From: Anand Jain <anand.j...@oracle.com>
This patch provides helper functions to force a device to failed,
and we need it for the following reasons,
1) a. It can be reported that device has failed when it does and
b. Close the device when it goes offline so that blocklayer can
cleanup
2) Identify the candidate for the auto replace
3) Stop further RW to the failing device and
4) A device in the multi device btrfs may fail, but as of now in
some system config whole of btrfs gets unmounted.
Signed-off-by: Anand Jain <anand.j...@oracle.com>
Tested-by: Austin S. Hemmelgarn <ahferro...@gmail.com>
---
V8: General misc cleanup. Based on v4.14-rc2
fs/btrfs/volumes.c | 104 +++++++++++++++++++++++++++++++++++++++++++++++++++++
fs/btrfs/volumes.h | 15 +++++++-
2 files changed, 118 insertions(+), 1 deletion(-)
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 0e8f16c305df..06e7cf4cef81 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -7255,3 +7255,107 @@ void btrfs_reset_fs_info_ptr(struct btrfs_fs_info
*fs_info)
fs_devices = fs_devices->seed;
}
}
+
+static void do_close_device(struct work_struct *work)
+{
+ struct btrfs_device *device;
+
+ device = container_of(work, struct btrfs_device, rcu_work);
+
+ if (device->closing_bdev)
+ blkdev_put(device->closing_bdev, device->mode);
+
+ device->closing_bdev = NULL;
+}
+
+static void btrfs_close_one_device(struct rcu_head *head)
+{
+ struct btrfs_device *device;
+
+ device = container_of(head, struct btrfs_device, rcu);
+
+ INIT_WORK(&device->rcu_work, do_close_device);
+ schedule_work(&device->rcu_work);
+}
+
+void btrfs_force_device_close(struct btrfs_device *device)
+{
+ struct btrfs_fs_info *fs_info;
+ struct btrfs_fs_devices *fs_devices;
+
+ fs_devices = device->fs_devices;
+ fs_info = fs_devices->fs_info;
+
+ btrfs_sysfs_rm_device_link(fs_devices, device);
+
+ mutex_lock(&fs_devices->device_list_mutex);
+ mutex_lock(&fs_devices->fs_info->chunk_mutex);
+
+ btrfs_assign_next_active_device(fs_devices->fs_info, device, NULL);
+
+ if (device->bdev)
+ fs_devices->open_devices--;
+
+ if (device->writeable) {
+ list_del_init(&device->dev_alloc_list);
+ fs_devices->rw_devices--;
+ }
+ device->writeable = 0;
+
+ /*
+ * Todo: We have miss-used missing flag all around, and here
+ * too for now. (In the long run I want to keep missing to only
+ * indicate that it was not present when RAID was assembled.)
+ */
+ device->missing = 1;
+ fs_devices->missing_devices++;
+ device->closing_bdev = device->bdev;
+ device->bdev = NULL;
+
+ call_rcu(&device->rcu, btrfs_close_one_device);
+
+ mutex_unlock(&fs_devices->fs_info->chunk_mutex);
+ mutex_unlock(&fs_devices->device_list_mutex);
+
+ rcu_barrier();
+
+ btrfs_warn_in_rcu(fs_info, "device %s failed",
+ rcu_str_deref(device->name));
+
+ /*
+ * We lost one/more disk, which means its not as it
+ * was configured by the user. Show mount should show
+ * degraded.
+ */
+ btrfs_set_opt(fs_info->mount_opt, DEGRADED);
+
+ /*
+ * Now having lost one of the device, check if chunk stripe
+ * is incomplete and handle fatal error if needed.
+ */
+ if (!btrfs_check_rw_degradable(fs_info))
+ btrfs_handle_fs_error(fs_info, -EIO,
+ "devices below critical level");
+}
+
+void btrfs_mark_device_failed(struct btrfs_device *dev)
+{
+ struct btrfs_fs_devices *fs_devices = dev->fs_devices;
+
+ /* This shouldn't be called if device is already missing */
+ if (dev->missing || !dev->bdev)
+ return;
+ if (dev->failed)
+ return;
+ dev->failed = 1;
+
+ /* Last RW device is requested to force close let FS handle it. */
+ if (fs_devices->rw_devices == 1) {
+ btrfs_handle_fs_error(fs_devices->fs_info, -EIO,
+ "Last RW device failed");
+ return;
+ }
+
+ /* Point of no return start here. */
+ btrfs_force_device_close(dev);
+}
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 6108fdfec67f..05b150c03995 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -65,13 +65,26 @@ struct btrfs_device {
struct btrfs_pending_bios pending_sync_bios;
struct block_device *bdev;
+ struct block_device *closing_bdev;
/* the mode sent to blkdev_get */
fmode_t mode;
int writeable;
int in_fs_metadata;
+ /* missing: device not found at the time of mount */
int missing;
+ /* failed: device confirmed to have experienced critical io failure */
+ int failed;
+ /*
+ * offline: system or user or block layer transport has removed
+ * offlined the device which was once present and without going
+ * through unmount. Implies an intriem communication break down
+ * and not necessarily a candidate for the device replace. And
+ * device might be online after user intervention or after
+ * block transport layer error recovery.
+ */
+ int offline;
int can_discard;
int is_tgtdev_for_dev_replace;
blk_status_t last_flush_error;
@@ -544,5 +557,5 @@ void btrfs_reset_fs_info_ptr(struct btrfs_fs_info *fs_info);
bool btrfs_check_rw_degradable(struct btrfs_fs_info *fs_info);
void btrfs_report_missing_device(struct btrfs_fs_info *fs_info, u64 devid,
u8 *uuid);
-
+void btrfs_mark_device_failed(struct btrfs_device *dev);
#endif
--
2.7.0
--
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