iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

bcachefs: Improve diagnostics when journal entries are missing

Browse Source 
There's an outstanding bug with journal entries being missing in journal
replay. This patch adds code to print out where the journal entries were
physically located that were around the entry(ies) being missing, which
should make debugging easier.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This commit is contained in:
Kent Overstreet 2021-01-26 16:04:12 -05:00 committed by Kent Overstreet
parent 522c25f068
commit e4c3f386b6
3 changed files with 96 additions and 28 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
fs/bcachefs/journal.c
View File

@ -1010,13 +1010,19 @@ int bch2_fs_journal_start(struct journal *j, u64 cur_seq,
}
list_for_each_entry(i, journal_entries, list) {
unsigned ptr;
seq = le64_to_cpu(i->j.seq);
BUG_ON(seq >= cur_seq);
if (seq < last_seq)
continue;
journal_seq_pin(j, seq)->devs = i->devs;
p = journal_seq_pin(j, seq);
p->devs.nr = 0;
for (ptr = 0; ptr < i->nr_ptrs; ptr++)
bch2_dev_list_add_dev(&p->devs, i->ptrs[ptr].dev);
}
spin_lock(&j->lock);

112
fs/bcachefs/journal_io.c
View File

@ -45,15 +45,16 @@ struct journal_list {
* be replayed:
*/
static int journal_entry_add(struct bch_fs *c, struct bch_dev *ca,
struct bch_extent_ptr entry_ptr,
struct journal_list *jlist, struct jset *j,
bool bad)
{
struct journal_replay *i, *pos;
struct bch_devs_list devs = { .nr = 0 };
struct journal_replay *i, *pos, *dup = NULL;
struct bch_extent_ptr *ptr;
struct list_head *where;
size_t bytes = vstruct_bytes(j);
u64 last_seq = 0;
int ret;
int ret = JOURNAL_ENTRY_ADD_OK;
list_for_each_entry_reverse(i, jlist->head, list) {
if (!JSET_NO_FLUSH(&i->j)) {
@ -87,28 +88,31 @@ static int journal_entry_add(struct bch_fs *c, struct bch_dev *ca,
where = jlist->head;
add:
i = where->next != jlist->head
dup = where->next != jlist->head
? container_of(where->next, struct journal_replay, list)
: NULL;
if (dup && le64_to_cpu(j->seq) != le64_to_cpu(dup->j.seq))
dup = NULL;
/*
* Duplicate journal entries? If so we want the one that didn't have a
* checksum error:
*/
if (i && le64_to_cpu(j->seq) == le64_to_cpu(i->j.seq)) {
if (i->bad) {
devs = i->devs;
__journal_replay_free(i);
if (dup) {
if (dup->bad) {
/* we'll replace @dup: */
} else if (bad) {
i = dup;
goto found;
} else {
fsck_err_on(bytes != vstruct_bytes(&i->j) ||
memcmp(j, &i->j, bytes), c,
fsck_err_on(bytes != vstruct_bytes(&dup->j) ||
memcmp(j, &dup->j, bytes), c,
"found duplicate but non identical journal entries (seq %llu)",
le64_to_cpu(j->seq));
i = dup;
goto found;
}
}
i = kvpmalloc(offsetof(struct journal_replay, j) + bytes, GFP_KERNEL);
@ -117,17 +121,34 @@ add:
goto out;
}
list_add(&i->list, where);
i->devs = devs;
i->bad = bad;
i->ignore = false;
i->nr_ptrs = 0;
i->bad = bad;
i->ignore = false;
unsafe_memcpy(&i->j, j, bytes, "embedded variable length struct");
if (dup) {
i->nr_ptrs = dup->nr_ptrs;
memcpy(i->ptrs, dup->ptrs, sizeof(dup->ptrs));
__journal_replay_free(dup);
}
list_add(&i->list, where);
found:
if (!bch2_dev_list_has_dev(i->devs, ca->dev_idx))
bch2_dev_list_add_dev(&i->devs, ca->dev_idx);
else
fsck_err_on(1, c, "duplicate journal entries on same device");
ret = JOURNAL_ENTRY_ADD_OK;
for (ptr = i->ptrs; ptr < i->ptrs + i->nr_ptrs; ptr++) {
