Re: [PATCH v1 04/10] NFS: Keep the readdir pagecache cursor updated

Signed-off-by: Benjamin Coddington <redacted>
---
 fs/nfs/dir.c | 29 +++++++++++++++++++++++++----
 1 file changed, 25 insertions(+), 4 deletions(-)

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 6626aff9f54d..7f6c84c8a412 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c

@@ -150,6 +150,10 @@ struct nfs_cache_array {

        struct nfs_cache_array_entry array[];
 };
 
+static const int cache_entries_per_page =
+       (PAGE_SIZE - sizeof(struct nfs_cache_array)) /
+       sizeof(struct nfs_cache_array_entry);
+
 struct nfs_readdir_descriptor {
        struct file     *file;
        struct page     *page;

@@ -251,6 +255,21 @@ static bool nfs_readdir_array_is_full(struct

nfs_cache_array *array)
        return array->page_full;
 }
 
+static void nfs_readdir_set_cursor(struct nfs_readdir_descriptor
*desc, int index)
+{
+       desc->pgc.entry_index = index;
+       desc->pgc.index_cookie = desc->dir_cookie;
+}
+
+static void nfs_readdir_cursor_next(struct nfs_dir_page_cursor *pgc,
u64 cookie)
+{
+       pgc->index_cookie = cookie;
+       if (++pgc->entry_index == cache_entries_per_page) {
+               pgc->entry_index = 0;
+               pgc->page_index++;
+       }
+}
+
 /*
  * the caller is responsible for freeing qstr.name
  * when called by nfs_readdir_add_to_array, the strings will be
freed in

@@ -424,7 +443,7 @@ static int nfs_readdir_search_for_pos(struct

nfs_cache_array *array,
 
        index = (unsigned int)diff;
        desc->dir_cookie = array->array[index].cookie;
-       desc->pgc.entry_index = index;
+       nfs_readdir_set_cursor(desc, index);
        return 0;
 out_eof:
        desc->eof = true;

@@ -492,7 +511,7 @@ static int nfs_readdir_search_for_cookie(struct

nfs_cache_array *array,
                        else
                                desc->ctx->pos = new_pos;
                        desc->prev_index = new_pos;
-                       desc->pgc.entry_index = i;
+                       nfs_readdir_set_cursor(desc, i);
                        return 0;
                }
        }

@@ -519,9 +538,9 @@ static int nfs_readdir_search_array(struct

nfs_readdir_descriptor *desc)
                status = nfs_readdir_search_for_cookie(array, desc);
 
        if (status == -EAGAIN) {
-               desc->pgc.index_cookie = array->last_cookie;
+               desc->pgc.entry_index = array->size - 1;
+               nfs_readdir_cursor_next(&desc->pgc, array-

quoted

last_cookie);

                desc->current_index += array->size;
-               desc->pgc.page_index++;
        }
        kunmap_atomic(array);
        return status;

@@ -1035,6 +1054,8 @@ static void nfs_do_filldir(struct

nfs_readdir_descriptor *desc)
                desc->eof = true;
 
        kunmap(desc->page);
+       desc->pgc.entry_index = i-1;
+       nfs_readdir_cursor_next(&desc->pgc, desc->dir_cookie);
        dfprintk(DIRCACHE, "NFS: nfs_do_filldir() filling ended @
cookie %llu\n",
                        (unsigned long long)desc->dir_cookie);
 }