LU-11427 llite: optimize read on open pages

Current read-on-open implementation does allocate cl_page after data
are piggied back by open request, which is expensive and not
necessary.

This patch improves the case by just adding the pages into page cache.
As long as those pages will be discarded at lock revocation, there
should be no concerns.

Signed-off-by: Jinshan Xiong <jinshan.xiong@uber.com>
Change-Id: Idef1b70483e3780790ba5b95c26ef2d4141add5f
Reviewed-on: https://review.whamcloud.com/33234
Tested-by: Jenkins
Reviewed-by: Mike Pershin <mpershin@whamcloud.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>

diff --git a/lustre/llite/file.c b/lustre/llite/file.c
index 4f7d2b8..8bb2901 100644 (file)
--- a/lustre/llite/file.c
+++ b/lustre/llite/file.c
@@ -414,14 +414,10 @@ void ll_dom_finish_open(struct inode *inode, struct ptlrpc_request *req,
        struct page *vmpage;
        struct niobuf_remote *rnb;
        char *data;
-       struct lu_env *env;
-       struct cl_io *io;
-       __u16 refcheck;
        struct lustre_handle lockh;
        struct ldlm_lock *lock;
        unsigned long index, start;
        struct niobuf_local lnb;
-       int rc;
        bool dom_lock = false;
 
        ENTRY;
@@ -436,33 +432,21 @@ void ll_dom_finish_open(struct inode *inode, struct ptlrpc_request *req,
                        dom_lock = ldlm_has_dom(lock);
                LDLM_LOCK_PUT(lock);
        }
-
        if (!dom_lock)
                RETURN_EXIT;
 
-       env = cl_env_get(&refcheck);
-       if (IS_ERR(env))
-               RETURN_EXIT;
-
        if (!req_capsule_has_field(&req->rq_pill, &RMF_NIOBUF_INLINE,
                                   RCL_SERVER))
-               GOTO(out_env, rc = -ENODATA);
+               RETURN_EXIT;
 
        rnb = req_capsule_server_get(&req->rq_pill, &RMF_NIOBUF_INLINE);
-       data = (char *)rnb + sizeof(*rnb);
-
        if (rnb == NULL || rnb->rnb_len == 0)
-               GOTO(out_env, rc = 0);
+               RETURN_EXIT;
 
        CDEBUG(D_INFO, "Get data buffer along with open, len %i, i_size %llu\n",
               rnb->rnb_len, i_size_read(inode));
 
-       io = vvp_env_thread_io(env);
-       io->ci_obj = obj;
-       io->ci_ignore_layout = 1;
-       rc = cl_io_init(env, io, CIT_MISC, obj);
-       if (rc)
-               GOTO(out_io, rc);
+       data = (char *)rnb + sizeof(*rnb);
 
        lnb.lnb_file_offset = rnb->rnb_offset;
        start = lnb.lnb_file_offset / PAGE_SIZE;
@@ -470,8 +454,6 @@ void ll_dom_finish_open(struct inode *inode, struct ptlrpc_request *req,
        LASSERT(lnb.lnb_file_offset % PAGE_SIZE == 0);
        lnb.lnb_page_offset = 0;
        do {
-               struct cl_page *clp;
-
                lnb.lnb_data = data + (index << PAGE_SHIFT);
                lnb.lnb_len = rnb->rnb_len - (index << PAGE_SHIFT);
                if (lnb.lnb_len > PAGE_SIZE)
@@ -487,34 +469,10 @@ void ll_dom_finish_open(struct inode *inode, struct ptlrpc_request *req,
                              PTR_ERR(vmpage));
                        break;
                }
-               lock_page(vmpage);
-               if (vmpage->mapping == NULL) {
-                       unlock_page(vmpage);
-                       put_page(vmpage);
-                       /* page was truncated */
-                       GOTO(out_io, rc = -ENODATA);
-               }
-               clp = cl_page_find(env, obj, vmpage->index, vmpage,
-                                  CPT_CACHEABLE);
-               if (IS_ERR(clp)) {
-                       unlock_page(vmpage);
-                       put_page(vmpage);
-                       GOTO(out_io, rc = PTR_ERR(clp));
-               }
-
-               /* export page */
-               cl_page_export(env, clp, 1);
-               cl_page_put(env, clp);
-               unlock_page(vmpage);
                put_page(vmpage);
                index++;
        } while (rnb->rnb_len > (index << PAGE_SHIFT));
-       rc = 0;
        EXIT;
-out_io:
-       cl_io_fini(env, io);
-out_env:
-       cl_env_put(env, &refcheck);
 }
 
 static int ll_intent_file_open(struct dentry *de, void *lmm, int lmmsize,

diff --git a/lustre/llite/namei.c b/lustre/llite/namei.c
index 7976133..8abf542 100644 (file)
--- a/lustre/llite/namei.c
+++ b/lustre/llite/namei.c
@@ -195,8 +195,12 @@ int ll_dom_lock_cancel(struct inode *inode, struct ldlm_lock *lock)
 
        ENTRY;
 
-       if (!lli->lli_clob)
+       if (!lli->lli_clob) {
+               /* due to DoM read on open, there may exist pages for Lustre
+                * regular file even though cl_object is not set up yet. */
+               truncate_inode_pages(inode->i_mapping, 0);
                RETURN(0);
+       }
 
        env = cl_env_get(&refcheck);
        if (IS_ERR(env))