This adds functions to get and put a spare device from the list.
So that hot repace code can pick a spare device when needed.
Signed-off-by: Anand Jain <anand.jain@xxxxxxxxxx>
Tested-by: Austin S. Hemmelgarn <ahferroin7@xxxxxxxxx>
---
fs/btrfs/ctree.h | 1 +
fs/btrfs/super.c | 5 +++++
fs/btrfs/volumes.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++++
fs/btrfs/volumes.h | 2 ++
4 files changed, 61 insertions(+)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 2c185a8e92f0..aa693cfdc9f0 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -4185,6 +4185,7 @@ void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info);
ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size);
/* super.c */
+struct file_system_type *btrfs_get_fs_type(void);
int btrfs_parse_options(struct btrfs_root *root, char *options,
unsigned long new_flags);
int btrfs_sync_fs(struct super_block *sb, int wait);
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 87639fa53b10..49ba899b2d36 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -69,6 +69,11 @@ static struct file_system_type btrfs_fs_type;
static int btrfs_remount(struct super_block *sb, int *flags, char *data);
+struct file_system_type *btrfs_get_fs_type()
+{
+ return &btrfs_fs_type;
+}
+
const char *btrfs_decode_error(int errno)
{
char *errstr = "unknown";
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index d729539f9612..072cefac958c 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -525,6 +525,59 @@ static void pending_bios_fn(struct btrfs_work *work)
run_scheduled_bios(device);
}
+int btrfs_get_spare_device(char **path)
+{
+ int ret = 1;
+ struct btrfs_fs_devices *fs_devices;
+ struct btrfs_device *device;
+ struct list_head *fs_uuids = btrfs_get_fs_uuids();
+
+ mutex_lock(&uuid_mutex);
+ list_for_each_entry(fs_devices, fs_uuids, list) {
+ if (!fs_devices->spare)
+ continue;
+
+ /* as of now there is only one device in the spare fs_devices */
+ device = list_entry(fs_devices->devices.next,
+ struct btrfs_device, dev_list);
+
+ if (!device || !device->name)
+ continue;
+
+ fs_devices->spare = 0;
+ /*
+ * Its under uuid_mutex and there is one spare per fsid
+ * so rcu lock is actually not required
+ */
+ *path = kstrdup(device->name->str, GFP_KERNEL);
+ if (*path)
+ ret = 0;
+ else
+ ret = -ENOMEM;
+ break;
+ }
+
+ if (!ret) {
+ btrfs_sysfs_remove_fsid(fs_devices);
+ list_del(&fs_devices->list);
+ free_fs_devices(fs_devices);
+ }
+ mutex_unlock(&uuid_mutex);
+
+ return ret;
+}
+
+void btrfs_put_spare_device(char *path)
+{
+ struct file_system_type *btrfs_fs_type;
+ struct btrfs_fs_devices *fs_devices;
+
+ btrfs_fs_type = btrfs_get_fs_type();
+
+ if (btrfs_scan_one_device(path, FMODE_READ,
+ btrfs_fs_type, &fs_devices))
+ printk(KERN_INFO "failed to return spare device\n");
+}
void btrfs_free_stale_device(struct btrfs_device *cur_dev)
{
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 51cf716eb35b..b4308afa3097 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -469,6 +469,8 @@ int btrfs_init_new_device(struct btrfs_root *root, char *path);
int btrfs_init_dev_replace_tgtdev(struct btrfs_root *root, char *device_path,
struct btrfs_device *srcdev,
struct btrfs_device **device_out);
+int btrfs_get_spare_device(char **path);
+void btrfs_put_spare_device(char *path);
int btrfs_balance(struct btrfs_balance_control *bctl,
struct btrfs_ioctl_balance_args *bargs);
int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info);
--
2.7.0
--
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