diff options
Diffstat (limited to 'fs/jbd2/transaction.c')
| -rw-r--r-- | fs/jbd2/transaction.c | 651 |
1 files changed, 415 insertions, 236 deletions
diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c index fb1ab9533b67..7aa9a32573bb 100644 --- a/fs/jbd2/transaction.c +++ b/fs/jbd2/transaction.c @@ -30,6 +30,8 @@ #include <linux/bug.h> #include <linux/module.h> +#include <trace/events/jbd2.h> + static void __jbd2_journal_temp_unlink_buffer(struct journal_head *jh); static void __jbd2_journal_unfile_buffer(struct journal_head *jh); @@ -87,7 +89,8 @@ jbd2_get_transaction(journal_t *journal, transaction_t *transaction) transaction->t_expires = jiffies + journal->j_commit_interval; spin_lock_init(&transaction->t_handle_lock); atomic_set(&transaction->t_updates, 0); - atomic_set(&transaction->t_outstanding_credits, 0); + atomic_set(&transaction->t_outstanding_credits, + atomic_read(&journal->j_reserved_credits)); atomic_set(&transaction->t_handle_count, 0); INIT_LIST_HEAD(&transaction->t_inode_list); INIT_LIST_HEAD(&transaction->t_private_list); @@ -100,6 +103,7 @@ jbd2_get_transaction(journal_t *journal, transaction_t *transaction) journal->j_running_transaction = transaction; transaction->t_max_wait = 0; transaction->t_start = jiffies; + transaction->t_requested = 0; return transaction; } @@ -138,6 +142,112 @@ static inline void update_t_max_wait(transaction_t *transaction, } /* + * Wait until running transaction passes T_LOCKED state. Also starts the commit + * if needed. The function expects running transaction to exist and releases + * j_state_lock. + */ +static void wait_transaction_locked(journal_t *journal) + __releases(journal->j_state_lock) +{ + DEFINE_WAIT(wait); + int need_to_start; + tid_t tid = journal->j_running_transaction->t_tid; + + prepare_to_wait(&journal->j_wait_transaction_locked, &wait, + TASK_UNINTERRUPTIBLE); + need_to_start = !tid_geq(journal->j_commit_request, tid); + read_unlock(&journal->j_state_lock); + if (need_to_start) + jbd2_log_start_commit(journal, tid); + schedule(); + finish_wait(&journal->j_wait_transaction_locked, &wait); +} + +static void sub_reserved_credits(journal_t *journal, int blocks) +{ + atomic_sub(blocks, &journal->j_reserved_credits); + wake_up(&journal->j_wait_reserved); +} + +/* + * Wait until we can add credits for handle to the running transaction. Called + * with j_state_lock held for reading. Returns 0 if handle joined the running + * transaction. Returns 1 if we had to wait, j_state_lock is dropped, and + * caller must retry. + */ +static int add_transaction_credits(journal_t *journal, int blocks, + int rsv_blocks) +{ + transaction_t *t = journal->j_running_transaction; + int needed; + int total = blocks + rsv_blocks; + + /* + * If the current transaction is locked down for commit, wait + * for the lock to be released. + */ + if (t->t_state == T_LOCKED) { + wait_transaction_locked(journal); + return 1; + } + + /* + * If there is not enough space left in the log to write all + * potential buffers requested by this operation, we need to + * stall pending a log checkpoint to free some more log space. + */ + needed = atomic_add_return(total, &t->t_outstanding_credits); + if (needed > journal->j_max_transaction_buffers) { + /* + * If the current transaction is already too large, + * then start to commit it: we can then go back and + * attach this handle to a new transaction. + */ + atomic_sub(total, &t->t_outstanding_credits); + wait_transaction_locked(journal); + return 1; + } + + /* + * The commit code assumes that it can get enough log space + * without forcing a checkpoint. This is *critical* for + * correctness: a checkpoint of a buffer which is also + * associated with a committing transaction creates a deadlock, + * so commit simply cannot force through checkpoints. + * + * We must therefore ensure the necessary space in the journal + * *before* starting to dirty potentially checkpointed buffers + * in the new transaction. + */ + if (jbd2_log_space_left(journal) < jbd2_space_needed(journal)) { + atomic_sub(total, &t->t_outstanding_credits); + read_unlock(&journal->j_state_lock); + write_lock(&journal->j_state_lock); + if (jbd2_log_space_left(journal) < jbd2_space_needed(journal)) + __jbd2_log_wait_for_space(journal); + write_unlock(&journal->j_state_lock); + return 1; + } + + /* No reservation? We are done... */ + if (!rsv_blocks) + return 0; + + needed = atomic_add_return(rsv_blocks, &journal->j_reserved_credits); + /* We allow at most half of a transaction to be reserved */ + if (needed > journal->j_max_transaction_buffers / 