Add '\n' for pr_err in function ovl_parse_param_lowerdir(), which
ensures that error message is displayed at once.
Fixes: b36a5780cb ("ovl: modify layer parameter parsing")
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Link: https://lore.kernel.org/r/20240705011510.794025-4-chengzhihao1@huawei.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
The max count of lowerdir is OVL_MAX_STACK[500], which is broken by
commit 37f32f526438("ovl: fix memory leak in ovl_parse_param()") for
parameter Opt_lowerdir. Since commit 819829f0319a("ovl: refactor layer
parsing helpers") and commit 24e16e385f22("ovl: add support for
appending lowerdirs one by one") added check ovl_mount_dir_check() in
function ovl_parse_param_lowerdir(), the 'ctx->nr' should be smaller
than OVL_MAX_STACK, after commit 37f32f526438("ovl: fix memory leak in
ovl_parse_param()") is applied, the 'ctx->nr' is updated before the
check ovl_mount_dir_check(), which leads the max count of lowerdir
to become 499 for parameter Opt_lowerdir.
Fix it by replacing lower layers parsing code with the existing helper
function ovl_parse_layer().
Fixes: 37f32f5264 ("ovl: fix memory leak in ovl_parse_param()")
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Link: https://lore.kernel.org/r/20240705011510.794025-3-chengzhihao1@huawei.com
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
We want the compiler to see that fdput() on empty instance
is a no-op. The emptiness check is that file reference is NULL,
while fdput() is "fput() if FDPUT_FPUT is present in flags".
The reason why fdput() on empty instance is a no-op is something
compiler can't see - it's that we never generate instances with
NULL file reference combined with non-zero flags.
It's not that hard to deal with - the real primitives behind
fdget() et.al. are returning an unsigned long value, unpacked by (inlined)
__to_fd() into the current struct file * + int. The lower bits are
used to store flags, while the rest encodes the pointer. Linus suggested
that keeping this unsigned long around with the extractions done by inlined
accessors should generate a sane code and that turns out to be the case.
Namely, turning struct fd into a struct-wrapped unsinged long, with
fd_empty(f) => unlikely(f.word == 0)
fd_file(f) => (struct file *)(f.word & ~3)
fdput(f) => if (f.word & 1) fput(fd_file(f))
ends up with compiler doing the right thing. The cost is the patch
footprint, of course - we need to switch f.file to fd_file(f) all over
the tree, and it's not doable with simple search and replace; there are
false positives, etc.
Note that the sole member of that structure is an opaque
unsigned long - all accesses should be done via wrappers and I don't
want to use a name that would invite manual casts to file pointers,
etc. The value of that member is equal either to (unsigned long)p | flags,
p being an address of some struct file instance, or to 0 for an empty fd.
For now the new predicate (fd_empty(f)) has no users; all the
existing checks have form (!fd_file(f)). We will convert to fd_empty()
use later; here we only define it (and tell the compiler that it's
unlikely to return true).
This commit only deals with representation change; there will
be followups.
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
For any changes of struct fd representation we need to
turn existing accesses to fields into calls of wrappers.
Accesses to struct fd::flags are very few (3 in linux/file.h,
1 in net/socket.c, 3 in fs/overlayfs/file.c and 3 more in
explicit initializers).
Those can be dealt with in the commit converting to
new layout; accesses to struct fd::file are too many for that.
This commit converts (almost) all of f.file to
fd_file(f). It's not entirely mechanical ('file' is used as
a member name more than just in struct fd) and it does not
even attempt to distinguish the uses in pointer context from
those in boolean context; the latter will be eventually turned
into a separate helper (fd_empty()).
NOTE: mass conversion to fd_empty(), tempting as it
might be, is a bad idea; better do that piecewise in commit
that convert from fdget...() to CLASS(...).
[conflicts in fs/fhandle.c, kernel/bpf/syscall.c, mm/memcontrol.c
caught by git; fs/stat.c one got caught by git grep]
[fs/xattr.c conflict]
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
To be consistent with most LSM hooks, convert the return value of
hook inode_copy_up_xattr to 0 or a negative error code.
Before:
- Hook inode_copy_up_xattr returns 0 when accepting xattr, 1 when
discarding xattr, -EOPNOTSUPP if it does not know xattr, or any
other negative error code otherwise.
After:
- Hook inode_copy_up_xattr returns 0 when accepting xattr, *-ECANCELED*
when discarding xattr, -EOPNOTSUPP if it does not know xattr, or
any other negative error code otherwise.
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
ovl_check_encode_origin() should return a positive number if the lower
dentry is to be encoded, zero otherwise. If there's no upper layer at all
(read-only overlay), then it obviously needs to return positive.
This was broken by commit 16aac5ad1f ("ovl: support encoding
non-decodable file handles"), which didn't take the lower-only
configuration into account.
Fix by checking the no-upper-layer case up-front.
Reported-and-tested-by: Youzhong Yang <youzhong@gmail.com>
Closes: https://lore.kernel.org/all/CADpNCvaBimi+zCYfRJHvCOhMih8OU0rmZkwLuh24MKKroRuT8Q@mail.gmail.com/
Fixes: 16aac5ad1f ("ovl: support encoding non-decodable file handles")
Cc: <stable@vger.kernel.org> # v6.6
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
-----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQSQHSd0lITzzeNWNm3h3BK/laaZPAUCZk3w7AAKCRDh3BK/laaZ
PFlfAQD7puZ3BowTZ6cTCJ0Zg6U9wNMszlYHl3WyDnYDicaiVgD9HTqlv1pbNoFh
e5hyXI4vgaMZkYfpET0zBhVkirSKEg4=
=1vRI
-----END PGP SIGNATURE-----
Merge tag 'ovl-update-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/overlayfs/vfs
Pull overlayfs updates from Miklos Szeredi:
- Add tmpfile support
- Clean up include
* tag 'ovl-update-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/overlayfs/vfs:
ovl: remove duplicate included header
ovl: remove upper umask handling from ovl_create_upper()
ovl: implement tmpfile
-----BEGIN PGP SIGNATURE-----
iHUEABYIAB0WIQQqUNBr3gm4hGXdBJlZ7Krx/gZQ6wUCZkzp/gAKCRBZ7Krx/gZQ
63KFAQCsKv3XdcF+2BO+QuwPvR6eAvDxFjrFEcQFyyOXgFVLaAD/UMM0HcEFWxBb
PCPvyKVP22wF9PbodkrKJn8DRdtRZwM=
=jvWv
-----END PGP SIGNATURE-----
Merge tag 'pull-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc vfs updates from Al Viro:
"Assorted commits that had missed the last merge window..."
* tag 'pull-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
remove call_{read,write}_iter() functions
do_dentry_open(): kill inode argument
kernel_file_open(): get rid of inode argument
get_file_rcu(): no need to check for NULL separately
fd_is_open(): move to fs/file.c
close_on_exec(): pass files_struct instead of fdtable
-----BEGIN PGP SIGNATURE-----
iIoEABYIADIWIQQdXVVFGN5XqKr1Hj7LwZzRsCrn5QUCZkQD2xQcem9oYXJAbGlu
dXguaWJtLmNvbQAKCRDLwZzRsCrn5b81APwINCoiLDB0L9KkyUhQjqvLLZCS85u9
Qo3/wdUGAb2tygD/RYKJgtGxvqO1Ap1IysytKHId0yo+vokdXG5stpMPJQE=
=dIrw
-----END PGP SIGNATURE-----
Merge tag 'integrity-v6.10' of ssh://ra.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity
Pull integrity updates from Mimi Zohar:
"Two IMA changes, one EVM change, a use after free bug fix, and a code
cleanup to address "-Wflex-array-member-not-at-end" warnings:
- The existing IMA {ascii, binary}_runtime_measurements lists include
a hard coded SHA1 hash. To address this limitation, define per TPM
enabled hash algorithm {ascii, binary}_runtime_measurements lists
- Close an IMA integrity init_module syscall measurement gap by
defining a new critical-data record
- Enable (partial) EVM support on stacked filesystems (overlayfs).
Only EVM portable & immutable file signatures are copied up, since
they do not contain filesystem specific metadata"
* tag 'integrity-v6.10' of ssh://ra.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
ima: add crypto agility support for template-hash algorithm
evm: Rename is_unsupported_fs to is_unsupported_hmac_fs
fs: Rename SB_I_EVM_UNSUPPORTED to SB_I_EVM_HMAC_UNSUPPORTED
evm: Enforce signatures on unsupported filesystem for EVM_INIT_X509
ima: re-evaluate file integrity on file metadata change
evm: Store and detect metadata inode attributes changes
ima: Move file-change detection variables into new structure
evm: Use the metadata inode to calculate metadata hash
evm: Implement per signature type decision in security_inode_copy_up_xattr
security: allow finer granularity in permitting copy-up of security xattrs
ima: Rename backing_inode to real_inode
integrity: Avoid -Wflex-array-member-not-at-end warnings
ima: define an init_module critical data record
ima: Fix use-after-free on a dentry's dname.name
This is already done by vfs_prepare_mode() when creating the upper object
by vfs_create(), vfs_mkdir() and vfs_mknod().
No regressions have been observed in xfstests run with posix acls turned
off for the upper filesystem.
Fixes: 1639a49ccd ("fs: move S_ISGID stripping into the vfs_*() helpers")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Combine inode creation with opening a file.
There are six separate objects that are being set up: the backing inode,
dentry and file, and the overlay inode, dentry and file. Cleanup in case
of an error is a bit of a challenge and is difficult to test, so careful
review is needed.
All tmpfile testcases except generic/509 now run/pass, and no regressions
are observed with full xfstests.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
always equal to ->dentry->d_inode of the path argument these
days.
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Now that EVM supports RSA signatures for previously completely
unsupported filesystems rename the flag SB_I_EVM_UNSUPPORTED to
SB_I_EVM_HMAC_UNSUPPORTED to reflect that only HMAC is not supported.
Suggested-by: Amir Goldstein <amir73il@gmail.com>
Suggested-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Acked-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Copying up xattrs is solely based on the security xattr name. For finer
granularity add a dentry parameter to the security_inode_copy_up_xattr
hook definition, allowing decisions to be based on the xattr content as
well.
Co-developed-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Acked-by: Amir Goldstein <amir73il@gmail.com>
Acked-by: Paul Moore <paul@paul-moore.com> (LSM,SELinux)
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Since both ext4 and overlayfs define the same macro to specify string
parameters that may allow empty values, define it in an header file so
that this helper can be shared.
Signed-off-by: Luis Henriques (SUSE) <luis.henriques@linux.dev>
Link: https://lore.kernel.org/r/20240312104757.27333-1-luis.henriques@linux.dev
Signed-off-by: Christian Brauner <brauner@kernel.org>
syzbot hit an assertion in copy up data loop which looks like it is
the result of a lower file whose size is being changed underneath
overlayfs.
This type of use case is documented to cause undefined behavior, so
returning EIO error for the copy up makes sense, but it should not be
causing a WARN_ON assertion.
Reported-and-tested-by: syzbot+3abd99031b42acf367ef@syzkaller.appspotmail.com
Fixes: ca7ab48240 ("ovl: add permission hooks outside of do_splice_direct()")
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Yes, yes, I know the slab people were planning on going slow and letting
every subsystem fight this thing on their own. But let's just rip off
the band-aid and get it over and done with. I don't want to see a
number of unnecessary pull requests just to get rid of a flag that no
longer has any meaning.
This was mainly done with a couple of 'sed' scripts and then some manual
cleanup of the end result.
Link: https://lore.kernel.org/all/CAHk-=wji0u+OOtmAOD-5JV3SXcRJF___k_+8XNKmak0yd5vW1Q@mail.gmail.com/
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCZem5LwAKCRCRxhvAZXjc
onZsAQCjMNabNWAty2VBAQrNIpGkZ+AMA2DxEajPldaPiJH5zQEA9ea7feB3T47i
NUrXXfMQ5DSop+k5Y65pPkEpbX4rhQo=
=NZgd
-----END PGP SIGNATURE-----
Merge tag 'vfs-6.9.uuid' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs uuid updates from Christian Brauner:
"This adds two new ioctl()s for getting the filesystem uuid and
retrieving the sysfs path based on the path of a mounted filesystem.
Getting the filesystem uuid has been implemented in filesystem
specific code for a while it's now lifted as a generic ioctl"
* tag 'vfs-6.9.uuid' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
xfs: add support for FS_IOC_GETFSSYSFSPATH
fs: add FS_IOC_GETFSSYSFSPATH
fat: Hook up sb->s_uuid
fs: FS_IOC_GETUUID
ovl: convert to super_set_uuid()
fs: super_set_uuid()
-----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCZem3wQAKCRCRxhvAZXjc
otRMAQDeo8qsuuIAcS2KUicKqZR5yMVvrY9r4sQzf7YRcJo5HQD+NQXkKwQuv1VO
OUeScsic/+I+136AgdjWnlEYO5dp0go=
=4WKU
-----END PGP SIGNATURE-----
Merge tag 'vfs-6.9.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull misc vfs updates from Christian Brauner:
"Misc features, cleanups, and fixes for vfs and individual filesystems.
Features:
- Support idmapped mounts for hugetlbfs.
- Add RWF_NOAPPEND flag for pwritev2(). This allows us to fix a bug
where the passed offset is ignored if the file is O_APPEND. The new
flag allows a caller to enforce that the offset is honored to
conform to posix even if the file was opened in append mode.
- Move i_mmap_rwsem in struct address_space to avoid false sharing
between i_mmap and i_mmap_rwsem.
- Convert efs, qnx4, and coda to use the new mount api.
- Add a generic is_dot_dotdot() helper that's used by various
filesystems and the VFS code instead of open-coding it multiple
times.
- Recently we've added stable offsets which allows stable ordering
when iterating directories exported through NFS on e.g., tmpfs
filesystems. Originally an xarray was used for the offset map but
that caused slab fragmentation issues over time. This switches the
offset map to the maple tree which has a dense mode that handles
this scenario a lot better. Includes tests.
- Finally merge the case-insensitive improvement series Gabriel has
been working on for a long time. This cleanly propagates case
insensitive operations through ->s_d_op which in turn allows us to
remove the quite ugly generic_set_encrypted_ci_d_ops() operations.
It also improves performance by trying a case-sensitive comparison
first and then fallback to case-insensitive lookup if that fails.
This also fixes a bug where overlayfs would be able to be mounted
over a case insensitive directory which would lead to all sort of
odd behaviors.
Cleanups:
- Make file_dentry() a simple accessor now that ->d_real() is
simplified because of the backing file work we did the last two
cycles.
- Use the dedicated file_mnt_idmap helper in ntfs3.
- Use smp_load_acquire/store_release() in the i_size_read/write
helpers and thus remove the hack to handle i_size reads in the
filemap code.
