fs/jffs2/jffs2_fs_sb.h

   1 /*
   2  * JFFS2 -- Journalling Flash File System, Version 2.
   3  *
   4  * Copyright © 2001-2007 Red Hat, Inc.
   5  *
   6  * Created by David Woodhouse <dwmw2@infradead.org>
   7  *
   8  * For licensing information, see the file 'LICENCE' in this directory.
   9  *
  10  */
  11
  12 #ifndef _JFFS2_FS_SB
  13 #define _JFFS2_FS_SB
  14
  15 #include <linux/types.h>
  16 #include <linux/spinlock.h>
  17 #include <linux/workqueue.h>
  18 #include <linux/completion.h>
  19 #include <asm/semaphore.h>
  20 #include <linux/timer.h>
  21 #include <linux/wait.h>
  22 #include <linux/list.h>
  23 #include <linux/rwsem.h>
  24
  25 #define JFFS2_SB_FLAG_RO 1
  26 #define JFFS2_SB_FLAG_SCANNING 2 /* Flash scanning is in progress */
  27 #define JFFS2_SB_FLAG_BUILDING 4 /* File system building is in progress */
  28
  29 struct jffs2_inodirty;
  30
  31 /* A struct for the overall file system control.  Pointers to
  32    jffs2_sb_info structs are named `c' in the source code.
  33    Nee jffs_control
  34 */
  35 struct jffs2_sb_info {
  36         struct mtd_info *mtd;
  37
  38         uint32_t highest_ino;
  39         uint32_t checked_ino;
  40
  41         unsigned int flags;
  42
  43         struct task_struct *gc_task;    /* GC task struct */
  44         struct completion gc_thread_start; /* GC thread start completion */
  45         struct completion gc_thread_exit; /* GC thread exit completion port */
  46
  47         struct semaphore alloc_sem;     /* Used to protect all the following
  48                                            fields, and also to protect against
  49                                            out-of-order writing of nodes. And GC. */
  50         uint32_t cleanmarker_size;      /* Size of an _inline_ CLEANMARKER
  51                                          (i.e. zero for OOB CLEANMARKER */
  52
  53         uint32_t flash_size;
  54         uint32_t used_size;
  55         uint32_t dirty_size;
  56         uint32_t wasted_size;
  57         uint32_t free_size;
  58         uint32_t erasing_size;
  59         uint32_t bad_size;
  60         uint32_t sector_size;
  61         uint32_t unchecked_size;
  62
  63         uint32_t nr_free_blocks;
  64         uint32_t nr_erasing_blocks;
  65
  66         /* Number of free blocks there must be before we... */
  67         uint8_t resv_blocks_write;      /* ... allow a normal filesystem write */
  68         uint8_t resv_blocks_deletion;   /* ... allow a normal filesystem deletion */
  69         uint8_t resv_blocks_gctrigger;  /* ... wake up the GC thread */
  70         uint8_t resv_blocks_gcbad;      /* ... pick a block from the bad_list to GC */
  71         uint8_t resv_blocks_gcmerge;    /* ... merge pages when garbage collecting */
  72         /* Number of 'very dirty' blocks before we trigger immediate GC */
  73         uint8_t vdirty_blocks_gctrigger;
  74
  75         uint32_t nospc_dirty_size;
  76
  77         uint32_t nr_blocks;
  78         struct jffs2_eraseblock *blocks;        /* The whole array of blocks. Used for getting blocks
  79                                                  * from the offset (blocks[ofs / sector_size]) */
  80         struct jffs2_eraseblock *nextblock;     /* The block we're currently filling */
  81
  82         struct jffs2_eraseblock *gcblock;       /* The block we're currently garbage-collecting */
  83
  84         struct list_head clean_list;            /* Blocks 100% full of clean data */
  85         struct list_head very_dirty_list;       /* Blocks with lots of dirty space */
  86         struct list_head dirty_list;            /* Blocks with some dirty space */
  87         struct list_head erasable_list;         /* Blocks which are completely dirty, and need erasing */
  88         struct list_head erasable_pending_wbuf_list;    /* Blocks which need erasing but only after the current wbuf is flushed */
  89         struct list_head erasing_list;          /* Blocks which are currently erasing */
  90         struct list_head erase_pending_list;    /* Blocks which need erasing now */
  91         struct list_head erase_complete_list;   /* Blocks which are erased and need the clean marker written to them */
  92         struct list_head free_list;             /* Blocks which are free and ready to be used */
  93         struct list_head bad_list;              /* Bad blocks. */
  94         struct list_head bad_used_list;         /* Bad blocks with valid data in. */
  95
  96         spinlock_t erase_completion_lock;       /* Protect free_list and erasing_list
  97                                                    against erase completion handler */
  98         wait_queue_head_t erase_wait;           /* For waiting for erases to complete */
  99
 100         wait_queue_head_t inocache_wq;
 101         struct jffs2_inode_cache **inocache_list;
 102         spinlock_t inocache_lock;
 103
 104         /* Sem to allow jffs2_garbage_collect_deletion_dirent to
 105            drop the erase_completion_lock while it's holding a pointer
 106            to an obsoleted node. I don't like this. Alternatives welcomed. */
 107         struct semaphore erase_free_sem;
 108
 109         uint32_t wbuf_pagesize; /* 0 for NOR and other flashes with no wbuf */
 110
 111 #ifdef CONFIG_JFFS2_FS_WBUF_VERIFY
 112         unsigned char *wbuf_verify; /* read-back buffer for verification */
 113 #endif
 114 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
 115         unsigned char *wbuf; /* Write-behind buffer for NAND flash */
 116         uint32_t wbuf_ofs;
 117         uint32_t wbuf_len;
 118         struct jffs2_inodirty *wbuf_inodes;
 119         struct rw_semaphore wbuf_sem;   /* Protects the write buffer */
 120
 121         unsigned char *oobbuf;
 122         int oobavail; /* How many bytes are available for JFFS2 in OOB */
 123 #endif
 124
 125         struct jffs2_summary *summary;          /* Summary information */
 126
 127 #ifdef CONFIG_JFFS2_FS_XATTR
 128 #define XATTRINDEX_HASHSIZE     (57)
 129         uint32_t highest_xid;
 130         uint32_t highest_xseqno;
 131         struct list_head xattrindex[XATTRINDEX_HASHSIZE];
 132         struct list_head xattr_unchecked;
 133         struct list_head xattr_dead_list;
 134         struct jffs2_xattr_ref *xref_dead_list;
 135         struct jffs2_xattr_ref *xref_temp;
 136         struct rw_semaphore xattr_sem;
 137         uint32_t xdatum_mem_usage;
 138         uint32_t xdatum_mem_threshold;
 139 #endif
 140         /* OS-private pointer for getting back to master superblock info */
 141         void *os_priv;
 142 };
 143
 144 #endif /* _JFFS2_FB_SB */