[mirror_ubuntu-artful-kernel.git] / fs / gfs2 / recovery.c

/*
 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
 * Copyright (C) 2004-2005 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 v.2.
 */

#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <asm/semaphore.h>

#include "gfs2.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"

int gfs2_replay_read_block(struct gfs2_jdesc *jd, unsigned int blk,
			   struct buffer_head **bh)
{
	struct gfs2_glock *gl = get_v2ip(jd->jd_inode)->i_gl;
	int new = 0;
	uint64_t dblock;
	uint32_t extlen;
	int error;

	error = gfs2_block_map(get_v2ip(jd->jd_inode), blk, &new, &dblock,
			       &extlen);
	if (error)
		return error;
	if (!dblock) {
		gfs2_consist_inode(get_v2ip(jd->jd_inode));
		return -EIO;
	}

	gfs2_meta_ra(gl, dblock, extlen);
	error = gfs2_meta_read(gl, dblock, DIO_START | DIO_WAIT, bh);

	return error;
}

int gfs2_revoke_add(struct gfs2_sbd *sdp, uint64_t 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, uint64_t 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 *head)
{
	struct buffer_head *bh;
	struct gfs2_log_header lh;
	uint32_t hash;
	int error;

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

	memcpy(&lh, bh->b_data, sizeof(struct gfs2_log_header));
	lh.lh_hash = 0;
	hash = gfs2_disk_hash((char *)&lh, sizeof(struct gfs2_log_header));
	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 *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(get_v2ip(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 *head)
{
	unsigned int blk = head->lh_blkno;
	struct gfs2_log_header 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(get_v2ip(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 *head)
{
	struct gfs2_log_header lh_1, lh_m;
	uint32_t 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 = get_v2ip(jd->jd_inode)->i_sbd;
	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 (be16_to_cpu(ld->ld_header.mh_type) == GFS2_METATYPE_LH) {
			struct gfs2_log_header lh;
			error = get_log_header(jd, start, &lh);
			if (!error) {
				gfs2_replay_incr_blk(sdp, &start);
				continue;
			}
			if (error == 1) {
				gfs2_consist_inode(get_v2ip(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 *head)
{
	struct gfs2_inode *ip = get_v2ip(jd->jd_inode);
	struct gfs2_sbd *sdp = ip->i_sbd;
	unsigned int lblock;
	int new = 0;
	uint64_t dblock;
	struct gfs2_log_header *lh;
	uint32_t hash;
	struct buffer_head *bh;
	int error;
	
	lblock = head->lh_blkno;
	gfs2_replay_incr_blk(sdp, &lblock);
	error = gfs2_block_map(ip, lblock, &new, &dblock, NULL);
	if (error)
		return error;
	if (!dblock) {
		gfs2_consist_inode(ip);
		return -EIO;
	}

	bh = sb_getblk(sdp->sd_vfs, dblock);
	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_be16(GFS2_METATYPE_LH);
	lh->lh_header.mh_format = cpu_to_be16(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
 * @wait: Don't return until the journal is clean (or an error is encountered)
 *
 * 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, int wait)
{
	struct gfs2_sbd *sdp = get_v2ip(jd->jd_inode)->i_sbd;
	struct gfs2_log_header head;
	struct gfs2_holder j_gh, ji_gh, t_gh;
	unsigned long t;
	int ro = 0;
	unsigned int pass;
	int error;

	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 |
				  ((wait) ? 0 : 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(get_v2ip(jd->jd_inode)->i_gl, LM_ST_SHARED,
				   LM_FLAG_NOEXP, &ji_gh);
	if (error)
		goto fail_gunlock_j;

	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_NEVER_RECURSE |
					   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_RU(jiffies - t, HZ);
		
		fs_info(sdp, "jid=%u: Journal replayed in %lus\n",
			jd->jd_jid, t);
	}

	gfs2_glock_dq_uninit(&ji_gh);