- The SLAB_MEM_SPREAD is a nop now. Remove it from various places in
fs/
- It's no longer necessary to perform a second built-in initramfs
unpack call because we retain the contents of the previous
extraction. Remove it.
- Now that we have removed various allocators kfree_rcu() always
works with kmem caches and kmalloc(). So simplify various places
that only use an rcu callback in order to handle the kmem cache
case.
- Convert the pipe code to use a lockdep comparison function instead
of open-coding the nesting making lockdep validation easier.
- Move code into fs-writeback.c that was located in a header but can
be made static as it's only used in that one file.
- Rewrite the alignment checking iterators for iovec and bvec to be
easier to read, and also significantly more compact in terms of
generated code. This saves 270 bytes of text on x86-64 (with
clang-18) and 224 bytes on arm64 (with gcc-13). In profiles it also
saves a bit of time for the same workload.
- Switch various places to use KMEM_CACHE instead of
kmem_cache_create().
- Use inode_set_ctime_to_ts() in inode_set_ctime_current()
- Use kzalloc() in name_to_handle_at() to avoid kernel infoleak.
- Various smaller cleanups for eventfds.
Fixes:
- Fix various comments and typos, and unneeded initializations.
- Fix stack allocation hack for clang in the select code.
- Improve dump_mapping() debug code on a best-effort basis.
- Fix build errors in various selftests.
- Avoid wrap-around instrumentation in various places.
- Don't allow user namespaces without an idmapping to be used for
idmapped mounts.
- Fix sysv sb_read() call.
- Fix fallback implementation of the get_name() export operation"
* tag 'vfs-6.9.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (70 commits)
hugetlbfs: support idmapped mounts
qnx4: convert qnx4 to use the new mount api
fs: use inode_set_ctime_to_ts to set inode ctime to current time
libfs: Drop generic_set_encrypted_ci_d_ops
ubifs: Configure dentry operations at dentry-creation time
f2fs: Configure dentry operations at dentry-creation time
ext4: Configure dentry operations at dentry-creation time
libfs: Add helper to choose dentry operations at mount-time
libfs: Merge encrypted_ci_dentry_ops and ci_dentry_ops
fscrypt: Drop d_revalidate once the key is added
fscrypt: Drop d_revalidate for valid dentries during lookup
fscrypt: Factor out a helper to configure the lookup dentry
ovl: Always reject mounting over case-insensitive directories
libfs: Attempt exact-match comparison first during casefolded lookup
efs: remove SLAB_MEM_SPREAD flag usage
jfs: remove SLAB_MEM_SPREAD flag usage
minix: remove SLAB_MEM_SPREAD flag usage
openpromfs: remove SLAB_MEM_SPREAD flag usage
proc: remove SLAB_MEM_SPREAD flag usage
qnx6: remove SLAB_MEM_SPREAD flag usage
...
- Patch case-insensitive lookup by trying the case-exact comparison
first, before falling back to costly utf8 casefolded comparison.
- Fix to forbid using a case-insensitive directory as part of an
overlayfs mount.
- Patchset to ensure d_op are set at d_alloc time for fscrypt and
casefold volumes, ensuring filesystem dentries will all have the correct
ops, whether they come from a lookup or not.
-----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQRIEdicmeMNCZKVCdo6u2Upsdk6RAUCZedXSQAKCRA6u2Upsdk6
RILBAQDXBwZjsdW4DM9CW1HYBKl7gx0rYOBI7HhlMd63ndHxvwD+N9kMWHCS+ERh
QdYPEK5q44NYKTLeRE9lILjLsUCM9Q0=
=dovM
-----END PGP SIGNATURE-----
gpgsig -----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCZemdjgAKCRCRxhvAZXjc
opLhAP9/oVGFQViYR7rAr8v/uh9yQYbRJwq5O1HRCBlwSR5/qgD/e8QVP+MYfgSb
/tKX+8n5rRnQlrieEsWFKfDtk6FvAQo=
=Nbke
-----END PGP SIGNATURE-----
Merge tag 'for-next-6.9' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/krisman/unicode into vfs.misc
Merge case-insensitive updates from Gabriel Krisman Bertazi:
- Patch case-insensitive lookup by trying the case-exact comparison
first, before falling back to costly utf8 casefolded comparison.
- Fix to forbid using a case-insensitive directory as part of an
overlayfs mount.
- Patchset to ensure d_op are set at d_alloc time for fscrypt and
casefold volumes, ensuring filesystem dentries will all have the
correct ops, whether they come from a lookup or not.
* tag 'for-next-6.9' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/krisman/unicode:
libfs: Drop generic_set_encrypted_ci_d_ops
ubifs: Configure dentry operations at dentry-creation time
f2fs: Configure dentry operations at dentry-creation time
ext4: Configure dentry operations at dentry-creation time
libfs: Add helper to choose dentry operations at mount-time
libfs: Merge encrypted_ci_dentry_ops and ci_dentry_ops
fscrypt: Drop d_revalidate once the key is added
fscrypt: Drop d_revalidate for valid dentries during lookup
fscrypt: Factor out a helper to configure the lookup dentry
ovl: Always reject mounting over case-insensitive directories
libfs: Attempt exact-match comparison first during casefolded lookup
Signed-off-by: Christian Brauner <brauner@kernel.org>
overlayfs relies on the filesystem setting DCACHE_OP_HASH or
DCACHE_OP_COMPARE to reject mounting over case-insensitive directories.
Since commit bb9cd9106b ("fscrypt: Have filesystems handle their
d_ops"), we set ->d_op through a hook in ->d_lookup, which
means the root dentry won't have them, causing the mount to accidentally
succeed.
In v6.7-rc7, the following sequence will succeed to mount, but any
dentry other than the root dentry will be a "weird" dentry to ovl and
fail with EREMOTE.
mkfs.ext4 -O casefold lower.img
mount -O loop lower.img lower
mount -t overlay -o lowerdir=lower,upperdir=upper,workdir=work ovl /mnt
Mounting on a subdirectory fails, as expected, because DCACHE_OP_HASH
and DCACHE_OP_COMPARE are properly set by ->lookup.
Fix by explicitly rejecting superblocks that allow case-insensitive
dentries. Yes, this will be solved when we move d_op configuration back
to ->s_d_op. Yet, we better have an explicit fix to avoid messing up
again.
While there, re-sort the entries to have more descriptive error messages
first.
Fixes: bb9cd9106b ("fscrypt: Have filesystems handle their d_ops")
Acked-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20240221171412.10710-2-krisman@suse.de
Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
-----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCZcoMdAAKCRCRxhvAZXjc
ogy4AQDVp4huR6BBnRMhOCZbIsmkuHmq6ynpIZNTTAM0DdMn5AEAlJ03aEIaG9WS
RQMdaYajeVpZfR/vIUg8UdVkHQxOEgw=
=akNF
-----END PGP SIGNATURE-----
Merge tag 'vfs-6.8-rc5.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs fixes from Christian Brauner:
- Fix performance regression introduced by moving the security
permission hook out of do_clone_file_range() and into its caller
vfs_clone_file_range().
This causes the security hook to be called in situation were it
wasn't called before as the fast permission checks were left in
do_clone_file_range().
Fix this by merging the two implementations back together and
restoring the old ordering: fast permission checks first, expensive
ones later.
- Tweak mount_setattr() permission checking so that mount properties on
the real rootfs can be changed.
When we added mount_setattr() we added additional checks compared to
legacy mount(2). If the mount had a parent then verify that the
caller and the mount namespace the mount is attached to match and if
not make sure that it's an anonymous mount.
But the real rootfs falls into neither category. It is neither an
anoymous mount because it is obviously attached to the initial mount
namespace but it also obviously doesn't have a parent mount. So that
means legacy mount(2) allows changing mount properties on the real
rootfs but mount_setattr(2) blocks this. This causes regressions (See
the commit for details).
Fix this by relaxing the check. If the mount has a parent or if it
isn't a detached mount, verify that the mount namespaces of the
caller and the mount are the same. Technically, we could probably
write this even simpler and check that the mount namespaces match if
it isn't a detached mount. But the slightly longer check makes it
clearer what conditions one needs to think about.
* tag 'vfs-6.8-rc5.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
fs: relax mount_setattr() permission checks
remap_range: merge do_clone_file_range() into vfs_clone_file_range()
We don't want to be settingc sb->s_uuid directly anymore, as there's a
length field that also has to be set, and this conversion was not
completely trivial.
Acked-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Link: https://lore.kernel.org/r/20240207025624.1019754-3-kent.overstreet@linux.dev
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: linux-unionfs@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
commit dfad37051a ("remap_range: move permission hooks out of
do_clone_file_range()") moved the permission hooks from
do_clone_file_range() out to its caller vfs_clone_file_range(),
but left all the fast sanity checks in do_clone_file_range().
This makes the expensive security hooks be called in situations
that they would not have been called before (e.g. fs does not support
clone).
The only reason for the do_clone_file_range() helper was that overlayfs
did not use to be able to call vfs_clone_file_range() from copy up
context with sb_writers lock held. However, since commit c63e56a4a6
("ovl: do not open/llseek lower file with upper sb_writers held"),
overlayfs just uses an open coded version of vfs_clone_file_range().
Merge_clone_file_range() into vfs_clone_file_range(), restoring the
original order of checks as it was before the regressing commit and adapt
the overlayfs code to call vfs_clone_file_range() before the permission
hooks that were added by commit ca7ab48240 ("ovl: add permission hooks
outside of do_splice_direct()").
Note that in the merge of do_clone_file_range(), the file_start_write()
context was reduced to cover ->remap_file_range() without holding it
over the permission hooks, which was the reason for doing the regressing
commit in the first place.
Reported-and-tested-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202401312229.eddeb9a6-oliver.sang@intel.com
Fixes: dfad37051a ("remap_range: move permission hooks out of do_clone_file_range()")
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://lore.kernel.org/r/20240202102258.1582671-1-amir73il@gmail.com
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
The only remaining user of ->d_real() method is d_real_inode(), which
passed NULL inode argument to get the real data dentry.
There are no longer any users that call ->d_real() with a non-NULL
inode argument for getting a detry from a specific underlying layer.
Remove the inode argument of the method and replace it with an integer
'type' argument, to allow callers to request the real metadata dentry
instead of the real data dentry.
All the current users of d_real_inode() (e.g. uprobe) continue to get
the real data inode. Caller that need to get the real metadata inode
(e.g. IMA/EVM) can use d_inode(d_real(dentry, D_REAL_METADATA)).
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://lore.kernel.org/r/20240202110132.1584111-3-amir73il@gmail.com
Tested-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Christian Brauner <brauner@kernel.org>
An opaque directory cannot have xwhiteouts, so instead of marking an
xwhiteouts directory with a new xattr, overload overlay.opaque xattr
for marking both opaque dir ('y') and xwhiteouts dir ('x').
This is more efficient as the overlay.opaque xattr is checked during
lookup of directory anyway.
This also prevents unnecessary checking the xattr when reading a
directory without xwhiteouts, i.e. most of the time.
Note that the xwhiteouts marker is not checked on the upper layer and
on the last layer in lowerstack, where xwhiteouts are not expected.
Fixes: bc8df7a3dc ("ovl: Add an alternative type of whiteout")
Cc: <stable@vger.kernel.org> # v6.7
Reviewed-by: Alexander Larsson <alexl@redhat.com>
Tested-by: Alexander Larsson <alexl@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
change of locking rules for __dentry_kill(), regularized refcounting
rules in that area, assorted cleanups and removal of weird corner
cases (e.g. now ->d_iput() on child is always called before the parent
might hit __dentry_kill(), etc.)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-----BEGIN PGP SIGNATURE-----
iHUEABYIAB0WIQQqUNBr3gm4hGXdBJlZ7Krx/gZQ6wUCZZ+sQQAKCRBZ7Krx/gZQ
6ybjAQDM5jiS93IUzfHjCWq0nVBX5YGbDAkZOeqxbmIdQb+2UAEA6elP5r0fBBcA
seo3bry4DirQMDaA/Cjh4+8r71YSOQs=
=7+Hk
-----END PGP SIGNATURE-----
Merge tag 'pull-dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull dcache updates from Al Viro:
"Change of locking rules for __dentry_kill(), regularized refcounting
rules in that area, assorted cleanups and removal of weird corner
cases (e.g. now ->d_iput() on child is always called before the parent
might hit __dentry_kill(), etc)"
* tag 'pull-dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (40 commits)
dcache: remove unnecessary NULL check in dget_dlock()
kill DCACHE_MAY_FREE
__d_unalias() doesn't use inode argument
d_alloc_parallel(): in-lookup hash insertion doesn't need an RCU variant
get rid of DCACHE_GENOCIDE
d_genocide(): move the extern into fs/internal.h
simple_fill_super(): don't bother with d_genocide() on failure
nsfs: use d_make_root()
d_alloc_pseudo(): move setting ->d_op there from the (sole) caller
kill d_instantate_anon(), fold __d_instantiate_anon() into remaining caller
retain_dentry(): introduce a trimmed-down lockless variant
__dentry_kill(): new locking scheme
d_prune_aliases(): use a shrink list
switch select_collect{,2}() to use of to_shrink_list()
to_shrink_list(): call only if refcount is 0
fold dentry_kill() into dput()
don't try to cut corners in shrink_lock_dentry()
fold the call of retain_dentry() into fast_dput()
Call retain_dentry() with refcount 0
dentry_kill(): don't bother with retain_dentry() on slow path
...
broken in 6.5; we really can't lock two unrelated directories
without holding ->s_vfs_rename_mutex first and in case of
same-parent rename of a subdirectory 6.5 ends up doing just
that.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-----BEGIN PGP SIGNATURE-----
iHUEABYIAB0WIQQqUNBr3gm4hGXdBJlZ7Krx/gZQ6wUCZZ+lyQAKCRBZ7Krx/gZQ
60MWAP94hTqeMIpjhsUIkrTnylrIFaiw4UCWFJzIRG1QQYKqCgD/XUaWI9np7dL6
0wR/j4CQSdJjiEFKUFE2pD3QoSuJYAQ=
=+x0+
-----END PGP SIGNATURE-----
Merge tag 'pull-rename' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull rename updates from Al Viro:
"Fix directory locking scheme on rename
This was broken in 6.5; we really can't lock two unrelated directories
without holding ->s_vfs_rename_mutex first and in case of same-parent
rename of a subdirectory 6.5 ends up doing just that"
* tag 'pull-rename' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
rename(): avoid a deadlock in the case of parents having no common ancestor
kill lock_two_inodes()
rename(): fix the locking of subdirectories
f2fs: Avoid reading renamed directory if parent does not change
ext4: don't access the source subdirectory content on same-directory rename
ext2: Avoid reading renamed directory if parent does not change
udf_rename(): only access the child content on cross-directory rename
ocfs2: Avoid touching renamed directory if parent does not change
reiserfs: Avoid touching renamed directory if parent does not change
-----BEGIN PGP SIGNATURE-----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=2Ohx
-----END PGP SIGNATURE-----
Merge tag 'ovl-update-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/overlayfs/vfs
Pull overlayfs updates from Amir Goldstein:
"This is a very small update with no bug fixes and no new features.
