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journal_ext3.c
资源名称：SBC-2410X_kernel.tar.gz　[点击查看]
上传用户：lgb322
上传日期：2013-02-24
资源大小：30529k
文件大小：7k
源码类别：

嵌入式Linux

开发平台：

Unix_Linux

journal_ext3.c：源码内容
  2. /*
  3.  * Intermezzo. (C) 1998 Peter J. Braam
  4.  * Intermezzo. (C) 2000 Red Hat, Inc.
  5.  * Intermezzo. (C) 2000 Los Alamos National Laboratory
  6.  * Intermezzo. (C) 2000 TurboLinux, Inc.
  7.  * Intermezzo. (C) 2001 Mountain View Data, Inc.
  8.  */
  10. #include <linux/types.h>
  11. #include <linux/param.h>
  12. #include <linux/kernel.h>
  13. #include <linux/sched.h>
  14. #include <linux/fs.h>
  15. #include <linux/slab.h>
  16. #include <linux/vmalloc.h>
  17. #include <linux/stat.h>
  18. #include <linux/errno.h>
  19. #include <linux/locks.h>
  20. #include <asm/segment.h>
  21. #include <asm/uaccess.h>
  22. #include <linux/string.h>
  23. #include <linux/smp_lock.h>
  24. #if defined(CONFIG_EXT3_FS) || defined (CONFIG_EXT3_FS_MODULE)
  25. #include <linux/jbd.h>
  26. #include <linux/ext3_fs.h>
  27. #include <linux/ext3_jbd.h>
  28. #endif
  30. #include <linux/intermezzo_fs.h>
  31. #include <linux/intermezzo_upcall.h>
  32. #include <linux/intermezzo_psdev.h>
  33. #include <linux/intermezzo_kml.h>
  35. #if defined(CONFIG_EXT3_FS) || defined (CONFIG_EXT3_FS_MODULE)
  37. #define MAX_PATH_BLOCKS(inode) (PATH_MAX >> EXT3_BLOCK_SIZE_BITS((inode)->i_sb))
  38. #define MAX_NAME_BLOCKS(inode) (NAME_MAX >> EXT3_BLOCK_SIZE_BITS((inode)->i_sb))
  40. /* space requirements: 
  41.    presto_do_truncate: 
  42.         used to truncate the KML forward to next fset->chunksize boundary
  43.           - zero partial block
  44.           - update inode
  45.    presto_write_record: 
  46.         write header (< one block) 
  47.         write one path (< MAX_PATHLEN) 
  48.         possibly write another path (< MAX_PATHLEN)
  49.         write suffix (< one block) 
  50.    presto_update_last_rcvd
  51.         write one block
  52. */
  54. static loff_t presto_e3_freespace(struct presto_cache *cache,
  55.                                          struct super_block *sb)
  56. {
  57.         loff_t freebl = le32_to_cpu(sb->u.ext3_sb.s_es->s_free_blocks_count);
  58.         loff_t avail =   freebl - 
  59.                 le32_to_cpu(sb->u.ext3_sb.s_es->s_r_blocks_count);
  60.         return (avail <<  EXT3_BLOCK_SIZE_BITS(sb));
  61. }
  63. /* start the filesystem journal operations */
  64. static void *presto_e3_trans_start(struct presto_file_set *fset, 
  65.                                    struct inode *inode, 
  66.                                    int op)
  67. {
  68.         int jblocks;
  69.         int trunc_blks, one_path_blks, extra_path_blks, 
  70.                 extra_name_blks, lml_blks; 
  71.         __u32 avail_kmlblocks;
  72.         handle_t *handle;
  74.         if ( presto_no_journal(fset) ||
  75.              strcmp(fset->fset_cache->cache_type, "ext3"))
  76.           {
  77.             CDEBUG(D_JOURNAL, "got cache_type "%s"n",
  78.                    fset->fset_cache->cache_type);
  79.             return NULL;
  80.           }
  82.         avail_kmlblocks = inode->i_sb->u.ext3_sb.s_es->s_free_blocks_count;
  83.         
  84.         if ( avail_kmlblocks < 3 ) {
  85.                 return ERR_PTR(-ENOSPC);
  86.         }
  87.         
  88.         if (  (op != PRESTO_OP_UNLINK && op != PRESTO_OP_RMDIR)
  89.               && avail_kmlblocks < 6 ) {
  90.                 return ERR_PTR(-ENOSPC);
  91.         }            
  93.         /* Need journal space for:
  94.              at least three writes to KML (two one block writes, one a path) 
  95.              possibly a second name (unlink, rmdir)
  96.              possibly a second path (symlink, rename)
  97.              a one block write to the last rcvd file 
  98.         */
  100.         trunc_blks = EXT3_DATA_TRANS_BLOCKS + 1; 
  101.         one_path_blks = 4*EXT3_DATA_TRANS_BLOCKS + MAX_PATH_BLOCKS(inode) + 3;
  102.         lml_blks = 4*EXT3_DATA_TRANS_BLOCKS + MAX_PATH_BLOCKS(inode) + 2;
  103.         extra_path_blks = EXT3_DATA_TRANS_BLOCKS + MAX_PATH_BLOCKS(inode); 
  104.         extra_name_blks = EXT3_DATA_TRANS_BLOCKS + MAX_NAME_BLOCKS(inode); 
