Cc: Linux Filesystems <linux-fsdevel@xxxxxxxxxxxxxxx>
Cc: mhalcrow@xxxxxxxxxx
Cc: phillip@xxxxxxxxxxxxxxxxxxxx
Cc: ecryptfs-devel@xxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Nick Piggin <npiggin@xxxxxxx>
fs/ecryptfs/crypto.c | 32 +++---
fs/ecryptfs/ecryptfs_kernel.h | 4
fs/ecryptfs/mmap.c | 213 +++++++++++++++++++-----------------------
3 files changed, 119 insertions(+), 130 deletions(-)
Index: linux-2.6/fs/ecryptfs/mmap.c
===================================================================
--- linux-2.6.orig/fs/ecryptfs/mmap.c
+++ linux-2.6/fs/ecryptfs/mmap.c
@@ -36,26 +36,6 @@
struct kmem_cache *ecryptfs_lower_page_cache;
-/**
- * ecryptfs_get1page
- *
- * Get one page from cache or lower f/s, return error otherwise.
- *
- * Returns unlocked and up-to-date page (if ok), with increased
- * refcnt.
- */
-static struct page *ecryptfs_get1page(struct file *file, int index)
-{
- struct dentry *dentry;
- struct inode *inode;
- struct address_space *mapping;
-
- dentry = file->f_path.dentry;
- inode = dentry->d_inode;
- mapping = inode->i_mapping;
- return read_mapping_page(mapping, index, (void *)file);
-}
-
static
int write_zeros(struct file *file, pgoff_t index, int start, int num_zeros);
@@ -360,17 +340,14 @@ out:
/**
* Called with lower inode mutex held.
*/
-static int fill_zeros_to_end_of_page(struct page *page, unsigned int to)
+static int fill_zeros_to_end_of_page(struct page *page, loff_t new_isize)
{
- struct inode *inode = page->mapping->host;
int end_byte_in_page;
char *page_virt;
- if ((i_size_read(inode) / PAGE_CACHE_SIZE) != page->index)
+ if ((new_isize >> PAGE_CACHE_SHIFT) != page->index)
goto out;
- end_byte_in_page = i_size_read(inode) % PAGE_CACHE_SIZE;
- if (to > end_byte_in_page)
- end_byte_in_page = to;
+ end_byte_in_page = new_isize % PAGE_CACHE_SIZE;
page_virt = kmap_atomic(page, KM_USER0);
memset((page_virt + end_byte_in_page), 0,
(PAGE_CACHE_SIZE - end_byte_in_page));
@@ -380,16 +357,35 @@ out:
return 0;
}
-static int ecryptfs_prepare_write(struct file *file, struct page *page,
- unsigned from, unsigned to)
+static int ecryptfs_write_begin(struct file *file,struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned flags,
+ struct page **pagep, void **fsdata)
{
+ struct page *page;
+ pgoff_t index;
int rc = 0;
- 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))
- rc = ecryptfs_do_readpage(file, page, page->index);
+ index = pos >> PAGE_CACHE_SHIFT;
+ page = __grab_cache_page(mapping, index);
+ if (!page) {
+ rc = -ENOMEM;
+ goto out;
+ }
+
+ /*
+ * If we are writing a full page (with no possibility of a short
+ * write), it will be guaranteed to end up being uptodate at
+ * write_end-time
+ */
+ if (flags & AOP_FLAG_UNINTERRUPTIBLE && len == PAGE_CACHE_SIZE)
+ goto out;
+ if (!PageUptodate(page)) {
+ rc = ecryptfs_do_readpage(file, page, index);
+ if (rc) {
+ unlock_page(page);
+ page_cache_release(page);
+ }
+ }
out:
return rc;
}
@@ -412,12 +408,6 @@ out:
return rc;
}
-static void ecryptfs_release_lower_page(struct page *lower_page)
-{
- unlock_page(lower_page);
- page_cache_release(lower_page);
-}
-
/**
* ecryptfs_write_inode_size_to_header
*
@@ -431,23 +421,17 @@ static int ecryptfs_write_inode_size_to_
{
int rc = 0;
