The various inode creation code paths do not account for the compression
property, POSIX ACLs, or the parent inode item when starting a
transaction. Fix it by refactoring all of these code paths to use a new
function, btrfs_new_inode_prepare(), which computes the correct number
of items. To do so, it needs to know whether POSIX ACLs will be created,
so move the ACL creation into that function. To reduce the number of
arguments that need to be passed around for inode creation, define
struct btrfs_new_inode_args containing all of the relevant information.
btrfs_new_inode_prepare() will also be a good place to set up the
fscrypt context and encrypted filename in the future.
Reviewed-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Commit 4a8b34afa9 ("btrfs: handle ACLs on idmapped mounts") added this
parameter but didn't use it. __btrfs_set_acl() is the low-level helper
that writes an ACL to disk. The higher-level btrfs_set_acl() is the one
that translates the ACL based on the user namespace.
Reviewed-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Merge tag 'ovl-update-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs
Pull overlayfs update from Miklos Szeredi:
- Copy up immutable/append/sync/noatime attributes (Amir Goldstein)
- Improve performance by enabling RCU lookup.
- Misc fixes and improvements
The reason this touches so many files is that the ->get_acl() method now
gets a "bool rcu" argument. The ->get_acl() API was updated based on
comments from Al and Linus:
Link: https://lore.kernel.org/linux-fsdevel/CAJfpeguQxpd6Wgc0Jd3ks77zcsAv_bn0q17L3VNnnmPKu11t8A@mail.gmail.com/
* tag 'ovl-update-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
ovl: enable RCU'd ->get_acl()
vfs: add rcu argument to ->get_acl() callback
ovl: fix BUG_ON() in may_delete() when called from ovl_cleanup()
ovl: use kvalloc in xattr copy-up
ovl: update ctime when changing fileattr
ovl: skip checking lower file's i_writecount on truncate
ovl: relax lookup error on mismatch origin ftype
ovl: do not set overlay.opaque for new directories
ovl: add ovl_allow_offline_changes() helper
ovl: disable decoding null uuid with redirect_dir
ovl: consistent behavior for immutable/append-only inodes
ovl: copy up sync/noatime fileattr flags
ovl: pass ovl_fs to ovl_check_setxattr()
fs: add generic helper for filling statx attribute flags
Make the ACL code idmapped mount aware. The POSIX default and POSIX
access ACLs are the only ACLs other than some specific xattrs that take
DAC permissions into account. On an idmapped mount they need to be
translated according to the mount's userns. The main change is done to
__btrfs_set_acl() which is responsible for translating POSIX ACLs to
their final on-disk representation.
The btrfs_init_acl() helper does not need to take the idmapped mount
into account since it is called in the context of file creation
operations (mknod, create, mkdir, symlink, tmpfile) and is used for
btrfs_init_inode_security() to copy POSIX default and POSIX access
permissions from the parent directory. These ACLs need to be inherited
unmodified from the parent directory. This is identical to what we do
for ext4 and xfs.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Add a rcu argument to the ->get_acl() callback to allow
get_cached_acl_rcu() to call the ->get_acl() method in the next patch.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Extend some inode methods with an additional user namespace argument. A
filesystem that is aware of idmapped mounts will receive the user
namespace the mount has been marked with. This can be used for
additional permission checking and also to enable filesystems to
translate between uids and gids if they need to. We have implemented all
relevant helpers in earlier patches.
As requested we simply extend the exisiting inode method instead of
introducing new ones. This is a little more code churn but it's mostly
mechanical and doesnt't leave us with additional inode methods.
Link: https://lore.kernel.org/r/20210121131959.646623-25-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
The posix acl permission checking helpers determine whether a caller is
privileged over an inode according to the acls associated with the
inode. Add helpers that make it possible to handle acls on idmapped
mounts.
The vfs and the filesystems targeted by this first iteration make use of
posix_acl_fix_xattr_from_user() and posix_acl_fix_xattr_to_user() to
translate basic posix access and default permissions such as the
ACL_USER and ACL_GROUP type according to the initial user namespace (or
the superblock's user namespace) to and from the caller's current user
namespace. Adapt these two helpers to handle idmapped mounts whereby we
either map from or into the mount's user namespace depending on in which
direction we're translating.
Similarly, cap_convert_nscap() is used by the vfs to translate user
namespace and non-user namespace aware filesystem capabilities from the
superblock's user namespace to the caller's user namespace. Enable it to
handle idmapped mounts by accounting for the mount's user namespace.
