fs/qnx4/fsync.c

   1 /*
   2  * QNX4 file system, Linux implementation.
   3  *
   4  * Version : 0.1
   5  *
   6  * Using parts of the xiafs filesystem.
   7  *
   8  * History :
   9  *
  10  * 24-03-1998 by Richard Frowijn : first release.
  11  */
  12
  13 #include <linux/config.h>
  14 #include <linux/errno.h>
  15 #include <linux/sched.h>
  16 #include <linux/stat.h>
  17 #include <linux/fcntl.h>
  18 #include <linux/locks.h>
  19
  20 #include <linux/fs.h>
  21 #include <linux/qnx4_fs.h>
  22
  23 #include <asm/segment.h>
  24 #include <asm/system.h>
  25
  26 #define blocksize QNX4_BLOCK_SIZE
  27
  28 /*
  29  * The functions for qnx4 fs file synchronization.
  30  */
  31
  32 #ifdef CONFIG_QNX4FS_RW
  33
  34 static int sync_block(struct inode *inode, unsigned short *block, int wait)
  35 {
  36         struct buffer_head *bh;
  37         unsigned short tmp;
  38
  39         if (!*block)
  40                 return 0;
  41         tmp = *block;
  42         bh = get_hash_table(inode->i_dev, *block, blocksize);
  43         if (!bh)
  44                 return 0;
  45         if (*block != tmp) {
  46                 brelse(bh);
  47                 return 1;
  48         }
  49         if (wait && buffer_req(bh) && !buffer_uptodate(bh)) {
  50                 brelse(bh);
  51                 return -1;
  52         }
  53         if (wait || !buffer_uptodate(bh) || !buffer_dirty(bh)) {
  54                 brelse(bh);
  55                 return 0;
  56         }
  57         ll_rw_block(WRITE, 1, &bh);
  58         bh->b_count--;
  59         return 0;
  60 }
  61
  62 static int sync_iblock(struct inode *inode, unsigned short *iblock,
  63                        struct buffer_head **bh, int wait)
  64 {
  65         int rc;
  66         unsigned short tmp;
  67
  68         *bh = NULL;
  69         tmp = *iblock;
  70         if (!tmp)
  71                 return 0;
  72         rc = sync_block(inode, iblock, wait);
  73         if (rc)
  74                 return rc;
  75         *bh = bread(inode->i_dev, tmp, blocksize);
  76         if (tmp != *iblock) {
  77                 brelse(*bh);
  78                 *bh = NULL;
  79                 return 1;
  80         }
  81         if (!*bh)
  82                 return -1;
  83         return 0;
  84 }
  85
  86 static int sync_direct(struct inode *inode, int wait)
  87 {
  88         int i;
  89         int rc, err = 0;
  90
  91         for (i = 0; i < 7; i++) {
  92                 rc = sync_block(inode,
  93                                 (unsigned short *) inode->u.qnx4_i.i_first_xtnt.xtnt_blk + i, wait);
  94                 if (rc > 0)
  95                         break;
  96                 if (rc)
  97                         err = rc;
  98         }
  99         return err;
 100 }
 101
 102 static int sync_indirect(struct inode *inode, unsigned short *iblock, int wait)
 103 {
 104         int i;
 105         struct buffer_head *ind_bh;
 106         int rc, err = 0;
 107
 108         rc = sync_iblock(inode, iblock, &ind_bh, wait);
 109         if (rc || !ind_bh)
 110                 return rc;
 111
 112         for (i = 0; i < 512; i++) {
 113                 rc = sync_block(inode,
 114                                 ((unsigned short *) ind_bh->b_data) + i,
 115                                 wait);
 116                 if (rc > 0)
 117                         break;
 118                 if (rc)
 119                         err = rc;
 120         }
 121         brelse(ind_bh);
 122         return err;
 123 }
 124
 125 static int sync_dindirect(struct inode *inode, unsigned short *diblock,
 126                           int wait)
 127 {
 128         int i;
 129         struct buffer_head *dind_bh;
 130         int rc, err = 0;
 131
 132         rc = sync_iblock(inode, diblock, &dind_bh, wait);
 133         if (rc || !dind_bh)
 134                 return rc;
 135
 136         for (i = 0; i < 512; i++) {
 137                 rc = sync_indirect(inode,
 138                                 ((unsigned short *) dind_bh->b_data) + i,
 139                                    wait);
 140                 if (rc > 0)
 141                         break;
 142                 if (rc)
 143                         err = rc;
 144         }
 145         brelse(dind_bh);
 146         return err;
 147 }
 148
 149 int qnx4_sync_file(struct file *file, struct dentry *dentry)
 150 {
 151         struct inode *inode = dentry->d_inode;
 152         int wait, err = 0;
 153
 154         (void) file;
 155         if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
 156               S_ISLNK(inode->i_mode)))
 157                 return -EINVAL;
 158
 159         for (wait = 0; wait <= 1; wait++) {
 160                 err |= sync_direct(inode, wait);
 161         }
 162         err |= qnx4_sync_inode(inode);
 163         return (err < 0) ? -EIO : 0;
 164 }
 165
 166 #endif