diff options
| -rw-r--r-- | fs/xfs/xfs_trans_ail.c | 79 | ||||
| -rw-r--r-- | fs/xfs/xfs_trans_priv.h | 4 |
2 files changed, 28 insertions, 55 deletions
diff --git a/fs/xfs/xfs_trans_ail.c b/fs/xfs/xfs_trans_ail.c index 7908c798a02b..43233e92f0f6 100644 --- a/fs/xfs/xfs_trans_ail.c +++ b/fs/xfs/xfs_trans_ail.c @@ -163,17 +163,11 @@ xfs_ail_max_lsn( } /* - * AIL traversal cursor initialisation. - * - * The cursor keeps track of where our current traversal is up - * to by tracking the next ƣtem in the list for us. However, for - * this to be safe, removing an object from the AIL needs to invalidate - * any cursor that points to it. hence the traversal cursor needs to - * be linked to the struct xfs_ail so that deletion can search all the - * active cursors for invalidation. - * - * We don't link the push cursor because it is embedded in the struct - * xfs_ail and hence easily findable. + * The cursor keeps track of where our current traversal is up to by tracking + * the next item in the list for us. However, for this to be safe, removing an + * object from the AIL needs to invalidate any cursor that points to it. hence + * the traversal cursor needs to be linked to the struct xfs_ail so that + * deletion can search all the active cursors for invalidation. */ STATIC void xfs_trans_ail_cursor_init( @@ -181,17 +175,12 @@ xfs_trans_ail_cursor_init( struct xfs_ail_cursor *cur) { cur->item = NULL; - if (cur == &ailp->xa_cursors) - return; - - cur->next = ailp->xa_cursors.next; - ailp->xa_cursors.next = cur; + list_add_tail(&cur->list, &ailp->xa_cursors); } /* - * Get the next item in the traversal and advance the cursor. - * If the cursor was invalidated (inidicated by a lip of 1), - * restart the traversal. + * Get the next item in the traversal and advance the cursor. If the cursor + * was invalidated (indicated by a lip of 1), restart the traversal. */ struct xfs_log_item * xfs_trans_ail_cursor_next( @@ -208,40 +197,25 @@ xfs_trans_ail_cursor_next( } /* - * Now that the traversal is complete, we need to remove the cursor - * from the list of traversing cursors. Avoid removing the embedded - * push cursor, but use the fact it is always present to make the - * list deletion simple. + * When the traversal is complete, we need to remove the cursor from the list + * of traversing cursors. */ void xfs_trans_ail_cursor_done( struct xfs_ail *ailp, - struct xfs_ail_cursor *done) + struct xfs_ail_cursor *cur) { - struct xfs_ail_cursor *prev = NULL; - struct xfs_ail_cursor *cur; - - done->item = NULL; - if (done == &ailp->xa_cursors) - return; - prev = &ailp->xa_cursors; - for (cur = prev->next; cur; prev = cur, cur = prev->next) { - if (cur == done) { - prev->next = cur->next; - break; - } - } - ASSERT(cur); + cur->item = NULL; + list_del_init(&cur->list); } /* - * Invalidate any cursor that is pointing to this item. This is - * called when an item is removed from the AIL. Any cursor pointing - * to this object is now invalid and the traversal needs to be - * terminated so it doesn't reference a freed object. We set the - * cursor item to a value of 1 so we can distinguish between an - * invalidation and the end of the list when getting the next item - * from the cursor. + * Invalidate any cursor that is pointing to this item. This is called when an + * item is removed from the AIL. Any cursor pointing to this object is now + * invalid and the traversal needs to be terminated so it doesn't reference a + * freed object. We set the low bit of the cursor item pointer so we can + * distinguish between an invalidation and the end of the list when getting the + * next item from the cursor. */ STATIC void xfs_trans_ail_cursor_clear( @@ -250,8 +224,7 @@ xfs_trans_ail_cursor_clear( { struct xfs_ail_cursor *cur; - /* need to search all cursors */ - for (cur = &ailp->xa_cursors; cur; cur = cur->next) { + list_for_each_entry(cur, &ailp->xa_cursors, list) { if (cur->item == lip) cur->item = (struct xfs_log_item *) ((__psint_t)cur->item | 1); @@ -405,7 +378,7 @@ xfs_ail_worker( struct xfs_ail *ailp = container_of(to_delayed_work(work), struct xfs_ail, xa_work); xfs_mount_t *mp = ailp->xa_mount; - struct xfs_ail_cursor *cur = &ailp->xa_cursors; + struct xfs_ail_cursor cur; xfs_log_item_t *lip; xfs_lsn_t lsn; xfs_lsn_t target; @@ -417,13 +390,12 @@ xfs_ail_worker( spin_lock(&ailp->xa_lock); target = ailp->xa_target; - xfs_trans_ail_cursor_init(ailp, cur); - lip = xfs_trans_ail_cursor_first(ailp, cur, ailp->xa_last_pushed_lsn); + lip = xfs_trans_ail_cursor_first(ailp, &cur, ailp->xa_last_pushed_lsn); if (!lip || XFS_FORCED_SHUTDOWN(mp)) { /* * AIL is empty or our push has reached the end. */ - xfs_trans_ail_cursor_done(ailp, cur); + xfs_trans_ail_cursor_done(ailp, &cur); spin_unlock(&ailp->xa_lock); goto out_done; } @@ -511,12 +483,12 @@ xfs_ail_worker( if (stuck > 100) break; - lip = xfs_trans_ail_cursor_next(ailp, cur); + lip = xfs_trans_ail_cursor_next(ailp, &cur); if (lip == NULL) break; lsn = lip->li_lsn; } - xfs_trans_ail_cursor_done(ailp, cur); + xfs_trans_ail_cursor_done(ailp, &cur); spin_unlock(&ailp->xa_lock); if (flush_log) { @@ -848,6 +820,7 @@ xfs_trans_ail_init( ailp->xa_mount = mp; INIT_LIST_HEAD(&ailp->xa_ail); + INIT_LIST_HEAD(&ailp->xa_cursors); spin_lock_init(&ailp->xa_lock); INIT_DELAYED_WORK(&ailp->xa_work, xfs_ail_worker); mp->m_ail = ailp; diff --git a/fs/xfs/xfs_trans_priv.h b/fs/xfs/xfs_trans_priv.h index c0cb40890329..212946b97239 100644 --- a/fs/xfs/xfs_trans_priv.h +++ b/fs/xfs/xfs_trans_priv.h @@ -53,7 +53,7 @@ void xfs_trans_committed_bulk(struct xfs_ail *ailp, struct xfs_log_vec *lv, * of the list to trigger traversal restarts. */ struct xfs_ail_cursor { - struct xfs_ail_cursor *next; + struct list_head list; struct xfs_log_item *item; }; @@ -66,7 +66,7 @@ struct xfs_ail { struct xfs_mount *xa_mount; struct list_head xa_ail; xfs_lsn_t xa_target; - struct xfs_ail_cursor xa_cursors; + struct list_head xa_cursors; spinlock_t xa_lock; struct delayed_work xa_work; xfs_lsn_t xa_last_pushed_lsn; |