/** * 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; }