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2020-10-18ext4: use ext4_sb_bread() instead of sb_bread()zhangyi (F)2-7/+7
We have already remove open codes that invoke helpers provide by fs/buffer.c in all places reading metadata buffers. This patch switch to use ext4_sb_bread() to replace all sb_bread() helpers, which is ext4_read_bh() helper back end. Signed-off-by: zhangyi (F) <yi.zhang@huawei.com> Link: https://lore.kernel.org/r/20200924073337.861472-7-yi.zhang@huawei.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-18ext4: introduce ext4_sb_breadahead_unmovable() to replace ↵zhangyi (F)3-2/+13
sb_breadahead_unmovable() If we readahead inode tables in __ext4_get_inode_loc(), it may bypass buffer_write_io_error() check, so introduce ext4_sb_breadahead_unmovable() to handle this special case. This patch also replace sb_breadahead_unmovable() in ext4_fill_super() for the sake of unification. Signed-off-by: zhangyi (F) <yi.zhang@huawei.com> Link: https://lore.kernel.org/r/20200924073337.861472-6-yi.zhang@huawei.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-18ext4: use ext4_buffer_uptodate() in __ext4_get_inode_loc()zhangyi (F)1-10/+1
We have already introduced ext4_buffer_uptodate() to re-set the uptodate bit on buffer which has been failed to write out to disk. Just remove the redundant codes and switch to use ext4_buffer_uptodate() in __ext4_get_inode_loc(). Signed-off-by: zhangyi (F) <yi.zhang@huawei.com> Link: https://lore.kernel.org/r/20200924073337.861472-5-yi.zhang@huawei.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-18ext4: use common helpers in all places reading metadata bufferszhangyi (F)9-54/+36
Revome all open codes that read metadata buffers, switch to use ext4_read_bh_*() common helpers. Signed-off-by: zhangyi (F) <yi.zhang@huawei.com> Suggested-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20200924073337.861472-4-yi.zhang@huawei.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-18ext4: introduce new metadata buffer read helperszhangyi (F)2-0/+67
The previous patch add clear_buffer_verified() before we read metadata block from disk again, but it's rather easy to miss clearing of this bit because currently we read metadata buffer through different open codes (e.g. ll_rw_block(), bh_submit_read() and invoke submit_bh() directly). So, it's time to add common helpers to unify in all the places reading metadata buffers instead. This patch add 3 helpers: - ext4_read_bh_nowait(): async read metadata buffer if it's actually not uptodate, clear buffer_verified bit before read from disk. - ext4_read_bh(): sync version of read metadata buffer, it will wait until the read operation return and check the return status. - ext4_read_bh_lock(): try to lock the buffer before read buffer, it will skip reading if the buffer is already locked. After this patch, we need to use these helpers in all the places reading metadata buffer instead of different open codes. Signed-off-by: zhangyi (F) <yi.zhang@huawei.com> Suggested-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20200924073337.861472-3-yi.zhang@huawei.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-18ext4: clear buffer verified flag if read meta block from diskzhangyi (F)5-1/+8
The metadata buffer is no longer trusted after we read it from disk again because it is not uptodate for some reasons (e.g. failed to write back). Otherwise we may get below memory corruption problem in ext4_ext_split()->memset() if we read stale data from the newly allocated extent block on disk which has been failed to async write out but miss verify again since the verified bit has already been set on the buffer. [ 29.774674] BUG: unable to handle kernel paging request at ffff88841949d000 ... [ 29.783317] Oops: 0002 [#2] SMP [ 29.784219] R10: 00000000000f4240 R11: 0000000000002e28 R12: ffff88842fa1c800 [ 29.784627] CPU: 1 PID: 126 Comm: kworker/u4:3 Tainted: G D W [ 29.785546] R13: ffffffff9cddcc20 R14: ffffffff9cddd420 R15: ffff88842fa1c2f8 [ 29.786679] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),BIOS ?-20190727_0738364 [ 29.787588] FS: 0000000000000000(0000) GS:ffff88842fa00000(0000) knlGS:0000000000000000 [ 29.789288] Workqueue: writeback wb_workfn [ 29.790319] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 29.790321] (flush-8:0) [ 29.790844] CR2: 0000000000000008 CR3: 00000004234f2000 CR4: 00000000000006f0 [ 29.791924] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 29.792839] RIP: 0010:__memset+0x24/0x30 [ 29.793739] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 29.794256] Code: 90 90 90 90 90 90 0f 1f 44 00 00 49 89 f9 48 89 d1 83 e2 07 48 c1 e9 033 [ 29.795161] Kernel panic - not syncing: Fatal exception in interrupt ... [ 29.808149] Call Trace: [ 29.808475] ext4_ext_insert_extent+0x102e/0x1be0 [ 29.809085] ext4_ext_map_blocks+0xa89/0x1bb0 [ 29.809652] ext4_map_blocks+0x290/0x8a0 [ 29.809085] ext4_ext_map_blocks+0xa89/0x1bb0 [ 29.809652] ext4_map_blocks+0x290/0x8a0 [ 29.810161] ext4_writepages+0xc85/0x17c0 ... Fix this by clearing buffer's verified bit if we read meta block from disk again. Signed-off-by: zhangyi (F) <yi.zhang@huawei.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200924073337.861472-2-yi.zhang@huawei.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-18ext4: limit entries returned when counting fsmap recordsDarrick J. Wong1-0/+3
If userspace asked fsmap to try to count the number of entries, we cannot return more than UINT_MAX entries because fmh_entries is u32. Therefore, stop counting if we hit this limit or else we will waste time to return truncated results. Fixes: 0c9ec4beecac ("ext4: support GETFSMAP ioctls") Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Link: https://lore.kernel.org/r/20201001222148.GA49520@magnolia Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-18ext4: make mb_check_counter per groupChunguang Xu2-5/+5
