LXR linux/fs/exofs/exofs.h

   1/*
   2 * Copyright (C) 2005, 2006
   3 * Avishay Traeger (avishay@gmail.com)
   4 * Copyright (C) 2008, 2009
   5 * Boaz Harrosh <bharrosh@panasas.com>
   6 *
   7 * Copyrights for code taken from ext2:
   8 *     Copyright (C) 1992, 1993, 1994, 1995
   9 *     Remy Card (card@masi.ibp.fr)
  10 *     Laboratoire MASI - Institut Blaise Pascal
  11 *     Universite Pierre et Marie Curie (Paris VI)
  12 *     from
  13 *     linux/fs/minix/inode.c
  14 *     Copyright (C) 1991, 1992  Linus Torvalds
  15 *
  16 * This file is part of exofs.
  17 *
  18 * exofs is free software; you can redistribute it and/or modify
  19 * it under the terms of the GNU General Public License as published by
  20 * the Free Software Foundation.  Since it is based on ext2, and the only
  21 * valid version of GPL for the Linux kernel is version 2, the only valid
  22 * version of GPL for exofs is version 2.
  23 *
  24 * exofs is distributed in the hope that it will be useful,
  25 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  26 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  27 * GNU General Public License for more details.
  28 *
  29 * You should have received a copy of the GNU General Public License
  30 * along with exofs; if not, write to the Free Software
  31 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  32 */
  33#ifndef __EXOFS_H__
  34#define __EXOFS_H__
  35
  36#include <linux/fs.h>
  37#include <linux/time.h>
  38#include <linux/backing-dev.h>
  39#include <scsi/osd_ore.h>
  40
  41#include "common.h"
  42
  43#define EXOFS_ERR(fmt, a...) printk(KERN_ERR "exofs: " fmt, ##a)
  44
  45#ifdef CONFIG_EXOFS_DEBUG
  46#define EXOFS_DBGMSG(fmt, a...) \
  47        printk(KERN_NOTICE "exofs @%s:%d: " fmt, __func__, __LINE__, ##a)
  48#else
  49#define EXOFS_DBGMSG(fmt, a...) \
  50        do { if (0) printk(fmt, ##a); } while (0)
  51#endif
  52
  53/* u64 has problems with printk this will cast it to unsigned long long */
  54#define _LLU(x) (unsigned long long)(x)
  55
  56struct exofs_dev {
  57        struct ore_dev ored;
  58        unsigned did;
  59};
  60/*
  61 * our extension to the in-memory superblock
  62 */
  63struct exofs_sb_info {
  64        struct backing_dev_info bdi;            /* register our bdi with VFS  */
  65        struct exofs_sb_stats s_ess;            /* Written often, pre-allocate*/
  66        int             s_timeout;              /* timeout for OSD operations */
  67        uint64_t        s_nextid;               /* highest object ID used     */
  68        uint32_t        s_numfiles;             /* number of files on fs      */
  69        spinlock_t      s_next_gen_lock;        /* spinlock for gen # update  */
  70        u32             s_next_generation;      /* next gen # to use          */
  71        atomic_t        s_curr_pending;         /* number of pending commands */
  72
  73        struct ore_layout       layout;         /* Default files layout       */
  74        struct ore_comp one_comp;               /* id & cred of partition id=0*/
  75        struct ore_components oc;               /* comps for the partition    */
  76};
  77
  78/*
  79 * our extension to the in-memory inode
  80 */
  81struct exofs_i_info {
  82        struct inode   vfs_inode;          /* normal in-memory inode          */
  83        wait_queue_head_t i_wq;            /* wait queue for inode            */
  84        unsigned long  i_flags;            /* various atomic flags            */
  85        uint32_t       i_data[EXOFS_IDATA];/*short symlink names and device #s*/
  86        uint32_t       i_dir_start_lookup; /* which page to start lookup      */
  87        uint64_t       i_commit_size;      /* the object's written length     */
  88        struct ore_comp one_comp;          /* same component for all devices  */
  89        struct ore_components oc;          /* inode view of the device table  */
  90};
  91
  92static inline osd_id exofs_oi_objno(struct exofs_i_info *oi)
  93{
  94        return oi->vfs_inode.i_ino + EXOFS_OBJ_OFF;
  95}
  96
  97/*
  98 * our inode flags
  99 */
 100#define OBJ_2BCREATED   0       /* object will be created soon*/
 101#define OBJ_CREATED     1       /* object has been created on the osd*/
 102
 103static inline int obj_2bcreated(struct exofs_i_info *oi)
 104{
 105        return test_bit(OBJ_2BCREATED, &oi->i_flags);
 106}
 107
 108static inline void set_obj_2bcreated(struct exofs_i_info *oi)
 109{
 110        set_bit(OBJ_2BCREATED, &oi->i_flags);
 111}
 112
 113static inline int obj_created(struct exofs_i_info *oi)
 114{
 115        return test_bit(OBJ_CREATED, &oi->i_flags);
