[ Upstream commit ba00b19067 ]
In the same spirit as commit ca57f02295 ("afs: Fix fileserver probe
RTT handling"), don't rule out using a vlserver just because there
haven't been enough packets yet to calculate a real rtt. Always set the
server's probe rtt from the estimate provided by rxrpc_kernel_get_srtt,
which is capped at 1 second.
This could lead to EDESTADDRREQ errors when accessing a cell for the
first time, even though the vl servers are known and have responded to a
probe.
Fixes: 1d4adfaf65 ("rxrpc: Make rxrpc_kernel_get_srtt() indicate validity")
Signed-off-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-afs@lists.infradead.org
Link: http://lists.infradead.org/pipermail/linux-afs/2023-June/006746.html
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a27648c742 ]
kafs incorrectly passes a zero mtime (ie. 1st Jan 1970) to the server when
creating a file, dir or symlink because the mtime recorded in the
afs_operation struct gets passed to the server by the marshalling routines,
but the afs_mkdir(), afs_create() and afs_symlink() functions don't set it.
This gets masked if a file or directory is subsequently modified.
Fix this by filling in op->mtime before calling the create op.
Fixes: e49c7b2f6d ("afs: Build an abstraction around an "operation" concept")
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeffrey Altman <jaltman@auristor.com>
Reviewed-by: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d7f74e9a91 ]
If the data version returned from the server is larger than expected,
the local data is invalidated, but we may still want to note the remote
file size.
Since we're setting change_size, we have to also set data_changed
for the i_size to get updated.
Fixes: 3f4aa98181 ("afs: Fix EOF corruption")
Signed-off-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 36f82c93ee ]
The afs_fs_probe_dispatcher() work function is passed a count on
net->servers_outstanding when it is scheduled (which may come via its
timer). This is passed back to the work_item, passed to the timer or
dropped at the end of the dispatcher function.
But, at the top of the dispatcher function, there are two checks which
skip the rest of the function: if the network namespace is being destroyed
or if there are no fileservers to probe. These two return paths, however,
do not drop the count passed to the dispatcher, and so, sometimes, the
destruction of a network namespace, such as induced by rmmod of the kafs
module, may get stuck in afs_purge_servers(), waiting for
net->servers_outstanding to become zero.
Fix this by adding the missing decrements in afs_fs_probe_dispatcher().
Fixes: f6cbb368bc ("afs: Actively poll fileservers to maintain NAT or firewall openings")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/167164544917.2072364.3759519569649459359.stgit@warthog.procyon.org.uk/
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ca57f02295 ]
The fileserver probing code attempts to work out the best fileserver to
use for a volume by retrieving the RTT calculated by AF_RXRPC for the
probe call sent to each server and comparing them. Sometimes, however,
no RTT estimate is available and rxrpc_kernel_get_srtt() returns false,
leading good fileservers to be given an RTT of UINT_MAX and thus causing
the rotation algorithm to ignore them.
Fix afs_select_fileserver() to ignore rxrpc_kernel_get_srtt()'s return
value and just take the estimated RTT it provides - which will be capped
at 1 second.
Fixes: 1d4adfaf65 ("rxrpc: Make rxrpc_kernel_get_srtt() indicate validity")
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Marc Dionne <marc.dionne@auristor.com>
Tested-by: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/166965503999.3392585.13954054113218099395.stgit@warthog.procyon.org.uk/
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 0066f1b0e2 ]
When trying to get a file lock on an AFS file, the server may return
UAEAGAIN to indicate that the lock is already held. This is currently
translated by the default path to -EREMOTEIO.
Translate it instead to -EAGAIN so that we know we can retry it.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeffrey E Altman <jaltman@auristor.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/166075761334.3533338.2591992675160918098.stgit@warthog.procyon.org.uk/
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7903192c4b ]
rxrpc and kafs between them try to use the receive timestamp on the first
data packet (ie. the one with sequence number 1) as a base from which to
calculate the time at which callback promise and lock expiration occurs.
However, we don't know how long it took for the server to send us the reply
from it having completed the basic part of the operation - it might then,
for instance, have to send a bunch of a callback breaks, depending on the
particular operation.
Fix this by using the time at which the operation is issued on the client
as a base instead. That should never be longer than the server's idea of
the expiry time.
Fixes: 781070551c ("afs: Fix calculation of callback expiry time")
Fixes: 2070a3e449 ("rxrpc: Allow the reply time to be obtained on a client call")
Suggested-by: Jeffrey E Altman <jaltman@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit cb78d1b5ef ]
The recent patch to make afs_getattr consult the server didn't account
for the pseudo-inodes employed by the dynamic root-type afs superblock
not having a volume or a server to access, and thus an oops occurs if
such a directory is stat'd.
Fix this by checking to see if the vnode->volume pointer actually points
anywhere before following it in afs_getattr().
This can be tested by stat'ing a directory in /afs. It may be
sufficient just to do "ls /afs" and the oops looks something like:
BUG: kernel NULL pointer dereference, address: 0000000000000020
...
