Rename the ->index and ->untried fields of the afs_vl_cursor and
afs_operation struct to ->server_index and ->untried_servers to avoid
confusion with address iteration fields when those get folded in.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Simplify error handling a bit by moving it from the afs_addr_cursor struct
to the afs_operation and afs_vl_cursor structs and using the error
prioritisation function for accumulating errors from multiple sources (AFS
tries to rotate between multiple fileservers, some of which may be
inaccessible or in some state of offlinedness).
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Don't put the afs_call struct in afs_wait_for_call_to_complete() but rather
have the caller do it. This will allow the caller to fish stuff out of the
afs_call struct rather than the afs_addr_cursor struct, thereby allowing a
subsequent patch to subsume it.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Wrap most op->error accesses with inline funcs which will make it easier
for a subsequent patch to replace op->error with something else. Two
functions are added to this end:
(1) afs_op_error() - Get the error code.
(2) afs_op_set_error() - Set the error code.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Set op->nr_iterations to -1 to indicate that we need to begin fileserver
iteration rather than setting error to SHRT_MAX. This makes it easier to
eliminate the address cursor.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Change rxrpc's API such that:
(1) A new function, rxrpc_kernel_lookup_peer(), is provided to look up an
rxrpc_peer record for a remote address and a corresponding function,
rxrpc_kernel_put_peer(), is provided to dispose of it again.
(2) When setting up a call, the rxrpc_peer object used during a call is
now passed in rather than being set up by rxrpc_connect_call(). For
afs, this meenat passing it to rxrpc_kernel_begin_call() rather than
the full address (the service ID then has to be passed in as a
separate parameter).
(3) A new function, rxrpc_kernel_remote_addr(), is added so that afs can
get a pointer to the transport address for display purposed, and
another, rxrpc_kernel_remote_srx(), to gain a pointer to the full
rxrpc address.
(4) The function to retrieve the RTT from a call, rxrpc_kernel_get_srtt(),
is then altered to take a peer. This now returns the RTT or -1 if
there are insufficient samples.
(5) Rename rxrpc_kernel_get_peer() to rxrpc_kernel_call_get_peer().
(6) Provide a new function, rxrpc_kernel_get_peer(), to get a ref on a
peer the caller already has.
This allows the afs filesystem to pin the rxrpc_peer records that it is
using, allowing faster lookups and pointer comparisons rather than
comparing sockaddr_rxrpc contents. It also makes it easier to get hold of
the RTT. The following changes are made to afs:
(1) The addr_list struct's addrs[] elements now hold a peer struct pointer
and a service ID rather than a sockaddr_rxrpc.
(2) When displaying the transport address, rxrpc_kernel_remote_addr() is
used.
(3) The port arg is removed from afs_alloc_addrlist() since it's always
overridden.
(4) afs_merge_fs_addr4() and afs_merge_fs_addr6() do peer lookup and may
now return an error that must be handled.
(5) afs_find_server() now takes a peer pointer to specify the address.
(6) afs_find_server(), afs_compare_fs_alists() and afs_merge_fs_addr[46]{}
now do peer pointer comparison rather than address comparison.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
AFS currently uses folio->private to store the range of bytes within a
folio that have been modified - the idea being that if we have, say, a 2MiB
folio and someone writes a single byte, we only have to write back that
single page and not the whole 2MiB folio - thereby saving on network
bandwidth.
Remove this, at least for now, and accept the extra network load (which
doesn't matter in the common case of writing a whole file at a time from
beginning to end).
This makes folio->private available for netfslib to use.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
Move the resource pinning-for-writeback from fscache code to netfslib code.
This is used to keep a cache backing object pinned whilst we have dirty
pages on the netfs inode in the pagecache such that VM writeback will be
able to reach it.
Whilst we're at it, switch the parameters of netfs_unpin_writeback() to
match ->write_inode() so that it can be used for that directly.
