Both the NFS protocols and the Linux VFS use a setattr operation with a
bitmap of attributs to set to set various file attributes including the
file size and the uid/gid.
The Linux syscalls never mixes size updates with unrelated updates like
the uid/gid, and some file systems like XFS and GFS2 rely on the fact
that truncates might not update random other attributes, and many other
file systems handle the case but do not update the different attributes
in the same transaction. NFSD on the other hand passes the attributes
it gets on the wire more or less directly through to the VFS, leading to
updates the file systems don't expect. XFS at least has an assert on
the allowed attributes, which caught an unusual NFS client setting the
size and group at the same time.
To handle this issue properly this switches nfsd to call vfs_truncate
for size changes, and then handle all other attributes through
notify_change. As a side effect this also means less boilerplace code
around the size change as we can now reuse the VFS code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
nfsd assigns the nfs4_free_lock_stateid to .sc_free in init_lock_stateid().
If nfsd doesn't go through init_lock_stateid() and put stateid at end,
there is a NULL reference to .sc_free when calling nfs4_put_stid(ns).
This patch let the nfs4_stid.sc_free assignment to nfs4_alloc_stid().
Cc: stable@vger.kernel.org
Fixes: 356a95ece7 "nfsd: clean up races in lock stateid searching..."
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Oops--in 916d2d844a I moved some constants into an array for
convenience, but here I'm accidentally writing to that array.
The effect is that if you ever encounter a filesystem lacking support
for ACLs or security labels, then all queries of supported attributes
will report that attribute as unsupported from then on.
Fixes: 916d2d844a "nfsd: clean up supported attribute handling"
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This was entirely automated, using the script by Al:
PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
$(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)
to do the replacement at the end of the merge window.
Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull partial readlink cleanups from Miklos Szeredi.
This is the uncontroversial part of the readlink cleanup patch-set that
simplifies the default readlink handling.
Miklos and Al are still discussing the rest of the series.
* git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
vfs: make generic_readlink() static
vfs: remove ".readlink = generic_readlink" assignments
vfs: default to generic_readlink()
vfs: replace calling i_op->readlink with vfs_readlink()
proc/self: use generic_readlink
ecryptfs: use vfs_get_link()
bad_inode: add missing i_op initializers
Pull overlayfs updates from Miklos Szeredi:
"This update contains:
- try to clone on copy-up
- allow renaming a directory
- split source into managable chunks
- misc cleanups and fixes
It does not contain the read-only fd data inconsistency fix, which Al
didn't like. I'll leave that to the next year..."
* 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: (36 commits)
ovl: fix reStructuredText syntax errors in documentation
ovl: fix return value of ovl_fill_super
ovl: clean up kstat usage
ovl: fold ovl_copy_up_truncate() into ovl_copy_up()
ovl: create directories inside merged parent opaque
ovl: opaque cleanup
ovl: show redirect_dir mount option
ovl: allow setting max size of redirect
ovl: allow redirect_dir to default to "on"
ovl: check for emptiness of redirect dir
ovl: redirect on rename-dir
ovl: lookup redirects
ovl: consolidate lookup for underlying layers
ovl: fix nested overlayfs mount
ovl: check namelen
ovl: split super.c
ovl: use d_is_dir()
ovl: simplify lookup
ovl: check lower existence of rename target
ovl: rename: simplify handling of lower/merged directory
...
that makes ACL inheritance a little more useful in environments that
default to restrictive umasks. Requires client-side support, also on
its way for 4.10.
Other than that, miscellaneous smaller fixes and cleanup, especially to
the server rdma code.
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Merge tag 'nfsd-4.10' of git://linux-nfs.org/~bfields/linux
Pull nfsd updates from Bruce Fields:
"The one new feature is support for a new NFSv4.2 mode_umask attribute
that makes ACL inheritance a little more useful in environments that
default to restrictive umasks. Requires client-side support, also on
its way for 4.10.