if (ptr->dev == ca->dev_idx) {
bch_err(c, "duplicate journal entry %llu on same device",
le64_to_cpu(i->j.seq));
goto out;
}
}
if (i->nr_ptrs >= ARRAY_SIZE(i->ptrs)) {
bch_err(c, "found too many copies of journal entry %llu",
le64_to_cpu(i->j.seq));
goto out;
}
i->ptrs[i->nr_ptrs++] = entry_ptr;
out:
fsck_err:
return ret;
@ -653,7 +674,10 @@ reread:
ja->bucket_seq[bucket] = le64_to_cpu(j->seq);
mutex_lock(&jlist->lock);
ret = journal_entry_add(c, ca, jlist, j, ret != 0);
ret = journal_entry_add(c, ca, (struct bch_extent_ptr) {
.dev = ca->dev_idx,
.offset = offset,
}, jlist, j, ret != 0);
mutex_unlock(&jlist->lock);
switch (ret) {
@ -741,6 +765,23 @@ err:
goto out;
}
static void bch2_journal_ptrs_to_text(struct printbuf *out, struct bch_fs *c,
struct journal_replay *j)
{
unsigned i;
for (i = 0; i < j->nr_ptrs; i++) {
struct bch_dev *ca = c->devs[j->ptrs[i].dev];
if (i)
pr_buf(out, " ");
pr_buf(out, "%u:%llu (offset %llu)",
j->ptrs[i].dev,
(u64) j->ptrs[i].offset,
(u64) j->ptrs[i].offset % ca->mi.bucket_size);
}
}
int bch2_journal_read(struct bch_fs *c, struct list_head *list,
u64 *blacklist_seq, u64 *start_seq)
{
@ -838,6 +879,7 @@ int bch2_journal_read(struct bch_fs *c, struct list_head *list,
while (seq < le64_to_cpu(i->j.seq)) {
u64 missing_start, missing_end;
char buf1[200], buf2[200];
while (seq < le64_to_cpu(i->j.seq) &&
bch2_journal_seq_is_blacklisted(c, seq, false))
@ -852,10 +894,23 @@ int bch2_journal_read(struct bch_fs *c, struct list_head *list,
!bch2_journal_seq_is_blacklisted(c, seq, false))
seq++;
if (i->list.prev != list) {
struct printbuf out = PBUF(buf1);
struct journal_replay *p = list_prev_entry(i, list);
bch2_journal_ptrs_to_text(&out, c, p);
pr_buf(&out, " size %llu", vstruct_sectors(&p->j, c->block_bits));
} else
sprintf(buf1, "(none)");
bch2_journal_ptrs_to_text(&PBUF(buf2), c, i);
missing_end = seq - 1;
fsck_err(c, "journal entries %llu-%llu missing! (replaying %llu-%llu)",
fsck_err(c, "journal entries %llu-%llu missing! (replaying %llu-%llu)\n"
" prev at %s\n"
" next at %s",
missing_start, missing_end,
last_seq, *blacklist_seq - 1);
last_seq, *blacklist_seq - 1,
buf1, buf2);
}
seq++;
@ -864,7 +919,11 @@ int bch2_journal_read(struct bch_fs *c, struct list_head *list,
list_for_each_entry(i, list, list) {
struct jset_entry *entry;
struct bkey_i *k, *_n;
struct bch_replicas_padded replicas;
struct bch_replicas_padded replicas = {
.e.data_type = BCH_DATA_journal,
.e.nr_required = 1,
};
unsigned ptr;
char buf[80];
if (i->ignore)
@ -874,13 +933,14 @@ int bch2_journal_read(struct bch_fs *c, struct list_head *list,
if (ret)
goto fsck_err;
for (ptr = 0; ptr < i->nr_ptrs; ptr++)
replicas.e.devs[replicas.e.nr_devs++] = i->ptrs[ptr].dev;
/*
* If we're mounting in degraded mode - if we didn't read all
* the devices - this is wrong:
*/
bch2_devlist_to_replicas(&replicas.e, BCH_DATA_journal, i->devs);
if (!degraded &&
(test_bit(BCH_FS_REBUILD_REPLICAS, &c->flags) ||
fsck_err_on(!bch2_replicas_marked(c, &replicas.e), c,

4
fs/bcachefs/journal_io.h
View File

@ -8,7 +8,9 @@
*/
struct journal_replay {
struct list_head list;
struct bch_devs_list devs;
struct bch_extent_ptr ptrs[BCH_REPLICAS_MAX];
unsigned nr_ptrs;
/* checksum error, but we may want to try using it anyways: */
bool bad;
bool ignore;