[PATCH] erofs: update ctx->pos for every emitted dirent

[Hongnan Li]

erofs_readdir update ctx->pos after filling a batch of dentries
and it may cause dir/files duplication for NFS readdirplus which
depends on ctx->pos to fill dir correctly. So update ctx->pos for
every emitted dirent in erofs_fill_dentries to fix it.

Fixes: 3e917cc305c6 ("erofs: make filesystem exportable")
Signed-off-by: Hongnan Li <hongnan...@linux.alibaba.com>
---
 fs/erofs/dir.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/fs/erofs/dir.c b/fs/erofs/dir.c
index 18e59821c597..3015974fe2ff 100644
--- a/fs/erofs/dir.c
+++ b/fs/erofs/dir.c
@@ -22,11 +22,12 @@ static void debug_one_dentry(unsigned char d_type, const 
char *de_name,
 }
 
 static int erofs_fill_dentries(struct inode *dir, struct dir_context *ctx,
-                              void *dentry_blk, unsigned int *ofs,
+                              void *dentry_blk, void *dentry_begin,
                               unsigned int nameoff, unsigned int maxsize)
 {
-       struct erofs_dirent *de = dentry_blk + *ofs;
+       struct erofs_dirent *de = dentry_begin;
        const struct erofs_dirent *end = dentry_blk + nameoff;
+       loff_t begin_pos = ctx->pos;
 
        while (de < end) {
                const char *de_name;
@@ -59,9 +60,9 @@ static int erofs_fill_dentries(struct inode *dir, struct 
dir_context *ctx,
                        /* stopped by some reason */
                        return 1;
                ++de;
-               *ofs += sizeof(struct erofs_dirent);
+               ctx->pos += sizeof(struct erofs_dirent);
        }
-       *ofs = maxsize;
+       ctx->pos = begin_pos + maxsize;
        return 0;
 }
 
@@ -110,11 +111,9 @@ static int erofs_readdir(struct file *f, struct 
dir_context *ctx)
                                goto skip_this;
                }
 
-               err = erofs_fill_dentries(dir, ctx, de, &ofs,
+               err = erofs_fill_dentries(dir, ctx, de, de + ofs,
                                          nameoff, maxsize);
 skip_this:
-               ctx->pos = blknr_to_addr(i) + ofs;
-
                if (err)
                        break;
                ++i;
-- 
2.35.1