nilfs2: get rid of bd_mount_sem use from nilfs

[pandora-kernel.git] / fs / nilfs2 / the_nilfs.h

diff --git a/fs/nilfs2/the_nilfs.h b/fs/nilfs2/the_nilfs.h
index 30fe587..e8adbff 100644 (file)
--- a/fs/nilfs2/the_nilfs.h
+++ b/fs/nilfs2/the_nilfs.h
@@ -43,12 +43,16 @@ enum {
  * struct the_nilfs - struct to supervise multiple nilfs mount points
  * @ns_flags: flags
  * @ns_count: reference count
+ * @ns_list: list head for nilfs_list
  * @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_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
  * @ns_sbh: buffer heads of on-disk super blocks
  * @ns_sbp: pointers to super block data
  * @ns_sbwtime: previous write time of super blocks
@@ -88,14 +92,23 @@ enum {
 struct the_nilfs {
        unsigned long           ns_flags;
        atomic_t                ns_count;
+       struct list_head        ns_list;
 
        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_super_sem;
+       struct mutex            ns_mount_mutex;
        struct mutex            ns_writer_mutex;
        atomic_t                ns_writer_refcount;
 
+       /*
+        * components protected by ns_super_sem
+        */
+       struct nilfs_sb_info   *ns_current;
+       struct list_head        ns_supers;
+
        /*
         * used for
         * - loading the latest checkpoint exclusively.
@@ -108,7 +121,6 @@ struct the_nilfs {
        time_t                  ns_sbwtime[2];
        unsigned                ns_sbsize;
        unsigned                ns_mount_state;
-       struct list_head        ns_supers;
 
        /*
         * Following fields are dedicated to a writable FS-instance.
@@ -191,11 +203,12 @@ THE_NILFS_FNS(DISCONTINUED, discontinued)
 #define NILFS_ALTSB_FREQ       60  /* spare superblock */
 
 void nilfs_set_last_segment(struct the_nilfs *, sector_t, u64, __u64);
-struct the_nilfs *alloc_nilfs(struct block_device *);
+struct the_nilfs *find_or_create_nilfs(struct block_device *);
 void put_nilfs(struct the_nilfs *);
 int init_nilfs(struct the_nilfs *, struct nilfs_sb_info *, char *);
 int load_nilfs(struct the_nilfs *, struct nilfs_sb_info *);
 int nilfs_count_free_blocks(struct the_nilfs *, sector_t *);
+struct nilfs_sb_info *nilfs_find_sbinfo(struct the_nilfs *, int, __u64);
 int nilfs_checkpoint_is_mounted(struct the_nilfs *, __u64, int);
 int nilfs_near_disk_full(struct the_nilfs *);
 void nilfs_fall_back_super_block(struct the_nilfs *);
@@ -238,6 +251,12 @@ nilfs_detach_writer(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi)
        mutex_unlock(&nilfs->ns_writer_mutex);
 }
 
+static inline void nilfs_put_sbinfo(struct nilfs_sb_info *sbi)
+{
+       if (!atomic_dec_and_test(&sbi->s_count))
+               kfree(sbi);
+}
+
 static inline void
 nilfs_get_segment_range(struct the_nilfs *nilfs, __u64 segnum,
                        sector_t *seg_start, sector_t *seg_end)