[readdir] convert procfs

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/hppfs/hppfs.c

@@ -542,8 +542,8 @@ static const struct file_operations hppfs_file_fops = {
 };
 
 struct hppfs_dirent {
-	void *vfs_dirent;
-	filldir_t filldir;
+	struct dir_context ctx;
+	struct dir_context *caller;
 	struct dentry *dentry;
 };
 
@@ -555,34 +555,29 @@ static int hppfs_filldir(void *d, const char *name, int size,
 	if (file_removed(dirent->dentry, name))
 		return 0;
 
-	return (*dirent->filldir)(dirent->vfs_dirent, name, size, offset,
-				  inode, type);
+	dirent->caller->pos = dirent->ctx.pos;
+	return !dir_emit(dirent->caller, name, size, inode, type);
 }
 
-static int hppfs_readdir(struct file *file, void *ent, filldir_t filldir)
+static int hppfs_readdir(struct file *file, struct dir_context *ctx)
 {
 	struct hppfs_private *data = file->private_data;
 	struct file *proc_file = data->proc_file;
-	int (*readdir)(struct file *, void *, filldir_t);
-	struct hppfs_dirent dirent = ((struct hppfs_dirent)
-		                      { .vfs_dirent  	= ent,
-					.filldir 	= filldir,
-					.dentry  	= file->f_path.dentry
-				      });
+	struct hppfs_dirent d = {
+		.ctx.actor	= hppfs_filldir,
+		.caller		= ctx,
+		.dentry  	= file->f_path.dentry
+	};
 	int err;
-
-	readdir = file_inode(proc_file)->i_fop->readdir;
-
-	proc_file->f_pos = file->f_pos;
-	err = (*readdir)(proc_file, &dirent, hppfs_filldir);
-	file->f_pos = proc_file->f_pos;
-
+	proc_file->f_pos = ctx->pos;
+	err = iterate_dir(proc_file, &d.ctx);
+	ctx->pos = d.ctx.pos;
 	return err;
 }
 
 static const struct file_operations hppfs_dir_fops = {
 	.owner		= NULL,
-	.readdir	= hppfs_readdir,
+	.iterate	= hppfs_readdir,
 	.open		= hppfs_dir_open,
 	.llseek		= default_llseek,
 	.release	= hppfs_release,

fs/proc/fd.c

@@ -219,74 +219,58 @@ static struct dentry *proc_lookupfd_common(struct inode *dir,
 	return result;
 }
 
-static int proc_readfd_common(struct file * filp, void * dirent,
-			      filldir_t filldir, instantiate_t instantiate)
+static int proc_readfd_common(struct file *file, struct dir_context *ctx,
+			      instantiate_t instantiate)
 {
-	struct dentry *dentry = filp->f_path.dentry;
-	struct inode *inode = dentry->d_inode;
-	struct task_struct *p = get_proc_task(inode);
+	struct task_struct *p = get_proc_task(file_inode(file));
 	struct files_struct *files;
-	unsigned int fd, ino;
-	int retval;
+	unsigned int fd;
 
-	retval = -ENOENT;
 	if (!p)
-		goto out_no_task;
-	retval = 0;
-
-	fd = filp->f_pos;
-	switch (fd) {
-		case 0:
-			if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
-				goto out;
-			filp->f_pos++;
-		case 1:
-			ino = parent_ino(dentry);
-			if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
-				goto out;
-			filp->f_pos++;
-		default:
-			files = get_files_struct(p);
-			if (!files)
-				goto out;
-			rcu_read_lock();
-			for (fd = filp->f_pos - 2;
-			     fd < files_fdtable(files)->max_fds;
-			     fd++, filp->f_pos++) {
-				char name[PROC_NUMBUF];
-				int len;
-				int rv;
-
-				if (!fcheck_files(files, fd))
-					continue;
-				rcu_read_unlock();
+		return -ENOENT;
 
