Hi Linus,
This is my very first pull-request. I've been working full-time as
a kernel developer for more than two years now. During this time I've
been fixing bugs reported by Coverity all over the tree and, as part
of my work, I'm also contributing to the KSPP. My work in the kernel
community has been supervised by Greg KH and Kees Cook.
OK. So, after the quick introduction above, please, pull the following
patches that mark switch cases where we are expecting to fall through.
These patches are part of the ongoing efforts to enable -Wimplicit-fallthrough.
They have been ignored for a long time (most of them more than 3 months,
even after pinging multiple times), which is the reason why I've created
this tree. Most of them have been baking in linux-next for a whole development
cycle. And with Stephen Rothwell's help, we've had linux-next nag-emails
going out for newly introduced code that triggers -Wimplicit-fallthrough
to avoid gaining more of these cases while we work to remove the ones
that are already present.
I'm happy to let you know that we are getting close to completing this
work. Currently, there are only 32 of 2311 of these cases left to be
addressed in linux-next. I'm auditing every case; I take a look into
the code and analyze it in order to determine if I'm dealing with an
actual bug or a false positive, as explained here:
https://lore.kernel.org/lkml/c2fad584-1705-a5f2-d63c-824e9b96cf50@embeddedor.com/
While working on this, I've found and fixed the following missing
break/return bugs, some of them introduced more than 5 years ago:
84242b82d87850b51b6c5e420fe63509186e5034b5be8531817264235ee7cc5034a5d2479826cc865340f23df8df997abeeb2f10d82373307b00c5e65d25ff7a54a7ed5b3e7dc24bfa8f21ad0eaee6199ba8376ce1dc586a60a1a8e9b186f14e57562b4860747828eac5b974bee9cc44ba91162c930e3d0a
Once this work is finish, we'll be able to universally enable
"-Wimplicit-fallthrough" to avoid any of these kinds of bugs from
entering the kernel again.
Thanks
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
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Merge tag 'Wimplicit-fallthrough-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux
Pull Wimplicit-fallthrough updates from Gustavo A. R. Silva:
"Mark switch cases where we are expecting to fall through.
This is part of the ongoing efforts to enable -Wimplicit-fallthrough.
Most of them have been baking in linux-next for a whole development
cycle. And with Stephen Rothwell's help, we've had linux-next
nag-emails going out for newly introduced code that triggers
-Wimplicit-fallthrough to avoid gaining more of these cases while we
work to remove the ones that are already present.
We are getting close to completing this work. Currently, there are
only 32 of 2311 of these cases left to be addressed in linux-next. I'm
auditing every case; I take a look into the code and analyze it in
order to determine if I'm dealing with an actual bug or a false
positive, as explained here:
https://lore.kernel.org/lkml/c2fad584-1705-a5f2-d63c-824e9b96cf50@embeddedor.com/
While working on this, I've found and fixed the several missing
break/return bugs, some of them introduced more than 5 years ago.
Once this work is finished, we'll be able to universally enable
"-Wimplicit-fallthrough" to avoid any of these kinds of bugs from
entering the kernel again"
* tag 'Wimplicit-fallthrough-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux: (27 commits)
memstick: mark expected switch fall-throughs
drm/nouveau/nvkm: mark expected switch fall-throughs
NFC: st21nfca: Fix fall-through warnings
NFC: pn533: mark expected switch fall-throughs
block: Mark expected switch fall-throughs
ASN.1: mark expected switch fall-through
lib/cmdline.c: mark expected switch fall-throughs
lib: zstd: Mark expected switch fall-throughs
scsi: sym53c8xx_2: sym_nvram: Mark expected switch fall-through
scsi: sym53c8xx_2: sym_hipd: mark expected switch fall-throughs
scsi: ppa: mark expected switch fall-through
scsi: osst: mark expected switch fall-throughs
scsi: lpfc: lpfc_scsi: Mark expected switch fall-throughs
scsi: lpfc: lpfc_nvme: Mark expected switch fall-through
scsi: lpfc: lpfc_nportdisc: Mark expected switch fall-through
scsi: lpfc: lpfc_hbadisc: Mark expected switch fall-throughs
scsi: lpfc: lpfc_els: Mark expected switch fall-throughs
scsi: lpfc: lpfc_ct: Mark expected switch fall-throughs
scsi: imm: mark expected switch fall-throughs
scsi: csiostor: csio_wr: mark expected switch fall-through
...
