Convert to const struct mnt_idmap.
A mount's idmapping is immutable. The only thing that is allowed to be
modified afterwards is the reference count and that is hidden behind
mnt_idmap_get() and mnt_idmap_put(). Everything else only ever reads
from the idmapping. This is the same model that struct cred uses and the
idmapping is also rather sensitive.
So make the idmap argument const wherever we can. The conversion is done
from the bottom up so callers can continue to pass a non-const pointer
to a const parameter until the conversion is finished.
No functional changes.
Link: https://patch.msgid.link/20260901-work-idmap-const-v1-24-54ccd48e100b@kernel.org
Acked-by: Paul Moore <paul@paul-moore.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Seth Forshee <sforshee@kernel.org>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Convert to const struct mnt_idmap.
A mount's idmapping is immutable. The only thing that is allowed to be
modified afterwards is the reference count and that is hidden behind
mnt_idmap_get() and mnt_idmap_put(). Everything else only ever reads
from the idmapping. This is the same model that struct cred uses and the
idmapping is also rather sensitive.
So make the idmap argument const wherever we can. The conversion is done
from the bottom up so callers can continue to pass a non-const pointer
to a const parameter until the conversion is finished.
No functional changes.
Link: https://patch.msgid.link/20260901-work-idmap-const-v1-22-54ccd48e100b@kernel.org
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Seth Forshee <sforshee@kernel.org>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Convert to const struct mnt_idmap.
A mount's idmapping is immutable. The only thing that is allowed to be
modified afterwards is the reference count and that is hidden behind
mnt_idmap_get() and mnt_idmap_put(). Everything else only ever reads
from the idmapping. This is the same model that struct cred uses and the
idmapping is also rather sensitive.
So make the idmap argument const wherever we can. The conversion is done
from the bottom up so callers can continue to pass a non-const pointer
to a const parameter until the conversion is finished.
No functional changes.
Link: https://patch.msgid.link/20260901-work-idmap-const-v1-21-54ccd48e100b@kernel.org
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Seth Forshee <sforshee@kernel.org>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Convert to const struct mnt_idmap.
A mount's idmapping is immutable. The only thing that is allowed to be
modified afterwards is the reference count and that is hidden behind
mnt_idmap_get() and mnt_idmap_put(). Everything else only ever reads
from the idmapping. This is the same model that struct cred uses and the
idmapping is also rather sensitive.
So make the idmap argument const wherever we can. The conversion is done
from the bottom up so callers can continue to pass a non-const pointer
to a const parameter until the conversion is finished.
No functional changes.
Link: https://patch.msgid.link/20260901-work-idmap-const-v1-20-54ccd48e100b@kernel.org
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Seth Forshee <sforshee@kernel.org>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Convert to const struct mnt_idmap.
A mount's idmapping is immutable. The only thing that is allowed to be
modified afterwards is the reference count and that is hidden behind
mnt_idmap_get() and mnt_idmap_put(). Everything else only ever reads
from the idmapping. This is the same model that struct cred uses and the
idmapping is also rather sensitive.
So make the idmap argument const wherever we can. The conversion is done
from the bottom up so callers can continue to pass a non-const pointer
to a const parameter until the conversion is finished.
No functional changes.
Link: https://patch.msgid.link/20260901-work-idmap-const-v1-19-54ccd48e100b@kernel.org
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Seth Forshee <sforshee@kernel.org>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Convert to const struct mnt_idmap.
A mount's idmapping is immutable. The only thing that is allowed to be
modified afterwards is the reference count and that is hidden behind
mnt_idmap_get() and mnt_idmap_put(). Everything else only ever reads
from the idmapping. This is the same model that struct cred uses and the
idmapping is also rather sensitive.
So make the idmap argument const wherever we can. The conversion is done
from the bottom up so callers can continue to pass a non-const pointer
to a const parameter until the conversion is finished.
No functional changes.
Link: https://patch.msgid.link/20260901-work-idmap-const-v1-18-54ccd48e100b@kernel.org
Acked-by: Paul Moore <paul@paul-moore.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Seth Forshee <sforshee@kernel.org>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Convert to const struct mnt_idmap.
A mount's idmapping is immutable. The only thing that is allowed to be
modified afterwards is the reference count and that is hidden behind
mnt_idmap_get() and mnt_idmap_put(). Everything else only ever reads
from the idmapping. This is the same model that struct cred uses and the
idmapping is also rather sensitive.
So make the idmap argument const wherever we can. The conversion is done
from the bottom up so callers can continue to pass a non-const pointer
to a const parameter until the conversion is finished.
No functional changes.
Link: https://patch.msgid.link/20260901-work-idmap-const-v1-12-54ccd48e100b@kernel.org
Acked-by: Paul Moore <paul@paul-moore.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Seth Forshee <sforshee@kernel.org>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
The only time that 'false' is passed as the 'excl' arg to the ->create
inode_operation is in lookup_open() when ->atomic_open is not provided
by the parent directory.
*all* directory inode_operations which do not have ->atomic_open
completely ignore the 'excl' arg.
