The use of the inode->i_lock was converted to a mutex, but we forgot
to remove the old inode unlock/lock() pair that allowed the layout
segment to be put inside the loop.
Reported-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Fixes: e824f99ada ("NFSv4: Use a mutex to protect the per-inode commit...")
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
The back channel size is allowed to be 1 or greater.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Catch the ERESTARTSYS error so that it can be processed by the callers.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Mark the destination state to indicate a server-side copy is
happening. On detecting a reboot and recovering open state check
if any state is engaged in a server-side copy, if so, find the
copy and mark it and then signal the waiting thread. Upon wakeup,
if copy was marked then propage EAGAIN to the nfsd_copy_file_range
and restart the copy from scratch.
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
A COPY with unstable write data needs a simple sync commit.
Filehandle value is gotten as a part of the inner loop so in
case of a reboot retry it should get the new value.
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
If client sent async COPY and server replied with
ERR_OFFLOAD_NO_REQS, client should retry with a synchronous copy.
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
When COPY is killed by the user send OFFLOAD_CANCEL to server
processing the copy.
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Make this function available to nfs42proc.c
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
It's possible that server replies back with CB_OFFLOAD call and
COPY reply at the same time such that client will process
CB_OFFLOAD before reply to COPY. For that keep a list of pending
callback stateids received and then before waiting on completion
check the pending list.
Cleanup any pending copies on the client shutdown.
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Change xdr to always send COPY asynchronously.
Keep the list copies send in a list under a server structure.
Once copy is sent, it waits on a completion structure that will
be signalled by the callback thread that receives CB_OFFLOAD.
If CB_OFFLOAD returned an error and even if it returned partial
bytes, ignore them (as we can't commit without a verifier to
match) and return an error.
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
If server returns async reply, it must include a callback stateid,
wr_callback_id in the write_response4.
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
When a direct-write completes, a work_struct is schedule to handle
the completion.
When NFS is being used for swap, the direct write might be a swap-out,
so memory allocation can block until the write completes.
The work queue currently used is not WQ_MEM_RECLAIM, so tasks
can block waiting for memory - this leads to deadlock.
So use nfsiod_workqueue instead. This will always have a running
thread, and work items should never block waiting for memory.
Signed-off-by: Neil Brown <neilb@suse.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Error code is set in the error handling cases but never used. Fix it.
Fixes: 937e3133cd ("NFSv4.1: Ensure we clear the SP4_MACH_CRED flags in nfs4_sp4_select_mode()")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Return statements in functions returning bool should use true or false
instead of an integer value.
This issue was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Layout segment validity is determined only by the NFS_LSEG_VALID flag. If
it is set, the layout segment is finable. As it is, when the flexfiles
driver sets NFS_LSEG_LAYOUTRETURN to indicate that we cannot discard
the layout segment, but that it must be returned, then this can result
in an unnecessary layoutget storm.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.
Warning level 2 was used: -Wimplicit-fallthrough=2
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
When we update the change attribute, we should also clear the flag that
says it is out of date.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
If the object being renamed from one directory to another is also
a directory, then 'nlink' will change for both directories.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Ensure that we always bump or drop the nlink count on the parent directory
when we do a mkdir or a rmdir(). This needs to be done by hand as we don't
have pre/post op attributes.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
If the server tells us that out layoutreturn raced with another layout
update, then we must ensure that the new layout segments are not in use
before we resend with an updated layout stateid.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
After a live data migration event at the NFS server, the client may send
I/O requests to the wrong server, causing a live hang due to repeated
recovery events. On the wire, this will appear as an I/O request failing
with NFS4ERR_BADSESSION, followed by successful CREATE_SESSION, repeatedly.
NFS4ERR_BADSSESSION is returned because the session ID being used was
issued by the other server and is not valid at the old server.
The failure is caused by async worker threads having cached the transport
(xprt) in the rpc_task structure. After the migration recovery completes,
the task is redispatched and the task resends the request to the wrong
server based on the old value still present in tk_xprt.
The solution is to recompute the tk_xprt field of the rpc_task structure
so that the request goes to the correct server.
