linux-stable/fs/gfs2/recovery.c
Andreas Gruenbacher 834ec3e1ee gfs2: Lock imbalance on error path in gfs2_recover_one
In gfs2_recover_one, fix a sd_log_flush_lock imbalance when a recovery
pass fails.

Fixes: c9ebc4b737 ("gfs2: allow journal replay to hold sd_log_flush_lock")
Cc: stable@vger.kernel.org # v5.7+
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2021-02-05 18:18:57 +01:00

582 lines
15 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
* Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
*/
#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_first_entry(head, struct gfs2_revoke_replay, rr_list);
list_del(&rr->rr_list);
kfree(rr);
}
}
int __get_log_header(struct gfs2_sbd *sdp, const struct gfs2_log_header *lh,
unsigned int blkno, struct gfs2_log_header_host *head)
{
u32 hash, crc;
if (lh->lh_header.mh_magic != cpu_to_be32(GFS2_MAGIC) ||
lh->lh_header.mh_type != cpu_to_be32(GFS2_METATYPE_LH) ||
(blkno && be32_to_cpu(lh->lh_blkno) != blkno))
return 1;
hash = crc32(~0, lh, LH_V1_SIZE - 4);
hash = ~crc32_le_shift(hash, 4); /* assume lh_hash is zero */
if (be32_to_cpu(lh->lh_hash) != hash)
return 1;
crc = crc32c(~0, (void *)lh + LH_V1_SIZE + 4,
sdp->sd_sb.sb_bsize - LH_V1_SIZE - 4);
if ((lh->lh_crc != 0 && be32_to_cpu(lh->lh_crc) != crc))
return 1;
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);
head->lh_local_total = be64_to_cpu(lh->lh_local_total);
head->lh_local_free = be64_to_cpu(lh->lh_local_free);
head->lh_local_dinodes = be64_to_cpu(lh->lh_local_dinodes);
return 0;
}
/**
* 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_sbd *sdp = GFS2_SB(jd->jd_inode);
struct buffer_head *bh;
int error;
error = gfs2_replay_read_block(jd, blk, &bh);
if (error)
return error;
error = __get_log_header(sdp, (const struct gfs2_log_header *)bh->b_data,
blk, head);
brelse(bh);
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, u32 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);
u32 lblock = head->lh_blkno;
gfs2_replay_incr_blk(jd, &lblock);
gfs2_write_log_header(sdp, jd, head->lh_sequence + 1, 0, lblock,
GFS2_LOG_HEAD_UNMOUNT | GFS2_LOG_HEAD_RECOVERY,
REQ_PREFLUSH | REQ_FUA | REQ_META | REQ_SYNC);
if (jd->jd_jid == sdp->sd_lockstruct.ls_jid) {
sdp->sd_log_flush_head = lblock;
gfs2_log_incr_head(sdp);
}
}
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);
}
/**
* update_statfs_inode - Update the master statfs inode or zero out the local
* statfs inode for a given journal.
* @jd: The journal
* @head: If NULL, @inode is the local statfs inode and we need to zero it out.
* Otherwise, it @head contains the statfs change info that needs to be
* synced to the master statfs inode (pointed to by @inode).
* @inode: statfs inode to update.
*/
static int update_statfs_inode(struct gfs2_jdesc *jd,
struct gfs2_log_header_host *head,
struct inode *inode)
{
struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
struct gfs2_inode *ip;
struct buffer_head *bh;
struct gfs2_statfs_change_host sc;
int error = 0;
BUG_ON(!inode);
ip = GFS2_I(inode);
error = gfs2_meta_inode_buffer(ip, &bh);
if (error)
goto out;
spin_lock(&sdp->sd_statfs_spin);
if (head) { /* Update the master statfs inode */
gfs2_statfs_change_in(&sc, bh->b_data + sizeof(struct gfs2_dinode));
sc.sc_total += head->lh_local_total;
sc.sc_free += head->lh_local_free;
sc.sc_dinodes += head->lh_local_dinodes;
gfs2_statfs_change_out(&sc, bh->b_data + sizeof(struct gfs2_dinode));
fs_info(sdp, "jid=%u: Updated master statfs Total:%lld, "
"Free:%lld, Dinodes:%lld after change "
"[%+lld,%+lld,%+lld]\n", jd->jd_jid, sc.sc_total,
sc.sc_free, sc.sc_dinodes, head->lh_local_total,
head->lh_local_free, head->lh_local_dinodes);
} else { /* Zero out the local statfs inode */
memset(bh->b_data + sizeof(struct gfs2_dinode), 0,
sizeof(struct gfs2_statfs_change));
/* If it's our own journal, reset any in-memory changes too */
if (jd->jd_jid == sdp->sd_lockstruct.ls_jid) {
memset(&sdp->sd_statfs_local, 0,
sizeof(struct gfs2_statfs_change_host));
}
}
spin_unlock(&sdp->sd_statfs_spin);
mark_buffer_dirty(bh);
brelse(bh);
gfs2_inode_metasync(ip->i_gl);
out:
return error;
}
/**
* recover_local_statfs - Update the master and local statfs changes for this
* journal.
*
* Previously, statfs updates would be read in from the local statfs inode and
* synced to the master statfs inode during recovery.
*
* We now use the statfs updates in the journal head to update the master statfs
* inode instead of reading in from the local statfs inode. To preserve backward
* compatibility with kernels that can't do this, we still need to keep the
* local statfs inode up to date by writing changes to it. At some point in the
* future, we can do away with the local statfs inodes altogether and keep the
* statfs changes solely in the journal.
*
* @jd: the journal
* @head: the journal head
*
* Returns: errno
*/
static void recover_local_statfs(struct gfs2_jdesc *jd,
struct gfs2_log_header_host *head)
{
int error;
struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
if (!head->lh_local_total && !head->lh_local_free
&& !head->lh_local_dinodes) /* No change */
goto zero_local;
/* First update the master statfs inode with the changes we
* found in the journal. */
error = update_statfs_inode(jd, head, sdp->sd_statfs_inode);
if (error)
goto out;
zero_local:
/* Zero out the local statfs inode so any changes in there
* are not re-recovered. */
error = update_statfs_inode(jd, NULL,
find_local_statfs_inode(sdp, jd->jd_jid));
out:
return;
}
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 = 0;
int jlocked = 0;
if (gfs2_withdrawn(sdp)) {
fs_err(sdp, "jid=%u: Recovery not attempted due to withdraw.\n",
jd->jd_jid);
goto fail;
}
t_start = ktime_get();
if (sdp->sd_args.ar_spectator)
goto fail;
if (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, true);
if (error)
goto fail_gunlock_ji;
t_jhd = ktime_get();
fs_info(sdp, "jid=%u: Journal head lookup took %lldms\n", jd->jd_jid,
ktime_ms_delta(t_jhd, t_jlck));
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_freeze_lock(sdp, &thaw_gh, LM_FLAG_PRIORITY);
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...0x%x to 0x%x\n",
jd->jd_jid, head.lh_tail, head.lh_blkno);
/* We take the sd_log_flush_lock here primarily to prevent log
* flushes and simultaneous journal replays from stomping on
* each other wrt jd_log_bio. */
down_read(&sdp->sd_log_flush_lock);
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) {
up_read(&sdp->sd_log_flush_lock);
goto fail_gunlock_thaw;
}
}
recover_local_statfs(jd, &head);
clean_journal(jd, &head);
up_read(&sdp->sd_log_flush_lock);
gfs2_freeze_unlock(&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_freeze_unlock(&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;
}