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-rw-r--r--fs/btrfs/transaction.c283
1 files changed, 198 insertions, 85 deletions
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 27c26004e050..77db875b5116 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -53,7 +53,7 @@ static noinline void switch_commit_root(struct btrfs_root *root)
/*
* either allocate a new transaction or hop into the existing one
*/
-static noinline int join_transaction(struct btrfs_root *root, int nofail)
+static noinline int join_transaction(struct btrfs_root *root, int type)
{
struct btrfs_transaction *cur_trans;
struct btrfs_fs_info *fs_info = root->fs_info;
@@ -67,7 +67,13 @@ loop:
}
if (fs_info->trans_no_join) {
- if (!nofail) {
+ /*
+ * If we are JOIN_NOLOCK we're already committing a current
+ * transaction, we just need a handle to deal with something
+ * when committing the transaction, such as inode cache and
+ * space cache. It is a special case.
+ */
+ if (type != TRANS_JOIN_NOLOCK) {
spin_unlock(&fs_info->trans_lock);
return -EBUSY;
}
@@ -87,6 +93,13 @@ loop:
}
spin_unlock(&fs_info->trans_lock);
+ /*
+ * If we are ATTACH, we just want to catch the current transaction,
+ * and commit it. If there is no transaction, just return ENOENT.
+ */
+ if (type == TRANS_ATTACH)
+ return -ENOENT;
+
cur_trans = kmem_cache_alloc(btrfs_transaction_cachep, GFP_NOFS);
if (!cur_trans)
return -ENOMEM;
@@ -267,13 +280,6 @@ static void wait_current_trans(struct btrfs_root *root)
}
}
-enum btrfs_trans_type {
- TRANS_START,
- TRANS_JOIN,
- TRANS_USERSPACE,
- TRANS_JOIN_NOLOCK,
-};
-
static int may_wait_transaction(struct btrfs_root *root, int type)
{
if (root->fs_info->log_root_recovering)
@@ -290,7 +296,8 @@ static int may_wait_transaction(struct btrfs_root *root, int type)
}
static struct btrfs_trans_handle *start_transaction(struct btrfs_root *root,
- u64 num_items, int type)
+ u64 num_items, int type,
+ int noflush)
{
struct btrfs_trans_handle *h;
struct btrfs_transaction *cur_trans;
@@ -324,9 +331,14 @@ static struct btrfs_trans_handle *start_transaction(struct btrfs_root *root,
}
num_bytes = btrfs_calc_trans_metadata_size(root, num_items);
- ret = btrfs_block_rsv_add(root,
- &root->fs_info->trans_block_rsv,
- num_bytes);
+ if (noflush)
+ ret = btrfs_block_rsv_add_noflush(root,
+ &root->fs_info->trans_block_rsv,
+ num_bytes);
+ else
+ ret = btrfs_block_rsv_add(root,
+ &root->fs_info->trans_block_rsv,
+ num_bytes);
if (ret)
return ERR_PTR(ret);
}
@@ -335,19 +347,34 @@ again:
if (!h)
return ERR_PTR(-ENOMEM);
- sb_start_intwrite(root->fs_info->sb);
+ /*
+ * If we are JOIN_NOLOCK we're already committing a transaction and
+ * waiting on this guy, so we don't need to do the sb_start_intwrite
+ * because we're already holding a ref. We need this because we could
+ * have raced in and did an fsync() on a file which can kick a commit
+ * and then we deadlock with somebody doing a freeze.
+ *
+ * If we are ATTACH, it means we just want to catch the current
+ * transaction and commit it, so we needn't do sb_start_intwrite().
