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* Merge tag 'docs-5.12' of git://git.lwn.net/linuxLinus Torvalds2021-02-221-6/+6
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull documentation updates from Jonathan Corbet: "It has been a relatively quiet cycle in docsland. - As promised, the minimum Sphinx version to build the docs is now 1.7, and we have dropped support for Python 2 entirely. That allowed the removal of a bunch of compatibility code. - A set of treewide warning fixups from Mauro that I applied after it became clear nobody else was going to deal with them. - The automarkup mechanism can now create cross-references from relative paths to RST files. - More translations, typo fixes, and warning fixes" * tag 'docs-5.12' of git://git.lwn.net/linux: (75 commits) docs: kernel-hacking: be more civil docs: Remove the Microsoft rhetoric Documentation/admin-guide: kernel-parameters: Update nohlt section doc/admin-guide: fix spelling mistake: "perfomance" -> "performance" docs: Document cross-referencing using relative path docs: Enable usage of relative paths to docs on automarkup docs: thermal: fix spelling mistakes Documentation: admin-guide: Update kvm/xen config option docs: Make syscalls' helpers naming consistent coding-style.rst: Avoid comma statements Documentation: /proc/loadavg: add 3 more field descriptions Documentation/submitting-patches: Add blurb about backtraces in commit messages Docs: drop Python 2 support Move our minimum Sphinx version to 1.7 Documentation: input: define ABS_PRESSURE/ABS_MT_PRESSURE resolution as grams scripts/kernel-doc: add internal hyperlink to DOC: sections Update Documentation/admin-guide/sysctl/fs.rst docs: Update DTB format references docs: zh_CN: add iio index.rst translation docs/zh_CN: add iio ep93xx_adc.rst translation ...
| * fs: fix kernel-doc markupsMauro Carvalho Chehab2021-01-211-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | Two markups are at the wrong place. Kernel-doc only support having the comment just before the identifier. Also, some identifiers have different names between their prototypes and the kernel-doc markup. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/96b1e1b388600ab092331f6c4e88ff8e8779ce6c.1610610937.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* | block: remove the NULL bdev check in bdev_read_onlyChristoph Hellwig2021-01-241-1/+2
|/ | | | | | | | | | | Only a single caller can end up in bdev_read_only, so move the check there. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: remove i_bdevChristoph Hellwig2020-12-011-25/+19
| | | | | | | | | | | | | | | | Switch the block device lookup interfaces to directly work with a dev_t so that struct block_device references are only acquired by the blkdev_get variants (and the blk-cgroup special case). This means that we now don't need an extra reference in the inode and can generally simplify handling of struct block_device to keep the lookups contained in the core block layer code. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Hannes Reinecke <hare@suse.de> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Coly Li <colyli@suse.de> [bcache] Signed-off-by: Jens Axboe <axboe@kernel.dk>
* fs: remove get_super_thawed and get_super_exclusive_thawedChristoph Hellwig2020-12-011-49/+2
| | | | | | | | | Just open code the wait in the only caller of both functions. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* vfs: move __sb_{start,end}_write* to fs.hDarrick J. Wong2020-11-101-30/+0
| | | | | | | | | Now that we've straightened out the callers, move these three functions to fs.h since they're fairly trivial. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz>
* vfs: separate __sb_start_write into blocking and non-blocking helpersDarrick J. Wong2020-11-101-6/+12
| | | | | | | | | | | Break this function into two helpers so that it's obvious that the trylock versions return a value that must be checked, and the blocking versions don't require that. While we're at it, clean up the return type mismatch. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de>
* vfs: remove lockdep bogosity in __sb_start_writeDarrick J. Wong2020-11-101-29/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | __sb_start_write has some weird looking lockdep code that claims to exist to handle nested freeze locking requests from xfs. The code as written seems broken -- if we think we hold a read lock on any of the higher freeze levels (e.g. we hold SB_FREEZE_WRITE and are trying to lock SB_FREEZE_PAGEFAULT), it converts a blocking lock attempt into a trylock. However, it's not correct to downgrade a blocking lock attempt to a trylock unless the downgrading code or the callers are prepared to deal with that situation. Neither __sb_start_write nor its callers handle this at all. For example: sb_start_pagefault ignores the return value completely, with the result that if xfs_filemap_fault loses a race with a different thread trying to fsfreeze, it will proceed without pagefault freeze protection (thereby breaking locking rules) and then unlocks the pagefault freeze lock that it doesn't own on its way out (thereby