RIP: 0010:afs_getattr+0x8b/0x14b
...
Call Trace:
<TASK>
vfs_statx+0x79/0xf5
vfs_fstatat+0x49/0x62
Fixes: 2aeb8c86d4 ("afs: Fix afs_getattr() to refetch file status if callback break occurred")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Marc Dionne <marc.dionne@auristor.com>
Tested-by: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/165408450783.1031787.7941404776393751186.stgit@warthog.procyon.org.uk/
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 17eabd4256 ]
In AFS, a directory is handled as a file that the client downloads and
parses locally for the purposes of performing lookup and getdents
operations. The in-kernel afs filesystem has a number of functions that
do this.
A directory file is arranged as a series of 2K blocks divided into
32-byte slots, where a directory entry occupies one or more slots, plus
each block starts with one or more metadata blocks.
When parsing a block, if the last slots are occupied by a dirent that
occupies more than a single slot and the file position points at a slot
that's not the initial one, the logic in afs_dir_iterate_block() that
skips over it won't advance the file pointer to the end of it. This
will cause an infinite loop in getdents() as it will keep retrying that
block and failing to advance beyond the final entry.
Fix this by advancing the file pointer if the next entry will be beyond
it when we skip a block.
This was found by the generic/676 xfstest but can also be triggered with
something like:
~/xfstests-dev/src/t_readdir_3 /xfstest.test/z 4000 1
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Marc Dionne <marc.dionne@auristor.com>
Tested-by: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Link: http://lore.kernel.org/r/165391973497.110268.2939296942213894166.stgit@warthog.procyon.org.uk/
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit adc9613ff6 ]
If a client's address changes, say if it is NAT'd, this can disrupt an in
progress operation. For most operations, this is not much of a problem,
but StoreData can be different as some servers modify the target file as
the data comes in, so if a store request is disrupted, the file can get
corrupted on the server.
The problem is that the server doesn't recognise packets that come after
the change of address as belonging to the original client and will bounce
them, either by sending an OUT_OF_SEQUENCE ACK to the apparent new call if
the packet number falls within the initial sequence number window of a call
or by sending an EXCEEDS_WINDOW ACK if it falls outside and then aborting
it. In both cases, firstPacket will be 1 and previousPacket will be 0 in
the ACK information.
Fix this by the following means:
(1) If a client call receives an EXCEEDS_WINDOW ACK with firstPacket as 1
and previousPacket as 0, assume this indicates that the server saw the
incoming packets from a different peer and thus as a different call.
Fail the call with error -ENETRESET.
(2) Also fail the call if a similar OUT_OF_SEQUENCE ACK occurs if the
first packet has been hard-ACK'd. If it hasn't been hard-ACK'd, the
ACK packet will cause it to get retransmitted, so the call will just
be repeated.
(3) Make afs_select_fileserver() treat -ENETRESET as a straight fail of
the operation.
(4) Prioritise the error code over things like -ECONNRESET as the server
did actually respond.
(5) Make writeback treat -ENETRESET as a retryable error and make it
redirty all the pages involved in a write so that the VM will retry.
Note that there is still a circumstance that I can't easily deal with: if
the operation is fully received and processed by the server, but the reply
is lost due to address change. There's no way to know if the op happened.
We can examine the server, but a conflicting change could have been made by
a third party - and we can't tell the difference. In such a case, a
message like:
kAFS: vnode modified {100058:146266} b7->b8 YFS.StoreData64 (op=2646a)
will be logged to dmesg on the next op to touch the file and the client
will reset the inode state, including invalidating clean parts of the
pagecache.
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-afs@lists.infradead.org
Link: http://lists.infradead.org/pipermail/linux-afs/2021-December/004811.html # v1
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit de696c4784 ]
The RX_USER_ABORT code should really only be used to indicate that the user
of the rxrpc service (ie. userspace) implicitly caused a call to be aborted
- for instance if the AF_RXRPC socket is closed whilst the call was in
progress. (The user may also explicitly abort a call and specify the abort
code to use).
Change some of the points of generation to use other abort codes instead:
(1) Abort the call with RXGEN_SS_UNMARSHAL or RXGEN_CC_UNMARSHAL if we see
ENOMEM and EFAULT during received data delivery and abort with
RX_CALL_DEAD in the default case.
(2) Abort with RXGEN_SS_MARSHAL if we get ENOMEM whilst trying to send a
reply.
(3) Abort with RX_CALL_DEAD if we stop hearing from the peer if we had
heard from the peer and abort with RX_CALL_TIMEOUT if we hadn't.
(4) Abort with RX_CALL_DEAD if we try to disconnect a call that's not
completed successfully or been aborted.
Reported-by: Jeffrey Altman <jaltman@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 2aeb8c86d4 ]
If a callback break occurs (change notification), afs_getattr() needs to
issue an FS.FetchStatus RPC operation to update the status of the file
being examined by the stat-family of system calls.
