| Commit message (Collapse) | Author | Age | Files | Lines |
|---|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
group and project quota hints are currently stored on the user
dquot. If we are attaching quotas to the inode, then the group and
project dquots are stored as hints on the user dquot to save having
to look them up again later.
The thing is, the hints are not used for that inode for the rest of
the life of the inode - the dquots are attached directly to the
inode itself - so the only time the hints are used is when an inode
first has dquots attached.
When the hints on the user dquot don't match the dquots being
attache dto the inode, they are then removed and replaced with the
new hints. If a user is concurrently modifying files in different
group and/or project contexts, then this leads to thrashing of the
hints attached to user dquot.
If user quotas are not enabled, then hints are never even used.
So, if the hints are used to avoid the cost of the lookup, is the
cost of the lookup significant enough to justify the hint
infrstructure? Maybe it was once, when there was a global quota
manager shared between all XFS filesystems and was hash table based.
However, lookups are now much simpler, requiring only a single lock and
radix tree lookup local to the filesystem and no hash or LRU
manipulations to be made. Hence the cost of lookup is much lower
than when hints were implemented. Turns out that benchmarks show
that, too, with thir being no differnce in performance when doing
file creation workloads as a single user with user, group and
project quotas enabled - the hints do not make the code go any
faster. In fact, removing the hints shows a 2-3% reduction in the
time it takes to create 50 million inodes....
So, let's just get rid of the hints and the complexity around them.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
Coverity noticed that if we sent junk into
xfs_qm_scall_trunc_qfiles(), we could get back an
uninitialized error value. So sanitize the flags we
will accept, and initialize error anyway for good measure.
(This bug may have been introduced via c61a9e39).
Should resolve Coverity CID 1163872.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jie Liu <jeff.liu@oracle.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
The Q_XQUOTARM quotactl was not working properly, because
we weren't passing around proper flags. The xfs_fs_set_xstate()
ioctl handler used the same flags for Q_XQUOTAON/OFF as
well as for Q_XQUOTARM, but Q_XQUOTAON/OFF look for
XFS_UQUOTA_ACCT, XFS_UQUOTA_ENFD, XFS_GQUOTA_ACCT etc,
i.e. quota type + state, while Q_XQUOTARM looks only for
the type of quota, i.e. XFS_DQ_USER, XFS_DQ_GROUP etc.
Unfortunately these flag spaces overlap a bit, so we
got semi-random results for Q_XQUOTARM; i.e. the value
for XFS_DQ_USER == XFS_UQUOTA_ACCT, etc. yeargh.
Add a new quotactl op vector specifically for the QUOTARM
operation, since it operates with a different flag space.
This has been broken more or less forever, AFAICT.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Acked-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
On 32 bit, size_t is "unsigned int", not "unsigned long", causing the
following warning when comparing with PAGE_SIZE, which is always "unsigned
long":
fs/cifs/file.c: In function ‘cifs_readdata_to_iov’:
fs/cifs/file.c:2757: warning: comparison of distinct pointer types lacks a cast
Introduced by commit 7f25bba819a3 ("cifs_iovec_read: keep iov_iter
between the calls of cifs_readdata_to_iov()"), which changed the
signedness of "remaining" and the code from min_t() to min().
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
| |\
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
Pull yet more networking updates from David Miller:
1) Various fixes to the new Redpine Signals wireless driver, from
Fariya Fatima.
2) L2TP PPP connect code takes PMTU from the wrong socket, fix from
Dmitry Petukhov.
3) UFO and TSO packets differ in whether they include the protocol
header in gso_size, account for that in skb_gso_transport_seglen().
From Florian Westphal.
4) If VLAN untagging fails, we double free the SKB in the bridging
output path. From Toshiaki Makita.
5) Several call sites of sk->sk_data_ready() were referencing an SKB
just added to the socket receive queue in order to calculate the
second argument via skb->len. This is dangerous because the moment
the skb is added to the receive queue it can be consumed in another
context and freed up.
