FUSE_NOTIFY_INC_EPOCH invalidates dentries, but does not invalidate cached
readdir results. A process with cwd inside a FUSE mount can therefore
observe stale readdir(".") output after an epoch bump.
Fix this by recording epoch in the readdir cache and checking it on reuse.
Minimal reproducer:
- mount a tiny FUSE fs with an empty root directory
- on opendir, enable fi->cache_readdir and fi->keep_cache
- chdir into the mount and call readdir(".") to populate readdir cache
- make the FUSE server report one file in the root directory
- send only FUSE_NOTIFY_INC_EPOCH
- call readdir(".") again; before this change it stays stale, after this
change it sees the new file
Fixes: 2396356a94 ("fuse: add more control over cache invalidation behaviour")
Signed-off-by: Jun Wu <quark@meta.com>
Reviewed-by: Joanne Koong <joannelkoong@gmail.com>
Reviewed-by: Luis Henriques <luis@igalia.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
This fixe does page cache invalidation after DIO and async DIO writes for
both O_DIRECT and FOPEN_DIRECT_IO cases.
Commit b359af8275 ("fuse: Invalidate the page cache after FOPEN_DIRECT_IO
write") fixed xfstests generic/209 for DIO writes in the FOPEN_DIRECT_IO
path. DIO writes without FOPEN_DIRECT_IO are already handled by
generic_file_direct_write().
However, async DIO writes (xfstests generic/451) remain unhandled.
After this fix:
- Async write with FUSE_ASYNC_DIO:
invalidate in fuse_aio_invalidate_worker()
- Otherwise (Sync or async write without FUSE_ASYNC_DIO):
- With FOPEN_DIRECT_IO:
invalidate in fuse_direct_write_iter()
- Without FOPEN_DIRECT_IO:
invalidate in generic_file_direct_write()
Workqueue is required for async write invalidation to prevent deadlock:
calling it directly in the I/O end routine (which is in fuse worker thread
context) can block on a folio lock held by a buffered I/O thread waiting
for the same fuse worker thread.
Co-developed-by: Jingbo Xu <jefflexu@linux.alibaba.com>
Signed-off-by: Jingbo Xu <jefflexu@linux.alibaba.com>
Signed-off-by: Cheng Ding <cding@ddn.com>
Reviewed-by: Jingbo Xu <jefflexu@linux.alibaba.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Some fuse source files are missing SPDX-License-Identifier
lines. Add appropriate IDs to these files, and remove old
license references from the headers.
Signed-off-by: Tim Bird <tim.bird@sony.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
FUSE backing files only need a stable snapshot of the current credentials
for later backing-file I/O. prepare_creds() allocates a mutable copy and
can fail, but this code never modifies or commits the result.
Use get_current_cred() instead and store it as a const pointer. This
matches the rest of the backing-file helpers and avoids an unnecessary
allocation and failure path.
Signed-off-by: GuoHan Zhao <zhaoguohan@kylinos.cn>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
When the contents of a directory is modified, some of its attributes may
also change, so they need to be invalidated. But this isn't the case
for every attribute. For instance, unlinking or creating a file doesn't
change the uid/gid of its parent directory.
This can cause unnecessary FUSE_GETATTRs to be sent to user-space. For
example, fuse_permission() checks if mode, uid, and gid are valid and
will issue a FUSE_GETATTR if they're not, which results in an extra
FUSE_GETATTR request for every FUSE_UNLINK when removing files in the
same directory.
Signed-off-by: Konrad Sztyber <ksztyber@nvidia.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Convert many comments to kernel-doc format to eliminate around 20
kernel-doc warnings like these:
Warning: fs/fuse/fuse_i.h:374 This comment starts with '/**', but isn't a kernel-doc comment. Refer to Documentation/doc-guide/kernel-doc.rst
* A Fuse connection.
Warning: fs/fuse/fuse_i.h:817 This comment starts with '/**', but isn't a kernel-doc comment. Refer to Documentation/doc-guide/kernel-doc.rst
* Get a filled in inode
Warning: fs/fuse/fuse_i.h:859 This comment starts with '/**', but isn't a kernel-doc comment. Refer to Documentation/doc-guide/kernel-doc.rst
* Send RELEASE or RELEASEDIR request
and more like this.