Fix afs_getattr() to do this if AFS_VNODE_CB_PROMISED has been cleared
on a vnode by a callback break. Skip this if AT_STATX_DONT_SYNC is set.
This can be tested by appending to a file on one AFS client and then
using "stat -L" to examine its length on a machine running kafs. This
can also be watched through tracing on the kafs machine. The callback
break is seen:
kworker/1:1-46 [001] ..... 978.910812: afs_cb_call: c=0000005f YFSCB.CallBack
kworker/1:1-46 [001] ...1. 978.910829: afs_cb_break: 100058:23b4c:242d2c2 b=2 s=1 break-cb
kworker/1:1-46 [001] ..... 978.911062: afs_call_done: c=0000005f ret=0 ab=0 [0000000082994ead]
And then the stat command generated no traffic if unpatched, but with
this change a call to fetch the status can be observed:
stat-4471 [000] ..... 986.744122: afs_make_fs_call: c=000000ab 100058:023b4c:242d2c2 YFS.FetchStatus
stat-4471 [000] ..... 986.745578: afs_call_done: c=000000ab ret=0 ab=0 [0000000087fc8c84]
Fixes: 08e0e7c82e ("[AF_RXRPC]: Make the in-kernel AFS filesystem use AF_RXRPC.")
Reported-by: Markus Suvanto <markus.suvanto@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Tested-by: Markus Suvanto <markus.suvanto@gmail.com>
Tested-by: kafs-testing+fedora34_64checkkafs-build-496@auristor.com
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216010
Link: https://lore.kernel.org/r/165308359800.162686.14122417881564420962.stgit@warthog.procyon.org.uk/ # v1
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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Merge tag 'misc-fixes-20211007' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs
Pull netfslib, cachefiles and afs fixes from David Howells:
- Fix another couple of oopses in cachefiles tracing stemming from the
possibility of passing in a NULL object pointer
- Fix netfs_clear_unread() to set READ on the iov_iter so that source
it is passed to doesn't do the wrong thing (some drivers look at the
flag on iov_iter rather than other available information to determine
the direction)
- Fix afs_launder_page() to write back at the correct file position on
the server so as not to corrupt data
* tag 'misc-fixes-20211007' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
afs: Fix afs_launder_page() to set correct start file position
netfs: Fix READ/WRITE confusion when calling iov_iter_xarray()
cachefiles: Fix oops with cachefiles_cull() due to NULL object
When an afs file or directory is modified locally such that the total file
size is extended, i_blocks needs to be recalculated too.
Fix this by making afs_write_end() and afs_edit_dir_add() call
afs_set_i_size() rather than setting inode->i_size directly as that also
recalculates inode->i_blocks.
This can be tested by creating and writing into directories and files and
then examining them with du. Without this change, directories show a 4
blocks (they start out at 2048 bytes) and files show 0 blocks; with this
change, they should show a number of blocks proportional to the file size
rounded up to 1024.
Fixes: 31143d5d51 ("AFS: implement basic file write support")
Fixes: 63a4681ff3 ("afs: Locally edit directory data for mkdir/create/unlink/...")
Reported-by: Markus Suvanto <markus.suvanto@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Marc Dionne <marc.dionne@auristor.com>
Tested-by: Markus Suvanto <markus.suvanto@gmail.com>
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/163113612442.352844.11162345591911691150.stgit@warthog.procyon.org.uk/
AFS-3 has two data fetch RPC variants, FS.FetchData and FS.FetchData64, and
Linux's afs client switches between them when talking to a non-YFS server
if the read size, the file position or the sum of the two have the upper 32
bits set of the 64-bit value.
This is a problem, however, since the file position and length fields of
FS.FetchData are *signed* 32-bit values.
Fix this by capturing the capability bits obtained from the fileserver when
it's sent an FS.GetCapabilities RPC, rather than just discarding them, and
then picking out the VICED_CAPABILITY_64BITFILES flag. This can then be
used to decide whether to use FS.FetchData or FS.FetchData64 - and also
FS.StoreData or FS.StoreData64 - rather than using upper_32_bits() to
switch on the parameter values.
This capabilities flag could also be used to limit the maximum size of the
file, but all servers must be checked for that.
Note that the issue does not exist with FS.StoreData - that uses *unsigned*
32-bit values. It's also not a problem with Auristor servers as its
YFS.FetchData64 op uses unsigned 64-bit values.
This can be tested by cloning a git repo through an OpenAFS client to an
OpenAFS server and then doing "git status" on it from a Linux afs
client[1]. Provided the clone has a pack file that's in the 2G-4G range,
the git status will show errors like:
error: packfile .git/objects/pack/pack-5e813c51d12b6847bbc0fcd97c2bca66da50079c.pack does not match index
error: packfile .git/objects/pack/pack-5e813c51d12b6847bbc0fcd97c2bca66da50079c.pack does not match index
This can be observed in the server's FileLog with something like the
following appearing:
Sun Aug 29 19:31:39 2021 SRXAFS_FetchData, Fid = 2303380852.491776.3263114, Host 192.168.11.201:7001, Id 1001
Sun Aug 29 19:31:39 2021 CheckRights: len=0, for host=192.168.11.201:7001
Sun Aug 29 19:31:39 2021 FetchData_RXStyle: Pos 18446744071815340032, Len 3154
Sun Aug 29 19:31:39 2021 FetchData_RXStyle: file size 2400758866
...
