and CIFS file attributes as BSD stat(2) flags.
This work is intended to be compatible with ZFS, the Solaris CIFS
server's interaction with ZFS, somewhat compatible with MacOS X,
and of course compatible with Windows.
The Windows attributes that are implemented were chosen based on
the attributes that ZFS already supports.
The summary of the flags is as follows:
UF_SYSTEM: Command line name: "system" or "usystem"
ZFS name: XAT_SYSTEM, ZFS_SYSTEM
Windows: FILE_ATTRIBUTE_SYSTEM
This flag means that the file is used by the
operating system. FreeBSD does not enforce any
special handling when this flag is set.
UF_SPARSE: Command line name: "sparse" or "usparse"
ZFS name: XAT_SPARSE, ZFS_SPARSE
Windows: FILE_ATTRIBUTE_SPARSE_FILE
This flag means that the file is sparse. Although
ZFS may modify this in some situations, there is
not generally any special handling for this flag.
UF_OFFLINE: Command line name: "offline" or "uoffline"
ZFS name: XAT_OFFLINE, ZFS_OFFLINE
Windows: FILE_ATTRIBUTE_OFFLINE
This flag means that the file has been moved to
offline storage. FreeBSD does not have any special
handling for this flag.
UF_REPARSE: Command line name: "reparse" or "ureparse"
ZFS name: XAT_REPARSE, ZFS_REPARSE
Windows: FILE_ATTRIBUTE_REPARSE_POINT
This flag means that the file is a Windows reparse
point. ZFS has special handling code for reparse
points, but we don't currently have the other
supporting infrastructure for them.
UF_HIDDEN: Command line name: "hidden" or "uhidden"
ZFS name: XAT_HIDDEN, ZFS_HIDDEN
Windows: FILE_ATTRIBUTE_HIDDEN
This flag means that the file may be excluded from
a directory listing if the application honors it.
FreeBSD has no special handling for this flag.
The name and bit definition for UF_HIDDEN are
identical to the definition in MacOS X.
UF_READONLY: Command line name: "urdonly", "rdonly", "readonly"
ZFS name: XAT_READONLY, ZFS_READONLY
Windows: FILE_ATTRIBUTE_READONLY
This flag means that the file may not written or
appended, but its attributes may be changed.
ZFS currently enforces this flag, but Illumos
developers have discussed disabling enforcement.
The behavior of this flag is different than MacOS X.
MacOS X uses UF_IMMUTABLE to represent the DOS
readonly permission, but that flag has a stronger
meaning than the semantics of DOS readonly permissions.
UF_ARCHIVE: Command line name: "uarch", "uarchive"
ZFS_NAME: XAT_ARCHIVE, ZFS_ARCHIVE
Windows name: FILE_ATTRIBUTE_ARCHIVE
The UF_ARCHIVED flag means that the file has changed and
needs to be archived. The meaning is same as
the Windows FILE_ATTRIBUTE_ARCHIVE attribute, and
the ZFS XAT_ARCHIVE and ZFS_ARCHIVE attribute.
msdosfs and ZFS have special handling for this flag.
i.e. they will set it when the file changes.
sys/param.h: Bump __FreeBSD_version to 1000047 for the
addition of new stat(2) flags.
chflags.1: Document the new command line flag names
(e.g. "system", "hidden") available to the
user.
ls.1: Reference chflags(1) for a list of file flags
and their meanings.
strtofflags.c: Implement the mapping between the new
command line flag names and new stat(2)
flags.
chflags.2: Document all of the new stat(2) flags, and
explain the intended behavior in a little
more detail. Explain how they map to
Windows file attributes.
Different filesystems behave differently
with respect to flags, so warn the
application developer to take care when
using them.
zfs_vnops.c: Add support for getting and setting the
UF_ARCHIVE, UF_READONLY, UF_SYSTEM, UF_HIDDEN,
UF_REPARSE, UF_OFFLINE, and UF_SPARSE flags.
All of these flags are implemented using
attributes that ZFS already supports, so
the on-disk format has not changed.
ZFS currently doesn't allow setting the
UF_REPARSE flag, and we don't really have
the other infrastructure to support reparse
points.
msdosfs_denode.c,
msdosfs_vnops.c: Add support for getting and setting
UF_HIDDEN, UF_SYSTEM and UF_READONLY
in MSDOSFS.
It supported SF_ARCHIVED, but this has been
changed to be UF_ARCHIVE, which has the same
semantics as the DOS archive attribute instead
of inverse semantics like SF_ARCHIVED.
After discussion with Bruce Evans, change
several things in the msdosfs behavior:
Use UF_READONLY to indicate whether a file
is writeable instead of file permissions, but
don't actually enforce it.
Refuse to change attributes on the root
directory, because it is special in FAT
filesystems, but allow most other attribute
changes on directories.
Don't set the archive attribute on a directory
when its modification time is updated.
Windows and DOS don't set the archive attribute
in that scenario, so we are now bug-for-bug
compatible.
smbfs_node.c,
smbfs_vnops.c: Add support for UF_HIDDEN, UF_SYSTEM,
UF_READONLY and UF_ARCHIVE in SMBFS.
This is similar to changes that Apple has
made in their version of SMBFS (as of
smb-583.8, posted on opensource.apple.com),
but not quite the same.
We map SMB_FA_READONLY to UF_READONLY,
because UF_READONLY is intended to match
the semantics of the DOS readonly flag.
The MacOS X code maps both UF_IMMUTABLE
and SF_IMMUTABLE to SMB_FA_READONLY, but
the immutable flags have stronger meaning
than the DOS readonly bit.
stat.h: Add definitions for UF_SYSTEM, UF_SPARSE,
UF_OFFLINE, UF_REPARSE, UF_ARCHIVE, UF_READONLY
and UF_HIDDEN.
The definition of UF_HIDDEN is the same as
the MacOS X definition.
Add commented-out definitions of
UF_COMPRESSED and UF_TRACKED. They are
defined in MacOS X (as of 10.8.2), but we
do not implement them (yet).
ufs_vnops.c: Add support for getting and setting
UF_ARCHIVE, UF_HIDDEN, UF_OFFLINE, UF_READONLY,
UF_REPARSE, UF_SPARSE, and UF_SYSTEM in UFS.
Alphabetize the flags that are supported.
These new flags are only stored, UFS does
not take any action if the flag is set.
Sponsored by: Spectra Logic
Reviewed by: bde (earlier version)
- Add -v to print file names as they are processed; -vv prints the flags
change as well.
- Add -f to ignore failures with the same semantics as chflags(1), neither
printing an error nor affecting the return code.
- Don't try to set the flags if they won't change.
I made minor cosmetic tweaks to the code in the patch.
MFC after: 1 week
PR: 112827
Submitted by: Ighighi <ighighi at gmail.com>
analogous to chmod(1)'s -h. It allows setting flags on symbolic links,
which *do* exist in 5.x+ despite a claim to the contrary in the
chflags(1) man page.
Suggested by: Chris Dillon
`opaque', fix reversed description of `nodump', and don't use
`nodump' as an example of adding a `no' prefix since the double
negative would be confusing (it's still confusing -- the implicitly
documented `nonodump' flag doesn't exist).)
These changes add the ability to specify that a UFS file/directory
cannot be unlinked. This is basically a scaled back version
of the IMMUTABLE flag. The reason is to allow an administrator
to create a directory hierarchy that a group of users
can arbitrarily add/delete files from, but that the hierarchy
itself is safe from removal by them.
If the NOUNLINK definition is set to 0
then this results in no change to what happens normally.
(and results in identical binary (in the kernel)).
It can be proven that if this bit is never set by the admin,
no new behaviour is introduced..
Several "good idea" comments from reviewers plus one grumble
about creeping featurism.
This code is in production in 2.2 based systems
