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eCryptfs: remove unnecessary page decrypt call

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The page decrypt calls in ecryptfs_write() are both pointless and buggy.
Pointless because ecryptfs_get_locked_page() has already brought the page
up to date, and buggy because prior mmap writes will just be blown away by
the decrypt call.

This patch also removes the declaration of a now-nonexistent function
ecryptfs_write_zeros().

Thanks to Eric Sandeen and David Kleikamp for helping to track this
down.

Eric said:

   fsx w/ mmap dies quickly ( < 100 ops) without this, and survives
   nicely (to millions of ops+) with it in place.

Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: Eric Sandeen <sandeen@redhat.com>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Michael Halcrow 2008-06-05 22:46:02 -07:00 committed by Linus Torvalds
parent c45dcabd26
commit d3e49afbb6
2 changed files with 0 additions and 24 deletions
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2
fs/ecryptfs/ecryptfs_kernel.h
View file

@ -660,8 +660,6 @@ int ecryptfs_get_tfm_and_mutex_for_cipher_name(struct crypto_blkcipher **tfm,
int ecryptfs_keyring_auth_tok_for_sig(struct key **auth_tok_key,
struct ecryptfs_auth_tok **auth_tok,
char *sig);
int ecryptfs_write_zeros(struct file *file, pgoff_t index, int start,
int num_zeros);
int ecryptfs_write_lower(struct inode *ecryptfs_inode, char *data,
loff_t offset, size_t size);
int ecryptfs_write_lower_page_segment(struct inode *ecryptfs_inode,

22
fs/ecryptfs/read_write.c
View file

@ -157,20 +157,6 @@ int ecryptfs_write(struct file *ecryptfs_file, char *data, loff_t offset,
ecryptfs_page_idx, rc);
goto out;
}
if (start_offset_in_page) {
/* Read in the page from the lower
* into the eCryptfs inode page cache,
* decrypting */
rc = ecryptfs_decrypt_page(ecryptfs_page);
if (rc) {
printk(KERN_ERR "%s: Error decrypting "
"page; rc = [%d]\n",
__func__, rc);
ClearPageUptodate(ecryptfs_page);
page_cache_release(ecryptfs_page);
goto out;
}
}
ecryptfs_page_virt = kmap_atomic(ecryptfs_page, KM_USER0);
/*
@ -349,14 +335,6 @@ int ecryptfs_read(char *data, loff_t offset, size_t size,
ecryptfs_page_idx, rc);
goto out;
}
rc = ecryptfs_decrypt_page(ecryptfs_page);
if (rc) {
printk(KERN_ERR "%s: Error decrypting "
"page; rc = [%d]\n", __func__, rc);
ClearPageUptodate(ecryptfs_page);
page_cache_release(ecryptfs_page);
goto out;
}
ecryptfs_page_virt = kmap_atomic(ecryptfs_page, KM_USER0);
memcpy((data + data_offset),
((char *)ecryptfs_page_virt + start_offset_in_page),