ocfs2.h

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/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 * ocfs2.h
 *
 * Defines macros and structures used in OCFS2
 *
 * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
 *
 * 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 021110-1307, USA.
 */

#ifndef OCFS2_H
#define OCFS2_H

#include <linux/spinlock.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/list.h>
#include <linux/rbtree.h>
#include <linux/workqueue.h>
#include <linux/kref.h>
#include <linux/mutex.h>
#include <linux/lockdep.h>
#include <linux/jbd2.h>

/* For union ocfs2_dlm_lksb */
#include "stackglue.h"

#include "ocfs2_fs.h"
#include "ocfs2_lockid.h"
#include "ocfs2_ioctl.h"

/* For struct ocfs2_blockcheck_stats */
#include "blockcheck.h"

#include "reservations.h"

/* Caching of metadata buffers */

/* Most user visible OCFS2 inodes will have very few pieces of
 * metadata, but larger files (including bitmaps, etc) must be taken
 * into account when designing an access scheme. We allow a small
 * amount of inlined blocks to be stored on an array and grow the
 * structure into a rb tree when necessary. */
#define OCFS2_CACHE_INFO_MAX_ARRAY 2

/* Flags for ocfs2_caching_info */

enum ocfs2_caching_info_flags {
    /* Indicates that the metadata cache is using the inline array */
    OCFS2_CACHE_FL_INLINE   = 1<<1,
};

struct ocfs2_caching_operations;
struct ocfs2_caching_info {
    /*
     * The parent structure provides the locks, but because the
     * parent structure can differ, it provides locking operations
     * to struct ocfs2_caching_info.
     */
    const struct ocfs2_caching_operations *ci_ops;

    /* next two are protected by trans_inc_lock */
    /* which transaction were we created on? Zero if none. */
    unsigned long       ci_created_trans;
    /* last transaction we were a part of. */
    unsigned long       ci_last_trans;

    /* Cache structures */
    unsigned int        ci_flags;
    unsigned int        ci_num_cached;
    union {
    sector_t    ci_array[OCFS2_CACHE_INFO_MAX_ARRAY];
        struct rb_root  ci_tree;
    } ci_cache;
};
/*
 * Need this prototype here instead of in uptodate.h because journal.h
 * uses it.
 */
struct super_block *ocfs2_metadata_cache_get_super(struct ocfs2_caching_info *ci);

/* this limits us to 256 nodes
 * if we need more, we can do a kmalloc for the map */
#define OCFS2_NODE_MAP_MAX_NODES    256
struct ocfs2_node_map {
    u16 num_nodes;
    unsigned long map[BITS_TO_LONGS(OCFS2_NODE_MAP_MAX_NODES)];
};

enum ocfs2_ast_action {
    OCFS2_AST_INVALID = 0,
    OCFS2_AST_ATTACH,
    OCFS2_AST_CONVERT,
    OCFS2_AST_DOWNCONVERT,
};

/* actions for an unlockast function to take. */
enum ocfs2_unlock_action {
    OCFS2_UNLOCK_INVALID = 0,
    OCFS2_UNLOCK_CANCEL_CONVERT,
    OCFS2_UNLOCK_DROP_LOCK,
};

/* ocfs2_lock_res->l_flags flags. */
#define OCFS2_LOCK_ATTACHED      (0x00000001) /* we have initialized
                           * the lvb */
#define OCFS2_LOCK_BUSY          (0x00000002) /* we are currently in
                           * dlm_lock */
#define OCFS2_LOCK_BLOCKED       (0x00000004) /* blocked waiting to
                           * downconvert*/
#define OCFS2_LOCK_LOCAL         (0x00000008) /* newly created inode */
#define OCFS2_LOCK_NEEDS_REFRESH (0x00000010)
#define OCFS2_LOCK_REFRESHING    (0x00000020)
#define OCFS2_LOCK_INITIALIZED   (0x00000040) /* track initialization
                           * for shutdown paths */
#define OCFS2_LOCK_FREEING       (0x00000080) /* help dlmglue track
                           * when to skip queueing
                           * a lock because it's
                           * about to be
                           * dropped. */
#define OCFS2_LOCK_QUEUED        (0x00000100) /* queued for downconvert */
#define OCFS2_LOCK_NOCACHE       (0x00000200) /* don't use a holder count */
#define OCFS2_LOCK_PENDING       (0x00000400) /* This lockres is pending a
                         call to dlm_lock.  Only
                         exists with BUSY set. */
#define OCFS2_LOCK_UPCONVERT_FINISHING (0x00000800) /* blocks the dc thread
                             * from downconverting
                             * before the upconvert
                             * has completed */

