user/sven/linux.git/kernel/power/swap.c, branch v6.4.3

PM: hibernate: Do not get block device exclusively in test_resume mode

2023-04-27T17:00:28Z

The system refused to do a test_resume because it found that the swap device has already been taken by someone else. Specifically, the swsusp_check()->blkdev_get_by_dev(FMODE_EXCL) is supposed to do this check. Steps to reproduce: dd if=/dev/zero of=/swapfile bs=$(cat /proc/meminfo | awk '/MemTotal/ {print $2}') count=1024 conv=notrunc mkswap /swapfile swapon /swapfile swap-offset /swapfile echo 34816 > /sys/power/resume_offset echo test_resume > /sys/power/disk echo disk > /sys/power/state PM: Using 3 thread(s) for compression PM: Compressing and saving image data (293150 pages)... PM: Image saving progress: 0% PM: Image saving progress: 10% ata1: SATA link up 1.5 Gbps (SStatus 113 SControl 300) ata1.00: configured for UDMA/100 ata2: SATA link down (SStatus 0 SControl 300) ata5: SATA link down (SStatus 0 SControl 300) ata6: SATA link down (SStatus 0 SControl 300) ata3: SATA link down (SStatus 0 SControl 300) ata4: SATA link down (SStatus 0 SControl 300) PM: Image saving progress: 20% PM: Image saving progress: 30% PM: Image saving progress: 40% PM: Image saving progress: 50% pcieport 0000:00:02.5: pciehp: Slot(0-5): No device found PM: Image saving progress: 60% PM: Image saving progress: 70% PM: Image saving progress: 80% PM: Image saving progress: 90% PM: Image saving done PM: hibernation: Wrote 1172600 kbytes in 2.70 seconds (434.29 MB/s) PM: S| PM: hibernation: Basic memory bitmaps freed PM: Image not found (code -16) This is because when using the swapfile as the hibernation storage, the block device where the swapfile is located has already been mounted by the OS distribution(usually mounted as the rootfs). This is not an issue for normal hibernation, because software_resume()->swsusp_check() happens before the block device(rootfs) mount. But it is a problem for the test_resume mode. Because when test_resume happens, the block device has been mounted already. Thus remove the FMODE_EXCL for test_resume mode. This would not be a problem because in test_resume stage, the processes have already been frozen, and the race condition described in Commit 39fbef4b0f77 ("PM: hibernate: Get block device exclusively in swsusp_check()") is unlikely to happen. Fixes: 39fbef4b0f77 ("PM: hibernate: Get block device exclusively in swsusp_check()") Reported-by: Yifan Li Suggested-by: Pavankumar Kondeti Tested-by: Pavankumar Kondeti Tested-by: Wendy Wang Signed-off-by: Chen Yu Signed-off-by: Rafael J. Wysocki

PM: hibernate: swap: don't use /** for non-kernel-doc comments

2023-01-20T13:49:48Z

kernel-doc complains about multiple occurrences of "/**" being used for something that is not a kernel-doc comment, so change all of these to just use "/*" comment style. The warning message for all of these is: FILE:LINE: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst kernel/power/swap.c:585: warning: ... Structure used for CRC32. kernel/power/swap.c:600: warning: ... * CRC32 update function that runs in its own thread. kernel/power/swap.c:627: warning: ... * Structure used for LZO data compression. kernel/power/swap.c:644: warning: ... * Compression function that runs in its own thread. kernel/power/swap.c:952: warning: ... * The following functions allow us to read data using a swap map kernel/power/swap.c:1111: warning: ... * Structure used for LZO data decompression. kernel/power/swap.c:1127: warning: ... * Decompression function that runs in its own thread. Also correct one spello/typo. Signed-off-by: Randy Dunlap Signed-off-by: Rafael J. Wysocki

PM: Use the enum req_op and blk_opf_t types

2022-07-14T18:14:33Z

Improve static type checking by using the enum req_op type for variables that represent a request operation and the new blk_opf_t type for variables that represent request flags. Combine the first two hib_submit_io() arguments into a single argument. Acked-by: Rafael J. Wysocki Cc: Christoph Hellwig Signed-off-by: Bart Van Assche Link: https://lore.kernel.org/r/20220714180729.1065367-62-bvanassche@acm.org Signed-off-by: Jens Axboe

