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This was done entirely with mindless brute force, using
git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'
to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.
Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.
For the same reason the 'flex' versions will be done as a separate
conversion.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:
Single allocations: kmalloc(sizeof(TYPE), ...)
are replaced with: kmalloc_obj(TYPE, ...)
Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with: kmalloc_objs(TYPE, COUNT, ...)
Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...)
(where TYPE may also be *VAR)
The resulting allocations no longer return "void *", instead returning
"TYPE *".
Signed-off-by: Kees Cook <kees@kernel.org>
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Improve the tracing of afs_volume objects to include displaying a debug ID
so that different instances of volumes with the same "vid" can be
distinguished.
Also be consistent about displaying the volume's refcount (and not the
cell's).
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/20250224234154.2014840-9-dhowells@redhat.com/ # v1
Link: https://lore.kernel.org/r/20250310094206.801057-5-dhowells@redhat.com/ # v4
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The max length of volume->vid value is 20 characters.
So increase idbuf[] size up to 24 to avoid overflow.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
[DH: Actually, it's 20 + NUL, so increase it to 24 and use snprintf()]
Fixes: d2ddc776a458 ("afs: Overhaul volume and server record caching and fileserver rotation")
Signed-off-by: Daniil Dulov <d.dulov@aladdin.ru>
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20240211150442.3416-1-d.dulov@aladdin.ru/ # v1
Link: https://lore.kernel.org/r/20240212083347.10742-1-d.dulov@aladdin.ru/ # v2
Link: https://lore.kernel.org/r/20240219143906.138346-3-dhowells@redhat.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Fix the fileserver rotation so that it doesn't use RTT as the basis for
deciding which server and address to use as this doesn't necessarily give a
good indication of the best path. Instead, use the configurable preference
list in conjunction with whatever probes have succeeded at the time of
looking.
To this end, make the following changes:
(1) Keep an array of "server states" to track what addresses we've tried
on each server and move the waitqueue entries there that we'll need
for probing.
(2) Each afs_server_state struct is made to pin the corresponding server's
endpoint state rather than the afs_operation struct carrying a pin on
the server we're currently looking at.
(3) Drop the server list preference; we now always rescan the server list.
(4) afs_wait_for_probes() now uses the server state list to guide it in
what it waits for (and to provide the waitqueue entries) and returns
an indication of whether we'd got a response, run out of responsive
addresses or the endpoint state had been superseded and we need to
restart the iteration.
(5) Call afs_get_address_preferences*() occasionally to refresh the
preference values.
(6) When picking a server, scan the addresses of the servers for which we
have as-yet untested communications, looking for the highest priority
one and use that instead of trying all the addresses for a particular
server in ascending-RTT order.
(7) When a Busy or Offline state is seen across all available servers, do
a short sleep.
(8) If we detect that we accessed a future RO volume version whilst it is
undergoing replication, reissue the op against the older version until
at least half of the servers are replicated.
(9) Whilst RO replication is ongoing, increase the frequency of Volume
Location server checks for that volume to every ten minutes instead of
hourly.
Also add a tracepoint to track progress through the rotation algorithm.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
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Overhaul the third party-induced invalidation handling, making use of the
previously added volume-level event counters (cb_scrub and cb_ro_snapshot)
that are now being parsed out of the VolSync record returned by the
fileserver in many of its replies.
This allows better handling of RO (and Backup) volumes. Since these are
snapshot of a RW volume that are updated atomically simultantanously across
all servers that host them, they only require a single callback promise for
the entire volume. The currently upstream code assumes that RO volumes
operate in the same manner as RW volumes, and that each file has its own
individual callback - which means that it does a status fetch for *every*
file in a RO volume, whether or not the volume got "released" (volume
callback breaks can occur for other reasons too, such as the volumeserver
taking ownership of a volume from a fileserver).
To this end, make the following changes:
(1) Change the meaning of the volume's cb_v_break counter so that it is
now a hint that we need to issue a status fetch to work out the state
of a volume. cb_v_break is incremented by volume break callbacks and
by server initialisation callbacks.
(2) Add a second counter, cb_v_check, to the afs_volume struct such that
if this differs from cb_v_break, we need to do a check. When the
check is complete, cb_v_check is advanced to what cb_v_break was at
the start of the status fetch.
(3) Move the list of mmap'd vnodes to the volume and trigger removal of
PTEs that map to files on a volume break rather than on a server
break.