struct page *header_page;
+ void *fsdata;
char *header_virt;
- const struct address_space_operations *lower_a_ops;
+ struct address_space *lower_mapping = lower_inode->i_mapping;
u64 file_size;
- header_page = grab_cache_page(lower_inode->i_mapping, 0);
- if (!header_page) {
- ecryptfs_printk(KERN_ERR, "grab_cache_page for "
- "lower_page_index 0 failed\n");
- rc = -EINVAL;
- goto out;
- }
- lower_a_ops = lower_inode->i_mapping->a_ops;
- rc = lower_a_ops->prepare_write(lower_file, header_page, 0, 8);
- if (rc) {
- ecryptfs_release_lower_page(header_page);
+ rc = pagecache_write_begin(lower_file, lower_mapping, 0, sizeof(u64),
+ AOP_FLAG_UNINTERRUPTIBLE,
+ &header_page, &fsdata);
+ if (rc)
goto out;
- }
+
file_size = (u64)i_size_read(inode);
ecryptfs_printk(KERN_DEBUG, "Writing size: [0x%.16x]\n", file_size);
file_size = cpu_to_be64(file_size);
@@ -455,13 +439,17 @@ static int ecryptfs_write_inode_size_to_
memcpy(header_virt, &file_size, sizeof(u64));
kunmap_atomic(header_virt, KM_USER0);
flush_dcache_page(header_page);
- rc = lower_a_ops->commit_write(lower_file, header_page, 0, 8);
- if (rc < 0)
+
+ rc = pagecache_write_end(lower_file, lower_mapping, 0, sizeof(u64),
+ sizeof(u64), header_page, fsdata);
+ if (rc != sizeof(u64)) {
ecryptfs_printk(KERN_ERR, "Error commiting header page "
"write\n");
- ecryptfs_release_lower_page(header_page);
+ if (rc > 0)
+ rc = -EINVAL; /* XXX: can we do better? */
+ }
lower_inode->i_mtime = lower_inode->i_ctime = CURRENT_TIME;
- mark_inode_dirty_sync(inode);
+ mark_inode_dirty_sync(inode); /* XXX: lower_inode? */
out:
return rc;
}
@@ -544,31 +532,21 @@ ecryptfs_write_inode_size_to_metadata(st
int ecryptfs_get_lower_page(struct page **lower_page, struct inode *lower_inode,
struct file *lower_file,
unsigned long lower_page_index, int byte_offset,
- int region_bytes)
+ int region_bytes, void **fsdata)
{
- int rc = 0;
+ int rc;
+ struct address_space *lower_mapping = lower_inode->i_mapping;
+ loff_t pos = (lower_page_index << PAGE_CACHE_SHIFT) + byte_offset;
-retry:
- *lower_page = grab_cache_page(lower_inode->i_mapping, lower_page_index);
- if (!(*lower_page)) {
- rc = -EINVAL;
- ecryptfs_printk(KERN_ERR, "Error attempting to grab "
- "lower page with index [0x%.16x]\n",
- lower_page_index);
- goto out;
- }
- rc = lower_inode->i_mapping->a_ops->prepare_write(lower_file,
- (*lower_page),
- byte_offset,
- region_bytes);
+ rc = pagecache_write_begin(lower_file, lower_mapping, pos, region_bytes,
+ AOP_FLAG_UNINTERRUPTIBLE, /* XXX: ok? */
+ lower_page, fsdata);
if (rc) {
- ecryptfs_printk(KERN_ERR, "prepare_write for "
+ ecryptfs_printk(KERN_ERR, "pagecache_write_begin for "
"lower_page_index = [0x%.16x] failed; rc = "
"[%d]\n", lower_page_index, rc);
- ecryptfs_release_lower_page(*lower_page);
(*lower_page) = NULL;
}
-out:
return rc;
}
@@ -580,18 +558,21 @@ out:
int
ecryptfs_commit_lower_page(struct page *lower_page, struct inode *lower_inode,
struct file *lower_file, int byte_offset,
- int region_size)
+ int region_size, void *fsdata)
{
- int rc = 0;
+ int rc;
+ struct address_space *lower_mapping = lower_inode->i_mapping;
+ loff_t pos = (lower_page->index << PAGE_CACHE_SHIFT) + byte_offset;
- rc = lower_inode->i_mapping->a_ops->commit_write(
