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-rw-r--r--fs/ext2/xip.c81
1 files changed, 47 insertions, 34 deletions
diff --git a/fs/ext2/xip.c b/fs/ext2/xip.c
index d44431d1a338..0aa5ac159c09 100644
--- a/fs/ext2/xip.c
+++ b/fs/ext2/xip.c
@@ -15,66 +15,79 @@
15#include "xip.h" 15#include "xip.h"
16 16
17static inline int 17static inline int
18__inode_direct_access(struct inode *inode, sector_t sector, unsigned long *data) { 18__inode_direct_access(struct inode *inode, sector_t sector,
19 unsigned long *data)
20{
19 BUG_ON(!inode->i_sb->s_bdev->bd_disk->fops->direct_access); 21 BUG_ON(!inode->i_sb->s_bdev->bd_disk->fops->direct_access);
20 return inode->i_sb->s_bdev->bd_disk->fops 22 return inode->i_sb->s_bdev->bd_disk->fops
21 ->direct_access(inode->i_sb->s_bdev,sector,data); 23 ->direct_access(inode->i_sb->s_bdev,sector,data);
22} 24}
23 25
26static 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)? */
39 if (!(*result)) {
40 BUG_ON(create);
41 rc = -ENODATA;
42 }
43
44 return rc;
45}
46
24int 47int
25ext2_clear_xip_target(struct inode *inode, int block) { 48ext2_clear_xip_target(struct inode *inode, int block)
26 sector_t sector = block*(PAGE_SIZE/512); 49{
50 sector_t sector = block * (PAGE_SIZE/512);
27 unsigned long data; 51 unsigned long data;
28 int rc; 52 int rc;
29 53
30 rc = __inode_direct_access(inode, sector, &data); 54 rc = __inode_direct_access(inode, sector, &data);
31 if (rc) 55 if (!rc)
32 return rc; 56 clear_page((void*)data);
33 clear_page((void*)data); 57 return rc;
34 return 0;
35} 58}
36 59
37void ext2_xip_verify_sb(struct super_block *sb) 60void ext2_xip_verify_sb(struct super_block *sb)
38{ 61{
39 struct ext2_sb_info *sbi = EXT2_SB(sb); 62 struct ext2_sb_info *sbi = EXT2_SB(sb);
40 63
41 if ((sbi->s_mount_opt & EXT2_MOUNT_XIP)) { 64 if ((sbi->s_mount_opt & EXT2_MOUNT_XIP) &&
42 if ((sb->s_bdev == NULL) || 65 !sb->s_bdev->bd_disk->fops->direct_access) {
43 sb->s_bdev->bd_disk == NULL || 66 sbi->s_mount_opt &= (~EXT2_MOUNT_XIP);
44 sb->s_bdev->bd_disk->fops == NULL || 67 ext2_warning(sb, __FUNCTION__,
45 sb->s_bdev->bd_disk->fops->direct_access == NULL) { 68 "ignoring xip option - not supported by bdev");
46 sbi->s_mount_opt &= (~EXT2_MOUNT_XIP);
47 ext2_warning(sb, __FUNCTION__,
48 "ignoring xip option - not supported by bdev");
49 }
50 } 69 }
51} 70}
52 71
53struct page* 72struct page *
54ext2_get_xip_page(struct address_space *mapping, sector_t blockno, 73ext2_get_xip_page(struct address_space *mapping, sector_t offset,
55 int create) 74 int create)
56{ 75{
57 int rc; 76 int rc;
58 unsigned long data; 77 unsigned long data;
59 struct buffer_head tmp; 78 sector_t sector;
60 79
61 tmp.b_state = 0; 80 /* first, retrieve the sector number */
62 tmp.b_blocknr = 0; 81 rc = __ext2_get_sector(mapping->host, offset, create, &sector);
63 rc = ext2_get_block(mapping->host, blockno/(PAGE_SIZE/512) , &tmp,
64 create);
65 if (rc) 82 if (rc)
66 return ERR_PTR(rc); 83 goto error;
67 if (tmp.b_blocknr == 0) {
68 /* SPARSE block */
69 BUG_ON(create);
70 return ERR_PTR(-ENODATA);
71 }
72 84
85 /* retrieve address of the target data */
73 rc = __inode_direct_access 86 rc = __inode_direct_access
74 (mapping->host,tmp.b_blocknr*(PAGE_SIZE/512) ,&data); 87 (mapping->host, sector * (PAGE_SIZE/512), &data);
75 if (rc) 88 if (!rc)
76 return ERR_PTR(rc); 89 return virt_to_page(data);
77 90
78 SetPageUptodate(virt_to_page(data)); 91 error:
79 return virt_to_page(data); 92 return ERR_PTR(rc);
80} 93}