Pull vfs inode freeing updates from Al Viro:
"Introduction of separate method for RCU-delayed part of
->destroy_inode() (if any).
Pretty much as posted, except that destroy_inode() stashes
->free_inode into the victim (anon-unioned with ->i_fops) before
scheduling i_callback() and the last two patches (sockfs conversion
and folding struct socket_wq into struct socket) are excluded - that
pair should go through netdev once davem reopens his tree"
* 'work.icache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (58 commits)
orangefs: make use of ->free_inode()
shmem: make use of ->free_inode()
hugetlb: make use of ->free_inode()
overlayfs: make use of ->free_inode()
jfs: switch to ->free_inode()
fuse: switch to ->free_inode()
ext4: make use of ->free_inode()
ecryptfs: make use of ->free_inode()
ceph: use ->free_inode()
btrfs: use ->free_inode()
afs: switch to use of ->free_inode()
dax: make use of ->free_inode()
ntfs: switch to ->free_inode()
securityfs: switch to ->free_inode()
apparmor: switch to ->free_inode()
rpcpipe: switch to ->free_inode()
bpf: switch to ->free_inode()
mqueue: switch to ->free_inode()
ufs: switch to ->free_inode()
coda: switch to ->free_inode()
...
debugging printks left in ->destroy_inode() and so's the
update of inode count; we could take the latter to RCU-delayed
part (would take only moving the check on module exit past
rcu_barrier() there), but debugging output ought to either
stay where it is or go into ->evict_inode()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The in-kernel afs filesystem client counts the number of server-level
callback invalidation events (CB.InitCallBackState* RPC operations) that it
receives from the server. This is stored in cb_s_break in various
structures, including afs_server and afs_vnode.
If an inode is examined by afs_validate(), say, the afs_server copy is
compared, along with other break counters, to those in afs_vnode, and if
one or more of the counters do not match, it is considered that the
server's callback promise is broken. At points where this happens,
AFS_VNODE_CB_PROMISED is cleared to indicate that the status must be
refetched from the server.
afs_validate() issues an FS.FetchStatus operation to get updated metadata -
and based on the updated data_version may invalidate the pagecache too.
However, the break counters are also used to determine whether to note a
new callback in the vnode (which would set the AFS_VNODE_CB_PROMISED flag)
and whether to cache the permit data included in the YFSFetchStatus record
by the server.
The problem comes when the server sends us a CB.InitCallBackState op. The
first such instance doesn't cause cb_s_break to be incremented, but rather
causes AFS_SERVER_FL_NEW to be cleared - but thereafter, say some hours
after last use and all the volumes have been automatically unmounted and
the server has forgotten about the client[*], this *will* likely cause an
increment.
[*] There are other circumstances too, such as the server restarting or
needing to make space in its callback table.
Note that the server won't send us a CB.InitCallBackState op until we talk
to it again.
So what happens is:
(1) A mount for a new volume is attempted, a inode is created for the root
vnode and vnode->cb_s_break and AFS_VNODE_CB_PROMISED aren't set
immediately, as we don't have a nominated server to talk to yet - and
we may iterate through a few to find one.
(2) Before the operation happens, afs_fetch_status(), say, notes in the
cursor (fc.cb_break) the break counter sum from the vnode, volume and
server counters, but the server->cb_s_break is currently 0.
(3) We send FS.FetchStatus to the server. The server sends us back
CB.InitCallBackState. We increment server->cb_s_break.
(4) Our FS.FetchStatus completes. The reply includes a callback record.
(5) xdr_decode_AFSCallBack()/xdr_decode_YFSCallBack() check to see whether
the callback promise was broken by checking the break counter sum from
step (2) against the current sum.
This fails because of step (3), so we don't set the callback record
and, importantly, don't set AFS_VNODE_CB_PROMISED on the vnode.
This does not preclude the syscall from progressing, and we don't loop here
rechecking the status, but rather assume it's good enough for one round
only and will need to be rechecked next time.
