diff options
Diffstat (limited to 'fs/zfs/dev.c')
| -rw-r--r-- | fs/zfs/dev.c | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/fs/zfs/dev.c b/fs/zfs/dev.c new file mode 100644 index 0000000000..d68372c808 --- /dev/null +++ b/fs/zfs/dev.c @@ -0,0 +1,137 @@ +/* + * + * based on code of fs/reiserfs/dev.c by + * + * (C) Copyright 2003 - 2004 + * Sysgo AG, <www.elinos.com>, Pavel Bartusek <pba@sysgo.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + + +#include <common.h> +#include <config.h> +#include <zfs_common.h> + +static block_dev_desc_t *zfs_block_dev_desc; +static disk_partition_t part_info; + +int zfs_set_blk_dev(block_dev_desc_t *rbdd, int part) +{ + zfs_block_dev_desc = rbdd; + + if (part == 0) { + /* disk doesn't use partition table */ + part_info.start = 0; + part_info.size = rbdd->lba; + part_info.blksz = rbdd->blksz; + } else { + if (get_partition_info(zfs_block_dev_desc, part, &part_info)) + return 0; + } + + return part_info.size; +} + +/* err */ +int zfs_devread(int sector, int byte_offset, int byte_len, char *buf) +{ + short sec_buffer[SECTOR_SIZE/sizeof(short)]; + char *sec_buf = (char *)sec_buffer; + unsigned block_len; + + /* + * Check partition boundaries + */ + if ((sector < 0) || + ((sector + ((byte_offset + byte_len - 1) >> SECTOR_BITS)) >= + part_info.size)) { + /* errnum = ERR_OUTSIDE_PART; */ + printf(" ** zfs_devread() read outside partition sector %d\n", sector); + return 1; + } + + /* + * Get the read to the beginning of a partition. + */ + sector += byte_offset >> SECTOR_BITS; + byte_offset &= SECTOR_SIZE - 1; + + debug(" <%d, %d, %d>\n", sector, byte_offset, byte_len); + + if (zfs_block_dev_desc == NULL) { + printf("** Invalid Block Device Descriptor (NULL)\n"); + return 1; + } + + if (byte_offset != 0) { + /* read first part which isn't aligned with start of sector */ + if (zfs_block_dev_desc->block_read(zfs_block_dev_desc->dev, + part_info.start + sector, 1, + (unsigned long *) sec_buf) != 1) { + printf(" ** zfs_devread() read error **\n"); + return 1; + } + memcpy(buf, sec_buf + byte_offset, + min(SECTOR_SIZE - byte_offset, byte_len)); + buf += min(SECTOR_SIZE - byte_offset, byte_len); + byte_len -= min(SECTOR_SIZE - byte_offset, byte_len); + sector++; + } + + if (byte_len == 0) + return 0; + + /* read sector aligned part */ + block_len = byte_len & ~(SECTOR_SIZE - 1); + + if (block_len == 0) { + u8 p[SECTOR_SIZE]; + + block_len = SECTOR_SIZE; + zfs_block_dev_desc->block_read(zfs_block_dev_desc->dev, + part_info.start + sector, + 1, (unsigned long *)p); + memcpy(buf, p, byte_len); + return 0; + } + + if (zfs_block_dev_desc->block_read(zfs_block_dev_desc->dev, + part_info.start + sector, + block_len / SECTOR_SIZE, + (unsigned long *) buf) != + block_len / SECTOR_SIZE) { + printf(" ** zfs_devread() read error - block\n"); + return 1; + } + + block_len = byte_len & ~(SECTOR_SIZE - 1); + buf += block_len; + byte_len -= block_len; + sector += block_len / SECTOR_SIZE; + + if (byte_len != 0) { + /* read rest of data which are not in whole sector */ + if (zfs_block_dev_desc-> + block_read(zfs_block_dev_desc->dev, + part_info.start + sector, 1, + (unsigned long *) sec_buf) != 1) { + printf(" ** zfs_devread() read error - last part\n"); + return 1; + } + memcpy(buf, sec_buf, byte_len); + } + return 0; +} |