Therefore we don't need the 'excl' arg. Those few ->create operations
which pay attention to the arg are only ever called with a value of
'true'.
We remove that arg and change all ->create operations to behave as those
thhe arg were 'true'.
Signed-off-by: NeilBrown <neil@brown.name>
Link: https://patch.msgid.link/178290671516.27465.15984496764174914338@noble.neil.brown.name
Reviewed-by: Jori Koolstra <jkoolstra@xs4all.nl>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
This was done entirely with mindless brute force, using
git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'
to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.
Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.
For the same reason the 'flex' versions will be done as a separate
conversion.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:
Single allocations: kmalloc(sizeof(TYPE), ...)
are replaced with: kmalloc_obj(TYPE, ...)
Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with: kmalloc_objs(TYPE, COUNT, ...)
Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...)
(where TYPE may also be *VAR)
The resulting allocations no longer return "void *", instead returning
"TYPE *".
Signed-off-by: Kees Cook <kees@kernel.org>
- initial SMP support (only kernel)
- major vDSO cleanups (and fixes for 32-bit)
-----BEGIN PGP SIGNATURE-----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=CNVA
-----END PGP SIGNATURE-----
Merge tag 'uml-for-linux-6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux
Pull UML updates from Johannes Berg:
"Apart from the usual small churn, we have
- initial SMP support (only kernel)
- major vDSO cleanups (and fixes for 32-bit)"
* tag 'uml-for-linux-6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux: (33 commits)
um: Disable KASAN_INLINE when STATIC_LINK is selected
um: Don't rename vmap to kernel_vmap
um: drivers: virtio: use string choices helper
um: Always set up AT_HWCAP and AT_PLATFORM
x86/um: Remove FIXADDR_USER_START and FIXADDR_USE_END
um: Remove __access_ok_vsyscall()
um: Remove redundant range check from __access_ok_vsyscall()
um: Remove fixaddr_user_init()
x86/um: Drop gate area handling
x86/um: Do not inherit vDSO from host
um: Split out default elf_aux_hwcap
x86/um: Move ELF_PLATFORM fallback to x86-specific code
um: Split out default elf_aux_platform
um: Avoid circular dependency on asm-offsets in pgtable.h
um: Enable SMP support on x86
asm-generic: percpu: Add assembly guard
um: vdso: Remove getcpu support on x86
um: Add initial SMP support
um: Define timers on a per-CPU basis
um: Determine sleep based on need_resched()
...
-----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCaSmOZAAKCRCRxhvAZXjc
omMSAP9GLhavxyWQ24Q+49CNWWRQWDY1wTOiUK2BwtIvZ0YEcAD8D1dAiMckL5pC
RwEAVA5p+y+qi+bZP0KXCBxQddoTIQM=
=zo/J
-----END PGP SIGNATURE-----
Merge tag 'vfs-6.19-rc1.inode' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs inode updates from Christian Brauner:
"Features:
- Hide inode->i_state behind accessors. Open-coded accesses prevent
asserting they are done correctly. One obvious aspect is locking,
but significantly more can be checked. For example it can be
detected when the code is clearing flags which are already missing,
or is setting flags when it is illegal (e.g., I_FREEING when
->i_count > 0)
- Provide accessors for ->i_state, converts all filesystems using
coccinelle and manual conversions (btrfs, ceph, smb, f2fs, gfs2,
overlayfs, nilfs2, xfs), and makes plain ->i_state access fail to
compile
- Rework I_NEW handling to operate without fences, simplifying the
code after the accessor infrastructure is in place
Cleanups:
- Move wait_on_inode() from writeback.h to fs.h
- Spell out fenced ->i_state accesses with explicit smp_wmb/smp_rmb
for clarity
- Cosmetic fixes to LRU handling
- Push list presence check into inode_io_list_del()
- Touch up predicts in __d_lookup_rcu()
- ocfs2: retire ocfs2_drop_inode() and I_WILL_FREE usage
- Assert on ->i_count in iput_final()
- Assert ->i_lock held in __iget()
Fixes:
- Add missing fences to I_NEW handling"
* tag 'vfs-6.19-rc1.inode' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (22 commits)
dcache: touch up predicts in __d_lookup_rcu()
fs: push list presence check into inode_io_list_del()
fs: cosmetic fixes to lru handling
fs: rework I_NEW handling to operate without fences
fs: make plain ->i_state access fail to compile
xfs: use the new ->i_state accessors
nilfs2: use the new ->i_state accessors
overlayfs: use the new ->i_state accessors
gfs2: use the new ->i_state accessors
f2fs: use the new ->i_state accessors
smb: use the new ->i_state accessors
ceph: use the new ->i_state accessors
btrfs: use the new ->i_state accessors
Manual conversion to use ->i_state accessors of all places not covered by coccinelle
Coccinelle-based conversion to use ->i_state accessors
fs: provide accessors for ->i_state
fs: spell out fenced ->i_state accesses with explicit smp_wmb/smp_rmb
fs: move wait_on_inode() from writeback.h to fs.h
fs: add missing fences to I_NEW handling
ocfs2: retire ocfs2_drop_inode() and I_WILL_FREE usage
...