-				len = snprintf(name, sizeof(name), "%d", fd);
-				rv = proc_fill_cache(filp, dirent, filldir,
-						     name, len, instantiate, p,
-						     (void *)(unsigned long)fd);
-				if (rv < 0)
-					goto out_fd_loop;
-				rcu_read_lock();
-			}
-			rcu_read_unlock();
-out_fd_loop:
-			put_files_struct(files);
+	if (!dir_emit_dots(file, ctx))
+		goto out;
+	if (!dir_emit_dots(file, ctx))
+		goto out;
+	files = get_files_struct(p);
+	if (!files)
+		goto out;
+
+	rcu_read_lock();
+	for (fd = ctx->pos - 2;
+	     fd < files_fdtable(files)->max_fds;
+	     fd++, ctx->pos++) {
+		char name[PROC_NUMBUF];
+		int len;
+
+		if (!fcheck_files(files, fd))
+			continue;
+		rcu_read_unlock();
+
+		len = snprintf(name, sizeof(name), "%d", fd);
+		if (!proc_fill_cache(file, ctx,
+				     name, len, instantiate, p,
+				     (void *)(unsigned long)fd))
+			goto out_fd_loop;
+		rcu_read_lock();
 	}
+	rcu_read_unlock();
+out_fd_loop:
+	put_files_struct(files);
 out:
 	put_task_struct(p);
-out_no_task:
-	return retval;
+	return 0;
 }
 
-static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir)
+static int proc_readfd(struct file *file, struct dir_context *ctx)
 {
-	return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate);
+	return proc_readfd_common(file, ctx, proc_fd_instantiate);
 }
 
 const struct file_operations proc_fd_operations = {
 	.read		= generic_read_dir,
-	.readdir	= proc_readfd,
+	.iterate	= proc_readfd,
 	.llseek		= default_llseek,
 };
 
@@ -351,9 +335,9 @@ proc_lookupfdinfo(struct inode *dir, struct dentry *dentry, unsigned int flags)
 	return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate);
 }
 
-static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir)
+static int proc_readfdinfo(struct file *file, struct dir_context *ctx)
 {
-	return proc_readfd_common(filp, dirent, filldir,
+	return proc_readfd_common(file, ctx,
 				  proc_fdinfo_instantiate);
 }
 
@@ -364,6 +348,6 @@ const struct inode_operations proc_fdinfo_inode_operations = {
 
 const struct file_operations proc_fdinfo_operations = {
 	.read		= generic_read_dir,
-	.readdir	= proc_readfdinfo,
+	.iterate	= proc_readfdinfo,
 	.llseek		= default_llseek,
 };

fs/proc/generic.c

@@ -233,76 +233,52 @@ struct dentry *proc_lookup(struct inode *dir, struct dentry *dentry,
  * value of the readdir() call, as long as it's non-negative
  * for success..
  */
-int proc_readdir_de(struct proc_dir_entry *de, struct file *filp, void *dirent,
-		filldir_t filldir)
+int proc_readdir_de(struct proc_dir_entry *de, struct file *file,
+		    struct dir_context *ctx)
 {
-	unsigned int ino;
 	int i;
-	struct inode *inode = file_inode(filp);
-	int ret = 0;
-
-	ino = inode->i_ino;
-	i = filp->f_pos;
-	switch (i) {
-		case 0:
-			if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
-				goto out;
-			i++;
-			filp->f_pos++;
-			/* fall through */
-		case 1:
-			if (filldir(dirent, "..", 2, i,
-				    parent_ino(filp->f_path.dentry),
-				    DT_DIR) < 0)
-				goto out;
-			i++;
-			filp->f_pos++;
-			/* fall through */
-		default:
-			spin_lock(&proc_subdir_lock);
-			de = de->subdir;
-			i -= 2;
-			for (;;) {
-				if (!de) {
-					ret = 1;
-					spin_unlock(&proc_subdir_lock);
-					goto out;
-				}
-				if (!i)
-					break;
-				de = de->next;
-				i--;
-			}
 
-			do {
-				struct proc_dir_entry *next;
-
-				/* filldir passes info to user space */
-				pde_get(de);
-				spin_unlock(&proc_subdir_lock);
-				if (filldir(dirent, de->name, de->namelen, filp->f_pos,
-					    de->low_ino, de->mode >> 12) < 0) {
-					pde_put(de);
-					goto out;
-				}
-				spin_lock(&proc_subdir_lock);
-				filp->f_pos++;
-				next = de->next;
-				pde_put(de);
-				de = next;
-			} while (de);
+	if (!dir_emit_dots(file, ctx))
+		return 0;
+
+	spin_lock(&proc_subdir_lock);
+	de = de->subdir;
+	i = ctx->pos - 2;
+	for (;;) {
+		if (!de) {
 			spin_unlock(&proc_subdir_lock);
+			return 0;
+		}
+		if (!i)
+			break;
+		de = de->next;
+		i--;
 	}
-	ret = 1;
-out:
-	return ret;	
+
+	do {
+		struct proc_dir_entry *next;
+		pde_get(de);
+		spin_unlock(&proc_subdir_lock);
+		if (!dir_emit(ctx, de->name, de->namelen,
+			    de->low_ino, de->mode >> 12)) {
+			pde_put(de);
+			return 0;
+		}
+		spin_lock(&proc_subdir_lock);
+		ctx->pos++;
+		next = de->next;
+		pde_put(de);
+		de = next;
+	} while (de);
+	spin_unlock(&proc_subdir_lock);
+	return 0;
 }
 
-int proc_readdir(struct file *filp, void *dirent, filldir_t filldir)
+int proc_readdir(struct file *file, struct dir_context *ctx)
 {
-	struct inode *inode = file_inode(filp);
+	struct inode *inode = file_inode(file);
 
-	return proc_readdir_de(PDE(inode), filp, dirent, filldir);
+	return proc_readdir_de(PDE(inode), file, ctx);
 }
 
 /*
@@ -313,7 +289,7 @@ int proc_readdir(struct file *filp, void *dirent, filldir_t filldir)
 static const struct file_operations proc_dir_operations = {
 	.llseek			= generic_file_llseek,
 	.read			= generic_read_dir,
-	.readdir		= proc_readdir,
+	.iterate		= proc_readdir,
 };
 
 /*

fs/proc/internal.h

@@ -165,14 +165,14 @@ extern int proc_setattr(struct dentry *, struct iattr *);
 extern struct inode *proc_pid_make_inode(struct super_block *, struct task_struct *);
 extern int pid_revalidate(struct dentry *, unsigned int);
 extern int pid_delete_dentry(const struct dentry *);
-extern int proc_pid_readdir(struct file *, void *, filldir_t);
+extern int proc_pid_readdir(struct file *, struct dir_context *);
 extern struct dentry *proc_pid_lookup(struct inode *, struct dentry *, unsigned int);
 extern loff_t mem_lseek(struct file *, loff_t, int);
 
 /* Lookups */
 typedef struct dentry *instantiate_t(struct inode *, struct dentry *,
 				     struct task_struct *, const void *);
-extern int proc_fill_cache(struct file *, void *, filldir_t, const char *, int,
+extern bool proc_fill_cache(struct file *, struct dir_context *, const char *, int,
 			   instantiate_t, struct task_struct *, const void *);
 
 /*
@@ -183,8 +183,8 @@ extern spinlock_t proc_subdir_lock;
 extern struct dentry *proc_lookup(struct inode *, struct dentry *, unsigned int);
 extern struct dentry *proc_lookup_de(struct proc_dir_entry *, struct inode *,
 				     struct dentry *);
-extern int proc_readdir(struct file *, void *, filldir_t);
-extern int proc_readdir_de(struct proc_dir_entry *, struct file *, void *, filldir_t);
+extern int proc_readdir(struct file *, struct dir_context *);
+extern int proc_readdir_de(struct proc_dir_entry *, struct file *, struct dir_context *);
 
 static inline struct proc_dir_entry *pde_get(struct proc_dir_entry *pde)
 {

fs/proc/namespaces.c

@@ -213,74 +213,36 @@ static struct dentry *proc_ns_instantiate(struct inode *dir,
 	return error;
 }
 
-static int proc_ns_fill_cache(struct file *filp, void *dirent,
-	filldir_t filldir, struct task_struct *task,
-	const struct proc_ns_operations *ops)
+static int proc_ns_dir_readdir(struct file *file, struct dir_context *ctx)
 {
-	return proc_fill_cache(filp, dirent, filldir,
-				ops->name, strlen(ops->name),
-				proc_ns_instantiate, task, ops);
-}
-
-static int proc_ns_dir_readdir(struct file *filp, void *dirent,
-				filldir_t filldir)
-{
-	int i;
-	struct dentry *dentry = filp->f_path.dentry;
-	struct inode *inode = dentry->d_inode;
-	struct task_struct *task = get_proc_task(inode);
+	struct task_struct *task = get_proc_task(file_inode(file));
 	const struct proc_ns_operations **entry, **last;
-	ino_t ino;
-	int ret;
 
-	ret = -ENOENT;
 	if (!task)
-		goto out_no_task;
+		return -ENOENT;
 
-	ret = 0;
-	i = filp->f_pos;
-	switch (i) {
-	case 0:
-		ino = inode->i_ino;
-		if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
-			goto out;
-		i++;
-		filp->f_pos++;
-		/* fall through */
-	case 1:
-		ino = parent_ino(dentry);
-		if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
-			goto out;
-		i++;
-		filp->f_pos++;
-		/* fall through */
-	default:
-		i -= 2;
-		if (i >= ARRAY_SIZE(ns_entries)) {
-			ret = 1;
-			goto out;
-		}
-		entry = ns_entries + i;
-		last = &ns_entries[ARRAY_SIZE(ns_entries) - 1];
-		while (entry <= last) {
-			if (proc_ns_fill_cache(filp, dirent, filldir,
-						task, *entry) < 0)
-				goto out;
-			filp->f_pos++;
-			entry++;
-		}
+	if (!dir_emit_dots(file, ctx))
+		goto out;
+	if (ctx->pos >= 2 + ARRAY_SIZE(ns_entries))
+		goto out;
+	entry = ns_entries + (ctx->pos - 2);
+	last = &ns_entries[ARRAY_SIZE(ns_entries) - 1];
+	while (entry <= last) {
+		const struct proc_ns_operations *ops = *entry;
+		if (!proc_fill_cache(file, ctx, ops->name, strlen(ops->name),
+				     proc_ns_instantiate, task, ops))
+			break;
+		ctx->pos++;
+		entry++;
 	}
-
-	ret = 1;
 out:
 	put_task_struct(task);
-out_no_task:
-	return ret;
+	return 0;
 }
 
 const struct file_operations proc_ns_dir_operations = {
 	.read		= generic_read_dir,
-	.readdir	= proc_ns_dir_readdir,
+	.iterate	= proc_ns_dir_readdir,
 };
 
 static struct dentry *proc_ns_dir_lookup(struct inode *dir,

fs/proc/proc_net.c

@@ -160,16 +160,15 @@ const struct inode_operations proc_net_inode_operations = {
 	.getattr	= proc_tgid_net_getattr,
 };
 
-static int proc_tgid_net_readdir(struct file *filp, void *dirent,
-		filldir_t filldir)
+static int proc_tgid_net_readdir(struct file *file, struct dir_context *ctx)
 {
 	int ret;
 	struct net *net;
 
 	ret = -EINVAL;
-	net = get_proc_task_net(file_inode(filp));
+	net = get_proc_task_net(file_inode(file));
 	if (net != NULL) {
-		ret = proc_readdir_de(net->proc_net, filp, dirent, filldir);
+		ret = proc_readdir_de(net->proc_net, file, ctx);
 		put_net(net);
 	}
 	return ret;
@@ -178,7 +177,7 @@ static int proc_tgid_net_readdir(struct file *filp, void *dirent,
 const struct file_operations proc_net_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= generic_read_dir,
-	.readdir	= proc_tgid_net_readdir,
+	.iterate	= proc_tgid_net_readdir,
 };
 
 static __net_init int proc_net_ns_init(struct net *net)

fs/proc/proc_sysctl.c

@@ -573,12 +573,12 @@ static unsigned int proc_sys_poll(struct file *filp, poll_table *wait)
 	return ret;
 }
 
-static int proc_sys_fill_cache(struct file *filp, void *dirent,
-				filldir_t filldir,
+static bool proc_sys_fill_cache(struct file *file,
+				struct dir_context *ctx,
 				struct ctl_table_header *head,
 				struct ctl_table *table)
 {
-	struct dentry *child, *dir = filp->f_path.dentry;
+	struct dentry *child, *dir = file->f_path.dentry;
 	struct inode *inode;
 	struct qstr qname;
 	ino_t ino = 0;
@@ -595,38 +595,38 @@ static int proc_sys_fill_cache(struct file *filp, void *dirent,
 			inode = proc_sys_make_inode(dir->d_sb, head, table);
 			if (!inode) {
 				dput(child);
-				return -ENOMEM;
+				return false;
 			} else {
 				d_set_d_op(child, &proc_sys_dentry_operations);
 				d_add(child, inode);
 			}
 		} else {
-			return -ENOMEM;
+			return false;
 		}
 	}
 	inode = child->d_inode;
 	ino  = inode->i_ino;
 	type = inode->i_mode >> 12;
 	dput(child);
-	return !!filldir(dirent, qname.name, qname.len, filp->f_pos, ino, type);
+	return dir_emit(ctx, qname.name, qname.len, ino, type);
 }
 
-static int proc_sys_link_fill_cache(struct file *filp, void *dirent,
-				    filldir_t filldir,
+static bool proc_sys_link_fill_cache(struct file *file,
+				    struct dir_context *ctx,
 				    struct ctl_table_header *head,
 				    struct ctl_table *table)
 {
-	int err, ret = 0;
+	bool ret = true;
 	head = sysctl_head_grab(head);
 
 	if (S_ISLNK(table->mode)) {
 		/* It is not an error if we can not follow the link ignore it */
-		err = sysctl_follow_link(&head, &table, current->nsproxy);
+		int err = sysctl_follow_link(&head, &table, current->nsproxy);
 		if (err)
 			goto out;
 	}
 
