The DCACHE_NEED_LOOKUP case referred to here was removed with
39e3c9553f "vfs: remove
DCACHE_NEED_LOOKUP".
There are only four real_lookup() callers and all of them pass in an
unhashed dentry just returned from d_alloc.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
DCACHE_DISCONNECTED should not be cleared until we're sure the dentry is
connected all the way up to the root of the filesystem. It *shouldn't*
be cleared as soon as the dentry is connected to a parent. That will
cause bugs at least on exportable filesystems.
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
I can't for the life of me see any reason why anyone should care whether
a dentry that is never hooked into the dentry cache would need
DCACHE_DISCONNECTED set.
This originates from 4b936885ab "fs:
improve scalability of pseudo filesystems", which probably just made the
false assumption the DCACHE_DISCONNECTED was meant to be set on anything
not connected to a parent somehow.
So this is just confusing. Ideally the only uses of DCACHE_DISCONNECTED
would be in the filehandle-lookup code, which needs it to ensure
dentries are connected into the dentry tree before use.
I left d_alloc_pseudo there even though it's now equivalent to
__d_alloc(), just on the theory the name is better documentation of its
intended use outside dcache.c.
Cc: Nick Piggin <npiggin@kernel.dk>
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Every hashed dentry is either hashed in the dentry_hashtable, or a
superblock's s_anon list.
__d_drop() assumes it can determine which is the case by checking
DCACHE_DISCONNECTED; this is not true.
It is true that when DCACHE_DISCONNECTED is cleared, the dentry is not
only hashed on dentry_hashtable, but is fully connected to its parents
back to the root.
But the converse is *not* true: fs/exportfs/expfs.c:reconnect_path()
attempts to connect a directory (found by filehandle lookup) back to
root by ascending to parents and performing lookups one at a time. It
does not clear DCACHE_DISCONNECTED until it's done, and that is not at
all an atomic process.
In particular, it is possible for DCACHE_DISCONNECTED to be set on a
dentry which is hashed on the dentry_hashtable.
Instead, use IS_ROOT() to check which hash chain a dentry is on. This
*does* work:
Dentries are hashed only by:
- d_obtain_alias, which adds an IS_ROOT() dentry to sb_anon.
- __d_rehash, called by _d_rehash: hashes to the dentry's
parent, and all callers of _d_rehash appear to have d_parent
set to a "real" parent.
- __d_rehash, called by __d_move: rehashes the moved dentry to
hash chain determined by target, and assigns target's d_parent
to its d_parent, before dropping the dentry's d_lock.
Therefore I believe it's safe for a holder of a dentry's d_lock to
assume that it is hashed on sb_anon if and only if IS_ROOT(dentry) is
true.
I believe the incorrect assumption about DCACHE_DISCONNECTED was
originally introduced by ceb5bdc2d2 "fs: dcache per-bucket dcache hash
locking".
Also add a comment while we're here.
Cc: Nick Piggin <npiggin@kernel.dk>
Acked-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Symptoms were spurious -ENOENTs on stat of an NFS filesystem from a
32-bit NFS server exporting a very large XFS filesystem, when the
server's cache is cold (so the inodes in question are not in cache).
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reported-by: Trevor Cordes <trevor@tecnopolis.ca>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The filehandle lookup code wants this version of getattr.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Put a type field into struct dentry::d_flags to indicate if the dentry is one
of the following types that relate particularly to pathwalk:
Miss (negative dentry)
Directory
"Automount" directory (defective - no i_op->lookup())
Symlink
Other (regular, socket, fifo, device)
The type field is set to one of the first five types on a dentry by calls to
__d_instantiate() and d_obtain_alias() from information in the inode (if one is
given).
The type is cleared by dentry_unlink_inode() when it reconstitutes an existing
dentry as a negative dentry.
Accessors provided are:
d_set_type(dentry, type)
d_is_directory(dentry)
d_is_autodir(dentry)
d_is_symlink(dentry)
d_is_file(dentry)
d_is_negative(dentry)
d_is_positive(dentry)
A bunch of checks in pathname resolution switched to those.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Don't abuse anon_inodes.c to host private files needed by aio;
we can bloody well declare a mini-fs of our own instead of
patching up what anon_inodes can create for us.
Tested-by: Benjamin LaHaise <bcrl@kvack.org>
Acked-by: Benjamin LaHaise <bcrl@kvack.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
... and deal with short writes properly - the output might be to pipe, after
all; as it is, e.g. no-MMU case of elf_fdpic coredump can write a whole lot
more than a page worth of data at one call.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
dump_write() analog, takes core_dump_params instead of file,
keeps track of the amount written in cprm->written and checks for
cprm->limit. Start using it in binfmt_elf.c...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The only thing we need it for is alt-sysrq-r (emergency remount r/o)
and these days we can do just as well without going through the
list of files.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* RCU-delayed freeing of vfsmounts
* vfsmount_lock replaced with a seqlock (mount_lock)
* sequence number from mount_lock is stored in nameidata->m_seq and
used when we exit RCU mode
* new vfsmount flag - MNT_SYNC_UMOUNT. Set by umount_tree() when its
caller knows that vfsmount will have no surviving references.
* synchronize_rcu() done between unlocking namespace_sem in namespace_unlock()
and doing pending mntput().
* new helper: legitimize_mnt(mnt, seq). Checks the mount_lock sequence
number against seq, then grabs reference to mnt. Then it rechecks mount_lock
again to close the race and either returns success or drops the reference it
has acquired. The subtle point is that in case of MNT_SYNC_UMOUNT we can
simply decrement the refcount and sod off - aforementioned synchronize_rcu()
makes sure that final mntput() won't come until we leave RCU mode. We need
that, since we don't want to end up with some lazy pathwalk racing with
umount() and stealing the final mntput() from it - caller of umount() may
expect it to return only once the fs is shut down and we don't want to break
that. In other cases (i.e. with MNT_SYNC_UMOUNT absent) we have to do
full-blown mntput() in case of mount_lock sequence number mismatch happening
just as we'd grabbed the reference, but in those cases we won't be stealing
the final mntput() from anything that would care.
