static int stuffed_readpage(struct gfs2_inode *ip, struct page *page)
{
struct buffer_head *dibh;
void *kaddr;
int error;
/*
* Due to the order of unstuffing files and ->fault(), we can be
* asked for a zero page in the case of a stuffed file being extended,
* so we need to supply one here. It doesn't happen often.
*/
if (unlikely(page->index)) {
zero_user(page, 0, PAGE_CACHE_SIZE);
return 0;
}
error = gfs2_meta_inode_buffer(ip, &dibh);
if (error)
return error;
kaddr = kmap_atomic(page, KM_USER0);
memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode),
ip->i_di.di_size);
memset(kaddr + ip->i_di.di_size, 0, PAGE_CACHE_SIZE - ip->i_di.di_size);
kunmap_atomic(kaddr, KM_USER0);
flush_dcache_page(page);
brelse(dibh);
SetPageUptodate(page);
return 0;
}
static int v9fs_write_end(struct file *filp, struct address_space *mapping,
loff_t pos, unsigned len, unsigned copied,
struct page *page, void *fsdata)
{
loff_t last_pos = pos + copied;
struct inode *inode = page->mapping->host;
//p9_debug(P9_DEBUG_VFS, "filp %p, mapping %p\n", filp, mapping);
if (unlikely(copied < len)) {
/*
* zero out the rest of the area
*/
unsigned from = pos & (PAGE_CACHE_SIZE - 1);
zero_user(page, from + copied, len - copied);
flush_dcache_page(page);
}
if (!PageUptodate(page))
SetPageUptodate(page);
/*
* No need to use i_size_read() here, the i_size
* cannot change under us because we hold the i_mutex.
*/
if (last_pos > inode->i_size) {
inode_add_bytes(inode, last_pos - inode->i_size);
i_size_write(inode, last_pos);
}
set_page_dirty(page);
unlock_page(page);
page_cache_release(page);
return copied;
}
static int truncate_partial_data_page(struct inode *inode, u64 from,
bool cache_only)
{
unsigned offset = from & (PAGE_CACHE_SIZE - 1);
pgoff_t index = from >> PAGE_CACHE_SHIFT;
struct address_space *mapping = inode->i_mapping;
struct page *page;
if (!offset && !cache_only)
return 0;
if (cache_only) {
page = grab_cache_page(mapping, index);
if (page && PageUptodate(page))
goto truncate_out;
f2fs_put_page(page, 1);
return 0;
}
page = get_lock_data_page(inode, index);
if (IS_ERR(page))
return 0;
truncate_out:
f2fs_wait_on_page_writeback(page, DATA);
zero_user(page, offset, PAGE_CACHE_SIZE - offset);
if (!cache_only || !f2fs_encrypted_inode(inode) || !S_ISREG(inode->i_mode))
set_page_dirty(page);
f2fs_put_page(page, 1);
return 0;
}
static int ocfs2_readpage(struct file *file, struct page *page)
{
struct inode *inode = page->mapping->host;
struct ocfs2_inode_info *oi = OCFS2_I(inode);
loff_t start = (loff_t)page->index << PAGE_CACHE_SHIFT;
int ret, unlock = 1;
mlog_entry("(0x%p, %lu)\n", file, (page ? page->index : 0));
ret = ocfs2_inode_lock_with_page(inode, NULL, 0, page);
if (ret != 0) {
if (ret == AOP_TRUNCATED_PAGE)
unlock = 0;
mlog_errno(ret);
goto out;
}
if (down_read_trylock(&oi->ip_alloc_sem) == 0) {
ret = AOP_TRUNCATED_PAGE;
goto out_inode_unlock;
}
/*
* i_size might have just been updated as we grabed the meta lock. We
* might now be discovering a truncate that hit on another node.
* block_read_full_page->get_block freaks out if it is asked to read
* beyond the end of a file, so we check here. Callers
* (generic_file_read, vm_ops->fault) are clever enough to check i_size
* and notice that the page they just read isn't needed.
*
* XXX sys_readahead() seems to get that wrong?