The HOSTFS_ATTR_* values were meant to be standalone for
communication between hostfs's kernel and user code parts.
However, it's easy to forget that HOSTFS_ATTR_* should be
used even on the kernel side, and that wasn't consistently
done. As a result, the values need to match ATTR_* values,
which is not useful to maintain by hand. Instead, generate
them via asm-offsets like other constants that UML needs
in user-side code that aren't otherwise available in any
header files that can be included there.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Hongbo Li <lihongbo22@huawei.com>
Link: https://patch.msgid.link/20251007071452.367989-3-johannes@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
In the old mount proceedure, hostfs could only pass root directory during
boot. This is because it constructed the root directory using the @root_ino
event without any mount options. However, when using it with the new mount
API, this step is no longer triggered. As a result, if users mounts without
specifying any mount options, the @host_root_path remains uninitialized. To
prevent this issue, the @host_root_path should be initialized at the time
of allocation.
Reported-by: Geoffrey Thorpe <geoff@geoffthorpe.net>
Closes: https://lore.kernel.org/all/643333a0-f434-42fb-82ac-d25a0b56f3b7@geoffthorpe.net/
Fixes: cd140ce9f6 ("hostfs: convert hostfs to use the new mount API")
Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
Link: https://patch.msgid.link/20251011092235.29880-1-lihongbo22@huawei.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
generic_delete_inode() is rather misleading for what the routine is
doing. inode_just_drop() should be much clearer.
The new naming is inconsistent with generic_drop_inode(), so rename that
one as well with inode_ as the suffix.
No functional changes.
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
-----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCaINCgQAKCRCRxhvAZXjc
os+nAP9LFHUwWO6EBzHJJGEVjJvvzsbzqeYrRFamYiMc5ulPJwD+KW4RIgJa/MWO
pcYE40CacaekD8rFWwYUyszpgmv6ewc=
=wCwp
-----END PGP SIGNATURE-----
Merge tag 'vfs-6.17-rc1.mmap_prepare' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull mmap_prepare updates from Christian Brauner:
"Last cycle we introduce f_op->mmap_prepare() in c84bf6dd2b ("mm:
introduce new .mmap_prepare() file callback").
This is preferred to the existing f_op->mmap() hook as it does require
a VMA to be established yet, thus allowing the mmap logic to invoke
this hook far, far earlier, prior to inserting a VMA into the virtual
address space, or performing any other heavy handed operations.
This allows for much simpler unwinding on error, and for there to be a
single attempt at merging a VMA rather than having to possibly
reattempt a merge based on potentially altered VMA state.
Far more importantly, it prevents inappropriate manipulation of
incompletely initialised VMA state, which is something that has been
the cause of bugs and complexity in the past.
The intent is to gradually deprecate f_op->mmap, and in that vein this
series coverts the majority of file systems to using f_op->mmap_prepare.
Prerequisite steps are taken - firstly ensuring all checks for mmap
capabilities use the file_has_valid_mmap_hooks() helper rather than
directly checking for f_op->mmap (which is now not a valid check) and
secondly updating daxdev_mapping_supported() to not require a VMA
parameter to allow ext4 and xfs to be converted.
Commit bb666b7c27 ("mm: add mmap_prepare() compatibility layer for
nested file systems") handles the nasty edge-case of nested file
systems like overlayfs, which introduces a compatibility shim to allow
f_op->mmap_prepare() to be invoked from an f_op->mmap() callback.
This allows for nested filesystems to continue to function correctly
with all file systems regardless of which callback is used. Once we
finally convert all file systems, this shim can be removed.
As a result, ecryptfs, fuse, and overlayfs remain unaltered so they
can nest all other file systems.
We additionally do not update resctl - as this requires an update to
remap_pfn_range() (or an alternative to it) which we defer to a later
series, equally we do not update cramfs which needs a mixed mapping
insertion with the same issue, nor do we update procfs, hugetlbfs,
syfs or kernfs all of which require VMAs for internal state and hooks.
We shall return to all of these later"
* tag 'vfs-6.17-rc1.mmap_prepare' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
doc: update porting, vfs documentation to describe mmap_prepare()
fs: replace mmap hook with .mmap_prepare for simple mappings
fs: convert most other generic_file_*mmap() users to .mmap_prepare()
fs: convert simple use of generic_file_*_mmap() to .mmap_prepare()
mm/filemap: introduce generic_file_*_mmap_prepare() helpers
fs/xfs: transition from deprecated .mmap hook to .mmap_prepare
fs/ext4: transition from deprecated .mmap hook to .mmap_prepare
fs/dax: make it possible to check dev dax support without a VMA
fs: consistently use can_mmap_file() helper
mm/nommu: use file_has_valid_mmap_hooks() helper
mm: rename call_mmap/mmap_prepare to vfs_mmap/mmap_prepare
-----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCaIM/KwAKCRCRxhvAZXjc
opT+AP407JwhRSBjUEmHg5JzUyDoivkOySdnthunRjaBKD8rlgEApM6SOIZYucU7
cPC3ZY6ORFM6Mwaw+iDW9lasM5ucHQ8=
=CHha
-----END PGP SIGNATURE-----
Merge tag 'vfs-6.17-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull misc VFS updates from Christian Brauner:
"This contains the usual selections of misc updates for this cycle.