Make bb_check_counter per group, so each group has the same chance to be checked, which can expose errors more easily. Signed-off-by: Chunguang Xu <brookxu@tencent.com> Link: https://lore.kernel.org/r/1601292995-32205-2-git-send-email-brookxu@tencent.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-18ext4: delete invalid comments near mb_buddy_adjust_borderChunguang Xu1-3/+0
The comment near mb_buddy_adjust_border seems meaningless, just clear it. Signed-off-by: Chunguang Xu <brookxu@tencent.com> Link: https://lore.kernel.org/r/1601292995-32205-1-git-send-email-brookxu@tencent.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-18ext4: fix bdev write error check failed when mount fs with roZhang Xiaoxu1-11/+2
Consider a situation when a filesystem was uncleanly shutdown and the orphan list is not empty and a read-only mount is attempted. The orphan list cleanup during mount will fail with: ext4_check_bdev_write_error:193: comm mount: Error while async write back metadata This happens because sbi->s_bdev_wb_err is not initialized when mounting the filesystem in read only mode and so ext4_check_bdev_write_error() falsely triggers. Initialize sbi->s_bdev_wb_err unconditionally to avoid this problem. Fixes: bc71726c7257 ("ext4: abort the filesystem if failed to async write metadata buffer") Cc: stable@kernel.org Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20200928020556.710971-1-zhangxiaoxu5@huawei.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-18ext4: rename system_blks to s_system_blks inside ext4_sb_infoChunguang Xu3-9/+9
Rename system_blks to s_system_blks inside ext4_sb_info, keep the naming rules consistent with other variables, which is convenient for code reading and writing. Signed-off-by: Chunguang Xu <brookxu@tencent.com> Reviewed-by: Andreas Dilger <adilger@dilger.ca> Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com> Link: https://lore.kernel.org/r/1600916623-544-2-git-send-email-brookxu@tencent.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-18ext4: rename journal_dev to s_journal_dev inside ext4_sb_infoChunguang Xu3-12/+12
Rename journal_dev to s_journal_dev inside ext4_sb_info, keep the naming rules consistent with other variables, which is convenient for code reading and writing. Signed-off-by: Chunguang Xu <brookxu@tencent.com> Reviewed-by: Andreas Dilger <adilger@dilger.ca> Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com> Link: https://lore.kernel.org/r/1600916623-544-1-git-send-email-brookxu@tencent.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-18jbd2: fix the comment of struct jbd2_journal_handleHui Su1-2/+2
the struct name was modified long ago, but the comment still use struct handle_s. Signed-off-by: Hui Su <sh_def@163.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20200922171231.GA53120@rlk Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-18ext4: add trace exit in exception path.Zhang Qilong2-2/+3
Missing trace exit in exception path of ext4_sync_file and ext4_ind_map_blocks. Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com> Link: https://lore.kernel.org/r/20200921124738.23352-1-zhangqilong3@huawei.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-18ext4: optimize file overwritesRitesh Harjani1-3/+15
In case if the file already has underlying blocks/extents allocated then we don't need to start a journal txn and can directly return the underlying mapping. Currently ext4_iomap_begin() is used by both DAX & DIO path. We can check if the write request is an overwrite & then directly return the mapping information. This could give a significant perf boost for multi-threaded writes specially random overwrites. On PPC64 VM with simulated pmem(DAX) device, ~10x perf improvement could be seen in random writes (overwrite). Also bcoz this optimizes away the spinlock contention during jbd2 slab cache allocation (jbd2_journal_handle). On x86 VM, ~2x perf improvement was observed. Reported-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> Link: https://lore.kernel.org/r/88e795d8a4d5cd22165c7ebe857ba91d68d8813e.1600401668.git.riteshh@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-18ext4: remove unused including <linux/version.h>Tian Tao1-1/+0
Remove including <linux/version.h> that don't need it. Signed-off-by: Tian Tao <tiantao6@hisilicon.com> Link: https://lore.kernel.org/r/1600397165-42873-1-git-send-email-tiantao6@hisilicon.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-18ext4: fix superblock checksum calculation raceConstantine Sapuntzakis1-0/+11
The race condition could cause the persisted superblock checksum to not match the contents of the superblock, causing the superblock to be considered corrupt. An example of the race follows. A first thread is interrupted in the middle of a checksum calculation. Then, another thread changes the superblock, calculates a new checksum, and sets it. Then, the first thread resumes and sets the checksum based on the older superblock. To fix, serialize the superblock checksum calculation using the buffer header lock. While a spinlock is sufficient, the buffer header is already there and there is precedent for locking it (e.g. in ext4_commit_super). Tested the patch by booting up a kernel with the patch, creating a filesystem and some files (including some orphans), and then unmounting and remounting the file system. Cc: stable@kernel.org Signed-off-by: Constantine Sapuntzakis <costa@purestorage.com> Reviewed-by: Jan Kara <jack@suse.cz> Suggested-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20200914161014.22275-1-costa@purestorage.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-18ext4: fix error handling code in add_new_gdbDinghao Liu1-1/+3
