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* Merge tag 'ovl-update-5.16' of ↵Linus Torvalds2021-11-096-14/+46
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs Pull overlayfs updates from Miklos Szeredi: - Fix a regression introduced in the last cycle - Fix a use-after-free in the AIO path - Fix a bogus warning reported by syzbot * tag 'ovl-update-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: ovl: fix filattr copy-up failure ovl: fix warning in ovl_create_real() ovl: fix use after free in struct ovl_aio_req
| * ovl: fix filattr copy-up failureMiklos Szeredi2021-11-042-6/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This regression can be reproduced with ntfs-3g and overlayfs: mkdir lower upper work overlay dd if=/dev/zero of=ntfs.raw bs=1M count=2 mkntfs -F ntfs.raw mount ntfs.raw lower touch lower/file.txt mount -t overlay -o lowerdir=lower,upperdir=upper,workdir=work - overlay mv overlay/file.txt overlay/file2.txt mv fails and (misleadingly) prints mv: cannot move 'overlay/file.txt' to a subdirectory of itself, 'overlay/file2.txt' The reason is that ovl_copy_fileattr() is triggered due to S_NOATIME being set on all inodes (by fuse) regardless of fileattr. ovl_copy_fileattr() tries to retrieve file attributes from lower file, but that fails because filesystem does not support this ioctl (this should fail with ENOTTY, but ntfs-3g return EINVAL instead). This failure is propagated to origial operation (in this case rename) that triggered the copy-up. The fix is to ignore ENOTTY and EINVAL errors from fileattr_get() in copy up. This also requires turning the internal ENOIOCTLCMD into ENOTTY. As a further measure to prevent unnecessary failures, only try the fileattr_get/set on upper if there are any flags to copy up. Side note: a number of filesystems set S_NOATIME (and sometimes other inode flags) irrespective of fileattr flags. This causes unnecessary calls during copy up, which might lead to a performance issue, especially if latency is high. To fix this, the kernel would need to differentiate between the two cases. E.g. introduce SB_NOATIME_UPDATE, a per-sb variant of S_NOATIME. SB_NOATIME doesn't work, because that's interpreted as "filesystem doesn't store an atime attribute" Reported-and-tested-by: Kevin Locke <kevin@kevinlocke.name> Fixes: 72db82115d2b ("ovl: copy up sync/noatime fileattr flags") Cc: <stable@vger.kernel.org> # v5.15 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| * ovl: fix warning in ovl_create_real()Miklos Szeredi2021-11-043-6/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Syzbot triggered the following warning in ovl_workdir_create() -> ovl_create_real(): if (!err && WARN_ON(!newdentry->d_inode)) { The reason is that the cgroup2 filesystem returns from mkdir without instantiating the new dentry. Weird filesystems such as this will be rejected by overlayfs at a later stage during setup, but to prevent such a warning, call ovl_mkdir_real() directly from ovl_workdir_create() and reject this case early. Reported-and-tested-by: syzbot+75eab84fd0af9e8bf66b@syzkaller.appspotmail.com Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| * ovl: fix use after free in struct ovl_aio_reqyangerkun2021-10-291-2/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Example for triggering use after free in a overlay on ext4 setup: aio_read ovl_read_iter vfs_iter_read ext4_file_read_iter ext4_dio_read_iter iomap_dio_rw -> -EIOCBQUEUED /* * Here IO is completed in a separate thread, * ovl_aio_cleanup_handler() frees aio_req which has iocb embedded */ file_accessed(iocb->ki_filp); /**BOOM**/ Fix by introducing a refcount in ovl_aio_req similarly to aio_kiocb. This guarantees that iocb is only freed after vfs_read/write_iter() returns on underlying fs. Fixes: 2406a307ac7d ("ovl: implement async IO routines") Signed-off-by: yangerkun <yangerkun@huawei.com> Link: https://lore.kernel.org/r/20210930032228.3199690-3-yangerkun@huawei.com/ Cc: <stable@vger.kernel.org> # v5.6 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* | fs: get rid of the res2 iocb->ki_complete argumentJens Axboe2021-10-251-2/+2
|/ | | | | | | | | | | The second argument was only used by the USB gadget code, yet everyone pays the overhead of passing a zero to be passed into aio, where it ends up being part of the aio res2 value. Now that everybody is passing in zero, kill off the extra argument. Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* ovl: fix IOCB_DIRECT if underlying fs doesn't support direct IOMiklos Szeredi2021-09-281-1/+14
| | | | | | | | | | | | | | | Normally the check at open time suffices, but e.g loop device does set IOCB_DIRECT after doing its own checks (which are not sufficent for overlayfs). Make sure we don't call the underlying filesystem read/write method with the IOCB_DIRECT if it's not supported. Reported-by: Huang Jianan <huangjianan@oppo.com> Fixes: 16914e6fc7e1 ("ovl: add ovl_read_iter()") Cc: <stable@vger.kernel.org> # v4.19 Tested-by: Huang Jianan <huangjianan@oppo.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: fix missing negative dentry check in ovl_rename()Zheng Liang2021-09-241-3/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following reproducer mkdir lower upper work merge touch lower/old touch lower/new mount -t overlay overlay -olowerdir=lower,upperdir=upper,workdir=work merge rm merge/new mv merge/old merge/new & unlink upper/new may result in this race: PROCESS A: rename("merge/old", "merge/new"); overwrite=true,ovl_lower_positive(old)=true, ovl_dentry_is_whiteout(new)=true -> flags |= RENAME_EXCHANGE PROCESS B: unlink("upper/new"); PROCESS A: lookup newdentry in new_upperdir call vfs_rename() with negative newdentry and RENAME_EXCHANGE Fix by adding the missing check for negative newdentry. Signed-off-by: Zheng Liang <zhengliang6@huawei.com> Fixes: e9be9d5e76e3 ("overlay filesystem") Cc: <stable@vger.kernel.org> # v3.18 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: enable RCU'd ->get_acl()Miklos Szeredi2021-08-181-3/+4
