patch-2.3.17 linux/fs/udf/file.c

• Lines: 444
• Date: Sat Sep 4 12:42:30 1999
• Orig file: v2.3.16/linux/fs/udf/file.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.16/linux/fs/udf/file.c linux/fs/udf/file.c
@@ -0,0 +1,443 @@
+/*
+ * file.c
+ *
+ * PURPOSE
+ *  File handling routines for the OSTA-UDF(tm) filesystem.
+ *
+ * CONTACTS
+ *  E-mail regarding any portion of the Linux UDF file system should be
+ *  directed to the development team mailing list (run by majordomo):
+ *    linux_udf@hootie.lvld.hp.com
+ *
+ * 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) 1998-1999 Ben Fennema
+ *  (C) 1999 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
+ *                ICB_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/udf_fs.h>
+#include <asm/uaccess.h>
+#include <linux/kernel.h>
+#include <linux/string.h> /* memset */
+#include <linux/errno.h>
+#include <linux/locks.h>
+
+#include "udf_i.h"
+#include "udf_sb.h"
+
+#define NBUF	32
+
+typedef void * poll_table; 
+
+static long long udf_file_llseek(struct file *, long long, int);
+static ssize_t udf_file_read_adinicb (struct file *, char *, size_t, loff_t *);
+static ssize_t udf_file_write (struct file *, const char *, size_t, loff_t *);
+#if BITS_PER_LONG < 64
+static int udf_open_file(struct inode *, struct file *);
+#endif
+static int udf_release_file(struct inode *, struct file *);
+
+static struct file_operations udf_file_operations = {
+	udf_file_llseek,	/* llseek */
+	generic_file_read,	/* read */
+	udf_file_write,		/* write */
+	NULL,				/* readdir */
+	NULL,				/* poll */
+	udf_ioctl,			/* ioctl */
+	generic_file_mmap,	/* mmap */
+#if BITS_PER_LONG == 64
+	NULL, 				/* open */
+#else
+	udf_open_file,		/* open */
+#endif
+	NULL,				/* flush */
+	udf_release_file,	/* release */
+	udf_sync_file,		/* fsync */
+	NULL,				/* fasync */
+	NULL,				/* check_media_change */
+	NULL,				/* revalidate */
+	NULL				/* lock */
+};
+
+struct inode_operations udf_file_inode_operations = {
+	&udf_file_operations,
+	NULL,					/* create */
+	NULL,					/* lookup */
+	NULL,					/* link */
+	NULL,					/* unlink */
+	NULL,					/* symlink */
+	NULL,					/* mkdir */
+	NULL,					/* rmdir */
+	NULL,					/* mknod */
+	NULL,					/* rename */
+	NULL,					/* readlink */
+	NULL,					/* follow_link */
+	udf_get_block,			/* get_block */
+	block_read_full_page,	/* readpage */
+	block_write_full_page,	/* writepage */
+	block_flushpage,		/* flushpage */
+#ifdef CONFIG_UDF_RW
+	udf_truncate,			/* truncate */
+#else
+	NULL,					/* truncate */
+#endif
+	NULL,					/* permission */
+	NULL,					/* smap */
+	NULL					/* revalidate */
+};
+
+static struct file_operations udf_file_operations_adinicb = {
+	udf_file_llseek,	/* llseek */
+	udf_file_read_adinicb,/* read */
+	udf_file_write,		/* write */
+	NULL,				/* readdir */
+	NULL,				/* poll */
+	udf_ioctl,			/* ioctl */
+	NULL,				/* mmap */
+	NULL, 				/* open */
+	NULL,				/* flush */
+	udf_release_file,	/* release */
+	udf_sync_file,		/* fsync */
+	NULL,				/* fasync */
+	NULL,				/* check_media_change */
+	NULL,				/* revalidate */
+	NULL				/* lock */
+};
+
+struct inode_operations udf_file_inode_operations_adinicb = {
+	&udf_file_operations_adinicb,
+	NULL,					/* create */
+	NULL,					/* lookup */
+	NULL,					/* link */
+	NULL,					/* unlink */
+	NULL,					/* symlink */
+	NULL,					/* mkdir */
+	NULL,					/* rmdir */
+	NULL,					/* mknod */
+	NULL,					/* rename */
+	NULL,					/* readlink */
+	NULL,					/* follow_link */
+	udf_get_block,			/* get_block */
+	block_read_full_page,	/* readpage */
+	block_write_full_page,	/* writepage */
+	block_flushpage,		/* flushpage */
+#ifdef CONFIG_UDF_RW
+	udf_truncate,			/* truncate */
+#else
+	NULL,					/* truncate */
+#endif
+	NULL,					/* permission */
+	NULL,					/* smap */
+	NULL					/* revalidate */
+};
+
+/*
+ * Make sure the offset never goes beyond the 32-bit mark..
