+// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2007 Oracle. All rights reserved.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public
- * License v2 as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public
- * License along with this program; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 021110-1307, USA.
*/
+
#include <linux/sched.h>
#include <linux/bio.h>
#include <linux/slab.h>
* device_list_mutex
* chunk_mutex
* balance_mutex
+ *
+ *
+ * Exclusive operations, BTRFS_FS_EXCL_OP
+ * ======================================
+ *
+ * Maintains the exclusivity of the following operations that apply to the
+ * whole filesystem and cannot run in parallel.
+ *
+ * - Balance (*)
+ * - Device add
+ * - Device remove
+ * - Device replace (*)
+ * - Resize
+ *
+ * The device operations (as above) can be in one of the following states:
+ *
+ * - Running state
+ * - Paused state
+ * - Completed state
+ *
+ * Only device operations marked with (*) can go into the Paused state for the
+ * following reasons:
+ *
+ * - ioctl (only Balance can be Paused through ioctl)
+ * - filesystem remounted as read-only
+ * - filesystem unmounted and mounted as read-only
+ * - system power-cycle and filesystem mounted as read-only
+ * - filesystem or device errors leading to forced read-only
+ *
+ * BTRFS_FS_EXCL_OP flag is set and cleared using atomic operations.
+ * During the course of Paused state, the BTRFS_FS_EXCL_OP remains set.
+ * A device operation in Paused or Running state can be canceled or resumed
+ * either by ioctl (Balance only) or when remounted as read-write.
+ * BTRFS_FS_EXCL_OP flag is cleared when the device operation is canceled or
+ * completed.
*/
DEFINE_MUTEX(uuid_mutex);
INIT_LIST_HEAD(&fs_devs->devices);
INIT_LIST_HEAD(&fs_devs->resized_devices);
INIT_LIST_HEAD(&fs_devs->alloc_list);
- INIT_LIST_HEAD(&fs_devs->list);
+ INIT_LIST_HEAD(&fs_devs->fs_list);
if (fsid)
memcpy(fs_devs->fsid, fsid, BTRFS_FSID_SIZE);
while (!list_empty(&fs_uuids)) {
fs_devices = list_entry(fs_uuids.next,
- struct btrfs_fs_devices, list);
- list_del(&fs_devices->list);
+ struct btrfs_fs_devices, fs_list);
+ list_del(&fs_devices->fs_list);
free_fs_devices(fs_devices);
}
}
static struct btrfs_device *find_device(struct btrfs_fs_devices *fs_devices,
u64 devid, const u8 *uuid)
{
- struct list_head *head = &fs_devices->devices;
struct btrfs_device *dev;
- list_for_each_entry(dev, head, dev_list) {
+ list_for_each_entry(dev, &fs_devices->devices, dev_list) {
if (dev->devid == devid &&
(!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
return dev;
{
struct btrfs_fs_devices *fs_devices;
- list_for_each_entry(fs_devices, &fs_uuids, list) {
+ list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
return fs_devices;
}
struct btrfs_fs_devices *fs_devs, *tmp_fs_devs;
struct btrfs_device *dev, *tmp_dev;
- list_for_each_entry_safe(fs_devs, tmp_fs_devs, &fs_uuids, list) {
+ list_for_each_entry_safe(fs_devs, tmp_fs_devs, &fs_uuids, fs_list) {
if (fs_devs->opened)
continue;
/* delete the stale device */
if (fs_devs->num_devices == 1) {
btrfs_sysfs_remove_fsid(fs_devs);
- list_del(&fs_devs->list);
+ list_del(&fs_devs->fs_list);
free_fs_devices(fs_devs);
break;
} else {
if (IS_ERR(fs_devices))
return ERR_CAST(fs_devices);
- list_add(&fs_devices->list, &fs_uuids);
+ list_add(&fs_devices->fs_list, &fs_uuids);
device = NULL;
} else {
new_device->fs_devices = device->fs_devices;
}
-static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
+static int close_fs_devices(struct btrfs_fs_devices *fs_devices)
{
struct btrfs_device *device, *tmp;
struct list_head pending_put;
int ret;
mutex_lock(&uuid_mutex);
- ret = __btrfs_close_devices(fs_devices);
+ ret = close_fs_devices(fs_devices);
if (!fs_devices->opened) {
seed_devices = fs_devices->seed;
fs_devices->seed = NULL;
while (seed_devices) {
fs_devices = seed_devices;
seed_devices = fs_devices->seed;
- __btrfs_close_devices(fs_devices);
