [<ffffffff810566bb>] __stack_chk_fail+0x1b/0x20 [<ffffffff81b15c7e>] printk_all_paritions+0x259/0x26xb [<ffffffff81aedfe0>] mount_block_root+0x1bc/0x27f [<ffffffff81aee0fa>] mount_root+0x57/0x5b [<ffffffff81aee23b>] prepare_namespace+0x13d/0x176 [<ffffffff8107eec0>] ? release_tgcred.isra.4+0x330/0x30 [<ffffffff81aedd60>] kernel_init+0x155/0x15a [<ffffffff81087b97>] ? schedule_tail+0x27/0xb0 [<ffffffff815f4d24>] kernel_thread_helper+0x5/0x10 [<ffffffff81aedc0b>] ? start_kernel+0x3c5/0x3c5 [<ffffffff815f4d20>] ? gs_change+0x13/0x13 Increase the buffer size, remove the dangerous part_unpack_uuid() and use snprintf() directly from printk_all_partitions(). Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Szymon Gruszczynski <sz.gruszczynski@googlemail.com> Cc: Will Drewry <wad@chromium.org> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-03-02Block: use a freezable workqueue for disk-event pollingAlan Stern1-5/+5
This patch (as1519) fixes a bug in the block layer's disk-events polling. The polling is done by a work routine queued on the system_nrt_wq workqueue. Since that workqueue isn't freezable, the polling continues even in the middle of a system sleep transition. Obviously, polling a suspended drive for media changes and such isn't a good thing to do; in the case of USB mass-storage devices it can lead to real problems requiring device resets and even re-enumeration. The patch fixes things by creating a new system-wide, non-reentrant, freezable workqueue and using it for disk-events polling. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> CC: <stable@kernel.org> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-03-02block: fix __blkdev_get and add_disk race conditionStanislaw Gruszka1-13/+19
The following situation might occur: __blkdev_get: add_disk: register_disk() get_gendisk() disk_block_events() disk->ev == NULL disk_add_events() __disk_unblock_events() disk->ev != NULL --ev->block Then we unblock events, when they are suppose to be blocked. This can trigger events related block/genhd.c warnings, but also can crash in sd_check_events() or other places. I'm able to reproduce crashes with the following scripts (with connected usb dongle as sdb disk). <snip> DEV=/dev/sdb ENABLE=/sys/bus/usb/devices/1-2/bConfigurationValue function stop_me() { for i in `jobs -p` ; do kill $i 2> /dev/null ; done exit } trap stop_me SIGHUP SIGINT SIGTERM for ((i = 0; i < 10; i++)) ; do while true; do fdisk -l $DEV 2>&1 > /dev/null ; done & done while true ; do echo 1 > $ENABLE sleep 1 echo 0 > $ENABLE done </snip> I use the script to verify patch fixing oops in sd_revalidate_disk http://marc.info/?l=linux-scsi&m=132935572512352&w=2 Without Jun'ichi Nomura patch titled "Fix NULL pointer dereference in sd_revalidate_disk" or this one, script easily crash kernel within a few seconds. With both patches applied I do not observe crash. Unfortunately after some time (dozen of minutes), script will hung in: [ 1563.906432] [<c08354f5>] schedule_timeout_uninterruptible+0x15/0x20 [ 1563.906437] [<c04532d5>] msleep+0x15/0x20 [ 1563.906443] [<c05d60b2>] blk_drain_queue+0x32/0xd0 [ 1563.906447] [<c05d6e00>] blk_cleanup_queue+0xd0/0x170 [ 1563.906454] [<c06d278f>] scsi_free_queue+0x3f/0x60 [ 1563.906459] [<c06d7e6e>] __scsi_remove_device+0x6e/0xb0 [ 1563.906463] [<c06d4aff>] scsi_forget_host+0x4f/0x60 [ 1563.906468] [<c06cd84a>] scsi_remove_host+0x5a/0xf0 [ 1563.906482] [<f7f030fb>] quiesce_and_remove_host+0x5b/0xa0 [usb_storage] [ 1563.906490] [<f7f03203>] usb_stor_disconnect+0x13/0x20 [usb_storage] Anyway I think this patch is some step forward. As drawback, I do not teardown on sysfs file create error, because I do not know how to nullify disk->ev (since it can be used). However add_disk error handling practically does not exist too, and things will work without this sysfs file, except events will not be exported to user space. Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: stable@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
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