(6) afs_validate() it triggered on the vnode, probably called from
d_revalidate() checking the parent directory.
(7) afs_validate() notes that AFS_VNODE_CB_PROMISED isn't set, so doesn't
update vnode->cb_s_break and assumes the vnode to be invalid.
(8) afs_validate() needs to calls afs_fetch_status(). Go back to step (2)
and repeat, every time the vnode is validated.
This primarily affects volume root dir vnodes. Everything subsequent to
those inherit an already incremented cb_s_break upon mounting.
The issue is that we assume that the callback record and the cached permit
information in a reply from the server can't be trusted after getting a
server break - but this is wrong since the server makes sure things are
done in the right order, holding up our ops if necessary[*].
[*] There is an extremely unlikely scenario where a reply from before the
CB.InitCallBackState could get its delivery deferred till after - at
which point we think we have a promise when we don't. This, however,
requires unlucky mass packet loss to one call.
AFS_SERVER_FL_NEW tries to paper over the cracks for the initial mount from
a server we've never contacted before, but this should be unnecessary.
It's also further insulated from the problem on an initial mount by
querying the server first with FS.GetCapabilities, which triggers the
CB.InitCallBackState.
Fix this by
(1) Remove AFS_SERVER_FL_NEW.
(2) In afs_calc_vnode_cb_break(), don't include cb_s_break in the
calculation.
(3) In afs_cb_is_broken(), don't include cb_s_break in the check.
Signed-off-by: David Howells <dhowells@redhat.com>
__pagevec_release() complains loudly if any page in the vector is still
locked. The pages need to be locked for generic_error_remove_page(), but
that function doesn't actually unlock them.
Unlock the pages afterwards.
Signed-off-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Jonathan Billings <jsbillin@umich.edu>
Differentiate an abort due to an unmarshalling error from an abort due to
other errors, such as ENETUNREACH. It doesn't make sense to set abort code
RXGEN_*_UNMARSHAL in such a case, so use RX_USER_ABORT instead.
Signed-off-by: David Howells <dhowells@redhat.com>
__tracepoint_str cannot be const because the tracepoint_str
section is not read-only. Remove the stray const.
Cc: dhowells@redhat.com
Cc: viro@zeniv.linux.org.uk
Signed-off-by: Andi Kleen <ak@linux.intel.com>
get_seconds() has a limited range on 32-bit architectures and is
deprecated because of that. While AFS uses the same limits for
its inode timestamps on the wire protocol, let's just use the
simpler current_time() as we do for other file systems.
This will still zero out the 'tv_nsec' field of the timestamps
internally.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David Howells <dhowells@redhat.com>
Check the state of the rxrpc call backing an afs call in each iteration of
the call wait loop in case the rxrpc call has already been terminated at
the rxrpc layer.
Interrupt the wait loop and mark the afs call as complete if the rxrpc
layer call is complete.
There were cases where rxrpc errors were not passed up to afs, which could
result in this loop waiting forever for an afs call to transition to
AFS_CALL_COMPLETE while the rx call was already complete.
Signed-off-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Make rxrpc_kernel_check_life() pass back the life counter through the
argument list and return true if the call has not yet completed.
Suggested-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.
Notice that in many cases I placed a /* Fall through */ comment
at the bottom of the case, which what GCC is expecting to find.
In other cases I had to tweak a bit the format of the comments.
This patch suppresses ALL missing-break-in-switch false positives
in fs/afs
Addresses-Coverity-ID: 115042 ("Missing break in switch")
Addresses-Coverity-ID: 115043 ("Missing break in switch")
Addresses-Coverity-ID: 115045 ("Missing break in switch")
Addresses-Coverity-ID: 1357430 ("Missing break in switch")
Addresses-Coverity-ID: 115047 ("Missing break in switch")
Addresses-Coverity-ID: 115050 ("Missing break in switch")
Addresses-Coverity-ID: 115051 ("Missing break in switch")
Addresses-Coverity-ID: 1467806 ("Missing break in switch")
Addresses-Coverity-ID: 1467807 ("Missing break in switch")
Addresses-Coverity-ID: 1467811 ("Missing break in switch")
Addresses-Coverity-ID: 115041 ("Missing break in switch")
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The marshalling of AFS.StoreData, AFS.StoreData64 and YFS.StoreData64 calls
generated by ->setattr() ops for the purpose of expanding a file is
incorrect due to older documentation incorrectly describing the way the RPC
'FileLength' parameter is meant to work.
