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2023-10-28fs: assert that open_mutex isn't held over holder opsChristian Brauner1-0/+1
With recent block level changes we should never be in a situation where we hold disk->open_mutex when calling into these helpers. So assert that in the code. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20231017184823.1383356-6-hch@lst.de Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-28fs: Avoid grabbing sb->s_umount under bdev->bd_holder_lockJan Kara1-18/+32
The implementation of bdev holder operations such as fs_bdev_mark_dead() and fs_bdev_sync() grab sb->s_umount semaphore under bdev->bd_holder_lock. This is problematic because it leads to disk->open_mutex -> sb->s_umount lock ordering which is counterintuitive (usually we grab higher level (e.g. filesystem) locks first and lower level (e.g. block layer) locks later) and indeed makes lockdep complain about possible locking cycles whenever we open a block device while holding sb->s_umount semaphore. Implement a function bdev_super_lock_shared() which safely transitions from holding bdev->bd_holder_lock to holding sb->s_umount on alive superblock without introducing the problematic lock dependency. We use this function fs_bdev_sync() and fs_bdev_mark_dead(). Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20231018152924.3858-1-jack@suse.cz Link: https://lore.kernel.org/r/20231017184823.1383356-1-hch@lst.de Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-28fs: Convert to bdev_open_by_dev()Jan Kara1-6/+9
Convert mount code to use bdev_open_by_dev() and propagate the handle around to bdev_release(). Acked-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20230927093442.25915-19-jack@suse.cz Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-31fs: export sget_dev()Christian Brauner1-19/+45
They will be used for mtd devices as well. Acked-by: Richard Weinberger <richard@nod.at> Reviewed-by: Jan Kara <jack@suse.cz> Message-Id: <20230829-vfs-super-mtd-v1-1-fecb572e5df3@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-29Merge tag 'for-6.6/block-2023-08-28' of git://git.kernel.dk/linuxLinus Torvalds1-1/+3
Pull block updates from Jens Axboe: "Pretty quiet round for this release. This contains: - Add support for zoned storage to ublk (Andreas, Ming) - Series improving performance for drivers that mark themselves as needing a blocking context for issue (Bart) - Cleanup the flush logic (Chengming) - sed opal keyring support (Greg) - Fixes and improvements to the integrity support (Jinyoung) - Add some exports for bcachefs that we can hopefully delete again in the future (Kent) - deadline throttling fix (Zhiguo) - Series allowing building the kernel without buffer_head support (Christoph) - Sanitize the bio page adding flow (Christoph) - Write back cache fixes (Christoph) - MD updates via Song: - Fix perf regression for raid0 large sequential writes (Jan) - Fix split bio iostat for raid0 (David) - Various raid1 fixes (Heinz, Xueshi) - raid6test build fixes (WANG) - Deprecate bitmap file support (Christoph) - Fix deadlock with md sync thread (Yu) - Refactor md io accounting (Yu) - Various non-urgent fixes (Li, Yu, Jack) - Various fixes and cleanups (Arnd, Azeem, Chengming, Damien, Li, Ming, Nitesh, Ruan, Tejun, Thomas, Xu)" * tag 'for-6.6/block-2023-08-28' of git://git.kernel.dk/linux: (113 commits) block: use strscpy() to instead of strncpy() block: sed-opal: keyring support for SED keys block: sed-opal: Implement IOC_OPAL_REVERT_LSP block: sed-opal: Implement IOC_OPAL_DISCOVERY blk-mq: prealloc tags when increase tagset nr_hw_queues blk-mq: delete redundant tagset map update when fallback blk-mq: fix tags leak when shrink nr_hw_queues ublk: zoned: support REQ_OP_ZONE_RESET_ALL md: raid0: account for split bio in iostat accounting md/raid0: Fix performance regression for large sequential writes md/raid0: Factor out helper for mapping and submitting a bio md raid1: allow writebehind to work on any leg device set WriteMostly md/raid1: hold the barrier until handle_read_error() finishes md/raid1: free the r1bio before waiting for blocked rdev md/raid1: call free_r1bio() before allow_barrier() in raid_end_bio_io() blk-cgroup: Fix NULL deref caused by blkg_policy_data being installed before init drivers/rnbd: restore sysfs interface to rnbd-client md/raid5-cache: fix null-ptr-deref for r5l_flush_stripe_to_raid() raid6: test: only check for Altivec if building on powerpc hosts raid6: test: make sure all intermediate and artifact files are .gitignored ...
