are subtle differences in the read and write completion path. Instead,
grab an extra write ref so the write path can drop it when we recursively
call bufdone(). I believe this may be the source of the wrong bufobj
panics.
Reported by: pho, kkenn
because it may change identities while we're sleeping on the lock.
Otherwise we may bail out of ffs_sync() early due to an error from
deadfs.
- Collapse a VOP_UNLOCK, vrele into a single vput().
two bugs.
- ffs_disk_prewrite was pulling the vp from the buf and checking for
COPYONWRITE, when really it wanted the vp from the bufobj that we're
writing to, which is the devvp. This lead to us skipping the copy on
write to all file data, which significantly broke snapshots for the
last few months.
- When the SOFTUPDATES option was not included in the kernel config we
would also skip the copy on write check, which would effectively disable
snapshots.
- Remove an invalid mp_fixme().
Debugging tips from: mckusick
Reported by: iedowse, others
Discussed with: phk
the filesystem. Check that rather than VI_XLOCK.
- Shorten ffs_reload by one step. The old check for an inactive vnode
was slightly racey, and the code which deals with still active vnodes
is not much more expensive.
Sponsored by: Isilon Systems, Inc.
patch from kan@).
Pull bufobj_invalbuf() out of vinvalbuf() and make g_vfs call it on
close. This is not yet a generally safe function, but for this very
specific use it is safe. This solves the problem with buffers not
being flushed by unmount or after failed mount attempts.
Give FFS vnodes a specific bufwrite method which contains all the
background write stuff and then calls into the default bufwrite()
for the rest of the job.
Remove all the background write related stuff from the normal bufwrite.
This drags the softdep_move_dependencies() back into FFS.
Long term, it is worth looking at simply copying the data into
allocated memory and issuing the bio directly and not create the
"shadow buf" in the first place (just like copy-on-write is done
in snapshots for instance). I don't think we really gain anything
but complexity from doing this with a buf.
The "business class upgrade" was implemented in UFS's VOP_LOCK
implementation ufs_lock() which is the wrong layer, so move it to
ffs_lock().
Also, as long as we have not abandonned advanced vfs-stacking we
should not preclude it from happening: instead of implementing a
copy locally, use the VOP_LOCK_APV(&ufs) to correctly arrive at
vop_stdlock() at the bottom.
- Use the buffer lock on the superblock buf to serialize calls to
sbupdate.
- Set the MNTK_MPSAFE flag when QUOTA is not defined in the kernel.
Sponsored By: Isilon Systems, Inc.
Without this fix, when ACLs are set via tunefs(8) on the root file system,
they are removed on boot when 'mount -a' is called, because mount(8)
called for the root file system always add MNT_UPDATE flag and MNT_UPDATE
flag isn't perfect.
Now, one cannot remove ACLs stored in superblock (configured with tunefs(8))
via 'mount -a' nor 'mount -u -o noacls <file system>', but it is still
possible to mount file system which doesn't have ACLs in superblock via
'mount -o acls <file system>' or /etc/fstab's 'acls' option.
Reported by: Lech Lorens/pl.comp.os.bsd
Discussed with: phk, rwatson
Reviewed by: rwatson
MFC after: 2 weeks
I'm not sure why a credential was added to these in the first place, it is
not used anywhere and it doesn't make much sense:
The credentials for syncing a file (ability to write to the
file) should be checked at the system call level.
Credentials for syncing one or more filesystems ("none")
should be checked at the system call level as well.
If the filesystem implementation needs a particular credential
to carry out the syncing it would logically have to the
cached mount credential, or a credential cached along with
any delayed write data.
Discussed with: rwatson
four different locations on a prospective filesystem.
If we found none, we forgot to invalidate the four buffers, thus the
following sequence would fails:
(md0 = blank disk)
mount /dev/md0 /mnt
(fails, no superblocks)
newfs /dev/md0
(writes using physio which does not go through buffercache).
mount /dev/md0 /mnt
(still fails, the four cached buffers still contain no superblocks)
Found by: ru
split the conversion of the remaining three filesystems out from the root
mounting changes, so in one go:
cd9660:
Convert to nmount.
Add omount compat shims.
Remove dedicated rootfs mounting code.
Use vfs_mountedfrom()
Rely on vfs_mount.c calling VFS_STATFS()
nfs(client):
Convert to nmount (the simple way, mount_nfs(8) is still necessary).
Add omount compat shims.
Drop COMPAT_PRELITE2 mount arg compatibility.
ffs:
Convert to nmount.
Add omount compat shims.
Remove dedicated rootfs mounting code.
Use vfs_mountedfrom()
Rely on vfs_mount.c calling VFS_STATFS()
Remove vfs_omount() method, all filesystems are now converted.
Remove MNTK_WANTRDWR, handling RO/RW conversions is a filesystem
task, and they all do it now.
Change rootmounting to use DEVFS trampoline:
vfs_mount.c:
Mount devfs on /. Devfs needs no 'from' so this is clean.
symlink /dev to /. This makes it possible to lookup /dev/foo.
Mount "real" root filesystem on /.
Surgically move the devfs mountpoint from under the real root
filesystem onto /dev in the real root filesystem.
Remove now unnecessary getdiskbyname().
kern_init.c:
Don't do devfs mounting and rootvnode assignment here, it was
already handled by vfs_mount.c.
Remove now unused bdevvp(), addaliasu() and addalias(). Put the
few necessary lines in devfs where they belong. This eliminates the
second-last source of bogo vnodes, leaving only the lemming-syncer.
Remove rootdev variable, it doesn't give meaning in a global context and
was not trustworth anyway. Correct information is provided by
statfs(/).
doesn't. Most of the implementations have grown weeds for this so they
copy some fields from mnt_stat if the passed argument isn't that.
Fix this the cleaner way: Always call the implementation on mnt_stat
and copy that in toto to the VFS_STATFS argument if different.
initializations but we did have lofty goals and big ideals.
Adjust to more contemporary circumstances and gain type checking.
Replace the entire vop_t frobbing thing with properly typed
structures. The only casualty is that we can not add a new
VOP_ method with a loadable module. History has not given
us reason to belive this would ever be feasible in the the
first place.
Eliminate in toto VOCALL(), vop_t, VNODEOP_SET() etc.
Give coda correct prototypes and function definitions for
all vop_()s.
Generate a bit more data from the vnode_if.src file: a
struct vop_vector and protype typedefs for all vop methods.
Add a new vop_bypass() and make vop_default be a pointer
to another struct vop_vector.
Remove a lot of vfs_init since vop_vector is ready to use
from the compiler.
Cast various vop_mumble() to void * with uppercase name,
for instance VOP_PANIC, VOP_NULL etc.
Implement VCALL() by making vdesc_offset the offsetof() the
relevant function pointer in vop_vector. This is disgusting
but since the code is generated by a script comparatively
safe. The alternative for nullfs etc. would be much worse.
Fix up all vnode method vectors to remove casts so they
become typesafe. (The bulk of this is generated by scripts)
This eliminates a bunch of vnode overhead (approx 1-2 % speed
improvement) and gives us more control over the access to the storage
device.
Access counts on the underlying device are not correctly tracked and
therefore it is possible to read-only mount the same disk device multiple
times:
syv# mount -p
/dev/md0 /var ufs rw 2 2
/dev/ad0 /mnt ufs ro 1 1
/dev/ad0 /mnt2 ufs ro 1 1
/dev/ad0 /mnt3 ufs ro 1 1
Since UFS/FFS is not a synchrousely consistent filesystem (ie: it caches
things in RAM) this is not possible with read-write mounts, and the system
will correctly reject this.
Details:
Add a geom consumer and a bufobj pointer to ufsmount.
Eliminate the vnode argument from softdep_disk_prewrite().
Pick the vnode out of bp->b_vp for now. Eventually we
should find it through bp->b_bufobj->b_private.
In the mountcode, use g_vfs_open() once we have used
VOP_ACCESS() to check permissions.
When upgrading and downgrading between r/o and r/w do the
right thing with GEOM access counts. Remove all the
workarounds for not being able to do this with VOP_OPEN().
If we are the root mount, drop the exclusive access count
until we upgrade to r/w. This allows fsck of the root
filesystem and the MNT_RELOAD to work correctly.
Set bo_private to the GEOM consumer on the device bufobj.
Change the ffs_ops->strategy function to call g_vfs_strategy()
In ufs_strategy() directly call the strategy on the disk
bufobj. Same in rawread.
In ffs_fsync() we will no longer see VCHR device nodes, so
remove code which synced the filesystem mounted on it, in
case we came there. I'm not sure this code made sense in
the first place since we would have taken the specfs route
on such a vnode.
Redo the highly bogus readblock() function in the snapshot
code to something slightly less bogus: Constructing an uio
and using physio was really quite a detour. Instead just
fill in a bio and ship it down.
Give ffs it's own bufobj->bo_ops vector and create a private strategy
routine, (currently misnamed for forwards compatibility), which is
just a copy of the generic bufstrategy routine except we call
softdep_disk_prewrite() directly instead of through the buf_prewrite()
indirection.
Teach UFS about the need for softdep_disk_prewrite() and call the
function directly in FFS.
Remove buf_prewrite() from the default bufstrategy() and from the
global bio_ops method vector.
We keep si_bsize_phys around for now as that is the simplest way to pull
the number out of disk device drivers in devfs_open(). The correct solution
would be to do an ioctl(DIOCGSECTORSIZE), but the point is probably mooth
when filesystems sit on GEOM, so don't bother for now.
It can be used to delay mounting root partition to give a chance to GEOM
providers to show up.
Now, when there is no needed provider, vfs_rootmount() function will look
for it every second and if it can't be find in defined time, it'll ask
for root device name (before this change it was done immediately).
This will allow to boot from gmirror device in degraded mode.
and refuse initializing filesystems with a wrong version. This will
aid maintenance activites on the 5-stable branch.
s/vfs_mount/vfs_omount/
s/vfs_nmount/vfs_mount/
Name our filesystems mount function consistently.
Eliminate the namiedata argument to both vfs_mount and vfs_omount.
It was originally there to save stack space. A few places abused
it to get hold of some credentials to pass around. Effectively
it is unused.
Reorganize the root filesystem selection code.
