[GitHub/mt8127/android_kernel_alcatel_ttab.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 = jd->jd_inode->i_gl;
	int new = 0;
	uint64_t dblock;
	uint32_t extlen;
	int error;

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