2023-08-29Merge tag 'v6.6-vfs.super.fixes' of ↵Linus Torvalds1-20/+31
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull superblock fixes from Christian Brauner: "Two follow-up fixes for the super work this cycle: - Move a misplaced lockep assertion before we potentially free the object containing the lock. - Ensure that filesystems which match superblocks in sget{_fc}() based on sb->s_fs_info are guaranteed to see a valid sb->s_fs_info as long as a superblock still appears on the filesystem type's superblock list. What we want as a proper solution for next cycle is to split sb->free_sb() out of sb->kill_sb() so that we can simply call kill_super_notify() after sb->kill_sb() but before sb->free_sb(). Currently, this is lumped together in sb->kill_sb()" * tag 'v6.6-vfs.super.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: super: ensure valid info super: move lockdep assert
2023-08-29super: ensure valid infoChristian Brauner1-19/+30
For keyed filesystems that recycle superblocks based on s_fs_info or information contained therein s_fs_info must be kept as long as the superblock is on the filesystem type super list. This isn't guaranteed as s_fs_info will be freed latest in sb->kill_sb(). The fix is simply to perform notification and list removal in kill_anon_super(). Any filesystem needs to free s_fs_info after they call the kill_*() helpers. If they don't they risk use-after-free right now so fixing it here is guaranteed that s_fs_info remain valid. For block backed filesystems notifying in pass sb->kill_sb() in deactivate_locked_super() remains unproblematic and is required because multiple other block devices can be shut down after kill_block_super() has been called from a filesystem's sb->kill_sb() handler. For example, ext4 and xfs close additional devices. Block based filesystems don't depend on s_fs_info (btrfs does use s_fs_info but also uses kill_anon_super() and not kill_block_super().). Sorry for that braino. Goal should be to unify this behavior during this cycle obviously. But let's please do a simple bugfix now. Fixes: 2c18a63b760a ("super: wait until we passed kill super") Fixes: syzbot+5b64180f8d9e39d3f061@syzkaller.appspotmail.com Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Reported-by: syzbot+5b64180f8d9e39d3f061@syzkaller.appspotmail.com Message-Id: <20230828-vfs-super-fixes-v1-2-b37a4a04a88f@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-29super: move lockdep assertChristian Brauner1-1/+1
Fix braino and move the lockdep assertion after put_super() otherwise we risk a use-after-free. Fixes: 2c18a63b760a ("super: wait until we passed kill super") Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Message-Id: <20230828-vfs-super-fixes-v1-1-b37a4a04a88f@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-28Merge tag 'v6.6-vfs.super' of ↵Linus Torvalds1-240/+525
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull superblock updates from Christian Brauner: "This contains the super rework that was ready for this cycle. The first part changes the order of how we open block devices and allocate superblocks, contains various cleanups, simplifications, and a new mechanism to wait on superblock state changes. This unblocks work to ultimately limit the number of writers to a block device. Jan has already scheduled follow-up work that will be ready for v6.7 and allows us to restrict the number of writers to a given block device. That series builds on this work right here. The second part contains filesystem freezing updates. Overview: The generic superblock changes are rougly organized as follows (ignoring additional minor cleanups): (1) Removal of the bd_super member from struct block_device. This was a very odd back pointer to struct super_block with unclear rules. For all relevant places we have other means to get the same information so just get rid of this. (2) Simplify rules for superblock cleanup. Roughly, everything that is allocated during fs_context initialization and that's stored in fs_context->s_fs_info needs to be cleaned up by the fs_context->free() implementation before the superblock allocation function has been called successfully. After sget_fc() returned fs_context->s_fs_info has been transferred to sb->s_fs_info at which point sb->kill_sb() if fully responsible for cleanup. Adhering to these rules means that cleanup of sb->s_fs_info in fill_super() is to be avoided as it's brittle and inconsistent. Cleanup shouldn't be duplicated between sb->put_super() as sb->put_super() is only called if sb->s_root has been set aka when the filesystem has been successfully born (SB_BORN). That complexity should be avoided. This also means that block devices are to be closed in sb->kill_sb() instead of sb->put_super(). More details in the lower section. (3) Make it possible to lookup or create a superblock before opening block devices There's a subtle dependency on (2) as some filesystems did rely on fill_super() to be called in order to correctly clean up sb->s_fs_info. All these filesystems have been fixed. (4) Switch most filesystem to follow the same logic as the generic mount code now does as outlined in (3). (5) Use the superblock as the holder of the block device. We can now easily go back from block device to owning superblock. (6) Export and extend the generic fs_holder_ops and use them as holder ops everywhere and remove the filesystem specific holder ops. (7) Call from the block layer up into the filesystem layer when the block device is removed, allowing to shut down the filesystem without risk of deadlocks. (8) Get rid of get_super(). We can now easily go back from the block device to owning superblock and can call up from the block layer into the filesystem layer when the device is removed. So no need to wade through all registered superblock to find the owning superblock anymore" Link: https://lore.kernel.org/lkml/20230824-prall-intakt-95dbffdee4a0@brauner/ * tag 'v6.6-vfs.super' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (47 commits) super: use higher-level helper for {freeze,thaw} super: wait until we passed kill super super: wait for nascent superblocks super: make locking naming consistent super: use locking helpers fs: simplify invalidate_inodes fs: remove get_super block: call into the file system for ioctl BLKFLSBUF block: call into the file system for bdev_mark_dead block: consolidate __invalidate_device and fsync_bdev block: drop the "busy inodes on changed media" log message dasd: also call __invalidate_device when setting the device offline amiflop: don't call fsync_bdev in FDFMTBEG floppy: call disk_force_media_change when changing the format block: simplify the disk_force_media_change interface nbd: call blk_mark_disk_dead in nbd_clear_sock_ioctl xfs use fs_holder_ops for the log and RT devices xfs: drop s_umount over opening the log and RT devices ext4: use fs_holder_ops for the log device ext4: drop s_umount over opening the log device ...
2023-08-23Merge tag 'vfs-6.6-merge-2' of ↵Christian Brauner1-18/+102
ssh://gitolite.kernel.org/pub/scm/fs/xfs/xfs-linux Pull filesystem freezing updates from Darrick Wong: New code for 6.6: * Allow the kernel to initiate a freeze of a filesystem. The kernel and userspace can both hold a freeze on a filesystem at the same time; the freeze is not lifted until /both/ holders lift it. This will enable us to fix a longstanding bug in XFS online fsck. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Message-Id: <20230822182604.GB11286@frogsfrogsfrogs> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-22super: use higher-level helper for {freeze,thaw}Christian Brauner1-3/+12
It's not necessary to use low-level locking helpers here. Use the higher-level locking helpers and log if the superblock is dying. Since the caller is assumed to already hold an active reference it isn't possible to observe a dying superblock. Suggested-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-21super: wait until we passed kill superChristian Brauner1-7/+64
Recent rework moved block device closing out of sb->put_super() and into sb->kill_sb() to avoid deadlocks as s_umount is held in put_super() and blkdev_put() can end up taking s_umount again. That means we need to move the removal of the superblock from @fs_supers out of generic_shutdown_super() and into deactivate_locked_super() to ensure that concurrent mounters don't fail to open block devices that are still in use because blkdev_put() in sb->kill_sb() hasn't been called yet. We can now do this as we can make iterators through @fs_super and @super_blocks wait without holding s_umount. Concurrent mounts will wait until a dying superblock is fully dead so until sb->kill_sb() has been called and SB_DEAD been set. Concurrent iterators can already discard any SB_DYING superblock. Reviewed-by: Jan Kara <jack@suse.cz> Message-Id: <20230818-vfs-super-fixes-v3-v3-4-9f0b1876e46b@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-21super: wait for nascent superblocksChristian Brauner1-51/+153
Recent patches experiment with making it possible to allocate a new superblock before opening the relevant block device. Naturally this has intricate side-effects that we get to learn about while developing this. Superblock allocators such as sget{_fc}() return with s_umount of the new superblock held and lock ordering currently requires that block level locks such as bdev_lock and open_mutex rank above s_umount. Before aca740cecbe5 ("fs: open block device after superblock creation") ordering was guaranteed to be correct as block devices were opened prior to superblock allocation and thus s_umount wasn't held. But now s_umount must be dropped before opening block devices to avoid locking violations. This has consequences. The main one being that iterators over @super_blocks and @fs_supers that grab a temporary reference to the superblock can now also grab s_umount before the caller has managed to open block devices and called fill_super(). So whereas before such iterators or concurrent mounts would have simply slept on s_umount until SB_BORN was set or the superblock was discard due to initalization failure they can now needlessly spin through sget{_fc}(). If the caller is sleeping on bdev_lock or open_mutex one caller waiting on SB_BORN will always spin somewhere and potentially this can go on for quite a while. It should be possible to drop s_umount while allowing iterators to wait on a nascent superblock to either be born or discarded. This patch implements a wait_var_event() mechanism allowing iterators to sleep until they are woken when the superblock is born or discarded. This also allows us to avoid relooping through @fs_supers and @super_blocks if a superblock isn't yet born or dying. Link: aca740cecbe5 ("fs: open block device after superblock creation") Reviewed-by: Jan Kara <jack@suse.cz> Message-Id: <20230818-vfs-super-fixes-v3-v3-3-9f0b1876e46b@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-21super: make locking naming consistentChristian Brauner1-14/+14
Make the naming consistent with the earlier introduced super_lock_{read,write}() helpers. Reviewed-by: Jan Kara <jack@suse.cz> Message-Id: <20230818-vfs-super-fixes-v3-v3-2-9f0b1876e46b@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-21super: use locking helpersChristian Brauner1-48/+78
Replace the open-coded {down,up}_{read,write}() calls with simple wrappers. Follow-up patches will benefit from this as well. Reviewed-by: Jan Kara <jack@suse.cz> Message-Id: <20230818-vfs-super-fixes-v3-v3-1-9f0b1876e46b@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-21fs: simplify invalidate_inodesChristoph Hellwig1-1/+1
kill_dirty has always been true for a long time, so hard code it and remove the unused return value. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Christian Brauner <brauner@kernel.org> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Message-Id: <20230811100828.1897174-18-hch@lst.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-21fs: remove get_superChristoph Hellwig1-37/+0
get_super is unused now, remove it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Christian Brauner <brauner@kernel.org> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Message-Id: <20230811100828.1897174-17-hch@lst.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-21block: call into the file system for ioctl BLKFLSBUFChristoph Hellwig1-0/+13
BLKFLSBUF is a historic ioctl that is called on a file handle to a block device and syncs either the file system mounted on that block device if there is one, or otherwise the just the data on the block device. Replace the get_super based syncing with a holder operation to remove the last usage of get_super, and to also support syncing the file system if the block device is not the main block device stored in s_dev. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Message-Id: <20230811100828.1897174-16-hch@lst.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-21block: call into the file system for bdev_mark_deadChristoph Hellwig1-2/+6
Combine the newly merged bdev_mark_dead helper with the existing mark_dead holder operation so that all operations that invalidate a device that is dead or being removed now go through the holder ops. This allows file systems to explicitly shutdown either ASAP (for a surprise removal) or after writing back data (for an orderly removal), and do so not only for the main device. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Message-Id: <20230811100828.1897174-15-hch@lst.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-21block: consolidate __invalidate_device and fsync_bdevChristoph Hellwig1-2/+2
We currently have two interfaces that take a block_devices and the find a mounted file systems to flush or invaldidate data on it. Both are a bit problematic because they only work for the "main" block devices that is used as s_dev for the super_block, and because they don't call into the file system at all. Merge the two into a new bdev_mark_dead helper that does both the syncing and invalidation and which is properly documented. This is in preparation of merging the functionality into the ->mark_dead holder operation so that it will work on additional block devices used by a file systems and give us a single entry point for invalidation of dead devices or media. Note that a single standalone fsync_bdev call for an obscure ioctl remains for now, but that one will also be deal with in a bit. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Message-Id: <20230811100828.1897174-14-hch@lst.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-14fs: add FSCONFIG_CMD_CREATE_EXCLChristian Brauner1-9/+27
Summary ======= This introduces FSCONFIG_CMD_CREATE_EXCL which will allows userspace to implement something like mount -t ext4 --exclusive /dev/sda /B which fails if a superblock for the requested filesystem does already exist: Before this patch ----------------- $ sudo ./move-mount -f xfs -o source=/dev/sda4 /A Requesting filesystem type xfs Mount options requested: source=/dev/sda4 Attaching mount at /A Moving single attached mount Setting key(source) with val(/dev/sda4) $ sudo ./move-mount -f xfs -o source=/dev/sda4 /B Requesting filesystem type xfs Mount options requested: source=/dev/sda4 Attaching mount at /B Moving single attached mount Setting key(source) with val(/dev/sda4) After this patch with --exclusive as a switch for FSCONFIG_CMD_CREATE_EXCL -------------------------------------------------------------------------- $ sudo ./move-mount -f xfs --exclusive -o source=/dev/sda4 /A Requesting filesystem type xfs Request exclusive superblock creation Mount options requested: source=/dev/sda4 Attaching mount at /A Moving single attached mount Setting key(source) with val(/dev/sda4) $ sudo ./move-mount -f xfs --exclusive -o source=/dev/sda4 /B Requesting filesystem type xfs Request exclusive superblock creation Mount options requested: source=/dev/sda4 Attaching mount at /B Moving single attached mount Setting key(source) with val(/dev/sda4) Device or resource busy | move-mount.c: 300: do_fsconfig: i xfs: reusing existing filesystem not allowed Details ======= As mentioned on the list (cf. [1]-[3]) mount requests like mount -t ext4 /dev/sda /A are ambigous for userspace. Either a new superblock has been created and mounted or an existing superblock has been reused and a bind-mount has been created. This becomes clear in the following example where two processes create the same mount for the same block device: P1 P2 fd_fs = fsopen("ext4"); fd_fs = fsopen("ext4"); fsconfig(fd_fs, FSCONFIG_SET_STRING, "source", "/dev/sda"); fsconfig(fd_fs, FSCONFIG_SET_STRING, "source", "/dev/sda"); fsconfig(fd_fs, FSCONFIG_SET_STRING, "dax", "always"); fsconfig(fd_fs, FSCONFIG_SET_STRING, "resuid", "1000"); // wins and creates superblock fsconfig(fd_fs, FSCONFIG_CMD_CREATE, ...) // finds compatible superblock of P1 // spins until P1 sets SB_BORN and grabs a reference fsconfig(fd_fs, FSCONFIG_CMD_CREATE, ...) fd_mnt1 = fsmount(fd_fs); fd_mnt2 = fsmount(fd_fs); move_mount(fd_mnt1, "/A") move_mount(fd_mnt2, "/B") Not just does P2 get a bind-mount but the mount options that P2 requestes are silently ignored. The VFS itself doesn't, can't and shouldn't enforce filesystem specific mount option compatibility. It only enforces incompatibility for read-only <-> read-write transitions: mount -t ext4 /dev/sda /A mount -t ext4 -o ro /dev/sda /B The read-only request will fail with EBUSY as the VFS can't just silently transition a superblock from read-write to read-only or vica versa without risking security issues. To userspace this silent superblock reuse can become a security issue in because there is currently no straightforward way for userspace to know that they did indeed manage to create a new superblock and didn't just reuse an existing one. This adds a new FSCONFIG_CMD_CREATE_EXCL command to fsconfig() that returns EBUSY if an existing superblock would be reused. Userspace that needs to be sure that it did create a new superblock with the requested mount options can request superblock creation using this command. If the command succeeds they can be sure that they did create a new superblock with the requested mount options. This requires the new mount api. With the old mount api it would be necessary to plumb this through every legacy filesystem's file_system_type->mount() method. If they want this feature they are most welcome to switch to the new mount api. Following is an analysis of the effect of FSCONFIG_CMD_CREATE_EXCL on each high-level superblock creation helper: (1) get_tree_nodev() Always allocate new superblock. Hence, FSCONFIG_CMD_CREATE and FSCONFIG_CMD_CREATE_EXCL are equivalent. The binderfs or overlayfs filesystems are examples. (4) get_tree_keyed() Finds an existing superblock based on sb->s_fs_info. Hence, FSCONFIG_CMD_CREATE would reuse an existing superblock whereas FSCONFIG_CMD_CREATE_EXCL would reject it with EBUSY. The mqueue or nfsd filesystems are examples. (2) get_tree_bdev() This effectively works like get_tree_keyed(). The ext4 or xfs filesystems are examples. (3) get_tree_single() Only one superblock of this filesystem type can ever exist. Hence, FSCONFIG_CMD_CREATE would reuse an existing superblock whereas FSCONFIG_CMD_CREATE_EXCL would reject it with EBUSY. The securityfs or configfs filesystems are examples. Note that some single-instance filesystems never destroy the superblock once it has been created during the first mount. For example, if securityfs has been mounted at least onces then the created superblock will never be destroyed again as long as there is still an LSM making use it. Consequently, even if securityfs is unmounted and the superblock seemingly destroyed it really isn't which means that FSCONFIG_CMD_CREATE_EXCL will continue rejecting reusing an existing superblock. This is acceptable thugh since special purpose filesystems such as this shouldn't have a need to use FSCONFIG_CMD_CREATE_EXCL anyway and if they do it's probably to make sure that mount options aren't ignored. Following is an analysis of the effect of FSCONFIG_CMD_CREATE_EXCL on filesystems that make use of the low-level sget_fc() helper directly. They're all effectively variants on get_tree_keyed(), get_tree_bdev(), or get_tree_nodev(): (5) mtd_get_sb() Similar logic to get_tree_keyed(). (6) afs_get_tree() Similar logic to get_tree_keyed(). (7) ceph_get_tree() Similar logic to get_tree_keyed(). Already explicitly allows forcing the allocation of a new superblock via CEPH_OPT_NOSHARE. This turns it into get_tree_nodev(). (8) fuse_get_tree_submount() Similar logic to get_tree_nodev(). (9) fuse_get_tree() Forces reuse of existing FUSE superblock. Forces reuse of existing superblock if passed in file refers to an existing FUSE connection. If FSCONFIG_CMD_CREATE_EXCL is specified together with an fd referring to an existing FUSE connections this would cause the superblock reusal to fail. If reusing is the intent then FSCONFIG_CMD_CREATE_EXCL shouldn't be specified. (10) fuse_get_tree() -> get_tree_nodev() Same logic as in get_tree_nodev(). (11) fuse_get_tree() -> get_tree_bdev() Same logic as in get_tree_bdev(). (12) virtio_fs_get_tree() Same logic as get_tree_keyed(). (13) gfs2_meta_get_tree() Forces reuse of existing gfs2 superblock. Mounting gfs2meta enforces that a gf2s superblock must already exist. If not, it will error out. Consequently, mounting gfs2meta with FSCONFIG_CMD_CREATE_EXCL would always fail. If reusing is the intent then FSCONFIG_CMD_CREATE_EXCL shouldn't be specified. (14) kernfs_get_tree() Similar logic to get_tree_keyed(). (15) nfs_get_tree_common() Similar logic to get_tree_keyed(). Already explicitly allows forcing the allocation of a new superblock via NFS_MOUNT_UNSHARED. This effectively turns it into get_tree_nodev(). Link: [1] https://lore.kernel.org/linux-block/20230704-fasching-wertarbeit-7c6ffb01c83d@brauner Link: [2] https://lore.kernel.org/linux-block/20230705-pumpwerk-vielversprechend-a4b1fd947b65@brauner Link: [3] https://lore.kernel.org/linux-fsdevel/20230725-einnahmen-warnschilder-17779aec0a97@brauner Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Aleksa Sarai <cyphar@cyphar.com> Message-Id: <20230802-vfs-super-exclusive-v2-4-95dc4e41b870@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-14super: remove get_tree_single_reconf()Christian Brauner1-23/+5
The get_tree_single_reconf() helper isn't used anywhere. Remove it. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Aleksa Sarai <cyphar@cyphar.com> Message-Id: <20230802-vfs-super-exclusive-v2-1-95dc4e41b870@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-11fs: export fs_holder_opsChristoph Hellwig1-1/+2
Export fs_holder_ops so that file systems that open additional block devices can use it as well. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Christian Brauner <brauner@kernel.org> Message-Id: <20230802154131.2221419-9-hch@lst.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-11fs: stop using get_super in fs_mark_deadChristoph Hellwig1-4/+26
fs_mark_dead currently uses get_super to find the superblock for the block device that is going away. This means it is limited to the main device stored in sb->s_dev, leading to a lot of code duplication for file systems that can use multiple block devices. Now that the holder for all block devices used by file systems is set to the super_block, we can instead look at that holder and then check if the file system is born and active, so do that instead. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Christian Brauner <brauner@kernel.org> Message-Id: <20230802154131.2221419-8-hch@lst.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-11fs: use the super_block as holder when mounting file systemsChristoph Hellwig1-4/+4
The file system type is not a very useful holder as it doesn't allow us to go back to the actual file system instance. Pass the super_block instead which is useful when passed back to the file system driver. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Christian Brauner <brauner@kernel.org> Message-Id: <20230802154131.2221419-7-hch@lst.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-10fs: export setup_bdev_superChristoph Hellwig1-1/+2
We'll want to use setup_bdev_super instead of duplicating it in nilfs2. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Christian Brauner <brauner@kernel.org> Message-Id: <20230802154131.2221419-2-hch@lst.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-10fs: open block device after superblock creationJan Kara1-93/+95
Currently get_tree_bdev and mount_bdev open the block device before committing to allocating a super block. That creates problems for restricting the number of writers to a device, and also leads to a unusual and not very helpful holder (the fs_type). Reorganize the super block code to first look whether the superblock for a particular device does already exist and open the block device only if it doesn't. [hch: port to before the bdev_handle changes, duplicate the bdev read-only check from blkdev_get_by_path, extend the fsfree_mutex coverage to protect against freezes, fix an open bdev leak when the bdev is frozen, use the bdev local variable more, rename the s variable to sb to be more descriptive] [brauner: remove references to mounts as they're mostly irrelevant] [brauner & hch: fold fixes for romfs and cramfs for syzbot+2faac0423fdc9692822b@syzkaller.appspotmail.com] Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Christoph Hellwig <hch@lst.de> Message-Id: <20230724175145.201318-1-hch@lst.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-09fs, block: remove bdev->bd_superChristoph Hellwig1-3/+0
bdev->bd_super is unused now, remove it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Christian Brauner <brauner@kernel.org> Message-Id: <20230807112625.652089-5-hch@lst.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-02fs: remove emergency_thaw_bdevChristoph Hellwig1-1/+3
Fold emergency_thaw_bdev into it's only caller, to prepare for buffer.c to be built only when buffer_head support is enabled. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Christian Brauner <brauner@kernel.org> Link: https://lore.kernel.org/r/20230801172201.1923299-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-07-17fs: wait for partially frozen filesystemsDarrick J. Wong1-2/+32
Jan Kara suggested that when one thread is in the middle of freezing a filesystem, another thread trying to freeze the same fs but with a different freeze_holder should wait until the freezer reaches either end state (UNFROZEN or COMPLETE) instead of returning EBUSY immediately. Neither caller can do anything sensible with this race other than retry but they cannot really distinguish EBUSY as in "some other holder of the same type has the sb already frozen" from "freezing raced with holder of a different type". Plumb in the extra code needed to wait for the fs freezer to reach an end state and try the freeze again. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz>
2023-07-17fs: distinguish between user initiated freeze and kernel initiated freezeDarrick J. Wong1-9/+70
Userspace can freeze a filesystem using the FIFREEZE ioctl or by suspending the block device; this state persists until userspace thaws the filesystem with the FITHAW ioctl or resuming the block device. Since commit 18e9e5104fcd ("Introduce freeze_super and thaw_super for the fsfreeze ioctl") we only allow the first freeze command to succeed. The kernel may decide that it is necessary to freeze a filesystem for its own internal purposes, such as suspends in progress, filesystem fsck activities, or quiescing a device prior to removal. Userspace thaw commands must never break a kernel freeze, and kernel thaw commands shouldn't undo userspace's freeze command. Introduce a couple of freeze holder flags and wire it into the sb_writers state. One kernel and one userspace freeze are allowed to coexist at the same time; the filesystem will not thaw until both are lifted. I wonder if the f2fs/gfs2 code should be using a kernel freeze here, but for now we'll use FREEZE_HOLDER_USERSPACE to preserve existing behaviors. Cc: mcgrof@kernel.org Cc: jack@suse.cz Cc: hch@infradead.org Cc: ruansy.fnst@fujitsu.com Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz>
2023-06-29Merge tag 'fs_for_v6.5-rc1' of ↵Linus Torvalds1-4/+0
git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs Pull misc filesystem updates from Jan Kara: - Rewrite kmap_local() handling in ext2 - Convert ext2 direct IO path to iomap (with some infrastructure tweaks associated with that) - Convert two boilerplate licenses in udf to SPDX identifiers - Other small udf, ext2, and quota fixes and cleanups * tag 'fs_for_v6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: udf: Fix uninitialized array access for some pathnames ext2: Drop fragment support quota: fix warning in dqgrab() quota: Properly disable quotas when add_dquot_ref() fails fs: udf: udftime: Replace LGPL boilerplate with SPDX identifier fs: udf: Replace GPL 2.0 boilerplate license notice with SPDX identifier fs: Drop wait_unfrozen wait queue ext2_find_entry()/ext2_dotdot(): callers don't need page_addr anymore ext2_{set_link,delete_entry}(): don't bother with page_addr ext2_put_page(): accept any pointer within the page ext2_get_page(): saner type ext2: use offset_in_page() instead of open-coding it as subtraction ext2_rename(): set_link and delete_entry may fail ext2: Add direct-io trace points ext2: Move direct-io to use iomap ext2: Use generic_buffers_fsync() implementation ext4: Use generic_buffers_fsync_noflush() implementation fs/buffer.c: Add generic_buffers_fsync*() implementation ext2/dax: Fix ext2_setsize when len is page aligned
2023-06-26Merge tag 'for-6.5/block-2023-06-23' of git://git.kernel.dk/linuxLinus Torvalds1-21/+27
Pull block updates from Jens Axboe: - NVMe pull request via Keith: - Various cleanups all around (Irvin, Chaitanya, Christophe) - Better struct packing (Christophe JAILLET) - Reduce controller error logs for optional commands (Keith) - Support for >=64KiB block sizes (Daniel Gomez) - Fabrics fixes and code organization (Max, Chaitanya, Daniel Wagner) - bcache updates via Coly: - Fix a race at init time (Mingzhe Zou) - Misc fixes and cleanups (Andrea, Thomas, Zheng, Ye) - use page pinning in the block layer for dio (David) - convert old block dio code to page pinning (David, Christoph) - cleanups for pktcdvd (Andy) - cleanups for rnbd (Guoqing) - use the unchecked __bio_add_page() for the initial single page additions (Johannes) - fix overflows in the Amiga partition handling code (Michael) - improve mq-deadline zoned device support (Bart) - keep passthrough requests out of the IO schedulers (Christoph, Ming) - improve support for flush requests, making them less special to deal with (Christoph) - add bdev holder ops and shutdown methods (Christoph) - fix the name_to_dev_t() situation and use cases (Christoph) - decouple the block open flags from fmode_t (Christoph) - ublk updates and cleanups, including adding user copy support (Ming) - BFQ sanity checking (Bart) - convert brd from radix to xarray (Pankaj) - constify various structures (Thomas, Ivan) - more fine grained persistent reservation ioctl capability checks (Jingbo) - misc fixes and cleanups (Arnd, Azeem, Demi, Ed, Hengqi, Hou, Jan, Jordy, Li, Min, Yu, Zhong, Waiman) * tag 'for-6.5/block-2023-06-23' of git://git.kernel.dk/linux: (266 commits) scsi/sg: don't grab scsi host module reference ext4: Fix warning in blkdev_put() block: don't return -EINVAL for not found names in devt_from_devname cdrom: Fix spectre-v1 gadget block: Improve kernel-doc headers blk-mq: don't insert passthrough request into sw queue bsg: make bsg_class a static const structure ublk: make ublk_chr_class a static const structure aoe: make aoe_class a static const structure block/rnbd: make all 'class' structures const block: fix the exclusive open mask in disk_scan_partitions block: add overflow checks for Amiga partition support block: change all __u32 annotations to __be32 in affs_hardblocks.h block: fix signed int overflow in Amiga partition support block: add capacity validation in bdev_add_partition() block: fine-granular CAP_SYS_ADMIN for Persistent Reservation block: disallow Persistent Reservation on partitions reiserfs: fix blkdev_put() warning from release_journal_dev() block: fix wrong mode for blkdev_get_by_dev() from disk_scan_partitions() block: document the holder argument to blkdev_get_by_path ...
