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
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
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
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
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
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
- 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
Use file name hash as a tree key, handle duplicate keys. Both VOP_LOOKUP
and VOP_READDIR operations utilize same tree for search. Directory
entry offset (cookie) is either file name hash or incremental id in case
of hash collisions (duplicate-cookies). Keep sorted per directory list
of duplicate-cookie entries to facilitate cookie number allocation.
Don't fail if previous VOP_READDIR() offset is no longer valid, start
with next dirent instead. Other file system handle it similarly.
Workaround race prone tn_readdir_last[pn] fields update.
Add tmpfs_dir_destroy() to free all dirents.
Set NFS cookies in tmpfs_dir_getdents(). Return EJUSTRETURN from
tmpfs_dir_getdents() instead of hard coded -1.
Mark directory traversal routines static as they are no longer
used outside of tmpfs_subr.c
Since r230208 update mounts were allowed if the list of mount options
contained the "export" option. This is not correct as tmpfs doesn't
really support updating all options.
Reviewed by: kevlo, trociny
allocator.
Replace UINT32_MAX checks with INT_MAX. Keeping more than 2^31 nodes in
memory is not likely to become possible in foreseeable feature and would
require new unit number allocator.
Discussed with: delphij
MFC after: 2 weeks
-- highly experimental even. So far the closest to a bug in TMPFS that people
have gotten to relates to how ZFS can take away from the memory that TMPFS
needs. One can argue that such is not a bug in TMPFS. Irrespective, even if
there is a bug here and there in TMPFS, it's not in our own advantage to
scare people away from using TMPFS. I for one have been using it, even with
ZFS, very successfully.
method, so that callers can indicate the minimum vnode
locking requirement. This will allow some file systems to choose
to return a LK_SHARED locked vnode when LK_SHARED is specified
for the flags argument. This patch only adds the flag. It
does not change any file system to use it and all callers
specify LK_EXCLUSIVE, so file system semantics are not changed.
Reviewed by: kib
maximum file size limit. Default is UINT64_MAX when the option is
not specified. It was useless to set the limit to the total amount of
memory and swap in the system.
Use tmpfs_mem_info() rather than get_swpgtotal() in tmpfs_mount() to
check if there is enough memory available.
Remove now unused get_swpgtotal().
Reviewed by: Gleb Kurtsou
Approved by: trasz (mentor)
convert its value. [1]
- Set default tm_nodes_max to min(pages + 3, UINT32_MAX). It's more
reasonable than the old four nodes per page (with page size 4096) because
non-empty regular files always use at least one page. This fixes possible
overflow in the calculation. [2]
- Don't allow more than tm_nodes_max nodes allocated in tmpfs_alloc_node().
PR: kern/138367
Suggested by: bde [1], Gleb Kurtsou [2]
Approved by: trasz (mentor)
with vfs_scanopt(9) using the "%qu" format string.
- Limit the maximum value of size_max to (SIZE_MAX - PAGE_SIZE) to
prevent overflow in howmany() macro.
PR: kern/141194
Approved by: trasz (mentor)
MFC after: 2 weeks
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.
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
conjuction with 'thread' argument passing which is always curthread.
Remove the unuseful extra-argument and pass explicitly curthread to lower
layer functions, when necessary.
KPI results broken by this change, which should affect several ports, so
version bumping and manpage update will be further committed.
Tested by: kris, pho, Diego Sardina <siarodx at gmail dot com>
Remove this argument and pass curthread directly to underlying
VOP_LOCK1() VFS method. This modify makes the code cleaner and in
particular remove an annoying dependence helping next lockmgr() cleanup.
KPI results, obviously, changed.
Manpage and FreeBSD_version will be updated through further commits.
As a side note, would be valuable to say that next commits will address
a similar cleanup about VFS methods, in particular vop_lock1 and
vop_unlock.
Tested by: Diego Sardina <siarodx at gmail dot com>,
Andrea Di Pasquale <whyx dot it at gmail dot com>
strees2 suite, to quote his letter, this change:
1. It removes the tn_lookup_dirent stuff. I think this cannot be fixed,
because nothing protects vnode/tmpfs node between lookup is done, and
actual operation is performed, in the case the vnode lock is dropped.
At least, this is the case with the from vnode for rename.
For now, we do the linear lookup in the parent node. This has its own
drawbacks. Not mentioning speed (that could be fixed by using hash), the
real problem is the situation where several hardlinks exist in the dvp.
But, I think this is fixable.
2. The patch restores the VV_ROOT flag on the root vnode after it became
reclaimed and allocated again. This fixes MPASS assertion at the start
of the tmpfs_lookup() reported by many.
Submitted by: kib
- Respect cnflag and don't lock vnode always as LK_EXCLUSIVE [1]
- Properly lock around tn_vnode to avoid NULL deference
- Be more careful handling vnodes (*)
(*) This is a WIP
[1] by pjd via howardsu
Thanks kib@ for his valuable VFS related comments.
Tested with: fsx, fstest, tmpfs regression test set
Found by: pho's stress2 suite
Approved by: re (tmpfs blanket)
This fixes tmpfs caculations on 32-bit systems equipped with more than
4GB swap.
Reported by: Craig Boston <craig xfoil gank org>
PR: kern/114870
Approved by: re (tmpfs blanket)
physical memory pages into account for tm_maxfilesize.
Reported by: Dominique Goncalves <dominique.goncalves gmail.com>
Submitted by: Howard Su
Approved by: re (tmpfs blanket)
- Plug memory leak.
- Respect underlying vnode's properties rather than assuming that
the user want root:wheel + 0755. Useful for using tmpfs(5) for
/tmp.
- Use roundup2 and howmany macros instead of rolling our own version.
- Try to fix fsx -W -R foo case.
- Instead of blindly zeroing a page, determine whether we need a pagein
order to prevent data corruption.
- Fix several bugs reported by Coverity.
Submitted by: Mingyan Guo <guomingyan gmail com>, Howard Su, delphij
Coverity ID: CID 2550, 2551, 2552, 2557
Approved by: re (tmpfs blanket)
- Remove unnecessary NULL checks after M_WAITOK allocations.
- Use VOP_ACCESS instead of hand-rolled suser_cred()
calls. [1]
- Use malloc(9) KPI to allocate memory for string. The
optimization taken from NetBSD is not valid for FreeBSD
because our malloc(9) already act that way. [2]
Requested by: rwatson [1]
Submitted by: Howard Su [2]
Approved by: re (tmpfs blanket)