struct ocfs2_lock_res_ops;

typedef void (*ocfs2_lock_callback)(int status, unsigned long data);

#ifdef CONFIG_OCFS2_FS_STATS
struct ocfs2_lock_stats {
    u64     ls_total;   /* Total wait in NSEC */
    u32     ls_gets;    /* Num acquires */
    u32     ls_fail;    /* Num failed acquires */

    /* Storing max wait in usecs saves 24 bytes per inode */
    u32     ls_max;     /* Max wait in USEC */
};
#endif

struct ocfs2_lock_res {
    void                    *l_priv;
    struct ocfs2_lock_res_ops *l_ops;


    struct list_head         l_blocked_list;
    struct list_head         l_mask_waiters;

    unsigned long        l_flags;
    char                     l_name[OCFS2_LOCK_ID_MAX_LEN];
    unsigned int             l_ro_holders;
    unsigned int             l_ex_holders;
    signed char      l_level;
    signed char      l_requested;
    signed char      l_blocking;

    /* Data packed - type enum ocfs2_lock_type */
    unsigned char            l_type;

    /* used from AST/BAST funcs. */
    /* Data packed - enum type ocfs2_ast_action */
    unsigned char            l_action;
    /* Data packed - enum type ocfs2_unlock_action */
    unsigned char            l_unlock_action;
    unsigned int             l_pending_gen;

    spinlock_t               l_lock;

    struct ocfs2_dlm_lksb    l_lksb;

    wait_queue_head_t        l_event;

    struct list_head         l_debug_list;

#ifdef CONFIG_OCFS2_FS_STATS
    struct ocfs2_lock_stats  l_lock_prmode;     /* PR mode stats */
    u32                      l_lock_refresh;    /* Disk refreshes */
    struct ocfs2_lock_stats  l_lock_exmode;     /* EX mode stats */
#endif
#ifdef CONFIG_DEBUG_LOCK_ALLOC
    struct lockdep_map   l_lockdep_map;
#endif
};

enum ocfs2_orphan_scan_state {
    ORPHAN_SCAN_ACTIVE,
    ORPHAN_SCAN_INACTIVE
};

struct ocfs2_orphan_scan {
    struct mutex        os_lock;
    struct ocfs2_super  *os_osb;
    struct ocfs2_lock_res   os_lockres;     /* lock to synchronize scans */
    struct delayed_work     os_orphan_scan_work;
    struct timespec     os_scantime;  /* time this node ran the scan */
    u32         os_count;      /* tracks node specific scans */
    u32             os_seqno;       /* tracks cluster wide scans */
    atomic_t        os_state;              /* ACTIVE or INACTIVE */
};

struct ocfs2_dlm_debug {
    struct kref d_refcnt;
    struct dentry *d_locking_state;
    struct list_head d_lockres_tracking;
};

enum ocfs2_vol_state
{
    VOLUME_INIT = 0,
    VOLUME_MOUNTED,
    VOLUME_MOUNTED_QUOTAS,
    VOLUME_DISMOUNTED,
    VOLUME_DISABLED
};

struct ocfs2_alloc_stats
{
    atomic_t moves;
    atomic_t local_data;
    atomic_t bitmap_data;
    atomic_t bg_allocs;
    atomic_t bg_extends;
};

