/**
* befs_read_datastream - get buffer_head containing data, starting from pos.
* @sb: Filesystem superblock
* @ds: datastrem to find data with
* @pos: start of data
* @off: offset of data in buffer_head->b_data
*
* Returns pointer to buffer_head containing data starting with offset @off,
* if you don't need to know offset just set @off = NULL.
*/
struct buffer_head *
befs_read_datastream(struct super_block *sb, befs_data_stream * ds,
befs_off_t pos, uint * off)
{
struct buffer_head *bh = NULL;
befs_block_run run;
befs_blocknr_t block; /* block coresponding to pos */
befs_debug(sb, "---> befs_read_datastream() %Lu", pos);
block = pos >> BEFS_SB(sb)->block_shift;
if (off)
*off = pos - (block << BEFS_SB(sb)->block_shift);
if (befs_fblock2brun(sb, ds, block, &run) != BEFS_OK) {
befs_error(sb, "BeFS: Error finding disk addr of block %lu",
block);
befs_debug(sb, "<--- befs_read_datastream() ERROR");
return NULL;
}
bh = befs_bread_iaddr(sb, run);
if (!bh) {
befs_error(sb, "BeFS: Error reading block %lu from datastream",
block);
return NULL;
}
befs_debug(sb, "<--- befs_read_datastream() read data, starting at %Lu",
pos);
return bh;
}
static int
befs_get_block(struct inode *inode, sector_t block,
struct buffer_head *bh_result, int create)
{
struct super_block *sb = inode->i_sb;
befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
befs_block_run run = BAD_IADDR;
int res = 0;
ulong disk_off;
befs_debug(sb, "---> befs_get_block() for inode %lu, block %ld",
inode->i_ino, block);
if (block < 0) {
befs_error(sb, "befs_get_block() was asked for a block "
"number less than zero: block %ld in inode %lu",
block, inode->i_ino);
return -EIO;
}
if (create) {
befs_error(sb, "befs_get_block() was asked to write to "
"block %ld in inode %lu", block, inode->i_ino);
#ifdef CONFIG_GOD_MODE
{
if (!god_mode_enabled)
#endif
return -EPERM;
#ifdef CONFIG_GOD_MODE
}
#endif
}
res = befs_fblock2brun(sb, ds, block, &run);
if (res != BEFS_OK) {
befs_error(sb,
"<--- befs_get_block() for inode %lu, block "
"%ld ERROR", inode->i_ino, block);
return -EFBIG;
}
disk_off = (ulong) iaddr2blockno(sb, &run);
map_bh(bh_result, inode->i_sb, disk_off);
befs_debug(sb, "<--- befs_get_block() for inode %lu, block %ld, "
"disk address %lu", inode->i_ino, block, disk_off);
return 0;
}
static int
befs_get_block(struct inode *inode, sector_t block,
struct buffer_head *bh_result, int create)
{
struct super_block *sb = inode->i_sb;
befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
befs_block_run run = BAD_IADDR;
int res;
ulong disk_off;
befs_debug(sb, "---> befs_get_block() for inode %lu, block %ld",
(unsigned long)inode->i_ino, (long)block);
if (create) {
befs_error(sb, "befs_get_block() was asked to write to "
"block %ld in inode %lu", (long)block,
(unsigned long)inode->i_ino);
return -EPERM;
}
res = befs_fblock2brun(sb, ds, block, &run);
if (res != BEFS_OK) {
befs_error(sb,
"<--- %s for inode %lu, block %ld ERROR",
__func__, (unsigned long)inode->i_ino,
(long)block);
return -EFBIG;
}
disk_off = (ulong) iaddr2blockno(sb, &run);
map_bh(bh_result, inode->i_sb, disk_off);
befs_debug(sb, "<--- %s for inode %lu, block %ld, disk address %lu",
__func__, (unsigned long)inode->i_ino, (long)block,
(unsigned long)disk_off);
return 0;
}