Note that this mechanism could be more generically useful than that for
network filesystems. Quite often they have to keep around other resources
(e.g. authentication tokens or network connections) until the writeback is
complete.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
When an afs_volume struct is put, its refcount is reduced to 0 before
the cell->volume_lock is taken and the volume removed from the
cell->volumes tree.
Unfortunately, this means that the lookup code can race and see a volume
with a zero ref in the tree, resulting in a use-after-free:
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 3 PID: 130782 at lib/refcount.c:25 refcount_warn_saturate+0x7a/0xda
...
RIP: 0010:refcount_warn_saturate+0x7a/0xda
...
Call Trace:
afs_get_volume+0x3d/0x55
afs_create_volume+0x126/0x1de
afs_validate_fc+0xfe/0x130
afs_get_tree+0x20/0x2e5
vfs_get_tree+0x1d/0xc9
do_new_mount+0x13b/0x22e
do_mount+0x5d/0x8a
__do_sys_mount+0x100/0x12a
do_syscall_64+0x3a/0x94
entry_SYSCALL_64_after_hwframe+0x62/0x6a
Fix this by:
(1) When putting, use a flag to indicate if the volume has been removed
from the tree and skip the rb_erase if it has.
(2) When looking up, use a conditional ref increment and if it fails
because the refcount is 0, replace the node in the tree and set the
removal flag.
Fixes: 20325960f8 ("afs: Reorganise volume and server trees to be rooted on the cell")
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeffrey Altman <jaltman@auristor.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for
array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).
While there, use struct_size() helper, instead of the open-coded
version, to calculate the size for the allocation of the whole
flexible structure, including of course, the flexible-array member.
This code was found with the help of Coccinelle, and audited and
fixed manually.
Signed-off-by: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/ZSVKwBmxQ1amv47E@work
Signed-off-by: Kees Cook <keescook@chromium.org>
afs_server_list is accessed with the rcu_read_lock() held from
volume->servers, so it needs to be cleaned up correctly.
Fix this by using kfree_rcu() instead of kfree().
Fixes: 8a070a9648 ("afs: Detect cell aliases 1 - Cells with root volumes")
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Pull hardening updates from Kees Cook:
"One of the more voluminous set of changes is for adding the new
__counted_by annotation[1] to gain run-time bounds checking of
dynamically sized arrays with UBSan.
- Add LKDTM test for stuck CPUs (Mark Rutland)
- Improve LKDTM selftest behavior under UBSan (Ricardo Cañuelo)
- Refactor more 1-element arrays into flexible arrays (Gustavo A. R.
Silva)
- Analyze and replace strlcpy and strncpy uses (Justin Stitt, Azeem
Shaikh)
- Convert group_info.usage to refcount_t (Elena Reshetova)
- Add __counted_by annotations (Kees Cook, Gustavo A. R. Silva)
- Add Kconfig fragment for basic hardening options (Kees Cook, Lukas
Bulwahn)
- Fix randstruct GCC plugin performance mode to stay in groups (Kees
Cook)
- Fix strtomem() compile-time check for small sources (Kees Cook)"
* tag 'hardening-v6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (56 commits)
hwmon: (acpi_power_meter) replace open-coded kmemdup_nul
reset: Annotate struct reset_control_array with __counted_by
kexec: Annotate struct crash_mem with __counted_by
virtio_console: Annotate struct port_buffer with __counted_by
ima: Add __counted_by for struct modsig and use struct_size()
MAINTAINERS: Include stackleak paths in hardening entry
string: Adjust strtomem() logic to allow for smaller sources
hardening: x86: drop reference to removed config AMD_IOMMU_V2
randstruct: Fix gcc-plugin performance mode to stay in group
mailbox: zynqmp: Annotate struct zynqmp_ipi_pdata with __counted_by
drivers: thermal: tsens: Annotate struct tsens_priv with __counted_by
irqchip/imx-intmux: Annotate struct intmux_data with __counted_by
KVM: Annotate struct kvm_irq_routing_table with __counted_by
virt: acrn: Annotate struct vm_memory_region_batch with __counted_by
hwmon: Annotate struct gsc_hwmon_platform_data with __counted_by
sparc: Annotate struct cpuinfo_tree with __counted_by
isdn: kcapi: replace deprecated strncpy with strscpy_pad
isdn: replace deprecated strncpy with strscpy
NFS/flexfiles: Annotate struct nfs4_ff_layout_segment with __counted_by
nfs41: Annotate struct nfs4_file_layout_dsaddr with __counted_by
...
