1 files changed, 308 insertions, 0 deletions
diff --git a/fs/fat/file.c b/fs/fat/file.c
new file mode 100644
index 000000000000..62ffa9139400
--- /dev/null
+++ b/fs/fat/file.c
@@ -0,0 +1,308 @@
+/*
+ *  linux/fs/fat/file.c
+ *
+ *  Written 1992,1993 by Werner Almesberger
+ *
+ *  regular file handling primitives for fat-based filesystems
+ */
+
+#include <linux/module.h>
+#include <linux/time.h>
+#include <linux/msdos_fs.h>
+#include <linux/smp_lock.h>
+#include <linux/buffer_head.h>
+
+static ssize_t fat_file_aio_write(struct kiocb *iocb, const char __user *buf,
+				  size_t count, loff_t pos)
+{
+	struct inode *inode = iocb->ki_filp->f_dentry->d_inode;
+	int retval;
+
+	retval = generic_file_aio_write(iocb, buf, count, pos);
+	if (retval > 0) {
+		inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
+		MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
+		mark_inode_dirty(inode);
+//		check the locking rules
+//		if (IS_SYNC(inode))
+//			fat_sync_inode(inode);
+	}
+	return retval;
+}
+
+static ssize_t fat_file_writev(struct file *filp, const struct iovec *iov,
+			       unsigned long nr_segs, loff_t *ppos)
+{
+	struct inode *inode = filp->f_dentry->d_inode;
+	int retval;
+
+	retval = generic_file_writev(filp, iov, nr_segs, ppos);
+	if (retval > 0) {
+		inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
+		MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
+		mark_inode_dirty(inode);
+	}
+	return retval;
+}
+
+int fat_generic_ioctl(struct inode *inode, struct file *filp,
+		      unsigned int cmd, unsigned long arg)
+{
+	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
+	u32 __user *user_attr = (u32 __user *)arg;
+
+	switch (cmd) {
+	case FAT_IOCTL_GET_ATTRIBUTES:
+	{
+		u32 attr;
+
+		if (inode->i_ino == MSDOS_ROOT_INO)
+			attr = ATTR_DIR;
+		else
+			attr = fat_attr(inode);
+
+		return put_user(attr, user_attr);
+	}
+	case FAT_IOCTL_SET_ATTRIBUTES:
+	{
+		u32 attr, oldattr;
+		int err, is_dir = S_ISDIR(inode->i_mode);
+		struct iattr ia;
+
+		err = get_user(attr, user_attr);
+		if (err)
+			return err;
+
+		down(&inode->i_sem);
+
+		if (IS_RDONLY(inode)) {
+			err = -EROFS;
+			goto up;
+		}
+
+		/*
+		 * ATTR_VOLUME and ATTR_DIR cannot be changed; this also
+		 * prevents the user from turning us into a VFAT
+		 * longname entry.  Also, we obviously can't set
+		 * any of the NTFS attributes in the high 24 bits.
+		 */
+		attr &= 0xff & ~(ATTR_VOLUME | ATTR_DIR);
+		/* Merge in ATTR_VOLUME and ATTR_DIR */
+		attr |= (MSDOS_I(inode)->i_attrs & ATTR_VOLUME) |
+			(is_dir ? ATTR_DIR : 0);
+		oldattr = fat_attr(inode);
+
+		/* Equivalent to a chmod() */
+		ia.ia_valid = ATTR_MODE | ATTR_CTIME;
+		if (is_dir) {
+			ia.ia_mode = MSDOS_MKMODE(attr,
+				S_IRWXUGO & ~sbi->options.fs_dmask)
+				| S_IFDIR;
+		} else {
+			ia.ia_mode = MSDOS_MKMODE(attr,
+				(S_IRUGO | S_IWUGO | (inode->i_mode & S_IXUGO))
+				& ~sbi->options.fs_fmask)
+				| S_IFREG;
+		}
+
+		/* The root directory has no attributes */
+		if (inode->i_ino == MSDOS_ROOT_INO && attr != ATTR_DIR) {
+			err = -EINVAL;
+			goto up;
+		}
+
+		if (sbi->options.sys_immutable) {
+			if ((attr | oldattr) & ATTR_SYS) {
+				if (!capable(CAP_LINUX_IMMUTABLE)) {
+					err = -EPERM;
+					goto up;
+				}
+			}
+		}
+
+		/* This MUST be done before doing anything irreversible... */
+		err = notify_change(filp->f_dentry, &ia);
+		if (err)
+			goto up;
+
+		if (sbi->options.sys_immutable) {
+			if (attr & ATTR_SYS)
+				inode->i_flags |= S_IMMUTABLE;
+			else
+				inode->i_flags &= S_IMMUTABLE;
+		}
+
+		MSDOS_I(inode)->i_attrs = attr & ATTR_UNUSED;
+		mark_inode_dirty(inode);
+	up:
+		up(&inode->i_sem);
+		return err;
+	}
+	default:
+		return -ENOTTY;	/* Inappropriate ioctl for device */
+	}
+}
+
+struct file_operations fat_file_operations = {
+	.llseek		= generic_file_llseek,
+	.read		= do_sync_read,
+	.write		= do_sync_write,
+	.readv		= generic_file_readv,
+	.writev		= fat_file_writev,
+	.aio_read	= generic_file_aio_read,
+	.aio_write	= fat_file_aio_write,
+	.mmap		= generic_file_mmap,
+	.ioctl		= fat_generic_ioctl,
+	.fsync		= file_fsync,
+	.sendfile	= generic_file_sendfile,
+};
+
+int fat_notify_change(struct dentry *dentry, struct iattr *attr)
+{
+	struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb);
+	struct inode *inode = dentry->d_inode;
+	int mask, error = 0;
+
+	lock_kernel();
+
+	/* FAT cannot truncate to a longer file */
+	if (attr->ia_valid & ATTR_SIZE) {
+		if (attr->ia_size > inode->i_size) {
+			error = -EPERM;
+			goto out;
+		}
+	}
+
+	error = inode_change_ok(inode, attr);
+	if (error) {
+		if (sbi->options.quiet)
+			error = 0;
+		goto out;
+	}
+	if (((attr->ia_valid & ATTR_UID) &&
+	     (attr->ia_uid != sbi->options.fs_uid)) ||
+	    ((attr->ia_valid & ATTR_GID) &&
+	     (attr->ia_gid != sbi->options.fs_gid)) ||
+	    ((attr->ia_valid & ATTR_MODE) &&
+	     (attr->ia_mode & ~MSDOS_VALID_MODE)))
+		error = -EPERM;
+
+	if (error) {
+		if (sbi->options.quiet)
+			error = 0;
+		goto out;
+	}
+	error = inode_setattr(inode, attr);
+	if (error)
+		goto out;
+
+	if (S_ISDIR(inode->i_mode))
+		mask = sbi->options.fs_dmask;
+	else
+		mask = sbi->options.fs_fmask;
+	inode->i_mode &= S_IFMT | (S_IRWXUGO & ~mask);
+out:
+	unlock_kernel();
+	return error;
+}
+
+EXPORT_SYMBOL(fat_notify_change);
+
+/* Free all clusters after the skip'th cluster. */
+static int fat_free(struct inode *inode, int skip)
+{
+	struct super_block *sb = inode->i_sb;
+	int err, wait, free_start, i_start, i_logstart;
+
+	if (MSDOS_I(inode)->i_start == 0)
+		return 0;
+
+	/*
+	 * Write a new EOF, and get the remaining cluster chain for freeing.
+	 */
+	wait = IS_DIRSYNC(inode);
+	if (skip) {
+		struct fat_entry fatent;
+		int ret, fclus, dclus;
+
+		ret = fat_get_cluster(inode, skip - 1, &fclus, &dclus);
+		if (ret < 0)
+			return ret;
+		else if (ret == FAT_ENT_EOF)
+			return 0;
+
+		fatent_init(&fatent);
+		ret = fat_ent_read(inode, &fatent, dclus);
+		if (ret == FAT_ENT_EOF) {
+			fatent_brelse(&fatent);
+			return 0;
+		} else if (ret == FAT_ENT_FREE) {
+			fat_fs_panic(sb,
+				     "%s: invalid cluster chain (i_pos %lld)",
+				     __FUNCTION__, MSDOS_I(inode)->i_pos);
+			ret = -EIO;
+		} else if (ret > 0) {
+			err = fat_ent_write(inode, &fatent, FAT_ENT_EOF, wait);
+			if (err)
+				ret = err;
+		}
+		fatent_brelse(&fatent);
+		if (ret < 0)
+			return ret;
+
+		free_start = ret;
+		i_start = i_logstart = 0;
+		fat_cache_inval_inode(inode);
+	} else {
+		fat_cache_inval_inode(inode);
+
+		i_start = free_start = MSDOS_I(inode)->i_start;
+		i_logstart = MSDOS_I(inode)->i_logstart;
+		MSDOS_I(inode)->i_start = 0;
+		MSDOS_I(inode)->i_logstart = 0;
+	}
+	MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
+	inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
+	if (wait) {
+		err = fat_sync_inode(inode);
+		if (err)
+			goto error;
+	} else
+		mark_inode_dirty(inode);
+	inode->i_blocks = skip << (MSDOS_SB(sb)->cluster_bits - 9);
+
+	/* Freeing the remained cluster chain */
+	return fat_free_clusters(inode, free_start);
+
+error:
+	if (i_start) {
+		MSDOS_I(inode)->i_start = i_start;
+		MSDOS_I(inode)->i_logstart = i_logstart;
+	}
+	return err;
+}
+
+void fat_truncate(struct inode *inode)
+{
+	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
+	const unsigned int cluster_size = sbi->cluster_size;
+	int nr_clusters;
+
+	/*
+	 * This protects against truncating a file bigger than it was then
+	 * trying to write into the hole.
+	 */
+	if (MSDOS_I(inode)->mmu_private > inode->i_size)
+		MSDOS_I(inode)->mmu_private = inode->i_size;
+
+	nr_clusters = (inode->i_size + (cluster_size - 1)) >> sbi->cluster_bits;
+
+	lock_kernel();
+	fat_free(inode, nr_clusters);
+	unlock_kernel();
+}
+
+struct inode_operations fat_file_inode_operations = {
+	.truncate	= fat_truncate,
+	.setattr	= fat_notify_change,
+};