Carsten Otte | 6d79125 | 2005-06-23 22:05:26 -0700 | [diff] [blame^] | 1 | /* |
| 2 | * linux/fs/ext2/xip.c |
| 3 | * |
| 4 | * Copyright (C) 2005 IBM Corporation |
| 5 | * Author: Carsten Otte (cotte@de.ibm.com) |
| 6 | */ |
| 7 | |
| 8 | #include <linux/mm.h> |
| 9 | #include <linux/fs.h> |
| 10 | #include <linux/genhd.h> |
| 11 | #include <linux/buffer_head.h> |
| 12 | #include <linux/ext2_fs_sb.h> |
| 13 | #include <linux/ext2_fs.h> |
| 14 | #include "ext2.h" |
| 15 | #include "xip.h" |
| 16 | |
| 17 | static inline int |
| 18 | __inode_direct_access(struct inode *inode, sector_t sector, unsigned long *data) { |
| 19 | BUG_ON(!inode->i_sb->s_bdev->bd_disk->fops->direct_access); |
| 20 | return inode->i_sb->s_bdev->bd_disk->fops |
| 21 | ->direct_access(inode->i_sb->s_bdev,sector,data); |
| 22 | } |
| 23 | |
| 24 | int |
| 25 | ext2_clear_xip_target(struct inode *inode, int block) { |
| 26 | sector_t sector = block*(PAGE_SIZE/512); |
| 27 | unsigned long data; |
| 28 | int rc; |
| 29 | |
| 30 | rc = __inode_direct_access(inode, sector, &data); |
| 31 | if (rc) |
| 32 | return rc; |
| 33 | clear_page((void*)data); |
| 34 | return 0; |
| 35 | } |
| 36 | |
| 37 | void ext2_xip_verify_sb(struct super_block *sb) |
| 38 | { |
| 39 | struct ext2_sb_info *sbi = EXT2_SB(sb); |
| 40 | |
| 41 | if ((sbi->s_mount_opt & EXT2_MOUNT_XIP)) { |
| 42 | if ((sb->s_bdev == NULL) || |
| 43 | sb->s_bdev->bd_disk == NULL || |
| 44 | sb->s_bdev->bd_disk->fops == NULL || |
| 45 | sb->s_bdev->bd_disk->fops->direct_access == NULL) { |
| 46 | sbi->s_mount_opt &= (~EXT2_MOUNT_XIP); |
| 47 | ext2_warning(sb, __FUNCTION__, |
| 48 | "ignoring xip option - not supported by bdev"); |
| 49 | } |
| 50 | } |
| 51 | } |
| 52 | |
| 53 | struct page* |
| 54 | ext2_get_xip_page(struct address_space *mapping, sector_t blockno, |
| 55 | int create) |
| 56 | { |
| 57 | int rc; |
| 58 | unsigned long data; |
| 59 | struct buffer_head tmp; |
| 60 | |
| 61 | tmp.b_state = 0; |
| 62 | tmp.b_blocknr = 0; |
| 63 | rc = ext2_get_block(mapping->host, blockno/(PAGE_SIZE/512) , &tmp, |
| 64 | create); |
| 65 | if (rc) |
| 66 | return ERR_PTR(rc); |
| 67 | if (tmp.b_blocknr == 0) { |
| 68 | /* SPARSE block */ |
| 69 | BUG_ON(create); |
| 70 | return ERR_PTR(-ENODATA); |
| 71 | } |
| 72 | |
| 73 | rc = __inode_direct_access |
| 74 | (mapping->host,tmp.b_blocknr*(PAGE_SIZE/512) ,&data); |
| 75 | if (rc) |
| 76 | return ERR_PTR(rc); |
| 77 | |
| 78 | SetPageUptodate(virt_to_page(data)); |
| 79 | return virt_to_page(data); |
| 80 | } |