[linux.git] / fs / gfs2 / recovery.c

/*
 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
 * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
 *
 * This copyrighted material is made available to anyone wishing to use,
 * modify, copy, or redistribute it subject to the terms and conditions
 * of the GNU General Public License version 2.
 */

#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/gfs2_ondisk.h>
#include <linux/crc32.h>
#include <linux/lm_interface.h>

#include "gfs2.h"
#include "incore.h"
#include "bmap.h"
#include "glock.h"
#include "glops.h"
#include "lm.h"
#include "lops.h"
#include "meta_io.h"
#include "recovery.h"
#include "super.h"
#include "util.h"
#include "dir.h"

int gfs2_replay_read_block(struct gfs2_jdesc *jd, unsigned int blk,
			   struct buffer_head **bh)
{
	struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
	struct gfs2_glock *gl = ip->i_gl;
	int new = 0;
	u64 dblock;
	u32 extlen;
	int error;

	error = gfs2_extent_map(&ip->i_inode, blk, &new, &dblock, &extlen);
	if (error)
		return error;
	if (!dblock) {
		gfs2_consist_inode(ip);
		return -EIO;
	}

	*bh = gfs2_meta_ra(gl, dblock, extlen);

	return error;
}

int gfs2_revoke_add(struct gfs2_sbd *sdp, u64 blkno, unsigned int where)
{
	struct list_head *head = &sdp->sd_revoke_list;
	struct gfs2_revoke_replay *rr;
	int found = 0;

	list_for_each_entry(rr, head, rr_list) {
		if (rr->rr_blkno == blkno) {
			found = 1;
			break;
		}
	}

	if (found) {
		rr->rr_where = where;
		return 0;
	}

	rr = kmalloc(sizeof(struct gfs2_revoke_replay), GFP_KERNEL);
	if (!rr)
		return -ENOMEM;

	rr->rr_blkno = blkno;
	rr->rr_where = where;
	list_add(&rr->rr_list, head);

	return 1;
}

int gfs2_revoke_check(struct gfs2_sbd *sdp, u64 blkno, unsigned int where)
{
	struct gfs2_revoke_replay *rr;
	int wrap, a, b, revoke;
	int found = 0;

	list_for_each_entry(rr, &sdp->sd_revoke_list, rr_list) {
		if (rr->rr_blkno == blkno) {
			found = 1;
			break;
		}
	}

	if (!found)
		return 0;

	wrap = (rr->rr_where < sdp->sd_replay_tail);
	a = (sdp->sd_replay_tail < where);
	b = (where < rr->rr_where);
	revoke = (wrap) ? (a || b) : (a && b);

	return revoke;
}

void gfs2_revoke_clean(struct gfs2_sbd *sdp)
{
	struct list_head *head = &sdp->sd_revoke_list;
	struct gfs2_revoke_replay *rr;

	while (!list_empty(head)) {
		rr = list_entry(head->next, struct gfs2_revoke_replay, rr_list);
		list_del(&rr->rr_list);
		kfree(rr);
	}
}

/**
 * get_log_header - read the log header for a given segment
 * @jd: the journal
 * @blk: the block to look at
 * @lh: the log header to return
 *
 * Read the log header for a given segement in a given journal.  Do a few
 * sanity checks on it.
 *
 * Returns: 0 on success,
 *          1 if the header was invalid or incomplete,
 *          errno on error
 */

static int get_log_header(struct gfs2_jdesc *jd, unsigned int blk,
			  struct gfs2_log_header_host *head)
{
	struct buffer_head *bh;
	struct gfs2_log_header_host lh;
static const u32 nothing = 0;
	u32 hash;
	int error;

	error = gfs2_replay_read_block(jd, blk, &bh);
	if (error)
		return error;

	hash = crc32_le((u32)~0, bh->b_data, sizeof(struct gfs2_log_header) -
					     sizeof(u32));
	hash = crc32_le(hash, (unsigned char const *)&nothing, sizeof(nothing));
	hash ^= (u32)~0;
	gfs2_log_header_in(&lh, bh->b_data);
	brelse(bh);

	if (lh.lh_header.mh_magic != GFS2_MAGIC ||
	    lh.lh_header.mh_type != GFS2_METATYPE_LH ||
	    lh.lh_blkno != blk || lh.lh_hash != hash)
		return 1;

	*head = lh;

	return 0;
}

/**
 * find_good_lh - find a good log header
 * @jd: the journal
 * @blk: the segment to start searching from
 * @lh: the log header to fill in
 * @forward: if true search forward in the log, else search backward
 *
 * Call get_log_header() to get a log header for a segment, but if the
 * segment is bad, either scan forward or backward until we find a good one.
 *
 * Returns: errno
 */

static int find_good_lh(struct gfs2_jdesc *jd, unsigned int *blk,
			struct gfs2_log_header_host *head)
{
	unsigned int orig_blk = *blk;
	int error;

	for (;;) {
		error = get_log_header(jd, *blk, head);
		if (error <= 0)
			return error;

		if (++*blk == jd->jd_blocks)
			*blk = 0;

		if (*blk == orig_blk) {
			gfs2_consist_inode(GFS2_I(jd->jd_inode));
			return -EIO;
		}
	}
}