Sun Aug 29 19:31:40 2021 SRXAFS_FetchData returns 5
Note the file position of 18446744071815340032. This is the requested file
position sign-extended.
Fixes: b9b1f8d593 ("AFS: write support fixes")
Reported-by: Markus Suvanto <markus.suvanto@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Marc Dionne <marc.dionne@auristor.com>
Tested-by: Markus Suvanto <markus.suvanto@gmail.com>
cc: linux-afs@lists.infradead.org
cc: openafs-devel@openafs.org
Link: https://bugzilla.kernel.org/show_bug.cgi?id=214217#c9 [1]
Link: https://lore.kernel.org/r/951332.1631308745@warthog.procyon.org.uk/
Try to avoid taking the RCU read lock when checking the validity of a
vnode's callback state. The only thing it's needed for is to pin the
parent volume's server list whilst we search it to find the record of the
server we're currently using to see if it has been reinitialised (ie. it
sent us a CB.InitCallBackState* RPC).
Do this by the following means:
(1) Keep an additional per-cell counter (fs_s_break) that's incremented
each time any of the fileservers in the cell reinitialises.
Since the new counter can be accessed without RCU from the vnode, we
can check that first - and only if it differs, get the RCU read lock
and check the volume's server list.
(2) Replace afs_get_s_break_rcu() with afs_check_server_good() which now
indicates whether the callback promise is still expected to be present
on the server. This does the checks as described in (1).
(3) Restructure afs_check_validity() to take account of the change in (2).
We can also get rid of the valid variable and just use the need_clear
variable with the addition of the afs_cb_break_no_promise reason.
(4) afs_check_validity() probably shouldn't be altering vnode->cb_v_break
and vnode->cb_s_break when it doesn't have cb_lock exclusively locked.
Move the change to vnode->cb_v_break to __afs_break_callback().
Delegate the change to vnode->cb_s_break to afs_select_fileserver()
and set vnode->cb_fs_s_break there also.
(5) afs_validate() no longer needs to get the RCU read lock around its
call to afs_check_validity() - and can skip the call entirely if we
don't have a promise.
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Markus Suvanto <markus.suvanto@gmail.com>
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/163111669583.283156.1397603105683094563.stgit@warthog.procyon.org.uk/
Fix the coherency management of mmap'd data such that 3rd-party changes
become visible as soon as possible after the callback notification is
delivered by the fileserver. This is done by the following means:
(1) When we break a callback on a vnode specified by the CB.CallBack call
from the server, we queue a work item (vnode->cb_work) to go and
clobber all the PTEs mapping to that inode.
This causes the CPU to trip through the ->map_pages() and
->page_mkwrite() handlers if userspace attempts to access the page(s)
again.
(Ideally, this would be done in the service handler for CB.CallBack,
but the server is waiting for our reply before considering, and we
have a list of vnodes, all of which need breaking - and the process of
getting the mmap_lock and stripping the PTEs on all CPUs could be
quite slow.)
(2) Call afs_validate() from the ->map_pages() handler to check to see if
the file has changed and to get a new callback promise from the
server.
Also handle the fileserver telling us that it's dropping all callbacks,
possibly after it's been restarted by sending us a CB.InitCallBackState*
call by the following means:
(3) Maintain a per-cell list of afs files that are currently mmap'd
(cell->fs_open_mmaps).
(4) Add a work item to each server that is invoked if there are any open
mmaps when CB.InitCallBackState happens. This work item goes through
the aforementioned list and invokes the vnode->cb_work work item for
each one that is currently using this server.
This causes the PTEs to be cleared, causing ->map_pages() or
->page_mkwrite() to be called again, thereby calling afs_validate()
again.
I've chosen to simply strip the PTEs at the point of notification reception
rather than invalidate all the pages as well because (a) it's faster, (b)
we may get a notification for other reasons than the data being altered (in
which case we don't want to clobber the pagecache) and (c) we need to ask
the server to find out - and I don't want to wait for the reply before
holding up userspace.