*/
if (start >= i_size_read(inode)) {
zero_user(page, 0, PAGE_SIZE);
SetPageUptodate(page);
ret = 0;
goto out_alloc;
}
if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL)
ret = ocfs2_readpage_inline(inode, page);
else
ret = block_read_full_page(page, ocfs2_get_block);
unlock = 0;
out_alloc:
up_read(&OCFS2_I(inode)->ip_alloc_sem);
out_inode_unlock:
ocfs2_inode_unlock(inode, 0);
out:
if (unlock)
unlock_page(page);
mlog_exit(ret);
return ret;
}
static int ocfs2_readpage(struct file *file, struct page *page)
{
struct inode *inode = page->mapping->host;
struct ocfs2_inode_info *oi = OCFS2_I(inode);
loff_t start = (loff_t)page->index << PAGE_CACHE_SHIFT;
int ret, unlock = 1;
trace_ocfs2_readpage((unsigned long long)oi->ip_blkno,
(page ? page->index : 0));
ret = ocfs2_inode_lock_with_page(inode, NULL, 0, page);
if (ret != 0) {
if (ret == AOP_TRUNCATED_PAGE)
unlock = 0;
mlog_errno(ret);
goto out;
}
if (down_read_trylock(&oi->ip_alloc_sem) == 0) {
ret = AOP_TRUNCATED_PAGE;
unlock_page(page);
unlock = 0;
down_read(&oi->ip_alloc_sem);
up_read(&oi->ip_alloc_sem);
goto out_inode_unlock;
}
if (start >= i_size_read(inode)) {
zero_user(page, 0, PAGE_SIZE);
SetPageUptodate(page);
ret = 0;
goto out_alloc;
}
if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL)
ret = ocfs2_readpage_inline(inode, page);
else
ret = block_read_full_page(page, ocfs2_get_block);
unlock = 0;
out_alloc:
up_read(&OCFS2_I(inode)->ip_alloc_sem);
out_inode_unlock:
ocfs2_inode_unlock(inode, 0);
out:
if (unlock)
unlock_page(page);
return ret;
}
/*
* xfs_iozero clears the specified range supplied via the page cache (except in
* the DAX case). Writes through the page cache will allocate blocks over holes,
* though the callers usually map the holes first and avoid them. If a block is
* not completely zeroed, then it will be read from disk before being partially
* zeroed.
*
* In the DAX case, we can just directly write to the underlying pages. This
* will not allocate blocks, but will avoid holes and unwritten extents and so
* not do unnecessary work.
*/
int
xfs_iozero(
struct xfs_inode *ip, /* inode */
loff_t pos, /* offset in file */
size_t count) /* size of data to zero */
{
struct page *page;
struct address_space *mapping;
int status = 0;
mapping = VFS_I(ip)->i_mapping;
do {
unsigned offset, bytes;
void *fsdata;
offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */
bytes = PAGE_CACHE_SIZE - offset;
if (bytes > count)
bytes = count;
if (IS_DAX(VFS_I(ip))) {
status = dax_zero_page_range(VFS_I(ip), pos, bytes,
xfs_get_blocks_direct);
if (status)
break;
} else {
status = pagecache_write_begin(NULL, mapping, pos, bytes,
AOP_FLAG_UNINTERRUPTIBLE,
&page, &fsdata);
if (status)
break;
zero_user(page, offset, bytes);
status = pagecache_write_end(NULL, mapping, pos, bytes,
bytes, page, fsdata);
WARN_ON(status <= 0); /* can't return less than zero! */
status = 0;
}
pos += bytes;
count -= bytes;
} while (count);
return status;
}
static void fill_zero(struct inode *inode, pgoff_t index,
loff_t start, loff_t len)
{
struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
struct page *page;
if (!len)
return;
f2fs_balance_fs(sbi);
f2fs_lock_op(sbi);
page = get_new_data_page(inode, NULL, index, false);
f2fs_unlock_op(sbi);
if (!IS_ERR(page)) {
f2fs_wait_on_page_writeback(page, DATA);
zero_user(page, start, len);
set_page_dirty(page);
f2fs_put_page(page, 1);
}
}
/*
* xfs_iozero
*
* xfs_iozero clears the specified range of buffer supplied,
* and marks all the affected blocks as valid and modified. If
* an affected block is not allocated, it will be allocated. If
* an affected block is not completely overwritten, and is not
* valid before the operation, it will be read from disk before
* being partially zeroed.