The older documentation says that this is the length the file is meant to
end up at the end of the operation; however, it was never implemented this
way in any of the servers, but rather the file is truncated down to this
before the write operation is effected, and never expanded to it (and,
indeed, it was renamed to 'TruncPos' in 2014).
Fix this by setting the position parameter to the new file length and doing
a zero-lengh write there.
The bug causes Xwayland to SIGBUS due to unexpected non-expansion of a file
it then mmaps. This can be tested by giving the following test program a
filename in an AFS directory:
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/mman.h>
int main(int argc, char *argv[])
{
char *p;
int fd;
if (argc != 2) {
fprintf(stderr,
"Format: test-trunc-mmap <file>\n");
exit(2);
}
fd = open(argv[1], O_RDWR | O_CREAT | O_TRUNC);
if (fd < 0) {
perror(argv[1]);
exit(1);
}
if (ftruncate(fd, 0x140008) == -1) {
perror("ftruncate");
exit(1);
}
p = mmap(NULL, 4096, PROT_READ | PROT_WRITE,
MAP_SHARED, fd, 0);
if (p == MAP_FAILED) {
perror("mmap");
exit(1);
}
p[0] = 'a';
if (munmap(p, 4096) < 0) {
perror("munmap");
exit(1);
}
if (close(fd) < 0) {
perror("close");
exit(1);
}
exit(0);
}
Fixes: 31143d5d51 ("AFS: implement basic file write support")
Reported-by: Jonathan Billings <jsbillin@umich.edu>
Tested-by: Jonathan Billings <jsbillin@umich.edu>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull vfs mount infrastructure updates from Al Viro:
"The rest of core infrastructure; no new syscalls in that pile, but the
old parts are switched to new infrastructure. At that point
conversions of individual filesystems can happen independently; some
are done here (afs, cgroup, procfs, etc.), there's also a large series
outside of that pile dealing with NFS (quite a bit of option-parsing
stuff is getting used there - it's one of the most convoluted
filesystems in terms of mount-related logics), but NFS bits are the
next cycle fodder.
It got seriously simplified since the last cycle; documentation is
probably the weakest bit at the moment - I considered dropping the
commit introducing Documentation/filesystems/mount_api.txt (cutting
the size increase by quarter ;-), but decided that it would be better
to fix it up after -rc1 instead.
That pile allows to do followup work in independent branches, which
should make life much easier for the next cycle. fs/super.c size
increase is unpleasant; there's a followup series that allows to
shrink it considerably, but I decided to leave that until the next
cycle"
* 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (41 commits)
afs: Use fs_context to pass parameters over automount
afs: Add fs_context support
vfs: Add some logging to the core users of the fs_context log
vfs: Implement logging through fs_context
vfs: Provide documentation for new mount API
vfs: Remove kern_mount_data()
hugetlbfs: Convert to fs_context
cpuset: Use fs_context
kernfs, sysfs, cgroup, intel_rdt: Support fs_context
cgroup: store a reference to cgroup_ns into cgroup_fs_context
cgroup1_get_tree(): separate "get cgroup_root to use" into a separate helper
cgroup_do_mount(): massage calling conventions
cgroup: stash cgroup_root reference into cgroup_fs_context
cgroup2: switch to option-by-option parsing
cgroup1: switch to option-by-option parsing
cgroup: take options parsing into ->parse_monolithic()
cgroup: fold cgroup1_mount() into cgroup1_get_tree()
cgroup: start switching to fs_context
ipc: Convert mqueue fs to fs_context
proc: Add fs_context support to procfs
...
All users of VM_MAX_READAHEAD actually convert it to kbytes and then to
pages. Define the macro explicitly as (SZ_128K / PAGE_SIZE). This
simplifies the expression in every filesystem. Also rename the macro to
VM_READAHEAD_PAGES to properly convey its meaning. Finally remove unused
VM_MIN_READAHEAD
[akpm@linux-foundation.org: fix fs/io_uring.c, per Stephen]
Link: http://lkml.kernel.org/r/20181221144053.24318-1-nborisov@suse.com
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Matthew Wilcox <willy@infradead.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Cc: Dominique Martinet <asmadeus@codewreck.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Alter the AFS automounting code to create and modify an fs_context struct
when parameterising a new mount triggered by an AFS mountpoint rather than
constructing device name and option strings.