- lower_file, lower_page, byte_offset, region_size);
- if (rc < 0) {
+ rc = pagecache_write_end(lower_file, lower_mapping, pos, region_size,
+ region_size, lower_page, fsdata);
+ if (rc != region_size) {
ecryptfs_printk(KERN_ERR,
"Error committing write; rc = [%d]\n", rc);
+ if (rc > 0)
+ rc = -EINVAL;
} else
rc = 0;
- ecryptfs_release_lower_page(lower_page);
return rc;
}
@@ -606,9 +587,10 @@ int ecryptfs_copy_page_to_lower(struct p
{
int rc = 0;
struct page *lower_page;
+ void *fsdata;
rc = ecryptfs_get_lower_page(&lower_page, lower_inode, lower_file,
- page->index, 0, PAGE_CACHE_SIZE);
+ page->index, 0, PAGE_CACHE_SIZE, &fsdata);
if (rc) {
ecryptfs_printk(KERN_ERR, "Error attempting to get page "
"at index [0x%.16x]\n", page->index);
@@ -618,7 +600,7 @@ int ecryptfs_copy_page_to_lower(struct p
memcpy((char *)page_address(lower_page), page_address(page),
PAGE_CACHE_SIZE);
rc = ecryptfs_commit_lower_page(lower_page, lower_inode, lower_file,
- 0, PAGE_CACHE_SIZE);
+ 0, PAGE_CACHE_SIZE, fsdata);
if (rc)
ecryptfs_printk(KERN_ERR, "Error attempting to commit page "
"at index [0x%.16x]\n", page->index);
@@ -629,31 +611,37 @@ out:
struct kmem_cache *ecryptfs_xattr_cache;
/**
- * ecryptfs_commit_write
+ * ecryptfs_write_end
* @file: The eCryptfs file object
- * @page: The eCryptfs page
- * @from: Ignored (we rotate the page IV on each write)
- * @to: Ignored
+ * @mapping: The eCryptfs address_space
+ * @pos: The start of the write
+ * @len: The length passed to write_begin (unused)
+ * @copied: The actual amount copied
+ * @page: The eCryptfs page returned by write_begin
+ * @fsdata: Filesystem private data (unused)
*
* This is where we encrypt the data and pass the encrypted data to
* the lower filesystem. In OpenPGP-compatible mode, we operate on
* entire underlying packets.
*/
-static int ecryptfs_commit_write(struct file *file, struct page *page,
- unsigned from, unsigned to)
+static int ecryptfs_write_end(struct file *file,
+ struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned copied,
+ struct page *page, void *fsdata)
{
struct ecryptfs_page_crypt_context ctx;
- loff_t pos;
+ loff_t isize;
struct inode *inode;
struct inode *lower_inode;
struct file *lower_file;
struct ecryptfs_crypt_stat *crypt_stat;
int rc;
- inode = page->mapping->host;
+ inode = mapping->host;
+ isize = inode->i_size; /* i_mutex is held */
lower_inode = ecryptfs_inode_to_lower(inode);
lower_file = ecryptfs_file_to_lower(file);
- mutex_lock(&lower_inode->i_mutex);
+ mutex_lock(&lower_inode->i_mutex); /* XXX: put this in write_begin? */
crypt_stat = &ecryptfs_inode_to_private(file->f_path.dentry->d_inode)
->crypt_stat;
if (crypt_stat->flags & ECRYPTFS_NEW_FILE) {
@@ -664,8 +652,8 @@ static int ecryptfs_commit_write(struct
ecryptfs_printk(KERN_DEBUG, "Not a new file\n");
ecryptfs_printk(KERN_DEBUG, "Calling fill_zeros_to_end_of_page"
"(page w/ index = [0x%.16x], to = [%d])\n", page->index,
- to);
- rc = fill_zeros_to_end_of_page(page, to);
+ max(isize, pos+copied));
+ rc = fill_zeros_to_end_of_page(page, max(isize, pos+copied));
if (rc) {
ecryptfs_printk(KERN_WARNING, "Error attempting to fill "
"zeros in page with index = [0x%.16x]\n",
