linux/fs/gfs2/recovery.c
Abhi Das 5e86d9d122 gfs2: time journal recovery steps accurately
This patch spits out the time taken by the various steps in the
journal recover process. Previously, the journal recovery time
didn't account for finding the journal head in the log which takes
up a significant portion of time.

Signed-off-by: Abhi Das <adas@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2018-03-29 10:41:27 -07:00

572 lines
13 KiB
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/module.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/crc32c.h>
#include <linux/ktime.h>
#include "gfs2.h"
#include "incore.h"
#include "bmap.h"
#include "glock.h"
#include "glops.h"
#include "log.h"
#include "lops.h"
#include "meta_io.h"
#include "recovery.h"
#include "super.h"
#include "util.h"
#include "dir.h"
struct workqueue_struct *gfs_recovery_wq;
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_jdesc *jd, u64 blkno, unsigned int where)
{
struct list_head *head = &jd->jd_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_NOFS);
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_jdesc *jd, u64 blkno, unsigned int where)
{
struct gfs2_revoke_replay *rr;
int wrap, a, b, revoke;
int found = 0;
list_for_each_entry(rr, &jd->jd_revoke_list, rr_list) {
if (rr->rr_blkno == blkno) {
found = 1;
break;
}
}
if (!found)
return 0;
wrap = (rr->rr_where < jd->jd_replay_tail);
a = (jd->jd_replay_tail < where);
b = (where < rr->rr_where);
revoke = (wrap) ? (a || b) : (a && b);
return revoke;
}
void gfs2_revoke_clean(struct gfs2_jdesc *jd)
{
struct list_head *head = &jd->jd_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 gfs2_log_header *lh;
struct buffer_head *bh;
u32 hash, crc;
int error;
error = gfs2_replay_read_block(jd, blk, &bh);
if (error)
return error;
lh = (void *)bh->b_data;
hash = crc32(~0, lh, LH_V1_SIZE - 4);
hash = ~crc32_le_shift(hash, 4); /* assume lh_hash is zero */
crc = crc32c(~0, (void *)lh + LH_V1_SIZE + 4,
bh->b_size - LH_V1_SIZE - 4);
error = lh->lh_header.mh_magic != cpu_to_be32(GFS2_MAGIC) ||
lh->lh_header.mh_type != cpu_to_be32(GFS2_METATYPE_LH) ||
be32_to_cpu(lh->lh_blkno) != blk ||
be32_to_cpu(lh->lh_hash) != hash ||
(lh->lh_crc != 0 && be32_to_cpu(lh->lh_crc) != crc);
brelse(bh);
if (!error) {
head->lh_sequence = be64_to_cpu(lh->lh_sequence);
head->lh_flags = be32_to_cpu(lh->lh_flags);
head->lh_tail = be32_to_cpu(lh->lh_tail);
head->lh_blkno = be32_to_cpu(lh->lh_blkno);
}
return error;
}
/**
* 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(jd, &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(jd, &start);
brelse(bh);
}
return 0;
}
/**
* clean_journal - mark a dirty journal as being clean
* @jd: the journal
* @head: the head journal to start from
*
* Returns: errno
*/
static void clean_journal(struct gfs2_jdesc *jd,
struct gfs2_log_header_host *head)
{
struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
sdp->sd_log_flush_head = head->lh_blkno;
gfs2_replay_incr_blk(jd, &sdp->sd_log_flush_head);
gfs2_write_log_header(sdp, jd, head->lh_sequence + 1, 0,
GFS2_LOG_HEAD_UNMOUNT | GFS2_LOG_HEAD_RECOVERY,
REQ_PREFLUSH | REQ_FUA | REQ_META | REQ_SYNC);
}
static void gfs2_recovery_done(struct gfs2_sbd *sdp, unsigned int jid,
unsigned int message)
{
char env_jid[20];
char env_status[20];
char *envp[] = { env_jid, env_status, NULL };
struct lm_lockstruct *ls = &sdp->sd_lockstruct;