The larger update of overlayfs for this cycle, the re-factoring of
overlayfs code into generic backing_file helpers, was already merged
via Christian.
Summary:
- Simplify/clarify some code
No bug fixes here, just some changes following questions from Al
about overlayfs code that could be a little more simple to follow.
- Overlayfs documentation style fixes
Mainly fixes for ReST formatting suggested by documentation
developers"
* tag 'ovl-update-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/overlayfs/vfs:
overlayfs.rst: fix ReST formatting
overlayfs.rst: use consistent feature names
ovl: initialize ovl_copy_up_ctx.destname inside ovl_do_copy_up()
ovl: remove redundant ofs->indexdir member
-----BEGIN PGP SIGNATURE-----
iIoEABYIADIWIQQdXVVFGN5XqKr1Hj7LwZzRsCrn5QUCZZ0pVhQcem9oYXJAbGlu
dXguaWJtLmNvbQAKCRDLwZzRsCrn5RVMAQDm9J+iiY/2Af75vOTKIZXtGF6KsBpx
9b9ALPqPNZPgugD+PfwSbS+6rO8AItXE0Q2+FwtDaV8LxgSwK9vGeCHI2wM=
=yinc
-----END PGP SIGNATURE-----
Merge tag 'integrity-v6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity
Pull integrity updates from Mimi Zohar:
- Add a new IMA/EVM maintainer and reviewer
- Disable EVM on overlayfs
The EVM HMAC and the original file signatures contain filesystem
specific metadata (e.g. i_ino, i_generation and s_uuid), preventing
the security.evm xattr from directly being copied up to the overlay.
Further before calculating and writing out the overlay file's EVM
HMAC, EVM must first verify the existing backing file's
'security.evm' value.
For now until a solution is developed, disable EVM on overlayfs.
- One bug fix and two cleanups
* tag 'integrity-v6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
overlay: disable EVM
evm: add support to disable EVM on unsupported filesystems
evm: don't copy up 'security.evm' xattr
MAINTAINERS: Add Eric Snowberg as a reviewer to IMA
MAINTAINERS: Add Roberto Sassu as co-maintainer to IMA and EVM
KEYS: encrypted: Add check for strsep
ima: Remove EXPERIMENTAL from Kconfig
ima: Reword IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY
-----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCZZUzXQAKCRCRxhvAZXjc
ogOtAQDpqUp1zY4dV/dZisCJ5xarZTsSZ1AvgmcxZBtS0NhbdgEAshWvYGA9ryS/
ChL5jjtjjZDLhRA//reoFHTQIrdp2w8=
=bF+R
-----END PGP SIGNATURE-----
Merge tag 'vfs-6.8.rw' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs rw updates from Christian Brauner:
"This contains updates from Amir for read-write backing file helpers
for stacking filesystems such as overlayfs:
- Fanotify is currently in the process of introducing pre content
events. Roughly, a new permission event will be added indicating
that it is safe to write to the file being accessed. These events
are used by hierarchical storage managers to e.g., fill the content
of files on first access.
During that work we noticed that our current permission checking is
inconsistent in rw_verify_area() and remap_verify_area().
Especially in the splice code permission checking is done multiple
times. For example, one time for the whole range and then again for
partial ranges inside the iterator.
In addition, we mostly do permission checking before we call
file_start_write() except for a few places where we call it after.
For pre-content events we need such permission checking to be done
before file_start_write(). So this is a nice reason to clean this
all up.
After this series, all permission checking is done before
file_start_write().
As part of this cleanup we also massaged the splice code a bit. We
got rid of a few helpers because we are alredy drowning in special
read-write helpers. We also cleaned up the return types for splice
helpers.
- Introduce generic read-write helpers for backing files. This lifts
some overlayfs code to common code so it can be used by the FUSE
passthrough work coming in over the next cycles. Make Amir and
Miklos the maintainers for this new subsystem of the vfs"
* tag 'vfs-6.8.rw' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (30 commits)
fs: fix __sb_write_started() kerneldoc formatting
fs: factor out backing_file_mmap() helper
fs: factor out backing_file_splice_{read,write}() helpers
fs: factor out backing_file_{read,write}_iter() helpers
fs: prepare for stackable filesystems backing file helpers
fsnotify: optionally pass access range in file permission hooks
fsnotify: assert that file_start_write() is not held in permission hooks
fsnotify: split fsnotify_perm() into two hooks
fs: use splice_copy_file_range() inline helper
splice: return type ssize_t from all helpers
fs: use do_splice_direct() for nfsd/ksmbd server-side-copy
fs: move file_start_write() into direct_splice_actor()
fs: fork splice_file_range() from do_splice_direct()
fs: create {sb,file}_write_not_started() helpers
fs: create file_write_started() helper
fs: create __sb_write_started() helper
fs: move kiocb_start_write() into vfs_iocb_iter_write()
fs: move permission hook out of do_iter_read()
fs: move permission hook out of do_iter_write()
fs: move file_start_write() into vfs_iter_write()
...
Assert that the file object is allocated in a backing_file container
so that file_user_path() could be used to display the user path and
not the backing file's path in /proc/<pid>/maps.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
There is not much in those helpers, but it makes sense to have them
logically next to the backing_file_{read,write}_iter() helpers as they
may grow more common logic in the future.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
In preparation for factoring out some backing file io helpers from
overlayfs, move backing_file_open() into a new file fs/backing-file.c
and header.
Add a MAINTAINERS entry for stackable filesystems and add a Kconfig
FS_STACK which stackable filesystems need to select.
For now, the backing_file struct, the backing_file alloc/free functions
and the backing_file_real_path() accessor remain internal to file_table.c.
We may change that in the future.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
-----BEGIN PGP SIGNATURE-----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=c+C2
-----END PGP SIGNATURE-----
Merge tag 'ovl-fixes-6.7-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/overlayfs/vfs
Pull overlayfs fix from Amir Goldstein:
"Fix a regression from this merge window"
* tag 'ovl-fixes-6.7-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/overlayfs/vfs:
ovl: fix dentry reference leak after changes to underlying layers
Until a complete solution is developed, update 'sb->s_iflags' to
disable EVM.
Acked-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
syzbot excercised the forbidden practice of moving the workdir under
lowerdir while overlayfs is mounted and tripped a dentry reference leak.
Fixes: c63e56a4a6 ("ovl: do not open/llseek lower file with upper sb_writers held")
Reported-and-tested-by: syzbot+8608bb4553edb8c78f41@syzkaller.appspotmail.com
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
The callers of do_splice_direct() hold file_start_write() on the output
file.
This may cause file permission hooks to be called indirectly on an
overlayfs lower layer, which is on the same filesystem of the output
file and could lead to deadlock with fanotify permission events.
To fix this potential deadlock, move file_start_write() from the callers
into the direct_splice_actor(), so file_start_write() will not be held
while splicing from the input file.
Suggested-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20231128214258.GA2398475@perftesting/
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://lore.kernel.org/r/20231130141624.3338942-3-amir73il@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
... and fix the directory locking documentation and proof of correctness.
Holding ->s_vfs_rename_mutex *almost* prevents ->d_parent changes; the
case where we really don't want it is splicing the root of disconnected
tree to somewhere.
In other words, ->s_vfs_rename_mutex is sufficient to stabilize "X is an
ancestor of Y" only if X and Y are already in the same tree. Otherwise
it can go from false to true, and one can construct a deadlock on that.
Make lock_two_directories() report an error in such case and update the
callers of lock_rename()/lock_rename_child() to handle such errors.
And yes, such conditions are not impossible to create ;-/
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCZWBq0gAKCRCRxhvAZXjc
ot4EAP48O5ExMtQ3/AIkNDo+/9/Iz4g7bE1HYmdyiMPO3Ou/uwEAySwBXRJrFAsS
9omvkEdqrfyguW0xgoYwcxBdATVHnAE=
=ScR3
-----END PGP SIGNATURE-----
Merge tag 'vfs-6.7-rc3.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs fixes from Christian Brauner:
- Avoid calling back into LSMs from vfs_getattr_nosec() calls.
IMA used to query inode properties accessing raw inode fields without
dedicated helpers. That was finally fixed a few releases ago by
forcing IMA to use vfs_getattr_nosec() helpers.
The goal of the vfs_getattr_nosec() helper is to query for attributes
without calling into the LSM layer which would be quite problematic
because incredibly IMA is called from __fput()...
__fput()
-> ima_file_free()
What it does is to call back into the filesystem to update the file's
IMA xattr. Querying the inode without using vfs_getattr_nosec() meant
that IMA didn't handle stacking filesystems such as overlayfs
correctly. So the switch to vfs_getattr_nosec() is quite correct. But
the switch to vfs_getattr_nosec() revealed another bug when used on
stacking filesystems:
__fput()
-> ima_file_free()
-> vfs_getattr_nosec()
-> i_op->getattr::ovl_getattr()
-> vfs_getattr()
-> i_op->getattr::$WHATEVER_UNDERLYING_FS_getattr()
-> security_inode_getattr() # calls back into LSMs
Now, if that __fput() happens from task_work_run() of an exiting task
current->fs and various other pointer could already be NULL. So
anything in the LSM layer relying on that not being NULL would be
quite surprised.
Fix that by passing the information that this is a security request
through to the stacking filesystem by adding a new internal
ATT_GETATTR_NOSEC flag. Now the callchain becomes:
__fput()
-> ima_file_free()
-> vfs_getattr_nosec()
-> i_op->getattr::ovl_getattr()
-> if (AT_GETATTR_NOSEC)
vfs_getattr_nosec()
else
vfs_getattr()
-> i_op->getattr::$WHATEVER_UNDERLYING_FS_getattr()
- Fix a bug introduced with the iov_iter rework from last cycle.
This broke /proc/kcore by copying too much and without the correct
offset.
- Add a missing NULL check when allocating the root inode in
autofs_fill_super().
- Fix stable writes for multi-device filesystems (xfs, btrfs etc) and
the block device pseudo filesystem.
Stable writes used to be a superblock flag only, making it a per
filesystem property. Add an additional AS_STABLE_WRITES mapping flag
to allow for fine-grained control.
- Ensure that offset_iterate_dir() returns 0 after reaching the end of
a directory so it adheres to getdents() convention.
* tag 'vfs-6.7-rc3.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
libfs: getdents() should return 0 after reaching EOD
xfs: respect the stable writes flag on the RT device
xfs: clean up FS_XFLAG_REALTIME handling in xfs_ioctl_setattr_xflags
block: update the stable_writes flag in bdev_add
filemap: add a per-mapping stable writes flag
autofs: add: new_inode check in autofs_fill_super()
iov_iter: fix copy_page_to_iter_nofault()
fs: Pass AT_GETATTR_NOSEC flag to getattr interface function
In vfs code, sb_start_write() is usually called after the permission hook
in rw_verify_area(). vfs_iocb_iter_write() is an exception to this rule,
where kiocb_start_write() is called by its callers.
Move kiocb_start_write() from the callers into vfs_iocb_iter_write()
after the rw_verify_area() checks, to make them "start-write-safe".
The semantics of vfs_iocb_iter_write() is changed, so that the caller is
responsible for calling kiocb_end_write() on completion only if async
iocb was queued. The completion handlers of both callers were adapted
to this semantic change.
This is needed for fanotify "pre content" events.
Suggested-by: Jan Kara <jack@suse.cz>
Suggested-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://lore.kernel.org/r/20231122122715.2561213-14-amir73il@gmail.com
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
All the callers of vfs_iter_write() call file_start_write() just before
calling vfs_iter_write() except for target_core_file's fd_do_rw().
Move file_start_write() from the callers into vfs_iter_write().
fd_do_rw() calls vfs_iter_write() with a non-regular file, so
file_start_write() is a no-op.
This is needed for fanotify "pre content" events.
Suggested-by: Jan Kara <jack@suse.cz>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://lore.kernel.org/r/20231122122715.2561213-11-amir73il@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
The main callers of do_splice_direct() also call rw_verify_area() for
the entire range that is being copied, e.g. by vfs_copy_file_range()
or do_sendfile() before calling do_splice_direct().
The only caller that does not have those checks for entire range is
ovl_copy_up_file(). In preparation for removing the checks inside
do_splice_direct(), add rw_verify_area() call in ovl_copy_up_file().
For extra safety, perform minimal sanity checks from rw_verify_area()
for non negative offsets also in the copy up do_splice_direct() loop
without calling the file permission hooks.
This is needed for fanotify "pre content" events.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://lore.kernel.org/r/20231122122715.2561213-2-amir73il@gmail.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
The ->destname member of struct ovl_copy_up_ctx is initialized inside
ovl_copy_up_one() to ->d_name of the overlayfs dentry being copied up
and then it may be overridden by index name inside ovl_do_copy_up().
ovl_inode_lock() in ovl_copy_up_start() and ovl_copy_up() in ovl_rename()
effectively stabilze ->d_name of the overlayfs dentry being copied up,
but ovl_inode_lock() is not held when ->d_name is being read.
It is not a correctness bug, because if ovl_do_copy_up() races with
ovl_rename() and ctx.destname is freed, we will not end up calling
ovl_do_copy_up() with the dead name reference.
The code becomes much easier to understand and to document if the
initialization of c->destname is always done inside ovl_do_copy_up(),
either to the index entry name, or to the overlay dentry ->d_name.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
When the index feature is disabled, ofs->indexdir is NULL.
When the index feature is enabled, ofs->indexdir has the same value as
ofs->workdir and takes an extra reference.
This makes the code harder to understand when it is not always clear
that ofs->indexdir in one function is the same dentry as ofs->workdir
in another function.
Remove this redundancy, by referencing ofs->workdir directly in index
helpers and by using the ovl_indexdir() accessor in generic code.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Commit f9c34674bc ("vfs: factor out helpers d_instantiate_anon() and
d_alloc_anon()") was introduced so overlayfs could initialize a non-dir
disconnected overlay dentry before overlay inode is attached to it.
Since commit ("0af950f57fef ovl: move ovl_entry into ovl_inode"), all
ovl_obtain_alias() can do is set DCACHE_OP_*REVALIDATE flags in ->d_flags
and OVL_E_UPPER_ALIAS flag in ->d_fsdata.
The DCACHE_OP_*REVALIDATE flags and OVL_E_UPPER_ALIAS flag are irrelevant
for a disconnected non-dir dentry, so it is better to use d_obtain_alias()
instead of open coding it.
Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
When vfs_getattr_nosec() calls a filesystem's getattr interface function
then the 'nosec' should propagate into this function so that
vfs_getattr_nosec() can again be called from the filesystem's gettattr
rather than vfs_getattr(). The latter would add unnecessary security
checks that the initial vfs_getattr_nosec() call wanted to avoid.
