diff options
Diffstat (limited to 'kernel/fs/udf/file.c')
| -rw-r--r-- | kernel/fs/udf/file.c | 273 |
1 files changed, 273 insertions, 0 deletions
diff --git a/kernel/fs/udf/file.c b/kernel/fs/udf/file.c new file mode 100644 index 000000000..7a95b8fed --- /dev/null +++ b/kernel/fs/udf/file.c @@ -0,0 +1,273 @@ +/* + * 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); + + kaddr = kmap(page); + memcpy(kaddr, iinfo->i_ext.i_data + iinfo->i_lenEAttr, inode->i_size); + memset(kaddr + inode->i_size, 0, PAGE_CACHE_SIZE - inode->i_size); + flush_dcache_page(page); + SetPageUptodate(page); + kunmap(page); +} + +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(page); + memcpy(iinfo->i_ext.i_data + iinfo->i_lenEAttr, kaddr, inode->i_size); + mark_inode_dirty(inode); + SetPageUptodate(page); + kunmap(page); + 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_CACHE_SIZE)) + return -EIO; + page = grab_cache_page_write_begin(mapping, 0, flags); + if (!page) + return -ENOMEM; + *pagep = page; + + if (!PageUptodate(page) && len != PAGE_CACHE_SIZE) + __udf_adinicb_readpage(page); + return 0; +} + +static ssize_t udf_adinicb_direct_IO(struct kiocb *iocb, struct iov_iter *iter, + loff_t offset) +{ + /* Fallback to buffered I/O. */ + return 0; +} + +const struct address_space_operations udf_adinicb_aops = { + .readpage = udf_adinicb_readpage, + .writepage = udf_adinicb_writepage, + .write_begin = udf_adinicb_write_begin, + .write_end = simple_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; + + mutex_lock(&inode->i_mutex); + + 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) { + mutex_unlock(&inode->i_mutex); + 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: + mutex_unlock(&inode->i_mutex); + + if (retval > 0) { + ssize_t err; + + mark_inode_dirty(inode); + err = generic_write_sync(file, iocb->ki_pos - retval, retval); + if (err < 0) + retval = err; + } + + 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 = -EINVAL; + + if (inode_permission(inode, MAY_READ) != 0) { + udf_debug("no permission to access inode %lu\n", inode->i_ino); + result = -EPERM; + goto out; + } + + if (!arg) { + udf_debug("invalid argument to udf_ioctl\n"); + result = -EINVAL; + goto out; + } + + switch (cmd) { + case UDF_GETVOLIDENT: + if (copy_to_user((char __user *)arg, + UDF_SB(inode->i_sb)->s_volume_ident, 32)) + result = -EFAULT; + else + result = 0; + goto out; + case UDF_RELOCATE_BLOCKS: + if (!capable(CAP_SYS_ADMIN)) { + result = -EPERM; + goto out; + } + if (get_user(old_block, (long __user *)arg)) { + result = -EFAULT; + goto out; + } + result = udf_relocate_blocks(inode->i_sb, + old_block, &new_block); + if (result == 0) + result = put_user(new_block, (long __user *)arg); + goto out; + case UDF_GETEASIZE: + result = put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg); + goto out; + case UDF_GETEABLOCK: + result = copy_to_user((char __user *)arg, + UDF_I(inode)->i_ext.i_data, + UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0; + goto out; + } + +out: + return result; +} + +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. + */ + mutex_lock(&inode->i_mutex); + 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); + mutex_unlock(&inode->i_mutex); + } + 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 = inode_change_ok(inode, 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, +}; 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