| | | | | | | | | | | | | | | | | Overlayfs does not cache ACL's (to avoid double caching). Instead it just calls the underlying filesystem's i_op->get_acl(), which will return the cached value, if possible. In rcu path walk, however, get_cached_acl_rcu() is employed to get the value from the cache, which will fail on overlayfs resulting in dropping out of rcu walk mode. This can result in a big performance hit in certain situations. Fix by calling ->get_acl() with rcu=true in case of ACL_DONT_CACHE (which indicates pass-through) Reported-by: garyhuang <zjh.20052005@163.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* vfs: add rcu argument to ->get_acl() callbackMiklos Szeredi2021-08-182-2/+5
| | | | | | | 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>
* ovl: fix BUG_ON() in may_delete() when called from ovl_cleanup()chenying2021-08-171-2/+4
| | | | | | | | | | | | | If function ovl_instantiate() returns an error, ovl_cleanup will be called and try to remove newdentry from wdir, but the newdentry has been moved to udir at this time. This will causes BUG_ON(victim->d_parent->d_inode != dir) in fs/namei.c:may_delete. Signed-off-by: chenying <chenying.kernel@bytedance.com> Fixes: 01b39dcc9568 ("ovl: use inode_insert5() to hash a newly created inode") Link: https://lore.kernel.org/linux-unionfs/e6496a94-a161-dc04-c38a-d2544633acb4@bytedance.com/ Cc: <stable@vger.kernel.org> # v4.18 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: use kvalloc in xattr copy-upMiklos Szeredi2021-08-171-4/+5
| | | | | | | Extended attributes are usually small, but could be up to 64k in size, so use the most efficient method for doing the allocation. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: update ctime when changing fileattrChengguang Xu2021-08-171-0/+3
| | | | | | | | | Currently we keep size, mode and times of overlay inode as the same as upper inode, so should update ctime when changing file attribution as well. Signed-off-by: Chengguang Xu <cgxu519@mykernel.net> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: skip checking lower file's i_writecount on truncateChengguang Xu2021-08-171-6/+0
| | | | | | | | | | | | | | | | | | | | | | | | It is possible that a directory tree is shared between multiple overlay instances as a lower layer. In this case when one instance executes a file residing on the lower layer, the other instance denies a truncate(2) call on this file. This only happens for truncate(2) and not for open(2) with the O_TRUNC flag. Fix this interference and inconsistency by removing the preliminary i_writecount check before copy-up. This means that unlike on normal filesystems truncate(argv[0]) will now succeed. If this ever causes a regression in a real world use case this needs to be revisited. One way to fix this properly would be to keep a correct i_writecount in the overlay inode, but that is difficult due to memory mapping code only dealing with the real file/inode. Signed-off-by: Chengguang Xu <cgxu519@mykernel.net> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: relax lookup error on mismatch origin ftypeAmir Goldstein2021-08-171-1/+1
| | | | | | | | | | | | | | | | | | | | | | We get occasional reports of lookup errors due to mismatched origin ftype from users that re-format a lower squashfs image. Commit 13c6ad0f45fd ("ovl: document lower modification caveats") tries to discourage the practice of re-formating lower layers and describes the expected behavior as undefined. Commit b0e0f69731cd ("ovl: restrict lower null uuid for "xino=auto"") limits the configurations in which origin file handles are followed. In addition to these measures, change the behavior in case of detecting a mismatch origin ftype in lookup to issue a warning, not follow origin, but not fail the lookup operation either. That should make overall more users happy without any big consequences. Link: https://lore.kernel.org/linux-unionfs/CAOQ4uxgPq9E9xxwU2CDyHy-_yCZZeymg+3n+-6AqkGGE1YtwvQ@mail.gmail.com/ Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: do not set overlay.opaque for new directoriesVyacheslav Yurkov2021-08-171-1/+3
| | | | | | | | | | | | | | | | | | | | | Enable optimizations only if user opted-in for any of extended features. If optimization is enabled, it breaks existing use case when a lower layer directory appears after directory was created on a merged layer. If overlay.opaque is applied, new files on lower layer are not visible. Consider the following scenario: - /lower and /upper are mounted to /merged - directory /merged/new-dir is created with a file test1 - overlay is unmounted - directory /lower/new-dir is created with a file test2 - overlay is mounted again If opaque is applied by default, file test2 is not going to be visible without explicitly clearing the overlay.opaque attribute Signed-off-by: Vyacheslav Yurkov <Vyacheslav.Yurkov@bruker.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: add ovl_allow_offline_changes() helperVyacheslav Yurkov2021-08-172-3/+13
