[PATCH v4 17/21] NFS: Handle NFS4ERR_NOT_SAME and NFSERR_BADCOOKIE from readdir calls

trondmy
2020-11-07T14:13:52Z

If the server returns NFS4ERR_NOT_SAME or tells us that the cookie is
bad in response to a READDIR call, then we should empty the page cache
so that we can fill it from scratch again.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
fs/nfs/dir.c | 24 ++++++++++++++++--------
fs/nfs/nfs4proc.c | 2 ++
2 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 3ee0668a9719..3b44bef3a1b4 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -861,15 +861,21 @@ static int find_and_lock_cache_page(struct nfs_readdir_descriptor *desc)
return -ENOMEM;
if (nfs_readdir_page_needs_filling(desc->page)) {
res = nfs_readdir_xdr_to_array(desc, desc->page, inode);
- if (res < 0)
- goto error;
+ if (res < 0) {
+ nfs_readdir_page_unlock_and_put_cached(desc);
+ if (res == -EBADCOOKIE || res == -ENOTSYNC) {
+ invalidate_inode_pages2(desc->file->f_mapping);
+ desc->page_index = 0;
+ return -EAGAIN;
+ }
+ return res;
+ }
}
res = nfs_readdir_search_array(desc);
if (res == 0) {
nfsi->page_index = desc->page_index;
return 0;
}
-error:
nfs_readdir_page_unlock_and_put_cached(desc);
return res;
}
@@ -879,12 +885,12 @@ static int readdir_search_pagecache(struct nfs_readdir_descriptor *desc)
{
int res;

- if (desc->page_index == 0) {
- desc->current_index = 0;
- desc->prev_index = 0;
- desc->last_cookie = 0;
- }
do {
+ if (desc->page_index == 0) {
+ desc->current_index = 0;
+ desc->prev_index = 0;
+ desc->last_cookie = 0;
+ }
res = find_and_lock_cache_page(desc);
} while (res == -EAGAIN);
return res;
@@ -1030,6 +1036,8 @@ static int nfs_readdir(struct file *file, struct dir_context *ctx)
res = uncached_readdir(desc);
if (res == 0)
continue;
+ if (res == -EBADCOOKIE || res == -ENOTSYNC)
+ res = 0;
}
break;
}
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 8e82f988a11f..3f1fdb06ba56 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -184,6 +184,8 @@ static int nfs4_map_errors(int err)
return -EPROTONOSUPPORT;
case -NFS4ERR_FILE_OPEN:
return -EBUSY;
+ case -NFS4ERR_NOT_SAME:
+ return -ENOTSYNC;
default:
dprintk("%s could not handle NFSv4 error %d\n",
__func__, -err);
--
2.28.0