FreeBSD/Linux Kernel Cross Reference
sys/fs/jffs2/nodelist.h

     /*
      * JFFS2 -- Journalling Flash File System, Version 2.
      *
      * Copyright (C) 2001 Red Hat, Inc.
      *
      * Created by David Woodhouse <dwmw2@cambridge.redhat.com>
      *
      * The original JFFS, from which the design for JFFS2 was derived,
      * was designed and implemented by Axis Communications AB.
     *
     * The contents of this file are subject to the Red Hat eCos Public
     * License Version 1.1 (the "Licence"); you may not use this file
     * except in compliance with the Licence.  You may obtain a copy of
     * the Licence at http://www.redhat.com/
     *
     * Software distributed under the Licence is distributed on an "AS IS"
     * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied.
     * See the Licence for the specific language governing rights and
     * limitations under the Licence.
     *
     * The Original Code is JFFS2 - Journalling Flash File System, version 2
     *
     * Alternatively, the contents of this file may be used under the
     * terms of the GNU General Public License version 2 (the "GPL"), in
     * which case the provisions of the GPL are applicable instead of the
     * above.  If you wish to allow the use of your version of this file
     * only under the terms of the GPL and not to allow others to use your
     * version of this file under the RHEPL, indicate your decision by
     * deleting the provisions above and replace them with the notice and
     * other provisions required by the GPL.  If you do not delete the
     * provisions above, a recipient may use your version of this file
     * under either the RHEPL or the GPL.
     *
     * $Id: nodelist.h,v 1.46.2.4 2003/02/24 21:49:33 dwmw2 Exp $
     *
     */
    
    #include <linux/config.h>
    #include <linux/fs.h>
    
    #include <linux/jffs2_fs_sb.h>
    #include <linux/jffs2_fs_i.h>
    
    #ifndef CONFIG_JFFS2_FS_DEBUG
    #define CONFIG_JFFS2_FS_DEBUG 2
    #endif
    
    #if CONFIG_JFFS2_FS_DEBUG > 0
    #define D1(x) x
    #else
    #define D1(x)
    #endif
    
    #if CONFIG_JFFS2_FS_DEBUG > 1
    #define D2(x) x
    #else
    #define D2(x)
    #endif
    
    /*
      This is all we need to keep in-core for each raw node during normal
      operation. As and when we do read_inode on a particular inode, we can
      scan the nodes which are listed for it and build up a proper map of 
      which nodes are currently valid. JFFSv1 always used to keep that whole
      map in core for each inode.
    */
    struct jffs2_raw_node_ref
    {
            struct jffs2_raw_node_ref *next_in_ino; /* Points to the next raw_node_ref
                    for this inode. If this is the last, it points to the inode_cache
                    for this inode instead. The inode_cache will have NULL in the first
                    word so you know when you've got there :) */
            struct jffs2_raw_node_ref *next_phys;
            //      __u32 ino;
            __u32 flash_offset;
            __u32 totlen;
    //      __u16 nodetype;
            
            /* flash_offset & 3 always has to be zero, because nodes are
               always aligned at 4 bytes. So we have a couple of extra bits
               to play with. So we set the least significant bit to 1 to
               signify that the node is obsoleted by later nodes.
            */
    };
    
    /* 
       Used for keeping track of deletion nodes &c, which can only be marked
       as obsolete when the node which they mark as deleted has actually been 
       removed from the flash.
    */
    struct jffs2_raw_node_ref_list {
            struct jffs2_raw_node_ref *rew;
            struct jffs2_raw_node_ref_list *next;
    };
    
    /* For each inode in the filesystem, we need to keep a record of
       nlink, because it would be a PITA to scan the whole directory tree
       at read_inode() time to calculate it, and to keep sufficient information
       in the raw_node_ref (basically both parent and child inode number for 
      dirent nodes) would take more space than this does. We also keep
      a pointer to the first physical node which is part of this inode, too.
   */
   struct jffs2_inode_cache {
           struct jffs2_scan_info *scan; /* Used during scan to hold
                   temporary lists of nodes, and later must be set to
                   NULL to mark the end of the raw_node_ref->next_in_ino
                   chain. */
           struct jffs2_inode_cache *next;
           struct jffs2_raw_node_ref *nodes;
           __u32 ino;
           int nlink;
   };
   
   struct jffs2_scan_info {
           struct jffs2_full_dirent *dents;
           struct jffs2_tmp_dnode_info *tmpnodes;
   };
   /*
     Larger representation of a raw node, kept in-core only when the 
     struct inode for this particular ino is instantiated.
   */
   
   struct jffs2_full_dnode
   {
           struct jffs2_raw_node_ref *raw;
           __u32 ofs; /* Don't really need this, but optimisation */
           __u32 size;
           __u32 frags; /* Number of fragments which currently refer
                           to this node. When this reaches zero, 
                           the node is obsolete.
                        */
   };
   