Other than that, miscellaneous smaller fixes and cleanup, especially
to the server rdma code"
[ The client side of the umask attribute was merged yesterday ]
* tag 'nfsd-4.10' of git://linux-nfs.org/~bfields/linux:
nfsd: add support for the umask attribute
sunrpc: use DEFINE_SPINLOCK()
svcrdma: Further clean-up of svc_rdma_get_inv_rkey()
svcrdma: Break up dprintk format in svc_rdma_accept()
svcrdma: Remove unused variable in rdma_copy_tail()
svcrdma: Remove unused variables in xprt_rdma_bc_allocate()
svcrdma: Remove svc_rdma_op_ctxt::wc_status
svcrdma: Remove DMA map accounting
svcrdma: Remove BH-disabled spin locking in svc_rdma_send()
svcrdma: Renovate sendto chunk list parsing
svcauth_gss: Close connection when dropping an incoming message
svcrdma: Clear xpt_bc_xps in xprt_setup_rdma_bc() error exit arm
nfsd: constify reply_cache_stats_operations structure
nfsd: update workqueue creation
sunrpc: GFP_KERNEL should be GFP_NOFS in crypto code
nfsd: catch errors in decode_fattr earlier
nfsd: clean up supported attribute handling
nfsd: fix error handling for clients that fail to return the layout
nfsd: more robust allocation failure handling in nfsd_reply_cache_init
Move sb_start_write()/sb_end_write() out of the vfs helper and up into the
ioctl handler.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Clients can set the umask attribute when creating files to cause the
server to apply it always except when inheriting permissions from the
parent directory. That way, the new files will end up with the same
permissions as files created locally.
See https://tools.ietf.org/html/draft-ietf-nfsv4-umask-02 for more
details.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Also check d_is_symlink() in callers instead of inode->i_op->readlink
because following patches will allow NULL ->readlink for symlinks.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Make struct pernet_operations::id unsigned.
There are 2 reasons to do so:
1)
This field is really an index into an zero based array and
thus is unsigned entity. Using negative value is out-of-bound
access by definition.
2)
On x86_64 unsigned 32-bit data which are mixed with pointers
via array indexing or offsets added or subtracted to pointers
are preffered to signed 32-bit data.
"int" being used as an array index needs to be sign-extended
to 64-bit before being used.
void f(long *p, int i)
{
g(p[i]);
}
roughly translates to
movsx rsi, esi
mov rdi, [rsi+...]
call g
MOVSX is 3 byte instruction which isn't necessary if the variable is
unsigned because x86_64 is zero extending by default.
Now, there is net_generic() function which, you guessed it right, uses
"int" as an array index:
static inline void *net_generic(const struct net *net, int id)
{
...
ptr = ng->ptr[id - 1];
...
}
And this function is used a lot, so those sign extensions add up.
Patch snipes ~1730 bytes on allyesconfig kernel (without all junk
messing with code generation):
add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730)
Unfortunately some functions actually grow bigger.
This is a semmingly random artefact of code generation with register
allocator being used differently. gcc decides that some variable
needs to live in new r8+ registers and every access now requires REX
prefix. Or it is shifted into r12, so [r12+0] addressing mode has to be
used which is longer than [r8]
However, overall balance is in negative direction:
add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730)
function old new delta
nfsd4_lock 3886 3959 +73
tipc_link_build_proto_msg 1096 1140 +44
mac80211_hwsim_new_radio 2776 2808 +32
tipc_mon_rcv 1032 1058 +26
svcauth_gss_legacy_init 1413 1429 +16
tipc_bcbase_select_primary 379 392 +13
nfsd4_exchange_id 1247 1260 +13
nfsd4_setclientid_confirm 782 793 +11
...
put_client_renew_locked 494 480 -14
ip_set_sockfn_get 730 716 -14
geneve_sock_add 829 813 -16
nfsd4_sequence_done 721 703 -18
nlmclnt_lookup_host 708 686 -22
nfsd4_lockt 1085 1063 -22
nfs_get_client 1077 1050 -27
tcf_bpf_init 1106 1076 -30
nfsd4_encode_fattr 5997 5930 -67
Total: Before=154856051, After=154854321, chg -0.00%
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
reply_cache_stats_operations, of type struct file_operations, is never
modified, so declare it as const.