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

	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:
	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, NO_WAIT);
	}
}
Commit	Line	Data
b3b94faa DT	1	/*
	2	* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
	3	* Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved.
	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
	7	* of the GNU General Public License v.2.
	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>
	15	#include <asm/semaphore.h>
	16
	17	#include "gfs2.h"
	18	#include "bmap.h"
	19	#include "glock.h"
	20	#include "glops.h"
	21	#include "lm.h"
	22	#include "lops.h"
	23	#include "meta_io.h"
	24	#include "recovery.h"
	25	#include "super.h"
	26
	27	int gfs2_replay_read_block(struct gfs2_jdesc *jd, unsigned int blk,
	28	struct buffer_head **bh)
	29	{
7359a19c	30	struct gfs2_glock *gl = get_v2ip(jd->jd_inode)->i_gl;
b3b94faa DT	31	int new = 0;
	32	uint64_t dblock;
	33	uint32_t extlen;
	34	int error;
	35
568f4c96 SW	36	error = gfs2_block_map(get_v2ip(jd->jd_inode), blk, &new, &dblock,
568f4c96 SW	37	&extlen);
b3b94faa DT	38	if (error)
	39	return error;
	40	if (!dblock) {
7359a19c	41	gfs2_consist_inode(get_v2ip(jd->jd_inode));
b3b94faa DT	42	return -EIO;
	43	}
	44
	45	gfs2_meta_ra(gl, dblock, extlen);
	46	error = gfs2_meta_read(gl, dblock, DIO_START \| DIO_WAIT, bh);
	47
	48	return error;
	49	}
	50
	51	int gfs2_revoke_add(struct gfs2_sbd *sdp, uint64_t blkno, unsigned int where)
	52	{
	53	struct list_head *head = &sdp->sd_revoke_list;
	54	struct gfs2_revoke_replay *rr;
	55	int found = 0;
	56
	57	list_for_each_entry(rr, head, rr_list) {
	58	if (rr->rr_blkno == blkno) {
	59	found = 1;
	60	break;
	61	}
	62	}
	63
	64	if (found) {
	65	rr->rr_where = where;
	66	return 0;
	67	}
	68
	69	rr = kmalloc(sizeof(struct gfs2_revoke_replay), GFP_KERNEL);
	70	if (!rr)
	71	return -ENOMEM;
	72
	73	rr->rr_blkno = blkno;
	74	rr->rr_where = where;
	75	list_add(&rr->rr_list, head);
	76
	77	return 1;
	78	}
	79
	80	int gfs2_revoke_check(struct gfs2_sbd *sdp, uint64_t blkno, unsigned int where)
	81	{
	82	struct gfs2_revoke_replay *rr;
	83	int wrap, a, b, revoke;
	84	int found = 0;
	85
	86	list_for_each_entry(rr, &sdp->sd_revoke_list, rr_list) {
	87	if (rr->rr_blkno == blkno) {
	88	found = 1;
	89	break;
	90	}
	91	}
	92
	93	if (!found)
	94	return 0;
	95
	96	wrap = (rr->rr_where < sdp->sd_replay_tail);
	97	a = (sdp->sd_replay_tail < where);
	98	b = (where < rr->rr_where);
	99	revoke = (wrap) ? (a \|\| b) : (a && b);
	100
	101	return revoke;
	102	}
	103
	104	void gfs2_revoke_clean(struct gfs2_sbd *sdp)
	105	{
106	struct list_head *head = &sdp->sd_revoke_list;
107	struct gfs2_revoke_replay *rr;
108
109	while (!list_empty(head)) {
110	rr = list_entry(head->next, struct gfs2_revoke_replay, rr_list);
111	list_del(&rr->rr_list);
112	kfree(rr);
113	}
114	}
115
116	/**
117	* get_log_header - read the log header for a given segment
