Al pointed out that the test for whether a mapping refers to a blockdev
inode in these tracepoints is garbage, as the superblock is always
non-NULL.
Add a new mapping_to_dev helper function that determines this the
correct way, and change the tracepoints to use it. Also, fix up the
indentation in this file.
Reported-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
include/linux/fs.h | 16 ++++++
include/trace/events/filemap.h | 99 +++++++++++++++-------------------
2 files changed, 60 insertions(+), 55 deletions(-)
Al, sorry.
I had based the original on an older tree. This one should merge more
cleanly, and also just adds a single, non-conditionally compiled helper.
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 40be2ccb87f3..264ac7d602a6 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2616,6 +2616,22 @@ static inline bool sb_is_blkdev_sb(struct super_block *sb)
return false;
}
#endif
+
+/*
+ * Return the device associated with this mapping.
+ *
+ * For normal inodes, return the sb of the backing filesystem, for blockdev
+ * inodes, return the block device number associated with the inode.
+ */
+static inline dev_t mapping_to_dev(struct address_space *mapping)
+{
+ struct inode *inode = mapping->host;
+
+ if (sb_is_blkdev_sb(inode->i_sb))
+ return inode->i_rdev;
+ return inode->i_sb->s_dev;
+}
+
extern int sync_filesystem(struct super_block *);
extern const struct file_operations def_blk_fops;
extern const struct file_operations def_chr_fops;
diff --git a/include/trace/events/filemap.h b/include/trace/events/filemap.h
index 796053e162d2..bddcc7d0bdfd 100644
--- a/include/trace/events/filemap.h
+++ b/include/trace/events/filemap.h
@@ -30,10 +30,7 @@ DECLARE_EVENT_CLASS(mm_filemap_op_page_cache,
__entry->pfn = page_to_pfn(page);
__entry->i_ino = page->mapping->host->i_ino;
__entry->index = page->index;
- if (page->mapping->host->i_sb)
- __entry->s_dev = page->mapping->host->i_sb->s_dev;
- else
- __entry->s_dev = page->mapping->host->i_rdev;
+ __entry->s_dev = mapping_to_dev(page->mapping);
),
TP_printk("dev %d:%d ino %lx page=%p pfn=%lu ofs=%lu",
@@ -55,60 +52,52 @@ DEFINE_EVENT(mm_filemap_op_page_cache, mm_filemap_add_to_page_cache,
);
TRACE_EVENT(filemap_set_wb_err,
- TP_PROTO(struct address_space *mapping, errseq_t eseq),
-
- TP_ARGS(mapping, eseq),
-
- TP_STRUCT__entry(
- __field(unsigned long, i_ino)
- __field(dev_t, s_dev)
- __field(errseq_t, errseq)
- ),
-
- TP_fast_assign(
- __entry->i_ino = mapping->host->i_ino;
- __entry->errseq = eseq;
- if (mapping->host->i_sb)
- __entry->s_dev = mapping->host->i_sb->s_dev;
- else
- __entry->s_dev = mapping->host->i_rdev;
- ),
-
- TP_printk("dev=%d:%d ino=0x%lx errseq=0x%x",
- MAJOR(__entry->s_dev), MINOR(__entry->s_dev),
- __entry->i_ino, __entry->errseq)
+ TP_PROTO(struct address_space *mapping, errseq_t eseq),
+
+ TP_ARGS(mapping, eseq),
+
+ TP_STRUCT__entry(
+ __field(unsigned long, i_ino)
+ __field(dev_t, s_dev)
+ __field(errseq_t, errseq)
+ ),
+
+ TP_fast_assign(
+ __entry->i_ino = mapping->host->i_ino;
+ __entry->errseq = eseq;
+ __entry->s_dev = mapping_to_dev(mapping);
+ ),
+
+ TP_printk("dev=%d:%d ino=0x%lx errseq=0x%x",
+ MAJOR(__entry->s_dev), MINOR(__entry->s_dev),
+ __entry->i_ino, __entry->errseq)
);
TRACE_EVENT(file_check_and_advance_wb_err,
- TP_PROTO(struct file *file, errseq_t old),
-
- TP_ARGS(file, old),
-
- TP_STRUCT__entry(
- __field(struct file *, file)
- __field(unsigned long, i_ino)
- __field(dev_t, s_dev)
- __field(errseq_t, old)
- __field(errseq_t, new)
- ),
-
- TP_fast_assign(
- __entry->file = file;
- __entry->i_ino = file->f_mapping->host->i_ino;
- if (file->f_mapping->host->i_sb)
- __entry->s_dev =
- file->f_mapping->host->i_sb->s_dev;
- else
- __entry->s_dev =
- file->f_mapping->host->i_rdev;
- __entry->old = old;
- __entry->new = file->f_wb_err;
- ),
-
- TP_printk("file=%p dev=%d:%d ino=0x%lx old=0x%x new=0x%x",
- __entry->file, MAJOR(__entry->s_dev),
- MINOR(__entry->s_dev), __entry->i_ino, __entry->old,
- __entry->new)
+ TP_PROTO(struct file *file, errseq_t old),
+
+ TP_ARGS(file, old),
+
+ TP_STRUCT__entry(
+ __field(struct file *, file)
+ __field(unsigned long, i_ino)
+ __field(dev_t, s_dev)
+ __field(errseq_t, old)
+ __field(errseq_t, new)
+ ),
+
+ TP_fast_assign(
+ __entry->file = file;
+ __entry->i_ino = file->f_mapping->host->i_ino;
+ __entry->s_dev = mapping_to_dev(file->f_mapping);
+ __entry->old = old;
+ __entry->new = file->f_wb_err;
+ ),
+
+ TP_printk("file=%p dev=%d:%d ino=0x%lx old=0x%x new=0x%x",
+ __entry->file, MAJOR(__entry->s_dev),
+ MINOR(__entry->s_dev), __entry->i_ino, __entry->old,
+ __entry->new)
);
#endif /* _TRACE_FILEMAP_H */
--
2.24.1
