md: support updating bitmap parameters via sysfs.
A new attribute directory 'bitmap' in 'md' is created which
contains files for configuring the bitmap.
'location' identifies where the bitmap is, either 'none',
or 'file' or 'sector offset from metadata'.
Writing 'location' can create or remove a bitmap.
Adding a 'file' bitmap this way is not yet supported.
'chunksize' and 'time_base' must be set before 'location'
can be set.
'chunksize' can be set before creating a bitmap, but is
currently always over-ridden by the bitmap superblock.
'time_base' and 'backlog' can be updated at any time.
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Andre Noll <maan@systemlinux.org>
diff --git a/drivers/md/md.h b/drivers/md/md.h
index b5c3069..fce0207 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -372,7 +372,7 @@
ssize_t (*show)(mddev_t *, char *);
ssize_t (*store)(mddev_t *, const char *, size_t);
};
-
+extern struct attribute_group md_bitmap_group;
static inline char * mdname (mddev_t * mddev)
{
@@ -465,5 +465,6 @@
extern int md_integrity_register(mddev_t *mddev);
extern void md_integrity_add_rdev(mdk_rdev_t *rdev, mddev_t *mddev);
extern int strict_strtoul_scaled(const char *cp, unsigned long *res, int scale);
+extern void restore_bitmap_write_access(struct file *file);
#endif /* _MD_MD_H */