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authorTheodore Ts'o <tytso@mit.edu>2019-11-06 00:02:20 +0300
committerTheodore Ts'o <tytso@mit.edu>2019-11-06 00:02:20 +0300
commita6d4040846bff49c7e870cee5693245f87f2cfce (patch)
tree215862ebc82e00599e7cb2fa8ae7b88356768c1b /fs/jbd2/transaction.c
parent0d0a60c92fedbd4bf484c4c9b5cd49c16d05fb3f (diff)
parent19014d697147c6aea3a34eea00a2844e698d070f (diff)
downloadlinux-a6d4040846bff49c7e870cee5693245f87f2cfce.tar.xz
Merge branch 'jk/jbd2-revoke-overflow'
Diffstat (limited to 'fs/jbd2/transaction.c')
-rw-r--r--fs/jbd2/transaction.c256
1 files changed, 149 insertions, 107 deletions
diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
index 7c11afe60532..c068912408dd 100644
--- a/fs/jbd2/transaction.c
+++ b/fs/jbd2/transaction.c
@@ -63,6 +63,28 @@ void jbd2_journal_free_transaction(transaction_t *transaction)
}
/*
+ * Base amount of descriptor blocks we reserve for each transaction.
+ */
+static int jbd2_descriptor_blocks_per_trans(journal_t *journal)
+{
+ int tag_space = journal->j_blocksize - sizeof(journal_header_t);
+ int tags_per_block;
+
+ /* Subtract UUID */
+ tag_space -= 16;
+ if (jbd2_journal_has_csum_v2or3(journal))
+ tag_space -= sizeof(struct jbd2_journal_block_tail);
+ /* Commit code leaves a slack space of 16 bytes at the end of block */
+ tags_per_block = (tag_space - 16) / journal_tag_bytes(journal);
+ /*
+ * Revoke descriptors are accounted separately so we need to reserve
+ * space for commit block and normal transaction descriptor blocks.
+ */
+ return 1 + DIV_ROUND_UP(journal->j_max_transaction_buffers,
+ tags_per_block);
+}
+
+/*
* jbd2_get_transaction: obtain a new transaction_t object.
*
* Simply initialise a new transaction. Initialize it in
@@ -88,7 +110,9 @@ static void jbd2_get_transaction(journal_t *journal,
spin_lock_init(&transaction->t_handle_lock);
atomic_set(&transaction->t_updates, 0);
atomic_set(&transaction->t_outstanding_credits,
+ jbd2_descriptor_blocks_per_trans(journal) +
atomic_read(&journal->j_reserved_credits));
+ atomic_set(&transaction->t_outstanding_revokes, 0);
atomic_set(&transaction->t_handle_count, 0);
INIT_LIST_HEAD(&transaction->t_inode_list);
INIT_LIST_HEAD(&transaction->t_private_list);
@@ -258,12 +282,13 @@ static int add_transaction_credits(journal_t *journal, int blocks,
* *before* starting to dirty potentially checkpointed buffers
* in the new transaction.
*/
- if (jbd2_log_space_left(journal) < jbd2_space_needed(journal)) {
+ if (jbd2_log_space_left(journal) < journal->j_max_transaction_buffers) {
atomic_sub(total, &t->t_outstanding_credits);
read_unlock(&journal->j_state_lock);
jbd2_might_wait_for_commit(journal);
write_lock(&journal->j_state_lock);
- if (jbd2_log_space_left(journal) < jbd2_space_needed(journal))
+ if (jbd2_log_space_left(journal) <
+ journal->j_max_transaction_buffers)
__jbd2_log_wait_for_space(journal);
write_unlock(&journal->j_state_lock);
return 1;
@@ -299,12 +324,12 @@ static int start_this_handle(journal_t *journal, handle_t *handle,
gfp_t gfp_mask)
{
transaction_t *transaction, *new_transaction = NULL;
- int blocks = handle->h_buffer_credits;
+ int blocks = handle->h_total_credits;
int rsv_blocks = 0;
unsigned long ts = jiffies;
if (handle->h_rsv_handle)
- rsv_blocks = handle->h_rsv_handle->h_buffer_credits;
+ rsv_blocks = handle->h_rsv_handle->h_total_credits;
/*
* Limit the number of reserved credits to 1/2 of maximum transaction
@@ -405,6 +430,7 @@ repeat:
update_t_max_wait(transaction, ts);
handle->h_transaction = transaction;
handle->h_requested_credits = blocks;
+ handle->h_revoke_credits_requested = handle->h_revoke_credits;
handle->h_start_jiffies = jiffies;
atomic_inc(&transaction->t_updates);
atomic_inc(&transaction->t_handle_count);
@@ -431,15 +457,15 @@ static handle_t *new_handle(int nblocks)
handle_t *handle = jbd2_alloc_handle(GFP_NOFS);
if (!handle)
return NULL;
- handle->h_buffer_credits = nblocks;
+ handle->h_total_credits = nblocks;
handle->h_ref = 1;
return handle;
}
handle_t *jbd2__journal_start(journal_t *journal, int nblocks, int rsv_blocks,
