diff --git a/fs/jbd2/checkpoint.c b/fs/jbd2/checkpoint.c index 6d27ba64e3725e83c24d942236ce098245b4fdf0..a87a39f028b9646500e25f4e35c42a4c93595330 100644 --- a/fs/jbd2/checkpoint.c +++ b/fs/jbd2/checkpoint.c @@ -204,20 +204,6 @@ int jbd2_log_do_checkpoint(journal_t *journal) jh = transaction->t_checkpoint_list; bh = jh2bh(jh); - /* - * The buffer may be writing back, or flushing out in the - * last couple of cycles, or re-adding into a new transaction, - * need to check it again until it's unlocked. - */ - if (buffer_locked(bh)) { - get_bh(bh); - spin_unlock(&journal->j_list_lock); - wait_on_buffer(bh); - /* the journal_head may have gone by now */ - BUFFER_TRACE(bh, "brelse"); - __brelse(bh); - goto retry; - } if (jh->b_transaction != NULL) { transaction_t *t = jh->b_transaction; tid_t tid = t->t_tid; @@ -252,7 +238,22 @@ int jbd2_log_do_checkpoint(journal_t *journal) spin_lock(&journal->j_list_lock); goto restart; } - if (!buffer_dirty(bh)) { + if (!trylock_buffer(bh)) { + /* + * The buffer is locked, it may be writing back, or + * flushing out in the last couple of cycles, or + * re-adding into a new transaction, need to check + * it again until it's unlocked. + */ + get_bh(bh); + spin_unlock(&journal->j_list_lock); + wait_on_buffer(bh); + /* the journal_head may have gone by now */ + BUFFER_TRACE(bh, "brelse"); + __brelse(bh); + goto retry; + } else if (!buffer_dirty(bh)) { + unlock_buffer(bh); BUFFER_TRACE(bh, "remove from checkpoint"); /* * If the transaction was released or the checkpoint @@ -262,6 +263,7 @@ int jbd2_log_do_checkpoint(journal_t *journal) !transaction->t_checkpoint_list) goto out; } else { + unlock_buffer(bh); /* * We are about to write the buffer, it could be * raced by some other transaction shrink or buffer @@ -347,50 +349,12 @@ int jbd2_cleanup_journal_tail(journal_t *journal) /* Checkpoint list management */ -/* - * journal_clean_one_cp_list - * - * Find all the written-back checkpoint buffers in the given list and - * release them. If 'destroy' is set, clean all buffers unconditionally. - * - * Called with j_list_lock held. - * Returns 1 if we freed the transaction, 0 otherwise. - */ -static int journal_clean_one_cp_list(struct journal_head *jh, bool destroy) -{ - struct journal_head *last_jh; - struct journal_head *next_jh = jh; - - if (!jh) - return 0; - - last_jh = jh->b_cpprev; - do { - jh = next_jh; - next_jh = jh->b_cpnext; - - if (!destroy && __cp_buffer_busy(jh)) - return 0; - - if (__jbd2_journal_remove_checkpoint(jh)) - return 1; - /* - * This function only frees up some memory - * if possible so we dont have an obligation - * to finish processing. Bail out if preemption - * requested: - */ - if (need_resched()) - return 0; - } while (jh != last_jh); - - return 0; -} +enum shrink_type {SHRINK_DESTROY, SHRINK_BUSY_STOP, SHRINK_BUSY_SKIP}; /* * journal_shrink_one_cp_list * - * Find 'nr_to_scan' written-back checkpoint buffers in the given list + * Find all the 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. @@ -398,7 +362,7 @@ static int journal_clean_one_cp_list(struct journal_head *jh, bool destroy) * Called with j_list_lock held. */ static unsigned long journal_shrink_one_cp_list(struct journal_head *jh, - unsigned long *nr_to_scan, + enum shrink_type type, bool *released) { struct journal_head *last_jh; @@ -406,7 +370,8 @@ static unsigned long journal_shrink_one_cp_list(struct journal_head *jh, unsigned long nr_freed = 0; int ret; - if (!jh || *nr_to_scan == 0) + *released = false; + if (!jh) return 0; last_jh = jh->b_cpprev; @@ -414,12 +379,18 @@ static unsigned long journal_shrink_one_cp_list(struct journal_head *jh, jh = next_jh; next_jh = jh->b_cpnext; - (*nr_to_scan)--; - if (__cp_buffer_busy(jh)) - continue; + if (type == SHRINK_DESTROY) { + ret = __jbd2_journal_remove_checkpoint(jh); + } else { + ret = jbd2_journal_try_remove_checkpoint(jh); + if (ret < 0) { + if (type == SHRINK_BUSY_SKIP) + continue; + break; + } + } nr_freed++; - ret = __jbd2_journal_remove_checkpoint(jh); if (ret) { *released = true; break; @@ -427,7 +398,7 @@ static unsigned long journal_shrink_one_cp_list(struct journal_head *jh, if (need_resched()) break; - } while (jh != last_jh && *nr_to_scan); + } while (jh != last_jh); return nr_freed; } @@ -445,11 +416,11 @@ unsigned long jbd2_journal_shrink_checkpoint_list(journal_t *journal, unsigned long *nr_to_scan) { transaction_t *transaction, *last_transaction, *next_transaction; - bool released; + bool __maybe_unused 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; + unsigned long freed; again: spin_lock(&journal->j_list_lock); @@ -478,10 +449,11 @@ unsigned long jbd2_journal_shrink_checkpoint_list(journal_t *journal, 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); + freed = journal_shrink_one_cp_list(transaction->t_checkpoint_list, + SHRINK_BUSY_SKIP, &released); + nr_freed += freed; + (*nr_to_scan) -= min(*nr_to_scan, freed); if (*nr_to_scan == 0) break; if (need_resched() || spin_needbreak(&journal->j_list_lock)) @@ -502,9 +474,8 @@ unsigned long jbd2_journal_shrink_checkpoint_list(journal_t *journal, 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); + nr_freed, next_tid); return nr_freed; } @@ -520,19 +491,21 @@ unsigned long jbd2_journal_shrink_checkpoint_list(journal_t *journal, void __jbd2_journal_clean_checkpoint_list(journal_t *journal, bool destroy) { transaction_t *transaction, *last_transaction, *next_transaction; - int ret; + enum shrink_type type; + bool released; transaction = journal->j_checkpoint_transactions; if (!transaction) return; + type = destroy ? SHRINK_DESTROY : SHRINK_BUSY_STOP; last_transaction = transaction->t_cpprev; next_transaction = transaction; do { transaction = next_transaction; next_transaction = transaction->t_cpnext; - ret = journal_clean_one_cp_list(transaction->t_checkpoint_list, - destroy); + journal_shrink_one_cp_list(transaction->t_checkpoint_list, + type, &released); /* * This function only frees up some memory if possible so we * dont have an obligation to finish processing. Bail out if @@ -545,7 +518,7 @@ void __jbd2_journal_clean_checkpoint_list(journal_t *journal, bool destroy) * avoids pointless scanning of transactions which still * weren't checkpointed. */ - if (!ret) + if (!released) return; } while (transaction != last_transaction); } @@ -655,6 +628,34 @@ int __jbd2_journal_remove_checkpoint(struct journal_head *jh) return 1; } +/* + * Check the checkpoint buffer and try to remove it from the checkpoint + * list if it's clean. Returns -EBUSY if it is not clean, returns 1 if + * it frees the transaction, 0 otherwise. + * + * This function is called with j_list_lock held. + */ +int jbd2_journal_try_remove_checkpoint(struct journal_head *jh) +{ + struct buffer_head *bh = jh2bh(jh); + + if (!trylock_buffer(bh)) + return -EBUSY; + if (buffer_dirty(bh)) { + unlock_buffer(bh); + return -EBUSY; + } + unlock_buffer(bh); + + /* + * Buffer is clean and the IO has finished (we held the buffer + * lock) so the checkpoint is done. We can safely remove the + * buffer from this transaction. + */ + JBUFFER_TRACE(jh, "remove from checkpoint list"); + return __jbd2_journal_remove_checkpoint(jh); +} + /* * journal_insert_checkpoint: put a committed buffer onto a checkpoint * list so that we know when it is safe to clean the transaction out of diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c index 6d9cce22106c94cfe99b1aa6b39dafdb031c06ec..44b0f4d83519f5cad92b18742e9570e91029820c 100644 --- a/fs/jbd2/transaction.c +++ b/fs/jbd2/transaction.c @@ -1758,8 +1758,7 @@ int jbd2_journal_forget(handle_t *handle, struct buffer_head *bh) * Otherwise, if the buffer has been written to disk, * it is safe to remove the checkpoint and drop it. */ - if (!buffer_dirty(bh)) { - __jbd2_journal_remove_checkpoint(jh); + if (jbd2_journal_try_remove_checkpoint(jh) >= 0) { spin_unlock(&journal->j_list_lock); goto drop; } @@ -2074,35 +2073,6 @@ void jbd2_journal_unfile_buffer(journal_t *journal, struct journal_head *jh) __brelse(bh); } -/* - * Called from jbd2_journal_try_to_free_buffers(). - * - * Called under jh->b_state_lock - */ -static void -__journal_try_to_free_buffer(journal_t *journal, struct buffer_head *bh) -{ - struct journal_head *jh; - - jh = bh2jh(bh); - - if (buffer_locked(bh) || buffer_dirty(bh)) - goto out; - - if (jh->b_next_transaction != NULL || jh->b_transaction != NULL) - goto out; - - spin_lock(&journal->j_list_lock); - if (jh->b_cp_transaction != NULL) { - /* written-back checkpointed metadata buffer */ - JBUFFER_TRACE(jh, "remove from checkpoint list"); - __jbd2_journal_remove_checkpoint(jh); - } - spin_unlock(&journal->j_list_lock); -out: - return; -} - /** * jbd2_journal_try_to_free_buffers() - try to free page buffers. * @journal: journal for operation @@ -2160,7 +2130,13 @@ int jbd2_journal_try_to_free_buffers(journal_t *journal, struct page *page) continue; spin_lock(&jh->b_state_lock); - __journal_try_to_free_buffer(journal, bh); + if (!jh->b_transaction && !jh->b_next_transaction) { + spin_lock(&journal->j_list_lock); + /* Remove written-back checkpointed metadata buffer */ + if (jh->b_cp_transaction != NULL) + jbd2_journal_try_remove_checkpoint(jh); + spin_unlock(&journal->j_list_lock); + } spin_unlock(&jh->b_state_lock); jbd2_journal_put_journal_head(jh); if (buffer_jbd(bh)) diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h index 5fd415c0af98132052ec0eafffe686812775d825..de9c0917299304c59402ecec4f34ad6a98f79b6f 100644 --- a/include/linux/jbd2.h +++ b/include/linux/jbd2.h @@ -1439,6 +1439,7 @@ extern void jbd2_journal_commit_transaction(journal_t *); void __jbd2_journal_clean_checkpoint_list(journal_t *journal, bool destroy); unsigned long jbd2_journal_shrink_checkpoint_list(journal_t *journal, unsigned long *nr_to_scan); int __jbd2_journal_remove_checkpoint(struct journal_head *); +int jbd2_journal_try_remove_checkpoint(struct journal_head *jh); void jbd2_journal_destroy_checkpoint(journal_t *journal); void __jbd2_journal_insert_checkpoint(struct journal_head *, transaction_t *); diff --git a/include/trace/events/jbd2.h b/include/trace/events/jbd2.h index a4dfe005983d3c0846de88dd67235656e06ce55e..2f693a31794ce240be66090df3f7cf8a31443afc 100644 --- a/include/trace/events/jbd2.h +++ b/include/trace/events/jbd2.h @@ -462,11 +462,9 @@ TRACE_EVENT(jbd2_shrink_scan_exit, TRACE_EVENT(jbd2_shrink_checkpoint_list, TP_PROTO(journal_t *journal, tid_t first_tid, tid_t tid, tid_t last_tid, - unsigned long nr_freed, unsigned long nr_scanned, - tid_t next_tid), + unsigned long nr_freed, tid_t next_tid), - TP_ARGS(journal, first_tid, tid, last_tid, nr_freed, - nr_scanned, next_tid), + TP_ARGS(journal, first_tid, tid, last_tid, nr_freed, next_tid), TP_STRUCT__entry( __field(dev_t, dev) @@ -474,7 +472,6 @@ TRACE_EVENT(jbd2_shrink_checkpoint_list, __field(tid_t, tid) __field(tid_t, last_tid) __field(unsigned long, nr_freed) - __field(unsigned long, nr_scanned) __field(tid_t, next_tid) ), @@ -484,15 +481,14 @@ TRACE_EVENT(jbd2_shrink_checkpoint_list, __entry->tid = tid; __entry->last_tid = last_tid; __entry->nr_freed = nr_freed; - __entry->nr_scanned = nr_scanned; __entry->next_tid = next_tid; ), TP_printk("dev %d,%d shrink transaction %u-%u(%u) freed %lu " - "scanned %lu next transaction %u", + "next transaction %u", MAJOR(__entry->dev), MINOR(__entry->dev), __entry->first_tid, __entry->tid, __entry->last_tid, - __entry->nr_freed, __entry->nr_scanned, __entry->next_tid) + __entry->nr_freed, __entry->next_tid) ); #endif /* _TRACE_JBD2_H */