[lustre-devel] [PATCH v2 11/29] lustre: obdclass: don't copy ops structures in to new type.
James Simmons
jsimmons at infradead.org
Mon May 20 05:50:53 PDT 2019
From: NeilBrown <neilb at suse.com>
The obd_ops and md_ops structures passed to class_register_type() are
read-only, and have a lifetime that is exceeds the lifetime of the
obd_type - they are static in a module which unregisters the type before
being unloaded.
So there is no need to copy the ops, just store a pointer.
Also mark all the structures as read-only to confirm they don't get
written. This is best-practice for structures of function pointers.
Reviewed-by: James Simmons <jsimmons at infradead.org>
Signed-off-by: NeilBrown <neilb at suse.com>
---
fs/lustre/include/obd.h | 4 ++--
fs/lustre/include/obd_class.h | 3 ++-
fs/lustre/lmv/lmv_obd.c | 4 ++--
fs/lustre/lov/lov_obd.c | 2 +-
fs/lustre/mdc/mdc_request.c | 4 ++--
fs/lustre/mgc/mgc_request.c | 2 +-
fs/lustre/obdclass/genops.c | 22 ++++++----------------
fs/lustre/obdecho/echo_client.c | 2 +-
fs/lustre/osc/osc_request.c | 2 +-
9 files changed, 18 insertions(+), 27 deletions(-)
diff --git a/fs/lustre/include/obd.h b/fs/lustre/include/obd.h
index 61fb815..3bdde31 100644
--- a/fs/lustre/include/obd.h
+++ b/fs/lustre/include/obd.h
@@ -99,8 +99,8 @@ struct obd_info {
};
struct obd_type {
- struct obd_ops *typ_dt_ops;
- struct md_ops *typ_md_ops;
+ const struct obd_ops *typ_dt_ops;
+ const struct md_ops *typ_md_ops;
struct dentry *typ_debugfs_entry;
atomic_t typ_refcnt;
struct lu_device_type *typ_lu;
diff --git a/fs/lustre/include/obd_class.h b/fs/lustre/include/obd_class.h
index a853ed5..a3394b2 100644
--- a/fs/lustre/include/obd_class.h
+++ b/fs/lustre/include/obd_class.h
@@ -60,7 +60,8 @@
/* genops.c */
struct obd_export *class_conn2export(struct lustre_handle *conn);
-int class_register_type(struct obd_ops *dt_ops, struct md_ops *md_ops,
+int class_register_type(const struct obd_ops *dt_ops,
+ const struct md_ops *md_ops,
const char *name, struct lu_device_type *ldt);
int class_unregister_type(const char *name);
diff --git a/fs/lustre/lmv/lmv_obd.c b/fs/lustre/lmv/lmv_obd.c
index aae80c7..64ebaf3 100644
--- a/fs/lustre/lmv/lmv_obd.c
+++ b/fs/lustre/lmv/lmv_obd.c
@@ -3043,7 +3043,7 @@ static int lmv_merge_attr(struct obd_export *exp,
return 0;
}
-static struct obd_ops lmv_obd_ops = {
+static const struct obd_ops lmv_obd_ops = {
.owner = THIS_MODULE,
.setup = lmv_setup,
.cleanup = lmv_cleanup,
@@ -3060,7 +3060,7 @@ static int lmv_merge_attr(struct obd_export *exp,
.quotactl = lmv_quotactl
};
-static struct md_ops lmv_md_ops = {
+static const struct md_ops lmv_md_ops = {
.get_root = lmv_get_root,
.null_inode = lmv_null_inode,
.close = lmv_close,
diff --git a/fs/lustre/lov/lov_obd.c b/fs/lustre/lov/lov_obd.c
index 203923f..652ed6a 100644
--- a/fs/lustre/lov/lov_obd.c
+++ b/fs/lustre/lov/lov_obd.c
@@ -1332,7 +1332,7 @@ static int lov_quotactl(struct obd_device *obd, struct obd_export *exp,
return rc;
}
-static struct obd_ops lov_obd_ops = {
+static const struct obd_ops lov_obd_ops = {
.owner = THIS_MODULE,
.setup = lov_setup,
.cleanup = lov_cleanup,
diff --git a/fs/lustre/mdc/mdc_request.c b/fs/lustre/mdc/mdc_request.c
index 705a4e3..6f933b5 100644
--- a/fs/lustre/mdc/mdc_request.c
+++ b/fs/lustre/mdc/mdc_request.c
@@ -2571,7 +2571,7 @@ static int mdc_process_config(struct obd_device *obd, u32 len, void *buf)
return count > 0 ? 0 : count;
}
-static struct obd_ops mdc_obd_ops = {
