/*
* Copyright (C) 2017 Oracle. All Rights Reserved.
*
* Author: Darrick J. Wong <darrick.wong@oracle.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it would be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_shared.h"
#include "xfs_format.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_defer.h"
#include "xfs_btree.h"
#include "xfs_bit.h"
#include "xfs_log_format.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_inode.h"
#include "xfs_icache.h"
#include "xfs_itable.h"
#include "xfs_alloc.h"
#include "xfs_alloc_btree.h"
#include "xfs_bmap.h"
#include "xfs_bmap_btree.h"
#include "xfs_ialloc.h"
#include "xfs_ialloc_btree.h"
#include "xfs_refcount.h"
#include "xfs_refcount_btree.h"
#include "xfs_rmap.h"
#include "xfs_rmap_btree.h"
#include "xfs_log.h"
#include "xfs_trans_priv.h"
#include "scrub/xfs_scrub.h"
#include "scrub/scrub.h"
#include "scrub/common.h"
#include "scrub/trace.h"
#include "scrub/btree.h"
/* Common code for the metadata scrubbers. */
/*
* Handling operational errors.
*
* The *_process_error() family of functions are used to process error return
* codes from functions called as part of a scrub operation.
*
* If there's no error, we return true to tell the caller that it's ok
* to move on to the next check in its list.
*
* For non-verifier errors (e.g. ENOMEM) we return false to tell the
* caller that something bad happened, and we preserve *error so that
* the caller can return the *error up the stack to userspace.
*
* Verifier errors (EFSBADCRC/EFSCORRUPTED) are recorded by setting
* OFLAG_CORRUPT in sm_flags and the *error is cleared. In other words,
* we track verifier errors (and failed scrub checks) via OFLAG_CORRUPT,
* not via return codes. We return false to tell the caller that
* something bad happened. Since the error has been cleared, the caller
* will (presumably) return that zero and scrubbing will move on to
* whatever's next.
*
* ftrace can be used to record the precise metadata location and the
* approximate code location of the failed operation.
*/
/* Check for operational errors. */
bool
xfs_scrub_process_error(
struct xfs_scrub_context *sc,
xfs_agnumber_t agno,
xfs_agblock_t bno,
int *error)
{
switch (*error) {
case 0:
return true;
case -EDEADLOCK:
/* Used to restart an op with deadlock avoidance. */
trace_xfs_scrub_deadlock_retry(sc->ip, sc->sm, *error);
break;
case -EFSBADCRC:
case -EFSCORRUPTED:
/* Note the badness but don't abort. */
sc->sm->sm_flags |= XFS_SCRUB_OFLAG_CORRUPT;
*error = 0;
/* fall through */
default:
trace_xfs_scrub_op_error(sc, agno, bno, *error,
__return_address);
break;
}
return false;
}
/* Check for operational errors for a file offset. */
bool
xfs_scrub_fblock_process_error(
struct xfs_scrub_context *sc,
int whichfork,
xfs_fileoff_t offset,
int *error)
{
switch (*error) {
case 0:
return true;
case -EDEADLOCK:
/* Used to restart an op with deadlock avoidance. */
trace_xfs_scrub_deadlock_retry(sc->ip, sc->sm, *error);
break;
case -EFSBADCRC:
case -EFSCORRUPTED:
/* Note the badness but don't abort. */
sc->sm->sm_flags |= XFS_SCRUB_OFLAG_CORRUPT;
*error = 0;
/* fall through */
default:
trace_xfs_scrub_file_op_error(sc, whichfork, offset, *error,
__return_address);
break;
}
return false;
}
/*
* Handling scrub corruption/optimization/warning checks.
*
* The *_set_{corrupt,preen,warning}() family of functions are used to
* record the presence of metadata that is incorrect (corrupt), could be
* optimized somehow (preen), or should be flagged for administrative
* review but is not incorrect (warn).
*
* ftrace can be used to record the precise metadata location and
* approximate code location of the failed check.
*/
/* Record a block which could be optimized. */
void
xfs_scrub_block_set_preen(
struct xfs_scrub_context *sc,
struct xfs_buf *bp)
{
sc->sm->sm_flags |= XFS_SCRUB_OFLAG_PREEN;
trace_xfs_scrub_block_preen(sc, bp->b_bn, __return_address);
}
/*
* Record an inode which could be optimized. The trace data will
* include the block given by bp if bp is given; otherwise it will use
* the block location of the inode record itself.
