There are certain users that wish to force the NFS client to choose
READDIRPLUS over READDIR for a particular mount. Add a new kernel mount
option "force_rdirplus" to carry that intent.
Signed-off-by: Benjamin Coddington <bcodding@xxxxxxxxxx>
---
fs/nfs/dir.c | 2 ++
fs/nfs/fs_context.c | 14 ++++++++++++--
include/linux/nfs_fs_sb.h | 1 +
3 files changed, 15 insertions(+), 2 deletions(-)
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 2b04038b0e40..c9de0e474cf5 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -666,6 +666,8 @@ static bool nfs_use_readdirplus(struct inode *dir, struct dir_context *ctx,
{
if (!nfs_server_capable(dir, NFS_CAP_READDIRPLUS))
return false;
+ if (NFS_SERVER(dir)->flags && NFS_MOUNT_FORCE_RDIRPLUS)
+ return true;
if (ctx->pos == 0 ||
cache_hits + cache_misses > NFS_READDIR_CACHE_USAGE_THRESHOLD)
return true;
diff --git a/fs/nfs/fs_context.c b/fs/nfs/fs_context.c
index b069385eea17..3ba44b444031 100644
--- a/fs/nfs/fs_context.c
+++ b/fs/nfs/fs_context.c
@@ -72,6 +72,7 @@ enum nfs_param {
Opt_posix,
Opt_proto,
Opt_rdirplus,
+ Opt_force_rdirplus,
Opt_rdma,
Opt_resvport,
Opt_retrans,
@@ -175,6 +176,7 @@ static const struct fs_parameter_spec nfs_fs_parameters[] = {
fsparam_flag_no("posix", Opt_posix),
fsparam_string("proto", Opt_proto),
fsparam_flag_no("rdirplus", Opt_rdirplus),
+ fsparam_flag ("force_rdirplus", Opt_force_rdirplus),
fsparam_flag ("rdma", Opt_rdma),
fsparam_flag_no("resvport", Opt_resvport),
fsparam_u32 ("retrans", Opt_retrans),
@@ -636,10 +638,18 @@ static int nfs_fs_context_parse_param(struct fs_context *fc,
ctx->flags &= ~NFS_MOUNT_NOACL;
break;
case Opt_rdirplus:
- if (result.negated)
+ if (result.negated) {
+ if (ctx->flags && NFS_MOUNT_FORCE_RDIRPLUS)
+ return nfs_invalf(fc, "NFS: Cannot both force and disable READDIR PLUS");
ctx->flags |= NFS_MOUNT_NORDIRPLUS;
- else
+ } else {
ctx->flags &= ~NFS_MOUNT_NORDIRPLUS;
+ }
+ break;
+ case Opt_force_rdirplus:
+ if (ctx->flags && NFS_MOUNT_NORDIRPLUS)
+ return nfs_invalf(fc, "NFS: Cannot both force and disable READDIR PLUS");
+ ctx->flags |= NFS_MOUNT_FORCE_RDIRPLUS;
break;
case Opt_sharecache:
if (result.negated)
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index f00bfcee7120..3774b2235a1e 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -167,6 +167,7 @@ struct nfs_server {
#define NFS_MOUNT_TRUNK_DISCOVERY 0x04000000
#define NFS_MOUNT_SHUTDOWN 0x08000000
#define NFS_MOUNT_NO_ALIGNWRITE 0x10000000
+#define NFS_MOUNT_FORCE_RDIRPLUS 0x20000000
unsigned int fattr_valid; /* Valid attributes */
unsigned int caps; /* server capabilities */
--
2.47.0
