Commit 02db0844 authored by Josef Bacik's avatar Josef Bacik Committed by Chris Mason

Btrfs: add DEVICE_READY ioctl

This will be used in conjunction with btrfs device ready <dev>.  This is
needed for initrd's to have a nice and lightweight way to tell if all of the
devices needed for a file system are in the cache currently.  This keeps
them from having to do mount+sleep loops waiting for devices to show up.
Thanks,
Signed-off-by: default avatarJosef Bacik <jbacik@fusionio.com>
parent 96c3f433
...@@ -363,7 +363,8 @@ struct btrfs_ioctl_get_dev_stats { ...@@ -363,7 +363,8 @@ struct btrfs_ioctl_get_dev_stats {
struct btrfs_ioctl_ino_path_args) struct btrfs_ioctl_ino_path_args)
#define BTRFS_IOC_LOGICAL_INO _IOWR(BTRFS_IOCTL_MAGIC, 36, \ #define BTRFS_IOC_LOGICAL_INO _IOWR(BTRFS_IOCTL_MAGIC, 36, \
struct btrfs_ioctl_ino_path_args) struct btrfs_ioctl_ino_path_args)
#define BTRFS_IOC_DEVICES_READY _IOR(BTRFS_IOCTL_MAGIC, 39, \
struct btrfs_ioctl_vol_args)
#define BTRFS_IOC_GET_DEV_STATS _IOWR(BTRFS_IOCTL_MAGIC, 52, \ #define BTRFS_IOC_GET_DEV_STATS _IOWR(BTRFS_IOCTL_MAGIC, 52, \
struct btrfs_ioctl_get_dev_stats) struct btrfs_ioctl_get_dev_stats)
#endif #endif
...@@ -1462,6 +1462,13 @@ static long btrfs_control_ioctl(struct file *file, unsigned int cmd, ...@@ -1462,6 +1462,13 @@ static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
ret = btrfs_scan_one_device(vol->name, FMODE_READ, ret = btrfs_scan_one_device(vol->name, FMODE_READ,
&btrfs_fs_type, &fs_devices); &btrfs_fs_type, &fs_devices);
break; break;
case BTRFS_IOC_DEVICES_READY:
ret = btrfs_scan_one_device(vol->name, FMODE_READ,
&btrfs_fs_type, &fs_devices);
if (ret)
break;
ret = !(fs_devices->num_devices == fs_devices->total_devices);
break;
} }
kfree(vol); kfree(vol);
......
...@@ -429,6 +429,7 @@ static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig) ...@@ -429,6 +429,7 @@ static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
mutex_init(&fs_devices->device_list_mutex); mutex_init(&fs_devices->device_list_mutex);
fs_devices->latest_devid = orig->latest_devid; fs_devices->latest_devid = orig->latest_devid;
fs_devices->latest_trans = orig->latest_trans; fs_devices->latest_trans = orig->latest_trans;
fs_devices->total_devices = orig->total_devices;
memcpy(fs_devices->fsid, orig->fsid, sizeof(fs_devices->fsid)); memcpy(fs_devices->fsid, orig->fsid, sizeof(fs_devices->fsid));
/* We have held the volume lock, it is safe to get the devices. */ /* We have held the volume lock, it is safe to get the devices. */
...@@ -739,6 +740,7 @@ int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder, ...@@ -739,6 +740,7 @@ int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
int ret; int ret;
u64 devid; u64 devid;
u64 transid; u64 transid;
u64 total_devices;
flags |= FMODE_EXCL; flags |= FMODE_EXCL;
bdev = blkdev_get_by_path(path, flags, holder); bdev = blkdev_get_by_path(path, flags, holder);
...@@ -760,6 +762,7 @@ int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder, ...@@ -760,6 +762,7 @@ int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
disk_super = (struct btrfs_super_block *)bh->b_data; disk_super = (struct btrfs_super_block *)bh->b_data;
devid = btrfs_stack_device_id(&disk_super->dev_item); devid = btrfs_stack_device_id(&disk_super->dev_item);
transid = btrfs_super_generation(disk_super); transid = btrfs_super_generation(disk_super);
total_devices = btrfs_super_num_devices(disk_super);
if (disk_super->label[0]) if (disk_super->label[0])
printk(KERN_INFO "device label %s ", disk_super->label); printk(KERN_INFO "device label %s ", disk_super->label);
else else
...@@ -767,7 +770,8 @@ int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder, ...@@ -767,7 +770,8 @@ int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
printk(KERN_CONT "devid %llu transid %llu %s\n", printk(KERN_CONT "devid %llu transid %llu %s\n",
(unsigned long long)devid, (unsigned long long)transid, path); (unsigned long long)devid, (unsigned long long)transid, path);
ret = device_list_add(path, disk_super, devid, fs_devices_ret); ret = device_list_add(path, disk_super, devid, fs_devices_ret);
if (!ret && fs_devices_ret)
(*fs_devices_ret)->total_devices = total_devices;
brelse(bh); brelse(bh);
error_close: error_close:
mutex_unlock(&uuid_mutex); mutex_unlock(&uuid_mutex);
...@@ -1433,6 +1437,7 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path) ...@@ -1433,6 +1437,7 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
list_del_rcu(&device->dev_list); list_del_rcu(&device->dev_list);
device->fs_devices->num_devices--; device->fs_devices->num_devices--;
device->fs_devices->total_devices--;
if (device->missing) if (device->missing)
root->fs_info->fs_devices->missing_devices--; root->fs_info->fs_devices->missing_devices--;
...@@ -1550,6 +1555,7 @@ static int btrfs_prepare_sprout(struct btrfs_root *root) ...@@ -1550,6 +1555,7 @@ static int btrfs_prepare_sprout(struct btrfs_root *root)
fs_devices->seeding = 0; fs_devices->seeding = 0;
fs_devices->num_devices = 0; fs_devices->num_devices = 0;
fs_devices->open_devices = 0; fs_devices->open_devices = 0;
fs_devices->total_devices = 0;
fs_devices->seed = seed_devices; fs_devices->seed = seed_devices;
generate_random_uuid(fs_devices->fsid); generate_random_uuid(fs_devices->fsid);
...@@ -1749,6 +1755,7 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path) ...@@ -1749,6 +1755,7 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
root->fs_info->fs_devices->num_devices++; root->fs_info->fs_devices->num_devices++;
root->fs_info->fs_devices->open_devices++; root->fs_info->fs_devices->open_devices++;
root->fs_info->fs_devices->rw_devices++; root->fs_info->fs_devices->rw_devices++;
root->fs_info->fs_devices->total_devices++;
if (device->can_discard) if (device->can_discard)
root->fs_info->fs_devices->num_can_discard++; root->fs_info->fs_devices->num_can_discard++;
root->fs_info->fs_devices->total_rw_bytes += device->total_bytes; root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
......
...@@ -126,6 +126,7 @@ struct btrfs_fs_devices { ...@@ -126,6 +126,7 @@ struct btrfs_fs_devices {
u64 missing_devices; u64 missing_devices;
u64 total_rw_bytes; u64 total_rw_bytes;
u64 num_can_discard; u64 num_can_discard;
u64 total_devices;
struct block_device *latest_bdev; struct block_device *latest_bdev;
/* all of the devices in the FS, protected by a mutex /* all of the devices in the FS, protected by a mutex
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment