Orangefs: merge to v4.5

Merge tag 'v4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux into current

Linux 4.5

12 files changed, 252 insertions, 181 deletions

diff --git a/fs/proc/array.c b/fs/proc/array.c
index d73291f5f0fc..b6c00ce0e29e 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -395,7 +395,7 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
 
 	state = *get_task_state(task);
 	vsize = eip = esp = 0;
-	permitted = ptrace_may_access(task, PTRACE_MODE_READ | PTRACE_MODE_NOAUDIT);
+	permitted = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS | PTRACE_MODE_NOAUDIT);
 	mm = get_task_mm(task);
 	if (mm) {
 		vsize = task_vsize(mm);
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 4bd5d3118acd..4f764c2ac1a5 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -403,7 +403,7 @@ static const struct file_operations proc_pid_cmdline_ops = {
 static int proc_pid_auxv(struct seq_file *m, struct pid_namespace *ns,
 			 struct pid *pid, struct task_struct *task)
 {
-	struct mm_struct *mm = mm_access(task, PTRACE_MODE_READ);
+	struct mm_struct *mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
 	if (mm && !IS_ERR(mm)) {
 		unsigned int nwords = 0;
 		do {
@@ -430,7 +430,8 @@ static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns,
 
 	wchan = get_wchan(task);
 
-	if (wchan && ptrace_may_access(task, PTRACE_MODE_READ) && !lookup_symbol_name(wchan, symname))
+	if (wchan && ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)
+			&& !lookup_symbol_name(wchan, symname))
 		seq_printf(m, "%s", symname);
 	else
 		seq_putc(m, '0');
@@ -444,7 +445,7 @@ static int lock_trace(struct task_struct *task)
 	int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
 	if (err)
 		return err;
-	if (!ptrace_may_access(task, PTRACE_MODE_ATTACH)) {
+	if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) {
 		mutex_unlock(&task->signal->cred_guard_mutex);
 		return -EPERM;
 	}
@@ -697,7 +698,7 @@ static int proc_fd_access_allowed(struct inode *inode)
 	 */
 	task = get_proc_task(inode);
 	if (task) {
-		allowed = ptrace_may_access(task, PTRACE_MODE_READ);
+		allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
 		put_task_struct(task);
 	}
 	return allowed;
@@ -732,7 +733,7 @@ static bool has_pid_permissions(struct pid_namespace *pid,
 		return true;
 	if (in_group_p(pid->pid_gid))
 		return true;
-	return ptrace_may_access(task, PTRACE_MODE_READ);
+	return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
 }
 
 
@@ -809,7 +810,7 @@ struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode)
 	struct mm_struct *mm = ERR_PTR(-ESRCH);
 
 	if (task) {
-		mm = mm_access(task, mode);
+		mm = mm_access(task, mode | PTRACE_MODE_FSCREDS);
 		put_task_struct(task);
 
 		if (!IS_ERR_OR_NULL(mm)) {
@@ -952,6 +953,7 @@ static ssize_t environ_read(struct file *file, char __user *buf,
 	unsigned long src = *ppos;
 	int ret = 0;
 	struct mm_struct *mm = file->private_data;
+	unsigned long env_start, env_end;
 
 	if (!mm)
 		return 0;
@@ -963,19 +965,25 @@ static ssize_t environ_read(struct file *file, char __user *buf,
 	ret = 0;
 	if (!atomic_inc_not_zero(&mm->mm_users))
 		goto free;
+
+	down_read(&mm->mmap_sem);
+	env_start = mm->env_start;
+	env_end = mm->env_end;
+	up_read(&mm->mmap_sem);
+
 	while (count > 0) {
 		size_t this_len, max_len;
 		int retval;
 
-		if (src >= (mm->env_end - mm->env_start))
+		if (src >= (env_end - env_start))
 			break;
 
-		this_len = mm->env_end - (mm->env_start + src);
+		this_len = env_end - (env_start + src);
 
 		max_len = min_t(size_t, PAGE_SIZE, count);
 		this_len = min(max_len, this_len);
 
-		retval = access_remote_vm(mm, (mm->env_start + src),
+		retval = access_remote_vm(mm, (env_start + src),
 			page, this_len, 0);
 
 		if (retval <= 0) {
@@ -1564,12 +1572,16 @@ static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
 		return -ENOENT;
 }
 
-static const char *proc_pid_follow_link(struct dentry *dentry, void **cookie)
+static const char *proc_pid_get_link(struct dentry *dentry,
+				     struct inode *inode,
+				     struct delayed_call *done)
 {
-	struct inode *inode = d_inode(dentry);
 	struct path path;
 	int error = -EACCES;
 
+	if (!dentry)
+		return ERR_PTR(-ECHILD);
+
 	/* Are we allowed to snoop on the tasks file descriptors? */
 	if (!proc_fd_access_allowed(inode))
 		goto out;
@@ -1630,7 +1642,7 @@ out:
 
 const struct inode_operations proc_pid_link_inode_operations = {
 	.readlink	= proc_pid_readlink,
-	.follow_link	= proc_pid_follow_link,
+	.get_link	= proc_pid_get_link,
 	.setattr	= proc_setattr,
 };
 
@@ -1856,7 +1868,7 @@ static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
 	if (!task)
 		goto out_notask;
 
-	mm = mm_access(task, PTRACE_MODE_READ);
+	mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
 	if (IS_ERR_OR_NULL(mm))
 		goto out;
 
@@ -1895,7 +1907,7 @@ static const struct dentry_operations tid_map_files_dentry_operations = {
 	.d_delete	= pid_delete_dentry,
 };
 
-static int proc_map_files_get_link(struct dentry *dentry, struct path *path)
+static int map_files_get_link(struct dentry *dentry, struct path *path)
 {
 	unsigned long vm_start, vm_end;
 	struct vm_area_struct *vma;
@@ -1945,20 +1957,22 @@ struct map_files_info {
  * path to the file in question.
  */
 static const char *
-proc_map_files_follow_link(struct dentry *dentry, void **cookie)
+proc_map_files_get_link(struct dentry *dentry,
+			struct inode *inode,
+		        struct delayed_call *done)
 {
 	if (!capable(CAP_SYS_ADMIN))
 		return ERR_PTR(-EPERM);
 
-	return proc_pid_follow_link(dentry, NULL);
+	return proc_pid_get_link(dentry, inode, done);
 }
 
 /*
- * Identical to proc_pid_link_inode_operations except for follow_link()
+ * Identical to proc_pid_link_inode_operations except for get_link()
  */
 static const struct inode_operations proc_map_files_link_inode_operations = {
 	.readlink	= proc_pid_readlink,
-	.follow_link	= proc_map_files_follow_link,
+	.get_link	= proc_map_files_get_link,
 	.setattr	= proc_setattr,
 };
 
@@ -1975,7 +1989,7 @@ proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
 		return -ENOENT;
 
 	ei = PROC_I(inode);
-	ei->op.proc_get_link = proc_map_files_get_link;
+	ei->op.proc_get_link = map_files_get_link;
 
 	inode->i_op = &proc_map_files_link_inode_operations;
 	inode->i_size = 64;
@@ -2007,7 +2021,7 @@ static struct dentry *proc_map_files_lookup(struct inode *dir,
 		goto out;
 
 	result = -EACCES;
-	if (!ptrace_may_access(task, PTRACE_MODE_READ))
+	if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
 		goto out_put_task;
 
 	result = -ENOENT;
@@ -2060,7 +2074,7 @@ proc_map_files_readdir(struct file *file, struct dir_context *ctx)
 		goto out;
 
 	ret = -EACCES;
-	if (!ptrace_may_access(task, PTRACE_MODE_READ))
+	if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
 		goto out_put_task;
 
 	ret = 0;
@@ -2359,7 +2373,7 @@ static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
 				   size_t count, loff_t *ppos)
 {
 	struct inode * inode = file_inode(file);
-	char *page;
+	void *page;
 	ssize_t length;
 	struct task_struct *task = get_proc_task(inode);
 
@@ -2374,14 +2388,11 @@ static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
 	if (*ppos != 0)
 		goto out;
 
-	length = -ENOMEM;
-	page = (char*)__get_free_page(GFP_TEMPORARY);
-	if (!page)
+	page = memdup_user(buf, count);
+	if (IS_ERR(page)) {
+		length = PTR_ERR(page);
 		goto out;
-
-	length = -EFAULT;
-	if (copy_from_user(page, buf, count))
-		goto out_free;
+	}
 
 	/* Guard against adverse ptrace interaction */
 	length = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
@@ -2390,10 +2401,10 @@ static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
 
 	length = security_setprocattr(task,
 				      (char*)file->f_path.dentry->d_name.name,
-				      (void*)page, count);
+				      page, count);
 	mutex_unlock(&task->signal->cred_guard_mutex);
 out_free:
-	free_page((unsigned long) page);
+	kfree(page);
 out:
 	put_task_struct(task);
 out_no_task:
@@ -2530,7 +2541,7 @@ static int do_io_accounting(struct task_struct *task, struct seq_file *m, int wh
 	if (result)
 		return result;
 
-	if (!ptrace_may_access(task, PTRACE_MODE_READ)) {
+	if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
 		result = -EACCES;
 		goto out_unlock;
 	}
diff --git a/fs/proc/fd.c b/fs/proc/fd.c
index 3c2a915c695a..56afa5ef08f2 100644
--- a/fs/proc/fd.c
+++ b/fs/proc/fd.c
@@ -258,6 +258,7 @@ static int proc_readfd_common(struct file *file, struct dir_context *ctx,
 				     name, len, instantiate, p,
 				     (void *)(unsigned long)fd))
 			goto out_fd_loop;
+		cond_resched();
 		rcu_read_lock();
 	}
 	rcu_read_unlock();
diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index bd95b9fdebb0..42305ddcbaa0 100644
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -95,7 +95,8 @@ void __init proc_init_inodecache(void)
 	proc_inode_cachep = kmem_cache_create("proc_inode_cache",
 					     sizeof(struct proc_inode),
 					     0, (SLAB_RECLAIM_ACCOUNT|
-						SLAB_MEM_SPREAD|SLAB_PANIC),
+						SLAB_MEM_SPREAD|SLAB_ACCOUNT|
+						SLAB_PANIC),
 					     init_once);
 }
 
