nilfs2: get rid of back pointer to writable sb instance
Nilfs object holds a back pointer to a writable super block instance
in nilfs->ns_writer, and this became eliminable since sb is now made
per device and all inodes have a valid pointer to it.
This deletes the ns_writer pointer and a reader/writer semaphore
protecting it.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
diff --git a/fs/nilfs2/mdt.c b/fs/nilfs2/mdt.c
index 32695f3..0a2ccfc 100644
--- a/fs/nilfs2/mdt.c
+++ b/fs/nilfs2/mdt.c
@@ -78,25 +78,11 @@
struct buffer_head *,
void *))
{
- struct the_nilfs *nilfs = NILFS_I_NILFS(inode);
struct super_block *sb = inode->i_sb;
struct nilfs_transaction_info ti;
struct buffer_head *bh;
int err;
- if (!sb) {
- /*
- * Make sure this function is not called from any
- * read-only context.
- */
- if (!nilfs->ns_writer) {
- WARN_ON(1);
- err = -EROFS;
- goto out;
- }
- sb = nilfs->ns_writer->s_super;
- }
-
nilfs_transaction_begin(sb, &ti, 0);
err = -ENOMEM;
@@ -112,7 +98,7 @@
if (buffer_uptodate(bh))
goto failed_bh;
- bh->b_bdev = nilfs->ns_bdev;
+ bh->b_bdev = sb->s_bdev;
err = nilfs_mdt_insert_new_block(inode, block, bh, init_block);
if (likely(!err)) {
get_bh(bh);
@@ -129,7 +115,7 @@
err = nilfs_transaction_commit(sb);
else
nilfs_transaction_abort(sb);
- out:
+
return err;
}
@@ -398,8 +384,6 @@
{
struct inode *inode;
struct super_block *sb;
- struct the_nilfs *nilfs;
- struct nilfs_sb_info *writer = NULL;
int err = 0;
redirty_page_for_writepage(wbc, page);
@@ -410,25 +394,12 @@
return 0;
sb = inode->i_sb;
- nilfs = NILFS_SB(sb)->s_nilfs;
-
- if (!sb) {
- down_read(&nilfs->ns_writer_sem);
- writer = nilfs->ns_writer;
- if (!writer) {
- up_read(&nilfs->ns_writer_sem);
- return -EROFS;
- }
- sb = writer->s_super;
- }
if (wbc->sync_mode == WB_SYNC_ALL)
err = nilfs_construct_segment(sb);
else if (wbc->for_reclaim)
nilfs_flush_segment(sb, inode->i_ino);
- if (writer)
- up_read(&nilfs->ns_writer_sem);
return err;
}
diff --git a/fs/nilfs2/recovery.c b/fs/nilfs2/recovery.c
index dcb5a98..5d2711c2 100644
--- a/fs/nilfs2/recovery.c
+++ b/fs/nilfs2/recovery.c
@@ -440,7 +440,6 @@
segnum[2] = ri->ri_segnum;
segnum[3] = ri->ri_nextnum;
- nilfs_attach_writer(nilfs, sbi);
/*
* Releasing the next segment of the latest super root.
* The next segment is invalidated by this recovery.
@@ -480,7 +479,6 @@
failed:
/* No need to recover sufile because it will be destroyed on error */
- nilfs_detach_writer(nilfs, sbi);
return err;
}
@@ -599,7 +597,6 @@
};
int state = RF_INIT_ST;
- nilfs_attach_writer(nilfs, sbi);
pseg_start = ri->ri_lsegs_start;
seg_seq = ri->ri_lsegs_start_seq;
segnum = nilfs_get_segnum_of_block(nilfs, pseg_start);
@@ -690,7 +687,6 @@
out:
brelse(bh_sum);
dispose_recovery_list(&dsync_blocks);
- nilfs_detach_writer(nilfs, sbi);
return err;
confused:
diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c
index b0c5e08..56350bf 100644
--- a/fs/nilfs2/segment.c
+++ b/fs/nilfs2/segment.c
@@ -2799,7 +2799,6 @@
int nilfs_attach_segment_constructor(struct nilfs_sb_info *sbi,
struct nilfs_root *root)
{
- struct the_nilfs *nilfs = sbi->s_nilfs;
int err;
if (NILFS_SC(sbi)) {
@@ -2815,10 +2814,8 @@
if (!sbi->s_sc_info)
return -ENOMEM;
- nilfs_attach_writer(nilfs, sbi);
err = nilfs_segctor_start_thread(NILFS_SC(sbi));
if (err) {
- nilfs_detach_writer(nilfs, sbi);
kfree(sbi->s_sc_info);
sbi->s_sc_info = NULL;
}
@@ -2855,5 +2852,4 @@
up_write(&nilfs->ns_segctor_sem);
nilfs_dispose_list(sbi, &garbage_list, 1);
- nilfs_detach_writer(nilfs, sbi);
}
diff --git a/fs/nilfs2/the_nilfs.c b/fs/nilfs2/the_nilfs.c
index 4cc705a..a94aa57 100644
--- a/fs/nilfs2/the_nilfs.c
+++ b/fs/nilfs2/the_nilfs.c
@@ -75,7 +75,6 @@
nilfs->ns_bdev = bdev;
atomic_set(&nilfs->ns_ndirtyblks, 0);
init_rwsem(&nilfs->ns_sem);
- init_rwsem(&nilfs->ns_writer_sem);
INIT_LIST_HEAD(&nilfs->ns_gc_inodes);
spin_lock_init(&nilfs->ns_last_segment_lock);
nilfs->ns_cptree = RB_ROOT;
diff --git a/fs/nilfs2/the_nilfs.h b/fs/nilfs2/the_nilfs.h
index cae56f3..bbbc1c7 100644
--- a/fs/nilfs2/the_nilfs.h
+++ b/fs/nilfs2/the_nilfs.h
@@ -48,9 +48,7 @@
* @ns_flags: flags
* @ns_bdev: block device
* @ns_bdi: backing dev info
- * @ns_writer: back pointer to writable nilfs_sb_info
* @ns_sem: semaphore for shared states
- * @ns_writer_sem: semaphore protecting ns_writer attach/detach
* @ns_sbh: buffer heads of on-disk super blocks
* @ns_sbp: pointers to super block data
* @ns_sbwtime: previous write time of super block
@@ -93,9 +91,7 @@
struct block_device *ns_bdev;
struct backing_dev_info *ns_bdi;
- struct nilfs_sb_info *ns_writer;
struct rw_semaphore ns_sem;
- struct rw_semaphore ns_writer_sem;
/*
* used for
@@ -252,23 +248,6 @@
atomic_inc(&root->count);
}
-static inline void
-nilfs_attach_writer(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi)
-{
- down_write(&nilfs->ns_writer_sem);
- nilfs->ns_writer = sbi;
- up_write(&nilfs->ns_writer_sem);
-}
-
-static inline void
-nilfs_detach_writer(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi)
-{
- down_write(&nilfs->ns_writer_sem);
- if (sbi == nilfs->ns_writer)
- nilfs->ns_writer = NULL;
- up_write(&nilfs->ns_writer_sem);
-}
-
static inline int nilfs_valid_fs(struct the_nilfs *nilfs)
{
unsigned valid_fs;
