fs/jffs2/jffs2_fs_sb.h

   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
  30 struct jffs2_inodirty;
  31
  32 struct 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 */
  48 struct jffs2_sb_info {
  49         struct mtd_info *mtd;
  50
  51         uint32_t highest_ino;
  52         uint32_t checked_ino;
  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 */