Signed-off-by: Bill Baker <bill.baker@oracle.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Helen Chao <helen.chao@oracle.com>
Fixes: fb43d17210 ("SUNRPC: Use the multipath iterator to assign a ...")
Cc: stable@vger.kernel.org # v4.9+
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
If there is an error during processing of a callback message, it leads
to refrence leak on the client structure and eventually an unclean
superblock.
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
kstrtoul() can return -ERANGE so Smatch complains that "num" can be
uninitialized. We check that it's within bounds so it's not a huge
deal.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
The existing rpc_print_iostats has a few shortcomings. First, the naming
is not consistent with other functions in the kernel that display stats.
Second, it is really displaying stats for an rpc_clnt structure as it
displays both xprt stats and per-op stats. Third, it does not handle
rpc_clnt clones, which is important for the one in-kernel tree caller
of this function, the NFS client's nfs_show_stats function.
Fix all of the above by renaming the rpc_print_iostats to
rpc_clnt_show_stats and looping through any rpc_clnt clones via
cl_parent.
Once this interface is fixed, this addresses a problem with NFSv4.
Before this patch, the /proc/self/mountstats always showed incorrect
counts for NFSv4 lease and session related opcodes such as SEQUENCE,
RENEW, SETCLIENTID, CREATE_SESSION, etc. These counts were always 0
even though many ops would go over the wire. The reason for this is
there are multiple rpc_clnt structures allocated for any given NFSv4
mount, and inside nfs_show_stats() we callled into rpc_print_iostats()
which only handled one of them, nfs_server->client. Fix these counts
by calling sunrpc's new rpc_clnt_show_stats() function, which handles
cloned rpc_clnt structs and prints the stats together.
Note that one side-effect of the above is that multiple mounts from
the same NFS server will show identical counts in the above ops due
to the fact the one rpc_clnt (representing the NFSv4 client state)
is shared across mounts.
Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
"dev->nr_children" is the number of children which were parsed
successfully in bl_parse_stripe(). It could be all of them and then, in
that case, it is equal to v->stripe.volumes_count. Either way, the >
should be >= so that we don't go beyond the end of what we're supposed
to.
Fixes: 5c83746a0c ("pnfs/blocklayout: in-kernel GETDEVICEINFO XDR parsing")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org # 3.17+
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Commit 530ea42192 ("nfs: Referrals should use the same proto setting
as their parent") encloses the fix with #ifdef CONFIG_SUNRPC_XPRT_RDMA.
CONFIG_SUNRPC_XPRT_RDMA is a tristate option, so it should be tested
with #if IS_ENABLED().
Fixes: 530ea42192 ("nfs: Referrals should use the same proto setting as their parent")
Reported-by: Helen Chao <helen.chao@oracle.com>
Tested-by: Helen Chao <helen.chao@oracle.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Bill Baker <bill.baker@oracle.com>
Signed-off-by: Calum Mackay <calum.mackay@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
When reclaiming a delegation via CLAIM_PREVIOUS open, the server can
indicate that the delegation has been recalled since it was issued by
setting the "recalled" flag in the delegation.
Ensure that we respect the flag by initiating a delegation return when
it is set.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Use new return type vm_fault_t for fault handler
in struct vm_operations_struct. For now, this is
just documenting that the function returns a
VM_FAULT value rather than an errno. Once all
instances are converted, vm_fault_t will become
a distinct type.
see commit 1c8f422059 ("mm: change return type to
vm_fault_t") for reference.
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Even though the caller of nfs_idmap_prepare_message() checks return
code in their side but it's better to add an error check for match_int()
so that we can avoid unnecessary operations when bad int arg is
detected.
Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Return -ESTALE to force a lookup when the file has no more links
Signed-off-by: Lance Shelton <lance.shelton@hammerspace.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
execute_ok() will only check the mode bits if the object is not a
directory, so we don't need to revalidate the attributes in that case.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
When nfs_update_inode() sets NFS_INO_INVALID_ACCESS it is a sign that
we want to revalidate the access cache, not the inode attributes.
In fact we only want to revalidate here if we see that the mode bits
are invalid, so check for NFS_INO_INVALID_OTHER instead.
