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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs d_revalidate updates from Al Viro:
"Provide stable parent and name to ->d_revalidate() instances
Most of the filesystem methods where we care about dentry name and
parent have their stability guaranteed by the callers;
->d_revalidate() is the major exception.
It's easy enough for callers to supply stable values for expected name
and expected parent of the dentry being validated. That kills quite a
bit of boilerplate in ->d_revalidate() instances, along with a bunch
of races where they used to access ->d_name without sufficient
precautions"
* tag 'pull-revalidate' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
9p: fix ->rename_sem exclusion
orangefs_d_revalidate(): use stable parent inode and name passed by caller
ocfs2_dentry_revalidate(): use stable parent inode and name passed by caller
nfs: fix ->d_revalidate() UAF on ->d_name accesses
nfs{,4}_lookup_validate(): use stable parent inode passed by caller
gfs2_drevalidate(): use stable parent inode and name passed by caller
fuse_dentry_revalidate(): use stable parent inode and name passed by caller
vfat_revalidate{,_ci}(): use stable parent inode passed by caller
exfat_d_revalidate(): use stable parent inode passed by caller
fscrypt_d_revalidate(): use stable parent inode passed by caller
ceph_d_revalidate(): propagate stable name down into request encoding
ceph_d_revalidate(): use stable parent inode passed by caller
afs_d_revalidate(): use stable name and parent inode passed by caller
Pass parent directory inode and expected name to ->d_revalidate()
generic_ci_d_compare(): use shortname_storage
ext4 fast_commit: make use of name_snapshot primitives
dissolve external_name.u into separate members
make take_dentry_name_snapshot() lockless
dcache: back inline names with a struct-wrapped array of unsigned long
make sure that DNAME_INLINE_LEN is a multiple of word size
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No need to bother with boilerplate for obtaining the latter and for
the former we really should not count upon ->d_name.name remaining
stable under us.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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->d_revalidate() often needs to access dentry parent and name; that has
to be done carefully, since the locking environment varies from caller
to caller. We are not guaranteed that dentry in question will not be
moved right under us - not unless the filesystem is such that nothing
on it ever gets renamed.
It can be dealt with, but that results in boilerplate code that isn't
even needed - the callers normally have just found the dentry via dcache
lookup and want to verify that it's in the right place; they already
have the values of ->d_parent and ->d_name stable. There is a couple
of exceptions (overlayfs and, to less extent, ecryptfs), but for the
majority of calls that song and dance is not needed at all.
It's easier to make ecryptfs and overlayfs find and pass those values if
there's a ->d_revalidate() instance to be called, rather than doing that
in the instances.
This commit only changes the calling conventions; making use of supplied
values is left to followups.
NOTE: some instances need more than just the parent - things like CIFS
may need to build an entire path from filesystem root, so they need
more precautions than the usual boilerplate. This series doesn't
do anything to that need - these filesystems have to keep their locking
mechanisms (rename_lock loops, use of dentry_path_raw(), private rwsem
a-la v9fs).
One thing to keep in mind when using name is that name->name will normally
point into the pathname being resolved; the filename in question occupies
name->len bytes starting at name->name, and there is NUL somewhere after it,
but it the next byte might very well be '/' rather than '\0'. Do not
ignore name->len.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Gabriel Krisman Bertazi <gabriel@krisman.be>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull afs updates from Christian Brauner:
"Dynamic root improvements:
- Create an /afs/.<cell> mountpoint to match the /afs/<cell>
mountpoint when a cell is created
- Add some more checks on cell names proposed by the user to prevent
dodgy symlink bodies from being created. Also prevent rootcell from
being altered once set to simplify the locking
- Change the handling of /afs/@cell from being a dentry name
substitution at lookup time to making it a symlink to the current
cell name and also provide a /afs/.@cell symlink to point to the
dotted cell mountpoint
Fixes:
- Fix the abort code check in the fallback handling for the
YFS.RemoveFile2 RPC call
- Use call->op->server() for oridnary filesystem RPC calls that have
an operation descriptor instead of call->server()"
* tag 'vfs-6.14-rc1.afs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
afs: Fix the fallback handling for the YFS.RemoveFile2 RPC call
afs: Make /afs/@cell and /afs/.@cell symlinks
afs: Add rootcell checks
afs: Make /afs/.<cell> as well as /afs/<cell> mountpoints
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs netfs updates from Christian Brauner:
"This contains read performance improvements and support for monolithic
single-blob objects that have to be read/written as such (e.g. AFS
directory contents). The implementation of the two parts is interwoven
as each makes the other possible.
- Read performance improvements
The read performance improvements are intended to speed up some
loss of performance detected in cifs and to a lesser extend in afs.
The problem is that we queue too many work items during the
collection of read results: each individual subrequest is collected
by its own work item, and then they have to interact with each
other when a series of subrequests don't exactly align with the
pattern of folios that are being read by the overall request.
Whilst the processing of the pages covered by individual
subrequests as they complete potentially allows folios to be woken
in parallel and with minimum delay, it can shuffle wakeups for
sequential reads out of order - and that is the most common I/O
pattern.
The final assessment and cleanup of an operation is then held up
until the last I/O completes - and for a synchronous sequential
operation, this means the bouncing around of work items just adds
latency.
Two changes have been made to make this work:
(1) All collection is now done in a single "work item" that works
progressively through the subrequests as they complete (and
also dispatches retries as necessary).
(2) For readahead and AIO, this work item be done on a workqueue
and can run in parallel with the ultimate consumer of the data;
for synchronous direct or unbuffered reads, the collection is
run in the application thread and not offloaded.
Functions such as smb2_readv_callback() then just tell netfslib
that the subrequest has terminated; netfslib does a minimal bit of
processing on the spot - stat counting and tracing mostly - and
then queues/wakes up the worker. This simplifies the logic as the
collector just walks sequentially through the subrequests as they
complete and walks through the folios, if buffered, unlocking them
as it goes. It also keeps to a minimum the amount of latency
injected into the filesystem's low-level I/O handling
The way netfs supports filesystems using the deprecated
PG_private_2 flag is changed: folios are flagged and added to a
write request as they complete and that takes care of scheduling
the writes to the cache. The originating read request can then just
unlock the pages whatever happens.
- Single-blob object support
Single-blob objects are files for which the content of the file
must be read from or written to the server in a single operation
because reading them in parts may yield inconsistent results. AFS
directories are an example of this as there exists the possibility
that the contents are generated on the fly and would differ between
reads or might change due to third party interference.
Such objects will be written to and retrieved from the cache if one
is present, though we allow/may need to propose multiple
subrequests to do so. The important part is that read from/write to
the *server* is monolithic.
Single blob reading is, for the moment, fully synchronous and does
result collection in the application thread and, also for the
moment, the API is supplied the buffer in the form of a folio_queue
chain rather than using the pagecache.
- Related afs changes
This series makes a number of changes to the kafs filesystem,
primarily in the area of directory handling:
- AFS's FetchData RPC reply processing is made partially
asynchronous which allows the netfs_io_request's outstanding
operation counter to be removed as part of reducing the
collection to a single work item.
- Directory and symlink reading are plumbed through netfslib using
the single-blob object API and are now cacheable with fscache.
This also allows the afs_read struct to be eliminated and
netfs_io_subrequest to be used directly instead.