/**
 * jhead_scan - make sure we've found the head of the log
 * @jd: the journal
 * @head: this is filled in with the log descriptor of the head
 *
 * At this point, seg and lh should be either the head of the log or just
 * before.  Scan forward until we find the head.
 *
 * Returns: errno
 */

static int jhead_scan(struct gfs2_jdesc *jd, struct gfs2_log_header_host *head)
{
	unsigned int blk = head->lh_blkno;
	struct gfs2_log_header_host lh;
	int error;

	for (;;) {
		if (++blk == jd->jd_blocks)
			blk = 0;

		error = get_log_header(jd, blk, &lh);
		if (error < 0)
			return error;
		if (error == 1)
			continue;

		if (lh.lh_sequence == head->lh_sequence) {
			gfs2_consist_inode(GFS2_I(jd->jd_inode));
			return -EIO;
		}
		if (lh.lh_sequence < head->lh_sequence)
			break;

		*head = lh;
	}

	return 0;
}

/**
 * gfs2_find_jhead - find the head of a log
 * @jd: the journal
 * @head: the log descriptor for the head of the log is returned here
 *
 * Do a binary search of a journal and find the valid log entry with the
 * highest sequence number.  (i.e. the log head)
 *
 * Returns: errno
 */

int gfs2_find_jhead(struct gfs2_jdesc *jd, struct gfs2_log_header_host *head)
{
	struct gfs2_log_header_host lh_1, lh_m;
	u32 blk_1, blk_2, blk_m;
	int error;

	blk_1 = 0;
	blk_2 = jd->jd_blocks - 1;

	for (;;) {
		blk_m = (blk_1 + blk_2) / 2;

		error = find_good_lh(jd, &blk_1, &lh_1);
		if (error)
			return error;

		error = find_good_lh(jd, &blk_m, &lh_m);
		if (error)
			return error;

		if (blk_1 == blk_m || blk_m == blk_2)
			break;

		if (lh_1.lh_sequence <= lh_m.lh_sequence)
			blk_1 = blk_m;
		else
			blk_2 = blk_m;
	}

	error = jhead_scan(jd, &lh_1);
	if (error)
		return error;

	*head = lh_1;

	return error;
}

/**
 * foreach_descriptor - go through the active part of the log
 * @jd: the journal
 * @start: the first log header in the active region
 * @end: the last log header (don't process the contents of this entry))
 *
 * Call a given function once for every log descriptor in the active
 * portion of the log.
 *
 * Returns: errno
 */

static int foreach_descriptor(struct gfs2_jdesc *jd, unsigned int start,
			      unsigned int end, int pass)
{
	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
	struct buffer_head *bh;
	struct gfs2_log_descriptor *ld;
	int error = 0;
	u32 length;
	__be64 *ptr;
	unsigned int offset = sizeof(struct gfs2_log_descriptor);
	offset += sizeof(__be64) - 1;
	offset &= ~(sizeof(__be64) - 1);

	while (start != end) {
		error = gfs2_replay_read_block(jd, start, &bh);
		if (error)
			return error;
		if (gfs2_meta_check(sdp, bh)) {
			brelse(bh);
			return -EIO;
		}
		ld = (struct gfs2_log_descriptor *)bh->b_data;
		length = be32_to_cpu(ld->ld_length);

		if (be32_to_cpu(ld->ld_header.mh_type) == GFS2_METATYPE_LH) {
			struct gfs2_log_header_host lh;
			error = get_log_header(jd, start, &lh);
			if (!error) {
				gfs2_replay_incr_blk(sdp, &start);
				brelse(bh);
				continue;
			}
			if (error == 1) {
				gfs2_consist_inode(GFS2_I(jd->jd_inode));
				error = -EIO;
			}
			brelse(bh);
			return error;
		} else if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_LD)) {
			brelse(bh);
			return -EIO;
		}
		ptr = (__be64 *)(bh->b_data + offset);
		error = lops_scan_elements(jd, start, ld, ptr, pass);
		if (error) {
			brelse(bh);
			return error;
		}

		while (length--)
			gfs2_replay_incr_blk(sdp, &start);

		brelse(bh);
	}

	return 0;
}

/**
 * clean_journal - mark a dirty journal as being clean
 * @sdp: the filesystem
 * @jd: the journal
 * @gl: the journal's glock
 * @head: the head journal to start from
 *
 * Returns: errno
 */

static int clean_journal(struct gfs2_jdesc *jd, struct gfs2_log_header_host *head)
{
	struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
	unsigned int lblock;
	struct gfs2_log_header *lh;
	u32 hash;
	struct buffer_head *bh;
	int error;
	struct buffer_head bh_map = { .b_state = 0, .b_blocknr = 0 };

	lblock = head->lh_blkno;
	gfs2_replay_incr_blk(sdp, &lblock);
	bh_map.b_size = 1 << ip->i_inode.i_blkbits;
	error = gfs2_block_map(&ip->i_inode, lblock, 0, &bh_map);
	if (error)
		return error;
	if (!bh_map.b_blocknr) {
		gfs2_consist_inode(ip);
		return -EIO;
	}

	bh = sb_getblk(sdp->sd_vfs, bh_map.b_blocknr);
	lock_buffer(bh);
	memset(bh->b_data, 0, bh->b_size);
	set_buffer_uptodate(bh);
	clear_buffer_dirty(bh);
	unlock_buffer(bh);

	lh = (struct gfs2_log_header *)bh->b_data;
	memset(lh, 0, sizeof(struct gfs2_log_header));
	lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
	lh->lh_header.mh_type = cpu_to_be32(GFS2_METATYPE_LH);
	lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH);
	lh->lh_sequence = cpu_to_be64(head->lh_sequence + 1);
	lh->lh_flags = cpu_to_be32(GFS2_LOG_HEAD_UNMOUNT);
	lh->lh_blkno = cpu_to_be32(lblock);
	hash = gfs2_disk_hash((const char *)lh, sizeof(struct gfs2_log_header));
	lh->lh_hash = cpu_to_be32(hash);

	set_buffer_dirty(bh);
	if (sync_dirty_buffer(bh))
		gfs2_io_error_bh(sdp, bh);
	brelse(bh);

	return error;
}

/**
 * gfs2_recover_journal - recovery a given journal
 * @jd: the struct gfs2_jdesc describing the journal
 *
 * Acquire the journal's lock, check to see if the journal is clean, and
 * do recovery if necessary.
 *
 * Returns: errno
 */

int gfs2_recover_journal(struct gfs2_jdesc *jd)
{
	struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
	struct gfs2_log_header_host head;
	struct gfs2_holder j_gh, ji_gh, t_gh;
	unsigned long t;
	int ro = 0;
	unsigned int pass;
	int error;

	if (jd->jd_jid != sdp->sd_lockstruct.ls_jid) {
		fs_info(sdp, "jid=%u: Trying to acquire journal lock...\n",
			jd->jd_jid);

		/* Aquire the journal lock so we can do recovery */

		error = gfs2_glock_nq_num(sdp, jd->jd_jid, &gfs2_journal_glops,
					  LM_ST_EXCLUSIVE,
					  LM_FLAG_NOEXP | LM_FLAG_TRY | GL_NOCACHE,
					  &j_gh);
		switch (error) {
		case 0:
			break;

		case GLR_TRYFAILED:
			fs_info(sdp, "jid=%u: Busy\n", jd->jd_jid);
			error = 0;

		default:
			goto fail;
		};

		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
					   LM_FLAG_NOEXP, &ji_gh);
		if (error)
			goto fail_gunlock_j;
	} else {
		fs_info(sdp, "jid=%u, already locked for use\n", jd->jd_jid);
	}

	fs_info(sdp, "jid=%u: Looking at journal...\n", jd->jd_jid);

	error = gfs2_jdesc_check(jd);
	if (error)
		goto fail_gunlock_ji;

	error = gfs2_find_jhead(jd, &head);
	if (error)
		goto fail_gunlock_ji;

	if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
		fs_info(sdp, "jid=%u: Acquiring the transaction lock...\n",
			jd->jd_jid);

		t = jiffies;

		/* Acquire a shared hold on the transaction lock */

		error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_SHARED,
					   LM_FLAG_NOEXP | LM_FLAG_PRIORITY |
					   GL_NOCANCEL | GL_NOCACHE, &t_gh);
		if (error)
			goto fail_gunlock_ji;

		if (test_bit(SDF_JOURNAL_CHECKED, &sdp->sd_flags)) {
			if (!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags))
				ro = 1;
		} else {
			if (sdp->sd_vfs->s_flags & MS_RDONLY)
				ro = 1;
		}

		if (ro) {
			fs_warn(sdp, "jid=%u: Can't replay: read-only FS\n",
				jd->jd_jid);
			error = -EROFS;
			goto fail_gunlock_tr;
		}

		fs_info(sdp, "jid=%u: Replaying journal...\n", jd->jd_jid);

		for (pass = 0; pass < 2; pass++) {
			lops_before_scan(jd, &head, pass);
			error = foreach_descriptor(jd, head.lh_tail,
						   head.lh_blkno, pass);
			lops_after_scan(jd, error, pass);
			if (error)
				goto fail_gunlock_tr;
		}

