ext2: Add direct-io trace points

This patch adds the trace point to ext2 direct-io apis
in fs/ext2/file.c

Here is how the output looks like

        a.out-467865 [006]  6758.170968: ext2_dio_write_begin: dev 7:12 ino 0xe isize 0x1000 pos 0x0 len 4096 flags DIRECT|WRITE aio 1 ret 0
        a.out-467865 [006]  6758.171061: ext2_dio_write_end:   dev 7:12 ino 0xe isize 0x1000 pos 0x0 len 0 flags DIRECT|WRITE aio 1 ret -529
kworker/3:153-444162 [003]  6758.171252: ext2_dio_write_endio: dev 7:12 ino 0xe isize 0x1000 pos 0x0 len 4096 flags DIRECT|WRITE aio 1 ret 0
        a.out-468222 [001]  6761.628924: ext2_dio_read_begin:  dev 7:12 ino 0xe isize 0x1000 pos 0x0 len 4096 flags DIRECT aio 1 ret 0
        a.out-468222 [001]  6761.629063: ext2_dio_read_end:    dev 7:12 ino 0xe isize 0x1000 pos 0x0 len 0 flags DIRECT aio 1 ret -529
        a.out-468428 [005]  6763.937454: ext2_dio_write_begin: dev 7:12 ino 0xe isize 0x1000 pos 0x0 len 4096 flags DIRECT aio 0 ret 0
        a.out-468428 [005]  6763.937829: ext2_dio_write_endio: dev 7:12 ino 0xe isize 0x1000 pos 0x0 len 4096 flags DIRECT aio 0 ret 0
        a.out-468428 [005]  6763.937847: ext2_dio_write_end:   dev 7:12 ino 0xe isize 0x1000 pos 0x1000 len 0 flags DIRECT aio 0 ret 4096
        a.out-468609 [000]  6765.702878: ext2_dio_read_begin:  dev 7:12 ino 0xe isize 0x1000 pos 0x0 len 4096 flags DIRECT aio 0 ret 0
        a.out-468609 [000]  6765.703243: ext2_dio_read_end:    dev 7:12 ino 0xe isize 0x1000 pos 0x1000 len 0 flags DIRECT aio 0 ret 4096

Reported-and-tested-by: Disha Goel <disgoel@linux.ibm.com>
[Need to add CFLAGS_trace for fixing unable to find trace file problem]
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Message-Id: <b8b0897fa2b273a448d7b4ba7317357ac73c08bc.1682069716.git.ritesh.list@gmail.com>

1 files changed, 9 insertions, 1 deletions

diff --git a/fs/ext2/file.c b/fs/ext2/file.c
index 98add36c1a59..7a32f202908e 100644
--- a/fs/ext2/file.c
+++ b/fs/ext2/file.c
@@ -29,6 +29,7 @@
 #include "ext2.h"
 #include "xattr.h"
 #include "acl.h"
+#include "trace.h"
 
 #ifdef CONFIG_FS_DAX
 static ssize_t ext2_dax_read_iter(struct kiocb *iocb, struct iov_iter *to)
@@ -168,9 +169,11 @@ static ssize_t ext2_dio_read_iter(struct kiocb *iocb, struct iov_iter *to)
 	struct inode *inode = file->f_mapping->host;
 	ssize_t ret;
 
+	trace_ext2_dio_read_begin(iocb, to, 0);
 	inode_lock_shared(inode);
 	ret = iomap_dio_rw(iocb, to, &ext2_iomap_ops, NULL, 0, NULL, 0);
 	inode_unlock_shared(inode);
+	trace_ext2_dio_read_end(iocb, to, ret);
 
 	return ret;
 }
@@ -198,6 +201,7 @@ static int ext2_dio_write_end_io(struct kiocb *iocb, ssize_t size,
 		mark_inode_dirty(inode);
 	}
 out:
+	trace_ext2_dio_write_endio(iocb, size, error);
 	return error;
 }
 
@@ -214,7 +218,9 @@ static ssize_t ext2_dio_write_iter(struct kiocb *iocb, struct iov_iter *from)
 	unsigned long blocksize = inode->i_sb->s_blocksize;
 	loff_t offset = iocb->ki_pos;
 	loff_t count = iov_iter_count(from);
+	ssize_t status = 0;
 
+	trace_ext2_dio_write_begin(iocb, from, 0);
 	inode_lock(inode);
 	ret = generic_write_checks(iocb, from);
 	if (ret <= 0)
@@ -242,7 +248,6 @@ static ssize_t ext2_dio_write_iter(struct kiocb *iocb, struct iov_iter *from)
 	/* handle case for partial write and for fallback to buffered write */
 	if (ret >= 0 && iov_iter_count(from)) {
 		loff_t pos, endbyte;
-		ssize_t status;
 		int ret2;
 
 		iocb->ki_flags &= ~IOCB_DIRECT;
@@ -268,6 +273,9 @@ static ssize_t ext2_dio_write_iter(struct kiocb *iocb, struct iov_iter *from)
 
 out_unlock:
 	inode_unlock(inode);
+	if (status)
+		trace_ext2_dio_write_buff_end(iocb, from, status);
+	trace_ext2_dio_write_end(iocb, from, ret);
 	return ret;
 }