  106.         /* additional blocks appear for "two pathname" operations
  107.            and operations involving the LML records 
  108.         */
  109.         switch (op) {
  110.         case PRESTO_OP_TRUNC:
  111.                 jblocks = one_path_blks + extra_name_blks + trunc_blks
  112.                         + EXT3_DELETE_TRANS_BLOCKS; 
  113.                 break;
  114.         case PRESTO_OP_RELEASE:
  115.                 /* 
  116.                 jblocks = one_path_blks + lml_blks + 2*trunc_blks; 
  117.                 */
  118.                 jblocks = one_path_blks; 
  119.                 break;
  120.         case PRESTO_OP_SETATTR:
  121.                 jblocks = one_path_blks + trunc_blks + 1 ; 
  122.                 break;
  123.         case PRESTO_OP_CREATE:
  124.                 jblocks = one_path_blks + trunc_blks 
  125.                         + EXT3_DATA_TRANS_BLOCKS + 3 + 2; 
  126.                 break;
  127.         case PRESTO_OP_LINK:
  128.                 jblocks = one_path_blks + trunc_blks 
  129.                         + EXT3_DATA_TRANS_BLOCKS + 2; 
  130.                 break;
  131.         case PRESTO_OP_UNLINK:
  132.                 jblocks = one_path_blks + extra_name_blks + trunc_blks
  133.                         + EXT3_DELETE_TRANS_BLOCKS + 2; 
  134.                 break;
  135.         case PRESTO_OP_SYMLINK:
  136.                 jblocks = one_path_blks + extra_path_blks + trunc_blks
  137.                         + EXT3_DATA_TRANS_BLOCKS + 5; 
  138.                 break;
  139.         case PRESTO_OP_MKDIR:
  140.                 jblocks = one_path_blks + trunc_blks
  141.                         + EXT3_DATA_TRANS_BLOCKS + 4 + 2;
  142.                 break;
  143.         case PRESTO_OP_RMDIR:
  144.                 jblocks = one_path_blks + extra_name_blks + trunc_blks
  145.                         + EXT3_DELETE_TRANS_BLOCKS + 1; 
  146.                 break;
  147.         case PRESTO_OP_MKNOD:
  148.                 jblocks = one_path_blks + trunc_blks + 
  149.                         EXT3_DATA_TRANS_BLOCKS + 3 + 2;
  150.                 break;
  151.         case PRESTO_OP_RENAME:
  152.                 jblocks = one_path_blks + extra_path_blks + trunc_blks + 
  153.                         2 * EXT3_DATA_TRANS_BLOCKS + 2 + 3;
  154.                 break;
  155.         case PRESTO_OP_WRITE:
  156.                 jblocks = one_path_blks; 
  157.                 /*  add this when we can wrap our transaction with 
  158.                     that of ext3_file_write (ordered writes)
  159.                     +  EXT3_DATA_TRANS_BLOCKS;
  160.                 */
  161.                 break;
  162.         default:
  163.                 CDEBUG(D_JOURNAL, "invalid operation %d for journaln", op);
  164.                 return NULL;
  165.         }
  167.         CDEBUG(D_JOURNAL, "creating journal handle (%d blocks)n", jblocks);
  168.         /* journal_start/stop does not do its own locking while updating
  169.          * the handle/transaction information. Hence we create our own
  170.          * critical section to protect these calls. -SHP
  171.          */
  172.         lock_kernel();
  173.         handle = journal_start(EXT3_JOURNAL(inode), jblocks);
  174.         unlock_kernel();
  175.         return handle;
  176. }
  178. void presto_e3_trans_commit(struct presto_file_set *fset, void *handle)
  179. {
  180.         if ( presto_no_journal(fset) || !handle)
  181.                 return;
  183.         /* See comments before journal_start above. -SHP */
  184.         lock_kernel();
  185.         journal_stop(handle);
  186.         unlock_kernel();
  187. }
  189. void presto_e3_journal_file_data(struct inode *inode)
  190. {
  191. #ifdef EXT3_JOURNAL_DATA_FL
  192.         inode->u.ext3_i.i_flags |= EXT3_JOURNAL_DATA_FL;
  193. #else
  194. #warning You must have a facility to enable journaled writes for recovery!
  195. #endif
  196. }
  198. struct journal_ops presto_ext3_journal_ops = {
  199.         tr_avail: presto_e3_freespace,
  200.         tr_start:  presto_e3_trans_start,
  201.         tr_commit: presto_e3_trans_commit,
  202.         tr_journal_data: presto_e3_journal_file_data
  203. };
  205. #endif /* CONFIG_EXT3_FS */