Therefore, introduce the getattr flag GETATTR_NOSEC and allow to pass
with the new getattr_flags parameter to the getattr interface function.
In overlayfs and ecryptfs use this flag to determine which one of the
two functions to call.
In a recent code change introduced to IMA vfs_getattr_nosec() ended up
calling vfs_getattr() in overlayfs, which in turn called
security_inode_getattr() on an exiting process that did not have
current->fs set anymore, which then caused a kernel NULL pointer
dereference. With this change the call to security_inode_getattr() can
be avoided, thus avoiding the NULL pointer dereference.
Reported-by: <syzbot+a67fc5321ffb4b311c98@syzkaller.appspotmail.com>
Fixes: db1d1e8b98 ("IMA: use vfs_getattr_nosec to get the i_version")
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: <linux-fsdevel@vger.kernel.org>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: Tyler Hicks <code@tyhicks.com>
Cc: Mimi Zohar <zohar@linux.ibm.com>
Suggested-by: Christian Brauner <brauner@kernel.org>
Co-developed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Link: https://lore.kernel.org/r/20231002125733.1251467-1-stefanb@linux.vnet.ibm.com
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
On failure to parse parameters in ovl_parse_param_lowerdir(), it is
necessary to update ctx->nr with the correct nr before using
ovl_reset_lowerdirs() to release l->name.
Reported-and-tested-by: syzbot+26eedf3631650972f17c@syzkaller.appspotmail.com
Fixes: c835110b58 ("ovl: remove unused code in lowerdir param parsing")
Co-authored-by: Edward Adam Davis <eadavis@qq.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
-----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCZUpEaAAKCRCRxhvAZXjc
ounBAQCAoS66gnOZ+k4kOWwB2zZ1Ueh3dPFC7IcEZ+pwFS8hpAEAxUQxV0TSWf5l
W/1oKRtAJyuSYvehHeMUSJmHVBiM8w4=
=bNm0
-----END PGP SIGNATURE-----
Merge tag 'vfs-6.7.fsid' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs fanotify fsid updates from Christian Brauner:
"This work is part of the plan to enable fanotify to serve as a drop-in
replacement for inotify. While inotify is availabe on all filesystems,
fanotify currently isn't.
In order to support fanotify on all filesystems two things are needed:
(1) all filesystems need to support AT_HANDLE_FID
(2) all filesystems need to report a non-zero f_fsid
This contains (1) and allows filesystems to encode non-decodable file
handlers for fanotify without implementing any exportfs operations by
encoding a file id of type FILEID_INO64_GEN from i_ino and
i_generation.
Filesystems that want to opt out of encoding non-decodable file ids
for fanotify that don't support NFS export can do so by providing an
empty export_operations struct.
This also partially addresses (2) by generating f_fsid for simple
filesystems as well as freevxfs. Remaining filesystems will be dealt
with by separate patches.
Finally, this contains the patch from the current exportfs maintainers
which moves exportfs under vfs with Chuck, Jeff, and Amir as
maintainers and vfs.git as tree"
* tag 'vfs-6.7.fsid' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
MAINTAINERS: create an entry for exportfs
fs: fix build error with CONFIG_EXPORTFS=m or not defined
freevxfs: derive f_fsid from bdev->bd_dev
fs: report f_fsid from s_dev for "simple" filesystems
exportfs: support encoding non-decodeable file handles by default
exportfs: define FILEID_INO64_GEN* file handle types
exportfs: make ->encode_fh() a mandatory method for NFS export
exportfs: add helpers to check if filesystem can encode/decode file handles
-----BEGIN PGP SIGNATURE-----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=MPCb
-----END PGP SIGNATURE-----
Merge tag 'ovl-update-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/overlayfs/vfs
Pull overlayfs updates from Amir Goldstein:
- Overlayfs aio cleanups and fixes
Cleanups and minor fixes in preparation for factoring out of
read/write passthrough code.
- Overlayfs lock ordering changes
Hold mnt_writers only throughout copy up instead of a long lived
elevated refcount.
- Add support for nesting overlayfs private xattrs
There are cases where you want to use an overlayfs mount as a
lowerdir for another overlayfs mount. For example, if the system
rootfs is on overlayfs due to composefs, or to make it volatile (via
tmpfs), then you cannot currently store a lowerdir on the rootfs,
because the inner overlayfs will eat all the whiteouts and overlay
xattrs. This means you can't e.g. store on the rootfs a prepared
container image for use with overlayfs.
This adds support for nesting of overlayfs mounts by escaping the
problematic features and unescaping them when exposing to the
overlayfs user.
- Add new mount options for appending lowerdirs
* tag 'ovl-update-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/overlayfs/vfs:
ovl: add support for appending lowerdirs one by one
ovl: refactor layer parsing helpers
ovl: store and show the user provided lowerdir mount option
ovl: remove unused code in lowerdir param parsing
ovl: Add documentation on nesting of overlayfs mounts
ovl: Add an alternative type of whiteout
ovl: Support escaped overlay.* xattrs
ovl: Add OVL_XATTR_TRUSTED/USER_PREFIX_LEN macros
ovl: Move xattr support to new xattrs.c file
ovl: do not encode lower fh with upper sb_writers held
ovl: do not open/llseek lower file with upper sb_writers held
ovl: reorder ovl_want_write() after ovl_inode_lock()
ovl: split ovl_want_write() into two helpers
ovl: add helper ovl_file_modified()
ovl: protect copying of realinode attributes to ovl inode
ovl: punt write aio completion to workqueue
ovl: propagate IOCB_APPEND flag on writes to realfile
ovl: use simpler function to convert iocb to rw flags
-----BEGIN PGP SIGNATURE-----
iIoEABYIADIWIQQdXVVFGN5XqKr1Hj7LwZzRsCrn5QUCZUDyWhQcem9oYXJAbGlu
dXguaWJtLmNvbQAKCRDLwZzRsCrn5QtIAPwLSdHw2qix1A6lMhbRiXqFOWINHcTF
DMtZkiPmpeuTKAEA0KaXfddKq5OC5S/ixPEEZCVqOq2ixxfMDhudyoh/qQs=
=lh3g
-----END PGP SIGNATURE-----
Merge tag 'integrity-v6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity
Pull integrity updates from Mimi Zohar:
"Four integrity changes: two IMA-overlay updates, an integrity Kconfig
cleanup, and a secondary keyring update"
* tag 'integrity-v6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
ima: detect changes to the backing overlay file
certs: Only allow certs signed by keys on the builtin keyring
integrity: fix indentation of config attributes
ima: annotate iint mutex to avoid lockdep false positive warnings
Commit 18b44bc5a6 ("ovl: Always reevaluate the file signature for
IMA") forced signature re-evaulation on every file access.
Instead of always re-evaluating the file's integrity, detect a change
to the backing file, by comparing the cached file metadata with the
backing file's metadata. Verifying just the i_version has not changed
is insufficient. In addition save and compare the i_ino and s_dev
as well.
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Tested-by: Eric Snowberg <eric.snowberg@oracle.com>
Tested-by: Raul E Rangel <rrangel@chromium.org>
Cc: stable@vger.kernel.org
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Add new mount options lowerdir+ and datadir+ that can be used to add
layers to lower layers stack one by one.
Unlike the legacy lowerdir mount option, special characters (i.e. colons
and cammas) are not unescaped with these new mount options.
The new mount options can be repeated to compose a large stack of lower
layers, but they may not be mixed with the lagacy lowerdir mount option,
because for displaying lower layers in mountinfo, we do not want to mix
escaped with unescaped lower layers path syntax.
Similar to data-only layer rules with the lowerdir mount option, the
datadir+ option must follow at least one lowerdir+ option and the
lowerdir+ option must not follow the datadir+ option.
If the legacy lowerdir mount option follows lowerdir+ and datadir+
mount options, it overrides them. Sepcifically, calling:
fsconfig(FSCONFIG_SET_STRING, "lowerdir", "", 0);
can be used to reset previously setup lower layers.
Suggested-by: Miklos Szeredi <miklos@szeredi.hu>
Link: https://lore.kernel.org/r/CAJfpegt7VC94KkRtb1dfHG8+4OzwPBLYqhtc8=QFUxpFJE+=RQ@mail.gmail.com/
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
In preparation for new mount options to add lowerdirs one by one,
generalize ovl_parse_param_upperdir() into helper ovl_parse_layer()
that will be used for parsing a single lower layers.
Suggested-by: Miklos Szeredi <miklos@szeredi.hu>
Link: https://lore.kernel.org/r/CAJfpegt7VC94KkRtb1dfHG8+4OzwPBLYqhtc8=QFUxpFJE+=RQ@mail.gmail.com/
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
We are about to add new mount options for adding lowerdir one by one,
but those mount options will not support escaping.
For the existing case, where lowerdir mount option is provided as a colon
separated list, store the user provided (possibly escaped) string and
display it as is when showing the lowerdir mount option.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Commit beae836e9c ("ovl: temporarily disable appending lowedirs")
removed the ability to append lowerdirs with syntax lowerdir=":<path>".
Remove leftover code and comments that are irrelevant with lowerdir
append mode disabled.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
An xattr whiteout (called "xwhiteout" in the code) is a reguar file of
zero size with the "overlay.whiteout" xattr set. A file like this in a
directory with the "overlay.whiteouts" xattrs set will be treated the
same way as a regular whiteout.
The "overlay.whiteouts" directory xattr is used in order to
efficiently handle overlay checks in readdir(), as we only need to
checks xattrs in affected directories.
The advantage of this kind of whiteout is that they can be escaped
using the standard overlay xattr escaping mechanism. So, a file with a
"overlay.overlay.whiteout" xattr would be unescaped to
"overlay.whiteout", which could then be consumed by another overlayfs
as a whiteout.
Overlayfs itself doesn't create whiteouts like this, but a userspace
mechanism could use this alternative mechanism to convert images that
may contain whiteouts to be used with overlayfs.
To work as a whiteout for both regular overlayfs mounts as well as
userxattr mounts both the "user.overlay.whiteout*" and the
"trusted.overlay.whiteout*" xattrs will need to be created.
Signed-off-by: Alexander Larsson <alexl@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
There are cases where you want to use an overlayfs mount as a lowerdir
for another overlayfs mount. For example, if the system rootfs is on
overlayfs due to composefs, or to make it volatile (via tmps), then
you cannot currently store a lowerdir on the rootfs. This means you
can't e.g. store on the rootfs a prepared container image for use
using overlayfs.
To work around this, we introduce an escapment mechanism for overlayfs
xattrs. Whenever the lower/upper dir has a xattr named
"overlay.overlay.XYZ", we list it as "overlay.XYZ" in listxattrs, and
when the user calls getxattr or setxattr on "overlay.XYZ", we apply to
"overlay.overlay.XYZ" in the backing directories.
This allows storing any kind of overlay xattrs in a overlayfs mount
that can be used as a lowerdir in another mount. It is possible to
stack this mechanism multiple times, such that
"overlay.overlay.overlay.XYZ" will survive two levels of overlay mounts,
however this is not all that useful in practice because of stack depth
limitations of overlayfs mounts.
Note: These escaped xattrs are copied to upper during copy-up.
Signed-off-by: Alexander Larsson <alexl@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
These match the ones for e.g. XATTR_TRUSTED_PREFIX_LEN.
Signed-off-by: Alexander Larsson <alexl@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
This moves the code from super.c and inode.c, and makes ovl_xattr_get/set()
static.
This is in preparation for doing more work on xattrs support.
Signed-off-by: Alexander Larsson <alexl@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
When lower fs is a nested overlayfs, calling encode_fh() on a lower
directory dentry may trigger copy up and take sb_writers on the upper fs
of the lower nested overlayfs.
The lower nested overlayfs may have the same upper fs as this overlayfs,
so nested sb_writers lock is illegal.
Move all the callers that encode lower fh to before ovl_want_write().
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
overlayfs file open (ovl_maybe_lookup_lowerdata) and overlay file llseek
take the ovl_inode_lock, without holding upper sb_writers.
In case of nested lower overlay that uses same upper fs as this overlay,
lockdep will warn about (possibly false positive) circular lock
dependency when doing open/llseek of lower ovl file during copy up with
our upper sb_writers held, because the locking ordering seems reverse to
the locking order in ovl_copy_up_start():
- lower ovl_inode_lock
- upper sb_writers
Let the copy up "transaction" keeps an elevated mnt write count on upper
mnt, but leaves taking upper sb_writers to lower level helpers only when
they actually need it. This allows to avoid holding upper sb_writers
during lower file open/llseek and prevents the lockdep warning.
Minimizing the scope of upper sb_writers during copy up is also needed
for fixing another possible deadlocks by a following patch.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Make the locking order of ovl_inode_lock() strictly between the two
vfs stacked layers, i.e.:
- ovl vfs locks: sb_writers, inode_lock, ...
- ovl_inode_lock
- upper vfs locks: sb_writers, inode_lock, ...
To that effect, move ovl_want_write() into the helpers ovl_nlink_start()
and ovl_copy_up_start which currently take the ovl_inode_lock() after
ovl_want_write().
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
ovl_get_write_access() gets write access to upper mnt without taking
freeze protection on upper sb and ovl_start_write() only takes freeze
protection on upper sb.
These helpers will be used to breakup the large ovl_want_write() scope
during copy up into finer grained freeze protection scopes.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
ovl_copyattr() may be called concurrently from aio completion context
without any lock and that could lead to overlay inode attributes getting
permanently out of sync with real inode attributes.
Use ovl inode spinlock to protect ovl_copyattr().
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
We want to protect concurrent updates of ovl inode size and mtime
(i.e. ovl_copyattr()) from aio completion context.
Punt write aio completion to a workqueue so that we can protect
ovl_copyattr() with a spinlock.
Export sb_init_dio_done_wq(), so that overlayfs can use its own
dio workqueue to punt aio completions.
Suggested-by: Jens Axboe <axboe@kernel.dk>
Link: https://lore.kernel.org/r/8620dfd3-372d-4ae0-aa3f-2fe97dda1bca@kernel.dk/
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
If ovl file is opened O_APPEND, the underlying realfile is also
opened O_APPEND, so it makes sense to propagate the IOCB_APPEND flags
on sync writes to realfile, just as we do with aio writes.
Effectively, because sync ovl writes are protected by inode lock,
this change only makes a difference if the realfile is written to (size
extending writes) from underneath overlayfs. The behavior in this case
is undefined, so it is ok if we change the behavior (to fail the ovl
IOCB_APPEND write).
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Overlayfs implements its own function to translate iocb flags into rw
flags, so that they can be passed into another vfs call.
With commit ce71bfea20 ("fs: align IOCB_* flags with RWF_* flags")
Jens created a 1:1 matching between the iocb flags and rw flags,
simplifying the conversion.
