Btrfs: implement online profile changing
Profile changing is done by launching a balance with
BTRFS_BALANCE_CONVERT bits set and target fields of respective
btrfs_balance_args structs initialized. Profile reducing code in this
case will pick restriper's target profile if it's available instead of
doing a blind reduce. If target profile is not yet available it goes
back to a plain reduce.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index a1a18ea..e6a832e 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3030,7 +3030,9 @@
/*
* @flags: available profiles in extended format (see ctree.h)
*
- * Returns reduced profile in chunk format.
+ * Returns reduced profile in chunk format. If profile changing is in
+ * progress (either running or paused) picks the target profile (if it's
+ * already available), otherwise falls back to plain reducing.
*/
u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags)
{
@@ -3042,6 +3044,34 @@
u64 num_devices = root->fs_info->fs_devices->rw_devices +
root->fs_info->fs_devices->missing_devices;
+ /* pick restriper's target profile if it's available */
+ spin_lock(&root->fs_info->balance_lock);
+ if (root->fs_info->balance_ctl) {
+ struct btrfs_balance_control *bctl = root->fs_info->balance_ctl;
+ u64 tgt = 0;
+
+ if ((flags & BTRFS_BLOCK_GROUP_DATA) &&
+ (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
+ (flags & bctl->data.target)) {
+ tgt = BTRFS_BLOCK_GROUP_DATA | bctl->data.target;
+ } else if ((flags & BTRFS_BLOCK_GROUP_SYSTEM) &&
+ (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
+ (flags & bctl->sys.target)) {
+ tgt = BTRFS_BLOCK_GROUP_SYSTEM | bctl->sys.target;
+ } else if ((flags & BTRFS_BLOCK_GROUP_METADATA) &&
+ (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
+ (flags & bctl->meta.target)) {
+ tgt = BTRFS_BLOCK_GROUP_METADATA | bctl->meta.target;
+ }
+
+ if (tgt) {
+ spin_unlock(&root->fs_info->balance_lock);
+ flags = tgt;
+ goto out;
+ }
+ }
+ spin_unlock(&root->fs_info->balance_lock);
+
if (num_devices == 1)
flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0);
if (num_devices < 4)
@@ -3065,6 +3095,7 @@
flags &= ~BTRFS_BLOCK_GROUP_RAID0;
}
+out:
/* extended -> chunk profile */
flags &= ~BTRFS_AVAIL_ALLOC_BIT_SINGLE;
return flags;
@@ -6795,6 +6826,29 @@
u64 stripped = BTRFS_BLOCK_GROUP_RAID0 |
BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
+ if (root->fs_info->balance_ctl) {
+ struct btrfs_balance_control *bctl = root->fs_info->balance_ctl;
+ u64 tgt = 0;
+
+ /* pick restriper's target profile and return */
+ if (flags & BTRFS_BLOCK_GROUP_DATA &&
+ bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) {
+ tgt = BTRFS_BLOCK_GROUP_DATA | bctl->data.target;
+ } else if (flags & BTRFS_BLOCK_GROUP_SYSTEM &&
+ bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
+ tgt = BTRFS_BLOCK_GROUP_SYSTEM | bctl->sys.target;
+ } else if (flags & BTRFS_BLOCK_GROUP_METADATA &&
+ bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) {
+ tgt = BTRFS_BLOCK_GROUP_METADATA | bctl->meta.target;
+ }
+
+ if (tgt) {
+ /* extended -> chunk profile */
+ tgt &= ~BTRFS_AVAIL_ALLOC_BIT_SINGLE;
+ return tgt;
+ }
+ }
+
/*
* we add in the count of missing devices because we want
* to make sure that any RAID levels on a degraded FS
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index e86c9e4..f08210e 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2438,6 +2438,75 @@
}
}
+ /*
+ * Profile changing sanity checks. Skip them if a simple
+ * balance is requested.
+ */
+ if (!((bctl->data.flags | bctl->sys.flags | bctl->meta.flags) &
+ BTRFS_BALANCE_ARGS_CONVERT))
+ goto do_balance;
+
+ allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
+ if (fs_info->fs_devices->num_devices == 1)
+ allowed |= BTRFS_BLOCK_GROUP_DUP;
+ else if (fs_info->fs_devices->num_devices < 4)
+ allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1);
+ else
+ allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
+ BTRFS_BLOCK_GROUP_RAID10);
+
+ if (!profile_is_valid(bctl->data.target, 1) ||
+ bctl->data.target & ~allowed) {
+ printk(KERN_ERR "btrfs: unable to start balance with target "
+ "data profile %llu\n",
+ (unsigned long long)bctl->data.target);
+ ret = -EINVAL;
+ goto out;
+ }
+ if (!profile_is_valid(bctl->meta.target, 1) ||
+ bctl->meta.target & ~allowed) {
+ printk(KERN_ERR "btrfs: unable to start balance with target "
+ "metadata profile %llu\n",
+ (unsigned long long)bctl->meta.target);
+ ret = -EINVAL;
+ goto out;
+ }
+ if (!profile_is_valid(bctl->sys.target, 1) ||
+ bctl->sys.target & ~allowed) {
+ printk(KERN_ERR "btrfs: unable to start balance with target "
+ "system profile %llu\n",
+ (unsigned long long)bctl->sys.target);
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (bctl->data.target & BTRFS_BLOCK_GROUP_DUP) {
+ printk(KERN_ERR "btrfs: dup for data is not allowed\n");
+ ret = -EINVAL;
+ goto out;
+ }
+
+ /* allow to reduce meta or sys integrity only if force set */
+ allowed = BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
+ BTRFS_BLOCK_GROUP_RAID10;
+ if (((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
+ (fs_info->avail_system_alloc_bits & allowed) &&
+ !(bctl->sys.target & allowed)) ||
+ ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
+ (fs_info->avail_metadata_alloc_bits & allowed) &&
+ !(bctl->meta.target & allowed))) {
+ if (bctl->flags & BTRFS_BALANCE_FORCE) {
+ printk(KERN_INFO "btrfs: force reducing metadata "
+ "integrity\n");
+ } else {
+ printk(KERN_ERR "btrfs: balance will reduce metadata "
+ "integrity, use force if you want this\n");
+ ret = -EINVAL;
+ goto out;
+ }
+ }
+
+do_balance:
set_balance_control(bctl);
mutex_unlock(&fs_info->balance_mutex);
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index eac26c3..79ee9c3 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -196,6 +196,9 @@
#define BTRFS_BALANCE_TYPE_MASK (BTRFS_BALANCE_DATA | \
BTRFS_BALANCE_SYSTEM | \
BTRFS_BALANCE_METADATA)
+
+#define BTRFS_BALANCE_FORCE (1ULL << 3)
+
/*
* Balance filters
*/
@@ -205,6 +208,8 @@
#define BTRFS_BALANCE_ARGS_DRANGE (1ULL << 3)
#define BTRFS_BALANCE_ARGS_VRANGE (1ULL << 4)
+#define BTRFS_BALANCE_ARGS_CONVERT (1ULL << 8)
+
struct btrfs_balance_args;
struct btrfs_balance_control {
struct btrfs_fs_info *fs_info;