@@ -393,24 +394,25 @@ static const struct file_operations proc_reg_file_ops_no_compat = {
 };
 #endif
 
-static const char *proc_follow_link(struct dentry *dentry, void **cookie)
+static void proc_put_link(void *p)
 {
-	struct proc_dir_entry *pde = PDE(d_inode(dentry));
-	if (unlikely(!use_pde(pde)))
-		return ERR_PTR(-EINVAL);
-	*cookie = pde;
-	return pde->data;
+	unuse_pde(p);
 }
 
-static void proc_put_link(struct inode *unused, void *p)
+static const char *proc_get_link(struct dentry *dentry,
+				 struct inode *inode,
+				 struct delayed_call *done)
 {
-	unuse_pde(p);
+	struct proc_dir_entry *pde = PDE(inode);
+	if (unlikely(!use_pde(pde)))
+		return ERR_PTR(-EINVAL);
+	set_delayed_call(done, proc_put_link, pde);
+	return pde->data;
 }
 
 const struct inode_operations proc_link_inode_operations = {
 	.readlink	= generic_readlink,
-	.follow_link	= proc_follow_link,
-	.put_link	= proc_put_link,
+	.get_link	= proc_get_link,
 };
 
 struct inode *proc_get_inode(struct super_block *sb, struct proc_dir_entry *de)
diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c
index 92e6726f6e37..a939f5ed7f89 100644
--- a/fs/proc/kcore.c
+++ b/fs/proc/kcore.c
@@ -552,9 +552,9 @@ static int open_kcore(struct inode *inode, struct file *filp)
 	if (kcore_need_update)
 		kcore_update_ram();
 	if (i_size_read(inode) != proc_root_kcore->size) {
-		mutex_lock(&inode->i_mutex);
+		inode_lock(inode);
 		i_size_write(inode, proc_root_kcore->size);
-		mutex_unlock(&inode->i_mutex);
+		inode_unlock(inode);
 	}
 	return 0;
 }
diff --git a/fs/proc/meminfo.c b/fs/proc/meminfo.c
index 9155a5a0d3b9..df4661abadc4 100644
--- a/fs/proc/meminfo.c
+++ b/fs/proc/meminfo.c
@@ -57,11 +57,8 @@ static int meminfo_proc_show(struct seq_file *m, void *v)
 	/*
 	 * Estimate the amount of memory available for userspace allocations,
 	 * without causing swapping.
-	 *
-	 * Free memory cannot be taken below the low watermark, before the
-	 * system starts swapping.
 	 */
-	available = i.freeram - wmark_low;
+	available = i.freeram - totalreserve_pages;
 
 	/*
 	 * Not all the page cache can be freed, otherwise the system will
diff --git a/fs/proc/namespaces.c b/fs/proc/namespaces.c
index f6e8354b8cea..276f12431dbf 100644
--- a/fs/proc/namespaces.c
+++ b/fs/proc/namespaces.c
@@ -30,19 +30,23 @@ static const struct proc_ns_operations *ns_entries[] = {
 	&mntns_operations,
 };
 
-static const char *proc_ns_follow_link(struct dentry *dentry, void **cookie)
+static const char *proc_ns_get_link(struct dentry *dentry,
+				    struct inode *inode,
+				    struct delayed_call *done)
 {
-	struct inode *inode = d_inode(dentry);
 	const struct proc_ns_operations *ns_ops = PROC_I(inode)->ns_ops;
 	struct task_struct *task;
 	struct path ns_path;
 	void *error = ERR_PTR(-EACCES);
 
+	if (!dentry)
+		return ERR_PTR(-ECHILD);
+
 	task = get_proc_task(inode);
 	if (!task)
 		return error;
 
-	if (ptrace_may_access(task, PTRACE_MODE_READ)) {
+	if (ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
 		error = ns_get_path(&ns_path, task, ns_ops);
 		if (!error)
 			nd_jump_link(&ns_path);
@@ -63,7 +67,7 @@ static int proc_ns_readlink(struct dentry *dentry, char __user *buffer, int bufl
 	if (!task)
 		return res;
 
