path: root/fs/xfs/xfs_buf_item.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 */
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_shared.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_bit.h"
#include "xfs_mount.h"
#include "xfs_trans.h"
#include "xfs_trans_priv.h"
#include "xfs_buf_item.h"
#include "xfs_inode.h"
#include "xfs_inode_item.h"
#include "xfs_quota.h"
#include "xfs_dquot_item.h"
#include "xfs_dquot.h"
#include "xfs_trace.h"
#include "xfs_log.h"
#include "xfs_log_priv.h"
#include "xfs_error.h"


struct kmem_cache	*xfs_buf_item_cache;

static inline struct xfs_buf_log_item *BUF_ITEM(struct xfs_log_item *lip)
{
	return container_of(lip, struct xfs_buf_log_item, bli_item);
}

static void
xfs_buf_item_get_format(
	struct xfs_buf_log_item	*bip,
	int			count)
{
	ASSERT(bip->bli_formats == NULL);
	bip->bli_format_count = count;

	if (count == 1) {
		bip->bli_formats = &bip->__bli_format;
		return;
	}

	bip->bli_formats = kzalloc(count * sizeof(struct xfs_buf_log_format),
				GFP_KERNEL | __GFP_NOFAIL);
}

static void
xfs_buf_item_free_format(
	struct xfs_buf_log_item	*bip)
{
	if (bip->bli_formats != &bip->__bli_format) {
		kfree(bip->bli_formats);
		bip->bli_formats = NULL;
	}
}

static void
xfs_buf_item_free(
	struct xfs_buf_log_item	*bip)
{
	xfs_buf_item_free_format(bip);
	kvfree(bip->bli_item.li_lv_shadow);
	kmem_cache_free(xfs_buf_item_cache, bip);
}

/*
 * xfs_buf_item_relse() is called when the buf log item is no longer needed.
 */
static void
xfs_buf_item_relse(
	struct xfs_buf_log_item	*bip)
{
	struct xfs_buf		*bp = bip->bli_buf;

	trace_xfs_buf_item_relse(bp, _RET_IP_);

	ASSERT(!test_bit(XFS_LI_IN_AIL, &bip->bli_item.li_flags));
	ASSERT(atomic_read(&bip->bli_refcount) == 0);

	bp->b_log_item = NULL;
	xfs_buf_rele(bp);
	xfs_buf_item_free(bip);
}

/* Is this log iovec plausibly large enough to contain the buffer log format? */
bool
xfs_buf_log_check_iovec(
	struct kvec			*iovec)
{
	struct xfs_buf_log_format	*blfp = iovec->iov_base;
	char				*bmp_end;
	char				*item_end;

	if (offsetof(struct xfs_buf_log_format, blf_data_map) > iovec->iov_len)
		return false;

	item_end = (char *)iovec->iov_base + iovec->iov_len;
	bmp_end = (char *)&blfp->blf_data_map[blfp->blf_map_size];
	return bmp_end <= item_end;
}

static inline int
xfs_buf_log_format_size(
	struct xfs_buf_log_format *blfp)
{
	return offsetof(struct xfs_buf_log_format, blf_data_map) +
			(blfp->blf_map_size * sizeof(blfp->blf_data_map[0]));
}

/*
 * Return the number of log iovecs and space needed to log the given buf log
 * item segment.
 *
 * It calculates this as 1 iovec for the buf log format structure and 1 for each
 * stretch of non-contiguous chunks to be logged.  Contiguous chunks are logged
 * in a single iovec.
 */
STATIC void
xfs_buf_item_size_segment(
	struct xfs_buf_log_item		*bip,
	struct xfs_buf_log_format	*blfp,
	uint				offset,
	int				*nvecs,
	int				*nbytes)
{
	int				first_bit;
	int				nbits;

	first_bit = xfs_next_bit(blfp->blf_data_map, blfp->blf_map_size, 0);
	if (first_bit == -1)
		return;

	(*nvecs)++;
	*nbytes += xfs_buf_log_format_size(blfp);

	do {
		nbits = xfs_contig_bits(blfp->blf_data_map,
					blfp->blf_map_size, first_bit);
		ASSERT