This was tested using the attached test program:
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/mman.h>
int main(int argc, char *argv[])
{
size_t size = getpagesize();
unsigned char *p;
bool mod = (argc == 3);
int fd;
if (argc != 2 && argc != 3) {
fprintf(stderr, "Format: %s <file> [mod]\n", argv[0]);
exit(2);
}
fd = open(argv[1], mod ? O_RDWR : O_RDONLY);
if (fd < 0) {
perror(argv[1]);
exit(1);
}
p = mmap(NULL, size, mod ? PROT_READ|PROT_WRITE : PROT_READ,
MAP_SHARED, fd, 0);
if (p == MAP_FAILED) {
perror("mmap");
exit(1);
}
for (;;) {
if (mod) {
p[0]++;
msync(p, size, MS_ASYNC);
fsync(fd);
}
printf("%02x", p[0]);
fflush(stdout);
sleep(1);
}
}
It runs in two modes: in one mode, it mmaps a file, then sits in a loop
reading the first byte, printing it and sleeping for a second; in the
second mode it mmaps a file, then sits in a loop incrementing the first
byte and flushing, then printing and sleeping.
Two instances of this program can be run on different machines, one doing
the reading and one doing the writing. The reader should see the changes
made by the writer, but without this patch, they aren't because validity
checking is being done lazily - only on entry to the filesystem.
Testing the InitCallBackState change is more complicated. The server has
to be taken offline, the saved callback state file removed and then the
server restarted whilst the reading-mode program continues to run. The
client machine then has to poke the server to trigger the InitCallBackState
call.
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Markus Suvanto <markus.suvanto@gmail.com>
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/163111668833.283156.382633263709075739.stgit@warthog.procyon.org.uk/
The AFS filesystem is currently triggering the silly-rename cleanup from
afs_d_revalidate() when it sees that a dentry has been changed by a third
party[1]. It should not be doing this as the cleanup includes deleting the
silly-rename target file on iput.
Fix this by removing the places in the d_revalidate handling that validate
anything other than the directory and the dirent. It probably should not
be looking to validate the target inode of the dentry also.
This includes removing the point in afs_d_revalidate() where the inode that
a dentry used to point to was marked as being deleted (AFS_VNODE_DELETED).
We don't know it got deleted. It could have been renamed or it could have
hard links remaining.
This was reproduced by cloning a git repo onto an afs volume on one
machine, switching to another machine and doing "git status", then
switching back to the first and doing "git status". The second status
would show weird output due to ".git/index" getting deleted by the above
mentioned mechanism.
A simpler way to do it is to do:
machine 1: touch a
machine 2: touch b; mv -f b a
machine 1: stat a
on an afs volume. The bug shows up as the stat failing with ENOENT and the
file server log showing that machine 1 deleted "a".
Fixes: 79ddbfa500 ("afs: Implement sillyrename for unlink and rename")
Reported-by: Markus Suvanto <markus.suvanto@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Markus Suvanto <markus.suvanto@gmail.com>
cc: linux-afs@lists.infradead.org
Link: https://bugzilla.kernel.org/show_bug.cgi?id=214217#c4 [1]
Link: https://lore.kernel.org/r/163111668100.283156.3851669884664475428.stgit@warthog.procyon.org.uk/
afs_d_revalidate() should only be validating the directory entry it is
given and the directory to which that belongs; it shouldn't be validating
the inode/vnode to which that dentry points. Besides, validation need to
be done even if we don't call afs_d_revalidate() - which might be the case
if we're starting from a file descriptor.
In order for afs_d_revalidate() to be fixed, validation points must be
added in some other places. Certain directory operations, such as
afs_unlink(), already check this, but not all and not all file operations
either.
Note that the validation of a vnode not only checks to see if the
attributes we have are correct, but also gets a promise from the server to
notify us if that file gets changed by a third party.
Add the following checks:
- Check the vnode we're going to make a hard link to.
- Check the vnode we're going to move/rename.
- Check the vnode we're going to read from.
- Check the vnode we're going to write to.
- Check the vnode we're going to sync.
- Check the vnode we're going to make a mapped page writable for.
Some of these aren't strictly necessary as we're going to perform a server
operation that might get the attributes anyway from which we can determine
if something changed - though it might not get us a callback promise.
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Markus Suvanto <markus.suvanto@gmail.com>
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/163111667354.283156.12720698333342917516.stgit@warthog.procyon.org.uk/
There's a loop in afs_extend_writeback() that adds extra pages to a write
we want to make to improve the efficiency of the writeback by making it
larger. This loop stops, however, if we hit a page we can't write back
from immediately, but it doesn't get rid of the page ref we speculatively
acquired.
This was caused by the removal of the cleanup loop when the code switched
from using find_get_pages_contig() to xarray scanning as the latter only
gets a single page at a time, not a batch.
Fix this by putting the page on a ref on an early break from the loop.
Unfortunately, we can't just add that page to the pagevec we're employing
as we'll go through that and add those pages to the RPC call.
This was found by the generic/074 test. It leaks ~4GiB of RAM each time it
is run - which can be observed with "top".
Fixes: e87b03f583 ("afs: Prepare for use of THPs")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-and-tested-by: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/163111666635.283156.177701903478910460.stgit@warthog.procyon.org.uk/
The afs_read objects created by afs_req_issue_op() get leaked because
afs_alloc_read() returns a ref and then afs_fetch_data() gets its own ref
which is released when the operation completes, but the initial ref is
never released.
