From 7d824b6f9cf28917d8a05891ef423fb0e4e34c69 Mon Sep 17 00:00:00 2001 From: David Sterba Date: Wed, 7 May 2014 17:37:51 +0200 Subject: [PATCH] btrfs: balance filter: add limit of processed chunks This started as debugging helper, to watch the effects of converting between raid levels on multiple devices, but could be useful standalone. In my case the usage filter was not finegrained enough and led to converting too many chunks at once. Another example use is in connection with drange+devid or vrange filters that allow to work with a specific chunk or even with a chunk on a given device. The limit filter applies last, the value of 0 means no limiting. CC: Ilya Dryomov CC: Hugo Mills Signed-off-by: David Sterba Signed-off-by: Chris Mason --- fs/btrfs/ctree.h | 7 ++++++- fs/btrfs/volumes.c | 18 ++++++++++++++++++ fs/btrfs/volumes.h | 1 + include/uapi/linux/btrfs.h | 3 ++- 4 files changed, 27 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index ba6b88528dc7..e6f899dc5e47 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -840,7 +840,10 @@ struct btrfs_disk_balance_args { /* BTRFS_BALANCE_ARGS_* */ __le64 flags; - __le64 unused[8]; + /* BTRFS_BALANCE_ARGS_LIMIT value */ + __le64 limit; + + __le64 unused[7]; } __attribute__ ((__packed__)); /* @@ -2897,6 +2900,7 @@ btrfs_disk_balance_args_to_cpu(struct btrfs_balance_args *cpu, cpu->vend = le64_to_cpu(disk->vend); cpu->target = le64_to_cpu(disk->target); cpu->flags = le64_to_cpu(disk->flags); + cpu->limit = le64_to_cpu(disk->limit); } static inline void @@ -2914,6 +2918,7 @@ btrfs_cpu_balance_args_to_disk(struct btrfs_disk_balance_args *disk, disk->vend = cpu_to_le64(cpu->vend); disk->target = cpu_to_le64(cpu->target); disk->flags = cpu_to_le64(cpu->flags); + disk->limit = cpu_to_le64(cpu->limit); } /* struct btrfs_super_block */ diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 49d7fab73360..3b761a456acd 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -2922,6 +2922,16 @@ static int should_balance_chunk(struct btrfs_root *root, return 0; } + /* + * limited by count, must be the last filter + */ + if ((bargs->flags & BTRFS_BALANCE_ARGS_LIMIT)) { + if (bargs->limit == 0) + return 0; + else + bargs->limit--; + } + return 1; } @@ -2944,6 +2954,9 @@ static int __btrfs_balance(struct btrfs_fs_info *fs_info) int ret; int enospc_errors = 0; bool counting = true; + u64 limit_data = bctl->data.limit; + u64 limit_meta = bctl->meta.limit; + u64 limit_sys = bctl->sys.limit; /* step one make some room on all the devices */ devices = &fs_info->fs_devices->devices; @@ -2982,6 +2995,11 @@ static int __btrfs_balance(struct btrfs_fs_info *fs_info) memset(&bctl->stat, 0, sizeof(bctl->stat)); spin_unlock(&fs_info->balance_lock); again: + if (!counting) { + bctl->data.limit = limit_data; + bctl->meta.limit = limit_meta; + bctl->sys.limit = limit_sys; + } key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID; key.offset = (u64)-1; key.type = BTRFS_CHUNK_ITEM_KEY; diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index 80754f9dd3df..1a15bbeb65e2 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -255,6 +255,7 @@ struct map_lookup { #define BTRFS_BALANCE_ARGS_DEVID (1ULL << 2) #define BTRFS_BALANCE_ARGS_DRANGE (1ULL << 3) #define BTRFS_BALANCE_ARGS_VRANGE (1ULL << 4) +#define BTRFS_BALANCE_ARGS_LIMIT (1ULL << 5) /* * Profile changing flags. When SOFT is set we won't relocate chunk if diff --git a/include/uapi/linux/btrfs.h b/include/uapi/linux/btrfs.h index b4d69092fbdb..901a3c563f60 100644 --- a/include/uapi/linux/btrfs.h +++ b/include/uapi/linux/btrfs.h @@ -211,7 +211,8 @@ struct btrfs_balance_args { __u64 flags; - __u64 unused[8]; + __u64 limit; /* limit number of processed chunks */ + __u64 unused[7]; } __attribute__ ((__packed__)); /* report balance progress to userspace */ -- 2.20.1