Done with the help of Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Reviewed-by: Jeff Layton <jlayton@poochiereds.net>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
No real change in functionality, but the old interface seems to be
deprecated.
We don't actually care about ordering necessarily, but we do depend on
running at most one work item at a time: nfsd4_process_cb_update()
assumes that no other thread is running it, and that no new callbacks
are starting while it's running.
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
3c8e03166a "NFSv4: do exact check about attribute specified" fixed
some handling of unsupported-attribute errors, but it also delayed
checking for unwriteable attributes till after we decode them. This
could lead to odd behavior in the case a client attemps to set an
attribute we don't know about followed by one we try to parse. In that
case the parser for the known attribute will attempt to parse the
unknown attribute. It should fail in some safe way, but the error might
at least be incorrect (probably bad_xdr instead of inval). So, it's
better to do that check at the start.
As far as I know this doesn't cause any problems with current clients
but it might be a minor issue e.g. if we encounter a future client that
supports a new attribute that we currently don't.
Cc: Yu Zhiguo <yuzg@cn.fujitsu.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Minor cleanup, no change in behavior.
Provide helpers for some common attribute bitmap operations. Drop some
comments that just echo the code.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Currently, when the client continually returns NFS4ERR_DELAY on a
CB_LAYOUTRECALL, we'll give up trying to retransmit after two lease
periods, but leave the layout in place.
What we really need to do here is fence the client in this case. Have it
fall through to that code in that case instead of into the
NFS4ERR_NOMATCHING_LAYOUT case.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Currently, we try to allocate the cache as a single, large chunk, which
can fail if no big chunks of memory are available. We _do_ try to size
it according to the amount of memory in the box, but if the server is
started well after boot time, then the allocation can fail due to memory
fragmentation.
Fall back to doing a vzalloc if the kcalloc fails, and switch the
shutdown code to do a kvfree to handle freeing correctly.
Reported-by: Olaf Hering <olaf@aepfle.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Bruce was hitting some lockdep warnings in testing, showing that we
could hit a deadlock with the new CB_NOTIFY_LOCK handling, involving a
rather complex situation involving four different spinlocks.
The crux of the matter is that we end up taking the nn->client_lock in
the lm_notify handler. The simplest fix is to just declare a new
per-nfsd_net spinlock to protect the new CB_NOTIFY_LOCK structures.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
benefit from user testing:
Anna Schumacker contributed a simple NFSv4.2 COPY implementation. COPY
is already supported on the client side, so a call to copy_file_range()
on a recent client should now result in a server-side copy that doesn't
require all the data to make a round trip to the client and back.
Jeff Layton implemented callbacks to notify clients when contended locks
become available, which should reduce latency on workloads with
contended locks.
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Merge tag 'nfsd-4.9' of git://linux-nfs.org/~bfields/linux
Pull nfsd updates from Bruce Fields:
"Some RDMA work and some good bugfixes, and two new features that could
benefit from user testing:
- Anna Schumacker contributed a simple NFSv4.2 COPY implementation.
COPY is already supported on the client side, so a call to
copy_file_range() on a recent client should now result in a
server-side copy that doesn't require all the data to make a round
trip to the client and back.
- Jeff Layton implemented callbacks to notify clients when contended
locks become available, which should reduce latency on workloads
with contended locks"
* tag 'nfsd-4.9' of git://linux-nfs.org/~bfields/linux:
NFSD: Implement the COPY call
nfsd: handle EUCLEAN
nfsd: only WARN once on unmapped errors
exportfs: be careful to only return expected errors.
