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Btrfs: use seqlock to protect fs_info->avail_{data, metadata, system}_alloc_bits

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There is no lock to protect
  fs_info->avail_{data, metadata, system}_alloc_bits,
it may introduce some problem, such as the wrong profile
information, so we add a seqlock to protect them.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
This commit is contained in:
Miao Xie 2013-01-29 10:13:12 +00:00 committed by Josef Bacik
parent df0af1a57f
commit de98ced9e7
4 changed files with 49 additions and 32 deletions
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2
fs/btrfs/ctree.h
View file

@ -1483,6 +1483,8 @@ struct btrfs_fs_info {
struct rb_root defrag_inodes;
atomic_t defrag_running;
/* Used to protect avail_{data, metadata, system}_alloc_bits */
seqlock_t profiles_lock;
/*
* these three are in extended format (availability of single
* chunks is denoted by BTRFS_AVAIL_ALLOC_BIT_SINGLE bit, other

1
fs/btrfs/disk-io.c
View file

@ -2040,6 +2040,7 @@ int open_ctree(struct super_block *sb,
spin_lock_init(&fs_info->tree_mod_seq_lock);
rwlock_init(&fs_info->tree_mod_log_lock);
mutex_init(&fs_info->reloc_mutex);
seqlock_init(&fs_info->profiles_lock);
init_completion(&fs_info->kobj_unregister);
INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);

22
fs/btrfs/extent-tree.c
View file

@ -3227,12 +3227,14 @@ static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
u64 extra_flags = chunk_to_extended(flags) &
BTRFS_EXTENDED_PROFILE_MASK;
write_seqlock(&fs_info->profiles_lock);
if (flags & BTRFS_BLOCK_GROUP_DATA)
fs_info->avail_data_alloc_bits |= extra_flags;
if (flags & BTRFS_BLOCK_GROUP_METADATA)
fs_info->avail_metadata_alloc_bits |= extra_flags;
if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
fs_info->avail_system_alloc_bits |= extra_flags;
write_sequnlock(&fs_info->profiles_lock);
}
/*
@ -3324,12 +3326,18 @@ u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags)
static u64 get_alloc_profile(struct btrfs_root *root, u64 flags)
{
if (flags & BTRFS_BLOCK_GROUP_DATA)
flags |= root->fs_info->avail_data_alloc_bits;
else if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
flags |= root->fs_info->avail_system_alloc_bits;
else if (flags & BTRFS_BLOCK_GROUP_METADATA)
flags |= root->fs_info->avail_metadata_alloc_bits;
unsigned seq;
do {
seq = read_seqbegin(&root->fs_info->profiles_lock);
if (flags & BTRFS_BLOCK_GROUP_DATA)
flags |= root->fs_info->avail_data_alloc_bits;
else if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
flags |= root->fs_info->avail_system_alloc_bits;
else if (flags & BTRFS_BLOCK_GROUP_METADATA)
flags |= root->fs_info->avail_metadata_alloc_bits;
} while (read_seqretry(&root->fs_info->profiles_lock, seq));
return btrfs_reduce_alloc_profile(root, flags);
}
@ -7967,12 +7975,14 @@ static void clear_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
u64 extra_flags = chunk_to_extended(flags) &
BTRFS_EXTENDED_PROFILE_MASK;
write_seqlock(&fs_info->profiles_lock);
if (flags & BTRFS_BLOCK_GROUP_DATA)
fs_info->avail_data_alloc_bits &= ~extra_flags;
if (flags & BTRFS_BLOCK_GROUP_METADATA)
fs_info->avail_metadata_alloc_bits &= ~extra_flags;
if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
fs_info->avail_system_alloc_bits &= ~extra_flags;
write_sequnlock(&fs_info->profiles_lock);
}
int btrfs_remove_block_group(struct btrfs_trans_handle *trans,

56
fs/btrfs/volumes.c
View file

@ -1430,14 +1430,19 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
u64 devid;
u64 num_devices;
u8 *dev_uuid;
unsigned seq;
int ret = 0;
bool clear_super = false;
mutex_lock(&uuid_mutex);
all_avail = root->fs_info->avail_data_alloc_bits |
root->fs_info->avail_system_alloc_bits |
root->fs_info->avail_metadata_alloc_bits;
do {
seq = read_seqbegin(&root->fs_info->profiles_lock);
all_avail = root->fs_info->avail_data_alloc_bits |
root->fs_info->avail_system_alloc_bits |
root->fs_info->avail_metadata_alloc_bits;
} while (read_seqretry(&root->fs_info->profiles_lock, seq));
num_devices = root->fs_info->fs_devices->num_devices;
btrfs_dev_replace_lock(&root->fs_info->dev_replace);
@ -3043,6 +3048,7 @@ int btrfs_balance(struct btrfs_balance_control *bctl,
int mixed = 0;
int ret;
u64 num_devices;
unsigned seq;
if (btrfs_fs_closing(fs_info) ||
atomic_read(&fs_info->balance_pause_req) ||
@ -3126,22 +3132,26 @@ int btrfs_balance(struct btrfs_balance_control *bctl,
/* 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 {
seq = read_seqbegin(&fs_info->profiles_lock);
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;
}
}
}
} while (read_seqretry(&fs_info->profiles_lock, seq));
if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
int num_tolerated_disk_barrier_failures;
@ -3980,10 +3990,7 @@ static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
if (ret)
return ret;
alloc_profile = BTRFS_BLOCK_GROUP_METADATA |
fs_info->avail_metadata_alloc_bits;
alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
alloc_profile = btrfs_get_alloc_profile(extent_root, 0);
ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
&stripe_size, chunk_offset, alloc_profile);
if (ret)
@ -3991,10 +3998,7 @@ static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
sys_chunk_offset = chunk_offset + chunk_size;
alloc_profile = BTRFS_BLOCK_GROUP_SYSTEM |
fs_info->avail_system_alloc_bits;
alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
alloc_profile = btrfs_get_alloc_profile(fs_info->chunk_root, 0);
ret = __btrfs_alloc_chunk(trans, extent_root, &sys_map,
&sys_chunk_size, &sys_stripe_size,
sys_chunk_offset, alloc_profile);