Also remove the cell=, vol= and rwpath options as they are then redundant.
The reason they existed is because the 'device name' may be derived
literally from a mountpoint object in the filesystem, so default cell and
parent-type information needed to be passed in by some other method from
the automount routines. The vol= option didn't end up being used.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Eric W. Biederman <ebiederm@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Add fs_context support to the AFS filesystem, converting the parameter
parsing to store options there.
This will form the basis for namespace propagation over mountpoints within
the AFS model, thereby allowing AFS to be used in containers more easily.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
When a cell with a volume location server list is added manually by
echoing the details into /proc/net/afs/cells, a record is added but the
flag saying it has been looked up isn't set.
This causes the VL server rotation code to wait forever, with the top of
/proc/pid/stack looking like:
afs_select_vlserver+0x3a6/0x6f3
afs_vl_lookup_vldb+0x4b/0x92
afs_create_volume+0x25/0x1b9
...
with the thread stuck in afs_start_vl_iteration() waiting for
AFS_CELL_FL_NO_LOOKUP_YET to be cleared.
Fix this by clearing AFS_CELL_FL_NO_LOOKUP_YET when setting up a record
if that record's details were supplied manually.
Fixes: 0a5143f2f8 ("afs: Implement VL server rotation")
Reported-by: Dave Botsch <dwb7@cornell.edu>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There's a race between afs_make_call() and afs_wake_up_async_call() in the
case that an error is returned from rxrpc_kernel_send_data() after it has
queued the final packet.
afs_make_call() will try and clean up the mess, but the call state may have
been moved on thereby causing afs_process_async_call() to also try and to
delete the call.
Fix this by:
(1) Getting an extra ref for an asynchronous call for the call itself to
hold. This makes sure the call doesn't evaporate on us accidentally
and will allow the call to be retained by the caller in a future
patch. The ref is released on leaving afs_make_call() or
afs_wait_for_call_to_complete().
(2) In the event of an error from rxrpc_kernel_send_data():
(a) Don't set the call state to AFS_CALL_COMPLETE until *after* the
call has been aborted and ended. This prevents
afs_deliver_to_call() from doing anything with any notifications
it gets.
(b) Explicitly end the call immediately to prevent further callbacks.
(c) Cancel any queued async_work and wait for the work if it's
executing. This allows us to be sure the race won't recur when we
change the state. We put the work queue's ref on the call if we
managed to cancel it.
(d) Put the call's ref that we got in (1). This belongs to us as long
as the call is in state AFS_CALL_CL_REQUESTING.
Fixes: 341f741f04 ("afs: Refcount the afs_call struct")
Signed-off-by: David Howells <dhowells@redhat.com>
Fix the refcounting of the authentication keys in the file locking code.
The vnode->lock_key member points to a key on which it expects to be
holding a ref, but it isn't always given an extra ref, however.
Fixes: 0fafdc9f88 ("afs: Fix file locking")
Signed-off-by: David Howells <dhowells@redhat.com>
A cb_interest record is not necessarily attached to the vnode on entry to
afs_validate(), which can cause an oops when we try to bring the vnode's
cb_s_break up to date in the default case (ie. no current callback promise
and the vnode has not been deleted).
Fix this by simply removing the line, as vnode->cb_s_break will be set when
needed by afs_register_server_cb_interest() when we next get a callback
promise from RPC call.
The oops looks something like:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000018
...
RIP: 0010:afs_validate+0x66/0x250 [kafs]
...
Call Trace:
afs_d_revalidate+0x8d/0x340 [kafs]
? __d_lookup+0x61/0x150
lookup_dcache+0x44/0x70
? lookup_dcache+0x44/0x70
__lookup_hash+0x24/0xa0
do_unlinkat+0x11d/0x2c0
__x64_sys_unlink+0x23/0x30
do_syscall_64+0x4d/0xf0
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Fixes: ae3b7361dc ("afs: Fix validation/callback interaction")
Signed-off-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
A lock type of 0 is "LockRead", which makes the fileserver record an
unintentional read lock on the new file. This will cause problems
later on if the file is the subject of locking operations.
