linux/fs/xfs/xfs_refcount_item.h
Brian Foster fbfa977d25 xfs: use transaction for intent recovery instead of raw dfops
Log intent recovery is the last user of an external (on-stack)
dfops. The pattern exists because the dfops is used to collect
additional deferred operations queued during the whole recovery
sequence. The dfops is finished with a new transaction after intent
recovery completes.

We already have a mechanism to create an empty, container-like
transaction to support the scrub infrastructure. We can reuse that
mechanism here to drop the final user of external dfops. This
facilitates folding dfops state (i.e., dop_low) into the
transaction, the elimination of now unused external dfops support
and also eliminates the only caller of __xfs_defer_cancel().

Replace the on-stack dfops with an empty transaction and pass it
around to the various helpers that queue and finish deferred
operations during intent recovery.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-08-02 23:05:13 -07:00

88 lines
2.7 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2016 Oracle. All Rights Reserved.
* Author: Darrick J. Wong <darrick.wong@oracle.com>
*/
#ifndef __XFS_REFCOUNT_ITEM_H__
#define __XFS_REFCOUNT_ITEM_H__
/*
* There are (currently) two pairs of refcount btree redo item types:
* increase and decrease. The log items for these are CUI (refcount
* update intent) and CUD (refcount update done). The redo item type
* is encoded in the flags field of each xfs_map_extent.
*
* *I items should be recorded in the *first* of a series of rolled
* transactions, and the *D items should be recorded in the same
* transaction that records the associated refcountbt updates.
*
* Should the system crash after the commit of the first transaction
* but before the commit of the final transaction in a series, log
* recovery will use the redo information recorded by the intent items
* to replay the refcountbt metadata updates.
*/
/* kernel only CUI/CUD definitions */
struct xfs_mount;
struct kmem_zone;
/*
* Max number of extents in fast allocation path.
*/
#define XFS_CUI_MAX_FAST_EXTENTS 16
/*
* Define CUI flag bits. Manipulated by set/clear/test_bit operators.
*/
#define XFS_CUI_RECOVERED 1
/*
* This is the "refcount update intent" log item. It is used to log
* the fact that some reverse mappings need to change. It is used in
* conjunction with the "refcount update done" log item described
* below.
*
* These log items follow the same rules as struct xfs_efi_log_item;
* see the comments about that structure (in xfs_extfree_item.h) for
* more details.
*/
struct xfs_cui_log_item {
struct xfs_log_item cui_item;
atomic_t cui_refcount;
atomic_t cui_next_extent;
unsigned long cui_flags; /* misc flags */
struct xfs_cui_log_format cui_format;
};
static inline size_t
xfs_cui_log_item_sizeof(
unsigned int nr)
{
return offsetof(struct xfs_cui_log_item, cui_format) +
xfs_cui_log_format_sizeof(nr);
}
/*
* This is the "refcount update done" log item. It is used to log the
* fact that some refcountbt updates mentioned in an earlier cui item
* have been performed.
*/
struct xfs_cud_log_item {
struct xfs_log_item cud_item;
struct xfs_cui_log_item *cud_cuip;
struct xfs_cud_log_format cud_format;
};
extern struct kmem_zone *xfs_cui_zone;
extern struct kmem_zone *xfs_cud_zone;
struct xfs_cui_log_item *xfs_cui_init(struct xfs_mount *, uint);
struct xfs_cud_log_item *xfs_cud_init(struct xfs_mount *,
struct xfs_cui_log_item *);
void xfs_cui_item_free(struct xfs_cui_log_item *);
void xfs_cui_release(struct xfs_cui_log_item *);
int xfs_cui_recover(struct xfs_trans *parent_tp, struct xfs_cui_log_item *cuip);
#endif /* __XFS_REFCOUNT_ITEM_H__ */