OpenCloudOS-Kernel/fs/udf/file.c

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/*
* file.c
*
* PURPOSE
* File handling routines for the OSTA-UDF(tm) filesystem.
*
* COPYRIGHT
* This file is distributed under the terms of the GNU General Public
* License (GPL). Copies of the GPL can be obtained from:
* ftp://prep.ai.mit.edu/pub/gnu/GPL
* Each contributing author retains all rights to their own work.
*
* (C) 1998-1999 Dave Boynton
* (C) 1998-2004 Ben Fennema
* (C) 1999-2000 Stelias Computing Inc
*
* HISTORY
*
* 10/02/98 dgb Attempt to integrate into udf.o
* 10/07/98 Switched to using generic_readpage, etc., like isofs
* And it works!
* 12/06/98 blf Added udf_file_read. uses generic_file_read for all cases but
* ICBTAG_FLAG_AD_IN_ICB.
* 04/06/99 64 bit file handling on 32 bit systems taken from ext2 file.c
* 05/12/99 Preliminary file write support
*/
#include "udfdecl.h"
#include <linux/fs.h>
#include <linux/uaccess.h>
#include <linux/kernel.h>
#include <linux/string.h> /* memset */
#include <linux/capability.h>
#include <linux/errno.h>
#include <linux/pagemap.h>
#include <linux/uio.h>
#include "udf_i.h"
#include "udf_sb.h"
static void __udf_adinicb_readpage(struct page *page)
{
struct inode *inode = page->mapping->host;
char *kaddr;
struct udf_inode_info *iinfo = UDF_I(inode);
loff_t isize = i_size_read(inode);
/*
* We have to be careful here as truncate can change i_size under us.
* So just sample it once and use the same value everywhere.
*/
kaddr = kmap_atomic(page);
memcpy(kaddr, iinfo->i_ext.i_data + iinfo->i_lenEAttr, isize);
memset(kaddr + isize, 0, PAGE_SIZE - isize);
flush_dcache_page(page);
SetPageUptodate(page);
kunmap_atomic(kaddr);
}
static int udf_adinicb_readpage(struct file *file, struct page *page)
{
BUG_ON(!PageLocked(page));
__udf_adinicb_readpage(page);
unlock_page(page);
return 0;
}
static int udf_adinicb_writepage(struct page *page,
struct writeback_control *wbc)
{
struct inode *inode = page->mapping->host;
char *kaddr;
struct udf_inode_info *iinfo = UDF_I(inode);
BUG_ON(!PageLocked(page));
kaddr = kmap_atomic(page);
memcpy(iinfo->i_ext.i_data + iinfo->i_lenEAttr, kaddr,
i_size_read(inode));
SetPageUptodate(page);
kunmap_atomic(kaddr);
mark_inode_dirty(inode);
unlock_page(page);
return 0;
}
static int udf_adinicb_write_begin(struct file *file,
struct address_space *mapping, loff_t pos,
unsigned len, unsigned flags, struct page **pagep,
void **fsdata)
{
struct page *page;
mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. We have many places where PAGE_CACHE_SIZE assumed to be equal to PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* or PAGE_* constant should be used in a particular case, especially on the border between fs and mm. Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much breakage to be doable. Let's stop pretending that pages in page cache are special. They are not. The changes are pretty straight-forward: - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; - page_cache_get() -> get_page(); - page_cache_release() -> put_page(); This patch contains automated changes generated with coccinelle using script below. For some reason, coccinelle doesn't patch header files. I've called spatch for them manually. The only adjustment after coccinelle is revert of changes to PAGE_CAHCE_ALIGN definition: we are going to drop it later. There are few places in the code where coccinelle didn't reach. I'll fix them manually in a separate patch. Comments and documentation also will be addressed with the separate patch. virtual patch @@ expression E; @@ - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ expression E; @@ - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ @@ - PAGE_CACHE_SHIFT + PAGE_SHIFT @@ @@ - PAGE_CACHE_SIZE + PAGE_SIZE @@ @@ - PAGE_CACHE_MASK + PAGE_MASK @@ expression E; @@ - PAGE_CACHE_ALIGN(E) + PAGE_ALIGN(E) @@ expression E; @@ - page_cache_get(E) + get_page(E) @@ expression E; @@ - page_cache_release(E) + put_page(E) Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-01 20:29:47 +08:00
if (WARN_ON_ONCE(pos >= PAGE_SIZE))
return -EIO;
page = grab_cache_page_write_begin(mapping, 0, flags);
if (!page)
return -ENOMEM;
*pagep = page;
if (!PageUptodate(page))
__udf_adinicb_readpage(page);
return 0;
}
static ssize_t udf_adinicb_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
