fs/xfs/xfs_refcount_item.c

Source file repositories/reference/linux-study-clean/fs/xfs/xfs_refcount_item.c

File Facts

System
Linux kernel
Corpus path
fs/xfs/xfs_refcount_item.c
Extension
.c
Size
23527 bytes
Lines
863
Domain
Core OS
Bucket
VFS And Filesystem Core
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2016 Oracle.  All Rights Reserved.
 * Author: Darrick J. Wong <darrick.wong@oracle.com>
 */
#include "xfs_platform.h"
#include "xfs_fs.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_bit.h"
#include "xfs_shared.h"
#include "xfs_mount.h"
#include "xfs_defer.h"
#include "xfs_trans.h"
#include "xfs_trans_priv.h"
#include "xfs_refcount_item.h"
#include "xfs_log.h"
#include "xfs_refcount.h"
#include "xfs_error.h"
#include "xfs_log_priv.h"
#include "xfs_log_recover.h"
#include "xfs_ag.h"
#include "xfs_btree.h"
#include "xfs_trace.h"
#include "xfs_rtgroup.h"

struct kmem_cache	*xfs_cui_cache;
struct kmem_cache	*xfs_cud_cache;

static const struct xfs_item_ops xfs_cui_item_ops;

static inline struct xfs_cui_log_item *CUI_ITEM(struct xfs_log_item *lip)
{
	return container_of(lip, struct xfs_cui_log_item, cui_item);
}

STATIC void
xfs_cui_item_free(
	struct xfs_cui_log_item	*cuip)
{
	kvfree(cuip->cui_item.li_lv_shadow);
	if (cuip->cui_format.cui_nextents > XFS_CUI_MAX_FAST_EXTENTS)
		kfree(cuip);
	else
		kmem_cache_free(xfs_cui_cache, cuip);
}

/*
 * Freeing the CUI requires that we remove it from the AIL if it has already
 * been placed there. However, the CUI may not yet have been placed in the AIL
 * when called by xfs_cui_release() from CUD processing due to the ordering of
 * committed vs unpin operations in bulk insert operations. Hence the reference
 * count to ensure only the last caller frees the CUI.
 */
STATIC void
xfs_cui_release(
	struct xfs_cui_log_item	*cuip)
{
	ASSERT(atomic_read(&cuip->cui_refcount) > 0);
	if (!atomic_dec_and_test(&cuip->cui_refcount))
		return;

	xfs_trans_ail_delete(&cuip->cui_item, 0);
	xfs_cui_item_free(cuip);
}


STATIC void
xfs_cui_item_size(
	struct xfs_log_item	*lip,
	int			*nvecs,
	int			*nbytes)
{
	struct xfs_cui_log_item	*cuip = CUI_ITEM(lip);

	*nvecs += 1;
	*nbytes += xfs_cui_log_format_sizeof(cuip->cui_format.cui_nextents);
}

unsigned int xfs_cui_log_space(unsigned int nr)
{
	return xlog_item_space(1, xfs_cui_log_format_sizeof(nr));
}

/*
 * This is called to fill in the vector of log iovecs for the
 * given cui log item. We use only 1 iovec, and we point that
 * at the cui_log_format structure embedded in the cui item.
 * It is at this point that we assert that all of the extent

Annotation

Implementation Notes