It turns out also that none of the sk->sk_data_ready()
implementations even care about this second argument.
So just kill it off and thus fix all these use-after-free bugs as a
side effect.
6) Fix inverted test in tcp_v6_send_response(), from Lorenzo Colitti.
7) pktgen needs to do locking properly for LLTX devices, from Daniel
Borkmann.
8) xen-netfront driver initializes TX array entries in RX loop :-) From
Vincenzo Maffione.
9) After refactoring, some tunnel drivers allow a tunnel to be
configured on top itself. Fix from Nicolas Dichtel.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (46 commits)
vti: don't allow to add the same tunnel twice
gre: don't allow to add the same tunnel twice
drivers: net: xen-netfront: fix array initialization bug
pktgen: be friendly to LLTX devices
r8152: check RTL8152_UNPLUG
net: sun4i-emac: add promiscuous support
net/apne: replace IS_ERR and PTR_ERR with PTR_ERR_OR_ZERO
net: ipv6: Fix oif in TCP SYN+ACK route lookup.
drivers: net: cpsw: enable interrupts after napi enable and clearing previous interrupts
drivers: net: cpsw: discard all packets received when interface is down
net: Fix use after free by removing length arg from sk_data_ready callbacks.
Drivers: net: hyperv: Address UDP checksum issues
Drivers: net: hyperv: Negotiate suitable ndis version for offload support
Drivers: net: hyperv: Allocate memory for all possible per-pecket information
bridge: Fix double free and memory leak around br_allowed_ingress
bonding: Remove debug_fs files when module init fails
i40evf: program RSS LUT correctly
i40evf: remove open-coded skb_cow_head
ixgb: remove open-coded skb_cow_head
igbvf: remove open-coded skb_cow_head
...
|
| | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
Several spots in the kernel perform a sequence like:
skb_queue_tail(&sk->s_receive_queue, skb);
sk->sk_data_ready(sk, skb->len);
But at the moment we place the SKB onto the socket receive queue it
can be consumed and freed up. So this skb->len access is potentially
to freed up memory.
Furthermore, the skb->len can be modified by the consumer so it is
possible that the value isn't accurate.
And finally, no actual implementation of this callback actually uses
the length argument. And since nobody actually cared about it's
value, lots of call sites pass arbitrary values in such as '0' and
even '1'.
So just remove the length argument from the callback, that way there
is no confusion whatsoever and all of these use-after-free cases get
fixed as a side effect.
Based upon a patch by Eric Dumazet and his suggestion to audit this
issue tree-wide.
Signed-off-by: David S. Miller <davem@davemloft.net>
|
| | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
The vfs merge caused a latent bug to show up:
In file included from fs/ceph/super.h:4:0,
from fs/ceph/ioctl.c:3:
include/linux/ceph/ceph_debug.h:4:0: warning: "pr_fmt" redefined [enabled by default]
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
^
In file included from include/linux/kernel.h:13:0,
from include/linux/uio.h:12,
from include/linux/socket.h:7,
from include/uapi/linux/in.h:22,
from include/linux/in.h:23,
from fs/ceph/ioctl.c:1:
include/linux/printk.h:214:0: note: this is the location of the previous definition
#define pr_fmt(fmt) fmt
^
where the reason is that <linux/ceph_debug.h> is included much too late
for the "pr_fmt()" define.
The include of <linux/ceph_debug.h> needs to be the first include in the
file, but fs/ceph/ioctl.c had for some reason missed that, and it wasn't
noticeable until some unrelated header file changes brought in an
indirect earlier include of <linux/kernel.h>.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
| |\ \
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | | |
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs updates from Al Viro:
"The first vfs pile, with deep apologies for being very late in this
window.
Assorted cleanups and fixes, plus a large preparatory part of iov_iter
work. There's a lot more of that, but it'll probably go into the next
merge window - it *does* shape up nicely, removes a lot of
boilerplate, gets rid of locking inconsistencie between aio_write and
splice_write and I hope to get Kent's direct-io rewrite merged into
the same queue, but some of the stuff after this point is having
(mostly trivial) conflicts with the things already merged into
mainline and with some I want more testing.
