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-rw-r--r--Documentation/filesystems/btrfs.rst1
-rw-r--r--MAINTAINERS1
-rw-r--r--fs/btrfs/Kconfig2
-rw-r--r--fs/btrfs/block-group.c12
-rw-r--r--fs/btrfs/delayed-inode.c104
-rw-r--r--fs/btrfs/disk-io.c22
-rw-r--r--fs/btrfs/ioctl.c8
-rw-r--r--fs/btrfs/locking.h2
-rw-r--r--fs/btrfs/ordered-data.c2
-rw-r--r--fs/btrfs/transaction.c39
-rw-r--r--fs/btrfs/transaction.h1
11 files changed, 128 insertions, 66 deletions
diff --git a/Documentation/filesystems/btrfs.rst b/Documentation/filesystems/btrfs.rst
index 992eddb0e11b..a81db8f54d68 100644
--- a/Documentation/filesystems/btrfs.rst
+++ b/Documentation/filesystems/btrfs.rst
@@ -37,7 +37,6 @@ For more information please refer to the documentation site or wiki
https://btrfs.readthedocs.io
- https://btrfs.wiki.kernel.org
that maintains information about administration tasks, frequently asked
questions, use cases, mount options, comprehensible changelogs, features,
diff --git a/MAINTAINERS b/MAINTAINERS
index 90f13281d297..79630b7d946e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4378,7 +4378,6 @@ M: David Sterba <dsterba@suse.com>
L: linux-btrfs@vger.kernel.org
S: Maintained
W: https://btrfs.readthedocs.io
-W: https://btrfs.wiki.kernel.org/
Q: https://patchwork.kernel.org/project/linux-btrfs/list/
C: irc://irc.libera.chat/btrfs
T: git git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux.git
diff --git a/fs/btrfs/Kconfig b/fs/btrfs/Kconfig
index 3282adc84d52..a25c9910d90b 100644
--- a/fs/btrfs/Kconfig
+++ b/fs/btrfs/Kconfig
@@ -31,7 +31,7 @@ config BTRFS_FS
continue to be mountable and usable by newer kernels.
For more information, please see the web pages at
- http://btrfs.wiki.kernel.org.
+ https://btrfs.readthedocs.io
To compile this file system support as a module, choose M here. The
module will be called btrfs.
diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index 0cb1dee965a0..b2e5107b7cec 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -3028,8 +3028,16 @@ static int update_block_group_item(struct btrfs_trans_handle *trans,
btrfs_mark_buffer_dirty(leaf);
fail:
btrfs_release_path(path);
- /* We didn't update the block group item, need to revert @commit_used. */
- if (ret < 0) {
+ /*
+ * We didn't update the block group item, need to revert commit_used
+ * unless the block group item didn't exist yet - this is to prevent a
+ * race with a concurrent insertion of the block group item, with
+ * insert_block_group_item(), that happened just after we attempted to
+ * update. In that case we would reset commit_used to 0 just after the
+ * insertion set it to a value greater than 0 - if the block group later
+ * becomes with 0 used bytes, we would incorrectly skip its update.
