[PATCH v1 03/10] NFS: Add a struct to track readdir pagecache location
From: Benjamin Coddington <hidden>
Date: 2021-01-20 17:03:13
Subsystem:
filesystems (vfs and infrastructure), nfs, sunrpc, and lockd clients, the rest · Maintainers:
Alexander Viro, Christian Brauner, Trond Myklebust, Anna Schumaker, Linus Torvalds
Directory entries in the NFS readdir pagecache are referenced by their cookie value and offset. By defining a structure to group these values, we'll simplify changes to validate pagecache pages in patches that follow. Signed-off-by: Benjamin Coddington <redacted> --- fs/nfs/dir.c | 34 +++++++++++++++++----------------- include/linux/nfs_fs.h | 6 ++++++ 2 files changed, 23 insertions(+), 17 deletions(-)
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index ade73ca42a52..6626aff9f54d 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c@@ -154,10 +154,9 @@ struct nfs_readdir_descriptor { struct file *file; struct page *page; struct dir_context *ctx; - pgoff_t page_index; u64 dir_cookie; - u64 last_cookie; u64 dup_cookie; + struct nfs_dir_page_cursor pgc; loff_t current_index; loff_t prev_index;
@@ -166,7 +165,6 @@ struct nfs_readdir_descriptor { unsigned long timestamp; unsigned long gencount; unsigned long attr_gencount; - unsigned int cache_entry_index; signed char duped; bool plus; bool eof;
@@ -426,7 +424,7 @@ static int nfs_readdir_search_for_pos(struct nfs_cache_array *array, index = (unsigned int)diff; desc->dir_cookie = array->array[index].cookie; - desc->cache_entry_index = index; + desc->pgc.entry_index = index; return 0; out_eof: desc->eof = true;
@@ -494,7 +492,7 @@ static int nfs_readdir_search_for_cookie(struct nfs_cache_array *array, else desc->ctx->pos = new_pos; desc->prev_index = new_pos; - desc->cache_entry_index = i; + desc->pgc.entry_index = i; return 0; } }
@@ -521,9 +519,9 @@ static int nfs_readdir_search_array(struct nfs_readdir_descriptor *desc) status = nfs_readdir_search_for_cookie(array, desc); if (status == -EAGAIN) { - desc->last_cookie = array->last_cookie; + desc->pgc.index_cookie = array->last_cookie; desc->current_index += array->size; - desc->page_index++; + desc->pgc.page_index++; } kunmap_atomic(array); return status;
@@ -927,8 +925,8 @@ static struct page * nfs_readdir_page_get_cached(struct nfs_readdir_descriptor *desc) { return nfs_readdir_page_get_locked(desc->file->f_mapping, - desc->page_index, - desc->last_cookie); + desc->pgc.page_index, + desc->pgc.index_cookie); } /*
@@ -952,7 +950,7 @@ static int find_and_lock_cache_page(struct nfs_readdir_descriptor *desc) nfs_readdir_page_unlock_and_put_cached(desc); if (res == -EBADCOOKIE || res == -ENOTSYNC) { invalidate_inode_pages2(desc->file->f_mapping); - desc->page_index = 0; + desc->pgc.page_index = 0; return -EAGAIN; } return res;
@@ -961,7 +959,7 @@ static int find_and_lock_cache_page(struct nfs_readdir_descriptor *desc) } res = nfs_readdir_search_array(desc); if (res == 0) { - nfsi->page_index = desc->page_index; + nfsi->page_index = desc->pgc.page_index; return 0; } nfs_readdir_page_unlock_and_put_cached(desc);
@@ -991,10 +989,10 @@ static int readdir_search_pagecache(struct nfs_readdir_descriptor *desc) return -EBADCOOKIE; do { - if (desc->page_index == 0) { + if (desc->pgc.page_index == 0) { desc->current_index = 0; desc->prev_index = 0; - desc->last_cookie = 0; + desc->pgc.index_cookie = 0; } res = find_and_lock_cache_page(desc); } while (res == -EAGAIN);
@@ -1012,7 +1010,7 @@ static void nfs_do_filldir(struct nfs_readdir_descriptor *desc) unsigned int i = 0; array = kmap(desc->page); - for (i = desc->cache_entry_index; i < array->size; i++) { + for (i = desc->pgc.entry_index; i < array->size; i++) { struct nfs_cache_array_entry *ent; ent = &array->array[i];
@@ -1070,8 +1068,10 @@ static int uncached_readdir(struct nfs_readdir_descriptor *desc) if (!arrays[0]) goto out; - desc->page_index = 0; - desc->last_cookie = desc->dir_cookie; + /* These values aren't referenced until we return, move/remove? */ + desc->pgc.page_index = 0; + desc->pgc.index_cookie = desc->dir_cookie; + desc->duped = 0; status = nfs_readdir_xdr_to_array(desc, desc->verf, verf, arrays, sz);
@@ -1154,7 +1154,7 @@ static int nfs_readdir(struct file *file, struct dir_context *ctx) if (res == -ETOOSMALL && desc->plus) { clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags); nfs_zap_caches(inode); - desc->page_index = 0; + desc->pgc.page_index = 0; desc->plus = false; desc->eof = false; continue;
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 681ed98e4ba8..557e54b7d555 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h@@ -91,6 +91,12 @@ struct nfs_open_context { struct rcu_head rcu_head; }; +struct nfs_dir_page_cursor { + __u64 index_cookie; + pgoff_t page_index; + unsigned int entry_index; +}; + struct nfs_open_dir_context { struct list_head list; unsigned long attr_gencount;
--
2.25.4