Initial import of modified Linux 2.6.28 tree

Original upstream URL:
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git | branch linux-2.6.28.y

1 files changed, 191 insertions, 0 deletions

diff --git a/fs/attr.c b/fs/attr.c
new file mode 100644
index 0000000..7a83819
--- /dev/null
+++ b/fs/attr.c
@@ -0,0 +1,191 @@
+/*
+ *  linux/fs/attr.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *  changes by Thomas Schoebel-Theuer
+ */
+
+#include <linux/module.h>
+#include <linux/time.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/capability.h>
+#include <linux/fsnotify.h>
+#include <linux/fcntl.h>
+#include <linux/quotaops.h>
+#include <linux/security.h>
+
+/* Taken over from the old code... */
+
+/* POSIX UID/GID verification for setting inode attributes. */
+int inode_change_ok(struct inode *inode, struct iattr *attr)
+{
+	int retval = -EPERM;
+	unsigned int ia_valid = attr->ia_valid;
+
+	/* If force is set do it anyway. */
+	if (ia_valid & ATTR_FORCE)
+		goto fine;
+
+	/* Make sure a caller can chown. */
+	if ((ia_valid & ATTR_UID) &&
+	    (current->fsuid != inode->i_uid ||
+	     attr->ia_uid != inode->i_uid) && !capable(CAP_CHOWN))
+		goto error;
+
+	/* Make sure caller can chgrp. */
+	if ((ia_valid & ATTR_GID) &&
+	    (current->fsuid != inode->i_uid ||
+	    (!in_group_p(attr->ia_gid) && attr->ia_gid != inode->i_gid)) &&
+	    !capable(CAP_CHOWN))
+		goto error;
+
+	/* Make sure a caller can chmod. */
+	if (ia_valid & ATTR_MODE) {
+		if (!is_owner_or_cap(inode))
+			goto error;
+		/* Also check the setgid bit! */
+		if (!in_group_p((ia_valid & ATTR_GID) ? attr->ia_gid :
+				inode->i_gid) && !capable(CAP_FSETID))
+			attr->ia_mode &= ~S_ISGID;
+	}
+
+	/* Check for setting the inode time. */
+	if (ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)) {
+		if (!is_owner_or_cap(inode))
+			goto error;
+	}
+fine:
+	retval = 0;
+error:
+	return retval;
+}
+
+EXPORT_SYMBOL(inode_change_ok);
+
+int inode_setattr(struct inode * inode, struct iattr * attr)
+{
+	unsigned int ia_valid = attr->ia_valid;
+
+	if (ia_valid & ATTR_SIZE &&
+	    attr->ia_size != i_size_read(inode)) {
+		int error = vmtruncate(inode, attr->ia_size);
+		if (error)
+			return error;
+	}
+
+	if (ia_valid & ATTR_UID)
+		inode->i_uid = attr->ia_uid;
+	if (ia_valid & ATTR_GID)
+		inode->i_gid = attr->ia_gid;
+	if (ia_valid & ATTR_ATIME)
+		inode->i_atime = timespec_trunc(attr->ia_atime,
+						inode->i_sb->s_time_gran);
+	if (ia_valid & ATTR_MTIME)
+		inode->i_mtime = timespec_trunc(attr->ia_mtime,
+						inode->i_sb->s_time_gran);
+	if (ia_valid & ATTR_CTIME)
+		inode->i_ctime = timespec_trunc(attr->ia_ctime,
+						inode->i_sb->s_time_gran);
+	if (ia_valid & ATTR_MODE) {
+		umode_t mode = attr->ia_mode;
+
+		if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
+			mode &= ~S_ISGID;
+		inode->i_mode = mode;
+	}
+	mark_inode_dirty(inode);
+
+	return 0;
+}
+EXPORT_SYMBOL(inode_setattr);
+
+int notify_change(struct dentry * dentry, struct iattr * attr)
+{
+	struct inode *inode = dentry->d_inode;
+	mode_t mode = inode->i_mode;
+	int error;
+	struct timespec now;
+	unsigned int ia_valid = attr->ia_valid;
+
+	if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID | ATTR_TIMES_SET)) {
+		if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
+			return -EPERM;
+	}
+
+	now = current_fs_time(inode->i_sb);
+
+	attr->ia_ctime = now;
+	if (!(ia_valid & ATTR_ATIME_SET))
+		attr->ia_atime = now;
+	if (!(ia_valid & ATTR_MTIME_SET))
+		attr->ia_mtime = now;
+	if (ia_valid & ATTR_KILL_PRIV) {
+		attr->ia_valid &= ~ATTR_KILL_PRIV;
+		ia_valid &= ~ATTR_KILL_PRIV;
+		error = security_inode_need_killpriv(dentry);
+		if (error > 0)
+			error = security_inode_killpriv(dentry);
+		if (error)
+			return error;
+	}
+
+	/*
+	 * We now pass ATTR_KILL_S*ID to the lower level setattr function so
+	 * that the function has the ability to reinterpret a mode change
+	 * that's due to these bits. This adds an implicit restriction that
+	 * no function will ever call notify_change with both ATTR_MODE and
+	 * ATTR_KILL_S*ID set.
+	 */
+	if ((ia_valid & (ATTR_KILL_SUID|ATTR_KILL_SGID)) &&
+	    (ia_valid & ATTR_MODE))
+		BUG();
+
+	if (ia_valid & ATTR_KILL_SUID) {
+		if (mode & S_ISUID) {
+			ia_valid = attr->ia_valid |= ATTR_MODE;
+			attr->ia_mode = (inode->i_mode & ~S_ISUID);
+		}
+	}
+	if (ia_valid & ATTR_KILL_SGID) {
+		if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) {
+			if (!(ia_valid & ATTR_MODE)) {
+				ia_valid = attr->ia_valid |= ATTR_MODE;
+				attr->ia_mode = inode->i_mode;
+			}
+			attr->ia_mode &= ~S_ISGID;
+		}
+	}
+	if (!(attr->ia_valid & ~(ATTR_KILL_SUID | ATTR_KILL_SGID)))
+		return 0;
+
+	error = security_inode_setattr(dentry, attr);
+	if (error)
+		return error;
+
+	if (ia_valid & ATTR_SIZE)
+		down_write(&dentry->d_inode->i_alloc_sem);
+
+	if (inode->i_op && inode->i_op->setattr) {
+		error = inode->i_op->setattr(dentry, attr);
+	} else {
+		error = inode_change_ok(inode, attr);
+		if (!error) {
+			if ((ia_valid & ATTR_UID && attr->ia_uid != inode->i_uid) ||
+			    (ia_valid & ATTR_GID && attr->ia_gid != inode->i_gid))
+				error = DQUOT_TRANSFER(inode, attr) ? -EDQUOT : 0;
+			if (!error)
+				error = inode_setattr(inode, attr);
+		}
+	}
+
+	if (ia_valid & ATTR_SIZE)
+		up_write(&dentry->d_inode->i_alloc_sem);
+
+	if (!error)
+		fsnotify_change(dentry, ia_valid);
+
+	return error;
+}
+
+EXPORT_SYMBOL(notify_change);