nilfs2: simplify remaining sget() use
This simplifies the test function passed on the remaining sget()
callsite in nilfs.
Instead of checking mount type (i.e. ro-mount/rw-mount/snapshot mount)
in the test function passed to sget(), this patch first looks up the
nilfs_sb_info struct which the given mount type matches, and then
acquires the super block instance holding the nilfs_sb_info.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index 5a8c5e4..1d1b6e1 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -336,7 +336,7 @@
put_nilfs(sbi->s_nilfs);
sbi->s_super = NULL;
sb->s_fs_info = NULL;
- kfree(sbi);
+ nilfs_put_sbinfo(sbi);
unlock_kernel();
}
@@ -785,6 +785,7 @@
get_nilfs(nilfs);
sbi->s_nilfs = nilfs;
sbi->s_super = sb;
+ atomic_set(&sbi->s_count, 1);
err = init_nilfs(nilfs, sbi, (char *)data);
if (err)
@@ -902,7 +903,7 @@
failed_sbi:
put_nilfs(nilfs);
sb->s_fs_info = NULL;
- kfree(sbi);
+ nilfs_put_sbinfo(sbi);
return err;
}
@@ -1014,6 +1015,7 @@
struct nilfs_super_data {
struct block_device *bdev;
+ struct nilfs_sb_info *sbi;
__u64 cno;
int flags;
};
@@ -1071,27 +1073,8 @@
static int nilfs_test_bdev_super(struct super_block *s, void *data)
{
struct nilfs_super_data *sd = data;
- int ret;
- if (s->s_bdev != sd->bdev)
- return 0;
-
- if (!((s->s_flags | sd->flags) & MS_RDONLY))
- return 1; /* Reuse an old R/W-mode super_block */
-
- if (s->s_flags & sd->flags & MS_RDONLY) {
- if (down_read_trylock(&s->s_umount)) {
- ret = s->s_root &&
- (sd->cno == NILFS_SB(s)->s_snapshot_cno);
- up_read(&s->s_umount);
- /*
- * This path is locked with sb_lock by sget().
- * So, drop_super() causes deadlock.
- */
- return ret;
- }
- }
- return 0;
+ return sd->sbi && s->s_fs_info == (void *)sd->sbi;
}
static int
@@ -1112,7 +1095,6 @@
* much more information than normal filesystems to identify mount
* instance. For snapshot mounts, not only a mount type (ro-mount
* or rw-mount) but also a checkpoint number is required.
- * The results are passed in sget() using nilfs_super_data.
*/
sd.cno = 0;
sd.flags = flags;
@@ -1148,13 +1130,23 @@
}
/*
- * Search specified snapshot or R/W mode super_block
+ * Find existing nilfs_sb_info struct
*/
+ sd.sbi = nilfs_find_sbinfo(nilfs, !(flags & MS_RDONLY), sd.cno);
+
if (!sd.cno)
/* trying to get the latest checkpoint. */
sd.cno = nilfs_last_cno(nilfs);
+ /*
+ * Get super block instance holding the nilfs_sb_info struct.
+ * A new instance is allocated if no existing mount is present or
+ * existing instance has been unmounted.
+ */
s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, &sd);
+ if (sd.sbi)
+ nilfs_put_sbinfo(sd.sbi);
+
if (IS_ERR(s)) {
err = PTR_ERR(s);
goto failed_unlock;