LU-12553 mdc: polling mode for changelog reader

[fs/lustre-release.git] / lustre / mdc / mdc_changelog.c

diff --git a/lustre/mdc/mdc_changelog.c b/lustre/mdc/mdc_changelog.c
index 9849220..4eeac84 100644 (file)
--- a/lustre/mdc/mdc_changelog.c
+++ b/lustre/mdc/mdc_changelog.c
@@ -23,6 +23,8 @@
  * Copyright (c) 2017, Commissariat a l'Energie Atomique et aux Energies
  *                     Alternatives.
  *
+ * Copyright (c) 2017, Intel Corporation.
+ *
  * Author: Henri Doreau <henri.doreau@cea.fr>
  */
 
@@ -34,6 +36,7 @@
 #include <linux/miscdevice.h>
 
 #include <lustre_log.h>
+#include <uapi/linux/lustre/lustre_ioctl.h>
 
 #include "mdc_internal.h"
 
@@ -87,6 +90,9 @@ struct chlg_reader_state {
        __u64                    crs_rec_count;
        /* List of prefetched enqueued_record::enq_linkage_items */
        struct list_head         crs_rec_queue;
+       unsigned int             crs_last_catidx;
+       unsigned int             crs_last_idx;
+       bool                     crs_poll;
 };
 
 struct chlg_rec_entry {
@@ -131,6 +137,9 @@ static int chlg_read_cat_process_cb(const struct lu_env *env,
 
        rec = container_of(hdr, struct llog_changelog_rec, cr_hdr);
 
+       crs->crs_last_catidx = llh->lgh_hdr->llh_cat_idx;
+       crs->crs_last_idx = hdr->lrh_index;
+
        if (rec->cr_hdr.lrh_type != CHANGELOG_REC) {
                rc = -EINVAL;
                CERROR("%s: not a changelog rec %x/%d in llog "DFID" rc = %d\n",
@@ -206,6 +215,10 @@ static int chlg_load(void *args)
        if (ctx == NULL)
                GOTO(err_out, rc = -ENOENT);
 
+       crs->crs_last_catidx = -1;
+       crs->crs_last_idx = 0;
+
+again:
        rc = llog_open(NULL, ctx, &llh, NULL, CHANGELOG_CATALOG,
                       LLOG_OPEN_EXISTS);
        if (rc) {
@@ -214,18 +227,33 @@ static int chlg_load(void *args)
                GOTO(err_out, rc);
        }
 
-       rc = llog_init_handle(NULL, llh, LLOG_F_IS_CAT|LLOG_F_EXT_JOBID, NULL);
+
+       rc = llog_init_handle(NULL, llh,
+                             LLOG_F_IS_CAT |
+                             LLOG_F_EXT_JOBID |
+                             LLOG_F_EXT_EXTRA_FLAGS |
+                             LLOG_F_EXT_X_UIDGID |
+                             LLOG_F_EXT_X_NID |
+                             LLOG_F_EXT_X_OMODE |
+                             LLOG_F_EXT_X_XATTR,
+                             NULL);
        if (rc) {
                CERROR("%s: fail to init llog handle: rc = %d\n",
                       obd->obd_name, rc);
                GOTO(err_out, rc);
        }
 
-       rc = llog_cat_process(NULL, llh, chlg_read_cat_process_cb, crs, 0, 0);
+       rc = llog_cat_process(NULL, llh, chlg_read_cat_process_cb, crs,
+                               crs->crs_last_catidx, crs->crs_last_idx);
        if (rc < 0) {
                CERROR("%s: fail to process llog: rc = %d\n", obd->obd_name, rc);
                GOTO(err_out, rc);
        }
+       if (!kthread_should_stop() && crs->crs_poll) {
+               llog_cat_close(NULL, llh);
+               schedule_timeout_interruptible(HZ);
+               goto again;
+       }
 
        crs->crs_eof = true;
 
@@ -580,6 +608,23 @@ static unsigned int chlg_poll(struct file *file, poll_table *wait)
        return mask;
 }
 
+static long chlg_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+       int rc;
+
+       struct chlg_reader_state *crs = file->private_data;
+       switch (cmd) {
+       case OBD_IOC_CHLG_POLL:
+               crs->crs_poll = !!arg;
+               rc = 0;
+               break;
+       default:
+               rc = -EINVAL;
+               break;
+       }
+       return rc;
+}
+
 static const struct file_operations chlg_fops = {
        .owner          = THIS_MODULE,
        .llseek         = chlg_llseek,
@@ -588,6 +633,7 @@ static const struct file_operations chlg_fops = {
        .open           = chlg_open,
        .release        = chlg_release,
        .poll           = chlg_poll,
+       .unlocked_ioctl = chlg_ioctl,
 };
 
 /**