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authorJared Hulbert <jaredeh@gmail.com>2008-04-28 05:13:02 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2008-04-28 11:58:23 -0400
commit30afcb4bd2762fa4b87b17ada9500aa46dc10b1b (patch)
tree0920f491a37683a8784c146270b98f82a7e0aa2c /fs/ext2/xip.c
parent423bad600443c590f34ed7ce357591f76f48f137 (diff)
return pfn from direct_access, for XIP
Alter the block device ->direct_access() API to work with the new get_xip_mem() API (that requires both kaddr and pfn are returned). Some architectures will not do the right thing in their virt_to_page() for use by XIP (to translate from the kernel virtual address returned by direct_access(), to a user mappable pfn in XIP's page fault handler. However, we can't switch it to just return the pfn and not the kaddr, because we have no good way to get a kva from a pfn, and XIP requires the kva for its read(2) and write(2) handlers. So we have to return both. Signed-off-by: Jared Hulbert <jaredeh@gmail.com> Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Carsten Otte <cotte@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux-mm@kvack.org Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/ext2/xip.c')
-rw-r--r--fs/ext2/xip.c24
1 files changed, 14 insertions, 10 deletions
diff --git a/fs/ext2/xip.c b/fs/ext2/xip.c
index ca7f0031238..430b4c8ee97 100644
--- a/fs/ext2/xip.c
+++ b/fs/ext2/xip.c
@@ -16,11 +16,13 @@
16 16
17static inline int 17static inline int
18__inode_direct_access(struct inode *inode, sector_t sector, 18__inode_direct_access(struct inode *inode, sector_t sector,
19 unsigned long *data) 19 void **kaddr, unsigned long *pfn)
20{ 20{
21 BUG_ON(!inode->i_sb->s_bdev->bd_disk->fops->direct_access); 21 struct block_device *bdev = inode->i_sb->s_bdev;
22 return inode->i_sb->s_bdev->bd_disk->fops 22 struct block_device_operations *ops = bdev->bd_disk->fops;
23 ->direct_access(inode->i_sb->s_bdev,sector,data); 23
24 BUG_ON(!ops->direct_access);
25 return ops->direct_access(bdev, sector, kaddr, pfn);
24} 26}
25 27
26static inline int 28static inline int
@@ -48,12 +50,13 @@ int
48ext2_clear_xip_target(struct inode *inode, int block) 50ext2_clear_xip_target(struct inode *inode, int block)
49{ 51{
50 sector_t sector = block * (PAGE_SIZE/512); 52 sector_t sector = block * (PAGE_SIZE/512);
51 unsigned long data; 53 void *kaddr;
54 unsigned long pfn;
52 int rc; 55 int rc;
53 56
54 rc = __inode_direct_access(inode, sector, &data); 57 rc = __inode_direct_access(inode, sector, &kaddr, &pfn);
55 if (!rc) 58 if (!rc)
56 clear_page((void*)data); 59 clear_page(kaddr);
57 return rc; 60 return rc;
58} 61}
59 62
@@ -74,7 +77,8 @@ ext2_get_xip_page(struct address_space *mapping, sector_t offset,
74 int create) 77 int create)
75{ 78{
76 int rc; 79 int rc;
77 unsigned long data; 80 void *kaddr;
81 unsigned long pfn;
78 sector_t sector; 82 sector_t sector;
79 83
80 /* first, retrieve the sector number */ 84 /* first, retrieve the sector number */
@@ -84,9 +88,9 @@ ext2_get_xip_page(struct address_space *mapping, sector_t offset,
84 88
85 /* retrieve address of the target data */ 89 /* retrieve address of the target data */
86 rc = __inode_direct_access 90 rc = __inode_direct_access
87 (mapping->host, sector * (PAGE_SIZE/512), &data); 91 (mapping->host, sector * (PAGE_SIZE/512), &kaddr, &pfn);
88 if (!rc) 92 if (!rc)
89 return virt_to_page(data); 93 return pfn_to_page(pfn);
90 94
91 error: 95 error:
92 return ERR_PTR(rc); 96 return ERR_PTR(rc);