		error = clean_journal(jd, &head);
		if (error)
			goto fail_gunlock_tr;

		gfs2_glock_dq_uninit(&t_gh);
		t = DIV_ROUND_UP(jiffies - t, HZ);
		fs_info(sdp, "jid=%u: Journal replayed in %lus\n",
			jd->jd_jid, t);
	}

	if (jd->jd_jid != sdp->sd_lockstruct.ls_jid)
		gfs2_glock_dq_uninit(&ji_gh);

	gfs2_lm_recovery_done(sdp, jd->jd_jid, LM_RD_SUCCESS);

	if (jd->jd_jid != sdp->sd_lockstruct.ls_jid)
		gfs2_glock_dq_uninit(&j_gh);

	fs_info(sdp, "jid=%u: Done\n", jd->jd_jid);
	return 0;

fail_gunlock_tr:
	gfs2_glock_dq_uninit(&t_gh);
fail_gunlock_ji:
	if (jd->jd_jid != sdp->sd_lockstruct.ls_jid) {
		gfs2_glock_dq_uninit(&ji_gh);
fail_gunlock_j:
		gfs2_glock_dq_uninit(&j_gh);
	}

	fs_info(sdp, "jid=%u: %s\n", jd->jd_jid, (error) ? "Failed" : "Done");

fail:
	gfs2_lm_recovery_done(sdp, jd->jd_jid, LM_RD_GAVEUP);
	return error;
}

/**
 * gfs2_check_journals - Recover any dirty journals
 * @sdp: the filesystem
 *
 */

void gfs2_check_journals(struct gfs2_sbd *sdp)
{
	struct gfs2_jdesc *jd;

	for (;;) {
		jd = gfs2_jdesc_find_dirty(sdp);
		if (!jd)
			break;

		if (jd != sdp->sd_jdesc)
			gfs2_recover_journal(jd);
	}
}
Commit	Line	Data
b3b94faa DT	1	/*
b3b94faa DT	2	* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3a8a9a10	3	* Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
b3b94faa DT	4	*
	5	* This copyrighted material is made available to anyone wishing to use,
	6	* modify, copy, or redistribute it subject to the terms and conditions
e9fc2aa0	7	* of the GNU General Public License version 2.
b3b94faa DT	8	*/
	9
	10	#include <linux/sched.h>
	11	#include <linux/slab.h>
	12	#include <linux/spinlock.h>
	13	#include <linux/completion.h>
	14	#include <linux/buffer_head.h>
5c676f6d	15	#include <linux/gfs2_ondisk.h>
71b86f56	16	#include <linux/crc32.h>
7d308590	17	#include <linux/lm_interface.h>
b3b94faa DT	18
b3b94faa DT	19	#include "gfs2.h"
5c676f6d	20	#include "incore.h"
b3b94faa DT	21	#include "bmap.h"
	22	#include "glock.h"
	23	#include "glops.h"
	24	#include "lm.h"
	25	#include "lops.h"
	26	#include "meta_io.h"
	27	#include "recovery.h"
	28	#include "super.h"
5c676f6d	29	#include "util.h"
71b86f56	30	#include "dir.h"
b3b94faa DT	31
	32	int gfs2_replay_read_block(struct gfs2_jdesc *jd, unsigned int blk,
	33	struct buffer_head **bh)
	34	{
feaa7bba	35	struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
5c676f6d	36	struct gfs2_glock *gl = ip->i_gl;
b3b94faa	37	int new = 0;
cd915493 SW	38	u64 dblock;
cd915493 SW	39	u32 extlen;
b3b94faa DT	40	int error;
b3b94faa DT	41
feaa7bba	42	error = gfs2_extent_map(&ip->i_inode, blk, &new, &dblock, &extlen);
b3b94faa DT	43	if (error)
	44	return error;
	45	if (!dblock) {
5c676f6d	46	gfs2_consist_inode(ip);
b3b94faa DT	47	return -EIO;
	48	}
	49
7276b3b0	50	*bh = gfs2_meta_ra(gl, dblock, extlen);
b3b94faa DT	51
	52	return error;
	53	}
	54
cd915493	55	int gfs2_revoke_add(struct gfs2_sbd *sdp, u64 blkno, unsigned int where)
b3b94faa DT	56	{
	57	struct list_head *head = &sdp->sd_revoke_list;
	58	struct gfs2_revoke_replay *rr;
	59	int found = 0;
	60
	61	list_for_each_entry(rr, head, rr_list) {
	62	if (rr->rr_blkno == blkno) {
	63	found = 1;
	64	break;
	65	}
	66	}
	67
	68	if (found) {
	69	rr->rr_where = where;
	70	return 0;
	71	}
	72
	73	rr = kmalloc(sizeof(struct gfs2_revoke_replay), GFP_KERNEL);
	74	if (!rr)
	75	return -ENOMEM;
	76
	77	rr->rr_blkno = blkno;
	78	rr->rr_where = where;
	79	list_add(&rr->rr_list, head);
	80
	81	return 1;
	82	}
	83
cd915493	84	int gfs2_revoke_check(struct gfs2_sbd *sdp, u64 blkno, unsigned int where)
b3b94faa DT	85	{
	86	struct gfs2_revoke_replay *rr;
	87	int wrap, a, b, revoke;
	88	int found = 0;
	89
	90	list_for_each_entry(rr, &sdp->sd_revoke_list, rr_list) {
	91	if (rr->rr_blkno == blkno) {
	92	found = 1;
	93	break;
	94	}
	95	}
	96
	97	if (!found)
	98	return 0;
	99
	100	wrap = (rr->rr_where < sdp->sd_replay_tail);
	101	a = (sdp->sd_replay_tail < where);
	102	b = (where < rr->rr_where);
	103	revoke = (wrap) ? (a \|\| b) : (a && b);
	104
	105	return revoke;
	106	}
	107
	108	void gfs2_revoke_clean(struct gfs2_sbd *sdp)
	109	{
	110	struct list_head *head = &sdp->sd_revoke_list;
	111	struct gfs2_revoke_replay *rr;
	112
	113	while (!list_empty(head)) {
	114	rr = list_entry(head->next, struct gfs2_revoke_replay, rr_list);
	115	list_del(&rr->rr_list);
	116	kfree(rr);
	117	}
	118	}
	119
	120	/**
	121	* get_log_header - read the log header for a given segment
	122	* @jd: the journal
	123	* @blk: the block to look at
	124	* @lh: the log header to return
	125	*
	126	* Read the log header for a given segement in a given journal. Do a few
	127	* sanity checks on it.
	128	*
	129	* Returns: 0 on success,
	130	* 1 if the header was invalid or incomplete,
	131	* errno on error
	132	*/
	133
	134	static int get_log_header(struct gfs2_jdesc *jd, unsigned int blk,
55167622	135	struct gfs2_log_header_host *head)
b3b94faa DT	136	{
b3b94faa DT	137	struct buffer_head *bh;
55167622	138	struct gfs2_log_header_host lh;
2a2c9824	139	static const u32 nothing = 0;
cd915493	140	u32 hash;
b3b94faa DT	141	int error;
	142
	143	error = gfs2_replay_read_block(jd, blk, &bh);
	144	if (error)
	145	return error;
	146
2a2c9824 SW	147	hash = crc32_le((u32)~0, bh->b_data, sizeof(struct gfs2_log_header) -
	148	sizeof(u32));
	149	hash = crc32_le(hash, (unsigned char const *)&nothing, sizeof(nothing));
	150	hash ^= (u32)~0;
b3b94faa	151	gfs2_log_header_in(&lh, bh->b_data);
b3b94faa DT	152	brelse(bh);
	153
	154	if (lh.lh_header.mh_magic != GFS2_MAGIC \|\|
	155	lh.lh_header.mh_type != GFS2_METATYPE_LH \|\|
59a1cc6b	156	lh.lh_blkno != blk \|\| lh.lh_hash != hash)
b3b94faa DT	157	return 1;
	158
	159	*head = lh;
	160
	161	return 0;
	162	}
	163
	164	/**
	165	* find_good_lh - find a good log header
	166	* @jd: the journal
	167	* @blk: the segment to start searching from
	168	* @lh: the log header to fill in
	169	* @forward: if true search forward in the log, else search backward
	170	*
	171	* Call get_log_header() to get a log header for a segment, but if the
	172	* segment is bad, either scan forward or backward until we find a good one.
	173	*
	174	* Returns: errno
	175	*/
	176
	177	static int find_good_lh(struct gfs2_jdesc jd, unsigned int blk,
55167622	178	struct gfs2_log_header_host *head)
b3b94faa DT	179	{
	180	unsigned int orig_blk = *blk;
	181	int error;
	182
	183	for (;;) {
	184	error = get_log_header(jd, *blk, head);
	185	if (error <= 0)
	186	return error;
	187
	188	if (++*blk == jd->jd_blocks)
	189	*blk = 0;
	190
	191	if (*blk == orig_blk) {
feaa7bba	192	gfs2_consist_inode(GFS2_I(jd->jd_inode));
b3b94faa DT	193	return -EIO;
	194	}
	195	}
	196	}
	197
	198	/**
	199	* jhead_scan - make sure we've found the head of the log
	200	* @jd: the journal
	201	* @head: this is filled in with the log descriptor of the head
	202	*
	203	* At this point, seg and lh should be either the head of the log or just
	204	* before. Scan forward until we find the head.
	205	*
	206	* Returns: errno
	207	*/
	208
55167622	209	static int jhead_scan(struct gfs2_jdesc jd, struct gfs2_log_header_host head)
b3b94faa DT	210	{
b3b94faa DT	211	unsigned int blk = head->lh_blkno;
55167622	212	struct gfs2_log_header_host lh;
b3b94faa DT	213	int error;
	214
	215	for (;;) {
	216	if (++blk == jd->jd_blocks)
	217	blk = 0;
	218
	219	error = get_log_header(jd, blk, &lh);
	220	if (error < 0)
	221	return error;
	222	if (error == 1)
	223	continue;
	224
	225	if (lh.lh_sequence == head->lh_sequence) {
feaa7bba	226	gfs2_consist_inode(GFS2_I(jd->jd_inode));
b3b94faa DT	227	return -EIO;
	228	}
	229	if (lh.lh_sequence < head->lh_sequence)
	230	break;
	231
	232	*head = lh;
	233	}
	234
	235	return 0;
	236	}
	237
	238	/**
	239	* gfs2_find_jhead - find the head of a log
	240	* @jd: the journal
	241	* @head: the log descriptor for the head of the log is returned here
	242	*
	243	* Do a binary search of a journal and find the valid log entry with the
	244	* highest sequence number. (i.e. the log head)
	245	*
	246	* Returns: errno
	247	*/
	248
55167622	249	int gfs2_find_jhead(struct gfs2_jdesc jd, struct gfs2_log_header_host head)
b3b94faa	250	{
55167622	251	struct gfs2_log_header_host lh_1, lh_m;
cd915493	252	u32 blk_1, blk_2, blk_m;
b3b94faa DT	253	int error;
	254
	255	blk_1 = 0;
	256	blk_2 = jd->jd_blocks - 1;
	257
	258	for (;;) {
	259	blk_m = (blk_1 + blk_2) / 2;
	260
	261	error = find_good_lh(jd, &blk_1, &lh_1);
	262	if (error)
	263	return error;
	264
	265	error = find_good_lh(jd, &blk_m, &lh_m);
	266	if (error)
	267	return error;
	268
	269	if (blk_1 == blk_m \|\| blk_m == blk_2)
	270	break;
	271
	272	if (lh_1.lh_sequence <= lh_m.lh_sequence)
	273	blk_1 = blk_m;
	274	else
	275	blk_2 = blk_m;
	276	}
	277
	278	error = jhead_scan(jd, &lh_1);
	279	if (error)
	280	return error;
	281
	282	*head = lh_1;
	283
	284	return error;
	285	}
	286
	287	/**
	288	* foreach_descriptor - go through the active part of the log
	289	* @jd: the journal
	290	* @start: the first log header in the active region
	291	* @end: the last log header (don't process the contents of this entry))
	292	*
	293	* Call a given function once for every log descriptor in the active
	294	* portion of the log.
	295	*
	296	* Returns: errno
	297	*/
	298
	299	static int foreach_descriptor(struct gfs2_jdesc *jd, unsigned int start,