* mntput_no_expire() doesn't lock anything on the fast path now. Incidentally,
SMP and UP cases are handled the same way - no ifdefs there.
* normal pathname resolution does *not* do any writes to mount_lock. It does,
of course, bump the refcounts of vfsmount and dentry in the very end, but that's
it.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
In current kernel wide source code, except other architectures, only
s390 scsi drivers use atomic_clear_mask(), and arm/arm64 need not
support s390 drivers.
So remove atomic_clear_mask() from "arm[64]/include/asm/atomic.h".
Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
For atomic_cmpxchg(), the type of 'oldval' need be 'int' to match the
type of "*ptr" (used by 'ldrex' instruction) and 'old' (used by 'teq'
instruction).
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
atomic* value is signed value, and atomic* functions need also process
signed value (parameter value, and return value), so 32-bit arm need
use 'long long' instead of 'u64'.
After replacement, it will also fix a bug for atomic64_add_negative():
"u64 is never less than 0".
The modifications are:
in vim, use "1,% s/\<u64\>/long long/g" command.
remove '__aligned(8)' which is useless for 64-bit.
be sure of 80 column limitation after replacement.
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Xilinx Zynq pl330 dma driver has 9 irqs which all have to
be used by the driver to get it work properly.
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Currently irq vector handlers for tracing are registered in both set_intr_gate()
and __trace_alloc_intr_gate() in alloc_intr_gate().
But, we don't need to do that twice.
So, let's delete __trace_alloc_intr_gate().
Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com>
Link: http://lkml.kernel.org/r/52716E1B.7090205@hds.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This patch registers exception handlers for tracing to a trace IDT.
To implemented it in set_intr_gate(), this patch does followings.
- Register the exception handlers to
the trace IDT by prepending "trace_" to the handler's names.
- Also, newly introduce trace_page_fault() to add tracepoints
in a subsequent patch.
Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com>
Link: http://lkml.kernel.org/r/52716DEC.5050204@hds.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Prepare to move set_intr_gate() into a macro by removing
__alloc_intr_gate().
The purpose is to avoid failing a kernel build after applying a
subsequent patch which changes set_intr_gate() into a macro.
Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com>
Link: http://lkml.kernel.org/r/52716DB8.1080702@hds.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
The number of stations in use is kept in the num_rx_pools counter
in the ixgbe_adapter structure. This is in turn used by the queue
allocation scheme to determine how many queues are needed to support
the number of pools in use with the current feature set.
This works as long as the pools are added and destroyed in order
because (num_rx_pools * queues_per_pool) is equal to the last
queue in use by a pool. But as soon as you delete a pool out of
order this is no longer the case. So the above multiplication
allocates to few queues and a pool may reference a ring that has
not been allocated/initialized.
To resolve use the bit mask of in use pools to determine the final
pool being used and allocate enough queues so that we don't
inadvertently remove its queues.
# ip link add link eth2 \
numtxqueues 4 numrxqueues 4 txqueuelen 50 type macvlan
# ip link set dev macvlan0 up
# ip link add link eth2 \
numtxqueues 4 numrxqueues 4 txqueuelen 50 type macvlan
# ip link set dev macvlan1 up
# for i in {0..100}; do
ip link set dev macvlan0 down; ip link set dev macvlan0 up;
done;
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In the recent support for layer 2 hardware acceleration, I added a
few references to real_num_rx_queues and num_rx_queues which are
only available with CONFIG_RPS.
The fix is first to remove unnecessary references to num_rx_queues.
Because the hardware offload case is limited to cases where RX queues
and TX queues are equal we only need a single check. Then wrap the
single case in an ifdef.
The patch that introduce this is here,
commit a6cc0cfa72
Author: John Fastabend <john.r.fastabend@intel.com>
Date: Wed Nov 6 09:54:46 2013 -0800
net: Add layer 2 hardware acceleration operations for macvlan devices
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As the rfc 4191 said, the Router Preference and Lifetime values in a
::/0 Route Information Option should override the preference and lifetime
values in the Router Advertisement header. But when the kernel deals with
a ::/0 Route Information Option, the rt6_get_route_info() always return
NULL, that means that overriding will not happen, because those default
routers were added without flag RTF_ROUTEINFO in rt6_add_dflt_router().
In order to deal with that condition, we should call rt6_get_dflt_router
when the prefix length is 0.
Signed-off-by: Duan Jiong <duanj.fnst@cn.fujitsu.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 0628b123c9 ("netfilter: nfnetlink: add batch support and use it
from nf_tables") introduced a bug leading to various crashes in netlink_ack
when netlink message with invalid nlmsg_len was sent by an unprivileged
user.
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When trying to delete a table >= 256 using iproute2 the local table
will be deleted.
The table id is specified as a netlink attribute when it needs more then
8 bits and iproute2 then sets the table field to RT_TABLE_UNSPEC (0).
Preconditions to matching the table id in the rule delete code
doesn't seem to take the "table id in netlink attribute" into condition
so the frh_get_table helper function never gets to do its job when
matching against current rule.
Use the helper function twice instead of peaking at the table value directly.
Originally reported at: http://bugs.debian.org/724783
Reported-by: Nicolas HICHER <nhicher@avencall.com>
Signed-off-by: Andreas Henriksson <andreas@fatal.se>
Signed-off-by: David S. Miller <davem@davemloft.net>
