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/errno.h>
  14 #include <linux/time.h>
  15 #include <linux/stat.h>
  16 #include <linux/fcntl.h>
  17 #include <linux/smp_lock.h>
  18 #include <linux/buffer_head.h>
  19
  20 #include <linux/fs.h>
  21 #include <linux/qnx4_fs.h>
  22
  23 #include <asm/system.h>
  24
  25 /*
  26  * The functions for qnx4 fs file synchronization.
  27  */
  28
  29 #ifdef CONFIG_QNX4FS_RW
  30
  31 static int sync_block(struct inode *inode, unsigned short *block, int wait)
  32 {
  33         struct buffer_head *bh;
  34         unsigned short tmp;
  35
  36         if (!*block)
  37                 return 0;
  38         tmp = *block;
  39         bh = sb_find_get_block(inode->i_sb, *block);
  40         if (!bh)
  41                 return 0;
  42         if (*block != tmp) {
  43                 brelse(bh);
  44                 return 1;
  45         }
  46         if (wait && buffer_req(bh) && !buffer_uptodate(bh)) {
  47                 brelse(bh);
  48                 return -1;
  49         }
  50         if (wait || !buffer_uptodate(bh) || !buffer_dirty(bh)) {
  51                 brelse(bh);
  52                 return 0;
  53         }
  54         ll_rw_block(WRITE, 1, &bh);
  55         atomic_dec(&bh->b_count);
  56         return 0;
  57 }
  58
  59 #ifdef WTF
  60 static int sync_iblock(struct inode *inode, unsigned short *iblock,
  61                        struct buffer_head **bh, int wait)
  62 {
  63         int rc;
  64         unsigned short tmp;
  65
  66         *bh = NULL;
  67         tmp = *iblock;
  68         if (!tmp)
  69                 return 0;
  70         rc = sync_block(inode, iblock, wait);
  71         if (rc)
  72                 return rc;
  73         *bh = sb_bread(inode->i_sb, tmp);
  74         if (tmp != *iblock) {
  75                 brelse(*bh);
  76                 *bh = NULL;
  77                 return 1;
  78         }
  79         if (!*bh)
  80                 return -1;
  81         return 0;
  82 }
  83 #endif
  84
  85 static int sync_direct(struct inode *inode, int wait)
  86 {
  87         int i;
  88         int rc, err = 0;
  89
  90         for (i = 0; i < 7; i++) {
  91                 rc = sync_block(inode,
  92                                 (unsigned short *) qnx4_raw_inode(inode)->di_first_xtnt.xtnt_blk + i, wait);
  93                 if (rc > 0)
  94                         break;
  95                 if (rc)
  96                         err = rc;
  97         }
  98         return err;
  99 }
 100
 101 #ifdef WTF
 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 #endif
 149
 150 int qnx4_sync_file(struct file *file, struct dentry *dentry, int unused)
 151 {
 152         struct inode *inode = dentry->d_inode;
 153         int wait, err = 0;
 154
 155         (void) file;
 156         if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
 157               S_ISLNK(inode->i_mode)))
 158                 return -EINVAL;
 159
 160         lock_kernel();
 161         for (wait = 0; wait <= 1; wait++) {
 162                 err |= sync_direct(inode, wait);
 163         }
 164         err |= qnx4_sync_inode(inode);
 165         unlock_kernel();
 166         return (err < 0) ? -EIO : 0;
 167 }
 168
 169 #endif