corrupting the lock state), which leads to a system hang shortly afterwards. Normally, this won't happen because our ownership of a read lock on a higher freeze protection level blocks fsfreeze from grabbing a write lock on that higher level. *However*, if lockdep is offline, lock_is_held_type unconditionally returns 1, which means that percpu_rwsem_is_held returns 1, which means that __sb_start_write unconditionally converts blocking freeze lock attempts into trylocks, even when we *don't* hold anything that would block a fsfreeze. Apparently this all held together until 5.10-rc1, when bugs in lockdep caused lockdep to shut itself off early in an fstests run, and once fstests gets to the "race writes with freezer" tests, kaboom. This might explain the long trail of vanishingly infrequent livelocks in fstests after lockdep goes offline that I've never been able to diagnose. We could fix it by spinning on the trylock if wait==true, but AFAICT the locking works fine if lockdep is not built at all (and I didn't see any complaints running fstests overnight), so remove this snippet entirely. NOTE: Commit f4b554af9931 in 2015 created the current weird logic (which used to exist in a different form in commit 5accdf82ba25c from 2012) in __sb_start_write. XFS solved this whole problem in the late 2.6 era by creating a variant of transactions (XFS_TRANS_NO_WRITECOUNT) that don't grab intwrite freeze protection, thus making lockdep's solution unnecessary. The commit claims that Dave Chinner explained that the trylock hack + comment could be removed, but nobody ever did. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz>
* bdi: replace BDI_CAP_STABLE_WRITES with a queue and a sb flagChristoph Hellwig2020-09-241-0/+2
| | | | | | | | | | | | | | | | | | The BDI_CAP_STABLE_WRITES is one of the few bits of information in the backing_dev_info shared between the block drivers and the writeback code. To help untangling the dependency replace it with a queue flag and a superblock flag derived from it. This also helps with the case of e.g. a file system requiring stable writes due to its own checksumming, but not forcing it on other users of the block device like the swap code. One downside is that we an't support the stable_pages_required bdi attribute in sysfs anymore. It is replaced with a queue attribute which also is writable for easier testing. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* Merge branch 'work.misc' of ↵Linus Torvalds2020-06-101-1/+1
|\ | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs fixes from Al Viro: "A couple of trivial patches that fell through the cracks last cycle" * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs: fix indentation in deactivate_super() vfs: Remove duplicated d_mountpoint check in __is_local_mountpoint
| * fs: fix indentation in deactivate_super()Yufen Yu2020-05-291-1/+1
| | | | | | | | | | | | | | Fix the breaked indent in deactive_super(). Signed-off-by: Yufen Yu <yuyufen@huawei.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | Merge tag 'for-5.8/block-2020-06-01' of git://git.kernel.dk/linux-blockLinus Torvalds2020-06-021-3/+1
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull block updates from Jens Axboe: "Core block changes that have been queued up for this release: - Remove dead blk-throttle and blk-wbt code (Guoqing) - Include pid in blktrace note traces (Jan) - Don't spew I/O errors on wouldblock termination (me) - Zone append addition (Johannes, Keith, Damien) - IO accounting improvements (Konstantin, Christoph) - blk-mq hardware map update improvements (Ming) - Scheduler dispatch improvement (Salman) - Inline block encryption support (Satya) - Request map fixes and improvements (Weiping) - blk-iocost tweaks (Tejun) - Fix for timeout failing with error injection (Keith) - Queue re-run fixes (Douglas) - CPU hotplug improvements (Christoph) - Queue entry/exit improvements (Christoph) - Move DMA drain handling to the few drivers that use it (Christoph) - Partition handling cleanups (Christoph)" * tag 'for-5.8/block-2020-06-01' of git://git.kernel.dk/linux-block: (127 commits) block: mark bio_wouldblock_error() bio with BIO_QUIET blk-wbt: rename __wbt_update_limits to wbt_update_limits blk-wbt: remove wbt_update_limits blk-throttle: remove tg_drain_bios blk-throttle: remove blk_throtl_drain null_blk: force complete for timeout request blk-mq: drain I/O when all CPUs in a hctx are offline blk-mq: add blk_mq_all_tag_iter blk-mq: open code __blk_mq_alloc_request in blk_mq_alloc_request_hctx blk-mq: use BLK_MQ_NO_TAG in more places blk-mq: rename BLK_MQ_TAG_FAIL to BLK_MQ_NO_TAG blk-mq: move more request initialization to blk_mq_rq_ctx_init blk-mq: simplify the blk_mq_get_request calling convention blk-mq: remove the bio argument to ->prepare_request nvme: force complete cancelled requests blk-mq: blk-mq: provide forced completion method block: fix a warning when blkdev.h is included for !CONFIG_BLOCK builds block: blk-crypto-fallback: remove redundant initialization of variable err block: reduce part_stat_lock() scope block: use __this_cpu_add() instead of access by smp_processor_id() ...
| * | bdi: remove the name field in struct backing_dev_infoChristoph Hellwig2020-05-091-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The name is only printed for a not registered bdi in writeback. Use the device name there as is more useful anyway for the unlike case that the warning triggers. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * | bdi: simplify bdi_allocChristoph Hellwig2020-05-091-1/+1
| |/ | | | | | | | | | | | | | | | | | | Merge the _node vs normal version and drop the superflous gfp_t argument. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* / Fix use after free in get_tree_bdev()David Howells2020-04-281-1/+1
|/ | | | | | | | | | | | | | | | | | | | | | Commit 6fcf0c72e4b9, a fix to get_tree_bdev() put a missing blkdev_put() in the wrong place, before a warnf() that displays the bdev under consideration rather after it. This results in a silent lockup in printk("%pg") called via warnf() from get_tree_bdev() under some circumstances when there's a race with the blockdev being frozen. This can be caused by xfstests/tests/generic/085 in combination with Lukas Czerner's ext4 mount API conversion patchset. It looks like it ought to occur with other users of get_tree_bdev() such as XFS, but apparently doesn't. Fix this by switching the order of the lines. Fixes: 6fcf0c72e4b9 ("vfs: add missing blkdev_put() in get_tree_bdev()") Reported-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: Ian Kent <raven@themaw.net> cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs: call fsnotify_sb_delete after evict_inodesEric Sandeen2019-12-181-1/+3
| | | | | | | | | | | | | | | | | | | | | | When a filesystem is unmounted, we currently call fsnotify_sb_delete() before evict_inodes(), which means that fsnotify_unmount_inodes() must iterate over all inodes on the superblock looking for any inodes with watches. This is inefficient and can lead to livelocks as it iterates over many unwatched inodes. At this point, SB_ACTIVE is gone and dropping refcount to zero kicks the inode out out immediately, so anything processed by fsnotify_sb_delete / fsnotify_unmount_inodes gets evicted in that loop. After that, the call to evict_inodes will evict everything else with a zero refcount. This should speed things up overall, and avoid livelocks in fsnotify_unmount_inodes(). Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge branch 'work.mount3' of ↵Linus Torvalds2019-10-101-1/+4
|\ | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull mount fixes from Al Viro: "A couple of regressions from the mount series" * 'work.mount3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: vfs: add missing blkdev_put() in get_tree_bdev() shmem: fix LSM options parsing
| * vfs: add missing blkdev_put() in get_tree_bdev()Ian Kent2019-10-091-1/+4
| | | | | | | | | | | | Is there are a couple of missing blkdev_put() in get_tree_bdev()? Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | Merge tag 'fuse-update-5.4' of ↵Linus Torvalds2019-09-251-5/+0
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse Pull fuse updates from Miklos Szeredi: - Continue separating the transport (user/kernel communication) and the filesystem layers of fuse. Getting rid of most layering violations will allow for easier cleanup and optimization later on. - Prepare for the addition of the virtio-fs filesystem. The actual filesystem will be introduced by a separate pull request. - Convert to new mount API. - Various fixes, optimizations and cleanups. * tag 'fuse-update-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: (55 commits) fuse: Make fuse_args_to_req static fuse: fix memleak in cuse_channel_open fuse: fix beyond-end-of-page access in fuse_parse_cache() fuse: unexport fuse_put_request fuse: kmemcg account fs data fuse: on 64-bit store time in d_fsdata directly fuse: fix missing unlock_page in fuse_writepage() fuse: reserve byteswapped init opcodes fuse: allow skipping control interface and forced unmount fuse: dissociate DESTROY from fuseblk fuse: delete dentry if timeout is zero fuse: separate fuse device allocation and installation in fuse_conn fuse: add fuse_iqueue_ops callbacks fuse: extract fuse_fill_super_common() fuse: export fuse_dequeue_forget() function fuse: export fuse_get_unique() fuse: export fuse_send_init_request() fuse: export fuse_len_args() fuse: export fuse_end_request() fuse: fix request limit ...
| * | vfs: subtype handling moved to fuseDavid Howells2019-09-061-5/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The unused vfs code can be removed. Don't pass empty subtype (same as if ->parse callback isn't called). The bits that are left involve determining whether it's permitted to split the filesystem type string passed in to mount(2). Consequently, this means that we cannot get rid of the FS_HAS_SUBTYPE flag unless we define that a type string with a dot in it always indicates a subtype specification. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* | | Merge branch 'work.mount2' of ↵Linus Torvalds2019-09-191-7/+28
|\ \ \ | | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull misc mount API conversions from Al Viro: "Conversions to new API for shmem and friends and for mount_mtd()-using filesystems. As for the rest of the mount API conversions in -next, some of them belong in the individual trees (e.g. binderfs one should definitely go through android folks, after getting redone on top of their changes). I'm going to drop those and send the rest (trivial ones + stuff ACKed by maintainers) in a separate series - by that point they are independent from each other. Some stuff has already migrated into individual trees (NFS conversion, for example, or FUSE stuff, etc.); those presumably will go through the regular merges from corresponding trees." * 'work.mount2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: vfs: Make fs_parse() handle fs_param_is_fd-type params better vfs: Convert ramfs, shmem, tmpfs, devtmpfs, rootfs to use the new mount API shmem_parse_one(): switch to use of fs_parse() shmem_parse_options(): take handling a single option into a helper shmem_parse_options(): don't bother with mpol in separate variable shmem_parse_options(): use a separate structure to keep the results make shmem_fill_super() static make ramfs_fill_super() static devtmpfs: don't mix {ramfs,shmem}_fill_super() with mount_single() vfs: Convert squashfs to use the new mount API mtd: Kill mount_mtd() vfs: Convert jffs2 to use the new mount API vfs: Convert cramfs to use the new mount API vfs: Convert romfs to use the new mount API vfs: Add a single-or-reconfig keying to vfs_get_super()
| * | vfs: Add a single-or-reconfig keying to vfs_get_super()David Howells2019-09-051-7/+28
| |/ | | | | | | | | | | | | | | | | | | | | | | | | Add an additional keying mode to vfs_get_super() to indicate that only a single superblock should exist in the system, and that, if it does, further mounts should invoke reconfiguration upon it. This allows mount_single() to be replaced. [Fix by Eric Biggers folded in] Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | Merge tag 'y2038-vfs' of ↵Linus Torvalds2019-09-191-0/+2
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground Pull y2038 vfs updates from Arnd Bergmann: "Add inode timestamp clamping. This series from Deepa Dinamani adds a per-superblock minimum/maximum timestamp limit for a file system, and clamps timestamps as they are written, to avoid random behavior from integer overflow as well as having different time stamps on disk vs in memory. At mount time, a warning is now printed for any file system that can represent current timestamps but not future timestamps more than 30 years into the future, similar to the arbitrary 30 year limit that was added to settimeofday(). This was picked as a compromise to warn users to migrate to other file systems (e.g. ext4 instead of ext3) when they need the file system to survive beyond 2038 (or similar limits in other file systems), but not get in the way of normal usage" * tag 'y2038-vfs' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground: ext4: Reduce ext4 timestamp warnings isofs: Initialize filesystem timestamp ranges pstore: fs superblock limits fs: omfs: Initialize filesystem timestamp ranges fs: hpfs: Initialize filesystem timestamp ranges fs: ceph: Initialize filesystem timestamp ranges fs: sysv: Initialize filesystem timestamp ranges fs: affs: Initialize filesystem timestamp ranges fs: fat: Initialize filesystem timestamp ranges fs: cifs: Initialize filesystem timestamp ranges fs: nfs: Initialize filesystem timestamp ranges ext4: Initialize timestamps limits 9p: Fill min and max timestamps in sb fs: Fill in max and min timestamps in superblock utimes: Clamp the timestamps before update mount: Add mount warning for impending timestamp expiry timestamp_truncate: Replace users of timespec64_trunc vfs: Add timestamp_truncate() api vfs: Add file timestamp range support
| * | vfs: Add file timestamp range supportDeepa Dinamani2019-08-301-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add fields to the superblock to track the min and max timestamps supported by filesystems. Initially, when a superblock is allocated, initialize it to the max and min values the fields can hold. Individual filesystems override these to match their actual limits. Pseudo filesystems are assumed to always support the min and max allowable values for the fields. Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Acked-by: Jeff Layton <jlayton@kernel.org>
* | | Merge tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscryptLinus Torvalds2019-09-181-0/+2
|\ \ \ | |_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull fscrypt updates from Eric Biggers: "This is a large update to fs/crypto/ which includes: - Add ioctls that add/remove encryption keys to/from a filesystem-level keyring. These fix user-reported issues where e.g. an encrypted home directory can break NetworkManager, sshd, Docker, etc. because they don't get access to the needed keyring. These ioctls also provide a way to lock encrypted directories that doesn't use the vm.drop_caches sysctl, so is faster, more reliable, and doesn't always need root. - Add a new encryption policy version ("v2") which switches to a more standard, secure, and flexible key derivation function, and starts verifying that the correct key was supplied before using it. The key derivation improvement is needed for its own sake as well as for ongoing feature work for which the current way is too inflexible. Work is in progress to update both Android and the 'fscrypt' userspace tool to use both these features. (Working patches are available and just need to be reviewed+merged.) Chrome OS will likely use them too. This has also been tested on ext4, f2fs, and ubifs with xfstests -- both the existing encryption tests, and the new tests for this. This has also been in linux-next since Aug 16 with no reported issues. I'm also using an fscrypt v2-encrypted home directory on my personal desktop" * tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscrypt: (27 commits) ext4 crypto: fix to check feature status before get policy fscrypt: document the new ioctls and policy version ubifs: wire up new fscrypt ioctls f2fs: wire up new fscrypt ioctls ext4: wire up new fscrypt ioctls fscrypt: require that key be added when setting a v2 encryption policy fscrypt: add FS_IOC_REMOVE_ENCRYPTION_KEY_ALL_USERS ioctl fscrypt: allow unprivileged users to add/remove keys for v2 policies fscrypt: v2 encryption policy support fscrypt: add an HKDF-SHA512 implementation fscrypt: add FS_IOC_GET_ENCRYPTION_KEY_STATUS ioctl fscrypt: add FS_IOC_REMOVE_ENCRYPTION_KEY ioctl fscrypt: add FS_IOC_ADD_ENCRYPTION_KEY ioctl fscrypt: rename keyinfo.c to keysetup.c fscrypt: move v1 policy key setup to keysetup_v1.c fscrypt: refactor key setup code in preparation for v2 policies fscrypt: rename fscrypt_master_key to fscrypt_direct_key fscrypt: add ->ci_inode to fscrypt_info fscrypt: use FSCRYPT_* definitions, not FS_* fscrypt: use FSCRYPT_ prefix for uapi constants ...
| * | fscrypt: add FS_IOC_ADD_ENCRYPTION_KEY ioctlEric Biggers2019-08-121-0/+2
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a new fscrypt ioctl, FS_IOC_ADD_ENCRYPTION_KEY. This ioctl adds an encryption key to the filesystem's fscrypt keyring ->s_master_keys, making any files encrypted with that key appear "unlocked". Why we need this ~~~~~~~~~~~~~~~~ The main problem is that the "locked/unlocked" (ciphertext/plaintext) status of encrypted files is global, but the fscrypt keys are not. fscrypt only looks for keys in the keyring(s) the process accessing the filesystem is subscribed to: the thread keyring, process keyring, and session keyring, where the session keyring may contain the user keyring. Therefore, userspace has to put fscrypt keys in the keyrings for individual users or sessions. But this means that when a process with a different keyring tries to access encrypted files, whether they appear "unlocked" or not is nondeterministic. This is because it depends on whether the files are currently present in the inode cache. Fixing this by consistently providing each process its own view of the filesystem depending on whether it has the key or not isn't feasible due to how the VFS caches work. Furthermore, while sometimes users expect this behavior, it is misguided for two reasons. First, it would be an OS-level access control mechanism largely redundant with existing access control mechanisms such as UNIX file permissions, ACLs, LSMs, etc. Encryption is actually for protecting the data at rest. Second, almost all users of fscrypt actually do need the keys to be global. The largest users of fscrypt, Android and Chromium OS, achieve this by having PID 1 create a "session keyring" that is inherited by every process. This works, but it isn't scalable because it prevents session keyrings from being used for any other purpose. On general-purpose Linux distros, the 'fscrypt' userspace tool [1] can't similarly abuse the session keyring, so to make 'sudo' work on all systems it has to link all the user keyrings into root's user keyring [2]. This is ugly and raises security concerns. Moreover it can't make the keys available to system services, such as sshd trying to access the user's '~/.ssh' directory (see [3], [4]) or NetworkManager trying to read certificates from the user's home directory (see [5]); or to Docker containers (see [6], [7]). By having an API to add a key to the *filesystem* we'll be able to fix the above bugs, remove userspace workarounds, and clearly express the intended semantics: the locked/unlocked status of an encrypted directory is global, and encryption is orthogonal to OS-level access control. Why not use the add_key() syscall ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ We use an ioctl for this API rather than the existing add_key() system call because the ioctl gives us the flexibility needed to implement fscrypt-specific semantics that will be introduced in later patches: - Supporting key removal with the semantics such that the secret is removed immediately and any unused inodes using the key are evicted; also, the eviction of any in-use inodes can be retried. - Calculating a key-dependent cryptographic identifier and returning it to userspace. - Allowing keys to be added and removed by non-root users, but only keys for v2 encryption policies; and to prevent denial-of-service attacks, users can only remove keys they themselves have added, and a key is only really removed after all users who added it have removed it. Trying to shoehorn these semantics into the keyrings syscalls would be very difficult, whereas the ioctls make things much easier. However, to reuse code the implementation still uses the keyrings service internally. Thus we get lockless RCU-mode key lookups without having to re-implement it, and the keys automatically show up in /proc/keys for debugging purposes. References: [1] https://github.com/google/fscrypt [2] https://goo.gl/55cCrI#heading=h.vf09isp98isb [3] https://github.com/google/fscrypt/issues/111#issuecomment-444347939 [4] https://github.com/google/fscrypt/issues/116 [5] https://bugs.launchpad.net/ubuntu/+source/fscrypt/+bug/1770715 [6] https://github.com/google/fscrypt/issues/128 [7] https://askubuntu.com/questions/1130306/cannot-run-docker-on-an-encrypted-filesystem Reviewed-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Eric Biggers <ebiggers@google.com>
* | vfs: Create fs_context-aware mount_bdev() replacementDavid Howells2019-09-051-0/+94
| | | | | | | | | | | | | | | | | | | | | | | | | | Create a function, get_tree_bdev(), that is fs_context-aware and a ->get_tree() counterpart of mount_bdev(). It caches the block device pointer in the fs_context struct so that this information can be passed into sget_fc()'s test and set functions. Signed-off-by: David Howells <dhowells@redhat.com> cc: Jens Axboe <axboe@kernel.dk> cc: linux-block@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | new helper: get_tree_keyed()Al Viro2019-09-051-0/+10
|/ | | | | | For vfs_get_keyed_super users. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Unbreak mount_capable()Al Viro2019-07-311-4/+1
| | | | | | | | | | | | | | | In "consolidate the capability checks in sget_{fc,userns}())" the wrong argument had been passed to mount_capable() by sget_fc(). That mistake had been further obscured later, when switching mount_capable() to fs_context has moved the calculation of bogus argument from sget_fc() to mount_capable() itself. It should've been fc->user_ns all along. Screwed-up-by: Al Viro <viro@zeniv.linux.org.uk> Reported-by: Christian Brauner <christian@brauner.io> Tested-by: Christian Brauner <christian@brauner.io> Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* convenience helper: get_tree_single()Al Viro2019-07-041-0/+8
| | | | | | counterpart of mount_single(); switch fusectl to it Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* convenience helper get_tree_nodev()Al Viro2019-07-041-0/+8
| | | | | | counterpart of mount_nodev(). Switch hugetlb and pseudo to it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: Kill sget_userns()David Howells2019-05-251-38/+16
| | | | | | | | Kill sget_userns(), folding it into sget() as that's the only remaining user. Signed-off-by: David Howells <dhowells@redhat.com> cc: linux-fsdevel@vger.kernel.org
* vfs: Provide sb->s_iflags settings in fs_context structDavid Howells2019-05-251-0/+1
| | | | | | | | Provide a field in the fs_context struct through which bits in the sb->s_iflags superblock field can be set. Signed-off-by: David Howells <dhowells@redhat.com> cc: linux-fsdevel@vger.kernel.org
* move mount_capable() further outAl Viro2019-05-251-6/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Call graph of vfs_get_tree(): vfs_fsconfig_locked() # neither kernmount, nor submount do_new_mount() # neither kernmount, nor submount fc_mount() afs_mntpt_do_automount() # submount mount_one_hugetlbfs() # kernmount pid_ns_prepare_proc() # kernmount mq_create_mount() # kernmount vfs_kern_mount() simple_pin_fs() # kernmount vfs_submount() # submount kern_mount() # kernmount init_mount_tree() btrfs_mount() nfs_do_root_mount() The first two need the check (unconditionally). init_mount_tree() is setting rootfs up; any capability checks make zero sense for that one. And btrfs_mount()/ nfs_do_root_mount() have the checks already done in their callers. IOW, we can shift mount_capable() handling into the two callers - one in the normal case of mount(2), another - in fsconfig(2) handling of FSCONFIG_CMD_CREATE. I.e. the syscalls that set a new filesystem up. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* move mount_capable() calls to vfs_get_tree()Al Viro2019-05-251-6/+6
| | | | | | | | | | | | | sget_fc() is called only from ->get_tree() instances and the only instance not calling it is legacy_get_tree(), which calls mount_capable() directly. In all sget_fc() callers the checks could be moved to the very beginning of ->get_tree() - ->user_ns is not changed in between. So lifting the checks to the only caller of ->get_tree() is OK. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* switch mount_capable() to fs_contextAl Viro2019-05-251-4/+7
| | | | | | | | | now both callers of mount_capable() have access to fs_context; the only difference is that for sget_fc() we have the possibility of fc->global being true, while for legacy_get_tree() it's guaranteed to be impossible. Unify to more generic variant... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* move the capability checks from sget_userns() to legacy_get_tree()Al Viro2019-05-251-4/+0
| | | | | | | | | | | | | | | | | | | | | | 1) all call chains leading to sget_userns() pass through ->mount() instances. 2) none of ->mount() instances is ever called directly - the only call site is legacy_get_tree() 3) all remaining ->mount() instances end up calling sget_userns() IOW, we might as well do the capability checks just before calling ->mount(). As for the arguments passed to mount_capable(), in case of call chains to sget_userns() going through sget(), we either don't call mount_capable() at all, or pass current_user_ns() to it. The call chains going through mount_pseudo_xattr() don't call mount_capable() at all (SB_KERNMOUNT in flags on those). That could've been split into smaller steps (lifting the checks into sget(), then callers of sget(), then all the way to the entries of every ->mount() out there, then to the sole caller), but that would be too much churn for little benefit... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: Kill mount_ns()David Howells2019-05-251-38/+0
| | | | | | | | | Kill mount_ns() as it has been replaced by vfs_get_super() in the new mount API. Signed-off-by: David Howells <dhowells@redhat.com> cc: linux-fsdevel@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* consolidate the capability checks in sget_{fc,userns}()Al Viro2019-05-251-18/+14
| | | | | | ... into a common helper - mount_capable(type, userns) Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* start massaging the checks in sget_...(): move to sget_userns()Al Viro2019-05-251-10/+4
| | | | | | | | | | | | | | | | | | | | | | | | | there are 3 remaining callers of sget_userns() - sget(), mount_ns() and mount_pseudo_xattr(). Extra check in sget() is conditional upon mount being neither KERNMOUNT nor SUBMOUNT, the identical one in mount_ns() - upon being not KERNMOUNT; mount_pseudo_xattr() has no such checks at all. However, mount_ns() is never used with SUBMOUNT and mount_pseudo_xattr() is used only for KERNMOUNT, so both would be fine with the same logics as currently done in sget(), allowing to consolidate the entire thing in sget_userns() itself. That's not where these checks will end up in the long run, though - the whole reason why they'd been done so deep in the bowels of mount(2) was that there had been no way for a filesystem to specify which userns to look at until it has entered ->mount(). Now there is a place where filesystem could override the defaults - ->init_fs_context(). Which allows to pull the checks out into the callers of vfs_get_tree(). That'll take quite a bit of massage, but that mess is possible to tease apart. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* [fix] get rid of checking for absent device name in vfs_get_tree()Al Viro2019-04-281-5/+0
| | | | | | | | It has no business being there, it's checked by relevant ->get_tree() as it is *and* it returns the wrong error for no reason whatsoever. Fixes: f3a09c92018a "introduce fs_context methods" Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: Add some logging to the core users of the fs_context logDavid Howells2019-02-281-1/+3
| | | | | | | | Add some logging to the core users of the fs_context log so that information can be extracted from them as to the reason for failure. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* convenience helpers: vfs_get_super() and sget_fc()Al Viro2019-02-281-0/+171
| | | | | | | | | | | | | | | the former is an analogue of mount_{single,nodev} for use in ->get_tree() instances, the latter - analogue of sget() for the same. These are fairly similar to the originals, but the callback signature for sget_fc() is different from sget() ones, so getting bits and pieces shared would be too convoluted; we might get around to that later, but for now let's just remember to keep them in sync. They do live next to each other, and changes in either won't be hard to spot. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* introduce fs_context methodsAl Viro2019-01-301-8/+28
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* convert do_remount_sb() to fs_contextDavid Howells2019-01-301-34/+73
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Replace do_remount_sb() with a function, reconfigure_super(), that's fs_context aware. The fs_context is expected to be parameterised already and have ->root pointing to the superblock to be reconfigured. A legacy wrapper is provided that is intended to be called from the fs_context ops when those appear, but for now is called directly from reconfigure_super(). This wrapper invokes the ->remount_fs() superblock op for the moment. It is intended that the remount_fs() op will be phased out. The fs_context->purpose is set to FS_CONTEXT_FOR_RECONFIGURE to indicate that the context is being used for reconfiguration. do_umount_root() is provided to consolidate remount-to-R/O for umount and emergency remount by creating a context and invoking reconfiguration. do_remount(), do_umount() and do_emergency_remount_callback() are switched to use the new process. [AV -- fold UMOUNT and EMERGENCY_REMOUNT in; fixes the umount / bug, gets rid of pointless complexity] [AV -- set ->net_ns in all cases; nfs remount will need that] [AV -- shift security_sb_remount() call into reconfigure_super(); the callers that didn't do security_sb_remount() have NULL fc->security anyway, so it's a no-op for them] Signed-off-by: David Howells <dhowells@redhat.com> Co-developed-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs_get_tree(): evict the call of security_sb_kern_mount()Al Viro2019-01-301-12/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Right now vfs_get_tree() calls security_sb_kern_mount() (i.e. mount MAC) unless it gets MS_KERNMOUNT or MS_SUBMOUNT in flags. Doing it that way is both clumsy and imprecise. Consider the callers' tree of vfs_get_tree(): vfs_get_tree() <- do_new_mount() <- vfs_kern_mount() <- simple_pin_fs() <- vfs_submount() <- kern_mount_data() <- init_mount_tree() <- btrfs_mount() <- vfs_get_tree() <- nfs_do_root_mount() <- nfs4_try_mount() <- nfs_fs_mount() <- vfs_get_tree() <- nfs4_referral_mount() do_new_mount() always does need MAC (we are guaranteed that neither MS_KERNMOUNT nor MS_SUBMOUNT will be passed there). simple_pin_fs(), vfs_submount() and kern_mount_data() pass explicit flags inhibiting that check. So does nfs4_referral_mount() (the flags there are ulimately coming from vfs_submount()). init_mount_tree() is called too early for anything LSM-related; it doesn't matter whether we attempt those checks, they'll do nothing. Finally, in case of btrfs_mount() and nfs_fs_mount(), doing MAC is pointless - either the caller will do it, or the flags are such that we wouldn't have done it either. In other words, the one and only case when we want that check done is when we are called from do_new_mount(), and there we want it unconditionally. So let's simply move it there. The superblock is still locked, so nobody is going to get access to it (via ustat(2), etc.) until we get a chance to apply the checks - we are free to move them to any point up to where we drop ->s_umount (in do_new_mount_fc()). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* teach vfs_get_tree() to handle subtype, switch do_new_mount() to itAl Viro2019-01-301-0/+5
| | | | | | | | | | | | | | | | | Roll the handling of subtypes into do_new_mount() and vfs_get_tree(). The former determines any subtype string and hangs it off the fs_context; the latter applies it. Make do_new_mount() create, parameterise and commit an fs_context and create a mount for itself rather than calling vfs_kern_mount(). [AV -- missing kstrdup()] [AV -- ... and no kstrdup() if we get to setting ->s_submount - we simply transfer it from fc, leaving NULL behind] [AV -- constify ->s_submount, while we are at it] Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: Introduce fs_context, switch vfs_kern_mount() to it.David Howells2019-01-301-27/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce a filesystem context concept to be used during superblock creation for mount and superblock reconfiguration for remount. This is allocated at the beginning of the mount procedure and into it is placed: (1) Filesystem type. (2) Namespaces. (3) Source/Device names (there may be multiple). (4) Superblock flags (SB_*). (5) Security details. (6) Filesystem-specific data, as set by the mount options. Accessor functions are then provided to set up a context, parameterise it from monolithic mount data (the data page passed to mount(2)) and tear it down again. A legacy wrapper is provided that implements what will be the basic operations, wrapping access to filesystems that aren't yet aware of the fs_context. Finally, vfs_kern_mount() is changed to make use of the fs_context and mount_fs() is replaced by vfs_get_tree(), called from vfs_kern_mount(). [AV -- add missing kstrdup()] [AV -- put_cred() can be unconditional - fc->cred can't be NULL] [AV -- take legacy_validate() contents into legacy_parse_monolithic()] [AV -- merge KERNEL_MOUNT and USER_MOUNT] [AV -- don't unlock superblock on success return from vfs_get_tree()] [AV -- kill 'reference' argument of init_fs_context()] Signed-off-by: David Howells <dhowells@redhat.com> Co-developed-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* mount_fs: suppress MAC on MS_SUBMOUNT as well as MS_KERNMOUNTAl Viro2018-12-211-1/+1
| | | | | Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* LSM: hide struct security_mnt_opts from any generic codeAl Viro2018-12-211-7/+5
| | | | | | | | | | | | | | | | | | | | | | | | | Keep void * instead, allocate on demand (in parse_str_opts, at the moment). Eventually both selinux and smack will be better off with private structures with several strings in those, rather than this "counter and two pointers to dynamically allocated arrays" ugliness. This commit allows to do that at leisure, without disrupting anything outside of given module. Changes: * instead of struct security_mnt_opt use an opaque pointer initialized to NULL. * security_sb_eat_lsm_opts(), security_sb_parse_opts_str() and security_free_mnt_opts() take it as var argument (i.e. as void **); call sites are unchanged. * security_sb_set_mnt_opts() and security_sb_remount() take it by value (i.e. as void *). * new method: ->sb_free_mnt_opts(). Takes void *, does whatever freeing that needs to be done. * ->sb_set_mnt_opts() and ->sb_remount() might get NULL as mnt_opts argument, meaning "empty". Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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