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         bool set_rp_size;
  42         unsigned int rp_size;
  43 };
  44
  45 /* A struct for the overall file system control.  Pointers to
  46    jffs2_sb_info structs are named `c' in the source code.
  47    Nee jffs_control
  48 */
  49 struct jffs2_sb_info {
  50         struct mtd_info *mtd;
  51
  52         uint32_t highest_ino;
  53         uint32_t check_ino;             /* *NEXT* inode to be checked */
  54
  55         unsigned int flags;
  56
  57         struct task_struct *gc_task;    /* GC task struct */
  58         struct completion gc_thread_start; /* GC thread start completion */
  59         struct completion gc_thread_exit; /* GC thread exit completion port */
  60
  61         struct mutex alloc_sem;         /* Used to protect all the following
  62                                            fields, and also to protect against
  63                                            out-of-order writing of nodes. And GC. */
  64         uint32_t cleanmarker_size;      /* Size of an _inline_ CLEANMARKER
  65                                          (i.e. zero for OOB CLEANMARKER */
  66
  67         uint32_t flash_size;
  68         uint32_t used_size;
  69         uint32_t dirty_size;
  70         uint32_t wasted_size;
  71         uint32_t free_size;
  72         uint32_t erasing_size;
  73         uint32_t bad_size;
  74         uint32_t sector_size;
  75         uint32_t unchecked_size;
  76
  77         uint32_t nr_free_blocks;
  78         uint32_t nr_erasing_blocks;
  79
  80         /* Number of free blocks there must be before we... */
  81         uint8_t resv_blocks_write;      /* ... allow a normal filesystem write */
  82         uint8_t resv_blocks_deletion;   /* ... allow a normal filesystem deletion */
  83         uint8_t resv_blocks_gctrigger;  /* ... wake up the GC thread */
  84         uint8_t resv_blocks_gcbad;      /* ... pick a block from the bad_list to GC */
  85         uint8_t resv_blocks_gcmerge;    /* ... merge pages when garbage collecting */
  86         /* Number of 'very dirty' blocks before we trigger immediate GC */
  87         uint8_t vdirty_blocks_gctrigger;
  88
  89         uint32_t nospc_dirty_size;
  90
  91         uint32_t nr_blocks;
  92         struct jffs2_eraseblock *blocks;        /* The whole array of blocks. Used for getting blocks
  93                                                  * from the offset (blocks[ofs / sector_size]) */
  94         struct jffs2_eraseblock *nextblock;     /* The block we're currently filling */
  95
  96         struct jffs2_eraseblock *gcblock;       /* The block we're currently garbage-collecting */
  97
  98         struct list_head clean_list;            /* Blocks 100% full of clean data */
  99         struct list_head very_dirty_list;       /* Blocks with lots of dirty space */
 100         struct list_head dirty_list;            /* Blocks with some dirty space */
 101         struct list_head erasable_list;         /* Blocks which are completely dirty, and need erasing */
 102         struct list_head erasable_pending_wbuf_list;    /* Blocks which need erasing but only after the current wbuf is flushed */
 103         struct list_head erasing_list;          /* Blocks which are currently erasing */
 104         struct list_head erase_checking_list;   /* Blocks which are being checked and marked */
 105         struct list_head erase_pending_list;    /* Blocks which need erasing now */
 106         struct list_head erase_complete_list;   /* Blocks which are erased and need the clean marker written to them */
 107         struct list_head free_list;             /* Blocks which are free and ready to be used */
 108         struct list_head bad_list;              /* Bad blocks. */
 109         struct list_head bad_used_list;         /* Bad blocks with valid data in. */
 110
 111         spinlock_t erase_completion_lock;       /* Protect free_list and erasing_list
 112                                                    against erase completion handler */
 113         wait_queue_head_t erase_wait;           /* For waiting for erases to complete */
 114
 115         wait_queue_head_t inocache_wq;
 116         int inocache_hashsize;
 117         struct jffs2_inode_cache **inocache_list;
 118         spinlock_t inocache_lock;
 119
 120         /* Sem to allow jffs2_garbage_collect_deletion_dirent to
 121            drop the erase_completion_lock while it's holding a pointer
 122            to an obsoleted node. I don't like this. Alternatives welcomed. */
 123         struct mutex erase_free_sem;
 124
 125         uint32_t wbuf_pagesize; /* 0 for NOR and other flashes with no wbuf */
 126
 127 #ifdef CONFIG_JFFS2_FS_WBUF_VERIFY
 128         unsigned char *wbuf_verify; /* read-back buffer for verification */
 129 #endif
 130 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
 131         unsigned char *wbuf; /* Write-behind buffer for NAND flash */
 132         uint32_t wbuf_ofs;
 133         uint32_t wbuf_len;
 134         struct jffs2_inodirty *wbuf_inodes;
 135         struct rw_semaphore wbuf_sem;   /* Protects the write buffer */
 136
 137         struct delayed_work wbuf_dwork; /* write-buffer write-out work */
 138
 139         unsigned char *oobbuf;
 140         int oobavail; /* How many bytes are available for JFFS2 in OOB */
 141 #endif
 142
 143         struct jffs2_summary *summary;          /* Summary information */
 144         struct jffs2_mount_opts mount_opts;
 145
 146 #ifdef CONFIG_JFFS2_FS_XATTR
 147 #define XATTRINDEX_HASHSIZE     (57)
 148         uint32_t highest_xid;
 149         uint32_t highest_xseqno;
 150         struct list_head xattrindex[XATTRINDEX_HASHSIZE];
 151         struct list_head xattr_unchecked;
 152         struct list_head xattr_dead_list;
 153         struct jffs2_xattr_ref *xref_dead_list;
 154         struct jffs2_xattr_ref *xref_temp;
 155         struct rw_semaphore xattr_sem;
 156         uint32_t xdatum_mem_usage;
 157         uint32_t xdatum_mem_threshold;
 158 #endif
 159         /* OS-private pointer for getting back to master superblock info */
 160         void *os_priv;
 161 };
 162
 163 #endif /* _JFFS2_FS_SB */