(4) When a server reinitialisation callback comes in, use the
server-to-volume reverse mapping added in a preceding patch to iterate
over all the volumes using that server and clear the volume callback
promises for that server and the general volume promise as a whole to
trigger reanalysis.
(5) Replace the AFS_VNODE_CB_PROMISED flag with an AFS_NO_CB_PROMISE
(TIME64_MIN) value in the cb_expires_at field, reducing the number of
checks we need to make.
(6) Change afs_check_validity() to quickly see if various event counters
have been incremented or if the vnode or volume callback promise is
due to expire/has expired without making any changes to the state.
That is now left to afs_validate() as this may get more complicated in
future as we may have to examine server records too.
(7) Overhaul afs_validate() so that it does a single status fetch if we
need to check the state of either the vnode or the volume - and do so
under appropriate locking. The function does the following steps:
(A) If the vnode/volume is no longer seen as valid, then we take the
vnode validation lock and, if the volume promise has expired, the
volume check lock also. The latter prevents redundant checks being
made to find out if a new version of the volume got released.
(B) If a previous RPC call found that the volsync changed unexpectedly
or that a RO volume was updated, then we unmap all PTEs pointing to
the file to stop mmap being used for access.
(C) If the vnode is still seen to be of uncertain validity, then we
perform an FS.FetchStatus RPC op to jointly update the volume status
and the vnode status. This assessment is done as part of parsing the
reply:
If the RO volume creation timestamp advances, cb_ro_snapshot is
incremented; if either the creation or update timestamps changes in
an unexpected way, the cb_scrub counter is incremented
If the Data Version returned doesn't match the copy we have
locally, then we ask for the pagecache to be zapped. This takes
care of handling RO update.
(D) If cb_scrub differs between volume and vnode, the vnode's
pagecache is zapped and the vnode's cb_scrub is updated unless the
file is marked as having been deleted.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
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A number of fileserver RPC operations return a VolSync record as part of
their reply that gives some information about the state of the volume being
accessed, including:
(1) A volume Creation timestamp. For an RW volume, this is the time at
which the volume was created; if it changes, the RW volume was
presumably restored from a backup and all cached data should be
scrubbed as Data Version numbers could regress on the files in the
volume.
For an RO volume, this is the time it was last snapshotted from the RW
volume. It is expected to advance each time this happens; if it
regresses, cached data should be scrubbed.
(2) A volume Update timestamp (Auristor only). For an RW volume, this is
updated any time any change is made to a volume or its contents. If
it regresses, all cached data must be scrubbed.
For an RO volume, this is a copy of the RW volume's Update timestamp
at the point of snapshotting. It can be used as a version number when
checking to see if a callback on a RO volume was due to a snapshot.
If it regresses, all cached data must be scrubbed.
but this is currently not made use of by the in-kernel afs filesystem.
Make the afs filesystem use this by:
(1) Add an update time field to the afs_volsync struct and use a value of
TIME64_MIN in both that and the creation time to indicate that they
are unset.
(2) Add creation and update time fields to the afs_volume struct and use
this to track the two timestamps.
(3) Add a volsync_lock mutex to the afs_volume struct to control
modification access for when we detect a change in these values.
(3) Add a 'pre-op volsync' struct to the afs_operation struct to record
the state of the volume tracking before the op.
(4) Add a new counter, cb_scrub, to the afs_volume struct to count events
that require all data to be scrubbed. A copy is placed in the
afs_vnode struct (inode) and if they no longer match, a scrub takes
place.
(5) When the result of an operation is being parsed, parse the VolSync
data too, if it is provided. Note that the two timestamps are handled
separately, since they don't work in quite the same way.
- If the afs_volume tracking is unset, just set it and do nothing
else.
- If the result timestamps are the same as the ones in afs_volume, do
nothing.
- If the timestamps regress, increment cb_scrub if not already done
so.
- If the creation timestamp on a RW volume changes, increment cb_scrub
if not already done so.
- If the creation timestamp on a RO volume advances, update the server
list and see if the current server has been excluded, if so reissue
the op. Once over half of the replication sites have been updated,
increment cb_ro_snapshot to indicate updates may be required and
switch over to excluding unupdated replication sites.
