jffs2_fs_sb.h

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/*
 * 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 checked_ino;

        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 */
        int wbuf_queued;                /* non-zero delayed work is queued */
        spinlock_t wbuf_dwork_lock;     /* protects wbuf_dwork and and wbuf_queued */

        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 */