jfs_incore.h

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/*
 *   Copyright (C) International Business Machines Corp., 2000-2004
 *   Portions Copyright (C) Christoph Hellwig, 2001-2002
 *
 *   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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
#ifndef _H_JFS_INCORE
#define _H_JFS_INCORE

#include <linux/mutex.h>
#include <linux/rwsem.h>
#include <linux/slab.h>
#include <linux/bitops.h>
#include "jfs_types.h"
#include "jfs_xtree.h"
#include "jfs_dtree.h"

/*
 * JFS magic number
 */
#define JFS_SUPER_MAGIC 0x3153464a /* "JFS1" */

/*
 * JFS-private inode information
 */
struct jfs_inode_info {
    int fileset;    /* fileset number (always 16)*/
    uint    mode2;      /* jfs-specific mode        */
    kuid_t  saved_uid;  /* saved for uid mount option */
    kgid_t  saved_gid;  /* saved for gid mount option */
    pxd_t   ixpxd;      /* inode extent descriptor  */
    dxd_t   acl;        /* dxd describing acl   */
    dxd_t   ea;     /* dxd describing ea    */
    time_t  otime;      /* time created */
    uint    next_index; /* next available directory entry index */
    int acltype;    /* Type of ACL  */
    short   btorder;    /* access order */
    short   btindex;    /* btpage entry index*/
    struct inode *ipimap;   /* inode map            */
    unsigned long cflag;    /* commit flags     */
    u64 agstart;    /* agstart of the containing IAG */
    u16 bxflag;     /* xflag of pseudo buffer?  */
    unchar  pad;
    signed char active_ag;  /* ag currently allocating from */
    lid_t   blid;       /* lid of pseudo buffer?    */
    lid_t   atlhead;    /* anonymous tlock list head    */
    lid_t   atltail;    /* anonymous tlock list tail    */
    spinlock_t ag_lock; /* protects active_ag       */
    struct list_head anon_inode_list; /* inodes having anonymous txns */
    /*
     * rdwrlock serializes xtree between reads & writes and synchronizes
     * changes to special inodes.  It's use would be redundant on
     * directories since the i_mutex taken in the VFS is sufficient.
     */
    struct rw_semaphore rdwrlock;
    /*
     * commit_mutex serializes transaction processing on an inode.
     * It must be taken after beginning a transaction (txBegin), since
     * dirty inodes may be committed while a new transaction on the
     * inode is blocked in txBegin or TxBeginAnon
     */
    struct mutex commit_mutex;
    /* xattr_sem allows us to access the xattrs without taking i_mutex */
    struct rw_semaphore xattr_sem;
    lid_t   xtlid;      /* lid of xtree lock on directory */
    union {
        struct {
            xtpage_t _xtroot;   /* 288: xtree root */
            struct inomap *_imap;   /* 4: inode map header  */
        } file;
        struct {
            struct dir_table_slot _table[12]; /* 96: dir index */
            dtroot_t _dtroot;   /* 288: dtree root */
        } dir;
        struct {
            unchar _unused[16]; /* 16: */
            dxd_t _dxd;     /* 16: */
            unchar _inline[128];    /* 128: inline symlink */
            /* _inline_ea may overlay the last part of
             * file._xtroot if maxentry = XTROOTINITSLOT
             */
            unchar _inline_ea[128]; /* 128: inline extended attr */
        } link;
    } u;
    u32 dev;    /* will die when we get wide dev_t */
    struct inode    vfs_inode;
};
#define i_xtroot u.file._xtroot
#define i_imap u.file._imap
#define i_dirtable u.dir._table
#define i_dtroot u.dir._dtroot
#define i_inline u.link._inline
#define i_inline_ea u.link._inline_ea

#define IREAD_LOCK(ip, subclass) \
    down_read_nested(&JFS_IP(ip)->rdwrlock, subclass)
#define IREAD_UNLOCK(ip)    up_read(&JFS_IP(ip)->rdwrlock)
#define IWRITE_LOCK(ip, subclass) \
    down_write_nested(&JFS_IP(ip)->rdwrlock, subclass)
#define IWRITE_UNLOCK(ip)   up_write(&JFS_IP(ip)->rdwrlock)

/*
 * cflag
 */
enum cflags {
    COMMIT_Nolink,      /* inode committed with zero link count */
    COMMIT_Inlineea,    /* commit inode inline EA */
    COMMIT_Freewmap,    /* free WMAP at iClose() */
    COMMIT_Dirty,       /* Inode is really dirty */
    COMMIT_Dirtable,    /* commit changes to di_dirtable */
    COMMIT_Stale,       /* data extent is no longer valid */
    COMMIT_Synclist,    /* metadata pages on group commit synclist */
};

/*
 * commit_mutex nesting subclasses:
 */
enum commit_mutex_class
{
    COMMIT_MUTEX_PARENT,
    COMMIT_MUTEX_CHILD,
    COMMIT_MUTEX_SECOND_PARENT, /* Renaming */
    COMMIT_MUTEX_VICTIM     /* Inode being unlinked due to rename */
};

/*
 * rdwrlock subclasses:
 * The dmap inode may be locked while a normal inode or the imap inode are
 * locked.
 */
enum rdwrlock_class
{
    RDWRLOCK_NORMAL,
    RDWRLOCK_IMAP,
    RDWRLOCK_DMAP
};

#define set_cflag(flag, ip) set_bit(flag, &(JFS_IP(ip)->cflag))
#define clear_cflag(flag, ip)   clear_bit(flag, &(JFS_IP(ip)->cflag))
#define test_cflag(flag, ip)    test_bit(flag, &(JFS_IP(ip)->cflag))
#define test_and_clear_cflag(flag, ip) \
    test_and_clear_bit(flag, &(JFS_IP(ip)->cflag))
/*
 * JFS-private superblock information.
 */
struct jfs_sb_info {
    struct super_block *sb;     /* Point back to vfs super block */
    unsigned long   mntflag;    /* aggregate attributes */
    struct inode    *ipbmap;    /* block map inode      */
    struct inode    *ipaimap;   /* aggregate inode map inode    */
    struct inode    *ipaimap2;  /* secondary aimap inode    */
    struct inode    *ipimap;    /* aggregate inode map inode    */
    struct jfs_log  *log;       /* log          */
    struct list_head log_list;  /* volumes associated with a journal */
    short       bsize;      /* logical block size   */
    short       l2bsize;    /* log2 logical block size  */
    short       nbperpage;  /* blocks per page      */
    short       l2nbperpage;    /* log2 blocks per page */
    short       l2niperblk; /* log2 inodes per page */
    dev_t       logdev;     /* external log device  */
    uint        aggregate;  /* volume identifier in log record */
    pxd_t       logpxd;     /* pxd describing log   */
    pxd_t       fsckpxd;    /* pxd describing fsck wkspc */
    pxd_t       ait2;       /* pxd describing AIT copy  */
    char        uuid[16];   /* 128-bit uuid for volume  */
    char        loguuid[16];    /* 128-bit uuid for log */
    /*
     * commit_state is used for synchronization of the jfs_commit
     * threads.  It is protected by LAZY_LOCK().
     */
    int     commit_state;   /* commit state */
    /* Formerly in ipimap */
    uint        gengen;     /* inode generation generator*/
    uint        inostamp;   /* shows inode belongs to fileset*/

    /* Formerly in ipbmap */
    struct bmap *bmap;      /* incore bmap descriptor   */
    struct nls_table *nls_tab;  /* current codepage     */
    struct inode *direct_inode; /* metadata inode */
    uint        state;      /* mount/recovery state */
    unsigned long   flag;       /* mount time flags */
    uint        p_state;    /* state prior to going no integrity */
    kuid_t      uid;        /* uid to override on-disk uid */
    kgid_t      gid;        /* gid to override on-disk gid */
    uint        umask;      /* umask to override on-disk umask */
    uint        minblks_trim;   /* minimum blocks, for online trim */
};

/* jfs_sb_info commit_state */
#define IN_LAZYCOMMIT 1

static inline struct jfs_inode_info *JFS_IP(struct inode *inode)
{
    return list_entry(inode, struct jfs_inode_info, vfs_inode);
}

static inline int jfs_dirtable_inline(struct inode *inode)
{
    return (JFS_IP(inode)->next_index <= (MAX_INLINE_DIRTABLE_ENTRY + 1));
}

static inline struct jfs_sb_info *JFS_SBI(struct super_block *sb)
{
    return sb->s_fs_info;
}

static inline int isReadOnly(struct inode *inode)
{
    if (JFS_SBI(inode->i_sb)->log)
        return 0;
    return 1;
}
#endif /* _H_JFS_INCORE */