lustre_fsfilt.h

非常经典的一个分布式系统

/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
 * vim:expandtab:shiftwidth=8:tabstop=8:
 *
 *  Copyright (C) 2001-2004 Cluster File Systems, Inc. <[e-mail]>
 *
 *   This file is part of Lustre, http://www.lustre.org.
 *
 *   Lustre is free software; you can redistribute it and/or
 *   modify it under the terms of version 2 of the GNU General Public
 *   License as published by the Free Software Foundation.
 *
 *   Lustre 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 Lustre; if not, write to the Free Software
 *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * Filesystem interface helper.
 *
 */

#ifndef _LINUX_LUSTRE_FSFILT_H
#define _LINUX_LUSTRE_FSFILT_H

#ifndef _LUSTRE_FSFILT_H
#error Do not #include this file directly. #include <lustre_fsfilt.h> instead
#endif

#ifdef __KERNEL__

#include <obd.h>
#include <obd_class.h>

typedef void (*fsfilt_cb_t)(struct obd_device *obd, __u64 last_rcvd,
                            void *data, int error);

struct fsfilt_objinfo {
        struct dentry *fso_dentry;
        int fso_bufcnt;
};

#define XATTR_LUSTRE_MDS_LOV_EA         "lov"

struct lustre_dquot;
struct fsfilt_operations {
        struct list_head fs_list;
        struct module *fs_owner;
        char   *fs_type;
        char   *(* fs_getlabel)(struct super_block *sb);
        int     (* fs_setlabel)(struct super_block *sb, char *label);
        char   *(* fs_uuid)(struct super_block *sb);
        void   *(* fs_start)(struct inode *inode, int op, void *desc_private,
                             int logs);
        void   *(* fs_brw_start)(int objcount, struct fsfilt_objinfo *fso,
                                 int niocount, struct niobuf_local *nb,
                                 void *desc_private, int logs);
        int     (* fs_extend)(struct inode *inode, unsigned nblocks, void *h);
        int     (* fs_commit)(struct inode *inode, void *handle,int force_sync);
        int     (* fs_commit_async)(struct inode *inode, void *handle,
                                        void **wait_handle);
        int     (* fs_commit_wait)(struct inode *inode, void *handle);
        int     (* fs_setattr)(struct dentry *dentry, void *handle,
                               struct iattr *iattr, int do_trunc);
        int     (* fs_iocontrol)(struct inode *inode, struct file *file,
                                 unsigned int cmd, unsigned long arg);
        int     (* fs_set_md)(struct inode *inode, void *handle, void *md,
                              int size, const char *name);
        int     (* fs_get_md)(struct inode *inode, void *md, int size,
                              const char *name);
        /*
         * this method is needed to make IO operation fsfilt nature depend.
         *
         * This operation maybe synchronous or asynchronous.
         *
         * Return convention: positive number of bytes written (synchronously)
         * on success. Negative errno value on failure. Zero if asynchronous
         * IO was submitted successfully.
         *
         */
        int     (* fs_send_bio)(int rw, struct inode *inode,struct kiobuf *bio);
        ssize_t (* fs_readpage)(struct file *file, char *buf, size_t count,
                                loff_t *offset);
        int     (* fs_add_journal_cb)(struct obd_device *obd, __u64 last_rcvd,
                                      void *handle, fsfilt_cb_t cb_func,
                                      void *cb_data);
        int     (* fs_statfs)(struct super_block *sb, struct obd_statfs *osfs);
        int     (* fs_sync)(struct super_block *sb);
        int     (* fs_map_inode_pages)(struct inode *inode, struct page **page,
                                       int pages, unsigned long *blocks,
                                       int *created, int create,
                                       struct semaphore *sem);
        int     (* fs_write_record)(struct file *, void *, int size, loff_t *,
                                    int force_sync);
        int     (* fs_read_record)(struct file *, void *, int size, loff_t *);
        int     (* fs_setup)(struct super_block *sb);
        int     (* fs_get_op_len)(int, struct fsfilt_objinfo *, int);
        int     (* fs_quotacheck)(struct super_block *sb,
                                  struct obd_quotactl *oqctl);
        __u64   (* fs_get_version) (struct inode *inode);
        __u64   (* fs_set_version) (struct inode *inode, __u64 new_version);
        int     (* fs_quotactl)(struct super_block *sb,
                                struct obd_quotactl *oqctl);
        int     (* fs_quotainfo)(struct lustre_quota_info *lqi, int type,
                                 int cmd);
        int     (* fs_qids)(struct file *file, struct inode *inode, int type,
                            struct list_head *list);
        int     (* fs_dquot)(struct lustre_dquot *dquot, int cmd);
        lvfs_sbdev_type (* fs_journal_sbdev)(struct super_block *sb);
};