*/
void
xfs_scrub_ino_set_preen(
struct xfs_scrub_context *sc,
xfs_ino_t ino,
struct xfs_buf *bp)
{
sc->sm->sm_flags |= XFS_SCRUB_OFLAG_PREEN;
trace_xfs_scrub_ino_preen(sc, ino, bp ? bp->b_bn : 0,
__return_address);
}
/* Record a corrupt block. */
void
xfs_scrub_block_set_corrupt(
struct xfs_scrub_context *sc,
struct xfs_buf *bp)
{
sc->sm->sm_flags |= XFS_SCRUB_OFLAG_CORRUPT;
trace_xfs_scrub_block_error(sc, bp->b_bn, __return_address);
}
/*
* Record a corrupt inode. The trace data will include the block given
* by bp if bp is given; otherwise it will use the block location of the
* inode record itself.
*/
void
xfs_scrub_ino_set_corrupt(
struct xfs_scrub_context *sc,
xfs_ino_t ino,
struct xfs_buf *bp)
{
sc->sm->sm_flags |= XFS_SCRUB_OFLAG_CORRUPT;
trace_xfs_scrub_ino_error(sc, ino, bp ? bp->b_bn : 0, __return_address);
}
/* Record corruption in a block indexed by a file fork. */
void
xfs_scrub_fblock_set_corrupt(
struct xfs_scrub_context *sc,
int whichfork,
xfs_fileoff_t offset)
{
sc->sm->sm_flags |= XFS_SCRUB_OFLAG_CORRUPT;
trace_xfs_scrub_fblock_error(sc, whichfork, offset, __return_address);
}
/*
* Warn about inodes that need administrative review but is not
* incorrect.
*/
void
xfs_scrub_ino_set_warning(
struct xfs_scrub_context *sc,
xfs_ino_t ino,
struct xfs_buf *bp)
{
sc->sm->sm_flags |= XFS_SCRUB_OFLAG_WARNING;
trace_xfs_scrub_ino_warning(sc, ino, bp ? bp->b_bn : 0,
__return_address);
}
/* Warn about a block indexed by a file fork that needs review. */
void
xfs_scrub_fblock_set_warning(
struct xfs_scrub_context *sc,
int whichfork,
xfs_fileoff_t offset)
{
sc->sm->sm_flags |= XFS_SCRUB_OFLAG_WARNING;
trace_xfs_scrub_fblock_warning(sc, whichfork, offset, __return_address);
}
/* Signal an incomplete scrub. */
void
xfs_scrub_set_incomplete(
struct xfs_scrub_context *sc)
{
sc->sm->sm_flags |= XFS_SCRUB_OFLAG_INCOMPLETE;
trace_xfs_scrub_incomplete(sc, __return_address);
}
/*
* AG scrubbing
*
* These helpers facilitate locking an allocation group's header
* buffers, setting up cursors for all btrees that are present, and
* cleaning everything up once we're through.
*/
/* Decide if we want to return an AG header read failure. */
static inline bool
want_ag_read_header_failure(
struct xfs_scrub_context *sc,
unsigned int type)
{
/* Return all AG header read failures when scanning btrees. */
if (sc->sm->sm_type != XFS_SCRUB_TYPE_AGF &&
sc->sm->sm_type != XFS_SCRUB_TYPE_AGFL &&
sc->sm->sm_type != XFS_SCRUB_TYPE_AGI)
return true;
/*
* If we're scanning a given type of AG header, we only want to
* see read failures from that specific header. We'd like the
* other headers to cross-check them, but this isn't required.
*/
if (sc->sm->sm_type == type)
return true;
return false;
}
/*
* Grab all the headers for an AG.
*
* The headers should be released by xfs_scrub_ag_free, but as a fail
* safe we attach all the buffers we grab to the scrub transaction so
* they'll all be freed when we cancel it.
