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-rw-r--r--fs/btrfs/backref.c6
-rw-r--r--fs/btrfs/backref.h3
-rw-r--r--fs/btrfs/delayed-ref.c4
-rw-r--r--fs/btrfs/qgroup.c38
-rw-r--r--fs/btrfs/qgroup.h2
-rw-r--r--fs/btrfs/tests/qgroup-tests.c20
6 files changed, 48 insertions, 25 deletions
diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index 7a8a2fc19533..78b202d198b8 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -1488,15 +1488,15 @@ static int btrfs_find_all_roots_safe(struct btrfs_trans_handle *trans,
int btrfs_find_all_roots(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info, u64 bytenr,
u64 time_seq, struct ulist **roots,
- bool ignore_offset)
+ bool ignore_offset, bool skip_commit_root_sem)
{
int ret;
- if (!trans)
+ if (!trans && !skip_commit_root_sem)
down_read(&fs_info->commit_root_sem);
ret = btrfs_find_all_roots_safe(trans, fs_info, bytenr,
time_seq, roots, ignore_offset);
- if (!trans)
+ if (!trans && !skip_commit_root_sem)
up_read(&fs_info->commit_root_sem);
return ret;
}
diff --git a/fs/btrfs/backref.h b/fs/btrfs/backref.h
index 17abde7f794c..ff5f07f9940b 100644
--- a/fs/btrfs/backref.h
+++ b/fs/btrfs/backref.h
@@ -47,7 +47,8 @@ int btrfs_find_all_leafs(struct btrfs_trans_handle *trans,
const u64 *extent_item_pos, bool ignore_offset);
int btrfs_find_all_roots(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info, u64 bytenr,
- u64 time_seq, struct ulist **roots, bool ignore_offset);
+ u64 time_seq, struct ulist **roots, bool ignore_offset,
+ bool skip_commit_root_sem);
char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path,
u32 name_len, unsigned long name_off,
struct extent_buffer *eb_in, u64 parent,
diff --git a/fs/btrfs/delayed-ref.c b/fs/btrfs/delayed-ref.c
index 06bc842ecdb3..ca848b183474 100644
--- a/fs/btrfs/delayed-ref.c
+++ b/fs/btrfs/delayed-ref.c
@@ -974,7 +974,7 @@ int btrfs_add_delayed_tree_ref(struct btrfs_trans_handle *trans,
kmem_cache_free(btrfs_delayed_tree_ref_cachep, ref);
if (qrecord_inserted)
- btrfs_qgroup_trace_extent_post(fs_info, record);
+ btrfs_qgroup_trace_extent_post(trans, record);
return 0;
}
@@ -1069,7 +1069,7 @@ int btrfs_add_delayed_data_ref(struct btrfs_trans_handle *trans,
if (qrecord_inserted)
- return btrfs_qgroup_trace_extent_post(fs_info, record);
+ return btrfs_qgroup_trace_extent_post(trans, record);
return 0;
}
diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index 07ec06d4e972..0fa121171ca1 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -1704,17 +1704,39 @@ int btrfs_qgroup_trace_extent_nolock(struct btrfs_fs_info *fs_info,
return 0;
}
-int btrfs_qgroup_trace_extent_post(struct btrfs_fs_info *fs_info,
+int btrfs_qgroup_trace_extent_post(struct btrfs_trans_handle *trans,
struct btrfs_qgroup_extent_record *qrecord)
{
struct ulist *old_root;
u64 bytenr = qrecord->bytenr;
int ret;
- ret = btrfs_find_all_roots(NULL, fs_info, bytenr, 0, &old_root, false);
+ /*
+ * We are always called in a context where we are already holding a
+ * transaction handle. Often we are called when adding a data delayed
+ * reference from btrfs_truncate_inode_items() (truncating or unlinking),
+ * in which case we will be holding a write lock on extent buffer from a
+ * subvolume tree. In this case we can't allow btrfs_find_all_roots() to
+ * acquire fs_info->commit_root_sem, because that is a higher level lock
+ * that must be acquired before locking any extent buffers.
+ *
+ * So we want btrfs_find_all_roots() to not acquire the commit_root_sem
+ * but we can't pass it a non-NULL transaction handle, because otherwise
+ * it would not use commit roots and would lock extent buffers, causing
+ * a deadlock if it ends up trying to read lock the same extent buffer
+ * that was previously write locked at btrfs_truncate_inode_items().
+ *
+ * So pass a NULL transaction handle to btrfs_find_all_roots() and
+ * explicitly tell it to not acquire the commit_root_sem - if we are
+ * holding a transaction handle we don't need its protection.
