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1275 |
phoenix |
/*
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* linux/fs/hpfs/file.c
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*
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* Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
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*
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* file VFS functions
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*/
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#include <linux/string.h>
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#include <linux/sched.h>
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#include <linux/smp_lock.h>
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#include "hpfs_fn.h"
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#define BLOCKS(size) (((size) + 511) >> 9)
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/* HUH? */
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int hpfs_open(struct inode *i, struct file *f)
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{
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lock_kernel();
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hpfs_lock_inode(i);
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hpfs_unlock_inode(i); /* make sure nobody is deleting the file */
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unlock_kernel();
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if (!i->i_nlink) return -ENOENT;
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return 0;
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}
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int hpfs_file_release(struct inode *inode, struct file *file)
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{
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lock_kernel();
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hpfs_write_if_changed(inode);
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unlock_kernel();
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return 0;
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}
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int hpfs_file_fsync(struct file *file, struct dentry *dentry, int datasync)
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{
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/*return file_fsync(file, dentry);*/
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return 0; /* Don't fsync :-) */
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}
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/*
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* generic_file_read often calls bmap with non-existing sector,
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* so we must ignore such errors.
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*/
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secno hpfs_bmap(struct inode *inode, unsigned file_secno)
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{
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unsigned n, disk_secno;
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struct fnode *fnode;
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struct buffer_head *bh;
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if (BLOCKS(inode->u.hpfs_i.mmu_private) <= file_secno) return 0;
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n = file_secno - inode->i_hpfs_file_sec;
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if (n < inode->i_hpfs_n_secs) return inode->i_hpfs_disk_sec + n;
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if (!(fnode = hpfs_map_fnode(inode->i_sb, inode->i_ino, &bh))) return 0;
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disk_secno = hpfs_bplus_lookup(inode->i_sb, inode, &fnode->btree, file_secno, bh);
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if (disk_secno == -1) return 0;
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if (hpfs_chk_sectors(inode->i_sb, disk_secno, 1, "bmap")) return 0;
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return disk_secno;
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}
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void hpfs_truncate(struct inode *i)
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{
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if (IS_IMMUTABLE(i)) return /*-EPERM*/;
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i->i_hpfs_n_secs = 0;
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i->i_blocks = 1 + ((i->i_size + 511) >> 9);
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i->u.hpfs_i.mmu_private = i->i_size;
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hpfs_truncate_btree(i->i_sb, i->i_ino, 1, ((i->i_size + 511) >> 9));
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hpfs_write_inode(i);
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}
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int hpfs_get_block(struct inode *inode, long iblock, struct buffer_head *bh_result, int create)
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{
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secno s;
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s = hpfs_bmap(inode, iblock);
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if (s) {
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bh_result->b_dev = inode->i_dev;
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bh_result->b_blocknr = s;
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bh_result->b_state |= (1UL << BH_Mapped);
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return 0;
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}
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if (!create) return 0;
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if (iblock<<9 != inode->u.hpfs_i.mmu_private) {
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BUG();
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return -EIO;
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}
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if ((s = hpfs_add_sector_to_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1)) == -1) {
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hpfs_truncate_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1);
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return -ENOSPC;
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}
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inode->i_blocks++;
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inode->u.hpfs_i.mmu_private += 512;
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bh_result->b_dev = inode->i_dev;
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bh_result->b_blocknr = s;
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bh_result->b_state |= (1UL << BH_Mapped) | (1UL << BH_New);
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return 0;
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}
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static int hpfs_writepage(struct page *page)
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{
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return block_write_full_page(page,hpfs_get_block);
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}
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static int hpfs_readpage(struct file *file, struct page *page)
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{
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return block_read_full_page(page,hpfs_get_block);
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}
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static int hpfs_prepare_write(struct file *file, struct page *page, unsigned from, unsigned to)
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{
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return cont_prepare_write(page,from,to,hpfs_get_block,
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&page->mapping->host->u.hpfs_i.mmu_private);
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}
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static int _hpfs_bmap(struct address_space *mapping, long block)
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{
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return generic_block_bmap(mapping,block,hpfs_get_block);
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}
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struct address_space_operations hpfs_aops = {
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readpage: hpfs_readpage,
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writepage: hpfs_writepage,
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sync_page: block_sync_page,
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prepare_write: hpfs_prepare_write,
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commit_write: generic_commit_write,
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bmap: _hpfs_bmap
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};
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ssize_t hpfs_file_write(struct file *file, const char *buf, size_t count, loff_t *ppos)
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{
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ssize_t retval;
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retval = generic_file_write(file, buf, count, ppos);
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if (retval > 0) {
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struct inode *inode = file->f_dentry->d_inode;
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inode->i_mtime = CURRENT_TIME;
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inode->i_hpfs_dirty = 1;
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}
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return retval;
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}
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