ntfs_valid_sid() required that the subauthority count be between 1 and 8
inclusively. However, Windows permits more than 8 subauthorities as well
as 0 subauthorities:
- The install.wim file for the latest Windows 10 build contains a file
whose DACL contains a SID with 10 subauthorities.
ntfs_set_ntfs_acl() was failing on this file.
- The IsValidSid() function on Windows returns true for subauthority
less than or equal to 15, including 0.
There was actually already a another SID validation function that had the
Windows-compatible behavior, so I merged the two together.
Contributed by Eric Biggers
Compressed records may be written as full clusters even though cluster
tails are meaningless. This is to avoid the lower levels doing a read-
modify-write cycle. Be sure to zero the meaningless bytes to avoid
leaking information.
Contributed by Eric Biggers
When the owner and the group of a file have the same SID, and permissions
for the group is the same as permissions for other, no ACE is needed for
the group.
Newer versions of Windows use more recent definitions of upper-case
table defined by the Unicode consortium. Now using the same table as
Windows 7, windows 8 and Windows 10. This only has an effect on file
systems newly created by mkntfs.
An unused MFT record may show a bad length, leading to fetch fixups from
unallocated memory when allocating the record to a new file. So check
the length before applying the fixups. Such records have been found after
the MFT has been reallocated by a defragmenter, and they are not cleaned
by chkdsk.
When chmod'ing a file, no new ACL has to be created if the one needed
is already present in the cache. However the read-only flag may have
to be updated, so that it is kept as the opposite of S_IWUSR.
When the security attribute is present, chkdsk may set a null security id
in the standard attributes, and this should not be considered as an error.
(this partially reverts commit [70e5b1])
This patch changes the algorithm to use hash chains instead of binary
trees, with much stronger hashing. It also introduces useful (for
performance) parameters, such as the "nice match length" and "maximum
search depth", that are similar to those used in other commonly used
compression algorithms such as zlib's DEFLATE implementation.
The speed improvement is very significant, with some loss of compression
rate. The compression rate is still better than then Windows one.
Contributed by Eric Biggers
The new way goes via /sys/dev/block/MAJOR:MINOR to map partitions to
devices and get discard parameters of the parent device. It also ensures
that the partition is aligned to the discard block size.
Contributed by Richard W.M. Jones
fstrim(8) discards unused blocks on a mounted filesystem. It is useful for
solid-state drives (SSDs) and thinly-provisioned storage.
Only trimming the full device (with no option) is supported.
Contributed by Richard W.M. Jones
When Posix ACLs are used, the umask is ignored and the initial permissions
of created files are taken for the parent directory. However the umask
should still be used when the Posix ACLs are not enabled in the mount
options.
Ownership of files should always represent the creator of files.
This fixes a situation, currently disabled, where there is no user
mapping and the owner of the parent directory is used as the owner
of the created file.
When using Windows inheritance, the cacheing of ACLs for files created
within a directory only depended on the directory. Actually it also
depends on the user who creates the file. With the patch, only the ACLs
created by the owner of the directory are cached.
When grouping of users are determined from /etc/group (a compile-time
option not currently used), the groups examined for checking access rights
to a file were wrongly derived from the uid of the file instead of the
uid of the current process.
Since Vista, the standard directory /Users/Public which should be accessed
by any user is actually restricted to a few group of users, among them
the interactive ones. To make this directory accessible without using
the Posix ACLs, all Linux users are considered as interactive.
However, when Posix ACLs are used, users supposed to be interactive have
to be put into a secondary group mapped to the equivalent Windows group.
When using the Windows permission inheritance mode and the current user
has not been mapped, try to derive a reasonable user from the parent
directory.
The Windows-type inheritance of an ACE may imply creating two ACE's : one
for access and one for further inheritance. The conditions for doing so,
and the flags set on created ACE were sometimes wrong.
Note : the rules have been derived from testing multiple situations, but
there still are some gray cases.
Since Vista, Windows defines a /Users/Public directory supposed to be
public, but actually only allowed to a few user categories (interactive,
batch, etc.) This patch makes possible to create equivalent Unix groups
and group users the same way as in Windows. Posix ACLs have to be enabled
for access to /Users/Public to be allowed to several groups.
chkdsk deletes the ACLs when they are bad or when they are not used any
more. This fixes inserting a new ACL after the previously last ACL (or
even all of them) was deleted.
A bug was introduced by commit d2c7d40a2b :
when the beginning of a file was a hole and the runlist span over several
MFT extents, the runlist was not mapped on filling the initial hole.
This lead to a crash when using torrent to download big files.
Windows applies legacy restrictions to file names, so when the option
windows_names is applied, reject the same reserved names, which are
CON, PRN, AUX, NUL, COM1..COM9, and LPT1..LPT9
When the runlist of the data attribute of MFT has to be split across
several extents, the location of each extent has to be known from the
runlist present in previous extents. So, force the first extent into
record 15 to avoid a bad layout.
When a hole in a sparse file was filled, the runlist was fully recomputed.
When a sparse file spans over several MFT extents, this patch leads to
only recompute the runlist from the modified extent to the end.
Updating an attribute may imply decompressing runlists which are not
contiguous, leaving an unmapped region between them. When checking whether
the attribute has been made sparse, such unmapped regions should be ignored
This mostly happens after updating an index. (fix by Forrest Liu)
Windows server 2012 apparently uses files with no ACEs in their DACL,
thus denying any access to any process except system backup.
Such DACLs should however be considered valid.
When calling ntfstruncate() to expand a resident attribute, the function
is called again recursively, losing the requirement for not inserting
holes. This is for forwarding the requirement (used by ntfscp).
When testing whether a stream has been wiped out for possibly changing
its compression status, only the non-resident case was considered.
This fixes the test for streams which were never made non-resident.
Windows 8 does not zero any more the end of a compression block beyond
what is needed to reach the end of a file. We must now be careful not
to decompress more data than needed.
When translating Windows-type symlinks to Linux ones, the directory
separator has to be changed from '\' to '/'. The change was wrong
for multiple "..\" and ".\"
The file /etc/mtab is traditionally checked to avoid multiple mountings
of the same device, but this is not accurate enough in some conditions.
So use /proc/mounts when available and fall back to /etc/mtab on
systems which do not have /proc/mounts.
Author: Anton Altaparmakov <anton@tuxera.com>
Date: Tue Feb 12 10:33:55 2013 +0000
Modify libntfs-3g to make use of hd library to get the legacy BIOS geometry
from EDD. We scan all whole disk devices on the system and check if they
match the open ntfs device and if not we scan all partition devices on the
system and check if they match the open ntfs device.
If we find a partition device to match then we find its parent device again
using the hd library.
Once we have the parent of the partition device or we matched a whole disk
device we get the legacy EDD sectors per track and heads again using the hd
library.
Use of the hd library is auto detected (based on finding <hd.h> header file,
being able to link against libhd and finding the hd_list symbol in libhd.
Use can also be disabled/enabled/libhd prefix specified at ./configure time.
See ./configure --help for details.
Note this obviously requires libhd to be installed. On Ubuntu 12/04 systems
the relevant packages needed are libhd-dev and libhd16 (on older Ubuntu
versions it will be libhdN where N is some number <= 16 but an easy way to
get the right package is to simply install libhd-dev which by dependency
pulls in the correct libhdN package) whilst on SLES systems the relevant
packages needed are hwinfo and hwinfo-devel.
Jean-Pierre André
Erik Larsson