fs/xfs/scrub/scrub.h - linux/torvalds/linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Copyright (C) 2017-2023 Oracle.  All Rights Reserved.
  * Author: Darrick J. Wong <djwong@kernel.org>
  */
 #ifndef __XFS_SCRUB_SCRUB_H__
 #define __XFS_SCRUB_SCRUB_H__

 struct xfs_scrub;

 struct xchk_relax {
 	unsigned long	next_resched;
 	unsigned int	resched_nr;
 	bool		interruptible;
 };

 /* Yield to the scheduler at most 10x per second. */
 #define XCHK_RELAX_NEXT		(jiffies + (HZ / 10))

 #define INIT_XCHK_RELAX	\
 	(struct xchk_relax){ \
 		.next_resched	= XCHK_RELAX_NEXT, \
 		.resched_nr	= 0, \
 		.interruptible	= true, \
 	}

 /*
  * Relax during a scrub operation and exit if there's a fatal signal pending.
  *
  * If preemption is disabled, we need to yield to the scheduler every now and
  * then so that we don't run afoul of the soft lockup watchdog or RCU stall
  * detector.  cond_resched calls are somewhat expensive (~5ns) so we want to
  * ratelimit this to 10x per second.  Amortize the cost of the other checks by
  * only doing it once every 100 calls.
  */
 static inline int xchk_maybe_relax(struct xchk_relax *widget)
 {
 	/* Amortize the cost of scheduling and checking signals. */
 	if (likely(++widget->resched_nr < 100))
 		return 0;
 	widget->resched_nr = 0;

 	if (unlikely(widget->next_resched <= jiffies)) {
 		cond_resched();
 		widget->next_resched = XCHK_RELAX_NEXT;
 	}

 	if (widget->interruptible && fatal_signal_pending(current))
 		return -EINTR;

 	return 0;
 }

 /*
  * Standard flags for allocating memory within scrub.  NOFS context is
  * configured by the process allocation scope.  Scrub and repair must be able
  * to back out gracefully if there isn't enough memory.  Force-cast to avoid
  * complaints from static checkers.
  */
 #define XCHK_GFP_FLAGS	((__force gfp_t)(GFP_KERNEL | __GFP_NOWARN | \
 					 __GFP_RETRY_MAYFAIL))

 /*
  * For opening files by handle for fsck operations, we don't trust the inumber
  * or the allocation state; therefore, perform an untrusted lookup.  We don't
  * want these inodes to pollute the cache, so mark them for immediate removal.
  */
 #define XCHK_IGET_FLAGS	(XFS_IGET_UNTRUSTED | XFS_IGET_DONTCACHE)

 /* Type info and names for the scrub types. */
 enum xchk_type {
 	ST_NONE = 1,	/* disabled */
 	ST_PERAG,	/* per-AG metadata */
 	ST_FS,		/* per-FS metadata */
 	ST_INODE,	/* per-inode metadata */
 };

 struct xchk_meta_ops {
 	/* Acquire whatever resources are needed for the operation. */
 	int		(*setup)(struct xfs_scrub *sc);

 	/* Examine metadata for errors. */
 	int		(*scrub)(struct xfs_scrub *);

 	/* Repair or optimize the metadata. */
 	int		(*repair)(struct xfs_scrub *);

 	/*
 	 * Re-scrub the metadata we repaired, in case there's extra work that
 	 * we need to do to check our repair work.  If this is NULL, we'll use
 	 * the ->scrub function pointer, assuming that the regular scrub is
 	 * sufficient.
 	 */
 	int		(*repair_eval)(struct xfs_scrub *sc);

 	/* Decide if we even have this piece of metadata. */
 	bool		(*has)(struct xfs_mount *);

 	/* type describing required/allowed inputs */
 	enum xchk_type	type;
 };

 /* Buffer pointers and btree cursors for an entire AG. */
 struct xchk_ag {
 	struct xfs_perag	*pag;

 	/* AG btree roots */
 	struct xfs_buf		*agf_bp;
 	struct xfs_buf		*agi_bp;