enum ocfs2_local_alloc_state
{
    OCFS2_LA_UNUSED = 0,    /* Local alloc will never be used for
                 * this mountpoint. */
    OCFS2_LA_ENABLED,   /* Local alloc is in use. */
    OCFS2_LA_THROTTLED, /* Local alloc is in use, but number
                 * of bits has been reduced. */
    OCFS2_LA_DISABLED   /* Local alloc has temporarily been
                 * disabled. */
};

enum ocfs2_mount_options
{
    OCFS2_MOUNT_HB_LOCAL = 1 << 0, /* Local heartbeat */
    OCFS2_MOUNT_BARRIER = 1 << 1,   /* Use block barriers */
    OCFS2_MOUNT_NOINTR  = 1 << 2,   /* Don't catch signals */
    OCFS2_MOUNT_ERRORS_PANIC = 1 << 3, /* Panic on errors */
    OCFS2_MOUNT_DATA_WRITEBACK = 1 << 4, /* No data ordering */
    OCFS2_MOUNT_LOCALFLOCKS = 1 << 5, /* No cluster aware user file locks */
    OCFS2_MOUNT_NOUSERXATTR = 1 << 6, /* No user xattr */
    OCFS2_MOUNT_INODE64 = 1 << 7,   /* Allow inode numbers > 2^32 */
    OCFS2_MOUNT_POSIX_ACL = 1 << 8, /* Force POSIX access control lists */
    OCFS2_MOUNT_NO_POSIX_ACL = 1 << 9,  /* Disable POSIX access
                           control lists */
    OCFS2_MOUNT_USRQUOTA = 1 << 10, /* We support user quotas */
    OCFS2_MOUNT_GRPQUOTA = 1 << 11, /* We support group quotas */
    OCFS2_MOUNT_COHERENCY_BUFFERED = 1 << 12, /* Allow concurrent O_DIRECT
                             writes */
    OCFS2_MOUNT_HB_NONE = 1 << 13, /* No heartbeat */
    OCFS2_MOUNT_HB_GLOBAL = 1 << 14, /* Global heartbeat */
};

#define OCFS2_OSB_SOFT_RO           0x0001
#define OCFS2_OSB_HARD_RO           0x0002
#define OCFS2_OSB_ERROR_FS          0x0004
#define OCFS2_OSB_DROP_DENTRY_LOCK_IMMED    0x0008

#define OCFS2_DEFAULT_ATIME_QUANTUM     60

struct ocfs2_journal;
struct ocfs2_slot_info;
struct ocfs2_recovery_map;
struct ocfs2_replay_map;
struct ocfs2_quota_recovery;
struct ocfs2_dentry_lock;
struct ocfs2_super
{
    struct task_struct *commit_task;
    struct super_block *sb;
    struct inode *root_inode;
    struct inode *sys_root_inode;
    struct inode *global_system_inodes[NUM_GLOBAL_SYSTEM_INODES];
    struct inode **local_system_inodes;

    struct ocfs2_slot_info *slot_info;

    u32 *slot_recovery_generations;

    spinlock_t node_map_lock;

    u64 root_blkno;
    u64 system_dir_blkno;
    u64 bitmap_blkno;
    u32 bitmap_cpg;
    u8 *uuid;
    char *uuid_str;
    u32 uuid_hash;
    u8 *vol_label;
    u64 first_cluster_group_blkno;
    u32 fs_generation;

    u32 s_feature_compat;
    u32 s_feature_incompat;
    u32 s_feature_ro_compat;

    /* Protects s_next_generation, osb_flags and s_inode_steal_slot.
     * Could protect more on osb as it's very short lived.
     */
    spinlock_t osb_lock;
    u32 s_next_generation;
    unsigned long osb_flags;
    s16 s_inode_steal_slot;
    s16 s_meta_steal_slot;
    atomic_t s_num_inodes_stolen;
    atomic_t s_num_meta_stolen;

    unsigned long s_mount_opt;
    unsigned int s_atime_quantum;

    unsigned int max_slots;
    unsigned int node_num;
    int slot_num;
    int preferred_slot;
    int s_sectsize_bits;
    int s_clustersize;
    int s_clustersize_bits;
    unsigned int s_xattr_inline_size;

    atomic_t vol_state;
    struct mutex recovery_lock;
    struct ocfs2_recovery_map *recovery_map;
    struct ocfs2_replay_map *replay_map;
    struct task_struct *recovery_thread_task;
    int disable_recovery;
    wait_queue_head_t checkpoint_event;
    atomic_t needs_checkpoint;
    struct ocfs2_journal *journal;
    unsigned long osb_commit_interval;

    struct delayed_work     la_enable_wq;