+ */
+ ASSERT(trans != NULL);
+
+ ret = btrfs_find_all_roots(NULL, trans->fs_info, bytenr, 0, &old_root,
+ false, true);
if (ret < 0) {
- fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
- btrfs_warn(fs_info,
+ trans->fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
+ btrfs_warn(trans->fs_info,
"error accounting new delayed refs extent (err code: %d), quota inconsistent",
ret);
return 0;
@@ -1758,7 +1780,7 @@ int btrfs_qgroup_trace_extent(struct btrfs_trans_handle *trans, u64 bytenr,
kfree(record);
return 0;
}
- return btrfs_qgroup_trace_extent_post(fs_info, record);
+ return btrfs_qgroup_trace_extent_post(trans, record);
}
int btrfs_qgroup_trace_leaf_items(struct btrfs_trans_handle *trans,
@@ -2629,7 +2651,7 @@ int btrfs_qgroup_account_extents(struct btrfs_trans_handle *trans)
/* Search commit root to find old_roots */
ret = btrfs_find_all_roots(NULL, fs_info,
record->bytenr, 0,
- &record->old_roots, false);
+ &record->old_roots, false, false);
if (ret < 0)
goto cleanup;
}
@@ -2645,7 +2667,7 @@ int btrfs_qgroup_account_extents(struct btrfs_trans_handle *trans)
* current root. It's safe inside commit_transaction().
*/
ret = btrfs_find_all_roots(trans, fs_info,
- record->bytenr, BTRFS_SEQ_LAST, &new_roots, false);
+ record->bytenr, BTRFS_SEQ_LAST, &new_roots, false, false);
if (ret < 0)
goto cleanup;
if (qgroup_to_skip) {
@@ -3179,7 +3201,7 @@ static int qgroup_rescan_leaf(struct btrfs_trans_handle *trans,
num_bytes = found.offset;
ret = btrfs_find_all_roots(NULL, fs_info, found.objectid, 0,
- &roots, false);
+ &roots, false, false);
if (ret < 0)
goto out;
/* For rescan, just pass old_roots as NULL */
diff --git a/fs/btrfs/qgroup.h b/fs/btrfs/qgroup.h
index 7283e4f549af..880e9df0dac1 100644
--- a/fs/btrfs/qgroup.h
+++ b/fs/btrfs/qgroup.h
@@ -298,7 +298,7 @@ int btrfs_qgroup_trace_extent_nolock(
* using current root, then we can move all expensive backref walk out of
* transaction committing, but not now as qgroup accounting will be wrong again.
*/
-int btrfs_qgroup_trace_extent_post(struct btrfs_fs_info *fs_info,
+int btrfs_qgroup_trace_extent_post(struct btrfs_trans_handle *trans,
struct btrfs_qgroup_extent_record *qrecord);
/*
diff --git a/fs/btrfs/tests/qgroup-tests.c b/fs/btrfs/tests/qgroup-tests.c
index f3137285a9e2..98b5aaba46f1 100644
--- a/fs/btrfs/tests/qgroup-tests.c
+++ b/fs/btrfs/tests/qgroup-tests.c
@@ -224,7 +224,7 @@ static int test_no_shared_qgroup(struct btrfs_root *root,
* quota.
*/
ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &old_roots,
- false);
+ false, false);
if (ret) {
ulist_free(old_roots);
test_err("couldn't find old roots: %d", ret);
@@ -237,7 +237,7 @@ static int test_no_shared_qgroup(struct btrfs_root *root,
return ret;
ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &new_roots,
- false);
+ false, false);
if (ret) {
ulist_free(old_roots);
ulist_free(new_roots);
@@ -261,7 +261,7 @@ static int test_no_shared_qgroup(struct btrfs_root *root,
new_roots = NULL;
ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &old_roots,
- false);
+ false, false);
if (ret) {
ulist_free(old_roots);
test_err("couldn't find old roots: %d", ret);
@@ -273,7 +273,7 @@ static int test_no_shared_qgroup(struct btrfs_root *root,
return -EINVAL;
ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &new_roots,
- false);
+ false, false);
if (ret) {
ulist_free(old_roots);
ulist_free(new_roots);
@@ -325,7 +325,7 @@ static int test_multiple_refs(struct btrfs_root *root,
}
ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &old_roots,
- false);
+ false, false);
if (ret) {
ulist_free(old_roots);
test_err("couldn't find old roots: %d", ret);
@@ -338,7 +338,7 @@ static int test_multiple_refs(struct btrfs_root *root,
return ret;
ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &new_roots,
- false);
+ false, false);
if (ret) {
ulist_free(old_roots);
ulist_free(new_roots);
@@ -360,7 +360,7 @@ static int test_multiple_refs(struct btrfs_root *root,
}
ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &old_roots,
- false);
+ false, false);
if (ret) {
ulist_free(old_roots);
test_err("couldn't find old roots: %d", ret);
@@ -373,7 +373,7 @@ static int test_multiple_refs(struct btrfs_root *root,
return ret;
ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &new_roots,
- false);
+ false, false);
if (ret) {
ulist_free(old_roots);
ulist_free(new_roots);
@@ -401,7 +401,7 @@ static int test_multiple_refs(struct btrfs_root *root,
}
ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &old_roots,
- false);
+ false, false);
if (ret) {
ulist_free(old_roots);
test_err("couldn't find old roots: %d", ret);
@@ -414,7 +414,7 @@ static int test_multiple_refs(struct btrfs_root *root,
return ret;
ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &new_roots,
- false);
+ false, false);
if (ret) {
ulist_free(old_roots);
ulist_free(new_roots);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-27 14:44:57 +0100