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Commit d3e49afb authored by Michael Halcrow's avatar Michael Halcrow Committed by Linus Torvalds
Browse files

eCryptfs: remove unnecessary page decrypt call 



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: default avatarMichael 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent c45dcabd

fs/ecryptfs/ecryptfs_kernel.h

+0 −2
Original line number Diff line number Diff line
@@ -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,

fs/ecryptfs/read_write.c

+0 −22
Original line number Diff line number Diff line
@@ -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),