- Directory and symlink content are now stored in a folio_queue
buffer rather than in the pagecache. This means we don't require
the RCU read lock and xarray iteration to access it, and folios
won't randomly disappear under us because the VM wants them
back.
- The vnode operation lock is changed from a mutex struct to a
private lock implementation. The problem is that the lock now
needs to be dropped in a separate thread and mutexes don't
permit that.
- When a new directory or symlink is created, we now initialise it
locally and mark it valid rather than downloading it (we know
what it's likely to look like).
- We now use the in-directory hashtable to reduce the number of
entries we need to scan when doing a lookup. The edit routines
have to maintain the hash chains.
- Cancellation (e.g. by signal) of an async call after the
rxrpc_call has been set up is now offloaded to the worker thread
as there will be a notification from rxrpc upon completion. This
avoids a double cleanup.
- A "rolling buffer" implementation is created to abstract out the
two separate folio_queue chaining implementations I had (one for
read and one for write).
- Functions are provided to create/extend a buffer in a folio_queue
chain and tear it down again.
This is used to handle AFS directories, but could also be used to
create bounce buffers for content crypto and transport crypto.
- The was_async argument is dropped from netfs_read_subreq_terminated()
Instead we wake the read collection work item by either queuing it
or waking up the app thread.
- We don't need to use BH-excluding locks when communicating between
the issuing thread and the collection thread as neither of them now
run in BH context.
- Also included are a number of new tracepoints; a split of the
netfslib write collection code to put retrying into its own file
(it gets more complicated with content encryption).
- There are also some minor fixes AFS included, including fixing the
AFS directory format struct layout, reducing some directory
over-invalidation and making afs_mkdir() translate EEXIST to
ENOTEMPY (which is not available on all systems the servers
support).
- Finally, there's a patch to try and detect entry into the folio
unlock function with no folio_queue structs in the buffer (which
isn't allowed in the cases that can get there).
This is a debugging patch, but should be minimal overhead"
* tag 'vfs-6.14-rc1.netfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (31 commits)
netfs: Report on NULL folioq in netfs_writeback_unlock_folios()
afs: Add a tracepoint for afs_read_receive()
afs: Locally initialise the contents of a new symlink on creation
afs: Use the contained hashtable to search a directory
afs: Make afs_mkdir() locally initialise a new directory's content
netfs: Change the read result collector to only use one work item
afs: Make {Y,}FS.FetchData an asynchronous operation
afs: Fix cleanup of immediately failed async calls
afs: Eliminate afs_read
afs: Use netfslib for symlinks, allowing them to be cached
afs: Use netfslib for directories
afs: Make afs_init_request() get a key if not given a file
netfs: Add support for caching single monolithic objects such as AFS dirs
netfs: Add functions to build/clean a buffer in a folio_queue
afs: Add more tracepoints to do with tracking validity
cachefiles: Add auxiliary data trace
cachefiles: Add some subrequest tracepoints
netfs: Remove some extraneous directory invalidations
afs: Fix directory format encoding struct
afs: Fix EEXIST error returned from afs_rmdir() to be ENOTEMPTY
...
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Fix a pair of bugs in the fallback handling for the YFS.RemoveFile2 RPC
call:
(1) Fix the abort code check to also look for RXGEN_OPCODE. The lack of
this masks the second bug.
(2) call->server is now not used for ordinary filesystem RPC calls that
have an operation descriptor. Fix to use call->op->server instead.
Fixes: e49c7b2f6de7 ("afs: Build an abstraction around an "operation" concept")
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/109541.1736865963@warthog.procyon.org.uk
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Make /afs/@cell a symlink in the /afs dynamic root to match what other AFS
clients do rather than doing a substitution in the dentry name. This has
the bonus of being tab-expandable also.
Further, provide a /afs/.@cell symlink to point to the dotted cell share.
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20250107183454.608451-4-dhowells@redhat.com
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Add some checks for the validity of the cell name. It's may get put into a
symlink, so preclude it containing any slashes or "..". Also disallow
starting/ending with a dot. This makes /afs/@cell/ as a symlink less of a
security risk.
Also disallow multiple setting of /proc/net/afs/rootcell for any given
network namespace. Once set, the value may not be changed. This makes it
easier to only create /afs/@cell and /afs/.@cell if there's a rootcell.
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20250107183454.608451-3-dhowells@redhat.com
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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When a cell is instantiated, automatically create an /afs/.<cell>
mountpoint to match the /afs/<cell> mountpoint to match other AFS clients.
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20250107183454.608451-2-dhowells@redhat.com
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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syzbot reported a lock held when returning to userspace[1]. This is
because if argc is less than 0 and the function returns directly, the held
inode lock is not released.
Fix this by store the error in ret and jump to done to clean up instead of
returning directly.
[dh: Modified Lizhi Xu's original patch to make it honour the error code
from afs_split_string()]
[1]
WARNING: lock held when returning to user space!
6.13.0-rc3-syzkaller-00209-g499551201b5f #0 Not tainted
------------------------------------------------
syz-executor133/5823 is leaving the kernel with locks still held!
1 lock held by syz-executor133/5823:
#0: ffff888071cffc00 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:818 [inline]
#0: ffff888071cffc00 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: afs_proc_addr_prefs_write+0x2bb/0x14e0 fs/afs/addr_prefs.c:388
Reported-by: syzbot+76f33569875eb708e575@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=76f33569875eb708e575
Signed-off-by: Lizhi Xu <lizhi.xu@windriver.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241226012616.2348907-1-lizhi.xu@windriver.com/
Link: https://lore.kernel.org/r/529850.1736261552@warthog.procyon.org.uk
Tested-by: syzbot+76f33569875eb708e575@syzkaller.appspotmail.com
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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The kafs filesystem limits the maximum length of a cell to 256 bytes, but a
problem occurs if someone actually does that: kafs tries to create a
directory under /proc/net/afs/ with the name of the cell, but that fails
with a warning:
WARNING: CPU: 0 PID: 9 at fs/proc/generic.c:405
because procfs limits the maximum filename length to 255.
However, the DNS limits the maximum lookup length and, by extension, the
maximum cell name, to 255 less two (length count and trailing NUL).
Fix this by limiting the maximum acceptable cellname length to 253. This
also allows us to be sure we can create the "/afs/.<cell>/" mountpoint too.
Further, split the YFS VL record cell name maximum to be the 256 allowed by
the protocol and ignore the record retrieved by YFSVL.GetCellName if it
exceeds 253.
Fixes: c3e9f888263b ("afs: Implement client support for the YFSVL.GetCellName RPC op")
Reported-by: syzbot+7848fee1f1e5c53f912b@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/r/6776d25d.050a0220.3a8527.0048.GAE@google.com/
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/376236.1736180460@warthog.procyon.org.uk
Tested-by: syzbot+7848fee1f1e5c53f912b@syzkaller.appspotmail.com
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Add a tracepoint for afs_read_receive() to allow potential missed wakeups
to be debugged.
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-32-dhowells@redhat.com
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Since we know what the contents of a symlink will be when we create it on
the server, initialise its contents locally too to avoid the need to
download it.
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-31-dhowells@redhat.com
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Each directory image contains a hashtable with 128 buckets to speed up
searching. Currently, kafs does not use this, but rather iterates over all
the occupied slots in the image as it can share this with readdir.