Fscache has an optimisation by which reads from the cache are skipped
until we know that (a) there's data there to be read and (b) that data
isn't entirely covered by pages resident in the netfs pagecache. This is
done with two flags manipulated by fscache_note_page_release():
if (...
test_bit(FSCACHE_COOKIE_HAVE_DATA, &cookie->flags) &&
test_bit(FSCACHE_COOKIE_NO_DATA_TO_READ, &cookie->flags))
clear_bit(FSCACHE_COOKIE_NO_DATA_TO_READ, &cookie->flags);
where the NO_DATA_TO_READ flag causes cachefiles_prepare_read() to
indicate that netfslib should download from the server or clear the page
instead.
The fscache_note_page_release() function is intended to be called from
->releasepage() - but that only gets called if PG_private or PG_private_2
is set - and currently the former is at the discretion of the network
filesystem and the latter is only set whilst a page is being written to
the cache, so sometimes we miss clearing the optimisation.
Fix this by following Willy's suggestion[1] and adding an address_space
flag, AS_RELEASE_ALWAYS, that causes filemap_release_folio() to always call
->release_folio() if it's set, even if PG_private or PG_private_2 aren't
set.
Note that this would require folio_test_private() and page_has_private() to
become more complicated. To avoid that, in the places[*] where these are
used to conditionalise calls to filemap_release_folio() and
try_to_release_page(), the tests are removed the those functions just
jumped to unconditionally and the test is performed there.
[*] There are some exceptions in vmscan.c where the check guards more than
just a call to the releaser. I've added a function, folio_needs_release()
to wrap all the checks for that.
AS_RELEASE_ALWAYS should be set if a non-NULL cookie is obtained from
fscache and cleared in ->evict_inode() before truncate_inode_pages_final()
is called.
Additionally, the FSCACHE_COOKIE_NO_DATA_TO_READ flag needs to be cleared
and the optimisation cancelled if a cachefiles object already contains data
when we open it.
[dwysocha@redhat.com: call folio_mapping() inside folio_needs_release()]
Link: 902c990e31
Link: https://lkml.kernel.org/r/20230628104852.3391651-3-dhowells@redhat.com
Fixes: 1f67e6d0b1 ("fscache: Provide a function to note the release of a page")
Fixes: 047487c947 ("cachefiles: Implement the I/O routines")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
Reported-by: Rohith Surabattula <rohiths.msft@gmail.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Tested-by: SeongJae Park <sj@kernel.org>
Cc: Daire Byrne <daire.byrne@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Steve French <sfrench@samba.org>
Cc: Shyam Prasad N <nspmangalore@gmail.com>
Cc: Rohith Surabattula <rohiths.msft@gmail.com>
Cc: Dave Wysochanski <dwysocha@redhat.com>
Cc: Dominique Martinet <asmadeus@codewreck.org>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Jingbo Xu <jefflexu@linux.alibaba.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pull networking fixes from Jakub Kicinski:
"Including fixes from netfilter.
