linux/fs/jffs2/jffs2_fs_sb.h
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   1/*
   2 * JFFS2 -- Journalling Flash File System, Version 2.
   3 *
   4 * Copyright © 2001-2007 Red Hat, Inc.
   5 * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
   6 *
   7 * Created by David Woodhouse <dwmw2@infradead.org>
   8 *
   9 * For licensing information, see the file 'LICENCE' in this directory.
  10 *
  11 */
  12
  13#ifndef _JFFS2_FS_SB
  14#define _JFFS2_FS_SB
  15
  16#include <linux/types.h>
  17#include <linux/spinlock.h>
  18#include <linux/workqueue.h>
  19#include <linux/completion.h>
  20#include <linux/mutex.h>
  21#include <linux/timer.h>
  22#include <linux/wait.h>
  23#include <linux/list.h>
  24#include <linux/rwsem.h>
  25
  26#define JFFS2_SB_FLAG_RO 1
  27#define JFFS2_SB_FLAG_SCANNING 2 /* Flash scanning is in progress */
  28#define JFFS2_SB_FLAG_BUILDING 4 /* File system building is in progress */
  29
  30struct jffs2_inodirty;
  31
  32struct jffs2_mount_opts {
  33        bool override_compr;
  34        unsigned int compr;
  35
  36        /* The size of the reserved pool. The reserved pool is the JFFS2 flash
  37         * space which may only be used by root cannot be used by the other
  38         * users. This is implemented simply by means of not allowing the
  39         * latter users to write to the file system if the amount if the
  40         * available space is less then 'rp_size'. */
  41        unsigned int rp_size;
  42};
  43
  44/* A struct for the overall file system control.  Pointers to
  45   jffs2_sb_info structs are named `c' in the source code.
  46   Nee jffs_control
  47*/
  48struct jffs2_sb_info {
  49        struct mtd_info *mtd;
  50
  51        uint32_t highest_ino;
  52        uint32_t check_ino;             /* *NEXT* inode to be checked */
  53
  54        unsigned int flags;
  55
  56        struct task_struct *gc_task;    /* GC task struct */
  57        struct completion gc_thread_start; /* GC thread start completion */
  58        struct completion gc_thread_exit; /* GC thread exit completion port */
  59
  60        struct mutex alloc_sem;         /* Used to protect all the following
  61                                           fields, and also to protect against
  62                                           out-of-order writing of nodes. And GC. */
  63        uint32_t cleanmarker_size;      /* Size of an _inline_ CLEANMARKER
  64                                         (i.e. zero for OOB CLEANMARKER */
  65
  66        uint32_t flash_size;
  67        uint32_t used_size;
  68        uint32_t dirty_size;
  69        uint32_t wasted_size;
  70        uint32_t free_size;
  71        uint32_t erasing_size;
  72        uint32_t bad_size;
  73        uint32_t sector_size;
  74        uint32_t unchecked_size;
  75
  76        uint32_t nr_free_blocks;
  77        uint32_t nr_erasing_blocks;
  78
  79        /* Number of free blocks there must be before we... */
  80        uint8_t resv_blocks_write;      /* ... allow a normal filesystem write */
  81        uint8_t resv_blocks_deletion;   /* ... allow a normal filesystem deletion */
  82        uint8_t resv_blocks_gctrigger;  /* ... wake up the GC thread */
  83        uint8_t resv_blocks_gcbad;      /* ... pick a block from the bad_list to GC */
  84        uint8_t resv_blocks_gcmerge;    /* ... merge pages when garbage collecting */
  85        /* Number of 'very dirty' blocks before we trigger immediate GC */
  86        uint8_t vdirty_blocks_gctrigger;
  87
  88        uint32_t nospc_dirty_size;
  89
  90        uint32_t nr_blocks;
  91        struct jffs2_eraseblock *blocks;        /* The whole array of blocks. Used for getting blocks
  92                                                 * from the offset (blocks[ofs / sector_size]) */
  93        struct jffs2_eraseblock *nextblock;     /* The block we're currently filling */
  94
  95        struct jffs2_eraseblock *gcblock;       /* The block we're currently garbage-collecting */
  96
  97        struct list_head clean_list;            /* Blocks 100% full of clean data */
  98        struct list_head very_dirty_list;       /* Blocks with lots of dirty space */
  99        struct list_head dirty_list;            /* Blocks with some dirty space */
 100        struct list_head erasable_list;         /* Blocks which are completely dirty, and need erasing */
 101        struct list_head erasable_pending_wbuf_list;    /* Blocks which need erasing but only after the current wbuf is flushed */
 102        struct list_head erasing_list;          /* Blocks which are currently erasing */
 103        struct list_head erase_checking_list;   /* Blocks which are being checked and marked */
 104        struct list_head erase_pending_list;    /* Blocks which need erasing now */
 105        struct list_head erase_complete_list;   /* Blocks which are erased and need the clean marker written to them */
 106        struct list_head free_list;             /* Blocks which are free and ready to be used */
 107        struct list_head bad_list;              /* Bad blocks. */
 108        struct list_head bad_used_list;         /* Bad blocks with valid data in. */
 109
 110        spinlock_t erase_completion_lock;       /* Protect free_list and erasing_list
 111                                                   against erase completion handler */
 112        wait_queue_head_t erase_wait;           /* For waiting for erases to complete */
 113
 114        wait_queue_head_t inocache_wq;
 115        int inocache_hashsize;
 116        struct jffs2_inode_cache **inocache_list;
 117        spinlock_t inocache_lock;
 118
 119        /* Sem to allow jffs2_garbage_collect_deletion_dirent to
 120           drop the erase_completion_lock while it's holding a pointer
 121           to an obsoleted node. I don't like this. Alternatives welcomed. */
 122        struct mutex erase_free_sem;
 123
 124        uint32_t wbuf_pagesize; /* 0 for NOR and other flashes with no wbuf */
 125
 126#ifdef CONFIG_JFFS2_FS_WBUF_VERIFY
 127        unsigned char *wbuf_verify; /* read-back buffer for verification */
 128#endif
 129#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
 130        unsigned char *wbuf; /* Write-behind buffer for NAND flash */
 131        uint32_t wbuf_ofs;
 132        uint32_t wbuf_len;
 133        struct jffs2_inodirty *wbuf_inodes;
 134        struct rw_semaphore wbuf_sem;   /* Protects the write buffer */
 135
 136        struct delayed_work wbuf_dwork; /* write-buffer write-out work */
 137
 138        unsigned char *oobbuf;
 139        int oobavail; /* How many bytes are available for JFFS2 in OOB */
 140#endif
 141
 142        struct jffs2_summary *summary;          /* Summary information */
 143        struct jffs2_mount_opts mount_opts;
 144
 145#ifdef CONFIG_JFFS2_FS_XATTR
 146#define XATTRINDEX_HASHSIZE     (57)
 147        uint32_t highest_xid;
 148        uint32_t highest_xseqno;
 149        struct list_head xattrindex[XATTRINDEX_HASHSIZE];
 150        struct list_head xattr_unchecked;
 151        struct list_head xattr_dead_list;
 152        struct jffs2_xattr_ref *xref_dead_list;
 153        struct jffs2_xattr_ref *xref_temp;
 154        struct rw_semaphore xattr_sem;
 155        uint32_t xdatum_mem_usage;
 156        uint32_t xdatum_mem_threshold;
 157#endif
 158        /* OS-private pointer for getting back to master superblock info */
 159        void *os_priv;
 160};
 161
 162#endif /* _JFFS2_FS_SB */
 163