When ext4_journal_get_write_access() fails, we should terminate the execution flow and release n_group_desc, iloc.bh, dind and gdb_bh. Cc: stable@kernel.org Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn> Reviewed-by: Andreas Dilger <adilger@dilger.ca> Link: https://lore.kernel.org/r/20200829025403.3139-1-dinghao.liu@zju.edu.cn Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-18ext4: disallow modifying DAX inode flag if inline_data has been setXiao Yang1-1/+1
inline_data is mutually exclusive to DAX so enabling both of them triggers the following issue: ------------------------------------------ # mkfs.ext4 -F -O inline_data /dev/pmem1 ... # mount /dev/pmem1 /mnt # echo 'test' >/mnt/file # lsattr -l /mnt/file /mnt/file Inline_Data # xfs_io -c "chattr +x" /mnt/file # xfs_io -c "lsattr -v" /mnt/file [dax] /mnt/file # umount /mnt # mount /dev/pmem1 /mnt # cat /mnt/file cat: /mnt/file: Numerical result out of range ------------------------------------------ Fixes: b383a73f2b83 ("fs/ext4: Introduce DAX inode flag") Signed-off-by: Xiao Yang <yangx.jy@cn.fujitsu.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Andreas Dilger <adilger@dilger.ca> Link: https://lore.kernel.org/r/20200828084330.15776-1-yangx.jy@cn.fujitsu.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-18ext4: remove unused argument from ext4_(inc|dec)_countNikolay Borisov1-10/+10
The 'handle' argument is not used for anything so simply remove it. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com> Link: https://lore.kernel.org/r/20200826133116.11592-1-nborisov@suse.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-18ext4: do not interpret high bytes if 64bit feature is disabledPetr Malat1-6/+8
Fields s_free_blocks_count_hi, s_r_blocks_count_hi and s_blocks_count_hi are not valid if EXT4_FEATURE_INCOMPAT_64BIT is not enabled and should be treated as zeroes. Signed-off-by: Petr Malat <oss@malat.biz> Link: https://lore.kernel.org/r/20200825150016.3363-1-oss@malat.biz Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-18ext4: delete duplicated words + other fixesRandy Dunlap5-6/+6
Delete repeated words in fs/ext4/. {the, this, of, we, after} Also change spelling of "xttr" in inline.c to "xattr" in 2 places. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20200805024850.12129-1-rdunlap@infradead.org Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-18ext4: flag as supporting buffered async readsJens Axboe1-1/+1
ext4 uses generic_file_read_iter(), which already supports this. Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Jens Axboe <axboe@kernel.dk> Link: https://lore.kernel.org/r/fb90cc2d-b12c-738f-21a4-dd7a8ae0556a@kernel.dk Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-18ext4: fix leaking sysfs kobject after failed mountEric Biggers1-0/+1
ext4_unregister_sysfs() only deletes the kobject. The reference to it needs to be put separately, like ext4_put_super() does. This addresses the syzbot report "memory leak in kobject_set_name_vargs (3)" (https://syzkaller.appspot.com/bug?extid=9f864abad79fae7c17e1). Reported-by: syzbot+9f864abad79fae7c17e1@syzkaller.appspotmail.com Fixes: 72ba74508b28 ("ext4: release sysfs kobject when failing to enable quotas on mount") Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> Link: https://lore.kernel.org/r/20200922162456.93657-1-ebiggers@kernel.org Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-18ext4: discard preallocations before releasing group lockJan Kara1-20/+13
ext4_mb_discard_group_preallocations() can be releasing group lock with preallocations accumulated on its local list. Thus although discard_pa_seq was incremented and concurrent allocating processes will be retrying allocations, it can happen that premature ENOSPC error is returned because blocks used for preallocations are not available for reuse yet. Make sure we always free locally accumulated preallocations before releasing group lock. Fixes: 07b5b8e1ac40 ("ext4: mballoc: introduce pcpu seqcnt for freeing PA to improve ENOSPC handling") Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20200924150959.4335-1-jack@suse.cz Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-18ext4: fix dead loop in ext4_mb_new_blocksYe Bin1-1/+3
As we test disk offline/online with running fsstress, we find fsstress process is keeping running state. kworker/u32:3-262 [004] ...1 140.787471: ext4_mb_discard_preallocations: dev 8,32 needed 114 .... kworker/u32:3-262 [004] ...1 140.787471: ext4_mb_discard_preallocations: dev 8,32 needed 114 ext4_mb_new_blocks repeat: ext4_mb_discard_preallocations_should_retry(sb, ac, &seq) freed = ext4_mb_discard_preallocations ext4_mb_discard_group_preallocations this_cpu_inc(discard_pa_seq); ---> freed == 0 seq_retry = ext4_get_discard_pa_seq_sum for_each_possible_cpu(__cpu) __seq += per_cpu(discard_pa_seq, __cpu); if (seq_retry != *seq) { *seq = seq_retry; ret = true; } As we see seq_retry is sum of discard_pa_seq every cpu, if ext4_mb_discard_group_preallocations return zero discard_pa_seq in this cpu maybe increase one, so condition "seq_retry != *seq" have always been met. Ritesh Harjani suggest to in ext4_mb_discard_group_preallocations function we only increase discard_pa_seq when there is some PA to free. Fixes: 07b5b8e1ac40 ("ext4: mballoc: introduce pcpu seqcnt for freeing PA to improve ENOSPC handling") Signed-off-by: Ye Bin <yebin10@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com> Link: https://lore.kernel.org/r/20200916113859.1556397-3-yebin10@huawei.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-18ext4: implement swap_activate aops using iomapRitesh Harjani1-0/+11