| | | | | | | | Allows to check whether any of extended features are enabled Signed-off-by: Vyacheslav Yurkov <Vyacheslav.Yurkov@bruker.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: disable decoding null uuid with redirect_dirVyacheslav Yurkov2021-08-171-1/+1
| | | | | | | | | | | Currently decoding origin with lower null uuid is not allowed unless user opted-in to one of the new features that require following the lower inode of non-dir upper (index, xino, metacopy). Now we add redirect_dir too to that feature list. Signed-off-by: Vyacheslav Yurkov <Vyacheslav.Yurkov@bruker.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: consistent behavior for immutable/append-only inodesAmir Goldstein2021-08-174-7/+158
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When a lower file has immutable/append-only fileattr flags, the behavior of overlayfs post copy up is inconsistent. Immediattely after copy up, ovl inode still has the S_IMMUTABLE/S_APPEND inode flags copied from lower inode, so vfs code still treats the ovl inode as immutable/append-only. After ovl inode evict or mount cycle, the ovl inode does not have these inode flags anymore. We cannot copy up the immutable and append-only fileattr flags, because immutable/append-only inodes cannot be linked and because overlayfs will not be able to set overlay.* xattr on the upper inodes. Instead, if any of the fileattr flags of interest exist on the lower inode, we store them in overlay.protattr xattr on the upper inode and we read the flags from xattr on lookup and on fileattr_get(). This gives consistent behavior post copy up regardless of inode eviction from cache. When user sets new fileattr flags, we update or remove the overlay.protattr xattr. Storing immutable/append-only fileattr flags in an xattr instead of upper fileattr also solves other non-standard behavior issues - overlayfs can now copy up children of "ovl-immutable" directories and lower aliases of "ovl-immutable" hardlinks. Reported-by: Chengguang Xu <cgxu519@mykernel.net> Link: https://lore.kernel.org/linux-unionfs/20201226104618.239739-1-cgxu519@mykernel.net/ Link: https://lore.kernel.org/linux-unionfs/20210210190334.1212210-5-amir73il@gmail.com/ Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: copy up sync/noatime fileattr flagsAmir Goldstein2021-08-173-21/+89
| | | | | | | | | | | | | | | | | | | | | | | | | When a lower file has sync/noatime fileattr flags, the behavior of overlayfs post copy up is inconsistent. Immediately after copy up, ovl inode still has the S_SYNC/S_NOATIME inode flags copied from lower inode, so vfs code still treats the ovl inode as sync/noatime. After ovl inode evict or mount cycle, the ovl inode does not have these inode flags anymore. To fix this inconsistency, try to copy the fileattr flags on copy up if the upper fs supports the fileattr_set() method. This gives consistent behavior post copy up regardless of inode eviction from cache. We cannot copy up the immutable/append-only inode flags in a similar manner, because immutable/append-only inodes cannot be linked and because overlayfs will not be able to set overlay.* xattr on the upper inodes. Those flags will be addressed by a followup patch. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: pass ovl_fs to ovl_check_setxattr()Amir Goldstein2021-08-175-15/+16
| | | | | | | Instead of passing the overlay dentry. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: fix uninitialized pointer read in ovl_lookup_real_one()Miklos Szeredi2021-08-101-1/+1
| | | | | | | | | | | One error path can result in release_dentry_name_snapshot() being called before "name" was initialized by take_dentry_name_snapshot(). Fix by moving the release_dentry_name_snapshot() to immediately after the only use. Reported-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: fix deadlock in splice writeMiklos Szeredi2021-08-101-1/+46
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's possibility of an ABBA deadlock in case of a splice write to an overlayfs file and a concurrent splice write to a corresponding real file. The call chain for splice to an overlay file: -> do_splice [takes sb_writers on overlay file] -> do_splice_from -> iter_file_splice_write [takes pipe->mutex] -> vfs_iter_write ... -> ovl_write_iter [takes sb_writers on real file] And the call chain for splice to a real file: -> do_splice [takes sb_writers on real file] -> do_splice_from -> iter_file_splice_write [takes pipe->mutex] Syzbot successfully bisected this to commit 82a763e61e2b ("ovl: simplify file splice"). Fix by reverting the write part of the above commit and by adding missing bits from ovl_write_iter() into ovl_splice_write(). Fixes: 82a763e61e2b ("ovl: simplify file splice") Reported-and-tested-by: syzbot+579885d1a9a833336209@syzkaller.appspotmail.com Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: skip stale entries in merge dir cache iterationAmir Goldstein2021-08-101-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | On the first getdents call, ovl_iterate() populates the readdir cache with a list of entries, but for upper entries with origin lower inode, p->ino remains zero. Following getdents calls traverse the readdir cache list and call ovl_cache_update_ino() for entries with zero p->ino to lookup the entry in the overlay and return d_ino that is consistent with st_ino. If the upper file was unlinked between the first getdents call and the getdents call that lists the file entry, ovl_cache_update_ino() will not find the entry and fall back to setting d_ino to the upper real st_ino, which is inconsistent with how this object was presented to users. Instead of listing a stale entry with inconsistent d_ino, simply skip the stale entry, which is better for users. xfstest overlay/077 is failing without this patch. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Link: https://lore.kernel.org/fstests/CAOQ4uxgR_cLnC_vdU5=seP3fwqVkuZM_-WfD6maFTMbMYq=a9w@mail.gmail.com/ Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* Merge tag 'ovl-update-5.13' of ↵Linus Torvalds2021-04-308-67/+124