Also add struct member and function parameter descriptions to avoid
these warnings:
Warning: fs/fuse/fuse_i.h:1071 struct member 'epoch_work' not described in 'fuse_conn'
Warning: fs/fuse/fuse_i.h:1071 struct member 'rcu' not described in 'fuse_conn'
Warning: fs/fuse/fuse_i.h:1423 function parameter 'fc' not described in 'fuse_reverse_inval_inode'
Warning: fs/fuse/fuse_i.h:1423 function parameter 'nodeid' not described in 'fuse_reverse_inval_inode'
Warning: fs/fuse/fuse_i.h:1423 function parameter 'offset' not described in 'fuse_reverse_inval_inode'
Warning: fs/fuse/fuse_i.h:1423 function parameter 'len' not described in 'fuse_reverse_inval_inode'
Warning: fs/fuse/fuse_i.h:1436 function parameter 'fc' not described in 'fuse_reverse_inval_entry'
Warning: fs/fuse/fuse_i.h:1436 function parameter 'parent_nodeid' not described in 'fuse_reverse_inval_entry'
Warning: fs/fuse/fuse_i.h:1436 function parameter 'child_nodeid' not described in 'fuse_reverse_inval_entry'
Warning: fs/fuse/fuse_i.h:1436 function parameter 'name' not described in 'fuse_reverse_inval_entry'
Warning: fs/fuse/fuse_i.h:1436 function parameter 'flags' not described in 'fuse_reverse_inval_entry'
Convert struct fuse_file, struct fuse_submount_lookup, struct fuse_inode,
and struct fuse_conn to kernel-doc.
Convert these to plain comments:
Warning: fs/fuse/fuse_i.h:1423 expecting prototype for File(). Prototype was for fuse_reverse_inval_inode() instead
Warning: fs/fuse/fuse_i.h:1436 expecting prototype for File(). Prototype was for fuse_reverse_inval_entry() instead
Change some "/**" to "/*" since they are not kernel-doc comments.
The changes above fix most kernel-doc warnings in this file but
these warnings are not fixed and still remain:
Warning: fs/fuse/fuse_i.h:1428 No description found for return value of 'fuse_fill_super_common'
Warning: fs/fuse/fuse_i.h:1455 No description found for return value of 'fuse_ctl_add_conn'
Binary build output is the same before and after these changes.
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Move a couple of function declarations from fuse_i.h to dev.h and
fuse_dev_i.h.
Add fuse_conn_get_id() helper that retrieves the connection ID (s_dev) from
fuse_conn.
With the exception of cuse.c, virtio_fs.c and trace.c source files now
either include fuse_i.h or fuse_dev_i/dev_uring_i.h but not both.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Create a new source file: req.c and add the request sending entry
functions:
__fuse_simple_request()
fuse_simple_background()
fuse_simple_notify_reply()
Introduce transport layer sending functions that are called by the
respective fs layer function:
fuse_chan_send()
fuse_chan_send_bg()
fuse_chan_send_notify_reply()
Move calculation of request header fields uid, gid and pid from
fuse_get_req() and fuse_force_creads() to a new helper: fuse_fill_creds().
These fileds are now passed to the transport layer via struct fuse_args.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
- rename fuse_abort_conn() to fuse_chan_abort(), pass fuse_chan pointer
instead of fuse_conn
- pass an abort_with_err argument that tells fuse_dev_(read|write) to
return with ECONNABORTED instead of ENODEV
- move fc->aborted to fch->abort_with_err
- rename fuse_wait_aborted() to fuse_chan_wait_aborted()
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Add helpers (get and set functions mainly) that cleanly separate the
layers.
Remove #include "fuse_dev_i.h" from:
- inode.c
- file.c
- control.c
Remove #include "dev_uring_i.h" from inode.c.
[Li Wang: drop redundant initializer in process_init_limits()]
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
And document which members they protect.
end_polls() is called with both, outer fch->lock is probably unnecessary,
but doesn't hurt for now.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Move the 'fiq' member from fuse_conn to fuse_chan.
Move iqueue related structure definitions and function declarations from
"fuse_i.h" to "fuse_dev_i.h".
Add a fuse_dev_chan_new() helper, that returns a fuse_chan initialized with
the fuse_dev_fiq_ops.
Add a fuse_chan_release() function, that calls fiq->ops->release().
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
The goal is to separate transport layer stuff out from struct fuse_conn,
leaving just the filesystem related members.
Add a new object referenced from fuse_conn. This patch just implements the
allocation and freeing of this object.
Following patches will move transport related members from fuse_conn to
fuse_chan.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
This marks the first step in cleanly separating the transport layer from
the filesystem layer.