   /* 
      Even larger representation of a raw node, kept in-core only while
      we're actually building up the original map of which nodes go where,
      in read_inode()
   */
   struct jffs2_tmp_dnode_info
   {
           struct jffs2_tmp_dnode_info *next;
           struct jffs2_full_dnode *fn;
           __u32 version;
   };       
   
   struct jffs2_full_dirent
   {
           struct jffs2_raw_node_ref *raw;
           struct jffs2_full_dirent *next;
           __u32 version;
           __u32 ino; /* == zero for unlink */
           unsigned int nhash;
           unsigned char type;
           unsigned char name[0];
   };
   /*
     Fragments - used to build a map of which raw node to obtain 
     data from for each part of the ino
   */
   struct jffs2_node_frag
   {
           struct jffs2_node_frag *next;
           struct jffs2_full_dnode *node; /* NULL for holes */
           __u32 size;
           __u32 ofs; /* Don't really need this, but optimisation */
   };
   
   struct jffs2_eraseblock
   {
           struct list_head list;
           int bad_count;
           __u32 offset;           /* of this block in the MTD */
   
           __u32 used_size;
           __u32 dirty_size;
           __u32 free_size;        /* Note that sector_size - free_size
                                      is the address of the first free space */
           struct jffs2_raw_node_ref *first_node;
           struct jffs2_raw_node_ref *last_node;
   
           struct jffs2_raw_node_ref *gc_node;     /* Next node to be garbage collected */
   
           /* For deletia. When a dirent node in this eraseblock is
              deleted by a node elsewhere, that other node can only 
              be marked as obsolete when this block is actually erased.
              So we keep a list of the nodes to mark as obsolete when
              the erase is completed.
           */
           // MAYBE        struct jffs2_raw_node_ref_list *deletia;
   };
   
   #define ACCT_SANITY_CHECK(c, jeb) do { \
           if (jeb->used_size + jeb->dirty_size + jeb->free_size != c->sector_size) { \
                   printk(KERN_NOTICE "Eeep. Space accounting for block at 0x%08x is screwed\n", jeb->offset); \
                   printk(KERN_NOTICE "free 0x%08x + dirty 0x%08x + used %08x != total %08x\n", \
                   jeb->free_size, jeb->dirty_size, jeb->used_size, c->sector_size); \
                   BUG(); \
           } \
           if (c->used_size + c->dirty_size + c->free_size + c->erasing_size + c->bad_size != c->flash_size) { \
                   printk(KERN_NOTICE "Eeep. Space accounting superblock info is screwed\n"); \
                   printk(KERN_NOTICE "free 0x%08x + dirty 0x%08x + used %08x + erasing %08x + bad %08x != total %08x\n", \
                   c->free_size, c->dirty_size, c->used_size, c->erasing_size, c->bad_size, c->flash_size); \
                   BUG(); \
           } \
   } while(0)
   
   #define ACCT_PARANOIA_CHECK(jeb) do { \
                   __u32 my_used_size = 0; \
                   struct jffs2_raw_node_ref *ref2 = jeb->first_node; \
                   while (ref2) { \
                           if (!(ref2->flash_offset & 1)) \
                                   my_used_size += ref2->totlen; \
                           ref2 = ref2->next_phys; \
                   } \
                   if (my_used_size != jeb->used_size) { \
                           printk(KERN_NOTICE "Calculated used size %08x != stored used size %08x\n", my_used_size, jeb->used_size); \
                           BUG(); \
                   } \
           } while(0)
   
   #define ALLOC_NORMAL    0       /* Normal allocation */
   #define ALLOC_DELETION  1       /* Deletion node. Best to allow it */
   #define ALLOC_GC        2       /* Space requested for GC. Give it or die */
   