+ close_fs_devices(fs_devices);
free_fs_devices(fs_devices);
}
return ret;
}
-static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
+static int open_fs_devices(struct btrfs_fs_devices *fs_devices,
fmode_t flags, void *holder)
{
- struct list_head *head = &fs_devices->devices;
struct btrfs_device *device;
struct btrfs_device *latest_dev = NULL;
int ret = 0;
flags |= FMODE_EXCL;
- list_for_each_entry(device, head, dev_list) {
+ list_for_each_entry(device, &fs_devices->devices, dev_list) {
/* Just open everything we can; ignore failures here */
if (btrfs_open_one_device(fs_devices, device, flags, holder))
continue;
ret = 0;
} else {
list_sort(NULL, &fs_devices->devices, devid_cmp);
- ret = __btrfs_open_devices(fs_devices, flags, holder);
+ ret = open_fs_devices(fs_devices, flags, holder);
}
mutex_unlock(&uuid_mutex);
return ret;
{
struct btrfs_device *device;
struct btrfs_fs_devices *cur_devices;
+ struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
u64 num_devices;
int ret = 0;
mutex_lock(&fs_info->volume_mutex);
mutex_lock(&uuid_mutex);
- num_devices = fs_info->fs_devices->num_devices;
+ num_devices = fs_devices->num_devices;
btrfs_dev_replace_read_lock(&fs_info->dev_replace);
if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace)) {
WARN_ON(num_devices < 1);
*/
cur_devices = device->fs_devices;
- mutex_lock(&fs_info->fs_devices->device_list_mutex);
+ mutex_lock(&fs_devices->device_list_mutex);
list_del_rcu(&device->dev_list);
device->fs_devices->num_devices--;
if (device->bdev) {
device->fs_devices->open_devices--;
/* remove sysfs entry */
- btrfs_sysfs_rm_device_link(fs_info->fs_devices, device);
+ btrfs_sysfs_rm_device_link(fs_devices, device);
}
num_devices = btrfs_super_num_devices(fs_info->super_copy) - 1;
btrfs_set_super_num_devices(fs_info->super_copy, num_devices);
- mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+ mutex_unlock(&fs_devices->device_list_mutex);
/*
* at this point, the device is zero sized and detached from
call_rcu(&device->rcu, free_device_rcu);
if (cur_devices->open_devices == 0) {
- struct btrfs_fs_devices *fs_devices;
- fs_devices = fs_info->fs_devices;
while (fs_devices) {
if (fs_devices->seed == cur_devices) {
fs_devices->seed = cur_devices->seed;
fs_devices = fs_devices->seed;
}
cur_devices->seed = NULL;
- __btrfs_close_devices(cur_devices);
+ close_fs_devices(cur_devices);
free_fs_devices(cur_devices);
}
if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
mutex_lock(&fs_info->chunk_mutex);
list_add(&device->dev_alloc_list,
- &fs_info->fs_devices->alloc_list);
+ &fs_devices->alloc_list);
device->fs_devices->rw_devices++;
mutex_unlock(&fs_info->chunk_mutex);
}
tmp_fs_devices = tmp_fs_devices->seed;
}
fs_devices->seed = NULL;
- __btrfs_close_devices(fs_devices);
+ close_fs_devices(fs_devices);
free_fs_devices(fs_devices);
}
}
return PTR_ERR(old_devices);
}
- list_add(&old_devices->list, &fs_uuids);
+ list_add(&old_devices->fs_list, &fs_uuids);
memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
seed_devices->opened = 1;
return 0;
}
+ /*
+ * A ro->rw remount sequence should continue with the paused balance
+ * regardless of who pauses it, system or the user as of now, so set
+ * the resume flag.
+ */
+ spin_lock(&fs_info->balance_lock);
+ fs_info->balance_ctl->flags |= BTRFS_BALANCE_RESUME;
+ spin_unlock(&fs_info->balance_lock);
+
tsk = kthread_run(balance_kthread, fs_info, "btrfs-balance");
return PTR_ERR_OR_ZERO(tsk);
}
if (IS_ERR(fs_devices))
return fs_devices;
- ret = __btrfs_open_devices(fs_devices, FMODE_READ,
- fs_info->bdev_holder);
+ ret = open_fs_devices(fs_devices, FMODE_READ, fs_info->bdev_holder);
if (ret) {
free_fs_devices(fs_devices);
fs_devices = ERR_PTR(ret);
}
if (!fs_devices->seeding) {
- __btrfs_close_devices(fs_devices);
+ close_fs_devices(fs_devices);
free_fs_devices(fs_devices);
fs_devices = ERR_PTR(-EINVAL);
goto out;
git.samba.org / sfrench / cifs-2.6.git / blobdiff