Add "dev.h", which will contain the interface definition for the transport
layer.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
- fuse_mutex is not needed for device cloning, because fuse_dev_install()
uses cmpxcg() to set fud->fc, which prevents races between clone/mount
or clone/clone. This makes the logic simpler
- Drop fc->dev_count. This is only used to check in release if the device
is the last clone, but checking list_empty(&fc->devices) is equivalent
after removing the released device from the list. Removing the fuse_dev
before calling fuse_abort_conn() is okay, since the processing and io
lists are now empty for this device.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
With the new mount API the sequence of syscalls would be:
fs_fd = fsopen("fuse", 0);
snprintf(opt, sizeof(opt), "%i", devfd);
fsconfig(fs_fd, FSCONFIG_SET_STRING, "fd", opt, 0);
/* ... */
fsconfig(fs_fd, FSCONFIG_CMD_CREATE, 0, 0, 0);
Current mount code just stores the value of devfd in the fs_context and
uses it in during FSCONFIG_CMD_CREATE, which is inelegant.
Instead grab a reference to the underlying fuse_dev, and use that during
the filesystem creation.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
This will make it possible to grab the fuse_dev and subsequently release
the file that it came from.
In the above case, fud->fc will be set to FUSE_DEV_FC_DISCONNECTED to
indicate that this is no longer a functional device.
When trying to assign an fc to such a disconnected fuse_dev, the fc is set
to the disconnected state.
Use atomic operations xchg() and cmpxchg() to prevent races.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Allocate struct fuse_dev when opening the device. This means that unlike
before, ->private_data is always set to a valid pointer.
The use of USE_DEV_SYNC_INIT magic pointer for the private_data is now
replaced with a simple bool sync_init member.
If sync INIT is not set, I/O on the device returns error before mount.
Keep this behavior by checking for the ->fc member. If fud->fc is set, the
mount has succeeded. Testing this used READ_ONCE(file->private_data) and
smp_mb() to try and provide the necessary semantics. Switch this to
smp_store_release() and smp_load_acquire().
Setting fud->fc is protected by fuse_mutex, this is unchanged.
Will need this later so the /dev/fuse open file reference is not held
during FSCONFIG_CMD_CREATE.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
When sync init is used and the server exits for some reason (error, crash)
while processing FUSE_INIT, the filesystem creation will hang. The reason
is that while all other threads will exit, the mounting thread (or process)
will keep the device fd open, which will prevent an abort from happening.
This is a regression from the async mount case, where the mount was done
first, and the FUSE_INIT processing afterwards, in which case there's no
such recursive syscall keeping the fd open.
Fixes: dfb84c3307 ("fuse: allow synchronous FUSE_INIT")
Cc: stable@vger.kernel.org # v6.18
Reviewed-by: Joanne Koong <joannelkoong@gmail.com>
Reviewed-by: Bernd Schubert <bernd@bsbernd.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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Merge tag 'fuse-update-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse
Pull fuse updates from Miklos Szeredi:
- Add mechanism for cleaning out unused, stale dentries; controlled via
a module option (Luis Henriques)
- Fix various bugs
- Cleanups
* tag 'fuse-update-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
fuse: Uninitialized variable in fuse_epoch_work()
fuse: fix io-uring list corruption for terminated non-committed requests
fuse: signal that a fuse inode should exhibit local fs behaviors
fuse: Always flush the page cache before FOPEN_DIRECT_IO write
fuse: Invalidate the page cache after FOPEN_DIRECT_IO write
fuse: rename 'namelen' to 'namesize'
fuse: use strscpy instead of strcpy
fuse: refactor fuse_conn_put() to remove negative logic.
fuse: new work queue to invalidate dentries from old epochs
fuse: new work queue to periodically invalidate expired dentries
dcache: export shrink_dentry_list() and add new helper d_dispose_if_unused()
fuse: add WARN_ON and comment for RCU revalidate
fuse: Fix whitespace for fuse_uring_args_to_ring() comment
fuse: missing copy_finish in fuse-over-io-uring argument copies
fuse: fix readahead reclaim deadlock
Create a new fuse inode flag that indicates that the kernel should
implement various local filesystem behaviors instead of passing vfs
commands straight through to the fuse server and expecting the server to
do all the work. For example, this means that we'll use the kernel to
transform some ACL updates into mode changes, and later to do
enforcement of the immutable and append iflags.
Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Joanne Koong <joannelkoong@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
With the infrastructure introduced to periodically invalidate expired
dentries, it is now possible to add an extra work queue to invalidate
dentries when an epoch is incremented. This work queue will only be
triggered when the 'inval_wq' parameter is set.
Signed-off-by: Luis Henriques <luis@igalia.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
This patch adds the necessary infrastructure to keep track of all dentries
created for FUSE file systems. A set of rbtrees, protected by hashed
locks, will be used to keep all these dentries sorted by expiry time.
A new module parameter 'inval_wq' is also added. When set, it will start
a work queue which will periodically invalidate expired dentries. The
value of this new parameter is the period, in seconds, for this work
queue. Once this parameter is set, every new dentry will be added to one
of the rbtrees.
When the work queue is executed, it will check all the rbtrees and will
invalidate those dentries that have timed-out.
The work queue period can not be smaller than 5 seconds, but can be
disabled by setting 'inval_wq' to zero (which is the default).
Signed-off-by: Luis Henriques <luis@igalia.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Now that fuse is integrated with iomap for read/readahead, we can remove
the workaround that was added in commit bd24d2108e ("fuse: fix fuseblk
i_blkbits for iomap partial writes"), which was previously needed to
avoid a race condition where an iomap partial write may be overwritten
by a read if blocksize < PAGE_SIZE. Now that fuse does iomap
read/readahead, this is protected against since there is granular
uptodate tracking of blocks, which means this workaround can be removed.
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Tested-by: syzbot@syzkaller.appspotmail.com
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
iomap support for fuse is also going to want the ability to attach
backing files to a fuse filesystem. Move the fuse_backing code into a
separate file so that both can use it.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
The fuse_request_{send,end} tracepoints capture the value of
req->in.h.unique in the trace output. It would be really nice if we
could use this to match a request to its response for debugging and
latency analysis, but the call to trace_fuse_request_send occurs before
the unique id has been set:
fuse_request_send: connection 8388608 req 0 opcode 1 (FUSE_LOOKUP) len 107
fuse_request_end: connection 8388608 req 6 len 16 error -2
(Notice that req moves from 0 to 6)
Move the callsites to trace_fuse_request_send to after the unique id has
been set by introducing a helper to do that for standard fuse_req
requests. FUSE_FORGET requests are not covered by this because they
appear to be synthesized into the event stream without a fuse_req
object and are never replied to.
Requests that are aborted without ever having been submitted to the fuse
server retain the behavior that only the fuse_request_end tracepoint
shows up in the trace record, and with req==0.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Some fuse servers need to prune their caches, which can only be done if the
kernel's own dentry/inode caches are pruned first to avoid dangling
references.
Add FUSE_NOTIFY_PRUNE, which takes an array of node ID's to try and get rid
of. Inodes with active references are skipped.
A similar functionality is already provided by FUSE_NOTIFY_INVAL_ENTRY with
the FUSE_EXPIRE_ONLY flag. Differences in the interface are
FUSE_NOTIFY_INVAL_ENTRY:
- can only prune one dentry
- dentry is determined by parent ID and name
- if inode has multiple aliases (cached hard links), then they would have
to be invalidated individually to be able to get rid of the inode
FUSE_NOTIFY_PRUNE:
- can prune multiple inodes
- inodes determined by their node ID
- aliases are taken care of automatically
Reviewed-by: Joanne Koong <joannelkoong@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
FUSE_INIT has always been asynchronous with mount. That means that the
server processed this request after the mount syscall returned.
This means that FUSE_INIT can't supply the root inode's ID, hence it
currently has a hardcoded value. There are other limitations such as not
being able to perform getxattr during mount, which is needed by selinux.
To remove these limitations allow server to process FUSE_INIT while
initializing the in-core super block for the fuse filesystem. This can
only be done if the server is prepared to handle this, so add
FUSE_DEV_IOC_SYNC_INIT ioctl, which
a) lets the server know whether this feature is supported, returning
ENOTTY othewrwise.
b) lets the kernel know to perform a synchronous initialization
The implementation is slightly tricky, since fuse_dev/fuse_conn are set up
only during super block creation. This is solved by setting the private
data of the fuse device file to a special value ((struct fuse_dev *) 1) and
waiting for this to be turned into a proper fuse_dev before commecing with
operations on the device file.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
The 'inode' parameter in fuse_passthrough_open() is never referenced
in the function implementation.
