LU-12691 ldlm: obd_max_recoverable_clients is not atomic

[fs/lustre-release.git] / lustre / obdclass / kernelcomm.c

diff --git a/lustre/obdclass/kernelcomm.c b/lustre/obdclass/kernelcomm.c
index ccd982c..7afb948 100644 (file)
--- a/lustre/obdclass/kernelcomm.c
+++ b/lustre/obdclass/kernelcomm.c
@@ -23,7 +23,7 @@
  * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
  * Use is subject to license terms.
  *
- * Copyright (c) 2015, Intel Corporation.
+ * Copyright (c) 2015, 2017, Intel Corporation.
  */
 /*
  * This file is part of Lustre, http://www.lustre.org/
@@ -36,33 +36,11 @@
 
 #define DEBUG_SUBSYSTEM S_CLASS
 
+#include <linux/file.h>
+
 #include <obd_support.h>
 #include <lustre_kernelcomm.h>
 
-/* write a userspace buffer to disk.
- * NOTE: this returns 0 on success, not the number of bytes written. */
-static ssize_t
-filp_user_write(struct file *filp, const void *buf, size_t count,
-               loff_t *offset)
-{
-       mm_segment_t fs;
-       ssize_t size = 0;
-
-       fs = get_fs();
-       set_fs(KERNEL_DS);
-       while ((ssize_t)count > 0) {
-               size = vfs_write(filp, (const void __user *)buf, count, offset);
-               if (size < 0)
-                       break;
-               count -= size;
-               buf += size;
-               size = 0;
-       }
-       set_fs(fs);
-
-       return size;
-}
-
 /**
  * libcfs_kkuc_msg_put - send an message from kernel to userspace
  * @param fp to send the message to
@@ -72,10 +50,11 @@ filp_user_write(struct file *filp, const void *buf, size_t count,
 int libcfs_kkuc_msg_put(struct file *filp, void *payload)
 {
        struct kuc_hdr *kuch = (struct kuc_hdr *)payload;
-       int rc = -ENOSYS;
+       ssize_t count = kuch->kuc_msglen;
        loff_t offset = 0;
+       int rc = 0;
 
-       if (filp == NULL || IS_ERR(filp))
+       if (IS_ERR_OR_NULL(filp))
                return -EBADF;
 
        if (kuch->kuc_magic != KUC_MAGIC) {
@@ -83,7 +62,15 @@ int libcfs_kkuc_msg_put(struct file *filp, void *payload)
                return -ENOSYS;
        }
 
-       rc = filp_user_write(filp, payload, kuch->kuc_msglen, &offset);
+       while (count > 0) {
+               rc = cfs_kernel_write(filp, payload, count, &offset);
+               if (rc < 0)
+                       break;
+               count -= rc;
+               payload += rc;
+               rc = 0;
+       }
+
        if (rc < 0)
                CWARN("message send failed (%d)\n", rc);
        else
@@ -99,6 +86,7 @@ EXPORT_SYMBOL(libcfs_kkuc_msg_put);
 /** A single group registration has a uid and a file pointer */
 struct kkuc_reg {
        struct list_head kr_chain;
+       struct obd_uuid  kr_uuid;
        int              kr_uid;
        struct file     *kr_fp;
        char             kr_data[0];
@@ -127,8 +115,8 @@ void libcfs_kkuc_init(void)
  * @param group group number
  * @param data user data
  */
-int libcfs_kkuc_group_add(struct file *filp, int uid, int group,
-                         void *data, size_t data_len)
+int libcfs_kkuc_group_add(struct file *filp, const struct obd_uuid *uuid,
+                         int uid, int group, void *data, size_t data_len)
 {
        struct kkuc_reg *reg;
 
@@ -142,10 +130,11 @@ int libcfs_kkuc_group_add(struct file *filp, int uid, int group,
                return -EBADF;
 
        /* freed in group_rem */
-       reg = kmalloc(sizeof(*reg) + data_len, 0);
+       reg = kzalloc(sizeof(*reg) + data_len, 0);
        if (reg == NULL)
                return -ENOMEM;
 
+       reg->kr_uuid = *uuid;
        reg->kr_fp = filp;
        reg->kr_uid = uid;
        memcpy(reg->kr_data, data, data_len);
@@ -160,7 +149,7 @@ int libcfs_kkuc_group_add(struct file *filp, int uid, int group,
 }
 EXPORT_SYMBOL(libcfs_kkuc_group_add);
 
-int libcfs_kkuc_group_rem(int uid, int group)
+int libcfs_kkuc_group_rem(const struct obd_uuid *uuid, int uid, int group)
 {
        struct kkuc_reg *reg, *next;
        ENTRY;
@@ -178,12 +167,13 @@ int libcfs_kkuc_group_rem(int uid, int group)
                lh.kuc_transport = KUC_TRANSPORT_GENERIC;
                lh.kuc_msgtype = KUC_MSG_SHUTDOWN;
                lh.kuc_msglen = sizeof(lh);
-               libcfs_kkuc_group_put(group, &lh);
+               libcfs_kkuc_group_put(uuid, group, &lh);
        }
 
        down_write(&kg_sem);
        list_for_each_entry_safe(reg, next, &kkuc_groups[group], kr_chain) {
-               if ((uid == 0) || (uid == reg->kr_uid)) {
+               if (obd_uuid_equals(uuid, &reg->kr_uuid) &&
+                   (uid == 0 || uid == reg->kr_uid)) {
                        list_del(&reg->kr_chain);
                        CDEBUG(D_HSM, "Removed uid=%d fp=%p from group %d\n",
                                reg->kr_uid, reg->kr_fp, group);
@@ -198,7 +188,7 @@ int libcfs_kkuc_group_rem(int uid, int group)
 }
 EXPORT_SYMBOL(libcfs_kkuc_group_rem);
 
-int libcfs_kkuc_group_put(int group, void *payload)
+int libcfs_kkuc_group_put(const struct obd_uuid *uuid, int group, void *payload)
 {
        struct kkuc_reg *reg;
        int              rc = 0;
@@ -220,7 +210,8 @@ int libcfs_kkuc_group_put(int group, void *payload)
        }
 
        list_for_each_entry(reg, &kkuc_groups[group], kr_chain) {
-               if (reg->kr_fp != NULL) {
+               if (obd_uuid_equals(uuid, &reg->kr_uuid) &&
+                   reg->kr_fp != NULL) {
                        rc = libcfs_kkuc_msg_put(reg->kr_fp, payload);
                        if (rc == 0)
                                one_success = 1;
@@ -247,8 +238,8 @@ EXPORT_SYMBOL(libcfs_kkuc_group_put);
  * @param cb_func the function to be called.
  * @param cb_arg extra argument to be passed to the callback function.
  */
-int libcfs_kkuc_group_foreach(int group, libcfs_kkuc_cb_t cb_func,
-                             void *cb_arg)
+int libcfs_kkuc_group_foreach(const struct obd_uuid *uuid, int group,
+                             libcfs_kkuc_cb_t cb_func, void *cb_arg)
 {
        struct kkuc_reg *reg;
        int              rc = 0;
@@ -261,7 +252,7 @@ int libcfs_kkuc_group_foreach(int group, libcfs_kkuc_cb_t cb_func,
 
        down_read(&kg_sem);
        list_for_each_entry(reg, &kkuc_groups[group], kr_chain) {
-               if (reg->kr_fp != NULL)
+               if (obd_uuid_equals(uuid, &reg->kr_uuid) && reg->kr_fp != NULL)
                        rc = cb_func(reg->kr_data, cb_arg);
        }
        up_read(&kg_sem);