[readdir] constify ->actor

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/arch/alpha/kernel/osf_sys.c b/arch/alpha/kernel/osf_sys.c
index ac19c72..1402fcc 100644
--- a/arch/alpha/kernel/osf_sys.c
+++ b/arch/alpha/kernel/osf_sys.c
@@ -147,17 +147,16 @@
 {
 	int error;
 	struct fd arg = fdget(fd);
-	struct osf_dirent_callback buf;
+	struct osf_dirent_callback buf = {
+		.ctx.actor = osf_filldir,
+		.dirent = dirent,
+		.basep = basep,
+		.count = count
+	};
 
 	if (!arg.file)
 		return -EBADF;
 
-	buf.dirent = dirent;
-	buf.basep = basep;
-	buf.count = count;
-	buf.error = 0;
-	buf.ctx.actor = osf_filldir;
-
 	error = iterate_dir(arg.file, &buf.ctx);
 	if (error >= 0)
 		error = buf.error;
diff --git a/arch/parisc/hpux/fs.c b/arch/parisc/hpux/fs.c
index eca8230..88d0962 100644
--- a/arch/parisc/hpux/fs.c
+++ b/arch/parisc/hpux/fs.c
@@ -111,19 +111,17 @@
 {
 	struct fd arg;
 	struct hpux_dirent __user * lastdirent;
-	struct getdents_callback buf;
+	struct getdents_callback buf = {
+		.ctx.actor = filldir,
+		.current_dir = dirent,
+		.count = count
+	};
 	int error;
 
 	arg = fdget(fd);
 	if (!arg.file)
 		return -EBADF;
 
-	buf.current_dir = dirent;
-	buf.previous = NULL;
-	buf.count = count;
-	buf.error = 0;
-	buf.ctx.actor = filldir;
-
 	error = iterate_dir(arg.file, &buf.ctx);
 	if (error >= 0)
 		error = buf.error;
diff --git a/fs/compat.c b/fs/compat.c
index 69ca1e3..6af20de 100644
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -874,15 +874,14 @@
 {
 	int error;
 	struct fd f = fdget(fd);
-	struct compat_readdir_callback buf;
+	struct compat_readdir_callback buf = {
+		.ctx.actor = compat_fillonedir,
+		.dirent = dirent
+	};
 
 	if (!f.file)
 		return -EBADF;
 
-	buf.result = 0;
-	buf.dirent = dirent;
-	buf.ctx.actor = compat_fillonedir;
-
 	error = iterate_dir(f.file, &buf.ctx);
 	if (buf.result)
 		error = buf.result;
@@ -954,7 +953,11 @@
 {
 	struct fd f;
 	struct compat_linux_dirent __user * lastdirent;
-	struct compat_getdents_callback buf;
+	struct compat_getdents_callback buf = {
+		.ctx.actor = compat_filldir,
+		.current_dir = dirent,
+		.count = count
+	};
 	int error;
 
 	if (!access_ok(VERIFY_WRITE, dirent, count))
@@ -964,12 +967,6 @@
 	if (!f.file)
 		return -EBADF;
 
-	buf.current_dir = dirent;
-	buf.previous = NULL;
-	buf.count = count;
-	buf.error = 0;
-	buf.ctx.actor = compat_filldir;
-
 	error = iterate_dir(f.file, &buf.ctx);
 	if (error >= 0)
 		error = buf.error;
@@ -1041,7 +1038,11 @@
 {
 	struct fd f;
 	struct linux_dirent64 __user * lastdirent;
-	struct compat_getdents_callback64 buf;
+	struct compat_getdents_callback64 buf = {
+		.ctx.actor = compat_filldir64,
+		.current_dir = dirent,
+		.count = count
+	};
 	int error;
 
 	if (!access_ok(VERIFY_WRITE, dirent, count))
@@ -1051,12 +1052,6 @@
 	if (!f.file)
 		return -EBADF;
 
-	buf.current_dir = dirent;
-	buf.previous = NULL;
-	buf.count = count;
-	buf.error = 0;
-	buf.ctx.actor = compat_filldir64;
-
 	error = iterate_dir(f.file, &buf.ctx);
 	if (error >= 0)
 		error = buf.error;
diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c
index 78072e6..293bc2e 100644
--- a/fs/exportfs/expfs.c
+++ b/fs/exportfs/expfs.c
@@ -255,7 +255,11 @@
 	struct inode *dir = path->dentry->d_inode;
 	int error;
 	struct file *file;
-	struct getdents_callback buffer;
+	struct getdents_callback buffer = {
+		.ctx.actor = filldir_one,
+		.name = name,
+		.ino = child->d_inode->i_ino
+	};
 
 	error = -ENOTDIR;
 	if (!dir || !S_ISDIR(dir->i_mode))
@@ -275,11 +279,7 @@
 	if (!file->f_op->iterate)
 		goto out_close;
 
