nilfs2: get rid of bd_mount_sem use from nilfs
This will remove every bd_mount_sem use in nilfs.
The intended exclusion control was replaced by the previous patch
("nilfs2: correct exclusion control in nilfs_remount function") for
nilfs_remount(), and this patch will replace remains with a new mutex
that this inserts in nilfs object.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/nilfs2/cpfile.c b/fs/nilfs2/cpfile.c
index 300f1cd..cadd36b 100644
--- a/fs/nilfs2/cpfile.c
+++ b/fs/nilfs2/cpfile.c
@@ -864,11 +864,11 @@
case NILFS_CHECKPOINT:
/*
* Check for protecting existing snapshot mounts:
- * bd_mount_sem is used to make this operation atomic and
+ * ns_mount_mutex is used to make this operation atomic and
* exclusive with a new mount job. Though it doesn't cover
* umount, it's enough for the purpose.
*/
- down(&nilfs->ns_bdev->bd_mount_sem);
+ mutex_lock(&nilfs->ns_mount_mutex);
if (nilfs_checkpoint_is_mounted(nilfs, cno, 1)) {
/* Current implementation does not have to protect
plain read-only mounts since they are exclusive
@@ -877,7 +877,7 @@
ret = -EBUSY;
} else
ret = nilfs_cpfile_clear_snapshot(cpfile, cno);
- up(&nilfs->ns_bdev->bd_mount_sem);
+ mutex_unlock(&nilfs->ns_mount_mutex);
return ret;
case NILFS_SNAPSHOT:
return nilfs_cpfile_set_snapshot(cpfile, cno);
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index f02762f..1777a34 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -764,7 +764,7 @@
* @silent: silent mode flag
* @nilfs: the_nilfs struct
*
- * This function is called exclusively by bd_mount_mutex.
+ * This function is called exclusively by nilfs->ns_mount_mutex.
* So, the recovery process is protected from other simultaneous mounts.
*/
static int
@@ -1105,7 +1105,7 @@
goto failed;
}
- down(&sd.bdev->bd_mount_sem);
+ mutex_lock(&nilfs->ns_mount_mutex);
if (!sd.cno) {
/*
@@ -1164,7 +1164,7 @@
need_to_close = 0;
}
- up(&sd.bdev->bd_mount_sem);
+ mutex_unlock(&nilfs->ns_mount_mutex);
put_nilfs(nilfs);
if (need_to_close)
close_bdev_exclusive(sd.bdev, flags);
@@ -1172,7 +1172,7 @@
return 0;
failed_unlock:
- up(&sd.bdev->bd_mount_sem);
+ mutex_unlock(&nilfs->ns_mount_mutex);
put_nilfs(nilfs);
failed:
close_bdev_exclusive(sd.bdev, flags);
@@ -1181,14 +1181,14 @@
cancel_new:
/* Abandoning the newly allocated superblock */
- up(&sd.bdev->bd_mount_sem);
+ mutex_unlock(&nilfs->ns_mount_mutex);
put_nilfs(nilfs);
up_write(&s->s_umount);
deactivate_super(s);
/*
* deactivate_super() invokes close_bdev_exclusive().
* We must finish all post-cleaning before this call;
- * put_nilfs() and unlocking bd_mount_sem need the block device.
+ * put_nilfs() needs the block device.
*/
return err;
}
diff --git a/fs/nilfs2/the_nilfs.c b/fs/nilfs2/the_nilfs.c
index 06e8dfd..e4e5c78 100644
--- a/fs/nilfs2/the_nilfs.c
+++ b/fs/nilfs2/the_nilfs.c
@@ -73,6 +73,7 @@
atomic_set(&nilfs->ns_ndirtyblks, 0);
init_rwsem(&nilfs->ns_sem);
init_rwsem(&nilfs->ns_super_sem);
+ mutex_init(&nilfs->ns_mount_mutex);
mutex_init(&nilfs->ns_writer_mutex);
INIT_LIST_HEAD(&nilfs->ns_list);
INIT_LIST_HEAD(&nilfs->ns_supers);
diff --git a/fs/nilfs2/the_nilfs.h b/fs/nilfs2/the_nilfs.h
index d0cf4fb..e8adbff 100644
--- a/fs/nilfs2/the_nilfs.h
+++ b/fs/nilfs2/the_nilfs.h
@@ -49,6 +49,7 @@
* @ns_writer: back pointer to writable nilfs_sb_info
* @ns_sem: semaphore for shared states
* @ns_super_sem: semaphore for global operations across super block instances
+ * @ns_mount_mutex: mutex protecting mount process of nilfs
* @ns_writer_mutex: mutex protecting ns_writer attach/detach
* @ns_writer_refcount: number of referrers on ns_writer
* @ns_current: back pointer to current mount
@@ -98,6 +99,7 @@
struct nilfs_sb_info *ns_writer;
struct rw_semaphore ns_sem;
struct rw_semaphore ns_super_sem;
+ struct mutex ns_mount_mutex;
struct mutex ns_writer_mutex;
atomic_t ns_writer_refcount;