Switch kafs to use the hashtable for lookups to reduce the latency. Care
must be taken that the hash chains are acyclic.
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-30-dhowells@redhat.com
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Initialise a new directory's content when it is created by mkdir locally
rather than downloading the content from the server as we can predict what
it's going to look like.
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-29-dhowells@redhat.com
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Change the way netfslib collects read results to do all the collection for
a particular read request using a single work item that walks along the
subrequest queue as subrequests make progress or complete, unlocking folios
progressively rather than doing the unlock in parallel as parallel requests
come in.
The code is remodelled to be more like the write-side code, though only
using a single stream. This makes it more directly comparable and thus
easier to duplicate fixes between the two sides.
This has a number of advantages:
(1) It's simpler. There doesn't need to be a complex donation mechanism
to handle mismatches between the size and alignment of subrequests and
folios. The collector unlocks folios as the subrequests covering each
complete.
(2) It should cause less scheduler overhead as there's a single work item
in play unlocking pages in parallel when a read gets split up into a
lot of subrequests instead of one per subrequest.
Whilst the parallellism is nice in theory, in practice, the vast
majority of loads are sequential reads of the whole file, so
committing a bunch of threads to unlocking folios out of order doesn't
help in those cases.
(3) It should make it easier to implement content decryption. A folio
cannot be decrypted until all the requests that contribute to it have
completed - and, again, most loads are sequential and so, most of the
time, we want to begin decryption sequentially (though it's great if
the decryption can happen in parallel).
There is a disadvantage in that we're losing the ability to decrypt and
unlock things on an as-things-arrive basis which may affect some
applications.
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-28-dhowells@redhat.com
cc: Jeff Layton <jlayton@kernel.org>
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Make FS.FetchData and YFS.FetchData an asynchronous operation in that the
request is queued in AF_RXRPC and then we return to the caller rather than
waiting. Processing of the returning packets is then done inline if it's a
synchronous VFS/VM call (readdir, read_folio, sync DIO, prep for write) or
offloaded to a workqueue if asynchronous VM calls (eg. readahead, async
DIO).
This reduces the chain of workqueues invoking workqueues and cuts out some
of the overhead, driving rxrpc data extraction and netfslib read collection
from a thread that's going to block to completion anyway if possible.
The ->done() call op is also split with ->immediate_cancel() handling the
cancellation on failure to begin the call and ->done() handling the rest.
This means that the AFS async FetchData code doesn't try to terminate the
netfs subrequest twice.
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-26-dhowells@redhat.com
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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If we manage to begin an async call, but fail to transmit any data on it
due to a signal, we then abort it which causes a race between the
notification of call completion from rxrpc and our attempt to cancel the
notification. The notification will be necessary, however, for async
FetchData to terminate the netfs subrequest.
However, since we get a notification from rxrpc upon completion of a call
(aborted or otherwise), we can just leave it to that.
This leads to calls not getting cleaned up, but appearing in
/proc/net/rxrpc/calls as being aborted with code 6.
Fix this by making the "error_do_abort:" case of afs_make_call() abort the
call and then abandon it to the notification handler.
Fixes: 34fa47612bfe ("afs: Fix race in async call refcounting")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-25-dhowells@redhat.com
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Now that directory and symlink reads go through netfslib, the afs_read
struct is mostly redundant with almost all data duplicated in the
netfs_io_request and netfs_io_subrequest structs that are also available
any time we're doing a fetch.
Eliminate afs_read by moving the one field we still need there to the
afs_call struct (we may be given a different amount of data than what we
asked for and have to track what remains of that) and using the
netfs_io_subrequest directly instead.
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-24-dhowells@redhat.com
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Use netfslib to read symlinks, thereby allowing them to be cached by
fscache and cachefiles.
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-23-dhowells@redhat.com
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-afs@lists.infradead.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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In the AFS ecosystem, directories are just a special type of file that is
downloaded and parsed locally. Download is done by the same mechanism as
ordinary files and the data can be cached. There is one important semantic
restriction on directories over files: the client must download the entire
directory in one go because, for example, the server could fabricate the
contents of the blob on the fly with each download and give a different
image each time.
So that we can cache the directory download, switch AFS directory support
over to using the netfslib single-object API, thereby allowing directory
content to be stored in the local cache.
To make this work, the following changes are made:
(1) A directory's contents are now stored in a folio_queue chain attached
to the afs_vnode (inode) struct rather than its associated pagecache,
though multipage folios are still used to hold the data. The folio
queue is discarded when the directory inode is evicted.
This also helps with the phasing out of ITER_XARRAY.
(2) Various directory operations are made to use and unuse the cache
cookie.
(3) The content checking, content dumping and content iteration are now
performed with a standard iov_iter iterator over the contents of the
folio queue.
(4) Iteration and modification must be done with the vnode's validate_lock
held. In conjunction with (1), this means that the iteration can be
done without the need to lock pages or take extra refs on them, unlike
when accessing ->i_pages.
(5) Convert to using netfs_read_single() to read data.
(6) Provide a ->writepages() to call netfs_writeback_single() to save the
data to the cache according to the VM's scheduling whilst holding the
validate_lock read-locked as (4).
(7) Change local directory image editing functions:
(a) Provide a function to get a specific block by number from the
folio_queue as we can no longer use the i_pages xarray to locate
folios by index. This uses a cursor to remember the current
position as we need to iterate through the directory contents.
The block is kmapped before being returned.
(b) Make the function in (a) extend the directory by an extra folio if
we run out of space.
(c) Raise the check of the block free space counter, for those blocks
that have one, higher in the function to eliminate a call to get a
block.
(d) Remove the page unlocking and putting done during the editing
loops. This is no longer necessary as the folio_queue holds the
references and the pages are no longer in the pagecache.
(e) Mark the inode dirty and pin the cache usage till writeback at the
end of a successful edit.
(8) Don't set the large_folios flag on the inode as we do the allocation
ourselves rather than the VM doing it automatically.
(9) Mark the inode as being a single object that isn't uploaded to the
server.
(10) Enable caching on directories.
(11) Only set the upload key for writeback for regular files.
Notes:
(*) We keep the ->release_folio(), ->invalidate_folio() and
->migrate_folio() ops as we set the mapping pointer on the folio.
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-22-dhowells@redhat.com
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-afs@lists.infradead.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
In a future patch, AFS directory caching will go through netfslib and this
will involve, at times, running on behalf of ->lookup(), which doesn't
provide us with a file from which we can get an authentication key.
If a file isn't provided, make afs_init_request() get a key from the
process's keyrings instead when setting up a read.
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-21-dhowells@redhat.com
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
Add wrappers to set and clear the callback promise and to mark a directory
as invalidated, and add tracepoints to track these events:
(1) afs_cb_promise: Log when a callback promise is set on a vnode.
(2) afs_vnode_invalid: Log when the server's callback promise for a vnode
is no longer valid and we need to refetch the vnode metadata.
(3) afs_dir_invalid: Log when the contents of a directory are marked
invalid and requiring refetching from the server and the cache
invalidating.
and two tracepoints to record data version number management:
(4) afs_set_dv: Log when the DV is recorded on a vnode.
(5) afs_dv_mismatch: Log when the DV recorded on a vnode plus the expected
delta for the operation does not match the DV we got back from the
server.
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-18-dhowells@redhat.com
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
In the directory editing code, we shouldn't re-invalidate the directory
if it is already invalidated.
