Commit 526aab5f authored by Darrick J. Wong's avatar Darrick J. Wong
Browse files

xfs: implement online scrubbing of rtsummary info 



Finish the realtime summary scrubber by adding the functions we need to
compute a fresh copy of the rtsummary info and comparing it to the copy
on disk.

Signed-off-by: default avatarDarrick J. Wong <djwong@kernel.org>
Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
parent b7d47a77

fs/xfs/scrub/common.h

+16 −2
Original line number Diff line number Diff line
@@ -88,10 +88,16 @@ int xchk_setup_xattr(struct xfs_scrub *sc); 
int xchk_setup_symlink(struct xfs_scrub *sc);

int xchk_setup_parent(struct xfs_scrub *sc);

#ifdef CONFIG_XFS_RT

int xchk_setup_rt(struct xfs_scrub *sc);

int xchk_setup_rtbitmap(struct xfs_scrub *sc);

int xchk_setup_rtsummary(struct xfs_scrub *sc);

#else

static inline int

xchk_setup_rt(struct xfs_scrub *sc)

xchk_setup_rtbitmap(struct xfs_scrub *sc)

{

	return -ENOENT;

}

static inline int

xchk_setup_rtsummary(struct xfs_scrub *sc)

{

	return -ENOENT;

}
@@ -163,6 +169,14 @@ static inline bool xchk_skip_xref(struct xfs_scrub_metadata *sm) 


int xchk_metadata_inode_forks(struct xfs_scrub *sc);



/*

 * Helper macros to allocate and format xfile description strings.

 * Callers must kfree the pointer returned.

 */

#define xchk_xfile_descr(sc, fmt, ...) \

	kasprintf(XCHK_GFP_FLAGS, "XFS (%s): " fmt, \

			(sc)->mp->m_super->s_id, ##__VA_ARGS__)



/*

 * Setting up a hook to wait for intents to drain is costly -- we have to take

 * the CPU hotplug lock and force an i-cache flush on all CPUs once to set it

fs/xfs/scrub/rtbitmap.c

+2 −2
Original line number Diff line number Diff line
@@ -19,12 +19,12 @@ 


/* Set us up with the realtime metadata locked. */

int

xchk_setup_rt(

xchk_setup_rtbitmap(

	struct xfs_scrub	*sc)

{

	int			error;



	error = xchk_setup_fs(sc);

	error = xchk_trans_alloc(sc, 0);

	if (error)

		return error;

fs/xfs/scrub/rtsummary.c

+232 −22
Original line number Diff line number Diff line
@@ -14,41 +14,251 @@ 
#include "xfs_log_format.h"

#include "xfs_trans.h"

#include "xfs_rtalloc.h"

#include "xfs_bit.h"

#include "xfs_bmap.h"

#include "scrub/scrub.h"

#include "scrub/common.h"

#include "scrub/trace.h"

#include "scrub/xfile.h"



/* Scrub the realtime summary. */

/*

 * Realtime Summary

 * ================

 *

 * We check the realtime summary by scanning the realtime bitmap file to create

 * a new summary file incore, and then we compare the computed version against

 * the ondisk version.  We use the 'xfile' functionality to store this

 * (potentially large) amount of data in pageable memory.

 */



/* Set us up to check the rtsummary file. */

int

xchk_rtsummary(

xchk_setup_rtsummary(

	struct xfs_scrub	*sc)

{

	struct xfs_inode	*rsumip = sc->mp->m_rsumip;

	struct xfs_inode	*old_ip = sc->ip;

	uint			old_ilock_flags = sc->ilock_flags;

	int			error = 0;

	struct xfs_mount	*mp = sc->mp;

	char			*descr;

	int			error;



	/*

	 * We ILOCK'd the rt bitmap ip in the setup routine, now lock the

	 * rt summary ip in compliance with the rt inode locking rules.

	 *

	 * Since we switch sc->ip to rsumip we have to save the old ilock

	 * flags so that we don't mix up the inode state that @sc tracks.

	 * Create an xfile to construct a new rtsummary file.  The xfile allows

	 * us to avoid pinning kernel memory for this purpose.

	 */

	sc->ip = rsumip;

	sc->ilock_flags = 0;

	descr = xchk_xfile_descr(sc, "realtime summary file");

	error = xfile_create(descr, mp->m_rsumsize, &sc->xfile);

	kfree(descr);

	if (error)

		return error;



	error = xchk_trans_alloc(sc, 0);

	if (error)

		return error;



	/* Allocate a memory buffer for the summary comparison. */

	sc->buf = kvmalloc(mp->m_sb.sb_blocksize, XCHK_GFP_FLAGS);

	if (!sc->buf)

		return -ENOMEM;



	error = xchk_install_live_inode(sc, mp->m_rsumip);

	if (error)

		return error;



	/*

	 * Locking order requires us to take the rtbitmap first.  We must be

	 * careful to unlock it ourselves when we are done with the rtbitmap

	 * file since the scrub infrastructure won't do that for us.  Only

	 * then we can lock the rtsummary inode.