Signed-off-by: Alessio Balsini <balsini@android.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
-----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCZTppYgAKCRCRxhvAZXjc
okIHAP9anLz1QDyMLH12ASuHjgBc0Of3jcB6NB97IWGpL4O21gEA46ohaD+vcJuC
YkBLU3lXqQ87nfu28ExFAzh10hG2jwM=
=m4pB
-----END PGP SIGNATURE-----
Merge tag 'vfs-6.7.ctime' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs
Pull vfs inode time accessor updates from Christian Brauner:
"This finishes the conversion of all inode time fields to accessor
functions as discussed on list. Changing timestamps manually as we
used to do before is error prone. Using accessors function makes this
robust.
It does not contain the switch of the time fields to discrete 64 bit
integers to replace struct timespec and free up space in struct inode.
But after this, the switch can be trivially made and the patch should
only affect the vfs if we decide to do it"
* tag 'vfs-6.7.ctime' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs: (86 commits)
fs: rename inode i_atime and i_mtime fields
security: convert to new timestamp accessors
selinux: convert to new timestamp accessors
apparmor: convert to new timestamp accessors
sunrpc: convert to new timestamp accessors
mm: convert to new timestamp accessors
bpf: convert to new timestamp accessors
ipc: convert to new timestamp accessors
linux: convert to new timestamp accessors
zonefs: convert to new timestamp accessors
xfs: convert to new timestamp accessors
vboxsf: convert to new timestamp accessors
ufs: convert to new timestamp accessors
udf: convert to new timestamp accessors
ubifs: convert to new timestamp accessors
tracefs: convert to new timestamp accessors
sysv: convert to new timestamp accessors
squashfs: convert to new timestamp accessors
server: convert to new timestamp accessors
client: convert to new timestamp accessors
...
-----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCZTppWAAKCRCRxhvAZXjc
okB2AP4jjoRErJBwj245OIDJqzoj4m4UVOVd0MH2AkiSpANczwD/TToChdpusY2y
qAYg1fQoGMbDVlb7Txaj9qI9ieCf9w0=
=2PXg
-----END PGP SIGNATURE-----
Merge tag 'vfs-6.7.xattr' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs
Pull vfs xattr updates from Christian Brauner:
"The 's_xattr' field of 'struct super_block' currently requires a
mutable table of 'struct xattr_handler' entries (although each handler
itself is const). However, no code in vfs actually modifies the
tables.
This changes the type of 's_xattr' to allow const tables, and modifies
existing file systems to move their tables to .rodata. This is
desirable because these tables contain entries with function pointers
in them; moving them to .rodata makes it considerably less likely to
be modified accidentally or maliciously at runtime"
* tag 'vfs-6.7.xattr' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs: (30 commits)
const_structs.checkpatch: add xattr_handler
net: move sockfs_xattr_handlers to .rodata
shmem: move shmem_xattr_handlers to .rodata
overlayfs: move xattr tables to .rodata
xfs: move xfs_xattr_handlers to .rodata
ubifs: move ubifs_xattr_handlers to .rodata
squashfs: move squashfs_xattr_handlers to .rodata
smb: move cifs_xattr_handlers to .rodata
reiserfs: move reiserfs_xattr_handlers to .rodata
orangefs: move orangefs_xattr_handlers to .rodata
ocfs2: move ocfs2_xattr_handlers and ocfs2_xattr_handler_map to .rodata
ntfs3: move ntfs_xattr_handlers to .rodata
nfs: move nfs4_xattr_handlers to .rodata
kernfs: move kernfs_xattr_handlers to .rodata
jfs: move jfs_xattr_handlers to .rodata
jffs2: move jffs2_xattr_handlers to .rodata
hfsplus: move hfsplus_xattr_handlers to .rodata
hfs: move hfs_xattr_handlers to .rodata
gfs2: move gfs2_xattr_handlers_max to .rodata
fuse: move fuse_xattr_handlers to .rodata
...
-----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCZTpoQAAKCRCRxhvAZXjc
ovFNAQDgIRjXfZ1Ku+USxsRRdqp8geJVaNc3PuMmYhOYhUenqgEAmC1m+p0y31dS
P6+HlL16Mqgu0tpLCcJK9BibpDZ0Ew4=
=7yD1
-----END PGP SIGNATURE-----
Merge tag 'vfs-6.7.misc' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs
Pull misc vfs updates from Christian Brauner:
"This contains the usual miscellaneous features, cleanups, and fixes
for vfs and individual fses.
Features:
- Rename and export helpers that get write access to a mount. They
are used in overlayfs to get write access to the upper mount.
- Print the pretty name of the root device on boot failure. This
helps in scenarios where we would usually only print
"unknown-block(1,2)".
- Add an internal SB_I_NOUMASK flag. This is another part in the
endless POSIX ACL saga in a way.
When POSIX ACLs are enabled via SB_POSIXACL the vfs cannot strip
the umask because if the relevant inode has POSIX ACLs set it might
take the umask from there. But if the inode doesn't have any POSIX
ACLs set then we apply the umask in the filesytem itself. So we end
up with:
(1) no SB_POSIXACL -> strip umask in vfs
(2) SB_POSIXACL -> strip umask in filesystem
The umask semantics associated with SB_POSIXACL allowed filesystems
that don't even support POSIX ACLs at all to raise SB_POSIXACL
purely to avoid umask stripping. That specifically means NFS v4 and
Overlayfs. NFS v4 does it because it delegates this to the server
and Overlayfs because it needs to delegate umask stripping to the
upper filesystem, i.e., the filesystem used as the writable layer.
This went so far that SB_POSIXACL is raised eve on kernels that
don't even have POSIX ACL support at all.
Stop this blatant abuse and add SB_I_NOUMASK which is an internal
superblock flag that filesystems can raise to opt out of umask
handling. That should really only be the two mentioned above. It's
not that we want any filesystems to do this. Ideally we have all
umask handling always in the vfs.
- Make overlayfs use SB_I_NOUMASK too.
- Now that we have SB_I_NOUMASK, stop checking for SB_POSIXACL in
IS_POSIXACL() if the kernel doesn't have support for it. This is a
very old patch but it's only possible to do this now with the wider
cleanup that was done.
- Follow-up work on fake path handling from last cycle. Citing mostly
from Amir:
When overlayfs was first merged, overlayfs files of regular files
and directories, the ones that are installed in file table, had a
"fake" path, namely, f_path is the overlayfs path and f_inode is
the "real" inode on the underlying filesystem.
In v6.5, we took another small step by introducing of the
backing_file container and the file_real_path() helper. This change
allowed vfs and filesystem code to get the "real" path of an
overlayfs backing file. With this change, we were able to make
fsnotify work correctly and report events on the "real" filesystem
objects that were accessed via overlayfs.
This method works fine, but it still leaves the vfs vulnerable to
new code that is not aware of files with fake path. A recent
example is commit db1d1e8b98 ("IMA: use vfs_getattr_nosec to get
the i_version"). This commit uses direct referencing to f_path in
IMA code that otherwise uses file_inode() and file_dentry() to
reference the filesystem objects that it is measuring.
This contains work to switch things around: instead of having
filesystem code opt-in to get the "real" path, have generic code
opt-in for the "fake" path in the few places that it is needed.
Is it far more likely that new filesystems code that does not use
the file_dentry() and file_real_path() helpers will end up causing
crashes or averting LSM/audit rules if we keep the "fake" path
exposed by default.
This change already makes file_dentry() moot, but for now we did
not change this helper just added a WARN_ON() in ovl_d_real() to
catch if we have made any wrong assumptions.
After the dust settles on this change, we can make file_dentry() a
plain accessor and we can drop the inode argument to ->d_real().
- Switch struct file to SLAB_TYPESAFE_BY_RCU. This looks like a small
change but it really isn't and I would like to see everyone on
their tippie toes for any possible bugs from this work.
Essentially we've been doing most of what SLAB_TYPESAFE_BY_RCU for
files since a very long time because of the nasty interactions
between the SCM_RIGHTS file descriptor garbage collection. So
extending it makes a lot of sense but it is a subtle change. There
are almost no places that fiddle with file rcu semantics directly
and the ones that did mess around with struct file internal under
rcu have been made to stop doing that because it really was always
dodgy.
I forgot to put in the link tag for this change and the discussion
in the commit so adding it into the merge message:
https://lore.kernel.org/r/20230926162228.68666-1-mjguzik@gmail.com
Cleanups:
- Various smaller pipe cleanups including the removal of a spin lock
that was only used to protect against writes without pipe_lock()
from O_NOTIFICATION_PIPE aka watch queues. As that was never
implemented remove the additional locking from pipe_write().
- Annotate struct watch_filter with the new __counted_by attribute.
- Clarify do_unlinkat() cleanup so that it doesn't look like an extra
iput() is done that would cause issues.
- Simplify file cleanup when the file has never been opened.
- Use module helper instead of open-coding it.
- Predict error unlikely for stale retry.
- Use WRITE_ONCE() for mount expiry field instead of just commenting
that one hopes the compiler doesn't get smart.
Fixes:
- Fix readahead on block devices.
- Fix writeback when layztime is enabled and inodes whose timestamp
is the only thing that changed reside on wb->b_dirty_time. This
caused excessively large zombie memory cgroup when lazytime was
enabled as such inodes weren't handled fast enough.
- Convert BUG_ON() to WARN_ON_ONCE() in open_last_lookups()"
* tag 'vfs-6.7.misc' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs: (26 commits)
file, i915: fix file reference for mmap_singleton()
vfs: Convert BUG_ON to WARN_ON_ONCE in open_last_lookups
writeback, cgroup: switch inodes with dirty timestamps to release dying cgwbs
chardev: Simplify usage of try_module_get()
ovl: rely on SB_I_NOUMASK
fs: fix umask on NFS with CONFIG_FS_POSIX_ACL=n
fs: store real path instead of fake path in backing file f_path
fs: create helper file_user_path() for user displayed mapped file path
fs: get mnt_writers count for an open backing file's real path
vfs: stop counting on gcc not messing with mnt_expiry_mark if not asked
vfs: predict the error in retry_estale as unlikely
backing file: free directly
vfs: fix readahead(2) on block devices
io_uring: use files_lookup_fd_locked()
file: convert to SLAB_TYPESAFE_BY_RCU
vfs: shave work on failed file open
fs: simplify misleading code to remove ambiguity regarding ihold()/iput()
watch_queue: Annotate struct watch_filter with __counted_by
fs/pipe: use spinlock in pipe_read() only if there is a watch_queue
fs/pipe: remove unnecessary spinlock from pipe_write()
...
The logic of whether filesystem can encode/decode file handles is open
coded in many places.
In preparation to changing the logic, move the open coded logic into
inline helpers.
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://lore.kernel.org/r/20231023180801.2953446-2-amir73il@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
In commit f61b9bb3f838 ("fs: add a new SB_I_NOUMASK flag") we added a
new SB_I_NOUMASK flag that is used by filesystems like NFS to indicate
that umask stripping is never supposed to be done in the vfs independent
of whether or not POSIX ACLs are supported.
Overlayfs falls into the same category as it raises SB_POSIXACL
unconditionally to defer umask application to the upper filesystem.
Now that we have SB_I_NOUMASK use that and make SB_POSIXACL properly
conditional on whether or not the kernel does have support for it. This
will enable use to turn IS_POSIXACL() into nop on kernels that don't
have POSIX ACL support avoding bugs from missed umask stripping.
Link: https://lore.kernel.org/r/20231012-einband-uferpromenade-80541a047a1f@brauner
Acked-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
A backing file struct stores two path's, one "real" path that is referring
to f_inode and one "fake" path, which should be displayed to users in
/proc/<pid>/maps.
There is a lot more potential code that needs to know the "real" path, then
code that needs to know the "fake" path.
Instead of code having to request the "real" path with file_real_path(),
store the "real" path in f_path and require code that needs to know the
"fake" path request it with file_user_path().
Replace the file_real_path() helper with a simple const accessor f_path().
After this change, file_dentry() is not expected to observe any files
with overlayfs f_path and real f_inode, so the call to ->d_real() should
not be needed. Leave the ->d_real() call for now and add an assertion
in ovl_d_real() to catch if we made wrong assumptions.
Suggested-by: Miklos Szeredi <miklos@szeredi.hu>
Link: https://lore.kernel.org/r/CAJfpegtt48eXhhjDFA1ojcHPNKj3Go6joryCPtEFAKpocyBsnw@mail.gmail.com/
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://lore.kernel.org/r/20231009153712.1566422-4-amir73il@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Kernel v6.5 converted overlayfs to new mount api.
As an added bonus, it also added a feature to allow appending lowerdirs
using lowerdir=:/lower2,lowerdir=::/data3 syntax.
This new syntax has raised some concerns regarding escaping of colons.
We decided to try and disable this syntax, which hasn't been in the wild
for so long and introduce it again in 6.7 using explicit mount options
lowerdir+=/lower2,datadir+=/data3.
Suggested-by: Miklos Szeredi <miklos@szeredi.hu>
Link: https://lore.kernel.org/r/CAJfpegsr3A4YgF2YBevWa6n3=AcP7hNndG6EPMu3ncvV-AM71A@mail.gmail.com/
Fixes: b36a5780cb ("ovl: modify layer parameter parsing")
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Before commit b36a5780cb ("ovl: modify layer parameter parsing"),
spaces and commas in lowerdir mount option value used to be escaped using
seq_show_option().
In current upstream, when lowerdir value has a space, it is not escaped
in /proc/mounts, e.g.:
none /mnt overlay rw,relatime,lowerdir=l l,upperdir=u,workdir=w 0 0
which results in broken output of the mount utility:
none on /mnt type overlay (rw,relatime,lowerdir=l)
Store the original lowerdir mount options before unescaping and show
them using the same escaping used for seq_show_option() in addition to
escaping the colon separator character.
Fixes: b36a5780cb ("ovl: modify layer parameter parsing")
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Ever since commit 91c7794713 ("ovl: allow filenames with comma"), the
following example was legit overlayfs mount options:
mount -t overlay overlay -o 'lowerdir=/tmp/a\,b/lower' /mnt
The conversion to new mount api moved to using the common helper
generic_parse_monolithic() and discarded the specialized ovl_next_opt()
option separator.
Bring back ovl_next_opt() and use vfs_parse_monolithic_sep() to fix the
regression.
Reported-by: Ryan Hendrickson <ryan.hendrickson@alum.mit.edu>
Closes: https://lore.kernel.org/r/8da307fb-9318-cf78-8a27-ba5c5a0aef6d@alum.mit.edu/
Fixes: 1784fbc2ed ("ovl: port to new mount api")
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
This makes it harder for accidental or malicious changes to
ovl_trusted_xattr_handlers or ovl_user_xattr_handlers at runtime.