	300	unsigned int end, int pass)
	301	{
feaa7bba	302	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
b3b94faa DT	303	struct buffer_head *bh;
	304	struct gfs2_log_descriptor *ld;
	305	int error = 0;
	306	u32 length;
	307	__be64 *ptr;
	308	unsigned int offset = sizeof(struct gfs2_log_descriptor);
a67cdbd4 SW	309	offset += sizeof(__be64) - 1;
a67cdbd4 SW	310	offset &= ~(sizeof(__be64) - 1);
b3b94faa DT	311
	312	while (start != end) {
	313	error = gfs2_replay_read_block(jd, start, &bh);
	314	if (error)
	315	return error;
	316	if (gfs2_meta_check(sdp, bh)) {
	317	brelse(bh);
	318	return -EIO;
	319	}
	320	ld = (struct gfs2_log_descriptor *)bh->b_data;
	321	length = be32_to_cpu(ld->ld_length);
	322
e3167ded	323	if (be32_to_cpu(ld->ld_header.mh_type) == GFS2_METATYPE_LH) {
55167622	324	struct gfs2_log_header_host lh;
b3b94faa DT	325	error = get_log_header(jd, start, &lh);
	326	if (!error) {
	327	gfs2_replay_incr_blk(sdp, &start);
88721877	328	brelse(bh);
b3b94faa DT	329	continue;
	330	}
	331	if (error == 1) {
feaa7bba	332	gfs2_consist_inode(GFS2_I(jd->jd_inode));
b3b94faa DT	333	error = -EIO;
	334	}
	335	brelse(bh);
	336	return error;
	337	} else if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_LD)) {
	338	brelse(bh);
	339	return -EIO;
	340	}
	341	ptr = (__be64 *)(bh->b_data + offset);
	342	error = lops_scan_elements(jd, start, ld, ptr, pass);
	343	if (error) {
	344	brelse(bh);
	345	return error;
	346	}
	347
	348	while (length--)
	349	gfs2_replay_incr_blk(sdp, &start);
	350
	351	brelse(bh);
	352	}
	353
	354	return 0;
	355	}
	356
	357	/**
	358	* clean_journal - mark a dirty journal as being clean
	359	* @sdp: the filesystem
	360	* @jd: the journal
	361	* @gl: the journal's glock
	362	* @head: the head journal to start from
	363	*
	364	* Returns: errno
	365	*/
	366
55167622	367	static int clean_journal(struct gfs2_jdesc jd, struct gfs2_log_header_host head)
b3b94faa	368	{
feaa7bba SW	369	struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
feaa7bba SW	370	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
b3b94faa	371	unsigned int lblock;
b3b94faa	372	struct gfs2_log_header *lh;
cd915493	373	u32 hash;
b3b94faa DT	374	struct buffer_head *bh;
b3b94faa DT	375	int error;
23591256	376	struct buffer_head bh_map = { .b_state = 0, .b_blocknr = 0 };
fd88de56	377
b3b94faa DT	378	lblock = head->lh_blkno;
b3b94faa DT	379	gfs2_replay_incr_blk(sdp, &lblock);
23591256 SW	380	bh_map.b_size = 1 << ip->i_inode.i_blkbits;
23591256 SW	381	error = gfs2_block_map(&ip->i_inode, lblock, 0, &bh_map);
b3b94faa DT	382	if (error)
b3b94faa DT	383	return error;
7a6bbacb	384	if (!bh_map.b_blocknr) {
b3b94faa DT	385	gfs2_consist_inode(ip);
	386	return -EIO;
	387	}
	388
7a6bbacb	389	bh = sb_getblk(sdp->sd_vfs, bh_map.b_blocknr);
b3b94faa DT	390	lock_buffer(bh);
	391	memset(bh->b_data, 0, bh->b_size);
	392	set_buffer_uptodate(bh);
	393	clear_buffer_dirty(bh);
	394	unlock_buffer(bh);
	395
	396	lh = (struct gfs2_log_header *)bh->b_data;
	397	memset(lh, 0, sizeof(struct gfs2_log_header));
	398	lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
88721877	399	lh->lh_header.mh_type = cpu_to_be32(GFS2_METATYPE_LH);
e3167ded	400	lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH);
b3b94faa DT	401	lh->lh_sequence = cpu_to_be64(head->lh_sequence + 1);
	402	lh->lh_flags = cpu_to_be32(GFS2_LOG_HEAD_UNMOUNT);
	403	lh->lh_blkno = cpu_to_be32(lblock);
	404	hash = gfs2_disk_hash((const char *)lh, sizeof(struct gfs2_log_header));
	405	lh->lh_hash = cpu_to_be32(hash);
	406
	407	set_buffer_dirty(bh);
	408	if (sync_dirty_buffer(bh))
	409	gfs2_io_error_bh(sdp, bh);
	410	brelse(bh);
	411
	412	return error;
	413	}
	414
	415	/**
	416	* gfs2_recover_journal - recovery a given journal
	417	* @jd: the struct gfs2_jdesc describing the journal
b3b94faa DT	418	*
	419	* Acquire the journal's lock, check to see if the journal is clean, and
	420	* do recovery if necessary.
	421	*
	422	* Returns: errno
	423	*/
	424
c63e31c2	425	int gfs2_recover_journal(struct gfs2_jdesc *jd)
b3b94faa	426	{
feaa7bba SW	427	struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
