[lustre-devel] [PATCH 414/622] lustre: mdc: polling mode for changelog reader
James Simmons
jsimmons at infradead.org
Thu Feb 27 13:14:42 PST 2020
From: Alex Zhuravlev <bzzz at whamcloud.com>
this allows the user (like lsom_sync and similar) to follow
the changelog and don't rescan getting duplicates.
WC-bug-id: https://jira.whamcloud.com/browse/LU-12553
Lustre-commit: e215002883d5 ("LU-12553 mdc: polling mode for changelog reader")
Signed-off-by: Alex Zhuravlev <bzzz at whamcloud.com>
Reviewed-on: https://review.whamcloud.com/35262
Reviewed-by: Patrick Farrell <pfarrell at whamcloud.com>
Reviewed-by: Andreas Dilger <adilger at whamcloud.com>
Signed-off-by: James Simmons <jsimmons at infradead.org>
---
fs/lustre/mdc/mdc_changelog.c | 37 +++++++++++++++++++++++++++++++-
include/uapi/linux/lustre/lustre_ioctl.h | 1 +
2 files changed, 37 insertions(+), 1 deletion(-)
diff --git a/fs/lustre/mdc/mdc_changelog.c b/fs/lustre/mdc/mdc_changelog.c
index fb0de68..ea74bab 100644
--- a/fs/lustre/mdc/mdc_changelog.c
+++ b/fs/lustre/mdc/mdc_changelog.c
@@ -37,6 +37,7 @@
#include <linux/miscdevice.h>
#include <lustre_log.h>
+#include <uapi/linux/lustre/lustre_ioctl.h>
#include "mdc_internal.h"
@@ -88,6 +89,9 @@ 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 {
@@ -132,6 +136,9 @@ 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 : rc = %d\n",
@@ -225,6 +232,10 @@ static int chlg_load(void *args)
goto err_out;
}
+ 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) {
@@ -248,12 +259,18 @@ static int chlg_load(void *args)
goto err_out;
}
- 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;
}
+ if (!kthread_should_stop() && crs->crs_poll) {
+ llog_cat_close(NULL, llh);
+ schedule_timeout_interruptible(HZ);
+ goto again;
+ }
crs->crs_eof = true;
@@ -602,6 +619,23 @@ 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)
+{
+ struct chlg_reader_state *crs = file->private_data;
+ int rc;
+
+ 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,
@@ -610,6 +644,7 @@ static unsigned int chlg_poll(struct file *file, poll_table *wait)
.open = chlg_open,
.release = chlg_release,
.poll = chlg_poll,
+ .unlocked_ioctl = chlg_ioctl,
};
/**
diff --git a/include/uapi/linux/lustre/lustre_ioctl.h b/include/uapi/linux/lustre/lustre_ioctl.h
index b067cc6..53dd34f 100644
--- a/include/uapi/linux/lustre/lustre_ioctl.h
+++ b/include/uapi/linux/lustre/lustre_ioctl.h
@@ -221,6 +221,7 @@ static inline __u32 obd_ioctl_packlen(struct obd_ioctl_data *data)
#define OBD_IOC_START_LFSCK _IOWR('f', 230, OBD_IOC_DATA_TYPE)
#define OBD_IOC_STOP_LFSCK _IOW('f', 231, OBD_IOC_DATA_TYPE)
#define OBD_IOC_QUERY_LFSCK _IOR('f', 232, struct obd_ioctl_data)
+#define OBD_IOC_CHLG_POLL _IOR('f', 233, long)
/* lustre/lustre_user.h 240-249 */
/* was LIBCFS_IOC_DEBUG_MASK _IOWR('f', 250, long) until 2.11 */
--
1.8.3.1
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