   #define JFFS2_RESERVED_BLOCKS_BASE 3                                            /* Number of free blocks there must be before we... */
   #define JFFS2_RESERVED_BLOCKS_WRITE (JFFS2_RESERVED_BLOCKS_BASE + 2)            /* ... allow a normal filesystem write */
   #define JFFS2_RESERVED_BLOCKS_DELETION (JFFS2_RESERVED_BLOCKS_BASE + 1)         /* ... allow a normal filesystem deletion */
   #define JFFS2_RESERVED_BLOCKS_GCTRIGGER (JFFS2_RESERVED_BLOCKS_BASE + 3)        /* ... wake up the GC thread */
   #define JFFS2_RESERVED_BLOCKS_GCBAD (JFFS2_RESERVED_BLOCKS_BASE + 1)            /* ... pick a block from the bad_list to GC */
   #define JFFS2_RESERVED_BLOCKS_GCMERGE (JFFS2_RESERVED_BLOCKS_BASE)              /* ... merge pages when garbage collecting */
   
   
   #define PAD(x) (((x)+3)&~3)
   
   static inline int jffs2_raw_ref_to_inum(struct jffs2_raw_node_ref *raw)
   {
           while(raw->next_in_ino) {
                   raw = raw->next_in_ino;
           }
   
           return ((struct jffs2_inode_cache *)raw)->ino;
   }
   
   /* nodelist.c */
   D1(void jffs2_print_frag_list(struct jffs2_inode_info *f));
   void jffs2_add_fd_to_list(struct jffs2_sb_info *c, struct jffs2_full_dirent *new, struct jffs2_full_dirent **list);
   void jffs2_add_tn_to_list(struct jffs2_tmp_dnode_info *tn, struct jffs2_tmp_dnode_info **list);
   int jffs2_get_inode_nodes(struct jffs2_sb_info *c, ino_t ino, struct jffs2_inode_info *f,
                             struct jffs2_tmp_dnode_info **tnp, struct jffs2_full_dirent **fdp,
                             __u32 *highest_version, __u32 *latest_mctime,
                             __u32 *mctime_ver);
   struct jffs2_inode_cache *jffs2_get_ino_cache(struct jffs2_sb_info *c, uint32_t ino);
   void jffs2_add_ino_cache (struct jffs2_sb_info *c, struct jffs2_inode_cache *new);
   void jffs2_del_ino_cache(struct jffs2_sb_info *c, struct jffs2_inode_cache *old);
   void jffs2_free_ino_caches(struct jffs2_sb_info *c);
   void jffs2_free_raw_node_refs(struct jffs2_sb_info *c);
   
   /* nodemgmt.c */
   int jffs2_reserve_space(struct jffs2_sb_info *c, __u32 minsize, __u32 *ofs, __u32 *len, int prio);
   int jffs2_reserve_space_gc(struct jffs2_sb_info *c, __u32 minsize, __u32 *ofs, __u32 *len);
   int jffs2_add_physical_node_ref(struct jffs2_sb_info *c, struct jffs2_raw_node_ref *new, __u32 len, int dirty);
   void jffs2_complete_reservation(struct jffs2_sb_info *c);
   void jffs2_mark_node_obsolete(struct jffs2_sb_info *c, struct jffs2_raw_node_ref *raw);
   
   /* write.c */
   struct inode *jffs2_new_inode (struct inode *dir_i, int mode, struct jffs2_raw_inode *ri);
   struct jffs2_full_dnode *jffs2_write_dnode(struct inode *inode, struct jffs2_raw_inode *ri, const unsigned char *data, __u32 datalen, __u32 flash_ofs,  __u32 *writelen);
   struct jffs2_full_dirent *jffs2_write_dirent(struct inode *inode, struct jffs2_raw_dirent *rd, const unsigned char *name, __u32 namelen, __u32 flash_ofs,  __u32 *writelen);
   
   /* readinode.c */
   void jffs2_truncate_fraglist (struct jffs2_sb_info *c, struct jffs2_node_frag **list, __u32 size);
   int jffs2_add_full_dnode_to_fraglist(struct jffs2_sb_info *c, struct jffs2_node_frag **list, struct jffs2_full_dnode *fn);
   int jffs2_add_full_dnode_to_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f, struct jffs2_full_dnode *fn);
   void jffs2_read_inode (struct inode *);
   void jffs2_clear_inode (struct inode *);
   