118	* @jd: the journal
119	* @blk: the block to look at
120	* @lh: the log header to return
121	*
122	* Read the log header for a given segement in a given journal. Do a few
123	* sanity checks on it.
124	*
125	* Returns: 0 on success,
126	* 1 if the header was invalid or incomplete,
127	* errno on error
128	*/
129
130	static int get_log_header(struct gfs2_jdesc *jd, unsigned int blk,
131	struct gfs2_log_header *head)
132	{
133	struct buffer_head *bh;
134	struct gfs2_log_header lh;
135	uint32_t hash;
136	int error;
137
138	error = gfs2_replay_read_block(jd, blk, &bh);
139	if (error)
140	return error;
141
142	memcpy(&lh, bh->b_data, sizeof(struct gfs2_log_header));
143	lh.lh_hash = 0;
144	hash = gfs2_disk_hash((char *)&lh, sizeof(struct gfs2_log_header));
145	gfs2_log_header_in(&lh, bh->b_data);
146
147	brelse(bh);
148
149	if (lh.lh_header.mh_magic != GFS2_MAGIC \|\|
150	lh.lh_header.mh_type != GFS2_METATYPE_LH \|\|
151	lh.lh_blkno != blk \|\|
152	lh.lh_hash != hash)
153	return 1;
154
155	*head = lh;
156
157	return 0;
158	}
159
160	/**
161	* find_good_lh - find a good log header
162	* @jd: the journal
163	* @blk: the segment to start searching from
164	* @lh: the log header to fill in
165	* @forward: if true search forward in the log, else search backward
166	*
167	* Call get_log_header() to get a log header for a segment, but if the
168	* segment is bad, either scan forward or backward until we find a good one.
169	*
170	* Returns: errno
171	*/
172
173	static int find_good_lh(struct gfs2_jdesc jd, unsigned int blk,
174	struct gfs2_log_header *head)
175	{
176	unsigned int orig_blk = *blk;
177	int error;
178
179	for (;;) {
180	error = get_log_header(jd, *blk, head);
181	if (error <= 0)
182	return error;
183
184	if (++*blk == jd->jd_blocks)
185	*blk = 0;
186
187	if (*blk == orig_blk) {
7359a19c	188	gfs2_consist_inode(get_v2ip(jd->jd_inode));
b3b94faa DT	189	return -EIO;
	190	}
	191	}
	192	}
	193
	194	/**
	195	* jhead_scan - make sure we've found the head of the log
	196	* @jd: the journal
	197	* @head: this is filled in with the log descriptor of the head
	198	*
	199	* At this point, seg and lh should be either the head of the log or just
	200	* before. Scan forward until we find the head.
	201	*
	202	* Returns: errno
	203	*/
	204
	205	static int jhead_scan(struct gfs2_jdesc jd, struct gfs2_log_header head)
	206	{
	207	unsigned int blk = head->lh_blkno;
	208	struct gfs2_log_header lh;
	209	int error;
	210
	211	for (;;) {
	212	if (++blk == jd->jd_blocks)
	213	blk = 0;
	214
	215	error = get_log_header(jd, blk, &lh);
	216	if (error < 0)
	217	return error;
	218	if (error == 1)
	219	continue;
	220
	221	if (lh.lh_sequence == head->lh_sequence) {
7359a19c	222	gfs2_consist_inode(get_v2ip(jd->jd_inode));
b3b94faa DT	223	return -EIO;
	224	}
	225	if (lh.lh_sequence < head->lh_sequence)
	226	break;
	227
	228	*head = lh;
	229	}
	230