@@ -682,11 +670,10 @@ static int ecryptfs_commit_write(struct
goto out;
}
inode->i_blocks = lower_inode->i_blocks;
- pos = (page->index << PAGE_CACHE_SHIFT) + to;
- if (pos > i_size_read(inode)) {
- i_size_write(inode, pos);
+ if (pos + copied > isize) {
+ i_size_write(inode, pos + copied);
ecryptfs_printk(KERN_DEBUG, "Expanded file size to "
- "[0x%.16x]\n", i_size_read(inode));
+ "[0x%.16x]\n", pos + copied);
}
rc = ecryptfs_write_inode_size_to_metadata(lower_file, lower_inode,
inode, file->f_dentry,
@@ -702,6 +689,9 @@ out:
else
SetPageUptodate(page);
mutex_unlock(&lower_inode->i_mutex);
+ unlock_page(page);
+ page_cache_release(page);
+
return rc;
}
@@ -722,32 +712,31 @@ int write_zeros(struct file *file, pgoff
int rc = 0;
struct page *tmp_page;
char *tmp_page_virt;
-
- tmp_page = ecryptfs_get1page(file, index);
- if (IS_ERR(tmp_page)) {
- ecryptfs_printk(KERN_ERR, "Error getting page at index "
- "[0x%.16x]\n", index);
- rc = PTR_ERR(tmp_page);
- goto out;
- }
- rc = ecryptfs_prepare_write(file, tmp_page, start, start + num_zeros);
+ void *fsdata;
+ struct address_space *mapping = file->f_path.dentry->d_inode->i_mapping;
+ loff_t pos = (index << PAGE_CACHE_SHIFT) + start;
+
+ rc = pagecache_write_begin(file, mapping, pos, num_zeros,
+ AOP_FLAG_UNINTERRUPTIBLE,
+ &tmp_page, &fsdata);
if (rc) {
ecryptfs_printk(KERN_ERR, "Error preparing to write zero's "
"to remainder of page at index [0x%.16x]\n",
index);
- page_cache_release(tmp_page);
goto out;
}
tmp_page_virt = kmap_atomic(tmp_page, KM_USER0);
memset(((char *)tmp_page_virt + start), 0, num_zeros);
kunmap_atomic(tmp_page_virt, KM_USER0);
flush_dcache_page(tmp_page);
- rc = ecryptfs_commit_write(file, tmp_page, start, start + num_zeros);
- if (rc < 0) {
+ rc = pagecache_write_end(file, mapping, pos, num_zeros, num_zeros,
+ tmp_page, fsdata);
+ if (rc != num_zeros) {
ecryptfs_printk(KERN_ERR, "Error attempting to write zero's "
"to remainder of page at index [0x%.16x]\n",
index);
- page_cache_release(tmp_page);
+ if (rc > 0)
+ rc = -EINVAL;
goto out;
}
rc = 0;
@@ -795,8 +784,8 @@ static void ecryptfs_sync_page(struct pa
struct address_space_operations ecryptfs_aops = {
.writepage = ecryptfs_writepage,
.readpage = ecryptfs_readpage,
- .prepare_write = ecryptfs_prepare_write,
- .commit_write = ecryptfs_commit_write,
+ .write_begin = ecryptfs_write_begin,
+ .write_end = ecryptfs_write_end,
.bmap = ecryptfs_bmap,
.sync_page = ecryptfs_sync_page,
};
Index: linux-2.6/fs/ecryptfs/crypto.c
===================================================================
--- linux-2.6.orig/fs/ecryptfs/crypto.c
+++ linux-2.6/fs/ecryptfs/crypto.c
@@ -375,7 +375,8 @@ ecryptfs_extent_to_lwr_pg_idx_and_offset
static int ecryptfs_write_out_page(struct ecryptfs_page_crypt_context *ctx,
struct page *lower_page,
struct inode *lower_inode,
- int byte_offset_in_page, int bytes_to_write)
+ int byte_offset_in_page, int bytes_to_write,
+ void *fsdata)
{
int rc = 0;
@@ -383,7 +384,7 @@ static int ecryptfs_write_out_page(struc
rc = ecryptfs_commit_lower_page(lower_page, lower_inode,
ctx->param.lower_file,
byte_offset_in_page,
- bytes_to_write);
+ bytes_to_write, fsdata);
if (rc) {
ecryptfs_printk(KERN_ERR, "Error calling lower "
"commit; rc = [%d]\n", rc);
@@ -407,7 +408,7 @@ static int ecryptfs_read_in_page(struct
struct page **lower_page,
struct inode *lower_inode,
unsigned long lower_page_idx,
- int byte_offset_in_page)
+ int byte_offset_in_page, void **fsdata)
{
int rc = 0;
@@ -419,13 +420,12 @@ static int ecryptfs_read_in_page(struct
lower_page_idx,
byte_offset_in_page,
(PAGE_CACHE_SIZE
- - byte_offset_in_page));
+ - byte_offset_in_page), fsdata);
if (rc) {
ecryptfs_printk(
- KERN_ERR, "Error attempting to grab, map, "
- "and prepare_write lower page with index "
+ KERN_ERR, "Error in ecryptfs_get_lower_page "
+ "lower page with index "
"[0x%.16x]; rc = [%d]\n", lower_page_idx, rc);
- goto out;
}
} else {
*lower_page = grab_cache_page(lower_inode->i_mapping,
@@ -436,10 +436,9 @@ static int ecryptfs_read_in_page(struct
KERN_ERR, "Error attempting to grab and map "
"lower page with index [0x%.16x]; rc = [%d]\n",
lower_page_idx, rc);
- goto out;
}
}
-out:
+
return rc;
}
@@ -475,6 +474,8 @@ int ecryptfs_encrypt_page(struct ecryptf
int lower_byte_offset = 0;
int orig_byte_offset = 0;
int num_extents_per_page;
+ void *fsdata;
+
#define ECRYPTFS_PAGE_STATE_UNREAD 0
#define ECRYPTFS_PAGE_STATE_READ 1
#define ECRYPTFS_PAGE_STATE_MODIFIED 2
@@ -503,10 +504,9 @@ int ecryptfs_encrypt_page(struct ecryptf
if (prior_lower_page_idx != lower_page_idx
&& page_state == ECRYPTFS_PAGE_STATE_MODIFIED) {
rc = ecryptfs_write_out_page(ctx, lower_page,
- lower_inode,
- orig_byte_offset,
- (PAGE_CACHE_SIZE
- - orig_byte_offset));
+ lower_inode, orig_byte_offset,
+ (PAGE_CACHE_SIZE - orig_byte_offset),
+ fsdata);
if (rc) {
ecryptfs_printk(KERN_ERR, "Error attempting "
"to write out page; rc = [%d]"
@@ -519,7 +519,7 @@ int ecryptfs_encrypt_page(struct ecryptf
|| page_state == ECRYPTFS_PAGE_STATE_WRITTEN) {
rc = ecryptfs_read_in_page(ctx, &lower_page,
lower_inode, lower_page_idx,
- lower_byte_offset);
+ lower_byte_offset, &fsdata);
if (rc) {
ecryptfs_printk(KERN_ERR, "Error attempting "
"to read in lower page with "
@@ -571,8 +571,8 @@ int ecryptfs_encrypt_page(struct ecryptf
}
BUG_ON(orig_byte_offset != 0);
rc = ecryptfs_write_out_page(ctx, lower_page, lower_inode, 0,
- (lower_byte_offset
- + crypt_stat->extent_size));
+ (lower_byte_offset + crypt_stat->extent_size),
+ fsdata);
if (rc) {
ecryptfs_printk(KERN_ERR, "Error attempting to write out "
"page; rc = [%d]\n", rc);
Index: linux-2.6/fs/ecryptfs/ecryptfs_kernel.h
===================================================================
--- linux-2.6.orig/fs/ecryptfs/ecryptfs_kernel.h
+++ linux-2.6/fs/ecryptfs/ecryptfs_kernel.h
@@ -503,11 +503,11 @@ int ecryptfs_write_inode_size_to_metadat
int ecryptfs_get_lower_page(struct page **lower_page, struct inode *lower_inode,
struct file *lower_file,
unsigned long lower_page_index, int byte_offset,
- int region_bytes);
+ int region_bytes, void **fsdata);
int
ecryptfs_commit_lower_page(struct page *lower_page, struct inode *lower_inode,
struct file *lower_file, int byte_offset,
- int region_size);
+ int region_size, void *fsdata);
int ecryptfs_copy_page_to_lower(struct page *page, struct inode *lower_inode,
struct file *lower_file);
int ecryptfs_do_readpage(struct file *file, struct page *page,
--
-
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