Reported-by: Olga Kornievskaia <aglo@umich.edu>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
If the writes are being rescheduled due to a pNFS error, then we really
want to immediately start a new flush. The O_DIRECT code already does
this, so we only need to worry about buffered writes.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
If the client is sending a layoutget, but the server issues a callback
to recall what it thinks may be an outstanding layout, then we may find
an uninitialised layout attached to the inode due to the layoutget.
In that case, it is appropriate to return NFS4ERR_NOMATCHING_LAYOUT
rather than NFS4ERR_DELAY, as the latter can end up deadlocking.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Even if the results of the permissions checks failed, we should parse
the results of the layout on open call so that we can return the
layout if required.
Note that we also want to ignore the sequence counter for whether or not
a layout recall occurred. If the recall pertained to our OPEN, then the
callback will know, and will attempt to wait for us to finih processing
anyway.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
If the old layout was recalled, and we returned NFS4ERR_NOMATCHINGLAYOUT
then we need to wait for all outstanding layoutget calls to complete
before we can send a new one.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
If a layout segment is carrying layoutstats or layout error information,
then we always want to return it rather than using a forgetful model.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
If a layout has been recalled, then we should fire off a layoutreturn as
soon as all the layout segments that match the recall have been retired.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
RFC5661 doesn't state directly that the client should update the layout
stateid if it returns NFS4ERR_NOMATCHING_LAYOUT in response to a recall,
however it does state that this error will "cleanly indicate completion"
on par with returning the layout. For this reason, we assume that the
client should update the layout stateid. The Linux pNFS server definitely
does expect this behaviour.
However, if the client replies NFS4ERR_DELAY, then it is stating that
the recall was not processed, so it would be very wrong to update the
layout stateid.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
If there are layout segments that are marked for return, then we need
to ensure that pnfs_mark_matching_lsegs_return() does not just
silently discard them, but it should tell the caller that there is a
layoutreturn scheduled.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
-----BEGIN PGP SIGNATURE-----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=yuI9
-----END PGP SIGNATURE-----
Merge tag 'fscache-fixes-20180725' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs
Pull fscache/cachefiles fixes from David Howells:
- Allow cancelled operations to be queued so they can be cleaned up.
- Fix a refcounting bug in the monitoring of reads on backend files
whereby a race can occur between monitor objects being listed for
work, the work processing being queued and the work processor running
and destroying the monitor objects.
- Fix a ref overput in object attachment, whereby a tentatively
considered object is put in error handling without first being 'got'.
- Fix a missing clear of the CACHEFILES_OBJECT_ACTIVE flag whereby an
assertion occurs when we retry because it seems the object is now
active.
- Wait rather BUG'ing on an object collision in the depths of
cachefiles as the active object should be being cleaned up - also
depends on the one above.
* tag 'fscache-fixes-20180725' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
cachefiles: Wait rather than BUG'ing on "Unexpected object collision"
cachefiles: Fix missing clear of the CACHEFILES_OBJECT_ACTIVE flag
fscache: Fix reference overput in fscache_attach_object() error handling
cachefiles: Fix refcounting bug in backing-file read monitoring
fscache: Allow cancelled operations to be enqueued
If we meet a conflicting object that is marked FSCACHE_OBJECT_IS_LIVE in
the active object tree, we have been emitting a BUG after logging
information about it and the new object.
Instead, we should wait for the CACHEFILES_OBJECT_ACTIVE flag to be cleared
on the old object (or return an error). The ACTIVE flag should be cleared
after it has been removed from the active object tree. A timeout of 60s is
used in the wait, so we shouldn't be able to get stuck there.
Fixes: 9ae326a690 ("CacheFiles: A cache that backs onto a mounted filesystem")
Signed-off-by: Kiran Kumar Modukuri <kiran.modukuri@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
In cachefiles_mark_object_active(), the new object is marked active and
then we try to add it to the active object tree. If a conflicting object
is already present, we want to wait for that to go away. After the wait,
we go round again and try to re-mark the object as being active - but it's
already marked active from the first time we went through and a BUG is
issued.
Fix this by clearing the CACHEFILES_OBJECT_ACTIVE flag before we try again.