ls->ls_recover_jid_done = jid;
ls->ls_recover_jid_status = message;
sprintf(env_jid, "JID=%u", jid);
sprintf(env_status, "RECOVERY=%s",
message == LM_RD_SUCCESS ? "Done" : "Failed");
kobject_uevent_env(&sdp->sd_kobj, KOBJ_CHANGE, envp);
if (sdp->sd_lockstruct.ls_ops->lm_recovery_result)
sdp->sd_lockstruct.ls_ops->lm_recovery_result(sdp, jid, message);
}
void gfs2_recover_func(struct work_struct *work)
{
struct gfs2_jdesc *jd = container_of(work, struct gfs2_jdesc, jd_work);
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, thaw_gh;
ktime_t t_start, t_jlck, t_jhd, t_tlck, t_rep;
int ro = 0;
unsigned int pass;
int error;
int jlocked = 0;
t_start = ktime_get();
if (sdp->sd_args.ar_spectator ||
(jd->jd_jid != sdp->sd_lockstruct.ls_jid)) {
fs_info(sdp, "jid=%u: Trying to acquire journal lock...\n",
jd->jd_jid);
jlocked = 1;
/* Acquire 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 | GL_NOCACHE, &ji_gh);
if (error)
goto fail_gunlock_j;
} else {
fs_info(sdp, "jid=%u, already locked for use\n", jd->jd_jid);
}
t_jlck = ktime_get();
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;
t_jhd = ktime_get();
if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
fs_info(sdp, "jid=%u: Acquiring the transaction lock...\n",
jd->jd_jid);
/* Acquire a shared hold on the freeze lock */
error = gfs2_glock_nq_init(sdp->sd_freeze_gl, LM_ST_SHARED,
LM_FLAG_NOEXP | LM_FLAG_PRIORITY,
&thaw_gh);
if (error)
goto fail_gunlock_ji;
if (test_bit(SDF_RORECOVERY, &sdp->sd_flags)) {
ro = 1;
} else if (test_bit(SDF_JOURNAL_CHECKED, &sdp->sd_flags)) {
if (!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags))
ro = 1;
} else {
if (sb_rdonly(sdp->sd_vfs)) {
/* check if device itself is read-only */
ro = bdev_read_only(sdp->sd_vfs->s_bdev);
if (!ro) {
fs_info(sdp, "recovery required on "
"read-only filesystem.\n");
fs_info(sdp, "write access will be "
"enabled during recovery.\n");
}
}
}
if (ro) {
fs_warn(sdp, "jid=%u: Can't replay: read-only block "
"device\n", jd->jd_jid);
error = -EROFS;
goto fail_gunlock_thaw;
}
t_tlck = ktime_get();
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_thaw;
}
clean_journal(jd, &head);
gfs2_glock_dq_uninit(&thaw_gh);
t_rep = ktime_get();
fs_info(sdp, "jid=%u: Journal replayed in %lldms [jlck:%lldms, "
"jhead:%lldms, tlck:%lldms, replay:%lldms]\n",
jd->jd_jid, ktime_ms_delta(t_rep, t_start),
ktime_ms_delta(t_jlck, t_start),
ktime_ms_delta(t_jhd, t_jlck),
ktime_ms_delta(t_tlck, t_jhd),
ktime_ms_delta(t_rep, t_tlck));
}
gfs2_recovery_done(sdp, jd->jd_jid, LM_RD_SUCCESS);
if (jlocked) {
gfs2_glock_dq_uninit(&ji_gh);
gfs2_glock_dq_uninit(&j_gh);
}
fs_info(sdp, "jid=%u: Done\n", jd->jd_jid);
goto done;
fail_gunlock_thaw:
gfs2_glock_dq_uninit(&thaw_gh);
fail_gunlock_ji:
if (jlocked) {
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:
jd->jd_recover_error = error;
gfs2_recovery_done(sdp, jd->jd_jid, LM_RD_GAVEUP);
done:
clear_bit(JDF_RECOVERY, &jd->jd_flags);
smp_mb__after_atomic();
wake_up_bit(&jd->jd_flags, JDF_RECOVERY);
}
int gfs2_recover_journal(struct gfs2_jdesc *jd, bool wait)
{
int rv;
if (test_and_set_bit(JDF_RECOVERY, &jd->jd_flags))
return -EBUSY;
/* we have JDF_RECOVERY, queue should always succeed */
rv = queue_work(gfs_recovery_wq, &jd->jd_work);
BUG_ON(!rv);
if (wait)
wait_on_bit(&jd->jd_flags, JDF_RECOVERY,
TASK_UNINTERRUPTIBLE);
return wait ? jd->jd_recover_error : 0;
}