// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2017-2023 Oracle. All Rights Reserved.
* Author: Darrick J. Wong <[email protected]>
*/
#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;
}
static inline int xchk_nothing(struct xfs_scrub *sc)
{
return -ENOENT;
}
/* 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
# define xchk_rtbitmap xchk_nothing
# define xchk_rtsummary xchk_nothing
#endif
#ifdef CONFIG_XFS_QUOTA
int xchk_quota(struct xfs_scrub *sc);
int xchk_quotacheck(struct xfs_scrub *sc);
#else
# define xchk_quota xchk_nothing
# define xchk_quotacheck xchk_nothing
#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__ */
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