ext4: pass context information to jbd2__journal_start()
So we can better understand what bits of ext4 are responsible for
long-running jbd2 handles, use jbd2__journal_start() so we can pass
context information for logging purposes.
The recommended way for finding the longer-running handles is:
T=/sys/kernel/debug/tracing
EVENT=$T/events/jbd2/jbd2_handle_stats
echo "interval > 5" > $EVENT/filter
echo 1 > $EVENT/enable
./run-my-fs-benchmark
cat $T/trace > /tmp/problem-handles
This will list handles that were active for longer than 20ms. Having
longer-running handles is bad, because a commit started at the wrong
time could stall for those 20+ milliseconds, which could delay an
fsync() or an O_SYNC operation. Here is an example line from the
trace file describing a handle which lived on for 311 jiffies, or over
1.2 seconds:
postmark-2917 [000] .... 196.435786: jbd2_handle_stats: dev 254,32
tid 570 type 2 line_no 2541 interval 311 sync 0 requested_blocks 1
dirtied_blocks 0
Signed-off-by: "Theodore Ts'o" <[email protected]>
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 34ed624d..5184103 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -2262,9 +2262,10 @@
dquot_initialize(dir);
retry:
- handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
- EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
- EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
+ handle = ext4_journal_start(dir, EXT4_HT_DIR,
+ (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
+ EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
+ EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb)));
if (IS_ERR(handle))
return PTR_ERR(handle);
@@ -2298,9 +2299,10 @@
dquot_initialize(dir);
retry:
- handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
- EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
- EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
+ handle = ext4_journal_start(dir, EXT4_HT_DIR,
+ (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
+ EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
+ EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb)));
if (IS_ERR(handle))
return PTR_ERR(handle);
@@ -2414,9 +2416,10 @@
dquot_initialize(dir);
retry:
- handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
- EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
- EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
+ handle = ext4_journal_start(dir, EXT4_HT_DIR,
+ (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
+ EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
+ EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb)));
if (IS_ERR(handle))
return PTR_ERR(handle);
@@ -2729,7 +2732,8 @@
dquot_initialize(dir);
dquot_initialize(dentry->d_inode);
- handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
+ handle = ext4_journal_start(dir, EXT4_HT_DIR,
+ EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
if (IS_ERR(handle))
return PTR_ERR(handle);
@@ -2791,7 +2795,8 @@
dquot_initialize(dir);
dquot_initialize(dentry->d_inode);
- handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
+ handle = ext4_journal_start(dir, EXT4_HT_DIR,
+ EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
if (IS_ERR(handle))
return PTR_ERR(handle);
@@ -2870,7 +2875,7 @@
EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb);
}
retry:
- handle = ext4_journal_start(dir, credits);
+ handle = ext4_journal_start(dir, EXT4_HT_DIR, credits);
if (IS_ERR(handle))
return PTR_ERR(handle);
@@ -2908,7 +2913,7 @@
* Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
* + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
*/
- handle = ext4_journal_start(dir,
+ handle = ext4_journal_start(dir, EXT4_HT_DIR,
EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
if (IS_ERR(handle)) {
@@ -2955,8 +2960,9 @@
dquot_initialize(dir);
retry:
- handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
- EXT4_INDEX_EXTRA_TRANS_BLOCKS);
+ handle = ext4_journal_start(dir, EXT4_HT_DIR,
+ (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
+ EXT4_INDEX_EXTRA_TRANS_BLOCKS));
if (IS_ERR(handle))
return PTR_ERR(handle);
@@ -3039,9 +3045,9 @@
* in separate transaction */
if (new_dentry->d_inode)
dquot_initialize(new_dentry->d_inode);
- handle = ext4_journal_start(old_dir, 2 *
- EXT4_DATA_TRANS_BLOCKS(old_dir->i_sb) +
- EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
+ handle = ext4_journal_start(old_dir, EXT4_HT_DIR,
+ (2 * EXT4_DATA_TRANS_BLOCKS(old_dir->i_sb) +
+ EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
if (IS_ERR(handle))
return PTR_ERR(handle);
