*/
inode->i_flags |= (S_NOCMTIME);
- inode->i_uid = current->fsuid;
- if (dir->i_mode & S_ISGID) {
- inode->i_gid = dir->i_gid;
- if (S_ISDIR(mode))
- mode |= S_ISGID;
- } else
- inode->i_gid = current->fsgid;
- inode->i_mode = mode;
+ inode_init_owner(inode, dir, mode);
inode->i_mtime = inode->i_atime = inode->i_ctime =
ubifs_current_time(inode);
inode->i_mapping->nrpages = 0;
return ERR_PTR(-EINVAL);
}
ubifs_warn("running out of inode numbers (current %lu, max %d)",
- c->highest_inum, INUM_WATERMARK);
+ (unsigned long)c->highest_inum, INUM_WATERMARK);
}
inode->i_ino = ++c->highest_inum;
}
/**
- * lock_2_inodes - lock two UBIFS inodes.
+ * lock_2_inodes - a wrapper for locking two UBIFS inodes.
* @inode1: first inode
* @inode2: second inode
+ *
+ * We do not implement any tricks to guarantee strict lock ordering, because
+ * VFS has already done it for us on the @i_mutex. So this is just a simple
+ * wrapper function.
*/
static void lock_2_inodes(struct inode *inode1, struct inode *inode2)
{
- if (inode1->i_ino < inode2->i_ino) {
- mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_2);
- mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_3);
- } else {
- mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2);
- mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_3);
- }
+ mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1);
+ mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2);
}
/**
- * unlock_2_inodes - unlock two UBIFS inodes inodes.
+ * unlock_2_inodes - a wrapper for unlocking two UBIFS inodes.
* @inode1: first inode
* @inode2: second inode
*/
static void unlock_2_inodes(struct inode *inode1, struct inode *inode2)
{
- mutex_unlock(&ubifs_inode(inode1)->ui_mutex);
mutex_unlock(&ubifs_inode(inode2)->ui_mutex);
+ mutex_unlock(&ubifs_inode(inode1)->ui_mutex);
}
static int ubifs_link(struct dentry *old_dentry, struct inode *dir,
dbg_gen("dent '%.*s' to ino %lu (nlink %d) in dir ino %lu",
dentry->d_name.len, dentry->d_name.name, inode->i_ino,
inode->i_nlink, dir->i_ino);
+ ubifs_assert(mutex_is_locked(&dir->i_mutex));
+ ubifs_assert(mutex_is_locked(&inode->i_mutex));
+
+ /*
+ * Return -ENOENT if we've raced with unlink and i_nlink is 0. Doing
+ * otherwise has the potential to corrupt the orphan inode list.
+ *
+ * Indeed, consider a scenario when 'vfs_link(dirA/fileA)' and
+ * 'vfs_unlink(dirA/fileA, dirB/fileB)' race. 'vfs_link()' does not
+ * lock 'dirA->i_mutex', so this is possible. Both of the functions
+ * lock 'fileA->i_mutex' though. Suppose 'vfs_unlink()' wins, and takes
+ * 'fileA->i_mutex' mutex first. Suppose 'fileA->i_nlink' is 1. In this
+ * case 'ubifs_unlink()' will drop the last reference, and put 'inodeA'
+ * to the list of orphans. After this, 'vfs_link()' will link
+ * 'dirB/fileB' to 'inodeA'. This is a problem because, for example,
+ * the subsequent 'vfs_unlink(dirB/fileB)' will add the same inode
+ * to the list of orphans.
+ */
+ if (inode->i_nlink == 0)
+ return -ENOENT;
+
err = dbg_check_synced_i_size(inode);
if (err)
return err;
dbg_gen("dent '%.*s' from ino %lu (nlink %d) in dir ino %lu",
dentry->d_name.len, dentry->d_name.name, inode->i_ino,
inode->i_nlink, dir->i_ino);
+ ubifs_assert(mutex_is_locked(&dir->i_mutex));
+ ubifs_assert(mutex_is_locked(&inode->i_mutex));
err = dbg_check_synced_i_size(inode);
if (err)
return err;
dbg_gen("directory '%.*s', ino %lu in dir ino %lu", dentry->d_name.len,
dentry->d_name.name, inode->i_ino, dir->i_ino);
-
+ ubifs_assert(mutex_is_locked(&dir->i_mutex));
+ ubifs_assert(mutex_is_locked(&inode->i_mutex));
err = check_dir_empty(c, dentry->d_inode);
if (err)
return err;
}
/**
- * lock_3_inodes - lock three UBIFS inodes for rename.