- gfp_t gfp_mask, unsigned int type,
- unsigned int line_no)
+ int revoke_records, gfp_t gfp_mask,
+ unsigned int type, unsigned int line_no)
{
handle_t *handle = journal_current_handle();
int err;
@@ -453,6 +479,8 @@ handle_t *jbd2__journal_start(journal_t *journal, int nblocks, int rsv_blocks,
return handle;
}
+ nblocks += DIV_ROUND_UP(revoke_records,
+ journal->j_revoke_records_per_block);
handle = new_handle(nblocks);
if (!handle)
return ERR_PTR(-ENOMEM);
@@ -468,6 +496,7 @@ handle_t *jbd2__journal_start(journal_t *journal, int nblocks, int rsv_blocks,
rsv_handle->h_journal = journal;
handle->h_rsv_handle = rsv_handle;
}
+ handle->h_revoke_credits = revoke_records;
err = start_this_handle(journal, handle, gfp_mask);
if (err < 0) {
@@ -508,16 +537,21 @@ EXPORT_SYMBOL(jbd2__journal_start);
*/
handle_t *jbd2_journal_start(journal_t *journal, int nblocks)
{
- return jbd2__journal_start(journal, nblocks, 0, GFP_NOFS, 0, 0);
+ return jbd2__journal_start(journal, nblocks, 0, 0, GFP_NOFS, 0, 0);
}
EXPORT_SYMBOL(jbd2_journal_start);
-void jbd2_journal_free_reserved(handle_t *handle)
+static void __jbd2_journal_unreserve_handle(handle_t *handle)
{
journal_t *journal = handle->h_journal;
WARN_ON(!handle->h_reserved);
- sub_reserved_credits(journal, handle->h_buffer_credits);
+ sub_reserved_credits(journal, handle->h_total_credits);
+}
+
+void jbd2_journal_free_reserved(handle_t *handle)
+{
+ __jbd2_journal_unreserve_handle(handle);
jbd2_free_handle(handle);
}
EXPORT_SYMBOL(jbd2_journal_free_reserved);
@@ -571,7 +605,7 @@ int jbd2_journal_start_reserved(handle_t *handle, unsigned int 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, handle->h_buffer_credits);
+ line_no, handle->h_total_credits);
return 0;
}
EXPORT_SYMBOL(jbd2_journal_start_reserved);
@@ -580,6 +614,7 @@ EXPORT_SYMBOL(jbd2_journal_start_reserved);
* int jbd2_journal_extend() - extend buffer credits.
* @handle: handle to 'extend'
* @nblocks: nr blocks to try to extend by.
+ * @revoke_records: number of revoke records to try to extend by.
*
* Some transactions, such as large extends and truncates, can be done
* atomically all at once or in several stages. The operation requests
@@ -596,7 +631,7 @@ EXPORT_SYMBOL(jbd2_journal_start_reserved);
* return code < 0 implies an error
* return code > 0 implies normal transaction-full status.
*/
-int jbd2_journal_extend(handle_t *handle, int nblocks)
+int jbd2_journal_extend(handle_t *handle, int nblocks, int revoke_records)
{
transaction_t *transaction = handle->h_transaction;
journal_t *journal;
@@ -618,6 +653,12 @@ int jbd2_journal_extend(handle_t *handle, int nblocks)
goto error_out;
}
+ nblocks += DIV_ROUND_UP(
+ handle->h_revoke_credits_requested + revoke_records,
+ journal->j_revoke_records_per_block) -
+ DIV_ROUND_UP(
+ handle->h_revoke_credits_requested,
+ journal->j_revoke_records_per_block);
spin_lock(&transaction->t_handle_lock);
wanted = atomic_add_return(nblocks,
&transaction->t_outstanding_credits);
@@ -629,22 +670,16 @@ int jbd2_journal_extend(handle_t *handle, int nblocks)
goto unlock;
}
- 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,
+ handle->h_total_credits,
nblocks);
- handle->h_buffer_credits += nblocks;
+ handle->h_total_credits += nblocks;
handle->h_requested_credits += nblocks;
+ handle->h_revoke_credits += revoke_records;
+ handle->h_revoke_credits_requested += revoke_records;
result = 0;
jbd_debug(3, "extended handle %p by %d\n", handle, nblocks);
@@ -655,11 +690,55 @@ error_out:
return result;
}
+static void stop_this_handle(handle_t *handle)
+{
+ transaction_t *transaction = handle->h_transaction;
+ journal_t *journal = transaction->t_journal;
+ int revokes;
+
+ J_ASSERT(journal_current_handle() == handle);
+ J_ASSERT(atomic_read(&transaction->t_updates) > 0);
+ current->journal_info = NULL;
+ /*
+ * Subtract necessary revoke descriptor blocks from handle credits. We
+ * take care to account only for revoke descriptor blocks the
+ * transaction will really need as large sequences of transactions with
+ * small numbers of revokes are relatively common.