 	/* AG btrees */
 	struct xfs_btree_cur	*bno_cur;
 	struct xfs_btree_cur	*cnt_cur;
 	struct xfs_btree_cur	*ino_cur;
 	struct xfs_btree_cur	*fino_cur;
 	struct xfs_btree_cur	*rmap_cur;
 	struct xfs_btree_cur	*refc_cur;
 };

 struct xfs_scrub {
 	/* General scrub state. */
 	struct xfs_mount		*mp;
 	struct xfs_scrub_metadata	*sm;
 	const struct xchk_meta_ops	*ops;
 	struct xfs_trans		*tp;

 	/* File that scrub was called with. */
 	struct file			*file;

 	/*
 	 * File that is undergoing the scrub operation.  This can differ from
 	 * the file that scrub was called with if we're checking file-based fs
 	 * metadata (e.g. rt bitmaps) or if we're doing a scrub-by-handle for
 	 * something that can't be opened directly (e.g. symlinks).
 	 */
 	struct xfs_inode		*ip;

 	/* Kernel memory buffer used by scrubbers; freed at teardown. */
 	void				*buf;

 	/*
 	 * Clean up resources owned by whatever is in the buffer.  Cleanup can
 	 * be deferred with this hook as a means for scrub functions to pass
 	 * data to repair functions.  This function must not free the buffer
 	 * itself.
 	 */
 	void				(*buf_cleanup)(void *buf);

 	/* xfile used by the scrubbers; freed at teardown. */
 	struct xfile			*xfile;

 	/* buffer target for in-memory btrees; also freed at teardown. */
 	struct xfs_buftarg		*xmbtp;

 	/* Lock flags for @ip. */
 	uint				ilock_flags;

 	/* The orphanage, for stashing files that have lost their parent. */
 	uint				orphanage_ilock_flags;
 	struct xfs_inode		*orphanage;

 	/* A temporary file on this filesystem, for staging new metadata. */
 	struct xfs_inode		*tempip;
 	uint				temp_ilock_flags;

 	/* See the XCHK/XREP state flags below. */
 	unsigned int			flags;

 	/*
 	 * The XFS_SICK_* flags that correspond to the metadata being scrubbed
 	 * or repaired.  We will use this mask to update the in-core fs health
 	 * status with whatever we find.
 	 */
 	unsigned int			sick_mask;

 	/* next time we want to cond_resched() */
 	struct xchk_relax		relax;

 	/* State tracking for single-AG operations. */
 	struct xchk_ag			sa;
 };

 /* XCHK state flags grow up from zero, XREP state flags grown down from 2^31 */
 #define XCHK_TRY_HARDER		(1U << 0)  /* can't get resources, try again */
 #define XCHK_HAVE_FREEZE_PROT	(1U << 1)  /* do we have freeze protection? */
 #define XCHK_FSGATES_DRAIN	(1U << 2)  /* defer ops draining enabled */
 #define XCHK_NEED_DRAIN		(1U << 3)  /* scrub needs to drain defer ops */
 #define XCHK_FSGATES_QUOTA	(1U << 4)  /* quota live update enabled */
 #define XCHK_FSGATES_DIRENTS	(1U << 5)  /* directory live update enabled */
 #define XCHK_FSGATES_RMAP	(1U << 6)  /* rmapbt live update enabled */
 #define XREP_RESET_PERAG_RESV	(1U << 30) /* must reset AG space reservation */
 #define XREP_ALREADY_FIXED	(1U << 31) /* checking our repair work */

 /*
  * The XCHK_FSGATES* flags reflect functionality in the main filesystem that
  * are only enabled for this particular online fsck.  When not in use, the
  * features are gated off via dynamic code patching, which is why the state
  * must be enabled during scrub setup and can only be torn down afterwards.
  */
 #define XCHK_FSGATES_ALL	(XCHK_FSGATES_DRAIN | \
 				 XCHK_FSGATES_QUOTA | \
 				 XCHK_FSGATES_DIRENTS | \
 				 XCHK_FSGATES_RMAP)

 struct xfs_scrub_subord {
 	struct xfs_scrub	sc;
 	struct xfs_scrub	*parent_sc;
 	unsigned int		old_smtype;
 	unsigned int		old_smflags;
 };

 struct xfs_scrub_subord *xchk_scrub_create_subord(struct xfs_scrub *sc,
 		unsigned int subtype);
 void xchk_scrub_free_subord(struct xfs_scrub_subord *sub);