-	if (ptrace_may_access(task, PTRACE_MODE_READ)) {
+	if (ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
 		res = ns_get_name(name, sizeof(name), task, ns_ops);
 		if (res >= 0)
 			res = readlink_copy(buffer, buflen, name);
@@ -74,7 +78,7 @@ static int proc_ns_readlink(struct dentry *dentry, char __user *buffer, int bufl
 
 static const struct inode_operations proc_ns_link_inode_operations = {
 	.readlink	= proc_ns_readlink,
-	.follow_link	= proc_ns_follow_link,
+	.get_link	= proc_ns_get_link,
 	.setattr	= proc_setattr,
 };
 
diff --git a/fs/proc/page.c b/fs/proc/page.c
index 93484034a03d..b2855eea5405 100644
--- a/fs/proc/page.c
+++ b/fs/proc/page.c
@@ -103,9 +103,9 @@ u64 stable_page_flags(struct page *page)
 	 * pseudo flags for the well known (anonymous) memory mapped pages
 	 *
 	 * Note that page->_mapcount is overloaded in SLOB/SLUB/SLQB, so the
-	 * simple test in page_mapped() is not enough.
+	 * simple test in page_mapcount() is not enough.
 	 */
-	if (!PageSlab(page) && page_mapped(page))
+	if (!PageSlab(page) && page_mapcount(page))
 		u |= 1 << KPF_MMAP;
 	if (PageAnon(page))
 		u |= 1 << KPF_ANON;
diff --git a/fs/proc/self.c b/fs/proc/self.c
index 113b8d061fc0..b6a8d3529fea 100644
--- a/fs/proc/self.c
+++ b/fs/proc/self.c
@@ -18,26 +18,28 @@ static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
 	return readlink_copy(buffer, buflen, tmp);
 }
 
-static const char *proc_self_follow_link(struct dentry *dentry, void **cookie)
+static const char *proc_self_get_link(struct dentry *dentry,
+				      struct inode *inode,
+				      struct delayed_call *done)
 {
-	struct pid_namespace *ns = dentry->d_sb->s_fs_info;
+	struct pid_namespace *ns = inode->i_sb->s_fs_info;
 	pid_t tgid = task_tgid_nr_ns(current, ns);
 	char *name;
 
 	if (!tgid)
 		return ERR_PTR(-ENOENT);
 	/* 11 for max length of signed int in decimal + NULL term */
-	name = kmalloc(12, GFP_KERNEL);
-	if (!name)
-		return ERR_PTR(-ENOMEM);
+	name = kmalloc(12, dentry ? GFP_KERNEL : GFP_ATOMIC);
+	if (unlikely(!name))
+		return dentry ? ERR_PTR(-ENOMEM) : ERR_PTR(-ECHILD);
 	sprintf(name, "%d", tgid);
-	return *cookie = name;
+	set_delayed_call(done, kfree_link, name);
+	return name;
 }
 
 static const struct inode_operations proc_self_inode_operations = {
 	.readlink	= proc_self_readlink,
-	.follow_link	= proc_self_follow_link,
-	.put_link	= kfree_put_link,
+	.get_link	= proc_self_get_link,
 };
 
 static unsigned self_inum;
@@ -48,7 +50,7 @@ int proc_setup_self(struct super_block *s)
 	struct pid_namespace *ns = s->s_fs_info;
 	struct dentry *self;
 	
-	mutex_lock(&root_inode->i_mutex);
+	inode_lock(root_inode);
 	self = d_alloc_name(s->s_root, "self");
 	if (self) {
 		struct inode *inode = new_inode_pseudo(s);
@@ -67,7 +69,7 @@ int proc_setup_self(struct super_block *s)
 	} else {
 		self = ERR_PTR(-ENOMEM);
 	}
-	mutex_unlock(&root_inode->i_mutex);
+	inode_unlock(root_inode);
 	if (IS_ERR(self)) {
 		pr_err("proc_fill_super: can't allocate /proc/self\n");
 		return PTR_ERR(self);
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 187b3b5f242e..fa95ab2d3674 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -14,6 +14,7 @@
 #include <linux/swapops.h>
 #include <linux/mmu_notifier.h>
 #include <linux/page_idle.h>
+#include <linux/shmem_fs.h>
 
 #include <asm/elf.h>
 #include <asm/uaccess.h>
@@ -22,9 +23,13 @@
 
 void task_mem(struct seq_file *m, struct mm_struct *mm)
 {
-	unsigned long data, text, lib, swap, ptes, pmds;
+	unsigned long text, lib, swap, ptes, pmds, anon, file, shmem;
 	unsigned long hiwater_vm, total_vm, hiwater_rss, total_rss;
 
+	anon = get_mm_counter(mm, MM_ANONPAGES);
+	file = get_mm_counter(mm, MM_FILEPAGES);
+	shmem = get_mm_counter(mm, MM_SHMEMPAGES);
+
 	/*
 	 * Note: to minimize their overhead, mm maintains hiwater_vm and
 	 * hiwater_rss only when about to *lower* total_vm or rss.  Any
@@ -35,11 +40,10 @@ void task_mem(struct seq_file *m, struct mm_struct *mm)
 	hiwater_vm = total_vm = mm->total_vm;
 	if (hiwater_vm < mm->hiwater_vm)
 		hiwater_vm = mm->hiwater_vm;
-	hiwater_rss = total_rss = get_mm_rss(mm);
+	hiwater_rss = total_rss = anon + file + shmem;
 	if (hiwater_rss < mm->hiwater_rss)
 		hiwater_rss = mm->hiwater_rss;
 