+ */
+ if (ret < 0 && ret != -ENOENT) {
spin_lock(&cache->lock);
cache->commit_used = old_commit_used;
spin_unlock(&cache->lock);
diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c
index 53c1211dd60b..caf0bbd028d1 100644
--- a/fs/btrfs/delayed-inode.c
+++ b/fs/btrfs/delayed-inode.c
@@ -412,6 +412,7 @@ static void finish_one_item(struct btrfs_delayed_root *delayed_root)
static void __btrfs_remove_delayed_item(struct btrfs_delayed_item *delayed_item)
{
+ struct btrfs_delayed_node *delayed_node = delayed_item->delayed_node;
struct rb_root_cached *root;
struct btrfs_delayed_root *delayed_root;
@@ -419,18 +420,21 @@ static void __btrfs_remove_delayed_item(struct btrfs_delayed_item *delayed_item)
if (RB_EMPTY_NODE(&delayed_item->rb_node))
return;
- delayed_root = delayed_item->delayed_node->root->fs_info->delayed_root;
+ /* If it's in a rbtree, then we need to have delayed node locked. */
+ lockdep_assert_held(&delayed_node->mutex);
+
+ delayed_root = delayed_node->root->fs_info->delayed_root;
BUG_ON(!delayed_root);
if (delayed_item->type == BTRFS_DELAYED_INSERTION_ITEM)
- root = &delayed_item->delayed_node->ins_root;
+ root = &delayed_node->ins_root;
else
- root = &delayed_item->delayed_node->del_root;
+ root = &delayed_node->del_root;
rb_erase_cached(&delayed_item->rb_node, root);
RB_CLEAR_NODE(&delayed_item->rb_node);
- delayed_item->delayed_node->count--;
+ delayed_node->count--;
finish_one_item(delayed_root);
}
@@ -1153,20 +1157,33 @@ static int __btrfs_run_delayed_items(struct btrfs_trans_handle *trans, int nr)
ret = __btrfs_commit_inode_delayed_items(trans, path,
curr_node);
if (ret) {
- btrfs_release_delayed_node(curr_node);
- curr_node = NULL;
btrfs_abort_transaction(trans, ret);
break;
}
prev_node = curr_node;
curr_node = btrfs_next_delayed_node(curr_node);
+ /*
+ * See the comment below about releasing path before releasing
+ * node. If the commit of delayed items was successful the path
+ * should always be released, but in case of an error, it may
+ * point to locked extent buffers (a leaf at the very least).
+ */
+ ASSERT(path->nodes[0] == NULL);
btrfs_release_delayed_node(prev_node);
}
+ /*
+ * Release the path to avoid a potential deadlock and lockdep splat when
+ * releasing the delayed node, as that requires taking the delayed node's
+ * mutex. If another task starts running delayed items before we take
+ * the mutex, it will first lock the mutex and then it may try to lock
+ * the same btree path (leaf).
+ */
+ btrfs_free_path(path);
+
if (curr_node)
btrfs_release_delayed_node(curr_node);
- btrfs_free_path(path);
trans->block_rsv = block_rsv;
return ret;
@@ -1413,7 +1430,29 @@ void btrfs_balance_delayed_items(struct btrfs_fs_info *fs_info)
btrfs_wq_run_delayed_node(delayed_root, fs_info, BTRFS_DELAYED_BATCH);
}
-/* Will return 0 or -ENOMEM */
+static void btrfs_release_dir_index_item_space(struct btrfs_trans_handle *trans)
+{
+ struct btrfs_fs_info *fs_info = trans->fs_info;
+ const u64 bytes = btrfs_calc_insert_metadata_size(fs_info, 1);
+
+ if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags))
+ return;
+
+ /*
+ * Adding the new dir index item does not require touching another
+ * leaf, so we can release 1 unit of metadata that was previously
+ * reserved when starting the transaction. This applies only to
+ * the case where we had a transaction start and excludes the
+ * transaction join case (when replaying log trees).
+ */
+ trace_btrfs_space_reservation(fs_info, "transaction",
+ trans->transid, bytes, 0);
+ btrfs_block_rsv_release(fs_info, trans->block_rsv, bytes, NULL);
+ ASSERT(trans->bytes_reserved >= bytes);
+ trans->bytes_reserved -= bytes;
+}
+
+/* Will return 0, -ENOMEM or -EEXIST (index number collision, unexpected). */
int btrfs_insert_delayed_dir_index(struct btrfs_trans_handle *trans,
const char *name, int name_len,
struct btrfs_inode *dir,
@@ -1455,6 +1494,27 @@ int btrfs_insert_delayed_dir_index(struct btrfs_trans_handle *trans,
mutex_lock(&delayed_node->mutex);
+ /*
+ * First attempt to insert the delayed item. This is to make the error
+ * handling path simpler in case we fail (-EEXIST). There's no risk of
+ * any other task coming in and running the delayed item before we do
+ * the metadata space reservation below, because we are holding the
+ * delayed node's mutex and that mutex must also be locked before the
+ * node's delayed items can be run.
+ */
+ ret = __btrfs_add_delayed_item(delayed_node, delayed_item);
+ if (unlikely(ret)) {
+ btrfs_err(trans->fs_info,
+"error adding delayed dir index item, name: %.*s, index: %llu, root: %llu, dir: %llu, dir->index_cnt: %llu, delayed_node->index_cnt: %llu, error: %d",
+ name_len, name, index, btrfs_root_id(delayed_node->root),
+ delayed_node->inode_id, dir->index_cnt,
+ delayed_node->index_cnt, ret);
+ btrfs_release_delayed_item(delayed_item);
+ btrfs_release_dir_index_item_space(trans);
+ mutex_unlock(&delayed_node->mutex);
+ goto release_node;
+ }
+
if (delayed_node->index_item_leaves == 0 ||
delayed_node->curr_index_batch_size + data_len > leaf_data_size) {
delayed_node->curr_index_batch_size = data_len;
@@ -1472,36 +1532,14 @@ int btrfs_insert_delayed_dir_index(struct btrfs_trans_handle *trans,
* impossible.
*/
if (WARN_ON(ret)) {
- mutex_unlock(&delayed_node->mutex);
btrfs_release_delayed_item(delayed_item);
+ mutex_unlock(&delayed_node->mutex);
goto release_node;
}
delayed_node->index_item_leaves++;
- } else if (!test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags)) {
- const u64 bytes = btrfs_calc_insert_metadata_size(fs_info, 1);
-
- /*
- * Adding the new dir index item does not require touching another
- * leaf, so we can release 1 unit of metadata that was previously
- * reserved when starting the transaction. This applies only to
- * the case where we had a transaction start and excludes the
- * transaction join case (when replaying log trees).
- */
- trace_btrfs_space_reservation(fs_info, "transaction",
- trans->transid, bytes, 0);
- btrfs_block_rsv_release(fs_info, trans->block_rsv, bytes, NULL);
- ASSERT(trans->bytes_reserved >= bytes);
- trans->bytes_reserved -= bytes;
- }
-
- ret = __btrfs_add_delayed_item(delayed_node, delayed_item);
- if (unlikely(ret)) {
- btrfs_err(trans->fs_info,
- "err add delayed dir index item(name: %.*s) into the insertion tree of the delayed node(root id: %llu, inode id: %llu, errno: %d)",
- name_len, name, delayed_node->root->root_key.objectid,
- delayed_node->inode_id, ret);
- BUG();
+ } else {
+ btrfs_release_dir_index_item_space(trans);
}
mutex_unlock(&delayed_node->mutex);
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 0a96ea8c1d3a..68f60d50e1fd 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -520,6 +520,7 @@ static bool btree_dirty_folio(struct address_space *mapping,
struct folio *folio)
{
struct btrfs_fs_info *fs_info = btrfs_sb(mapping->host->i_sb);
+ struct btrfs_subpage_info *spi = fs_info->subpage_info;
struct btrfs_subpage *subpage;
struct extent_buffer *eb;
int cur_bit = 0;
@@ -533,18 +534,19 @@ static bool btree_dirty_folio(struct address_space *mapping,
btrfs_assert_tree_write_locked(eb);