 /*
  * We /could/ terminate a scrub/repair operation early.  If we're not
  * in a good place to continue (fatal signal, etc.) then bail out.
  * Note that we're careful not to make any judgements about *error.
  */
 static inline bool
 xchk_should_terminate(
 	struct xfs_scrub	*sc,
 	int			*error)
 {
 	if (xchk_maybe_relax(&sc->relax)) {
 		if (*error == 0)
 			*error = -EINTR;
 		return true;
 	}
 	return false;
 }

 /* Metadata scrubbers */
 int xchk_tester(struct xfs_scrub *sc);
 int xchk_superblock(struct xfs_scrub *sc);
 int xchk_agf(struct xfs_scrub *sc);
 int xchk_agfl(struct xfs_scrub *sc);
 int xchk_agi(struct xfs_scrub *sc);
 int xchk_allocbt(struct xfs_scrub *sc);
 int xchk_iallocbt(struct xfs_scrub *sc);
 int xchk_rmapbt(struct xfs_scrub *sc);
 int xchk_refcountbt(struct xfs_scrub *sc);
 int xchk_inode(struct xfs_scrub *sc);
 int xchk_bmap_data(struct xfs_scrub *sc);
 int xchk_bmap_attr(struct xfs_scrub *sc);
 int xchk_bmap_cow(struct xfs_scrub *sc);
 int xchk_directory(struct xfs_scrub *sc);
 int xchk_xattr(struct xfs_scrub *sc);
 int xchk_symlink(struct xfs_scrub *sc);
 int xchk_parent(struct xfs_scrub *sc);
 int xchk_dirtree(struct xfs_scrub *sc);
 #ifdef CONFIG_XFS_RT
 int xchk_rtbitmap(struct xfs_scrub *sc);
 int xchk_rtsummary(struct xfs_scrub *sc);
 #else
 static inline int
 xchk_rtbitmap(struct xfs_scrub *sc)
 {
 	return -ENOENT;
 }
 static inline int
 xchk_rtsummary(struct xfs_scrub *sc)
 {
 	return -ENOENT;
 }
 #endif
 #ifdef CONFIG_XFS_QUOTA
 int xchk_quota(struct xfs_scrub *sc);
 int xchk_quotacheck(struct xfs_scrub *sc);
 #else
 static inline int
 xchk_quota(struct xfs_scrub *sc)
 {
 	return -ENOENT;
 }
 static inline int
 xchk_quotacheck(struct xfs_scrub *sc)
 {
 	return -ENOENT;
 }
 #endif
 int xchk_fscounters(struct xfs_scrub *sc);
 int xchk_nlinks(struct xfs_scrub *sc);

 /* cross-referencing helpers */
 void xchk_xref_is_used_space(struct xfs_scrub *sc, xfs_agblock_t agbno,
 		xfs_extlen_t len);
 void xchk_xref_is_not_inode_chunk(struct xfs_scrub *sc, xfs_agblock_t agbno,
 		xfs_extlen_t len);
 void xchk_xref_is_inode_chunk(struct xfs_scrub *sc, xfs_agblock_t agbno,
 		xfs_extlen_t len);
 void xchk_xref_is_only_owned_by(struct xfs_scrub *sc, xfs_agblock_t agbno,
 		xfs_extlen_t len, const struct xfs_owner_info *oinfo);
 void xchk_xref_is_not_owned_by(struct xfs_scrub *sc, xfs_agblock_t agbno,
 		xfs_extlen_t len, const struct xfs_owner_info *oinfo);
 void xchk_xref_has_no_owner(struct xfs_scrub *sc, xfs_agblock_t agbno,
 		xfs_extlen_t len);
 void xchk_xref_is_cow_staging(struct xfs_scrub *sc, xfs_agblock_t bno,
 		xfs_extlen_t len);
 void xchk_xref_is_not_shared(struct xfs_scrub *sc, xfs_agblock_t bno,
 		xfs_extlen_t len);
 void xchk_xref_is_not_cow_staging(struct xfs_scrub *sc, xfs_agblock_t bno,
 		xfs_extlen_t len);
 #ifdef CONFIG_XFS_RT
 void xchk_xref_is_used_rt_space(struct xfs_scrub *sc, xfs_rtblock_t rtbno,
 		xfs_extlen_t len);
 #else
 # define xchk_xref_is_used_rt_space(sc, rtbno, len) do { } while (0)
 #endif

