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authorMichael Halcrow <mhalcrow@us.ibm.com>2008-02-06 01:38:32 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2008-02-06 10:41:12 -0800
commitcc11beffdf80ca31dff21422fa2a5e54d25f1494 (patch)
tree3b0e28d18f493a7c59b089c4c6fc59c79945937e /fs/ecryptfs/mmap.c
parent7896b631823c6e8f1a520d89390624a51445840e (diff)
eCryptfs: track header bytes rather than extents
Remove internal references to header extents; just keep track of header bytes instead. Headers can easily span multiple pages with the recent persistent file changes. Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/ecryptfs/mmap.c')
-rw-r--r--fs/ecryptfs/mmap.c21
1 files changed, 12 insertions, 9 deletions
diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c
index 9a5e0d17f1c5..dc74b186145d 100644
--- a/fs/ecryptfs/mmap.c
+++ b/fs/ecryptfs/mmap.c
@@ -100,13 +100,14 @@ static void set_header_info(char *page_virt,
struct ecryptfs_crypt_stat *crypt_stat)
{
size_t written;
- int save_num_header_extents_at_front =
- crypt_stat->num_header_extents_at_front;
+ size_t save_num_header_bytes_at_front =
+ crypt_stat->num_header_bytes_at_front;
- crypt_stat->num_header_extents_at_front = 1;
+ crypt_stat->num_header_bytes_at_front =
+ ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE;
ecryptfs_write_header_metadata(page_virt + 20, crypt_stat, &written);
- crypt_stat->num_header_extents_at_front =
- save_num_header_extents_at_front;
+ crypt_stat->num_header_bytes_at_front =
+ save_num_header_bytes_at_front;
}
/**
@@ -132,8 +133,11 @@ ecryptfs_copy_up_encrypted_with_header(struct page *page,
loff_t view_extent_num = ((((loff_t)page->index)
* num_extents_per_page)
+ extent_num_in_page);
+ size_t num_header_extents_at_front =
+ (crypt_stat->num_header_bytes_at_front
+ / crypt_stat->extent_size);
- if (view_extent_num < crypt_stat->num_header_extents_at_front) {
+ if (view_extent_num < num_header_extents_at_front) {
/* This is a header extent */
char *page_virt;
@@ -155,9 +159,8 @@ ecryptfs_copy_up_encrypted_with_header(struct page *page,
} else {
/* This is an encrypted data extent */
loff_t lower_offset =
- ((view_extent_num -
- crypt_stat->num_header_extents_at_front)
- * crypt_stat->extent_size);
+ ((view_extent_num * crypt_stat->extent_size)
+ - crypt_stat->num_header_bytes_at_front);
rc = ecryptfs_read_lower_page_segment(
page, (lower_offset >> PAGE_CACHE_SHIFT),