When renaming a directory it passes through several intermediate
states. First its new name will be created causing it to have two
names (from possibly different parents). Next, if it has different
parents, its value of ".." will be changed from pointing to the old
parent to pointing to the new parent. Concurrently, its old name
will be removed bringing it back into a consistent state. When fsck
encounters an extra name for a directory, it offers to remove the
"extraneous hard link"; when it finds that the names have been
changed but the update to ".." has not happened, it offers to rewrite
".." to point at the correct parent. Both of these changes were
considered unexpected so would cause fsck in preen mode or fsck in
background mode to fail with the need to run fsck manually to fix
these problems. Fsck running in preen mode or background mode now
corrects these expected inconsistencies that arise during directory
rename. The functionality added with this update is used by fsck
running in background mode to make these fixes.
Solution:
This update adds three new fsck sysctl commands to support background
fsck in correcting expected inconsistencies that arise from incomplete
directory rename operations. They are:
setcwd(dirinode) - set the current directory to dirinode in the
filesystem associated with the snapshot.
setdotdot(oldvalue, newvalue) - Verify that the inode number for ".."
in the current directory is oldvalue then change it to newvalue.
unlink(nameptr, oldvalue) - Verify that the inode number associated
with nameptr in the current directory is oldvalue then unlink it.
As with all other fsck sysctls, these new ones may only be used by
processes with appropriate priviledge.
Reported by: jeff
Security issues: rwatson
flag. Besides providing the redundand information, need to update both
vnode and object flags causes more acquisition of vnode interlock.
OBJ_MIGHTBEDIRTY is only checked for vnode-backed vm objects.
Remove VI_OBJDIRTY and make sure that OBJ_MIGHTBEDIRTY is set only for
vnode-backed vm objects.
Suggested and reviewed by: alc
Tested by: pho
MFC after: 3 weeks
dead_vnodeops before calling vgone(). Revert r189706 and corresponding
part of the r186560.
Noted and reviewed by: tegge
Approved by: des (pseudofs part)
MFC after: 3 days
truncate(2) call, or by being removed or truncated on open, either
new softupdate freeblks structure is allocated to track the freed
blocks of the node, or truncation is done syncronously when too many SU
dependencies are accumulated. The decision does not take into account
the allocated freeblks dependencies, allowing workloads that do huge
amount of truncations to exhaust the kernel memory.
Take the number of allocated freeblks into consideration for
softdep_slowdown().
Reported by: pluknet gmail com
Diagnosed and tested by: pho
Approved by: re (rwatson)
MFC after: 1 month
display '+' on them. Taken from kern/125613, with cosmetic
changes.
PR: kern/125613
Submitted by: Jaakko Heinonen <jh at saunalahti dot fi>
Approved by: re (kib)
around the sequence that drop vnode lock and then busies the mount point.
Not having vlocked node or direct reference to the mp allows for the
forced unmount to proceed, making mp unmounted or reused.
Tested by: pho
Reviewed by: jeff
Approved by: re (kensmith)
MFC after: 2 weeks
threads to put dirty buffers on the vnode bufobj list. For regular files
and synchronous fsync requests, check for the condition and restart the
fsync vop if a new dirty buffer arrived.
Tested by: pho
Approved by: re (kensmith)
MFC after: 1 month
Use inlined (due to FFSV_FORCEINSMQ) version of vn_vget_ino() to prevent
mountpoint from being unmounted and freed while no vnodes are locked.
Tested by: pho
Approved by: re (kensmith)
MFC after: 1 month
vfs.ufs.dirhash_maxmem below the current amount of memory used by dirhash. When
ufsdirhash_build() is called with the memory in use greater than dirhash_maxmem,
it attempts to free up memory by calling ufsdirhash_recycle(). If successful in
freeing enough memory, ufsdirhash_recycle() leaves the dirhash list locked. But
at this point in ufsdirhash_build(), the list is not explicitly unlocked after
the call(s) to ufsdirhash_recycle(). When we next attempt to lock the dirhash
list, we will get a "panic: _mtx_lock_sleep: recursed on non-recursive mutex
dirhash list".
Tested by: pho
Approved by: dwmalone (mentor)
MFC after: 3 weeks
NGROUPS_MAX, eliminate ABI dependencies on them, and raise the to 1024
and 1023 respectively. (Previously they were equal, but under a close
reading of POSIX, NGROUPS_MAX was defined to be too large by 1 since it
is the number of supplemental groups, not total number of groups.)
The bulk of the change consists of converting the struct ucred member
cr_groups from a static array to a pointer. Do the equivalent in
kinfo_proc.
Introduce new interfaces crcopysafe() and crsetgroups() for duplicating
a process credential before modifying it and for setting group lists
respectively. Both interfaces take care for the details of allocating
groups array. crsetgroups() takes care of truncating the group list
to the current maximum (NGROUPS) if necessary. In the future,
crsetgroups() may be responsible for insuring invariants such as sorting
the supplemental groups to allow groupmember() to be implemented as a
binary search.
Because we can not change struct xucred without breaking application
ABIs, we leave it alone and introduce a new XU_NGROUPS value which is
always 16 and is to be used or NGRPS as appropriate for things such as
NFS which need to use no more than 16 groups. When feasible, truncate
the group list rather than generating an error.
Minor changes:
- Reduce the number of hand rolled versions of groupmember().
- Do not assign to both cr_gid and cr_groups[0].
- Modify ipfw to cache ucreds instead of part of their contents since
they are immutable once referenced by more than one entity.
Submitted by: Isilon Systems (initial implementation)
X-MFC after: never
PR: bin/113398 kern/133867
a potential race pointed out by pjd. Also use TAILQ_FOREACH_SAFE to iterate over
dirhashes in ufsdirhash_lowmem(), so that we can continue iterating even after a
dirhash is destroyed.
Suggested by: pjd
Tested by: pho
Approved by: dwmalone (mentor)
and used in a large number of files, but also because an increasing number
of incorrect uses of MAC calls were sneaking in due to copy-and-paste of
MAC-aware code without the associated opt_mac.h include.
Discussed with: pjd
deleted when the system is low on memory. This ought to allow an increase to
vfs.ufs.dirhash_maxmem on machines that have lots of memory, without
degrading performance by having too much memory reserved for dirhash when
other things need it. The default value for dirhash_maxmem is being kept at
2MB for now, though.
This work was mostly done during the 2008 Google Summer of Code.
Approved by: dwmalone (mentor), re
MFC after: 3 months
by creating a child jail, which is visible to that jail and to any
parent jails. Child jails may be restricted more than their parents,
but never less. Jail names reflect this hierarchy, being MIB-style
dot-separated strings.
Every thread now points to a jail, the default being prison0, which
contains information about the physical system. Prison0's root
directory is the same as rootvnode; its hostname is the same as the
global hostname, and its securelevel replaces the global securelevel.
Note that the variable "securelevel" has actually gone away, which
should not cause any problems for code that properly uses
securelevel_gt() and securelevel_ge().
Some jail-related permissions that were kept in global variables and
set via sysctls are now per-jail settings. The sysctls still exist for
backward compatibility, used only by the now-deprecated jail(2) system
call.
Approved by: bz (mentor)
the VFS. Now all the VFS_* functions and relating parts don't want the
context as long as it always refers to curthread.
In some points, in particular when dealing with VOPs and functions living
in the same namespace (eg. vflush) which still need to be converted,
pass curthread explicitly in order to retain the old behaviour.
Such loose ends will be fixed ASAP.
While here fix a bug: now, UFS_EXTATTR can be compiled alone without the
UFS_EXTATTR_AUTOSTART option.
VFS KPI is heavilly changed by this commit so thirdy parts modules needs
to be recompiled. Bump __FreeBSD_version in order to signal such
situation.
Credential might need to hang around longer than its parent and be used
outside of mnt_explock scope controlling netcred lifetime. Use separate
reference-counted ucred allocated separately instead.
While there, extend mnt_explock coverage in vfs_stdexpcheck and clean-up
some unused declarations in new NFS code.
Reported by: John Hickey
PR: kern/133439
Reviewed by: dfr, kib
the nfsv4 Change attribute. There are 2 changes:
1 - The value now changes on metadata changes as well as data
modifications (incremented for IN_CHANGE instead of IN_UPDATE).
2 - It is now saved in spare space in the on-disk i-node so that it
survives a crash.