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs Pull overlayfs update from Miklos Szeredi: - Fix a regression introduced in 5.2 that resulted in valid overlayfs mounts being rejected with ELOOP (Too many levels of symbolic links) - Fix bugs found by various tools - Miscellaneous improvements and cleanups * tag 'ovl-update-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: ovl: add debug print to ovl_do_getxattr() ovl: invalidate readdir cache on changes to dir with origin ovl: allow upperdir inside lowerdir ovl: show "userxattr" in the mount data ovl: trivial typo fixes in the file inode.c ovl: fix misspellings using codespell tool ovl: do not copy attr several times ovl: remove ovl_map_dev_ino() return value ovl: fix error for ovl_fill_super() ovl: fix missing revert_creds() on error path ovl: fix leaked dentry ovl: restrict lower null uuid for "xino=auto" ovl: check that upperdir path is not on a read-only mount ovl: plumb through flush method
| * ovl: add debug print to ovl_do_getxattr()Amir Goldstein2021-04-121-1/+6
| | | | | | | | | | | | | | It was the only ovl_do helper missing it. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| * ovl: invalidate readdir cache on changes to dir with originAmir Goldstein2021-04-123-37/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The test in ovl_dentry_version_inc() was out-dated and did not include the case where readdir cache is used on a non-merge dir that has origin xattr, indicating that it may contain leftover whiteouts. To make the code more robust, use the same helper ovl_dir_is_real() to determine if readdir cache should be used and if readdir cache should be invalidated. Fixes: b79e05aaa166 ("ovl: no direct iteration for dir with origin xattr") Link: https://lore.kernel.org/linux-unionfs/CAOQ4uxht70nODhNHNwGFMSqDyOKLXOKrY0H6g849os4BQ7cokA@mail.gmail.com/ Cc: Chris Murphy <lists@colorremedies.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| * ovl: allow upperdir inside lowerdirMiklos Szeredi2021-04-121-5/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 146d62e5a586 ("ovl: detect overlapping layers") made sure we don't have overlapping layers, but it also broke the arguably valid use case of mount -olowerdir=/,upperdir=/subdir,.. where upperdir overlaps lowerdir on the same filesystem. This has been causing regressions. Revert the check, but only for the specific case where upperdir and/or workdir are subdirectories of lowerdir. Any other overlap (e.g. lowerdir is subdirectory of upperdir, etc) case is crazy, so leave the check in place for those. Overlaps are detected at lookup time too, so reverting the mount time check should be safe. Fixes: 146d62e5a586 ("ovl: detect overlapping layers") Cc: <stable@vger.kernel.org> # v5.2 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| * ovl: show "userxattr" in the mount dataGiuseppe Scrivano2021-04-121-0/+2
| | | | | | | | | | | | | | | | | | This was missed when adding the option. Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com> Reviewed-by: Vivek Goyal <vgoyal@redhat.com> Fixes: 2d2f2d7322ff ("ovl: user xattr") Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| * ovl: trivial typo fixes in the file inode.cBhaskar Chowdhury2021-04-121-3/+3
| | | | | | | | | | | | | | | | | | s/peresistent/persistent/ s/xatts/xattrs/ s/annotaion/annotation/ Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| * ovl: fix misspellings using codespell toolXiong Zhenwu2021-04-121-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | A typo is found out by codespell tool: $ codespell ./fs/overlayfs/ ./fs/overlayfs/util.c:217: dependig ==> depending Fix a typo found by codespell. Signed-off-by: Xiong Zhenwu <xiong.zhenwu@zte.com.cn> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| * ovl: do not copy attr several timesChengguang Xu2021-04-121-3/+0
| | | | | | | | | | | | | | | | In ovl_xattr_set() we have already copied attr of real inode so no need to copy it again in ovl_posix_acl_xattr_set(). Signed-off-by: Chengguang Xu <cgxu519@mykernel.net> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| * ovl: remove ovl_map_dev_ino() return valueyoungjun2021-04-121-8/+4
| | | | | | | | | | | | | | ovl_map_dev_ino() always returns success. Remove unnecessary return value. Signed-off-by: youngjun <her0gyugyu@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| * ovl: fix error for ovl_fill_super()Chengguang Xu2021-04-121-0/+4
| | | | | | | | | | | | | | | | | | | | There are some places should return -EINVAL instead of -ENOMEM in ovl_fill_super(). [Amir] Consistently set error before checking the error condition. Signed-off-by: Chengguang Xu <cgxu519@mykernel.net> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| * ovl: fix missing revert_creds() on error pathDan Carpenter2021-04-121-1/+2
| | | | | | | | | | | | | | | | | | | | Smatch complains about missing that the ovl_override_creds() doesn't have a matching revert_creds() if the dentry is disconnected. Fix this by moving the ovl_override_creds() until after the disconnected check. Fixes: aa3ff3c152ff ("ovl: copy up of disconnected dentries") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| * ovl: fix leaked dentryMickaël Salaün2021-04-121-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since commit 6815f479ca90 ("ovl: use only uppermetacopy state in ovl_lookup()"), overlayfs doesn't put temporary dentry when there is a metacopy error, which leads to dentry leaks when shutting down the related superblock: overlayfs: refusing to follow metacopy origin for (/file0) ... BUG: Dentry (____ptrval____){i=3f33,n=file3} still in use (1) [unmount of overlay overlay] ... WARNING: CPU: 1 PID: 432 at umount_check.cold+0x107/0x14d CPU: 1 PID: 432 Comm: unmount-overlay Not tainted 5.12.0-rc5 #1 ... RIP: 0010:umount_check.cold+0x107/0x14d ... Call Trace: d_walk+0x28c/0x950 ? dentry_lru_isolate+0x2b0/0x2b0 ? __kasan_slab_free+0x12/0x20 do_one_tree+0x33/0x60 shrink_dcache_for_umount+0x78/0x1d0 generic_shutdown_super+0x70/0x440 kill_anon_super+0x3e/0x70 deactivate_locked_super+0xc4/0x160 deactivate_super+0xfa/0x140 cleanup_mnt+0x22e/0x370 __cleanup_mnt+0x1a/0x30 task_work_run+0x139/0x210 do_exit+0xb0c/0x2820 ? __kasan_check_read+0x1d/0x30 ? find_held_lock+0x35/0x160 ? lock_release+0x1b6/0x660 ? mm_update_next_owner+0xa20/0xa20 ? reacquire_held_locks+0x3f0/0x3f0 ? __sanitizer_cov_trace_const_cmp4+0x22/0x30 do_group_exit+0x135/0x380 __do_sys_exit_group.isra.0+0x20/0x20 __x64_sys_exit_group+0x3c/0x50 do_syscall_64+0x45/0x70 entry_SYSCALL_64_after_hwframe+0x44/0xae ... VFS: Busy inodes after unmount of overlay. Self-destruct in 5 seconds. Have a nice day... This fix has been tested with a syzkaller reproducer. Cc: Amir Goldstein <amir73il@gmail.com> Cc: <stable@vger.kernel.org> # v5.8+ Reported-by: syzbot <syzkaller@googlegroups.com> Fixes: 6815f479ca90 ("ovl: use only uppermetacopy state in ovl_lookup()") Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com> Link: https://lore.kernel.org/r/20210329164907.2133175-1-mic@digikod.net Reviewed-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| * ovl: restrict lower null uuid for "xino=auto"Amir Goldstein2021-04-121-6/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit a888db310195 ("ovl: fix regression with re-formatted lower squashfs") attempted to fix a regression with existing setups that use a practice that we are trying to discourage. The discourage part was described this way in the commit message: "To avoid the reported regression while still allowing the new features with single lower squashfs, do not allow decoding origin with lower null uuid unless user opted-in to one of the new features that require following the lower inode of non-dir upper (index, xino, metacopy)." The three mentioned features are disabled by default in Kconfig, so it was assumed that if they are enabled, the user opted-in for them. Apparently, distros started to configure CONFIG_OVERLAY_FS_XINO_AUTO=y some time ago, so users upgrading their kernels can still be affected by said regression even though they never opted-in for any new feature. To fix this, treat "xino=on" as "user opted-in", but not "xino=auto". Since we are changing the behavior of "xino=auto" to no longer follow to lower origin with null uuid, take this one step further and disable xino in that corner case. To be consistent, disable xino also in cases of lower fs without file handle support and upper fs without xattr support. Update documentation w.r.t the new "xino=auto" behavior and fix the out dated bits of documentation regarding "xino" and regarding offline modifications to lower layers. Link: https://lore.kernel.org/linux-unionfs/b36a429d7c563730c28d763d4d57a6fc30508a4f.1615216996.git.kevin@kevinlocke.name/ Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| * ovl: check that upperdir path is not on a read-only mountAmir Goldstein2021-04-121-2/+2
| | | | | | | | | | | | | | | | So far we only checked that sb is not read-only. Suggested-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| * ovl: plumb through flush methodSargun Dhillon2021-04-121-0/+21
| | | | | | | | | | | | | | | | | | | | | | Filesystems can implement their own flush method that release resources, or manipulate caches. Currently if one of these filesystems is used with overlayfs, the flush method is not called. [Amir: fix fd leak in ovl_flush()] Signed-off-by: Sargun Dhillon <sargun@sargun.me> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* | Merge branch 'miklos.fileattr' of ↵Linus Torvalds2021-04-275-116/+82
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull fileattr conversion updates from Miklos Szeredi via Al Viro: "This splits the handling of FS_IOC_[GS]ETFLAGS from ->ioctl() into a separate method. The interface is reasonably uniform across the filesystems that support it and gives nice boilerplate removal" * 'miklos.fileattr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (23 commits) ovl: remove unneeded ioctls fuse: convert to fileattr fuse: add internal open/release helpers fuse: unsigned open flags fuse: move ioctl to separate source file vfs: remove unused ioctl helpers ubifs: convert to fileattr reiserfs: convert to fileattr ocfs2: convert to fileattr nilfs2: convert to fileattr jfs: convert to fileattr hfsplus: convert to fileattr efivars: convert to fileattr xfs: convert to fileattr orangefs: convert to fileattr gfs2: convert to fileattr f2fs: convert to fileattr ext4: convert to fileattr ext2: convert to fileattr btrfs: convert to fileattr ...