+ * lock_3_inodes - a wrapper for locking three UBIFS inodes.
* @inode1: first inode
* @inode2: second inode
* @inode3: third inode
*
- * For 'ubifs_rename()', @inode1 may be the same as @inode2 whereas @inode3 may
- * be null.
+ * This function is used for 'ubifs_rename()' and @inode1 may be the same as
+ * @inode2 whereas @inode3 may be %NULL.
+ *
+ * We do not implement any tricks to guarantee strict lock ordering, because
+ * VFS has already done it for us on the @i_mutex. So this is just a simple
+ * wrapper function.
*/
static void lock_3_inodes(struct inode *inode1, struct inode *inode2,
struct inode *inode3)
{
- struct inode *i1, *i2, *i3;
-
- if (!inode3) {
- if (inode1 != inode2) {
- lock_2_inodes(inode1, inode2);
- return;
- }
- mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1);
- return;
- }
-
- if (inode1 == inode2) {
- lock_2_inodes(inode1, inode3);
- return;
- }
-
- /* 3 different inodes */
- if (inode1 < inode2) {
- i3 = inode2;
- if (inode1 < inode3) {
- i1 = inode1;
- i2 = inode3;
- } else {
- i1 = inode3;
- i2 = inode1;
- }
- } else {
- i3 = inode1;
- if (inode2 < inode3) {
- i1 = inode2;
- i2 = inode3;
- } else {
- i1 = inode3;
- i2 = inode2;
- }
- }
- mutex_lock_nested(&ubifs_inode(i1)->ui_mutex, WB_MUTEX_1);
- lock_2_inodes(i2, i3);
+ mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1);
+ if (inode2 != inode1)
+ mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2);
+ if (inode3)
+ mutex_lock_nested(&ubifs_inode(inode3)->ui_mutex, WB_MUTEX_3);
}
/**
- * unlock_3_inodes - unlock three UBIFS inodes for rename.
+ * unlock_3_inodes - a wrapper for unlocking three UBIFS inodes for rename.
* @inode1: first inode
* @inode2: second inode
* @inode3: third inode
static void unlock_3_inodes(struct inode *inode1, struct inode *inode2,
struct inode *inode3)
{
- mutex_unlock(&ubifs_inode(inode1)->ui_mutex);
- if (inode1 != inode2)
- mutex_unlock(&ubifs_inode(inode2)->ui_mutex);
if (inode3)
mutex_unlock(&ubifs_inode(inode3)->ui_mutex);
+ if (inode1 != inode2)
+ mutex_unlock(&ubifs_inode(inode2)->ui_mutex);
+ mutex_unlock(&ubifs_inode(inode1)->ui_mutex);
}
static int ubifs_rename(struct inode *old_dir, struct dentry *old_dentry,
"dir ino %lu", old_dentry->d_name.len, old_dentry->d_name.name,
old_inode->i_ino, old_dir->i_ino, new_dentry->d_name.len,
new_dentry->d_name.name, new_dir->i_ino);
+ ubifs_assert(mutex_is_locked(&old_dir->i_mutex));
+ ubifs_assert(mutex_is_locked(&new_dir->i_mutex));
+ if (unlink)
+ ubifs_assert(mutex_is_locked(&new_inode->i_mutex));
+
if (unlink && is_dir) {
err = check_dir_empty(c, new_inode);
if (release)
ubifs_release_budget(c, &ino_req);
if (IS_SYNC(old_inode))
- err = old_inode->i_sb->s_op->write_inode(old_inode, 1);
+ err = old_inode->i_sb->s_op->write_inode(old_inode, NULL);
return err;
out_cancel:
return 0;
}
-struct inode_operations ubifs_dir_inode_operations = {
+const struct inode_operations ubifs_dir_inode_operations = {
.lookup = ubifs_lookup,
.create = ubifs_create,
.link = ubifs_link,
#endif
};
-struct file_operations ubifs_dir_operations = {
+const struct file_operations ubifs_dir_operations = {
.llseek = ubifs_dir_llseek,
.release = ubifs_dir_release,
.read = generic_read_dir,
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff