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eCryptfs: Simplify lower file offset calculation

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Now that lower filesystem IO operations occur for complete
PAGE_CACHE_SIZE bytes, the calculation for converting an eCryptfs extent
index into a lower file offset can be simplified.

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
This commit is contained in:
Tyler Hicks 2013-04-15 17:28:09 -07:00
parent 0f89617623
commit 24d15266bd
1 changed files with 7 additions and 11 deletions
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18
fs/ecryptfs/crypto.c
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@ -407,15 +407,15 @@ out:
} }
/** /**
* ecryptfs_lower_offset_for_extent * lower_offset_for_page
* *
* Convert an eCryptfs page index into a lower byte offset * Convert an eCryptfs page index into a lower byte offset
*/ */
static void ecryptfs_lower_offset_for_extent(loff_t *offset, loff_t extent_num, static loff_t lower_offset_for_page(struct ecryptfs_crypt_stat *crypt_stat,
struct ecryptfs_crypt_stat *crypt_stat) struct page *page)
{ {
(*offset) = ecryptfs_lower_header_size(crypt_stat) return ecryptfs_lower_header_size(crypt_stat) +
+ (crypt_stat->extent_size * extent_num); (page->index << PAGE_CACHE_SHIFT);
} }
/** /**
@ -517,9 +517,7 @@ int ecryptfs_encrypt_page(struct page *page)
} }
} }
ecryptfs_lower_offset_for_extent(&lower_offset, lower_offset = lower_offset_for_page(crypt_stat, page);
page->index * (PAGE_CACHE_SIZE / crypt_stat->extent_size),
crypt_stat);
enc_extent_virt = kmap(enc_extent_page); enc_extent_virt = kmap(enc_extent_page);
rc = ecryptfs_write_lower(ecryptfs_inode, enc_extent_virt, lower_offset, rc = ecryptfs_write_lower(ecryptfs_inode, enc_extent_virt, lower_offset,
PAGE_CACHE_SIZE); PAGE_CACHE_SIZE);
@ -612,9 +610,7 @@ int ecryptfs_decrypt_page(struct page *page)
goto out; goto out;
} }
ecryptfs_lower_offset_for_extent(&lower_offset, lower_offset = lower_offset_for_page(crypt_stat, page);
page->index * (PAGE_CACHE_SIZE / crypt_stat->extent_size),
crypt_stat);
enc_extent_virt = kmap(enc_extent_page); enc_extent_virt = kmap(enc_extent_page);
rc = ecryptfs_read_lower(enc_extent_virt, lower_offset, PAGE_CACHE_SIZE, rc = ecryptfs_read_lower(enc_extent_virt, lower_offset, PAGE_CACHE_SIZE,
ecryptfs_inode); ecryptfs_inode);