   /* malloc.c */
   void jffs2_free_tmp_dnode_info_list(struct jffs2_tmp_dnode_info *tn);
   void jffs2_free_full_dirent_list(struct jffs2_full_dirent *fd);
   
   int jffs2_create_slab_caches(void);
   void jffs2_destroy_slab_caches(void);
   
   struct jffs2_full_dirent *jffs2_alloc_full_dirent(int namesize);
   void jffs2_free_full_dirent(struct jffs2_full_dirent *);
   struct jffs2_full_dnode *jffs2_alloc_full_dnode(void);
   void jffs2_free_full_dnode(struct jffs2_full_dnode *);
   struct jffs2_raw_dirent *jffs2_alloc_raw_dirent(void);
   void jffs2_free_raw_dirent(struct jffs2_raw_dirent *);
   struct jffs2_raw_inode *jffs2_alloc_raw_inode(void);
   void jffs2_free_raw_inode(struct jffs2_raw_inode *);
   struct jffs2_tmp_dnode_info *jffs2_alloc_tmp_dnode_info(void);
   void jffs2_free_tmp_dnode_info(struct jffs2_tmp_dnode_info *);
   struct jffs2_raw_node_ref *jffs2_alloc_raw_node_ref(void);
   void jffs2_free_raw_node_ref(struct jffs2_raw_node_ref *);
   struct jffs2_node_frag *jffs2_alloc_node_frag(void);
   void jffs2_free_node_frag(struct jffs2_node_frag *);
   struct jffs2_inode_cache *jffs2_alloc_inode_cache(void);
   void jffs2_free_inode_cache(struct jffs2_inode_cache *);
   
   /* gc.c */
   int jffs2_garbage_collect_pass(struct jffs2_sb_info *c);
   
   /* background.c */
   int jffs2_start_garbage_collect_thread(struct jffs2_sb_info *c);
   void jffs2_stop_garbage_collect_thread(struct jffs2_sb_info *c);
   void jffs2_garbage_collect_trigger(struct jffs2_sb_info *c);
   
   /* dir.c */
   extern struct file_operations jffs2_dir_operations;
   extern struct inode_operations jffs2_dir_inode_operations;
   
   /* file.c */
   extern struct file_operations jffs2_file_operations;
   extern struct inode_operations jffs2_file_inode_operations;
   extern struct address_space_operations jffs2_file_address_operations;
   int jffs2_null_fsync(struct file *, struct dentry *, int);
   int jffs2_setattr (struct dentry *dentry, struct iattr *iattr);
   int jffs2_do_readpage_nolock (struct inode *inode, struct page *pg);
   int jffs2_do_readpage_unlock (struct inode *inode, struct page *pg);
   int jffs2_readpage (struct file *, struct page *);
   int jffs2_prepare_write (struct file *, struct page *, unsigned, unsigned);
   int jffs2_commit_write (struct file *, struct page *, unsigned, unsigned);
   
   /* ioctl.c */
   int jffs2_ioctl(struct inode *, struct file *, unsigned int, unsigned long);
   
   /* read.c */
   int jffs2_read_dnode(struct jffs2_sb_info *c, struct jffs2_full_dnode *fd, unsigned char *buf, int ofs, int len);
   
   /* compr.c */
   unsigned char jffs2_compress(unsigned char *data_in, unsigned char *cpage_out, 
                                __u32 *datalen, __u32 *cdatalen);
   int jffs2_decompress(unsigned char comprtype, unsigned char *cdata_in, 
                        unsigned char *data_out, __u32 cdatalen, __u32 datalen);
   
   /* scan.c */
   int jffs2_scan_medium(struct jffs2_sb_info *c);
   
   /* build.c */
   int jffs2_build_filesystem(struct jffs2_sb_info *c);
   
   /* symlink.c */
   extern struct inode_operations jffs2_symlink_inode_operations;
   
   /* erase.c */
   void jffs2_erase_block(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb);
   void jffs2_erase_pending_blocks(struct jffs2_sb_info *c);
   void jffs2_mark_erased_blocks(struct jffs2_sb_info *c);
   void jffs2_erase_pending_trigger(struct jffs2_sb_info *c);
   
   /* compr_zlib.c */
   int jffs2_zlib_init(void);
   void jffs2_zlib_exit(void);

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