Features:
- Add ext4 IOCB_DONTCACHE support
This refactors the address_space_operations write_begin() and
write_end() callbacks to take const struct kiocb * as their first
argument, allowing IOCB flags such as IOCB_DONTCACHE to propagate
to the filesystem's buffered I/O path.
Ext4 is updated to implement handling of the IOCB_DONTCACHE flag
and advertises support via the FOP_DONTCACHE file operation flag.
Additionally, the i915 driver's shmem write paths are updated to
bypass the legacy write_begin/write_end interface in favor of
directly calling write_iter() with a constructed synchronous kiocb.
Another i915 change replaces a manual write loop with
kernel_write() during GEM shmem object creation.
Cleanups:
- don't duplicate vfs_open() in kernel_file_open()
- proc_fd_getattr(): don't bother with S_ISDIR() check
- fs/ecryptfs: replace snprintf with sysfs_emit in show function
- vfs: Remove unnecessary list_for_each_entry_safe() from
evict_inodes()
- filelock: add new locks_wake_up_waiter() helper
- fs: Remove three arguments from block_write_end()
- VFS: change old_dir and new_dir in struct renamedata to dentrys
- netfs: Remove unused declaration netfs_queue_write_request()
Fixes:
- eventpoll: Fix semi-unbounded recursion
- eventpoll: fix sphinx documentation build warning
- fs/read_write: Fix spelling typo
- fs: annotate data race between poll_schedule_timeout() and
pollwake()
- fs/pipe: set FMODE_NOWAIT in create_pipe_files()
- docs/vfs: update references to i_mutex to i_rwsem
- fs/buffer: remove comment about hard sectorsize
- fs/buffer: remove the min and max limit checks in __getblk_slow()
- fs/libfs: don't assume blocksize <= PAGE_SIZE in
generic_check_addressable
- fs_context: fix parameter name in infofc() macro
- fs: Prevent file descriptor table allocations exceeding INT_MAX"
* tag 'vfs-6.17-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (24 commits)
netfs: Remove unused declaration netfs_queue_write_request()
eventpoll: fix sphinx documentation build warning
ext4: support uncached buffered I/O
mm/pagemap: add write_begin_get_folio() helper function
fs: change write_begin/write_end interface to take struct kiocb *
drm/i915: Refactor shmem_pwrite() to use kiocb and write_iter
drm/i915: Use kernel_write() in shmem object create
eventpoll: Fix semi-unbounded recursion
vfs: Remove unnecessary list_for_each_entry_safe() from evict_inodes()
fs/libfs: don't assume blocksize <= PAGE_SIZE in generic_check_addressable
fs/buffer: remove the min and max limit checks in __getblk_slow()
fs: Prevent file descriptor table allocations exceeding INT_MAX
fs: Remove three arguments from block_write_end()
fs/ecryptfs: replace snprintf with sysfs_emit in show function
fs: annotate suspected data race between poll_schedule_timeout() and pollwake()
docs/vfs: update references to i_mutex to i_rwsem
fs/buffer: remove comment about hard sectorsize
fs_context: fix parameter name in infofc() macro
VFS: change old_dir and new_dir in struct renamedata to dentrys
proc_fd_getattr(): don't bother with S_ISDIR() check
...
Change the address_space_operations callbacks write_begin() and
write_end() to take struct kiocb * as the first argument instead of
struct file *.
Update all affected function prototypes, implementations, call sites,
and related documentation across VFS, filesystems, and block layer.
Part of a series refactoring address_space_operations write_begin and
write_end callbacks to use struct kiocb for passing write context and
flags.
Signed-off-by: Taotao Chen <chentaotao@didiglobal.com>
Link: https://lore.kernel.org/20250716093559.217344-4-chentaotao@didiglobal.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Since commit c84bf6dd2b ("mm: introduce new .mmap_prepare() file
callback"), the f_op->mmap() hook has been deprecated in favour of
f_op->mmap_prepare().
We have provided generic .mmap_prepare() equivalents, so update all file
systems that specify these directly in their file_operations structures.
This updates 9p, adfs, affs, bfs, fat, hfs, hfsplus, hostfs, hpfs, jffs2,
jfs, minix, omfs, ramfs and ufs file systems directly.
It updates generic_ro_fops which impacts qnx4, cramfs, befs, squashfs,
frebxfs, qnx6, efs, romfs, erofs and isofs file systems.
There are remaining file systems which use generic hooks in a less direct
way which we address in a subsequent commit.
