Files
scoutfs/kmod/src/inode.h
T
Zach Brown 603af327ac Ignore I_FREEING in all inode hash lookups
Previously we added a ilookup variant that ignored I_FREEING inodes
to avoid a deadlock between lock invalidation (lock->I_FREEING) and
eviction (I_FREEING->lock);

Now we're seeing similar deadlocks between eviction (I_FREEING->lock)
and fh_to_dentry's iget (lock->I_FREEING).

I think it's reasonable to ignore all inodes with I_FREEING set when
we're using our _test callback in ilookup or iget.  We can remove the
_nofreeing ilookup variant and move its I_FREEING test into the
iget_test callback provided to both ilookup and iget.

Callers will get the same result, it will just happen without waiting
for a previously I_FREEING inode to leave.  They'll get NULL instead of
waiting from ilookup.  They'll allocate and start to initialize a newer
instance of the inode and insert it along side the previous instance.

We don't have inode number re-use so we don't have the problem where a
newly allocated inode number is relying on inode cache serialization to
not find a previously allocated inode that is being evicted.

This change does allow for concurrent iget of an inode number that is
being deleted on a local node.  This could happen in fh_to_dentry with a
raw inode number.  But this was already a problem between mounts because
they don't have a shared inode cache to serialize them.  Once we fix
that between nodes, we fix it on a single node as well.

Signed-off-by: Zach Brown <zab@versity.com>
2021-04-28 12:22:10 -07:00

139 lines
4.6 KiB
C

#ifndef _SCOUTFS_INODE_H_
#define _SCOUTFS_INODE_H_
#include "key.h"
#include "lock.h"
#include "per_task.h"
#include "format.h"
#include "data.h"
struct scoutfs_lock;
struct scoutfs_inode_info {
/* read or initialized for each inode instance */
u64 ino;
u64 next_readdir_pos;
u64 next_xattr_id;
u64 meta_seq;
u64 data_seq;
u64 data_version;
u64 online_blocks;
u64 offline_blocks;
u32 flags;
/*
* Protects per-inode extent items, most particularly readers
* who want to serialize writers without holding i_mutex. (only
* used in data.c, it's the only place that understands file
* extent items)
*/
struct rw_semaphore extent_sem;
/*
* The in-memory item info caches the current index item values
* so that we can decide to update them with comparisons instead
* of by maintaining state that tracks the inode differing from
* the item. The "item_" prefix is a bit clumsy :/.
*/
struct mutex item_mutex;
bool have_item;
u64 item_majors[SCOUTFS_INODE_INDEX_NR];
u32 item_minors[SCOUTFS_INODE_INDEX_NR];
/* updated at on each new lock acquisition */
atomic64_t last_refreshed;
/* initialized once for slab object */
seqcount_t seqcount;
bool staging; /* holder of i_mutex is staging */
struct scoutfs_per_task pt_data_lock;
struct scoutfs_data_waitq data_waitq;
struct rw_semaphore xattr_rwsem;
struct rb_node writeback_node;
struct scoutfs_lock_coverage ino_lock_cov;
/* drop if i_count hits 0, allows drop while invalidate holds coverage */
bool drop_invalidated;
struct llist_node inv_iput_llnode;
atomic_t inv_iput_count;
struct inode inode;
};
static inline struct scoutfs_inode_info *SCOUTFS_I(struct inode *inode)
{
return container_of(inode, struct scoutfs_inode_info, inode);
}
static inline u64 scoutfs_ino(struct inode *inode)
{
return SCOUTFS_I(inode)->ino;
}
struct inode *scoutfs_alloc_inode(struct super_block *sb);
void scoutfs_destroy_inode(struct inode *inode);
int scoutfs_drop_inode(struct inode *inode);
void scoutfs_evict_inode(struct inode *inode);
int scoutfs_orphan_inode(struct inode *inode);
struct inode *scoutfs_iget(struct super_block *sb, u64 ino);
struct inode *scoutfs_ilookup(struct super_block *sb, u64 ino);
void scoutfs_inode_init_index_key(struct scoutfs_key *key, u8 type, u64 major,
u32 minor, u64 ino);
int scoutfs_inode_index_start(struct super_block *sb, u64 *seq);
int scoutfs_inode_index_prepare(struct super_block *sb, struct list_head *list,
struct inode *inode, bool set_data_seq);
int scoutfs_inode_index_prepare_ino(struct super_block *sb,
struct list_head *list, u64 ino,
umode_t mode);
int scoutfs_inode_index_try_lock_hold(struct super_block *sb,
struct list_head *list, u64 seq);
int scoutfs_inode_index_lock_hold(struct inode *inode, struct list_head *list,
bool set_data_seq);
void scoutfs_inode_index_unlock(struct super_block *sb, struct list_head *list);
int scoutfs_dirty_inode_item(struct inode *inode, struct scoutfs_lock *lock);
void scoutfs_update_inode_item(struct inode *inode, struct scoutfs_lock *lock,
struct list_head *ind_locks);
int scoutfs_alloc_ino(struct super_block *sb, bool is_dir, u64 *ino_ret);
struct inode *scoutfs_new_inode(struct super_block *sb, struct inode *dir,
umode_t mode, dev_t rdev, u64 ino,
struct scoutfs_lock *lock);
void scoutfs_inode_set_meta_seq(struct inode *inode);
void scoutfs_inode_set_data_seq(struct inode *inode);
void scoutfs_inode_inc_data_version(struct inode *inode);
void scoutfs_inode_set_data_version(struct inode *inode, u64 data_version);
void scoutfs_inode_add_onoff(struct inode *inode, s64 on, s64 off);
u64 scoutfs_inode_meta_seq(struct inode *inode);
u64 scoutfs_inode_data_seq(struct inode *inode);
u64 scoutfs_inode_data_version(struct inode *inode);
void scoutfs_inode_get_onoff(struct inode *inode, s64 *on, s64 *off);
int scoutfs_complete_truncate(struct inode *inode, struct scoutfs_lock *lock);
int scoutfs_inode_refresh(struct inode *inode, struct scoutfs_lock *lock,
int flags);
int scoutfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
struct kstat *stat);
int scoutfs_setattr(struct dentry *dentry, struct iattr *attr);
int scoutfs_scan_orphans(struct super_block *sb);
int scoutfs_orphan_dirty(struct super_block *sb, u64 ino);
int scoutfs_orphan_delete(struct super_block *sb, u64 ino);
void scoutfs_inode_queue_writeback(struct inode *inode);
int scoutfs_inode_walk_writeback(struct super_block *sb, bool write);
u64 scoutfs_last_ino(struct super_block *sb);
void scoutfs_inode_exit(void);
int scoutfs_inode_init(void);
int scoutfs_inode_setup(struct super_block *sb);
void scoutfs_inode_destroy(struct super_block *sb);
#endif