After moving ext4's bmap to iomap interface, swapon functionality on files created using fallocate (which creates unwritten extents) are failing. This is since iomap_bmap interface returns 0 for unwritten extents and thus generic_swapfile_activate considers this as holes and hence bail out with below kernel msg :- [340.915835] swapon: swapfile has holes To fix this we need to implement ->swap_activate aops in ext4 which will use ext4_iomap_report_ops. Since we only need to return the list of extents so ext4_iomap_report_ops should be enough. Cc: stable@kernel.org Reported-by: Yuxuan Shui <yshuiv7@gmail.com> Fixes: ac58e4fb03f ("ext4: move ext4 bmap to use iomap infrastructure") Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> Link: https://lore.kernel.org/r/20200904091653.1014334-1-riteshh@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-09-27Linux 5.9-rc7v5.9-rc7Linus Torvalds1-1/+1
2020-09-27Merge tag 'kbuild-fixes-v5.9-4' of ↵Linus Torvalds2-3/+17
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild fixes from Masahiro Yamada: - ignore compiler stubs for PPC to fix builds - fix the usage of --target mentioned in the LLVM document * tag 'kbuild-fixes-v5.9-4' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: Documentation/llvm: Fix clang target examples scripts/kallsyms: skip ppc compiler stub *.long_branch.* / *.plt_branch.*
2020-09-27Merge tag 'x86-urgent-2020-09-27' of ↵Linus Torvalds7-12/+68
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: "Two fixes for the x86 interrupt code: - Unbreak the magic 'search the timer interrupt' logic in IO/APIC code which got wreckaged when the core interrupt code made the state tracking logic stricter. That caused the interrupt line to stay masked after switching from IO/APIC to PIC delivery mode, which obviously prevents interrupts from being delivered. - Make run_on_irqstack_code() typesafe. The function argument is a void pointer which is then cast to 'void (*fun)(void *). This breaks Control Flow Integrity checking in clang. Use proper helper functions for the three variants reuqired" * tag 'x86-urgent-2020-09-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/ioapic: Unbreak check_timer() x86/irq: Make run_on_irqstack_cond() typesafe
2020-09-27Merge tag 'timers-urgent-2020-09-27' of ↵Linus Torvalds3-22/+25
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer updates from Thomas Gleixner: "A set of clocksource/clockevents updates: - Reset the TI/DM timer before enabling it instead of doing it the other way round. - Initialize the reload value for the GX6605s timer correctly so the hardware counter starts at 0 again after overrun. - Make error return value negative in the h8300 timer init function" * tag 'timers-urgent-2020-09-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: clocksource/drivers/timer-gx6605s: Fixup counter reload clocksource/drivers/timer-ti-dm: Do reset before enable clocksource/drivers/h8300_timer8: Fix wrong return value in h8300_8timer_init()
2020-09-27mm/thp: Split huge pmds/puds if they're pinned when fork()Peter Xu1-0/+28
Pinned pages shouldn't be write-protected when fork() happens, because follow up copy-on-write on these pages could cause the pinned pages to be replaced by random newly allocated pages. For huge PMDs, we split the huge pmd if pinning is detected. So that future handling will be done by the PTE level (with our latest changes, each of the small pages will be copied). We can achieve this by let copy_huge_pmd() return -EAGAIN for pinned pages, so that we'll fallthrough in copy_pmd_range() and finally land the next copy_pte_range() call. Huge PUDs will be even more special - so far it does not support anonymous pages. But it can actually be done the same as the huge PMDs even if the split huge PUDs means to erase the PUD entries. It'll guarantee the follow up fault ins will remap the same pages in either parent/child later. This might not be the most efficient way, but it should be easy and clean enough. It should be fine, since we're tackling with a very rare case just to make sure userspaces that pinned some thps will still work even without MADV_DONTFORK and after they fork()ed. Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-09-27mm: Do early cow for pinned pages during fork() for ptesPeter Xu1-16/+189
This allows copy_pte_range() to do early cow if the pages were pinned on the source mm. Currently we don't have an accurate way to know whether a page is pinned or not. The only thing we have is page_maybe_dma_pinned(). However that's good enough for now. Especially, with the newly added mm->has_pinned flag to make sure we won't affect processes that never pinned any pages. It would be easier if we can do GFP_KERNEL allocation within copy_one_pte(). Unluckily, we can't because we're with the page table locks held for both the parent and child processes. So the page allocation needs to be done outside copy_one_pte(). Some trick is there in copy_present_pte(), majorly the wrprotect trick to block concurrent fast-gup. Comments in the function should explain better in place. Oleg Nesterov reported a (probably harmless) bug during review that we didn't reset entry.val properly in copy_pte_range() so that potentially there's chance to call add_swap_count_continuation() multiple times on the same swp entry. However that should be harmless since even if it happens, the same function (add_swap_count_continuation()) will return directly noticing that there're enough space for the swp counter. So instead of a standalone stable patch, it is touched up in this patch directly. Link: https://lore.kernel.org/lkml/20200914143829.GA1424636@nvidia.com/ Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-09-27mm/fork: Pass new vma pointer into copy_page_range()Peter Xu3-7/+11