| * | ovl: remove unneeded ioctlsMiklos Szeredi2021-04-123-116/+0
| | | | | | | | | | | | | | | | | | | | | | | | The FS_IOC_[GS]ETFLAGS/FS_IOC_FS[GS]ETXATTR ioctls are now handled via the fileattr api. The only unconverted filesystem remaining is CIFS and it is not allowed to be overlayed due to case insensitive filenames. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| * | ovl: stack fileattr opsMiklos Szeredi2021-04-123-0/+82
| |/ | | | | | | | | | | | | | | | | Add stacking for the fileattr operations. Add hack for calling security_file_ioctl() for now. Probably better to have a pair of specific hooks for these operations. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* | Merge branch 'work.inode-type-fixes' of ↵Linus Torvalds2021-04-271-2/+2
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs inode type handling updates from Al Viro: "We should never change the type bits of ->i_mode or the method tables (->i_op and ->i_fop) of a live inode. Unfortunately, not all filesystems took care to prevent that" * 'work.inode-type-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: spufs: fix bogosity in S_ISGID handling 9p: missing chunk of "fs/9p: Don't update file type when updating file attributes" openpromfs: don't do unlock_new_inode() until the new inode is set up hostfs_mknod(): don't bother with init_special_inode() cifs: have cifs_fattr_to_inode() refuse to change type on live inode cifs: have ->mkdir() handle race with another client sanely do_cifs_create(): don't set ->i_mode of something we had not created gfs2: be careful with inode refresh ocfs2_inode_lock_update(): make sure we don't change the type bits of i_mode orangefs_inode_is_stale(): i_mode type bits do *not* form a bitmap... vboxsf: don't allow to change the inode type afs: Fix updating of i_mode due to 3rd party change ceph: don't allow type or device number to change on non-I_NEW inodes ceph: fix up error handling with snapdirs new helper: inode_wrong_type()
| * | new helper: inode_wrong_type()Al Viro2021-03-081-2/+2
| |/ | | | | | | | | | | | | | | inode_wrong_type(inode, mode) returns true if setting inode->i_mode to given value would've changed the inode type. We have enough of those checks open-coded to make a helper worthwhile. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* / ovl: fix reference counting in ovl_mmap error pathChristian König2021-04-231-10/+1
|/ | | | | | | | | | | | | | | | | | mmap_region() now calls fput() on the vma->vm_file. Fix this by using vma_set_file() so it doesn't need to be handled manually here any more. Link: https://lkml.kernel.org/r/20210421132012.82354-2-christian.koenig@amd.com Fixes: 1527f926fd04 ("mm: mmap: fix fput in error path v2") Signed-off-by: Christian König <christian.koenig@amd.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Jan Harkes <jaharkes@cs.cmu.edu> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: <stable@vger.kernel.org> [5.11+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge tag 'idmapped-mounts-v5.12' of ↵Linus Torvalds2021-02-237-66/+90
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux Pull idmapped mounts from Christian Brauner: "This introduces idmapped mounts which has been in the making for some time. Simply put, different mounts can expose the same file or directory with different ownership. This initial implementation comes with ports for fat, ext4 and with Christoph's port for xfs with more filesystems being actively worked on by independent people and maintainers. Idmapping mounts handle a wide range of long standing use-cases. Here are just a few: - Idmapped mounts make it possible to easily share files between multiple users or multiple machines especially in complex scenarios. For example, idmapped mounts will be used in the implementation of portable home directories in systemd-homed.service(8) where they allow users to move their home directory to an external storage device and use it on multiple computers where they are assigned different uids and gids. This effectively makes it possible to assign random uids and gids at login time. - It is possible to share files from the host with unprivileged containers without having to change ownership permanently through chown(2). - It is possible to idmap a container's rootfs and without having to mangle every file. For example, Chromebooks use it to share the user's Download folder with their unprivileged containers in their Linux subsystem. - It is possible to share files between containers with non-overlapping idmappings. - Filesystem that lack a proper concept of ownership such as fat can use idmapped mounts to implement discretionary access (DAC) permission checking. - They allow users to efficiently changing ownership on a per-mount basis without having to (recursively) chown(2) all files. In contrast to chown (2) changing ownership of large sets of files is instantenous with idmapped mounts. This is especially useful when ownership of a whole root filesystem of a virtual machine or container is changed. With idmapped mounts a single syscall mount_setattr syscall will be sufficient to change the ownership of all files. - Idmapped mounts always take the current ownership into account as idmappings specify what a given uid or gid is supposed to be mapped to. This contrasts with the chown(2) syscall which cannot by itself take the current ownership of the files it changes into account. It simply changes the ownership to the specified uid and gid. This is especially problematic when recursively chown(2)ing a large set of files which is commong with the aforementioned portable home directory and container and vm scenario. - Idmapped mounts allow to change ownership locally, restricting it to specific mounts, and