Currently, for pre_alloc or delay_alloc, the bytes will be accounted
in space_info by the three guys.
space_info->bytes_may_use --- space_info->reserved --- space_info->used.
But on the other hand, in qgroup, there are only two counters to account the
bytes, qgroup->reserved and qgroup->excl. And qg->reserved accounts
bytes in space_info->bytes_may_use and qg->excl accounts bytes in
space_info->used. So the bytes in space_info->reserved is not accounted
in qgroup. If so, there is a window we can exceed the quota limit when
bytes is in space_info->reserved.
Example:
# btrfs quota enable /mnt
# btrfs qgroup limit -e 10M /mnt
# for((i=0;i<20;i++));do fallocate -l 1M /mnt/data$i; done
# sync
# btrfs qgroup show -pcre /mnt
qgroupid rfer excl max_rfer max_excl parent child
-------- ---- ---- -------- -------- ------ -----
0/5 20987904 20987904 0 10485760 --- ---
qg->excl is 20987904 larger than max_excl 10485760.
This patch introduce a new counter named may_use to qgroup, then
there are three counters in qgroup to account bytes in space_info
as below.
space_info->bytes_may_use --- space_info->reserved --- space_info->used.
qgroup->may_use --- qgroup->reserved --- qgroup->excl
With this patch applied:
# btrfs quota enable /mnt
# btrfs qgroup limit -e 10M /mnt
# for((i=0;i<20;i++));do fallocate -l 1M /mnt/data$i; done
fallocate: /mnt/data9: fallocate failed: Disk quota exceeded
fallocate: /mnt/data10: fallocate failed: Disk quota exceeded
fallocate: /mnt/data11: fallocate failed: Disk quota exceeded
fallocate: /mnt/data12: fallocate failed: Disk quota exceeded
fallocate: /mnt/data13: fallocate failed: Disk quota exceeded
fallocate: /mnt/data14: fallocate failed: Disk quota exceeded
fallocate: /mnt/data15: fallocate failed: Disk quota exceeded
fallocate: /mnt/data16: fallocate failed: Disk quota exceeded
fallocate: /mnt/data17: fallocate failed: Disk quota exceeded
fallocate: /mnt/data18: fallocate failed: Disk quota exceeded
fallocate: /mnt/data19: fallocate failed: Disk quota exceeded
# sync
# btrfs qgroup show -pcre /mnt
qgroupid rfer excl max_rfer max_excl parent child
-------- ---- ---- -------- -------- ------ -----
0/5 9453568 9453568 0 10485760 --- ---
Reported-by: Cyril SCETBON<cyril.scetbon@xxxxxxx>
Signed-off-by: Dongsheng Yang<yangds.fnst@xxxxxxxxxxxxxx>
---
Changelog:
v1 -> v2:
Remove the redundant check for fs_info->quota_enabled.
fs/btrfs/extent-tree.c | 20 ++++++++++++++-
fs/btrfs/inode.c | 18 ++++++++++++-
fs/btrfs/qgroup.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++---
fs/btrfs/qgroup.h | 4 +++
4 files changed, 104 insertions(+), 6 deletions(-)
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 014b7f2..f4ad737 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -5500,8 +5500,12 @@ static int pin_down_extent(struct btrfs_root *root,
set_extent_dirty(root->fs_info->pinned_extents, bytenr,
bytenr + num_bytes - 1, GFP_NOFS | __GFP_NOFAIL);
- if (reserved)
+ if (reserved) {
+ btrfs_qgroup_update_reserved_bytes(root->fs_info,
+ root->root_key.objectid,
+ num_bytes, -1);
trace_btrfs_reserved_extent_free(root, bytenr, num_bytes);
+ }
return 0;
}
@@ -6230,6 +6234,9 @@ void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