Signed-off-by: Chunsheng Luo <luochunsheng@ustc.edu>
Reviewed-by: Joanne Koong <joannelkoong@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
The FUSE protocol uses struct fuse_write_out to convey the return value of
copy_file_range, which is restricted to uint32_t. But the COPY_FILE_RANGE
interface supports a 64-bit size copies and there's no reason why copies
should be limited to 32-bit.
Introduce a new op COPY_FILE_RANGE_64, which is identical, except the
number of bytes copied is returned in a 64-bit value.
If the fuse server does not support COPY_FILE_RANGE_64, fall back to
COPY_FILE_RANGE.
Reported-by: Florian Weimer <fweimer@redhat.com>
Closes: https://lore.kernel.org/all/lhuh5ynl8z5.fsf@oldenburg.str.redhat.com/
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
On regular fuse filesystems, i_blkbits is set to PAGE_SHIFT which means
any iomap partial writes will mark the entire folio as uptodate. However
fuseblk filesystems work differently and allow the blocksize to be less
than the page size. As such, this may lead to data corruption if fuseblk
sets its blocksize to less than the page size, uses the writeback cache,
and does a partial write, then a read and the read happens before the
write has undergone writeback, since the folio will not be marked
uptodate from the partial write so the read will read in the entire
folio from disk, which will overwrite the partial write.
The long-term solution for this, which will also be needed for fuse to
enable large folios with the writeback cache on, is to have fuse also
use iomap for folio reads, but until that is done, the cleanest
workaround is to use the page size for fuseblk's internal kernel inode
blksize/blkbits values while maintaining current behavior for stat().
This was verified using ntfs-3g:
$ sudo mkfs.ntfs -f -c 512 /dev/vdd1
$ sudo ntfs-3g /dev/vdd1 ~/fuseblk
$ stat ~/fuseblk/hi.txt
IO Block: 512
Fixes: a4c9ab1d49 ("fuse: use iomap for buffered writes")
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
As pointed out by Miklos[1], in the fuse_update_get_attr() path, the
attributes returned to stat may be cached values instead of fresh ones
fetched from the server. In the case where the server returned a
modified blocksize value, we need to cache it and reflect it back to
stat if values are not re-fetched since we now no longer directly change
inode->i_blkbits.
Link: https://lore.kernel.org/linux-fsdevel/CAJfpeguCOxeVX88_zPd1hqziB_C+tmfuDhZP5qO2nKmnb-dTUA@mail.gmail.com/ [1]
Fixes: 542ede096e ("fuse: keep inode->i_blkbits constant")
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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Merge tag 'vfs-6.17-rc1.fileattr' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull fileattr updates from Christian Brauner:
"This introduces the new file_getattr() and file_setattr() system calls
after lengthy discussions.
Both system calls serve as successors and extensible companions to
the FS_IOC_FSGETXATTR and FS_IOC_FSSETXATTR system calls which have
started to show their age in addition to being named in a way that
makes it easy to conflate them with extended attribute related
operations.
These syscalls allow userspace to set filesystem inode attributes on
special files. One of the usage examples is the XFS quota projects.
XFS has project quotas which could be attached to a directory. All new
inodes in these directories inherit project ID set on parent
directory.
The project is created from userspace by opening and calling
FS_IOC_FSSETXATTR on each inode. This is not possible for special
files such as FIFO, SOCK, BLK etc. Therefore, some inodes are left
with empty project ID. Those inodes then are not shown in the quota
accounting but still exist in the directory. This is not critical but
in the case when special files are created in the directory with
already existing project quota, these new inodes inherit extended
attributes. This creates a mix of special files with and without
attributes. Moreover, special files with attributes don't have a
possibility to become clear or change the attributes. This, in turn,
prevents userspace from re-creating quota project on these existing
files.
In addition, these new system calls allow the implementation of
additional attributes that we couldn't or didn't want to fit into the
legacy ioctls anymore"
* tag 'vfs-6.17-rc1.fileattr' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
fs: tighten a sanity check in file_attr_to_fileattr()
tree-wide: s/struct fileattr/struct file_kattr/g
fs: introduce file_getattr and file_setattr syscalls
fs: prepare for extending file_get/setattr()
fs: make vfs_fileattr_[get|set] return -EOPNOTSUPP
selinux: implement inode_file_[g|s]etattr hooks
lsm: introduce new hooks for setting/getting inode fsxattr
fs: split fileattr related helpers into separate file
places; unfortunately, it's easy to get wrong. A number of open-coded
attempts are out there, with varying amount of bogosities.
simple_recursive_removal() had been introduced for doing that with
all precautions needed; it does an equivalent of rm -rf, with sufficient
locking, eviction of anything mounted on top of the subtree, etc.