- If the creation timestamp on a Backup volume advances, just
increment cb_ro_snapshot to trigger updates.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
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Defer volume record destruction to a workqueue so that afs_put_volume()
isn't going to run the destruction process in the callback workqueue whilst
the server is holding up other clients whilst waiting for us to reply to a
CB.CallBack notification RPC.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
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Make it possible to find the afs_volume structs that are using an
afs_server struct to aid in breaking volume callbacks.
The way this is done is that each afs_volume already has an array of
afs_server_entry records that point to the servers where that volume might
be found. An afs_volume backpointer and a list node is added to each entry
and each entry is then added to an RCU-traversable list on the afs_server
to which it points.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
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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: 20325960f875 ("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>
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Variable nr_servers is no longer being used, the last reference
to it was removed in commit 45df8462730d ("afs: Fix server list handling")
so clean up the code by removing it.
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/20221020173923.21342-1-colin.i.king@gmail.com/
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Use refcount_t rather than atomic_t in afs to make use of the count
checking facilities provided.
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/165911277768.3745403.423349776836296452.stgit@warthog.procyon.org.uk/ # v1
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Remove an unused global variable and make another static as reported by
make C=1.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-afs@lists.infradead.org
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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
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Add a tracepoint to log the cell refcount and active user count and pass in
a reason code through various functions that manipulate these counters.
Additionally, a helper function, afs_see_cell(), is provided to log
interesting places that deal with a cell without actually doing any
accounting directly.
Signed-off-by: David Howells <dhowells@redhat.com>
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Management of the lifetime of afs_cell struct has some problems due to the
usage counter being used to determine whether objects of that type are in
use in addition to whether anyone might be interested in the structure.
This is made trickier by cell objects being cached for a period of time in
case they're quickly reused as they hold the result of a setup process that
may be slow (DNS lookups, AFS RPC ops).
Problems include the cached root volume from alias resolution pinning its
parent cell record, rmmod occasionally hanging and occasionally producing
assertion failures.
Fix this by splitting the count of active users from the struct reference
count. Things then work as follows:
(1) The cell cache keeps +1 on the cell's activity count and this has to
be dropped before the cell can be removed. afs_manage_cell() tries to
exchange the 1 to a 0 with the cells_lock write-locked, and if
successful, the record is removed from the net->cells.
(2) One struct ref is 'owned' by the activity count. That is put when the
active count is reduced to 0 (final_destruction label).
(3) A ref can be held on a cell whilst it is queued for management on a
work queue without confusing the active count. afs_queue_cell() is
added to wrap this.
(4) The queue's ref is dropped at the end of the management. This is
split out into a separate function, afs_manage_cell_work().
(5) The root volume record is put after a cell is removed (at the
final_destruction label) rather then in the RCU destruction routine.
(6) Volumes hold struct refs, but aren't active users.
(7) Both counts are displayed in /proc/net/afs/cells.
There are some management function changes:
(*) afs_put_cell() now just decrements the refcount and triggers the RCU
destruction if it becomes 0. It no longer sets a timer to have the
manager do this.
(*) afs_use_cell() and afs_unuse_cell() are added to increase and decrease
the active count. afs_unuse_cell() sets the management timer.
(*) afs_queue_cell() is added to queue a cell with approprate refs.
There are also some other fixes:
(*) Don't let /proc/net/afs/cells access a cell's vllist if it's NULL.
(*) Make sure that candidate cells in lookups are properly destroyed
rather than being simply kfree'd. This ensures the bits it points to
are destroyed also.
(*) afs_dec_cells_outstanding() is now called in cell destruction rather
than at "final_destruction". This ensures that cell->net is still
valid to the end of the destructor.
(*) As a consequence of the previous two changes, move the increment of
net->cells_outstanding that was at the point of insertion into the
tree to the allocation routine to correctly balance things.
Fixes: 989782dcdc91 ("afs: Overhaul cell database management")
Signed-off-by: David Howells <dhowells@redhat.com>
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Reorganise afs_volume objects such that they're in a tree keyed on volume
ID, rooted at on an afs_cell object rather than being in multiple trees,
each of which is rooted on an afs_server object.
afs_server structs become per-cell and acquire a pointer to the cell.
The process of breaking a callback then starts with finding the server by
its network address, following that to the cell and then looking up each
volume ID in the volume tree.
This is simpler than the afs_vol_interest/afs_cb_interest N:M mapping web
and allows those structs and the code for maintaining them to be simplified
or removed.
