xfs_fsmap.c | Explore in Territory

// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2017 Oracle.  All Rights Reserved.
 * Author: Darrick J. Wong <[email protected]>
 */
#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_mount.h"
#include "xfs_inode.h"
#include "xfs_trans.h"
#include "xfs_btree.h"
#include "xfs_rmap_btree.h"
#include "xfs_trace.h"
#include "xfs_rmap.h"
#include "xfs_alloc.h"
#include "xfs_bit.h"
#include <linux/fsmap.h>
#include "xfs_fsmap.h"
#include "xfs_refcount.h"
#include "xfs_refcount_btree.h"
#include "xfs_alloc_btree.h"
#include "xfs_rtbitmap.h"
#include "xfs_ag.h"

/* Convert an xfs_fsmap to an fsmap. */
static void
xfs_fsmap_from_internal(
	struct fsmap		*dest,
	struct xfs_fsmap	*src)
{ … }

/* Convert an fsmap to an xfs_fsmap. */
void
xfs_fsmap_to_internal(
	struct xfs_fsmap	*dest,
	struct fsmap		*src)
{ … }

/* Convert an fsmap owner into an rmapbt owner. */
static int
xfs_fsmap_owner_to_rmap(
	struct xfs_rmap_irec	*dest,
	const struct xfs_fsmap	*src)
{ … }

/* Convert an rmapbt owner into an fsmap owner. */
static int
xfs_fsmap_owner_from_rmap(
	struct xfs_fsmap		*dest,
	const struct xfs_rmap_irec	*src)
{ … }

/* getfsmap query state */
struct xfs_getfsmap_info { … };

/* Associate a device with a getfsmap handler. */
struct xfs_getfsmap_dev { … };

/* Compare two getfsmap device handlers. */
static int
xfs_getfsmap_dev_compare(
	const void			*p1,
	const void			*p2)
{ … }

/* Decide if this mapping is shared. */
STATIC int
xfs_getfsmap_is_shared(
	struct xfs_trans		*tp,
	struct xfs_getfsmap_info	*info,
	const struct xfs_rmap_irec	*rec,
	bool				*stat)
{ … }

static inline void
xfs_getfsmap_format(
	struct xfs_mount		*mp,
	struct xfs_fsmap		*xfm,
	struct xfs_getfsmap_info	*info)
{ … }

static inline bool
xfs_getfsmap_rec_before_start(
	struct xfs_getfsmap_info	*info,
	const struct xfs_rmap_irec	*rec,
	xfs_daddr_t			rec_daddr)
{ … }

/*
 * Format a reverse mapping for getfsmap, having translated rm_startblock
 * into the appropriate daddr units.  Pass in a nonzero @len_daddr if the
 * length could be larger than rm_blockcount in struct xfs_rmap_irec.
 */
STATIC int
xfs_getfsmap_helper(
	struct xfs_trans		*tp,
	struct xfs_getfsmap_info	*info,
	const struct xfs_rmap_irec	*rec,
	xfs_daddr_t			rec_daddr,
	xfs_daddr_t			len_daddr)
{ … }

/* Transform a rmapbt irec into a fsmap */
STATIC int
xfs_getfsmap_datadev_helper(
	struct xfs_btree_cur		*cur,
	const struct xfs_rmap_irec	*rec,
	void				*priv)
{ … }

/* Transform a bnobt irec into a fsmap */
STATIC int
xfs_getfsmap_datadev_bnobt_helper(
	struct xfs_btree_cur		*cur,
	const struct xfs_alloc_rec_incore *rec,
	void				*priv)
{ … }

/* Set rmap flags based on the getfsmap flags */
static void
xfs_getfsmap_set_irec_flags(
	struct xfs_rmap_irec	*irec,
	const struct xfs_fsmap	*fmr)
{ … }

/* Execute a getfsmap query against the log device. */
STATIC int
xfs_getfsmap_logdev(
	struct xfs_trans		*tp,
	const struct xfs_fsmap		*keys,
	struct xfs_getfsmap_info	*info)
{ … }

