fix: ext4: Reserve revoke credits for freed blocks (v5.5)

See upstream commit:

  commit 83448bdfb59731c2f54784ed3f4a93ff95be6e7e
  Author: Jan Kara <jack@suse.cz>
  Date:   Tue Nov 5 17:44:29 2019 +0100

    ext4: Reserve revoke credits for freed blocks

    So far we have reserved only relatively high fixed amount of revoke
    credits for each transaction. We over-reserved by large amount for most
    cases but when freeing large directories or files with data journalling,
    the fixed amount is not enough. In fact the worst case estimate is
    inconveniently large (maximum extent size) for freeing of one extent.

    We fix this by doing proper estimate of the amount of blocks that need
    to be revoked when removing blocks from the inode due to truncate or
    hole punching and otherwise reserve just a small amount of revoke
    credits for each transaction to accommodate freeing of xattrs block or
    so.

Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

diff --git a/instrumentation/events/lttng-module/ext4.h b/instrumentation/events/lttng-module/ext4.h
index b2ca8a7c3ece814596b28a6e2b9a18228587c6fd..17809d21fa82373ddb96ecc4318af49cf90d0726 100644 (file)
--- a/instrumentation/events/lttng-module/ext4.h
+++ b/instrumentation/events/lttng-module/ext4.h
@@ -1255,7 +1255,36 @@ LTTNG_TRACEPOINT_EVENT(ext4_load_inode,
        )
 )
 
-#if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,11,0))
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,5,0))
+
+LTTNG_TRACEPOINT_EVENT(ext4_journal_start,
+       TP_PROTO(struct super_block *sb, int blocks, int rsv_blocks,
+                int revoke_creds, unsigned long IP),
+
+       TP_ARGS(sb, blocks, rsv_blocks, revoke_creds, IP),
+
+       TP_FIELDS(
+               ctf_integer(dev_t, dev, sb->s_dev)
+               ctf_integer(unsigned long, ip, IP)
+               ctf_integer(int, blocks, blocks)
+               ctf_integer(int, rsv_blocks, rsv_blocks)
+               ctf_integer(int, revoke_creds, revoke_creds)
+       )
+)
+
+LTTNG_TRACEPOINT_EVENT(ext4_journal_start_reserved,
+       TP_PROTO(struct super_block *sb, int blocks, unsigned long IP),
+
+       TP_ARGS(sb, blocks, IP),
+
+       TP_FIELDS(
+               ctf_integer(dev_t, dev, sb->s_dev)
+               ctf_integer(unsigned long, ip, IP)
+               ctf_integer(int, blocks, blocks)
+       )
+)
+
+#elif (LINUX_VERSION_CODE >= KERNEL_VERSION(3,11,0))
 
 LTTNG_TRACEPOINT_EVENT(ext4_journal_start,
        TP_PROTO(struct super_block *sb, int blocks, int rsv_blocks,