nfsd4: setclientid_confirm with unmatched verifier should fail
nfsd: randomize SETCLIENTID reply to help distinguish servers
nfsd: set the MAY_NOTIFY_LOCK flag in OPEN replies
nfs: add a new NFS4_OPEN_RESULT_MAY_NOTIFY_LOCK constant
nfsd: add a LRU list for blocked locks
nfsd: have nfsd4_lock use blocking locks for v4.1+ locks
nfsd: plumb in a CB_NOTIFY_LOCK operation
NFSD: fix corruption in notifier registration
svcrdma: support Remote Invalidation
svcrdma: Server-side support for rpcrdma_connect_private
rpcrdma: RDMA/CM private message data structure
svcrdma: Skip put_page() when send_reply() fails
svcrdma: Tail iovec leaves an orphaned DMA mapping
nfsd: fix dprintk in nfsd4_encode_getdeviceinfo
nfsd: eliminate cb_minorversion field
nfsd: don't set a FL_LAYOUT lease for flexfiles layouts
Pull more vfs updates from Al Viro:
">rename2() work from Miklos + current_time() from Deepa"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fs: Replace current_fs_time() with current_time()
fs: Replace CURRENT_TIME_SEC with current_time() for inode timestamps
fs: Replace CURRENT_TIME with current_time() for inode timestamps
fs: proc: Delete inode time initializations in proc_alloc_inode()
vfs: Add current_time() api
vfs: add note about i_op->rename changes to porting
fs: rename "rename2" i_op to "rename"
vfs: remove unused i_op->rename
fs: make remaining filesystems use .rename2
libfs: support RENAME_NOREPLACE in simple_rename()
fs: support RENAME_NOREPLACE for local filesystems
ncpfs: fix unused variable warning
Pull misc vfs updates from Al Viro:
"Assorted misc bits and pieces.
There are several single-topic branches left after this (rename2
series from Miklos, current_time series from Deepa Dinamani, xattr
series from Andreas, uaccess stuff from from me) and I'd prefer to
send those separately"
* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (39 commits)
proc: switch auxv to use of __mem_open()
hpfs: support FIEMAP
cifs: get rid of unused arguments of CIFSSMBWrite()
posix_acl: uapi header split
posix_acl: xattr representation cleanups
fs/aio.c: eliminate redundant loads in put_aio_ring_file
fs/internal.h: add const to ns_dentry_operations declaration
compat: remove compat_printk()
fs/buffer.c: make __getblk_slow() static
proc: unsigned file descriptors
fs/file: more unsigned file descriptors
fs: compat: remove redundant check of nr_segs
cachefiles: Fix attempt to read i_blocks after deleting file [ver #2]
cifs: don't use memcpy() to copy struct iov_iter
get rid of separate multipage fault-in primitives
fs: Avoid premature clearing of capabilities
fs: Give dentry to inode_change_ok() instead of inode
fuse: Propagate dentry down to inode_change_ok()
ceph: Propagate dentry down to inode_change_ok()
xfs: Propagate dentry down to inode_change_ok()
...
Current supplementary groups code can massively overallocate memory and
is implemented in a way so that access to individual gid is done via 2D
array.
If number of gids is <= 32, memory allocation is more or less tolerable
(140/148 bytes). But if it is not, code allocates full page (!)
regardless and, what's even more fun, doesn't reuse small 32-entry
array.
2D array means dependent shifts, loads and LEAs without possibility to
optimize them (gid is never known at compile time).
All of the above is unnecessary. Switch to the usual
trailing-zero-len-array scheme. Memory is allocated with
kmalloc/vmalloc() and only as much as needed. Accesses become simpler
(LEA 8(gi,idx,4) or even without displacement).
Maximum number of gids is 65536 which translates to 256KB+8 bytes. I
think kernel can handle such allocation.
On my usual desktop system with whole 9 (nine) aux groups, struct
group_info shrinks from 148 bytes to 44 bytes, yay!
Nice side effects:
- "gi->gid[i]" is shorter than "GROUP_AT(gi, i)", less typing,
- fix little mess in net/ipv4/ping.c
should have been using GROUP_AT macro but this point becomes moot,
- aux group allocation is persistent and should be accounted as such.
Link: http://lkml.kernel.org/r/20160817201927.GA2096@p183.telecom.by
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Vasily Kulikov <segoon@openwall.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I only implemented the sync version of this call, since it's the
easiest. I can simply call vfs_copy_range() and have the vfs do the
right thing for the filesystem being exported.
