Commit Graph

181 Commits

Author SHA1 Message Date
Rick Macklem
5e99212d36 Post r230394, the Lookup RPC counts for both NFS clients increased
significantly. Upon investigation this was caused by name cache
misses for lookups of "..". For name cache entries for non-".."
directories, the cache entry serves double duty. It maps both the
named directory plus ".." for the parent of the directory. As such,
two ctime values (one for each of the directory and its parent) need
to be saved in the name cache entry.
This patch adds an entry for ctime of the parent directory to the
name cache. It also adds an additional uma zone for large entries
with this time value, in order to minimize memory wastage.
As well, it fixes a couple of cases where the mtime of the parent
directory was being saved instead of ctime for positive name cache
entries. With this patch, Lookup RPC counts return to values similar
to pre-r230394 kernels.

Reported by:	bde
Discussed with:	kib
Reviewed by:	jhb
MFC after:	2 weeks
2012-03-03 01:06:54 +00:00
Maxim Konovalov
7dfdd83d56 o Reduce chances for integer overflow.
o More verbose sysctl description added.

MFC after:	2 weeks
Sponsored by:	Nginx, Inc.
2012-02-25 12:06:40 +00:00
John Baldwin
bf40d24a3f Rename cache_lookup_times() to cache_lookup() and retire the old API and
ABI stub for cache_lookup().
2012-02-06 17:00:28 +00:00
Konstantin Belousov
d5210589b7 Fix remaining calls to cache_enter() in both NFS clients to provide
appropriate timestamps.  Restore the assertions which verify that
NCF_TS is set when timestamp is asked for.

Reviewed by:  jhb (previous version)
MFC after:    2 weeks
2012-01-25 20:48:20 +00:00
Konstantin Belousov
7a7e609a32 Apparently, both nfs clients do not use cache_enter_time()
consistently, creating some namecache entries without NCF_TS flag.
This causes panic due to failed assertion.

As a temporal relief, remove the assert. Return epoch timestamp for
the entries without timestamp if asked.

While there, consolidate the code which returns timestamps, into a
helper cache_out_ts().

Discussed with:	 jhb
MFC after: 2 weeks
2012-01-23 17:09:23 +00:00
Konstantin Belousov
c2b396f294 Remove the nc_time and nc_ticks elements from struct namecache, and
provide struct namecache_ts which is the old struct namecache. Only
allocate struct namecache_ts if non-null struct timespec *tsp was
passed to cache_enter_time, otherwise use struct namecache.

Change struct namecache allocation and deallocation macros into static
functions, since logic becomes somewhat twisty.  Provide accessor for
the nc_name member of struct namecache to hide difference between
struct namecache and namecache_ts.

The aim of the change is to not waste 20 bytes per small namecache
entry.

Reviewed by:	 jhb
MFC after: 2 weeks
X-MFC-note:  after r230394
2012-01-22 01:11:06 +00:00
John Baldwin
5aefb4cbbf Close a race in NFS lookup processing that could result in stale name cache
entries on one client when a directory was renamed on another client.  The
root cause for the stale entry being trusted is that each per-vnode nfsnode
structure has a single 'n_ctime' timestamp used to validate positive name
cache entries.  However, if there are multiple entries for a single vnode,
they all share a single timestamp.  To fix this, extend the name cache
to allow filesystems to optionally store a timestamp value in each name
cache entry.  The NFS clients now fetch the timestamp associated with
each name cache entry and use that to validate cache hits instead of the
timestamps previously stored in the nfsnode.  Another part of the fix is
that the NFS clients now use timestamps from the post-op attributes of
RPCs when adding name cache entries rather than pulling the timestamps out
of the file's attribute cache.  The latter is subject to races with other
lookups updating the attribute cache concurrently.  Some more details:
- Add a variant of nfsm_postop_attr() to the old NFS client that can return
  a vattr structure with a copy of the post-op attributes.
- Handle lookups of "." as a special case in the NFS clients since the name
  cache does not store name cache entries for ".", so we cannot get a
  useful timestamp.  It didn't really make much sense to recheck the
  attributes on the the directory to validate the namecache hit for "."
  anyway.
- ABI compat shims for the name cache routines are present in this commit
  so that it is safe to MFC.

MFC after:	2 weeks
2012-01-20 20:02:01 +00:00
Martin Matuska
9cbe30e1d5 Fix missing in r230129:
kern_jail.c: initialize fullpath_disabled to zero
vfs_cache.c: add missing dot in comment

Reported by:	kib
MFC after:	1 month
2012-01-15 18:08:15 +00:00
Martin Matuska
f6e633a9e1 Introduce vn_path_to_global_path()
This function updates path string to vnode's full global path and checks
the size of the new path string against the pathlen argument.

In vfs_domount(), sys_unmount() and kern_jail_set() this new function
is used to update the supplied path argument to the respective global path.

Unbreaks jailed zfs(8) with enforce_statfs set to 1.

Reviewed by:	kib
MFC after:	1 month
2012-01-15 12:08:20 +00:00
Andriy Gapon
7a7ce668ef put sys/systm.h at its proper place or add it if missing
Reported by:	lstewart, tinderbox
Pointyhat to:	avg, attilio
MFC after:	1 week
MFC with:	r228430
2011-12-12 10:05:13 +00:00
Konstantin Belousov
f82360acf2 Existing VOP_VPTOCNP() interface has a fatal flow that is critical for
nullfs.  The problem is that resulting vnode is only required to be
held on return from the successfull call to vop, instead of being
referenced.

Nullfs VOP_INACTIVE() method reclaims the vnode, which in combination
with the VOP_VPTOCNP() interface means that the directory vnode
returned from VOP_VPTOCNP() is reclaimed in advance, causing
vn_fullpath() to error with EBADF or like.

Change the interface for VOP_VPTOCNP(), now the dvp must be
referenced. Convert all in-tree implementations of VOP_VPTOCNP(),
which is trivial, because vhold(9) and vref(9) are similar in the
locking prerequisites. Out-of-tree fs implementation of VOP_VPTOCNP(),
if any, should have no trouble with the fix.

Tested by:	pho
Reviewed by:	mckusick
MFC after:	3 weeks (subject of re approval)
2011-11-19 07:50:49 +00:00
Ed Schouten
6472ac3d8a Mark all SYSCTL_NODEs static that have no corresponding SYSCTL_DECLs.
The SYSCTL_NODE macro defines a list that stores all child-elements of
that node. If there's no SYSCTL_DECL macro anywhere else, there's no
reason why it shouldn't be static.
2011-11-07 15:43:11 +00:00
Kip Macy
8451d0dd78 In order to maximize the re-usability of kernel code in user space this
patch modifies makesyscalls.sh to prefix all of the non-compatibility
calls (e.g. not linux_, freebsd32_) with sys_ and updates the kernel
entry points and all places in the code that use them. It also
fixes an additional name space collision between the kernel function
psignal and the libc function of the same name by renaming the kernel
psignal kern_psignal(). By introducing this change now we will ease future
MFCs that change syscalls.

Reviewed by:	rwatson
Approved by:	re (bz)
2011-09-16 13:58:51 +00:00
Rebecca Cran
8d065a3914 Fix some more style(9) issues. 2010-11-14 16:10:15 +00:00
Rebecca Cran
b389be97db Fix style(9) issues from r215281 and r215282.
MFC after:	1 week
2010-11-14 08:06:29 +00:00
Rebecca Cran
2baa5cddb6 Add some descriptions to sys/kern sysctls.
PR:	kern/148710
Tested by:	Chip Camden <sterling at camdensoftware.com>
MFC after:	1 week
2010-11-14 06:09:50 +00:00
Konstantin Belousov
3a40a00d56 Remove sysctl debug.ncnegfactor, it is renamed to vfs.ncnegfactor.
MFC:	do not
2010-10-30 14:08:26 +00:00
Konstantin Belousov
420cfbb460 Provide vfs.ncsizefactor instead of hard-coding namecache ratio.
Move debug.ncnegfactor to vfs.ncnegfactor [1].
Provide some descriptions for the namecache related sysctls [1].

Based on the submission by:	Rogier R. Mulhuijzen <drwilco drwilco net> [1]
MFC after:	2 weeks
X-MFC-note:	remove debug.ncnegfactor in HEAD after MFC
2010-10-16 09:44:31 +00:00
Rui Paulo
79856499bd Add an extra comment to the SDT probes definition. This allows us to get
use '-' in probe names, matching the probe names in Solaris.[1]

Add userland SDT probes definitions to sys/sdt.h.

Sponsored by:	The FreeBSD Foundation
Discussed with:	rwaston [1]
2010-08-22 11:18:57 +00:00
Ed Schouten
60ae52f785 Use ISO C99 integer types in sys/kern where possible.
There are only about 100 occurences of the BSD-specific u_int*_t
datatypes in sys/kern. The ISO C99 integer types are used here more
often.
2010-06-21 09:55:56 +00:00
Konstantin Belousov
5673e3cb08 The cache_enter(9) function shall not be called for doomed dvp.
Assert this.

In the reported panic, vdestroy() fired the assertion "vp has namecache
for ..", because pseudofs may end up doing cache_enter() with reclaimed
dvp, after dotdot lookup temporary unlocked dvp.
Similar problem exists in ufs_lookup() for "." lookup, when vnode
lock needs to be upgraded.

Verify that dvp is not reclaimed before calling cache_enter().

Reported and tested by:	pho
Reviewed by:	kan
MFC after:	2 weeks
2010-04-20 10:19:27 +00:00
Konstantin Belousov
3e22320c43 Fix typo.
MFC after:	3 days
2010-04-15 17:17:02 +00:00
Konstantin Belousov
8f40845151 Correctly handle unlock for !MAKEENTRY case, after successfull attempt of
lock upgrade cache shall be unlocked from write.

Reported by:	Lucius Windschuh <lwindschuh googlemail com>
Reviewed by:	kan
Approved by:	re (rwatson)
2009-08-14 10:57:28 +00:00
Konstantin Belousov
c808c9632d Add explicit struct ucred * argument for VOP_VPTOCNP, to be used by
vn_open_cred in default implementation. Valid struct ucred is needed for
audit and MAC, and curthread credentials may be wrong.

This further requires modifying the interface of vn_fullpath(9), but it
is out of scope of this change.

Reviewed by:	rwatson
2009-06-21 19:21:01 +00:00
Joe Marcus Clarke
8a4444049e Unlock the cache lock before returning when we run out of buffer space
trying to fill in the full path name.

Reported by:	David Naylor <naylor.b.david@gmail.com>
Approved by:	kib
2009-06-05 16:44:42 +00:00
Konstantin Belousov
1358a7957d Unbreak the build. Add missed probes.
Reviewed by:	rwatson
Pointy hat to:	me
2009-05-31 20:16:06 +00:00
Konstantin Belousov
0449e6e1eb Eliminate code duplication in vn_fullpath1() around the cache lookups
and calls to vn_vptocnp() by moving more of the common code to
vn_vptocnp(). Rename vn_vptocnp() to vn_vptocnp_locked() to signify that
cache is locked around the call.

Do not track buffer position by both the pointer and offset, use only
buflen to record the start of the free space.

Export vn_vptocnp() for external consumers as a wrapper around
vn_vptocnp_locked() that locks the cache and handles hold counts.

Tested by:	pho
2009-05-31 14:57:43 +00:00
Alexander Kabaev
348496ad39 More fallout from negative dotdot caching. Negative entries should
be removed from and reinserted to proper ncneg list.

Reported by:  pho
Submitted by: kib
2009-04-17 18:11:11 +00:00
Alexander Kabaev
9cf6772211 Redo previous change using simpler patch that happens to be also
more correct.

Submitted by: tor
2009-04-14 23:56:48 +00:00
Alexander Kabaev
eed8a9edba Fix yet another negative dotodot entry fallout.
Reported by: pho
2009-04-14 23:46:57 +00:00
Alexander Kabaev
9d75482f99 Fix v_cache_dd handling for negative entries. v_cache_dd pointer was
not populated in parent directory if negative entry was being
created, yet entry itself was added to the nc_neg list. It was
possible for parent vnode to get discarded later, leaving negative
entry pointing to now unused memory block.

Reported by:	dho
Revewed by:	kib
2009-04-11 20:23:08 +00:00
Konstantin Belousov
fd409594c6 When zapping v_cache_dd for !MAKEENTRY case in cache_lookup(), we shall
lock cache as writer.

Reviewed by:	kan
2009-04-11 16:12:20 +00:00
Konstantin Belousov
3f54086eba Cache_lookup() for DOTDOT drops dvp vnode lock, allowing dvp to be reclaimed.
Check the condition and return ENOENT then.

In nfs_lookup(), respect ENOENT return from cache_lookup() when it is caused
by dvp reclaim.

Reported and tested by:	pho
2009-04-10 10:22:44 +00:00
Robert Watson
5d5c174869 Nul-terminate strings in the VFS name cache, which negligibly change
the size and cost of name cache entries, but make adding debugging
and tracing easier.

Add SDT DTrace probes for various namecache events:

  vfs:namecache:enter:done - new entry in the name cache, passed parent
    directory vnode pointer, name added to the cache, and child vnode
    pointer.

  vfs:namecache:enter_negative:done - new negative entry in the name cache,
    passed parent vnode pointer, name added to the cache.

  vfs:namecache:fullpath:enter - call to vn_fullpath1() is made, passed
    the vnode to resolve to a name.

  vfs:namecache:fullpath:hit - vn_fullpath1() successfully resolved a
    search for the parent of an object using the namecache, passed the
    discovered parent directory vnode pointer, name, and child vnode
    pointer.

  vfs:namecache:fullpath:miss - vn_fullpath1() failed to resolve a search
    for the parent of an object using the namecache, passed the child
    vnode pointer.

  vfs:namecache:fullpath:return - vn_fullpath1() has completed, passed the
    error number, and if that is zero, the vnode to resolve, and the
    returned path.

  vfs:namecache:lookup:hit - postive name cache entry hit, passed the
    parent directory vnode pointer, name, and child vnode pointer.

  vfs:namecache:lookup:hit_negative - negative name cache entry hit,
    passed the parent directory vnode pointer and name.

  vfs:namecache:lookup:miss - name cache miss, passed the parent directory
    pointer and the full remaining component name (not terminated after the
    cache miss component).

  vfs:namecache:purge:done - name cache purge for a vnode, passed the vnode
    pointer to purge.

  vfs:namecache:purge_negative:done - name cache purge of negative entries
    for children of a vnode, passed the vnode pointer to purge.

  vfs:namecache:purgevfs - name cache purge for a mountpoint, passed the
    mount pointer.  Separate probes will also be invoked for each cache
    entry zapped.

  vfs:namecache:zap:done - name cache entry zapped, passed the parent
    directory vnode pointer, name, and child vnode pointer.

  vfs:namecache:zap_negative:done - negative name cache entry zapped,
    passed the parent directory vnode pointer and name.

For any probes involving an extant name cache entry (enter, hit, zapp),
we use the nul-terminated string for the name component.  For misses,
the remainder of the path, including later components, is provided as
an argument instead since there is no handy nul-terminated version of
the string around.  This is arguably a bug.

MFC after:      1 month
Sponsored by:   Google, Inc.
Reviewed by:	jhb, kan, kib (earlier version)
2009-04-07 20:58:56 +00:00
Alexander Kabaev
bb6418cbe3 Revert change 190655 temporarily. It breaks many setups where nullfs is
used and needs to be revisited.
2009-04-04 17:48:38 +00:00
Peter Wemm
0e875ecafe vn_vptocnp() unlocks the name cache and forgets to re-lock it before
returning in one error case, and mistakenly unlocks it for the
umount -f case.
2009-04-02 21:16:20 +00:00
Alexander Kabaev
607fc40b04 Replace v_dd vnode pointer with v_cache_dd pointer to struct namecache
in directory vnodes. Allow namecache dotdot entry to be created pointing
from child vnode to parent vnode if no existing links in opposite
direction exist. Use direct link from parent to child for dotdot lookups
otherwise.

This restores more efficient dotdot caching in NFS filesystems which
was lost when vnodes stoppped being type stable.

Reviewed by:	kib
2009-03-29 21:25:40 +00:00
John Baldwin
049ce0934f When a file lookup fails due to encountering a doomed vnode from a forced
unmount, consistently return ENOENT rather than EBADF.

Reviewed by:	kib
MFC after:	1 month
2009-03-24 18:16:42 +00:00
Konstantin Belousov
15fb32c07d Do not underflow the buffer and then report the problem. Check for the
condition before the buffer write.
Also, since buflen is unsigned, previous check was ignored.

Reviewed by:	marcus
Tested by:	pho
2009-03-20 11:08:57 +00:00
Konstantin Belousov
83817ce3b1 Remove unneeded braces to reduce used vertical screen space.
The location was missed in r190140.
2009-03-20 11:03:55 +00:00
Konstantin Belousov
9194007261 Do not forget to adjust buflen for the first resolution of the path
from namecache.
While there, compare pointers for equiality.

Reviewed by:	marcus
Tested by:	pho
2009-03-20 11:00:39 +00:00
Konstantin Belousov
065fc451f8 The nc_nlen member of the struct namecache contains the length of the cached
name, not the length + 1.

PR:	132620, 132542
Reported by:	bf2006a yahoo com
Tested by:	bf2006a, pho
Reviewed by:	marcus
2009-03-20 10:59:06 +00:00
Konstantin Belousov
c4a8c2ee24 When ktracing namei operations, log a result of the __getcwd().
MFC after:	1 week
2009-03-20 10:47:16 +00:00
Konstantin Belousov
bf5c835e1c Remove unneeded braces to reduce used vertical screen space. 2009-03-20 10:04:00 +00:00
John Baldwin
4ab2a9a022 Move the debug.hashstat sysctl tree under DIAGNOSTIC. I measured the
debug.hashstat.rawnchash sysctl in particular as taking 7 milliseconds on
a 3GHz Intel Xeon (4x2) running 7.1.  It accounted for almost a quarter of
the total runtime of 'sysctl -a'.  It also performs lots of copyout's while
holding the namecache lock (this does not attempt to fix that).

MFC after:	2 weeks
2009-03-09 19:04:53 +00:00
John Baldwin
03964c8e09 Enable caching of negative pathname lookups in the NFS client. To avoid
stale entries, we save a copy of the directory's modification time when
the first negative cache entry was added in the directory's NFS node.
When a negative cache entry is hit during a pathname lookup, the parent
directory's modification time is checked.  If it has changed, all of the
negative cache entries for that parent are purged and the lookup falls
back to using the RPC.  This required adding a new cache_purge_negative()
method to the name cache to purge only negative cache entries for a given
directory.

Submitted by:	mohans, Rick Macklem, Ricardo Labiaga @ NetApp
Reviewed by:	mohans
2009-02-19 22:28:48 +00:00
John Baldwin
9078981ab1 Convert the global mutex protecting the directory lookup name cache from a
mutex to a reader/writer lock.  Lookup operations first grab a read lock and
perform the lookup.  If the operation results in a need to modify the cache,
then it tries to do an upgrade.  If that fails, it drops the read lock,
obtains a write lock, and redoes the lookup.
2009-01-28 19:05:18 +00:00
John Baldwin
8a7ef10b71 - Mark all standalone INT/LONG/QUAD sysctl's MPSAFE. This is done
inside the SYSCTL() macros and thus does not need to be done for
  all of the nodes scattered across the source tree.
- Mark the name-cache related sysctl's (including debug.hashstat.*) MPSAFE.
- Mark vm.loadavg MPSAFE.
- Remove GIANT_REQUIRED from vmtotal() (everything in this routine already
  has sufficient locking) and mark vm.vmtotal MPSAFE.
- Mark the vm.stats.(sys|vm).* sysctls MPSAFE.
2009-01-23 22:49:23 +00:00
Stephen McKay
58c1607e03 Add a limit on namecache entries.
In normal operation, the number of cache entries is roughly equal to the
number of active vnodes.  However, when most of the recently accessed
vnodes have many hard links, the number of cache entries can be 32000
times as large, exhausting kernel memory and provoking a panic in
kmem_malloc().

MFC after: 2 weeks
2009-01-20 04:21:21 +00:00
Konstantin Belousov
83e73926ad In r185557, the check for existing negative entry for the given name
did not compared nc_dvp with supplied parent directory vnode pointer.
Add the check and note that now branches for vp != NULL and vp == NULL
are the same, thus can be merged.

Reported and reviewed by:	kan
Tested by:	pho
MFC after:	2 weeks
2008-12-30 12:51:14 +00:00