-	buffer.name = name;
-	buffer.ino = child->d_inode->i_ino;
-	buffer.found = 0;
 	buffer.sequence = 0;
-	buffer.ctx.actor = filldir_one;
 	while (1) {
 		int old_seq = buffer.sequence;
 
diff --git a/fs/gfs2/export.c b/fs/gfs2/export.c
index aed4003..8b9b377 100644
--- a/fs/gfs2/export.c
+++ b/fs/gfs2/export.c
@@ -89,7 +89,10 @@
 	struct inode *dir = parent->d_inode;
 	struct inode *inode = child->d_inode;
 	struct gfs2_inode *dip, *ip;
-	struct get_name_filldir gnfd;
+	struct get_name_filldir gnfd = {
+		.ctx.actor = get_name_filldir,
+		.name = name
+	};
 	struct gfs2_holder gh;
 	int error;
 	struct file_ra_state f_ra = { .start = 0 };
@@ -106,9 +109,6 @@
 	*name = 0;
 	gnfd.inum.no_addr = ip->i_no_addr;
 	gnfd.inum.no_formal_ino = ip->i_no_formal_ino;
-	gnfd.name = name;
-	gnfd.ctx.actor = get_name_filldir;
-	gnfd.ctx.pos = 0;
 
 	error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &gh);
 	if (error)
diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
index 2fa2e2eb..105a3b0 100644
--- a/fs/nfsd/nfs4recover.c
+++ b/fs/nfsd/nfs4recover.c
@@ -268,7 +268,10 @@
 {
 	const struct cred *original_cred;
 	struct dentry *dir = nn->rec_file->f_path.dentry;
-	struct nfs4_dir_ctx ctx;
+	struct nfs4_dir_ctx ctx = {
+		.ctx.actor = nfsd4_build_namelist,
+		.names = LIST_HEAD_INIT(ctx.names)
+	};
 	int status;
 
 	status = nfs4_save_creds(&original_cred);
@@ -281,8 +284,6 @@
 		return status;
 	}
 
-	INIT_LIST_HEAD(&ctx.names);	
-	ctx.ctx.actor = nfsd4_build_namelist;
 	status = iterate_dir(nn->rec_file, &ctx.ctx);
 	mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT);
 	while (!list_empty(&ctx.names)) {
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index f939ba9..a6bc8a7 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1944,14 +1944,15 @@
 static __be32 nfsd_buffered_readdir(struct file *file, filldir_t func,
 				    struct readdir_cd *cdp, loff_t *offsetp)
 {
-	struct readdir_data buf;
 	struct buffered_dirent *de;
 	int host_err;
 	int size;
 	loff_t offset;
+	struct readdir_data buf = {
+		.ctx.actor = nfsd_buffered_filldir,
+		.dirent = (void *)__get_free_page(GFP_KERNEL)
+	};
 
-	buf.ctx.actor = nfsd_buffered_filldir;
-	buf.dirent = (void *)__get_free_page(GFP_KERNEL);
 	if (!buf.dirent)
 		return nfserrno(-ENOMEM);
 
diff --git a/fs/readdir.c b/fs/readdir.c
index a6245c9..93d71e5 100644
--- a/fs/readdir.c
+++ b/fs/readdir.c
@@ -109,15 +109,14 @@
 {
 	int error;
 	struct fd f = fdget(fd);
-	struct readdir_callback buf;
+	struct readdir_callback buf = {
+		.ctx.actor = fillonedir,
+		.dirent = dirent
+	};
 
 	if (!f.file)
 		return -EBADF;
 
-	buf.ctx.actor = fillonedir;
-	buf.result = 0;
-	buf.dirent = dirent;
-
 	error = iterate_dir(f.file, &buf.ctx);
 	if (buf.result)
 		error = buf.result;
@@ -195,7 +194,11 @@
 {
 	struct fd f;
 	struct linux_dirent __user * lastdirent;
-	struct getdents_callback buf;
+	struct getdents_callback buf = {
+		.ctx.actor = filldir,
+		.count = count,
+		.current_dir = dirent
+	};
 	int error;
 
 	if (!access_ok(VERIFY_WRITE, dirent, count))
@@ -205,12 +208,6 @@
 	if (!f.file)
 		return -EBADF;
 
-	buf.current_dir = dirent;
-	buf.previous = NULL;
-	buf.count = count;
-	buf.error = 0;
-	buf.ctx.actor = filldir;
-
 	error = iterate_dir(f.file, &buf.ctx);
 	if (error >= 0)
 		error = buf.error;
@@ -277,7 +274,11 @@
 {
 	struct fd f;
 	struct linux_dirent64 __user * lastdirent;
-	struct getdents_callback64 buf;
+	struct getdents_callback64 buf = {
+		.ctx.actor = filldir64,
+		.count = count,
+		.current_dir = dirent
+	};
 	int error;
 
 	if (!access_ok(VERIFY_WRITE, dirent, count))
@@ -287,12 +288,6 @@
 	if (!f.file)
 		return -EBADF;
 
-	buf.current_dir = dirent;
-	buf.previous = NULL;
-	buf.count = count;
-	buf.error = 0;
-	buf.ctx.actor = filldir64;
-
 	error = iterate_dir(f.file, &buf.ctx);
 	if (error >= 0)
 		error = buf.error;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 237af62..7c30e3a 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1507,7 +1507,7 @@
  */
 typedef int (*filldir_t)(void *, const char *, int, loff_t, u64, unsigned);
 struct dir_context {
-	filldir_t actor;
+	const filldir_t actor;
 	loff_t pos;
 };