Fix this by discarding the initial ref at the end of afs_req_issue_op().
This leak also covered another bug whereby a ref isn't got on the key
attached to the read record by afs_req_issue_op(). This isn't a problem as
long as the afs_read req never goes away...
Fix this by calling key_get() in afs_req_issue_op().
This was found by the generic/074 test. It leaks a bunch of kmalloc-192
objects each time it is run, which can be observed by watching
/proc/slabinfo.
Fixes: f7605fa869cf ("afs: Fix leak of afs_read objects")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-and-tested-by: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/163010394740.3035676.8516846193899793357.stgit@warthog.procyon.org.uk/
Link: https://lore.kernel.org/r/163111665914.283156.3038561975681836591.stgit@warthog.procyon.org.uk/
We added CONFIG_MANDATORY_FILE_LOCKING in 2015, and soon after turned it
off in Fedora and RHEL8. Several other distros have followed suit.
I've heard of one problem in all that time: Someone migrated from an
older distro that supported "-o mand" to one that didn't, and the host
had a fstab entry with "mand" in it which broke on reboot. They didn't
actually _use_ mandatory locking so they just removed the mount option
and moved on.
This patch rips out mandatory locking support wholesale from the kernel,
along with the Kconfig option and the Documentation file. It also
changes the mount code to ignore the "mand" mount option instead of
erroring out, and to throw a big, ugly warning.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Variable ret is set to -ENOENT and -ENOMEM but this value is never
read as it is overwritten or not used later on, hence it is a
redundant assignment and can be removed.
Cleans up the following clang-analyzer warning:
fs/afs/dir.c:2014:4: warning: Value stored to 'ret' is never read
[clang-analyzer-deadcode.DeadStores].
fs/afs/dir.c:659:2: warning: Value stored to 'ret' is never read
[clang-analyzer-deadcode.DeadStores].
[DH made the following modifications:
- In afs_rename(), -ENOMEM should be placed in op->error instead of ret,
rather than the assignment being removed entirely. afs_put_operation()
will pick it up from there and return it.
- If afs_sillyrename() fails, its error code should be placed in op->error
rather than in ret also.
]
Fixes: e49c7b2f6d ("afs: Build an abstraction around an "operation" concept")
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/1619691492-83866-1-git-send-email-jiapeng.chong@linux.alibaba.com
Link: https://lore.kernel.org/r/162609465444.3133237.7562832521724298900.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/162610729052.3408253.17364333638838151299.stgit@warthog.procyon.org.uk/ # v2
To quote Alexey[1]:
I was adding custom tracepoint to the kernel, grabbed full F34 kernel
.config, disabled modules and booted whole shebang as VM kernel.
Then did
perf record -a -e ...
It crashed:
general protection fault, probably for non-canonical address 0x435f5346592e4243: 0000 [#1] SMP PTI
CPU: 1 PID: 842 Comm: cat Not tainted 5.12.6+ #26
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-1.fc33 04/01/2014
RIP: 0010:t_show+0x22/0xd0
Then reproducer was narrowed to
# cat /sys/kernel/tracing/printk_formats
Original F34 kernel with modules didn't crash.
So I started to disable options and after disabling AFS everything
started working again.
The root cause is that AFS was placing char arrays content into a
section full of _pointers_ to strings with predictable consequences.
Non canonical address 435f5346592e4243 is "CB.YFS_" which came from
CM_NAME macro.
Steps to reproduce:
CONFIG_AFS=y
CONFIG_TRACING=y
# cat /sys/kernel/tracing/printk_formats
Fix this by the following means:
(1) Add enum->string translation tables in the event header with the AFS
and YFS cache/callback manager operations listed by RPC operation ID.
(2) Modify the afs_cb_call tracepoint to print the string from the
translation table rather than using the string at the afs_call name
pointer.
(3) Switch translation table depending on the service we're being accessed
as (AFS or YFS) in the tracepoint print clause. Will this cause
problems to userspace utilities?
Note that the symbolic representation of the YFS service ID isn't
available to this header, so I've put it in as a number. I'm not sure
if this is the best way to do this.
(4) Remove the name wrangling (CM_NAME) macro and put the names directly
into the afs_call_type structs in cmservice.c.
Fixes: 8e8d7f13b6 ("afs: Add some tracepoints")
Reported-by: Alexey Dobriyan (SK hynix) <adobriyan@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Marc Dionne <marc.dionne@auristor.com>
cc: Andrew Morton <akpm@linux-foundation.org>
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/YLAXfvZ+rObEOdc%2F@localhost.localdomain/ [1]
Link: https://lore.kernel.org/r/643721.1623754699@warthog.procyon.org.uk/
Link: https://lore.kernel.org/r/162430903582.2896199.6098150063997983353.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/162609463957.3133237.15916579353149746363.stgit@warthog.procyon.org.uk/ # v1 (repost)
Link: https://lore.kernel.org/r/162610726860.3408253.445207609466288531.stgit@warthog.procyon.org.uk/ # v2
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Merge tag 'netfs-fixes-20210621' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs
Pull netfs fixes from David Howells:
"This contains patches to fix netfs_write_begin() and afs_write_end()
in the following ways:
(1) In netfs_write_begin(), extract the decision about whether to skip
a page out to its own helper and have that clear around the region
to be written, but not clear that region. This requires the
filesystem to patch it up afterwards if the hole doesn't get
completely filled.