Analysis from Kiran Kumar Modukuri:
[Impact]
Oops during heavy NFS + FSCache + Cachefiles
CacheFiles: Error: Overlong wait for old active object to go away.
BUG: unable to handle kernel NULL pointer dereference at 0000000000000002
CacheFiles: Error: Object already active kernel BUG at
fs/cachefiles/namei.c:163!
[Cause]
In a heavily loaded system with big files being read and truncated, an
fscache object for a cookie is being dropped and a new object being
looked. The new object being looked for has to wait for the old object
to go away before the new object is moved to active state.
[Fix]
Clear the flag 'CACHEFILES_OBJECT_ACTIVE' for the new object when
retrying the object lookup.
[Testcase]
Have run ~100 hours of NFS stress tests and have not seen this bug recur.
[Regression Potential]
- Limited to fscache/cachefiles.
Fixes: 9ae326a690 ("CacheFiles: A cache that backs onto a mounted filesystem")
Signed-off-by: Kiran Kumar Modukuri <kiran.modukuri@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
When a cookie is allocated that causes fscache_object structs to be
allocated, those objects are initialised with the cookie pointer, but
aren't blessed with a ref on that cookie unless the attachment is
successfully completed in fscache_attach_object().
If attachment fails because the parent object was dying or there was a
collision, fscache_attach_object() returns without incrementing the cookie
counter - but upon failure of this function, the object is released which
then puts the cookie, whether or not a ref was taken on the cookie.
Fix this by taking a ref on the cookie when it is assigned in
fscache_object_init(), even when we're creating a root object.
Analysis from Kiran Kumar:
This bug has been seen in 4.4.0-124-generic #148-Ubuntu kernel
BugLink: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1776277
fscache cookie ref count updated incorrectly during fscache object
allocation resulting in following Oops.
kernel BUG at /build/linux-Y09MKI/linux-4.4.0/fs/fscache/internal.h:321!
kernel BUG at /build/linux-Y09MKI/linux-4.4.0/fs/fscache/cookie.c:639!
[Cause]
Two threads are trying to do operate on a cookie and two objects.
(1) One thread tries to unmount the filesystem and in process goes over a
huge list of objects marking them dead and deleting the objects.
cookie->usage is also decremented in following path:
nfs_fscache_release_super_cookie
-> __fscache_relinquish_cookie
->__fscache_cookie_put
->BUG_ON(atomic_read(&cookie->usage) <= 0);
(2) A second thread tries to lookup an object for reading data in following
path:
fscache_alloc_object
1) cachefiles_alloc_object
-> fscache_object_init
-> assign cookie, but usage not bumped.
2) fscache_attach_object -> fails in cant_attach_object because the
cookie's backing object or cookie's->parent object are going away
3) fscache_put_object
-> cachefiles_put_object
->fscache_object_destroy
->fscache_cookie_put
->BUG_ON(atomic_read(&cookie->usage) <= 0);
[NOTE from dhowells] It's unclear as to the circumstances in which (2) can
take place, given that thread (1) is in nfs_kill_super(), however a
conflicting NFS mount with slightly different parameters that creates a
different superblock would do it. A backtrace from Kiran seems to show
that this is a possibility:
kernel BUG at/build/linux-Y09MKI/linux-4.4.0/fs/fscache/cookie.c:639!
...
RIP: __fscache_cookie_put+0x3a/0x40 [fscache]
Call Trace:
__fscache_relinquish_cookie+0x87/0x120 [fscache]
nfs_fscache_release_super_cookie+0x2d/0xb0 [nfs]
nfs_kill_super+0x29/0x40 [nfs]
deactivate_locked_super+0x48/0x80
deactivate_super+0x5c/0x60
cleanup_mnt+0x3f/0x90
__cleanup_mnt+0x12/0x20
task_work_run+0x86/0xb0
exit_to_usermode_loop+0xc2/0xd0
syscall_return_slowpath+0x4e/0x60
int_ret_from_sys_call+0x25/0x9f
[Fix] Bump up the cookie usage in fscache_object_init, when it is first
being assigned a cookie atomically such that the cookie is added and bumped
up if its refcount is not zero. Remove the assignment in
fscache_attach_object().
[Testcase]
I have run ~100 hours of NFS stress tests and not seen this bug recur.
