ecryptfs: clean up page flag handling
The functions that eventually call down to ecryptfs_read_lower(),
ecryptfs_decrypt_page(), and ecryptfs_copy_up_encrypted_with_header()
should have the responsibility of managing the page Uptodate
status. This patch gets rid of some of the ugliness that resulted from
trying to push some of the page flag setting too far down the stack.
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>
diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index e890d59..1ae90ef 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -605,14 +605,14 @@
printk(KERN_ERR "%s: Error attempting to copy "
"page at index [%ld]\n", __FUNCTION__,
page->index);
- goto out_clear_uptodate;
+ goto out;
}
enc_extent_virt = kmalloc(PAGE_CACHE_SIZE, GFP_USER);
if (!enc_extent_virt) {
rc = -ENOMEM;
ecryptfs_printk(KERN_ERR, "Error allocating memory for "
"encrypted extent\n");
- goto out_clear_uptodate;
+ goto out;
}
enc_extent_page = virt_to_page(enc_extent_virt);
for (extent_offset = 0;
@@ -631,21 +631,17 @@
ecryptfs_printk(KERN_ERR, "Error attempting "
"to read lower page; rc = [%d]"
"\n", rc);
- goto out_clear_uptodate;
+ goto out;
}
rc = ecryptfs_decrypt_extent(page, crypt_stat, enc_extent_page,
extent_offset);
if (rc) {
printk(KERN_ERR "%s: Error encrypting extent; "
"rc = [%d]\n", __FUNCTION__, rc);
- goto out_clear_uptodate;
+ goto out;
}
extent_offset++;
}
- SetPageUptodate(page);
- goto out;
-out_clear_uptodate:
- ClearPageUptodate(page);
out:
kfree(enc_extent_virt);
return rc;
diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h
index bb92b74..ce7a5d4 100644
--- a/fs/ecryptfs/ecryptfs_kernel.h
+++ b/fs/ecryptfs/ecryptfs_kernel.h
@@ -648,6 +648,6 @@
struct inode *ecryptfs_inode);
int ecryptfs_read(char *data, loff_t offset, size_t size,
struct file *ecryptfs_file);
-struct page *ecryptfs_get1page(struct file *file, loff_t index);
+struct page *ecryptfs_get_locked_page(struct file *file, loff_t index);
#endif /* #ifndef ECRYPTFS_KERNEL_H */
diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c
index 4eb09c1..16a7a55 100644
--- a/fs/ecryptfs/mmap.c
+++ b/fs/ecryptfs/mmap.c
@@ -37,23 +37,27 @@
struct kmem_cache *ecryptfs_lower_page_cache;
/**
- * ecryptfs_get1page
+ * ecryptfs_get_locked_page
*
* Get one page from cache or lower f/s, return error otherwise.
*
- * Returns unlocked and up-to-date page (if ok), with increased
+ * Returns locked and up-to-date page (if ok), with increased
* refcnt.
*/
-struct page *ecryptfs_get1page(struct file *file, loff_t index)
+struct page *ecryptfs_get_locked_page(struct file *file, loff_t index)
{
struct dentry *dentry;
struct inode *inode;
struct address_space *mapping;
+ struct page *page;
dentry = file->f_path.dentry;
inode = dentry->d_inode;
mapping = inode->i_mapping;
- return read_mapping_page(mapping, index, (void *)file);
+ page = read_mapping_page(mapping, index, (void *)file);
+ if (!IS_ERR(page))
+ lock_page(page);
+ return page;
}
/**
@@ -146,12 +150,10 @@
kunmap_atomic(page_virt, KM_USER0);
flush_dcache_page(page);
if (rc) {
- ClearPageUptodate(page);
printk(KERN_ERR "%s: Error reading xattr "
"region; rc = [%d]\n", __FUNCTION__, rc);
goto out;
}
- SetPageUptodate(page);
} else {
/* This is an encrypted data extent */
loff_t lower_offset =
@@ -232,6 +234,10 @@
}
}
out:
+ if (rc)
+ ClearPageUptodate(page);
+ else
+ SetPageUptodate(page);