(2) Use offset_in_thp() in (1) rather than manually calculating the
offset into the page.
(3) Due to (1), afs_write_end() now needs to handle short data write
into the page by generic_perform_write(). I've adopted an
analogous approach to ceph of just returning 0 in this case and
letting the caller go round again.
It also adds a note that (in the future) the len parameter may extend
beyond the page allocated. This is because the page allocation is
deferred to write_begin() and that gets to decide what size of THP to
allocate."
Jeff Layton points out:
"The netfs fix in particular fixes a data corruption bug in cephfs"
* tag 'netfs-fixes-20210621' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
netfs: fix test for whether we can skip read when writing beyond EOF
afs: Fix afs_write_end() to handle short writes
Fix afs_write_end() to correctly handle a short copy into the intended
write region of the page. Two things are necessary:
(1) If the page is not up to date, then we should just return 0
(ie. indicating a zero-length copy). The loop in
generic_perform_write() will go around again, possibly breaking up the
iterator into discrete chunks[1].
This is analogous to commit b9de313cf0
for ceph.
(2) The page should not have been set uptodate if it wasn't completely set
up by netfs_write_begin() (this will be fixed in the next patch), so
we need to set uptodate here in such a case.
Also remove the assertion that was checking that the page was set uptodate
since it's now set uptodate if it wasn't already a few lines above. The
assertion was from when uptodate was set elsewhere.
Changes:
v3: Remove the handling of len exceeding the end of the page.
Fixes: 3003bbd069 ("afs: Use the netfs_write_begin() helper")
Reported-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
cc: Al Viro <viro@zeniv.linux.org.uk>
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/YMwVp268KTzTf8cN@zeniv-ca.linux.org.uk/ [1]
Link: https://lore.kernel.org/r/162367682522.460125.5652091227576721609.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/162391825688.1173366.3437507255136307904.stgit@warthog.procyon.org.uk/ # v2
If a task is killed during a page fault, it does not currently call
sb_end_pagefault(), which means that the filesystem cannot be frozen
at any time thereafter. This may be reported by lockdep like this:
====================================
WARNING: fsstress/10757 still has locks held!
5.13.0-rc4-build4+ #91 Not tainted
------------------------------------
1 lock held by fsstress/10757:
#0: ffff888104eac530
(
sb_pagefaults
as filesystem freezing is modelled as a lock.
Fix this by removing all the direct returns from within the function,
and using 'ret' to indicate whether we were interrupted or successful.
Fixes: 1cf7a1518a ("afs: Implement shared-writeable mmap")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/20210616154900.1958373-1-willy@infradead.org/
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In commit e87b03f583 ("afs: Prepare for use of THPs"), the return
value for afs_write_back_from_locked_page was changed from a number
of pages to a length in bytes. The loop in afs_writepages_region uses
the return value to compute the index that will be used to find dirty
pages in the next iteration, but treats it as a number of pages and
wrongly multiplies it by PAGE_SIZE. This gives a very large index value,
potentially skipping any dirty data that was not covered in the first
pass, which is limited to 256M.
This causes fsync(), and indirectly close(), to only do a partial
writeback of a large file's dirty data. The rest is eventually written
back by background threads after dirty_expire_centisecs.
Fixes: e87b03f583 ("afs: Prepare for use of THPs")
Signed-off-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeffrey Altman <jaltman@auristor.com>
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/20210604175504.4055-1-marc.c.dionne@gmail.com/
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix rename of one directory over another such that the nlink on the deleted
directory is cleared to 0 rather than being decremented to 1.
This was causing the generic/035 xfstest to fail.
Fixes: e49c7b2f6d ("afs: Build an abstraction around an "operation" concept")
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/162194384460.3999479.7605572278074191079.stgit@warthog.procyon.org.uk/ # v1
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The generic/464 xfstest causes kAFS to emit occasional warnings of the
form:
kAFS: vnode modified {100055:8a} 30->31 YFS.StoreData64 (c=6015)
This indicates that the data version received back from the server did not
match the expected value (the DV should be incremented monotonically for
each individual modification op committed to a vnode).
What is happening is that a lookup call is doing a bulk status fetch
speculatively on a bunch of vnodes in a directory besides getting the
status of the vnode it's actually interested in. This is racing with a
StoreData operation (though it could also occur with, say, a MakeDir op).
On the client, a modification operation locks the vnode, but the bulk
status fetch only locks the parent directory, so no ordering is imposed
there (thereby avoiding an avenue to deadlock).