Current release - regressions:
- sched: act_pedit: free pedit keys on bail from offset check
Current release - new code bugs:
- pds_core:
- Kconfig fixes (DEBUGFS and AUXILIARY_BUS)
- fix mutex double unlock in error path
Previous releases - regressions:
- sched: cls_api: remove block_cb from driver_list before freeing
- nf_tables: fix ct untracked match breakage
- eth: mtk_eth_soc: drop generic vlan rx offload
- sched: flower: fix error handler on replace
Previous releases - always broken:
- tcp: fix skb_copy_ubufs() vs BIG TCP
- ipv6: fix skb hash for some RST packets
- af_packet: don't send zero-byte data in packet_sendmsg_spkt()
- rxrpc: timeout handling fixes after moving client call connection
to the I/O thread
- ixgbe: fix panic during XDP_TX with > 64 CPUs
- igc: RMW the SRRCTL register to prevent losing timestamp config
- dsa: mt7530: fix corrupt frames using TRGMII on 40 MHz XTAL MT7621
- r8152:
- fix flow control issue of RTL8156A
- fix the poor throughput for 2.5G devices
- move setting r8153b_rx_agg_chg_indicate() to fix coalescing
- enable autosuspend
- ncsi: clear Tx enable mode when handling a Config required AEN
- octeontx2-pf: macsec: fixes for CN10KB ASIC rev
Misc:
- 9p: remove INET dependency"
* tag 'net-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (69 commits)
net: bcmgenet: Remove phy_stop() from bcmgenet_netif_stop()
pds_core: fix mutex double unlock in error path
net/sched: flower: fix error handler on replace
Revert "net/sched: flower: Fix wrong handle assignment during filter change"
net/sched: flower: fix filter idr initialization
net: fec: correct the counting of XDP sent frames
bonding: add xdp_features support
net: enetc: check the index of the SFI rather than the handle
sfc: Add back mailing list
virtio_net: suppress cpu stall when free_unused_bufs
ice: block LAN in case of VF to VF offload
net: dsa: mt7530: fix network connectivity with multiple CPU ports
net: dsa: mt7530: fix corrupt frames using trgmii on 40 MHz XTAL MT7621
9p: Remove INET dependency
netfilter: nf_tables: fix ct untracked match breakage
af_packet: Don't send zero-byte data in packet_sendmsg_spkt().
igc: read before write to SRRCTL register
pds_core: add AUXILIARY_BUS and NET_DEVLINK to Kconfig
pds_core: remove CONFIG_DEBUG_FS from makefile
ionic: catch failure from devlink_alloc
...
afs_make_call() calls rxrpc_kernel_begin_call() to begin a call (which may
get stalled in the background waiting for a connection to become
available); it then calls rxrpc_kernel_set_max_life() to set the timeouts -
but that starts the call timer so the call timer might then expire before
we get a connection assigned - leading to the following oops if the call
stalled:
BUG: kernel NULL pointer dereference, address: 0000000000000000
...
CPU: 1 PID: 5111 Comm: krxrpcio/0 Not tainted 6.3.0-rc7-build3+ #701
RIP: 0010:rxrpc_alloc_txbuf+0xc0/0x157
...
Call Trace:
<TASK>
rxrpc_send_ACK+0x50/0x13b
rxrpc_input_call_event+0x16a/0x67d
rxrpc_io_thread+0x1b6/0x45f
? _raw_spin_unlock_irqrestore+0x1f/0x35
? rxrpc_input_packet+0x519/0x519
kthread+0xe7/0xef
? kthread_complete_and_exit+0x1b/0x1b
ret_from_fork+0x22/0x30
Fix this by noting the timeouts in struct rxrpc_call when the call is
created. The timer will be started when the first packet is transmitted.
It shouldn't be possible to trigger this directly from userspace through
AF_RXRPC as sendmsg() will return EBUSY if the call is in the
waiting-for-conn state if it dropped out of the wait due to a signal.
Fixes: 9d35d880e0 ("rxrpc: Move client call connection to the I/O thread")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org
cc: linux-kernel@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull vfs idmapping updates from Christian Brauner:
- Last cycle we introduced the dedicated struct mnt_idmap type for
mount idmapping and the required infrastucture in 256c8aed2b ("fs:
introduce dedicated idmap type for mounts"). As promised in last
cycle's pull request message this converts everything to rely on
struct mnt_idmap.
Currently we still pass around the plain namespace that was attached
to a mount. This is in general pretty convenient but it makes it easy
to conflate namespaces that are relevant on the filesystem with
namespaces that are relevant on the mount level. Especially for
non-vfs developers without detailed knowledge in this area this was a
potential source for bugs.
This finishes the conversion. Instead of passing the plain namespace
around this updates all places that currently take a pointer to a
mnt_userns with a pointer to struct mnt_idmap.
Now that the conversion is done all helpers down to the really
low-level helpers only accept a struct mnt_idmap argument instead of
two namespace arguments.
Conflating mount and other idmappings will now cause the compiler to
complain loudly thus eliminating the possibility of any bugs. This
makes it impossible for filesystem developers to mix up mount and
filesystem idmappings as they are two distinct types and require
distinct helpers that cannot be used interchangeably.
Everything associated with struct mnt_idmap is moved into a single
separate file. With that change no code can poke around in struct
mnt_idmap. It can only be interacted with through dedicated helpers.
That means all filesystems are and all of the vfs is completely
oblivious to the actual implementation of idmappings.
We are now also able to extend struct mnt_idmap as we see fit. For
example, we can decouple it completely from namespaces for users that
don't require or don't want to use them at all. We can also extend
the concept of idmappings so we can cover filesystem specific
requirements.
In combination with the vfs{g,u}id_t work we finished in v6.2 this
makes this feature substantially more robust and thus difficult to
implement wrong by a given filesystem and also protects the vfs.
- Enable idmapped mounts for tmpfs and fulfill a longstanding request.
A long-standing request from users had been to make it possible to
create idmapped mounts for tmpfs. For example, to share the host's
tmpfs mount between multiple sandboxes. This is a prerequisite for
some advanced Kubernetes cases. Systemd also has a range of use-cases
to increase service isolation. And there are more users of this.
However, with all of the other work going on this was way down on the
priority list but luckily someone other than ourselves picked this
up.
As usual the patch is tiny as all the infrastructure work had been
done multiple kernel releases ago. In addition to all the tests that
we already have I requested that Rodrigo add a dedicated tmpfs
testsuite for idmapped mounts to xfstests. It is to be included into
xfstests during the v6.3 development cycle. This should add a slew of
additional tests.
* tag 'fs.idmapped.v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping: (26 commits)
shmem: support idmapped mounts for tmpfs
fs: move mnt_idmap
fs: port vfs{g,u}id helpers to mnt_idmap
fs: port fs{g,u}id helpers to mnt_idmap
fs: port i_{g,u}id_into_vfs{g,u}id() to mnt_idmap
fs: port i_{g,u}id_{needs_}update() to mnt_idmap
quota: port to mnt_idmap
fs: port privilege checking helpers to mnt_idmap
fs: port inode_owner_or_capable() to mnt_idmap
fs: port inode_init_owner() to mnt_idmap
fs: port acl to mnt_idmap
fs: port xattr to mnt_idmap
fs: port ->permission() to pass mnt_idmap
fs: port ->fileattr_set() to pass mnt_idmap
fs: port ->set_acl() to pass mnt_idmap
fs: port ->get_acl() to pass mnt_idmap
fs: port ->tmpfile() to pass mnt_idmap
fs: port ->rename() to pass mnt_idmap
fs: port ->mknod() to pass mnt_idmap
fs: port ->mkdir() to pass mnt_idmap
...
Convert to struct mnt_idmap.
Last cycle we merged the necessary infrastructure in
256c8aed2b ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.
Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.
Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Convert to struct mnt_idmap.
Last cycle we merged the necessary infrastructure in
256c8aed2b ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.
Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.
Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Convert to struct mnt_idmap.
Last cycle we merged the necessary infrastructure in
256c8aed2b ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.
Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.
Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
The file locking definitions have lived in fs.h since the dawn of time,
but they are only used by a small subset of the source files that
include it.
Move the file locking definitions to a new header file, and add the
appropriate #include directives to the source files that need them. By
doing this we trim down fs.h a bit and limit the amount of rebuilding
that has to be done when we make changes to the file locking APIs.