temporarily as the ownership changes only apply as long as the mount exists. Several userspace projects have either already put up patches and pull-requests for this feature or will do so should you decide to pull this: - systemd: In a wide variety of scenarios but especially right away in their implementation of portable home directories. https://systemd.io/HOME_DIRECTORY/ - container runtimes: containerd, runC, LXD:To share data between host and unprivileged containers, unprivileged and privileged containers, etc. The pull request for idmapped mounts support in containerd, the default Kubernetes runtime is already up for quite a while now: https://github.com/containerd/containerd/pull/4734 - The virtio-fs developers and several users have expressed interest in using this feature with virtual machines once virtio-fs is ported. - ChromeOS: Sharing host-directories with unprivileged containers. I've tightly synced with all those projects and all of those listed here have also expressed their need/desire for this feature on the mailing list. For more info on how people use this there's a bunch of talks about this too. Here's just two recent ones: https://www.cncf.io/wp-content/uploads/2020/12/Rootless-Containers-in-Gitpod.pdf https://fosdem.org/2021/schedule/event/containers_idmap/ This comes with an extensive xfstests suite covering both ext4 and xfs: https://git.kernel.org/brauner/xfstests-dev/h/idmapped_mounts It covers truncation, creation, opening, xattrs, vfscaps, setid execution, setgid inheritance and more both with idmapped and non-idmapped mounts. It already helped to discover an unrelated xfs setgid inheritance bug which has since been fixed in mainline. It will be sent for inclusion with the xfstests project should you decide to merge this. In order to support per-mount idmappings vfsmounts are marked with user namespaces. The idmapping of the user namespace will be used to map the ids of vfs objects when they are accessed through that mount. By default all vfsmounts are marked with the initial user namespace. The initial user namespace is used to indicate that a mount is not idmapped. All operations behave as before and this is verified in the testsuite. Based on prior discussions we want to attach the whole user namespace and not just a dedicated idmapping struct. This allows us to reuse all the helpers that already exist for dealing with idmappings instead of introducing a whole new range of helpers. In addition, if we decide in the future that we are confident enough to enable unprivileged users to setup idmapped mounts the permission checking can take into account whether the caller is privileged in the user namespace the mount is currently marked with. The user namespace the mount will be marked with can be specified by passing a file descriptor refering to the user namespace as an argument to the new mount_setattr() syscall together with the new MOUNT_ATTR_IDMAP flag. The system call follows the openat2() pattern of extensibility. The following conditions must be met in order to create an idmapped mount: - The caller must currently have the CAP_SYS_ADMIN capability in the user namespace the underlying filesystem has been mounted in. - The underlying filesystem must support idmapped mounts. - The mount must not already be idmapped. This also implies that the idmapping of a mount cannot be altered once it has been idmapped. - The mount must be a detached/anonymous mount, i.e. it must have been created by calling open_tree() with the OPEN_TREE_CLONE flag and it must not already have been visible in the filesystem. The last two points guarantee easier semantics for userspace and the kernel and make the implementation significantly simpler. By default vfsmounts are marked with the initial user namespace and no behavioral or performance changes are observed. The manpage with a detailed description can be found here: https://git.kernel.org/brauner/man-pages/c/1d7b902e2875a1ff342e036a9f866a995640aea8 In order to support idmapped mounts, filesystems need to be changed and mark themselves with the FS_ALLOW_IDMAP flag in fs_flags. The patches to convert individual filesystem are not very large or complicated overall as can be seen from the included fat, ext4, and xfs ports. Patches for other filesystems are actively worked on and will be sent out separately. The xfstestsuite can be used to verify that port has been done correctly. The mount_setattr() syscall is motivated independent of the idmapped mounts patches and it's been around since July 2019. One of the most valuable features of the new mount api is the ability to perform mounts based on file descriptors only. Together with the lookup restrictions available in the openat2() RESOLVE_* flag namespace which we added in v5.6 this is the first time we are close to hardened and race-free (e.g. symlinks) mounting and path resolution. While userspace has started porting to the new mount api to mount proper filesystems and create new bind-mounts it is currently not possible to change mount options of an already existing bind mount in the new mount api since the mount_setattr() syscall is missing. With the addition of the mount_setattr() syscall we remove this last restriction and userspace can now fully port to the new mount api, covering every use-case the old mount api could. We also add the crucial ability to recursively change mount options for a whole mount tree, both removing and adding mount options at the same time. This syscall has been requested multiple times by various people and projects. There is a simple tool available at https://github.com/brauner/mount-idmapped that allows to create idmapped mounts so people can play with this patch series. I'll add support for the regular mount