Since va_filerev is not passed out into user space, the only current
use of va_filerev is in the nfs server, which uses it as the directory
cookie verifier. Since this verifier is only passed back to the server
by a client verbatim and then the server doesn't check it, changing the
semantics should not break anything currently in FreeBSD.
Reviewed by: bde
Approved by: kib (mentor)
the same inode number after VFS_VGET() and relock of the vp. If '..'
changed, redo the lookup. To reduce code duplication, move the code to
read '..' dirent into the static helper function ufs_dir_dd_ino().
Supply the source inode number as an argument to ufs_checkpath() instead
of the source inode itself. The inode is unlocked, thus it might be
reclaimed, causing accesses to the freed memory.
Use vn_vget_ino() to get the '..' vnode by its inode number, instead of
directly code VFS_VGET() and relock, to properly busy the mount point
while vp lock is dropped.
Noted and reviewed by: tegge
Tested by: pho
MFC after: 1 month
error if '..' is still there but changed between lookup and check.
Start relookup instead. Rename is supposed to change '..' reference
atomically, so transient failures introduced by r191137 are wrong.
While rearranging the code to allow lookup restart in ufs_lookup(),
remove the comment that only distracts the reader.
Noted and reviewed by: tegge
Also reported by: pho
MFC after: 1 month
VFS_VGET() has returned in ufs_lookup(). If the '..' lookup started
immediately before the parent directory was removed, we might return
either cleared or unrelated inode otherwise.
Ufs_lookup() is split into new function ufs_lookup_() that either does
lookup, or verifies that directory entry exists and references supplied
inode number.
Reviewed by: tegge
Tested by: pho,
Andreas Tobler <andreast-list fgznet ch> (previous version)
MFC after: 1 month
the removal of NQNFS, but was left in in case it was required for NFSv4.
Since our new NFSv4 client and server can't use it for their
requirements, GC the old mechanism, as well as other unused lease-
related code and interfaces.
Due to its impact on kernel programming and binary interfaces, this
change should not be MFC'd.
Proposed by: jeff
Reviewed by: jeff
Discussed with: rmacklem, zach loafman @ isilon
The later may need blocks from the underlying device that belongs
to normal files, that should not be locked while snap lock is held.
Reported and tested by: pho
MFC after: 1 month
the "nbufkv" sleep.
First, ffs background cg group block write requests a new buffer for
the shadow copy. When ffs_bufwrite() is called from the bufdaemon due
to buffers shortage, requesting the buffer deadlock bufdaemon.
Introduce a new flag for getnewbuf(), GB_NOWAIT_BD, to request getblk
to not block while allocating the buffer, and return failure
instead. Add a flag argument to the geteblk to allow to pass the flags
to getblk(). Do not repeat the getnewbuf() call from geteblk if buffer
allocation failed and either GB_NOWAIT_BD is specified, or geteblk()
is called from bufdaemon (or its helper, see below). In
ffs_bufwrite(), fall back to synchronous cg block write if shadow
block allocation failed.
Since r107847, buffer write assumes that vnode owning the buffer is
locked. The second problem is that buffer cache may accumulate many
buffers belonging to limited number of vnodes. With such workload,
quite often threads that own the mentioned vnodes locks are trying to
read another block from the vnodes, and, due to buffer cache
exhaustion, are asking bufdaemon for help. Bufdaemon is unable to make
any substantial progress because the vnodes are locked.
Allow the threads owning vnode locks to help the bufdaemon by doing
the flush pass over the buffer cache before getnewbuf() is going to
uninterruptible sleep. Move the flushing code from buf_daemon() to new
helper function buf_do_flush(), that is called from getnewbuf(). The
number of buffers flushed by single call to buf_do_flush() from
getnewbuf() is limited by new sysctl vfs.flushbufqtarget. Prevent
recursive calls to buf_do_flush() by marking the bufdaemon and threads
that temporarily help bufdaemon by TDP_BUFNEED flag.
In collaboration with: pho
Reviewed by: tegge (previous version)
Tested by: glebius, yandex ...
MFC after: 3 weeks
Provide a custom lock around initializing and tearing down EA area,
to prevent both memory leaks and double-free of it. Count the number
of EA area accessors.
Lock protocol requires either holding exclusive vnode lock to modify
i_ea_area, or shared vnode lock and owning IN_EA_LOCKED flag in i_flag.