This prepares for the future work to trigger early cow on pinned pages during fork(). No functional change intended. Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-09-27mm: Introduce mm_struct.has_pinnedPeter Xu3-0/+17
(Commit message majorly collected from Jason Gunthorpe) Reduce the chance of false positive from page_maybe_dma_pinned() by keeping track if the mm_struct has ever been used with pin_user_pages(). This allows cases that might drive up the page ref_count to avoid any penalty from handling dma_pinned pages. Future work is planned, to provide a more sophisticated solution, likely to turn it into a real counter. For now, make it atomic_t but use it as a boolean for simplicity. Suggested-by: Jason Gunthorpe <jgg@ziepe.ca> Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-09-27Merge tag 'timers-v5.9-rc4' of ↵Thomas Gleixner3-22/+25
https://git.linaro.org/people/daniel.lezcano/linux into timers/urgent Pull clocksource/clockevent fixes from Daniel Lezcano: - Fix wrong signed return value when checking of_iomap in the probe function for the h8300 timer (Tianjia Zhang) - Fix reset sequence when setting up the timer on the dm_timer (Tony Lindgren) - Fix counter reload when the interrupt fires on gx6605s (Guo Ren)
2020-09-26Merge tag 'scsi-fixes' of ↵Linus Torvalds6-73/+159
git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi Pull SCSI fixes from James Bottomley: "Three fixes: one in drivers (lpfc) and two for zoned block devices. The latter also impinges on the block layer but only to introduce a new block API for setting the zone model rather than fiddling with the queue directly in the zoned block driver" * tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: scsi: sd: sd_zbc: Fix ZBC disk initialization scsi: sd: sd_zbc: Fix handling of host-aware ZBC disks scsi: lpfc: Fix initial FLOGI failure due to BBSCN not supported
2020-09-26Merge tag 'io_uring-5.9-2020-09-25' of git://git.kernel.dk/linux-blockLinus Torvalds1-7/+7
Pull io_uring fixes from Jens Axboe: "Two fixes for regressions in this cycle, and one that goes to 5.8 stable: - fix leak of getname() retrieved filename - remove plug->nowait assignment, fixing a regression with btrfs - fix for async buffered retry" * tag 'io_uring-5.9-2020-09-25' of git://git.kernel.dk/linux-block: io_uring: ensure async buffered read-retry is setup properly io_uring: don't unconditionally set plug->nowait = true io_uring: ensure open/openat2 name is cleaned on cancelation
2020-09-26Merge tag 'block-5.9-2020-09-25' of git://git.kernel.dk/linux-blockLinus Torvalds6-24/+29
Pull block fixes from Jens Axboe: "NVMe pull request from Christoph, and removal of a dead define. - fix error during controller probe that cause double free irqs (Keith Busch) - FC connection establishment fix (James Smart) - properly handle completions for invalid tags (Xianting Tian) - pass the correct nsid to the command effects and supported log (Chaitanya Kulkarni)" * tag 'block-5.9-2020-09-25' of git://git.kernel.dk/linux-block: block: remove unused BLK_QC_T_EAGAIN flag nvme-core: don't use NVME_NSID_ALL for command effects and supported log nvme-fc: fail new connections to a deleted host or remote port nvme-pci: fix NULL req in completion handler nvme: return errors for hwmon init
2020-09-26Merge tag 's390-5.9-7' of ↵Linus Torvalds1-1/+2
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 fix from Vasily Gorbik: "Fix truncated ZCRYPT_PERDEV_REQCNT ioctl result. Copy entire reqcnt list" * tag 's390-5.9-7' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/zcrypt: Fix ZCRYPT_PERDEV_REQCNT ioctl
2020-09-26Merge branch 'akpm' (patches from Andrew)Linus Torvalds17-84/+181
Merge misc fixes from Andrew Morton: "9 patches. Subsystems affected by this patch series: mm (thp, memcg, gup, migration, memory-hotplug), lib, and x86" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: mm: don't rely on system state to detect hot-plug operations mm: replace memmap_context by meminit_context arch/x86/lib/usercopy_64.c: fix __copy_user_flushcache() cache writeback lib/memregion.c: include memregion.h lib/string.c: implement stpcpy mm/migrate: correct thp migration stats mm/gup: fix gup_fast with dynamic page table folding mm: memcontrol: fix missing suffix of workingset_restore mm, THP, swap: fix allocating cluster for swapfile by mistake
2020-09-26mm: validate pmd after splittingMinchan Kim1-1/+1
syzbot reported the following KASAN splat: general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f] CPU: 1 PID: 6826 Comm: syz-executor142 Not tainted 5.9.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__lock_acquire+0x84/0x2ae0 kernel/locking/lockdep.c:4296 Code: ff df 8a 04 30 84 c0 0f 85 e3 16 00 00 83 3d 56 58 35 08 00 0f 84 0e 17 00 00 83 3d 25 c7 f5 07 00 74 2c 4c 89 e8 48 c1 e8 03 <80> 3c 30 00 74 12 4c 89 ef e8 3e d1 5a 00 48 be 00 00 00 00 00 fc RSP: 0018:ffffc90004b9f850 EFLAGS: 00010006 Call Trace: lock_acquire+0x140/0x6f0 kernel/locking/lockdep.c:5006 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:354 [inline] madvise_cold_or_pageout_pte_range+0x52f/0x25c0 mm/madvise.c:389 walk_pmd_range mm/pagewalk.c:89 [inline] walk_pud_range mm/pagewalk.c:160 [inline] walk_p4d_range mm/pagewalk.c:193 [inline] walk_pgd_range mm/pagewalk.c:229 [inline] __walk_page_range+0xe7b/0x1da0 mm/pagewalk.c:331 walk_page_range+0x2c3/0x5c0 mm/pagewalk.c:427 madvise_pageout_page_range mm/madvise.c:521 [inline] madvise_pageout mm/madvise.c:557 [inline] madvise_vma mm/madvise.c:946 [inline] do_madvise+0x12d0/0x2090 mm/madvise.c:1145 __do_sys_madvise mm/madvise.c:1171 [inline] __se_sys_madvise mm/madvise.c:1169 [inline] __x64_sys_madvise+0x76/0x80 mm/madvise.c:1169 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The backing vma was shmem. In case of split page of file-backed THP, madvise zaps the pmd instead of remapping of sub-pages. So we need to check pmd validity after split. Reported-by: syzbot+ecf80462cb7d5d552bc7@syzkaller.appspotmail.com Fixes: 1a4e58cce84e ("mm: introduce MADV_PAGEOUT") Signed-off-by: Minchan Kim <minchan@kernel.org> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-09-26mm: don't rely on system state to detect hot-plug operationsLaurent Dufour3-35/+64