The correct default value should be -1 ("LockNone").
Fix the operation marshalling code to set the value and provide an enum to
symbolise the values whilst we're at it.
Fixes: 30062bd13e ("afs: Implement YFS support in the fs client")
Signed-off-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
One of the more common cases of allocation size calculations is finding the
size of a structure that has a zero-sized array at the end, along with
memory for some number of elements for that array. For example:
struct foo {
int stuff;
void *entry[];
};
instance = kzalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);
Instead of leaving these open-coded and prone to type mistakes, we can now
use the new struct_size() helper:
instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL);
This code was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Multiple filesystems open code lru_to_page(). Rectify this by moving
the macro from mm_inline (which is specific to lru stuff) to the more
generic mm.h header and start using the macro where appropriate.
No functional changes.
Link: http://lkml.kernel.org/r/20181129104810.23361-1-nborisov@suse.com
Link: https://lkml.kernel.org/r/20181129075301.29087-1-nborisov@suse.com
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Pankaj gupta <pagupta@redhat.com>
Acked-by: "Yan, Zheng" <zyan@redhat.com> [ceph]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is already done for us internally by the signal machinery.
[akpm@linux-foundation.org: fix fs/buffer.c]
Link: http://lkml.kernel.org/r/20181116002713.8474-7-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull vfs fixes from Al Viro:
"Assorted fixes all over the place.
The iov_iter one is this cycle regression (splice from UDP triggering
WARN_ON()), the rest is older"
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
afs: Use d_instantiate() rather than d_add() and don't d_drop()
afs: Fix missing net error handling
afs: Fix validation/callback interaction
iov_iter: teach csum_and_copy_to_iter() to handle pipe-backed ones
exportfs: do not read dentry after free
exportfs: fix 'passing zero to ERR_PTR()' warning
aio: fix failure to put the file pointer
sysv: return 'err' instead of 0 in __sysv_write_inode
Use d_instantiate() rather than d_add() and don't d_drop() in
afs_vnode_new_inode(). The dentry shouldn't be removed as it's not
changing its name.
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
kAFS can be given certain network errors (EADDRNOTAVAIL, EHOSTDOWN and
ERFKILL) that it doesn't handle in its server/address rotation algorithms.
They cause the probing and rotation to abort immediately rather than
rotating.
Fix this by:
(1) Abstracting out the error prioritisation from the VL and FS rotation
algorithms into a common function and expand usage into the server
probing code.
When multiple errors are available, this code selects the one we'd
prefer to return.
(2) Add handling for EADDRNOTAVAIL, EHOSTDOWN and ERFKILL.
Fixes: 0fafdc9f88 ("afs: Fix file locking")
Fixes: 0338747d8454 ("afs: Probe multiple fileservers simultaneously")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
When afs_validate() is called to validate a vnode (inode), there are two
unhandled cases in the fastpath at the top of the function:
(1) If the vnode is promised (AFS_VNODE_CB_PROMISED is set), the break
counters match and the data has expired, then there's an implicit case
in which the vnode needs revalidating.
This has no consequences since the default "valid = false" set at the
top of the function happens to do the right thing.
(2) If the vnode is not promised and it hasn't been deleted
(AFS_VNODE_DELETED is not set) then there's a default case we're not
handling in which the vnode is invalid. If the vnode is invalid, we
need to bring cb_s_break and cb_v_break up to date before we refetch
the status.
As a consequence, once the server loses track of the client
(ie. sufficient time has passed since we last sent it an operation),
it will send us a CB.InitCallBackState* operation when we next try to
talk to it. This calls afs_init_callback_state() which increments
afs_server::cb_s_break, but this then doesn't propagate to the
afs_vnode record.
The result being that every afs_validate() call thereafter sends a
status fetch operation to the server.
Clarify and fix this by:
(A) Setting valid in all the branches rather than initialising it at the
top so that the compiler catches where we've missed.