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Link: https://lore.kernel.org/c7dc90e44a9e75e750939ea369290d6e441a18e6.1750099179.git.lorenzo.stoakes@oracle.com
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Viacheslav Dubeyko <Slava.Dubeyko@ibm.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Default ->d_op being simple_dentry_operations is equivalent to leaving
it NULL and putting DCACHE_DONTCACHE into ->s_d_flags.
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
... to be used instead of manually assigning to ->s_d_op.
All in-tree filesystem converted (and field itself is renamed,
so any out-of-tree ones in need of conversion will be caught
by compiler).
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
- proper nofault accesses and read-only rodata
- hostfs fix for host inode number reuse
- fixes for host errno handling
- various cleanups/small fixes
-----BEGIN PGP SIGNATURE-----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=MSjq
-----END PGP SIGNATURE-----
Merge tag 'uml-for-linux-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux
Pull UML updates from Johannes Berg:
- proper nofault accesses and read-only rodata
- hostfs fix for host inode number reuse
- fixes for host errno handling
- various cleanups/small fixes
* tag 'uml-for-linux-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux:
um: Rewrite the sigio workaround based on epoll and tgkill
um: Prohibit the VM_CLONE flag in run_helper_thread()
um: Switch to the pthread-based helper in sigio workaround
um: ubd: Switch to the pthread-based helper
um: Add pthread-based helper support
um: x86: clean up elf specific definitions
um: Store full CSGSFS and SS register from mcontext
um: virt-pci: Refactor virtio_pcidev into its own module
um: work around sched_yield not yielding in time-travel mode
um/locking: Remove semicolon from "lock" prefix
um: Update min_low_pfn to match changes in uml_reserved
um: use str_yes_no() to remove hardcoded "yes" and "no"
um: hostfs: avoid issues on inode number reuse by host
um: Allocate vdso page pointer statically
um: remove copy_from_kernel_nofault_allowed
um: mark rodata read-only and implement _nofault accesses
um: Pass the correct Rust target and options with gcc
Some file systems (e.g. ext4) may reuse inode numbers once the inode is
not in use anymore. Usually hostfs will keep an FD open for each inode,
but this is not always the case. In the case of sockets, this cannot
even be done properly.
As such, the following sequence of events was possible:
* application creates and deletes a socket
* hostfs creates/deletes the socket on the host
* inode is still in the hostfs cache
* hostfs creates a new file
* ext4 on the outside reuses the inode number
* hostfs finds the socket inode for the newly created file
* application receives -ENXIO when opening the file
As mentioned, this can only happen if the deleted file is a special file
that is never opened on the host (i.e. no .open fop).
As such, to prevent issues, it is sufficient to check that the inode
has the expected type. That said, also add a check for the inode birth
time, just to be on the safe side.
Fixes: 74ce793bcb ("hostfs: Fix ephemeral inodes")
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Reviewed-by: Mickaël Salaün <mic@digikod.net>
Tested-by: Mickaël Salaün <mic@digikod.net>
Link: https://patch.msgid.link/20250214092822.1241575-1-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
After handling a mkdir, get the inode for the name and use
d_splice_alias() to store the correct dentry in the dcache.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Link: https://lore.kernel.org/r/20250227013949.536172-3-neilb@suse.de
Signed-off-by: Christian Brauner <brauner@kernel.org>
Some filesystems, such as NFS, cifs, ceph, and fuse, do not have
complete control of sequencing on the actual filesystem (e.g. on a
different server) and may find that the inode created for a mkdir
request already exists in the icache and dcache by the time the mkdir
request returns. For example, if the filesystem is mounted twice the
directory could be visible on the other mount before it is on the
original mount, and a pair of name_to_handle_at(), open_by_handle_at()
calls could instantiate the directory inode with an IS_ROOT() dentry
before the first mkdir returns.
This means that the dentry passed to ->mkdir() may not be the one that
is associated with the inode after the ->mkdir() completes. Some
callers need to interact with the inode after the ->mkdir completes and
they currently need to perform a lookup in the (rare) case that the
dentry is no longer hashed.
This lookup-after-mkdir requires that the directory remains locked to
avoid races. Planned future patches to lock the dentry rather than the
directory will mean that this lookup cannot be performed atomically with
the mkdir.
To remove this barrier, this patch changes ->mkdir to return the
resulting dentry if it is different from the one passed in.
Possible returns are:
NULL - the directory was created and no other dentry was used
ERR_PTR() - an error occurred
non-NULL - this other dentry was spliced in
This patch only changes file-systems to return "ERR_PTR(err)" instead of
"err" or equivalent transformations. Subsequent patches will make
further changes to some file-systems to return a correct dentry.
Not all filesystems reliably result in a positive hashed dentry:
- NFS, cifs, hostfs will sometimes need to perform a lookup of
the name to get inode information. Races could result in this
returning something different. Note that this lookup is
non-atomic which is what we are trying to avoid. Placing the
lookup in filesystem code means it only happens when the filesystem
has no other option.
