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-rw-r--r--fs/attr.c208
1 files changed, 208 insertions, 0 deletions
diff --git a/fs/attr.c b/fs/attr.c
new file mode 100644
index 000000000000..c3c76fe78346
--- /dev/null
+++ b/fs/attr.c
@@ -0,0 +1,208 @@
+/*
+ * 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/smp_lock.h>
+#include <linux/dnotify.h>
+#include <linux/fcntl.h>
+#include <linux/quotaops.h>
+#include <linux/security.h>
+#include <linux/time.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 ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
+ 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)) {
+ if (current->fsuid != inode->i_uid && !capable(CAP_FOWNER))
+ 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;
+ int error = 0;
+
+ if (ia_valid & ATTR_SIZE) {
+ if (attr->ia_size != i_size_read(inode)) {
+ error = vmtruncate(inode, attr->ia_size);
+ if (error || (ia_valid == ATTR_SIZE))
+ goto out;
+ } else {
+ /*
+ * We skipped the truncate but must still update
+ * timestamps
+ */
+ ia_valid |= ATTR_MTIME|ATTR_CTIME;
+ }
+ }
+
+ 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);
+out:
+ return error;
+}
+
+EXPORT_SYMBOL(inode_setattr);
+
+int setattr_mask(unsigned int ia_valid)
+{
+ unsigned long dn_mask = 0;
+
+ if (ia_valid & ATTR_UID)
+ dn_mask |= DN_ATTRIB;
+ if (ia_valid & ATTR_GID)
+ dn_mask |= DN_ATTRIB;
+ if (ia_valid & ATTR_SIZE)
+ dn_mask |= DN_MODIFY;
+ /* both times implies a utime(s) call */
+ if ((ia_valid & (ATTR_ATIME|ATTR_MTIME)) == (ATTR_ATIME|ATTR_MTIME))
+ dn_mask |= DN_ATTRIB;
+ else if (ia_valid & ATTR_ATIME)
+ dn_mask |= DN_ACCESS;
+ else if (ia_valid & ATTR_MTIME)
+ dn_mask |= DN_MODIFY;
+ if (ia_valid & ATTR_MODE)
+ dn_mask |= DN_ATTRIB;
+ return dn_mask;
+}
+
+int notify_change(struct dentry * dentry, struct iattr * attr)
+{
+ struct inode *inode = dentry->d_inode;
+ mode_t mode;
+ int error;
+ struct timespec now;
+ unsigned int ia_valid = attr->ia_valid;
+
+ if (!inode)
+ BUG();
+
+ mode = inode->i_mode;
+ 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_SUID) {
+ attr->ia_valid &= ~ATTR_KILL_SUID;
+ if (mode & S_ISUID) {
+ if (!(ia_valid & ATTR_MODE)) {
+ ia_valid = attr->ia_valid |= ATTR_MODE;
+ attr->ia_mode = inode->i_mode;
+ }
+ attr->ia_mode &= ~S_ISUID;
+ }
+ }
+ if (ia_valid & ATTR_KILL_SGID) {
+ attr->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)
+ return 0;
+
+ if (ia_valid & ATTR_SIZE)
+ down_write(&dentry->d_inode->i_alloc_sem);
+
+ if (inode->i_op && inode->i_op->setattr) {
+ error = security_inode_setattr(dentry, attr);
+ if (!error)
+ error = inode->i_op->setattr(dentry, attr);
+ } else {
+ error = inode_change_ok(inode, attr);
+ if (!error)
+ error = security_inode_setattr(dentry, 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) {
+ unsigned long dn_mask = setattr_mask(ia_valid);
+ if (dn_mask)
+ dnotify_parent(dentry, dn_mask);
+ }
+ return error;
+}
+
+EXPORT_SYMBOL(notify_change);