lwn.git/fs/ubifs/xattr.c, branch docs-4.16

fs, fscrypt: add an S_ENCRYPTED inode flag

2017-10-18T23:52:36+00:00

Introduce a flag S_ENCRYPTED which can be set in ->i_flags to indicate that the inode is encrypted using the fscrypt (fs/crypto/) mechanism. Checking this flag will give the same information that inode->i_sb->s_cop->is_encrypted(inode) currently does, but will be more efficient. This will be useful for adding higher-level helper functions for filesystems to use. For example we'll be able to replace this: if (ext4_encrypted_inode(inode)) { ret = fscrypt_get_encryption_info(inode); if (ret) return ret; if (!fscrypt_has_encryption_key(inode)) return -ENOKEY; } with this: ret = fscrypt_require_key(inode); if (ret) return ret; ... since we'll be able to retain the fast path for unencrypted files as a single flag check, using an inline function. This wasn't possible before because we'd have had to frequently call through the ->i_sb->s_cop->is_encrypted function pointer, even when the encryption support was disabled or not being used. Note: we don't define S_ENCRYPTED to 0 if CONFIG_FS_ENCRYPTION is disabled because we want to continue to return an error if an encrypted file is accessed without encryption support, rather than pretending that it is unencrypted. Reviewed-by: Chao Yu Acked-by: Dave Chinner Signed-off-by: Eric Biggers Signed-off-by: Theodore Ts'o

ubifs: Massage assert in ubifs_xattr_set() wrt. init_xattrs

2017-07-14T20:50:54+00:00

The inode is not locked in init_xattrs when creating a new inode. Without this patch, there will occurs assert when booting or creating a new file, if the kernel config CONFIG_SECURITY_SMACK is enabled. Log likes: UBIFS assert failed in ubifs_xattr_set at 298 (pid 1156) CPU: 1 PID: 1156 Comm: ldconfig Tainted: G S 4.12.0-rc1-207440-g1e70b02 #2 Hardware name: MediaTek MT2712 evaluation board (DT) Call trace: [] dump_backtrace+0x0/0x238 [] show_stack+0x14/0x20 [] dump_stack+0x9c/0xc0 [] ubifs_xattr_set+0x374/0x5e0 [] init_xattrs+0x5c/0xb8 [] security_inode_init_security+0x110/0x190 [] ubifs_init_security+0x30/0x68 [] ubifs_mkdir+0x100/0x200 [] vfs_mkdir+0x11c/0x1b8 [] SyS_mkdirat+0x74/0xd0 [] __sys_trace_return+0x0/0x4 Signed-off-by: Xiaolei Li Signed-off-by: Richard Weinberger

ubifs: Correctly evict xattr inodes

2017-07-14T20:49:04+00:00

UBIFS handles extended attributes just like files, as consequence of that, they also have inodes. Therefore UBIFS does all the inode machinery also for xattrs. Since new inodes have i_nlink of 1, a file or xattr inode will be evicted if i_nlink goes down to 0 after an unlink. UBIFS assumes this model also for xattrs, which is not correct. One can create a file "foo" with xattr "user.test". By reading "user.test" an inode will be created, and by deleting "user.test" it will get evicted later. The assumption breaks if the file "foo", which hosts the xattrs, will be removed. VFS nor UBIFS does not remove each xattr via ubifs_xattr_remove(), it just removes the host inode from the TNC and all underlying xattr nodes too and the inode will remain in the cache and wastes memory. To solve this problem, remove xattr inodes from the VFS inode cache in ubifs_xattr_remove() to make sure that they get evicted. Fixes: 1e51764a3c2ac05a ("UBIFS: add new flash file system") Cc: Signed-off-by: Richard Weinberger

Merge tag 'upstream-4.12-rc1' of git://git.infradead.org/linux-ubifs

2017-05-13T17:23:12+00:00

Pull UBI/UBIFS updates from Richard Weinberger: - new config option CONFIG_UBIFS_FS_SECURITY - minor improvements - random fixes * tag 'upstream-4.12-rc1' of git://git.infradead.org/linux-ubifs: ubi: Add debugfs file for tracking PEB state ubifs: Fix a typo in comment of ioctl2ubifs & ubifs2ioctl ubifs: Remove unnecessary assignment ubifs: Fix cut and paste error on sb type comparisons ubi: fastmap: Fix slab corruption ubifs: Add CONFIG_UBIFS_FS_SECURITY to disable/enable security labels ubi: Make mtd parameter readable ubi: Fix section mismatch

fs: ubifs: replace CURRENT_TIME_SEC with current_time

2017-05-09T00:15:15+00:00

CURRENT_TIME_SEC is not y2038 safe. current_time() will be transitioned to use 64 bit time along with vfs in a separate patch. There is no plan to transition CURRENT_TIME_SEC to use y2038 safe time interfaces. current_time() returns timestamps according to the granularities set in the inode's super_block. The granularity check to call current_fs_time() or CURRENT_TIME_SEC is not required. Use current_time() directly to update inode timestamp. Use timespec_trunc during file system creation, before the first inode is created. Link: http://lkml.kernel.org/r/1491613030-11599-9-git-send-email-deepa.kernel@gmail.com Signed-off-by: Deepa Dinamani Reviewed-by: Arnd Bergmann Cc: Richard Weinberger Cc: Artem Bityutskiy Cc: Adrian Hunter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ubifs: Add CONFIG_UBIFS_FS_SECURITY to disable/enable security labels

2017-05-08T18:48:23+00:00

When write syscall is called, every time security label is searched to determine that file's privileges should be changed. If LSM(Linux Security Model) is not used, this is useless. So introduce CONFIG_UBIFS_SECURITY to disable security labels. it's default value is "y". Signed-off-by: Hyunchul Lee Signed-off-by: Richard Weinberger

ubifs: Implement encrypted filenames

2016-12-12T22:07:38+00:00

Signed-off-by: Richard Weinberger Signed-off-by: David Gstir Signed-off-by: Richard Weinberger

ubifs: Massage assert in ubifs_xattr_set() wrt. fscrypto

2016-12-12T22:07:38+00:00

When we're creating a new inode in UBIFS the inode is not yet exposed and fscrypto calls ubifs_xattr_set() without holding the inode mutex. This is okay but ubifs_xattr_set() has to know about this. Signed-off-by: Richard Weinberger

ubifs: Massage ubifs_listxattr() for encryption context

2016-12-12T22:07:38+00:00

We have to make sure that we don't expose our internal crypto context to userspace. Signed-off-by: Richard Weinberger

ubifs: Add skeleton for fscrypto

2016-12-12T22:07:38+00:00

This is the first building block to provide file level encryption on UBIFS. Signed-off-by: Richard Weinberger