*/
int
xfs_scrub_ag_read_headers(
struct xfs_scrub_context *sc,
xfs_agnumber_t agno,
struct xfs_buf **agi,
struct xfs_buf **agf,
struct xfs_buf **agfl)
{
struct xfs_mount *mp = sc->mp;
int error;
error = xfs_ialloc_read_agi(mp, sc->tp, agno, agi);
if (error && want_ag_read_header_failure(sc, XFS_SCRUB_TYPE_AGI))
goto out;
error = xfs_alloc_read_agf(mp, sc->tp, agno, 0, agf);
if (error && want_ag_read_header_failure(sc, XFS_SCRUB_TYPE_AGF))
goto out;
error = xfs_alloc_read_agfl(mp, sc->tp, agno, agfl);
if (error && want_ag_read_header_failure(sc, XFS_SCRUB_TYPE_AGFL))
goto out;
out:
return error;
}
/* Release all the AG btree cursors. */
void
xfs_scrub_ag_btcur_free(
struct xfs_scrub_ag *sa)
{
if (sa->refc_cur)
xfs_btree_del_cursor(sa->refc_cur, XFS_BTREE_ERROR);
if (sa->rmap_cur)
xfs_btree_del_cursor(sa->rmap_cur, XFS_BTREE_ERROR);
if (sa->fino_cur)
xfs_btree_del_cursor(sa->fino_cur, XFS_BTREE_ERROR);
if (sa->ino_cur)
xfs_btree_del_cursor(sa->ino_cur, XFS_BTREE_ERROR);
if (sa->cnt_cur)
xfs_btree_del_cursor(sa->cnt_cur, XFS_BTREE_ERROR);
if (sa->bno_cur)
xfs_btree_del_cursor(sa->bno_cur, XFS_BTREE_ERROR);
sa->refc_cur = NULL;
sa->rmap_cur = NULL;
sa->fino_cur = NULL;
sa->ino_cur = NULL;
sa->bno_cur = NULL;
sa->cnt_cur = NULL;
}
/* Initialize all the btree cursors for an AG. */
int
xfs_scrub_ag_btcur_init(
struct xfs_scrub_context *sc,
struct xfs_scrub_ag *sa)
{
struct xfs_mount *mp = sc->mp;
xfs_agnumber_t agno = sa->agno;
if (sa->agf_bp) {
/* Set up a bnobt cursor for cross-referencing. */
sa->bno_cur = xfs_allocbt_init_cursor(mp, sc->tp, sa->agf_bp,
agno, XFS_BTNUM_BNO);
if (!sa->bno_cur)
goto err;
/* Set up a cntbt cursor for cross-referencing. */
sa->cnt_cur = xfs_allocbt_init_cursor(mp, sc->tp, sa->agf_bp,
agno, XFS_BTNUM_CNT);
if (!sa->cnt_cur)
goto err;
}
/* Set up a inobt cursor for cross-referencing. */
if (sa->agi_bp) {
sa->ino_cur = xfs_inobt_init_cursor(mp, sc->tp, sa->agi_bp,
agno, XFS_BTNUM_INO);
if (!sa->ino_cur)
goto err;
}
/* Set up a finobt cursor for cross-referencing. */
if (sa->agi_bp && xfs_sb_version_hasfinobt(&mp->m_sb)) {
sa->fino_cur = xfs_inobt_init_cursor(mp, sc->tp, sa->agi_bp,
agno, XFS_BTNUM_FINO);
if (!sa->fino_cur)
goto err;
}
/* Set up a rmapbt cursor for cross-referencing. */
if (sa->agf_bp && xfs_sb_version_hasrmapbt(&mp->m_sb)) {
sa->rmap_cur = xfs_rmapbt_init_cursor(mp, sc->tp, sa->agf_bp,
agno);
if (!sa->rmap_cur)
goto err;
}
/* Set up a refcountbt cursor for cross-referencing. */
if (sa->agf_bp && xfs_sb_version_hasreflink(&mp->m_sb)) {
sa->refc_cur = xfs_refcountbt_init_cursor(mp, sc->tp,
sa->agf_bp, agno, NULL);
if (!sa->refc_cur)
goto err;
}
return 0;
err:
return -ENOMEM;
}
/* Release the AG header context and btree cursors. */
void
xfs_scrub_ag_free(
struct xfs_scrub_context *sc,
struct xfs_scrub_ag *sa)
{
xfs_scrub_ag_btcur_free(sa);
if (sa->agfl_bp) {
xfs_trans_brelse(sc->tp, sa->agfl_bp);
sa->agfl_bp = NULL;
}
if (sa->agf_bp) {
xfs_trans_brelse(sc->tp, sa->agf_bp);
sa->agf_bp = NULL;
}
if (sa->agi_bp) {
xfs_trans_brelse(sc->tp, sa->agi_bp);
sa->agi_bp = NULL;
}
sa->agno = NULLAGNUMBER;
}
/*
* For scrub, grab the AGI and the AGF headers, in that order. Locking
* order requires us to get the AGI before the AGF. We use the
* transaction to avoid deadlocking on crosslinked metadata buffers;
* either the caller passes one in (bmap scrub) or we have to create a
* transaction ourselves.
