nilfs2: add inode and other major structures

This adds the following common structures of the NILFS2 file system.

* nilfs_inode_info structure:
  gives on-memory inode.

* nilfs_sb_info structure:
  keeps per-mount state and a special inode for the ifile.
  This structure is attached to the super_block structure.

* the_nilfs structure:
  keeps shared state and locks among a read/write mount and snapshot
  mounts.  This keeps special inodes for the sufile, cpfile, dat, and
  another dat inode used during GC (gcdat).  This also has a hash table
  of dummy inodes to cache disk blocks during GC (gcinodes).

* nilfs_transaction_info structure:
  keeps per task state while nilfs is writing logs or doing indivisible
  inode or namespace operations.  This structure is used to identify
  context during log making and store nest level of the lock which
  ensures atomicity of file system operations.

Signed-off-by: Koji Sato <sato.koji@lab.ntt.co.jp>
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, 102 insertions, 0 deletions

diff --git a/fs/nilfs2/sb.h b/fs/nilfs2/sb.h
new file mode 100644
index 000000000000..adccd4fc654e
--- /dev/null
+++ b/fs/nilfs2/sb.h
@@ -0,0 +1,102 @@
+/*
+ * sb.h - NILFS on-memory super block structure.
+ *
+ * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * Written by Ryusuke Konishi <ryusuke@osrg.net>
+ *
+ */
+
+#ifndef _NILFS_SB
+#define _NILFS_SB
+
+#include <linux/types.h>
+#include <linux/fs.h>
+
+/*
+ * Mount options
+ */
+struct nilfs_mount_options {
+        unsigned long mount_opt;
+        __u64 snapshot_cno;
+};
+
+struct the_nilfs;
+struct nilfs_sc_info;
+
+/*
+ * NILFS super-block data in memory
+ */
+struct nilfs_sb_info {
+        /* Snapshot status */
+        __u64 s_snapshot_cno;           /* Checkpoint number */
+        atomic_t s_inodes_count;
+        atomic_t s_blocks_count;        /* Reserved (might be deleted) */
+
+        /* Mount options */
+        unsigned long s_mount_opt;
+        uid_t s_resuid;
+        gid_t s_resgid;
+
+        unsigned long s_interval;       /* construction interval */
+        unsigned long s_watermark;      /* threshold of data amount
+                                           for the segment construction */
+
+        /* Fundamental members */
+        struct super_block *s_super;    /* reverse pointer to super_block */
+        struct the_nilfs *s_nilfs;
+        struct list_head s_list;        /* list head for nilfs->ns_supers */
+
+        /* Segment constructor */
+        struct list_head s_dirty_files; /* dirty files list */
+        struct nilfs_sc_info *s_sc_info; /* segment constructor info */
+        spinlock_t s_inode_lock;        /* Lock for the nilfs inode.
+                                           It covers s_dirty_files list */
+
+        /* Metadata files */
+        struct inode *s_ifile;          /* index file inode */
+
+        /* Inode allocator */
+        spinlock_t s_next_gen_lock;
+        u32 s_next_generation;
+};
+
+static inline struct nilfs_sb_info *NILFS_SB(struct super_block *sb)
+{
+        return sb->s_fs_info;
+}
+
+static inline struct nilfs_sc_info *NILFS_SC(struct nilfs_sb_info *sbi)
+{
+        return sbi->s_sc_info;
+}
+
+/*
+ * Bit operations for the mount option
+ */
+#define nilfs_clear_opt(sbi, opt)  \
+        do { (sbi)->s_mount_opt &= ~NILFS_MOUNT_##opt; } while (0)
+#define nilfs_set_opt(sbi, opt)  \
+        do { (sbi)->s_mount_opt |= NILFS_MOUNT_##opt; } while (0)
+#define nilfs_test_opt(sbi, opt)   ((sbi)->s_mount_opt & NILFS_MOUNT_##opt)
+#define nilfs_write_opt(sbi, mask, opt)                                 \
+        do { (sbi)->s_mount_opt =                                       \
+                (((sbi)->s_mount_opt & ~NILFS_MOUNT_##mask) |           \
+                 NILFS_MOUNT_##opt);                                    \
+        } while (0)
+
+#endif /* _NILFS_SB */