(B) Restructuring the logic in the 'promised' branch so that we set valid
to false if the callback is due to expire (or has expired) and so that
the final case is that the vnode is still valid.
(C) Adding an else-statement that ups cb_s_break and cb_v_break if the
promised and deleted cases don't match.
Fixes: c435ee3455 ("afs: Overhaul the callback handling")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The life-checking function, which is used by kAFS to make sure that a call
is still live in the event of a pending signal, only samples the received
packet serial number counter; it doesn't actually provoke a change in the
counter, rather relying on the server to happen to give us a packet in the
time window.
Fix this by adding a function to force a ping to be transmitted.
kAFS then keeps track of whether there's been a stall, and if so, uses the
new function to ping the server, resetting the timeout to allow the reply
to come back.
If there's a stall, a ping and the call is *still* stalled in the same
place after another period, then the call will be aborted.
Fixes: bc5e3a546d ("rxrpc: Use MSG_WAITALL to tell sendmsg() to temporarily ignore signals")
Fixes: f4d15fb6f9 ("rxrpc: Provide functions for allowing cleaner handling of signals")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Send probes to all the unprobed fileservers in a fileserver list on all
addresses simultaneously in an attempt to find out the fastest route whilst
not getting stuck for 20s on any server or address that we don't get a
reply from.
This alleviates the problem whereby attempting to access a new server can
take a long time because the rotation algorithm ends up rotating through
all servers and addresses until it finds one that responds.
Signed-off-by: David Howells <dhowells@redhat.com>
In some circumstances, the callback interest pointer is NULL, so in such a
case we can't dereference it when checking to see if the callback is
broken. This causes an oops in some circumstances.
Fix this by replacing the function that worked out the aggregate break
counter with one that actually does the comparison, and then make that
return true (ie. broken) if there is no callback interest as yet (ie. the
pointer is NULL).
Fixes: 68251f0a68 ("afs: Fix whole-volume callback handling")
Signed-off-by: David Howells <dhowells@redhat.com>
Eliminate the address pointer from the address list cursor as it's
redundant (ac->addrs[ac->index] can be used to find the same address) and
address lists must be replaced rather than being rearranged, so is of
limited value.
Signed-off-by: David Howells <dhowells@redhat.com>
Provide an option to allow the file or volume location server cursor to be
dumped if the rotation routine falls off the end without managing to
contact a server.
Signed-off-by: David Howells <dhowells@redhat.com>
Implement support for talking to YFS-variant fileservers in the cache
manager and the filesystem client. These implement upgraded services on
the same port as their AFS services.
YFS fileservers provide expanded capabilities over AFS.
Signed-off-by: David Howells <dhowells@redhat.com>
Expand fields in various data structures to support the expanded
information that YFS is capable of returning.
Signed-off-by: David Howells <dhowells@redhat.com>
Get the target vnode in afs_rmdir() and validate it before we attempt the
deletion, The vnode pointer will be passed through to the delivery function
in a later patch so that the delivery function can mark it deleted.
Signed-off-by: David Howells <dhowells@redhat.com>
Calculate the callback expiration time at the point of operation reply
delivery, using the reply time queried from AF_RXRPC on that call as a
base.
Signed-off-by: David Howells <dhowells@redhat.com>
The FS.FetchStatus reply delivery function was updating inode of the
directory in which a lookup had been done with the status of the looked up
file. This corrupts some of the directory state.
Fixes: 5cf9dd55a0 ("afs: Prospectively look up extra files when doing a single lookup")
Signed-off-by: David Howells <dhowells@redhat.com>
Implement the YFS cache manager service which gives extra capabilities on
top of AFS. This is done by listening for an additional service on the
same port and indicating that anyone requesting an upgrade should be
upgraded to the YFS port.
Signed-off-by: David Howells <dhowells@redhat.com>
Remove unnecessary details of a broken callback, such as version, expiry
and type, from the afs_callback_break struct as they're not actually used
and make the list take more memory.
Signed-off-by: David Howells <dhowells@redhat.com>
Call the function to commit the status on a new file, dir or symlink so
that the access rights for the caller's key are cached for that object.
Without this, the next access to the file will cause a FetchStatus
operation to be emitted to retrieve the access rights.