    /*
     * Must hold local alloc i_mutex and osb->osb_lock to change
     * local_alloc_bits. Reads can be done under either lock.
     */
    unsigned int local_alloc_bits;
    unsigned int local_alloc_default_bits;
    /* osb_clusters_at_boot can become stale! Do not trust it to
     * be up to date. */
    unsigned int osb_clusters_at_boot;

    enum ocfs2_local_alloc_state local_alloc_state; /* protected
                             * by osb_lock */

    struct buffer_head *local_alloc_bh;

    u64 la_last_gd;

    struct ocfs2_reservation_map    osb_la_resmap;

    unsigned int    osb_resv_level;
    unsigned int    osb_dir_resv_level;

    /* Next three fields are for local node slot recovery during
     * mount. */
    int dirty;
    struct ocfs2_dinode *local_alloc_copy;
    struct ocfs2_quota_recovery *quota_rec;

    struct ocfs2_blockcheck_stats osb_ecc_stats;
    struct ocfs2_alloc_stats alloc_stats;
    char dev_str[20];       /* "major,minor" of the device */

    u8 osb_stackflags;

    char osb_cluster_stack[OCFS2_STACK_LABEL_LEN + 1];
    struct ocfs2_cluster_connection *cconn;
    struct ocfs2_lock_res osb_super_lockres;
    struct ocfs2_lock_res osb_rename_lockres;
    struct ocfs2_lock_res osb_nfs_sync_lockres;
    struct ocfs2_dlm_debug *osb_dlm_debug;

    struct dentry *osb_debug_root;
    struct dentry *osb_ctxt;

    wait_queue_head_t recovery_event;

    spinlock_t dc_task_lock;
    struct task_struct *dc_task;
    wait_queue_head_t dc_event;
    unsigned long dc_wake_sequence;
    unsigned long dc_work_sequence;

    /*
     * Any thread can add locks to the list, but the downconvert
     * thread is the only one allowed to remove locks. Any change
     * to this rule requires updating
     * ocfs2_downconvert_thread_do_work().
     */
    struct list_head blocked_lock_list;
    unsigned long blocked_lock_count;

    /* List of dentry locks to release. Anyone can add locks to
     * the list, ocfs2_wq processes the list  */
    struct ocfs2_dentry_lock *dentry_lock_list;
    struct work_struct dentry_lock_work;

    wait_queue_head_t       osb_mount_event;

    /* Truncate log info */
    struct inode            *osb_tl_inode;
    struct buffer_head      *osb_tl_bh;
    struct delayed_work     osb_truncate_log_wq;
    /*
     * How many clusters in our truncate log.
     * It must be protected by osb_tl_inode->i_mutex.
     */
    unsigned int truncated_clusters;

    struct ocfs2_node_map       osb_recovering_orphan_dirs;
    unsigned int            *osb_orphan_wipes;
    wait_queue_head_t       osb_wipe_event;

    struct ocfs2_orphan_scan    osb_orphan_scan;

    /* used to protect metaecc calculation check of xattr. */
    spinlock_t osb_xattr_lock;

    unsigned int            osb_dx_mask;
    u32             osb_dx_seed[4];

    /* the group we used to allocate inodes. */
    u64             osb_inode_alloc_group;

    /* rb tree root for refcount lock. */
    struct rb_root  osb_rf_lock_tree;
    struct ocfs2_refcount_tree *osb_ref_tree_lru;
};

#define OCFS2_SB(sb)        ((struct ocfs2_super *)(sb)->s_fs_info)

