Re: [PATCH 05/39] whiteout/NFSD: Don't return information aboutwhiteouts to userspace

From: Neil Brown
Date: Mon May 03 2010 - 19:37:50 EST


On Mon, 3 May 2010 16:12:04 -0700
Valerie Aurora <vaurora@xxxxxxxxxx> wrote:

> From: Jan Blunck <jblunck@xxxxxxx>
>
> Userspace isn't ready for handling another file type, so silently drop
> whiteout directory entries before they leave the kernel.

Feels very intrusive doesn't it....

Have you considered something like the following?

NeilBrown

diff --git a/fs/readdir.c b/fs/readdir.c
index 7723401..4c5b347 100644
--- a/fs/readdir.c
+++ b/fs/readdir.c
@@ -19,10 +19,26 @@

#include <asm/uaccess.h>

+struct readdir_info {
+ filldir_t filler;
+ void *data;
+};
+
+static int white_out(void *vrdi, const char *name, int namlen,
+ loff_t offset, u64 ino, unsigned int d_type)
+{
+ struct readdir_info *rdi = vrdi;
+ if (d_type == DT_WHT)
+ return 0;
+ return rdi->filler(rdi->data, name, namlen, offset, info, d_type);
+}
+
int vfs_readdir(struct file *file, filldir_t filler, void *buf)
{
struct inode *inode = file->f_path.dentry->d_inode;
int res = -ENOTDIR;
+ struct readir_info rdi = { filler, buf };
+
if (!file->f_op || !file->f_op->readdir)
goto out;

@@ -36,7 +52,7 @@ int vfs_readdir(struct file *file, filldir_t filler, void *buf)

res = -ENOENT;
if (!IS_DEADDIR(inode)) {
- res = file->f_op->readdir(file, buf, filler);
+ res = file->f_op->readdir(file, &rdi, white_out);
file_accessed(file);
}
mutex_unlock(&inode->i_mutex);
--
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