diff options
Diffstat (limited to 'fs/jbd2/checkpoint.c')
| -rw-r--r-- | fs/jbd2/checkpoint.c | 216 |
1 files changed, 173 insertions, 43 deletions
diff --git a/fs/jbd2/checkpoint.c b/fs/jbd2/checkpoint.c index 96bf33986d03..51bd38da21cd 100644 --- a/fs/jbd2/checkpoint.c +++ b/fs/jbd2/checkpoint.c @@ -80,23 +80,15 @@ static inline void __buffer_relink_io(struct journal_head *jh) } /* - * Try to release a checkpointed buffer from its transaction. - * Returns 1 if we released it and 2 if we also released the - * whole transaction. + * Check a checkpoint buffer could be release or not. * * Requires j_list_lock */ -static int __try_to_free_cp_buf(struct journal_head *jh) +static inline bool __cp_buffer_busy(struct journal_head *jh) { - int ret = 0; struct buffer_head *bh = jh2bh(jh); - if (jh->b_transaction == NULL && !buffer_locked(bh) && - !buffer_dirty(bh) && !buffer_write_io_error(bh)) { - JBUFFER_TRACE(jh, "remove from checkpoint list"); - ret = __jbd2_journal_remove_checkpoint(jh) + 1; - } - return ret; + return (jh->b_transaction || buffer_locked(bh) || buffer_dirty(bh)); } /* @@ -106,6 +98,8 @@ static int __try_to_free_cp_buf(struct journal_head *jh) * for a checkpoint to free up some space in the log. */ void __jbd2_log_wait_for_space(journal_t *journal) +__acquires(&journal->j_state_lock) +__releases(&journal->j_state_lock) { int nblocks, space_left; /* assert_spin_locked(&journal->j_state_lock); */ @@ -209,7 +203,7 @@ int jbd2_log_do_checkpoint(journal_t *journal) tid_t this_tid; int result, batch_count = 0; - jbd_debug(1, "Start checkpoint\n"); + jbd2_debug(1, "Start checkpoint\n"); /* * First thing: if there are any transactions in the log which @@ -218,7 +212,7 @@ int jbd2_log_do_checkpoint(journal_t *journal) */ result = jbd2_cleanup_journal_tail(journal); trace_jbd2_checkpoint(journal, result); - jbd_debug(1, "cleanup_journal_tail returned %d\n", result); + jbd2_debug(1, "cleanup_journal_tail returned %d\n", result); if (result <= 0) return result; @@ -226,7 +220,6 @@ int jbd2_log_do_checkpoint(journal_t *journal) * OK, we need to start writing disk blocks. Take one transaction * and write it. */ - result = 0; spin_lock(&journal->j_list_lock); if (!journal->j_checkpoint_transactions) goto out; @@ -293,8 +286,6 @@ restart: goto restart; } if (!buffer_dirty(bh)) { - if (unlikely(buffer_write_io_error(bh)) && !result) - result = -EIO; BUFFER_TRACE(bh, "remove from checkpoint"); if (__jbd2_journal_remove_checkpoint(jh)) /* The transaction was released; we're done */ @@ -354,8 +345,6 @@ restart2: spin_lock(&journal->j_list_lock); goto restart2; } - if (unlikely(buffer_write_io_error(bh)) && !result) - result = -EIO; /* * Now in whatever state the buffer currently is, we @@ -367,10 +356,7 @@ restart2: } out: spin_unlock(&journal->j_list_lock); - if (result < 0) - jbd2_journal_abort(journal, result); - else - result = jbd2_cleanup_journal_tail(journal); + result = jbd2_cleanup_journal_tail(journal); return (result < 0) ? result : 0; } @@ -414,7 +400,7 @@ int jbd2_cleanup_journal_tail(journal_t *journal) * jbd2_cleanup_journal_tail() doesn't get called all that often. */ if (journal->j_flags & JBD2_BARRIER) - blkdev_issue_flush(journal->j_fs_dev, GFP_NOFS, NULL); + blkdev_issue_flush(journal->j_fs_dev); return __jbd2_update_log_tail(journal, first_tid, blocknr); } @@ -435,7 +421,6 @@ static int journal_clean_one_cp_list(struct journal_head *jh, bool destroy) { struct journal_head *last_jh; struct journal_head *next_jh = jh; - int ret; if (!jh) return 0; @@ -444,13 +429,11 @@ static int journal_clean_one_cp_list(struct journal_head *jh, bool destroy) do { jh = next_jh; next_jh = jh->b_cpnext; - if (!destroy) - ret = __try_to_free_cp_buf(jh); - else - ret = __jbd2_journal_remove_checkpoint(jh) + 1; - if (!ret) + + if (!destroy && __cp_buffer_busy(jh)) return 0; - if (ret == 2) + + if (__jbd2_journal_remove_checkpoint(jh)) return 1; /* * This function only frees up some memory @@ -466,6 +449,137 @@ static int journal_clean_one_cp_list(struct journal_head *jh, bool destroy) } /* + * journal_shrink_one_cp_list + * + * Find 'nr_to_scan' written-back checkpoint buffers in the given list + * and try to release them. If the whole transaction is released, set + * the 'released' parameter. Return the number of released checkpointed + * buffers. + * + * Called with j_list_lock held. + */ +static unsigned long journal_shrink_one_cp_list(struct journal_head *jh, + unsigned long *nr_to_scan, + bool *released) +{ + struct journal_head *last_jh; + struct journal_head *next_jh = jh; + unsigned long nr_freed = 0; + int ret; + + if (!jh || *nr_to_scan == 0) + return 0; + + last_jh = jh->b_cpprev; + do { + jh = next_jh; + next_jh = jh->b_cpnext; + + (*nr_to_scan)--; + if (__cp_buffer_busy(jh)) + continue; + + nr_freed++; + ret = __jbd2_journal_remove_checkpoint(jh); + if (ret) { + *released = true; + break; + } + + if (need_resched()) + break; + } while (jh != last_jh && *nr_to_scan); + + return nr_freed; +} + +/* + * jbd2_journal_shrink_checkpoint_list + * + * Find 'nr_to_scan' written-back checkpoint buffers in the journal + * and try to release them. Return the number of released checkpointed + * buffers. + * + * Called with j_list_lock held. + */ +unsigned long jbd2_journal_shrink_checkpoint_list(journal_t *journal, + unsigned long *nr_to_scan) +{ + transaction_t *transaction, *last_transaction, *next_transaction; + bool released; + tid_t first_tid = 0, last_tid = 0, next_tid = 0; + tid_t tid = 0; + unsigned long nr_freed = 0; + unsigned long nr_scanned = *nr_to_scan; + +again: + spin_lock(&journal->j_list_lock); + if (!journal->j_checkpoint_transactions) { + spin_unlock(&journal->j_list_lock); + goto out; + } + + /* + * Get next shrink transaction, resume previous scan or start + * over again. If some others do checkpoint and drop transaction + * from the checkpoint list, we ignore saved j_shrink_transaction + * and start over unconditionally. + */ + if (journal->j_shrink_transaction) + transaction = journal->j_shrink_transaction; + else + transaction = journal->j_checkpoint_transactions; + + if (!first_tid) + first_tid = transaction->t_tid; + last_transaction = journal->j_checkpoint_transactions->t_cpprev; + next_transaction = transaction; + last_tid = last_transaction->t_tid; + do { + transaction = next_transaction; + next_transaction = transaction->t_cpnext; + tid = transaction->t_tid; + released = false; + + nr_freed += journal_shrink_one_cp_list(transaction->t_checkpoint_list, + nr_to_scan, &released); + if (*nr_to_scan == 0) + break; + if (need_resched() || spin_needbreak(&journal->j_list_lock)) + break; + if (released) + continue; + + nr_freed += journal_shrink_one_cp_list(transaction->t_checkpoint_io_list, + nr_to_scan, &released); + if (*nr_to_scan == 0) + break; + if (need_resched() || spin_needbreak(&journal->j_list_lock)) + break; + } while (transaction != last_transaction); + + if (transaction != last_transaction) { + journal->j_shrink_transaction = next_transaction; + next_tid = next_transaction->t_tid; + } else { + journal->j_shrink_transaction = NULL; + next_tid = 0; + } + + spin_unlock(&journal->j_list_lock); + cond_resched(); + + if (*nr_to_scan && next_tid) + goto again; +out: + nr_scanned -= *nr_to_scan; + trace_jbd2_shrink_checkpoint_list(journal, first_tid, tid, last_tid, + nr_freed, nr_scanned, next_tid); + + return nr_freed; +} + +/* * journal_clean_checkpoint_list * * Find all the written-back checkpoint buffers in the journal and release them. @@ -562,24 +676,37 @@ int __jbd2_journal_remove_checkpoint(struct journal_head *jh) struct transaction_chp_stats_s *stats; transaction_t *transaction; journal_t *journal; - int ret = 0; + struct buffer_head *bh = jh2bh(jh); JBUFFER_TRACE(jh, "entry"); - if ((transaction = jh->b_cp_transaction) == NULL) { + transaction = jh->b_cp_transaction; + if (!transaction) { JBUFFER_TRACE(jh, "not on transaction"); - goto out; + return 0; } journal = transaction->t_journal; JBUFFER_TRACE(jh, "removing from transaction"); + + /* + * If we have failed to write the buffer out to disk, the filesystem + * may become inconsistent. We cannot abort the journal here since + * we hold j_list_lock and we have to be careful about races with + * jbd2_journal_destroy(). So mark the writeback IO error in the + * journal here and we abort the journal later from a better context. + */ + if (buffer_write_io_error(bh)) + set_bit(JBD2_CHECKPOINT_IO_ERROR, &journal->j_atomic_flags); + __buffer_unlink(jh); jh->b_cp_transaction = NULL; + percpu_counter_dec(&journal->j_checkpoint_jh_count); jbd2_journal_put_journal_head(jh); - if (transaction->t_checkpoint_list != NULL || - transaction->t_checkpoint_io_list != NULL) - goto out; + /* Is this transaction empty? */ + if (transaction->t_checkpoint_list || transaction->t_checkpoint_io_list) + return 0; /* * There is one special case to worry about: if we have just pulled the @@ -591,10 +718,12 @@ int __jbd2_journal_remove_checkpoint(struct journal_head *jh) * See the comment at the end of jbd2_journal_commit_transaction(). */ if (transaction->t_state != T_FINISHED) - goto out; + return 0; - /* OK, that was the last buffer for the transaction: we can now - safely remove this transaction from the log */ + /* + * OK, that was the last buffer for the transaction, we can now + * safely remove this transaction from the log. + */ stats = &transaction->t_chp_stats; if (stats->cs_chp_time) stats->cs_chp_time = jbd2_time_diff(stats->cs_chp_time, @@ -604,9 +733,7 @@ int __jbd2_journal_remove_checkpoint(struct journal_head *jh) __jbd2_journal_drop_transaction(journal, transaction); jbd2_journal_free_transaction(transaction); - ret = 1; -out: - return ret; + return 1; } /* @@ -637,6 +764,7 @@ void __jbd2_journal_insert_checkpoint(struct journal_head *jh, jh->b_cpnext->b_cpprev = jh; } transaction->t_checkpoint_list = jh; + percpu_counter_inc(&transaction->t_journal->j_checkpoint_jh_count); } /* @@ -652,6 +780,8 @@ void __jbd2_journal_insert_checkpoint(struct journal_head *jh, void __jbd2_journal_drop_transaction(journal_t *journal, transaction_t *transaction) { assert_spin_locked(&journal->j_list_lock); + + journal->j_shrink_transaction = NULL; if (transaction->t_cpnext) { transaction->t_cpnext->t_cpprev = transaction->t_cpprev; transaction->t_cpprev->t_cpnext = transaction->t_cpnext; @@ -674,5 +804,5 @@ void __jbd2_journal_drop_transaction(journal_t *journal, transaction_t *transact trace_jbd2_drop_transaction(journal, transaction); - jbd_debug(1, "Dropping transaction %d, all done\n", transaction->t_tid); + jbd2_debug(1, "Dropping transaction %d, all done\n", transaction->t_tid); } |