return filemap_dirty_folio(mapping, folio);
}
+
+ ASSERT(spi);
subpage = folio_get_private(folio);
- ASSERT(subpage->dirty_bitmap);
- while (cur_bit < BTRFS_SUBPAGE_BITMAP_SIZE) {
+ for (cur_bit = spi->dirty_offset;
+ cur_bit < spi->dirty_offset + spi->bitmap_nr_bits;
+ cur_bit++) {
unsigned long flags;
u64 cur;
- u16 tmp = (1 << cur_bit);
spin_lock_irqsave(&subpage->lock, flags);
- if (!(tmp & subpage->dirty_bitmap)) {
+ if (!test_bit(cur_bit, subpage->bitmaps)) {
spin_unlock_irqrestore(&subpage->lock, flags);
- cur_bit++;
continue;
}
spin_unlock_irqrestore(&subpage->lock, flags);
@@ -557,7 +559,7 @@ static bool btree_dirty_folio(struct address_space *mapping,
btrfs_assert_tree_write_locked(eb);
free_extent_buffer(eb);
- cur_bit += (fs_info->nodesize >> fs_info->sectorsize_bits);
+ cur_bit += (fs_info->nodesize >> fs_info->sectorsize_bits) - 1;
}
return filemap_dirty_folio(mapping, folio);
}
@@ -1547,7 +1549,7 @@ static int transaction_kthread(void *arg)
delta = ktime_get_seconds() - cur->start_time;
if (!test_and_clear_bit(BTRFS_FS_COMMIT_TRANS, &fs_info->flags) &&
- cur->state < TRANS_STATE_COMMIT_START &&
+ cur->state < TRANS_STATE_COMMIT_PREP &&
delta < fs_info->commit_interval) {
spin_unlock(&fs_info->trans_lock);
delay -= msecs_to_jiffies((delta - 1) * 1000);
@@ -2682,8 +2684,8 @@ void btrfs_init_fs_info(struct btrfs_fs_info *fs_info)
btrfs_lockdep_init_map(fs_info, btrfs_trans_num_extwriters);
btrfs_lockdep_init_map(fs_info, btrfs_trans_pending_ordered);
btrfs_lockdep_init_map(fs_info, btrfs_ordered_extent);
- btrfs_state_lockdep_init_map(fs_info, btrfs_trans_commit_start,
- BTRFS_LOCKDEP_TRANS_COMMIT_START);
+ btrfs_state_lockdep_init_map(fs_info, btrfs_trans_commit_prep,
+ BTRFS_LOCKDEP_TRANS_COMMIT_PREP);
btrfs_state_lockdep_init_map(fs_info, btrfs_trans_unblocked,
BTRFS_LOCKDEP_TRANS_UNBLOCKED);
btrfs_state_lockdep_init_map(fs_info, btrfs_trans_super_committed,
@@ -4870,7 +4872,7 @@ static int btrfs_cleanup_transaction(struct btrfs_fs_info *fs_info)
while (!list_empty(&fs_info->trans_list)) {
t = list_first_entry(&fs_info->trans_list,
struct btrfs_transaction, list);
- if (t->state >= TRANS_STATE_COMMIT_START) {
+ if (t->state >= TRANS_STATE_COMMIT_PREP) {
refcount_inc(&t->use_count);
spin_unlock(&fs_info->trans_lock);
btrfs_wait_for_commit(fs_info, t->transid);
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index a18ee7b5a166..75ab766fe156 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1958,6 +1958,13 @@ static int btrfs_search_path_in_tree_user(struct mnt_idmap *idmap,
goto out_put;
}
+ /*
+ * We don't need the path anymore, so release it and
+ * avoid deadlocks and lockdep warnings in case
+ * btrfs_iget() needs to lookup the inode from its root
+ * btree and lock the same leaf.
+ */
+ btrfs_release_path(path);
temp_inode = btrfs_iget(sb, key2.objectid, root);
if (IS_ERR(temp_inode)) {
ret = PTR_ERR(temp_inode);
@@ -1978,7 +1985,6 @@ static int btrfs_search_path_in_tree_user(struct mnt_idmap *idmap,
goto out_put;
}
- btrfs_release_path(path);
key.objectid = key.offset;
key.offset = (u64)-1;
dirid = key.objectid;
diff --git a/fs/btrfs/locking.h b/fs/btrfs/locking.h
index edb9b4a0dba1..7d6ee1e609bf 100644
--- a/fs/btrfs/locking.h
+++ b/fs/btrfs/locking.h
@@ -79,7 +79,7 @@ enum btrfs_lock_nesting {
};
enum btrfs_lockdep_trans_states {
- BTRFS_LOCKDEP_TRANS_COMMIT_START,
+ BTRFS_LOCKDEP_TRANS_COMMIT_PREP,
BTRFS_LOCKDEP_TRANS_UNBLOCKED,
BTRFS_LOCKDEP_TRANS_SUPER_COMMITTED,
BTRFS_LOCKDEP_TRANS_COMPLETED,
diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
index b46ab348e8e5..345c449d588c 100644
--- a/fs/btrfs/ordered-data.c
+++ b/fs/btrfs/ordered-data.c
@@ -639,7 +639,7 @@ void btrfs_remove_ordered_extent(struct btrfs_inode *btrfs_inode,
refcount_inc(&trans->use_count);
spin_unlock(&fs_info->trans_lock);
- ASSERT(trans);
+ ASSERT(trans || BTRFS_FS_ERROR(fs_info));
if (trans) {
if (atomic_dec_and_test(&trans->pending_ordered))
wake_up(&trans->pending_wait);
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 874e4394df86..0bf42dccb041 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -56,12 +56,17 @@ static struct kmem_cache *btrfs_trans_handle_cachep;
* | Call btrfs_commit_transaction() on any trans handle attached to
* | transaction N
* V
- * Transaction N [[TRANS_STATE_COMMIT_START]]
+ * Transaction N [[TRANS_STATE_COMMIT_PREP]]
+ * |
+ * | If there are simultaneous calls to btrfs_commit_transaction() one will win
+ * | the race and the rest will wait for the winner to commit the transaction.
+ * |
+ * | The winner will wait for previous running transaction to completely finish
+ * | if there is one.
* |
- * | Will wait for previous running transaction to completely finish if there
- * | is one
+ * Transaction N [[TRANS_STATE_COMMIT_START]]
* |
- * | Then one of the following happes:
+ * | Then one of the following happens:
* | - Wait for all other trans handle holders to release.
* | The btrfs_commit_transaction() caller will do the commit work.
* | - Wait for current transaction to be committed by others.
@@ -112,6 +117,7 @@ static struct kmem_cache *btrfs_trans_handle_cachep;
*/
static const unsigned int btrfs_blocked_trans_types[TRANS_STATE_MAX] = {
[TRANS_STATE_RUNNING] = 0U,
+ [TRANS_STATE_COMMIT_PREP] = 0U,
[TRANS_STATE_COMMIT_START] = (__TRANS_START | __TRANS_ATTACH),
[TRANS_STATE_COMMIT_DOING] = (__TRANS_START |
__TRANS_ATTACH |
@@ -1982,7 +1988,7 @@ void btrfs_commit_transaction_async(struct btrfs_trans_handle *trans)
* Wait for the current transaction commit to start and block
* subsequent transaction joins
*/
- btrfs_might_wait_for_state(fs_info, BTRFS_LOCKDEP_TRANS_COMMIT_START);
+ btrfs_might_wait_for_state(fs_info, BTRFS_LOCKDEP_TRANS_COMMIT_PREP);
wait_event(fs_info->transaction_blocked_wait,
cur_trans->state >= TRANS_STATE_COMMIT_START ||
TRANS_ABORTED(cur_trans));
@@ -2129,7 +2135,7 @@ static void add_pending_snapshot(struct btrfs_trans_handle *trans)
return;
lockdep_assert_held(&trans->fs_info->trans_lock);
- ASSERT(cur_trans->state >= TRANS_STATE_COMMIT_START);
+ ASSERT(cur_trans->state >= TRANS_STATE_COMMIT_PREP);
list_add(&trans->pending_snapshot->list, &cur_trans->pending_snapshots);
}
@@ -2153,7 +2159,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans)
ktime_t interval;
ASSERT(refcount_read(&trans->use_count) == 1);
- btrfs_trans_state_lockdep_acquire(fs_info, BTRFS_LOCKDEP_TRANS_COMMIT_START);
+ btrfs_trans_state_lockdep_acquire(fs_info, BTRFS_LOCKDEP_TRANS_COMMIT_PREP);
clear_bit(BTRFS_FS_NEED_TRANS_COMMIT, &fs_info->flags);
@@ -2213,7 +2219,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans)
}
spin_lock(&fs_info->trans_lock);
- if (cur_trans->state >= TRANS_STATE_COMMIT_START) {
+ if (cur_trans->state >= TRANS_STATE_COMMIT_PREP) {
enum btrfs_trans_state want_state = TRANS_STATE_COMPLETED;
add_pending_snapshot(trans);
@@ -2225,7 +2231,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans)
want_state = TRANS_STATE_SUPER_COMMITTED;
btrfs_trans_state_lockdep_release(fs_info,
- BTRFS_LOCKDEP_TRANS_COMMIT_START);
+ BTRFS_LOCKDEP_TRANS_COMMIT_PREP);
ret = btrfs_end_transaction(trans);
wait_for_commit(cur_trans, want_state);
@@ -2237,9 +2243,9 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans)
return ret;
}
- cur_trans->state = TRANS_STATE_COMMIT_START;
+ cur_trans->state = TRANS_STATE_COMMIT_PREP;
wake_up(&fs_info->transaction_blocked_wait);
- btrfs_trans_state_lockdep_release(fs_info, BTRFS_LOCKDEP_TRANS_COMMIT_START);
+ btrfs_trans_state_lockdep_release(fs_info, BTRFS_LOCKDEP_TRANS_COMMIT_PREP);
if (cur_trans->list.prev != &fs_info->trans_list) {
enum btrfs_trans_state want_state = TRANS_STATE_COMPLETED;
@@ -2260,11 +2266,9 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans)
btrfs_put_transaction(prev_trans);
if (ret)
goto lockdep_release;
- } else {
- spin_unlock(&fs_info->trans_lock);
+ spin_lock(&fs_info->trans_lock);
}
} else {
- spin_unlock(&fs_info->trans_lock);
/*
* The previous transaction was aborted and was already removed
* from the list of transactions at fs_info->trans_list. So we
@@ -2272,11 +2276,16 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans)
* corrupt state (pointing to trees with unwritten nodes/leafs).
*/
if (BTRFS_FS_ERROR(fs_info)) {
+ spin_unlock(&fs_info->trans_lock);
ret = -EROFS;
goto lockdep_release;
}
}
+ cur_trans->state = TRANS_STATE_COMMIT_START;
+ wake_up(&fs_info->transaction_blocked_wait);
+ spin_unlock(&fs_info->trans_lock);
+
/*
* Get the time spent on the work done by the commit thread and not
* the time spent waiting on a previous commit
@@ -2586,7 +2595,7 @@ lockdep_release:
goto cleanup_transaction;
lockdep_trans_commit_start_release:
- btrfs_trans_state_lockdep_release(fs_info, BTRFS_LOCKDEP_TRANS_COMMIT_START);
+ btrfs_trans_state_lockdep_release(fs_info, BTRFS_LOCKDEP_TRANS_COMMIT_PREP);
btrfs_end_transaction(trans);
return ret;
}
diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h
index 8e9fa23bd7fe..6b309f8a99a8 100644
--- a/fs/btrfs/transaction.h
+++ b/fs/btrfs/transaction.h
@@ -14,6 +14,7 @@
enum btrfs_trans_state {
TRANS_STATE_RUNNING,
+ TRANS_STATE_COMMIT_PREP,
TRANS_STATE_COMMIT_START,
TRANS_STATE_COMMIT_DOING,
TRANS_STATE_UNBLOCKED,
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-09 12:51:08 +0000