btrfs: Use ref_cnt for set_block_group_ro()
More than one code call set_block_group_ro() and restore rw in fail.
Old code use bool bit to save blockgroup's ro state, it can not
support parallel case(it is confirmd exist in my debug log).
This patch use ref count to store ro state, and rename
set_block_group_ro/set_block_group_rw
to
inc_block_group_ro/dec_block_group_ro.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index aac314e..f57e6ca 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1300,7 +1300,7 @@
/* for raid56, this is a full stripe, without parity */
unsigned long full_stripe_len;
- unsigned int ro:1;
+ unsigned int ro;
unsigned int iref:1;
unsigned int has_caching_ctl:1;
unsigned int removed:1;
@@ -3495,9 +3495,9 @@
void btrfs_block_rsv_release(struct btrfs_root *root,
struct btrfs_block_rsv *block_rsv,
u64 num_bytes);
-int btrfs_set_block_group_ro(struct btrfs_root *root,
+int btrfs_inc_block_group_ro(struct btrfs_root *root,
struct btrfs_block_group_cache *cache);
-void btrfs_set_block_group_rw(struct btrfs_root *root,
+void btrfs_dec_block_group_ro(struct btrfs_root *root,
struct btrfs_block_group_cache *cache);
void btrfs_put_block_group_cache(struct btrfs_fs_info *info);
u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo);
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 07204bf..5cefa02 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -8723,14 +8723,13 @@
return flags;
}
-static int set_block_group_ro(struct btrfs_block_group_cache *cache, int force)
+static int inc_block_group_ro(struct btrfs_block_group_cache *cache, int force)
{
struct btrfs_space_info *sinfo = cache->space_info;
u64 num_bytes;
u64 min_allocable_bytes;
int ret = -ENOSPC;
-
/*
* We need some metadata space and system metadata space for
* allocating chunks in some corner cases until we force to set
@@ -8747,6 +8746,7 @@
spin_lock(&cache->lock);
if (cache->ro) {
+ cache->ro++;
ret = 0;
goto out;
}
@@ -8758,7 +8758,7 @@
sinfo->bytes_may_use + sinfo->bytes_readonly + num_bytes +
min_allocable_bytes <= sinfo->total_bytes) {
sinfo->bytes_readonly += num_bytes;
- cache->ro = 1;
+ cache->ro++;
list_add_tail(&cache->ro_list, &sinfo->ro_bgs);
ret = 0;
}
@@ -8768,7 +8768,7 @@
return ret;
}
-int btrfs_set_block_group_ro(struct btrfs_root *root,
+int btrfs_inc_block_group_ro(struct btrfs_root *root,
struct btrfs_block_group_cache *cache)
{
@@ -8776,8 +8776,6 @@
u64 alloc_flags;
int ret;
- BUG_ON(cache->ro);
-
again:
trans = btrfs_join_transaction(root);
if (IS_ERR(trans))
@@ -8820,7 +8818,7 @@
goto out;
}
- ret = set_block_group_ro(cache, 0);
+ ret = inc_block_group_ro(cache, 0);
if (!ret)
goto out;
alloc_flags = get_alloc_profile(root, cache->space_info->flags);
@@ -8828,7 +8826,7 @@
CHUNK_ALLOC_FORCE);
if (ret < 0)
goto out;
- ret = set_block_group_ro(cache, 0);
+ ret = inc_block_group_ro(cache, 0);
out:
if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) {
alloc_flags = update_block_group_flags(root, cache->flags);
@@ -8891,7 +8889,7 @@
return free_bytes;
}
-void btrfs_set_block_group_rw(struct btrfs_root *root,
+void btrfs_dec_block_group_ro(struct btrfs_root *root,
struct btrfs_block_group_cache *cache)
{