2) { + sub_reserved_credits(journal, rsv_blocks); + atomic_sub(total, &t->t_outstanding_credits); + read_unlock(&journal->j_state_lock); + wait_event(journal->j_wait_reserved, + atomic_read(&journal->j_reserved_credits) + rsv_blocks + <= journal->j_max_transaction_buffers / 2); + return 1; + } + return 0; +} + +/* * start_this_handle: Given a handle, deal with any locking or stalling * needed to make sure that there is enough journal space for the handle * to begin. Attach the handle to a transaction and set up the @@ -148,18 +258,24 @@ static int start_this_handle(journal_t *journal, handle_t *handle, gfp_t gfp_mask) { transaction_t *transaction, *new_transaction = NULL; - tid_t tid; - int needed, need_to_start; - int nblocks = handle->h_buffer_credits; + int blocks = handle->h_buffer_credits; + int rsv_blocks = 0; unsigned long ts = jiffies; - if (nblocks > journal->j_max_transaction_buffers) { + /* + * 1/2 of transaction can be reserved so we can practically handle + * only 1/2 of maximum transaction size per operation + */ + if (WARN_ON(blocks > journal->j_max_transaction_buffers / 2)) { printk(KERN_ERR "JBD2: %s wants too many credits (%d > %d)\n", - current->comm, nblocks, - journal->j_max_transaction_buffers); + current->comm, blocks, + journal->j_max_transaction_buffers / 2); return -ENOSPC; } + if (handle->h_rsv_handle) + rsv_blocks = handle->h_rsv_handle->h_buffer_credits; + alloc_transaction: if (!journal->j_running_transaction) { new_transaction = kmem_cache_zalloc(transaction_cache, @@ -196,8 +312,12 @@ repeat: return -EROFS; } - /* Wait on the journal's transaction barrier if necessary */ - if (journal->j_barrier_count) { + /* + * Wait on the journal's transaction barrier if necessary. Specifically + * we allow reserved handles to proceed because otherwise commit could + * deadlock on page writeback not being able to complete. + */ + if (!handle->h_reserved && journal->j_barrier_count) { read_unlock(&journal->j_state_lock); wait_event(journal->j_wait_transaction_locked, journal->j_barrier_count == 0); @@ -209,7 +329,8 @@ repeat: if (!new_transaction) goto alloc_transaction; write_lock(&journal->j_state_lock); - if (!journal->j_running_transaction) { + if (!journal->j_running_transaction && + (handle->h_reserved || !journal->j_barrier_count)) { jbd2_get_transaction(journal, new_transaction); new_transaction = NULL; } @@ -219,85 +340,18 @@ repeat: transaction = journal->j_running_transaction; - /* - * If the current transaction is locked down for commit, wait for the - * lock to be released. - */ - if (transaction->t_state == T_LOCKED) { - DEFINE_WAIT(wait); - - prepare_to_wait(&journal->j_wait_transaction_locked, - &wait, TASK_UNINTERRUPTIBLE); - read_unlock(&journal->j_state_lock); - schedule(); - finish_wait(&journal->j_wait_transaction_locked, &wait); - goto repeat; - } - - /* - * If there is not enough space left in the log to write all potential - * buffers requested by this operation, we need to stall pending a log - * checkpoint to free some more log space. - */ - needed = atomic_add_return(nblocks, - &transaction->t_outstanding_credits); - - if (needed > journal->j_max_transaction_buffers) { + if (!handle->h_reserved) { + /* We may have dropped j_state_lock - restart in that case */ + if (add_transaction_credits(journal, blocks, rsv_blocks)) + goto repeat; + } else { /* - * If the current transaction is already too large, then start - * to commit it: we can then go back and attach this handle to - * a new transaction. + * We have handle reserved so we are allowed to join T_LOCKED + * transaction and we don't have to check for transaction size + * and journal space. */ - DEFINE_WAIT(wait); - - jbd_debug(2, "Handle %p starting new commit...\n", handle); - atomic_sub(nblocks, &transaction->t_outstanding_credits); - prepare_to_wait(&journal->j_wait_transaction_locked, &wait, - TASK_UNINTERRUPTIBLE); - tid = transaction->t_tid; - need_to_start = !tid_geq(journal->j_commit_request, tid); - read_unlock(&journal->j_state_lock); - if (need_to_start) - jbd2_log_start_commit(journal, tid); - schedule(); - finish_wait(&journal->j_wait_transaction_locked, &wait); - goto repeat; - } - - /* - * The commit code assumes that it can get enough log space - * without forcing a checkpoint. This is *critical* for - * correctness: a checkpoint of a buffer which is also - * associated with a committing transaction creates a deadlock, - * so commit simply cannot force through checkpoints. - * - * We must therefore ensure the necessary space in the journal - * *before* starting to dirty potentially checkpointed buffers - * in