nilfs2: extend nilfs_sustat ioctl struct

This adds a new argument to the nilfs_sustat structure.

The extended field allows to delete volatile active state of segments,
which was needed to protect freshly-created segments from garbage
collection but has confused code dealing with segments.  This
extension alleviates the mess and gives room for further
simplifications.

The volatile active flag is not persistent, so it's eliminable on this
occasion without affecting compatibility other than the ioctl change.

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, 6 insertions, 2 deletions

diff --git a/fs/nilfs2/sufile.c b/fs/nilfs2/sufile.c
index b3674a8162a1..cc714c72b138 100644
--- a/fs/nilfs2/sufile.c
+++ b/fs/nilfs2/sufile.c
@@ -446,6 +446,7 @@ int nilfs_sufile_get_stat(struct inode *sufile, struct nilfs_sustat *sustat)
 {
         struct buffer_head *header_bh;
         struct nilfs_sufile_header *header;
+        struct the_nilfs *nilfs = NILFS_MDT(sufile)->mi_nilfs;
         void *kaddr;
         int ret;
 
@@ -460,8 +461,11 @@ int nilfs_sufile_get_stat(struct inode *sufile, struct nilfs_sustat *sustat)
         sustat->ss_nsegs = nilfs_sufile_get_nsegments(sufile);
         sustat->ss_ncleansegs = le64_to_cpu(header->sh_ncleansegs);
         sustat->ss_ndirtysegs = le64_to_cpu(header->sh_ndirtysegs);
-        sustat->ss_ctime = NILFS_MDT(sufile)->mi_nilfs->ns_ctime;
-        sustat->ss_nongc_ctime = NILFS_MDT(sufile)->mi_nilfs->ns_nongc_ctime;
+        sustat->ss_ctime = nilfs->ns_ctime;
+        sustat->ss_nongc_ctime = nilfs->ns_nongc_ctime;
+        spin_lock(&nilfs->ns_last_segment_lock);
+        sustat->ss_prot_seq = nilfs->ns_prot_seq;
+        spin_unlock(&nilfs->ns_last_segment_lock);
         kunmap_atomic(kaddr, KM_USER0);
         brelse(header_bh);