This series converts a bunch of open-coded instances to using that.
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Merge tag 'pull-simple_recursive_removal' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull simple_recursive_removal() update from Al Viro:
"Removing subtrees of kernel filesystems is done in quite a few places;
unfortunately, it's easy to get wrong. A number of open-coded attempts
are out there, with varying amount of bogosities.
simple_recursive_removal() had been introduced for doing that with all
precautions needed; it does an equivalent of rm -rf, with sufficient
locking, eviction of anything mounted on top of the subtree, etc.
This series converts a bunch of open-coded instances to using that"
* tag 'pull-simple_recursive_removal' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
functionfs, gadgetfs: use simple_recursive_removal()
kill binderfs_remove_file()
fuse_ctl: use simple_recursive_removal()
pstore: switch to locked_recursive_removal()
binfmt_misc: switch to locked_recursive_removal()
spufs: switch to locked_recursive_removal()
add locked_recursive_removal()
better lockdep annotations for simple_recursive_removal()
simple_recursive_removal(): saner interaction with fsnotify
Now that we expose struct file_attr as our uapi struct rename all the
internal struct to struct file_kattr to clearly communicate that it is a
kernel internal struct. This is similar to struct mount_{k}attr and
others.
Link: https://lore.kernel.org/20250703-restlaufzeit-baurecht-9ed44552b481@brauner
Signed-off-by: Christian Brauner <brauner@kernel.org>
easier that way - no need to keep that array of dentry references, etc.
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
->d_revalidate() is never called for root anyway...
Reviewed-by: Christian Brauner <brauner@kernel.org>
Acked-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
In the current FUSE writeback design (see commit 3be5a52b30
("fuse: support writable mmap")), a temp page is allocated for every
dirty page to be written back, the contents of the dirty page are copied
over to the temp page, and the temp page gets handed to the server to
write back.
This is done so that writeback may be immediately cleared on the dirty
page, and this in turn is done in order to mitigate the following
deadlock scenario that may arise if reclaim waits on writeback on the
dirty page to complete:
* single-threaded FUSE server is in the middle of handling a request
that needs a memory allocation
* memory allocation triggers direct reclaim
* direct reclaim waits on a folio under writeback
* the FUSE server can't write back the folio since it's stuck in
direct reclaim
With a recent change that added AS_WRITEBACK_MAY_DEADLOCK_ON_RECLAIM and
mitigates the situation described above, FUSE writeback does not need
to use temp pages if it sets AS_WRITEBACK_MAY_DEADLOCK_ON_RECLAIM on its
inode mappings.
This commit sets AS_WRITEBACK_MAY_DEADLOCK_ON_RECLAIM on the inode
mappings and removes the temporary pages + extra copying and the internal
rb tree.
fio benchmarks --
(using averages observed from 10 runs, throwing away outliers)
Setup:
sudo mount -t tmpfs -o size=30G tmpfs ~/tmp_mount
./libfuse/build/example/passthrough_ll -o writeback -o max_threads=4 -o source=~/tmp_mount ~/fuse_mount
fio --name=writeback --ioengine=sync --rw=write --bs={1k,4k,1M} --size=2G
--numjobs=2 --ramp_time=30 --group_reporting=1 --directory=/root/fuse_mount
bs = 1k 4k 1M
Before 351 MiB/s 1818 MiB/s 1851 MiB/s
After 341 MiB/s 2246 MiB/s 2685 MiB/s
% diff -3% 23% 45%
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Reviewed-by: Jingbo Xu <jefflexu@linux.alibaba.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Currently userspace is able to notify the kernel to invalidate the cache
for an inode. This means that, if all the inodes in a filesystem need to
be invalidated, then userspace needs to iterate through all of them and do
this kernel notification separately.
This patch adds the concept of 'epoch': each fuse connection will have the
current epoch initialized and every new dentry will have it's d_time set to
the current epoch value. A new operation will then allow userspace to
increment the epoch value. Every time a dentry is d_revalidate()'ed, it's
epoch is compared with the current connection epoch and invalidated if it's
value is different.
Signed-off-by: Luis Henriques <luis@igalia.com>
Tested-by: Laura Promberger <laura.promberger@cern.ch>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
