When a file is unlinked, the denode is not reclaimed until the last
reference is dropped, but the directory entry is immediately up for reuse.
This is a problem later when createde goes to grab a denode for the newly
created entry -- we search the hash and find a dead denode, then return that
without even bumping the reference count and the data later gets truncated
when the the last reference to the unlinked file is dropped.
This manifested itself as a broken in-place strip(1) on msdosfs. elfcopy
will do a sequence incredibly roughly like this:
open("/mnt/foo", ...) => fd 3
mmap()
unlink("/mnt/foo")
open("/mnt/foo", ...) => fd 4
write(4, ...)
close(4)
close(3)
and the resulting file would be truncated, but the write succeeded, as long
as a reference to the unlinked file had not been closed.
Some archaeology indicates that this bug has likely existed since msdosfs
was converted to use vfs_hash instead of a home rolled hash implementation
in r143570. Prior to that point, the hashget implementation would do a
refcnt check while searching and explicitly only return a denode with
de_refcnt != 0. vfs_hash did not yet have the callback that it does today,
so this slipped away and did not come back when it later grew that
functionality.
The comment indicating that we want to skip these denodes has been updated
to reflect where this is actually done. My repo-diving session seems to
indicate that the refcnt check was likely never actually below the comment,
to be pedantic, but instead a detail wrapped up in the hashget
implementation since the beginning of its inclusion into FreeBSD.
This bug was the cause behind the issue addressed in r352557.
Reported by: jhibbits
Reviewed by: kib
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D21731
Current implementation of vnode_create_vobject() and
vnode_destroy_vobject() is written so that it prepared to handle the
vm object destruction for live vnode. Practically, no filesystems use
this, except for some remnants that were present in UFS till today.
One of the consequences of that model is that each filesystem must
call vnode_destroy_vobject() in VOP_RECLAIM() or earlier, as result
all of them get rid of the v_object in reclaim.
Move the call to vnode_destroy_vobject() to vgonel() before
VOP_RECLAIM(). This makes v_object stable: either the object is NULL,
or it is valid vm object till the vnode reclamation. Remove code from
vnode_create_vobject() to handle races with the parallel destruction.
Reviewed by: markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D21412
vtruncbuf takes a "struct ucred*" argument. AFAICT, it's been unused ever
since that function was first added in r34611. Remove it. Also, remove some
"struct ucred" arguments from fuse and nfs functions that were only used by
vtruncbuf.
Reviewed by: cem
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D20377
Despite the call to vtruncbuf() from detrunc(), which results in
zeroing part of the partial page after EOF, there still is a
possibility to retain the stale data which is revived on file
enlargement. If the filesystem block size is greater than the page
size, partial block might keep other after-EOF pages wired and they
get reused then. Fix it by zeroing whole part of the partial buffer
after EOF, not relying on vnode_pager_setsize().
PR: 236977
Reported by: asomers
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Most filesystems, with the notable exceptions of msdosfs and autofs use
only vfs_timestamp() to read the current time. This has the benefit of
configurable granularity (using the vfs.timestamp_precision sysctl).
For convenience, use it on msdosfs too.
Submitted by: Damjan Jovanovic
Differential Revision: https://reviews.freebsd.org/D15297
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.
The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
Inspired by a patch submission by longwitz@incore.de with many changes
for ino64 in HEAD.
PR: 199152
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
This somewhat simplifies use of msdosfs code in userland (for makefs),
reduces diffs with NetBSD and is standard C as of C89.
Reviewed by: imp
MFC after: 1 month
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D11014
There are a number of msdosfs improvements in NetBSD that may be worth
bringing over, and this reduces noise in the comparison.
Differential Revision: https://reviews.freebsd.org/D1466
Reviewed by: kib
Sponsored by: The FreeBSD Foundation
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)
system crash which happen after successfull fsync() return, the data
is accessible. For msdosfs, this means that FAT entries for the file
must be written.
Since we do not track the FAT blocks containing entries for the
current file, just do a sloppy sync of the devvp vnode for the mount,
which buffers, among other things, contain FAT blocks.
Simultaneously, for deupdat():
- optimize by clearing the modified flags before short-circuiting a
return, if the mount is read-only;
- only ignore the rest of the function for denode with DE_MODIFIED
flag clear when the waitfor argument is false. The directory buffer
for the entry might be of delayed write;
- microoptimize by comparing the updated directory entry with the
current block content;
- try to cluster the write, fall back to bawrite() if low on
resources.
Based on the submission by: bde
MFC after: 2 weeks
received granular locking) but the comment present in UFS has been
copied all over other filesystems code incorrectly for several times.
