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294 lines
7.4 KiB
294 lines
7.4 KiB
/* |
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* file.c |
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* |
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* PURPOSE |
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* File handling routines for the OSTA-UDF(tm) filesystem. |
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* |
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* COPYRIGHT |
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* This file is distributed under the terms of the GNU General Public |
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* License (GPL). Copies of the GPL can be obtained from: |
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* ftp://prep.ai.mit.edu/pub/gnu/GPL |
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* Each contributing author retains all rights to their own work. |
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* |
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* (C) 1998-1999 Dave Boynton |
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* (C) 1998-2004 Ben Fennema |
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* (C) 1999-2000 Stelias Computing Inc |
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* |
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* HISTORY |
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* |
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* 10/02/98 dgb Attempt to integrate into udf.o |
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* 10/07/98 Switched to using generic_readpage, etc., like isofs |
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* And it works! |
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* 12/06/98 blf Added udf_file_read. uses generic_file_read for all cases but |
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* ICBTAG_FLAG_AD_IN_ICB. |
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* 04/06/99 64 bit file handling on 32 bit systems taken from ext2 file.c |
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* 05/12/99 Preliminary file write support |
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*/ |
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#include "udfdecl.h" |
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#include <linux/fs.h> |
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#include <linux/uaccess.h> |
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#include <linux/kernel.h> |
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#include <linux/string.h> /* memset */ |
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#include <linux/capability.h> |
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#include <linux/errno.h> |
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#include <linux/pagemap.h> |
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#include <linux/uio.h> |
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#include "udf_i.h" |
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#include "udf_sb.h" |
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static void __udf_adinicb_readpage(struct page *page) |
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{ |
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struct inode *inode = page->mapping->host; |
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char *kaddr; |
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struct udf_inode_info *iinfo = UDF_I(inode); |
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loff_t isize = i_size_read(inode); |
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/* |
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* We have to be careful here as truncate can change i_size under us. |
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* So just sample it once and use the same value everywhere. |
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*/ |
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kaddr = kmap_atomic(page); |
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memcpy(kaddr, iinfo->i_data + iinfo->i_lenEAttr, isize); |
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memset(kaddr + isize, 0, PAGE_SIZE - isize); |
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flush_dcache_page(page); |
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SetPageUptodate(page); |
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kunmap_atomic(kaddr); |
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} |
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static int udf_adinicb_readpage(struct file *file, struct page *page) |
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{ |
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BUG_ON(!PageLocked(page)); |
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__udf_adinicb_readpage(page); |
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unlock_page(page); |
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return 0; |
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} |
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static int udf_adinicb_writepage(struct page *page, |
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struct writeback_control *wbc) |
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{ |
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struct inode *inode = page->mapping->host; |
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char *kaddr; |
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struct udf_inode_info *iinfo = UDF_I(inode); |
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BUG_ON(!PageLocked(page)); |
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kaddr = kmap_atomic(page); |
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memcpy(iinfo->i_data + iinfo->i_lenEAttr, kaddr, i_size_read(inode)); |
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SetPageUptodate(page); |
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kunmap_atomic(kaddr); |
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mark_inode_dirty(inode); |
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unlock_page(page); |
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return 0; |
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} |
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static int udf_adinicb_write_begin(struct file *file, |
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struct address_space *mapping, loff_t pos, |
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unsigned len, unsigned flags, struct page **pagep, |
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void **fsdata) |
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{ |
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struct page *page; |
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if (WARN_ON_ONCE(pos >= PAGE_SIZE)) |
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return -EIO; |
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page = grab_cache_page_write_begin(mapping, 0, flags); |
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if (!page) |
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return -ENOMEM; |
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*pagep = page; |
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if (!PageUptodate(page)) |
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__udf_adinicb_readpage(page); |
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return 0; |
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} |
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static ssize_t udf_adinicb_direct_IO(struct kiocb *iocb, struct iov_iter *iter) |
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{ |
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/* Fallback to buffered I/O. */ |
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return 0; |
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} |
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static int udf_adinicb_write_end(struct file *file, struct address_space *mapping, |
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loff_t pos, unsigned len, unsigned copied, |
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struct page *page, void *fsdata) |
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{ |
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struct inode *inode = page->mapping->host; |
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loff_t last_pos = pos + copied; |
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if (last_pos > inode->i_size) |
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i_size_write(inode, last_pos); |
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set_page_dirty(page); |
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unlock_page(page); |
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put_page(page); |
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return copied; |
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} |
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const struct address_space_operations udf_adinicb_aops = { |
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.set_page_dirty = __set_page_dirty_buffers, |
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.readpage = udf_adinicb_readpage, |
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.writepage = udf_adinicb_writepage, |
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.write_begin = udf_adinicb_write_begin, |
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.write_end = udf_adinicb_write_end, |
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.direct_IO = udf_adinicb_direct_IO, |
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}; |
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static ssize_t udf_file_write_iter(struct kiocb *iocb, struct iov_iter *from) |
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{ |
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ssize_t retval; |
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struct file *file = iocb->ki_filp; |
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struct inode *inode = file_inode(file); |
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struct udf_inode_info *iinfo = UDF_I(inode); |
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int err; |
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inode_lock(inode); |
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retval = generic_write_checks(iocb, from); |
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if (retval <= 0) |
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goto out; |
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down_write(&iinfo->i_data_sem); |
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if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) { |
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loff_t end = iocb->ki_pos + iov_iter_count(from); |
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if (inode->i_sb->s_blocksize < |
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(udf_file_entry_alloc_offset(inode) + end)) { |
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err = udf_expand_file_adinicb(inode); |
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if (err) { |
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inode_unlock(inode); |
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udf_debug("udf_expand_adinicb: err=%d\n", err); |
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return err; |
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} |
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} else { |
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iinfo->i_lenAlloc = max(end, inode->i_size); |
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up_write(&iinfo->i_data_sem); |
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} |
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} else |
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up_write(&iinfo->i_data_sem); |
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retval = __generic_file_write_iter(iocb, from); |
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out: |
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inode_unlock(inode); |
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if (retval > 0) { |
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mark_inode_dirty(inode); |
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retval = generic_write_sync(iocb, retval); |
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} |
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return retval; |
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} |
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long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) |
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{ |
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struct inode *inode = file_inode(filp); |
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long old_block, new_block; |
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int result; |
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if (file_permission(filp, MAY_READ) != 0) { |
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udf_debug("no permission to access inode %lu\n", inode->i_ino); |
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return -EPERM; |
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} |
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if (!arg && ((cmd == UDF_GETVOLIDENT) || (cmd == UDF_GETEASIZE) || |
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(cmd == UDF_RELOCATE_BLOCKS) || (cmd == UDF_GETEABLOCK))) { |
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udf_debug("invalid argument to udf_ioctl\n"); |
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return -EINVAL; |
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} |
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switch (cmd) { |
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case UDF_GETVOLIDENT: |
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if (copy_to_user((char __user *)arg, |
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UDF_SB(inode->i_sb)->s_volume_ident, 32)) |
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return -EFAULT; |
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return 0; |
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case UDF_RELOCATE_BLOCKS: |
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if (!capable(CAP_SYS_ADMIN)) |
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return -EPERM; |
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if (get_user(old_block, (long __user *)arg)) |
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return -EFAULT; |
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result = udf_relocate_blocks(inode->i_sb, |
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old_block, &new_block); |
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if (result == 0) |
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result = put_user(new_block, (long __user *)arg); |
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return result; |
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case UDF_GETEASIZE: |
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return put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg); |
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case UDF_GETEABLOCK: |
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return copy_to_user((char __user *)arg, |
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UDF_I(inode)->i_data, |
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UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0; |
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default: |
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return -ENOIOCTLCMD; |
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} |
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return 0; |
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} |
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static int udf_release_file(struct inode *inode, struct file *filp) |
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{ |
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if (filp->f_mode & FMODE_WRITE && |
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atomic_read(&inode->i_writecount) == 1) { |
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/* |
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* Grab i_mutex to avoid races with writes changing i_size |
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* while we are running. |
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*/ |
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inode_lock(inode); |
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down_write(&UDF_I(inode)->i_data_sem); |
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udf_discard_prealloc(inode); |
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udf_truncate_tail_extent(inode); |
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up_write(&UDF_I(inode)->i_data_sem); |
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inode_unlock(inode); |
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} |
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return 0; |
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} |
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const struct file_operations udf_file_operations = { |
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.read_iter = generic_file_read_iter, |
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.unlocked_ioctl = udf_ioctl, |
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.open = generic_file_open, |
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.mmap = generic_file_mmap, |
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.write_iter = udf_file_write_iter, |
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.release = udf_release_file, |
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.fsync = generic_file_fsync, |
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.splice_read = generic_file_splice_read, |
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.llseek = generic_file_llseek, |
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}; |
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static int udf_setattr(struct user_namespace *mnt_userns, struct dentry *dentry, |
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struct iattr *attr) |
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{ |
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struct inode *inode = d_inode(dentry); |
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struct super_block *sb = inode->i_sb; |
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int error; |
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error = setattr_prepare(&init_user_ns, dentry, attr); |
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if (error) |
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return error; |
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if ((attr->ia_valid & ATTR_UID) && |
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UDF_QUERY_FLAG(sb, UDF_FLAG_UID_SET) && |
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!uid_eq(attr->ia_uid, UDF_SB(sb)->s_uid)) |
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return -EPERM; |
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if ((attr->ia_valid & ATTR_GID) && |
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UDF_QUERY_FLAG(sb, UDF_FLAG_GID_SET) && |
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!gid_eq(attr->ia_gid, UDF_SB(sb)->s_gid)) |
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return -EPERM; |
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if ((attr->ia_valid & ATTR_SIZE) && |
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attr->ia_size != i_size_read(inode)) { |
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error = udf_setsize(inode, attr->ia_size); |
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if (error) |
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return error; |
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} |
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if (attr->ia_valid & ATTR_MODE) |
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udf_update_extra_perms(inode, attr->ia_mode); |
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setattr_copy(&init_user_ns, inode, attr); |
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mark_inode_dirty(inode); |
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return 0; |
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} |
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const struct inode_operations udf_file_inode_operations = { |
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.setattr = udf_setattr, |
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};
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