branches: 1.1.6;
Add overlay, a layered file system which overlays itself on
the underlying fs, rather than exporting it to another part of the
directory name space.

Define layerfs as an attribute.

Define filesystem attributes with vfs dependency.

branches: 1.1.6; 1.1.8; 1.1.162;
Cleanup how file system configuration information is declared, grouping
related information together, with the file system code itself.

This is just low-hanging fruit -- more to come.

Field "layerm_vfs" of "struct layer_mount" got superseded by "mnt_lower".
Adapt consumers and remove the now unused field.

Ride 7.99.68

branches: 1.8.40; 1.8.60; 1.8.64; 1.8.68;
Create sysctl entries during module initialisation and destroy them
appropriately.

Many of these file systems are now ready for modularisation.

branches: 1.7.70; 1.7.74; 1.7.76; 1.7.78;
merge ktrace-lwp.

Remove __P()

branches: 1.5.12;
Tweak sysctl setup functions (the macros, actually) for use in lkms,
and tweak lkminit_*.c (where applicable) to call them, and to call
sysctl_teardown() when being unloaded.

This consists of (1) making setup functions not be static when being
compiled as lkms (change to sys/sysctl.h), (2) making prototypes
visible for the various setup functions in header files (changes to
various header files), and (3) making simple "load" and "unload"
functions in the actual lkminit stuff.

linux_sysctl.c also needs its root exposed (ie, made not static) for
this (when built as an lkm).

branches: 1.4.2;
Move UCB-licensed code from 4-clause to 3-clause licence.

Patches provided by Joel Baker in PR 22364, verified by myself.

branches: 1.3.22;
Typos and grammer fixes in comments (misc/13133 by Michael K. Sanders)

branches: 1.2.6; 1.2.8;
Fix doubled 'the's in comments.

Add overlay, a layered file system which overlays itself on
the underlying fs, rather than exporting it to another part of the
directory name space.

remove unecessary branches

branches: 1.73.8;
Add a helper to set or clear lower mount and use it.
Always add a reference to the lower mount.

Ride 9.99.105

Don't use LK_RETRY as we need an active vnode here.

Replace most uses of vp->v_usecount with a call to vrefcnt(vp), a function
that hides the details and does atomic_load_relaxed(). Signature matches
FreeBSD.

branches: 1.70.2;
Finish the transition to SYSCTL_SETUP by removing local sysctllog
in favor of the one provided by the module infrastructure.

Use the module subsystem's ability to process SYSCTL_SETUP() entries to
automate installation of sysctl nodes.

Note that there are still a number of device and pseudo-device modules
that create entries tied to individual device units, rather than to the
module itself. These are not changed.

Set "mnt_lower" before the first file system operation on the new file system.

branches: 1.67.12;
Field "layerm_vfs" of "struct layer_mount" got superseded by "mnt_lower".
Adapt consumers and remove the now unused field.

Ride 7.99.68

Change _fstrans_start() to allocate per lwp info for layered file
systems to get a reference on the mount.

Set mnt_lower on successfull mount only.

Add field "mnt_lower" to "struct mount" to track the file system
a layered file system is mounted on.

Welcome to 7.99.65

Add generic genfs_suspendctl() and use it for all file systems.
Layered file systems need work.

branches: 1.63.2; 1.63.4; 1.63.6;
Do not uselessly include <sys/malloc.h>.

branches: 1.62.2;
Change layerfs from hashlist to vcache.
Make VI_LOCKSHARE public again.

Ride 6.99.43

An (un)privileged user can easily make the kernel dereference a NULL
pointer.

The kernel allows 'data' to be NULL; it's the fs's responsibility to
ensure that it isn't NULL (if the fs actually needs data).

ok christos@

branches: 1.60.2;
Change all vfsops to use C99 designated initializers.

No functional changes intended.

Ensure that the top level sysctl nodes (kern, vfs, net, ...) exist before
the sysctl link sets are processed, and remove redundancy.

Shaves >13kB off of an amd64 GENERIC, not to mention >1k duplicate
lines of code.

Change layerfs_vget(), layerfs_fhtovp() and the various layer xxx_mount()
functions to unlock/relock the node for the call to layer_node_create().

Finally remove dirty hacks (LK_NOWAIT, kpause) from layer_node_find().

branches: 1.57.2; 1.57.4;
- Replace some malloc(9) uses with kmem(9).
- G/C M_IPMOPTS, M_IPMADDR and M_BWMETER.

branches: 1.56.8; 1.56.12; 1.56.14; 1.56.18; 1.56.20;
Replace vget() with vref()/vn_lock(), this node already has a reference.

Clean up vnode lock operations pass 2:

VOP_UNLOCK(vp, flags) -> VOP_UNLOCK(vp): Remove the unneeded flags argument.

Welcome to 5.99.32.

Discussed on tech-kern.

branches: 1.54.6; 1.54.8;
PR kern/40110: null, overlay and umap modules loading -> panic (layerfs symbols not there)

Add a layerfs module.

branches: 1.53.2; 1.53.4; 1.53.6; 1.53.12; 1.53.16;
Create sysctl entries during module initialisation and destroy them
appropriately.

Many of these file systems are now ready for modularisation.

branches: 1.52.2;
mnt_data is a pointer, set it to NULL not 0 when we're finished with it.

Convert file systems to dynamically attach with the new module interface.
Make VFS hooks dynamic while we're here and say farewell to VFS_ATTACH and
VFS_HOOKS_ATTACH linksets.

As a consequence, most of the file systems can now be loaded as new style
modules.

Quick sanity check by ad@.

branches: 1.50.2;
- Convert hashinit() to use kmem_alloc(). The hash tables can be large
and it's better to not have them in kmem_map.
- Convert a couple of minor items along the way to kmem_alloc().
- Fix some memory leaks.

PR kern/38057 ffs makes assuptions about devvp file system
PR kern/33406 softdeps get stuck in endless loop

Introduce VFS_FSYNC() and call it when syncing a block device, if it
has a mounted file system.

branches: 1.48.6; 1.48.8; 1.48.10;
Fix some race conditions in rename.
Introduce a per-FS rename lock and new vfsops to manipulate it.
Get this lock while renaming. Also add another relookup() in do_sys_rename,
which is a hack to kludge around some of the worst deficiencies of
ufs_rename.
reviewed-by: pooka (and an earlier rev by ad)
posted on tech-kern with no objections.

Merge vmlocking2 to head.

branches: 1.46.4;
Destroy ovm_hashlock before freeing.

branches: 1.45.2;
Remove the "struct lwp *" argument from all VFS and VOP interfaces.
The general trend is to remove it from all kernel interfaces and
this is a start. In case the calling lwp is desired, curlwp should
be used.

quick consensus on tech-kern

branches: 1.44.4;
Merge from vmlocking:

- Split vnode::v_flag into three fields, depending on field locking.
- simple_lock -> kmutex in a few places.
- Fix some simple locking problems.

branches: 1.43.2; 1.43.4; 1.43.6; 1.43.8;
* nuke the nameidata parameter from VFS_MOUNT(). Nobody on tech-kern
knew what it was supposed to be used for and wrstuden gave a go-ahead
* while rototilling, convert file systems which went easily to
use VFS_PROTOS() instead of manually prototyping the methods

Use eopnotsupp() instead of vfs_stdsuspendctl() and retire the latter.

branches: 1.41.2;
Make set_statvfs_info() take a parameter for the vfs name instead
of always retrieving it from mp->mnt_op->vfs_name

christos ok

Change the VFS_MOUNT() interface so that the 'data' buffer passed to the
fs code is a kernel buffer, pass though the length of the buffer as well.
Since the length of the userspace buffer isn'it (yet) passed through the mount
system call, add a field to the vfsops structure containing the default length.
Split sys_mount() for calls from compat code.
Ride one of the recent kernel version changes - old fs LKMs will load, but
sys_mount() will reject any attempt to use them.

* allow unmount even if rootvp has a usecount > 1 provided that
MNT_FORCE is given
* decrease cargo cult index by getting rid of commented sections
with mntflushbuf() in them - AFAICT the call was removed from our
kernel over 13 years ago with the 4.4BSDlite import

Remove now obsolete vn_start_write() and vn_finished_write() and
corresponding flags.

Revert softdep_trackbufs() to its state before vn_start_write() was added.

Remove from struct mount now unneeded flags IMNT_SUSPEND* and
members mnt_writeopcountupper, mnt_writeopcountlower and mnt_leaf.

Welcome to 4.99.17

branches: 1.37.2; 1.37.6; 1.37.8; 1.37.10;
New file system suspension API to replace vn_start_write and vn_finished_write.
The suspension helpers are now put into file system specific operations.
This means every file system not supporting these helpers cannot be suspended
and therefore snapshots are no longer possible.

Implemented for file systems of type ffs.

The new API is enabled on a kernel option NEWVNGATE. This option is
not enabled by default in any kernel config.

Presented and discussed on tech-kern with much input from
Bill Studenmund <wrstuden@netbsd.org> and YAMAMOTO Takashi <yamt@netbsd.org>.

Welcome to 4.99.9 (new vfs op vfs_suspendctl).

__unused removal on arguments; approved by core.

- sprinkle __unused on function decls.
- fix a couple of unused bugs
- no more -Wno-unused for i386

branches: 1.34.2; 1.34.4;
add missing initializers

branches: 1.33.4; 1.33.8;
merge ktrace-lwp.

Apply the NFS exports list rototill patch:

- Remove all NFS related stuff from file system specific code.
- Drop the vfs_checkexp hook and generalize it in the new nfs_check_export
function, thus removing redundancy from all file systems.
- Move all NFS export-related stuff from kern/vfs_subr.c to the new
file sys/nfs/nfs_export.c. The former was becoming large and its code
is always compiled, regardless of the build options. Using the latter,
the code is only compiled in when NFSSERVER is enabled. While doing this,
also make some functions in nfs_subs.c conditional to NFSSERVER.
- Add a new command in nfssvc(2), called NFSSVC_SETEXPORTSLIST, that takes a
path and a set of export entries. At the moment it can only clear the
exports list or append entries, one by one, but it is done in a way that
allows setting the whole set of entries atomically in the future (see the
comment in mountd_set_exports_list or in doc/TODO).
- Change mountd(8) to use the nfssvc(2) system call instead of mount(2) so
that it becomes file system agnostic. In fact, all this whole thing was
done to remove a 'XXX' block from this utility!
- Change the mount*, newfs and fsck* userland utilities to not deal with NFS
exports initialization; done internally by the kernel when initializing
the NFS support for each file system.
- Implement an interface for VFS (called VFS hooks) so that several kernel
subsystems can run arbitrary code upon receipt of specific VFS events.
At the moment, this only provides support for unmount and is used to
destroy NFS exports lists from the file systems being unmounted, though it
has room for extension.

Thanks go to yamt@, chs@, thorpej@, wrstuden@ and others for their comments
and advice in the development of this patch.

Remove __P()

branches: 1.30.2;
- Define a VFS_ATTACH() macro that places a reference to a vfsops structure
into the "vfsops" link set.
- Use VFS_ATTACH() where vfsops are declared for individual file systems.
- In vfsinit(), traverse the "vfsops" link set, rather than vfs_list_initial[].

nuke trailing whitespace

branches: 1.28.2; 1.28.4;
Add the system call and VFS infrastructure for file system extended
attributes.

From FreeBSD.

Keep a pointer to the leaf mount. Needed for write gating where a
file system gets suspended and has layered mounts above it.

Welcome to 2.0G

Reviewed by: Bill Studenmund <wrstuden@netbsd.org>

Add layerfs_snapshot() as a handler routine for VFS_SNAPSHOT() calls
through a layered file system.

Note: we don't actually support snapshots through a layered file system,
and this routine returns an error. However we: 1) have clearly documented
what needs fixing (which isn't trivial to fix) and 2) if we do fix
this, all layered file systems can take advantage of it at once.

Add ffs internal snapshots. Written by Marshall Kirk McKusick for FreeBSD.

- Not enabled by default. Needs kernel option FFS_SNAPSHOT.
- Change parameters of ffs_blkfree.
- Let the copy-on-write functions return an error so spec_strategy
may fail if the copy-on-write fails.
- Change genfs_*lock*() to use vp->v_vnlock instead of &vp->v_lock.
- Add flag B_METAONLY to VOP_BALLOC to return indirect block buffer.
- Add a function ffs_checkfreefile needed for snapshot creation.
- Add special handling of snapshot files:
Snapshots may not be opened for writing and the attributes are read-only.
Use the mtime as the time this snapshot was taken.
Deny mtime updates for snapshot files.
- Add function transferlockers to transfer any waiting processes from
one lock to another.
- Add vfsop VFS_SNAPSHOT to take a snapshot and make it accessible through
a vnode.
- Add snapshot support to ls, fsck_ffs and dump.

Welcome to 2.0F.

Approved by: Jason R. Thorpe <thorpej@netbsd.org>

Sysctl descriptions under vfs subtree

Removed remaining caddr_t casts we do not need in miscfs. Recompiled
kernel and ran for a day or so. There are still some caddr_t types in
the arguments of some calls, I will do those separately (later) as
they touch a lot more of the system.
Approved by christos@NetBSD.org.

Replace the statfs() family of system calls with statvfs().
Retain binary compatibility.

branches: 1.21.2;
Tango on sysctl_createv() and flags. The flags have all been renamed,
and sysctl_createv() now uses more arguments.

Remove pointless comment about layerfs_sysctl()

Dynamic sysctl.

Gone are the old kern_sysctl(), cpu_sysctl(), hw_sysctl(),
vfs_sysctl(), etc, routines, along with sysctl_int() et al. Now all
nodes are registered with the tree, and nodes can be added (or
removed) easily, and I/O to and from the tree is handled generically.

Since the nodes are registered with the tree, the mapping from name to
number (and back again) can now be discovered, instead of having to be
hard coded. Adding new nodes to the tree is likewise much simpler --
the new infrastructure handles almost all the work for simple types,
and just about anything else can be done with a small helper function.

All existing nodes are where they were before (numerically speaking),
so all existing consumers of sysctl information should notice no
difference.

PS - I'm sorry, but there's a distinct lack of documentation at the
moment. I'm working on sysctl(3/8/9) right now, and I promise to
watch out for buses.

Move UCB-licensed code from 4-clause to 3-clause licence.

Patches provided by Joel Baker in PR 22364, verified by myself.

branches: 1.17.2;
Back out the lwp/ktrace changes. They contained a lot of colateral damage,
and need to be examined and discussed more.

Undo part of the ktrace/lwp changes. In particular:
* Remove the "lwp *" argument that was added to vget(). Turns out
that nothing actually used it!
* Remove the "lwp *" arguments that were added to VFS_ROOT(), VFS_VGET(),
and VFS_FHTOVP(); all they did was pass it to vget() (which, as noted
above, didn't use it).
* Remove all of the "lwp *" arguments to internal functions that were added
just to appease the above.

Adjust for ktrace/lwp changes.

Pass lwp pointers throughtout the kernel, as required, so that the lwpid can
be inserted into ktrace records. The general change has been to replace
"struct proc *" with "struct lwp *" in various function prototypes, pass
the lwp through and use l_proc to get the process pointer when needed.

Bump the kernel rev up to 1.6V

PR/1796: John Kohl: statfs misbehaves under chrooted environments.

- Under chroot it displays only the visible filesystems with appropriate paths.
- The statfs f_mntonname gets adjusted to contain the real path from root.
- While was there, fixed a bug in ext2fs, locking problems with vfs_getfsstat(),
and factored out some of the vfsop statfs() code to copy_statfs_info(). This
fixes the problem where some filesystems forgot to set fsid.
- Made coda look more like a normal fs.

MNT_GETARGS support

Die, qaddr_t, die! - mnt_data in struct mount is already effectively
a void *, so stop pretending otherwise.

branches: 1.10.8;
don't need <sys/types.h> when including <sys/param.h>

add RCSIDs

branches: 1.8.2;
add a new VFS op, vfs_reinit, which is called when desiredvnodes is
adjusted via sysctl. file systems that have hash tables which are
sized based on the value of this variable now resize those hash tables
using the new value. the max number of FFS softdeps is also recalculated.

convert various file systems to use the <sys/queue.h> macros for
their hash tables.

branches: 1.7.2; 1.7.4;
Typos and grammer fixes in comments (misc/13133 by Michael K. Sanders)

branches: 1.6.2;
make filesystem vnodeop, specop, fifoop and vnodeopv_* arrays const

branches: 1.5.2;
Update for hashinit() change.

make vfs_getnewfsid only take one argument and fetch the name of the
filesystem from the supplied mount argument. also make makefstype
take a const parameter. update all the callers.

branches: 1.3.2;
Add new VFS op routine - vfs_done and call it on filesystem detach
in vfs_detach(). vfs_done may free global filesystem's resources,
typically those allocated in respective filesystem's init function.
Needed so those filesystems which went in via LKM have a chance to
clean after themselves before unloading. This fixes random panics
when LKM for filesystem using pools was loaded and unloaded several
times.

For each leaf filesystem, add appropriate vfs_done routine.

Fix doubled 'the's in comments.

Add overlay, a layered file system which overlays itself on
the underlying fs, rather than exporting it to another part of the
directory name space.

Add ACL support for FFS. From FreeBSD.

Locking a layer vnode using the regular bypass routine is no longer
racy. Undo the change from 2017-03-30 11:16:52, commitid eurqbzuGxGRlryLz
and make vi_lock a krwlock_t again.

branches: 1.23.6;
Locking a layer vnode is racy as it may become reclaimed before
calling the operation on the lower vnode.

Replace vi_lock with a rw_obj and change layered file systems
to share the lock with the lower vnode.

Layered file systems now use genfs_lock()/_unlock/_islocked().

Welcome to 7.99.67

Handle v_writecount from layer_open(), layer_close() and layer_revoke()
so lower file system vnodes get marked as open for writing.

branches: 1.21.2; 1.21.4; 1.21.6;
Do not uselessly include <sys/malloc.h>.

branches: 1.20.4;
The current implementation of vn_lock() is racy. Modification of
the vnode operations vector for active vnodes is unsafe because it
is not known whether deadfs or the original file system will be
called.

- Pass down LK_RETRY to the lock operation (hint for deadfs only).

- Change deadfs lock operation to return ENOENT if LK_RETRY is unset.

- Change all other lock operations to check for dead vnode once
the vnode is locked and unlock and return ENOENT in this case.

With these changes in place vnode lock operations will never succeed
after vclean() has marked the vnode as VI_XLOCK and before vclean()
has changed the operations vector.

Adresses PR kern/37706 (Forced unmount of file systems is unsafe)

Discussed on tech-kern.

Welcome to 6.99.33

branches: 1.19.2; 1.19.12; 1.19.16;
Change VOP_BWRITE() to take a vnode as its first argument like all other
VOPs do. Layered file systems no longer have to modify bp->b_vp and run
into trouble when an async VOP_BWRITE() uses the wrong vnode.

- change all occurences of VOP_BWRITE(bp) to VOP_BWRITE(bp->b_vp, bp).
- remove layer_bwrite().
- welcome to 5.99.55

Adresses PR kern/38762 panic: vwakeup: neg numoutput

No objections from tech-kern@.

Add layer_revoke() that adjusts the lower vnode use count to be at least as
high as the upper vnode count before passing down the VOP_REVOKE().

This way vclean() check for active (vp->v_usecount > 1) vnodes gets it right.

Should fix PR kern/43456.

LK_INTERLOCK is no longer a valid flag for VOP_LOCK(). This makes
layer_*lock*() obsolete. Remove them and handle lock operations
with the generic bypass function.

Ride 5.99.34.

branches: 1.16.74; 1.16.96; 1.16.98;
merge ktrace-lwp.

Remove __P()

branches: 1.14.12;
Do LAYERFS_REMOVED for vop_rmdir.

Reviewed by: Bill Studenmund <wrstuden@netbsd.org>

do a LAYERFS_REMOVED hack for vop_rename as well.

Since VOP_UPCALL() has been a long time in coming, add this partial
fix for layered-file-removal. It will work for the case of accessing
and deleting a file through the layered file system. Accessing via
the layer and deleting on the underlying still won't work, nor will
accessing via complicated structures (like two umap layers over a
given file systems).

We still need VOP_UPCALL(), but this is better than things were before.

This patch has been discussed off & on for a while. This incarnation
was tested by hannken at netbsd dot org.

branches: 1.11.2;
Make VOP_STRATEGY(bp) a real VOP as discussed on tech-kern.

VOP_STRATEGY(bp) is replaced by one of two new functions:

- VOP_STRATEGY(vp, bp) Call the strategy routine of vp for bp.
- DEV_STRATEGY(bp) Call the d_strategy routine of bp->b_dev for bp.

DEV_STRATEGY(bp) is used only for block-to-block device situations.

Move UCB-licensed code from 4-clause to 3-clause licence.

Patches provided by Joel Baker in PR 22364, verified by myself.

branches: 1.9.16;
add the entry for layer_getpages() to the VOP tables of the
layered file systems that need it.

add VOP_GETPAGES and VOP_PUTPAGES methods for layered filesystems.
drop the interlock on the upper layer, acquire the interlock on the
lower layer.

don't need <sys/types.h> when including <sys/param.h>

add RCSIDs

branches: 1.5.2; 1.5.6;
Some more corrections by Michael K. Sanders.

Typos and grammer fixes in comments (misc/13133 by Michael K. Sanders)

branches: 1.3.2;
make filesystem vnodeop, specop, fifoop and vnodeopv_* arrays const

branches: 1.2.6;
Fix doubled 'the's in comments.

Add overlay, a layered file system which overlays itself on
the underlying fs, rather than exporting it to another part of the
directory name space.