ext4: add more tracepoints and use dev_t in the trace buffer

- Add more ext4 tracepoints.
- Change ext4 tracepoints to use dev_t field with MAJOR/MINOR macros
so that we can save 4 bytes in the ring buffer on some platforms.
- Add sync_mode to ext4_da_writepages, ext4_da_write_pages, and
ext4_da_writepages_result tracepoints. Also remove for_reclaim
field from ext4_da_writepages since it is usually not very useful.

Signed-off-by: Jiaying Zhang <jiayingz@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 12 insertions, 1 deletions

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 9ea1bc64ca6d..f46f6e3c02d7 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -44,6 +44,8 @@
 #include "ext4_jbd2.h"
 #include "ext4_extents.h"
 
+#include <trace/events/ext4.h>
+
 static int ext4_ext_truncate_extend_restart(handle_t *handle,
                                             struct inode *inode,
                                             int needed)
@@ -664,6 +666,8 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
                 if (unlikely(!bh))
                         goto err;
                 if (!bh_uptodate_or_lock(bh)) {
+                        trace_ext4_ext_load_extent(inode, block,
+                                                path[ppos].p_block);
                         if (bh_submit_read(bh) < 0) {
                                 put_bh(bh);
                                 goto err;
@@ -3297,7 +3301,7 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
         struct ext4_ext_path *path = NULL;
         struct ext4_extent_header *eh;
         struct ext4_extent newex, *ex;
-        ext4_fsblk_t newblock;
+        ext4_fsblk_t newblock = 0;
         int err = 0, depth, ret;
         unsigned int allocated = 0;
         struct ext4_allocation_request ar;
@@ -3305,6 +3309,7 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
 
         ext_debug("blocks %u/%u requested for inode %lu\n",
                   map->m_lblk, map->m_len, inode->i_ino);
+        trace_ext4_ext_map_blocks_enter(inode, map->m_lblk, map->m_len, flags);
 
         /* check in cache */
         if (ext4_ext_in_cache(inode, map->m_lblk, &newex)) {
@@ -3525,6 +3530,8 @@ out2:
                 ext4_ext_drop_refs(path);
                 kfree(path);
         }
+        trace_ext4_ext_map_blocks_exit(inode, map->m_lblk,
+                newblock, map->m_len, err ? err : allocated);
         return err ? err : allocated;
 }
 
@@ -3658,6 +3665,7 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
         if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
                 return -EOPNOTSUPP;
 
+        trace_ext4_fallocate_enter(inode, offset, len, mode);
         map.m_lblk = offset >> blkbits;
         /*
          * We can't just convert len to max_blocks because
@@ -3673,6 +3681,7 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
         ret = inode_newsize_ok(inode, (len + offset));
         if (ret) {
                 mutex_unlock(&inode->i_mutex);
+                trace_ext4_fallocate_exit(inode, offset, max_blocks, ret);
                 return ret;
         }
 retry:
@@ -3717,6 +3726,8 @@ retry:
                 goto retry;
         }
         mutex_unlock(&inode->i_mutex);
+        trace_ext4_fallocate_exit(inode, offset, max_blocks,
+                                ret > 0 ? ret2 : ret);
         return ret > 0 ? ret2 : ret;
 }