In addition the fileystems targeted in the first iteration of this patch
series make use of the posix_acl_chmod() and, posix_acl_update_mode()
helpers. Both helpers perform permission checks on the target inode. Let
them handle idmapped mounts. These two helpers are called when posix
acls are set by the respective filesystems to handle this case we extend
the ->set() method to take an additional user namespace argument to pass
the mount's user namespace down.
Link: https://lore.kernel.org/r/20210121131959.646623-9-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Previous patch made sure that btrfs_setxattr_trans() is called only when
transaction NULL. Clean up btrfs_setxattr_trans() and drop the
parameter.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When the caller has already created the transaction handle,
btrfs_setxattr() will use it. Also adds assert in btrfs_setxattr().
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Rename btrfs_setxattr() to btrfs_setxattr_trans(), so that do_setxattr()
can be renamed to btrfs_setxattr().
Preparatory patch, no functional changes.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We are holding a transaction handle when setting an acl, therefore we can
not allocate the xattr value buffer using GFP_KERNEL, as we could deadlock
if reclaim is triggered by the allocation, therefore setup a nofs context.
Fixes: 39a27ec100 ("btrfs: use GFP_KERNEL for xattr and acl allocations")
CC: stable@vger.kernel.org # 4.9+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
It's only coding style fix not functinal change. When if/else has only
one statement then the braces are not needed.
Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
It's not good to override the error code when failing from
btrfs_getxattr() in btrfs_get_acl() because it hides the real reason of
the failure.
Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There is no chance to get into -ERANGE error condition because we first
call btrfs_getxattr to get the length of the attribute, then we do a
subsequent call with the size from the first call. Between the 2 calls
the size shouldn't change. So remove the unnecessary -ERANGE error
check.
Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In btrfs_get_acl() the first call of btr_getxattr() is for getting the
length of attribute, the value buffer is never used in this case. So
it's better to replace empty string with NULL.
Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The caller of btrfs_get_acl() checks error condition so there is no
impact from this change. In practice there is no chance to get into
default case of switch statement because VFS has already checked the
type.
Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Remove GPL boilerplate text (long, short, one-line) and keep the rest,
ie. personal, company or original source copyright statements. Add the
SPDX header.
Signed-off-by: David Sterba <dsterba@suse.com>
The fs_mutex has been killed in 2008, a213501153 ("Btrfs: Replace
the big fs_mutex with a collection of other locks"), still remembered in
some comments.
We don't have any extra needs for locking in the ACL handlers.
Signed-off-by: David Sterba <dsterba@suse.com>
When changing a file's acl mask, btrfs_set_acl() will first set the
group bits of i_mode to the value of the mask, and only then set the
actual extended attribute representing the new acl.
If the second part fails (due to lack of space, for example) and the
file had no acl attribute to begin with, the system will from now on
assume that the mask permission bits are actual group permission bits,
potentially granting access to the wrong users.
Prevent this by restoring the original mode bits if __btrfs_set_acl
fails.
Signed-off-by: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When new directory 'DIR1' is created in a directory 'DIR0' with SGID bit
set, DIR1 is expected to have SGID bit set (and owning group equal to
the owning group of 'DIR0'). However when 'DIR0' also has some default
ACLs that 'DIR1' inherits, setting these ACLs will result in SGID bit on
'DIR1' to get cleared if user is not member of the owning group.
Fix the problem by moving posix_acl_update_mode() out of
__btrfs_set_acl() into btrfs_set_acl(). That way the function will not be
called when inheriting ACLs which is what we want as it prevents SGID
bit clearing and the mode has been properly set by posix_acl_create()
anyway.
Fixes: 073931017b
CC: stable@vger.kernel.org
CC: linux-btrfs@vger.kernel.org
CC: David Sterba <dsterba@suse.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: David Sterba <dsterba@suse.com>
When file permissions are modified via chmod(2) and the user is not in
the owning group or capable of CAP_FSETID, the setgid bit is cleared in
inode_change_ok(). Setting a POSIX ACL via setxattr(2) sets the file
permissions as well as the new ACL, but doesn't clear the setgid bit in
a similar way; this allows to bypass the check in chmod(2). Fix that.
References: CVE-2016-7097
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
size contains the value returned by posix_acl_from_xattr(), which
returns -ERANGE, -ENODATA, zero, or an integer greater than zero. So
replace -ENOENT by -ERANGE.
Signed-off-by: Salah Triki <salah.triki@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When get_acl() is called for an inode whose ACL is not cached yet, the
get_acl inode operation is called to fetch the ACL from the filesystem.
The inode operation is responsible for updating the cached acl with
set_cached_acl(). This is done without locking at the VFS level, so
another task can call set_cached_acl() or forget_cached_acl() before the
get_acl inode operation gets to calling set_cached_acl(), and then
get_acl's call to set_cached_acl() results in caching an outdate ACL.
Prevent this from happening by setting the cached ACL pointer to a
task-specific sentinel value before calling the get_acl inode operation.
Move the responsibility for updating the cached ACL from the get_acl
inode operations to get_acl(). There, only set the cached ACL if the
sentinel value hasn't changed.
The sentinel values are chosen to have odd values. Likewise, the value
of ACL_NOT_CACHED is odd. In contrast, ACL object pointers always have
an even value (ACLs are aligned in memory). This allows to distinguish
uncached ACLs values from ACL objects.
In addition, switch from guarding inode->i_acl and inode->i_default_acl
upates by the inode->i_lock spinlock to using xchg() and cmpxchg().
Filesystems that do not want ACLs returned from their get_acl inode
operations to be cached must call forget_cached_acl() to prevent the VFS
from doing so.
(Patch written by Al Viro and Andreas Gruenbacher.)
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull btrfs updates from Chris Mason:
"This has our usual assortment of fixes and cleanups, but the biggest
change included is Omar Sandoval's free space tree. It's not the
default yet, mounting -o space_cache=v2 enables it and sets a readonly
compat bit. The tree can actually be deleted and regenerated if there
are any problems, but it has held up really well in testing so far.
For very large filesystems (30T+) our existing free space caching code
can end up taking a huge amount of time during commits. The new tree
based code is faster and less work overall to update as the commit
progresses.
Omar worked on this during the summer and we'll hammer on it in
production here at FB over the next few months"
* 'for-linus-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (73 commits)
Btrfs: fix fitrim discarding device area reserved for boot loader's use
Btrfs: Check metadata redundancy on balance
btrfs: statfs: report zero available if metadata are exhausted
btrfs: preallocate path for snapshot creation at ioctl time
btrfs: allocate root item at snapshot ioctl time
btrfs: do an allocation earlier during snapshot creation
btrfs: use smaller type for btrfs_path locks
btrfs: use smaller type for btrfs_path lowest_level
btrfs: use smaller type for btrfs_path reada
btrfs: cleanup, use enum values for btrfs_path reada
btrfs: constify static arrays
btrfs: constify remaining structs with function pointers
btrfs tests: replace whole ops structure for free space tests
btrfs: use list_for_each_entry* in backref.c
btrfs: use list_for_each_entry_safe in free-space-cache.c
btrfs: use list_for_each_entry* in check-integrity.c
Btrfs: use linux/sizes.h to represent constants
btrfs: cleanup, remove stray return statements
btrfs: zero out delayed node upon allocation
btrfs: pass proper enum type to start_transaction()
...
Remove POSIX_ACL_XATTR_{ACCESS,DEFAULT} and GFS2_POSIX_ACL_{ACCESS,DEFAULT}
and replace them with the definitions in <include/uapi/linux/xattr.h>.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
We don't have to use GFP_NOFS in context of ACL or XATTR actions, not
possible to loop through the allocator and it's safe to fail with
ENOMEM.
Signed-off-by: David Sterba <dsterba@suse.com>
posix_acl_xattr_set() already does the check, and it's the only
way to feed in an ACL from userspace.
So the check here is useless, remove it.
Signed-off-by: zhang zhen <zhenzhang.zhang@huawei.com>
Signed-off-by: Chris Mason <clm@fb.com>
Also don't bother to set up a .get_acl method for symlinks as we do not
support access control (ACLs or even mode bits) for symlinks in Linux.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Rename the current posix_acl_created to __posix_acl_create and add
a fully featured helper to set up the ACLs on file creation that
uses get_acl().
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Rename the current posix_acl_chmod to __posix_acl_chmod and add
a fully featured ACL chmod helper that uses the ->set_acl inode
operation.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
When a directory has a default ACL and a subdirectory is created
under that directory, btrfs_init_acl() is called when the
subdirectory's inode is created to initialize the inode's ACL
(inherited from the parent directory) but it was clearing the ACL
from the inode after setting it if posix_acl_create() returned
success, instead of clearing it only if it returned an error.
To reproduce this issue:
$ mkfs.btrfs -f /dev/loop0
$ mount /dev/loop0 /mnt
$ mkdir /mnt/acl
$ setfacl -d --set u::rwx,g::rwx,o::- /mnt/acl
$ getfacl /mnt/acl
user::rwx
group::rwx
other::r-x
default:user::rwx
default:group::rwx
default:other::---
$ mkdir /mnt/acl/dir1
$ getfacl /mnt/acl/dir1
user::rwx
group::rwx
other::---
After unmounting and mounting again the filesystem, fgetacl returned the
expected ACL:
$ umount /mnt/acl
$ mount /dev/loop0 /mnt
$ getfacl /mnt/acl/dir1
user::rwx
group::rwx
other::---
default:user::rwx
default:group::rwx
default:other::---
Meaning that the underlying xattr was persisted.
Reported-by: Giuseppe Fierro <giuseppe@fierro.org>
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
If the acl can be exactly represented in the traditional file
mode permission bits, we don't set another acl attribute.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
- Pass the user namespace the uid and gid values in the xattr are stored
in into posix_acl_from_xattr.
- Pass the user namespace kuid and kgid values should be converted into
when storing uid and gid values in an xattr in posix_acl_to_xattr.
- Modify all callers of posix_acl_from_xattr and posix_acl_to_xattr to
pass in &init_user_ns.
In the short term this change is not strictly needed but it makes the
code clearer. In the longer term this change is necessary to be able to
mount filesystems outside of the initial user namespace that natively
store posix acls in the linux xattr format.
Cc: Theodore Tso <tytso@mit.edu>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Jan Kara <jack@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
When running compilebench I noticed we were spending some time looking up
acls on new inodes, which shouldn't be happening since there were no acls.
This is because when we init acls on the inode after creating them we don't
cache the fact there are no acls if there aren't any. Doing this adds a
little bit of a bump to my compilebench runs. Thanks,
Btrfs: cache no acl on new inodes
Signed-off-by: Josef Bacik <josef@redhat.com>
In btrfs_get_acl(), when the second __btrfs_getxattr() call fails,
acl is not correctly set.
Therefore, a wrong value might return to the caller.
Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: (31 commits)
Btrfs: don't call writepages from within write_full_page
Btrfs: Remove unused variable 'last_index' in file.c
Btrfs: clean up for find_first_extent_bit()
Btrfs: clean up for wait_extent_bit()
Btrfs: clean up for insert_state()
Btrfs: remove unused members from struct extent_state
Btrfs: clean up code for merging extent maps
Btrfs: clean up code for extent_map lookup
Btrfs: clean up search_extent_mapping()
Btrfs: remove redundant code for dir item lookup
Btrfs: make acl functions really no-op if acl is not enabled
Btrfs: remove remaining ref-cache code
Btrfs: remove a BUG_ON() in btrfs_commit_transaction()
Btrfs: use wait_event()
Btrfs: check the nodatasum flag when writing compressed files
Btrfs: copy string correctly in INO_LOOKUP ioctl
Btrfs: don't print the leaf if we had an error
btrfs: make btrfs_set_root_node void
Btrfs: fix oops while writing data to SSD partitions
Btrfs: Protect the readonly flag of block group
...
Fix up trivial conflicts (due to acl and writeback cleanups) in
- fs/btrfs/acl.c
- fs/btrfs/ctree.h
- fs/btrfs/extent_io.c
Replace the ->check_acl method with a ->get_acl method that simply reads an
ACL from disk after having a cache miss. This means we can replace the ACL
checking boilerplate code with a single implementation in namei.c.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
new helper: posix_acl_create(&acl, gfp, mode_p). Replaces acl with
modified clone, on failure releases acl and replaces with NULL.
Returns 0 or -ve on error. All callers of posix_acl_create_masq()
switched.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
new helper: posix_acl_chmod(&acl, gfp, mode). Replaces acl with modified
clone or with NULL if that has failed; returns 0 or -ve on error. All
callers of posix_acl_chmod_masq() switched to that - they'd been doing
exactly the same thing.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This moves logic for checking the cached ACL values from low-level
filesystems into generic code. The end result is a streamlined ACL
check that doesn't need to load the inode->i_op->check_acl pointer at
all for the common cached case.
The filesystems also don't need to check for a non-blocking RCU walk
case in their acl_check() functions, because that is all handled at a
VFS layer.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
If posix_acl_from_xattr() returns an error code, a negative address is
dereferenced causing an oops; fix by checking for error code first.
Signed-off-by: Daniel J Blueman <daniel.blueman@gmail.com>
Reviewed-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Omar Sandoval