Noted by: YAMAMOTO, Taku <taku tackymt homeip net>
Tested by: pho (previous version)
MFC after: 2 weeks
filesystem supports additional operations using shared vnode locks.
Currently this is used to enable shared locks for open() and close() of
read-only file descriptors.
- When an ISOPEN namei() request is performed with LOCKSHARED, use a
shared vnode lock for the leaf vnode only if the mount point has the
extended shared flag set.
- Set LOCKSHARED in vn_open_cred() for requests that specify O_RDONLY but
not O_CREAT.
- Use a shared vnode lock around VOP_CLOSE() if the file was opened with
O_RDONLY and the mountpoint has the extended shared flag set.
- Adjust md(4) to upgrade the vnode lock on the vnode it gets back from
vn_open() since it now may only have a shared vnode lock.
- Don't enable shared vnode locks on FIFO vnodes in ZFS and UFS since
FIFO's require exclusive vnode locks for their open() and close()
routines. (My recent MPSAFE patches for UDF and cd9660 already included
this change.)
- Enable extended shared operations on UFS, cd9660, and UDF.
Submitted by: ups
Reviewed by: pjd (ZFS bits)
MFC after: 1 month
address space sizes to be longs instead of ints. Specifically, the follow
values are now longs: runningbufspace, bufspace, maxbufspace,
bufmallocspace, maxbufmallocspace, lobufspace, hibufspace, lorunningspace,
hirunningspace, maxswzone, maxbcache, and maxpipekva. Previously, a
relatively small number (~ 44000) of buffers set in kern.nbuf would result
in integer overflows resulting either in hangs or bogus values of
hidirtybuffers and lodirtybuffers. Now one has to overflow a long to see
such problems. There was a check for a nbuf setting that would cause
overflows in the auto-tuning of nbuf. I've changed it to always check and
cap nbuf but warn if a user-supplied tunable would cause overflow.
Note that this changes the ABI of several sysctls that are used by things
like top(1), etc., so any MFC would probably require a some gross shims
to allow for that.
MFC after: 1 month
msdosfs_unmount() and ffs_unmount() exit early after getting ENXIO.
However, dounmount() treats ENXIO as a success and proceeds with
unmounting. In effect, the filesystem gets unmounted without closing
GEOM provider etc.
Reviewed by: kib
Approved by: rwatson (mentor)
Tested by: dho
Sponsored by: FreeBSD Foundation
cleanup. Before the GEOM consumer would not have been closed.
- Bump the reference on the character device being mounted while the
associated devfs vnode is locked.
Reviewed by: kib
of devvp becomes VBAD, which UFS incorrectly interprets as snapshot
vnode, which in turns causes panic. Fix it by replacing '!= VCHR'
with '== VREG'.
With this fix in place, you should no longer be able to panic the system
by removing a device with an UFS filesystem mounted from it - assuming
you don't use softupdates.
Reviewed by: kib
Tested by: pho
Approved by: rwatson (mentor)
Sponsored by: FreeBSD Foundation
extended attributes since FreeBSD 5, make the following semantic
changes:
- Don't update the inode modification time (mtime) when extended
attributes (and hence also ACLs) are added, modified, or removed.
- Don't update the inode access tie (atime) when extended attributes
(and hence also ACLs) are queried.
This means that rsync (and related tools) won't improperly think
that the data in the file has changed when only the ACL has changed.
Note that ffs_reallocblks() has not been changed to not update on an
IO_EXT transaction, but currently EAs don't use the cluster write
routines so this shouldn't be a problem. If EAs grow support for
clustering, then VOP_REALLOCBLKS() will need to grow a flag argument
to carry down IO_EXT to UFS.
MFC after: 1 week
PR: ports/125739
Reported by: Alexander Zagrebin <alexz@visp.ru>
Tested by: pluknet <pluknet@gmail.com>,
Greg Byshenk <freebsd@byshenk.net>
Discussed with: kib, kientzle, timur, Alexander Bokovoy <ab@samba.org>
the helper function. It is supposed to be useful for any filesystem
that has to unlock dvp to walk to the ".." entry in lookup routine.
Requested by: jhb
Tested by: pho
MFC after: 1 month