-	data = mm->total_vm - mm->shared_vm - mm->stack_vm;
 	text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK)) >> 10;
 	lib = (mm->exec_vm << (PAGE_SHIFT-10)) - text;
 	swap = get_mm_counter(mm, MM_SWAPENTS);
@@ -52,6 +56,9 @@ void task_mem(struct seq_file *m, struct mm_struct *mm)
 		"VmPin:\t%8lu kB\n"
 		"VmHWM:\t%8lu kB\n"
 		"VmRSS:\t%8lu kB\n"
+		"RssAnon:\t%8lu kB\n"
+		"RssFile:\t%8lu kB\n"
+		"RssShmem:\t%8lu kB\n"
 		"VmData:\t%8lu kB\n"
 		"VmStk:\t%8lu kB\n"
 		"VmExe:\t%8lu kB\n"
@@ -65,7 +72,10 @@ void task_mem(struct seq_file *m, struct mm_struct *mm)
 		mm->pinned_vm << (PAGE_SHIFT-10),
 		hiwater_rss << (PAGE_SHIFT-10),
 		total_rss << (PAGE_SHIFT-10),
-		data << (PAGE_SHIFT-10),
+		anon << (PAGE_SHIFT-10),
+		file << (PAGE_SHIFT-10),
+		shmem << (PAGE_SHIFT-10),
+		mm->data_vm << (PAGE_SHIFT-10),
 		mm->stack_vm << (PAGE_SHIFT-10), text, lib,
 		ptes >> 10,
 		pmds >> 10,
@@ -82,10 +92,11 @@ unsigned long task_statm(struct mm_struct *mm,
 			 unsigned long *shared, unsigned long *text,
 			 unsigned long *data, unsigned long *resident)
 {
-	*shared = get_mm_counter(mm, MM_FILEPAGES);
+	*shared = get_mm_counter(mm, MM_FILEPAGES) +
+			get_mm_counter(mm, MM_SHMEMPAGES);
 	*text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
 								>> PAGE_SHIFT;
-	*data = mm->total_vm - mm->shared_vm;
+	*data = mm->data_vm + mm->stack_vm;
 	*resident = *shared + get_mm_counter(mm, MM_ANONPAGES);
 	return mm->total_vm;
 }
@@ -248,23 +259,29 @@ static int do_maps_open(struct inode *inode, struct file *file,
 				sizeof(struct proc_maps_private));
 }
 
-static pid_t pid_of_stack(struct proc_maps_private *priv,
-				struct vm_area_struct *vma, bool is_pid)
+/*
+ * Indicate if the VMA is a stack for the given task; for
+ * /proc/PID/maps that is the stack of the main task.
+ */
+static int is_stack(struct proc_maps_private *priv,
+		    struct vm_area_struct *vma, int is_pid)
 {
-	struct inode *inode = priv->inode;
-	struct task_struct *task;
-	pid_t ret = 0;
+	int stack = 0;
 
-	rcu_read_lock();
-	task = pid_task(proc_pid(inode), PIDTYPE_PID);
-	if (task) {
-		task = task_of_stack(task, vma, is_pid);
+	if (is_pid) {
+		stack = vma->vm_start <= vma->vm_mm->start_stack &&
+			vma->vm_end >= vma->vm_mm->start_stack;
+	} else {
+		struct inode *inode = priv->inode;
+		struct task_struct *task;
+
+		rcu_read_lock();
+		task = pid_task(proc_pid(inode), PIDTYPE_PID);
 		if (task)
-			ret = task_pid_nr_ns(task, inode->i_sb->s_fs_info);
+			stack = vma_is_stack_for_task(vma, task);
+		rcu_read_unlock();
 	}
-	rcu_read_unlock();
-
-	return ret;
+	return stack;
 }
 
 static void
@@ -324,8 +341,6 @@ show_map_vma(struct seq_file *m, struct vm_area_struct *vma, int is_pid)
 
 	name = arch_vma_name(vma);
 	if (!name) {
-		pid_t tid;
-
 		if (!mm) {
 			name = "[vdso]";
 			goto done;
@@ -337,21 +352,8 @@ show_map_vma(struct seq_file *m, struct vm_area_struct *vma, int is_pid)
 			goto done;
 		}
 
-		tid = pid_of_stack(priv, vma, is_pid);
-		if (tid != 0) {
-			/*
-			 * Thread stack in /proc/PID/task/TID/maps or
-			 * the main process stack.
-			 */
-			if (!is_pid || (vma->vm_start <= mm->start_stack &&
-			    vma->vm_end >= mm->start_stack)) {
-				name = "[stack]";
-			} else {
-				/* Thread stack in /proc/PID/maps */
-				seq_pad(m, ' ');
-				seq_printf(m, "[stack:%d]", tid);
-			}
-		}
+		if (is_stack(priv, vma, is_pid))
+			name = "[stack]";
 	}
 
 done:
@@ -451,12 +453,14 @@ struct mem_size_stats {
 	unsigned long private_hugetlb;
 	u64 pss;
 	u64 swap_pss;
+	bool check_shmem_swap;
 };
 
 static void smaps_account(struct mem_size_stats *mss, struct page *page,
-		unsigned long size, bool young, bool dirty)
+		bool compound, bool young, bool dirty)
 {
-	int mapcount;
+	int i, nr = compound ? 1 << compound_order(page) : 1;
+	unsigned long size = nr * PAGE_SIZE;
 
 	if (PageAnon(page))
 		mss->anonymous += size;
@@ -465,26 +469,53 @@ static void smaps_account(struct mem_size_stats *mss, struct page *page,
 	/* Accumulate the size in pages that have been accessed. */
 	if (young || page_is_young(page) || PageReferenced(page))
 		mss->referenced += size;
-	mapcount = page_mapcount(page);
-	if (mapcount >= 2) {
-		u64 pss_delta;
 
-		if (dirty || PageDirty(page))
-			mss->shared_dirty += size;
-		else
-			mss->shared_clean += size;
-		pss_delta = (u64)size << PSS_SHIFT;
-		do_div(pss_delta, mapcount);
-		mss->pss += pss_delta;
-	} else {
+	/*
+	 * page_count(page) == 1 guarantees the page is mapped exactly once.
+	 * If any subpage of the compound page mapped with PTE it would elevate
+	 * page_count().
+	 */
+	if (page_count(page) == 1) {
 		if (dirty || PageDirty(page))
 			mss->private_dirty += size;
 		else
 			mss->private_clean += size;
 		mss->pss += (u64)size << PSS_SHIFT;
+		return;
+	}
+
+	for (i = 0; i < nr; i++, page++) {
+		int mapcount = page_mapcount(page);
+
+		if (mapcount >= 2) {
+			if (dirty || PageDirty(page))
+				mss->shared_dirty += PAGE_SIZE;
+			else
+				mss->shared_clean += PAGE_SIZE;
+			mss->pss += (PAGE_SIZE << PSS_SHIFT) / mapcount;
+		} else {
+			if (dirty || PageDirty(page))
+				mss->private_dirty += PAGE_SIZE;
+			else
+				mss->private_clean += PAGE_SIZE;
+			mss->pss += PAGE_SIZE << PSS_SHIFT;
+		}
 	}
 }
 
+#ifdef CONFIG_SHMEM
+static int smaps_pte_hole(unsigned long addr, unsigned long end,
+		struct mm_walk *walk)
+{
+	struct mem_size_stats *mss = walk->private;
+
+	mss->swap += shmem_partial_swap_usage(
+			walk->vma->vm_file->f_mapping, addr, end);
+
+	return 0;
+}
+#endif
+
 static void smaps_pte_entry(pte_t *pte, unsigned long addr,
 		struct mm_walk *walk)
 {
@@ -512,11 +543,25 @@ static void smaps_pte_entry(pte_t *pte, unsigned long addr,
 			}
 		} else if (is_migration_entry(swpent))
 			page = migration_entry_to_page(swpent);
+	} else if (unlikely(IS_ENABLED(CONFIG_SHMEM) && mss->check_shmem_swap
+							&& pte_none(*pte))) {
+		page = find_get_entry(vma->vm_file->f_mapping,
+						linear_page_index(vma, addr));
+		if (!page)
+			return;
+
+		if (radix_tree_exceptional_entry(page))
+			mss->swap += PAGE_SIZE;
+		else
+			page_cache_release(page);
+
+		return;
 	}
 
 	if (!page)
 		return;
-	smaps_account(mss, page, PAGE_SIZE, pte_young(*pte), pte_dirty(*pte));
+
+	smaps_account(mss, page, false, pte_young(*pte), pte_dirty(*pte));
 }
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
@@ -532,8 +577,7 @@ static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
 	if (IS_ERR_OR_NULL(page))
 		return;
 	mss->anonymous_thp += HPAGE_PMD_SIZE;
-	smaps_account(mss, page, HPAGE_PMD_SIZE,
-			pmd_young(*pmd), pmd_dirty(*pmd));
+	smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd));
 }
 #else
 static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
@@ -549,7 +593,8 @@ static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
 	pte_t *pte;
 	spinlock_t *ptl;
 