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-15-dhowells@redhat.com
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
The AFS directory format structure, union afs_xdr_dir_block::meta, has too
many alloc counter slots declared and so pushes the hash table along and
over the data. This doesn't cause a problem at the moment because I'm
currently ignoring the hash table and only using the correct number of
alloc_ctrs in the code anyway. In future, however, I should start using
the hash table to try and speed up afs_lookup().
Fix this by using the correct constant to declare the counter array.
Fixes: 4ea219a839bf ("afs: Split the directory content defs into a header")
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-14-dhowells@redhat.com
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
AFS servers pass back a code indicating EEXIST when they're asked to remove
a directory that is not empty rather than ENOTEMPTY because not all the
systems that an AFS server can run on have the latter error available and
AFS preexisted the addition of that error in general.
Fix afs_rmdir() to translate EEXIST to ENOTEMPTY.
Fixes: 260a980317da ("[AFS]: Add "directory write" support.")
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-13-dhowells@redhat.com
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
Don't use the standard mutex for the I/O operation lock, but rather
implement our own as the standard mutex must be released in the same thread
as locked it. This is a problem when it comes to doing async FetchData
where the lock will be dropped from the workqueue that processed the
incoming data and not from the issuing thread.
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-12-dhowells@redhat.com
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
Drop the was_async argument from netfs_read_subreq_terminated(). Almost
every caller is either in process context and passes false. Some
filesystems delegate the call to a workqueue to avoid doing the work in
their network message queue parsing thread.
The only exception is netfs_cache_read_terminated() which handles
completion in the cache - which is usually a callback from the backing
filesystem in softirq context, though it can be from process context if an
error occurred. In this case, delegate to a workqueue.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/CAHk-=wiVC5Cgyz6QKXFu6fTaA6h4CjexDR-OV9kL6Vo5x9v8=A@mail.gmail.com/
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-10-dhowells@redhat.com
cc: Jeff Layton <jlayton@kernel.org>
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
Drop the error argument from netfs_read_subreq_terminated() in favour of
passing the value in subreq->error.
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-9-dhowells@redhat.com
cc: Jeff Layton <jlayton@kernel.org>
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
syzkaller reported recursion with a loop of three calls (netfs_rreq_assess,
netfs_retry_reads and netfs_rreq_terminated) hitting the limit of the stack
during an unbuffered or direct I/O read.
There are a number of issues:
(1) There is no limit on the number of retries.
(2) A subrequest is supposed to be abandoned if it does not transfer
anything (NETFS_SREQ_NO_PROGRESS), but that isn't checked under all
circumstances.
(3) The actual root cause, which is this:
if (atomic_dec_and_test(&rreq->nr_outstanding))
netfs_rreq_terminated(rreq, ...);
When we do a retry, we bump the rreq->nr_outstanding counter to
prevent the final cleanup phase running before we've finished
dispatching the retries. The problem is if we hit 0, we have to do
the cleanup phase - but we're in the cleanup phase and end up
repeating the retry cycle, hence the recursion.
Work around the problem by limiting the number of retries. This is based
on Lizhi Xu's patch[1], and makes the following changes:
(1) Replace NETFS_SREQ_NO_PROGRESS with NETFS_SREQ_MADE_PROGRESS and make
the filesystem set it if it managed to read or write at least one byte
of data. Clear this bit before issuing a subrequest.
(2) Add a ->retry_count member to the subrequest and increment it any time
we do a retry.
(3) Remove the NETFS_SREQ_RETRYING flag as it is superfluous with
->retry_count. If the latter is non-zero, we're doing a retry.
(4) Abandon a subrequest if retry_count is non-zero and we made no
progress.
(5) Use ->retry_count in both the write-side and the read-size.
[?] Question: Should I set a hard limit on retry_count in both read and
write? Say it hits 50, we always abandon it. The problem is that
these changes only mitigate the issue. As long as it made at least one
byte of progress, the recursion is still an issue. This patch
mitigates the problem, but does not fix the underlying cause. I have
patches that will do that, but it's an intrusive fix that's currently
pending for the next merge window.
The oops generated by KASAN looks something like:
BUG: TASK stack guard page was hit at ffffc9000482ff48 (stack is ffffc90004830000..ffffc90004838000)
Oops: stack guard page: 0000 [#1] PREEMPT SMP KASAN NOPTI
...
RIP: 0010:mark_lock+0x25/0xc60 kernel/locking/lockdep.c:4686
...
mark_usage kernel/locking/lockdep.c:4646 [inline]
__lock_acquire+0x906/0x3ce0 kernel/locking/lockdep.c:5156
lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825
local_lock_acquire include/linux/local_lock_internal.h:29 [inline]
___slab_alloc+0x123/0x1880 mm/slub.c:3695
__slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3908
__slab_alloc_node mm/slub.c:3961 [inline]
slab_alloc_node mm/slub.c:4122 [inline]
kmem_cache_alloc_noprof+0x2a7/0x2f0 mm/slub.c:4141
radix_tree_node_alloc.constprop.0+0x1e8/0x350 lib/radix-tree.c:253
idr_get_free+0x528/0xa40 lib/radix-tree.c:1506
idr_alloc_u32+0x191/0x2f0 lib/idr.c:46
idr_alloc+0xc1/0x130 lib/idr.c:87
p9_tag_alloc+0x394/0x870 net/9p/client.c:321
p9_client_prepare_req+0x19f/0x4d0 net/9p/client.c:644
p9_client_zc_rpc.constprop.0+0x105/0x880 net/9p/client.c:793
p9_client_read_once+0x443/0x820 net/9p/client.c:1570
p9_client_read+0x13f/0x1b0 net/9p/client.c:1534
v9fs_issue_read+0x115/0x310 fs/9p/vfs_addr.c:74
netfs_retry_read_subrequests fs/netfs/read_retry.c:60 [inline]
netfs_retry_reads+0x153a/0x1d00 fs/netfs/read_retry.c:232
netfs_rreq_assess+0x5d3/0x870 fs/netfs/read_collect.c:371
netfs_rreq_terminated+0xe5/0x110 fs/netfs/read_collect.c:407
netfs_retry_reads+0x155e/0x1d00 fs/netfs/read_retry.c:235
netfs_rreq_assess+0x5d3/0x870 fs/netfs/read_collect.c:371
netfs_rreq_terminated+0xe5/0x110 fs/netfs/read_collect.c:407
netfs_retry_reads+0x155e/0x1d00 fs/netfs/read_retry.c:235
netfs_rreq_assess+0x5d3/0x870 fs/netfs/read_collect.c:371
...
