Commit 24bbcf04 authored by Yan, Zheng's avatar Yan, Zheng Committed by Chris Mason
Browse files

Btrfs: Add delayed iput



iput() can trigger new transactions if we are dropping the
final reference, so calling it in btrfs_commit_transaction
may end up deadlock. This patch adds delayed iput to avoid
the issue.
Signed-off-by: default avatarYan Zheng <zheng.yan@oracle.com>
Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent f34f57a3
......@@ -872,6 +872,9 @@ struct btrfs_fs_info {
struct list_head dead_roots;
struct list_head caching_block_groups;
spinlock_t delayed_iput_lock;
struct list_head delayed_iputs;
atomic_t nr_async_submits;
atomic_t async_submit_draining;
atomic_t nr_async_bios;
......@@ -2301,7 +2304,7 @@ int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
struct inode *inode, u64 new_size,
u32 min_type);
int btrfs_start_delalloc_inodes(struct btrfs_root *root);
int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput);
int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end);
int btrfs_writepages(struct address_space *mapping,
struct writeback_control *wbc);
......@@ -2341,6 +2344,8 @@ int btrfs_orphan_del(struct btrfs_trans_handle *trans, struct inode *inode);
void btrfs_orphan_cleanup(struct btrfs_root *root);
int btrfs_cont_expand(struct inode *inode, loff_t size);
int btrfs_invalidate_inodes(struct btrfs_root *root);
void btrfs_add_delayed_iput(struct inode *inode);
void btrfs_run_delayed_iputs(struct btrfs_root *root);
extern const struct dentry_operations btrfs_dentry_operations;
/* ioctl.c */
......
......@@ -1476,6 +1476,7 @@ static int cleaner_kthread(void *arg)
if (!(root->fs_info->sb->s_flags & MS_RDONLY) &&
mutex_trylock(&root->fs_info->cleaner_mutex)) {
btrfs_run_delayed_iputs(root);
btrfs_clean_old_snapshots(root);
mutex_unlock(&root->fs_info->cleaner_mutex);
}
......@@ -1605,6 +1606,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
INIT_LIST_HEAD(&fs_info->trans_list);
INIT_LIST_HEAD(&fs_info->dead_roots);
INIT_LIST_HEAD(&fs_info->delayed_iputs);
INIT_LIST_HEAD(&fs_info->hashers);
INIT_LIST_HEAD(&fs_info->delalloc_inodes);
INIT_LIST_HEAD(&fs_info->ordered_operations);
......@@ -1613,6 +1615,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
spin_lock_init(&fs_info->new_trans_lock);
spin_lock_init(&fs_info->ref_cache_lock);
spin_lock_init(&fs_info->fs_roots_radix_lock);
spin_lock_init(&fs_info->delayed_iput_lock);
init_completion(&fs_info->kobj_unregister);
fs_info->tree_root = tree_root;
......@@ -2386,6 +2389,7 @@ int btrfs_commit_super(struct btrfs_root *root)
int ret;
mutex_lock(&root->fs_info->cleaner_mutex);
btrfs_run_delayed_iputs(root);
btrfs_clean_old_snapshots(root);
mutex_unlock(&root->fs_info->cleaner_mutex);
......
......@@ -2880,9 +2880,9 @@ static noinline void flush_delalloc_async(struct btrfs_work *work)
root = async->root;
info = async->info;
btrfs_start_delalloc_inodes(root);
btrfs_start_delalloc_inodes(root, 0);
wake_up(&info->flush_wait);
btrfs_wait_ordered_extents(root, 0);
btrfs_wait_ordered_extents(root, 0, 0);
spin_lock(&info->lock);
info->flushing = 0;
......@@ -2956,8 +2956,8 @@ static void flush_delalloc(struct btrfs_root *root,
return;
flush:
btrfs_start_delalloc_inodes(root);
btrfs_wait_ordered_extents(root, 0);
btrfs_start_delalloc_inodes(root, 0);
btrfs_wait_ordered_extents(root, 0, 0);
spin_lock(&info->lock);
info->flushing = 0;
......
......@@ -2022,6 +2022,54 @@ zeroit:
return -EIO;
}
struct delayed_iput {
struct list_head list;
struct inode *inode;
};
void btrfs_add_delayed_iput(struct inode *inode)
{
struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
struct delayed_iput *delayed;
if (atomic_add_unless(&inode->i_count, -1, 1))
return;
delayed = kmalloc(sizeof(*delayed), GFP_NOFS | __GFP_NOFAIL);
delayed->inode = inode;
spin_lock(&fs_info->delayed_iput_lock);
list_add_tail(&delayed->list, &fs_info->delayed_iputs);
spin_unlock(&fs_info->delayed_iput_lock);
}
void btrfs_run_delayed_iputs(struct btrfs_root *root)
{
LIST_HEAD(list);
struct btrfs_fs_info *fs_info = root->fs_info;
struct delayed_iput *delayed;
int empty;
spin_lock(&fs_info->delayed_iput_lock);
empty = list_empty(&fs_info->delayed_iputs);
spin_unlock(&fs_info->delayed_iput_lock);
if (empty)
return;
down_read(&root->fs_info->cleanup_work_sem);
spin_lock(&fs_info->delayed_iput_lock);
list_splice_init(&fs_info->delayed_iputs, &list);
spin_unlock(&fs_info->delayed_iput_lock);
while (!list_empty(&list)) {
delayed = list_entry(list.next, struct delayed_iput, list);
list_del(&delayed->list);
iput(delayed->inode);
kfree(delayed);
}
up_read(&root->fs_info->cleanup_work_sem);
}
/*
* This creates an orphan entry for the given inode in case something goes
* wrong in the middle of an unlink/truncate.