struct btrfs_space_info *sinfo = cache->space_info;
@@ -8901,11 +8899,13 @@
spin_lock(&sinfo->lock);
spin_lock(&cache->lock);
- num_bytes = cache->key.offset - cache->reserved - cache->pinned -
- cache->bytes_super - btrfs_block_group_used(&cache->item);
- sinfo->bytes_readonly -= num_bytes;
- cache->ro = 0;
- list_del_init(&cache->ro_list);
+ if (!--cache->ro) {
+ num_bytes = cache->key.offset - cache->reserved -
+ cache->pinned - cache->bytes_super -
+ btrfs_block_group_used(&cache->item);
+ sinfo->bytes_readonly -= num_bytes;
+ list_del_init(&cache->ro_list);
+ }
spin_unlock(&cache->lock);
spin_unlock(&sinfo->lock);
}
@@ -9421,7 +9421,7 @@
set_avail_alloc_bits(root->fs_info, cache->flags);
if (btrfs_chunk_readonly(root, cache->key.objectid)) {
- set_block_group_ro(cache, 1);
+ inc_block_group_ro(cache, 1);
} else if (btrfs_block_group_used(&cache->item) == 0) {
spin_lock(&info->unused_bgs_lock);
/* Should always be true but just in case. */
@@ -9449,11 +9449,11 @@
list_for_each_entry(cache,
&space_info->block_groups[BTRFS_RAID_RAID0],
list)
- set_block_group_ro(cache, 1);
+ inc_block_group_ro(cache, 1);
list_for_each_entry(cache,
&space_info->block_groups[BTRFS_RAID_SINGLE],
list)
- set_block_group_ro(cache, 1);
+ inc_block_group_ro(cache, 1);
}
init_global_block_rsv(info);
@@ -9941,7 +9941,7 @@
spin_unlock(&block_group->lock);
/* We don't want to force the issue, only flip if it's ok. */
- ret = set_block_group_ro(block_group, 0);
+ ret = inc_block_group_ro(block_group, 0);
up_write(&space_info->groups_sem);
if (ret < 0) {
ret = 0;
@@ -9955,7 +9955,7 @@
/* 1 for btrfs_orphan_reserve_metadata() */
trans = btrfs_start_transaction(root, 1);
if (IS_ERR(trans)) {
- btrfs_set_block_group_rw(root, block_group);
+ btrfs_dec_block_group_ro(root, block_group);
ret = PTR_ERR(trans);
goto next;
}
@@ -9982,14 +9982,14 @@
EXTENT_DIRTY, GFP_NOFS);
if (ret) {
mutex_unlock(&fs_info->unused_bg_unpin_mutex);
- btrfs_set_block_group_rw(root, block_group);
+ btrfs_dec_block_group_ro(root, block_group);
goto end_trans;
}
ret = clear_extent_bits(&fs_info->freed_extents[1], start, end,
EXTENT_DIRTY, GFP_NOFS);
if (ret) {
mutex_unlock(&fs_info->unused_bg_unpin_mutex);
- btrfs_set_block_group_rw(root, block_group);
+ btrfs_dec_block_group_ro(root, block_group);
goto end_trans;
}
mutex_unlock(&fs_info->unused_bg_unpin_mutex);
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 88cbb59..52fe55a 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -4215,14 +4215,12 @@
rc->block_group = btrfs_lookup_block_group(fs_info, group_start);
BUG_ON(!rc->block_group);
- if (!rc->block_group->ro) {
- ret = btrfs_set_block_group_ro(extent_root, rc->block_group);
- if (ret) {
- err = ret;
- goto out;
- }
- rw = 1;
+ ret = btrfs_inc_block_group_ro(extent_root, rc->block_group);
+ if (ret) {
+ err = ret;
+ goto out;
}
+ rw = 1;
path = btrfs_alloc_path();
if (!path) {
@@ -4294,7 +4292,7 @@
WARN_ON(btrfs_block_group_used(&rc->block_group->item) > 0);
out:
if (err && rw)
- btrfs_set_block_group_rw(extent_root, rc->block_group);
+ btrfs_dec_block_group_ro(extent_root, rc->block_group);
iput(rc->data_inode);
btrfs_put_block_group(rc->block_group);
kfree(rc);