	231	return 0;
	232	}
	233
	234	/**
	235	* gfs2_find_jhead - find the head of a log
	236	* @jd: the journal
	237	* @head: the log descriptor for the head of the log is returned here
	238	*
	239	* Do a binary search of a journal and find the valid log entry with the
	240	* highest sequence number. (i.e. the log head)
	241	*
	242	* Returns: errno
	243	*/
	244
	245	int gfs2_find_jhead(struct gfs2_jdesc jd, struct gfs2_log_header head)
	246	{
	247	struct gfs2_log_header lh_1, lh_m;
	248	uint32_t blk_1, blk_2, blk_m;
	249	int error;
	250
	251	blk_1 = 0;
	252	blk_2 = jd->jd_blocks - 1;
	253
	254	for (;;) {
	255	blk_m = (blk_1 + blk_2) / 2;
	256
	257	error = find_good_lh(jd, &blk_1, &lh_1);
	258	if (error)
	259	return error;
	260
	261	error = find_good_lh(jd, &blk_m, &lh_m);
	262	if (error)
	263	return error;
	264
	265	if (blk_1 == blk_m \|\| blk_m == blk_2)
	266	break;
	267
	268	if (lh_1.lh_sequence <= lh_m.lh_sequence)
	269	blk_1 = blk_m;
	270	else
	271	blk_2 = blk_m;
	272	}
	273
	274	error = jhead_scan(jd, &lh_1);
	275	if (error)
	276	return error;
	277
	278	*head = lh_1;
	279
	280	return error;
	281	}
	282
	283	/**
	284	* foreach_descriptor - go through the active part of the log
	285	* @jd: the journal
	286	* @start: the first log header in the active region
287	* @end: the last log header (don't process the contents of this entry))
288	*
289	* Call a given function once for every log descriptor in the active
290	* portion of the log.
291	*
292	* Returns: errno
293	*/
294
295	static int foreach_descriptor(struct gfs2_jdesc *jd, unsigned int start,
296	unsigned int end, int pass)
297	{
7359a19c	298	struct gfs2_sbd *sdp = get_v2ip(jd->jd_inode)->i_sbd;
b3b94faa DT	299	struct buffer_head *bh;
	300	struct gfs2_log_descriptor *ld;
	301	int error = 0;
	302	u32 length;
	303	__be64 *ptr;
	304	unsigned int offset = sizeof(struct gfs2_log_descriptor);
	305	offset += (sizeof(__be64)-1);
	306	offset &= ~(sizeof(__be64)-1);
	307
	308	while (start != end) {
	309	error = gfs2_replay_read_block(jd, start, &bh);
	310	if (error)
	311	return error;
	312	if (gfs2_meta_check(sdp, bh)) {
	313	brelse(bh);
	314	return -EIO;
	315	}
	316	ld = (struct gfs2_log_descriptor *)bh->b_data;
	317	length = be32_to_cpu(ld->ld_length);
	318
	319	if (be16_to_cpu(ld->ld_header.mh_type) == GFS2_METATYPE_LH) {
	320	struct gfs2_log_header lh;
	321	error = get_log_header(jd, start, &lh);
	322	if (!error) {
	323	gfs2_replay_incr_blk(sdp, &start);
	324	continue;
	325	}
	326	if (error == 1) {
7359a19c	327	gfs2_consist_inode(get_v2ip(jd->jd_inode));
b3b94faa DT	328	error = -EIO;
	329	}
	330	brelse(bh);
	331	return error;
	332	} else if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_LD)) {
	333	brelse(bh);
	334	return -EIO;
	335	}
	336	ptr = (__be64 *)(bh->b_data + offset);
	337	error = lops_scan_elements(jd, start, ld, ptr, pass);
	338	if (error) {
	339	brelse(bh);
	340	return error;
	341	}
	342