feaa7bba SW	428	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
55167622	429	struct gfs2_log_header_host head;
b3b94faa DT	430	struct gfs2_holder j_gh, ji_gh, t_gh;
	431	unsigned long t;
	432	int ro = 0;
	433	unsigned int pass;
	434	int error;
	435
5965b1f4 SW	436	if (jd->jd_jid != sdp->sd_lockstruct.ls_jid) {
	437	fs_info(sdp, "jid=%u: Trying to acquire journal lock...\n",
	438	jd->jd_jid);
b3b94faa	439
5965b1f4	440	/* Aquire the journal lock so we can do recovery */
b3b94faa	441
5965b1f4 SW	442	error = gfs2_glock_nq_num(sdp, jd->jd_jid, &gfs2_journal_glops,
	443	LM_ST_EXCLUSIVE,
	444	LM_FLAG_NOEXP \| LM_FLAG_TRY \| GL_NOCACHE,
	445	&j_gh);
	446	switch (error) {
	447	case 0:
	448	break;
907b9bce	449
5965b1f4 SW	450	case GLR_TRYFAILED:
	451	fs_info(sdp, "jid=%u: Busy\n", jd->jd_jid);
	452	error = 0;
907b9bce	453
5965b1f4 SW	454	default:
	455	goto fail;
	456	};
b3b94faa	457
5965b1f4 SW	458	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
	459	LM_FLAG_NOEXP, &ji_gh);
	460	if (error)
	461	goto fail_gunlock_j;
	462	} else {
	463	fs_info(sdp, "jid=%u, already locked for use\n", jd->jd_jid);
	464	}
b3b94faa DT	465
	466	fs_info(sdp, "jid=%u: Looking at journal...\n", jd->jd_jid);
	467
	468	error = gfs2_jdesc_check(jd);
	469	if (error)
	470	goto fail_gunlock_ji;
	471
	472	error = gfs2_find_jhead(jd, &head);
	473	if (error)
	474	goto fail_gunlock_ji;
	475
	476	if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
	477	fs_info(sdp, "jid=%u: Acquiring the transaction lock...\n",
	478	jd->jd_jid);
	479
	480	t = jiffies;
	481
	482	/* Acquire a shared hold on the transaction lock */
	483
59a1cc6b	484	error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_SHARED,
5965b1f4	485	LM_FLAG_NOEXP \| LM_FLAG_PRIORITY \|
59a1cc6b	486	GL_NOCANCEL \| GL_NOCACHE, &t_gh);
b3b94faa DT	487	if (error)
	488	goto fail_gunlock_ji;
	489
	490	if (test_bit(SDF_JOURNAL_CHECKED, &sdp->sd_flags)) {
	491	if (!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags))
	492	ro = 1;
	493	} else {
	494	if (sdp->sd_vfs->s_flags & MS_RDONLY)
	495	ro = 1;
	496	}
	497
	498	if (ro) {
	499	fs_warn(sdp, "jid=%u: Can't replay: read-only FS\n",
	500	jd->jd_jid);
	501	error = -EROFS;
	502	goto fail_gunlock_tr;
	503	}
	504
	505	fs_info(sdp, "jid=%u: Replaying journal...\n", jd->jd_jid);
	506
	507	for (pass = 0; pass < 2; pass++) {
	508	lops_before_scan(jd, &head, pass);
	509	error = foreach_descriptor(jd, head.lh_tail,
	510	head.lh_blkno, pass);
	511	lops_after_scan(jd, error, pass);
	512	if (error)
	513	goto fail_gunlock_tr;
	514	}
	515
	516	error = clean_journal(jd, &head);
	517	if (error)
	518	goto fail_gunlock_tr;
	519
	520	gfs2_glock_dq_uninit(&t_gh);
5c676f6d	521	t = DIV_ROUND_UP(jiffies - t, HZ);
b3b94faa DT	522	fs_info(sdp, "jid=%u: Journal replayed in %lus\n",
	523	jd->jd_jid, t);
	524	}
	525
5965b1f4 SW	526	if (jd->jd_jid != sdp->sd_lockstruct.ls_jid)
5965b1f4 SW	527	gfs2_glock_dq_uninit(&ji_gh);
b3b94faa DT	528
	529	gfs2_lm_recovery_done(sdp, jd->jd_jid, LM_RD_SUCCESS);
	530
5965b1f4 SW	531	if (jd->jd_jid != sdp->sd_lockstruct.ls_jid)
5965b1f4 SW	532	gfs2_glock_dq_uninit(&j_gh);
b3b94faa DT	533
b3b94faa DT	534	fs_info(sdp, "jid=%u: Done\n", jd->jd_jid);
b3b94faa DT	535	return 0;
b3b94faa DT	536
5965b1f4	537	fail_gunlock_tr:
b3b94faa	538	gfs2_glock_dq_uninit(&t_gh);
5965b1f4 SW	539	fail_gunlock_ji:
	540	if (jd->jd_jid != sdp->sd_lockstruct.ls_jid) {
	541	gfs2_glock_dq_uninit(&ji_gh);
	542	fail_gunlock_j:
	543	gfs2_glock_dq_uninit(&j_gh);
	544	}
b3b94faa DT	545
	546	fs_info(sdp, "jid=%u: %s\n", jd->jd_jid, (error) ? "Failed" : "Done");
	547
5965b1f4	548	fail:
b3b94faa	549	gfs2_lm_recovery_done(sdp, jd->jd_jid, LM_RD_GAVEUP);
b3b94faa DT	550	return error;
	551	}
	552
	553	/**
	554	* gfs2_check_journals - Recover any dirty journals
	555	* @sdp: the filesystem
	556	*
	557	*/
	558
	559	void gfs2_check_journals(struct gfs2_sbd *sdp)
	560	{
	561	struct gfs2_jdesc *jd;
	562
	563	for (;;) {
	564	jd = gfs2_jdesc_find_dirty(sdp);
	565	if (!jd)
	566	break;
	567
	568	if (jd != sdp->sd_jdesc)
c63e31c2	569	gfs2_recover_journal(jd);
b3b94faa DT	570	}
	571	}
	572