+ */
+ revokes = handle->h_revoke_credits_requested - handle->h_revoke_credits;
+ if (revokes) {
+ int t_revokes, revoke_descriptors;
+ int rr_per_blk = journal->j_revoke_records_per_block;
+
+ WARN_ON_ONCE(DIV_ROUND_UP(revokes, rr_per_blk)
+ > handle->h_total_credits);
+ t_revokes = atomic_add_return(revokes,
+ &transaction->t_outstanding_revokes);
+ revoke_descriptors =
+ DIV_ROUND_UP(t_revokes, rr_per_blk) -
+ DIV_ROUND_UP(t_revokes - revokes, rr_per_blk);
+ handle->h_total_credits -= revoke_descriptors;
+ }
+ atomic_sub(handle->h_total_credits,
+ &transaction->t_outstanding_credits);
+ if (handle->h_rsv_handle)
+ __jbd2_journal_unreserve_handle(handle->h_rsv_handle);
+ if (atomic_dec_and_test(&transaction->t_updates))
+ wake_up(&journal->j_wait_updates);
+
+ rwsem_release(&journal->j_trans_commit_map, 1, _THIS_IP_);
+ /*
+ * Scope of the GFP_NOFS context is over here and so we can restore the
+ * original alloc context.
+ */
+ memalloc_nofs_restore(handle->saved_alloc_context);
+}
/**
* int jbd2_journal_restart() - restart a handle .
* @handle: handle to restart
* @nblocks: nr credits requested
+ * @revoke_records: number of revoke record credits requested
* @gfp_mask: memory allocation flags (for start_this_handle)
*
* Restart a handle for a multi-transaction filesystem
@@ -672,56 +751,48 @@ error_out:
* 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)
+int jbd2__journal_restart(handle_t *handle, int nblocks, int revoke_records,
+ gfp_t gfp_mask)
{
transaction_t *transaction = handle->h_transaction;
journal_t *journal;
tid_t tid;
- int need_to_start, ret;
+ int need_to_start;
+ int ret;
/* 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;
+ tid = transaction->t_tid;
/*
* First unlink the handle from its current transaction, and start the
* commit on that.
*/
- J_ASSERT(atomic_read(&transaction->t_updates) > 0);
- J_ASSERT(journal_current_handle() == handle);
-
- read_lock(&journal->j_state_lock);
- 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);
+ jbd_debug(2, "restarting handle %p\n", handle);
+ stop_this_handle(handle);
handle->h_transaction = NULL;
- current->journal_info = NULL;
- jbd_debug(2, "restarting handle %p\n", handle);
+ /*
+ * TODO: If we use READ_ONCE / WRITE_ONCE for j_commit_request we can
+ * get rid of pointless j_state_lock traffic like this.
+ */
+ read_lock(&journal->j_state_lock);
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);
-
- rwsem_release(&journal->j_trans_commit_map, 1, _THIS_IP_);
- handle->h_buffer_credits = nblocks;
- /*
- * Restore the original nofs context because the journal restart
- * is basically the same thing as journal stop and start.
- * start_this_handle will start a new nofs context.
- */
- memalloc_nofs_restore(handle->saved_alloc_context);
+ handle->h_total_credits = nblocks +
+ DIV_ROUND_UP(revoke_records,
+ journal->j_revoke_records_per_block);
+ handle->h_revoke_credits = revoke_records;
ret = start_this_handle(journal, handle, gfp_mask);
+ trace_jbd2_handle_restart(journal->j_fs_dev->bd_dev,
+ ret ? 0 : handle->h_transaction->t_tid,
+ handle->h_type, handle->h_line_no,
+ handle->h_total_credits);
return ret;
}
EXPORT_SYMBOL(jbd2__journal_restart);
@@ -729,7 +800,7 @@ EXPORT_SYMBOL(jbd2__journal_restart);
int jbd2_journal_restart(handle_t *handle, int nblocks)
{
- return jbd2__journal_restart(handle, nblocks, GFP_NOFS);
+ return jbd2__journal_restart(handle, nblocks, 0, GFP_NOFS);
}
EXPORT_SYMBOL(jbd2_journal_restart);
@@ -1423,12 +1494,12 @@ int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh)
* of the transaction. This needs to be done
* once a transaction -bzzz
*/
- if (handle->h_buffer_credits <= 0) {
+ if (WARN_ON_ONCE(jbd2_handle_buffer_credits(handle) <= 0)) {
ret = -ENOSPC;
goto out_unlock_bh;
}
jh->b_modified = 1;
- handle->h_buffer_credits--;
+ handle->h_total_credits--;
}
/*
@@ -1671,7 +1742,7 @@ drop:
jbd2_journal_put_journal_head(jh);
if (drop_reserve) {
/* no need to reserve log space for this block -bzzz */
- handle->h_buffer_credits++;
+ handle->h_total_credits++;
}
return err;
}
@@ -1700,45 +1771,34 @@ int jbd2_journal_stop(handle_t *handle)
tid_t tid;
pid_t pid;
+ if (--handle->h_ref > 0) {
+ jbd_debug(4, "h_ref %d -> %d\n", handle->h_ref + 1,
+ handle->h_ref);
+ if (is_handle_aborted(handle))
+ return -EIO;
+ return 0;
+ }
if (!transaction) {
/*
- * Handle is already detached from the transaction so
- * there is nothing to do other than decrease a refcount,
- * or free the handle if refcount drops to zero
+ * Handle is already detached from the transaction so there is
+ * nothing to do other than free the handle.