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: linux-unionfs@vger.kernel.org
Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com>
Link: https://lore.kernel.org/r/20230930050033.41174-28-wedsonaf@gmail.com
Acked-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
A wrong return value from ovl_check_encode_origin() would cause
ovl_dentry_to_fid() to try to encode fid from NULL upper dentry.
Reported-by: syzbot+2208f82282740c1c8915@syzkaller.appspotmail.com
Fixes: 16aac5ad1f ("ovl: support encoding non-decodable file handles")
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
ovl_permission() accesses ->layers[...].mnt; we can't have ->layers
freed without an RCU delay on fs shutdown.
Fortunately, kern_unmount_array() that is used to drop those mounts
does include an RCU delay, so freeing is delayed; unfortunately, the
array passed to kern_unmount_array() is formed by mangling ->layers
contents and that happens without any delays.
The ->layers[...].name string entries are used to store the strings to
display in "lowerdir=..." by ovl_show_options(). Those entries are not
accessed in RCU walk.
Move the name strings into a separate array ofs->config.lowerdirs and
reuse the ofs->config.lowerdirs array as the temporary mount array to
pass to kern_unmount_array().
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Link: https://lore.kernel.org/r/20231002023711.GP3389589@ZenIV/
Acked-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
d_inode_rcu() is right - we might be in rcu pathwalk;
however, OVL_E() hides plain d_inode() on the same dentry...
Fixes: a6ff2bc0be ("ovl: use OVL_E() and OVL_E_FLAGS() accessors")
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
... into ->free_inode(), that is.
Fixes: 0af950f57f "ovl: move ovl_entry into ovl_inode"
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Commit 724768a393 ("ovl: fix incorrect fdput() on aio completion")
took a refcount on real file before submitting aio, but forgot to
avoid clearing FDPUT_FPUT from real.flags stack variable.
This can result in a file reference leak.
Fixes: 724768a393 ("ovl: fix incorrect fdput() on aio completion")
Reported-by: Gil Lev <contact@levgil.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
-----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCZRKHuAAKCRCRxhvAZXjc
ohOLAQDU9Fxq5UdqCdmsyi/b24XJFZlQhcVIZy2Hrhcor9TiVQEAjuECGlxFPSgj
atVOWLdugDJquiHextqTEMgIecJpNw4=
=uINF
-----END PGP SIGNATURE-----
Merge tag 'v6.6-rc4.vfs.fixes' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs
Pull vfs fixes from Christian Brauner:
"This contains the usual miscellaneous fixes and cleanups for vfs and
individual fses:
Fixes:
- Revert ki_pos on error from buffered writes for direct io fallback
- Add missing documentation for block device and superblock handling
for changes merged this cycle
- Fix reiserfs flexible array usage
- Ensure that overlayfs sets ctime when setting mtime and atime
- Disable deferred caller completions with overlayfs writes until
proper support exists
Cleanups:
- Remove duplicate initialization in pipe code
- Annotate aio kioctx_table with __counted_by"
* tag 'v6.6-rc4.vfs.fixes' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs:
overlayfs: set ctime when setting mtime and atime
ntfs3: put resources during ntfs_fill_super()
ovl: disable IOCB_DIO_CALLER_COMP
porting: document superblock as block device holder
porting: document new block device opening order
fs/pipe: remove duplicate "offset" initializer
fs-writeback: do not requeue a clean inode having skipped pages
aio: Annotate struct kioctx_table with __counted_by
direct_write_fallback(): on error revert the ->ki_pos update from buffered write
reiserfs: Replace 1-element array with C99 style flex-array
Nathan reported that he was seeing the new warning in
setattr_copy_mgtime pop when starting podman containers. Overlayfs is
trying to set the atime and mtime via notify_change without also
setting the ctime.
POSIX states that when the atime and mtime are updated via utimes() that
we must also update the ctime to the current time. The situation with
overlayfs copy-up is analogies, so add ATTR_CTIME to the bitmask.
notify_change will fill in the value.
Reported-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Christian Brauner <brauner@kernel.org>
Acked-by: Amir Goldstein <amir73il@gmail.com>
Message-Id: <20230913-ctime-v1-1-c6bc509cbc27@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
overlayfs copies the kiocb flags when it sets up a new kiocb to handle
a write, but it doesn't properly support dealing with the deferred
caller completions of the kiocb. This means it doesn't get the final
write completion value, and hence will complete the write with '0' as
the result.
We could support the caller completions in overlayfs, but for now let's
just disable them in the generated write kiocb.
Reported-by: Zorro Lang <zlang@redhat.com>
Link: https://lore.kernel.org/io-uring/20230924142754.ejwsjen5pvyc32l4@dell-per750-06-vm-08.rhts.eng.pek2.redhat.com/
Fixes: 8c052fb300 ("iomap: support IOCB_DIO_CALLER_COMP")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Message-Id: <71897125-e570-46ce-946a-d4729725e28f@kernel.dk>
Signed-off-by: Christian Brauner <brauner@kernel.org>
ovl_{read,write}_iter() always call fdput(real) to put one or zero
refcounts of the real file, but for aio, whether it was submitted or not,
ovl_aio_put() also calls fdput(), which is not balanced. This is only a
problem in the less common case when FDPUT_FPUT flag is set.
To fix the problem use get_file() to take file refcount and use fput()
instead of fdput() in ovl_aio_put().
Fixes: 2406a307ac ("ovl: implement async IO routines")
Cc: <stable@vger.kernel.org> # v5.6
Reviewed-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Some local filesystems support setting persistent fileattr flags
(e.g. FS_NOATIME_FL) on directories and regular files via ioctl.
Some of those persistent fileattr flags are reflected to vfs as
in-memory inode flags (e.g. S_NOATIME).
Overlayfs uses the in-memory inode flags (e.g. S_NOATIME) on a lower file
as an indication that a the lower file may have persistent inode fileattr
flags (e.g. FS_NOATIME_FL) that need to be copied to upper file.
However, in some cases, the S_NOATIME in-memory flag could be a false
indication for persistent FS_NOATIME_FL fileattr. For example, with NFS
and FUSE lower fs, as was the case in the two bug reports, the S_NOATIME
flag is set unconditionally for all inodes.
Users cannot set persistent fileattr flags on symlinks and special files,
but in some local fs, such as ext4/btrfs/tmpfs, the FS_NOATIME_FL fileattr
flag are inheritted to symlinks and special files from parent directory.
In both cases described above, when lower symlink has the S_NOATIME flag,
overlayfs will try to copy the symlink's fileattrs and fail with error
ENOXIO, because it could not open the symlink for the ioctl security hook.
To solve this failure, do not attempt to copyup fileattrs for anything
other than directories and regular files.
Reported-by: Ruiwen Zhao <ruiwen@google.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217850
Fixes: 72db82115d ("ovl: copy up sync/noatime fileattr flags")
Cc: <stable@vger.kernel.org> # v5.15
Reviewed-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
-----BEGIN PGP SIGNATURE-----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=F4Hi
-----END PGP SIGNATURE-----
Merge tag 'ovl-update-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/overlayfs/vfs
Pull overlayfs updates from Amir Goldstein:
- add verification feature needed by composefs (Alexander Larsson)
- improve integration of overlayfs and fanotify (Amir Goldstein)
- fortify some overlayfs code (Andrea Righi)
* tag 'ovl-update-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/overlayfs/vfs:
ovl: validate superblock in OVL_FS()
ovl: make consistent use of OVL_FS()
ovl: Kconfig: introduce CONFIG_OVERLAY_FS_DEBUG
ovl: auto generate uuid for new overlay filesystems
ovl: store persistent uuid/fsid with uuid=on
ovl: add support for unique fsid per instance
ovl: support encoding non-decodable file handles
ovl: Handle verity during copy-up
ovl: Validate verity xattr when resolving lowerdata
ovl: Add versioned header for overlay.metacopy xattr
ovl: Add framework for verity support
-----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCZOXTxQAKCRCRxhvAZXjc
okaVAP94WAlItvDRt/z2Wtzf0+RqPZeTXEdGTxua8+RxqCyYIQD+OO5nRfKQPHlV
AqqGJMKItQMSMIYgB5ftqVhNWZfnHgM=
=pSEW
-----END PGP SIGNATURE-----
Merge tag 'v6.6-vfs.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull misc vfs updates from Christian Brauner:
"This contains the usual miscellaneous features, cleanups, and fixes
for vfs and individual filesystems.
Features:
- Block mode changes on symlinks and rectify our broken semantics
- Report file modifications via fsnotify() for splice
- Allow specifying an explicit timeout for the "rootwait" kernel
command line option. This allows to timeout and reboot instead of
always waiting indefinitely for the root device to show up
- Use synchronous fput for the close system call
Cleanups:
- Get rid of open-coded lockdep workarounds for async io submitters
and replace it all with a single consolidated helper
- Simplify epoll allocation helper
- Convert simple_write_begin and simple_write_end to use a folio
- Convert page_cache_pipe_buf_confirm() to use a folio
- Simplify __range_close to avoid pointless locking
- Disable per-cpu buffer head cache for isolated cpus
- Port ecryptfs to kmap_local_page() api
- Remove redundant initialization of pointer buf in pipe code
- Unexport the d_genocide() function which is only used within core
vfs
- Replace printk(KERN_ERR) and WARN_ON() with WARN()
Fixes:
- Fix various kernel-doc issues
- Fix refcount underflow for eventfds when used as EFD_SEMAPHORE
- Fix a mainly theoretical issue in devpts
- Check the return value of __getblk() in reiserfs
- Fix a racy assert in i_readcount_dec
- Fix integer conversion issues in various functions
- Fix LSM security context handling during automounts that prevented
NFS superblock sharing"
* tag 'v6.6-vfs.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (39 commits)
cachefiles: use kiocb_{start,end}_write() helpers
ovl: use kiocb_{start,end}_write() helpers
aio: use kiocb_{start,end}_write() helpers
io_uring: use kiocb_{start,end}_write() helpers
fs: create kiocb_{start,end}_write() helpers
fs: add kerneldoc to file_{start,end}_write() helpers
io_uring: rename kiocb_end_write() local helper
splice: Convert page_cache_pipe_buf_confirm() to use a folio
libfs: Convert simple_write_begin and simple_write_end to use a folio
fs/dcache: Replace printk and WARN_ON by WARN
fs/pipe: remove redundant initialization of pointer buf
fs: Fix kernel-doc warnings
devpts: Fix kernel-doc warnings
doc: idmappings: fix an error and rephrase a paragraph
init: Add support for rootwait timeout parameter
vfs: fix up the assert in i_readcount_dec
fs: Fix one kernel-doc comment
docs: filesystems: idmappings: clarify from where idmappings are taken
fs/buffer.c: disable per-CPU buffer_head cache for isolated CPUs
vfs, security: Fix automount superblock LSM init problem, preventing NFS sb sharing
...
-----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCZOXTKAAKCRCRxhvAZXjc
oifJAQCzi/p+AdQu8LA/0XvR7fTwaq64ZDCibU4BISuLGT2kEgEAuGbuoFZa0rs2
XYD/s4+gi64p9Z01MmXm2XO1pu3GPg0=
=eJz5
-----END PGP SIGNATURE-----
Merge tag 'v6.6-vfs.ctime' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs timestamp updates from Christian Brauner:
"This adds VFS support for multi-grain timestamps and converts tmpfs,
xfs, ext4, and btrfs to use them. This carries acks from all relevant
filesystems.
The VFS always uses coarse-grained timestamps when updating the ctime
and mtime after a change. This has the benefit of allowing filesystems
to optimize away a lot of metadata updates, down to around 1 per
jiffy, even when a file is under heavy writes.
Unfortunately, this has always been an issue when we're exporting via
NFSv3, which relies on timestamps to validate caches. A lot of changes
can happen in a jiffy, so timestamps aren't sufficient to help the
client decide to invalidate the cache.
Even with NFSv4, a lot of exported filesystems don't properly support
a change attribute and are subject to the same problems with timestamp
granularity. Other applications have similar issues with timestamps
(e.g., backup applications).
If we were to always use fine-grained timestamps, that would improve
the situation, but that becomes rather expensive, as the underlying
filesystem would have to log a lot more metadata updates.
This introduces fine-grained timestamps that are used when they are
actively queried.
This uses the 31st bit of the ctime tv_nsec field to indicate that
something has queried the inode for the mtime or ctime. When this flag
is set, on the next mtime or ctime update, the kernel will fetch a
fine-grained timestamp instead of the usual coarse-grained one.
As POSIX generally mandates that when the mtime changes, the ctime
must also change the kernel always stores normalized ctime values, so
only the first 30 bits of the tv_nsec field are ever used.
Filesytems can opt into this behavior by setting the FS_MGTIME flag in
the fstype. Filesystems that don't set this flag will continue to use
coarse-grained timestamps.
Various preparatory changes, fixes and cleanups are included:
- Fixup all relevant places where POSIX requires updating ctime
together with mtime. This is a wide-range of places and all
maintainers provided necessary Acks.
- Add new accessors for inode->i_ctime directly and change all
callers to rely on them. Plain accesses to inode->i_ctime are now
gone and it is accordingly rename to inode->__i_ctime and commented
as requiring accessors.
- Extend generic_fillattr() to pass in a request mask mirroring in a
sense the statx() uapi. This allows callers to pass in a request
mask to only get a subset of attributes filled in.
- Rework timestamp updates so it's possible to drop the @now
parameter the update_time() inode operation and associated helpers.
- Add inode_update_timestamps() and convert all filesystems to it
removing a bunch of open-coding"
* tag 'v6.6-vfs.ctime' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (107 commits)
btrfs: convert to multigrain timestamps
ext4: switch to multigrain timestamps
xfs: switch to multigrain timestamps
tmpfs: add support for multigrain timestamps
fs: add infrastructure for multigrain timestamps
fs: drop the timespec64 argument from update_time
xfs: have xfs_vn_update_time gets its own timestamp
fat: make fat_update_time get its own timestamp
fat: remove i_version handling from fat_update_time
ubifs: have ubifs_update_time use inode_update_timestamps
btrfs: have it use inode_update_timestamps
fs: drop the timespec64 arg from generic_update_time
fs: pass the request_mask to generic_fillattr
fs: remove silly warning from current_time
gfs2: fix timestamp handling on quota inodes
fs: rename i_ctime field to __i_ctime
selinux: convert to ctime accessor functions
security: convert to ctime accessor functions
apparmor: convert to ctime accessor functions
sunrpc: convert to ctime accessor functions
...
Use helpers instead of the open coded dance to silence lockdep warnings.
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Message-Id: <20230817141337.1025891-7-amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
When CONFIG_OVERLAY_FS_DEBUG is enabled add an explicit check to make
sure that OVL_FS() is always used with a valid overlayfs superblock.
Otherwise trigger a WARN_ON_ONCE().
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Always use OVL_FS() to retrieve the corresponding struct ovl_fs from a
struct super_block.