+ */
+ if (type < TRANS_JOIN_NOLOCK)
+ sb_start_intwrite(root->fs_info->sb);
if (may_wait_transaction(root, type))
wait_current_trans(root);
do {
- ret = join_transaction(root, type == TRANS_JOIN_NOLOCK);
+ ret = join_transaction(root, type);
if (ret == -EBUSY)
wait_current_trans(root);
} while (ret == -EBUSY);
if (ret < 0) {
- sb_end_intwrite(root->fs_info->sb);
+ /* We must get the transaction if we are JOIN_NOLOCK. */
+ BUG_ON(type == TRANS_JOIN_NOLOCK);
+
+ if (type < TRANS_JOIN_NOLOCK)
+ sb_end_intwrite(root->fs_info->sb);
kmem_cache_free(btrfs_trans_handle_cachep, h);
return ERR_PTR(ret);
}
@@ -367,7 +394,9 @@ again:
h->aborted = 0;
h->qgroup_reserved = qgroup_reserved;
h->delayed_ref_elem.seq = 0;
+ h->type = type;
INIT_LIST_HEAD(&h->qgroup_ref_list);
+ INIT_LIST_HEAD(&h->new_bgs);
smp_mb();
if (cur_trans->blocked && may_wait_transaction(root, type)) {
@@ -393,21 +422,33 @@ got_it:
struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
int num_items)
{
- return start_transaction(root, num_items, TRANS_START);
+ return start_transaction(root, num_items, TRANS_START, 0);
+}
+
+struct btrfs_trans_handle *btrfs_start_transaction_noflush(
+ struct btrfs_root *root, int num_items)
+{
+ return start_transaction(root, num_items, TRANS_START, 1);
}
+
struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root)
{
- return start_transaction(root, 0, TRANS_JOIN);
+ return start_transaction(root, 0, TRANS_JOIN, 0);
}
struct btrfs_trans_handle *btrfs_join_transaction_nolock(struct btrfs_root *root)
{
- return start_transaction(root, 0, TRANS_JOIN_NOLOCK);
+ return start_transaction(root, 0, TRANS_JOIN_NOLOCK, 0);
}
struct btrfs_trans_handle *btrfs_start_ioctl_transaction(struct btrfs_root *root)
{
- return start_transaction(root, 0, TRANS_USERSPACE);
+ return start_transaction(root, 0, TRANS_USERSPACE, 0);
+}
+
+struct btrfs_trans_handle *btrfs_attach_transaction(struct btrfs_root *root)
+{
+ return start_transaction(root, 0, TRANS_ATTACH, 0);
}
/* wait for a transaction commit to be fully complete */
@@ -506,11 +547,12 @@ int btrfs_should_end_transaction(struct btrfs_trans_handle *trans,
}
static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
- struct btrfs_root *root, int throttle, int lock)
+ struct btrfs_root *root, int throttle)
{
struct btrfs_transaction *cur_trans = trans->transaction;
struct btrfs_fs_info *info = root->fs_info;
int count = 0;
+ int lock = (trans->type != TRANS_JOIN_NOLOCK);
int err = 0;
if (--trans->use_count) {
@@ -536,6 +578,9 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
trans->qgroup_reserved = 0;
}
+ if (!list_empty(&trans->new_bgs))
+ btrfs_create_pending_block_groups(trans, root);
+
while (count < 2) {
unsigned long cur = trans->delayed_ref_updates;
trans->delayed_ref_updates = 0;
@@ -551,7 +596,8 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
btrfs_trans_release_metadata(trans, root);
trans->block_rsv = NULL;
- sb_end_intwrite(root->fs_info->sb);
+ if (!list_empty(&trans->new_bgs))
+ btrfs_create_pending_block_groups(trans, root);
if (lock && !atomic_read(&root->fs_info->open_ioctl_trans) &&
should_end_transaction(trans, root)) {
@@ -573,6 +619,9 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
}
}
+ if (trans->type < TRANS_JOIN_NOLOCK)
+ sb_end_intwrite(root->fs_info->sb);
+
WARN_ON(cur_trans != info->running_transaction);
WARN_ON(atomic_read(&cur_trans->num_writers) < 1);
atomic_dec(&cur_trans->num_writers);
@@ -604,7 +653,7 @@ int btrfs_end_transaction(struct btrfs_trans_handle *trans,
{
int ret;
- ret = __btrfs_end_transaction(trans, root, 0, 1);
+ ret = __btrfs_end_transaction(trans, root, 0);
if (ret)
return ret;
return 0;
@@ -615,18 +664,7 @@ int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans,
{
int ret;