*/
- if (--handle->h_ref > 0) {
- jbd_debug(4, "h_ref %d -> %d\n", handle->h_ref + 1,
- handle->h_ref);
- return err;
- } else {
- if (handle->h_rsv_handle)
- jbd2_free_handle(handle->h_rsv_handle);
- goto free_and_exit;
- }
+ memalloc_nofs_restore(handle->saved_alloc_context);
+ goto free_and_exit;
}
journal = transaction->t_journal;
-
- J_ASSERT(journal_current_handle() == handle);
+ tid = transaction->t_tid;
if (is_handle_aborted(handle))
err = -EIO;
- else
- J_ASSERT(atomic_read(&transaction->t_updates) > 0);
-
- if (--handle->h_ref > 0) {
- jbd_debug(4, "h_ref %d -> %d\n", handle->h_ref + 1,
- handle->h_ref);
- return err;
- }
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,
+ 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));
+ handle->h_total_credits));
/*
* Implement synchronous transaction batching. If the handle
@@ -1798,19 +1858,13 @@ int jbd2_journal_stop(handle_t *handle)
if (handle->h_sync)
transaction->t_synchronous_commit = 1;
- current->journal_info = NULL;
- atomic_sub(handle->h_buffer_credits,
- &transaction->t_outstanding_credits);
/*
* If the handle is marked SYNC, we need to set another commit
- * going! We also want to force a commit if the current
- * transaction is occupying too much of the log, or if the
- * transaction is too old now.
+ * going! We also want to force a commit if the transaction is too
+ * old now.
*/
if (handle->h_sync ||
- (atomic_read(&transaction->t_outstanding_credits) >
- journal->j_max_transaction_buffers) ||
time_after_eq(jiffies, transaction->t_expires)) {
/* Do this even for aborted journals: an abort still
* completes the commit thread, it just doesn't write
@@ -1819,7 +1873,7 @@ int jbd2_journal_stop(handle_t *handle)
jbd_debug(2, "transaction too old, requesting commit for "
"handle %p\n", handle);
/* This is non-blocking */
- jbd2_log_start_commit(journal, transaction->t_tid);
+ jbd2_log_start_commit(journal, tid);
/*
* Special case: JBD2_SYNC synchronous updates require us
@@ -1830,31 +1884,19 @@ int jbd2_journal_stop(handle_t *handle)
}
/*
- * Once we drop t_updates, if it goes to zero the transaction
- * could start committing on us and eventually disappear. So
- * once we do this, we must not dereference transaction
- * pointer again.
+ * Once stop_this_handle() drops t_updates, the transaction could start
+ * committing on us and eventually disappear. So we must not
+ * dereference transaction pointer again after calling
+ * stop_this_handle().
*/
- tid = transaction->t_tid;
- if (atomic_dec_and_test(&transaction->t_updates)) {
- wake_up(&journal->j_wait_updates);
- if (journal->j_barrier_count)
- wake_up(&journal->j_wait_transaction_locked);
- }
-
- rwsem_release(&journal->j_trans_commit_map, 1, _THIS_IP_);
+ stop_this_handle(handle);
if (wait_for_commit)
err = jbd2_log_wait_commit(journal, tid);
- if (handle->h_rsv_handle)
- jbd2_journal_free_reserved(handle->h_rsv_handle);
free_and_exit:
- /*
- * Scope of the GFP_NOFS context is over here and so we can restore the
- * original alloc context.
- */
- memalloc_nofs_restore(handle->saved_alloc_context);
+ if (handle->h_rsv_handle)
+ jbd2_free_handle(handle->h_rsv_handle);
jbd2_free_handle(handle);
return err;
}