LU-6179 llite: Implement ladvise lockahead

[fs/lustre-release.git] / lustre / llite / glimpse.c

diff --git a/lustre/llite/glimpse.c b/lustre/llite/glimpse.c
index d34be28..166fff0 100644 (file)
--- a/lustre/llite/glimpse.c
+++ b/lustre/llite/glimpse.c
@@ -92,7 +92,7 @@ int cl_glimpse_lock(const struct lu_env *env, struct cl_io *io,
        CDEBUG(D_DLMTRACE, "Glimpsing inode "DFID"\n", PFID(fid));
 
        /* NOTE: this looks like DLM lock request, but it may
-        *       not be one. Due to CEF_ASYNC flag (translated
+        *       not be one. Due to CEF_GLIMPSE flag (translated
         *       to LDLM_FL_HAS_INTENT by osc), this is
         *       glimpse request, that won't revoke any
         *       conflicting DLM locks held. Instead,
@@ -107,14 +107,10 @@ int cl_glimpse_lock(const struct lu_env *env, struct cl_io *io,
        *descr = whole_file;
        descr->cld_obj = clob;
        descr->cld_mode = CLM_READ;
-       descr->cld_enq_flags = CEF_ASYNC | CEF_MUST;
+       descr->cld_enq_flags = CEF_GLIMPSE | CEF_MUST;
        if (agl)
-               descr->cld_enq_flags |= CEF_AGL;
+               descr->cld_enq_flags |= CEF_SPECULATIVE | CEF_NONBLOCK;
        /*
-        * CEF_ASYNC is used because glimpse sub-locks cannot
-        * deadlock (because they never conflict with other
-        * locks) and, hence, can be enqueued out-of-order.
-        *
         * CEF_MUST protects glimpse lock from conversion into
         * a lockless mode.
         */
@@ -140,7 +136,20 @@ int cl_glimpse_lock(const struct lu_env *env, struct cl_io *io,
        RETURN(result);
 }
 
-static int cl_io_get(struct inode *inode, struct lu_env **envout,
+/**
+ * Get an IO environment for special operations such as glimpse locks and
+ * manually requested locks (ladvise lockahead)
+ *
+ * \param[in]  inode   inode the operation is being performed on
+ * \param[out] envout  thread specific execution environment
+ * \param[out] ioout   client io description
+ * \param[out] refcheck        reference check
+ *
+ * \retval 1           on success
+ * \retval 0           not a regular file, cannot get environment
+ * \retval negative    negative errno on error
+ */
+int cl_io_get(struct inode *inode, struct lu_env **envout,
                     struct cl_io **ioout, __u16 *refcheck)
 {
        struct lu_env           *env;