upstream commit: d3e49afbb66109613c3474f2273f5830ac2dcb09

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>
[chrisw: backport to 2.6.25.5]
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
[tim.gardner: backport to 2.6.24]
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
---
fs/ecryptfs/ecryptfs_kernel.h | 2 --
fs/ecryptfs/read_write.c | 22 ----------------------
2 files changed, 0 insertions(+), 24 deletions(-)

diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h
index ce7a5d4..b2b4ce4 100644
--- a/fs/ecryptfs/ecryptfs_kernel.h
+++ b/fs/ecryptfs/ecryptfs_kernel.h
@@ -629,8 +629,6 @@ 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);
void ecryptfs_lower_offset_for_extent(loff_t *offset, loff_t extent_num,
struct ecryptfs_crypt_stat *crypt_stat);
int ecryptfs_write_lower(struct inode *ecryptfs_inode, char *data,
diff --git a/fs/ecryptfs/read_write.c b/fs/ecryptfs/read_write.c
index 948f576..1c8a354 100644
--- a/fs/ecryptfs/read_write.c
+++ b/fs/ecryptfs/read_write.c
@@ -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]
",
- __FUNCTION__, rc);
- ClearPageUptodate(ecryptfs_page);
- page_cache_release(ecryptfs_page);
- goto out;
- }
- }
ecryptfs_page_virt = kmap_atomic(ecryptfs_page, KM_USER0);

/*
@@ -348,14 +334,6 @@ 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]
", __FUNCTION__, 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),
--
1.5.4.3


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