/* Useful typedef for passing around journal access functions */
typedef int (*ocfs2_journal_access_func)(handle_t *handle,
                     struct ocfs2_caching_info *ci,
                     struct buffer_head *bh, int type);

static inline int ocfs2_should_order_data(struct inode *inode)
{
    if (!S_ISREG(inode->i_mode))
        return 0;
    if (OCFS2_SB(inode->i_sb)->s_mount_opt & OCFS2_MOUNT_DATA_WRITEBACK)
        return 0;
    return 1;
}

static inline int ocfs2_sparse_alloc(struct ocfs2_super *osb)
{
    if (osb->s_feature_incompat & OCFS2_FEATURE_INCOMPAT_SPARSE_ALLOC)
        return 1;
    return 0;
}

static inline int ocfs2_writes_unwritten_extents(struct ocfs2_super *osb)
{
    /*
     * Support for sparse files is a pre-requisite
     */
    if (!ocfs2_sparse_alloc(osb))
        return 0;

    if (osb->s_feature_ro_compat & OCFS2_FEATURE_RO_COMPAT_UNWRITTEN)
        return 1;
    return 0;
}

static inline int ocfs2_supports_inline_data(struct ocfs2_super *osb)
{
    if (osb->s_feature_incompat & OCFS2_FEATURE_INCOMPAT_INLINE_DATA)
        return 1;
    return 0;
}

static inline int ocfs2_supports_xattr(struct ocfs2_super *osb)
{
    if (osb->s_feature_incompat & OCFS2_FEATURE_INCOMPAT_XATTR)
        return 1;
    return 0;
}

static inline int ocfs2_meta_ecc(struct ocfs2_super *osb)
{
    if (osb->s_feature_incompat & OCFS2_FEATURE_INCOMPAT_META_ECC)
        return 1;
    return 0;
}

static inline int ocfs2_supports_indexed_dirs(struct ocfs2_super *osb)
{
    if (osb->s_feature_incompat & OCFS2_FEATURE_INCOMPAT_INDEXED_DIRS)
        return 1;
    return 0;
}

static inline int ocfs2_supports_discontig_bg(struct ocfs2_super *osb)
{
    if (osb->s_feature_incompat & OCFS2_FEATURE_INCOMPAT_DISCONTIG_BG)
        return 1;
    return 0;
}

static inline unsigned int ocfs2_link_max(struct ocfs2_super *osb)
{
    if (ocfs2_supports_indexed_dirs(osb))
        return OCFS2_DX_LINK_MAX;
    return OCFS2_LINK_MAX;
}

static inline unsigned int ocfs2_read_links_count(struct ocfs2_dinode *di)
{
    u32 nlink = le16_to_cpu(di->i_links_count);
    u32 hi = le16_to_cpu(di->i_links_count_hi);

    if (di->i_dyn_features & cpu_to_le16(OCFS2_INDEXED_DIR_FL))
        nlink |= (hi << OCFS2_LINKS_HI_SHIFT);

    return nlink;
}

static inline void ocfs2_set_links_count(struct ocfs2_dinode *di, u32 nlink)
{
    u16 lo, hi;

    lo = nlink;
    hi = nlink >> OCFS2_LINKS_HI_SHIFT;

    di->i_links_count = cpu_to_le16(lo);
    di->i_links_count_hi = cpu_to_le16(hi);
}

static inline void ocfs2_add_links_count(struct ocfs2_dinode *di, int n)
{
    u32 links = ocfs2_read_links_count(di);

    links += n;

    ocfs2_set_links_count(di, links);
}

static inline int ocfs2_refcount_tree(struct ocfs2_super *osb)
{
    if (osb->s_feature_incompat & OCFS2_FEATURE_INCOMPAT_REFCOUNT_TREE)
        return 1;
    return 0;
}