 #endif	/* __XFS_SCRUB_SCRUB_H__ */
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* Copyright (C) 2017-2023 Oracle. All Rights Reserved.
	* Author: Darrick J. Wong <djwong@kernel.org>
	*/
	#ifndef __XFS_SCRUB_SCRUB_H__
	#define __XFS_SCRUB_SCRUB_H__

	struct xfs_scrub;

	struct xchk_relax {
	unsigned long next_resched;
	unsigned int resched_nr;
	bool interruptible;
	};

	/* Yield to the scheduler at most 10x per second. */
	#define XCHK_RELAX_NEXT (jiffies + (HZ / 10))

	#define INIT_XCHK_RELAX \
	(struct xchk_relax){ \
	.next_resched = XCHK_RELAX_NEXT, \
	.resched_nr = 0, \
	.interruptible = true, \
	}

	/*
	* Relax during a scrub operation and exit if there's a fatal signal pending.
	*
	* If preemption is disabled, we need to yield to the scheduler every now and
	* then so that we don't run afoul of the soft lockup watchdog or RCU stall
	* detector. cond_resched calls are somewhat expensive (~5ns) so we want to
	* ratelimit this to 10x per second. Amortize the cost of the other checks by
	* only doing it once every 100 calls.
	*/
	static inline int xchk_maybe_relax(struct xchk_relax *widget)
	{
	/* Amortize the cost of scheduling and checking signals. */
	if (likely(++widget->resched_nr < 100))
	return 0;
	widget->resched_nr = 0;

	if (unlikely(widget->next_resched <= jiffies)) {
	cond_resched();
	widget->next_resched = XCHK_RELAX_NEXT;
	}

	if (widget->interruptible && fatal_signal_pending(current))
	return -EINTR;

	return 0;
	}

	/*
	* Standard flags for allocating memory within scrub. NOFS context is
	* configured by the process allocation scope. Scrub and repair must be able
	* to back out gracefully if there isn't enough memory. Force-cast to avoid
	* complaints from static checkers.
	*/
	#define XCHK_GFP_FLAGS ((__force gfp_t)(GFP_KERNEL \| __GFP_NOWARN \| \
	__GFP_RETRY_MAYFAIL))

	/*
	* For opening files by handle for fsck operations, we don't trust the inumber
	* or the allocation state; therefore, perform an untrusted lookup. We don't
	* want these inodes to pollute the cache, so mark them for immediate removal.
	*/
	#define XCHK_IGET_FLAGS (XFS_IGET_UNTRUSTED \| XFS_IGET_DONTCACHE)

	/* Type info and names for the scrub types. */
	enum xchk_type {
	ST_NONE = 1, /* disabled */
	ST_PERAG, /* per-AG metadata */
	ST_FS, /* per-FS metadata */
	ST_INODE, /* per-inode metadata */
	};

	struct xchk_meta_ops {
	/* Acquire whatever resources are needed for the operation. */
	int (setup)(struct xfs_scrub sc);

	/* Examine metadata for errors. */
	int (scrub)(struct xfs_scrub );

	/* Repair or optimize the metadata. */
	int (repair)(struct xfs_scrub );

	/*
	* Re-scrub the metadata we repaired, in case there's extra work that
	* we need to do to check our repair work. If this is NULL, we'll use
	* the ->scrub function pointer, assuming that the regular scrub is
	* sufficient.
	*/
	int (repair_eval)(struct xfs_scrub sc);

	/* Decide if we even have this piece of metadata. */
	bool (has)(struct xfs_mount );

	/* type describing required/allowed inputs */
	enum xchk_type type;
	};

	/* Buffer pointers and btree cursors for an entire AG. */
	struct xchk_ag {
	struct xfs_perag *pag;

	/* AG btree roots */
	struct xfs_buf *agf_bp;
	struct xfs_buf *agi_bp;