*/
STATIC int
xfs_iozero(
struct xfs_inode *ip,
loff_t pos,
size_t count)
{
struct page *page;
struct address_space *mapping;
int status;
mapping = VFS_I(ip)->i_mapping;
do {
unsigned offset, bytes;
void *fsdata;
offset = (pos & (PAGE_CACHE_SIZE -1));
bytes = PAGE_CACHE_SIZE - offset;
if (bytes > count)
bytes = count;
status = pagecache_write_begin(NULL, mapping, pos, bytes,
AOP_FLAG_UNINTERRUPTIBLE,
&page, &fsdata);
if (status)
break;
zero_user(page, offset, bytes);
status = pagecache_write_end(NULL, mapping, pos, bytes, bytes,
page, fsdata);
WARN_ON(status <= 0);
pos += bytes;
count -= bytes;
status = 0;
} while (count);
return (-status);
}
/*
* xfs_iozero
*
* xfs_iozero clears the specified range of buffer supplied,
* and marks all the affected blocks as valid and modified. If
* an affected block is not allocated, it will be allocated. If
* an affected block is not completely overwritten, and is not
* valid before the operation, it will be read from disk before
* being partially zeroed.
*/
STATIC int
xfs_iozero(
struct xfs_inode *ip, /* inode */
loff_t pos, /* offset in file */
size_t count) /* size of data to zero */
{
struct page *page;
struct address_space *mapping;
int status;
mapping = ip->i_vnode->i_mapping;
do {
unsigned offset, bytes;
void *fsdata;
offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */
bytes = PAGE_CACHE_SIZE - offset;
if (bytes > count)
bytes = count;
status = pagecache_write_begin(NULL, mapping, pos, bytes,
AOP_FLAG_UNINTERRUPTIBLE,
&page, &fsdata);
if (status)
break;
zero_user(page, offset, bytes);
status = pagecache_write_end(NULL, mapping, pos, bytes, bytes,
page, fsdata);
WARN_ON(status <= 0); /* can't return less than zero! */
pos += bytes;
count -= bytes;
status = 0;
} while (count);
return (-status);
}
static int truncate_partial_data_page(struct inode *inode, u64 from)
{
unsigned offset = from & (PAGE_CACHE_SIZE - 1);
struct page *page;
if (!offset)
return 0;
page = find_data_page(inode, from >> PAGE_CACHE_SHIFT, false);
if (IS_ERR(page))
return 0;
lock_page(page);
if (unlikely(!PageUptodate(page) ||
page->mapping != inode->i_mapping))
goto out;
f2fs_wait_on_page_writeback(page, DATA);
zero_user(page, offset, PAGE_CACHE_SIZE - offset);
set_page_dirty(page);
out:
f2fs_put_page(page, 1);
return 0;
}
/**
* ecryptfs_readpage
* @file: An eCryptfs file
* @page: Page from eCryptfs inode mapping into which to stick the read data
*
* Read in a page, decrypting if necessary.
*
* Returns zero on success; non-zero on error.
*/
static int ecryptfs_readpage(struct file *file, struct page *page)
{
struct ecryptfs_crypt_stat *crypt_stat =
&ecryptfs_inode_to_private(page->mapping->host)->crypt_stat;
#ifdef CONFIG_CRYPTO_DEV_KFIPS
struct ecryptfs_page_crypt_req *page_crypt_req = NULL;
#endif
int rc = 0;
if (!crypt_stat || !(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
rc = ecryptfs_read_lower_page_segment(page, page->index, 0,
PAGE_CACHE_SIZE,
page->mapping->host);
} else if (crypt_stat->flags & ECRYPTFS_VIEW_AS_ENCRYPTED) {
if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) {
rc = ecryptfs_copy_up_encrypted_with_header(page,
crypt_stat);
if (rc) {
printk(KERN_ERR "%s: Error attempting to copy "
"the encrypted content from the lower "
"file whilst inserting the metadata "
"from the xattr into the header; rc = "
"[%d]\n", __func__, rc);
goto out;
}
} else {
rc = ecryptfs_read_lower_page_segment(
page, page->index, 0, PAGE_CACHE_SIZE,
page->mapping->host);
if (rc) {
printk(KERN_ERR "Error reading page; rc = "
"[%d]\n", rc);
goto out;
}
}
} else {
#ifndef CONFIG_CRYPTO_DEV_KFIPS
rc = ecryptfs_decrypt_page(page);
if (rc) {
ecryptfs_printk(KERN_ERR, "Error decrypting page; "
"rc = [%d]\n", rc);
#else
page_crypt_req = ecryptfs_alloc_page_crypt_req(
page, ecryptfs_readpage_complete);
if (!page_crypt_req) {
rc = -ENOMEM;
ecryptfs_printk(KERN_ERR,
"Failed to allocate page crypt request "
"for decryption\n");
#endif
goto out;
}
#ifdef CONFIG_CRYPTO_DEV_KFIPS
ecryptfs_decrypt_page_async(page_crypt_req);
goto out_async_started;
#endif
}
out:
#ifndef CONFIG_CRYPTO_DEV_KFIPS
if (rc)
#else
if (unlikely(rc))
#endif
ClearPageUptodate(page);
else
SetPageUptodate(page);
ecryptfs_printk(KERN_DEBUG, "Unlocking page with index = [0x%.16lx]\n",
page->index);
unlock_page(page);
#ifdef CONFIG_CRYPTO_DEV_KFIPS
out_async_started:
#endif
return rc;
}
/**
* Called with lower inode mutex held.
*/
static int fill_zeros_to_end_of_page(struct page *page, unsigned int to)
{
struct inode *inode = page->mapping->host;
int end_byte_in_page;
if ((i_size_read(inode) / PAGE_CACHE_SIZE) != 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;
zero_user_segment(page, end_byte_in_page, PAGE_CACHE_SIZE);
out:
return 0;
}
/**
* ecryptfs_write_begin
* @file: The eCryptfs file
* @mapping: The eCryptfs object
* @pos: The file offset at which to start writing
* @len: Length of the write
* @flags: Various flags
* @pagep: Pointer to return the page
* @fsdata: Pointer to return fs data (unused)
*
* This function must zero any hole we create
*
* Returns zero on success; non-zero otherwise
*/
static int ecryptfs_write_begin(struct file *file,
struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata)
{
pgoff_t index = pos >> PAGE_CACHE_SHIFT;
struct page *page;
loff_t prev_page_end_size;
int rc = 0;
page = grab_cache_page_write_begin(mapping, index, flags);
if (!page)
return -ENOMEM;
*pagep = page;
prev_page_end_size = ((loff_t)index << PAGE_CACHE_SHIFT);
if (!PageUptodate(page)) {
struct ecryptfs_crypt_stat *crypt_stat =
&ecryptfs_inode_to_private(mapping->host)->crypt_stat;
if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
rc = ecryptfs_read_lower_page_segment(
page, index, 0, PAGE_CACHE_SIZE, mapping->host);
if (rc) {
printk(KERN_ERR "%s: Error attemping to read "
"lower page segment; rc = [%d]\n",
__func__, rc);
ClearPageUptodate(page);
goto out;
} else
SetPageUptodate(page);
} else if (crypt_stat->flags & ECRYPTFS_VIEW_AS_ENCRYPTED) {
if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) {
rc = ecryptfs_copy_up_encrypted_with_header(
page, crypt_stat);
if (rc) {
printk(KERN_ERR "%s: Error attempting "
"to copy the encrypted content "
"from the lower file whilst "
"inserting the metadata from "
"the xattr into the header; rc "
"= [%d]\n", __func__, rc);
ClearPageUptodate(page);
goto out;
}
SetPageUptodate(page);
} else {
rc = ecryptfs_read_lower_page_segment(
page, index, 0, PAGE_CACHE_SIZE,
mapping->host);
if (rc) {
printk(KERN_ERR "%s: Error reading "
"page; rc = [%d]\n",
__func__, rc);
ClearPageUptodate(page);
goto out;
}
SetPageUptodate(page);
}
} else {
if (prev_page_end_size
>= i_size_read(page->mapping->host)) {
zero_user(page, 0, PAGE_CACHE_SIZE);
} else {
rc = ecryptfs_decrypt_page(page);
if (rc) {
printk(KERN_ERR "%s: Error decrypting "
"page at index [%ld]; "
"rc = [%d]\n",
__func__, page->index, rc);
ClearPageUptodate(page);
goto out;
}
}
SetPageUptodate(page);
}
}
/* If creating a page or more of holes, zero them out via truncate.
* Note, this will increase i_size. */
if (index != 0) {
if (prev_page_end_size > i_size_read(page->mapping->host)) {
rc = ecryptfs_truncate(file->f_path.dentry,
prev_page_end_size);
if (rc) {
printk(KERN_ERR "%s: Error on attempt to "
"truncate to (higher) offset [%lld];"
" rc = [%d]\n", __func__,
prev_page_end_size, rc);
goto out;
}
}
}
/* Writing to a new page, and creating a small hole from start
* of page? Zero it out. */
if ((i_size_read(mapping->host) == prev_page_end_size)
&& (pos != 0))
zero_user(page, 0, PAGE_CACHE_SIZE);
out:
if (unlikely(rc)) {
unlock_page(page);
page_cache_release(page);
*pagep = NULL;
}
return rc;
}
/**
* ecryptfs_prepare_write
* @file: The eCryptfs file
* @page: The eCryptfs page
* @from: The start byte from which we will write
* @to: The end byte to which we will write
*
* This function must zero any hole we create
*
* Returns zero on success; non-zero otherwise
*/
static int ecryptfs_prepare_write(struct file *file, struct page *page,
unsigned from, unsigned to)
{
loff_t prev_page_end_size;
int rc = 0;
if (!PageUptodate(page)) {
struct ecryptfs_crypt_stat *crypt_stat =
&ecryptfs_inode_to_private(
file->f_dentry->d_inode)->crypt_stat;
if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)
|| (crypt_stat->flags & ECRYPTFS_NEW_FILE)) {
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",
__func__, rc);
ClearPageUptodate(page);
goto out;
} else
SetPageUptodate(page);
} else if (crypt_stat->flags & ECRYPTFS_VIEW_AS_ENCRYPTED) {
if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) {
rc = ecryptfs_copy_up_encrypted_with_header(
page, crypt_stat);
if (rc) {
printk(KERN_ERR "%s: Error attempting "
"to copy the encrypted content "
"from the lower file whilst "
"inserting the metadata from "
"the xattr into the header; rc "
"= [%d]\n", __func__, rc);
ClearPageUptodate(page);
goto out;
}
SetPageUptodate(page);
} else {
rc = ecryptfs_read_lower_page_segment(
page, page->index, 0, PAGE_CACHE_SIZE,
page->mapping->host);
if (rc) {
printk(KERN_ERR "%s: Error reading "
"page; rc = [%d]\n",
__func__, rc);
ClearPageUptodate(page);
goto out;
}
SetPageUptodate(page);
}
} else {
rc = ecryptfs_decrypt_page(page);
if (rc) {
printk(KERN_ERR "%s: Error decrypting page "
"at index [%ld]; rc = [%d]\n",
__func__, page->index, rc);
ClearPageUptodate(page);
goto out;
}
SetPageUptodate(page);
}
}
prev_page_end_size = ((loff_t)page->index << PAGE_CACHE_SHIFT);
/* If creating a page or more of holes, zero them out via truncate.
* Note, this will increase i_size. */
if (page->index != 0) {
if (prev_page_end_size > i_size_read(page->mapping->host)) {
rc = ecryptfs_truncate(file->f_dentry,
prev_page_end_size);
if (rc) {
printk(KERN_ERR "%s: Error on attempt to "
"truncate to (higher) offset [%lld];"
" rc = [%d]\n", __func__,
prev_page_end_size, rc);
goto out;
}
}
}
/* Writing to a new page, and creating a small hole from start
* of page? Zero it out. */
if ((i_size_read(page->mapping->host) == prev_page_end_size)
&& (from != 0))
zero_user(page, 0, PAGE_CACHE_SIZE);
out:
return rc;
}