	343	while (length--)
	344	gfs2_replay_incr_blk(sdp, &start);
	345
	346	brelse(bh);
	347	}
	348
	349	return 0;
	350	}
	351
	352	/**
	353	* clean_journal - mark a dirty journal as being clean
	354	* @sdp: the filesystem
	355	* @jd: the journal
	356	* @gl: the journal's glock
	357	* @head: the head journal to start from
	358	*
	359	* Returns: errno
	360	*/
	361
	362	static int clean_journal(struct gfs2_jdesc jd, struct gfs2_log_header head)
	363	{
7359a19c	364	struct gfs2_inode *ip = get_v2ip(jd->jd_inode);
b3b94faa DT	365	struct gfs2_sbd *sdp = ip->i_sbd;
	366	unsigned int lblock;
	367	int new = 0;
	368	uint64_t dblock;
	369	struct gfs2_log_header *lh;
	370	uint32_t hash;
	371	struct buffer_head *bh;
	372	int error;
	373
	374	lblock = head->lh_blkno;
	375	gfs2_replay_incr_blk(sdp, &lblock);
	376	error = gfs2_block_map(ip, lblock, &new, &dblock, NULL);
	377	if (error)
	378	return error;
	379	if (!dblock) {
	380	gfs2_consist_inode(ip);
	381	return -EIO;
	382	}
	383
	384	bh = sb_getblk(sdp->sd_vfs, dblock);
	385	lock_buffer(bh);
	386	memset(bh->b_data, 0, bh->b_size);
	387	set_buffer_uptodate(bh);
	388	clear_buffer_dirty(bh);
	389	unlock_buffer(bh);
	390
	391	lh = (struct gfs2_log_header *)bh->b_data;
	392	memset(lh, 0, sizeof(struct gfs2_log_header));
	393	lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
	394	lh->lh_header.mh_type = cpu_to_be16(GFS2_METATYPE_LH);
	395	lh->lh_header.mh_format = cpu_to_be16(GFS2_FORMAT_LH);
	396	lh->lh_sequence = cpu_to_be64(head->lh_sequence + 1);
	397	lh->lh_flags = cpu_to_be32(GFS2_LOG_HEAD_UNMOUNT);
	398	lh->lh_blkno = cpu_to_be32(lblock);
	399	hash = gfs2_disk_hash((const char *)lh, sizeof(struct gfs2_log_header));
	400	lh->lh_hash = cpu_to_be32(hash);
	401
	402	set_buffer_dirty(bh);
	403	if (sync_dirty_buffer(bh))
	404	gfs2_io_error_bh(sdp, bh);
	405	brelse(bh);
	406
	407	return error;
	408	}
	409
	410	/**
	411	* gfs2_recover_journal - recovery a given journal
	412	* @jd: the struct gfs2_jdesc describing the journal
	413	* @wait: Don't return until the journal is clean (or an error is encountered)
	414	*
	415	* Acquire the journal's lock, check to see if the journal is clean, and
	416	* do recovery if necessary.
	417	*
	418	* Returns: errno
	419	*/
	420
	421	int gfs2_recover_journal(struct gfs2_jdesc *jd, int wait)
	422	{
7359a19c	423	struct gfs2_sbd *sdp = get_v2ip(jd->jd_inode)->i_sbd;
b3b94faa DT	424	struct gfs2_log_header head;
	425	struct gfs2_holder j_gh, ji_gh, t_gh;
	426	unsigned long t;
	427	int ro = 0;
	428	unsigned int pass;
	429	int error;
	430
	431	fs_info(sdp, "jid=%u: Trying to acquire journal lock...\n", jd->jd_jid);
	432
	433	/* Aquire the journal lock so we can do recovery */
	434
	435	error = gfs2_glock_nq_num(sdp,
	436	jd->jd_jid, &gfs2_journal_glops,
	437	LM_ST_EXCLUSIVE,
	438	LM_FLAG_NOEXP \|
	439	((wait) ? 0 : LM_FLAG_TRY) \|
	440	GL_NOCACHE, &j_gh);
	441	switch (error) {
	442	case 0:
	443	break;
	444
	445	case GLR_TRYFAILED:
	446	fs_info(sdp, "jid=%u: Busy\n", jd->jd_jid);
	447	error = 0;
	448
	449	default:
	450	goto fail;
	451	};
	452
7359a19c	453	error = gfs2_glock_nq_init(get_v2ip(jd->jd_inode)->i_gl, LM_ST_SHARED,
b3b94faa DT	454	LM_FLAG_NOEXP, &ji_gh);
	455	if (error)
	456	goto fail_gunlock_j;
	457
	458	fs_info(sdp, "jid=%u: Looking at journal...\n", jd->jd_jid);
	459
	460	error = gfs2_jdesc_check(jd);
	461	if (error)
	462	goto fail_gunlock_ji;
	463
	464	error = gfs2_find_jhead(jd, &head);
	465	if (error)
	466	goto fail_gunlock_ji;
	467
	468	if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
	469	fs_info(sdp, "jid=%u: Acquiring the transaction lock...\n",
	470	jd->jd_jid);
	471
	472	t = jiffies;
	473
	474	/* Acquire a shared hold on the transaction lock */
	475
	476	error = gfs2_glock_nq_init(sdp->sd_trans_gl,
	477	LM_ST_SHARED,
	478	LM_FLAG_NOEXP \|
	479	LM_FLAG_PRIORITY \|
	480	GL_NEVER_RECURSE \|
	481	GL_NOCANCEL \|
	482	GL_NOCACHE,
	483	&t_gh);
	484	if (error)
	485	goto fail_gunlock_ji;
	486
	487	if (test_bit(SDF_JOURNAL_CHECKED, &sdp->sd_flags)) {
	488	if (!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags))
	489	ro = 1;
	490	} else {
	491	if (sdp->sd_vfs->s_flags & MS_RDONLY)
	492	ro = 1;
	493	}
	494
	495	if (ro) {
	496	fs_warn(sdp, "jid=%u: Can't replay: read-only FS\n",
	497	jd->jd_jid);
	498	error = -EROFS;
	499	goto fail_gunlock_tr;
	500	}
	501
	502	fs_info(sdp, "jid=%u: Replaying journal...\n", jd->jd_jid);
	503
	504	for (pass = 0; pass < 2; pass++) {
	505	lops_before_scan(jd, &head, pass);
	506	error = foreach_descriptor(jd, head.lh_tail,
	507	head.lh_blkno, pass);
	508	lops_after_scan(jd, error, pass);
	509	if (error)
	510	goto fail_gunlock_tr;
	511	}
	512
	513	error = clean_journal(jd, &head);
	514	if (error)
	515	goto fail_gunlock_tr;
	516
	517	gfs2_glock_dq_uninit(&t_gh);
518
519	t = DIV_RU(jiffies - t, HZ);
520
521	fs_info(sdp, "jid=%u: Journal replayed in %lus\n",
522	jd->jd_jid, t);
523	}
524
525	gfs2_glock_dq_uninit(&ji_gh);
526
527	gfs2_lm_recovery_done(sdp, jd->jd_jid, LM_RD_SUCCESS);
528
529	gfs2_glock_dq_uninit(&j_gh);
530
531	fs_info(sdp, "jid=%u: Done\n", jd->jd_jid);
532
533	return 0;
534
535	fail_gunlock_tr:
536	gfs2_glock_dq_uninit(&t_gh);
537
538	fail_gunlock_ji:
539	gfs2_glock_dq_uninit(&ji_gh);
540
541	fail_gunlock_j:
542	gfs2_glock_dq_uninit(&j_gh);
543
544	fs_info(sdp, "jid=%u: %s\n", jd->jd_jid, (error) ? "Failed" : "Done");
545
546	fail:
547	gfs2_lm_recovery_done(sdp, jd->jd_jid, LM_RD_GAVEUP);
548
549	return error;
550	}
551
552	/**
553	* gfs2_check_journals - Recover any dirty journals
554	* @sdp: the filesystem
555	*
556	*/
557
558	void gfs2_check_journals(struct gfs2_sbd *sdp)
559	{
560	struct gfs2_jdesc *jd;
561
562	for (;;) {
563	jd = gfs2_jdesc_find_dirty(sdp);
564	if (!jd)
565	break;
566
567	if (jd != sdp->sd_jdesc)
568	gfs2_recover_journal(jd, NO_WAIT);
569	}
570	}
571