[PATCH 23/28] staging/lustre/llite: Restore proper opencache operations

Oleg Drokin
2016-06-20T02:14:29Z

From: Oleg Drokin <oleg.drokin@intel.com>

Mark dentries that came to us via NFS in a special way so that
we can tell them apart during open and activate open cache
(we really don't want to do open/close RPC for every NFS IO).

This became needed since dentry revlidate no longer reimplements
any RPCs for lookup, and as such if a dentry is valid,
ll_revalidate_dentry returns 1 and ll_lookup_it() is never visited
during opens, we get straght into ll_file_open() without a valid
intent/RPC. This used to be only true for NFS, so opencache was
engaged needlessly, and it carries a cost of it's own if there is
in fact no repetitive file opening-closing going on

Signed-off-by: Oleg Drokin <oleg.drokin@intel.com>
Reviewed-on: http://review.whamcloud.com/20354
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-8019
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Li Xi <lixi@ddn.com>
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
---
drivers/staging/lustre/lustre/llite/file.c | 14 +++++++++++++-
drivers/staging/lustre/lustre/llite/llite_internal.h | 1 +
drivers/staging/lustre/lustre/llite/llite_nfs.c | 18 ++++++++++++++++++
3 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/lustre/lustre/llite/file.c b/drivers/staging/lustre/lustre/llite/file.c
index a188366..6a5e8c7 100644
--- a/drivers/staging/lustre/lustre/llite/file.c
+++ b/drivers/staging/lustre/lustre/llite/file.c
@@ -411,7 +411,19 @@ static int ll_intent_file_open(struct dentry *dentry, void *lmm,
* parameters. No need for the open lock
*/
if (!lmm && lmmsize == 0) {
- itp->it_flags |= MDS_OPEN_LOCK;
+ struct ll_dentry_data *ldd = ll_d2d(dentry);
+ /*
+ * If we came via ll_iget_for_nfs, then we need to request
+ * struct ll_dentry_data *ldd = ll_d2d(file->f_dentry);
+ *
+ * NB: when ldd is NULL, it must have come via normal
+ * lookup path only, since ll_iget_for_nfs always calls
+ * ll_d_init().
+ */
+ if (ldd && ldd->lld_nfs_dentry) {
+ ldd->lld_nfs_dentry = 0;
+ itp->it_flags |= MDS_OPEN_LOCK;
+ }
if (itp->it_flags & FMODE_WRITE)
opc = LUSTRE_OPC_CREATE;
}
diff --git a/drivers/staging/lustre/lustre/llite/llite_internal.h b/drivers/staging/lustre/lustre/llite/llite_internal.h
index 3692102..1d4e91e 100644
--- a/drivers/staging/lustre/lustre/llite/llite_internal.h
+++ b/drivers/staging/lustre/lustre/llite/llite_internal.h
@@ -64,6 +64,7 @@ struct ll_dentry_data {
struct lookup_intent *lld_it;
unsigned int lld_sa_generation;
unsigned int lld_invalid:1;
+ unsigned int lld_nfs_dentry:1;
struct rcu_head lld_rcu_head;
};

diff --git a/drivers/staging/lustre/lustre/llite/llite_nfs.c b/drivers/staging/lustre/lustre/llite/llite_nfs.c
index d7878e5..65972c8 100644
--- a/drivers/staging/lustre/lustre/llite/llite_nfs.c
+++ b/drivers/staging/lustre/lustre/llite/llite_nfs.c
@@ -168,6 +168,24 @@ ll_iget_for_nfs(struct super_block *sb, struct lu_fid *fid, struct lu_fid *paren

/* N.B. d_obtain_alias() drops inode ref on error */
result = d_obtain_alias(inode);
+ if (!IS_ERR(result)) {
+ int rc;
+
+ rc = ll_d_init(result);
+ if (rc < 0) {
+ dput(result);
+ result = ERR_PTR(rc);
+ } else {
+ struct ll_dentry_data *ldd = ll_d2d(result);
+
+ /*
+ * Need to signal to the ll_intent_file_open that
+ * we came from NFS and so opencache needs to be
+ * enabled for this one
+ */
+ ldd->lld_nfs_dentry = 1;
+ }
+ }

return result;
}
--
2.7.4