	/* AG btrees */
	struct xfs_btree_cur *bno_cur;
	struct xfs_btree_cur *cnt_cur;
	struct xfs_btree_cur *ino_cur;
	struct xfs_btree_cur *fino_cur;
	struct xfs_btree_cur *rmap_cur;
	struct xfs_btree_cur *refc_cur;
	};

	struct xfs_scrub {
	/* General scrub state. */
	struct xfs_mount *mp;
	struct xfs_scrub_metadata *sm;
	const struct xchk_meta_ops *ops;
	struct xfs_trans *tp;

	/* File that scrub was called with. */
	struct file *file;

	/*
	* File that is undergoing the scrub operation. This can differ from
	* the file that scrub was called with if we're checking file-based fs
	* metadata (e.g. rt bitmaps) or if we're doing a scrub-by-handle for
	* something that can't be opened directly (e.g. symlinks).
	*/
	struct xfs_inode *ip;

	/* Kernel memory buffer used by scrubbers; freed at teardown. */
	void *buf;

	/*
	* Clean up resources owned by whatever is in the buffer. Cleanup can
	* be deferred with this hook as a means for scrub functions to pass
	* data to repair functions. This function must not free the buffer
	* itself.
	*/
	void (buf_cleanup)(void buf);

	/* xfile used by the scrubbers; freed at teardown. */
	struct xfile *xfile;

	/* buffer target for in-memory btrees; also freed at teardown. */
	struct xfs_buftarg *xmbtp;

	/* Lock flags for @ip. */
	uint ilock_flags;

	/* The orphanage, for stashing files that have lost their parent. */
	uint orphanage_ilock_flags;
	struct xfs_inode *orphanage;

	/* A temporary file on this filesystem, for staging new metadata. */
	struct xfs_inode *tempip;
	uint temp_ilock_flags;

	/* See the XCHK/XREP state flags below. */
	unsigned int flags;

	/*
	* The XFS_SICK_* flags that correspond to the metadata being scrubbed
	* or repaired. We will use this mask to update the in-core fs health
	* status with whatever we find.
	*/
	unsigned int sick_mask;

	/* next time we want to cond_resched() */
	struct xchk_relax relax;

	/* State tracking for single-AG operations. */
	struct xchk_ag sa;
	};

	/* XCHK state flags grow up from zero, XREP state flags grown down from 2^31 */
	#define XCHK_TRY_HARDER (1U << 0) /* can't get resources, try again */
	#define XCHK_HAVE_FREEZE_PROT (1U << 1) /* do we have freeze protection? */
	#define XCHK_FSGATES_DRAIN (1U << 2) /* defer ops draining enabled */
	#define XCHK_NEED_DRAIN (1U << 3) /* scrub needs to drain defer ops */
	#define XCHK_FSGATES_QUOTA (1U << 4) /* quota live update enabled */
	#define XCHK_FSGATES_DIRENTS (1U << 5) /* directory live update enabled */
	#define XCHK_FSGATES_RMAP (1U << 6) /* rmapbt live update enabled */
	#define XREP_RESET_PERAG_RESV (1U << 30) /* must reset AG space reservation */
	#define XREP_ALREADY_FIXED (1U << 31) /* checking our repair work */

	/*
	* The XCHK_FSGATES* flags reflect functionality in the main filesystem that
	* are only enabled for this particular online fsck. When not in use, the
	* features are gated off via dynamic code patching, which is why the state
	* must be enabled during scrub setup and can only be torn down afterwards.
	*/
	#define XCHK_FSGATES_ALL (XCHK_FSGATES_DRAIN \| \
	XCHK_FSGATES_QUOTA \| \
	XCHK_FSGATES_DIRENTS \| \
	XCHK_FSGATES_RMAP)

	struct xfs_scrub_subord {
	struct xfs_scrub sc;
	struct xfs_scrub *parent_sc;
	unsigned int old_smtype;
	unsigned int old_smflags;
	};

	struct xfs_scrub_subord xchk_scrub_create_subord(struct xfs_scrub sc,
	unsigned int subtype);
	void xchk_scrub_free_subord(struct xfs_scrub_subord *sub);