Signed-off-by: Anna Schumaker <bjschuma@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Eric Sandeen reports that xfs can return this if filesystem corruption
prevented completing the operation.
Reported-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
No need to spam the logs here.
The only drawback is losing information if we ever encounter two
different unmapped errors, but in practice we've rarely see even one.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
current_fs_time() uses struct super_block* as an argument.
As per Linus's suggestion, this is changed to take struct
inode* as a parameter instead. This is because the function
is primarily meant for vfs inode timestamps.
Also the function was renamed as per Arnd's suggestion.
Change all calls to current_fs_time() to use the new
current_time() function instead. current_fs_time() will be
deleted.
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
A setclientid_confirm with (clientid, verifier) both matching an
existing confirmed record is assumed to be a replay, but if the verifier
doesn't match, it shouldn't be.
This would be a very rare case, except that clients following
https://tools.ietf.org/html/rfc7931#section-5.8 may depend on the
failure.
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
NFSv4.1 has built-in trunking support that allows a client to determine
whether two connections to two different IP addresses are actually to
the same server. NFSv4.0 does not, but RFC 7931 attempts to provide
clients a means to do this, basically by performing a SETCLIENTID to one
address and confirming it with a SETCLIENTID_CONFIRM to the other.
Linux clients since 05f4c350ee "NFS: Discover NFSv4 server trunking
when mounting" implement a variation on this suggestion. It is possible
that other clients do too.
This depends on the clientid and verifier not being accepted by an
unrelated server. Since both are 64-bit values, that would be very
unlikely if they were random numbers. But they aren't:
knfsd generates the 64-bit clientid by concatenating the 32-bit boot
time (in seconds) and a counter. This makes collisions between
clientids generated by the same server extremely unlikely. But
collisions are very likely between clientids generated by servers that
boot at the same time, and it's quite common for multiple servers to
boot at the same time. The verifier is a concatenation of the
SETCLIENTID time (in seconds) and a counter, so again collisions between
different servers are likely if multiple SETCLIENTIDs are done at the
same time, which is a common case.
Therefore recent NFSv4.0 clients may decide two different servers are
really the same, and mount a filesystem from the wrong server.
Fortunately the Linux client, since 55b9df93dd "nfsv4/v4.1: Verify the
client owner id during trunking detection", only does this when given
the non-default "migration" mount option.
The fault is really with RFC 7931, and needs a client fix, but in the
meantime we can mitigate the chance of these collisions by randomizing
the starting value of the counters used to generate clientids and
verifiers.
Reported-by: Frank Sorenson <fsorenso@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
If we are using v4.1+, then we can send notification when contended
locks become free. Inform the client of that fact.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
It's possible for a client to call in on a lock that is blocked for a
long time, but discontinue polling for it. A malicious client could
even set a lock on a file, and then spam the server with failing lock
requests from different lockowners that pile up in a DoS attack.
Add the blocked lock structures to a per-net namespace LRU when hashing
them, and timestamp them. If the lock request is not revisited after a
lease period, we'll drop it under the assumption that the client is no
longer interested.
This also gives us a mechanism to clean up these objects at server
shutdown time as well.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Create a new per-lockowner+per-inode structure that contains a
file_lock. Have nfsd4_lock add this structure to the lockowner's list
prior to setting the lock. Then call the vfs and request a blocking lock
(by setting FL_SLEEP). If we get anything besides FILE_LOCK_DEFERRED
back, then we dequeue the block structure and free it. When the next
lock request comes in, we'll look for an existing block for the same
filehandle and dequeue and reuse it if there is one.
When the lock comes free (a'la an lm_notify call), we dequeue it
from the lockowner's list and kick off a CB_NOTIFY_LOCK callback to
inform the client that it should retry the lock request.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Add the encoding/decoding for CB_NOTIFY_LOCK operations.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
By design notifier can be registered once only, however nfsd registers
the same inetaddr notifiers per net-namespace. When this happen it
corrupts list of notifiers, as result some notifiers can be not called
on proper event, traverse on list can be cycled forever, and second
unregister can access already freed memory.