+ */
+static long long udf_file_llseek(struct file * file, long long offset, int origin)
+{
+	struct inode * inode = file->f_dentry->d_inode;
+
+	switch (origin)
+	{
+		case 2:
+		{
+			offset += inode->i_size;
+			break;
+		}
+		case 1:
+		{
+			offset += file->f_pos;
+			break;
+		}
+	}
+	if (((unsigned long long) offset >> 32) != 0)
+	{
+#if BITS_PER_LONG < 64
+		return -EINVAL;
+#else
+		if (offset > ???)
+			return -EINVAL;
+#endif
+	}
+	if (offset != file->f_pos)
+	{
+		file->f_pos = offset;
+		file->f_reada = 0;
+		file->f_version = ++event;
+	}
+	return offset;
+}
+
+static inline void remove_suid(struct inode * inode)
+{
+	unsigned int mode;
+
+	/* set S_IGID if S_IXGRP is set, and always set S_ISUID */
+	mode = (inode->i_mode & S_IXGRP)*(S_ISGID/S_IXGRP) | S_ISUID;
+
+	/* was any of the uid bits set? */
+	mode &= inode->i_mode;
+	if (mode && !capable(CAP_FSETID))
+	{
+		inode->i_mode &= ~mode;
+		mark_inode_dirty(inode);
+	}
+}
+
+static ssize_t udf_file_write(struct file * file, const char * buf,
+	size_t count, loff_t *ppos)
+{
+	ssize_t retval;
+	struct inode *inode = file->f_dentry->d_inode;
+	remove_suid(inode);
+
+	if (UDF_I_ALLOCTYPE(inode) == ICB_FLAG_AD_IN_ICB)
+	{
+		int i, err;
+		struct buffer_head *bh;
+
+		if ((bh = udf_expand_adinicb(inode, &i, 0, &err)))
+			udf_release_data(bh);
+	}
+
+	retval = generic_file_write(file, buf, count, ppos, block_write_partial_page);
+
+	if (retval > 0)
+	{
+		inode->i_ctime = inode->i_mtime = CURRENT_TIME;
+		UDF_I_UCTIME(inode) = UDF_I_UMTIME(inode) = CURRENT_UTIME;
+	}
+	mark_inode_dirty(inode);
+	return retval;
+}
+
+/*
+ * udf_file_read
+ *
+ * PURPOSE
+ *	Read from an open file.
+ *
+ * DESCRIPTION
+ *	Optional - sys_read() will return -EINVAL if this routine is not
+ *	available.
+ *
+ *	Refer to sys_read() in fs/read_write.c
+ *	sys_read() -> .
+ *
+ *	Note that you can use generic_file_read() instead, which requires that
+ *	udf_readpage() be available, but you can use generic_readpage(), which
+ *	requires that udf_block_map() be available. Reading will then be done by
+ *	memory-mapping the file a page at a time. This is not suitable for
+ *	devices that don't handle read-ahead [example: CD-R/RW that may have
+ *	blank sectors that shouldn't be read].
+ *
+ *	Refer to generic_file_read() in mm/filemap.c and to generic_readpage()
+ *	in fs/buffer.c
+ *
+ *	Block devices can use block_read() instead. Refer to fs/block_dev.c
+ *
+ * PRE-CONDITIONS
+ *	inode			Pointer to inode to read from (never NULL).
+ *	filp			Pointer to file to read from (never NULL).
+ *	buf			Point to read buffer (validated).
+ *	bufsize			Size of read buffer.
+ *
+ * POST-CONDITIONS
+ *	<return>		Bytes read (>=0) or an error code (<0) that
+ *				sys_read() will return.
+ *
+ * HISTORY
+ *	July 1, 1997 - Andrew E. Mileski
+ *	Written, tested, and released.
+ */
+static ssize_t udf_file_read_adinicb(struct file * filp, char * buf,
+	size_t bufsize, loff_t * loff)
+{
+	struct inode *inode = filp->f_dentry->d_inode;
+	Uint32 size, left, pos, block;
+	struct buffer_head *bh = NULL;
+
+	size = inode->i_size;
+	if (*loff > size)
+		left = 0;
+	else
+		left = size - *loff;
+	if (left > bufsize)
+		left = bufsize;
+
+	if (left <= 0)
+		return 0;
+
+	pos = *loff + UDF_I_EXT0OFFS(inode);
+	block = udf_block_map(inode, 0);
+	if (!(bh = udf_tread(inode->i_sb,
+		udf_get_lb_pblock(inode->i_sb, UDF_I_LOCATION(inode), 0),
+		inode->i_sb->s_blocksize)))
+	{
+		return 0;
+	}
+	if (!copy_to_user(buf, bh->b_data + pos, left))
+		*loff += left;
+	else
+		return -EFAULT;
+
+	return left;
+}
+
+/*
+ * udf_ioctl
+ *
+ * PURPOSE
+ *	Issue an ioctl.
+ *
+ * DESCRIPTION
+ *	Optional - sys_ioctl() will return -ENOTTY if this routine is not
+ *	available, and the ioctl cannot be handled without filesystem help.
+ *
+ *	sys_ioctl() handles these ioctls that apply only to regular files:
+ *		FIBMAP [requires udf_block_map()], FIGETBSZ, FIONREAD
+ *	These ioctls are also handled by sys_ioctl():
+ *		FIOCLEX, FIONCLEX, FIONBIO, FIOASYNC
+ *	All other ioctls are passed to the filesystem.
+ *
+ *	Refer to sys_ioctl() in fs/ioctl.c
+ *	sys_ioctl() -> .
+ *
+ * PRE-CONDITIONS
+ *	inode			Pointer to inode that ioctl was issued on.
+ *	filp			Pointer to file that ioctl was issued on.
+ *	cmd			The ioctl command.
+ *	arg			The ioctl argument [can be interpreted as a
+ *				user-space pointer if desired].
+ *
+ * POST-CONDITIONS
+ *	<return>		Success (>=0) or an error code (<=0) that
+ *				sys_ioctl() will return.
+ *
+ * HISTORY
+ *	July 1, 1997 - Andrew E. Mileski
+ *	Written, tested, and released.
+ */
+int udf_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
+	unsigned long arg)
+{
+	int result=-1;
+	int size;
+	struct buffer_head *bh = NULL;
+	struct FileEntry *fe;
+	Uint16 ident;
+
+	if ( permission(inode, MAY_READ) != 0 )
+	{
+		udf_debug("no permission to access inode %lu\n",
+						inode->i_ino);
+		return -EPERM;
+	}
+
+	if ( !arg )
+	{
+		udf_debug("invalid argument to udf_ioctl\n");
+		return -EINVAL;
+	}
+
+	/* first, do ioctls that don't need to udf_read */
+	switch (cmd)
+	{
+		case UDF_GETVOLIDENT:
+			if ( (result == verify_area(VERIFY_WRITE, (char *)arg, 32)) == 0)
+				result = copy_to_user((char *)arg, UDF_SB_VOLIDENT(inode->i_sb), 32);
+			return result;
+
+	}
+
+	/* ok, we need to read the inode */
+	bh = udf_read_ptagged(inode->i_sb, UDF_I_LOCATION(inode), 0, &ident);
+
+	if (!bh || ident != TID_FILE_ENTRY)
+	{
+		udf_debug("bread failed (ino=%ld) or ident (%d) != TID_FILE_ENTRY",
+			inode->i_ino, ident);
+		return -EFAULT;
+	}
+
+	fe = (struct FileEntry *)bh->b_data;
+	size = le32_to_cpu(fe->lengthExtendedAttr);
+
+	switch (cmd) 
+	{
+		case UDF_GETEASIZE:
+			if ( (result = verify_area(VERIFY_WRITE, (char *)arg, 4)) == 0) 
+				result= put_user(size, (int *)arg);
+			break;
+
+		case UDF_GETEABLOCK:
+			if ( (result = verify_area(VERIFY_WRITE, (char *)arg, size)) == 0) 
+				result= copy_to_user((char *)arg, fe->extendedAttr, size);
+			break;
+
+		default:
+			udf_debug("ino=%ld, cmd=%d\n", inode->i_ino, cmd);
+			break;
+	}
+
+	udf_release_data(bh);
+	return result;
+}
+
+/*
+ * udf_release_file
+ *
+ * PURPOSE
+ *  Called when all references to the file are closed
+ *
+ * DESCRIPTION
+ *  Discard prealloced blocks
+ *
+ * HISTORY
+ *
+ */
+static int udf_release_file(struct inode * inode, struct file * filp)
+{
+	if (filp->f_mode & FMODE_WRITE)
+		udf_discard_prealloc(inode);
+	return 0;
+}
+
+#if BITS_PER_LONG < 64
+/*
+ * udf_open_file
+ *
+ * PURPOSE
+ *  Called when an inode is about to be open.
+ *
+ * DESCRIPTION
+ *  Use this to disallow opening RW large files on 32 bit systems.
+ *
+ * HISTORY
+ *
+ */
+static int udf_open_file(struct inode * inode, struct file * filp)
+{
+	if (inode->i_size == (Uint32)-1 && (filp->f_mode & FMODE_WRITE))
+		return -EFBIG;
+	return 0;
+}
+#endif