[Regression Potential]
- Limited to fscache/cachefiles.
Fixes: ccc4fc3d11 ("FS-Cache: Implement the cookie management part of the netfs API")
Signed-off-by: Kiran Kumar Modukuri <kiran.modukuri@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cachefiles_read_waiter() has the right to access a 'monitor' object by
virtue of being called under the waitqueue lock for one of the pages in its
purview. However, it has no ref on that monitor object or on the
associated operation.
What it is allowed to do is to move the monitor object to the operation's
to_do list, but once it drops the work_lock, it's actually no longer
permitted to access that object. However, it is trying to enqueue the
retrieval operation for processing - but it can only do this via a pointer
in the monitor object, something it shouldn't be doing.
If it doesn't enqueue the operation, the operation may not get processed.
If the order is flipped so that the enqueue is first, then it's possible
for the work processor to look at the to_do list before the monitor is
enqueued upon it.
Fix this by getting a ref on the operation so that we can trust that it
will still be there once we've added the monitor to the to_do list and
dropped the work_lock. The op can then be enqueued after the lock is
dropped.
The bug can manifest in one of a couple of ways. The first manifestation
looks like:
FS-Cache:
FS-Cache: Assertion failed
FS-Cache: 6 == 5 is false
------------[ cut here ]------------
kernel BUG at fs/fscache/operation.c:494!
RIP: 0010:fscache_put_operation+0x1e3/0x1f0
...
fscache_op_work_func+0x26/0x50
process_one_work+0x131/0x290
worker_thread+0x45/0x360
kthread+0xf8/0x130
? create_worker+0x190/0x190
? kthread_cancel_work_sync+0x10/0x10
ret_from_fork+0x1f/0x30
This is due to the operation being in the DEAD state (6) rather than
INITIALISED, COMPLETE or CANCELLED (5) because it's already passed through
fscache_put_operation().
The bug can also manifest like the following:
kernel BUG at fs/fscache/operation.c:69!
...
[exception RIP: fscache_enqueue_operation+246]
...
#7 [ffff883fff083c10] fscache_enqueue_operation at ffffffffa0b793c6
#8 [ffff883fff083c28] cachefiles_read_waiter at ffffffffa0b15a48
#9 [ffff883fff083c48] __wake_up_common at ffffffff810af028
I'm not entirely certain as to which is line 69 in Lei's kernel, so I'm not
entirely clear which assertion failed.
Fixes: 9ae326a690 ("CacheFiles: A cache that backs onto a mounted filesystem")
Reported-by: Lei Xue <carmark.dlut@gmail.com>
Reported-by: Vegard Nossum <vegard.nossum@gmail.com>
Reported-by: Anthony DeRobertis <aderobertis@metrics.net>
Reported-by: NeilBrown <neilb@suse.com>
Reported-by: Daniel Axtens <dja@axtens.net>
Reported-by: Kiran Kumar Modukuri <kiran.modukuri@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Daniel Axtens <dja@axtens.net>
Alter the state-check assertion in fscache_enqueue_operation() to allow
cancelled operations to be given processing time so they can be cleaned up.
Also fix a debugging statement that was requiring such operations to have
an object assigned.
Fixes: 9ae326a690 ("CacheFiles: A cache that backs onto a mounted filesystem")
Reported-by: Kiran Kumar Modukuri <kiran.modukuri@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Pull vfs fixes from Al Viro:
"Fix several places that screw up cleanups after failures halfway
through opening a file (one open-coding filp_clone_open() and getting
it wrong, two misusing alloc_file()). That part is -stable fodder from
the 'work.open' branch.
And Christoph's regression fix for uapi breakage in aio series;
include/uapi/linux/aio_abi.h shouldn't be pulling in the kernel
definition of sigset_t, the reason for doing so in the first place had
been bogus - there's no need to expose struct __aio_sigset in
aio_abi.h at all"
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
aio: don't expose __aio_sigset in uapi
ocxlflash_getfile(): fix double-iput() on alloc_file() failures
cxl_getfile(): fix double-iput() on alloc_file() failures
drm_mode_create_lease_ioctl(): fix open-coded filp_clone_open()
