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_file_read(struct inode *inode, struct file *filp,
char *buf, int count)
{
unsigned q, r, n, n0;
struct buffer_head *bh;
char *block;
char *start;
if (inode == 0 || !S_ISREG(inode->i_mode))
return -EINVAL;
/*
* truncate count at EOF
*/
if (count > inode->i_size - (off_t) filp->f_pos)
count = inode->i_size - filp->f_pos;
start = buf;
while (count > 0) {
/*
* get file sector number, offset in sector, length to end of
* sector
*/
q = filp->f_pos >> 9;
r = filp->f_pos & 511;
n = 512 - r;
/*
* get length to copy to user buffer
*/
if (n > count)
n = count;
/*
* read the sector, copy to user
*/
block = map_sector(inode->i_dev, hpfs_bmap(inode, q), &bh);
if (!block)
return -EIO;
/*
* but first decide if it has \r\n, if the mount option said
* to do that
*/
if (inode->i_hpfs_conv == CONV_AUTO)
inode->i_hpfs_conv = choose_conv(block + r, n);
if (inode->i_hpfs_conv == CONV_BINARY) {
/*
* regular copy, output length is same as input
* length
*/
memcpy_tofs(buf, block + r, n);
n0 = n;
}
else {
/*
* squeeze out \r, output length varies
*/
n0 = convcpy_tofs(buf, block + r, n);
if (count > inode->i_size - (off_t) filp->f_pos - n + n0)
count = inode->i_size - filp->f_pos - n + n0;
}
brelse(bh);
/*
* advance input n bytes, output n0 bytes
*/
filp->f_pos += n;
buf += n0;
count -= n0;
}
return buf - start;
}