binary should you decide to pull this in the following weeks: Here's an example to a simple idmapped mount of another user's home directory: u1001@f2-vm:/$ sudo ./mount --idmap both:1000:1001:1 /home/ubuntu/ /mnt u1001@f2-vm:/$ ls -al /home/ubuntu/ total 28 drwxr-xr-x 2 ubuntu ubuntu 4096 Oct 28 22:07 . drwxr-xr-x 4 root root 4096 Oct 28 04:00 .. -rw------- 1 ubuntu ubuntu 3154 Oct 28 22:12 .bash_history -rw-r--r-- 1 ubuntu ubuntu 220 Feb 25 2020 .bash_logout -rw-r--r-- 1 ubuntu ubuntu 3771 Feb 25 2020 .bashrc -rw-r--r-- 1 ubuntu ubuntu 807 Feb 25 2020 .profile -rw-r--r-- 1 ubuntu ubuntu 0 Oct 16 16:11 .sudo_as_admin_successful -rw------- 1 ubuntu ubuntu 1144 Oct 28 00:43 .viminfo u1001@f2-vm:/$ ls -al /mnt/ total 28 drwxr-xr-x 2 u1001 u1001 4096 Oct 28 22:07 . drwxr-xr-x 29 root root 4096 Oct 28 22:01 .. -rw------- 1 u1001 u1001 3154 Oct 28 22:12 .bash_history -rw-r--r-- 1 u1001 u1001 220 Feb 25 2020 .bash_logout -rw-r--r-- 1 u1001 u1001 3771 Feb 25 2020 .bashrc -rw-r--r-- 1 u1001 u1001 807 Feb 25 2020 .profile -rw-r--r-- 1 u1001 u1001 0 Oct 16 16:11 .sudo_as_admin_successful -rw------- 1 u1001 u1001 1144 Oct 28 00:43 .viminfo u1001@f2-vm:/$ touch /mnt/my-file u1001@f2-vm:/$ setfacl -m u:1001:rwx /mnt/my-file u1001@f2-vm:/$ sudo setcap -n 1001 cap_net_raw+ep /mnt/my-file u1001@f2-vm:/$ ls -al /mnt/my-file -rw-rwxr--+ 1 u1001 u1001 0 Oct 28 22:14 /mnt/my-file u1001@f2-vm:/$ ls -al /home/ubuntu/my-file -rw-rwxr--+ 1 ubuntu ubuntu 0 Oct 28 22:14 /home/ubuntu/my-file u1001@f2-vm:/$ getfacl /mnt/my-file getfacl: Removing leading '/' from absolute path names # file: mnt/my-file # owner: u1001 # group: u1001 user::rw- user:u1001:rwx group::rw- mask::rwx other::r-- u1001@f2-vm:/$ getfacl /home/ubuntu/my-file getfacl: Removing leading '/' from absolute path names # file: home/ubuntu/my-file # owner: ubuntu # group: ubuntu user::rw- user:ubuntu:rwx group::rw- mask::rwx other::r--" * tag 'idmapped-mounts-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: (41 commits) xfs: remove the possibly unused mp variable in xfs_file_compat_ioctl xfs: support idmapped mounts ext4: support idmapped mounts fat: handle idmapped mounts tests: add mount_setattr() selftests fs: introduce MOUNT_ATTR_IDMAP fs: add mount_setattr() fs: add attr_flags_to_mnt_flags helper fs: split out functions to hold writers namespace: only take read lock in do_reconfigure_mnt() mount: make {lock,unlock}_mount_hash() static namespace: take lock_mount_hash() directly when changing flags nfs: do not export idmapped mounts overlayfs: do not mount on top of idmapped mounts ecryptfs: do not mount on top of idmapped mounts ima: handle idmapped mounts apparmor: handle idmapped mounts fs: make helpers idmap mount aware exec: handle idmapped mounts would_dump: handle idmapped mounts ...
| * overlayfs: do not mount on top of idmapped mountsChristian Brauner2021-01-241-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Prevent overlayfs from being mounted on top of idmapped mounts. Stacking filesystems need to be prevented from being mounted on top of idmapped mounts until they have have been converted to handle this. Link: https://lore.kernel.org/r/20210121131959.646623-29-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: James Morris <jamorris@linux.microsoft.com> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
| * fs: make helpers idmap mount awareChristian Brauner2021-01-244-19/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * namei: prepare for idmapped mountsChristian Brauner2021-01-242-11/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The various vfs_*() helpers are called by filesystems or by the vfs itself to perform core operations such as create, link, mkdir, mknod, rename, rmdir, tmpfile and unlink. Enable them to handle idmapped mounts. If the inode is accessed through an idmapped mount map it into the mount's user namespace and pass it down. Afterwards the checks and operations are identical to non-idmapped mounts. If the initial user namespace is passed nothing changes so non-idmapped mounts will see identical behavior as before. Link: https://lore.kernel.org/r/20210121131959.646623-15-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>
| * namei: introduce struct renamedataChristian Brauner2021-01-241-1/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to handle idmapped mounts we will extend the vfs rename helper to take two new arguments in follow up patches. Since this operations already takes a bunch of arguments add a simple struct renamedata and make the current helper use it before we extend it. Link: https://lore.kernel.org/r/20210121131959.646623-14-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>
| * xattr: handle idmapped mountsTycho Andersen2021-01-245-17/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When interacting with extended attributes the vfs verifies that the caller is privileged over the inode with which the extended attribute is associated. For posix access and posix default extended attributes a uid or gid can be stored on-disk. Let the functions handle posix extended attributes on idmapped mounts. If the inode is accessed through an idmapped mount we need to map it according to the mount's user namespace. Afterwards the checks are identical to non-idmapped mounts. This has no effect for e.g. security xattrs since they don't store uids or gids and don't perform permission checks on them like posix acls do. Link: https://lore.kernel.org/r/20210121131959.646623-10-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> Reviewed-by: James Morris <jamorris@linux.microsoft.com> Signed-off-by: Tycho Andersen <tycho@tycho.pizza> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
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