FreeBSD/Linux Kernel Cross Reference
sys/fs/hpfs/file.c

     /*
      *  linux/fs/hpfs/file.c
      *
      *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
      *
      *  file VFS functions
      */
     
     #include "hpfs_fn.h"
    
    #define BLOCKS(size) (((size) + 511) >> 9)
    
    static int hpfs_file_release(struct inode *inode, struct file *file)
    {
            hpfs_lock(inode->i_sb);
            hpfs_write_if_changed(inode);
            hpfs_unlock(inode->i_sb);
            return 0;
    }
    
    int hpfs_file_fsync(struct file *file, loff_t start, loff_t end, int datasync)
    {
            struct inode *inode = file->f_mapping->host;
            int ret;
    
            ret = filemap_write_and_wait_range(file->f_mapping, start, end);
            if (ret)
                    return ret;
            return sync_blockdev(inode->i_sb->s_bdev);
    }
    
    /*
     * generic_file_read often calls bmap with non-existing sector,
     * so we must ignore such errors.
     */
    
    static secno hpfs_bmap(struct inode *inode, unsigned file_secno)
    {
            struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);
            unsigned n, disk_secno;
            struct fnode *fnode;
            struct buffer_head *bh;
            if (BLOCKS(hpfs_i(inode)->mmu_private) <= file_secno) return 0;
            n = file_secno - hpfs_inode->i_file_sec;
            if (n < hpfs_inode->i_n_secs) return hpfs_inode->i_disk_sec + n;
            if (!(fnode = hpfs_map_fnode(inode->i_sb, inode->i_ino, &bh))) return 0;
            disk_secno = hpfs_bplus_lookup(inode->i_sb, inode, &fnode->btree, file_secno, bh);
            if (disk_secno == -1) return 0;
            if (hpfs_chk_sectors(inode->i_sb, disk_secno, 1, "bmap")) return 0;
            return disk_secno;
    }
    
    void hpfs_truncate(struct inode *i)
    {
            if (IS_IMMUTABLE(i)) return /*-EPERM*/;
            hpfs_lock_assert(i->i_sb);
    
            hpfs_i(i)->i_n_secs = 0;
            i->i_blocks = 1 + ((i->i_size + 511) >> 9);
            hpfs_i(i)->mmu_private = i->i_size;
            hpfs_truncate_btree(i->i_sb, i->i_ino, 1, ((i->i_size + 511) >> 9));
            hpfs_write_inode(i);
            hpfs_i(i)->i_n_secs = 0;
    }
    
    static int hpfs_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create)
    {
            int r;
            secno s;
            hpfs_lock(inode->i_sb);
            s = hpfs_bmap(inode, iblock);
            if (s) {
                    map_bh(bh_result, inode->i_sb, s);
                    goto ret_0;
            }
            if (!create) goto ret_0;
            if (iblock<<9 != hpfs_i(inode)->mmu_private) {
                    BUG();
                    r = -EIO;
                    goto ret_r;
            }
            if ((s = hpfs_add_sector_to_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1)) == -1) {
                    hpfs_truncate_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1);
                    r = -ENOSPC;
                    goto ret_r;
            }
            inode->i_blocks++;
            hpfs_i(inode)->mmu_private += 512;
            set_buffer_new(bh_result);
            map_bh(bh_result, inode->i_sb, s);
            ret_0:
            r = 0;
            ret_r:
            hpfs_unlock(inode->i_sb);
            return r;
    }
    
    static int hpfs_writepage(struct page *page, struct writeback_control *wbc)
    {
           return block_write_full_page(page,hpfs_get_block, wbc);
   }
   
   static int hpfs_readpage(struct file *file, struct page *page)
   {
           return block_read_full_page(page,hpfs_get_block);
   }
   
   static void hpfs_write_failed(struct address_space *mapping, loff_t to)
   {
           struct inode *inode = mapping->host;
   
           if (to > inode->i_size) {
                   truncate_pagecache(inode, to, inode->i_size);
                   hpfs_truncate(inode);
           }
   }
   
   static int hpfs_write_begin(struct file *file, struct address_space *mapping,
                           loff_t pos, unsigned len, unsigned flags,
                           struct page **pagep, void **fsdata)
   {
           int ret;
   
           *pagep = NULL;
           ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
                                   hpfs_get_block,
                                   &hpfs_i(mapping->host)->mmu_private);
           if (unlikely(ret))
                   hpfs_write_failed(mapping, pos + len);
   
           return ret;
   }
   
   static sector_t _hpfs_bmap(struct address_space *mapping, sector_t block)
   {
           return generic_block_bmap(mapping,block,hpfs_get_block);
   }
   
   const struct address_space_operations hpfs_aops = {
           .readpage = hpfs_readpage,
           .writepage = hpfs_writepage,
           .write_begin = hpfs_write_begin,
           .write_end = generic_write_end,
           .bmap = _hpfs_bmap
   };
   
   static ssize_t hpfs_file_write(struct file *file, const char __user *buf,
                           size_t count, loff_t *ppos)
   {
           ssize_t retval;
   
           retval = do_sync_write(file, buf, count, ppos);
           if (retval > 0) {
                   hpfs_lock(file->f_path.dentry->d_sb);
                   hpfs_i(file->f_path.dentry->d_inode)->i_dirty = 1;
                   hpfs_unlock(file->f_path.dentry->d_sb);
           }
           return retval;
   }
   
   const struct file_operations hpfs_file_ops =
   {
           .llseek         = generic_file_llseek,
           .read           = do_sync_read,
           .aio_read       = generic_file_aio_read,
           .write          = hpfs_file_write,
           .aio_write      = generic_file_aio_write,
           .mmap           = generic_file_mmap,
           .release        = hpfs_file_release,
           .fsync          = hpfs_file_fsync,
           .splice_read    = generic_file_splice_read,
   };
   
   const struct inode_operations hpfs_file_iops =
   {
           .setattr        = hpfs_setattr,
   };

Cache object: 56f2d1af85a033649e9ef7410e147a82