netfs_rreq_terminated+0xe5/0x110 fs/netfs/read_collect.c:407
netfs_retry_reads+0x155e/0x1d00 fs/netfs/read_retry.c:235
netfs_rreq_assess+0x5d3/0x870 fs/netfs/read_collect.c:371
netfs_rreq_terminated+0xe5/0x110 fs/netfs/read_collect.c:407
netfs_retry_reads+0x155e/0x1d00 fs/netfs/read_retry.c:235
netfs_rreq_assess+0x5d3/0x870 fs/netfs/read_collect.c:371
netfs_rreq_terminated+0xe5/0x110 fs/netfs/read_collect.c:407
netfs_dispatch_unbuffered_reads fs/netfs/direct_read.c:103 [inline]
netfs_unbuffered_read fs/netfs/direct_read.c:127 [inline]
netfs_unbuffered_read_iter_locked+0x12f6/0x19b0 fs/netfs/direct_read.c:221
netfs_unbuffered_read_iter+0xc5/0x100 fs/netfs/direct_read.c:256
v9fs_file_read_iter+0xbf/0x100 fs/9p/vfs_file.c:361
do_iter_readv_writev+0x614/0x7f0 fs/read_write.c:832
vfs_readv+0x4cf/0x890 fs/read_write.c:1025
do_preadv fs/read_write.c:1142 [inline]
__do_sys_preadv fs/read_write.c:1192 [inline]
__se_sys_preadv fs/read_write.c:1187 [inline]
__x64_sys_preadv+0x22d/0x310 fs/read_write.c:1187
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
Fixes: ee4cdf7ba857 ("netfs: Speed up buffered reading")
Closes: https://syzkaller.appspot.com/bug?extid=1fc6f64c40a9d143cfb6
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241108034020.3695718-1-lizhi.xu@windriver.com/ [1]
Link: https://lore.kernel.org/r/20241213135013.2964079-9-dhowells@redhat.com
Tested-by: syzbot+885c03ad650731743489@syzkaller.appspotmail.com
Suggested-by: Lizhi Xu <lizhi.xu@windriver.com>
cc: Dominique Martinet <asmadeus@codewreck.org>
cc: Jeff Layton <jlayton@kernel.org>
cc: v9fs@lists.linux.dev
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Reported-by: syzbot+885c03ad650731743489@syzkaller.appspotmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs
Pull filesystem fixes from Christian Brauner:
"VFS:
- Fix copy_page_from_iter_atomic() if KMAP_LOCAL_FORCE_MAP=y is set
- Add a get_tree_bdev_flags() helper that allows to modify e.g.,
whether errors are logged into the filesystem context during
superblock creation. This is used by erofs to fix a userspace
regression where an error is currently logged when its used on a
regular file which is an new allowed mode in erofs.
netfs:
- Fix the sysfs debug path in the documentation.
- Fix iov_iter_get_pages*() for folio queues by skipping the page
extracation if we're at the end of a folio.
afs:
- Fix moving subdirectories to different parent directory.
autofs:
- Fix handling of AUTOFS_DEV_IOCTL_TIMEOUT_CMD ioctl in
validate_dev_ioctl(). The actual ioctl number, not the ioctl
command needs to be checked for autofs"
* tag 'vfs-6.12-rc6.fixes' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs:
iov_iter: fix copy_page_from_iter_atomic() if KMAP_LOCAL_FORCE_MAP
autofs: fix thinko in validate_dev_ioctl()
iov_iter: Fix iov_iter_get_pages*() for folio_queue
afs: Fix missing subdir edit when renamed between parent dirs
doc: correcting the debug path for cachefiles
erofs: use get_tree_bdev_flags() to avoid misleading messages
fs/super.c: introduce get_tree_bdev_flags()
|
|
When rename moves an AFS subdirectory between parent directories, the
subdir also needs a bit of editing: the ".." entry needs updating to point
to the new parent (though I don't make use of the info) and the DV needs
incrementing by 1 to reflect the change of content. The server also sends
a callback break notification on the subdirectory if we have one, but we
can take care of recovering the promise next time we access the subdir.
This can be triggered by something like:
mount -t afs %example.com:xfstest.test20 /xfstest.test/
mkdir /xfstest.test/{aaa,bbb,aaa/ccc}
touch /xfstest.test/bbb/ccc/d
mv /xfstest.test/{aaa/ccc,bbb/ccc}
touch /xfstest.test/bbb/ccc/e
When the pathwalk for the second touch hits "ccc", kafs spots that the DV
is incorrect and downloads it again (so the fix is not critical).
Fix this, if the rename target is a directory and the old and new
parents are different, by:
(1) Incrementing the DV number of the target locally.
(2) Editing the ".." entry in the target to refer to its new parent's
vnode ID and uniquifier.
Link: https://lore.kernel.org/r/3340431.1729680010@warthog.procyon.org.uk
Fixes: 63a4681ff39c ("afs: Locally edit directory data for mkdir/create/unlink/...")
cc: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
afs_wake_up_async_call() can incur lock recursion. The problem is that it
is called from AF_RXRPC whilst holding the ->notify_lock, but it tries to
take a ref on the afs_call struct in order to pass it to a work queue - but
if the afs_call is already queued, we then have an extraneous ref that must
be put... calling afs_put_call() may call back down into AF_RXRPC through
rxrpc_kernel_shutdown_call(), however, which might try taking the
->notify_lock again.
This case isn't very common, however, so defer it to a workqueue. The oops
looks something like:
BUG: spinlock recursion on CPU#0, krxrpcio/7001/1646
lock: 0xffff888141399b30, .magic: dead4ead, .owner: krxrpcio/7001/1646, .owner_cpu: 0
CPU: 0 UID: 0 PID: 1646 Comm: krxrpcio/7001 Not tainted 6.12.0-rc2-build3+ #4351
Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014
Call Trace:
<TASK>
dump_stack_lvl+0x47/0x70
do_raw_spin_lock+0x3c/0x90
rxrpc_kernel_shutdown_call+0x83/0xb0
afs_put_call+0xd7/0x180
rxrpc_notify_socket+0xa0/0x190
rxrpc_input_split_jumbo+0x198/0x1d0
rxrpc_input_data+0x14b/0x1e0
? rxrpc_input_call_packet+0xc2/0x1f0
rxrpc_input_call_event+0xad/0x6b0
rxrpc_input_packet_on_conn+0x1e1/0x210
rxrpc_input_packet+0x3f2/0x4d0
rxrpc_io_thread+0x243/0x410
? __pfx_rxrpc_io_thread+0x10/0x10
kthread+0xcf/0xe0
? __pfx_kthread+0x10/0x10
ret_from_fork+0x24/0x40
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1a/0x30
</TASK>
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/1394602.1729162732@warthog.procyon.org.uk
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
In afs_wait_for_operation(), we set transcribe the call responded flag to
the server record that we used after doing the fileserver iteration loop -
but it's possible to exit the loop having had a response from the server
that we've discarded (e.g. it returned an abort or we started receiving
data, but the call didn't complete).
This means that op->server might be NULL, but we don't check that before
attempting to set the server flag.
Fixes: 98f9fda2057b ("afs: Fold the afs_addr_cursor struct in")
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20240923150756.902363-7-dhowells@redhat.com
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
The struct afs_address_list and the function prototype
afs_put_address_list() are not used anymore and can be removed. Remove
them.
Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20240911095046.3749-2-thorsten.blum@toblux.com/
Link: https://lore.kernel.org/r/20240923150756.902363-5-dhowells@redhat.com
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
A return code of 0 from afs_wait_for_one_fs_probe is an indication
that the endpoint state attached to the operation is stale and has
been superseded. In that case the iteration needs to be restarted
so that the newer probe result state gets used.
Failure to do so can result in an tight infinite loop around the
iterate_address label, where all addresses are thought to be responsive
and have been tried, with nothing to refresh the endpoint state.