It does make a couple of things a bit more tricky, though:
(1) Operations now start with a volume, not a server, so there can be more
than one answer as to whether or not the server we'll end up using
supports the FS.InlineBulkStatus RPC.
(2) CB RPC operations that specify the server UUID. There's still a tree
of servers by UUID on the afs_net struct, but the UUIDs in it aren't
guaranteed unique.
Signed-off-by: David Howells <dhowells@redhat.com>
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Add a tracepoint to track the lifetime of the afs_volume struct.
Signed-off-by: David Howells <dhowells@redhat.com>
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Put in the first phase of cell alias detection. This part handles alias
detection for cells that have root.cell volumes (which is expected to be
likely).
When a cell becomes newly active, it is probed for its root.cell volume,
and if it has one, this volume is compared against other root.cell volumes
to find out if the list of fileserver UUIDs have any in common - and if
that's the case, do the address lists of those fileservers have any
addresses in common. If they do, the new cell is adjudged to be an alias
of the old cell and the old cell is used instead.
Comparing is aided by the server list in struct afs_server_list being
sorted in UUID order and the addresses in the fileserver address lists
being sorted in address order.
The cell then retains the afs_volume object for the root.cell volume, even
if it's not mounted for future alias checking.
This necessary because:
(1) Whilst fileservers have UUIDs that are meant to be globally unique, in
practice they are not because cells get cloned without changing the
UUIDs - so afs_server records need to be per cell.
(2) Sometimes the DNS is used to make cell aliases - but if we don't know
they're the same, we may end up with multiple superblocks and multiple
afs_server records for the same thing, impairing our ability to
deliver callback notifications of third party changes
(3) The fileserver RPC API doesn't contain the cell name, so it can't tell
us which cell it's notifying and can't see that a change made to to
one cell should notify the same client that's also accessed as the
other cell.
Reported-by: Jeffrey Altman <jaltman@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
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Turn the afs_operation struct into the main way that most fileserver
operations are managed. Various things are added to the struct, including
the following:
(1) All the parameters and results of the relevant operations are moved
into it, removing corresponding fields from the afs_call struct.
afs_call gets a pointer to the op.
(2) The target volume is made the main focus of the operation, rather than
the target vnode(s), and a bunch of op->vnode->volume are made
op->volume instead.
(3) Two vnode records are defined (op->file[]) for the vnode(s) involved
in most operations. The vnode record (struct afs_vnode_param)
contains:
- The vnode pointer.
- The fid of the vnode to be included in the parameters or that was
returned in the reply (eg. FS.MakeDir).
- The status and callback information that may be returned in the
reply about the vnode.
- Callback break and data version tracking for detecting
simultaneous third-parth changes.
(4) Pointers to dentries to be updated with new inodes.
(5) An operations table pointer. The table includes pointers to functions
for issuing AFS and YFS-variant RPCs, handling the success and abort
of an operation and handling post-I/O-lock local editing of a
directory.
To make this work, the following function restructuring is made:
(A) The rotation loop that issues calls to fileservers that can be found
in each function that wants to issue an RPC (such as afs_mkdir()) is
extracted out into common code, in a new file called fs_operation.c.
(B) The rotation loops, such as the one in afs_mkdir(), are replaced with
a much smaller piece of code that allocates an operation, sets the
parameters and then calls out to the common code to do the actual
work.
(C) The code for handling the success and failure of an operation are
moved into operation functions (as (5) above) and these are called
from the core code at appropriate times.
(D) The pseudo inode getting stuff used by the dynamic root code is moved
over into dynroot.c.
(E) struct afs_iget_data is absorbed into the operation struct and
afs_iget() expects to be given an op pointer and a vnode record.
(F) Point (E) doesn't work for the root dir of a volume, but we know the
FID in advance (it's always vnode 1, unique 1), so a separate inode
getter, afs_root_iget(), is provided to special-case that.
(G) The inode status init/update functions now also take an op and a vnode
record.
(H) The RPC marshalling functions now, for the most part, just take an
afs_operation struct as their only argument. All the data they need
is held there. The result delivery functions write their answers
there as well.
(I) The call is attached to the operation and then the operation core does
the waiting.
And then the new operation code is, for the moment, made to just initialise
the operation, get the appropriate vnode I/O locks and do the same rotation
loop as before.
This lays the foundation for the following changes in the future:
(*) Overhauling the rotation (again).