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Provide a Kconfig option to enable extra debugging checks for overlayfs.
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Add a new mount option uuid=auto, which is the default.
If a persistent UUID xattr is found it is used.
Otherwise, an existing ovelrayfs with copied up subdirs in upper dir
that was never mounted with uuid=on retains the null UUID.
A new overlayfs with no copied up subdirs, generates the persistent UUID
on first mount.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
With uuid=on, store a persistent uuid in xattr on the upper dir to
give the overlayfs instance a persistent identifier.
This also makes f_fsid persistent and more reliable for reporting
fid info in fanotify events.
uuid=on is not supported on non-upper overlayfs or with upper fs
that does not support xattrs.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
The legacy behavior of ovl_statfs() reports the f_fsid filled by
underlying upper fs. This fsid is not unique among overlayfs instances
on the same upper fs.
With mount option uuid=on, generate a non-persistent uuid per overlayfs
instance and use it as the seed for f_fsid, similar to tmpfs.
This is useful for reporting fanotify events with fid info from different
instances of overlayfs over the same upper fs.
The old behavior of null uuid and upper fs fsid is retained with the
mount option uuid=null, which is the default.
The mount option uuid=off that disables uuid checks in underlying layers
also retains the legacy behavior.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
When all layers support file handles, we support encoding non-decodable
file handles (a.k.a. fid) even with nfs_export=off.
When file handles do not need to be decoded, we do not need to copy up
redirected lower directories on encode, and we encode also non-indexed
upper with lower file handle, so fid will not change on copy up.
This enables reporting fanotify events with file handles on overlayfs
with default config/mount options.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
During regular metacopy, if lowerdata file has fs-verity enabled, and
the verity option is enabled, we add the digest to the metacopy xattr.
If verity is required, and lowerdata does not have fs-verity enabled,
fall back to full copy-up (or the generated metacopy would not
validate).
Signed-off-by: Alexander Larsson <alexl@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
The new digest field in the metacopy xattr is used during lookup to
record whether the header contained a digest in the OVL_HAS_DIGEST
flags.
When accessing file data the first time, if OVL_HAS_DIGEST is set, we
reload the metadata and check that the source lowerdata inode matches
the specified digest in it (according to the enabled verity
options). If the verity check passes we store this info in the inode
flags as OVL_VERIFIED_DIGEST, so that we can avoid doing it again if
the inode remains in memory.
The verification is done in ovl_maybe_validate_verity() which needs to
be called in the same places as ovl_maybe_lookup_lowerdata(), so there
is a new ovl_verify_lowerdata() helper that calls these in the right
order, and all current callers of ovl_maybe_lookup_lowerdata() are
changed to call it instead.
Signed-off-by: Alexander Larsson <alexl@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Historically overlay.metacopy was a zero-size xattr, and it's
existence marked a metacopy file. This change adds a versioned header
with a flag field, a length and a digest. The initial use-case of this
will be for validating a fs-verity digest, but the flags field could
also be used later for other new features.
ovl_check_metacopy_xattr() now returns the size of the xattr,
emulating a size of OVL_METACOPY_MIN_SIZE for empty xattrs to
distinguish it from the no-xattr case.
Signed-off-by: Alexander Larsson <alexl@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
This adds the scaffolding (docs, config, mount options) for supporting
the new digest field in the metacopy xattr. This contains a fs-verity
digest that need to match the fs-verity digest of the lowerdata
file. The mount option "verity" specifies how this xattr is handled.
If you enable verity ("verity=on") all existing xattrs are validated
before use, and during metacopy we generate verity xattr in the upper
metacopy file (if the source file has verity enabled). This means
later accesses can guarantee that the same data is used.
Additionally you can use "verity=require". In this mode all metacopy
files must have a valid verity xattr. For this to work metadata
copy-up must be able to create a verity xattr (so that later accesses
are validated). Therefore, in this mode, if the lower data file
doesn't have fs-verity enabled we fall back to a full copy rather than
a metacopy.
Actual implementation follows in a separate commit.
Signed-off-by: Alexander Larsson <alexl@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Acked-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Now that all of the update_time operations are prepared for it, we can
drop the timespec64 argument from the update_time operation. Do that and
remove it from some associated functions like inode_update_time and
inode_needs_update_time.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Message-Id: <20230807-mgctime-v7-8-d1dec143a704@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
All users now just use '->iterate_shared()', which only takes the
directory inode lock for reading.
Filesystems that never got convered to shared mode now instead use a
wrapper that drops the lock, re-takes it in write mode, calls the old
function, and then downgrades the lock back to read mode.
This way the VFS layer and other callers no longer need to care about
filesystems that never got converted to the modern era.
The filesystems that use the new wrapper are ceph, coda, exfat, jfs,
ntfs, ocfs2, overlayfs, and vboxsf.
Honestly, several of them look like they really could just iterate their
directories in shared mode and skip the wrapper entirely, but the point
of this change is to not change semantics or fix filesystems that
haven't been fixed in the last 7+ years, but to finally get rid of the
dual iterators.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Commit db1d1e8b98 ("IMA: use vfs_getattr_nosec to get the i_version")
partially closed an IMA integrity issue when directly modifying a file
on the lower filesystem. If the overlay file is first opened by a user
and later the lower backing file is modified by root, but the extended
attribute is NOT updated, the signature validation succeeds with the old
original signature.
Update the super_block s_iflags to SB_I_IMA_UNVERIFIABLE_SIGNATURE to
force signature reevaluation on every file access until a fine grained
solution can be found.
Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.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.
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Message-Id: <20230705190309.579783-64-jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
While initially I thought that we couldn't move all new mount api
handling into params.{c,h} it turns out it is possible. So this just
moves a good chunk of code out of super.c and into params.{c,h}.
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
-----BEGIN PGP SIGNATURE-----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=KPxq
-----END PGP SIGNATURE-----
Merge tag 'ovl-update-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/overlayfs/vfs
Pull overlayfs update from Amir Goldstein:
- fix two NULL pointer deref bugs (Zhihao Cheng)
- add support for "data-only" lower layers destined to be used by
composefs
- port overlayfs to the new mount api (Christian Brauner)
* tag 'ovl-update-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/overlayfs/vfs: (26 commits)
ovl: add Amir as co-maintainer
ovl: reserve ability to reconfigure mount options with new mount api
ovl: modify layer parameter parsing
ovl: port to new mount api
ovl: factor out ovl_parse_options() helper
ovl: store enum redirect_mode in config instead of a string
ovl: pass ovl_fs to xino helpers
ovl: clarify ovl_get_root() semantics
ovl: negate the ofs->share_whiteout boolean
ovl: check type and offset of struct vfsmount in ovl_entry
ovl: implement lazy lookup of lowerdata in data-only layers
ovl: prepare for lazy lookup of lowerdata inode
ovl: prepare to store lowerdata redirect for lazy lowerdata lookup
ovl: implement lookup in data-only layers
ovl: introduce data-only lower layers
ovl: remove unneeded goto instructions
ovl: deduplicate lowerdata and lowerstack[]
ovl: deduplicate lowerpath and lowerstack[]
ovl: move ovl_entry into ovl_inode
ovl: factor out ovl_free_entry() and ovl_stack_*() helpers
...
-----BEGIN PGP SIGNATURE-----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=KhW4
-----END PGP SIGNATURE-----
Merge tag 'for-6.5/splice-2023-06-23' of git://git.kernel.dk/linux
Pull splice updates from Jens Axboe:
"This kills off ITER_PIPE to avoid a race between truncate,
iov_iter_revert() on the pipe and an as-yet incomplete DMA to a bio
with unpinned/unref'ed pages from an O_DIRECT splice read. This causes
memory corruption.
Instead, we either use (a) filemap_splice_read(), which invokes the
buffered file reading code and splices from the pagecache into the
pipe; (b) copy_splice_read(), which bulk-allocates a buffer, reads
into it and then pushes the filled pages into the pipe; or (c) handle
it in filesystem-specific code.
Summary:
- Rename direct_splice_read() to copy_splice_read()
- Simplify the calculations for the number of pages to be reclaimed
in copy_splice_read()
- Turn do_splice_to() into a helper, vfs_splice_read(), so that it
can be used by overlayfs and coda to perform the checks on the
lower fs
- Make vfs_splice_read() jump to copy_splice_read() to handle
direct-I/O and DAX
- Provide shmem with its own splice_read to handle non-existent pages
in the pagecache. We don't want a ->read_folio() as we don't want
to populate holes, but filemap_get_pages() requires it
- Provide overlayfs with its own splice_read to call down to a lower
layer as overlayfs doesn't provide ->read_folio()
- Provide coda with its own splice_read to call down to a lower layer
as coda doesn't provide ->read_folio()
- Direct ->splice_read to copy_splice_read() in tty, procfs, kernfs
and random files as they just copy to the output buffer and don't
splice pages
- Provide wrappers for afs, ceph, ecryptfs, ext4, f2fs, nfs, ntfs3,
ocfs2, orangefs, xfs and zonefs to do locking and/or revalidation
- Make cifs use filemap_splice_read()
- Replace pointers to generic_file_splice_read() with pointers to
filemap_splice_read() as DIO and DAX are handled in the caller;
filesystems can still provide their own alternate ->splice_read()
op
- Remove generic_file_splice_read()
- Remove ITER_PIPE and its paraphernalia as generic_file_splice_read
was the only user"
* tag 'for-6.5/splice-2023-06-23' of git://git.kernel.dk/linux: (31 commits)
splice: kdoc for filemap_splice_read() and copy_splice_read()
iov_iter: Kill ITER_PIPE
splice: Remove generic_file_splice_read()
splice: Use filemap_splice_read() instead of generic_file_splice_read()
cifs: Use filemap_splice_read()
trace: Convert trace/seq to use copy_splice_read()
zonefs: Provide a splice-read wrapper
xfs: Provide a splice-read wrapper
orangefs: Provide a splice-read wrapper
ocfs2: Provide a splice-read wrapper
ntfs3: Provide a splice-read wrapper
nfs: Provide a splice-read wrapper
f2fs: Provide a splice-read wrapper
ext4: Provide a splice-read wrapper
ecryptfs: Provide a splice-read wrapper
ceph: Provide a splice-read wrapper
afs: Provide a splice-read wrapper
9p: Add splice_read wrapper
net: Make sock_splice_read() use copy_splice_read() by default
tty, proc, kernfs, random: Use copy_splice_read()
...
Using the old mount api to remount an overlayfs superblock via
mount(MS_REMOUNT) all mount options will be silently ignored. For
example, if you create an overlayfs mount:
mount -t overlay overlay -o lowerdir=/mnt/a:/mnt/b,upperdir=/mnt/upper,workdir=/mnt/work /mnt/merged
and then issue a remount via:
# force mount(8) to use mount(2)
export LIBMOUNT_FORCE_MOUNT2=always
mount -t overlay overlay -o remount,WOOTWOOT,lowerdir=/DOESNT-EXIST /mnt/merged
with completely nonsensical mount options whatsoever it will succeed
nonetheless. This prevents us from every changing any mount options we
might introduce in the future that could reasonably be changed during a
remount.
We don't need to carry this issue into the new mount api port. Similar
to FUSE we can use the fs_context::oldapi member to figure out that this
is a request coming through the legacy mount api. If we detect it we
continue silently ignoring all mount options.
But for the new mount api we simply report that mount options cannot
currently be changed. This will allow us to potentially alter mount
properties for new or even old properties. It any case, silently
ignoring everything is not something new apis should do.
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
We ran into issues where mount(8) passed multiple lower layers as one
big string through fsconfig(). But the fsconfig() FSCONFIG_SET_STRING
option is limited to 256 bytes in strndup_user(). While this would be
fixable by extending the fsconfig() buffer I'd rather encourage users to
append layers via multiple fsconfig() calls as the interface allows
nicely for this. This has also been requested as a feature before.
With this port to the new mount api the following will be possible:
fsconfig(fs_fd, FSCONFIG_SET_STRING, "lowerdir", "/lower1", 0);
/* set upper layer */
fsconfig(fs_fd, FSCONFIG_SET_STRING, "upperdir", "/upper", 0);
/* append "/lower2", "/lower3", and "/lower4" */
fsconfig(fs_fd, FSCONFIG_SET_STRING, "lowerdir", ":/lower2:/lower3:/lower4", 0);
/* turn index feature on */
fsconfig(fs_fd, FSCONFIG_SET_STRING, "index", "on", 0);
/* append "/lower5" */
fsconfig(fs_fd, FSCONFIG_SET_STRING, "lowerdir", ":/lower5", 0);
Specifying ':' would have been rejected so this isn't a regression. And
we can't simply use "lowerdir=/lower" to append on top of existing
layers as "lowerdir=/lower,lowerdir=/other-lower" would make
"/other-lower" the only lower layer so we'd break uapi if we changed
this. So the ':' prefix seems a good compromise.
Users can choose to specify multiple layers at once or individual
layers. A layer is appended if it starts with ":". This requires that
the user has already added at least one layer before. If lowerdir is
specified again without a leading ":" then all previous layers are
dropped and replaced with the new layers. If lowerdir is specified and
empty than all layers are simply dropped.
An additional change is that overlayfs will now parse and resolve layers
right when they are specified in fsconfig() instead of deferring until
super block creation. This allows users to receive early errors.
It also allows users to actually use up to 500 layers something which
was theoretically possible but ended up not working due to the mount
option string passed via mount(2) being too large.
This also allows a more privileged process to set config options for a
lesser privileged process as the creds for fsconfig() and the creds for
fsopen() can differ. We could restrict that they match by enforcing that
the creds of fsopen() and fsconfig() match but I don't see why that
needs to be the case and allows for a good delegation mechanism.
Plus, in the future it means we're able to extend overlayfs mount
options and allow users to specify layers via file descriptors instead
of paths:
fsconfig(FSCONFIG_SET_PATH{_EMPTY}, "lowerdir", "lower1", dirfd);
/* append */
fsconfig(FSCONFIG_SET_PATH{_EMPTY}, "lowerdir", "lower2", dirfd);
/* append */
fsconfig(FSCONFIG_SET_PATH{_EMPTY}, "lowerdir", "lower3", dirfd);
/* clear all layers specified until now */
fsconfig(FSCONFIG_SET_STRING, "lowerdir", NULL, 0);
This would be especially nice if users create an overlayfs mount on top
of idmapped layers or just in general private mounts created via
open_tree(OPEN_TREE_CLONE). Those mounts would then never have to appear
anywhere in the filesystem. But for now just do the minimal thing.
We should probably aim to move more validation into ovl_fs_parse_param()
so users get errors before fsconfig(FSCONFIG_CMD_CREATE). But that can
be done in additional patches later.
This is now also rebased on top of the lazy lowerdata lookup which
allows the specificatin of data only layers using the new "::" syntax.
The rules are simple. A data only layers cannot be followed by any
regular layers and data layers must be preceeded by at least one regular
layer.