ecryptfs_printk(KERN_DEBUG, "Unlocking page with index = [0x%.16x]\n",
page->index);
unlock_page(page);
@@ -265,10 +271,18 @@
if (from == 0 && to == PAGE_CACHE_SIZE)
goto out; /* If we are writing a full page, it will be
up to date. */
- if (!PageUptodate(page))
+ if (!PageUptodate(page)) {
rc = ecryptfs_read_lower_page_segment(page, page->index, 0,
PAGE_CACHE_SIZE,
page->mapping->host);
+ if (rc) {
+ printk(KERN_ERR "%s: Error attemping to read lower "
+ "page segment; rc = [%d]\n", __FUNCTION__, rc);
+ ClearPageUptodate(page);
+ goto out;
+ } else
+ SetPageUptodate(page);
+ }
if (page->index != 0) {
loff_t end_of_prev_pg_pos =
(((loff_t)page->index << PAGE_CACHE_SHIFT) - 1);
diff --git a/fs/ecryptfs/read_write.c b/fs/ecryptfs/read_write.c
index 272eaeb..2150edf 100644
--- a/fs/ecryptfs/read_write.c
+++ b/fs/ecryptfs/read_write.c
@@ -142,8 +142,8 @@
if (num_bytes > total_remaining_zeros)
num_bytes = total_remaining_zeros;
}
- ecryptfs_page = ecryptfs_get1page(ecryptfs_file,
- ecryptfs_page_idx);
+ ecryptfs_page = ecryptfs_get_locked_page(ecryptfs_file,
+ ecryptfs_page_idx);
if (IS_ERR(ecryptfs_page)) {
rc = PTR_ERR(ecryptfs_page);
printk(KERN_ERR "%s: Error getting page at "
@@ -161,6 +161,7 @@
printk(KERN_ERR "%s: Error decrypting "
"page; rc = [%d]\n",
__FUNCTION__, rc);
+ ClearPageUptodate(ecryptfs_page);
page_cache_release(ecryptfs_page);
goto out;
}
@@ -180,14 +181,15 @@
}
kunmap_atomic(ecryptfs_page_virt, KM_USER0);
flush_dcache_page(ecryptfs_page);
+ SetPageUptodate(ecryptfs_page);
+ unlock_page(ecryptfs_page);
rc = ecryptfs_encrypt_page(ecryptfs_page);
+ page_cache_release(ecryptfs_page);
if (rc) {
printk(KERN_ERR "%s: Error encrypting "
"page; rc = [%d]\n", __FUNCTION__, rc);
- page_cache_release(ecryptfs_page);
goto out;
}
- page_cache_release(ecryptfs_page);
pos += num_bytes;
}
if ((offset + size) > ecryptfs_file_size) {
@@ -225,7 +227,6 @@
ecryptfs_inode_to_private(ecryptfs_inode);
ssize_t octets_read;
mm_segment_t fs_save;
- size_t i;
int rc = 0;
mutex_lock(&inode_info->lower_file_mutex);
@@ -242,16 +243,6 @@
rc = -EINVAL;
}
mutex_unlock(&inode_info->lower_file_mutex);
- for (i = 0; i < size; i += PAGE_CACHE_SIZE) {
- struct page *data_page;
-
- data_page = virt_to_page(data + i);
- flush_dcache_page(data_page);
- if (rc)
- ClearPageUptodate(data_page);
- else
- SetPageUptodate(data_page);
- }
return rc;
}
@@ -283,6 +274,7 @@
virt = kmap(page_for_ecryptfs);
rc = ecryptfs_read_lower(virt, offset, size, ecryptfs_inode);
kunmap(page_for_ecryptfs);
+ flush_dcache_page(page_for_ecryptfs);
return rc;
}
@@ -331,8 +323,8 @@
if (num_bytes > total_remaining_bytes)
num_bytes = total_remaining_bytes;
- ecryptfs_page = ecryptfs_get1page(ecryptfs_file,
- ecryptfs_page_idx);
+ ecryptfs_page = ecryptfs_get_locked_page(ecryptfs_file,
+ ecryptfs_page_idx);
if (IS_ERR(ecryptfs_page)) {
rc = PTR_ERR(ecryptfs_page);
printk(KERN_ERR "%s: Error getting page at "
@@ -345,6 +337,7 @@
if (rc) {
printk(KERN_ERR "%s: Error decrypting "
"page; rc = [%d]\n", __FUNCTION__, rc);
+ ClearPageUptodate(ecryptfs_page);
page_cache_release(ecryptfs_page);
goto out;
}
@@ -353,6 +346,9 @@
((char *)ecryptfs_page_virt + start_offset_in_page),
num_bytes);
kunmap_atomic(ecryptfs_page_virt, KM_USER0);
+ flush_dcache_page(ecryptfs_page);
+ SetPageUptodate(ecryptfs_page);
+ unlock_page(ecryptfs_page);
page_cache_release(ecryptfs_page);
pos += num_bytes;
data_offset += num_bytes;