Unverified Commit bd6ae049 authored by Konstantin Komarov's avatar Konstantin Komarov
Browse files

fs/ntfs3: Add comments about cluster size 



This commit adds additional info about CONFIG_NTFS3_64BIT_CLUSTER

Signed-off-by: default avatarKonstantin Komarov <almaz.alexandrovich@paragon-software.com>
parent f76349cf

fs/ntfs3/frecord.c

+1 −1
Original line number Diff line number Diff line
@@ -557,7 +557,7 @@ static int ni_repack(struct ntfs_inode *ni) 
		}



		if (!mi_p) {

			/* Do not try if not enogh free space. */

			/* Do not try if not enough free space. */

			if (le32_to_cpu(mi->mrec->used) + 8 >= rs)

				continue;

fs/ntfs3/record.c

+4 −0
Original line number Diff line number Diff line
@@ -537,6 +537,10 @@ bool mi_resize_attr(struct mft_inode *mi, struct ATTRIB *attr, int bytes) 
	return true;

}



/*

 * Pack runs in MFT record.

 * If failed record is not changed.

 */

int mi_pack_runs(struct mft_inode *mi, struct ATTRIB *attr,

		 struct runs_tree *run, CLST len)

{

fs/ntfs3/super.c

+24 −0
Original line number Diff line number Diff line
@@ -21,6 +21,30 @@ 
 * https://docs.microsoft.com/en-us/windows/wsl/file-permissions

 * It stores uid/gid/mode/dev in xattr

 *

 * ntfs allows up to 2^64 clusters per volume.

 * It means you should use 64 bits lcn to operate with ntfs.

 * Implementation of ntfs.sys uses only 32 bits lcn.

 * Default ntfs3 uses 32 bits lcn too.

 * ntfs3 built with CONFIG_NTFS3_64BIT_CLUSTER (ntfs3_64) uses 64 bits per lcn.

 *

 *

 *     ntfs limits, cluster size is 4K (2^12)

 * -----------------------------------------------------------------------------

 * | Volume size   | Clusters | ntfs.sys | ntfs3  | ntfs3_64 | mkntfs | chkdsk |

 * -----------------------------------------------------------------------------

 * | < 16T, 2^44   |  < 2^32  |  yes     |  yes   |   yes    |  yes   |  yes   |

 * | > 16T, 2^44   |  > 2^32  |  no      |  no    |   yes    |  yes   |  yes   |

 * ----------------------------------------------------------|------------------

 *

 * To mount large volumes as ntfs one should use large cluster size (up to 2M)

 * The maximum volume size in this case is 2^32 * 2^21 = 2^53 = 8P

 *

 *     ntfs limits, cluster size is 2M (2^31)

 * -----------------------------------------------------------------------------

 * | < 8P, 2^54    |  < 2^32  |  yes     |  yes   |   yes    |  yes   |  yes   |

 * | > 8P, 2^54    |  > 2^32  |  no      |  no    |   yes    |  yes   |  yes   |

 * ----------------------------------------------------------|------------------

 *

 */



#include <linux/blkdev.h>