Removes comments that makes no sense now.
Reviewed by: kib
MFC after: 3 days
and vop_reclaim() methods. They seems to be unused, and the reported
situation is normal for the forced unmount.
MFC after: 1 week
X-MFC-note: keep prtactive symbol in vfs_subr.c
SLOT_EMPTY deName[0] values. Besides conforming to FAT specification, it
also clears the issue where vfs_hash_insert found the vnode in hash, and
newly allocated vnode is vput()ed. There, deName[0] == 0, and vnode is
not reclaimed, indefinitely kept on mountlist.
Tested by: pho
MFC after: 3 weeks
The plan is to use vnode lock to protect denode and fat cache,
and having separate lock for block use map.
Change the check and return on impossible condition into KASSERT().
Tested by: pho
MFC after: 3 weeks
- Remove the "thread" argument from the lockmgr() function as it is
always curthread now
- Axe lockcount() function as it is no longer used
- Axe LOCKMGR_ASSERT() as it is bogus really and no currently used.
Hopefully this will be soonly replaced by something suitable for it.
- Remove the prototype for dumplockinfo() as the function is no longer
present
Addictionally:
- Introduce a KASSERT() in lockstatus() in order to let it accept only
curthread or NULL as they should only be passed
- Do a little bit of style(9) cleanup on lockmgr.h
KPI results heavilly broken by this change, so manpages and
FreeBSD_version will be modified accordingly by further commits.
Tested by: matteo
This is much simpler than for ffs since there are many fewer places
where we need to choose between a delayed write and a sync write --
just 5 in msdosfs and more than 30 in ffs.
This is more complete and correct than in ffs. Several places in ffs
are are still missing the choice. ffs_update() has a layering violation
that breaks callers which want to force a sync update (mainly fsync(2)
and O_SYNC write(2)).
However, fsync(2) and O_SYNC write(2) are still more broken than in
ffs, since they are broken for default (non-sync non-async) mounts
too. Both fail to sync the FAT in all cases, and both fail to sync
the directory entry in some cases after losing a race. Async everything
is probably safer than the half-baked sync of metadata given by default
mounts.
remove some parentheses; fix some whitespace errors; fix only one case of
a boolean comparison of a non-boolean).
Improve an error message by quoting ".", and by not printing large positive
values as negative ones.
Approved by: re (kensmith) (blanket)
late stages of unmount). On failure, the vnode is recycled.
Add insmntque1(), to allow for file system specific cleanup when
recycling vnode on failure.
Change getnewvnode() to no longer call insmntque(). Previously,
embryonic vnodes were put onto the list of vnode belonging to a file
system, which is unsafe for a file system marked MPSAFE.
Change vfs_hash_insert() to no longer lock the vnode. The caller now
has that responsibility.
Change most file systems to lock the vnode and call insmntque() or
insmntque1() after a new vnode has been sufficiently setup. Handle
failed insmntque*() calls by propagating errors to callers, possibly
after some file system specific cleanup.
Approved by: re (kensmith)
Reviewed by: kib
In collaboration with: kib
last few days. I tracked it down to the fact that nfs_reclaim()
is setting vp->v_data to NULL _before_ calling vnode_destroy_object().
After silence from the mailing list I checked further and discovered
that ufs_reclaim() is unique among FreeBSD filesystems for calling
vnode_destroy_object() early, long before tossing v_data or much
of anything else, for that matter. The rest, including NFS, appear
to be identical, as if they were just clones of one original routine.
The enclosed patch fixes all file systems in essentially the same
way, by moving the call to vnode_destroy_object() to early in the
routine (before the call to vfs_hash_remove(), if any). I have
only tested NFS, but I've now run for over eighteen hours with the
patch where I wouldn't get past four or five without it.
Submitted by: Frank Mayhar
Requested by: Mohan Srinivasan
MFC After: 1 week
- Prefer '_' to ' ', as it results in more easily parsed results in
memory monitoring tools such as vmstat.
- Remove punctuation that is incompatible with using memory type names
as file names, such as '/' characters.
- Disambiguate some collisions by adding subsystem prefixes to some
memory types.
- Generally prefer lower case to upper case.
- If the same type is defined in multiple architecture directories,
attempt to use the same name in additional cases.
Not all instances were caught in this change, so more work is required to
finish this conversion. Similar changes are required for UMA zone names.
the filesystem. Check that rather than VI_XLOCK.
- VOP_INACTIVE should no longer drop the vnode lock.
- The vnode lock is required around calls to vrecycle() and vgone().
Sponsored by: Isilon Systems, Inc.
