Commit ecce9212 authored by Hongnan Li's avatar Hongnan Li Committed by Gao Xiang
Browse files

erofs: update ctx->pos for every emitted dirent 



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.

Also fix the update of ctx->pos when the initial file position has
exceeded nameoff.

Fixes: 3e917cc3 ("erofs: make filesystem exportable")
Signed-off-by: default avatarHongnan Li <hongnan.li@linux.alibaba.com>
Signed-off-by: default avatarJeffle Xu <jefflexu@linux.alibaba.com>
Reviewed-by: default avatarGao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: default avatarChao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20220722082732.30935-1-jefflexu@linux.alibaba.com


Signed-off-by: default avatarGao Xiang <hsiangkao@linux.alibaba.com>
parent cc2a1713

fs/erofs/dir.c

+7 −9
Original line number Diff line number Diff line
@@ -22,10 +22,9 @@ 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, struct erofs_dirent *de,

			       unsigned int nameoff, unsigned int maxsize)

{

	struct erofs_dirent *de = dentry_blk + *ofs;

	const struct erofs_dirent *end = dentry_blk + nameoff;



	while (de < end) {
@@ -59,9 +58,8 @@ 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;

	return 0;

}
@@ -95,7 +93,7 @@ static int erofs_readdir(struct file *f, struct dir_context *ctx) 
				  "invalid de[0].nameoff %u @ nid %llu",

				  nameoff, EROFS_I(dir)->nid);

			err = -EFSCORRUPTED;

			goto skip_this;

			break;

		}



		maxsize = min_t(unsigned int,
@@ -106,17 +104,17 @@ static int erofs_readdir(struct file *f, struct dir_context *ctx) 
			initial = false;



			ofs = roundup(ofs, sizeof(struct erofs_dirent));

			ctx->pos = blknr_to_addr(i) + ofs;

			if (ofs >= nameoff)

				goto skip_this;

		}



		err = erofs_fill_dentries(dir, ctx, de, &ofs,

		err = erofs_fill_dentries(dir, ctx, de, (void *)de + ofs,

					  nameoff, maxsize);

skip_this:

		ctx->pos = blknr_to_addr(i) + ofs;



		if (err)

			break;

skip_this:

		ctx->pos = blknr_to_addr(i) + maxsize;

		++i;

		ofs = 0;

	}