#ifdef CONFIG_XFS_RT
/* Transform a rtbitmap "record" into a fsmap */
STATIC int
xfs_getfsmap_rtdev_rtbitmap_helper(
	struct xfs_mount		*mp,
	struct xfs_trans		*tp,
	const struct xfs_rtalloc_rec	*rec,
	void				*priv)
{ … }

/* Execute a getfsmap query against the realtime device rtbitmap. */
STATIC int
xfs_getfsmap_rtdev_rtbitmap(
	struct xfs_trans		*tp,
	const struct xfs_fsmap		*keys,
	struct xfs_getfsmap_info	*info)
{ … }
#endif /* CONFIG_XFS_RT */

static inline bool
rmap_not_shareable(struct xfs_mount *mp, const struct xfs_rmap_irec *r)
{ … }

/* Execute a getfsmap query against the regular data device. */
STATIC int
__xfs_getfsmap_datadev(
	struct xfs_trans		*tp,
	const struct xfs_fsmap		*keys,
	struct xfs_getfsmap_info	*info,
	int				(*query_fn)(struct xfs_trans *,
						    struct xfs_getfsmap_info *,
						    struct xfs_btree_cur **,
						    void *),
	void				*priv)
{ … }

/* Actually query the rmap btree. */
STATIC int
xfs_getfsmap_datadev_rmapbt_query(
	struct xfs_trans		*tp,
	struct xfs_getfsmap_info	*info,
	struct xfs_btree_cur		**curpp,
	void				*priv)
{ … }

/* Execute a getfsmap query against the regular data device rmapbt. */
STATIC int
xfs_getfsmap_datadev_rmapbt(
	struct xfs_trans		*tp,
	const struct xfs_fsmap		*keys,
	struct xfs_getfsmap_info	*info)
{ … }

/* Actually query the bno btree. */
STATIC int
xfs_getfsmap_datadev_bnobt_query(
	struct xfs_trans		*tp,
	struct xfs_getfsmap_info	*info,
	struct xfs_btree_cur		**curpp,
	void				*priv)
{ … }

/* Execute a getfsmap query against the regular data device's bnobt. */
STATIC int
xfs_getfsmap_datadev_bnobt(
	struct xfs_trans		*tp,
	const struct xfs_fsmap		*keys,
	struct xfs_getfsmap_info	*info)
{ … }

/* Do we recognize the device? */
STATIC bool
xfs_getfsmap_is_valid_device(
	struct xfs_mount	*mp,
	struct xfs_fsmap	*fm)
{ … }

/* Ensure that the low key is less than the high key. */
STATIC bool
xfs_getfsmap_check_keys(
	struct xfs_fsmap		*low_key,
	struct xfs_fsmap		*high_key)
{ … }

/*
 * There are only two devices if we didn't configure RT devices at build time.
 */
#ifdef CONFIG_XFS_RT
#define XFS_GETFSMAP_DEVS …
#else
#define XFS_GETFSMAP_DEVS …
#endif /* CONFIG_XFS_RT */

/*
 * Get filesystem's extents as described in head, and format for output. Fills
 * in the supplied records array until there are no more reverse mappings to
 * return or head.fmh_entries == head.fmh_count.  In the second case, this
 * function returns -ECANCELED to indicate that more records would have been
 * returned.
 *
 * Key to Confusion
 * ----------------
 * There are multiple levels of keys and counters at work here:
 * xfs_fsmap_head.fmh_keys	-- low and high fsmap keys passed in;
 *				   these reflect fs-wide sector addrs.
 * dkeys			-- fmh_keys used to query each device;
 *				   these are fmh_keys but w/ the low key
 *				   bumped up by fmr_length.
 * xfs_getfsmap_info.next_daddr	-- next disk addr we expect to see; this
 *				   is how we detect gaps in the fsmap
				   records and report them.
 * xfs_getfsmap_info.low/high	-- per-AG low/high keys computed from
 *				   dkeys; used to query the metadata.
 */
int
xfs_getfsmap(
	struct xfs_mount		*mp,
	struct xfs_fsmap_head		*head,
	struct fsmap			*fsmap_recs)
{ … }
linux/fs/xfs/xfs_fsmap.c
