nilfs2: add struct nilfs_suinfo_update and flags

Add the nilfs_suinfo_update structure, which contains the information
needed to update one segment usage entry.  The flags specify, which
fields need to be updated.

Signed-off-by: Andreas Rohner <andreas.rohner@gmx.net>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 42 insertions, 0 deletions

diff --git a/include/linux/nilfs2_fs.h b/include/linux/nilfs2_fs.h
index 98755767c7b0..252657874a19 100644
--- a/include/linux/nilfs2_fs.h
+++ b/include/linux/nilfs2_fs.h
@@ -710,6 +710,48 @@ static inline int nilfs_suinfo_clean(const struct nilfs_suinfo *si)
 }
 
 /* ioctl */
+/**
+ * nilfs_suinfo_update - segment usage information update
+ * @sup_segnum: segment number
+ * @sup_flags: flags for which fields are active in sup_sui
+ * @sup_reserved: reserved necessary for alignment
+ * @sup_sui: segment usage information
+ */
+struct nilfs_suinfo_update {
+        __u64 sup_segnum;
+        __u32 sup_flags;
+        __u32 sup_reserved;
+        struct nilfs_suinfo sup_sui;
+};
+
+enum {
+        NILFS_SUINFO_UPDATE_LASTMOD,
+        NILFS_SUINFO_UPDATE_NBLOCKS,
+        NILFS_SUINFO_UPDATE_FLAGS,
+        __NR_NILFS_SUINFO_UPDATE_FIELDS,
+};
+
+#define NILFS_SUINFO_UPDATE_FNS(flag, name)                             \
+static inline void                                                      \
+nilfs_suinfo_update_set_##name(struct nilfs_suinfo_update *sup)         \
+{                                                                       \
+        sup->sup_flags |= 1UL << NILFS_SUINFO_UPDATE_##flag;            \
+}                                                                       \
+static inline void                                                      \
+nilfs_suinfo_update_clear_##name(struct nilfs_suinfo_update *sup)       \
+{                                                                       \
+        sup->sup_flags &= ~(1UL << NILFS_SUINFO_UPDATE_##flag);         \
+}                                                                       \
+static inline int                                                       \
+nilfs_suinfo_update_##name(const struct nilfs_suinfo_update *sup)       \
+{                                                                       \
+        return !!(sup->sup_flags & (1UL << NILFS_SUINFO_UPDATE_##flag));\
+}
+
+NILFS_SUINFO_UPDATE_FNS(LASTMOD, lastmod)
+NILFS_SUINFO_UPDATE_FNS(NBLOCKS, nblocks)
+NILFS_SUINFO_UPDATE_FNS(FLAGS, flags)
+
 enum {
         NILFS_CHECKPOINT,
         NILFS_SNAPSHOT,