Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 updates from Ted Ts'o:
 "Added new ext4 debugging ioctls to allow userspace to get information
  about the state of the extent status cache.

  Dropped workaround for pre-1970 dates which were encoded incorrectly
  in pre-4.4 kernels. Since both the kernel correctly generates, and
  e2fsck detects and fixes this issue for the past four years, it'e time
  to drop the workaround. (Also, it's not like files with dates in the
  distant past were all that common in the first place.)

  A lot of miscellaneous bug fixes and cleanups, including some ext4
  Documentation fixes. Also included are two minor bug fixes in
  fs/unicode"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (21 commits)
  unicode: make array 'token' static const, makes object smaller
  unicode: Move static keyword to the front of declarations
  ext4: add missing bigalloc documentation.
  ext4: fix kernel oops caused by spurious casefold flag
  ext4: fix integer overflow when calculating commit interval
  ext4: use percpu_counters for extent_status cache hits/misses
  ext4: fix potential use after free after remounting with noblock_validity
  jbd2: add missing tracepoint for reserved handle
  ext4: fix punch hole for inline_data file systems
  ext4: rework reserved cluster accounting when invalidating pages
  ext4: documentation fixes
  ext4: treat buffers with write errors as containing valid data
  ext4: fix warning inside ext4_convert_unwritten_extents_endio
  ext4: set error return correctly when ext4_htree_store_dirent fails
  ext4: drop legacy pre-1970 encoding workaround
  ext4: add new ioctl EXT4_IOC_GET_ES_CACHE
  ext4: add a new ioctl EXT4_IOC_GETSTATE
  ext4: add a new ioctl EXT4_IOC_CLEAR_ES_CACHE
  jbd2: flush_descriptor(): Do not decrease buffer head's ref count
  ext4: remove unnecessary error check
  ...

fs/ext4/ioctl.c

@@ -745,6 +745,74 @@ static void ext4_fill_fsxattr(struct inode *inode, struct fsxattr *fa)
 		fa->fsx_projid = from_kprojid(&init_user_ns, ei->i_projid);
 }
 
+/* copied from fs/ioctl.c */
+static int fiemap_check_ranges(struct super_block *sb,
+			       u64 start, u64 len, u64 *new_len)
+{
+	u64 maxbytes = (u64) sb->s_maxbytes;
+
+	*new_len = len;
+
+	if (len == 0)
+		return -EINVAL;
+
+	if (start > maxbytes)
+		return -EFBIG;
+
+	/*
+	 * Shrink request scope to what the fs can actually handle.
+	 */
+	if (len > maxbytes || (maxbytes - len) < start)
+		*new_len = maxbytes - start;
+
+	return 0;
+}
+
+/* So that the fiemap access checks can't overflow on 32 bit machines. */
+#define FIEMAP_MAX_EXTENTS	(UINT_MAX / sizeof(struct fiemap_extent))
+
+static int ext4_ioctl_get_es_cache(struct file *filp, unsigned long arg)
+{
+	struct fiemap fiemap;
+	struct fiemap __user *ufiemap = (struct fiemap __user *) arg;
+	struct fiemap_extent_info fieinfo = { 0, };
+	struct inode *inode = file_inode(filp);
+	struct super_block *sb = inode->i_sb;
+	u64 len;
+	int error;
+
+	if (copy_from_user(&fiemap, ufiemap, sizeof(fiemap)))
+		return -EFAULT;
+
+	if (fiemap.fm_extent_count > FIEMAP_MAX_EXTENTS)
+		return -EINVAL;
+
+	error = fiemap_check_ranges(sb, fiemap.fm_start, fiemap.fm_length,
+				    &len);
+	if (error)
+		return error;
+
+	fieinfo.fi_flags = fiemap.fm_flags;
+	fieinfo.fi_extents_max = fiemap.fm_extent_count;
+	fieinfo.fi_extents_start = ufiemap->fm_extents;
+
+	if (fiemap.fm_extent_count != 0 &&
+	    !access_ok(fieinfo.fi_extents_start,
+		       fieinfo.fi_extents_max * sizeof(struct fiemap_extent)))
+		return -EFAULT;
+
+	if (fieinfo.fi_flags & FIEMAP_FLAG_SYNC)
+		filemap_write_and_wait(inode->i_mapping);
+
+	error = ext4_get_es_cache(inode, &fieinfo, fiemap.fm_start, len);
+	fiemap.fm_flags = fieinfo.fi_flags;
+	fiemap.fm_mapped_extents = fieinfo.fi_extents_mapped;
+	if (copy_to_user(ufiemap, &fiemap, sizeof(fiemap)))
+		error = -EFAULT;
+
+	return error;
+}
+
 long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
 	struct inode *inode = file_inode(filp);
@@ -1142,6 +1210,33 @@ resizefs_out:
 			return -EOPNOTSUPP;
 		return fscrypt_ioctl_get_key_status(filp, (void __user *)arg);
 
+	case EXT4_IOC_CLEAR_ES_CACHE:
+	{
+		if (!inode_owner_or_capable(inode))
+			return -EACCES;
+		ext4_clear_inode_es(inode);
+		return 0;
+	}
+
+	case EXT4_IOC_GETSTATE:
+	{
+		__u32	state = 0;
+
+		if (ext4_test_inode_state(inode, EXT4_STATE_EXT_PRECACHED))
+			state |= EXT4_STATE_FLAG_EXT_PRECACHED;
+		if (ext4_test_inode_state(inode, EXT4_STATE_NEW))
+			state |= EXT4_STATE_FLAG_NEW;
+		if (ext4_test_inode_state(inode, EXT4_STATE_NEWENTRY))
+			state |= EXT4_STATE_FLAG_NEWENTRY;
+		if (ext4_test_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE))
+			state |= EXT4_STATE_FLAG_DA_ALLOC_CLOSE;
+
+		return put_user(state, (__u32 __user *) arg);
+	}
+
+	case EXT4_IOC_GET_ES_CACHE:
+		return ext4_ioctl_get_es_cache(filp, arg);
+
 	case EXT4_IOC_FSGETXATTR:
 	{
 		struct fsxattr fa;
@@ -1278,6 +1373,9 @@ long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	case FS_IOC_GETFSMAP:
 	case FS_IOC_ENABLE_VERITY:
 	case FS_IOC_MEASURE_VERITY:
+	case EXT4_IOC_CLEAR_ES_CACHE:
+	case EXT4_IOC_GETSTATE:
+	case EXT4_IOC_GET_ES_CACHE:
 		break;
 	default:
 		return -ENOIOCTLCMD;