jffs2_fs_sb.h

/*
 * JFFS2 -- Journalling Flash File System, Version 2.
 *
 * Copyright © 2001-2007 Red Hat, Inc.
 * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
 *
 * Created by David Woodhouse <dwmw2@infradead.org>
 *
 * For licensing information, see the file 'LICENCE' in this directory.
 *
 */

#ifndef _JFFS2_FS_SB
#define _JFFS2_FS_SB

#include <linux/types.h>
#include <linux/spinlock.h>
#include <linux/workqueue.h>
#include <linux/completion.h>
#include <linux/mutex.h>
#include <linux/timer.h>
#include <linux/wait.h>
#include <linux/list.h>
#include <linux/rwsem.h>

#define JFFS2_SB_FLAG_RO 1
#define JFFS2_SB_FLAG_SCANNING 2 /* Flash scanning is in progress */
#define JFFS2_SB_FLAG_BUILDING 4 /* File system building is in progress */

struct jffs2_inodirty;

struct jffs2_mount_opts {
    bool override_compr;
    unsigned int compr;

    /* The size of the reserved pool. The reserved pool is the JFFS2 flash
     * space which may only be used by root cannot be used by the other
     * users. This is implemented simply by means of not allowing the
     * latter users to write to the file system if the amount if the
     * available space is less then 'rp_size'. */
    unsigned int rp_size;
};

/* A struct for the overall file system control.  Pointers to
   jffs2_sb_info structs are named `c' in the source code.
   Nee jffs_control
*/
struct jffs2_sb_info {
    struct mtd_info *mtd;

    uint32_t highest_ino;
    uint32_t check_ino;     /* *NEXT* inode to be checked */

    unsigned int flags;

    struct task_struct *gc_task;    /* GC task struct */
    struct completion gc_thread_start; /* GC thread start completion */
    struct completion gc_thread_exit; /* GC thread exit completion port */

    struct mutex alloc_sem;     /* Used to protect all the following
                       fields, and also to protect against
                       out-of-order writing of nodes. And GC. */
    uint32_t cleanmarker_size;  /* Size of an _inline_ CLEANMARKER
                     (i.e. zero for OOB CLEANMARKER */

    uint32_t flash_size;
    uint32_t used_size;
    uint32_t dirty_size;
    uint32_t wasted_size;
    uint32_t free_size;
    uint32_t erasing_size;
    uint32_t bad_size;
    uint32_t sector_size;
    uint32_t unchecked_size;

    uint32_t nr_free_blocks;
    uint32_t nr_erasing_blocks;

    /* Number of free blocks there must be before we... */
    uint8_t resv_blocks_write;  /* ... allow a normal filesystem write */
    uint8_t resv_blocks_deletion;   /* ... allow a normal filesystem deletion */
    uint8_t resv_blocks_gctrigger;  /* ... wake up the GC thread */
    uint8_t resv_blocks_gcbad;  /* ... pick a block from the bad_list to GC */
    uint8_t resv_blocks_gcmerge;    /* ... merge pages when garbage collecting */
    /* Number of 'very dirty' blocks before we trigger immediate GC */
    uint8_t vdirty_blocks_gctrigger;

    uint32_t nospc_dirty_size;

    uint32_t nr_blocks;
    struct jffs2_eraseblock *blocks;    /* The whole array of blocks. Used for getting blocks
                         * from the offset (blocks[ofs / sector_size]) */
    struct jffs2_eraseblock *nextblock; /* The block we're currently filling */

    struct jffs2_eraseblock *gcblock;   /* The block we're currently garbage-collecting */

    struct list_head clean_list;        /* Blocks 100% full of clean data */
    struct list_head very_dirty_list;   /* Blocks with lots of dirty space */
    struct list_head dirty_list;        /* Blocks with some dirty space */
    struct list_head erasable_list;     /* Blocks which are completely dirty, and need erasing */
    struct list_head erasable_pending_wbuf_list;    /* Blocks which need erasing but only after the current wbuf is flushed */
    struct list_head erasing_list;      /* Blocks which are currently erasing */
    struct list_head erase_checking_list;   /* Blocks which are being checked and marked */
    struct list_head erase_pending_list;    /* Blocks which need erasing now */
    struct list_head erase_complete_list;   /* Blocks which are erased and need the clean marker written to them */
    struct list_head free_list;     /* Blocks which are free and ready to be used */
    struct list_head bad_list;      /* Bad blocks. */
    struct list_head bad_used_list;     /* Bad blocks with valid data in. */

    spinlock_t erase_completion_lock;   /* Protect free_list and erasing_list
                           against erase completion handler */
    wait_queue_head_t erase_wait;       /* For waiting for erases to complete */

    wait_queue_head_t inocache_wq;
    int inocache_hashsize;
    struct jffs2_inode_cache **inocache_list;
    spinlock_t inocache_lock;

    /* Sem to allow jffs2_garbage_collect_deletion_dirent to
       drop the erase_completion_lock while it's holding a pointer
       to an obsoleted node. I don't like this. Alternatives welcomed. */
    struct mutex erase_free_sem;

    uint32_t wbuf_pagesize; /* 0 for NOR and other flashes with no wbuf */

#ifdef CONFIG_JFFS2_FS_WBUF_VERIFY
    unsigned char *wbuf_verify; /* read-back buffer for verification */
#endif
#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
    unsigned char *wbuf; /* Write-behind buffer for NAND flash */
    uint32_t wbuf_ofs;
    uint32_t wbuf_len;
    struct jffs2_inodirty *wbuf_inodes;
    struct rw_semaphore wbuf_sem;   /* Protects the write buffer */

    struct delayed_work wbuf_dwork; /* write-buffer write-out work */

    unsigned char *oobbuf;
    int oobavail; /* How many bytes are available for JFFS2 in OOB */
#endif

    struct jffs2_summary *summary;      /* Summary information */
    struct jffs2_mount_opts mount_opts;

#ifdef CONFIG_JFFS2_FS_XATTR
#define XATTRINDEX_HASHSIZE (57)
    uint32_t highest_xid;
    uint32_t highest_xseqno;
    struct list_head xattrindex[XATTRINDEX_HASHSIZE];
    struct list_head xattr_unchecked;
    struct list_head xattr_dead_list;
    struct jffs2_xattr_ref *xref_dead_list;
    struct jffs2_xattr_ref *xref_temp;
    struct rw_semaphore xattr_sem;
    uint32_t xdatum_mem_usage;
    uint32_t xdatum_mem_threshold;
#endif
    /* OS-private pointer for getting back to master superblock info */
    void *os_priv;
};

#endif /* _JFFS2_FS_SB */