(*) Support for asynchronous I/O, where the fileserver rotation must be
done asynchronously also.
Signed-off-by: David Howells <dhowells@redhat.com>
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As a prelude to implementing asynchronous fileserver operations in the afs
filesystem, rename struct afs_fs_cursor to afs_operation.
This struct is going to form the core of the operation management and is
going to acquire more members in later.
Signed-off-by: David Howells <dhowells@redhat.com>
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When an AFS client accesses a file, it receives a limited-duration callback
promise that the server will notify it if another client changes a file.
This callback duration can be a few hours in length.
If a client mounts a volume and then an application prevents it from being
unmounted, say by chdir'ing into it, but then does nothing for some time,
the rxrpc_peer record will expire and rxrpc-level keepalive will cease.
If there is NAT or a firewall between the client and the server, the route
back for the server may close after a comparatively short duration, meaning
that attempts by the server to notify the client may then bounce.
The client, however, may (so far as it knows) still have a valid unexpired
promise and will then rely on its cached data and will not see changes made
on the server by a third party until it incidentally rechecks the status or
the promise needs renewal.
To deal with this, the client needs to regularly probe the server. This
has two effects: firstly, it keeps a route open back for the server, and
secondly, it causes the server to disgorge any notifications that got
queued up because they couldn't be sent.
Fix this by adding a mechanism to emit regular probes.
Two levels of probing are made available: Under normal circumstances the
'slow' queue will be used for a fileserver - this just probes the preferred
address once every 5 mins or so; however, if server fails to respond to any
probes, the server will shift to the 'fast' queue from which all its
interfaces will be probed every 30s. When it finally responds, the record
will switch back to the slow queue.
Further notes:
(1) Probing is now no longer driven from the fileserver rotation
algorithm.
(2) Probes are dispatched to all interfaces on a fileserver when that an
afs_server object is set up to record it.
(3) The afs_server object is removed from the probe queues when we start
to probe it. afs_is_probing_server() returns true if it's not listed
- ie. it's undergoing probing.
(4) The afs_server object is added back on to the probe queue when the
final outstanding probe completes, but the probed_at time is set when
we're about to launch a probe so that it's not dependent on the probe
duration.
(5) The timer and the work item added for this must be handed a count on
net->servers_outstanding, which they hand on or release. This makes
sure that network namespace cleanup waits for them.
Fixes: d2ddc776a458 ("afs: Overhaul volume and server record caching and fileserver rotation")
Reported-by: Dave Botsch <botsch@cnf.cornell.edu>
Signed-off-by: David Howells <dhowells@redhat.com>
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When an operation is meant to be done uninterruptibly (such as
FS.StoreData), we should not be allowing volume and server record checking
to be interrupted.
Fixes: d2ddc776a458 ("afs: Overhaul volume and server record caching and fileserver rotation")
Signed-off-by: David Howells <dhowells@redhat.com>
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fs/afs/volume.c:15:26: warning:
afs_voltypes defined but not used [-Wunused-const-variable=]
It is not used since commit d2ddc776a458 ("afs: Overhaul
volume and server record caching and fileserver rotation")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: David Howells <dhowells@redhat.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs
Pull AFS fixes from David Howells:
"The in-kernel AFS client has been undergoing testing on opendev.org on
one of their mirror machines. They are using AFS to hold data that is
then served via apache, and Ian Wienand had reported seeing oopses,
spontaneous machine reboots and updates to volumes going missing. This
patch series appears to have fixed the problem, very probably due to
patch (2), but it's not 100% certain.
(1) Fix the printing of the "vnode modified" warning to exclude checks
on files for which we don't have a callback promise from the
server (and so don't expect the server to tell us when it
changes).
Without this, for every file or directory for which we still have
an in-core inode that gets changed on the server, we may get a
message logged when we next look at it. This can happen in bulk
if, for instance, someone does "vos release" to update a R/O
volume from a R/W volume and a whole set of files are all changed
together.
We only really want to log a message if the file changed and the
server didn't tell us about it or we failed to track the state
internally.
(2) Fix accidental corruption of either afs_vlserver struct objects or
the the following memory locations (which could hold anything).
The issue is caused by a union that points to two different
structs in struct afs_call (to save space in the struct). The call
cleanup code assumes that it can simply call the cleanup for one
of those structs if not NULL - when it might be actually pointing
to the other struct.
This means that every Volume Location RPC op is going to corrupt
something.
(3) Fix an uninitialised spinlock. This isn't too bad, it just causes
a one-off warning if lockdep is enabled when "vos release" is
called, but the spinlock still behaves correctly.
(4) Fix the setting of i_block in the inode. This causes du, for
example, to produce incorrect results, but otherwise should not be
dangerous to the kernel"
* tag 'afs-fixes-20190620' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
afs: Fix setting of i_blocks
afs: Fix uninitialised spinlock afs_volume::cb_break_lock
afs: Fix vlserver record corruption
afs: Fix over zealous "vnode modified" warnings
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Fix the cb_break_lock spinlock in afs_volume struct by initialising it when
the volume record is allocated.
Also rename the lock to cb_v_break_lock to distinguish it from the lock of
the same name in the afs_server struct.
Without this, the following trace may be observed when a volume-break
callback is received:
INFO: trying to register non-static key.
the code is fine but needs lockdep annotation.
turning off the locking correctness validator.
CPU: 2 PID: 50 Comm: kworker/2:1 Not tainted 5.2.0-rc1-fscache+ #3045
Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014
Workqueue: afs SRXAFSCB_CallBack
Call Trace:
dump_stack+0x67/0x8e
register_lock_class+0x23b/0x421
? check_usage_forwards+0x13c/0x13c
__lock_acquire+0x89/0xf73
lock_acquire+0x13b/0x166
? afs_break_callbacks+0x1b2/0x3dd
_raw_write_lock+0x2c/0x36
? afs_break_callbacks+0x1b2/0x3dd
afs_break_callbacks+0x1b2/0x3dd
? trace_event_raw_event_afs_server+0x61/0xac
SRXAFSCB_CallBack+0x11f/0x16c
process_one_work+0x2c5/0x4ee
? worker_thread+0x234/0x2ac
worker_thread+0x1d8/0x2ac
? cancel_delayed_work_sync+0xf/0xf
kthread+0x11f/0x127
? kthread_park+0x76/0x76
ret_from_fork+0x24/0x30
Fixes: 68251f0a6818 ("afs: Fix whole-volume callback handling")
Signed-off-by: David Howells <dhowells@redhat.com>
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Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 3029 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Add fs_context support to the AFS filesystem, converting the parameter
parsing to store options there.
This will form the basis for namespace propagation over mountpoints within
the AFS model, thereby allowing AFS to be used in containers more easily.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Send probes to all the unprobed fileservers in a fileserver list on all
addresses simultaneously in an attempt to find out the fastest route whilst
not getting stuck for 20s on any server or address that we don't get a
reply from.
This alleviates the problem whereby attempting to access a new server can
take a long time because the rotation algorithm ends up rotating through
all servers and addresses until it finds one that responds.
Signed-off-by: David Howells <dhowells@redhat.com>
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Eliminate the address pointer from the address list cursor as it's
redundant (ac->addrs[ac->index] can be used to find the same address) and
address lists must be replaced rather than being rearranged, so is of
limited value.
Signed-off-by: David Howells <dhowells@redhat.com>
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Increase the sizes of the volume ID to 64 bits and the vnode ID (inode
number equivalent) to 96 bits to allow the support of YFS.
This requires the iget comparator to check the vnode->fid rather than i_ino
and i_generation as i_ino is not sufficiently capacious. It also requires
this data to be placed into the vnode cache key for fscache.
For the moment, just discard the top 32 bits of the vnode ID when returning
it though stat.
Signed-off-by: David Howells <dhowells@redhat.com>
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Track VL servers as independent entities rather than lumping all their
addresses together into one set and implement server-level rotation by:
(1) Add the concept of a VL server list, where each server has its own
separate address list. This code is similar to the FS server list.
(2) Use the DNS resolver to retrieve a set of servers and their associated
addresses, ports, preference and weight ratings.
(3) In the case of a legacy DNS resolver or an address list given directly
through /proc/net/afs/cells, create a list containing just a dummy
server record and attach all the addresses to that.
(4) Implement a simple rotation policy, for the moment ignoring the
priorities and weights assigned to the servers.
(5) Show the address list through /proc/net/afs/<cell>/vlservers. This
also displays the source and status of the data as indicated by the
upcall.
Signed-off-by: David Howells <dhowells@redhat.com>
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Pass the object size in to fscache_acquire_cookie() and
fscache_write_page() rather than the netfs providing a callback by which it
can be received. This makes it easier to update the size of the object
when a new page is written that extends the object.
The current object size is also passed by fscache to the check_aux
function, obviating the need to store it in the aux data.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Anna Schumaker <anna.schumaker@netapp.com>
Tested-by: Steve Dickson <steved@redhat.com>
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Attach copies of the index key and auxiliary data to the fscache cookie so
that:
(1) The callbacks to the netfs for this stuff can be eliminated. This
can simplify things in the cache as the information is still
available, even after the cache has relinquished the cookie.
(2) Simplifies the locking requirements of accessing the information as we
don't have to worry about the netfs object going away on us.
(3) The cache can do lazy updating of the coherency information on disk.
As long as the cache is flushed before reboot/poweroff, there's no
need to update the coherency info on disk every time it changes.
(4) Cookies can be hashed or put in a tree as the index key is easily
available. This allows:
(a) Checks for duplicate cookies can be made at the top fscache layer
rather than down in the bowels of the cache backend.
(b) Caching can be added to a netfs object that has a cookie if the
cache is brought online after the netfs object is allocated.
A certain amount of space is made in the cookie for inline copies of the
data, but if it won't fit there, extra memory will be allocated for it.
The downside of this is that live cache operation requires more memory.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Anna Schumaker <anna.schumaker@netapp.com>
Tested-by: Steve Dickson <steved@redhat.com>
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Fix server list handling in the following ways:
(1) In afs_alloc_volume(), remove duplicate server list build code. This
was already done by afs_alloc_server_list() which afs_alloc_volume()
previously called. This just results in twice as many VL RPCs.
(2) In afs_deliver_vl_get_entry_by_name_u(), use the number of server
records indicated by ->nServers in the UVLDB record returned by the
VL.GetEntryByNameU RPC call rather than scanning all NMAXNSERVERS
slots. Unused slots may contain garbage.
(3) In afs_alloc_server_list(), don't stop converting a UVLDB record into
a server list just because we can't look up one of the servers. Just
skip that server and go on to the next. If we can't look up any of
the servers then we'll fail at the end.
Without this patch, an attempt to view the umich.edu root cell using
something like "ls /afs/umich.edu" on a dynamic root (future patch) mount
or an autocell mount will result in ENOMEDIUM. The failure is due to kafs
not stopping after nServers'worth of records have been read, but then
trying to access a server with a garbage UUID and getting an error, which
aborts the server list build.
Fixes: d2ddc776a458 ("afs: Overhaul volume and server record caching and fileserver rotation")
Reported-by: Jonathan Billings <jsbillings@jsbillings.org>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: stable@vger.kernel.org
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afs_alloc_volume() needs to release the cell ref it obtained in the case of
an error. Fix this by adding an afs_put_cell() call into the error path.
This can triggered when a lookup for a cell in a dynamic root or an
autocell mount returns an error whilst trying to look up the server (such
as ENOMEDIUM). This results in an assertion failure oops when the module
is unloaded due to outstanding refs on a cell record.
Fixes: d2ddc776a458 ("afs: Overhaul volume and server record caching and fileserver rotation")
Signed-off-by: David Howells <dhowells@redhat.com>
cc: stable@vger.kernel.org
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YFS VL servers offer an upgraded Volume Location service that can return
IPv6 addresses to fileservers and volume servers in addition to IPv4
addresses using the YFSVL.GetEndpoints operation which we should use if
it's available.
To this end:
(1) Make rxrpc_kernel_recv_data() return the call's current service ID so
that the caller can detect service upgrade and see what the service
was upgraded to.
(2) When we see a VL server address we haven't seen before, send a
VL.GetCapabilities operation to it with the service upgrade bit set.
If we get an upgrade to the YFS VL service, change the service ID in
the address list for that address to use the upgraded service and set
a flag to note that this appears to be a YFS-compatible server.
(3) If, when a server's addresses are being looked up, we note that we
previously detected a YFS-compatible server, then send the
YFSVL.GetEndpoints operation rather than VL.GetAddrsU.
(4) Build a fileserver address list from the reply of YFSVL.GetEndpoints,
including both IPv4 and IPv6 addresses. Volume server addresses are
discarded.
(5) The address list is sorted by address and port now, instead of just
address. This allows multiple servers on the same host sitting on
different ports.
Signed-off-by: David Howells <dhowells@redhat.com>
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