/* set / clear functions because cluster events can make these happen
 * in parallel so we want the transitions to be atomic. this also
 * means that any future flags osb_flags must be protected by spinlock
 * too! */
static inline void ocfs2_set_osb_flag(struct ocfs2_super *osb,
                      unsigned long flag)
{
    spin_lock(&osb->osb_lock);
    osb->osb_flags |= flag;
    spin_unlock(&osb->osb_lock);
}


static inline unsigned long  ocfs2_test_osb_flag(struct ocfs2_super *osb,
                         unsigned long flag)
{
    unsigned long ret;

    spin_lock(&osb->osb_lock);
    ret = osb->osb_flags & flag;
    spin_unlock(&osb->osb_lock);
    return ret;
}

static inline void ocfs2_set_ro_flag(struct ocfs2_super *osb,
                     int hard)
{
    spin_lock(&osb->osb_lock);
    osb->osb_flags &= ~(OCFS2_OSB_SOFT_RO|OCFS2_OSB_HARD_RO);
    if (hard)
        osb->osb_flags |= OCFS2_OSB_HARD_RO;
    else
        osb->osb_flags |= OCFS2_OSB_SOFT_RO;
    spin_unlock(&osb->osb_lock);
}

static inline int ocfs2_is_hard_readonly(struct ocfs2_super *osb)
{
    int ret;

    spin_lock(&osb->osb_lock);
    ret = osb->osb_flags & OCFS2_OSB_HARD_RO;
    spin_unlock(&osb->osb_lock);

    return ret;
}

static inline int ocfs2_is_soft_readonly(struct ocfs2_super *osb)
{
    int ret;

    spin_lock(&osb->osb_lock);
    ret = osb->osb_flags & OCFS2_OSB_SOFT_RO;
    spin_unlock(&osb->osb_lock);

    return ret;
}

static inline int ocfs2_clusterinfo_valid(struct ocfs2_super *osb)
{
    return (osb->s_feature_incompat &
        (OCFS2_FEATURE_INCOMPAT_USERSPACE_STACK |
         OCFS2_FEATURE_INCOMPAT_CLUSTERINFO));
}

static inline int ocfs2_userspace_stack(struct ocfs2_super *osb)
{
    if (ocfs2_clusterinfo_valid(osb) &&
        memcmp(osb->osb_cluster_stack, OCFS2_CLASSIC_CLUSTER_STACK,
           OCFS2_STACK_LABEL_LEN))
        return 1;
    return 0;
}

static inline int ocfs2_o2cb_stack(struct ocfs2_super *osb)
{
    if (ocfs2_clusterinfo_valid(osb) &&
        !memcmp(osb->osb_cluster_stack, OCFS2_CLASSIC_CLUSTER_STACK,
           OCFS2_STACK_LABEL_LEN))
        return 1;
    return 0;
}

static inline int ocfs2_cluster_o2cb_global_heartbeat(struct ocfs2_super *osb)
{
    return ocfs2_o2cb_stack(osb) &&
        (osb->osb_stackflags & OCFS2_CLUSTER_O2CB_GLOBAL_HEARTBEAT);
}

static inline int ocfs2_mount_local(struct ocfs2_super *osb)
{
    return (osb->s_feature_incompat & OCFS2_FEATURE_INCOMPAT_LOCAL_MOUNT);
}

static inline int ocfs2_uses_extended_slot_map(struct ocfs2_super *osb)
{
    return (osb->s_feature_incompat &
        OCFS2_FEATURE_INCOMPAT_EXTENDED_SLOT_MAP);
}


#define OCFS2_IS_VALID_DINODE(ptr)                  \
    (!strcmp((ptr)->i_signature, OCFS2_INODE_SIGNATURE))

#define OCFS2_IS_VALID_EXTENT_BLOCK(ptr)                \
    (!strcmp((ptr)->h_signature, OCFS2_EXTENT_BLOCK_SIGNATURE))

#define OCFS2_IS_VALID_GROUP_DESC(ptr)                  \
    (!strcmp((ptr)->bg_signature, OCFS2_GROUP_DESC_SIGNATURE))


#define OCFS2_IS_VALID_XATTR_BLOCK(ptr)                 \
    (!strcmp((ptr)->xb_signature, OCFS2_XATTR_BLOCK_SIGNATURE))

