From: Yulei Zhang <yuleixzhang@xxxxxxxxxxx> dmemfs register the mce handler, send signal to the procs whose vma is mapped in mce pfn. Signed-off-by: Haiwei Li <lihaiwei@xxxxxxxxxxx> Signed-off-by: Yulei Zhang <yuleixzhang@xxxxxxxxxxx> --- fs/dmemfs/inode.c | 141 +++++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/dmem.h | 7 +++ include/linux/mm.h | 2 + mm/dmem.c | 34 +++++++++++++ mm/memory-failure.c | 64 ++++++++++++++++------- 5 files changed, 231 insertions(+), 17 deletions(-) diff --git a/fs/dmemfs/inode.c b/fs/dmemfs/inode.c index f698b9d..4303bcdc 100644 --- a/fs/dmemfs/inode.c +++ b/fs/dmemfs/inode.c @@ -36,6 +36,47 @@ static uint __read_mostly max_alloc_try_dpages = 1; +struct dmemfs_inode { + struct inode *inode; + struct list_head link; +}; + +static LIST_HEAD(dmemfs_inode_list); +static DEFINE_SPINLOCK(dmemfs_inode_lock); + +static struct dmemfs_inode * +dmemfs_create_dmemfs_inode(struct inode *inode) +{ + struct dmemfs_inode *dmemfs_inode; + + spin_lock(&dmemfs_inode_lock); + dmemfs_inode = kmalloc(sizeof(struct dmemfs_inode), GFP_NOIO); + if (!dmemfs_inode) { + pr_err("DMEMFS: Out of memory while getting dmemfs inode\n"); + goto out; + } + dmemfs_inode->inode = inode; + list_add_tail(&dmemfs_inode->link, &dmemfs_inode_list); +out: + spin_unlock(&dmemfs_inode_lock); + return dmemfs_inode; +} + +static void dmemfs_delete_dmemfs_inode(struct inode *inode) +{ + struct dmemfs_inode *i, *next; + + spin_lock(&dmemfs_inode_lock); + list_for_each_entry_safe(i, next, &dmemfs_inode_list, link) { + if (i->inode == inode) { + list_del(&i->link); + kfree(i); + break; + } + } + spin_unlock(&dmemfs_inode_lock); +} + struct dmemfs_mount_opts { unsigned long dpage_size; }; @@ -218,6 +259,13 @@ static unsigned long dmem_pgoff_to_index(struct inode *inode, pgoff_t pgoff) return pgoff >> (sb->s_blocksize_bits - PAGE_SHIFT); } +static pgoff_t dmem_index_to_pgoff(struct inode *inode, unsigned long index) +{ + struct super_block *sb = inode->i_sb; + + return index << (sb->s_blocksize_bits - PAGE_SHIFT); +} + static void *dmem_addr_to_entry(struct inode *inode, phys_addr_t addr) { struct super_block *sb = inode->i_sb; @@ -806,6 +854,23 @@ static void dmemfs_evict_inode(struct inode *inode) clear_inode(inode); } +static struct inode *dmemfs_alloc_inode(struct super_block *sb) +{ + struct inode *inode; + + inode = alloc_inode_nonrcu(); + if (inode) + dmemfs_create_dmemfs_inode(inode); + return inode; +} + +static void dmemfs_destroy_inode(struct inode *inode) +{ + if (inode) + dmemfs_delete_dmemfs_inode(inode); + free_inode_nonrcu(inode); +} + /* * Display the mount options in /proc/mounts. */ @@ -819,9 +884,11 @@ static int dmemfs_show_options(struct seq_file *m, struct dentry *root) } static const struct super_operations dmemfs_ops = { + .alloc_inode = dmemfs_alloc_inode, .statfs = dmemfs_statfs, .evict_inode = dmemfs_evict_inode, .drop_inode = generic_delete_inode, + .destroy_inode = dmemfs_destroy_inode, .show_options = dmemfs_show_options, }; @@ -901,17 +968,91 @@ static void dmemfs_kill_sb(struct super_block *sb) .kill_sb = dmemfs_kill_sb, }; +static struct inode * +dmemfs_find_inode_by_addr(phys_addr_t addr, pgoff_t *pgoff) +{ + struct dmemfs_inode *di; + struct inode *inode; + struct address_space *mapping; + void *entry, **slot; + void *mce_entry; + + list_for_each_entry(di, &dmemfs_inode_list, link) { + inode = di->inode; + mapping = inode->i_mapping; + mce_entry = dmem_addr_to_entry(inode, addr); + XA_STATE(xas, &mapping->i_pages, 0); + rcu_read_lock(); + + xas_for_each(&xas, entry, ULONG_MAX) { + if (xas_retry(&xas, entry)) + continue; + + if (unlikely(entry != xas_reload(&xas))) + goto retry; + + if (mce_entry != entry) + continue; + *pgoff = dmem_index_to_pgoff(inode, xas.xa_index); + rcu_read_unlock(); + return inode; +retry: + xas_reset(&xas); + } + rcu_read_unlock(); + } + return NULL; +} + +static int dmemfs_mce_handler(struct notifier_block *this, unsigned long pfn, + void *v) +{ + struct dmem_mce_notifier_info *info = + (struct dmem_mce_notifier_info *)v; + int flags = info->flags; + struct inode *inode; + phys_addr_t mce_addr = __pfn_to_phys(pfn); + pgoff_t pgoff; + + spin_lock(&dmemfs_inode_lock); + inode = dmemfs_find_inode_by_addr(mce_addr, &pgoff); + if (!inode || !atomic_read(&inode->i_count)) + goto out; + + collect_procs_and_signal_inode(inode, pgoff, pfn, flags); +out: + spin_unlock(&dmemfs_inode_lock); + return 0; +} + +static struct notifier_block dmemfs_mce_notifier = { + .notifier_call = dmemfs_mce_handler, +}; + static int __init dmemfs_init(void) { int ret; + pr_info("dmemfs initialized\n"); ret = register_filesystem(&dmemfs_fs_type); + if (ret) + goto reg_fs_fail; + + ret = dmem_register_mce_notifier(&dmemfs_mce_notifier); + if (ret) + goto reg_notifier_fail; + return 0; + +reg_notifier_fail: + unregister_filesystem(&dmemfs_fs_type); +reg_fs_fail: return ret; } static void __exit dmemfs_uninit(void) { + dmem_unregister_mce_notifier(&dmemfs_mce_notifier); unregister_filesystem(&dmemfs_fs_type); } diff --git a/include/linux/dmem.h b/include/linux/dmem.h index cd17a91..fe0b270 100644 --- a/include/linux/dmem.h +++ b/include/linux/dmem.h @@ -23,6 +23,13 @@ #define dmem_free_page(addr) dmem_free_pages(addr, 1) bool dmem_memory_failure(unsigned long pfn, int flags); + +struct dmem_mce_notifier_info { + int flags; +}; + +int dmem_register_mce_notifier(struct notifier_block *nb); +int dmem_unregister_mce_notifier(struct notifier_block *nb); #else static inline int dmem_reserve_init(void) { diff --git a/include/linux/mm.h b/include/linux/mm.h index 2f3135fe..fa20f9c 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -3041,6 +3041,8 @@ enum mf_flags { extern void memory_failure_queue(unsigned long pfn, int flags); extern void memory_failure_queue_kick(int cpu); extern int unpoison_memory(unsigned long pfn); +extern void collect_procs_and_signal_inode(struct inode *inode, pgoff_t pgoff, + unsigned long pfn, int flags); extern int sysctl_memory_failure_early_kill; extern int sysctl_memory_failure_recovery; extern void shake_page(struct page *p, int access); diff --git a/mm/dmem.c b/mm/dmem.c index 16438db..dd81b24 100644 --- a/mm/dmem.c +++ b/mm/dmem.c @@ -70,6 +70,7 @@ struct dmem_node { struct dmem_pool { struct mutex lock; + struct raw_notifier_head mce_notifier_chain; unsigned long region_num; unsigned long registered_pages; @@ -92,6 +93,7 @@ struct dmem_pool { static struct dmem_pool dmem_pool = { .lock = __MUTEX_INITIALIZER(dmem_pool.lock), + .mce_notifier_chain = RAW_NOTIFIER_INIT(dmem_pool.mce_notifier_chain), }; #define DMEM_PAGE_SIZE (1UL << dmem_pool.dpage_shift) @@ -121,6 +123,35 @@ struct dmem_pool { #define for_each_dmem_region(_dnode, _dregion) \ list_for_each_entry(_dregion, &(_dnode)->regions, node) +int dmem_register_mce_notifier(struct notifier_block *nb) +{ + int ret; + + mutex_lock(&dmem_pool.lock); + ret = raw_notifier_chain_register(&dmem_pool.mce_notifier_chain, nb); + mutex_unlock(&dmem_pool.lock); + return ret; +} +EXPORT_SYMBOL(dmem_register_mce_notifier); + +int dmem_unregister_mce_notifier(struct notifier_block *nb) +{ + int ret; + + mutex_lock(&dmem_pool.lock); + ret = raw_notifier_chain_unregister(&dmem_pool.mce_notifier_chain, nb); + mutex_unlock(&dmem_pool.lock); + return ret; +} +EXPORT_SYMBOL(dmem_unregister_mce_notifier); + +static int dmem_mce_notify(unsigned long pfn, + struct dmem_mce_notifier_info *info) +{ + return raw_notifier_call_chain(&dmem_pool.mce_notifier_chain, + pfn, info); +} + static inline int *dmem_nodelist(int nid) { return nid_to_dnode(nid)->nodelist; @@ -1003,6 +1034,7 @@ bool dmem_memory_failure(unsigned long pfn, int flags) u64 pos; phys_addr_t addr = __pfn_to_phys(pfn); bool used = false; + struct dmem_mce_notifier_info info; dregion = find_dmem_region(addr, &pdnode); if (!dregion) @@ -1022,6 +1054,8 @@ bool dmem_memory_failure(unsigned long pfn, int flags) pos = phys_to_dpage(addr) - dregion->dpage_start_pfn; if (__test_and_set_bit(pos, dregion->bitmap)) { used = true; + info.flags = flags; + dmem_mce_notify(pfn, &info); } else { pr_info("MCE: free dpage, mark %#lx disabled in dmem\n", pfn); dnode_count_free_dpages(pdnode, -1); diff --git a/mm/memory-failure.c b/mm/memory-failure.c index dda45d2..3aa7fe7 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -334,8 +334,8 @@ static unsigned long dev_pagemap_mapping_shift(struct page *page, * Uses GFP_ATOMIC allocations to avoid potential recursions in the VM. */ static void add_to_kill(struct task_struct *tsk, struct page *p, - struct vm_area_struct *vma, - struct list_head *to_kill) + struct vm_area_struct *vma, unsigned long pfn, + pgoff_t pgoff, struct list_head *to_kill) { struct to_kill *tk; @@ -345,12 +345,17 @@ static void add_to_kill(struct task_struct *tsk, struct page *p, return; } - tk->addr = page_address_in_vma(p, vma); - if (is_zone_device_page(p)) - tk->size_shift = dev_pagemap_mapping_shift(p, vma); - else - tk->size_shift = page_shift(compound_head(p)); - + if (p) { + tk->addr = page_address_in_vma(p, vma); + if (is_zone_device_page(p)) + tk->size_shift = dev_pagemap_mapping_shift(p, vma); + else + tk->size_shift = page_shift(compound_head(p)); + } else { + tk->size_shift = PAGE_SHIFT; + tk->addr = vma->vm_start + + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT); + } /* * Send SIGKILL if "tk->addr == -EFAULT". Also, as * "tk->size_shift" is always non-zero for !is_zone_device_page(), @@ -363,7 +368,7 @@ static void add_to_kill(struct task_struct *tsk, struct page *p, */ if (tk->addr == -EFAULT) { pr_info("Memory failure: Unable to find user space address %lx in %s\n", - page_to_pfn(p), tsk->comm); + pfn, tsk->comm); } else if (tk->size_shift == 0) { kfree(tk); return; @@ -496,7 +501,8 @@ static void collect_procs_anon(struct page *page, struct list_head *to_kill, if (!page_mapped_in_vma(page, vma)) continue; if (vma->vm_mm == t->mm) - add_to_kill(t, page, vma, to_kill); + add_to_kill(t, page, vma, page_to_pfn(page), + page_to_pgoff(page), to_kill); } } read_unlock(&tasklist_lock); @@ -504,19 +510,17 @@ static void collect_procs_anon(struct page *page, struct list_head *to_kill, } /* - * Collect processes when the error hit a file mapped page. + * Collect processes when the error hit a file mapped memory. */ -static void collect_procs_file(struct page *page, struct list_head *to_kill, - int force_early) +static void __collect_procs_file(struct address_space *mapping, pgoff_t pgoff, + struct page *page, unsigned long pfn, + struct list_head *to_kill, int force_early) { struct vm_area_struct *vma; struct task_struct *tsk; - struct address_space *mapping = page->mapping; - pgoff_t pgoff; i_mmap_lock_read(mapping); read_lock(&tasklist_lock); - pgoff = page_to_pgoff(page); for_each_process(tsk) { struct task_struct *t = task_early_kill(tsk, force_early); @@ -532,7 +536,7 @@ static void collect_procs_file(struct page *page, struct list_head *to_kill, * to be informed of all such data corruptions. */ if (vma->vm_mm == t->mm) - add_to_kill(t, page, vma, to_kill); + add_to_kill(t, page, vma, pfn, pgoff, to_kill); } } read_unlock(&tasklist_lock); @@ -540,6 +544,32 @@ static void collect_procs_file(struct page *page, struct list_head *to_kill, } /* + * Collect processes when the error hit a file mapped page. + */ +static void collect_procs_file(struct page *page, struct list_head *to_kill, + int force_early) +{ + struct address_space *mapping = page->mapping; + + __collect_procs_file(mapping, page_to_pgoff(page), page, + page_to_pfn(page), to_kill, force_early); +} + +void collect_procs_and_signal_inode(struct inode *inode, pgoff_t pgoff, + unsigned long pfn, int flags) +{ + int forcekill; + struct address_space *mapping = &inode->i_data; + LIST_HEAD(tokill); + + __collect_procs_file(mapping, pgoff, NULL, pfn, &tokill, + flags & MF_ACTION_REQUIRED); + forcekill = flags & MF_MUST_KILL; + kill_procs(&tokill, forcekill, false, pfn, flags); +} +EXPORT_SYMBOL(collect_procs_and_signal_inode); + +/* * Collect the processes who have the corrupted page mapped to kill. */ static void collect_procs(struct page *page, struct list_head *tokill, -- 1.8.3.1