diff options
Diffstat (limited to 'fs/xfs/xfs_trans_priv.h')
| -rw-r--r-- | fs/xfs/xfs_trans_priv.h | 55 |
1 files changed, 44 insertions, 11 deletions
diff --git a/fs/xfs/xfs_trans_priv.h b/fs/xfs/xfs_trans_priv.h index 98317fdc33b5..f114d388570a 100644 --- a/fs/xfs/xfs_trans_priv.h +++ b/fs/xfs/xfs_trans_priv.h @@ -44,20 +44,33 @@ xfs_log_busy_slot_t *xfs_trans_add_busy(xfs_trans_t *tp, xfs_extlen_t idx); /* - * From xfs_trans_ail.c + * AIL traversal cursor. + * + * Rather than using a generation number for detecting changes in the ail, use + * a cursor that is protected by the ail lock. The aild cursor exists in the + * struct xfs_ail, but other traversals can declare it on the stack and link it + * to the ail list. + * + * When an object is deleted from or moved int the AIL, the cursor list is + * searched to see if the object is a designated cursor item. If it is, it is + * deleted from the cursor so that the next time the cursor is used traversal + * will return to the start. + * + * This means a traversal colliding with a removal will cause a restart of the + * list scan, rather than any insertion or deletion anywhere in the list. The + * low bit of the item pointer is set if the cursor has been invalidated so + * that we can tell the difference between invalidation and reaching the end + * of the list to trigger traversal restarts. */ -void xfs_trans_update_ail(struct xfs_mount *mp, - struct xfs_log_item *lip, xfs_lsn_t lsn) - __releases(mp->m_ail_lock); -void xfs_trans_delete_ail(struct xfs_mount *mp, - struct xfs_log_item *lip) - __releases(mp->m_ail_lock); -struct xfs_log_item *xfs_trans_first_ail(struct xfs_mount *, int *); -struct xfs_log_item *xfs_trans_next_ail(struct xfs_mount *, - struct xfs_log_item *, int *, int *); +struct xfs_ail_cursor { + struct xfs_ail_cursor *next; + struct xfs_log_item *item; +}; /* - * AIL push thread support + * Private AIL structures. + * + * Eventually we need to drive the locking in here as well. */ struct xfs_ail { struct xfs_mount *xa_mount; @@ -65,8 +78,28 @@ struct xfs_ail { uint xa_gen; struct task_struct *xa_task; xfs_lsn_t xa_target; + struct xfs_ail_cursor xa_cursors; }; +/* + * From xfs_trans_ail.c + */ +void xfs_trans_update_ail(struct xfs_mount *mp, + struct xfs_log_item *lip, xfs_lsn_t lsn) + __releases(mp->m_ail_lock); +void xfs_trans_delete_ail(struct xfs_mount *mp, + struct xfs_log_item *lip) + __releases(mp->m_ail_lock); +struct xfs_log_item *xfs_trans_first_ail(struct xfs_mount *mp, + struct xfs_ail_cursor *cur); +struct xfs_log_item *xfs_trans_next_ail(struct xfs_mount *mp, + struct xfs_ail_cursor *cur); + +void xfs_trans_ail_cursor_init(struct xfs_ail *ailp, + struct xfs_ail_cursor *cur); +void xfs_trans_ail_cursor_done(struct xfs_ail *ailp, + struct xfs_ail_cursor *cur); + long xfsaild_push(struct xfs_ail *, xfs_lsn_t *); void xfsaild_wakeup(struct xfs_ail *, xfs_lsn_t); int xfsaild_start(struct xfs_ail *); |