#define OCFS2_IS_VALID_DIR_TRAILER(ptr)                 \
    (!strcmp((ptr)->db_signature, OCFS2_DIR_TRAILER_SIGNATURE))

#define OCFS2_IS_VALID_DX_ROOT(ptr)                 \
    (!strcmp((ptr)->dr_signature, OCFS2_DX_ROOT_SIGNATURE))

#define OCFS2_IS_VALID_DX_LEAF(ptr)                 \
    (!strcmp((ptr)->dl_signature, OCFS2_DX_LEAF_SIGNATURE))

#define OCFS2_IS_VALID_REFCOUNT_BLOCK(ptr)              \
    (!strcmp((ptr)->rf_signature, OCFS2_REFCOUNT_BLOCK_SIGNATURE))

static inline unsigned long ino_from_blkno(struct super_block *sb,
                       u64 blkno)
{
    return (unsigned long)(blkno & (u64)ULONG_MAX);
}

static inline u64 ocfs2_clusters_to_blocks(struct super_block *sb,
                       u32 clusters)
{
    int c_to_b_bits = OCFS2_SB(sb)->s_clustersize_bits -
        sb->s_blocksize_bits;

    return (u64)clusters << c_to_b_bits;
}

static inline u32 ocfs2_blocks_to_clusters(struct super_block *sb,
                       u64 blocks)
{
    int b_to_c_bits = OCFS2_SB(sb)->s_clustersize_bits -
        sb->s_blocksize_bits;

    return (u32)(blocks >> b_to_c_bits);
}

static inline unsigned int ocfs2_clusters_for_bytes(struct super_block *sb,
                            u64 bytes)
{
    int cl_bits = OCFS2_SB(sb)->s_clustersize_bits;
    unsigned int clusters;

    bytes += OCFS2_SB(sb)->s_clustersize - 1;
    /* OCFS2 just cannot have enough clusters to overflow this */
    clusters = (unsigned int)(bytes >> cl_bits);

    return clusters;
}

static inline u64 ocfs2_blocks_for_bytes(struct super_block *sb,
                     u64 bytes)
{
    bytes += sb->s_blocksize - 1;
    return bytes >> sb->s_blocksize_bits;
}

static inline u64 ocfs2_clusters_to_bytes(struct super_block *sb,
                      u32 clusters)
{
    return (u64)clusters << OCFS2_SB(sb)->s_clustersize_bits;
}

static inline u64 ocfs2_block_to_cluster_start(struct super_block *sb,
                           u64 blocks)
{
    int bits = OCFS2_SB(sb)->s_clustersize_bits - sb->s_blocksize_bits;
    unsigned int clusters;

    clusters = ocfs2_blocks_to_clusters(sb, blocks);
    return (u64)clusters << bits;
}

static inline u64 ocfs2_align_bytes_to_clusters(struct super_block *sb,
                        u64 bytes)
{
    int cl_bits = OCFS2_SB(sb)->s_clustersize_bits;
    unsigned int clusters;

    clusters = ocfs2_clusters_for_bytes(sb, bytes);
    return (u64)clusters << cl_bits;
}

static inline u64 ocfs2_align_bytes_to_blocks(struct super_block *sb,
                          u64 bytes)
{
    u64 blocks;

        blocks = ocfs2_blocks_for_bytes(sb, bytes);
    return blocks << sb->s_blocksize_bits;
}

static inline unsigned long ocfs2_align_bytes_to_sectors(u64 bytes)
{
    return (unsigned long)((bytes + 511) >> 9);
}

static inline unsigned int ocfs2_page_index_to_clusters(struct super_block *sb,
                            unsigned long pg_index)
{
    u32 clusters = pg_index;
    unsigned int cbits = OCFS2_SB(sb)->s_clustersize_bits;

    if (unlikely(PAGE_CACHE_SHIFT > cbits))
        clusters = pg_index << (PAGE_CACHE_SHIFT - cbits);
    else if (PAGE_CACHE_SHIFT < cbits)
        clusters = pg_index >> (cbits - PAGE_CACHE_SHIFT);