Cc: stable@vger.kernel.org
fixes: 36684996 ("nfsd: Register callbacks on the inetaddr_chain and inet6addr_chain")
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
nfserr is big-endian, so we should convert it to host-endian before
printing it.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
inode_change_ok() will be resposible for clearing capabilities and IMA
extended attributes and as such will need dentry. Give it as an argument
to inode_change_ok() instead of an inode. Also rename inode_change_ok()
to setattr_prepare() to better relect that it does also some
modifications in addition to checks.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
We already have that info in the client pointer. No need to pass around
a copy.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
We currently can hit a deadlock (of sorts) when trying to use flexfiles
layouts with XFS. XFS will call break_layout when something wants to
write to the file. In the case of the (super-simple) flexfiles layout
driver in knfsd, the MDS and DS are the same machine.
The client can get a layout and then issue a v3 write to do its I/O. XFS
will then call xfs_break_layouts, which will cause a CB_LAYOUTRECALL to
be issued to the client. The client however can't return the layout
until the v3 WRITE completes, but XFS won't allow the write to proceed
until the layout is returned.
Christoph says:
XFS only cares about block-like layouts where the client has direct
access to the file blocks. I'd need to look how to propagate the
flag into break_layout, but in principle we don't need to do any
recalls on truncate ever for file and flexfile layouts.
If we're never going to recall the layout, then we don't even need to
set the lease at all. Just skip doing so on flexfiles layouts by
adding a new flag to struct nfsd4_layout_ops and skipping the lease
setting and removal when that flag is true.
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
nfsd4_lock will take the st_mutex before working with the stateid it
gets, but between the time when we drop the cl_lock and take the mutex,
the stateid could become unhashed (a'la FREE_STATEID). If that happens
the lock stateid returned to the client will be forgotten.
Fix this by first moving the st_mutex acquisition into
lookup_or_create_lock_state. Then, have it check to see if the lock
stateid is still hashed after taking the mutex. If it's not, then put
the stateid and try the find/create again.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Tested-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Cc: stable@vger.kernel.org # feb9dad5 nfsd: Always lock state exclusively.
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
When running LTP's nfslock01 test, the Linux client can send a LOCK
and a FREE_STATEID request at the same time. The outcome is:
Frame 324 R OPEN stateid [2,O]
Frame 115004 C LOCK lockowner_is_new stateid [2,O] offset 672000 len 64
Frame 115008 R LOCK stateid [1,L]
Frame 115012 C WRITE stateid [0,L] offset 672000 len 64
Frame 115016 R WRITE NFS4_OK
Frame 115019 C LOCKU stateid [1,L] offset 672000 len 64
Frame 115022 R LOCKU NFS4_OK
Frame 115025 C FREE_STATEID stateid [2,L]
Frame 115026 C LOCK lockowner_is_new stateid [2,O] offset 672128 len 64
Frame 115029 R FREE_STATEID NFS4_OK
Frame 115030 R LOCK stateid [3,L]
Frame 115034 C WRITE stateid [0,L] offset 672128 len 64
Frame 115038 R WRITE NFS4ERR_BAD_STATEID
In other words, the server returns stateid L in a successful LOCK
reply, but it has already released it. Subsequent uses of stateid L
fail.
To address this, protect the generation check in nfsd4_free_stateid
with the st_mutex. This should guarantee that only one of two
outcomes occurs: either LOCK returns a fresh valid stateid, or
FREE_STATEID returns NFS4ERR_LOCKS_HELD.
Reported-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Fix-suggested-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
b44061d0b9 introduced a dentry ref counting bug. Previously we were
grabbing one ref to dchild in nfsd_create(), but with the creation of
nfsd_create_locked() we have a ref for dchild from the lookup in
nfsd_create(), and then another ref in nfsd_create_locked(). The ref
from the lookup in nfsd_create() is never dropped and results in
dentries still in use at unmount.
