From: Ilya Dryomov Date: Mon, 16 Jan 2012 20:04:49 +0000 (+0200) Subject: Btrfs: allow for canceling restriper X-Git-Tag: firefly_0821_release~3680^2~3391^2~49^2~2 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=a7e99c691af553fc15ac46a51f130b7c59a65f76;p=firefly-linux-kernel-4.4.55.git Btrfs: allow for canceling restriper Implement an ioctl for canceling restriper. Currently we wait until relocation of the current block group is finished, in future this can be done by triggering a commit. Balance item is deleted and no memory about the interrupted balance is kept. Signed-off-by: Ilya Dryomov --- diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 1afda75d5414..dfc136cc07d7 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -1216,6 +1216,7 @@ struct btrfs_fs_info { struct mutex balance_mutex; atomic_t balance_running; atomic_t balance_pause_req; + atomic_t balance_cancel_req; struct btrfs_balance_control *balance_ctl; wait_queue_head_t balance_wait_q; diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 8ce837407800..c23b82d8ec08 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -2006,6 +2006,7 @@ struct btrfs_root *open_ctree(struct super_block *sb, mutex_init(&fs_info->balance_mutex); atomic_set(&fs_info->balance_running, 0); atomic_set(&fs_info->balance_pause_req, 0); + atomic_set(&fs_info->balance_cancel_req, 0); fs_info->balance_ctl = NULL; init_waitqueue_head(&fs_info->balance_wait_q); diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index f572c53dda4f..60852217ce9a 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -3076,6 +3076,8 @@ void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, bargs->state |= BTRFS_BALANCE_STATE_RUNNING; if (atomic_read(&fs_info->balance_pause_req)) bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ; + if (atomic_read(&fs_info->balance_cancel_req)) + bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ; memcpy(&bargs->data, &bctl->data, sizeof(bargs->data)); memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta)); @@ -3157,6 +3159,8 @@ static long btrfs_ioctl_balance_ctl(struct btrfs_root *root, int cmd) switch (cmd) { case BTRFS_BALANCE_CTL_PAUSE: return btrfs_pause_balance(root->fs_info); + case BTRFS_BALANCE_CTL_CANCEL: + return btrfs_cancel_balance(root->fs_info); } return -EINVAL; diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h index e972e11a8d77..cd19d10794b9 100644 --- a/fs/btrfs/ioctl.h +++ b/fs/btrfs/ioctl.h @@ -111,6 +111,7 @@ struct btrfs_ioctl_fs_info_args { /* balance control ioctl modes */ #define BTRFS_BALANCE_CTL_PAUSE 1 +#define BTRFS_BALANCE_CTL_CANCEL 2 /* * this is packed, because it should be exactly the same as its disk @@ -142,6 +143,7 @@ struct btrfs_balance_progress { #define BTRFS_BALANCE_STATE_RUNNING (1ULL << 0) #define BTRFS_BALANCE_STATE_PAUSE_REQ (1ULL << 1) +#define BTRFS_BALANCE_STATE_CANCEL_REQ (1ULL << 2) struct btrfs_ioctl_balance_args { __u64 flags; /* in/out */ diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index d32660ce753d..c32667318ae4 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -2492,7 +2492,8 @@ static int __btrfs_balance(struct btrfs_fs_info *fs_info) key.type = BTRFS_CHUNK_ITEM_KEY; while (1) { - if (atomic_read(&fs_info->balance_pause_req)) { + if (atomic_read(&fs_info->balance_pause_req) || + atomic_read(&fs_info->balance_cancel_req)) { ret = -ECANCELED; goto error; } @@ -2560,7 +2561,10 @@ error: static inline int balance_need_close(struct btrfs_fs_info *fs_info) { - return atomic_read(&fs_info->balance_pause_req) == 0; + /* cancel requested || normal exit path */ + return atomic_read(&fs_info->balance_cancel_req) || + (atomic_read(&fs_info->balance_pause_req) == 0 && + atomic_read(&fs_info->balance_cancel_req) == 0); } static void __cancel_balance(struct btrfs_fs_info *fs_info) @@ -2586,7 +2590,8 @@ int btrfs_balance(struct btrfs_balance_control *bctl, int ret; if (btrfs_fs_closing(fs_info) || - atomic_read(&fs_info->balance_pause_req)) { + atomic_read(&fs_info->balance_pause_req) || + atomic_read(&fs_info->balance_cancel_req)) { ret = -EINVAL; goto out; } @@ -2832,6 +2837,42 @@ int btrfs_pause_balance(struct btrfs_fs_info *fs_info) return ret; } +int btrfs_cancel_balance(struct btrfs_fs_info *fs_info) +{ + mutex_lock(&fs_info->balance_mutex); + if (!fs_info->balance_ctl) { + mutex_unlock(&fs_info->balance_mutex); + return -ENOTCONN; + } + + atomic_inc(&fs_info->balance_cancel_req); + /* + * if we are running just wait and return, balance item is + * deleted in btrfs_balance in this case + */ + if (atomic_read(&fs_info->balance_running)) { + mutex_unlock(&fs_info->balance_mutex); + wait_event(fs_info->balance_wait_q, + atomic_read(&fs_info->balance_running) == 0); + mutex_lock(&fs_info->balance_mutex); + } else { + /* __cancel_balance needs volume_mutex */ + mutex_unlock(&fs_info->balance_mutex); + mutex_lock(&fs_info->volume_mutex); + mutex_lock(&fs_info->balance_mutex); + + if (fs_info->balance_ctl) + __cancel_balance(fs_info); + + mutex_unlock(&fs_info->volume_mutex); + } + + BUG_ON(fs_info->balance_ctl || atomic_read(&fs_info->balance_running)); + atomic_dec(&fs_info->balance_cancel_req); + mutex_unlock(&fs_info->balance_mutex); + return 0; +} + /* * shrinking a device means finding all of the device extents past * the new size, and then following the back refs to the chunks. diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index 80953afb12b9..caa9abd218ef 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -274,6 +274,7 @@ int btrfs_balance(struct btrfs_balance_control *bctl, struct btrfs_ioctl_balance_args *bargs); int btrfs_recover_balance(struct btrfs_root *tree_root); int btrfs_pause_balance(struct btrfs_fs_info *fs_info); +int btrfs_cancel_balance(struct btrfs_fs_info *fs_info); int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset); int find_free_dev_extent(struct btrfs_trans_handle *trans, struct btrfs_device *device, u64 num_bytes,