......@@ -5568,7 +5616,7 @@ out_fail:
* some fairly slow code that needs optimization. This walks the list
* of all the inodes with pending delalloc and forces them to disk.
*/
int btrfs_start_delalloc_inodes(struct btrfs_root *root)
int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
{
struct list_head *head = &root->fs_info->delalloc_inodes;
struct btrfs_inode *binode;
......@@ -5587,7 +5635,10 @@ int btrfs_start_delalloc_inodes(struct btrfs_root *root)
spin_unlock(&root->fs_info->delalloc_lock);
if (inode) {
filemap_flush(inode->i_mapping);
iput(inode);
if (delay_iput)
btrfs_add_delayed_iput(inode);
else
iput(inode);
}
cond_resched();
spin_lock(&root->fs_info->delalloc_lock);
......
......@@ -352,7 +352,8 @@ int btrfs_remove_ordered_extent(struct inode *inode,
* wait for all the ordered extents in a root. This is done when balancing
* space between drives.
*/
int btrfs_wait_ordered_extents(struct btrfs_root *root, int nocow_only)
int btrfs_wait_ordered_extents(struct btrfs_root *root,
int nocow_only, int delay_iput)
{
struct list_head splice;
struct list_head *cur;
......@@ -389,7 +390,10 @@ int btrfs_wait_ordered_extents(struct btrfs_root *root, int nocow_only)
if (inode) {
btrfs_start_ordered_extent(inode, ordered, 1);
btrfs_put_ordered_extent(ordered);
iput(inode);
if (delay_iput)
btrfs_add_delayed_iput(inode);
else
iput(inode);
} else {
btrfs_put_ordered_extent(ordered);
}
......@@ -447,7 +451,7 @@ again:
btrfs_wait_ordered_range(inode, 0, (u64)-1);
else
filemap_flush(inode->i_mapping);
iput(inode);
btrfs_add_delayed_iput(inode);
}
cond_resched();
......
......@@ -153,9 +153,10 @@ btrfs_lookup_first_ordered_extent(struct inode * inode, u64 file_offset);
int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,
struct btrfs_ordered_extent *ordered);
int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr, u32 *sum);
int btrfs_wait_ordered_extents(struct btrfs_root *root, int nocow_only);
int btrfs_run_ordered_operations(struct btrfs_root *root, int wait);
int btrfs_add_ordered_operation(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *inode);
int btrfs_wait_ordered_extents(struct btrfs_root *root,
int nocow_only, int delay_iput);
#endif
......@@ -3541,8 +3541,8 @@ int btrfs_relocate_block_group(struct btrfs_root *extent_root, u64 group_start)
(unsigned long long)rc->block_group->key.objectid,
(unsigned long long)rc->block_group->flags);
btrfs_start_delalloc_inodes(fs_info->tree_root);
btrfs_wait_ordered_extents(fs_info->tree_root, 0);
btrfs_start_delalloc_inodes(fs_info->tree_root, 0);
btrfs_wait_ordered_extents(fs_info->tree_root, 0, 0);
while (1) {
rc->extents_found = 0;
......
......@@ -405,8 +405,8 @@ int btrfs_sync_fs(struct super_block *sb, int wait)
return 0;
}
btrfs_start_delalloc_inodes(root);
btrfs_wait_ordered_extents(root, 0);
btrfs_start_delalloc_inodes(root, 0);
btrfs_wait_ordered_extents(root, 0, 0);
trans = btrfs_start_transaction(root, 1);
ret = btrfs_commit_transaction(trans, root);
......
......@@ -333,6 +333,9 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
memset(trans, 0, sizeof(*trans));
kmem_cache_free(btrfs_trans_handle_cachep, trans);
if (throttle)
btrfs_run_delayed_iputs(root);
return 0;
}
......@@ -991,11 +994,11 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
mutex_unlock(&root->fs_info->trans_mutex);
if (flush_on_commit) {
btrfs_start_delalloc_inodes(root);
ret = btrfs_wait_ordered_extents(root, 0);
btrfs_start_delalloc_inodes(root, 1);
ret = btrfs_wait_ordered_extents(root, 0, 1);
BUG_ON(ret);
} else if (snap_pending) {
ret = btrfs_wait_ordered_extents(root, 1);
ret = btrfs_wait_ordered_extents(root, 0, 1);
BUG_ON(ret);
}
......@@ -1113,6 +1116,10 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
current->journal_info = NULL;
kmem_cache_free(btrfs_trans_handle_cachep, trans);
if (current != root->fs_info->transaction_kthread)
btrfs_run_delayed_iputs(root);
return ret;
}
......
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