	 */

	xfs_ilock(mp->m_rbmip, XFS_ILOCK_SHARED | XFS_ILOCK_RTBITMAP);

	xchk_ilock(sc, XFS_ILOCK_EXCL | XFS_ILOCK_RTSUM);

	return 0;

}



/* Helper functions to record suminfo words in an xfile. */



typedef unsigned int xchk_rtsumoff_t;



static inline int

xfsum_load(

	struct xfs_scrub	*sc,

	xchk_rtsumoff_t		sumoff,

	xfs_suminfo_t		*info)

{

	return xfile_obj_load(sc->xfile, info, sizeof(xfs_suminfo_t),

			sumoff << XFS_WORDLOG);

}



static inline int

xfsum_store(

	struct xfs_scrub	*sc,

	xchk_rtsumoff_t		sumoff,

	const xfs_suminfo_t	info)

{

	return xfile_obj_store(sc->xfile, &info, sizeof(xfs_suminfo_t),

			sumoff << XFS_WORDLOG);

}



static inline int

xfsum_copyout(

	struct xfs_scrub	*sc,

	xchk_rtsumoff_t		sumoff,

	xfs_suminfo_t		*info,

	unsigned int		nr_words)

{

	return xfile_obj_load(sc->xfile, info, nr_words << XFS_WORDLOG,

			sumoff << XFS_WORDLOG);

}



/* Update the summary file to reflect the free extent that we've accumulated. */

STATIC int

xchk_rtsum_record_free(

	struct xfs_mount		*mp,

	struct xfs_trans		*tp,

	const struct xfs_rtalloc_rec	*rec,

	void				*priv)

{

	struct xfs_scrub		*sc = priv;

	xfs_fileoff_t			rbmoff;

	xfs_rtblock_t			rtbno;

	xfs_filblks_t			rtlen;

	xchk_rtsumoff_t			offs;

	unsigned int			lenlog;

	xfs_suminfo_t			v = 0;

	int				error = 0;



	if (xchk_should_terminate(sc, &error))

		return error;



	/* Compute the relevant location in the rtsum file. */

	rbmoff = XFS_BITTOBLOCK(mp, rec->ar_startext);

	lenlog = XFS_RTBLOCKLOG(rec->ar_extcount);

	offs = XFS_SUMOFFS(mp, lenlog, rbmoff);



	rtbno = rec->ar_startext * mp->m_sb.sb_rextsize;

	rtlen = rec->ar_extcount * mp->m_sb.sb_rextsize;



	if (!xfs_verify_rtext(mp, rtbno, rtlen)) {

		xchk_ino_xref_set_corrupt(sc, mp->m_rbmip->i_ino);

		return -EFSCORRUPTED;

	}



	/* Bump the summary count. */

	error = xfsum_load(sc, offs, &v);

	if (error)

		return error;



	v++;

	trace_xchk_rtsum_record_free(mp, rec->ar_startext, rec->ar_extcount,

			lenlog, offs, v);



	return xfsum_store(sc, offs, v);

}



/* Compute the realtime summary from the realtime bitmap. */

STATIC int

xchk_rtsum_compute(

	struct xfs_scrub	*sc)

{

	struct xfs_mount	*mp = sc->mp;

	unsigned long long	rtbmp_bytes;



	/* If the bitmap size doesn't match the computed size, bail. */

	rtbmp_bytes = howmany_64(mp->m_sb.sb_rextents, NBBY);

	if (roundup_64(rtbmp_bytes, mp->m_sb.sb_blocksize) !=

			mp->m_rbmip->i_disk_size)

		return -EFSCORRUPTED;



	return xfs_rtalloc_query_all(sc->mp, sc->tp, xchk_rtsum_record_free,

			sc);

}



/* Compare the rtsummary file against the one we computed. */

STATIC int

xchk_rtsum_compare(

	struct xfs_scrub	*sc)

{

	struct xfs_mount	*mp = sc->mp;

	struct xfs_buf		*bp;

	struct xfs_bmbt_irec	map;

	xfs_fileoff_t		off;

	xchk_rtsumoff_t		sumoff = 0;

	int			nmap;



	for (off = 0; off < XFS_B_TO_FSB(mp, mp->m_rsumsize); off++) {

		int		error = 0;



		if (xchk_should_terminate(sc, &error))

			return error;

		if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)

			return 0;



		/* Make sure we have a written extent. */

		nmap = 1;

		error = xfs_bmapi_read(mp->m_rsumip, off, 1, &map, &nmap,

				XFS_DATA_FORK);

		if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, off, &error))

			return error;



		if (nmap != 1 || !xfs_bmap_is_written_extent(&map)) {

			xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, off);

			return 0;

		}



		/* Read a block's worth of ondisk rtsummary file. */

		error = xfs_rtbuf_get(mp, sc->tp, off, 1, &bp);

		if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, off, &error))

			return error;



		/* Read a block's worth of computed rtsummary file. */

		error = xfsum_copyout(sc, sumoff, sc->buf, mp->m_blockwsize);

		if (error) {

			xfs_trans_brelse(sc->tp, bp);

			return error;

		}



		if (memcmp(bp->b_addr, sc->buf,

					mp->m_blockwsize << XFS_WORDLOG) != 0)

			xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, off);



		xfs_trans_brelse(sc->tp, bp);

		sumoff += mp->m_blockwsize;

	}



	return 0;

}



/* Scrub the realtime summary. */

int

xchk_rtsummary(

	struct xfs_scrub	*sc)

{

	struct xfs_mount	*mp = sc->mp;

	int			error = 0;



	/* Invoke the fork scrubber. */

	error = xchk_metadata_inode_forks(sc);

	if (error || (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))

		goto out;



	/* XXX: implement this some day */

	xchk_set_incomplete(sc);

out:

	/* Switch back to the rtbitmap inode and lock flags. */

	xchk_iunlock(sc, XFS_ILOCK_EXCL | XFS_ILOCK_RTSUM);

	sc->ilock_flags = old_ilock_flags;

	sc->ip = old_ip;

		goto out_rbm;



	/* Construct the new summary file from the rtbitmap. */

	error = xchk_rtsum_compute(sc);

	if (error == -EFSCORRUPTED) {

		/*

		 * EFSCORRUPTED means the rtbitmap is corrupt, which is an xref

		 * error since we're checking the summary file.

		 */

		xchk_ino_xref_set_corrupt(sc, mp->m_rbmip->i_ino);

		error = 0;

		goto out_rbm;

	}

	if (error)

		goto out_rbm;



	/* Does the computed summary file match the actual rtsummary file? */

	error = xchk_rtsum_compare(sc);



out_rbm:

	/* Unlock the rtbitmap since we're done with it. */

	xfs_iunlock(mp->m_rbmip, XFS_ILOCK_SHARED | XFS_ILOCK_RTBITMAP);

	return error;

}

fs/xfs/scrub/scrub.c

+7 −2
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ 
#include "scrub/repair.h"

#include "scrub/health.h"

#include "scrub/stats.h"

#include "scrub/xfile.h"



/*

 * Online Scrub and Repair
@@ -183,6 +184,10 @@ xchk_teardown( 
	}

	if (sc->sm->sm_flags & XFS_SCRUB_IFLAG_REPAIR)

		mnt_drop_write_file(sc->file);

	if (sc->xfile) {

		xfile_destroy(sc->xfile);

		sc->xfile = NULL;

	}

	if (sc->buf) {

		if (sc->buf_cleanup)

			sc->buf_cleanup(sc->buf);
@@ -317,14 +322,14 @@ static const struct xchk_meta_ops meta_scrub_ops[] = { 
	},

	[XFS_SCRUB_TYPE_RTBITMAP] = {	/* realtime bitmap */

		.type	= ST_FS,

		.setup	= xchk_setup_rt,

		.setup	= xchk_setup_rtbitmap,

		.scrub	= xchk_rtbitmap,

		.has	= xfs_has_realtime,

		.repair	= xrep_notsupported,

	},

	[XFS_SCRUB_TYPE_RTSUM] = {	/* realtime summary */

		.type	= ST_FS,

		.setup	= xchk_setup_rt,

		.setup	= xchk_setup_rtsummary,

		.scrub	= xchk_rtsummary,

		.has	= xfs_has_realtime,

		.repair	= xrep_notsupported,

fs/xfs/scrub/scrub.h

+4 −0
Original line number Diff line number Diff line
@@ -88,6 +88,10 @@ struct xfs_scrub { 
	 */

	void				(*buf_cleanup)(void *buf);



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

	struct xfile			*xfile;



	/* Lock flags for @ip. */

	uint				ilock_flags;



	/* See the XCHK/XREP state flags below. */