This is basically a debugging patch that I've been using to monitor what
exactly xfs is sending back to iomap, and thought I ought to pitch it to
the mailing list universe to see what reaction I get.
--D
---
From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Add some tracepoints so that we can more easily debug what the
filesystem is returning from ->iomap_begin.
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
fs/iomap/apply.c | 7 ++++
fs/iomap/trace.h | 103 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 110 insertions(+)
diff --git a/fs/iomap/apply.c b/fs/iomap/apply.c
index 484dd8eda861..76925b40b5fd 100644
--- a/fs/iomap/apply.c
+++ b/fs/iomap/apply.c
@@ -7,6 +7,7 @@
#include <linux/compiler.h>
#include <linux/fs.h>
#include <linux/iomap.h>
+#include "trace.h"
/*
* Execute a iomap write on a segment of the mapping that spans a
@@ -28,6 +29,8 @@ iomap_apply(struct inode *inode, loff_t pos, loff_t length, unsigned flags,
loff_t written = 0, ret;
u64 end;
+ trace_iomap_apply(inode, pos, length, flags, ops, actor, _RET_IP_);
+
/*
* Need to map a range from start position for length bytes. This can
* span multiple pages - it is only guaranteed to return a range of a
@@ -48,6 +51,10 @@ iomap_apply(struct inode *inode, loff_t pos, loff_t length, unsigned flags,
if (WARN_ON(iomap.length == 0))
return -EIO;
+ trace_iomap_apply_dstmap(inode, &iomap);
+ if (srcmap.type != IOMAP_HOLE)
+ trace_iomap_apply_srcmap(inode, &srcmap);
+
/*
* Cut down the length to the one actually provided by the filesystem,
* as it might not be able to give us the whole size that we requested.
diff --git a/fs/iomap/trace.h b/fs/iomap/trace.h
index 4ca1aa2f3f6e..6dc227b8c47e 100644
--- a/fs/iomap/trace.h
+++ b/fs/iomap/trace.h
@@ -80,6 +80,109 @@ DEFINE_PAGE_EVENT(iomap_writepage);
DEFINE_PAGE_EVENT(iomap_releasepage);
DEFINE_PAGE_EVENT(iomap_invalidatepage);
+#define IOMAP_TYPE_STRINGS \
+ { IOMAP_HOLE, "HOLE" }, \
+ { IOMAP_DELALLOC, "DELALLOC" }, \
+ { IOMAP_MAPPED, "MAPPED" }, \
+ { IOMAP_UNWRITTEN, "UNWRITTEN" }, \
+ { IOMAP_INLINE, "INLINE" }
+
+#define IOMAP_FLAGS_STRINGS \
+ { IOMAP_WRITE, "WRITE" }, \
+ { IOMAP_ZERO, "ZERO" }, \
+ { IOMAP_REPORT, "REPORT" }, \
+ { IOMAP_FAULT, "FAULT" }, \
+ { IOMAP_DIRECT, "DIRECT" }, \
+ { IOMAP_NOWAIT, "NOWAIT" }
+
+#define IOMAP_F_FLAGS_STRINGS \
+ { IOMAP_F_NEW, "NEW" }, \
+ { IOMAP_F_DIRTY, "DIRTY" }, \
+ { IOMAP_F_SHARED, "SHARED" }, \
+ { IOMAP_F_MERGED, "MERGED" }, \
+ { IOMAP_F_BUFFER_HEAD, "BH" }, \
+ { IOMAP_F_SIZE_CHANGED, "SIZE_CHANGED" }
+
+DECLARE_EVENT_CLASS(iomap_class,
+ TP_PROTO(struct inode *inode, struct iomap *iomap),
+ TP_ARGS(inode, iomap),
+ TP_STRUCT__entry(
+ __field(dev_t, dev)
+ __field(u64, ino)
+ __field(u64, addr)
+ __field(loff_t, offset)
+ __field(u64, length)
+ __field(u16, type)
+ __field(u16, flags)
+ __field(dev_t, bdev)
+ ),
+ TP_fast_assign(
+ __entry->dev = inode->i_sb->s_dev;
+ __entry->ino = inode->i_ino;
+ __entry->addr = iomap->addr;
+ __entry->offset = iomap->offset;
+ __entry->length = iomap->length;
+ __entry->type = iomap->type;
+ __entry->flags = iomap->flags;
+ __entry->bdev = iomap->bdev ? iomap->bdev->bd_dev : 0;
+ ),
+ TP_printk("dev %d:%d ino 0x%llx bdev %d:%d addr %lld offset %lld "
+ "length %llu type %s flags %s",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ __entry->ino,
+ MAJOR(__entry->bdev), MINOR(__entry->bdev),
+ __entry->addr,
+ __entry->offset,
+ __entry->length,
+ __print_symbolic(__entry->type, IOMAP_TYPE_STRINGS),
+ __print_flags(__entry->flags, "|", IOMAP_F_FLAGS_STRINGS))
+)
+
+#define DEFINE_IOMAP_EVENT(name) \
+DEFINE_EVENT(iomap_class, name, \
+ TP_PROTO(struct inode *inode, struct iomap *iomap), \
+ TP_ARGS(inode, iomap))
+DEFINE_IOMAP_EVENT(iomap_apply_dstmap);
+DEFINE_IOMAP_EVENT(iomap_apply_srcmap);
+
+TRACE_EVENT(iomap_apply,
+ TP_PROTO(struct inode *inode, loff_t pos, loff_t length,
+ unsigned int flags, const void *ops, void *actor,
+ unsigned long caller),
+ TP_ARGS(inode, pos, length, flags, ops, actor, caller),
+ TP_STRUCT__entry(
+ __field(dev_t, dev)
+ __field(u64, ino)
+ __field(loff_t, pos)
+ __field(loff_t, length)
+ __field(unsigned int, flags)
+ __field(const void *, ops)
+ __field(void *, actor)
+ __field(unsigned long, caller)
+ ),
+ TP_fast_assign(
+ __entry->dev = inode->i_sb->s_dev;
+ __entry->ino = inode->i_ino;
+ __entry->pos = pos;
+ __entry->length = length;
+ __entry->flags = flags;
+ __entry->ops = ops;
+ __entry->actor = actor;
+ __entry->caller = caller;
+ ),
+ TP_printk("dev %d:%d ino 0x%llx pos %lld length %lld flags %s (0x%x) "
+ "ops %ps caller %pS actor %ps",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ __entry->ino,
+ __entry->pos,
+ __entry->length,
+ __print_flags(__entry->flags, "|", IOMAP_FLAGS_STRINGS),
+ __entry->flags,
+ __entry->ops,
+ (void *)__entry->caller,
+ __entry->actor)
+);
+
#endif /* _IOMAP_TRACE_H */
#undef TRACE_INCLUDE_PATH