-	if (pmd_trans_huge_lock(pmd, vma, &ptl) == 1) {
+	ptl = pmd_trans_huge_lock(pmd, vma);
+	if (ptl) {
 		smaps_pmd_entry(pmd, addr, walk);
 		spin_unlock(ptl);
 		return 0;
@@ -671,6 +716,31 @@ static int show_smap(struct seq_file *m, void *v, int is_pid)
 	};
 
 	memset(&mss, 0, sizeof mss);
+
+#ifdef CONFIG_SHMEM
+	if (vma->vm_file && shmem_mapping(vma->vm_file->f_mapping)) {
+		/*
+		 * For shared or readonly shmem mappings we know that all
+		 * swapped out pages belong to the shmem object, and we can
+		 * obtain the swap value much more efficiently. For private
+		 * writable mappings, we might have COW pages that are
+		 * not affected by the parent swapped out pages of the shmem
+		 * object, so we have to distinguish them during the page walk.
+		 * Unless we know that the shmem object (or the part mapped by
+		 * our VMA) has no swapped out pages at all.
+		 */
+		unsigned long shmem_swapped = shmem_swap_usage(vma);
+
+		if (!shmem_swapped || (vma->vm_flags & VM_SHARED) ||
+					!(vma->vm_flags & VM_WRITE)) {
+			mss.swap = shmem_swapped;
+		} else {
+			mss.check_shmem_swap = true;
+			smaps_walk.pte_hole = smaps_pte_hole;
+		}
+	}
+#endif
+
 	/* mmap_sem is held in m_start */
 	walk_page_vma(vma, &smaps_walk);
 
@@ -817,9 +887,6 @@ static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
 	pmd = pmd_wrprotect(pmd);
 	pmd = pmd_clear_soft_dirty(pmd);
 
-	if (vma->vm_flags & VM_SOFTDIRTY)
-		vma->vm_flags &= ~VM_SOFTDIRTY;
-
 	set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
 }
 #else
@@ -838,7 +905,8 @@ static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
 	spinlock_t *ptl;
 	struct page *page;
 
-	if (pmd_trans_huge_lock(pmd, vma, &ptl) == 1) {
+	ptl = pmd_trans_huge_lock(pmd, vma);
+	if (ptl) {
 		if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
 			clear_soft_dirty_pmd(vma, addr, pmd);
 			goto out;
@@ -1112,7 +1180,8 @@ static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end,
 	int err = 0;
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
-	if (pmd_trans_huge_lock(pmdp, vma, &ptl) == 1) {
+	ptl = pmd_trans_huge_lock(pmdp, vma);
+	if (ptl) {
 		u64 flags = 0, frame = 0;
 		pmd_t pmd = *pmdp;
 
@@ -1444,7 +1513,8 @@ static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
 	pte_t *orig_pte;
 	pte_t *pte;
 
-	if (pmd_trans_huge_lock(pmd, vma, &ptl) == 1) {
+	ptl = pmd_trans_huge_lock(pmd, vma);
+	if (ptl) {
 		pte_t huge_pte = *(pte_t *)pmd;
 		struct page *page;
 
@@ -1473,18 +1543,19 @@ static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
 		unsigned long addr, unsigned long end, struct mm_walk *walk)
 {
+	pte_t huge_pte = huge_ptep_get(pte);
 	struct numa_maps *md;
 	struct page *page;
 
-	if (!pte_present(*pte))
+	if (!pte_present(huge_pte))
 		return 0;
 
-	page = pte_page(*pte);
+	page = pte_page(huge_pte);
 	if (!page)
 		return 0;
 
 	md = walk->private;
-	gather_stats(page, md, pte_dirty(*pte), 1);
+	gather_stats(page, md, pte_dirty(huge_pte), 1);
 	return 0;
 }
 
@@ -1538,19 +1609,8 @@ static int show_numa_map(struct seq_file *m, void *v, int is_pid)
 		seq_file_path(m, file, "\n\t= ");
 	} else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) {
 		seq_puts(m, " heap");
-	} else {
-		pid_t tid = pid_of_stack(proc_priv, vma, is_pid);
-		if (tid != 0) {
-			/*
-			 * Thread stack in /proc/PID/task/TID/maps or
-			 * the main process stack.
-			 */
-			if (!is_pid || (vma->vm_start <= mm->start_stack &&
-			    vma->vm_end >= mm->start_stack))
-				seq_puts(m, " stack");
-			else
-				seq_printf(m, " stack:%d", tid);
-		}
+	} else if (is_stack(proc_priv, vma, is_pid)) {
+		seq_puts(m, " stack");
 	}
 
 	if (is_vm_hugetlb_page(vma))
diff --git a/fs/proc/task_nommu.c b/fs/proc/task_nommu.c
index e0d64c92e4f6..faacb0c0d857 100644
--- a/fs/proc/task_nommu.c
+++ b/fs/proc/task_nommu.c
@@ -123,23 +123,26 @@ unsigned long task_statm(struct mm_struct *mm,
 	return size;
 }
 