Fixes: 495f2ae9e355 ("afs: Fix fileserver rotation")
Reported-by: Markus Suvanto <markus.suvanto@gmail.com>
Link: https://lists.infradead.org/pipermail/linux-afs/2024-July/008628.html
cc: linux-afs@lists.infradead.org
Signed-off-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20240906134019.131553-1-marc.dionne@auristor.com/
Link: https://lore.kernel.org/r/20240923150756.902363-6-dhowells@redhat.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
afs_retry_request() is supposed to be pointed to by the afs_req_ops netfs
operations table, but the pointer got lost somewhere. The function is used
during writeback to rotate through the authentication keys that were in
force when the file was modified locally.
Fix this by adding the pointer to the function.
Fixes: 1ecb146f7cd8 ("netfs, afs: Use writeback retry to deal with alternate keys")
Reported-by: Dr. David Alan Gilbert <linux@treblig.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/1690847.1726346402@warthog.procyon.org.uk
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-afs@lists.infradead.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
Improve the efficiency of buffered reads in a number of ways:
(1) Overhaul the algorithm in general so that it's a lot more compact and
split the read submission code between buffered and unbuffered
versions. The unbuffered version can be vastly simplified.
(2) Read-result collection is handed off to a work queue rather than being
done in the I/O thread. Multiple subrequests can be processes
simultaneously.
(3) When a subrequest is collected, any folios it fully spans are
collected and "spare" data on either side is donated to either the
previous or the next subrequest in the sequence.
Notes:
(*) Readahead expansion is massively slows down fio, presumably because it
causes a load of extra allocations, both folio and xarray, up front
before RPC requests can be transmitted.
(*) RDMA with cifs does appear to work, both with SIW and RXE.
(*) PG_private_2-based reading and copy-to-cache is split out into its own
file and altered to use folio_queue. Note that the copy to the cache
now creates a new write transaction against the cache and adds the
folios to be copied into it. This allows it to use part of the
writeback I/O code.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/20240814203850.2240469-20-dhowells@redhat.com/ # v2
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
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Perform AFS read subrequests in a work item rather than in the calling
thread. For normal buffered reads, this will allow the calling thread to
copy data from the pagecache to the application at the same time as the
demarshalling thread is shovelling data from skbuffs into the pagecache.
This will also allow the RA mark to trigger a new read before we've
finished shovelling the data from the current one.
Note: This would be a bit safer if the FS.FetchData RPC ops returned the
metadata (including the data version number) before returning the data.
This would allow me to flush the pagecache before installing the new data.
In future, it may be possible to asynchronously flush the pagecache either
side of the region being read.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-afs@lists.infradead.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/20240814203850.2240469-19-dhowells@redhat.com/ # v2
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Move max_len/max_nr_segs from struct netfs_io_subrequest to struct
netfs_io_stream as we only issue one subreq at a time and then don't need
these values again for that subreq unless and until we have to retry it -
in which case we want to renegotiate them.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/20240814203850.2240469-8-dhowells@redhat.com/ # v2
Signed-off-by: Christian Brauner <brauner@kernel.org>
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At the end of an kAFS RPC operation, there is an "edit" phase (originally
intended for post-directory modification ops to edit the local image) that
the setattr VFS op uses to fix up the pagecache if the RPC that requested
truncation of a file was successful.
afs_setattr_edit_file() calls truncate_setsize() which sets i_size, expands
the pagecache if needed and truncates the pagecache. The first two of
those, however, are redundant as they've already been done by
afs_setattr_success() under the io_lock and the first is also done under
the callback lock (cb_lock).
Fix afs_setattr_edit_file() to call truncate_pagecache() instead (which is
called by truncate_setsize(), thereby skipping the redundant parts.
Fixes: 100ccd18bb41 ("netfs: Optimise away reads above the point at which there can be no data")
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20240823200819.532106-3-dhowells@redhat.com
cc: Matthew Wilcox (Oracle) <willy@infradead.org>
cc: Pankaj Raghav <p.raghav@samsung.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
cc: netfs@lists.linux.dev
cc: linux-mm@kvack.org
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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If a program is watching a file on a 9p mount, it won't see any change in
size if the file being exported by the server is changed directly in the
source filesystem, presumably because 9p doesn't have change notifications,
and because netfs skips the reads if the file is empty.
Fix this by attempting to read the full size specified when a DIO read is
requested (such as when 9p is operating in unbuffered mode) and dealing
with a short read if the EOF was less than the expected read.
To make this work, filesystems using netfslib must not set
NETFS_SREQ_CLEAR_TAIL if performing a DIO read where that read hit the EOF.
I don't want to mandatorily clear this flag in netfslib for DIO because,
say, ceph might make a read from an object that is not completely filled,
but does not reside at the end of file - and so we need to clear the
excess.
This can be tested by watching an empty file over 9p within a VM (such as
in the ktest framework):
while true; do read content; if [ -n "$content" ]; then echo $content; break; fi; done < /host/tmp/foo
then writing something into the empty file. The watcher should immediately
display the file content and break out of the loop. Without this fix, it
remains in the loop indefinitely.
Fixes: 80105ed2fd27 ("9p: Use netfslib read/write_iter")
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218916
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/1229195.1723211769@warthog.procyon.org.uk
cc: Eric Van Hensbergen <ericvh@kernel.org>
cc: Latchesar Ionkov <lucho@ionkov.net>
cc: Christian Schoenebeck <linux_oss@crudebyte.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Ilya Dryomov <idryomov@gmail.com>
cc: Steve French <sfrench@samba.org>
cc: Paulo Alcantara <pc@manguebit.com>
cc: Trond Myklebust <trond.myklebust@hammerspace.com>
cc: v9fs@lists.linux.dev
cc: linux-afs@lists.infradead.org
cc: ceph-devel@vger.kernel.org
cc: linux-cifs@vger.kernel.org
cc: linux-nfs@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- In the series "mm: Avoid possible overflows in dirty throttling" Jan
Kara addresses a couple of issues in the writeback throttling code.
These fixes are also targetted at -stable kernels.
- Ryusuke Konishi's series "nilfs2: fix potential issues related to
reserved inodes" does that. This should actually be in the
mm-nonmm-stable tree, along with the many other nilfs2 patches. My
bad.
- More folio conversions from Kefeng Wang in the series "mm: convert to
folio_alloc_mpol()"
- Kemeng Shi has sent some cleanups to the writeback code in the series
"Add helper functions to remove repeated code and improve readability
of cgroup writeback"
- Kairui Song has made the swap code a little smaller and a little
faster in the series "mm/swap: clean up and optimize swap cache
index".
- In the series "mm/memory: cleanly support zeropage in
vm_insert_page*(), vm_map_pages*() and vmf_insert_mixed()" David
Hildenbrand has reworked the rather sketchy handling of the use of
the zeropage in MAP_SHARED mappings. I don't see any runtime effects
here - more a cleanup/understandability/maintainablity thing.
- Dev Jain has improved selftests/mm/va_high_addr_switch.c's handling
of higher addresses, for aarch64. The (poorly named) series is
"Restructure va_high_addr_switch".
- The core TLB handling code gets some cleanups and possible slight
optimizations in Bang Li's series "Add update_mmu_tlb_range() to
simplify code".
- Jane Chu has improved the handling of our
fake-an-unrecoverable-memory-error testing feature MADV_HWPOISON in
the series "Enhance soft hwpoison handling and injection".
- Jeff Johnson has sent a billion patches everywhere to add
MODULE_DESCRIPTION() to everything. Some landed in this pull.