+static const struct obd_ops mdc_obd_ops = {
.owner = THIS_MODULE,
.setup = mdc_setup,
.precleanup = mdc_precleanup,
@@ -2593,7 +2593,7 @@ static int mdc_process_config(struct obd_device *obd, u32 len, void *buf)
.quotactl = mdc_quotactl,
};
-static struct md_ops mdc_md_ops = {
+static const struct md_ops mdc_md_ops = {
.get_root = mdc_get_root,
.null_inode = mdc_null_inode,
.close = mdc_close,
diff --git a/fs/lustre/mgc/mgc_request.c b/fs/lustre/mgc/mgc_request.c
index d8be54d..1eca81a 100644
--- a/fs/lustre/mgc/mgc_request.c
+++ b/fs/lustre/mgc/mgc_request.c
@@ -1810,7 +1810,7 @@ static int mgc_process_config(struct obd_device *obd, u32 len, void *buf)
return rc;
}
-static struct obd_ops mgc_obd_ops = {
+static const struct obd_ops mgc_obd_ops = {
.owner = THIS_MODULE,
.setup = mgc_setup,
.precleanup = mgc_precleanup,
diff --git a/fs/lustre/obdclass/genops.c b/fs/lustre/obdclass/genops.c
index 9c9ad9c..6d33414 100644
--- a/fs/lustre/obdclass/genops.c
+++ b/fs/lustre/obdclass/genops.c
@@ -141,8 +141,6 @@ static void class_sysfs_release(struct kobject *kobj)
debugfs_remove_recursive(type->typ_debugfs_entry);
- kfree(type->typ_md_ops);
- kfree(type->typ_dt_ops);
kfree(type);
}
@@ -153,7 +151,8 @@ static void class_sysfs_release(struct kobject *kobj)
#define CLASS_MAX_NAME 1024
-int class_register_type(struct obd_ops *dt_ops, struct md_ops *md_ops,
+int class_register_type(const struct obd_ops *dt_ops,
+ const struct md_ops *md_ops,
const char *name,
struct lu_device_type *ldt)
{
@@ -182,17 +181,8 @@ int class_register_type(struct obd_ops *dt_ops, struct md_ops *md_ops,
type->typ_debugfs_entry = debugfs_create_dir(name, debugfs_lustre_root);
- type->typ_dt_ops = kzalloc(sizeof(*type->typ_dt_ops), GFP_NOFS);
- type->typ_md_ops = kzalloc(sizeof(*type->typ_md_ops), GFP_NOFS);
-
- if (!type->typ_dt_ops ||
- !type->typ_md_ops)
- goto failed;
-
- *type->typ_dt_ops = *dt_ops;
- /* md_ops is optional */
- if (md_ops)
- *type->typ_md_ops = *md_ops;
+ type->typ_dt_ops = dt_ops;
+ type->typ_md_ops = md_ops;
if (ldt) {
type->typ_lu = ldt;
@@ -223,8 +213,8 @@ int class_unregister_type(const char *name)
CERROR("type %s has refcount (%d)\n", name, atomic_read(&type->typ_refcnt));
/* This is a bad situation, let's make the best of it */
/* Remove ops, but leave the name for debugging */
- kfree(type->typ_dt_ops);
- kfree(type->typ_md_ops);
+ type->typ_dt_ops = NULL;
+ type->typ_md_ops = NULL;
kobject_put(&type->typ_kobj);
return -EBUSY;
}
diff --git a/fs/lustre/obdecho/echo_client.c b/fs/lustre/obdecho/echo_client.c
index 317123f..baf34c8 100644
--- a/fs/lustre/obdecho/echo_client.c
+++ b/fs/lustre/obdecho/echo_client.c
@@ -1676,7 +1676,7 @@ static int echo_client_disconnect(struct obd_export *exp)
return rc;
}
-static struct obd_ops echo_client_obd_ops = {
+static const struct obd_ops echo_client_obd_ops = {
.owner = THIS_MODULE,
.iocontrol = echo_client_iocontrol,
.connect = echo_client_connect,
diff --git a/fs/lustre/osc/osc_request.c b/fs/lustre/osc/osc_request.c
index 104bf43..9484b9a 100644
--- a/fs/lustre/osc/osc_request.c
+++ b/fs/lustre/osc/osc_request.c
@@ -2988,7 +2988,7 @@ static int osc_process_config(struct obd_device *obd, u32 len, void *buf)
return osc_process_config_base(obd, buf);
}
-static struct obd_ops osc_obd_ops = {
+static const struct obd_ops osc_obd_ops = {
.owner = THIS_MODULE,
.setup = osc_setup,
.precleanup = osc_precleanup,
--
1.8.3.1
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