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fs/udf/file.c
6.93 KB
81f7e3824 Initial Release, ... |
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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; 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 ", 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 ", 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 "); 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); int error; error = setattr_prepare(dentry, attr); if (error) return error; 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, }; |