@@ -2183,6 +2183,10 @@ static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
ret = btrfs_scan_one_device(vol->name, FMODE_READ,
&btrfs_fs_type, &fs_devices);
break;
+ case BTRFS_IOC_IGNORE_DEV:
+ ret = btrfs_ignore_one_device(vol->name, FMODE_READ,
+ &btrfs_fs_type, &fs_devices);
+ break;
case BTRFS_IOC_DEVICES_READY:
ret = btrfs_scan_one_device(vol->name, FMODE_READ,
&btrfs_fs_type, &fs_devices);
@@ -1214,6 +1214,70 @@ int btrfs_read_disk_super(struct block_device *bdev, u64 bytenr,
return 0;
}
+static int device_list_remove(struct btrfs_super_block *disk_super, u64 devid)
+{
+ int ret = 0;
+ struct btrfs_fs_devices *fs_devices;
+ struct btrfs_device *device;
+
+ fs_devices = find_fsid(disk_super->fsid);
+ if (!fs_devices)
+ return -ENOENT;
+
+ if (fs_devices->opened)
+ return -EBUSY;
+
+ mutex_lock(&uuid_mutex);
+
+ device = find_device(fs_devices, devid, disk_super->dev_item.uuid);
+ if (device)
+ delete_device_from_list(device);
+
+ mutex_unlock(&uuid_mutex);
+
+ return ret;
+}
+
+int btrfs_ignore_one_device(const char *path, fmode_t flags, void *holder,
+ struct btrfs_fs_devices **fs_devices_ret)
+{
+ struct btrfs_super_block *disk_super;
+ struct block_device *bdev;
+ struct page *page;
+ int ret = -EINVAL;
+ u64 devid;
+ u64 bytenr;
+
+ bytenr = btrfs_sb_offset(0);
+ flags |= FMODE_EXCL;
+
+ bdev = blkdev_get_by_path(path, flags, holder);
+ if (IS_ERR(bdev)) {
+ ret = PTR_ERR(bdev);
+ goto error;
+ }
+
+ if (btrfs_read_disk_super(bdev, bytenr, &page, &disk_super))
+ goto error_bdev_put;
+
+ devid = btrfs_stack_device_id(&disk_super->dev_item);
+
+ ret = device_list_remove(disk_super, devid);
+ if (ret)
+ pr_err("BTRFS: %pU device %s devid %llu failed to ignore: %d\n",
+ disk_super->fsid, path, devid, ret);
+ else
+ pr_info("BTRFS: %pU device %s devid %llu ignored\n",
+ disk_super->fsid, path, devid);
+
+ btrfs_release_disk_super(page);
+
+error_bdev_put:
+ blkdev_put(bdev, flags);
+error:
+ return ret;
+}
+
/*
* Look for a btrfs signature on a device. This may be called out of the mount path
* and we are not allowed to call set_blocksize during the scan. The superblock
@@ -421,6 +421,8 @@ int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
fmode_t flags, void *holder);
int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
struct btrfs_fs_devices **fs_devices_ret);
+int btrfs_ignore_one_device(const char *path, fmode_t flags, void *holder,
+ struct btrfs_fs_devices **fs_devices_ret);
int btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
void btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices, int step);
void btrfs_assign_next_active_device(struct btrfs_fs_info *fs_info,
@@ -740,6 +740,8 @@ enum btrfs_err_code {
struct btrfs_ioctl_vol_args)
#define BTRFS_IOC_SCAN_DEV _IOW(BTRFS_IOCTL_MAGIC, 4, \
struct btrfs_ioctl_vol_args)
+#define BTRFS_IOC_IGNORE_DEV _IOW(BTRFS_IOCTL_MAGIC, 5, \
+ struct btrfs_ioctl_vol_args)
/* trans start and trans end are dangerous, and only for
* use by applications that know how to avoid the
* resulting deadlocks
Support for a new command is being added here: btrfs dev ignore <dev> Which shall undo the effects of the command btrfs dev scan <dev> This cli/ioctl is needed as there is no way to continue to mount in degraded mode if the device is already scanned, which is required to recover from the split brain raid conditions. This patch proposes to use ioctl #5 as it was empty. IOW(BTRFS_IOCTL_MAGIC, 5, ..) If #5 is reserved for some other purpose, I think I should change this. Signed-off-by: Anand Jain <anand.jain@oracle.com> --- v2: Use -EBUSY instead of -ENOENT Since now delete_device_from_list() holds device_list_mutex more fine grined as required, so dont hole device_list_mutex here. Reword and indent pr_err/info. fs/btrfs/super.c | 4 +++ fs/btrfs/volumes.c | 64 ++++++++++++++++++++++++++++++++++++++++++++++ fs/btrfs/volumes.h | 2 ++ include/uapi/linux/btrfs.h | 2 ++ 4 files changed, 72 insertions(+)