Commit | Line | Data |
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6d79125b CO |
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 | |
afa597ba CO |
18 | __inode_direct_access(struct inode *inode, sector_t sector, |
19 | unsigned long *data) | |
20 | { | |
6d79125b CO |
21 | BUG_ON(!inode->i_sb->s_bdev->bd_disk->fops->direct_access); |
22 | return inode->i_sb->s_bdev->bd_disk->fops | |
23 | ->direct_access(inode->i_sb->s_bdev,sector,data); | |
24 | } | |
25 | ||
afa597ba CO |
26 | static inline int |
27 | __ext2_get_sector(struct inode *inode, sector_t offset, int create, | |
28 | sector_t *result) | |
29 | { | |
30 | struct buffer_head tmp; | |
31 | int rc; | |
32 | ||
33 | memset(&tmp, 0, sizeof(struct buffer_head)); | |
34 | rc = ext2_get_block(inode, offset/ (PAGE_SIZE/512), &tmp, | |
35 | create); | |
36 | *result = tmp.b_blocknr; | |
37 | ||
38 | /* did we get a sparse block (hole in the file)? */ | |
0cfc11ed | 39 | if (!tmp.b_blocknr && !rc) { |
afa597ba CO |
40 | BUG_ON(create); |
41 | rc = -ENODATA; | |
42 | } | |
43 | ||
44 | return rc; | |
45 | } | |
46 | ||
6d79125b | 47 | int |
afa597ba CO |
48 | ext2_clear_xip_target(struct inode *inode, int block) |
49 | { | |
50 | sector_t sector = block * (PAGE_SIZE/512); | |
6d79125b CO |
51 | unsigned long data; |
52 | int rc; | |
53 | ||
54 | rc = __inode_direct_access(inode, sector, &data); | |
afa597ba CO |
55 | if (!rc) |
56 | clear_page((void*)data); | |
57 | return rc; | |
6d79125b CO |
58 | } |
59 | ||
60 | void ext2_xip_verify_sb(struct super_block *sb) | |
61 | { | |
62 | struct ext2_sb_info *sbi = EXT2_SB(sb); | |
63 | ||
afa597ba CO |
64 | if ((sbi->s_mount_opt & EXT2_MOUNT_XIP) && |
65 | !sb->s_bdev->bd_disk->fops->direct_access) { | |
66 | sbi->s_mount_opt &= (~EXT2_MOUNT_XIP); | |
67 | ext2_warning(sb, __FUNCTION__, | |
68 | "ignoring xip option - not supported by bdev"); | |
6d79125b CO |
69 | } |
70 | } | |
71 | ||
afa597ba CO |
72 | struct page * |
73 | ext2_get_xip_page(struct address_space *mapping, sector_t offset, | |
6d79125b CO |
74 | int create) |
75 | { | |
76 | int rc; | |
77 | unsigned long data; | |
afa597ba | 78 | sector_t sector; |
6d79125b | 79 | |
afa597ba CO |
80 | /* first, retrieve the sector number */ |
81 | rc = __ext2_get_sector(mapping->host, offset, create, §or); | |
6d79125b | 82 | if (rc) |
afa597ba | 83 | goto error; |
6d79125b | 84 | |
afa597ba | 85 | /* retrieve address of the target data */ |
6d79125b | 86 | rc = __inode_direct_access |
afa597ba CO |
87 | (mapping->host, sector * (PAGE_SIZE/512), &data); |
88 | if (!rc) | |
89 | return virt_to_page(data); | |
6d79125b | 90 | |
afa597ba CO |
91 | error: |
92 | return ERR_PTR(rc); | |
6d79125b | 93 | } |