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| author | Yongqiang Yang <xiaoqiangnk@gmail.com> | 2011-11-19 17:34:29 +0800 |
|---|---|---|
| committer | Jan Kara <jack@suse.cz> | 2011-11-22 01:20:53 +0100 |
| commit | 8c111b3f56332a216b18cd57950bdf04ac8f2a98 (patch) | |
| tree | 9295744be006082391c9bfeed2cabf43b29cc4ea /fs/jbd | |
| parent | 63894ab9f63a688f6b0b8cdd01ac0a9f36d507b8 (diff) | |
| download | lwn-8c111b3f56332a216b18cd57950bdf04ac8f2a98.tar.gz lwn-8c111b3f56332a216b18cd57950bdf04ac8f2a98.zip | |
jbd: clear revoked flag on buffers before a new transaction started
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>
Diffstat (limited to 'fs/jbd')
| -rw-r--r-- | fs/jbd/commit.c | 6 | ||||
| -rw-r--r-- | fs/jbd/revoke.c | 34 |
2 files changed, 40 insertions, 0 deletions
diff --git a/fs/jbd/commit.c b/fs/jbd/commit.c index 8799207df058..f2b9a571f4cf 100644 --- a/fs/jbd/commit.c +++ b/fs/jbd/commit.c @@ -392,6 +392,12 @@ 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. */ journal_switch_revoke_table(journal); diff --git a/fs/jbd/revoke.c b/fs/jbd/revoke.c index 305a90763154..25c713e7071c 100644 --- a/fs/jbd/revoke.c +++ b/fs/jbd/revoke.c @@ -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 |