Signed-off-by: Josef Bacik <jbacik@fb.com>
Fixes: b44061d0b9 "nfsd: reorganize nfsd_create"
Reported-by: kernel test robot <xiaolong.ye@intel.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Trond made a change to the server's tcp logic that allows a fast
client to better take advantage of high bandwidth networks, but
may increase the risk that a single client could starve other
clients; a new sunrpc.svc_rpc_per_connection_limit parameter
should help mitigate this in the (hopefully unlikely) event this
becomes a problem in practice.
Tom Haynes added a minimal flex-layout pnfs server, which is of
no use in production for now--don't build it unless you're doing
client testing or further server development.
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Merge tag 'nfsd-4.8' of git://linux-nfs.org/~bfields/linux
Pull nfsd updates from Bruce Fields:
"Highlights:
- Trond made a change to the server's tcp logic that allows a fast
client to better take advantage of high bandwidth networks, but may
increase the risk that a single client could starve other clients;
a new sunrpc.svc_rpc_per_connection_limit parameter should help
mitigate this in the (hopefully unlikely) event this becomes a
problem in practice.
- Tom Haynes added a minimal flex-layout pnfs server, which is of no
use in production for now--don't build it unless you're doing
client testing or further server development"
* tag 'nfsd-4.8' of git://linux-nfs.org/~bfields/linux: (32 commits)
nfsd: remove some dead code in nfsd_create_locked()
nfsd: drop unnecessary MAY_EXEC check from create
nfsd: clean up bad-type check in nfsd_create_locked
nfsd: remove unnecessary positive-dentry check
nfsd: reorganize nfsd_create
nfsd: check d_can_lookup in fh_verify of directories
nfsd: remove redundant zero-length check from create
nfsd: Make creates return EEXIST instead of EACCES
SUNRPC: Detect immediate closure of accepted sockets
SUNRPC: accept() may return sockets that are still in SYN_RECV
nfsd: allow nfsd to advertise multiple layout types
nfsd: Close race between nfsd4_release_lockowner and nfsd4_lock
nfsd/blocklayout: Make sure calculate signature/designator length aligned
xfs: abstract block export operations from nfsd layouts
SUNRPC: Remove unused callback xpo_adjust_wspace()
SUNRPC: Change TCP socket space reservation
SUNRPC: Add a server side per-connection limit
SUNRPC: Micro optimisation for svc_data_ready
SUNRPC: Call the default socket callbacks instead of open coding
SUNRPC: lock the socket while detaching it
...
We changed this around in f135af1041f ('nfsd: reorganize nfsd_create')
so "dchild" can't be an error pointer any more. Also, dchild can't be
NULL here (and dput would already handle this even if it was).
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
We need an fh_verify to make sure we at least have a dentry, but actual
permission checks happen later.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
vfs_{create,mkdir,mknod} each begin with a call to may_create(), which
returns EEXIST if the object already exists.
This check is therefore unnecessary.
(In the NFSv2 case, nfsd_proc_create also has such a check. Contrary to
RFC 1094, our code seems to believe that a CREATE of an existing file
should succeed. I'm leaving that behavior alone.)
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
There's some odd logic in nfsd_create() that allows it to be called with
the parent directory either locked or unlocked. The only already-locked
caller is NFSv2's nfsd_proc_create(). It's less confusing to split out
the unlocked case into a separate function which the NFSv2 code can call
directly.
Also fix some comments while we're here.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Create and other nfsd ops generally assume we can call lookup_one_len on
inodes with S_IFDIR set. Al says that this assumption isn't true in
general, though it should be for the filesystem objects nfsd sees.
Add a check just to make sure our assumption isn't violated.
Remove a couple checks for i_op->lookup in create code.
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
lookup_one_len already has this check.
The only effect of this patch is to return access instead of perm in the
0-length-filename case. I actually prefer nfserr_perm (or _inval?), but
I doubt anyone cares.
The isdotent check seems redundant too, but I worry that some client
might actually care about that strange nfserr_exist error.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Christoph Hellwig