Signed-off-by: David Howells <dhowells@redhat.com>
Increase the sizes of the volume ID to 64 bits and the vnode ID (inode
number equivalent) to 96 bits to allow the support of YFS.
This requires the iget comparator to check the vnode->fid rather than i_ino
and i_generation as i_ino is not sufficiently capacious. It also requires
this data to be placed into the vnode cache key for fscache.
For the moment, just discard the top 32 bits of the vnode ID when returning
it though stat.
Signed-off-by: David Howells <dhowells@redhat.com>
When writing a new page, clear space in the page rather than attempting to
load it from the server if the space is beyond the EOF.
Signed-off-by: David Howells <dhowells@redhat.com>
Fix afs_deliver_to_call() to handle -EIO being returned by the operation
delivery function, indicating that the call found itself in the wrong
state, by printing an error and aborting the call.
Currently, an assertion failure will occur. This can happen, say, if the
delivery function falls off the end without calling afs_extract_data() with
the want_more parameter set to false to collect the end of the Rx phase of
a call.
The assertion failure looks like:
AFS: Assertion failed
4 == 7 is false
0x4 == 0x7 is false
------------[ cut here ]------------
kernel BUG at fs/afs/rxrpc.c:462!
and is matched in the trace buffer by a line like:
kworker/7:3-3226 [007] ...1 85158.030203: afs_io_error: c=0003be0c r=-5 CM_REPLY
Fixes: 98bf40cd99 ("afs: Protect call->state changes against signals")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Currently the TTL on VL server and address lists isn't set in all
circumstances and may be set to poor choices in others, since the TTL is
derived from the SRV/AFSDB DNS record if and when available.
Fix the TTL by limiting the range to a minimum and maximum from the current
time. At some point these can be made into sysctl knobs. Further, use the
TTL we obtained from the upcall to set the expiry on negative results too;
in future a mechanism can be added to force reloading of such data.
Signed-off-by: David Howells <dhowells@redhat.com>
Track VL servers as independent entities rather than lumping all their
addresses together into one set and implement server-level rotation by:
(1) Add the concept of a VL server list, where each server has its own
separate address list. This code is similar to the FS server list.
(2) Use the DNS resolver to retrieve a set of servers and their associated
addresses, ports, preference and weight ratings.
(3) In the case of a legacy DNS resolver or an address list given directly
through /proc/net/afs/cells, create a list containing just a dummy
server record and attach all the addresses to that.
(4) Implement a simple rotation policy, for the moment ignoring the
priorities and weights assigned to the servers.
(5) Show the address list through /proc/net/afs/<cell>/vlservers. This
also displays the source and status of the data as indicated by the
upcall.
Signed-off-by: David Howells <dhowells@redhat.com>
Improve the error handling in FS server rotation by:
(1) Cache the latest useful error value for the fs operation as a whole in
struct afs_fs_cursor separately from the error cached in the
afs_addr_cursor struct. The one in the address cursor gets clobbered
occasionally. Copy over the error to the fs operation only when it's
something we'd be interested in passing to userspace.
(2) Make it so that EDESTADDRREQ is the default that is seen only if no
addresses are available to be accessed.
(3) When calling utility functions, such as checking a volume status or
probing a fileserver, don't let a successful result clobber the cached
error in the cursor; instead, stash the result in a temporary variable
until it has been assessed.
(4) Don't return ETIMEDOUT or ETIME if a better error, such as
ENETUNREACH, is already cached.
(5) On leaving the rotation loop, turn any remote abort code into a more
useful error than ECONNABORTED.
Fixes: d2ddc776a4 ("afs: Overhaul volume and server record caching and fileserver rotation")
Signed-off-by: David Howells <dhowells@redhat.com>
afs_extract_data sets up a temporary iov_iter and passes it to AF_RXRPC
each time it is called to describe the remaining buffer to be filled.
Instead:
(1) Put an iterator in the afs_call struct.
(2) Set the iterator for each marshalling stage to load data into the
appropriate places. A number of convenience functions are provided to
this end (eg. afs_extract_to_buf()).
This iterator is then passed to afs_extract_data().
(3) Use the new ITER_DISCARD iterator to discard any excess data provided
by FetchData.
Signed-off-by: David Howells <dhowells@redhat.com>