btrfs_update_reserved_bytes(cache, buf->len, RESERVE_FREE, 0);
trace_btrfs_reserved_extent_free(root, buf->start, buf->len);
pin = 0;
+ btrfs_qgroup_update_reserved_bytes(root->fs_info,
+ root->root_key.objectid,
+ buf->len, -1);
}
out:
if (pin)
@@ -6964,7 +6971,11 @@ static int __btrfs_free_reserved_extent(struct btrfs_root *root,
else {
btrfs_add_free_space(cache, start, len);
btrfs_update_reserved_bytes(cache, len, RESERVE_FREE, delalloc);
+ btrfs_qgroup_update_reserved_bytes(root->fs_info,
+ root->root_key.objectid,
+ len, -1);
}
+
btrfs_put_block_group(cache);
trace_btrfs_reserved_extent_free(root, start, len);
@@ -7200,6 +7211,9 @@ int btrfs_alloc_logged_file_extent(struct btrfs_trans_handle *trans,
BUG_ON(ret); /* logic error */
ret = alloc_reserved_file_extent(trans, root, 0, root_objectid,
0, owner, offset, ins, 1);
+ btrfs_qgroup_update_reserved_bytes(root->fs_info,
+ root->root_key.objectid,
+ ins->offset, 1);
btrfs_put_block_group(block_group);
return ret;
}
@@ -7346,6 +7360,10 @@ struct extent_buffer *btrfs_alloc_tree_block(struct btrfs_trans_handle *trans,
return ERR_PTR(ret);
}
+ btrfs_qgroup_update_reserved_bytes(root->fs_info,
+ root_objectid,
+ ins.offset, 1);
+
buf = btrfs_init_new_buffer(trans, root, ins.objectid,
blocksize, level);
BUG_ON(IS_ERR(buf)); /* -ENOMEM */
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index d23362f..0c824f3 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -59,6 +59,7 @@
#include "backref.h"
#include "hash.h"
#include "props.h"
+#include "qgroup.h"
struct btrfs_iget_args {
struct btrfs_key *location;
@@ -739,7 +740,9 @@ retry:
}
goto out_free;
}
-
+ btrfs_qgroup_update_reserved_bytes(root->fs_info,
+ root->root_key.objectid,
+ ins.offset, 1);
/*
* here we're doing allocation and writeback of the
* compressed pages
@@ -951,6 +954,10 @@ static noinline int cow_file_range(struct inode *inode,
if (ret < 0)
goto out_unlock;
+ btrfs_qgroup_update_reserved_bytes(root->fs_info,
+ root->root_key.objectid,
+ ins.offset, 1);
+
em = alloc_extent_map();
if (!em) {
ret = -ENOMEM;
@@ -6745,6 +6752,10 @@ static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
return ERR_PTR(ret);
}
+ btrfs_qgroup_update_reserved_bytes(root->fs_info,
+ root->root_key.objectid,
+ ins.offset, 1);
+
return em;
}
@@ -9266,6 +9277,11 @@ static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
btrfs_end_transaction(trans, root);
break;
}
+
+ btrfs_qgroup_update_reserved_bytes(root->fs_info,
+ root->root_key.objectid,
+ ins.offset, 1);
+
btrfs_drop_extent_cache(inode, cur_offset,
cur_offset + ins.offset -1, 0);
diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index 48b60db..d147082 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -72,6 +72,7 @@ struct btrfs_qgroup {
/*
* reservation tracking
*/
+ u64 may_use;
u64 reserved;
/*
@@ -1414,6 +1415,8 @@ static int qgroup_excl_accounting(struct btrfs_fs_info *fs_info,
WARN_ON(sign < 0 && qgroup->excl < oper->num_bytes);
qgroup->excl += sign * oper->num_bytes;
qgroup->excl_cmpr += sign * oper->num_bytes;
+ if (sign > 0)
+ qgroup->reserved -= oper->num_bytes;
qgroup_dirty(fs_info, qgroup);
@@ -1434,6 +1437,8 @@ static int qgroup_excl_accounting(struct btrfs_fs_info *fs_info,
qgroup->excl += sign * oper->num_bytes;
if (sign < 0)
WARN_ON(qgroup->excl < oper->num_bytes);
+ if (sign > 0)
+ qgroup->reserved -= oper->num_bytes;
qgroup->excl_cmpr += sign * oper->num_bytes;
qgroup_dirty(fs_info, qgroup);
@@ -2359,6 +2364,61 @@ out:
return ret;
}
+int btrfs_qgroup_update_reserved_bytes(struct btrfs_fs_info *fs_info,
+ u64 ref_root,
+ u64 num_bytes,
+ int sign)
+{
+ struct btrfs_root *quota_root;
+ struct btrfs_qgroup *qgroup;
+ int ret = 0;
+ struct ulist_node *unode;
+ struct ulist_iterator uiter;
+
+ if (!is_fstree(ref_root) || !fs_info->quota_enabled)
+ return 0;
+
+ if (num_bytes == 0)
+ return 0;
+
+ spin_lock(&fs_info->qgroup_lock);
+ quota_root = fs_info->quota_root;
+ if (!quota_root)
+ goto out;
+
+ qgroup = find_qgroup_rb(fs_info, ref_root);
+ if (!qgroup)
+ goto out;
+
+ ulist_reinit(fs_info->qgroup_ulist);
+ ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
+ (uintptr_t)qgroup, GFP_ATOMIC);
+ if (ret < 0)
+ goto out;
+
+ ULIST_ITER_INIT(&uiter);
+ while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
+ struct btrfs_qgroup *qg;
+ struct btrfs_qgroup_list *glist;
+
+ qg = u64_to_ptr(unode->aux);
+
+ qg->reserved += sign * num_bytes;
+
+ list_for_each_entry(glist, &qg->groups, next_group) {
+ ret = ulist_add(fs_info->qgroup_ulist,
+ glist->group->qgroupid,
+ (uintptr_t)glist->group, GFP_ATOMIC);
+ if (ret < 0)
+ goto out;
+ }
+ }
+
+out:
+ spin_unlock(&fs_info->qgroup_lock);
+ return ret;
+}
+
/*
* reserve some space for a qgroup and all its parents. The reservation takes
* place with start_transaction or dealloc_reserve, similar to ENOSPC
@@ -2407,14 +2467,14 @@ int btrfs_qgroup_reserve(struct btrfs_root *root, u64 num_bytes)
qg = u64_to_ptr(unode->aux);
if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_RFER) &&
- qg->reserved + (s64)qg->rfer + num_bytes >
+ qg->reserved + qg->may_use + (s64)qg->rfer + num_bytes >
qg->max_rfer) {
ret = -EDQUOT;
goto out;
}
if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) &&
- qg->reserved + (s64)qg->excl + num_bytes >
+ qg->reserved + qg->may_use + (s64)qg->excl + num_bytes >
qg->max_excl) {
ret = -EDQUOT;
goto out;
@@ -2438,7 +2498,7 @@ int btrfs_qgroup_reserve(struct btrfs_root *root, u64 num_bytes)
qg = u64_to_ptr(unode->aux);
- qg->reserved += num_bytes;
+ qg->may_use += num_bytes;
}
out:
@@ -2484,7 +2544,7 @@ void btrfs_qgroup_free(struct btrfs_root *root, u64 num_bytes)
qg = u64_to_ptr(unode->aux);
- qg->reserved -= num_bytes;
+ qg->may_use -= num_bytes;
list_for_each_entry(glist, &qg->groups, next_group) {
ret = ulist_add(fs_info->qgroup_ulist,
diff --git a/fs/btrfs/qgroup.h b/fs/btrfs/qgroup.h
index 18cc68c..31de88e 100644
--- a/fs/btrfs/qgroup.h
+++ b/fs/btrfs/qgroup.h
@@ -95,6 +95,10 @@ int btrfs_run_qgroups(struct btrfs_trans_handle *trans,
int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info, u64 srcid, u64 objectid,
struct btrfs_qgroup_inherit *inherit);
+int btrfs_qgroup_update_reserved_bytes(struct btrfs_fs_info *fs_info,
+ u64 ref_root,
+ u64 num_bytes,
+ int sign);
int btrfs_qgroup_reserve(struct btrfs_root *root, u64 num_bytes);
void btrfs_qgroup_free(struct btrfs_root *root, u64 num_bytes);
