[RFC PATCH 45/76] cachefiles: Add I/O tracepoints

[David Howells]

Add some cache I/O tracepoints.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---

 fs/cachefiles/interface.c         |    2 +
 fs/cachefiles/io.c                |    2 +
 include/trace/events/cachefiles.h |  125 +++++++++++++++++++++++++++++++++++++
 3 files changed, 129 insertions(+)

diff --git a/fs/cachefiles/interface.c b/fs/cachefiles/interface.c
index c14e2b4f5b24..654c6efb5a0a 100644
--- a/fs/cachefiles/interface.c
+++ b/fs/cachefiles/interface.c
@@ -179,6 +179,7 @@ static void cachefiles_update_object(struct fscache_object *_object)
 			.dentry	= object->dentry
 		};
 		_debug("trunc %llx -> %llx", i_size, object_size);
+		trace_cachefiles_trunc(object, inode, i_size, object_size);
 		ret = vfs_truncate(&path, object_size);
 		if (ret < 0) {
 			cachefiles_io_error_obj(object, "Trunc-to-size failed");
@@ -190,6 +191,7 @@ static void cachefiles_update_object(struct fscache_object *_object)
 		i_size = i_size_read(inode);
 		_debug("trunc %llx -> %llx", i_size, object_size);
 		if (i_size < object_size) {
+			trace_cachefiles_trunc(object, inode, i_size, object_size);
 			ret = vfs_truncate(&path, object_size);
 			if (ret < 0) {
 				cachefiles_io_error_obj(object, "Trunc-to-dio-size failed");
diff --git a/fs/cachefiles/io.c b/fs/cachefiles/io.c
index 4c66b9183dd6..c9866bd5e010 100644
--- a/fs/cachefiles/io.c
+++ b/fs/cachefiles/io.c
@@ -139,6 +139,7 @@ int cachefiles_read(struct fscache_op_resources *opr,
 
 	cachefiles_grab_object(&object->fscache, fscache_obj_get_ioreq);
 
+	trace_cachefiles_read(object, file_inode(file), ki->iocb.ki_pos, len - skipped);
 	old_nofs = memalloc_nofs_save();
 	ret = call_read_iter(file, &ki->iocb, iter);
 	memalloc_nofs_restore(old_nofs);
@@ -267,6 +268,7 @@ int cachefiles_write(struct fscache_op_resources *opr,
 
 	cachefiles_grab_object(&object->fscache, fscache_obj_get_ioreq);
 
+	trace_cachefiles_write(object, inode, ki->iocb.ki_pos, len);
 	old_nofs = memalloc_nofs_save();
 	ret = call_write_iter(file, &ki->iocb, iter);
 	memalloc_nofs_restore(old_nofs);
diff --git a/include/trace/events/cachefiles.h b/include/trace/events/cachefiles.h
index e7af1d683009..f9f48c0f5080 100644
--- a/include/trace/events/cachefiles.h
+++ b/include/trace/events/cachefiles.h
@@ -351,6 +351,131 @@ TRACE_EVENT(cachefiles_coherency,
 		      __entry->content)
 	    );
 
+TRACE_EVENT(cachefiles_read,
+	    TP_PROTO(struct cachefiles_object *obj,
+		     struct inode *backer,
+		     loff_t start,
+		     size_t len),
+
+	    TP_ARGS(obj, backer, start, len),
+
+	    TP_STRUCT__entry(
+		    __field(unsigned int,			obj	)
+		    __field(unsigned int,			backer	)
+		    __field(size_t,				len	)
+		    __field(loff_t,				start	)
+			     ),
+
+	    TP_fast_assign(
+		    __entry->obj	= obj->fscache.debug_id;
+		    __entry->backer	= backer->i_ino;
+		    __entry->start	= start;
+		    __entry->len	= len;
+			   ),
+
+	    TP_printk("o=%08x b=%08x s=%llx l=%zx",
+		      __entry->obj,
+		      __entry->backer,
+		      __entry->start,
+		      __entry->len)
+	    );
+
+TRACE_EVENT(cachefiles_write,
+	    TP_PROTO(struct cachefiles_object *obj,
+		     struct inode *backer,
+		     loff_t start,
+		     size_t len),
+
+	    TP_ARGS(obj, backer, start, len),
+
+	    TP_STRUCT__entry(
+		    __field(unsigned int,			obj	)
+		    __field(unsigned int,			backer	)
+		    __field(size_t,				len	)
+		    __field(loff_t,				start	)
+			     ),
+
+	    TP_fast_assign(
+		    __entry->obj	= obj->fscache.debug_id;
+		    __entry->backer	= backer->i_ino;
+		    __entry->start	= start;
+		    __entry->len	= len;
+			   ),
+
+	    TP_printk("o=%08x b=%08x s=%llx l=%zx",
+		      __entry->obj,
+		      __entry->backer,
+		      __entry->start,
+		      __entry->len)
+	    );
+
+TRACE_EVENT(cachefiles_trunc,
+	    TP_PROTO(struct cachefiles_object *obj, struct inode *backer,
+		     loff_t from, loff_t to),
+
+	    TP_ARGS(obj, backer, from, to),
+
+	    TP_STRUCT__entry(
+		    __field(unsigned int,			obj	)
+		    __field(unsigned int,			backer	)
+		    __field(loff_t,				from	)
+		    __field(loff_t,				to	)
+			     ),
+
+	    TP_fast_assign(
+		    __entry->obj	= obj->fscache.debug_id;
+		    __entry->backer	= backer->i_ino;
+		    __entry->from	= from;
+		    __entry->to		= to;
+			   ),
+
+	    TP_printk("o=%08x b=%08x l=%llx->%llx",
+		      __entry->obj,
+		      __entry->backer,
+		      __entry->from,
+		      __entry->to)
+	    );
+
+TRACE_EVENT(cachefiles_tmpfile,
+	    TP_PROTO(struct cachefiles_object *obj, struct inode *backer),
+
+	    TP_ARGS(obj, backer),
+
+	    TP_STRUCT__entry(
+		    __field(unsigned int,			obj	)
+		    __field(unsigned int,			backer	)
+			     ),
+
+	    TP_fast_assign(
+		    __entry->obj	= obj->fscache.debug_id;
+		    __entry->backer	= backer->i_ino;
+			   ),
+
+	    TP_printk("o=%08x b=%08x",
+		      __entry->obj,
+		      __entry->backer)
+	    );
+
+TRACE_EVENT(cachefiles_link,
+	    TP_PROTO(struct cachefiles_object *obj, struct inode *backer),
+
+	    TP_ARGS(obj, backer),
+
+	    TP_STRUCT__entry(
+		    __field(unsigned int,			obj	)
+		    __field(unsigned int,			backer	)
+			     ),
+
+	    TP_fast_assign(
+		    __entry->obj	= obj->fscache.debug_id;
+		    __entry->backer	= backer->i_ino;
+			   ),
+
+	    TP_printk("o=%08x b=%08x",
+		      __entry->obj,
+		      __entry->backer)
+	    );
+
 #endif /* _TRACE_CACHEFILES_H */
 
 /* This part must be outside protection */