On the server, the StoreData op handler doesn't lock the vnode until it's
received all the request data, and downgrades the lock after committing the
data until it has finished sending change notifications to other clients -
which allows the status fetch to occur before it has finished.
This means that:
- a status fetch can access the target vnode either side of the exclusive
section of the modification
- the status fetch could start before the modification, yet finish after,
and vice-versa.
- the status fetch and the modification RPCs can complete in either order.
- the status fetch can return either the before or the after DV from the
modification.
- the status fetch might regress the locally cached DV.
Some of these are handled by the previous fix[1], but that's not sufficient
because it checks the DV it received against the DV it cached at the start
of the op, but the DV might've been updated in the meantime by a locally
generated modification op.
Fix this by the following means:
(1) Keep track of when we're performing a modification operation on a
vnode. This is done by marking vnode parameters with a 'modification'
note that causes the AFS_VNODE_MODIFYING flag to be set on the vnode
for the duration.
(2) Alter the speculation race detection to ignore speculative status
fetches if either the vnode is marked as being modified or the data
version number is not what we expected.
Note that whilst the "vnode modified" warning does get recovered from as it
causes the client to refetch the status at the next opportunity, it will
also invalidate the pagecache, so changes might get lost.
Fixes: a9e5c87ca7 ("afs: Fix speculative status fetch going out of order wrt to modifications")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-and-reviewed-by: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/160605082531.252452.14708077925602709042.stgit@warthog.procyon.org.uk/ [1]
Link: https://lore.kernel.org/linux-fsdevel/161961335926.39335.2552653972195467566.stgit@warthog.procyon.org.uk/ # v1
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Merge tag 'afs-netfs-lib-20210426' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs
Pull AFS updates from David Howells:
"Use the new netfs lib.
Begin the process of overhauling the use of the fscache API by AFS and
the introduction of support for features such as Transparent Huge
Pages (THPs).
- Add some support for THPs, including using core VM helper functions
to find details of pages.
- Use the ITER_XARRAY I/O iterator to mediate access to the pagecache
as this handles THPs and doesn't require allocation of large bvec
arrays.
- Delegate address_space read/pre-write I/O methods for AFS to the
netfs helper library. A method is provided to the library that
allows it to issue a read against the server.
This includes a change in use for PG_fscache (it now indicates a
DIO write in progress from the marked page), so a number of waits
need to be deployed for it.
- Split the core AFS writeback function to make it easier to modify
in future patches to handle writing to the cache. [This might
feasibly make more sense moved out into my fscache-iter branch].
I've tested these with "xfstests -g quick" against an AFS volume
(xfstests needs patching to make it work). With this, AFS without a
cache passes all expected xfstests; with a cache, there's an extra
failure, but that's also there before these patches. Fixing that
probably requires a greater overhaul (as can be found on my
fscache-iter branch, but that's for a later time).
Thanks should go to Marc Dionne and Jeff Altman of AuriStor for
exercising the patches in their test farm also"
Link: https://lore.kernel.org/lkml/3785063.1619482429@warthog.procyon.org.uk/
* tag 'afs-netfs-lib-20210426' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
afs: Use the netfs_write_begin() helper
afs: Use new netfs lib read helper API
afs: Use the fs operation ops to handle FetchData completion
afs: Prepare for use of THPs
afs: Extract writeback extension into its own function
afs: Wait on PG_fscache before modifying/releasing a page
afs: Use ITER_XARRAY for writing
afs: Set up the iov_iter before calling afs_extract_data()
afs: Log remote unmarshalling errors
afs: Don't truncate iter during data fetch
afs: Move key to afs_read struct
afs: Print the operation debug_id when logging an unexpected data version
afs: Pass page into dirty region helpers to provide THP size
afs: Disable use of the fscache I/O routines
Pull vfs inode type handling updates from Al Viro:
"We should never change the type bits of ->i_mode or the method tables
(->i_op and ->i_fop) of a live inode.
Unfortunately, not all filesystems took care to prevent that"
* 'work.inode-type-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
spufs: fix bogosity in S_ISGID handling
9p: missing chunk of "fs/9p: Don't update file type when updating file attributes"
openpromfs: don't do unlock_new_inode() until the new inode is set up
hostfs_mknod(): don't bother with init_special_inode()
cifs: have cifs_fattr_to_inode() refuse to change type on live inode
cifs: have ->mkdir() handle race with another client sanely
do_cifs_create(): don't set ->i_mode of something we had not created
gfs2: be careful with inode refresh
ocfs2_inode_lock_update(): make sure we don't change the type bits of i_mode
orangefs_inode_is_stale(): i_mode type bits do *not* form a bitmap...
vboxsf: don't allow to change the inode type
afs: Fix updating of i_mode due to 3rd party change
ceph: don't allow type or device number to change on non-I_NEW inodes
ceph: fix up error handling with snapdirs
new helper: inode_wrong_type()