- ret = __btrfs_end_transaction(trans, root, 1, 1);
- if (ret)
- return ret;
- return 0;
-}
-
-int btrfs_end_transaction_nolock(struct btrfs_trans_handle *trans,
- struct btrfs_root *root)
-{
- int ret;
-
- ret = __btrfs_end_transaction(trans, root, 0, 0);
+ ret = __btrfs_end_transaction(trans, root, 1);
if (ret)
return ret;
return 0;
@@ -635,7 +673,7 @@ int btrfs_end_transaction_nolock(struct btrfs_trans_handle *trans,
int btrfs_end_transaction_dmeta(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
- return __btrfs_end_transaction(trans, root, 1, 1);
+ return __btrfs_end_transaction(trans, root, 1);
}
/*
@@ -649,13 +687,15 @@ int btrfs_write_marked_extents(struct btrfs_root *root,
int err = 0;
int werr = 0;
struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
+ struct extent_state *cached_state = NULL;
u64 start = 0;
u64 end;
while (!find_first_extent_bit(dirty_pages, start, &start, &end,
- mark)) {
- convert_extent_bit(dirty_pages, start, end, EXTENT_NEED_WAIT, mark,
- GFP_NOFS);
+ mark, &cached_state)) {
+ convert_extent_bit(dirty_pages, start, end, EXTENT_NEED_WAIT,
+ mark, &cached_state, GFP_NOFS);
+ cached_state = NULL;
err = filemap_fdatawrite_range(mapping, start, end);
if (err)
werr = err;
@@ -679,12 +719,14 @@ int btrfs_wait_marked_extents(struct btrfs_root *root,
int err = 0;
int werr = 0;
struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
+ struct extent_state *cached_state = NULL;
u64 start = 0;
u64 end;
while (!find_first_extent_bit(dirty_pages, start, &start, &end,
- EXTENT_NEED_WAIT)) {
- clear_extent_bits(dirty_pages, start, end, EXTENT_NEED_WAIT, GFP_NOFS);
+ EXTENT_NEED_WAIT, &cached_state)) {
+ clear_extent_bit(dirty_pages, start, end, EXTENT_NEED_WAIT,
+ 0, 0, &cached_state, GFP_NOFS);
err = filemap_fdatawait_range(mapping, start, end);
if (err)
werr = err;
@@ -955,6 +997,8 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
struct btrfs_root *parent_root;
struct btrfs_block_rsv *rsv;
struct inode *parent_inode;
+ struct btrfs_path *path;
+ struct btrfs_dir_item *dir_item;
struct dentry *parent;
struct dentry *dentry;
struct extent_buffer *tmp;
@@ -967,18 +1011,22 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
u64 root_flags;
uuid_le new_uuid;
- rsv = trans->block_rsv;
+ path = btrfs_alloc_path();
+ if (!path) {
+ ret = pending->error = -ENOMEM;
+ goto path_alloc_fail;
+ }
new_root_item = kmalloc(sizeof(*new_root_item), GFP_NOFS);
if (!new_root_item) {
ret = pending->error = -ENOMEM;
- goto fail;
+ goto root_item_alloc_fail;
}
ret = btrfs_find_free_objectid(tree_root, &objectid);
if (ret) {
pending->error = ret;
- goto fail;
+ goto no_free_objectid;
}
btrfs_reloc_pre_snapshot(trans, pending, &to_reserve);
@@ -988,22 +1036,22 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
to_reserve);
if (ret) {
pending->error = ret;
- goto fail;
+ goto no_free_objectid;
}
}
ret = btrfs_qgroup_inherit(trans, fs_info, root->root_key.objectid,
objectid, pending->inherit);
- kfree(pending->inherit);
if (ret) {
pending->error = ret;
- goto fail;
+ goto no_free_objectid;
}
key.objectid = objectid;
key.offset = (u64)-1;
key.type = BTRFS_ROOT_ITEM_KEY;
+ rsv = trans->block_rsv;
trans->block_rsv = &pending->block_rsv;
dentry = pending->dentry;
@@ -1017,24 +1065,21 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
*/
ret = btrfs_set_inode_index(parent_inode, &index);
BUG_ON(ret); /* -ENOMEM */
- ret = btrfs_insert_dir_item(trans, parent_root,
- dentry->d_name.name, dentry->d_name.len,
- parent_inode, &key,
- BTRFS_FT_DIR, index);
- if (ret == -EEXIST) {
+
+ /* check if there is a file/dir which has the same name. */
+ dir_item = btrfs_lookup_dir_item(NULL, parent_root, path,
+ btrfs_ino(parent_inode),
+ dentry->d_name.name,
+ dentry->d_name.len, 0);