- kernfs and tracefs leave the dentry negative and the ->revalidate
operation ensures that lookup will be called to correctly populate
the dentry. This could be fixed but I don't think it is important
to any of the users of vfs_mkdir() which look at the dentry.
The recommendation to use
d_drop();d_splice_alias()
is ugly but fits with current practice. A planned future patch will
change this.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: NeilBrown <neilb@suse.de>
Link: https://lore.kernel.org/r/20250227013949.536172-2-neilb@suse.de
Signed-off-by: Christian Brauner <brauner@kernel.org>
use of strcpy() with overlapping source and destination is a UB;
original loop hadn't been. More to the point, the whole thing
is much easier done with memcpy() + memmove().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-----BEGIN PGP SIGNATURE-----
iHUEABYIAB0WIQQqUNBr3gm4hGXdBJlZ7Krx/gZQ6wUCZ5yI4gAKCRBZ7Krx/gZQ
632bAQCTq1Zgm9lNqvpqZTn6COZlZcG1Ux1qhzeIsvDsYUb+5QD9HCDBAIlLnOLp
3C/PxpxE70NApXYhvvAYcF24dR43wAY=
=CxjV
-----END PGP SIGNATURE-----
Merge tag 'pull-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull hostfs fix from Al Viro:
"Fix hostfs __dentry_name() string handling.
The use of strcpy() with overlapping source and destination is a UB;
original loop hadn't been. More to the point, the whole thing is much
easier done with memcpy() + memmove()"
* tag 'pull-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
hostfs: fix string handling in __dentry_name()
strcpy() should not be used with destination potentially overlapping
the source; what's more, strscpy() in there is pointless - we already
know the amount we want to copy; might as well use memcpy().
Fixes: c278e81b8a "hostfs: Remove open coded strcpy()"
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
If we add a migrate_folio operation, we can convert the writepage
operation to writepages. The large folio support here is illusory;
we would need to kmap each page in turn for proper support. But we do
remove a few hidden calls to compound_head().
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://patch.msgid.link/20241220051500.1919389-1-willy@infradead.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
The __filemap_get_folio() function returns error pointers.
It never returns NULL. So use IS_ERR() to check it.
Fixes: 1da86618bd ("fs: Convert aops->write_begin to take a folio")
Signed-off-by: ZhangPeng <zhangpeng362@huawei.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Richard Weinberger <richard@nod.at>
This parameter is UML specific and is unknown to kernel. It should not
be propagated to kernel, otherwise it will be passed to user space as
an environment option by kernel with a warning like:
Unknown kernel command line parameters "hostfs=/foo", will be passed to user space.
Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Link: https://patch.msgid.link/20241011040441.1586345-7-tiwei.btw@antgroup.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Convert all callers from working on a page to working on one page
of a folio (support for working on an entire folio can come later).
Removes a lot of folio->page->folio conversions.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Most callers have a folio, and most implementations operate on a folio,
so remove the conversion from folio->page->folio to fit through this
interface.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Convert the passed page to a folio and operate on that.
Replaces four calls to compound_head() with one.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
-----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCZqSoSAAKCRCRxhvAZXjc
omGDAP9g7+3hDDFvDfYm3cjSw5CcbYodaS0cjzSZV9FQ8jSLUgEAv9741X4c5og1
u8hjOnkYXVJPKn+DzfwBza0wV8qtVQM=
=YIoY
-----END PGP SIGNATURE-----
Merge tag 'vfs-6.11-rc1.fixes.3' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs fixes from Christian Brauner:
"This contains two fixes for this merge window:
VFS:
- I noticed that it is possible for a privileged user to mount most
filesystems with a non-initial user namespace in sb->s_user_ns.
When fsopen() is called in a non-init namespace the caller's
namespace is recorded in fs_context->user_ns. If the returned file
descriptor is then passed to a process privileged in init_user_ns,
that process can call fsconfig(fd_fs, FSCONFIG_CMD_CREATE*),
creating a new superblock with sb->s_user_ns set to the namespace
of the process which called fsopen().
This is problematic as only filesystems that raise FS_USERNS_MOUNT
are known to be able to support a non-initial s_user_ns. Others may
suffer security issues, on-disk corruption or outright crash the
kernel. Prevent that by restricting such delegation to filesystems
that allow FS_USERNS_MOUNT.
Note, that this delegation requires a privileged process to
actually create the superblock so either the privileged process is
cooperaing or someone must have tricked a privileged process into
operating on a fscontext file descriptor whose origin it doesn't
know (a stupid idea).
The bug dates back to about 5 years afaict.
Misc:
- Fix hostfs parsing when the mount request comes in via the legacy
mount api.
In the legacy mount api hostfs allows to specify the host directory
mount without any key.
Restore that behavior"
* tag 'vfs-6.11-rc1.fixes.3' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
hostfs: fix the host directory parse when mounting.
fs: don't allow non-init s_user_ns for filesystems without FS_USERNS_MOUNT
hostfs not keep the host directory when mounting. When the host
directory is none (default), fc->source is used as the host root
directory, and this is wrong. Here we use `parse_monolithic` to
handle the old mount path for parsing the root directory. For new
mount path, The `parse_param` is used for the host directory parse.