- In the series "mm: cleanup MIGRATE_SYNC_NO_COPY mode", Kefeng Wang
has simplified migration's use of hardware-offload memory copying.
- Yosry Ahmed performs more folio API conversions in his series "mm:
zswap: trivial folio conversions".
- In the series "large folios swap-in: handle refault cases first",
Chuanhua Han inches us forward in the handling of large pages in the
swap code. This is a cleanup and optimization, working toward the end
objective of full support of large folio swapin/out.
- In the series "mm,swap: cleanup VMA based swap readahead window
calculation", Huang Ying has contributed some cleanups and a possible
fixlet to his VMA based swap readahead code.
- In the series "add mTHP support for anonymous shmem" Baolin Wang has
taught anonymous shmem mappings to use multisize THP. By default this
is a no-op - users must opt in vis sysfs controls. Dramatic
improvements in pagefault latency are realized.
- David Hildenbrand has some cleanups to our remaining use of
page_mapcount() in the series "fs/proc: move page_mapcount() to
fs/proc/internal.h".
- David also has some highmem accounting cleanups in the series
"mm/highmem: don't track highmem pages manually".
- Build-time fixes and cleanups from John Hubbard in the series
"cleanups, fixes, and progress towards avoiding "make headers"".
- Cleanups and consolidation of the core pagemap handling from Barry
Song in the series "mm: introduce pmd|pte_needs_soft_dirty_wp helpers
and utilize them".
- Lance Yang's series "Reclaim lazyfree THP without splitting" has
reduced the latency of the reclaim of pmd-mapped THPs under fairly
common circumstances. A 10x speedup is seen in a microbenchmark.
It does this by punting to aother CPU but I guess that's a win unless
all CPUs are pegged.
- hugetlb_cgroup cleanups from Xiu Jianfeng in the series
"mm/hugetlb_cgroup: rework on cftypes".
- Miaohe Lin's series "Some cleanups for memory-failure" does just that
thing.
- Someone other than SeongJae has developed a DAMON feature in Honggyu
Kim's series "DAMON based tiered memory management for CXL memory".
This adds DAMON features which may be used to help determine the
efficiency of our placement of CXL/PCIe attached DRAM.
- DAMON user API centralization and simplificatio work in SeongJae
Park's series "mm/damon: introduce DAMON parameters online commit
function".
- In the series "mm: page_type, zsmalloc and page_mapcount_reset()"
David Hildenbrand does some maintenance work on zsmalloc - partially
modernizing its use of pageframe fields.
- Kefeng Wang provides more folio conversions in the series "mm: remove
page_maybe_dma_pinned() and page_mkclean()".
- More cleanup from David Hildenbrand, this time in the series
"mm/memory_hotplug: use PageOffline() instead of PageReserved() for
!ZONE_DEVICE". It "enlightens memory hotplug more about PageOffline()
pages" and permits the removal of some virtio-mem hacks.
- Barry Song's series "mm: clarify folio_add_new_anon_rmap() and
__folio_add_anon_rmap()" is a cleanup to the anon folio handling in
preparation for mTHP (multisize THP) swapin.
- Kefeng Wang's series "mm: improve clear and copy user folio"
implements more folio conversions, this time in the area of large
folio userspace copying.
- The series "Docs/mm/damon/maintaier-profile: document a mailing tool
and community meetup series" tells people how to get better involved
with other DAMON developers. From SeongJae Park.
- A large series ("kmsan: Enable on s390") from Ilya Leoshkevich does
that.
- David Hildenbrand sends along more cleanups, this time against the
migration code. The series is "mm/migrate: move NUMA hinting fault
folio isolation + checks under PTL".
- Jan Kara has found quite a lot of strangenesses and minor errors in
the readahead code. He addresses this in the series "mm: Fix various
readahead quirks".
- SeongJae Park's series "selftests/damon: test DAMOS tried regions and
{min,max}_nr_regions" adds features and addresses errors in DAMON's
self testing code.
- Gavin Shan has found a userspace-triggerable WARN in the pagecache
code. The series "mm/filemap: Limit page cache size to that supported
by xarray" addresses this. The series is marked cc:stable.
- Chengming Zhou's series "mm/ksm: cmp_and_merge_page() optimizations
and cleanup" cleans up and slightly optimizes KSM.
- Roman Gushchin has separated the memcg-v1 and memcg-v2 code - lots of
code motion. The series (which also makes the memcg-v1 code
Kconfigurable) are "mm: memcg: separate legacy cgroup v1 code and put
under config option" and "mm: memcg: put cgroup v1-specific memcg
data under CONFIG_MEMCG_V1"
- Dan Schatzberg's series "Add swappiness argument to memory.reclaim"
adds an additional feature to this cgroup-v2 control file.
- The series "Userspace controls soft-offline pages" from Jiaqi Yan
permits userspace to stop the kernel's automatic treatment of
excessive correctable memory errors. In order to permit userspace to
monitor and handle this situation.
- Kefeng Wang's series "mm: migrate: support poison recover from
migrate folio" teaches the kernel to appropriately handle migration
from poisoned source folios rather than simply panicing.
- SeongJae Park's series "Docs/damon: minor fixups and improvements"
does those things.
- In the series "mm/zsmalloc: change back to per-size_class lock"
Chengming Zhou improves zsmalloc's scalability and memory
utilization.
- Vivek Kasireddy's series "mm/gup: Introduce memfd_pin_folios() for
pinning memfd folios" makes the GUP code use FOLL_PIN rather than
bare refcount increments. So these paes can first be moved aside if
they reside in the movable zone or a CMA block.
- Andrii Nakryiko has added a binary ioctl()-based API to
/proc/pid/maps for much faster reading of vma information. The series
is "query VMAs from /proc/<pid>/maps".
- In the series "mm: introduce per-order mTHP split counters" Lance
Yang improves the kernel's presentation of developer information
related to multisize THP splitting.
- Michael Ellerman has developed the series "Reimplement huge pages
without hugepd on powerpc (8xx, e500, book3s/64)". This permits
userspace to use all available huge page sizes.
- In the series "revert unconditional slab and page allocator fault
injection calls" Vlastimil Babka removes a performance-affecting and
not very useful feature from slab fault injection.
* tag 'mm-stable-2024-07-21-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (411 commits)
mm/mglru: fix ineffective protection calculation
mm/zswap: fix a white space issue
mm/hugetlb: fix kernel NULL pointer dereference when migrating hugetlb folio
mm/hugetlb: fix possible recursive locking detected warning
mm/gup: clear the LRU flag of a page before adding to LRU batch
mm/numa_balancing: teach mpol_to_str about the balancing mode
mm: memcg1: convert charge move flags to unsigned long long
alloc_tag: fix page_ext_get/page_ext_put sequence during page splitting
lib: reuse page_ext_data() to obtain codetag_ref
lib: add missing newline character in the warning message
mm/mglru: fix overshooting shrinker memory
mm/mglru: fix div-by-zero in vmpressure_calc_level()
mm/kmemleak: replace strncpy() with strscpy()
mm, page_alloc: put should_fail_alloc_page() back behing CONFIG_FAIL_PAGE_ALLOC
mm, slab: put should_failslab() back behind CONFIG_SHOULD_FAILSLAB
mm: ignore data-race in __swap_writepage
hugetlbfs: ensure generic_hugetlb_get_unmapped_area() returns higher address than mmap_min_addr
mm: shmem: rename mTHP shmem counters
mm: swap_state: use folio_alloc_mpol() in __read_swap_cache_async()
mm/migrate: putback split folios when numa hint migration fails
...
|
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folio_file_pos is only needed for mixed usage of page cache and swap
cache, for pure page cache usage, the caller can just use folio_pos
instead.
