staging/lustre/llite: Restore proper opencache operations

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/lustre/lustre/llite/file.c b/drivers/staging/lustre/lustre/llite/file.c
index 39c487d33d2e34199deb2d5d6384a1794b8ea5b1..57281b9e31ffc1d71691bab4ba08a8037282ceb3 100644 (file)
--- a/drivers/staging/lustre/lustre/llite/file.c
+++ b/drivers/staging/lustre/lustre/llite/file.c
@@ -399,7 +399,19 @@ 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 08cc2c169807c81bb6e6215270bf09038402358c..4d6d589a1677892ece653ab14aeeee920c8fec13 100644 (file)
--- 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 d7878e504aca5a7470a8f0332e91007ea80bcfa2..65972c892731498a76330beeac6c700da7026e39 100644 (file)
--- 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;
 }