 116}
 117
 118static inline void set_obj_created(struct exofs_i_info *oi)
 119{
 120        set_bit(OBJ_CREATED, &oi->i_flags);
 121}
 122
 123int __exofs_wait_obj_created(struct exofs_i_info *oi);
 124static inline int wait_obj_created(struct exofs_i_info *oi)
 125{
 126        if (likely(obj_created(oi)))
 127                return 0;
 128
 129        return __exofs_wait_obj_created(oi);
 130}
 131
 132/*
 133 * get to our inode from the vfs inode
 134 */
 135static inline struct exofs_i_info *exofs_i(struct inode *inode)
 136{
 137        return container_of(inode, struct exofs_i_info, vfs_inode);
 138}
 139
 140/*
 141 * Maximum count of links to a file
 142 */
 143#define EXOFS_LINK_MAX           32000
 144
 145/*************************
 146 * function declarations *
 147 *************************/
 148
 149/* inode.c               */
 150unsigned exofs_max_io_pages(struct ore_layout *layout,
 151                            unsigned expected_pages);
 152int exofs_setattr(struct dentry *, struct iattr *);
 153int exofs_write_begin(struct file *file, struct address_space *mapping,
 154                loff_t pos, unsigned len, unsigned flags,
 155                struct page **pagep, void **fsdata);
 156extern struct inode *exofs_iget(struct super_block *, unsigned long);
 157struct inode *exofs_new_inode(struct inode *, int);
 158extern int exofs_write_inode(struct inode *, struct writeback_control *wbc);
 159extern void exofs_evict_inode(struct inode *);
 160
 161/* dir.c:                */
 162int exofs_add_link(struct dentry *, struct inode *);
 163ino_t exofs_inode_by_name(struct inode *, struct dentry *);
 164int exofs_delete_entry(struct exofs_dir_entry *, struct page *);
 165int exofs_make_empty(struct inode *, struct inode *);
 166struct exofs_dir_entry *exofs_find_entry(struct inode *, struct dentry *,
 167                                         struct page **);
 168int exofs_empty_dir(struct inode *);
 169struct exofs_dir_entry *exofs_dotdot(struct inode *, struct page **);
 170ino_t exofs_parent_ino(struct dentry *child);
 171int exofs_set_link(struct inode *, struct exofs_dir_entry *, struct page *,
 172                    struct inode *);
 173
 174/* super.c               */
 175void exofs_make_credential(u8 cred_a[OSD_CAP_LEN],
 176                           const struct osd_obj_id *obj);
 177int exofs_sbi_write_stats(struct exofs_sb_info *sbi);
 178
 179/*********************
 180 * operation vectors *
 181 *********************/
 182/* dir.c:            */
 183extern const struct file_operations exofs_dir_operations;
 184
 185/* file.c            */
 186extern const struct inode_operations exofs_file_inode_operations;
 187extern const struct file_operations exofs_file_operations;
 188
 189/* inode.c           */
 190extern const struct address_space_operations exofs_aops;
 191
 192/* namei.c           */
 193extern const struct inode_operations exofs_dir_inode_operations;
 194extern const struct inode_operations exofs_special_inode_operations;
 195
 196/* symlink.c         */
 197extern const struct inode_operations exofs_symlink_inode_operations;
 198extern const struct inode_operations exofs_fast_symlink_inode_operations;
 199
 200/* exofs_init_comps will initialize an ore_components device array
 201 * pointing to a single ore_comp struct, and a round-robin view
 202 * of the device table.
 203 * The first device of each inode is the [inode->ino % num_devices]
 204 * and the rest of the devices sequentially following where the
 205 * first device is after the last device.
 206 * It is assumed that the global device array at @sbi is twice
 207 * bigger and that the device table repeats twice.
 208 * See: exofs_read_lookup_dev_table()
 209 */
 210static inline void exofs_init_comps(struct ore_components *oc,
 211                                    struct ore_comp *one_comp,
 212                                    struct exofs_sb_info *sbi, osd_id oid)
 213{
 214        unsigned dev_mod = (unsigned)oid, first_dev;
 215
 216        one_comp->obj.partition = sbi->one_comp.obj.partition;
 217        one_comp->obj.id = oid;
 218        exofs_make_credential(one_comp->cred, &one_comp->obj);
 219
 220        oc->first_dev = 0;
 221        oc->numdevs = sbi->layout.group_width * sbi->layout.mirrors_p1 *
 222                                                        sbi->layout.group_count;
 223        oc->single_comp = EC_SINGLE_COMP;
 224        oc->comps = one_comp;
 225
 226        /* Round robin device view of the table */
 227        first_dev = (dev_mod * sbi->layout.mirrors_p1) % sbi->oc.numdevs;
 228        oc->ods = &sbi->oc.ods[first_dev];
 229}
 230
 231#endif
 232