+ if (dir_item != NULL && !IS_ERR(dir_item)) {
pending->error = -EEXIST;
- dput(parent);
goto fail;
- } else if (ret) {
- goto abort_trans_dput;
+ } else if (IS_ERR(dir_item)) {
+ ret = PTR_ERR(dir_item);
+ btrfs_abort_transaction(trans, root, ret);
+ goto fail;
}
-
- btrfs_i_size_write(parent_inode, parent_inode->i_size +
- dentry->d_name.len * 2);
- parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
- ret = btrfs_update_inode(trans, parent_root, parent_inode);
- if (ret)
- goto abort_trans_dput;
+ btrfs_release_path(path);
/*
* pull in the delayed directory update
@@ -1043,8 +1088,8 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
* snapshot
*/
ret = btrfs_run_delayed_items(trans, root);
- if (ret) { /* Transaction aborted */
- dput(parent);
+ if (ret) { /* Transaction aborted */
+ btrfs_abort_transaction(trans, root, ret);
goto fail;
}
@@ -1079,7 +1124,8 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
if (ret) {
btrfs_tree_unlock(old);
free_extent_buffer(old);
- goto abort_trans_dput;
+ btrfs_abort_transaction(trans, root, ret);
+ goto fail;
}
btrfs_set_lock_blocking(old);
@@ -1088,8 +1134,10 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
/* clean up in any case */
btrfs_tree_unlock(old);
free_extent_buffer(old);
- if (ret)
- goto abort_trans_dput;
+ if (ret) {
+ btrfs_abort_transaction(trans, root, ret);
+ goto fail;
+ }
/* see comments in should_cow_block() */
root->force_cow = 1;
@@ -1101,8 +1149,10 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
ret = btrfs_insert_root(trans, tree_root, &key, new_root_item);
btrfs_tree_unlock(tmp);
free_extent_buffer(tmp);
- if (ret)
- goto abort_trans_dput;
+ if (ret) {
+ btrfs_abort_transaction(trans, root, ret);
+ goto fail;
+ }
/*
* insert root back/forward references
@@ -1111,32 +1161,58 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
parent_root->root_key.objectid,
btrfs_ino(parent_inode), index,
dentry->d_name.name, dentry->d_name.len);
- dput(parent);
- if (ret)
+ if (ret) {
+ btrfs_abort_transaction(trans, root, ret);
goto fail;
+ }
key.offset = (u64)-1;
pending->snap = btrfs_read_fs_root_no_name(root->fs_info, &key);
if (IS_ERR(pending->snap)) {
ret = PTR_ERR(pending->snap);
- goto abort_trans;
+ btrfs_abort_transaction(trans, root, ret);
+ goto fail;
}
ret = btrfs_reloc_post_snapshot(trans, pending);
+ if (ret) {
+ btrfs_abort_transaction(trans, root, ret);
+ goto fail;
+ }
+
+ ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
+ if (ret) {
+ btrfs_abort_transaction(trans, root, ret);
+ goto fail;
+ }
+
+ ret = btrfs_insert_dir_item(trans, parent_root,
+ dentry->d_name.name, dentry->d_name.len,
+ parent_inode, &key,
+ BTRFS_FT_DIR, index);
+ /* We have check then name at the beginning, so it is impossible. */
+ BUG_ON(ret == -EEXIST);
+ if (ret) {
+ btrfs_abort_transaction(trans, root, ret);
+ goto fail;
+ }
+
+ btrfs_i_size_write(parent_inode, parent_inode->i_size +
+ dentry->d_name.len * 2);
+ parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
+ ret = btrfs_update_inode(trans, parent_root, parent_inode);
if (ret)
- goto abort_trans;
- ret = 0;
+ btrfs_abort_transaction(trans, root, ret);
fail:
- kfree(new_root_item);
+ dput(parent);
trans->block_rsv = rsv;
+no_free_objectid:
+ kfree(new_root_item);
+root_item_alloc_fail:
+ btrfs_free_path(path);
+path_alloc_fail:
btrfs_block_rsv_release(root, &pending->block_rsv, (u64)-1);
return ret;
-
-abort_trans_dput:
- dput(parent);
-abort_trans:
- btrfs_abort_transaction(trans, root, ret);
- goto fail;
}
/*
@@ -1229,6 +1305,16 @@ static void do_async_commit(struct work_struct *work)
struct btrfs_async_commit *ac =
container_of(work, struct btrfs_async_commit, work.work);
+ /*
+ * We've got freeze protection passed with the transaction.
