and always reread the directory entry by inumber. For directories
the directory entry is always its "." entry.
Always read directories via the device vnode to prevent buffer cache
inconsistency. Keep i_devvp as a hint for fstat(1) and friends and
always use im_devvp for reads. No need to vref()/vrele() i_devvp.
The additional bread is either cached because cd9660_lookup() just
released the buffer or will be used in the near future when the
directory gets traversed during lookup.
No objections on tech-kern@
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
and spec_node_setmountedfs() to manage the file system mounted on a device.
Assert the device is a block device.
Welcome to 6.99.24
Discussed on tech-kern@ some time ago.
Reviewed by: David Holland <dholland@netbsd.org>
A type specifier of the form
enum identifier
without an enumerator list shall only appear after the type it
specifies is complete.
which means that we cannot pass an "enum vtype" argument to
kauth_access_action() without fully specifying the type first.
Unfortunately there is a complicated include file loop which
makes that difficult, so convert this minimal function into a
macro (and capitalize it).
(ok elad@)
error and modify all callers to not brelse() on error.
Welcome to 6.99.16
PR kern/46282 (6.0_BETA crash: msdosfs_bmap -> pcbmap -> bread -> bio_doread)
This uglifies the interface, because several operations need to be
passed the namei flags and cache_lookup also needs for the time being
to be passed cnp->cn_nameiop. Nonetheless, it's a net benefit.
The glop should be able to go away eventually but requires structural
cleanup elsewhere first.
This change requires a kernel bump.
- Move the namecache's hash computation to inside the namecache code,
instead of being spread out all over the place. Remove cn_hash from
struct componentname and delete all uses of it.
- It is no longer necessary (if it ever was) for cache_lookup and
cache_lookup_raw to clear MAKEENTRY from cnp->cn_flags for the cases
that cache_enter already checks for.
- Rearrange the interface of cache_lookup (and cache_lookup_raw) to
make it somewhat simpler, to exclude certain nonexistent error
conditions, and (most importantly) to make it not require write access
to cnp->cn_flags.
This change requires a kernel bump.
- Reorganize locking in UVM and provide extra serialisation for pmap(9).
New lock order: [vmpage-owner-lock] -> pmap-lock.
- Simplify locking in some pmap(9) modules by removing P->V locking.
- Use lock object on vmobjlock (and thus vnode_t::v_interlock) to share
the locks amongst UVM objects where necessary (tmpfs, layerfs, unionfs).
- Rewrite and optimise x86 TLB shootdown code, make it simpler and cleaner.
Add TLBSTATS option for x86 to collect statistics about TLB shootdowns.
- Unify /dev/mem et al in MI code and provide required locking (removes
kernel-lock on some ports). Also, avoid cache-aliasing issues.
Thanks to Andrew Doran and Joerg Sonnenberger, as their initial patches
formed the core changes of this branch.
in the vnode. All LK_* flags move from sys/lock.h to sys/vnode.h. Calls
to vlockmgr() in file systems get replaced with VOP_LOCK() or VOP_UNLOCK().
Welcome to 5.99.34.
Discussed on tech-kern.
msdosfs and cd9660 are the only filesystems that verify the filesystem
type in the label. This is the wrong place, sanity checks should only
rely on the inner structure of the filesystem (like signatures or
magic numbers).
msdosfs also used the device type information from the label to
deduce a filesystem parameter heuristically for the gemdos variant.
If there is no information inside the filesystem data itself, this
should be an explicit mount option.
years ago when the kernel was modified to not alter ABI based on
DIAGNOSTIC, and now just call the respective function interfaces
(in lowercase). Plenty of mix'n match upper/lowercase has creeped
into the tree since then. Nuke the macros and convert all callsites
to lowercase.
no functional change
Change cd9660_mount, in MNT_UPDATE case, to check dev_t's for equality
instead of just vnode pointers. Fixes erroneous "Invalid argument"
errors from mount(8) with -u against cd9660 root in the presence of
mfs or tmpfs /dev prepared after initial mountroot.
Tested on QEMU running cobalt Restore CD.
check_console, veriexecclose, veriexec_delete, veriexec_file_add,
emul_find_root, coff_load_shlib (sh3 version), coff_load_shlib,
compat_20_sys_statfs, compat_20_netbsd32_statfs,
ELFNAME2(netbsd32,probe_noteless), darwin_sys_statfs,
ibcs2_sys_statfs, ibcs2_sys_statvfs, linux_sys_uselib,
osf1_sys_statfs, sunos_sys_statfs, sunos32_sys_statfs,
ultrix_sys_statfs, do_sys_mount, fss_create_files (3 of 4),
adosfs_mount, cd9660_mount, coda_ioctl, coda_mount, ext2fs_mount,
ffs_mount, filecore_mount, hfs_mount, lfs_mount, msdosfs_mount,
ntfs_mount, sysvbfs_mount, udf_mount, union_mount, sys_chflags,
sys_lchflags, sys_chmod, sys_lchmod, sys_chown, sys_lchown,
sys___posix_chown, sys___posix_lchown, sys_link, do_sys_pstatvfs,
sys_quotactl, sys_revoke, sys_truncate, do_sys_utimes, sys_extattrctl,
sys_extattr_set_file, sys_extattr_set_link, sys_extattr_get_file,
sys_extattr_get_link, sys_extattr_delete_file,
sys_extattr_delete_link, sys_extattr_list_file, sys_extattr_list_link,
sys_setxattr, sys_lsetxattr, sys_getxattr, sys_lgetxattr,
sys_listxattr, sys_llistxattr, sys_removexattr, sys_lremovexattr
All have been scrutinized (several times, in fact) and compile-tested,
but not all have been explicitly tested in action.
XXX: While I haven't (intentionally) changed the use or nonuse of
XXX: TRYEMULROOT in any of these places, I'm not convinced all the
XXX: uses are correct; an audit might be desirable.
the other routines of the same spirit.
Adjust file-system code to use it.
Keep vaccess() for KPI compatibility and to keep element of least
surprise. A "diagnostic" message warning that vaccess() is deprecated will
be printed when it's used (obviously, only in DIAGNOSTIC kernels).
No objections on tech-kern@:
http://mail-index.netbsd.org/tech-kern/2009/06/21/msg005310.html
the security checks when mounting a device (VOP_ACCESS() + kauth(9) call)).
Proposed with no objections on tech-kern@:
http://mail-index.netbsd.org/tech-kern/2009/04/20/msg004859.html
The vnode is always expected to be locked, so no locking is done outside
the file-system code.
run through copy-on-write. Call fscow_run() with valid data where possible.
The LP_UFSCOW hack is no longer needed to protect ffs_copyonwrite() against
endless recursion.
- Add a flag B_MODIFY to bread(), breada() and breadn(). If set the caller
intends to modify the buffer returned.
- Always run copy-on-write on buffers returned from ffs_balloc().
- Add new function ffs_getblk() that gets a buffer, assigns a new blkno,
may clear the buffer and runs copy-on-write. Process possible errors
from getblk() or fscow_run(). Part of PR kern/38664.
Welcome to 4.99.63
Reviewed by: YAMAMOTO Takashi <yamt@netbsd.org>
Simplify the mount locking. Remove all the crud to deal with recursion on
the mount lock, and crud to deal with unmount as another weirdo lock.
Hopefully this will once and for all fix the deadlocks with this. With this
commit there are two locks on each mount:
- krwlock_t mnt_unmounting. This is used to prevent unmount across critical
sections like getnewvnode(). It's only ever read locked with rw_tryenter(),
and is only ever write locked in dounmount(). A write hold can't be taken
on this lock if the current LWP could hold a vnode lock.
- kmutex_t mnt_updating. This is taken by threads updating the mount, for
example when going r/o -> r/w, and is only present to serialize updates.
In order to take this lock, a read hold must first be taken on
mnt_unmounting, and the two need to be held across the operation.
One effect of this change: previously if an unmount failed, we would make a
half hearted attempt to back out of it gracefully, but that was unlikely to
work in a lot of cases. Now while an unmount that will be aborted is in
progress, new file operations within the mount will fail instead of being
delayed. That is unlikely to be a problem though, because if the admin
requests unmount of a file system then s(he) has made a decision to deny
access to the resource.