This one passes LTP and xfstests without regressions, in addition to
usual beating. BTW, readahead02 in ltp syscalls testsuite has started
giving failures since "mm/readahead.c: fix readahead failure for
memoryless NUMA nodes and limit readahead pages" - might be a false
positive, might be a real regression..."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
missing bits of "splice: fix racy pipe->buffers uses"
cifs: fix the race in cifs_writev()
ceph_sync_{,direct_}write: fix an oops on ceph_osdc_new_request() failure
kill generic_file_buffered_write()
ocfs2_file_aio_write(): switch to generic_perform_write()
ceph_aio_write(): switch to generic_perform_write()
xfs_file_buffered_aio_write(): switch to generic_perform_write()
export generic_perform_write(), start getting rid of generic_file_buffer_write()
generic_file_direct_write(): get rid of ppos argument
btrfs_file_aio_write(): get rid of ppos
kill the 5th argument of generic_file_buffered_write()
kill the 4th argument of __generic_file_aio_write()
lustre: don't open-code kernel_recvmsg()
ocfs2: don't open-code kernel_recvmsg()
drbd: don't open-code kernel_recvmsg()
constify blk_rq_map_user_iov() and friends
lustre: switch to kernel_sendmsg()
ocfs2: don't open-code kernel_sendmsg()
take iov_iter stuff to mm/iov_iter.c
process_vm_access: tidy up a bit
...
|
| | | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | | |
O_APPEND handling there hadn't been completely fixed by Pavel's
patch; it checks the right value, but it's racy - we can't really
do that until i_mutex has been taken.
Fix by switching to __generic_file_aio_write() (open-coding
generic_file_aio_write(), actually) and pulling mutex_lock() above
inode_size_read().
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
| | | |
| | |
| | |
| | |
| | |
| | |
| | | |
ceph_osdc_put_request(ERR_PTR(-error)) oopses. What we want there
is break, not goto out.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
| | | |
| | |
| | |
| | | |
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
| | | |
| | |
| | |
| | | |
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
| | | |
| | |
| | |
| | | |
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
| | | |
| | |
| | |
| | |
| | |
| | | |
always equal to &iocb->ki_pos.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
| | | |
| | |
| | |
| | | |
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
| | | |
| | |
| | |
| | |
| | |
| | | |
same story - it's &iocb->ki_pos in all cases
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
| | | |
| | |
| | |
| | |
| | |
| | |
| | | |
It's always equal to &iocb->ki_pos, where iocb is the value of the 1st
argument.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
| | | |
| | |
| | |
| | | |
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
| | | |
| | |
| | |
| | |
| | |
| | | |
sg_iovec array passed to it can be const
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
| | | |
| | |
| | |
| | | |
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
| | | |
| | |
| | |
| | |
| | |
| | |
| | |
| | | |
... and don't skip on sanity checks. It's *not* a hot path, TYVM
(a couple of calls per a.out execve(), for pity sake) and headers of
random a.out binary are not to be trusted.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
| | | |
| | |
| | |
| | | |
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
| | | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | | |
... we are doing them on adjacent parts of file, so what happens is that
each subsequent call works to rebuild the iov_iter to exact state it
had been abandoned in by previous one. Just keep it through the entire
cifs_iovec_read(). And use copy_page_to_iter() instead of doing
kmap/copy_to_user/kunmap manually...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
| | | |
| | |
| | |
| | |
| | |
| | |
| | |
| | | |
I've switched the sanity checks on iovec to rw_copy_check_uvector();
we might need to do a local analog, if any behaviour differences are
not actually bugfixes here...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
| | | |
| | |
| | |
| | | |
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
| | | |
| | |
| | |
| | |
| | |
| | |
| | |
| | | |
... by that point the request we'd just resent is in the
head of the list anyway. Just return to the beginning of
the loop body...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
| | | |
| | |
| | |
| | |
| | |
| | | |
... it does that itself (via kmap_atomic())
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
| | | |
| | |
| | |
| | | |
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
| | | |
| | |
| | |
| | |
| | |
| | | |