extern int fsfilt_register_ops(struct fsfilt_operations *fs_ops);
extern void fsfilt_unregister_ops(struct fsfilt_operations *fs_ops);
extern struct fsfilt_operations *fsfilt_get_ops(const char *type);
extern void fsfilt_put_ops(struct fsfilt_operations *fs_ops);

static inline char *fsfilt_get_label(struct obd_device *obd,
                                     struct super_block *sb)
{
        if (obd->obd_fsops->fs_getlabel == NULL)
                return NULL;
        if (obd->obd_fsops->fs_getlabel(sb)[0] == '\0')
                return NULL;

        return obd->obd_fsops->fs_getlabel(sb);
}

static inline int fsfilt_set_label(struct obd_device *obd,
                                   struct super_block *sb, char *label)
{
        if (obd->obd_fsops->fs_setlabel == NULL)
                return -ENOSYS;
        return (obd->obd_fsops->fs_setlabel(sb, label));
}

static inline __u8 *fsfilt_uuid(struct obd_device *obd, struct super_block *sb)
{
        if (obd->obd_fsops->fs_uuid == NULL)
                return NULL;

        return obd->obd_fsops->fs_uuid(sb);
}

static inline lvfs_sbdev_type fsfilt_journal_sbdev(struct obd_device *obd,
                                                   struct super_block *sb)
{
        if (obd && obd->obd_fsops && obd->obd_fsops->fs_journal_sbdev)
                return obd->obd_fsops->fs_journal_sbdev(sb);
        return (lvfs_sbdev_type)0;
}

#define FSFILT_OP_UNLINK         1
#define FSFILT_OP_RMDIR          2
#define FSFILT_OP_RENAME         3
#define FSFILT_OP_CREATE         4
#define FSFILT_OP_MKDIR          5
#define FSFILT_OP_SYMLINK        6
#define FSFILT_OP_MKNOD          7
#define FSFILT_OP_SETATTR        8
#define FSFILT_OP_LINK           9
#define FSFILT_OP_CANCEL_UNLINK 10
#define FSFILT_OP_JOIN          11
#define FSFILT_OP_NOOP          15

#define fsfilt_check_slow(obd, start, timeout, msg)                     \
do {                                                                    \
        if (time_before(jiffies, start + 15 * HZ))                      \
                break;                                                  \
        else if (time_before(jiffies, start + 30 * HZ))                 \
                CDEBUG(D_VFSTRACE, "%s: slow %s %lus\n", obd->obd_name, \
                       msg, (jiffies-start) / HZ);                      \
        else if (time_before(jiffies, start + timeout / 2 * HZ))        \
                CWARN("%s: slow %s %lus\n", obd->obd_name, msg,         \
                      (jiffies - start) / HZ);                          \
        else                                                            \
                CERROR("%s: slow %s %lus\n", obd->obd_name, msg,        \
                       (jiffies - start) / HZ);                         \
} while (0)

static inline void *fsfilt_start_log(struct obd_device *obd,
                                     struct inode *inode, int op,
                                     struct obd_trans_info *oti, int logs)
{
        unsigned long now = jiffies;
        void *parent_handle = oti ? oti->oti_handle : NULL;
        void *handle;

        if (obd->obd_fail)
                return ERR_PTR(-EROFS);

        handle = obd->obd_fsops->fs_start(inode, op, parent_handle, logs);
        CDEBUG(D_INFO, "started handle %p (%p)\n", handle, parent_handle);

        if (oti != NULL) {
                if (parent_handle == NULL) {
                        oti->oti_handle = handle;
                } else if (handle != parent_handle) {
                        CERROR("mismatch: parent %p, handle %p, oti %p\n",
                               parent_handle, handle, oti);
                        LBUG();
                }
        }
        fsfilt_check_slow(obd, now, obd_timeout, "journal start");
        return handle;
}

static inline void *fsfilt_start(struct obd_device *obd, struct inode *inode,
                                 int op, struct obd_trans_info *oti)
{
        return fsfilt_start_log(obd, inode, op, oti, 0);
}

static inline void *fsfilt_brw_start_log(struct obd_device *obd, int objcount,
                                         struct fsfilt_objinfo *fso,
                                         int niocount, struct niobuf_local *nb,
                                         struct obd_trans_info *oti, int logs)
{
        unsigned long now = jiffies;
        void *parent_handle = oti ? oti->oti_handle : NULL;
        void *handle;

        if (obd->obd_fail)
                return ERR_PTR(-EROFS);

        handle = obd->obd_fsops->fs_brw_start(objcount, fso, niocount, nb,
                                              parent_handle, logs);
        CDEBUG(D_INFO, "started handle %p (%p)\n", handle, parent_handle);

        if (oti != NULL) {
                if (parent_handle == NULL) {
                        oti->oti_handle = handle;
                } else if (handle != parent_handle) {
                        CERROR("mismatch: parent %p, handle %p, oti %p\n",
                               parent_handle, handle, oti);