    return clusters;
}

/*
 * Find the 1st page index which covers the given clusters.
 */
static inline pgoff_t ocfs2_align_clusters_to_page_index(struct super_block *sb,
                            u32 clusters)
{
    unsigned int cbits = OCFS2_SB(sb)->s_clustersize_bits;
        pgoff_t index = clusters;

    if (PAGE_CACHE_SHIFT > cbits) {
        index = (pgoff_t)clusters >> (PAGE_CACHE_SHIFT - cbits);
    } else if (PAGE_CACHE_SHIFT < cbits) {
        index = (pgoff_t)clusters << (cbits - PAGE_CACHE_SHIFT);
    }

    return index;
}

static inline unsigned int ocfs2_pages_per_cluster(struct super_block *sb)
{
    unsigned int cbits = OCFS2_SB(sb)->s_clustersize_bits;
    unsigned int pages_per_cluster = 1;

    if (PAGE_CACHE_SHIFT < cbits)
        pages_per_cluster = 1 << (cbits - PAGE_CACHE_SHIFT);

    return pages_per_cluster;
}

static inline unsigned int ocfs2_megabytes_to_clusters(struct super_block *sb,
                               unsigned int megs)
{
    BUILD_BUG_ON(OCFS2_MAX_CLUSTERSIZE > 1048576);

    return megs << (20 - OCFS2_SB(sb)->s_clustersize_bits);
}

static inline unsigned int ocfs2_clusters_to_megabytes(struct super_block *sb,
                               unsigned int clusters)
{
    return clusters >> (20 - OCFS2_SB(sb)->s_clustersize_bits);
}

static inline void _ocfs2_set_bit(unsigned int bit, unsigned long *bitmap)
{
    __set_bit_le(bit, bitmap);
}
#define ocfs2_set_bit(bit, addr) _ocfs2_set_bit((bit), (unsigned long *)(addr))

static inline void _ocfs2_clear_bit(unsigned int bit, unsigned long *bitmap)
{
    __clear_bit_le(bit, bitmap);
}
#define ocfs2_clear_bit(bit, addr) _ocfs2_clear_bit((bit), (unsigned long *)(addr))

#define ocfs2_test_bit test_bit_le
#define ocfs2_find_next_zero_bit find_next_zero_bit_le
#define ocfs2_find_next_bit find_next_bit_le

static inline void *correct_addr_and_bit_unaligned(int *bit, void *addr)
{
#if BITS_PER_LONG == 64
    *bit += ((unsigned long) addr & 7UL) << 3;
    addr = (void *) ((unsigned long) addr & ~7UL);
#elif BITS_PER_LONG == 32
    *bit += ((unsigned long) addr & 3UL) << 3;
    addr = (void *) ((unsigned long) addr & ~3UL);
#else
#error "how many bits you are?!"
#endif
    return addr;
}

static inline void ocfs2_set_bit_unaligned(int bit, void *bitmap)
{
    bitmap = correct_addr_and_bit_unaligned(&bit, bitmap);
    ocfs2_set_bit(bit, bitmap);
}

static inline void ocfs2_clear_bit_unaligned(int bit, void *bitmap)
{
    bitmap = correct_addr_and_bit_unaligned(&bit, bitmap);
    ocfs2_clear_bit(bit, bitmap);
}

static inline int ocfs2_test_bit_unaligned(int bit, void *bitmap)
{
    bitmap = correct_addr_and_bit_unaligned(&bit, bitmap);
    return ocfs2_test_bit(bit, bitmap);
}

static inline int ocfs2_find_next_zero_bit_unaligned(void *bitmap, int max,
                            int start)
{
    int fix = 0, ret, tmpmax;
    bitmap = correct_addr_and_bit_unaligned(&fix, bitmap);
    tmpmax = max + fix;
    start += fix;

    ret = ocfs2_find_next_zero_bit(bitmap, tmpmax, start) - fix;
    if (ret > max)
        return max;
    return ret;
}

#endif  /* OCFS2_H */