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>

diff --git a/fs/ext2/Makefile b/fs/ext2/Makefile
index 311479d864a75e42dd4363455fb09dbba1d98229..8860948ef9ca4e0a9c3f90311c3cecf0c5b70c63 100644 (file)
--- a/fs/ext2/Makefile
+++ b/fs/ext2/Makefile
@@ -6,7 +6,10 @@
 obj-$(CONFIG_EXT2_FS) += ext2.o
 
 ext2-y := balloc.o dir.o file.o ialloc.o inode.o \
-         ioctl.o namei.o super.o symlink.o
+         ioctl.o namei.o super.o symlink.o trace.o
+
+# For tracepoints to include our trace.h from tracepoint infrastructure
+CFLAGS_trace.o := -I$(src)
 
 ext2-$(CONFIG_EXT2_FS_XATTR)    += xattr.o xattr_user.o xattr_trusted.o
 ext2-$(CONFIG_EXT2_FS_POSIX_ACL) += acl.o

diff --git a/fs/ext2/file.c b/fs/ext2/file.c
index 98add36c1a5907da7a7fec0fec2bb6f16d5f9da5..7a32f202908e9e86a5342aa73525843c92863466 100644 (file)
--- 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;
 }
 

diff --git a/fs/ext2/trace.c b/fs/ext2/trace.c
new file mode 100644 (file)
index 0000000..b01cdf6
--- /dev/null
+++ b/fs/ext2/trace.c
@@ -0,0 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "ext2.h"
+#include <linux/uio.h>
+
+#define CREATE_TRACE_POINTS
+#include "trace.h"

diff --git a/fs/ext2/trace.h b/fs/ext2/trace.h
new file mode 100644 (file)
index 0000000..7d230e1
--- /dev/null
+++ b/fs/ext2/trace.h
@@ -0,0 +1,94 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM ext2
+
+#if !defined(_EXT2_TRACE_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _EXT2_TRACE_H
+
+#include <linux/tracepoint.h>
+
+DECLARE_EVENT_CLASS(ext2_dio_class,
+       TP_PROTO(struct kiocb *iocb, struct iov_iter *iter, ssize_t ret),
+       TP_ARGS(iocb, iter, ret),
+       TP_STRUCT__entry(
+               __field(dev_t,  dev)
+               __field(ino_t,  ino)
+               __field(loff_t, isize)
+               __field(loff_t, pos)
+               __field(size_t, count)
+               __field(int,    ki_flags)
+               __field(bool,   aio)
+               __field(ssize_t, ret)
+       ),
+       TP_fast_assign(
+               __entry->dev = file_inode(iocb->ki_filp)->i_sb->s_dev;
+               __entry->ino = file_inode(iocb->ki_filp)->i_ino;
+               __entry->isize = file_inode(iocb->ki_filp)->i_size;
+               __entry->pos = iocb->ki_pos;
+               __entry->count = iov_iter_count(iter);
+               __entry->ki_flags = iocb->ki_flags;
+               __entry->aio = !is_sync_kiocb(iocb);
+               __entry->ret = ret;
+       ),
+       TP_printk("dev %d:%d ino 0x%lx isize 0x%llx pos 0x%llx len %zu flags %s aio %d ret %zd",
+                 MAJOR(__entry->dev), MINOR(__entry->dev),
+                 __entry->ino,
+                 __entry->isize,
+                 __entry->pos,
+                 __entry->count,
+                 __print_flags(__entry->ki_flags, "|", TRACE_IOCB_STRINGS),
+                 __entry->aio,
+                 __entry->ret)
+);
+
+#define DEFINE_DIO_RW_EVENT(name)                                        \
+DEFINE_EVENT(ext2_dio_class, name,                                       \
+       TP_PROTO(struct kiocb *iocb, struct iov_iter *iter, ssize_t ret), \
+       TP_ARGS(iocb, iter, ret))
+DEFINE_DIO_RW_EVENT(ext2_dio_write_begin);
+DEFINE_DIO_RW_EVENT(ext2_dio_write_end);
+DEFINE_DIO_RW_EVENT(ext2_dio_write_buff_end);
+DEFINE_DIO_RW_EVENT(ext2_dio_read_begin);
+DEFINE_DIO_RW_EVENT(ext2_dio_read_end);
+
+TRACE_EVENT(ext2_dio_write_endio,
+       TP_PROTO(struct kiocb *iocb, ssize_t size, int ret),
+       TP_ARGS(iocb, size, ret),
+       TP_STRUCT__entry(
+               __field(dev_t,  dev)
+               __field(ino_t,  ino)
+               __field(loff_t, isize)
+               __field(loff_t, pos)
+               __field(ssize_t, size)
+               __field(int,    ki_flags)
+               __field(bool,   aio)
+               __field(int,    ret)
+       ),
+       TP_fast_assign(
+               __entry->dev = file_inode(iocb->ki_filp)->i_sb->s_dev;
+               __entry->ino = file_inode(iocb->ki_filp)->i_ino;
+               __entry->isize = file_inode(iocb->ki_filp)->i_size;
+               __entry->pos = iocb->ki_pos;
+               __entry->size = size;
+               __entry->ki_flags = iocb->ki_flags;
+               __entry->aio = !is_sync_kiocb(iocb);
+               __entry->ret = ret;
+       ),
+       TP_printk("dev %d:%d ino 0x%lx isize 0x%llx pos 0x%llx len %zd flags %s aio %d ret %d",
+                 MAJOR(__entry->dev), MINOR(__entry->dev),
+                 __entry->ino,
+                 __entry->isize,
+                 __entry->pos,
+                 __entry->size,
+                 __print_flags(__entry->ki_flags, "|", TRACE_IOCB_STRINGS),
+                 __entry->aio,
+                 __entry->ret)
+);
+
+#endif /* _EXT2_TRACE_H */
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#define TRACE_INCLUDE_FILE trace
+#include <trace/define_trace.h>