The option "nonc" disables using of namecache for the created mount,
by default namecache is used. The rationale for the option is that
namecache duplicates the information which is already kept in memory
by tmpfs. Since it believed that namecache scales better than tmpfs,
or will scale better, do not enable the option by default. On the
other hand, smaller machines may benefit from lesser namecache
pressure.
Discussed with: mjg
Tested by: pho (as part of larger patch)
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
For directories, node->tn_spec.tn_dir.tn_parent pointer to the parent
is used. For non-directories, the implementation is naive, all
directory nodes are scanned to find a dirent linking the specified
node. This can be significantly improved by maintaining tn_parent for
all nodes, later.
Tested by: pho (as part of larger patch)
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
On dotdot lookup and fhtovp operations, it is possible for the file
represented by tmpfs node to be removed after the thread calculated
the pointer. In this case, tmpfs_alloc_vp() accesses freed memory.
Introduce the reference count on the nodes. The allnodes list from
tmpfs mount owns 1 reference, and threads performing unlocked
operations on the node, add one transient reference. Similarly, since
struct tmpfs_mount maintains the list where nodes are enlisted,
refcount it by one reference from struct mount and one reference from
each node on the list. Both nodes and tmpfs_mounts are removed when
refcount goes to zero.
Note that this means that nodes and tmpfs_mounts might survive some
time after the node is deleted or tmpfs_unmount() finished. The
tmpfs_alloc_vp() in these cases returns error either due to node
removal (tn_nlinks == 0) or because of insmntque1(9) error.
Tested by: pho (as part of larger patch)
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Remove TMPFS_ASSERT_ELOCKED(). Its claims are already stated by other
asserts nearby and by VFS guarantees.
Change TMPFS_ASSERT_LOCKED() and one inlined place to use
ASSERT_VOP_(E)LOCKED() instead of hand-rolled imprecise asserts.
Tested by: pho (as part of the larger patch)
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Edit comments which explain no longer relevant details, and add
locking annotations to the struct tmpfs_node members.
Tested by: pho (as part of the larger patch)
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
If tmpfs vnode is only shared locked, tn_status field still needs
updates to note the access time modification. Use the same locking
scheme as for UFS, protect tn_status with the node interlock + shared
vnode lock.
Fix nearby style.
Noted and reviewed by: mjg
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
truncation, immediately queue the page for asynchronous laundering rather
than making the page pass through inactive queue first.
Reviewed by: kib, markj
longer used. More precisely, they are always zero because the code that
decremented and incremented them no longer exists.
Bump __FreeBSD_version to mark this change.
Reviewed by: kib, markj
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D8583
not remove user-space visible fields from vm_cnt or all of the references to
cached pages from comments. Those changes will come later.)
Reviewed by: kib, markj
Tested by: pho
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D8497
The offset of the directory file, passed to getdirentries(2) syscall,
is user-controllable. The value of the offset must not be asserted,
instead the invalid value should be checked and rejected if invalid.
Reported and tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
It is otherwise left dangling, and callers that request cookies always free
the cookie buffer, even when VOP_READDIR(9) returns an error. This results
in a double free if tmpfs_readdir() returns an error to the NFS server or
the Linux getdents(2) emulation code.
Reported by: pho
MFC after: 1 week
Security: double free of malloc(9)-backed memory
Sponsored by: EMC / Isilon Storage Division
o With new KPI consumers can request contiguous ranges of pages, and
unlike before, all pages will be kept busied on return, like it was
done before with the 'reqpage' only. Now the reqpage goes away. With
new interface it is easier to implement code protected from race
conditions.
Such arrayed requests for now should be preceeded by a call to
vm_pager_haspage() to make sure that request is possible. This
could be improved later, making vm_pager_haspage() obsolete.
Strenghtening the promises on the business of the array of pages
allows us to remove such hacks as swp_pager_free_nrpage() and
vm_pager_free_nonreq().
o New KPI accepts two integer pointers that may optionally point at
values for read ahead and read behind, that a pager may do, if it
can. These pages are completely owned by pager, and not controlled
by the caller.
This shifts the UFS-specific readahead logic from vm_fault.c, which
should be file system agnostic, into vnode_pager.c. It also removes
one VOP_BMAP() request per hard fault.
Discussed with: kib, alc, jeff, scottl
Sponsored by: Nginx, Inc.
Sponsored by: Netflix
determining whether a node changed.
Other filesystems, e.g., UFS, only check on seconds, when determining
whether something changed.
This also corrects the birthtime case, where we checked tv_nsec
twice, instead of tv_sec and tv_nsec (PR).
PR: 201284
Submitted by: David Binderman
Patch suggested by: kib
Reviewed by: kib
MFC after: 2 weeks
Committed from: Essen FreeBSD Hackathon
This obviates the need for a MNTK_SUSPENDABLE flag, since passthrough
filesystems like nullfs and unionfs no longer need to inherit this
information from their lower layer(s). This change also restores the
pre-r273336 behaviour of using the presence of a susp_clean VFS method to
request suspension support.
Reviewed by: kib, mjg
Differential Revision: https://reviews.freebsd.org/D2937
* GENERAL
- Update copyright.
- Make kernel options for RANDOM_YARROW and RANDOM_DUMMY. Set
neither to ON, which means we want Fortuna
- If there is no 'device random' in the kernel, there will be NO
random(4) device in the kernel, and the KERN_ARND sysctl will
return nothing. With RANDOM_DUMMY there will be a random(4) that
always blocks.
- Repair kern.arandom (KERN_ARND sysctl). The old version went
through arc4random(9) and was a bit weird.
- Adjust arc4random stirring a bit - the existing code looks a little
suspect.
- Fix the nasty pre- and post-read overloading by providing explictit
functions to do these tasks.
- Redo read_random(9) so as to duplicate random(4)'s read internals.
This makes it a first-class citizen rather than a hack.
- Move stuff out of locked regions when it does not need to be
there.
- Trim RANDOM_DEBUG printfs. Some are excess to requirement, some
behind boot verbose.
- Use SYSINIT to sequence the startup.
- Fix init/deinit sysctl stuff.
- Make relevant sysctls also tunables.
- Add different harvesting "styles" to allow for different requirements
(direct, queue, fast).
- Add harvesting of FFS atime events. This needs to be checked for
weighing down the FS code.
- Add harvesting of slab allocator events. This needs to be checked for
weighing down the allocator code.
- Fix the random(9) manpage.
- Loadable modules are not present for now. These will be re-engineered
when the dust settles.
- Use macros for locks.
- Fix comments.
* src/share/man/...
- Update the man pages.
* src/etc/...
- The startup/shutdown work is done in D2924.
* src/UPDATING
- Add UPDATING announcement.
* src/sys/dev/random/build.sh
- Add copyright.
- Add libz for unit tests.
* src/sys/dev/random/dummy.c
- Remove; no longer needed. Functionality incorporated into randomdev.*.
* live_entropy_sources.c live_entropy_sources.h
- Remove; content moved.
- move content to randomdev.[ch] and optimise.
* src/sys/dev/random/random_adaptors.c src/sys/dev/random/random_adaptors.h
- Remove; plugability is no longer used. Compile-time algorithm
selection is the way to go.
* src/sys/dev/random/random_harvestq.c src/sys/dev/random/random_harvestq.h
- Add early (re)boot-time randomness caching.
* src/sys/dev/random/randomdev_soft.c src/sys/dev/random/randomdev_soft.h
- Remove; no longer needed.
* src/sys/dev/random/uint128.h
- Provide a fake uint128_t; if a real one ever arrived, we can use
that instead. All that is needed here is N=0, N++, N==0, and some
localised trickery is used to manufacture a 128-bit 0ULLL.
* src/sys/dev/random/unit_test.c src/sys/dev/random/unit_test.h
- Improve unit tests; previously the testing human needed clairvoyance;
now the test will do a basic check of compressibility. Clairvoyant
talent is still a good idea.
- This is still a long way off a proper unit test.
* src/sys/dev/random/fortuna.c src/sys/dev/random/fortuna.h
- Improve messy union to just uint128_t.
- Remove unneeded 'static struct fortuna_start_cache'.
- Tighten up up arithmetic.
- Provide a method to allow eternal junk to be introduced; harden
it against blatant by compress/hashing.
- Assert that locks are held correctly.
- Fix the nasty pre- and post-read overloading by providing explictit
functions to do these tasks.
- Turn into self-sufficient module (no longer requires randomdev_soft.[ch])
* src/sys/dev/random/yarrow.c src/sys/dev/random/yarrow.h
- Improve messy union to just uint128_t.
- Remove unneeded 'staic struct start_cache'.
- Tighten up up arithmetic.
- Provide a method to allow eternal junk to be introduced; harden
it against blatant by compress/hashing.
- Assert that locks are held correctly.
- Fix the nasty pre- and post-read overloading by providing explictit
functions to do these tasks.
- Turn into self-sufficient module (no longer requires randomdev_soft.[ch])
- Fix some magic numbers elsewhere used as FAST and SLOW.
Differential Revision: https://reviews.freebsd.org/D2025
Reviewed by: vsevolod,delphij,rwatson,trasz,jmg
Approved by: so (delphij)
dup entry, upon detach from the parent directory. If the node is
renamed, the entry is re-attached at the different directory, and
invalud cookie value triggers assert (or corrupts directory rb tree,
it seems).
Reported by: clusteradm (gjb, antoine)
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
in the requested array, then it is responsible for disposition of previous
page and is responsible for updating the entry in the requested array.
Now consumers of KPI do not need to re-lookup the pages after call to
vm_pager_get_pages().
Reviewed by: kib
Sponsored by: Netflix
Sponsored by: Nginx, Inc.
For VREG vnodes, return the resident page count (multiplied by PAGE_SIZE)
for the tmpfs node's anonymous VM object that stores actual file contents.
For all other vnodes, return the tmpfs_node's tn_size, which should not
be rounded to a page.
This change allows using stat(2) to identify a sparse file on tmpfs.
Reviewed by: kib
MFC after: 1 week
removed. Postponing it until tmpfs_getattr() is called causes
discordant values reported for file times vs. directory times.
Reported and tested by: madpilot
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
modification and last file status change timestamps of the file".
Currently, tmpfs only modifies ctime when file was extended. Since
r277828 followed tmpfs_write(), mmaped writes also do not modify
ctime.
Fix this, by updating both ctime and mtime for writes to tmpfs files.
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
to UFS, perform updates during syncer scans, which in particular means
that tmpfs now performs scan on sync. Also, this means that a mtime
update may be delayed up to 30 seconds after the write.
The vm_object' OBJ_TMPFS_DIRTY flag for tmpfs swap object is similar
to the OBJ_MIGHTBEDIRTY flag for the vnode object, it indicates that
object could have been dirtied. Adapt fast page fault handler and
vm_object_set_writeable_dirty() to handle OBJ_TMPFS_NODE same as
OBJT_VNODE.
Reported by: Ronald Klop <ronald-lists@klop.ws>
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
into namecache, to avoid cache trashing when doing large operations.
E.g., tar archive extraction is not usually followed by access to many
of the files created.
Right now, each VOP_LOOKUP() implementation explicitely knowns about
this quirk and tests for both MAKEENTRY flag presence and op != CREATE
to make the call to cache_enter(). Centralize the handling of the
quirk into VFS, by deciding to cache only by MAKEENTRY flag in VOP.
VFS now sets NOCACHE flag for CREATE namei() calls.
Note that the change in semantic is backward-compatible and could be
merged to the stable branch, and is compatible with non-changed
third-party filesystems which correctly handle MAKEENTRY.
Suggested by: Chris Torek <torek@pi-coral.com>
Reviewed by: mckusick
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
two.
nullfs and unionfs need to request suspension if underlying filesystem(s)
use it. Utilize mnt_kern_flag for this purpose.
This is a fixup for 273271.
No strong objections from: kib
Pointy hat to: mjg
MFC after: 2 weeks
forcing filesystem VOP_LINK() methods to repeat the code. In
tmpfs_link(), remove redundand check for the type of the source,
already done by VFS.
Note that NFS server already performs this check before calling
VOP_LINK().
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
- Suspend filesystem for unmount. This prevents new tmpfs nodes from
instantiating, and also ensures that only unmount thread can destroy
nodes.
- Do not start tmpfs node deletion until all vnodes are reclaimed,
which guarantees that no thread can access tmpfs data. For this,
call vflush() in the loop, until the mnt_nvnodelistsize is non-zero.
Note that after mnt_nvnodelistsize becomes 0, insmntque() blocks
insertion of a vnode germ into the mount list of vnodes.
- Fail node allocation when the filesystem is being unmounted. This
is race-free due to the vflush() call in loop. This is mostly
cosmetic, avoiding some more work which might be done until
suspension in unmount is started.
Note that there is currently no way to prevent new vnode instantiation
from readers during the unmount. Due to this, forced unmount might
live-lock if vflush() loop cannot get to the zero vnode count due to
races with readers. The unmount would proceed after the load is
lifted.
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