Parsing the lowerdir mount option must change because of this. The
original patchset used the old lowerdir parsing function to split a
lowerdir mount option string such as:
lowerdir=/lower1:/lower2::/lower3::/lower4
simply replacing each non-escaped ":" by "\0". So sequences of
non-escaped ":" were counted as layers. For example, the previous
lowerdir mount option above would've counted 6 layers instead of 4 and a
lowerdir mount option such as:
lowerdir="/lower1:/lower2::/lower3::/lower4:::::::::::::::::::::::::::"
would be counted as 33 layers. Other than being ugly this didn't matter
much because kern_path() would reject the first "\0" layer. However,
this overcounting of layers becomes problematic when we base allocations
on it where we very much only want to allocate space for 4 layers
instead of 33.
So the new parsing function rejects non-escaped sequences of colons
other than ":" and "::" immediately instead of relying on kern_path().
Link: https://github.com/util-linux/util-linux/issues/2287
Link: https://github.com/util-linux/util-linux/issues/1992
Link: https://bugs.archlinux.org/task/78702
Link: https://lore.kernel.org/linux-unionfs/20230530-klagen-zudem-32c0908c2108@brauner
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Overlayfs creates the real underlying files with fake f_path, whose
f_inode is on the underlying fs and f_path on overlayfs.
Those real files were open with FMODE_NONOTIFY, because fsnotify code was
not prapared to handle fsnotify hooks on files with fake path correctly
and fanotify would report unexpected event->fd with fake overlayfs path,
when the underlying fs was being watched.
Teach fsnotify to handle events on the real files, and do not set real
files to FMODE_NONOTIFY to allow operations on real file (e.g. open,
access, modify, close) to generate async and permission events.
Because fsnotify does not have notifications on address space
operations, we do not need to worry about ->vm_file not reporting
events to a watched overlayfs when users are accessing a mapped
overlayfs file.
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Message-Id: <20230615112229.2143178-6-amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Overlayfs uses open_with_fake_path() to allocate internal kernel files,
with a "fake" path - whose f_path is not on the same fs as f_inode.
Allocate a container struct backing_file for those internal files, that
is used to hold the "fake" ovl path along with the real path.
backing_file_real_path() can be used to access the stored real path.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Message-Id: <20230615112229.2143178-5-amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Overlayfs and cachefiles use vfs_open_tmpfile() to open a tmpfile
without accounting for nr_files.
Rename this helper to kernel_tmpfile_open() to better reflect this
helper is used for kernel internal users.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Message-Id: <20230615112229.2143178-2-amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
We recently ported util-linux to the new mount api. Now the mount(8)
tool will by default use the new mount api. While trying hard to fall
back to the old mount api gracefully there are still cases where we run
into issues that are difficult to handle nicely.
Now with mount(8) and libmount supporting the new mount api I expect an
increase in the number of bug reports and issues we're going to see with
filesystems that don't yet support the new mount api. So it's time we
rectify this.
When ovl_fill_super() fails before setting sb->s_root, we need to cleanup
sb->s_fs_info. The logic is a bit convoluted but tl;dr: If sget_fc() has
succeeded fc->s_fs_info will have been transferred to sb->s_fs_info.
So by the time ->fill_super()/ovl_fill_super() is called fc->s_fs_info
is NULL consequently fs_context->free() won't call ovl_free_fs().
If we fail before sb->s_root() is set then ->put_super() won't be called
which would call ovl_free_fs(). IOW, if we fail in ->fill_super() before
sb->s_root we have to clean it up.
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Do all the logic to set the mode during mount options parsing and
do not keep the option string around.
Use a constant_table to translate from enum redirect mode to string
in preperation for new mount api option parsing.
The mount option "off" is translated to either "follow" or "nofollow",
depending on the "redirect_always_follow" build/module config, so
in effect, there are only three possible redirect modes.
This results in a minor change to the string that is displayed
in show_options() - when redirect_dir is enabled by default and the user
mounts with the option "redirect_dir=off", instead of displaying the mode
"redirect_dir=off" in show_options(), the displayed mode will be either
"redirect_dir=follow" or "redirect_dir=nofollow", depending on the value
of "redirect_always_follow" build/module config.
The displayed mode reflects the effective mode, so mounting overlayfs
again with the dispalyed redirect_dir option will result with the same
effective and displayed mode.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Internal ovl methods should use ovl_fs and not sb as much as
possible.
Use a constant_table to translate from enum xino mode to string
in preperation for new mount api option parsing.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Change the semantics to take a reference on upperdentry instead
of transferrig the reference.
This is needed for upcoming port to new mount api.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
The default common case is that whiteout sharing is enabled.
Change to storing the negated no_shared_whiteout state, so we will not
need to initialize it.
This is the first step towards removing all config and feature
initializations out of ovl_fill_super().
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Porting overlayfs to the new amount api I started experiencing random
crashes that couldn't be explained easily. So after much debugging and
reasoning it became clear that struct ovl_entry requires the point to
struct vfsmount to be the first member and of type struct vfsmount.
During the port I added a new member at the beginning of struct
ovl_entry which broke all over the place in the form of random crashes
and cache corruptions. While there's a comment in ovl_free_fs() to the
effect of "Hack! Reuse ofs->layers as a vfsmount array before freeing
it" there's no such comment on struct ovl_entry which makes this easy to
trip over.
Add a comment and two static asserts for both the offset and the type of
pointer in struct ovl_entry.
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Defer lookup of lowerdata in the data-only layers to first data access
or before copy up.
We perform lowerdata lookup before copy up even if copy up is metadata
only copy up. We can further optimize this lookup later if needed.
We do best effort lazy lookup of lowerdata for d_real_inode(), because
this interface does not expect errors. The only current in-tree caller
of d_real_inode() is trace_uprobe and this caller is likely going to be
followed reading from the file, before placing uprobes on offset within
the file, so lowerdata should be available when setting the uprobe.
Tested-by: kernel test robot <oliver.sang@intel.com>
Reviewed-by: Alexander Larsson <alexl@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Make the code handle the case of numlower > 1 and missing lowerdata
dentry gracefully.
Missing lowerdata dentry is an indication for lazy lookup of lowerdata
and in that case the lowerdata_redirect path is stored in ovl_inode.
Following commits will defer lookup and perform the lazy lookup on
access.
Reviewed-by: Alexander Larsson <alexl@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Prepare to allow ovl_lookup() to leave the last entry in a non-dir
lowerstack empty to signify lazy lowerdata lookup.
In this case, ovl_lookup() stores the redirect path from metacopy to
lowerdata in ovl_inode, which is going to be used later to perform the
lazy lowerdata lookup.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Lookup in data-only layers only for a lower metacopy with an absolute
redirect xattr.
The metacopy xattr is not checked on files found in the data-only layers
and redirect xattr are not followed in the data-only layers.
Reviewed-by: Alexander Larsson <alexl@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Introduce the format lowerdir=lower1:lower2::lowerdata1::lowerdata2
where the lower layers on the right of the :: separators are not merged
into the overlayfs merge dirs.
Data-only lower layers are only allowed at the bottom of the stack.
The files in those layers are only meant to be accessible via absolute
redirect from metacopy files in lower layers. Following changes will
implement lookup in the data layers.
This feature was requested for composefs ostree use case, where the
lower data layer should only be accessiable via absolute redirects
from metacopy inodes.
The lower data layers are not required to a have a unique uuid or any
uuid at all, because they are never used to compose the overlayfs inode
st_ino/st_dev.
Reviewed-by: Alexander Larsson <alexl@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
There is nothing in the out goto target of ovl_get_layers().
Reviewed-by: Alexander Larsson <alexl@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
The ovl_inode contains a copy of lowerdata in lowerstack[], so the
lowerdata inode member can be removed.
Use accessors ovl_lowerdata*() to get the lowerdata whereever the member
was accessed directly.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
The ovl_inode contains a copy of lowerpath in lowerstack[0], so the
lowerpath member can be removed.
Use accessor ovl_lowerpath() to get the lowerpath whereever the member
was accessed directly.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
The lower stacks of all the ovl inode aliases should be identical
and there is redundant information in ovl_entry and ovl_inode.
Move lowerstack into ovl_inode and keep only the OVL_E_FLAGS
per overlay dentry.
Following patches will deduplicate redundant ovl_inode fields.
Note that for pure upper and negative dentries, OVL_E(dentry) may be
NULL now, so it is imporatnt to use the ovl_numlower() accessor.
Reviewed-by: Alexander Larsson <alexl@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
In preparation for moving lowerstack into ovl_inode.
Note that in ovl_lookup() the temp stack dentry refs are now cloned
into the final ovl_lowerstack instead of being transferred, so cleanup
always needs to call ovl_stack_free(stack).
Reviewed-by: Alexander Larsson <alexl@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
This helps fortify against dereferencing a NULL ovl_entry,
before we move the ovl_entry reference into ovl_inode.
Reviewed-by: Alexander Larsson <alexl@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Instead of open coded instances, because we are about to split
the two apart.
Reviewed-by: Alexander Larsson <alexl@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
After copy up, we may need to update d_flags if upper dentry is on a
remote fs and lower dentries are not.
Add helpers to allow incremental update of the revalidate flags.
Fixes: bccece1ead ("ovl: allow remote upper")
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Let helper ovl_i_path_real() return the realinode to prepare for
checking non-null realinode in RCU walking path.
[msz] Use d_inode_rcu() since we are depending on the consitency
between dentry and inode being non-NULL in an RCU setting.
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Fixes: ffa5723c6d ("ovl: store lower path in ovl_inode")
Cc: <stable@vger.kernel.org> # v5.19
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Implement splice-read for overlayfs by passing the request down a layer
rather than going through generic_file_splice_read() which is going to be
changed to assume that ->read_folio() is present on buffered files.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Christian Brauner <brauner@kernel.org>
cc: Christoph Hellwig <hch@lst.de>
cc: Jens Axboe <axboe@kernel.dk>
cc: Al Viro <viro@zeniv.linux.org.uk>
cc: John Hubbard <jhubbard@nvidia.com>
cc: David Hildenbrand <david@redhat.com>
cc: Matthew Wilcox <willy@infradead.org>
cc: Miklos Szeredi <miklos@szeredi.hu>
cc: Amir Goldstein <amir73il@gmail.com>
cc: linux-unionfs@vger.kernel.org
cc: linux-block@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
Link: https://lore.kernel.org/r/20230522135018.2742245-11-dhowells@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We have decoupled vfs_listxattr() from IOP_XATTR. Instead we just need
to check whether inode->i_op->listxattr is implemented.
Cc: linux-unionfs@vger.kernel.org
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Remove struct posix_acl_{access,default}_handler for all filesystems
that don't depend on the xattr handler in their inode->i_op->listxattr()
method in any way. There's nothing more to do than to simply remove the
handler. It's been effectively unused ever since we introduced the new
posix acl api.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
-----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCY+5NlQAKCRCRxhvAZXjc
orOaAP9i2h3OJy95nO2Fpde0Bt2UT+oulKCCcGlvXJ8/+TQpyQD/ZQq47gFQ0EAz
Br5NxeyGeecAb0lHpFz+CpLGsxMrMwQ=
=+BG5
-----END PGP SIGNATURE-----
Merge tag 'fs.idmapped.v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping
Pull vfs idmapping updates from Christian Brauner:
- Last cycle we introduced the dedicated struct mnt_idmap type for
mount idmapping and the required infrastucture in 256c8aed2b ("fs:
introduce dedicated idmap type for mounts"). As promised in last
cycle's pull request message this converts everything to rely on
struct mnt_idmap.
Currently we still pass around the plain namespace that was attached
to a mount. This is in general pretty convenient but it makes it easy
to conflate namespaces that are relevant on the filesystem with
namespaces that are relevant on the mount level. Especially for
non-vfs developers without detailed knowledge in this area this was a
potential source for bugs.
This finishes the conversion. Instead of passing the plain namespace
around this updates all places that currently take a pointer to a
mnt_userns with a pointer to struct mnt_idmap.
Now that the conversion is done all helpers down to the really
low-level helpers only accept a struct mnt_idmap argument instead of
two namespace arguments.
Conflating mount and other idmappings will now cause the compiler to
complain loudly thus eliminating the possibility of any bugs. This
makes it impossible for filesystem developers to mix up mount and
filesystem idmappings as they are two distinct types and require
distinct helpers that cannot be used interchangeably.
Everything associated with struct mnt_idmap is moved into a single
separate file. With that change no code can poke around in struct
mnt_idmap. It can only be interacted with through dedicated helpers.
That means all filesystems are and all of the vfs is completely
oblivious to the actual implementation of idmappings.
We are now also able to extend struct mnt_idmap as we see fit. For
example, we can decouple it completely from namespaces for users that
don't require or don't want to use them at all. We can also extend
the concept of idmappings so we can cover filesystem specific
requirements.
In combination with the vfs{g,u}id_t work we finished in v6.2 this
makes this feature substantially more robust and thus difficult to
implement wrong by a given filesystem and also protects the vfs.
- Enable idmapped mounts for tmpfs and fulfill a longstanding request.
A long-standing request from users had been to make it possible to
create idmapped mounts for tmpfs. For example, to share the host's
tmpfs mount between multiple sandboxes. This is a prerequisite for
some advanced Kubernetes cases. Systemd also has a range of use-cases
to increase service isolation. And there are more users of this.
However, with all of the other work going on this was way down on the
priority list but luckily someone other than ourselves picked this
up.
As usual the patch is tiny as all the infrastructure work had been
done multiple kernel releases ago. In addition to all the tests that
we already have I requested that Rodrigo add a dedicated tmpfs
testsuite for idmapped mounts to xfstests. It is to be included into
xfstests during the v6.3 development cycle. This should add a slew of
additional tests.
* tag 'fs.idmapped.v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping: (26 commits)
shmem: support idmapped mounts for tmpfs
fs: move mnt_idmap
fs: port vfs{g,u}id helpers to mnt_idmap
fs: port fs{g,u}id helpers to mnt_idmap
fs: port i_{g,u}id_into_vfs{g,u}id() to mnt_idmap
fs: port i_{g,u}id_{needs_}update() to mnt_idmap
quota: port to mnt_idmap
fs: port privilege checking helpers to mnt_idmap
fs: port inode_owner_or_capable() to mnt_idmap
fs: port inode_init_owner() to mnt_idmap
fs: port acl to mnt_idmap
fs: port xattr to mnt_idmap
fs: port ->permission() to pass mnt_idmap
fs: port ->fileattr_set() to pass mnt_idmap
fs: port ->set_acl() to pass mnt_idmap
fs: port ->get_acl() to pass mnt_idmap
fs: port ->tmpfile() to pass mnt_idmap
fs: port ->rename() to pass mnt_idmap
fs: port ->mknod() to pass mnt_idmap
fs: port ->mkdir() to pass mnt_idmap
...