In register_mem_sect_under_node() the system_state's value is checked to detect whether the call is made during boot time or during an hot-plug operation. Unfortunately, that check against SYSTEM_BOOTING is wrong because regular memory is registered at SYSTEM_SCHEDULING state. In addition, memory hot-plug operation can be triggered at this system state by the ACPI [1]. So checking against the system state is not enough. The consequence is that on system with interleaved node's ranges like this: Early memory node ranges node 1: [mem 0x0000000000000000-0x000000011fffffff] node 2: [mem 0x0000000120000000-0x000000014fffffff] node 1: [mem 0x0000000150000000-0x00000001ffffffff] node 0: [mem 0x0000000200000000-0x000000048fffffff] node 2: [mem 0x0000000490000000-0x00000007ffffffff] This can be seen on PowerPC LPAR after multiple memory hot-plug and hot-unplug operations are done. At the next reboot the node's memory ranges can be interleaved and since the call to link_mem_sections() is made in topology_init() while the system is in the SYSTEM_SCHEDULING state, the node's id is not checked, and the sections registered to multiple nodes: $ ls -l /sys/devices/system/memory/memory21/node* total 0 lrwxrwxrwx 1 root root 0 Aug 24 05:27 node1 -> ../../node/node1 lrwxrwxrwx 1 root root 0 Aug 24 05:27 node2 -> ../../node/node2 In that case, the system is able to boot but if later one of theses memory blocks is hot-unplugged and then hot-plugged, the sysfs inconsistency is detected and this is triggering a BUG_ON(): kernel BUG at /Users/laurent/src/linux-ppc/mm/memory_hotplug.c:1084! Oops: Exception in kernel mode, sig: 5 [#1] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries Modules linked in: rpadlpar_io rpaphp pseries_rng rng_core vmx_crypto gf128mul binfmt_misc ip_tables x_tables xfs libcrc32c crc32c_vpmsum autofs4 CPU: 8 PID: 10256 Comm: drmgr Not tainted 5.9.0-rc1+ #25 Call Trace: add_memory_resource+0x23c/0x340 (unreliable) __add_memory+0x5c/0xf0 dlpar_add_lmb+0x1b4/0x500 dlpar_memory+0x1f8/0xb80 handle_dlpar_errorlog+0xc0/0x190 dlpar_store+0x198/0x4a0 kobj_attr_store+0x30/0x50 sysfs_kf_write+0x64/0x90 kernfs_fop_write+0x1b0/0x290 vfs_write+0xe8/0x290 ksys_write+0xdc/0x130 system_call_exception+0x160/0x270 system_call_common+0xf0/0x27c This patch addresses the root cause by not relying on the system_state value to detect whether the call is due to a hot-plug operation. An extra parameter is added to link_mem_sections() detailing whether the operation is due to a hot-plug operation. [1] According to Oscar Salvador, using this qemu command line, ACPI memory hotplug operations are raised at SYSTEM_SCHEDULING state: $QEMU -enable-kvm -machine pc -smp 4,sockets=4,cores=1,threads=1 -cpu host -monitor pty \ -m size=$MEM,slots=255,maxmem=4294967296k \ -numa node,nodeid=0,cpus=0-3,mem=512 -numa node,nodeid=1,mem=512 \ -object memory-backend-ram,id=memdimm0,size=134217728 -device pc-dimm,node=0,memdev=memdimm0,id=dimm0,slot=0 \ -object memory-backend-ram,id=memdimm1,size=134217728 -device pc-dimm,node=0,memdev=memdimm1,id=dimm1,slot=1 \ -object memory-backend-ram,id=memdimm2,size=134217728 -device pc-dimm,node=0,memdev=memdimm2,id=dimm2,slot=2 \ -object memory-backend-ram,id=memdimm3,size=134217728 -device pc-dimm,node=0,memdev=memdimm3,id=dimm3,slot=3 \ -object memory-backend-ram,id=memdimm4,size=134217728 -device pc-dimm,node=1,memdev=memdimm4,id=dimm4,slot=4 \ -object memory-backend-ram,id=memdimm5,size=134217728 -device pc-dimm,node=1,memdev=memdimm5,id=dimm5,slot=5 \ -object memory-backend-ram,id=memdimm6,size=134217728 -device pc-dimm,node=1,memdev=memdimm6,id=dimm6,slot=6 \ Fixes: 4fbce633910e ("mm/memory_hotplug.c: make register_mem_sect_under_node() a callback of walk_memory_range()") Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Nathan Lynch <nathanl@linux.ibm.com> Cc: Scott Cheloha <cheloha@linux.ibm.com> Cc: Tony Luck <tony.luck@intel.com> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20200915094143.79181-3-ldufour@linux.ibm.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-09-26mm: replace memmap_context by meminit_contextLaurent Dufour5-13/+18
Patch series "mm: fix memory to node bad links in sysfs", v3. Sometimes, firmware may expose interleaved memory layout like this: Early memory node ranges node 1: [mem 0x0000000000000000-0x000000011fffffff] node 2: [mem 0x0000000120000000-0x000000014fffffff] node 1: [mem 0x0000000150000000-0x00000001ffffffff] node 0: [mem 0x0000000200000000-0x000000048fffffff] node 2: [mem 0x0000000490000000-0x00000007ffffffff] In that case, we can see memory blocks assigned to multiple nodes in sysfs: $ ls -l /sys/devices/system/memory/memory21 total 0 lrwxrwxrwx 1 root root 0 Aug 24 05:27 node1 -> ../../node/node1 lrwxrwxrwx 1 root root 0 Aug 24 05:27 node2 -> ../../node/node2 -rw-r--r-- 1 root root 65536 Aug 24 05:27 online -r--r--r-- 1 root root 65536 Aug 24 05:27 phys_device -r--r--r-- 1 root root 65536 Aug 24 05:27 phys_index drwxr-xr-x 2 root root 0 Aug 24 05:27 power -r--r--r-- 1 