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jbd: clear revoked flag on buffers before a new transaction started

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Currently, we clear revoked flag only when a block is reused.  However,
this can tigger a false journal error.  Consider a situation when a block
is used as a meta block and is deleted(revoked) in ordered mode, then the
block is allocated as a data block to a file.  At this moment, user changes
the file's journal mode from ordered to journaled and truncates the file.
The block will be considered re-revoked by journal because it has revoked
flag still pending from the last transaction and an assertion triggers.

We fix the problem by keeping the revoked status more uptodate - we clear
revoked flag when switching revoke tables to reflect there is no revoked
buffers in current transaction any more.

Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
This commit is contained in:
Yongqiang Yang 2011-11-19 17:34:29 +08:00 committed by Jan Kara
parent 63894ab9f6
commit 8c111b3f56
3 changed files with 41 additions and 0 deletions
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6
fs/jbd/commit.c
View File

@ -391,6 +391,12 @@ void journal_commit_transaction(journal_t *journal)
jbd_debug (3, "JBD: commit phase 1\n");
/*
* Clear revoked flag to reflect there is no revoked buffers
* in the next transaction which is going to be started.
*/
journal_clear_buffer_revoked_flags(journal);
/*
* Switch to a new revoke table.
*/

34
fs/jbd/revoke.c
View File

@ -47,6 +47,10 @@
* overwriting the new data. We don't even need to clear the revoke
* bit here.
*
* We cache revoke status of a buffer in the current transaction in b_states
* bits. As the name says, revokevalid flag indicates that the cached revoke
* status of a buffer is valid and we can rely on the cached status.
*
* Revoke information on buffers is a tri-state value:
*
* RevokeValid clear: no cached revoke status, need to look it up
@ -479,6 +483,36 @@ int journal_cancel_revoke(handle_t *handle, struct journal_head *jh)
return did_revoke;
}
/*
* journal_clear_revoked_flags clears revoked flag of buffers in
* revoke table to reflect there is no revoked buffer in the next
* transaction which is going to be started.
*/
void journal_clear_buffer_revoked_flags(journal_t *journal)
{
struct jbd_revoke_table_s *revoke = journal->j_revoke;
int i = 0;
for (i = 0; i < revoke->hash_size; i++) {
struct list_head *hash_list;
struct list_head *list_entry;
hash_list = &revoke->hash_table[i];
list_for_each(list_entry, hash_list) {
struct jbd_revoke_record_s *record;
struct buffer_head *bh;
record = (struct jbd_revoke_record_s *)list_entry;
bh = __find_get_block(journal->j_fs_dev,
record->blocknr,
journal->j_blocksize);
if (bh) {
clear_buffer_revoked(bh);
__brelse(bh);
}
}
}
}
/* journal_switch_revoke table select j_revoke for next transaction
* we do not want to suspend any processing until all revokes are
* written -bzzz

1
include/linux/jbd.h
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@ -913,6 +913,7 @@ extern int journal_set_revoke(journal_t *, unsigned int, tid_t);
extern int journal_test_revoke(journal_t *, unsigned int, tid_t);
extern void journal_clear_revoke(journal_t *);
extern void journal_switch_revoke_table(journal_t *journal);
extern void journal_clear_buffer_revoked_flags(journal_t *journal);
/*
* The log thread user interface: