diff options
Diffstat (limited to 'fs/jbd/checkpoint.c')
| -rw-r--r-- | fs/jbd/checkpoint.c | 166 |
1 files changed, 125 insertions, 41 deletions
diff --git a/fs/jbd/checkpoint.c b/fs/jbd/checkpoint.c index a5432bbbfb8..08c03044abd 100644 --- a/fs/jbd/checkpoint.c +++ b/fs/jbd/checkpoint.c @@ -22,6 +22,8 @@ #include <linux/jbd.h> #include <linux/errno.h> #include <linux/slab.h> +#include <linux/blkdev.h> +#include <trace/events/jbd.h> /* * Unlink a buffer from a transaction checkpoint list. @@ -93,11 +95,16 @@ static int __try_to_free_cp_buf(struct journal_head *jh) int ret = 0; struct buffer_head *bh = jh2bh(jh); - if (jh->b_jlist == BJ_None && !buffer_locked(bh) && !buffer_dirty(bh)) { + if (jh->b_jlist == BJ_None && !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 = __journal_remove_checkpoint(jh) + 1; jbd_unlock_bh_state(bh); - journal_remove_journal_head(bh); BUFFER_TRACE(bh, "release"); __brelse(bh); } else { @@ -114,7 +121,7 @@ static int __try_to_free_cp_buf(struct journal_head *jh) */ void __log_wait_for_space(journal_t *journal) { - int nblocks; + int nblocks, space_left; assert_spin_locked(&journal->j_state_lock); nblocks = jbd_space_needed(journal); @@ -126,14 +133,46 @@ void __log_wait_for_space(journal_t *journal) /* * Test again, another process may have checkpointed while we - * were waiting for the checkpoint lock + * were waiting for the checkpoint lock. If there are no + * transactions ready to be checkpointed, try to recover + * journal space by calling cleanup_journal_tail(), and if + * that doesn't work, by waiting for the currently committing + * transaction to complete. If there is absolutely no way + * to make progress, this is either a BUG or corrupted + * filesystem, so abort the journal and leave a stack + * trace for forensic evidence. */ spin_lock(&journal->j_state_lock); + spin_lock(&journal->j_list_lock); nblocks = jbd_space_needed(journal); - if (__log_space_left(journal) < nblocks) { + space_left = __log_space_left(journal); + if (space_left < nblocks) { + int chkpt = journal->j_checkpoint_transactions != NULL; + tid_t tid = 0; + + if (journal->j_committing_transaction) + tid = journal->j_committing_transaction->t_tid; + spin_unlock(&journal->j_list_lock); spin_unlock(&journal->j_state_lock); - log_do_checkpoint(journal); + if (chkpt) { + log_do_checkpoint(journal); + } else if (cleanup_journal_tail(journal) == 0) { + /* We were able to recover space; yay! */ + ; + } else if (tid) { + log_wait_commit(journal, tid); + } else { + printk(KERN_ERR "%s: needed %d blocks and " + "only had %d space available\n", + __func__, nblocks, space_left); + printk(KERN_ERR "%s: no way to get more " + "journal space\n", __func__); + WARN_ON(1); + journal_abort(journal, 0); + } spin_lock(&journal->j_state_lock); + } else { + spin_unlock(&journal->j_list_lock); } mutex_unlock(&journal->j_checkpoint_mutex); } @@ -160,21 +199,25 @@ static void jbd_sync_bh(journal_t *journal, struct buffer_head *bh) * buffers. Note that we take the buffers in the opposite ordering * from the one in which they were submitted for IO. * + * Return 0 on success, and return <0 if some buffers have failed + * to be written out. + * * Called with j_list_lock held. */ -static void __wait_cp_io(journal_t *journal, transaction_t *transaction) +static int __wait_cp_io(journal_t *journal, transaction_t *transaction) { struct journal_head *jh; struct buffer_head *bh; tid_t this_tid; int released = 0; + int ret = 0; this_tid = transaction->t_tid; restart: /* Did somebody clean up the transaction in the meanwhile? */ if (journal->j_checkpoint_transactions != transaction || transaction->t_tid != this_tid) - return; + return ret; while (!released && transaction->t_checkpoint_io_list) { jh = transaction->t_checkpoint_io_list; bh = jh2bh(jh); @@ -183,8 +226,8 @@ restart: spin_lock(&journal->j_list_lock); goto restart; } + get_bh(bh); if (buffer_locked(bh)) { - atomic_inc(&bh->b_count); spin_unlock(&journal->j_list_lock); jbd_unlock_bh_state(bh); wait_on_buffer(bh); @@ -194,15 +237,19 @@ restart: spin_lock(&journal->j_list_lock); goto restart; } + if (unlikely(buffer_write_io_error(bh))) + ret = -EIO; + /* * Now in whatever state the buffer currently is, we know that * it has been written out and so we can drop it from the list */ released = __journal_remove_checkpoint(jh); jbd_unlock_bh_state(bh); - journal_remove_journal_head(bh); __brelse(bh); } + + return ret; } #define NR_BATCH 64 @@ -211,8 +258,13 @@ static void __flush_batch(journal_t *journal, struct buffer_head **bhs, int *batch_count) { int i; + struct blk_plug plug; + + blk_start_plug(&plug); + for (i = 0; i < *batch_count; i++) + write_dirty_buffer(bhs[i], WRITE_SYNC); + blk_finish_plug(&plug); - ll_rw_block(SWRITE, *batch_count, bhs); for (i = 0; i < *batch_count; i++) { struct buffer_head *bh = bhs[i]; clear_buffer_jwrite(bh); @@ -226,7 +278,8 @@ __flush_batch(journal_t *journal, struct buffer_head **bhs, int *batch_count) * Try to flush one buffer from the checkpoint list to disk. * * Return 1 if something happened which requires us to abort the current - * scan of the checkpoint list. + * scan of the checkpoint list. Return <0 if the buffer has failed to + * be written out. * * Called with j_list_lock held and drops it if 1 is returned * Called under jbd_lock_bh_state(jh2bh(jh)), and drops it @@ -238,7 +291,7 @@ static int __process_buffer(journal_t *journal, struct journal_head *jh, int ret = 0; if (buffer_locked(bh)) { - atomic_inc(&bh->b_count); + get_bh(bh); spin_unlock(&journal->j_list_lock); jbd_unlock_bh_state(bh); wait_on_buffer(bh); @@ -256,14 +309,16 @@ static int __process_buffer(journal_t *journal, struct journal_head *jh, log_wait_commit(journal, tid); ret = 1; } else if (!buffer_dirty(bh)) { + ret = 1; + if (unlikely(buffer_write_io_error(bh))) + ret = -EIO; + get_bh(bh); J_ASSERT_JH(jh, !buffer_jbddirty(bh)); BUFFER_TRACE(bh, "remove from checkpoint"); __journal_remove_checkpoint(jh); spin_unlock(&journal->j_list_lock); jbd_unlock_bh_state(bh); - journal_remove_journal_head(bh); __brelse(bh); - ret = 1; } else { /* * Important: we are about to write the buffer, and @@ -295,6 +350,7 @@ static int __process_buffer(journal_t *journal, struct journal_head *jh, * to disk. We submit larger chunks of data at once. * * The journal should be locked before calling this function. + * Called with j_checkpoint_mutex held. */ int log_do_checkpoint(journal_t *journal) { @@ -310,6 +366,7 @@ int log_do_checkpoint(journal_t *journal) * journal straight away. */ result = cleanup_journal_tail(journal); + trace_jbd_checkpoint(journal, result); jbd_debug(1, "cleanup_journal_tail returned %d\n", result); if (result <= 0) return result; @@ -318,6 +375,7 @@ int 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; @@ -334,7 +392,7 @@ restart: int batch_count = 0; struct buffer_head *bhs[NR_BATCH]; struct journal_head *jh; - int retry = 0; + int retry = 0, err; while (!retry && transaction->t_checkpoint_list) { struct buffer_head *bh; @@ -347,6 +405,8 @@ restart: break; } retry = __process_buffer(journal, jh, bhs,&batch_count); + if (retry < 0 && !result) + result = retry; if (!retry && (need_resched() || spin_needbreak(&journal->j_list_lock))) { spin_unlock(&journal->j_list_lock); @@ -371,14 +431,18 @@ restart: * Now we have cleaned up the first transaction's checkpoint * list. Let's clean up the second one */ - __wait_cp_io(journal, transaction); + err = __wait_cp_io(journal, transaction); + if (!result) + result = err; } out: spin_unlock(&journal->j_list_lock); - result = cleanup_journal_tail(journal); if (result < 0) - return result; - return 0; + journal_abort(journal, result); + else + result = cleanup_journal_tail(journal); + + return (result < 0) ? result : 0; } /* @@ -389,28 +453,31 @@ out: * * Return <0 on error, 0 on success, 1 if there was nothing to clean up. * - * Called with the journal lock held. - * * This is the only part of the journaling code which really needs to be * aware of transaction aborts. Checkpointing involves writing to the * main filesystem area rather than to the journal, so it can proceed - * even in abort state, but we must not update the journal superblock if - * we have an abort error outstanding. + * even in abort state, but we must not update the super block if + * checkpointing may have failed. Otherwise, we would lose some metadata + * buffers which should be written-back to the filesystem. */ int cleanup_journal_tail(journal_t *journal) { transaction_t * transaction; tid_t first_tid; - unsigned long blocknr, freed; + unsigned int blocknr, freed; - /* OK, work out the oldest transaction remaining in the log, and + if (is_journal_aborted(journal)) + return 1; + + /* + * OK, work out the oldest transaction remaining in the log, and * the log block it starts at. * * If the log is now empty, we need to work out which is the * next transaction ID we will write, and where it will - * start. */ - + * start. + */ spin_lock(&journal->j_state_lock); spin_lock(&journal->j_list_lock); transaction = journal->j_checkpoint_transactions; @@ -436,7 +503,24 @@ int cleanup_journal_tail(journal_t *journal) spin_unlock(&journal->j_state_lock); return 1; } + spin_unlock(&journal->j_state_lock); + + /* + * We need to make sure that any blocks that were recently written out + * --- perhaps by log_do_checkpoint() --- are flushed out before we + * drop the transactions from the journal. Similarly we need to be sure + * superblock makes it to disk before next transaction starts reusing + * freed space (otherwise we could replay some blocks of the new + * transaction thinking they belong to the old one). So we use + * WRITE_FLUSH_FUA. It's unlikely this will be necessary, especially + * with an appropriately sized journal, but we need this to guarantee + * correctness. Fortunately cleanup_journal_tail() doesn't get called + * all that often. + */ + journal_update_sb_log_tail(journal, first_tid, blocknr, + WRITE_FLUSH_FUA); + spin_lock(&journal->j_state_lock); /* OK, update the superblock to recover the freed space. * Physical blocks come first: have we wrapped beyond the end of * the log? */ @@ -444,17 +528,16 @@ int cleanup_journal_tail(journal_t *journal) if (blocknr < journal->j_tail) freed = freed + journal->j_last - journal->j_first; + trace_jbd_cleanup_journal_tail(journal, first_tid, blocknr, freed); jbd_debug(1, - "Cleaning journal tail from %d to %d (offset %lu), " - "freeing %lu\n", + "Cleaning journal tail from %d to %d (offset %u), " + "freeing %u\n", journal->j_tail_sequence, first_tid, blocknr, freed); journal->j_free += freed; journal->j_tail_sequence = first_tid; journal->j_tail = blocknr; spin_unlock(&journal->j_state_lock); - if (!(journal->j_flags & JFS_ABORT)) - journal_update_superblock(journal, 1); return 0; } @@ -464,11 +547,11 @@ int cleanup_journal_tail(journal_t *journal) /* * journal_clean_one_cp_list * - * Find all the written-back checkpoint buffers in the given list and release them. + * Find all the written-back checkpoint buffers in the given list and release + * them. * - * Called with the journal locked. * Called with j_list_lock held. - * Returns number of bufers reaped (for debug) + * Returns number of buffers reaped (for debug) */ static int journal_clean_one_cp_list(struct journal_head *jh, int *released) @@ -573,8 +656,8 @@ out: * checkpoint lists. * * The function returns 1 if it frees the transaction, 0 otherwise. + * The function can free jh and bh. * - * This function is called with the journal locked. * This function is called with j_list_lock held. * This function is called with jbd_lock_bh_state(jh2bh(jh)) */ @@ -593,13 +676,14 @@ int __journal_remove_checkpoint(struct journal_head *jh) } journal = transaction->t_journal; + JBUFFER_TRACE(jh, "removing from transaction"); __buffer_unlink(jh); jh->b_cp_transaction = NULL; + journal_put_journal_head(jh); if (transaction->t_checkpoint_list != NULL || transaction->t_checkpoint_io_list != NULL) goto out; - JBUFFER_TRACE(jh, "transaction has no more buffers"); /* * There is one special case to worry about: if we have just pulled the @@ -610,10 +694,8 @@ int __journal_remove_checkpoint(struct journal_head *jh) * The locking here around t_state is a bit sleazy. * See the comment at the end of journal_commit_transaction(). */ - if (transaction->t_state != T_FINISHED) { - JBUFFER_TRACE(jh, "belongs to running/committing transaction"); + if (transaction->t_state != T_FINISHED) goto out; - } /* OK, that was the last buffer for the transaction: we can now safely remove this transaction from the log */ @@ -625,7 +707,6 @@ int __journal_remove_checkpoint(struct journal_head *jh) wake_up(&journal->j_wait_logspace); ret = 1; out: - JBUFFER_TRACE(jh, "exit"); return ret; } @@ -644,6 +725,8 @@ void __journal_insert_checkpoint(struct journal_head *jh, J_ASSERT_JH(jh, buffer_dirty(jh2bh(jh)) || buffer_jbddirty(jh2bh(jh))); J_ASSERT_JH(jh, jh->b_cp_transaction == NULL); + /* Get reference for checkpointing transaction */ + journal_grab_journal_head(jh2bh(jh)); jh->b_cp_transaction = transaction; if (!transaction->t_checkpoint_list) { @@ -693,6 +776,7 @@ void __journal_drop_transaction(journal_t *journal, transaction_t *transaction) J_ASSERT(journal->j_committing_transaction != transaction); J_ASSERT(journal->j_running_transaction != transaction); + trace_jbd_drop_transaction(journal, transaction); jbd_debug(1, "Dropping transaction %d, all done\n", transaction->t_tid); kfree(transaction); } |