all pipe_buffer_operations have the same instances of those...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
| | | |
| | |
| | |
| | | |
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
| | | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | | |
Make delayed_free() call free_vfsmnt() so that we don't have two functions
doing the same job. This requires the calls to mnt_free_id() in free_vfsmnt()
to be moved into the callers of that function.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
| | | |
| | |
| | |
| | | |
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
| | | |
| | |
| | |
| | | |
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
| | | |
| | |
| | |
| | | |
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
| | | |
| | |
| | |
| | | |
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
| | | |
| | |
| | |
| | |
| | |
| | |
| | |
| | | |
the only thing it's doing these days is calculation of
upper limit for fs.nr_open sysctl and that can be done
statically
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
| | | |
| | |
| | |
| | | |
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
| | | |
| | |
| | |
| | | |
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
| | | |
| | |
| | |
| | | |
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
| | | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | | |
new flag in ->f_mode - FMODE_WRITER. Set by do_dentry_open() in case
when it has grabbed write access, checked by __fput() to decide whether
it wants to drop the sucker. Allows to stop bothering with mnt_clone_write()
in alloc_file(), along with fewer special_file() checks.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
| | | |
| | |
| | |
| | | |
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
| | | |
| | |
| | |
| | |
| | |
| | | |
it only makes control flow in __fput() and friends more convoluted.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
| | | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | | |
it's pointless and actually leads to wrong behaviour in at least one
moderately convoluted case (pipe(), close one end, try to get to
another via /proc/*/fd and run into ETXTBUSY).
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
| | | |
| | |
| | |
| | | |
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
| | | |
| | |
| | |
| | | |
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
| | | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | | |
The current mainline has copies propagated to *all* nodes, then
tears down the copies we made for nodes that do not contain
counterparts of the desired mountpoint. That sets the right
propagation graph for the copies (at teardown time we move
the slaves of removed node to a surviving peer or directly
to master), but we end up paying a fairly steep price in
useless allocations. It's fairly easy to create a situation
where N calls of mount(2) create exactly N bindings, with
O(N^2) vfsmounts allocated and freed in process.
Fortunately, it is possible to avoid those allocations/freeings.
The trick is to create copies in the right order and find which
one would've eventually become a master with the current algorithm.
It turns out to be possible in O(nodes getting propagation) time
and with no extra allocations at all.
One part is that we need to make sure that eventual master will be
created before its slaves, so we need to walk the propagation
tree in a different order - by peer groups. And iterate through
the peers before dealing with the next group.
Another thing is finding the (earlier) copy that will be a master
of one we are about to create; to do that we are (temporary) marking
the masters of mountpoints we are attaching the copies to.
Either we are in a peer of the last mountpoint we'd dealt with,
or we have the following situation: we are attaching to mountpoint M,
the last copy S_0 had been attached to M_0 and there are sequences
S_0...S_n, M_0...M_n such that S_{i+1} is a master of S_{i},
S_{i} mounted on M{i} and we need to create a slave of the first S_{k}
such that M is getting propagation from M_{k}. It means that the master
of M_{k} will be among the sequence of masters of M. On the
other hand, the nearest marked node in that sequence will either
be the master of M_{k} or the master of M_{k-1} (the latter -
in the case if M_{k-1} is a slave of something M gets propagation
from, but in a wrong peer group).
So we go through the sequence of masters of M until we find
a marked one (P). Let N be the one before it. Then we go through
the sequence of masters of S_0 until we find one (say, S) mounted
on a node D that has P as master and check if D is a peer of N.
If it is, S will be the master of new copy, if not - the master of S
will be.
