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
VOP_MARKATIME() since unlike the rest of VOP_SETATTR(), VA_MARKATIME
can be performed while holding a shared vnode lock (the same functionality
is done internally by VOP_READ which can run with a shared vnode lock).
Add missing locking of the vnode interlock to the ufs implementation and
remove a special note and test from the NFS client about not supporting the
feature.
Inspired by: ups
Tested by: pho
indirect block pages are not removed by the mentioned invocation of
the vnode_pager_setsize().
Put a common code into the helper function ffs_pages_remove().
Reported and tested by: dchagin
Reviewed by: ups
MFC after: 3 weeks
address space where to put vnode pages, and then call UFS_BALLOC(),
to actually allocate new block and map it. When UFS_BALLOC() returns
error, sometimes we forget to revert the vm object size increase,
allowing for the pages that are not backed by the logical disk blocks.
Revert vnode_pager_setsize() back when UFS_BALLOC() failed, for
ffs_truncate() and ffs_write().
PR: 129956
Reviewed by: ups
MFC after: 3 weeks
vnode, from -1 down. When vinvalbuf(vp, V_ALT) is done for the vnode, it
incorrectly does vm_object_page_remove(0, 0), removing all pages from
the underlying vm object, not only the pages that back the extended
attributes data.
Change vinvalbuf() to not remove any pages from the object when
V_NORMAL or V_ALT are specified. Instead, the only in-tree caller
in ffs_inode.c:ffs_truncate() that specifies V_ALT explicitely
removes the corresponding page range. The V_NORMAL caller
does vnode_pager_setsize(vp, 0) immediately after the call to
vinvalbuf(V_NORMAL) already.
Reported by: csjp
Reviewed by: ups
MFC after: 3 weeks
anything other than 0. Make it so. This fixes
"panic: VOP_STRATEGY failed bp=0xc320dd90 vp=0xc3b9f648",
encountered when writing to an orphaned filesystem. Reason
for the panic was the following assert:
KASSERT(i == 0, ("VOP_STRATEGY failed bp=%p vp=%p", bp, bp->b_vp));
at vfs_bio:bufstrategy().
Reviewed by: scottl, phk
Approved by: rwatson (mentor)
Sponsored by: FreeBSD Foundation
does final drop of the the dq reference to put it onto the free list.
There is a possibility that the dq would be found by another thread
after sync and before the dqh lock is acquired. If that other thread
drops the dq before we have taken the dqh lock, the dirty dq is put on
the free list.
Recheck the DQ_MOD after the dqh lock is relocked. Repeat dqsync() if
the dq is dirty. This ensures that up to date dq is written in the quota
file and fixes assertion in dqget().
Reported and tested by: Frode Nordahl <frode nordahl net>
MFC after: 3 days
mnt_lock is before lock of any vnode on the mp, it uses LK_NOWAIT. Since
MNTK_UNMOUNT may be transient, pdp lock is dropped when vfs_busy()
failed, and operation is retried after some time. This way, ffs_vget()
is not called on the mp that may be in the process of being destroyed by
unmount.
Check for the VI_DOOMED flag on pdp after its lock is reacquired, to
better detect some situations where directory containing ".."
entry is removed during the lookup.
Reviewed by: tegge, attilio (previous version)
Tested by: pho
MFC after: 1 month
up space. If the buffer cache fills up then the disk systems can
grind to a halt. Better tuning can be figured out later.
Tested by: Tim, others and work
Reviewed by: Kostik Belousov
PR: 128832
flag. Specifically, if two threads race to create a dirhash for a
directory, then one might already have created a private dirhash
structure (and locked it) when it realizes the directory now has a
structure and tries to lock that one.
- Implement real draining for vfs consumers by not relying on the
mnt_lock and using instead a refcount in order to keep track of lock
requesters.
- Due to the change above, remove the mnt_lock lockmgr because it is now
useless.
- Due to the change above, vfs_busy() is no more linked to a lockmgr.
Change so its KPI by removing the interlock argument and defining 2 new
flags for it: MBF_NOWAIT which basically replaces the LK_NOWAIT of the
old version (which was unlinked from the lockmgr alredy) and
MBF_MNTLSTLOCK which provides the ability to drop the mountlist_mtx
once the mnt interlock is held (ability still desired by most consumers).
- The stub used into vfs_mount_destroy(), that allows to override the
mnt_ref if running for more than 3 seconds, make it totally useless.
Remove it as it was thought to work into older versions.
If a problem of "refcount held never going away" should appear, we will
need to fix properly instead than trust on such hackish solution.
- Fix a bug where returning (with an error) from dounmount() was still
leaving the MNTK_MWAIT flag on even if it the waiters were actually
woken up. Just a place in vfs_mount_destroy() is left because it is
going to recycle the structure in any case, so it doesn't matter.
- Remove the markercnt refcount as it is useless.
This patch modifies VFS ABI and breaks KPI for vfs_busy() so manpages and
__FreeBSD_version will be modified accordingly.
Discussed with: kib
Tested by: pho
to add more V* constants, and the variables changed by this patch were often
being assigned to mode_t variables, which is 16 bit.
Approved by: rwatson (mentor)
and ffs_lock. This cannot catch situations where holdcnt is incremented
not by curthread, but I think it is useful.
Reviewed by: tegge, attilio
Tested by: pho
MFC after: 2 weeks
In particular following functions KPI results modified:
- bufobj_invalbuf()
- bufsync()
and BO_SYNC() "virtual method" of the buffer objects set.
Main consumers of bufobj functions are affected by this change too and,
in particular, functions which changed their KPI are:
- vinvalbuf()
- g_vfs_close()
Due to the KPI breakage, __FreeBSD_version will be bumped in a later
commit.
As a side note, please consider just temporary the 'curthread' argument
passing to VOP_SYNC() (in bufsync()) as it will be axed out ASAP
Reviewed by: kib
Tested by: Giovanni Trematerra <giovanni dot trematerra at gmail dot com>
ufsdirhash_free() introduced in my last commit by removing the dirhash
about to be free'd in ufsdirhash_free() from the global dirhash list
before dropping the sx lock.
Tested by: kris
initialize va_vaflags and va_spare because they are not part of the
VOP_GETATTR() API. Also don't initialize birthtime to ctime or zero.
Submitted by: Jaakko Heinonen <jh saunalahti fi>
Reviewed by: bde
Discussed on: freebsd-fs
MFC after: 1 month
during a DELETE lookup operation, lookup would cache the length of the
directory entry to be deleted in 'i_reclen'. Later, the actual VOP to
remove the directory entry (ufs_remove, ufs_rename, etc.) would call
ufs_dirremove() which extended the length of the previous directory
entry to "remove" the deleted entry.
However, we always read the entire block containing the directory
entry when doing the removal, so we always have the directory entry to
be deleted in-memory when doing the update to the directory block.
Also, we already have to figure out where the directory entry that is
being removed is in the block so that we can pass the component name
to the dirhash code to update the dirhash. So, instead of passing
'i_reclen' from ufs_lookup() to the ufs_dirremove() routine, just read
the 'd_reclen' field directly out of the entry being removed when
updating the length of the previous entry in the block.
This avoids a cosmetic issue of writing to 'i_reclen' while holding a
shared vnode lock. It also slightly reduces the amount of side-band
data passed from ufs_lookup() to operations updating a directory via
the directory's i-node.
Reviewed by: jeff
cap on memory usage, then shared LOOKUP operations could start free'ing
dirhash structures. Without these fixes, concurrent free's on the same
directory could result in one of the threads blocked on a lock in a dirhash
structure free'd by the other thread.
- Replace the lockmgr lock in the dirhash structure with an sx lock.
- Use a reference count managed with ufsdirhash_hold()/drop() to determine
when to free the dirhash structures. The directory i-node holds a
reference while the dirhash is attached to an i-node. Code that wishes
to lock the dirhash while holding a shared vnode lock must first
acquire a private reference to the dirhash while holding the vnode
interlock before acquiring the dirhash sx lock. After acquiring the sx
lock, it drops the private reference after checking to see if the
dirhash is still used by the directory i-node.
non-LOOKUP operations.
- Relax a VOP assertion for a DELETE lookup. rename() uses WANTPARENT
instead of LOCKPARENT when looking up the source pathname. ufs_rename()
uses a relookup() to lock the parent directory when it decides to finally
remove the source path. Thus, it is ok for a DELETE with WANTPARENT set
instead of LOCKPARENT to use a shared vnode lock rather than an exclusive
vnode lock.
Reported by: kris (2)
Reviewed by: jeff
upgrades the vnode lock if it is share locked was dropping the interlock
before actually checking VI_DOOMED. Fix this by do the vdropl() after the
check and relying on it to drop the vnode interlock.
Reported by: pho
Reviewed by: kib
MFC after: 1 week
wait until the current suspension is lifted instead of silently returning
success immediately. The consequences of calling vfs_write() resume when
not owning the suspension are not well-defined at best.
Add the vfs_susp_clean() mount method to be called from
vfs_write_resume(). Set it to process_deferred_inactive() for ffs, and
stop calling it manually.
Add the thread flag TDP_IGNSUSP that allows to bypass the suspension
point in the vn_start_write. It is intended for use by VFS in the
situations where the suspender want to do some i/o requiring calls to
vn_start_write(), and this i/o cannot be done later.
Reviewed by: tegge
In collaboration with: pho
MFC after: 1 month
Show the b_dep value for the buffer in the show buffer command.
Add a comand to dump the dirty/clean buffer list for vnode.
Reviewed by: tegge
Tested and used by: pho
MFC after: 1 month
MNT_RDONLY flag before the VFS_MOUNT() is called. In ufs_inactive()
and ufs_itimes_locked(), UFS verifies whether the fs is read-only by
checking MNT_RDONLY, but this may cause loss of the IN_MODIFIED flag
for inode on the fs being remounted rw->ro.
Introduce UFS_RDONLY() struct ufsmount' method that reports the value
of the fs_ronly. The later is set to 1 only after the remount is
finished.
Reviewed by: tegge
In collaboration with: pho
MFC after: 1 month
inode having number ino. In r170991, the ip was marked IN_MODIFIED, that
is not quite correct.
Mark only the right inode modified by checking inode number.
Reviewed by: tegge
In collaboration with: pho
MFC after: 1 month
insert new vnode into the mount vnode list. Then, for the SU-enabled
mount, ffs_vfree could create freefile dependency. This dependency can
hang around forever since inode is not marked as IN_MODIFIED and
correspondingly inodeblock may be not marked as dirty.
After ffs_vget() fails, retry with FFSV_FORCEINSMQ, mark the inode as
modified, and vput() it immediately. Take care of the dup alloc.
Tested by: pho
Reviewed by: tegge
MFC after: 1 month
dependencies. In particular, it may need this while syncing filesystem
being unmounted. Since during unmount MNTK_NOINSMNTQUE flag is set,
that could sometimes disallow insertion of the vnode into the vnode
mount list, softdep code needs to overwrite the MNTK_NOINSMNTQUE flag.
Create the ffs_vgetf() function that sets the VV_FORCEINSMQ flag for
new vnode and use it consistently from the softdep code instead of
ffs_vget().
Add the retry logic to the softdep_flushfiles() to flush the vnodes
that could be instantiated while flushing softdep dependencies.
Tested by: pho, kris
Reviewed by: tegge
MFC after: 1 month
ufs_access()." The call to getinoquota in ufs_access() serves the
purpose of instantiating inode dquot from the vn_open(). Since quotas
are accounted only for the inodes with already attached dquot, removal
of the call prevented opened inodes from participation in the quota
calculations.
Since ufs_access() may be called with the vnode being only shared
locked, upgrade (and then downgrade) vnode lock if calling
getinoquota().
Reported by: simon at optinet com
In collaboration with: pho
MFC after: 1 week
performed with snapshot option, while the mp->mnt_opt is NULL.
Protect against NULL pointer dereference.
Noted by: Mateusz Guzik <mjguzik gmail com>
MFC after: 3 days
vnode buffers locked at once. In particular, there are indirect buffers
among locked ones. The bdwrite() may start the flushing to keep dirty
buffer list at the bounds. If any buffer on the dirty list requires
translation from logical to physical block number, code may ends up
trying to lock an indirect buffer already locked in ffs_balloc_ufsX.
Prevent the bdflush() activity when several buffers are locked at once
by setting the TDP_INBDFUSH for the problematic code blocks.
Reported and tested by: pho, Josef Buchsteiner at Juniper
In collaboration with: kan
MFC after: 1 month
delete "snapshot" from the persistent mount options list.
This should fix problems with doing a mount -o snapshot of a file system, followed by
an NFS export of the same file system.
PR: 122833
Reported by: Leon Kos <leon.kos lecad fs uni-lj si>,
Jaakko Heinonen <jh saunalahti fi>
MFC after: 1 month
here, because we already do them further up in vfs_donmount() in vfs_mount.c
async -> MNT_ASYNC
force -> MNT_FORCE
multilabel -> MNT_MULTILABEL
noatime -> MNT_NOATIME
noclusterr -> MNT_NOCLUSTERR
noclusterw -> MNT_NOCLUSTERW
MFC after: 1 month
Directory IO without a VM object will store data in 'malloced' buffers
severely limiting caching of the data. Without this change VM objects for
directories are only created on an open() of the directory.
TODO: Inline test if VM object already exists to avoid locking/function call
overhead.
Tested by: kris@
Reviewed by: jeff@
Reported by: David Filo
communicate between two parts of this one function. This was causing
problems with shared lookups as each would trash the ino value in the
inode.
- Remove the unused i_ino field from the inode structure.
filesystem-specific vnode data to the struct vnode. Provide the
default implementation for the vop_advlock and vop_advlockasync.
Purge the locks on the vnode reclaim by using the lf_purgelocks().
The default implementation is augmented for the nfs and smbfs.
In the nfs_advlock, push the Giant inside the nfs_dolock.
Before the change, the vop_advlock and vop_advlockasync have taken the
unlocked vnode and dereferenced the fs-private inode data, racing with
with the vnode reclamation due to forced unmount. Now, the vop_getattr
under the shared vnode lock is used to obtain the inode size, and
later, in the lf_advlockasync, after locking the vnode interlock, the
VI_DOOMED flag is checked to prevent an operation on the doomed vnode.
The implementation of the lf_purgelocks() is submitted by dfr.
Reported by: kris
Tested by: kris, pho
Discussed with: jeff, dfr
MFC after: 2 weeks
may be held for the duration of the various dirhash operations which
avoids many complex unlock/lock/revalidate sequences.
- Permit shared locks on lookup. To protect the ip->i_dirhash pointer we
use the vnode interlock in the shared case. Callers holding the
exclusive vnode lock can run without fear of concurrent modification to
i_dirhash.
- Hold an exclusive dirhash lock when creating the dirhash structure for
the first time or when re-creating a dirhash structure which has been
recycled.
Tested by: kris, pho
indexes so directory lookup becomes shared lock safe. In the modifying
cases an exclusive lock is held here so the commit routine may
rely on the state of i_offset.
- Similarly handle i_diroff by fetching at the start and setting only once
the operation is complete. Without the exclusive lock these are only
considered hints.
- Assert that an exclusive lock is held when we're preparing for a commit
routine.
- Honor the lock type request from lookup instead of always using exclusive
locking.
Tested by: pho, kris
state transitioning flags and of msleep(9) callings.
Use, instead, an algorithm very similar to what sx(9) and rwlock(9)
alredy do and direct accesses to the sleepqueue(9) primitive.
In order to avoid writer starvation a mechanism very similar to what
rwlock(9) uses now is implemented, with the correspective per-thread
shared lockmgrs counter.
This patch also adds 2 new functions to lockmgr KPI: lockmgr_rw() and
lockmgr_args_rw(). These two are like the 2 "normal" versions, but they
both accept a rwlock as interlock. In order to realize this, the general
lockmgr manager function "__lockmgr_args()" has been implemented through
the generic lock layer. It supports all the blocking primitives, but
currently only these 2 mappers live.
The patch drops the support for WITNESS atm, but it will be probabilly
added soon. Also, there is a little race in the draining code which is
also present in the current CVS stock implementation: if some sharers,
once they wakeup, are in the runqueue they can contend the lock with
the exclusive drainer. This is hard to be fixed but the now committed
code mitigate this issue a lot better than the (past) CVS version.
In addition assertive KA_HELD and KA_UNHELD have been made mute
assertions because they are dangerous and they will be nomore supported
soon.
In order to avoid namespace pollution, stack.h is splitted into two
parts: one which includes only the "struct stack" definition (_stack.h)
and one defining the KPI. In this way, newly added _lockmgr.h can
just include _stack.h.
Kernel ABI results heavilly changed by this commit (the now committed
version of "struct lock" is a lot smaller than the previous one) and
KPI results broken by lockmgr_rw() / lockmgr_args_rw() introduction,
so manpages and __FreeBSD_version will be updated accordingly.
Tested by: kris, pho, jeff, danger
Reviewed by: jeff
Sponsored by: Google, Summer of Code program 2007
to protect the v_lock pointer. Removing the interlock acquisition
here allows vn_lock() to proceed without requiring the interlock
at all.
- If the lock mutated while we were sleeping on it the interlock has
been dropped. It is conceivable that the upper layer code was
relying on the interlock and LK_NOWAIT to protect the identity or
state of the vnode while acquiring the lock. In this case return
EBUSY rather than trying the new lock to prevent potential races.
Reviewed by: tegge
Keeping the lockmgr lock valid allows us to switch the v_lock pointer
in snapshot vnodes between the embedded lockmgr lock and snapdata
lock without needing the vnode interlock to protect against races
- Keep unused snapdata structures in a list.
- Add a function to lock the devvp and allocate a snapdata to it or
acquire a new one without races. The old function was safe from
creation races because we set the mount flag when creating snapshots
and thus serializing them. However, it might have been subject to
destroying races.
Reviewed by: tegge
(such as 'atime' vs 'noatime'). The filesystems will always see either
'nofoo' or 'nonofoo', never plain 'foo'. As such, their list of valid
mount options should include 'nofoo' instead of 'foo'. With this fix,
you can do 'mount -u -o atime' on a FFS filesystem that isn't marked as
noatime without getting an error. You can also update a noatime FFS
filesystem mounted via mount(2) (e.g. 6.x /sbin/mount binary) to 'atime'
using nmount(2) (e.g. 7.x /sbin/mount binary).
MFC after: 1 week
Reviewed by: crodig