+ * Tell lockdep about it.
+ */
+ rwsem_acquire_read(
+ &ac->root->fs_info->sb->s_writers.lock_map[SB_FREEZE_FS-1],
+ 0, 1, _THIS_IP_);
+
+ current->journal_info = ac->newtrans;
+
btrfs_commit_transaction(ac->newtrans, ac->root);
kfree(ac);
}
@@ -1258,6 +1344,14 @@ int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans,
atomic_inc(&cur_trans->use_count);
btrfs_end_transaction(trans, root);
+
+ /*
+ * Tell lockdep we've released the freeze rwsem, since the
+ * async commit thread will be the one to unlock it.
+ */
+ rwsem_release(&root->fs_info->sb->s_writers.lock_map[SB_FREEZE_FS-1],
+ 1, _THIS_IP_);
+
schedule_delayed_work(&ac->work, 0);
/* wait for transaction to start and unblock */
@@ -1348,6 +1442,9 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
*/
cur_trans->delayed_refs.flushing = 1;
+ if (!list_empty(&trans->new_bgs))
+ btrfs_create_pending_block_groups(trans, root);
+
ret = btrfs_run_delayed_refs(trans, root, 0);
if (ret)
goto cleanup_transaction;
@@ -1403,7 +1500,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
if (flush_on_commit || snap_pending) {
btrfs_start_delalloc_inodes(root, 1);
- btrfs_wait_ordered_extents(root, 0, 1);
+ btrfs_wait_ordered_extents(root, 1);
}
ret = btrfs_run_delayed_items(trans, root);
@@ -1456,13 +1553,28 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
*/
mutex_lock(&root->fs_info->reloc_mutex);
- ret = btrfs_run_delayed_items(trans, root);
+ /*
+ * We needn't worry about the delayed items because we will
+ * deal with them in create_pending_snapshot(), which is the
+ * core function of the snapshot creation.
+ */
+ ret = create_pending_snapshots(trans, root->fs_info);
if (ret) {
mutex_unlock(&root->fs_info->reloc_mutex);
goto cleanup_transaction;
}
- ret = create_pending_snapshots(trans, root->fs_info);
+ /*
+ * We insert the dir indexes of the snapshots and update the inode
+ * of the snapshots' parents after the snapshot creation, so there
+ * are some delayed items which are not dealt with. Now deal with
+ * them.
+ *
+ * We needn't worry that this operation will corrupt the snapshots,
+ * because all the tree which are snapshoted will be forced to COW
+ * the nodes and leaves.
+ */
+ ret = btrfs_run_delayed_items(trans, root);
if (ret) {
mutex_unlock(&root->fs_info->reloc_mutex);
goto cleanup_transaction;
@@ -1584,7 +1696,8 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
put_transaction(cur_trans);
put_transaction(cur_trans);
- sb_end_intwrite(root->fs_info->sb);
+ if (trans->type < TRANS_JOIN_NOLOCK)
+ sb_end_intwrite(root->fs_info->sb);
trace_btrfs_transaction_commit(root);
generated by cgit 1.2.3-korg (git 2.39.0) at 2024-05-07 07:50:07 +0000