root root 65536 Aug 24 05:27 removable -rw-r--r-- 1 root root 65536 Aug 24 05:27 state lrwxrwxrwx 1 root root 0 Aug 24 05:25 subsystem -> ../../../../bus/memory -rw-r--r-- 1 root root 65536 Aug 24 05:25 uevent -r--r--r-- 1 root root 65536 Aug 24 05:27 valid_zones The same applies in the node's directory with a memory21 link in both the node1 and node2's directory. This is wrong but doesn't prevent the system to run. However when later, one of these memory blocks is hot-unplugged and then hot-plugged, the system is detecting an inconsistency in the sysfs layout and a BUG_ON() is raised: kernel BUG at /Users/laurent/src/linux-ppc/mm/memory_hotplug.c:1084! LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries Modules linked in: rpadlpar_io rpaphp pseries_rng rng_core vmx_crypto gf128mul binfmt_misc ip_tables x_tables xfs libcrc32c crc32c_vpmsum autofs4 CPU: 8 PID: 10256 Comm: drmgr Not tainted 5.9.0-rc1+ #25 Call Trace: add_memory_resource+0x23c/0x340 (unreliable) __add_memory+0x5c/0xf0 dlpar_add_lmb+0x1b4/0x500 dlpar_memory+0x1f8/0xb80 handle_dlpar_errorlog+0xc0/0x190 dlpar_store+0x198/0x4a0 kobj_attr_store+0x30/0x50 sysfs_kf_write+0x64/0x90 kernfs_fop_write+0x1b0/0x290 vfs_write+0xe8/0x290 ksys_write+0xdc/0x130 system_call_exception+0x160/0x270 system_call_common+0xf0/0x27c This has been seen on PowerPC LPAR. The root cause of this issue is that when node's memory is registered, the range used can overlap another node's range, thus the memory block is registered to multiple nodes in sysfs. There are two issues here: (a) The sysfs memory and node's layouts are broken due to these multiple links (b) The link errors in link_mem_sections() should not lead to a system panic. To address (a) register_mem_sect_under_node should not rely on the system state to detect whether the link operation is triggered by a hot plug operation or not. This is addressed by the patches 1 and 2 of this series. Issue (b) will be addressed separately. This patch (of 2): The memmap_context enum is used to detect whether a memory operation is due to a hot-add operation or happening at boot time. Make it general to the hotplug operation and rename it as meminit_context. There is no functional change introduced by this patch Suggested-by: David Hildenbrand <david@redhat.com> Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J . Wysocki" <rafael@kernel.org> Cc: Nathan Lynch <nathanl@linux.ibm.com> Cc: Scott Cheloha <cheloha@linux.ibm.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20200915094143.79181-1-ldufour@linux.ibm.com Link: https://lkml.kernel.org/r/20200915132624.9723-1-ldufour@linux.ibm.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-09-26arch/x86/lib/usercopy_64.c: fix __copy_user_flushcache() cache writebackMikulas Patocka1-1/+1
If we copy less than 8 bytes and if the destination crosses a cache line, __copy_user_flushcache would invalidate only the first cache line. This patch makes it invalidate the second cache line as well. Fixes: 0aed55af88345b ("x86, uaccess: introduce copy_from_iter_flushcache for pmem / cache-bypass operations") Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Dan Williams <dan.j.wiilliams@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/alpine.LRH.2.02.2009161451140.21915@file01.intranet.prod.int.rdu2.redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-09-26lib/memregion.c: include memregion.hJason Yan1-0/+1
This addresses the following sparse warning: lib/memregion.c:8:5: warning: symbol 'memregion_alloc' was not declared. Should it be static? lib/memregion.c:14:6: warning: symbol 'memregion_free' was not declared. Should it be static? Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Jason Yan <yanaijie@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: https://lkml.kernel.org/r/20200921142852.875312-1-yanaijie@huawei.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-09-26lib/string.c: implement stpcpyNick Desaulniers1-0/+24
LLVM implemented a recent "libcall optimization" that lowers calls to `sprintf(dest, "%s", str)` where the return value is used to `stpcpy(dest, str) - dest`. This generally avoids the machinery involved in parsing format strings. `stpcpy` is just like `strcpy` except it returns the pointer to the new tail of `dest`. This optimization was introduced into clang-12. Implement this so that we don't observe linkage failures due to missing symbol definitions for `stpcpy`. Similar to last year's fire drill with: commit 5f074f3e192f ("lib/string.c: implement a basic bcmp") The kernel is somewhere between a "freestanding" environment (no full libc) and "hosted" environment (many symbols from libc exist with the same type, function signature, and semantics). As Peter Anvin notes, there's not really a great way to inform the compiler that you're targeting a freestanding environment but would like to opt-in to some libcall optimizations (see pr/47280 below), rather than opt-out. Arvind notes, -fno-builtin-* behaves slightly differently between GCC and Clang, and Clang is missing many __builtin_* definitions, which I consider a bug in Clang and am working on fixing. Masahiro summarizes the subtle distinction between compilers justly: To prevent transformation from foo() into bar(), there are two ways in Clang to do that; -fno-builtin-foo, and -fno-builtin-bar. There is only one in GCC; -fno-buitin-foo. (Any difference in that behavior in Clang is likely a bug from a missing __builtin_* definition.) Masahiro also notes: We want to disable optimization from foo() to bar(), but we may still benefit from the optimization from foo() into something else. If GCC implements the same transform, we would run into a problem because it is not -fno-builtin-bar, but -fno-builtin-foo that disables that optimization. In this regard, -fno-builtin-foo would be more future-proof than -fno-built-bar, but -fno-builtin-foo is still potentially overkill. We may want to prevent calls from foo() being optimized into calls to bar(), but we still may want other optimization on calls to foo(). It seems that compilers today don't quite provide the fine grain control over which libcall optimizations pseudo-freestanding environments would prefer. Finally, Kees notes that this interface is unsafe, so we should not encourage its use. As such, I've removed the declaration from any header, but it still needs to be exported to avoid linkage errors in modules. Reported-by: Sami Tolvanen <samitolvanen@google.com> Suggested-by: Andy Lavr <andy.lavr@gmail.com> Suggested-by: Arvind Sankar <nivedita@alum.mit.edu> Suggested-by: Joe Perches <joe@perches.com> Suggested-by: Kees Cook <keescook@chromium.org> Suggested-by: Masahiro Yamada <masahiroy@kernel.org> Suggested-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Tested-by: Nathan Chancellor <natechancellor@gmail.com> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20200914161643.938408-1-ndesaulniers@google.com Link: https://bugs.llvm.org/show_bug.cgi?id=47162 Link: https://bugs.llvm.org/show_bug.cgi?id=47280 Link: https://github.com/ClangBuiltLinux/linux/issues/1126 Link: https://man7.org/linux/man-pages/man3/stpcpy.3.html Link: https://pubs.opengroup.org/onlinepubs/9699919799/functions/stpcpy.html Link: https://reviews.llvm.org/D85963 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-09-26mm/migrate: correct thp migration statsZi Yan1-4/+3
PageTransHuge returns true for both thp and hugetlb, so thp stats was counting both thp and hugetlb migrations. Exclude hugetlb migration by setting is_thp variable right. Clean up thp handling code too when we are there. Fixes: 1a5bae25e3cf ("mm/vmstat: add events for THP migration without split") Signed-off-by: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Link: https://lkml.kernel.org/r/20200917210413.1462975-1-zi.yan@sent.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-09-26mm/gup: fix gup_fast with dynamic page table foldingVasily Gorbik3-21/+49
Currently to make sure that every page table entry is read just once gup_fast walks perform READ_ONCE and pass pXd value down to the next gup_pXd_range function by value e.g.: static int gup_pud_range(p4d_t p4d, unsigned long addr, unsigned long end, unsigned int flags, struct page **pages, int *nr) ... pudp = pud_offset(&p4d, addr); This function passes a reference on that local value copy to pXd_offset, and might get the very same pointer in return. This happens when the level is folded (on most arches), and that pointer should not be iterated. On s390 due to the fact that each task might have different 5,4 or 3-level address translation and hence different levels folded the logic is more complex and non-iteratable pointer to a local copy leads to severe problems. Here is an example of what happens with gup_fast on s390, for a task with 3-level paging, crossing a 2 GB pud boundary: // addr = 0x1007ffff000, end = 0x10080001000 static int gup_pud_range(p4d_t p4d, unsigned long addr, unsigned long end, unsigned int flags, struct page **pages, int *nr) { unsigned long next; pud_t *pudp; // pud_offset returns &p4d itself (a pointer to a value on stack) pudp = pud_offset(&p4d, addr); do { // on second iteratation reading "random" stack value pud_t pud = READ_ONCE(*pudp); // next = 0x10080000000, due to PUD_SIZE/MASK != PGDIR_SIZE/MASK on s390 next = pud_addr_end(addr, end); ... } while (pudp++, addr = next, addr != end); // pudp++ iterating over stack return 1; } This happens since s390 moved to common gup code with commit d1874a0c2805 ("s390/mm: make the pxd_offset functions more robust") and commit 1a42010cdc26 ("s390/mm: convert to the generic get_user_pages_fast code"). s390 tried to mimic static level folding by changing pXd_offset primitives to always calculate top level page table offset in pgd_offset and just return the value passed when pXd_offset has to act as folded. What is crucial for gup_fast and what has been overlooked is that PxD_SIZE/MASK and thus pXd_addr_end should also change correspondingly. And the latter is not possible with dynamic folding. To fix the issue in addition to pXd values pass original pXdp pointers down to gup_pXd_range functions. And introduce pXd_offset_lockless helpers, which take an additional pXd entry value parameter. This has already been discussed in https://lkml.kernel.org/r/20190418100218.0a4afd51@mschwideX1 Fixes: 1a42010cdc26 ("s390/mm: convert to the generic get_user_pages_fast code") Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: <stable@vger.kernel.org> [5.2+] Link: https://lkml.kernel.org/r/patch.git-943f1e5dcff2.your-ad-here.call-01599856292-ext-8676@work.hours Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-09-26mm: memcontrol: fix missing suffix of workingset_restoreMuchun Song2-9/+20
We forget to add the suffix to the workingset_restore string, so fix it. And also update the documentation of cgroup-v2.rst. Fixes: 170b04b7ae49 ("mm/workingset: prepare the workingset detection infrastructure for anon LRU") Signed-off-by: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Shakeel Butt <shakeelb@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Tejun Heo <tj@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Roman Gushchin <guro@fb.com> Cc: Randy Dunlap <rdunlap@infradead.org> Link: https://lkml.kernel.org/r/20200916100030.71698-1-songmuchun@bytedance.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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