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author | Theodore Ts'o <tytso@mit.edu> | 2014-09-04 18:09:22 -0400 |
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committer | Theodore Ts'o <tytso@mit.edu> | 2014-09-04 18:09:22 -0400 |
commit | dc6e8d669cf5cb3ff84707c372c0a2a8a5e80845 (patch) | |
tree | a96b09d5670e5f4a502dc246de2d9526a2bb261a /fs | |
parent | 754cfed6bbcfdea6afb14f2686f7f8d71e94d4e2 (diff) | |
download | op-kernel-dev-dc6e8d669cf5cb3ff84707c372c0a2a8a5e80845.zip op-kernel-dev-dc6e8d669cf5cb3ff84707c372c0a2a8a5e80845.tar.gz |
jbd2: don't call get_bh() before calling __jbd2_journal_remove_checkpoint()
The __jbd2_journal_remove_checkpoint() doesn't require an elevated
b_count; indeed, until the jh structure gets released by the call to
jbd2_journal_put_journal_head(), the bh's b_count is elevated by
virtue of the existence of the jh structure.
Suggested-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/jbd2/checkpoint.c | 19 |
1 files changed, 5 insertions, 14 deletions
diff --git a/fs/jbd2/checkpoint.c b/fs/jbd2/checkpoint.c index 18c7a8d..90d6091 100644 --- a/fs/jbd2/checkpoint.c +++ b/fs/jbd2/checkpoint.c @@ -96,15 +96,8 @@ static int __try_to_free_cp_buf(struct journal_head *jh) if (jh->b_transaction == NULL && !buffer_locked(bh) && !buffer_dirty(bh) && !buffer_write_io_error(bh)) { - /* - * Get our reference so that bh cannot be freed before - * we unlock it - */ - get_bh(bh); JBUFFER_TRACE(jh, "remove from checkpoint list"); ret = __jbd2_journal_remove_checkpoint(jh) + 1; - BUFFER_TRACE(bh, "release"); - __brelse(bh); } return ret; } @@ -216,7 +209,7 @@ int jbd2_log_do_checkpoint(journal_t *journal) struct buffer_head *bh; transaction_t *transaction; tid_t this_tid; - int result, batch_count = 0, done = 0; + int result, batch_count = 0; jbd_debug(1, "Start checkpoint\n"); @@ -291,11 +284,9 @@ restart: if (!buffer_dirty(bh)) { if (unlikely(buffer_write_io_error(bh)) && !result) result = -EIO; - get_bh(bh); BUFFER_TRACE(bh, "remove from checkpoint"); __jbd2_journal_remove_checkpoint(jh); spin_unlock(&journal->j_list_lock); - __brelse(bh); goto retry; } /* @@ -338,12 +329,12 @@ restart2: transaction->t_tid != this_tid) goto out; - while (!done && transaction->t_checkpoint_io_list) { + while (transaction->t_checkpoint_io_list) { jh = transaction->t_checkpoint_io_list; bh = jh2bh(jh); - get_bh(bh); if (buffer_locked(bh)) { spin_unlock(&journal->j_list_lock); + get_bh(bh); wait_on_buffer(bh); /* the journal_head may have gone by now */ BUFFER_TRACE(bh, "brelse"); @@ -359,8 +350,8 @@ restart2: * know that it has been written out and so we can * drop it from the list */ - done = __jbd2_journal_remove_checkpoint(jh); - __brelse(bh); + if (__jbd2_journal_remove_checkpoint(jh)) + break; } out: spin_unlock(&journal->j_list_lock); |