{
/* Fallback to buffered I/O. */
return 0;
}
static int udf_adinicb_write_end(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned copied,
struct page *page, void *fsdata)
{
struct inode *inode = page->mapping->host;
loff_t last_pos = pos + copied;
if (last_pos > inode->i_size)
i_size_write(inode, last_pos);
set_page_dirty(page);
unlock_page(page);
put_page(page);
return copied;
}
const struct address_space_operations udf_adinicb_aops = {
.readpage = udf_adinicb_readpage,
.writepage = udf_adinicb_writepage,
.write_begin = udf_adinicb_write_begin,
.write_end = udf_adinicb_write_end,
.direct_IO = udf_adinicb_direct_IO,
};
static ssize_t udf_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
{
ssize_t retval;
struct file *file = iocb->ki_filp;
struct inode *inode = file_inode(file);
struct udf_inode_info *iinfo = UDF_I(inode);
int err;
inode_lock(inode);
retval = generic_write_checks(iocb, from);
if (retval <= 0)
goto out;
down_write(&iinfo->i_data_sem);
if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
loff_t end = iocb->ki_pos + iov_iter_count(from);
if (inode->i_sb->s_blocksize <
(udf_file_entry_alloc_offset(inode) + end)) {
err = udf_expand_file_adinicb(inode);
if (err) {
inode_unlock(inode);
udf_debug("udf_expand_adinicb: err=%d\n", err);
return err;
}
} else {
iinfo->i_lenAlloc = max(end, inode->i_size);
up_write(&iinfo->i_data_sem);
}
} else
up_write(&iinfo->i_data_sem);
retval = __generic_file_write_iter(iocb, from);
out:
inode_unlock(inode);
if (retval > 0) {
mark_inode_dirty(inode);
retval = generic_write_sync(iocb, retval);
}
return retval;
}
long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
struct inode *inode = file_inode(filp);
long old_block, new_block;
int result;
if (inode_permission(inode, MAY_READ) != 0) {
udf_debug("no permission to access inode %lu\n", inode->i_ino);
return -EPERM;
}
if (!arg && ((cmd == UDF_GETVOLIDENT) || (cmd == UDF_GETEASIZE) ||
(cmd == UDF_RELOCATE_BLOCKS) || (cmd == UDF_GETEABLOCK))) {
udf_debug("invalid argument to udf_ioctl\n");
return -EINVAL;
}
switch (cmd) {
case UDF_GETVOLIDENT:
if (copy_to_user((char __user *)arg,
UDF_SB(inode->i_sb)->s_volume_ident, 32))
return -EFAULT;
return 0;
case UDF_RELOCATE_BLOCKS:
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (get_user(old_block, (long __user *)arg))
return -EFAULT;
result = udf_relocate_blocks(inode->i_sb,
old_block, &new_block);
if (result == 0)
result = put_user(new_block, (long __user *)arg);
return result;
case UDF_GETEASIZE:
return put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg);
case UDF_GETEABLOCK:
return copy_to_user((char __user *)arg,
UDF_I(inode)->i_ext.i_data,
UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0;
default:
return -ENOIOCTLCMD;
}
return 0;
}
static int udf_release_file(struct inode *inode, struct file *filp)
{
if (filp->f_mode & FMODE_WRITE &&
atomic_read(&inode->i_writecount) == 1) {
/*
* Grab i_mutex to avoid races with writes changing i_size
* while we are running.
*/
inode_lock(inode);
down_write(&UDF_I(inode)->i_data_sem);
udf_discard_prealloc(inode);
udf_truncate_tail_extent(inode);
up_write(&UDF_I(inode)->i_data_sem);
inode_unlock(inode);
}
return 0;
}
const struct file_operations udf_file_operations = {
.read_iter = generic_file_read_iter,
.unlocked_ioctl = udf_ioctl,
.open = generic_file_open,
.mmap = generic_file_mmap,
.write_iter = udf_file_write_iter,
.release = udf_release_file,
.fsync = generic_file_fsync,
.splice_read = generic_file_splice_read,
.llseek = generic_file_llseek,
};
static int udf_setattr(struct dentry *dentry, struct iattr *attr)
{
struct inode *inode = d_inode(dentry);
struct super_block *sb = inode->i_sb;
int error;
error = setattr_prepare(dentry, attr);
if (error)
return error;
if ((attr->ia_valid & ATTR_UID) &&
UDF_QUERY_FLAG(sb, UDF_FLAG_UID_SET) &&
!uid_eq(attr->ia_uid, UDF_SB(sb)->s_uid))
return -EPERM;
if ((attr->ia_valid & ATTR_GID) &&
UDF_QUERY_FLAG(sb, UDF_FLAG_GID_SET) &&
!gid_eq(attr->ia_gid, UDF_SB(sb)->s_gid))
return -EPERM;
if ((attr->ia_valid & ATTR_SIZE) &&
attr->ia_size != i_size_read(inode)) {
error = udf_setsize(inode, attr->ia_size);
if (error)
return error;
}
setattr_copy(inode, attr);
mark_inode_dirty(inode);
return 0;
}
const struct inode_operations udf_file_inode_operations = {
.setattr = udf_setattr,
};