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Howells <dhowells@redhat.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Acked-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: Steve French <stfrench@microsoft.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
READ/WRITE proved to be actively confusing - the meanings are
"data destination, as used with read(2)" and "data source, as
used with write(2)", but people keep interpreting those as
"we read data from it" and "we write data to it", i.e. exactly
the wrong way.
Call them ITER_DEST and ITER_SOURCE - at least that is harder
to misinterpret...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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>
Change the signature of netfs helper functions to take a struct netfs_inode
pointer rather than a struct inode pointer where appropriate, thereby
relieving the need for the network filesystem to convert its internal inode
format down to the VFS inode only for netfslib to bounce it back up. For
type safety, it's better not to do that (and it's less typing too).
Give netfs_write_begin() an extra argument to pass in a pointer to the
netfs_inode struct rather than deriving it internally from the file
pointer. Note that the ->write_begin() and ->write_end() ops are intended
to be replaced in the future by netfslib code that manages this without the
need to call in twice for each page.
netfs_readpage() and similar are intended to be pointed at directly by the
address_space_operations table, so must stick to the signature dictated by
the function pointers there.
Changes
=======
- Updated the kerneldoc comments and documentation [DH].
Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/CAHk-=wgkwKyNmNdKpQkqZ6DnmUL-x9hp0YBnUGjaPFEAdxDTbw@mail.gmail.com/
A straightforward conversion as they already work in terms of folios.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
There are no more aop flags left, so remove the parameter.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Pull netfs updates from David Howells:
"Netfs prep for write helpers.
Having had a go at implementing write helpers and content encryption
support in netfslib, it seems that the netfs_read_{,sub}request
structs and the equivalent write request structs were almost the same
and so should be merged, thereby requiring only one set of
alloc/get/put functions and a common set of tracepoints.
Merging the structs also has the advantage that if a bounce buffer is
added to the request struct, a read operation can be performed to fill
the bounce buffer, the contents of the buffer can be modified and then
a write operation can be performed on it to send the data wherever it
needs to go using the same request structure all the way through. The
I/O handlers would then transparently perform any required crypto.
This should make it easier to perform RMW cycles if needed.
The potentially common functions and structs, however, by their names
all proclaim themselves to be associated with the read side of things.
The bulk of these changes alter this in the following ways:
- Rename struct netfs_read_{,sub}request to netfs_io_{,sub}request.
- Rename some enums, members and flags to make them more appropriate.
- Adjust some comments to match.
- Drop "read"/"rreq" from the names of common functions. For
instance, netfs_get_read_request() becomes netfs_get_request().
- The ->init_rreq() and ->issue_op() methods become ->init_request()
and ->issue_read(). I've kept the latter as a read-specific
function and in another branch added an ->issue_write() method.
The driver source is then reorganised into a number of files:
fs/netfs/buffered_read.c Create read reqs to the pagecache
fs/netfs/io.c Dispatchers for read and write reqs
fs/netfs/main.c Some general miscellaneous bits
fs/netfs/objects.c Alloc, get and put functions
fs/netfs/stats.c Optional procfs statistics.
and future development can be fitted into this scheme, e.g.:
fs/netfs/buffered_write.c Modify the pagecache
fs/netfs/buffered_flush.c Writeback from the pagecache
fs/netfs/direct_read.c DIO read support
fs/netfs/direct_write.c DIO write support
fs/netfs/unbuffered_write.c Write modifications directly back
Beyond the above changes, there are also some changes that affect how
things work:
- Make fscache_end_operation() generally available.
- In the netfs tracing header, generate enums from the symbol ->
string mapping tables rather than manually coding them.
- Add a struct for filesystems that uses netfslib to put into their
inode wrapper structs to hold extra state that netfslib is
interested in, such as the fscache cookie. This allows netfslib
functions to be set in filesystem operation tables and jumped to
directly without having to have a filesystem wrapper.
- Add a member to the struct added above to track the remote inode
length as that may differ if local modifications are buffered. We
may need to supply an appropriate EOF pointer when storing data (in
AFS for example).
- Pass extra information to netfs_alloc_request() so that the
->init_request() hook can access it and retain information to
indicate the origin of the operation.