That's it for the hard part; the rest is fairly simple. Iterator
is in next_group(), handling of one prospective mountpoint is
propagate_one().
It seems to survive all tests and gives a noticably better performance
than the current mainline for setups that are seriously using shared
subtrees.
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
| |\ \ \
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
| | | | |
Pull audit updates from Eric Paris.
* git://git.infradead.org/users/eparis/audit: (28 commits)
AUDIT: make audit_is_compat depend on CONFIG_AUDIT_COMPAT_GENERIC
audit: renumber AUDIT_FEATURE_CHANGE into the 1300 range
audit: do not cast audit_rule_data pointers pointlesly
AUDIT: Allow login in non-init namespaces
audit: define audit_is_compat in kernel internal header
kernel: Use RCU_INIT_POINTER(x, NULL) in audit.c
sched: declare pid_alive as inline
audit: use uapi/linux/audit.h for AUDIT_ARCH declarations
syscall_get_arch: remove useless function arguments
audit: remove stray newline from audit_log_execve_info() audit_panic() call
audit: remove stray newlines from audit_log_lost messages
audit: include subject in login records
audit: remove superfluous new- prefix in AUDIT_LOGIN messages
audit: allow user processes to log from another PID namespace
audit: anchor all pid references in the initial pid namespace
audit: convert PPIDs to the inital PID namespace.
pid: get pid_t ppid of task in init_pid_ns
audit: rename the misleading audit_get_context() to audit_take_context()
audit: Add generic compat syscall support
audit: Add CONFIG_HAVE_ARCH_AUDITSYSCALL
...
|
| | | | |
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
| | | | |
Re-factor proc_pid_cmdline() to use get_cmdline() helper
from mm.h.
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: William Roberts <wroberts@tresys.com>
Acked-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
|
| |\ \ \ \
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | | |
Pull aio ctx->ring_pages migration serialization fix from Ben LaHaise.
* git://git.kvack.org/~bcrl/aio-next:
aio: v4 ensure access to ctx->ring_pages is correctly serialised for migration
|
| | | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | | |
As reported by Tang Chen, Gu Zheng and Yasuaki Isimatsu, the following issues
exist in the aio ring page migration support.
As a result, for example, we have the following problem:
thread 1 | thread 2
|
aio_migratepage() |
|-> take ctx->completion_lock |
|-> migrate_page_copy(new, old) |
| *NOW*, ctx->ring_pages[idx] == old |
|
| *NOW*, ctx->ring_pages[idx] == old
| aio_read_events_ring()
| |-> ring = kmap_atomic(ctx->ring_pages[0])
| |-> ring->head = head; *HERE, write to the old ring page*
| |-> kunmap_atomic(ring);
|
|-> ctx->ring_pages[idx] = new |
| *BUT NOW*, the content of |
| ring_pages[idx] is old. |
|-> release ctx->completion_lock |
As above, the new ring page will not be updated.
Fix this issue, as well as prevent races in aio_ring_setup() by holding
the ring_lock mutex during kioctx setup and page migration. This avoids
the overhead of taking another spinlock in aio_read_events_ring() as Tang's
and Gu's original fix did, pushing the overhead into the migration code.
Note that to handle the nesting of ring_lock inside of mmap_sem, the
migratepage operation uses mutex_trylock(). Page migration is not a 100%
critical operation in this case, so the ocassional failure can be
tolerated. This issue was reported by Sasha Levin.
Based on feedback from Linus, avoid the extra taking of ctx->completion_lock.
Instead, make page migration fully serialised by mapping->private_lock, and
have aio_free_ring() simply disconnect the kioctx from the mapping by calling
put_aio_ring_file() before touching ctx->ring_pages[]. This simplifies the
error handling logic in aio_migratepage(), and should improve robustness.
v4: always do mutex_unlock() in cases when kioctx setup fails.
Reported-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Gu Zheng <guz.fnst@cn.fujitsu.com>
Cc: stable@vger.kernel.org
|
