From f1653c2e2831e9db6cd68473bbec581782df03a5 Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Fri, 6 Aug 2021 11:05:37 -0700 Subject: xfs: introduce CPU hotplug infrastructure We need to move to per-cpu state for both deferred inode inactivation and CIL tracking, but to do that we need to handle CPUs being removed from the system by the hot-plug code. Introduce generic XFS infrastructure to handle CPU hotplug events that is set up at module init time and torn down at module exit time. Initially, we only need CPU dead notifications, so we only set up a callback for these notifications. The infrastructure can be updated in future for other CPU hotplug state machine notifications easily if ever needed. Signed-off-by: Dave Chinner [djwong: rearrange some macros, fix function prototypes] Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- include/linux/cpuhotplug.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index f39b34b13871..439adc05be4e 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -52,6 +52,7 @@ enum cpuhp_state { CPUHP_FS_BUFF_DEAD, CPUHP_PRINTK_DEAD, CPUHP_MM_MEMCQ_DEAD, + CPUHP_XFS_DEAD, CPUHP_PERCPU_CNT_DEAD, CPUHP_RADIX_DEAD, CPUHP_PAGE_ALLOC, -- cgit v1.2.3 From de2860f4636256836450c6543be744a50118fc66 Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Mon, 9 Aug 2021 10:10:00 -0700 Subject: mm: Add kvrealloc() During log recovery of an XFS filesystem with 64kB directory buffers, rebuilding a buffer split across two log records results in a memory allocation warning from krealloc like this: xfs filesystem being mounted at /mnt/scratch supports timestamps until 2038 (0x7fffffff) XFS (dm-0): Unmounting Filesystem XFS (dm-0): Mounting V5 Filesystem XFS (dm-0): Starting recovery (logdev: internal) ------------[ cut here ]------------ WARNING: CPU: 5 PID: 3435170 at mm/page_alloc.c:3539 get_page_from_freelist+0xdee/0xe40 ..... RIP: 0010:get_page_from_freelist+0xdee/0xe40 Call Trace: ? complete+0x3f/0x50 __alloc_pages+0x16f/0x300 alloc_pages+0x87/0x110 kmalloc_order+0x2c/0x90 kmalloc_order_trace+0x1d/0x90 __kmalloc_track_caller+0x215/0x270 ? xlog_recover_add_to_cont_trans+0x63/0x1f0 krealloc+0x54/0xb0 xlog_recover_add_to_cont_trans+0x63/0x1f0 xlog_recovery_process_trans+0xc1/0xd0 xlog_recover_process_ophdr+0x86/0x130 xlog_recover_process_data+0x9f/0x160 xlog_recover_process+0xa2/0x120 xlog_do_recovery_pass+0x40b/0x7d0 ? __irq_work_queue_local+0x4f/0x60 ? irq_work_queue+0x3a/0x50 xlog_do_log_recovery+0x70/0x150 xlog_do_recover+0x38/0x1d0 xlog_recover+0xd8/0x170 xfs_log_mount+0x181/0x300 xfs_mountfs+0x4a1/0x9b0 xfs_fs_fill_super+0x3c0/0x7b0 get_tree_bdev+0x171/0x270 ? suffix_kstrtoint.constprop.0+0xf0/0xf0 xfs_fs_get_tree+0x15/0x20 vfs_get_tree+0x24/0xc0 path_mount+0x2f5/0xaf0 __x64_sys_mount+0x108/0x140 do_syscall_64+0x3a/0x70 entry_SYSCALL_64_after_hwframe+0x44/0xae Essentially, we are taking a multi-order allocation from kmem_alloc() (which has an open coded no fail, no warn loop) and then reallocating it out to 64kB using krealloc(__GFP_NOFAIL) and that is then triggering the above warning. This is a regression caused by converting this code from an open coded no fail/no warn reallocation loop to using __GFP_NOFAIL. What we actually need here is kvrealloc(), so that if contiguous page allocation fails we fall back to vmalloc() and we don't get nasty warnings happening in XFS. Fixes: 771915c4f688 ("xfs: remove kmem_realloc()") Signed-off-by: Dave Chinner Acked-by: Mel Gorman Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- include/linux/mm.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux') diff --git a/include/linux/mm.h b/include/linux/mm.h index 7ca22e6e694a..e59646a5d44d 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -829,6 +829,8 @@ static inline void *kvcalloc(size_t n, size_t size, gfp_t flags) return kvmalloc_array(n, size, flags | __GFP_ZERO); } +extern void *kvrealloc(const void *p, size_t oldsize, size_t newsize, + gfp_t flags); extern void kvfree(const void *addr); extern void kvfree_sensitive(const void *addr, size_t len); -- cgit v1.2.3