-	ret = proc_sys_fill_cache(filp, dirent, filldir, head, table);
+	ret = proc_sys_fill_cache(file, ctx, head, table);
 out:
 	sysctl_head_finish(head);
 	return ret;
@@ -634,67 +634,50 @@ static int proc_sys_link_fill_cache(struct file *filp, void *dirent,
 
 static int scan(struct ctl_table_header *head, ctl_table *table,
 		unsigned long *pos, struct file *file,
-		void *dirent, filldir_t filldir)
+		struct dir_context *ctx)
 {
-	int res;
+	bool res;
 
-	if ((*pos)++ < file->f_pos)
-		return 0;
+	if ((*pos)++ < ctx->pos)
+		return true;
 
 	if (unlikely(S_ISLNK(table->mode)))
-		res = proc_sys_link_fill_cache(file, dirent, filldir, head, table);
+		res = proc_sys_link_fill_cache(file, ctx, head, table);
 	else
-		res = proc_sys_fill_cache(file, dirent, filldir, head, table);
+		res = proc_sys_fill_cache(file, ctx, head, table);
 
-	if (res == 0)
-		file->f_pos = *pos;
+	if (res)
+		ctx->pos = *pos;
 
 	return res;
 }
 
-static int proc_sys_readdir(struct file *filp, void *dirent, filldir_t filldir)
+static int proc_sys_readdir(struct file *file, struct dir_context *ctx)
 {
-	struct dentry *dentry = filp->f_path.dentry;
-	struct inode *inode = dentry->d_inode;
-	struct ctl_table_header *head = grab_header(inode);
+	struct ctl_table_header *head = grab_header(file_inode(file));
 	struct ctl_table_header *h = NULL;
 	struct ctl_table *entry;
 	struct ctl_dir *ctl_dir;
 	unsigned long pos;
-	int ret = -EINVAL;
 
 	if (IS_ERR(head))
 		return PTR_ERR(head);
 
 	ctl_dir = container_of(head, struct ctl_dir, header);
 
-	ret = 0;
-	/* Avoid a switch here: arm builds fail with missing __cmpdi2 */
-	if (filp->f_pos == 0) {
-		if (filldir(dirent, ".", 1, filp->f_pos,
-				inode->i_ino, DT_DIR) < 0)
-			goto out;
-		filp->f_pos++;
-	}
-	if (filp->f_pos == 1) {
-		if (filldir(dirent, "..", 2, filp->f_pos,
-				parent_ino(dentry), DT_DIR) < 0)
-			goto out;
-		filp->f_pos++;
-	}
+	if (!dir_emit_dots(file, ctx))
+		return 0;
+
 	pos = 2;
 
 	for (first_entry(ctl_dir, &h, &entry); h; next_entry(&h, &entry)) {
-		ret = scan(h, entry, &pos, filp, dirent, filldir);
-		if (ret) {
+		if (!scan(h, entry, &pos, file, ctx)) {
 			sysctl_head_finish(h);
 			break;
 		}
 	}
-	ret = 1;
-out:
 	sysctl_head_finish(head);
-	return ret;
+	return 0;
 }
 
 static int proc_sys_permission(struct inode *inode, int mask)
@@ -769,7 +752,7 @@ static const struct file_operations proc_sys_file_operations = {
 
 static const struct file_operations proc_sys_dir_file_operations = {
 	.read		= generic_read_dir,
-	.readdir	= proc_sys_readdir,
+	.iterate	= proc_sys_readdir,
 	.llseek		= generic_file_llseek,
 };
 

fs/proc/root.c

@@ -202,21 +202,14 @@ static struct dentry *proc_root_lookup(struct inode * dir, struct dentry * dentr
 	return proc_pid_lookup(dir, dentry, flags);
 }
 
-static int proc_root_readdir(struct file * filp,
-	void * dirent, filldir_t filldir)
+static int proc_root_readdir(struct file *file, struct dir_context *ctx)
 {
-	unsigned int nr = filp->f_pos;
-	int ret;
-
-	if (nr < FIRST_PROCESS_ENTRY) {
-		int error = proc_readdir(filp, dirent, filldir);
-		if (error <= 0)
-			return error;
-		filp->f_pos = FIRST_PROCESS_ENTRY;