-static pid_t pid_of_stack(struct proc_maps_private *priv,
-				struct vm_area_struct *vma, bool is_pid)
+static int is_stack(struct proc_maps_private *priv,
+		    struct vm_area_struct *vma, int is_pid)
 {
-	struct inode *inode = priv->inode;
-	struct task_struct *task;
-	pid_t ret = 0;
-
-	rcu_read_lock();
-	task = pid_task(proc_pid(inode), PIDTYPE_PID);
-	if (task) {
-		task = task_of_stack(task, vma, is_pid);
+	struct mm_struct *mm = vma->vm_mm;
+	int stack = 0;
+
+	if (is_pid) {
+		stack = vma->vm_start <= mm->start_stack &&
+			vma->vm_end >= mm->start_stack;
+	} else {
+		struct inode *inode = priv->inode;
+		struct task_struct *task;
+
+		rcu_read_lock();
+		task = pid_task(proc_pid(inode), PIDTYPE_PID);
 		if (task)
-			ret = task_pid_nr_ns(task, inode->i_sb->s_fs_info);
+			stack = vma_is_stack_for_task(vma, task);
+		rcu_read_unlock();
 	}
-	rcu_read_unlock();
-
-	return ret;
+	return stack;
 }
 
 /*
@@ -181,21 +184,9 @@ static int nommu_vma_show(struct seq_file *m, struct vm_area_struct *vma,
 	if (file) {
 		seq_pad(m, ' ');
 		seq_file_path(m, file, "");
-	} else if (mm) {
-		pid_t tid = pid_of_stack(priv, vma, is_pid);
-
-		if (tid != 0) {
-			seq_pad(m, ' ');
-			/*
-			 * Thread stack in /proc/PID/task/TID/maps or
-			 * the main process stack.
-			 */
-			if (!is_pid || (vma->vm_start <= mm->start_stack &&
-			    vma->vm_end >= mm->start_stack))
-				seq_printf(m, "[stack]");
-			else
-				seq_printf(m, "[stack:%d]", tid);
-		}
+	} else if (mm && is_stack(priv, vma, is_pid)) {
+		seq_pad(m, ' ');
+		seq_printf(m, "[stack]");
 	}
 
 	seq_putc(m, '\n');
diff --git a/fs/proc/thread_self.c b/fs/proc/thread_self.c
index 947b0f4fd0a1..e58a31e8fb2a 100644
--- a/fs/proc/thread_self.c
+++ b/fs/proc/thread_self.c
@@ -19,26 +19,29 @@ static int proc_thread_self_readlink(struct dentry *dentry, char __user *buffer,
 	return readlink_copy(buffer, buflen, tmp);
 }
 
-static const char *proc_thread_self_follow_link(struct dentry *dentry, void **cookie)
+static const char *proc_thread_self_get_link(struct dentry *dentry,
+					     struct inode *inode,
+					     struct delayed_call *done)
 {
-	struct pid_namespace *ns = dentry->d_sb->s_fs_info;
+	struct pid_namespace *ns = inode->i_sb->s_fs_info;
 	pid_t tgid = task_tgid_nr_ns(current, ns);
 	pid_t pid = task_pid_nr_ns(current, ns);
 	char *name;
 
 	if (!pid)
 		return ERR_PTR(-ENOENT);
-	name = kmalloc(PROC_NUMBUF + 6 + PROC_NUMBUF, GFP_KERNEL);
-	if (!name)
-		return ERR_PTR(-ENOMEM);
+	name = kmalloc(PROC_NUMBUF + 6 + PROC_NUMBUF,
+				dentry ? GFP_KERNEL : GFP_ATOMIC);
+	if (unlikely(!name))
+		return dentry ? ERR_PTR(-ENOMEM) : ERR_PTR(-ECHILD);
 	sprintf(name, "%d/task/%d", tgid, pid);
-	return *cookie = name;
+	set_delayed_call(done, kfree_link, name);
+	return name;
 }
 
 static const struct inode_operations proc_thread_self_inode_operations = {
 	.readlink	= proc_thread_self_readlink,
-	.follow_link	= proc_thread_self_follow_link,
-	.put_link	= kfree_put_link,
+	.get_link	= proc_thread_self_get_link,
 };
 
 static unsigned thread_self_inum;
@@ -49,7 +52,7 @@ int proc_setup_thread_self(struct super_block *s)
 	struct pid_namespace *ns = s->s_fs_info;
 	struct dentry *thread_self;
 
-	mutex_lock(&root_inode->i_mutex);
+	inode_lock(root_inode);
 	thread_self = d_alloc_name(s->s_root, "thread-self");
 	if (thread_self) {
 		struct inode *inode = new_inode_pseudo(s);
@@ -68,7 +71,7 @@ int proc_setup_thread_self(struct super_block *s)
 	} else {
 		thread_self = ERR_PTR(-ENOMEM);
 	}
-	mutex_unlock(&root_inode->i_mutex);
+	inode_unlock(root_inode);
 	if (IS_ERR(thread_self)) {
 		pr_err("proc_fill_super: can't allocate /proc/thread_self\n");
 		return PTR_ERR(thread_self);