Hi Trond,
On Wed, Feb 23, 2022 at 8:25 PM <trondmy@xxxxxxxxxx> wrote:
>
> From: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
>
> When reading a very large directory, we want to try to keep the page
> cache up to date if doing so is inexpensive. With the change to allow
> readdir to continue reading even when the cache is incomplete, we no
> longer need to fall back to uncached readdir in order to scale to large
> directories.
>
> Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
As of this patch, cthon tests are passing again.
Anna
Anna
> ---
> fs/nfs/dir.c | 23 +++--------------------
> 1 file changed, 3 insertions(+), 20 deletions(-)
>
> diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
> index 9b0f13b52dbf..982b5dbe30d7 100644
> --- a/fs/nfs/dir.c
> +++ b/fs/nfs/dir.c
> @@ -986,28 +986,11 @@ static int find_and_lock_cache_page(struct nfs_readdir_descriptor *desc)
> return res;
> }
>
> -static bool nfs_readdir_dont_search_cache(struct nfs_readdir_descriptor *desc)
> -{
> - struct address_space *mapping = desc->file->f_mapping;
> - struct inode *dir = file_inode(desc->file);
> - unsigned int dtsize = NFS_SERVER(dir)->dtsize;
> - loff_t size = i_size_read(dir);
> -
> - /*
> - * Default to uncached readdir if the page cache is empty, and
> - * we're looking for a non-zero cookie in a large directory.
> - */
> - return desc->dir_cookie != 0 && mapping->nrpages == 0 && size > dtsize;
> -}
> -
> /* Search for desc->dir_cookie from the beginning of the page cache */
> static int readdir_search_pagecache(struct nfs_readdir_descriptor *desc)
> {
> int res;
>
> - if (nfs_readdir_dont_search_cache(desc))
> - return -EBADCOOKIE;
> -
> do {
> if (desc->page_index == 0) {
> desc->current_index = 0;
> @@ -1262,10 +1245,10 @@ static loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int whence)
> }
> if (offset != filp->f_pos) {
> filp->f_pos = offset;
> - if (!nfs_readdir_use_cookie(filp)) {
> + dir_ctx->page_index = 0;
> + if (!nfs_readdir_use_cookie(filp))
> dir_ctx->dir_cookie = 0;
> - dir_ctx->page_index = 0;
> - } else
> + else
> dir_ctx->dir_cookie = offset;
> if (offset == 0)
> memset(dir_ctx->verf, 0, sizeof(dir_ctx->verf));
> --
> 2.35.1
>
