lustre/smfs/journal_ext3.c

   1 /*
   2  *  smfs/journal_ext3.c
   3  *
   4  */
   5
   6 #define DEBUG_SUBSYSTEM S_SM
   7
   8 #include <linux/kmod.h>
   9 #include <linux/init.h>
  10 #include <linux/fs.h>
  11 #include <linux/slab.h>
  12 #include <linux/string.h>
  13 #include <linux/smp_lock.h>
  14 #include <linux/lustre_idl.h>
  15 #if defined(CONFIG_EXT3_FS) || defined (CONFIG_EXT3_FS_MODULE)
  16 #include <linux/jbd.h>
  17 #include <linux/ext3_fs.h>
  18 #include <linux/ext3_jbd.h>
  19 #endif
  20
  21 #include "smfs_internal.h"
  22 #include "kml_idl.h"
  23
  24 #if defined(CONFIG_EXT3_FS) || defined (CONFIG_EXT3_FS_MODULE)
  25
  26 #define MAX_PATH_BLOCKS(inode) (PATH_MAX >> EXT3_BLOCK_SIZE_BITS((inode)->i_sb))
  27 #define MAX_NAME_BLOCKS(inode) (NAME_MAX >> EXT3_BLOCK_SIZE_BITS((inode)->i_sb))
  28
  29 static void *smfs_e3_trans_start(struct inode *inode,
  30                                 int op)
  31 {
  32
  33         int trunc_blks, one_path_blks, extra_path_blks;
  34         int extra_name_blks, lml_blks, jblocks;
  35         __u32 avail_kmlblocks;
  36         handle_t *handle;
  37
  38         avail_kmlblocks = inode->i_sb->u.ext3_sb.s_es->s_free_blocks_count;
  39
  40         if ( avail_kmlblocks < 3 ) {
  41                 return ERR_PTR(-ENOSPC);
  42         }
  43
  44         if ((op != KML_OPCODE_UNLINK && op != KML_OPCODE_RMDIR)
  45              && avail_kmlblocks < 6 ) {
  46                 return ERR_PTR(-ENOSPC);
  47         }
  48         /* Need journal space for:
  49              at least three writes to KML (two one block writes, one a path)
  50              possibly a second name (unlink, rmdir)
  51              possibly a second path (symlink, rename)
  52              a one block write to the last rcvd file
  53         */
  54
  55         trunc_blks = EXT3_DATA_TRANS_BLOCKS + 1;
  56         one_path_blks = 4*EXT3_DATA_TRANS_BLOCKS + MAX_PATH_BLOCKS(inode) + 3;
  57         lml_blks = 4*EXT3_DATA_TRANS_BLOCKS + MAX_PATH_BLOCKS(inode) + 2;
  58         extra_path_blks = EXT3_DATA_TRANS_BLOCKS + MAX_PATH_BLOCKS(inode);
  59         extra_name_blks = EXT3_DATA_TRANS_BLOCKS + MAX_NAME_BLOCKS(inode);
  60
  61         /* additional blocks appear for "two pathname" operations
  62            and operations involving the LML records
  63         */
  64
  65         switch (op) {
  66         case KML_OPCODE_MKDIR:
  67                 jblocks = one_path_blks + trunc_blks
  68                           + EXT3_DATA_TRANS_BLOCKS + 4 + 2;
  69                 break;
  70         default:
  71                 CDEBUG(D_INODE, "invalid operation %d for journal\n", op);
  72                 return NULL;
  73         }
  74
  75         CDEBUG(D_INODE, "creating journal handle (%d blocks)\n", jblocks);
  76
  77         lock_kernel();
  78         handle = journal_start(EXT3_JOURNAL(inode), jblocks);
  79         unlock_kernel();
  80
  81         return handle;
  82 }
  83
  84 static void smfs_e3_trans_commit(void *handle)
  85 {
  86         lock_kernel();
  87         journal_stop(handle);
  88         unlock_kernel();
  89 }
  90
  91 struct journal_operations smfs_ext3_journal_ops = {
  92         .tr_start   = smfs_e3_trans_start,
  93         .tr_commit  = smfs_e3_trans_commit,
  94 };
  95 #endif
  96