*/
int
xfs_scrub_ag_init(
struct xfs_scrub_context *sc,
xfs_agnumber_t agno,
struct xfs_scrub_ag *sa)
{
int error;
sa->agno = agno;
error = xfs_scrub_ag_read_headers(sc, agno, &sa->agi_bp,
&sa->agf_bp, &sa->agfl_bp);
if (error)
return error;
return xfs_scrub_ag_btcur_init(sc, sa);
}
/* Per-scrubber setup functions */
/* Set us up with a transaction and an empty context. */
int
xfs_scrub_setup_fs(
struct xfs_scrub_context *sc,
struct xfs_inode *ip)
{
return xfs_scrub_trans_alloc(sc->sm, sc->mp, &sc->tp);
}
/* Set us up with AG headers and btree cursors. */
int
xfs_scrub_setup_ag_btree(
struct xfs_scrub_context *sc,
struct xfs_inode *ip,
bool force_log)
{
struct xfs_mount *mp = sc->mp;
int error;
/*
* If the caller asks us to checkpont the log, do so. This
* expensive operation should be performed infrequently and only
* as a last resort. Any caller that sets force_log should
* document why they need to do so.
*/
if (force_log) {
error = xfs_scrub_checkpoint_log(mp);
if (error)
return error;
}
error = xfs_scrub_setup_ag_header(sc, ip);
if (error)
return error;
return xfs_scrub_ag_init(sc, sc->sm->sm_agno, &sc->sa);
}
/* Push everything out of the log onto disk. */
int
xfs_scrub_checkpoint_log(
struct xfs_mount *mp)
{
int error;
error = _xfs_log_force(mp, XFS_LOG_SYNC, NULL);
if (error)
return error;
xfs_ail_push_all_sync(mp->m_ail);
return 0;
}
/*
* Given an inode and the scrub control structure, grab either the
* inode referenced in the control structure or the inode passed in.
* The inode is not locked.
*/
int
xfs_scrub_get_inode(
struct xfs_scrub_context *sc,
struct xfs_inode *ip_in)
{
struct xfs_mount *mp = sc->mp;
struct xfs_inode *ip = NULL;
int error;
/*
* If userspace passed us an AG number or a generation number
* without an inode number, they haven't got a clue so bail out
* immediately.
*/
if (sc->sm->sm_agno || (sc->sm->sm_gen && !sc->sm->sm_ino))
return -EINVAL;
/* We want to scan the inode we already had opened. */
if (sc->sm->sm_ino == 0 || sc->sm->sm_ino == ip_in->i_ino) {
sc->ip = ip_in;
return 0;
}
/* Look up the inode, see if the generation number matches. */
if (xfs_internal_inum(mp, sc->sm->sm_ino))
return -ENOENT;
error = xfs_iget(mp, NULL, sc->sm->sm_ino,
XFS_IGET_UNTRUSTED | XFS_IGET_DONTCACHE, 0, &ip);
if (error == -ENOENT || error == -EINVAL) {
/* inode doesn't exist... */
return -ENOENT;
} else if (error) {
trace_xfs_scrub_op_error(sc,
XFS_INO_TO_AGNO(mp, sc->sm->sm_ino),
XFS_INO_TO_AGBNO(mp, sc->sm->sm_ino),
error, __return_address);
return error;
}
if (VFS_I(ip)->i_generation != sc->sm->sm_gen) {
iput(VFS_I(ip));
return -ENOENT;
}
sc->ip = ip;
return 0;
}
/* Set us up to scrub a file's contents. */
int
xfs_scrub_setup_inode_contents(
struct xfs_scrub_context *sc,
struct xfs_inode *ip,
unsigned int resblks)
{
struct xfs_mount *mp = sc->mp;
int error;
error = xfs_scrub_get_inode(sc, ip);
if (error)
return error;
/* Got the inode, lock it and we're ready to go. */
sc->ilock_flags = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL;
xfs_ilock(sc->ip, sc->ilock_flags);
error = xfs_scrub_trans_alloc(sc->sm, mp, &sc->tp);
if (error)
goto out;
sc->ilock_flags |= XFS_ILOCK_EXCL;
xfs_ilock(sc->ip, XFS_ILOCK_EXCL);
out:
/* scrub teardown will unlock and release the inode for us */
return error;
}