- Make the ->init_request() hook return an error, thereby allowing a
filesystem that isn't allowed to cache an inode (ceph or cifs, for
example) to skip readahead.
- Switch to using refcount_t for subrequests and add tracepoints to
log refcount changes for the request and subrequest structs.
- Add a function to consolidate dispatching a read request. Similar
code is used in three places and another couple are likely to be
added in the future"
Link: https://lore.kernel.org/all/2639515.1648483225@warthog.procyon.org.uk/
* tag 'netfs-prep-20220318' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
afs: Maintain netfs_i_context::remote_i_size
netfs: Keep track of the actual remote file size
netfs: Split some core bits out into their own file
netfs: Split fs/netfs/read_helper.c
netfs: Rename read_helper.c to io.c
netfs: Prepare to split read_helper.c
netfs: Add a function to consolidate beginning a read
netfs: Add a netfs inode context
ceph: Make ceph_init_request() check caps on readahead
netfs: Change ->init_request() to return an error code
netfs: Refactor arguments for netfs_alloc_read_request
netfs: Adjust the netfs_failure tracepoint to indicate non-subreq lines
netfs: Trace refcounting on the netfs_io_subrequest struct
netfs: Trace refcounting on the netfs_io_request struct
netfs: Adjust the netfs_rreq tracepoint slightly
netfs: Split netfs_io_* object handling out
netfs: Finish off rename of netfs_read_request to netfs_io_request
netfs: Rename netfs_read_*request to netfs_io_*request
netfs: Generate enums from trace symbol mapping lists
fscache: export fscache_end_operation()
Change the afs filesystem to support the new afs driver.
The following changes have been made:
(1) The fscache_netfs struct is no more, and there's no need to register
the filesystem as a whole. There's also no longer a cell cookie.
(2) The volume cookie is now an fscache_volume cookie, allocated with
fscache_acquire_volume(). This function takes three parameters: a
string representing the "volume" in the index, a string naming the
cache to use (or NULL) and a u64 that conveys coherency metadata for
the volume.
For afs, I've made it render the volume name string as:
"afs,<cell>,<volume_id>"
and the coherency data is currently 0.
(3) The fscache_cookie_def is no more and needed information is passed
directly to fscache_acquire_cookie(). The cache no longer calls back
into the filesystem, but rather metadata changes are indicated at
other times.
fscache_acquire_cookie() is passed the same keying and coherency
information as before, except that these are now stored in big endian
form instead of cpu endian. This makes the cache more copyable.
(4) fscache_use_cookie() and fscache_unuse_cookie() are called when a file
is opened or closed to prevent a cache file from being culled and to
keep resources to hand that are needed to do I/O.
fscache_use_cookie() is given an indication if the cache is likely to
be modified locally (e.g. the file is open for writing).
fscache_unuse_cookie() is given a coherency update if we had the file
open for writing and will update that.
(5) fscache_invalidate() is now given uptodate auxiliary data and a file
size. It can also take a flag to indicate if this was due to a DIO
write. This is wrapped into afs_fscache_invalidate() now for
convenience.
(6) fscache_resize() now gets called from the finalisation of
afs_setattr(), and afs_setattr() does use/unuse of the cookie around
the call to support this.
(7) fscache_note_page_release() is called from afs_release_page().
(8) Use a killable wait in nfs_vm_page_mkwrite() when waiting for
PG_fscache to be cleared.
Render the parts of the cookie key for an afs inode cookie as big endian.
Changes
=======
ver #2:
- Use gfpflags_allow_blocking() rather than using flag directly.
- fscache_acquire_volume() now returns errors.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Jeff Layton <jlayton@kernel.org>
Tested-by: kafs-testing@auristor.com
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/163819661382.215744.1485608824741611837.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/163906970002.143852.17678518584089878259.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/163967174665.1823006.1301789965454084220.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/164021568841.640689.6684240152253400380.stgit@warthog.procyon.org.uk/ # v4
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 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>