Reported-and-tested-by: Maciej Żenczykowski <maze@google.com>
Fixes: cd140ce9f6 ("hostfs: convert hostfs to use the new mount API")
Link: https://lore.kernel.org/all/CANP3RGceNzwdb7w=vPf5=7BCid5HVQDmz1K5kC9JG42+HVAh_g@mail.gmail.com/
Cc: Christian Brauner <brauner@kernel.org>
Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
Link: https://lore.kernel.org/r/20240725065130.1821964-1-lihongbo22@huawei.com
[brauner: minor fixes]
Signed-off-by: Christian Brauner <brauner@kernel.org>
- Support for preemption
- i386 Rust support
- Huge cleanup by Benjamin Berg
- UBSAN support
- Removal of dead code
-----BEGIN PGP SIGNATURE-----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=ybqq
-----END PGP SIGNATURE-----
Merge tag 'uml-for-linus-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux
Pull UML updates from Richard Weinberger:
- Support for preemption
- i386 Rust support
- Huge cleanup by Benjamin Berg
- UBSAN support
- Removal of dead code
* tag 'uml-for-linus-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux: (41 commits)
um: vector: always reset vp->opened
um: vector: remove vp->lock
um: register power-off handler
um: line: always fill *error_out in setup_one_line()
um: remove pcap driver from documentation
um: Enable preemption in UML
um: refactor TLB update handling
um: simplify and consolidate TLB updates
um: remove force_flush_all from fork_handler
um: Do not flush MM in flush_thread
um: Delay flushing syscalls until the thread is restarted
um: remove copy_context_skas0
um: remove LDT support
um: compress memory related stub syscalls while adding them
um: Rework syscall handling
um: Add generic stub_syscall6 function
um: Create signal stack memory assignment in stub_data
um: Remove stub-data.h include from common-offsets.h
um: time-travel: fix signal blocking race/hang
um: time-travel: remove time_exit()
...
Commit e3ec0fe944 ("hostfs: Convert hostfs_read_folio() to use a
folio") simplified hostfs_read_folio(), but in the process of converting
to using folios natively also mis-used the folio_zero_tail() function
due to the very confusing API of that function.
Very arguably it's folio_zero_tail() API itself that is buggy, since it
would make more sense (and the documentation kind of implies) that the
third argument would be the pointer to the beginning of the folio
buffer.
But no, the third argument to folio_zero_tail() is where we should start
zeroing the tail (even if we already also pass in the offset separately
as the second argument).
So fix the hostfs caller, and we can leave any folio_zero_tail() sanity
cleanup for later.
Reported-and-tested-by: Maciej Żenczykowski <maze@google.com>
Fixes: e3ec0fe944 ("hostfs: Convert hostfs_read_folio() to use a folio")
Link: https://lore.kernel.org/all/CANP3RGceNzwdb7w=vPf5=7BCid5HVQDmz1K5kC9JG42+HVAh_g@mail.gmail.com/
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Christian Brauner <brauner@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCZpEGjAAKCRCRxhvAZXjc
okXfAP4tFUYszUsSqYdsgy9UvXw3Dr5zOIzQmN++NdjGkbU5fgEAs2ystqEfJgr3
v7XvGbu65CvL4/slNhBZOU4yekGx5Qc=
=C4QD
-----END PGP SIGNATURE-----
Merge tag 'vfs-6.11.mount.api' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs mount API updates from Christian Brauner:
- Add a generic helper to parse uid and gid mount options.
Currently we open-code the same logic in various filesystems which is
error prone, especially since the verification of uid and gid mount
options is a sensitive operation in the face of idmappings.
Add a generic helper and convert all filesystems over to it. Make
sure that filesystems that are mountable in unprivileged containers
verify that the specified uid and gid can be represented in the
owning namespace of the filesystem.
- Convert hostfs to the new mount api.
* tag 'vfs-6.11.mount.api' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
fuse: Convert to new uid/gid option parsing helpers
fuse: verify {g,u}id mount options correctly
fat: Convert to new uid/gid option parsing helpers
fat: Convert to new mount api
fat: move debug into fat_mount_options
vboxsf: Convert to new uid/gid option parsing helpers
tracefs: Convert to new uid/gid option parsing helpers
smb: client: Convert to new uid/gid option parsing helpers
tmpfs: Convert to new uid/gid option parsing helpers
ntfs3: Convert to new uid/gid option parsing helpers
isofs: Convert to new uid/gid option parsing helpers
hugetlbfs: Convert to new uid/gid option parsing helpers
ext4: Convert to new uid/gid option parsing helpers
exfat: Convert to new uid/gid option parsing helpers
efivarfs: Convert to new uid/gid option parsing helpers
debugfs: Convert to new uid/gid option parsing helpers
autofs: Convert to new uid/gid option parsing helpers
fs_parse: add uid & gid option option parsing helpers
hostfs: Add const qualifier to host_root in hostfs_fill_super()
hostfs: convert hostfs to use the new mount API
With ARCH=um, make allmodconfig && make W=1 C=1 reports:
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/hostfs/hostfs.o
Add the missing invocation of the MODULE_DESCRIPTION() macro.
Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Link: https://patch.msgid.link/20240702-md-um-fs-hostfs-v1-1-fd2b565027e7@quicinc.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
dev_t is a kernel type and may have different definitions
in kernel and userspace. On 32-bit x86 this currently makes
the stat structure being 4 bytes longer in the user code,
causing stack corruption.
However, this is (potentially) not the only problem, since
dev_t is a different type on user/kernel side, so we don't
know that the major/minor encoding isn't also different.
Decode/encode it instead to address both problems.
Cc: stable@vger.kernel.org
Fixes: 74ce793bcb ("hostfs: Fix ephemeral inodes")
Link: https://patch.msgid.link/20240702092440.acc960585dd5.Id0767e12f562a69c6cd3c3262dc3d765db350cf6@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
After the recent conversion to the new mount API, there is a warning
when building hostfs (which may be upgraded to an error via
CONFIG_WERROR=y):
fs/hostfs/hostfs_kern.c: In function 'hostfs_fill_super':
fs/hostfs/hostfs_kern.c:942:27: warning: initialization discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
942 | char *host_root = fc->source;
| ^~
Add the 'const' qualifier, as host_root will not be modified after its
assignment. Move the assignment to keep the existing reverse Christmas
tree order intact.
Fixes: cd140ce9f6 ("hostfs: convert hostfs to use the new mount API")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20240611-hostfs-fix-mount-api-conversion-v1-1-ef75bbc77f44@kernel.org
Acked-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Convert the hostfs filesystem to the new internal mount API as the old
one will be obsoleted and removed. This allows greater flexibility in
communication of mount parameters between userspace, the VFS and the
filesystem.
See Documentation/filesystems/mount_api.txt for more information.
Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
Link: https://lore.kernel.org/r/20240530120111.3794664-1-lihongbo22@huawei.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Remove the use of page APIs, including setting/clearing the error flag
which is never checked on hostfs folios. This does not include support
for large folios as kmap_local_folio() maps only one page at a time.
Cc: Richard Weinberger <richard@nod.at>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: linux-um@lists.infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20240530202110.2653630-8-willy@infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
In later patches, we're going to change how the inode's ctime field is
used. Switch to using accessor functions instead of raw accesses of
inode->i_ctime.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Message-Id: <20230705190309.579783-48-jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
-----BEGIN PGP SIGNATURE-----
iIYEABYIAC4WIQSVyBthFV4iTW/VU1/l49DojIL20gUCZJlO/xAcbWljQGRpZ2lr
b2QubmV0AAoJEOXj0OiMgvbS/FwA/A5GFGtKnLzFpIAXgc1G3kr8c+J/WF7RVUD+
PJNEsH6PAP41l3BTqVSeVZ+tdLSC7NbesoX0MTd+rCgAWnr+Pko2Cw==
=KqpG
-----END PGP SIGNATURE-----
Merge tag 'landlock-6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mic/linux
Pull landlock updates from Mickaël Salaün:
"Add support for Landlock to UML.
To do this, this fixes the way hostfs manages inodes according to the
underlying filesystem [1]. They are now properly handled as for other
filesystems, which enables Landlock support (and probably other
features).
This also extends Landlock's tests with 6 pseudo filesystems,
including hostfs"
[1] https://lore.kernel.org/all/20230612191430.339153-1-mic@digikod.net/
* tag 'landlock-6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mic/linux:
selftests/landlock: Add hostfs tests
selftests/landlock: Add tests for pseudo filesystems
selftests/landlock: Make mounts configurable
selftests/landlock: Add supports_filesystem() helper
selftests/landlock: Don't create useless file layouts
hostfs: Fix ephemeral inodes
hostfs creates a new inode for each opened or created file, which
created useless inode allocations and forbade identifying a host file
with a kernel inode.
Fix this uncommon filesystem behavior by tying kernel inodes to host
file's inode and device IDs. Even if the host filesystem inodes may be
recycled, this cannot happen while a file referencing it is opened,
which is the case with hostfs. It should be noted that hostfs inode IDs
may not be unique for the same hostfs superblock because multiple host's
(backed) superblocks may be used.
Delete inodes when dropping them to force backed host's file descriptors
closing.
This enables to entirely remove ARCH_EPHEMERAL_INODES, and then makes
Landlock fully supported by UML. This is very useful for testing
changes.
These changes also factor out and simplify some helpers thanks to the
new hostfs_inode_update() and the hostfs_iget() revamp: read_name(),
hostfs_create(), hostfs_lookup(), hostfs_mknod(), and
hostfs_fill_sb_common().
A following commit with new Landlock tests check this new hostfs inode
consistency.
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Richard Weinberger <richard@nod.at>
Link: https://lore.kernel.org/r/20230612191430.339153-2-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