It can't be a swap cache page here. Swap mapping may only call into fs
through swap_rw and that is not supported for afs. So just drop it and
use folio_pos instead.
Link: https://lkml.kernel.org/r/20240521175854.96038-6-ryncsn@gmail.com
Signed-off-by: Kairui Song <kasong@tencent.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Marc Dionne <marc.dionne@auristor.com>
Cc: Anna Schumaker <anna@kernel.org>
Cc: Barry Song <v-songbaohua@oppo.com>
Cc: Chao Yu <chao@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: NeilBrown <neilb@suse.de>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Xiubo Li <xiubli@redhat.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Replace a comma between expression statements by a semicolon.
Signed-off-by: Chen Ni <nichen@iscas.ac.cn>
Link: https://lore.kernel.org/r/20240702024055.1411407-1-nichen@iscas.ac.cn/
Link: https://lore.kernel.org/r/20240702024055.1411407-1-nichen@iscas.ac.cn
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
There's a problem in 9p's interaction with netfslib whereby a crash occurs
because the 9p_fid structs get forcibly destroyed during client teardown
(without paying attention to their refcounts) before netfslib has finished
with them. However, it's not a simple case of deferring the clunking that
p9_fid_put() does as that requires the p9_client record to still be
present.
The problem is that netfslib has to unlock pages and clear the IN_PROGRESS
flag before destroying the objects involved - including the fid - and, in
any case, nothing checks to see if writeback completed barring looking at
the page flags.
Fix this by keeping a count of outstanding I/O requests (of any type) and
waiting for it to quiesce during inode eviction.
Reported-by: syzbot+df038d463cca332e8414@syzkaller.appspotmail.com
Link: https://lore.kernel.org/all/0000000000005be0aa061846f8d6@google.com/
Reported-by: syzbot+d7c7a495a5e466c031b6@syzkaller.appspotmail.com
Link: https://lore.kernel.org/all/000000000000b86c5e06130da9c6@google.com/
Reported-by: syzbot+1527696d41a634cc1819@syzkaller.appspotmail.com
Link: https://lore.kernel.org/all/000000000000041f960618206d7e@google.com/
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/755891.1716560771@warthog.procyon.org.uk
Tested-by: syzbot+d7c7a495a5e466c031b6@syzkaller.appspotmail.com
Reviewed-by: Dominique Martinet <asmadeus@codewreck.org>
cc: Eric Van Hensbergen <ericvh@kernel.org>
cc: Latchesar Ionkov <lucho@ionkov.net>
cc: Christian Schoenebeck <linux_oss@crudebyte.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: Steve French <sfrench@samba.org>
cc: Hillf Danton <hdanton@sina.com>
cc: v9fs@lists.linux.dev
cc: linux-afs@lists.infradead.org
cc: linux-cifs@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Reported-and-tested-by: syzbot+d7c7a495a5e466c031b6@syzkaller.appspotmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
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Don't cross a mountpoint that explicitly specifies a backup volume
(target is <vol>.backup) when starting from a backup volume.
It it not uncommon to mount a volume's backup directly in the volume
itself. This can cause tools that are not paying attention to get
into a loop mounting the volume onto itself as they attempt to
traverse the tree, leading to a variety of problems.
This doesn't prevent the general case of loops in a sequence of
mountpoints, but addresses a common special case in the same way
as other afs clients.
Reported-by: Jan Henrik Sylvester <jan.henrik.sylvester@uni-hamburg.de>
Link: http://lists.infradead.org/pipermail/linux-afs/2024-May/008454.html
Reported-by: Markus Suvanto <markus.suvanto@gmail.com>
Link: http://lists.infradead.org/pipermail/linux-afs/2024-February/008074.html
Signed-off-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/768760.1716567475@warthog.procyon.org.uk
Reviewed-by: Jeffrey Altman <jaltman@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull netfs updates from Christian Brauner:
"This reworks the netfslib writeback implementation so that pages read
from the cache are written to the cache through ->writepages(),
thereby allowing the fscache page flag to be retired.
The reworking also:
- builds on top of the new writeback_iter() infrastructure
- makes it possible to use vectored write RPCs as discontiguous
streams of pages can be accommodated
- makes it easier to do simultaneous content crypto and stream
division
- provides support for retrying writes and re-dividing a stream
- replaces the ->launder_folio() op, so that ->writepages() is used
instead
- uses mempools to allocate the netfs_io_request and
netfs_io_subrequest structs to avoid allocation failure in the
writeback path
Some code that uses the fscache page flag is retained for
compatibility purposes with nfs and ceph. The code is switched to
using the synonymous private_2 label instead and marked with
deprecation comments.
The merge commit contains additional details on the new algorithm that
I've left out of here as it would probably be excessively detailed.
On top of the netfslib infrastructure this contains the work to
convert cifs over to netfslib"
* tag 'vfs-6.10.netfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (38 commits)
cifs: Enable large folio support
cifs: Remove some code that's no longer used, part 3
cifs: Remove some code that's no longer used, part 2
cifs: Remove some code that's no longer used, part 1
cifs: Cut over to using netfslib
cifs: Implement netfslib hooks
cifs: Make add_credits_and_wake_if() clear deducted credits
cifs: Add mempools for cifs_io_request and cifs_io_subrequest structs
cifs: Set zero_point in the copy_file_range() and remap_file_range()
cifs: Move cifs_loose_read_iter() and cifs_file_write_iter() to file.c
cifs: Replace the writedata replay bool with a netfs sreq flag
cifs: Make wait_mtu_credits take size_t args
cifs: Use more fields from netfs_io_subrequest
cifs: Replace cifs_writedata with a wrapper around netfs_io_subrequest
cifs: Replace cifs_readdata with a wrapper around netfs_io_subrequest
cifs: Use alternative invalidation to using launder_folio
netfs, afs: Use writeback retry to deal with alternate keys
netfs: Miscellaneous tidy ups
netfs: Remove the old writeback code
netfs: Cut over to using new writeback code
...
|
|
Fix the fileserver rotation code in a couple of ways:
(1) op->server_states is an array, not a pointer to a single record, so
fix the places that access it to index it.
(2) In the places that go through an address list to work out which one
has the best priority, fix the loops to skip known failed addresses.
Without this, the rotation algorithm may get stuck on addresses that are
inaccessible or don't respond.
This can be triggered manually by finding a server that advertises a
non-routable address and giving it a higher priority, eg.:
echo "add udp 192.168.0.0/16 3000" >/proc/fs/afs/addr_prefs
if the server, say, includes the address 192.168.7.7 in its address list,
and then attempting to access a volume on that server.
Fixes: 495f2ae9e355 ("afs: Fix fileserver rotation")
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/4005300.1712309731@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/998836.1714746152@warthog.procyon.org.uk
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
Use a hook in the new writeback code's retry algorithm to rotate the keys
once all the outstanding subreqs have failed rather than doing it
separately on each subreq.
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: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
|