	/*
	* We /could/ terminate a scrub/repair operation early. If we're not
	* in a good place to continue (fatal signal, etc.) then bail out.
	* Note that we're careful not to make any judgements about *error.
	*/
	static inline bool
	xchk_should_terminate(
	struct xfs_scrub *sc,
	int *error)
	{
	if (xchk_maybe_relax(&sc->relax)) {
	if (*error == 0)
	*error = -EINTR;
	return true;
	}
	return false;
	}

	/* Metadata scrubbers */
	int xchk_tester(struct xfs_scrub *sc);
	int xchk_superblock(struct xfs_scrub *sc);
	int xchk_agf(struct xfs_scrub *sc);
	int xchk_agfl(struct xfs_scrub *sc);
	int xchk_agi(struct xfs_scrub *sc);
	int xchk_allocbt(struct xfs_scrub *sc);
	int xchk_iallocbt(struct xfs_scrub *sc);
	int xchk_rmapbt(struct xfs_scrub *sc);
	int xchk_refcountbt(struct xfs_scrub *sc);
	int xchk_inode(struct xfs_scrub *sc);
	int xchk_bmap_data(struct xfs_scrub *sc);
	int xchk_bmap_attr(struct xfs_scrub *sc);
	int xchk_bmap_cow(struct xfs_scrub *sc);
	int xchk_directory(struct xfs_scrub *sc);
	int xchk_xattr(struct xfs_scrub *sc);
	int xchk_symlink(struct xfs_scrub *sc);
	int xchk_parent(struct xfs_scrub *sc);
	int xchk_dirtree(struct xfs_scrub *sc);
	#ifdef CONFIG_XFS_RT
	int xchk_rtbitmap(struct xfs_scrub *sc);
	int xchk_rtsummary(struct xfs_scrub *sc);
	#else
	static inline int
	xchk_rtbitmap(struct xfs_scrub *sc)
	{
	return -ENOENT;
	}
	static inline int
	xchk_rtsummary(struct xfs_scrub *sc)
	{
	return -ENOENT;
	}
	#endif
	#ifdef CONFIG_XFS_QUOTA
	int xchk_quota(struct xfs_scrub *sc);
	int xchk_quotacheck(struct xfs_scrub *sc);
	#else
	static inline int
	xchk_quota(struct xfs_scrub *sc)
	{
	return -ENOENT;
	}
	static inline int
	xchk_quotacheck(struct xfs_scrub *sc)
	{
	return -ENOENT;
	}
	#endif
	int xchk_fscounters(struct xfs_scrub *sc);
	int xchk_nlinks(struct xfs_scrub *sc);

	/* cross-referencing helpers */
	void xchk_xref_is_used_space(struct xfs_scrub *sc, xfs_agblock_t agbno,
	xfs_extlen_t len);
	void xchk_xref_is_not_inode_chunk(struct xfs_scrub *sc, xfs_agblock_t agbno,
	xfs_extlen_t len);
	void xchk_xref_is_inode_chunk(struct xfs_scrub *sc, xfs_agblock_t agbno,
	xfs_extlen_t len);
	void xchk_xref_is_only_owned_by(struct xfs_scrub *sc, xfs_agblock_t agbno,
	xfs_extlen_t len, const struct xfs_owner_info *oinfo);
	void xchk_xref_is_not_owned_by(struct xfs_scrub *sc, xfs_agblock_t agbno,
	xfs_extlen_t len, const struct xfs_owner_info *oinfo);
	void xchk_xref_has_no_owner(struct xfs_scrub *sc, xfs_agblock_t agbno,
	xfs_extlen_t len);
	void xchk_xref_is_cow_staging(struct xfs_scrub *sc, xfs_agblock_t bno,
	xfs_extlen_t len);
	void xchk_xref_is_not_shared(struct xfs_scrub *sc, xfs_agblock_t bno,
	xfs_extlen_t len);
	void xchk_xref_is_not_cow_staging(struct xfs_scrub *sc, xfs_agblock_t bno,
	xfs_extlen_t len);
	#ifdef CONFIG_XFS_RT
	void xchk_xref_is_used_rt_space(struct xfs_scrub *sc, xfs_rtblock_t rtbno,
	xfs_extlen_t len);
	#else
	# define xchk_xref_is_used_rt_space(sc, rtbno, len) do { } while (0)
	#endif

	#endif /* __XFS_SCRUB_SCRUB_H__ */