the new transaction. - * - * The worst part is, any transaction currently committing can - * reduce the free space arbitrarily. Be careful to account for - * those buffers when checkpointing. - */ - - /* - * @@@ AKPM: This seems rather over-defensive. We're giving commit - * a _lot_ of headroom: 1/4 of the journal plus the size of - * the committing transaction. Really, we only need to give it - * committing_transaction->t_outstanding_credits plus "enough" for - * the log control blocks. - * Also, this test is inconsistent with the matching one in - * jbd2_journal_extend(). - */ - if (__jbd2_log_space_left(journal) < jbd_space_needed(journal)) { - jbd_debug(2, "Handle %p waiting for checkpoint...\n", handle); - atomic_sub(nblocks, &transaction->t_outstanding_credits); - read_unlock(&journal->j_state_lock); - write_lock(&journal->j_state_lock); - if (__jbd2_log_space_left(journal) < jbd_space_needed(journal)) - __jbd2_log_wait_for_space(journal); - write_unlock(&journal->j_state_lock); - goto repeat; + sub_reserved_credits(journal, blocks); + handle->h_reserved = 0; } /* OK, account for the buffers that this operation expects to @@ -305,13 +359,16 @@ repeat: */ update_t_max_wait(transaction, ts); handle->h_transaction = transaction; + handle->h_requested_credits = blocks; + handle->h_start_jiffies = jiffies; atomic_inc(&transaction->t_updates); atomic_inc(&transaction->t_handle_count); - jbd_debug(4, "Handle %p given %d credits (total %d, free %d)\n", - handle, nblocks, + jbd_debug(4, "Handle %p given %d credits (total %d, free %lu)\n", + handle, blocks, atomic_read(&transaction->t_outstanding_credits), - __jbd2_log_space_left(journal)); + jbd2_log_space_left(journal)); read_unlock(&journal->j_state_lock); + current->journal_info = handle; lock_map_acquire(&handle->h_lockdep_map); jbd2_journal_free_transaction(new_transaction); @@ -326,7 +383,6 @@ static handle_t *new_handle(int nblocks) handle_t *handle = jbd2_alloc_handle(GFP_NOFS); if (!handle) return NULL; - memset(handle, 0, sizeof(*handle)); handle->h_buffer_credits = nblocks; handle->h_ref = 1; @@ -343,15 +399,21 @@ static handle_t *new_handle(int nblocks) * * We make sure that the transaction can guarantee at least nblocks of * modified buffers in the log. We block until the log can guarantee - * that much space. - * - * This function is visible to journal users (like ext3fs), so is not - * called with the journal already locked. + * that much space. Additionally, if rsv_blocks > 0, we also create another + * handle with rsv_blocks reserved blocks in the journal. This handle is + * is stored in h_rsv_handle. It is not attached to any particular transaction + * and thus doesn't block transaction commit. If the caller uses this reserved + * handle, it has to set h_rsv_handle to NULL as otherwise jbd2_journal_stop() + * on the parent handle will dispose the reserved one. Reserved handle has to + * be converted to a normal handle using jbd2_journal_start_reserved() before + * it can be used. * * Return a pointer to a newly allocated handle, or an ERR_PTR() value * on failure. */ -handle_t *jbd2__journal_start(journal_t *journal, int nblocks, gfp_t gfp_mask) +handle_t *jbd2__journal_start(journal_t *journal, int nblocks, int rsv_blocks, + gfp_t gfp_mask, unsigned int type, + unsigned int line_no) { handle_t *handle = journal_current_handle(); int err; @@ -368,15 +430,31 @@ handle_t *jbd2__journal_start(journal_t *journal, int nblocks, gfp_t gfp_mask) handle = new_handle(nblocks); if (!handle) return ERR_PTR(-ENOMEM); + if (rsv_blocks) { + handle_t *rsv_handle; - current->journal_info = handle; + rsv_handle = new_handle(rsv_blocks); + if (!rsv_handle) { + jbd2_free_handle(handle); + return ERR_PTR(-ENOMEM); + } + rsv_handle->h_reserved = 1; + rsv_handle->h_journal = journal; + handle->h_rsv_handle = rsv_handle; + } err = start_this_handle(journal, handle, gfp_mask); if (err < 0) { + if (handle->h_rsv_handle) + jbd2_free_handle(handle->h_rsv_handle); jbd2_free_handle(handle); - current->journal_info = NULL; - handle = ERR_PTR(err); + return ERR_PTR(err); } + handle->h_type = type; + handle->h_line_no = line_no; + trace_jbd2_handle_start(journal->j_fs_dev->bd_dev, + handle->h_transaction->t_tid, type, + line_no, nblocks); return handle; } EXPORT_SYMBOL(jbd2__journal_start); @@ -384,10 +462,65 @@ EXPORT_SYMBOL(jbd2__journal_start); handle_t *jbd2_journal_start(journal_t *journal, int nblocks) { - return jbd2__journal_start(journal, nblocks, GFP_NOFS); + return jbd2__journal_start(journal, nblocks, 0, GFP_NOFS, 0, 0); } EXPORT_SYMBOL(jbd2_journal_start); +void jbd2_journal_free_reserved(handle_t *handle) +{ + journal_t *journal = handle->h_journal; + + WARN_ON(!handle->h_reserved); + sub_reserved_credits(journal, handle->h_buffer_credits); + jbd2_free_handle(handle); +} +EXPORT_SYMBOL(jbd2_journal_free_reserved); + +/** + * int jbd2_journal_start_reserved(handle_t *handle) - start reserved handle + * @handle: handle to start + * + * Start handle that has been previously reserved with jbd2_journal_reserve(). + * This attaches @handle to the running transaction (or creates one if there's + * not transaction running). Unlike jbd2_journal_start() this function cannot + * block on journal commit, checkpointing, or similar stuff. It can block on + * memory allocation or frozen journal though. + * + * Return 0 on success, non-zero on error - handle is freed in that case. + */ +int jbd2_journal_start_reserved(handle_t *handle, unsigned int type, + unsigned int line_no) +{ + journal_t *journal = handle->h_journal; + int ret = -EIO; + + if (WARN_ON(!handle->h_reserved)) { + /* Someone passed in normal handle? Just stop it. */ + jbd2_journal_stop(handle); + return ret; + } + /* + * Usefulness of mixing of reserved and unreserved handles is + * questionable. So far nobody seems to need it so just error out. + */ + if (WARN_ON(current->journal_info)) { + jbd2_journal_free_reserved(handle); + return ret; + } + + handle->h_journal = NULL; + /* + * GFP_NOFS is here because callers are likely from writeback or + * similarly constrained call sites + */ + ret = start_this_handle(journal, handle, GFP_NOFS); + if (ret < 0) + jbd2_journal_free_reserved(handle); + handle->h_type = type; + handle->h_line_no = line_no; + return ret; +} +EXPORT_SYMBOL(jbd2_journal_start_reserved); /** * int jbd2_journal_extend() - extend buffer credits. @@ -412,42 +545,53 @@ EXPORT_SYMBOL(jbd2_journal_start); int jbd2_journal_extend(handle_t *handle, int nblocks) { transaction_t *transaction = handle->h_transaction; - journal_t *journal = transaction->t_journal; + journal_t *journal; int result; int wanted; - result = -EIO; + WARN_ON(!transaction); if (is_handle_aborted(handle)) - goto out; + return -EROFS; + journal = transaction->t_journal; result = 1; read_lock(&journal->j_state_lock); /* Don't extend a locked-down transaction! */ - if (handle->h_transaction->t_state != T_RUNNING) { + if (transaction->t_state != T_RUNNING) { jbd_debug(3, "denied handle %p %d blocks: " "transaction not running\n", handle, nblocks); goto error_out; } spin_lock(&transaction->t_handle_lock); - wanted = atomic_read(&transaction->t_outstanding_credits) + nblocks; + wanted = atomic_add_return(nblocks, + &transaction->t_outstanding_credits); if (wanted > journal->j_max_transaction_buffers) { jbd_debug(3, "denied handle %p %d blocks: " "transaction too large\n", handle, nblocks); + atomic_sub(nblocks, &transaction->t_outstanding_credits); goto unlock; } - if (wanted > __jbd2_log_space_left(journal)) { + if (wanted + (wanted >> JBD2_CONTROL_BLOCKS_SHIFT) > + jbd2_log_space_left(journal)) { jbd_debug(3, "denied handle %p %d blocks: " "insufficient log space\n", handle, nblocks); + atomic_sub(nblocks, &transaction->t_outstanding_credits); goto unlock; } + trace_jbd2_handle_extend(journal->j_fs_dev->bd_dev, + transaction->t_tid, + handle->h_type, handle->h_line_no, + handle->h_buffer_credits, + nblocks); + handle->h_buffer_credits += nblocks; - atomic_add(nblocks, &transaction->t_outstanding_credits); + handle->h_requested_credits += nblocks; result = 0; jbd_debug(3, "extended handle %p by %d\n", handle, nblocks); @@ -455,7 +599,6 @@ unlock: spin_unlock(&transaction->t_handle_lock); error_out: read_unlock(&journal->j_state_lock); -out: return result; } @@ -472,19 +615,22 @@ out: * to a running handle, a call to jbd2_journal_restart will commit the * handle's transaction so far and reattach the handle to a new * transaction capabable of guaranteeing the requested number of - * credits. + * credits. We preserve reserved handle if there's any attached to the + * passed in handle. */ int jbd2__journal_restart(handle_t *handle, int nblocks, gfp_t gfp_mask) { transaction_t *transaction = handle->h_transaction; - journal_t *journal = transaction->t_journal; + journal_t *journal; tid_t tid; int need_to_start, ret; + WARN_ON(!transaction); /* If we've had an abort of any type, don't even think about * actually doing the restart! */ if (is_handle_aborted(handle)) return 0; + journal = transaction->t_journal; /* * First unlink the handle from its current transaction, and start the @@ -497,12 +643,18 @@ int jbd2__journal_restart(handle_t *handle, int nblocks, gfp_t gfp_mask) spin_lock(&transaction->t_handle_lock); atomic_sub(handle->h_buffer_credits, &transaction->t_outstanding_credits); + if (handle->h_rsv_handle) { + sub_reserved_credits(journal, + handle->h_rsv_handle->h_buffer_credits); + } if (atomic_dec_and_test(&transaction->t_updates)) wake_up(&journal->j_wait_updates); + tid = transaction->t_tid; spin_unlock(&transaction->t_handle_lock); + handle->h_transaction = NULL; + current->journal_info = NULL; jbd_debug(2, "restarting handle %p\n", handle); - tid = transaction->t_tid; need_to_start = !tid_geq(journal->j_commit_request, tid); read_unlock(&journal->j_state_lock); if (need_to_start) @@ -539,6 +691,14 @@ void jbd2_journal_lock_updates(journal_t *journal) write_lock(&journal->j_state_lock); ++journal->j_barrier_count; + /* Wait until there are no reserved handles */ + if (atomic_read(&journal->j_reserved_credits)) { + write_unlock(&journal->j_state_lock); + wait_event(journal->j_wait_reserved, + atomic_read(&journal->j_reserved_credits) == 0); + write_lock(&journal->j_state_lock); + } + /* Wait until there are no running updates */ while (1) { transaction_t *transaction = journal->j_running_transaction; @@ -601,6 +761,12 @@ static void warn_dirty_buffer(struct buffer_head *bh) bdevname(bh->b_bdev, b), (unsigned long long)bh->b_blocknr); } +static int sleep_on_shadow_bh(void *word) +{ + io_schedule(); + return 0; +} + /* * If the buffer is already part of the current transaction, then there * is nothing we need to do. If it is already part of a prior @@ -616,16 +782,16 @@ do_get_write_access(handle_t *handle, struct journal_head *jh, int force_copy) { struct buffer_head *bh; - transaction_t *transaction; + transaction_t *transaction = handle->h_transaction; journal_t *journal; int error; char *frozen_buffer = NULL; int need_copy = 0; + unsigned long start_lock, time_lock; + WARN_ON(!transaction); if (is_handle_aborted(handle)) return -EROFS; - - transaction = handle->h_transaction; journal = transaction->t_journal; jbd_debug(5, "journal_head %p, force_copy %d\n", jh, force_copy); @@ -636,9 +802,16 @@ repeat: /* @@@ Need to check for errors here at some point. */ + start_lock = jiffies; lock_buffer(bh); jbd_lock_bh_state(bh); + /* If it takes too long to lock the buffer, trace it */ + time_lock = jbd2_time_diff(start_lock, jiffies); + if (time_lock > HZ/10) + trace_jbd2_lock_buffer_stall(bh->b_bdev->bd_dev, + jiffies_to_msecs(time_lock)); + /* We now hold the buffer lock so it is safe to query the buffer * state. Is the buffer dirty? * @@ -728,41 +901,29 @@ repeat: * journaled. If the primary copy is already going to * disk then we cannot do copy-out here. */ - if (jh->b_jlist == BJ_Shadow) { - DEFINE_WAIT_BIT(wait, &bh->b_state, BH_Unshadow); - wait_queue_head_t *wqh; - - wqh = bit_waitqueue(&bh->b_state, BH_Unshadow); - + if (buffer_shadow(bh)) { JBUFFER_TRACE(jh, "on shadow: sleep"); jbd_unlock_bh_state(bh); - /* commit wakes up all shadow buffers after IO */ - for ( ; ; ) { - prepare_to_wait(wqh, &wait.wait, - TASK_UNINTERRUPTIBLE); - if (jh->b_jlist != BJ_Shadow) - break; - schedule(); - } - finish_wait(wqh, &wait.wait); + wait_on_bit(&bh->b_state, BH_Shadow, + sleep_on_shadow_bh, TASK_UNINTERRUPTIBLE); goto repeat; } - /* Only do the copy if the currently-owning transaction - * still needs it. If it is on the Forget list, the - * committing transaction is past that stage. The - * buffer had better remain locked during the kmalloc, - * but that should be true --- we hold the journal lock - * still and the buffer is already on the BUF_JOURNAL - * list so won't be flushed. + /* + * Only do the copy if the currently-owning transaction still + * needs it. If buffer isn't on BJ_Metadata list, the + * committing transaction is past that stage (here we use the + * fact that BH_Shadow is set under bh_state lock together with + * refiling to BJ_Shadow list and at this point we know the + * buffer doesn't have BH_Shadow set). * * Subtle point, though: if this is a get_undo_access, * then we will be relying on the frozen_data to contain * the new value of the committed_data record after the * transaction, so we HAVE to force the frozen_data copy - * in that case. */ - - if (jh->b_jlist != BJ_Forget || force_copy) { + * in that case. + */ + if (jh->b_jlist == BJ_Metadata || force_copy) { JBUFFER_TRACE(jh, "generate frozen data"); if (!frozen_buffer) { JBUFFER_TRACE(jh, "allocate memory for buffer"); @@ -889,14 +1050,16 @@ int jbd2_journal_get_write_access(handle_t *handle, struct buffer_head *bh) int jbd2_journal_get_create_access(handle_t *handle, struct buffer_head *bh) { transaction_t *transaction = handle->h_transaction; - journal_t *journal = transaction->t_journal; + journal_t *journal; struct journal_head *jh = jbd2_journal_add_journal_head(bh); int err; jbd_debug(5, "journal_head %p\n", jh); + WARN_ON(!transaction); err = -EROFS; if (is_handle_aborted(handle)) goto out; + journal = transaction->t_journal; err = 0; JBUFFER_TRACE(jh, "entry"); @@ -1046,9 +1209,12 @@ out: void jbd2_journal_set_triggers(struct buffer_head *bh, struct jbd2_buffer_trigger_type *type) { - struct journal_head *jh = bh2jh(bh); + struct journal_head *jh = jbd2_journal_grab_journal_head(bh); + if (WARN_ON(!jh)) + return; jh->b_triggers = type; + jbd2_journal_put_journal_head(jh); } void jbd2_buffer_frozen_trigger(struct journal_head *jh, void *mapped_data, @@ -1099,18 +1265,21 @@ void jbd2_buffer_abort_trigger(struct journal_head *jh, int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh) { transaction_t *transaction = handle->h_transaction; - journal_t *journal = transaction->t_journal; - struct journal_head *jh = bh2jh(bh); + journal_t *journal; + struct journal_head *jh; int ret = 0; - jbd_debug(5, "journal_head %p\n", jh); - JBUFFER_TRACE(jh, "entry"); + WARN_ON(!transaction); if (is_handle_aborted(handle)) - goto out; - if (!buffer_jbd(bh)) { + return -EROFS; + journal = transaction->t_journal; + jh = jbd2_journal_grab_journal_head(bh); + if (!jh) { ret = -EUCLEAN; goto out; } + jbd_debug(5, "journal_head %p\n", jh); + JBUFFER_TRACE(jh, "entry"); jbd_lock_bh_state(bh); @@ -1197,27 +1366,17 @@ int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh) JBUFFER_TRACE(jh, "file as BJ_Metadata"); spin_lock(&journal->j_list_lock); - __jbd2_journal_file_buffer(jh, handle->h_transaction, BJ_Metadata); + __jbd2_journal_file_buffer(jh, transaction, BJ_Metadata); spin_unlock(&journal->j_list_lock); out_unlock_bh: jbd_unlock_bh_state(bh); + jbd2_journal_put_journal_head(jh); out: JBUFFER_TRACE(jh, "exit"); WARN_ON(ret); /* All errors are bugs, so dump the stack */ return ret; } -/* - * jbd2_journal_release_buffer: undo a get_write_access without any buffer - * updates, if the update decided in the end that it didn't need access. - * - */ -void -jbd2_journal_release_buffer(handle_t *handle, struct buffer_head *bh) -{ - BUFFER_TRACE(bh, "entry"); -} - /** * void jbd2_journal_forget() - bforget() for potentially-journaled buffers. * @handle: transaction handle @@ -1238,12 +1397,17 @@ jbd2_journal_release_buffer(handle_t *handle, struct buffer_head *bh) int jbd2_journal_forget (handle_t *handle, struct buffer_head *bh) { transaction_t *transaction = handle->h_transaction; - journal_t *journal = transaction->t_journal; + journal_t *journal; struct journal_head *jh; int drop_reserve = 0; int err = 0; int was_modified = 0; + WARN_ON(!transaction); + if (is_handle_aborted(handle)) + return -EROFS; + journal = transaction->t_journal; + BUFFER_TRACE(bh, "entry"); jbd_lock_bh_state(bh); @@ -1261,7 +1425,7 @@ int jbd2_journal_forget (handle_t *handle, struct buffer_head *bh) goto not_jbd; } - /* keep track of wether or not this transaction modified us */ + /* keep track of whether or not this transaction modified us */ was_modified = jh->b_modified; /* @@ -1270,7 +1434,7 @@ int jbd2_journal_forget (handle_t *handle, struct buffer_head *bh) */ jh->b_modified = 0; - if (jh->b_transaction == handle->h_transaction) { + if (jh->b_transaction == transaction) { J_ASSERT_JH(jh, !jh->b_frozen_data); /* If we are forgetting a buffer which is already part @@ -1365,19 +1529,21 @@ drop: int jbd2_journal_stop(handle_t *handle) { transaction_t *transaction = handle->h_transaction; - journal_t *journal = transaction->t_journal; - int err, wait_for_commit = 0; + journal_t *journal; + int err = 0, wait_for_commit = 0; tid_t tid; pid_t pid; + if (!transaction) + goto free_and_exit; + journal = transaction->t_journal; + J_ASSERT(journal_current_handle() == handle); if (is_handle_aborted(handle)) err = -EIO; - else { + else J_ASSERT(atomic_read(&transaction->t_updates) > 0); - err = 0; - } if (--handle->h_ref > 0) { jbd_debug(4, "h_ref %d -> %d\n", handle->h_ref + 1, @@ -1386,6 +1552,13 @@ int jbd2_journal_stop(handle_t *handle) } jbd_debug(4, "Handle %p going down\n", handle); + trace_jbd2_handle_stats(journal->j_fs_dev->bd_dev, + transaction->t_tid, + handle->h_type, handle->h_line_no, + jiffies - handle->h_start_jiffies, + handle->h_sync, handle->h_requested_credits, + (handle->h_requested_credits - + handle->h_buffer_credits)); /* * Implement synchronous transaction batching. If the handle @@ -1491,33 +1664,13 @@ int jbd2_journal_stop(handle_t *handle) lock_map_release(&handle->h_lockdep_map); + if (handle->h_rsv_handle) + jbd2_journal_free_reserved(handle->h_rsv_handle); +free_and_exit: jbd2_free_handle(handle); return err; } -/** - * int jbd2_journal_force_commit() - force any uncommitted transactions - * @journal: journal to force - * - * For synchronous operations: force any uncommitted transactions - * to disk. May seem kludgy, but it reuses all the handle batching - * code in a very simple manner. - */ -int jbd2_journal_force_commit(journal_t *journal) -{ - handle_t *handle; - int ret; - - handle = jbd2_journal_start(journal, 1); - if (IS_ERR(handle)) { - ret = PTR_ERR(handle); - } else { - handle->h_sync = 1; - ret = jbd2_journal_stop(handle); - } - return ret; -} - /* * * List management code snippets: various functions for manipulating the @@ -1574,10 +1727,10 @@ __blist_del_buffer(struct journal_head **list, struct journal_head *jh) * Remove a buffer from the appropriate transaction list. * * Note that this function can *change* the value of - * bh->b_transaction->t_buffers, t_forget, t_iobuf_list, t_shadow_list, - * t_log_list or t_reserved_list. If the caller is holding onto a copy of one - * of these pointers, it could go bad. Generally the caller needs to re-read - * the pointer from the transaction_t. + * bh->b_transaction->t_buffers, t_forget, t_shadow_list, t_log_list or + * t_reserved_list. If the caller is holding onto a copy of one of these + * pointers, it could go bad. Generally the caller needs to re-read the + * pointer from the transaction_t. * * Called under j_list_lock. */ @@ -1607,15 +1760,9 @@ static void __jbd2_journal_temp_unlink_buffer(struct journal_head *jh) case BJ_Forget: list = &transaction->t_forget; break; - case BJ_IO: - list = &transaction->t_iobuf_list; - break; case BJ_Shadow: list = &transaction->t_shadow_list; break; - case BJ_LogCtl: - list = &transaction->t_log_list; - break; case BJ_Reserved: list = &transaction->t_reserved_list; break; @@ -1841,12 +1988,12 @@ static int __dispose_buffer(struct journal_head *jh, transaction_t *transaction) * We're outside-transaction here. Either or both of j_running_transaction * and j_committing_transaction may be NULL. */ -static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh) +static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh, + int partial_page) { transaction_t *transaction; struct journal_head *jh; int may_free = 1; - int ret; BUFFER_TRACE(bh, "entry"); @@ -1878,10 +2025,18 @@ static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh) * clear the buffer dirty bit at latest at the moment when the * transaction marking the buffer as freed in the filesystem * structures is committed because from that moment on the - * buffer can be reallocated and used by a different page. + * block can be reallocated and used by a different page. * Since the block hasn't been freed yet but the inode has * already been added to orphan list, it is safe for us to add * the buffer to BJ_Forget list of the newest transaction. + * + * Also we have to clear buffer_mapped flag of a truncated buffer + * because the buffer_head may be attached to the page straddling + * i_size (can happen only when blocksize < pagesize) and thus the + * buffer_head can be reused when the file is extended again. So we end + * up keeping around invalidated buffers attached to transactions' + * BJ_Forget list just to stop checkpointing code from cleaning up + * the transaction this buffer was modified in. */ transaction = jh->b_transaction; if (transaction == NULL) { @@ -1908,13 +2063,9 @@ static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh) * committed, the buffer won't be needed any * longer. */ JBUFFER_TRACE(jh, "checkpointed: add to BJ_Forget"); - ret = __dispose_buffer(jh, + may_free = __dispose_buffer(jh, journal->j_running_transaction); - jbd2_journal_put_journal_head(jh); - spin_unlock(&journal->j_list_lock); - jbd_unlock_bh_state(bh); - write_unlock(&journal->j_state_lock); - return ret; + goto zap_buffer; } else { /* There is no currently-running transaction. So the * orphan record which we wrote for this file must have @@ -1922,13 +2073,9 @@ static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh) * the committing transaction, if it exists. */ if (journal->j_committing_transaction) { JBUFFER_TRACE(jh, "give to committing trans"); - ret = __dispose_buffer(jh, + may_free = __dispose_buffer(jh, journal->j_committing_transaction); - jbd2_journal_put_journal_head(jh); - spin_unlock(&journal->j_list_lock); - jbd_unlock_bh_state(bh); - write_unlock(&journal->j_state_lock); - return ret; + goto zap_buffer; } else { /* The orphan record's transaction has * committed. We can cleanse this buffer */ @@ -1940,10 +2087,21 @@ static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh) JBUFFER_TRACE(jh, "on committing transaction"); /* * The buffer is committing, we simply cannot touch - * it. So we just set j_next_transaction to the - * running transaction (if there is one) and mark - * buffer as freed so that commit code knows it should - * clear dirty bits when it is done with the buffer. + * it. If the page is straddling i_size we have to wait + * for commit and try again. + */ + if (partial_page) { + jbd2_journal_put_journal_head(jh); + spin_unlock(&journal->j_list_lock); + jbd_unlock_bh_state(bh); + write_unlock(&journal->j_state_lock); + return -EBUSY; + } + /* + * OK, buffer won't be reachable after truncate. We just set + * j_next_transaction to the running transaction (if there is + * one) and mark buffer as freed so that commit code knows it + * should clear dirty bits when it is done with the buffer. */ set_buffer_freed(bh); if (journal->j_running_transaction && buffer_jbddirty(bh)) @@ -1966,6 +2124,15 @@ static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh) } zap_buffer: + /* + * This is tricky. Although the buffer is truncated, it may be reused + * if blocksize < pagesize and it is attached to the page straddling + * EOF. Since the buffer might have been added to BJ_Forget list of the + * running transaction, journal_get_write_access() won't clear + * b_modified and credit accounting gets confused. So clear b_modified + * here. + */ + jh->b_modified = 0; jbd2_journal_put_journal_head(jh); zap_buffer_no_jh: spin_unlock(&journal->j_list_lock); @@ -1987,23 +2154,32 @@ zap_buffer_unlocked: * void jbd2_journal_invalidatepage() * @journal: journal to use for flush... * @page: page to flush - * @offset: length of page to invalidate. - * - * Reap page buffers containing data after offset in page. + * @offset: start of the range to invalidate + * @length: length of the range to invalidate * + * Reap page buffers containing data after in the specified range in page. + * Can return -EBUSY if buffers are part of the committing transaction and + * the page is straddling i_size. Caller then has to wait for current commit + * and try again. */ -void jbd2_journal_invalidatepage(journal_t *journal, - struct page *page, - unsigned long offset) +int jbd2_journal_invalidatepage(journal_t *journal, + struct page *page, + unsigned int offset, + unsigned int length) { struct buffer_head *head, *bh, *next; + unsigned int stop = offset + length; unsigned int curr_off = 0; + int partial_page = (offset || length < PAGE_CACHE_SIZE); int may_free = 1; + int ret = 0; if (!PageLocked(page)) BUG(); if (!page_has_buffers(page)) - return; + return 0; + + BUG_ON(stop > PAGE_CACHE_SIZE || stop < length); /* We will potentially be playing with lists other than just the * data lists (especially for journaled data mode), so be @@ -2014,21 +2190,28 @@ void jbd2_journal_invalidatepage(journal_t *journal, unsigned int next_off = curr_off + bh->b_size; next = bh->b_this_page; + if (next_off > stop) + return 0; + if (offset <= curr_off) { /* This block is wholly outside the truncation point */ lock_buffer(bh); - may_free &= journal_unmap_buffer(journal, bh); + ret = journal_unmap_buffer(journal, bh, partial_page); unlock_buffer(bh); + if (ret < 0) + return ret; + may_free &= ret; } curr_off = next_off; bh = next; } while (bh != head); - if (!offset) { + if (!partial_page) { if (may_free && try_to_free_buffers(page)) J_ASSERT(!page_has_buffers(page)); } + return 0; } /* @@ -2085,15 +2268,9 @@ void __jbd2_journal_file_buffer(struct journal_head *jh, case BJ_Forget: list = &transaction->t_forget; break; - case BJ_IO: - list = &transaction->t_iobuf_list; - break; case BJ_Shadow: list = &transaction->t_shadow_list; break; - case BJ_LogCtl: - list = &transaction->t_log_list; - break; case BJ_Reserved: list = &transaction->t_reserved_list; break; @@ -2195,10 +2372,12 @@ void jbd2_journal_refile_buffer(journal_t *journal, struct journal_head *jh) int jbd2_journal_file_inode(handle_t *handle, struct jbd2_inode *jinode) { transaction_t *transaction = handle->h_transaction; - journal_t *journal = transaction->t_journal; + journal_t *journal; + WARN_ON(!transaction); if (is_handle_aborted(handle)) - return -EIO; + return -EROFS; + journal = transaction->t_journal; jbd_debug(4, "Adding inode %lu, tid:%d\n", jinode->i_vfs_inode->i_ino, transaction->t_tid); |