Merge tag 'for-5.18/block-2022-03-18' of git://git.kernel.dk/linux-block

2022-03-21T23:48:55Z

Pull block updates from Jens Axboe: - BFQ cleanups and fixes (Yu, Zhang, Yahu, Paolo) - blk-rq-qos completion fix (Tejun) - blk-cgroup merge fix (Tejun) - Add offline error return value to distinguish it from an IO error on the device (Song) - IO stats fixes (Zhang, Christoph) - blkcg refcount fixes (Ming, Yu) - Fix for indefinite dispatch loop softlockup (Shin'ichiro) - blk-mq hardware queue management improvements (Ming) - sbitmap dead code removal (Ming, John) - Plugging merge improvements (me) - Show blk-crypto capabilities in sysfs (Eric) - Multiple delayed queue run improvement (David) - Block throttling fixes (Ming) - Start deprecating auto module loading based on dev_t (Christoph) - bio allocation improvements (Christoph, Chaitanya) - Get rid of bio_devname (Christoph) - bio clone improvements (Christoph) - Block plugging improvements (Christoph) - Get rid of genhd.h header (Christoph) - Ensure drivers use appropriate flush helpers (Christoph) - Refcounting improvements (Christoph) - Queue initialization and teardown improvements (Ming, Christoph) - Misc fixes/improvements (Barry, Chaitanya, Colin, Dan, Jiapeng, Lukas, Nian, Yang, Eric, Chengming) * tag 'for-5.18/block-2022-03-18' of git://git.kernel.dk/linux-block: (127 commits) block: cancel all throttled bios in del_gendisk() block: let blkcg_gq grab request queue's refcnt block: avoid use-after-free on throttle data block: limit request dispatch loop duration block/bfq-iosched: Fix spelling mistake "tenative" -> "tentative" sr: simplify the local variable initialization in sr_block_open() block: don't merge across cgroup boundaries if blkcg is enabled block: fix rq-qos breakage from skipping rq_qos_done_bio() block: flush plug based on hardware and software queue order block: ensure plug merging checks the correct queue at least once block: move rq_qos_exit() into disk_release() block: do more work in elevator_exit block: move blk_exit_queue into disk_release block: move q_usage_counter release into blk_queue_release block: don't remove hctx debugfs dir from blk_mq_exit_queue block: move blkcg initialization/destroy into disk allocation/release handler sr: implement ->free_disk to simplify refcounting sd: implement ->free_disk to simplify refcounting sd: delay calling free_opal_dev sd: call sd_zbc_release_disk before releasing the scsi_device reference ...

PM: hibernate: Clean up non-kernel-doc comments

2022-03-01T15:20:46Z

Address the following W=1 kernel build warning: kernel/power/swap.c:120: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst. Reported-by: Abaci Robot Signed-off-by: Jiapeng Chong Signed-off-by: Rafael J. Wysocki

block: pass a block_device and opf to bio_alloc

2022-02-02T14:49:59Z

Pass the block_device and operation that we plan to use this bio for to bio_alloc to optimize the assignment. NULL/0 can be passed, both for the passthrough case on a raw request_queue and to temporarily avoid refactoring some nasty code. Also move the gfp_mask argument after the nr_vecs argument for a much more logical calling convention matching what most of the kernel does. Signed-off-by: Christoph Hellwig Reviewed-by: Chaitanya Kulkarni Link: https://lore.kernel.org/r/20220124091107.642561-18-hch@lst.de Signed-off-by: Jens Axboe

block: remove genhd.h

2022-02-02T14:49:59Z

There is no good reason to keep genhd.h separate from the main blkdev.h header that includes it. So fold the contents of genhd.h into blkdev.h and remove genhd.h entirely. Signed-off-by: Christoph Hellwig Reviewed-by: Chaitanya Kulkarni Reviewed-by: Martin K. Petersen Link: https://lore.kernel.org/r/20220124093913.742411-4-hch@lst.de Signed-off-by: Jens Axboe

PM: hibernate: Allow ACPI hardware signature to be honoured

2021-12-08T15:06:10Z

Theoretically, when the hardware signature in FACS changes, the OS is supposed to gracefully decline to attempt to resume from S4: "If the signature has changed, OSPM will not restore the system context and can boot from scratch" In practice, Windows doesn't do this and many laptop vendors do allow the signature to change especially when docking/undocking, so it would be a bad idea to simply comply with the specification by default in the general case. However, there are use cases where we do want the compliant behaviour and we know it's safe. Specifically, when resuming virtual machines where we know the hypervisor has changed sufficiently that resume will fail. We really want to be able to *tell* the guest kernel not to try, so it boots cleanly and doesn't just crash. This patch provides a way to opt in to the spec-compliant behaviour on the command line. A follow-up patch may do this automatically for certain "known good" machines based on a DMI match, or perhaps just for all hypervisor guests since there's no good reason a hypervisor would change the hardware_signature that it exposes to guests *unless* it wants them to obey the ACPI specification. Signed-off-by: David Woodhouse Signed-off-by: Rafael J. Wysocki

PM: hibernate: Get block device exclusively in swsusp_check()

2021-10-21T17:38:32Z

The following kernel crash can be triggered: [ 89.266592] ------------[ cut here ]------------ [ 89.267427] kernel BUG at fs/buffer.c:3020! [ 89.268264] invalid opcode: 0000 [#1] SMP KASAN PTI [ 89.269116] CPU: 7 PID: 1750 Comm: kmmpd-loop0 Not tainted 5.10.0-862.14.0.6.x86_64-08610-gc932cda3cef4-dirty #20 [ 89.273169] RIP: 0010:submit_bh_wbc.isra.0+0x538/0x6d0 [ 89.277157] RSP: 0018:ffff888105ddfd08 EFLAGS: 00010246 [ 89.278093] RAX: 0000000000000005 RBX: ffff888124231498 RCX: ffffffffb2772612 [ 89.279332] RDX: 1ffff11024846293 RSI: 0000000000000008 RDI: ffff888124231498 [ 89.280591] RBP: ffff8881248cc000 R08: 0000000000000001 R09: ffffed1024846294 [ 89.281851] R10: ffff88812423149f R11: ffffed1024846293 R12: 0000000000003800 [ 89.283095] R13: 0000000000000001 R14: 0000000000000000 R15: ffff8881161f7000 [ 89.284342] FS: 0000000000000000(0000) GS:ffff88839b5c0000(0000) knlGS:0000000000000000 [ 89.285711] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 89.286701] CR2: 00007f166ebc01a0 CR3: 0000000435c0e000 CR4: 00000000000006e0 [ 89.287919] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 89.289138] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 89.290368] Call Trace: [ 89.290842] write_mmp_block+0x2ca/0x510 [ 89.292218] kmmpd+0x433/0x9a0 [ 89.294902] kthread+0x2dd/0x3e0 [ 89.296268] ret_from_fork+0x22/0x30 [ 89.296906] Modules linked in: by running the following commands: 1. mkfs.ext4 -O mmp /dev/sda -b 1024 2. mount /dev/sda /home/test 3. echo "/dev/sda" > /sys/power/resume That happens because swsusp_check() calls set_blocksize() on the target partition which confuses the file system: Thread1 Thread2 mount /dev/sda /home/test get s_mmp_bh --> has mapped flag start kmmpd thread echo "/dev/sda" > /sys/power/resume resume_store software_resume swsusp_check set_blocksize truncate_inode_pages_range truncate_cleanup_page block_invalidatepage discard_buffer --> clean mapped flag write_mmp_block submit_bh submit_bh_wbc BUG_ON(!buffer_mapped(bh)) To address this issue, modify swsusp_check() to open the target block device with exclusive access. Signed-off-by: Ye Bin [ rjw: Subject and changelog edits ] Signed-off-by: Rafael J. Wysocki

PM: hibernate: swap: Use vzalloc() and kzalloc()

2021-10-21T11:04:57Z

Replace vmalloc()/memset() with vzalloc() and kmalloc()/memset() with kzalloc() to simplify the code. Signed-off-by: Cai Huoqing Signed-off-by: Rafael J. Wysocki