2023-06-26Merge tag 'v6.5/vfs.misc' of ↵Linus Torvalds1-9/+13
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull misc vfs updates from Christian Brauner: "Miscellaneous features, cleanups, and fixes for vfs and individual fs Features: - Use mode 0600 for file created by cachefilesd so it can be run by unprivileged users. This aligns them with directories which are already created with mode 0700 by cachefilesd - Reorder a few members in struct file to prevent some false sharing scenarios - Indicate that an eventfd is used a semaphore in the eventfd's fdinfo procfs file - Add a missing uapi header for eventfd exposing relevant uapi defines - Let the VFS protect transitions of a superblock from read-only to read-write in addition to the protection it already provides for transitions from read-write to read-only. Protecting read-only to read-write transitions allows filesystems such as ext4 to perform internal writes, keeping writers away until the transition is completed Cleanups: - Arnd removed the architecture specific arch_report_meminfo() prototypes and added a generic one into procfs.h. Note, we got a report about a warning in amdpgpu codepaths that suggested this was bisectable to this change but we concluded it was a false positive - Remove unused parameters from split_fs_names() - Rename put_and_unmap_page() to unmap_and_put_page() to let the name reflect the order of the cleanup operation that has to unmap before the actual put - Unexport buffer_check_dirty_writeback() as it is not used outside of block device aops - Stop allocating aio rings from highmem - Protecting read-{only,write} transitions in the VFS used open-coded barriers in various places. Replace them with proper little helpers and document both the helpers and all barrier interactions involved when transitioning between read-{only,write} states - Use flexible array members in old readdir codepaths Fixes: - Use the correct type __poll_t for epoll and eventfd - Replace all deprecated strlcpy() invocations, whose return value isn't checked with an equivalent strscpy() call - Fix some kernel-doc warnings in fs/open.c - Reduce the stack usage in jffs2's xattr codepaths finally getting rid of this: fs/jffs2/xattr.c:887:1: error: the frame size of 1088 bytes is larger than 1024 bytes [-Werror=frame-larger-than=] royally annoying compilation warning - Use __FMODE_NONOTIFY instead of FMODE_NONOTIFY where an int and not fmode_t is required to avoid fmode_t to integer degradation warnings - Create coredumps with O_WRONLY instead of O_RDWR. There's a long explanation in that commit how O_RDWR is actually a bug which we found out with the help of Linus and git archeology - Fix "no previous prototype" warnings in the pipe codepaths - Add overflow calculations for remap_verify_area() as a signed addition overflow could be triggered in xfstests - Fix a null pointer dereference in sysv - Use an unsigned variable for length calculations in jfs avoiding compilation warnings with gcc 13 - Fix a dangling pipe pointer in the watch queue codepath - The legacy mount option parser provided as a fallback by the VFS for filesystems not yet converted to the new mount api did prefix the generated mount option string with a leading ',' causing issues for some filesystems - Fix a repeated word in a comment in fs.h - autofs: Update the ctime when mtime is updated as mandated by POSIX" * tag 'v6.5/vfs.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (27 commits) readdir: Replace one-element arrays with flexible-array members fs: Provide helpers for manipulating sb->s_readonly_remount fs: Protect reconfiguration of sb read-write from racing writes eventfd: add a uapi header for eventfd userspace APIs autofs: set ctime as well when mtime changes on a dir eventfd: show the EFD_SEMAPHORE flag in fdinfo fs/aio: Stop allocating aio rings from HIGHMEM fs: Fix comment typo fs: unexport buffer_check_dirty_writeback fs: avoid empty option when generating legacy mount string watch_queue: prevent dangling pipe pointer fs.h: Optimize file struct to prevent false sharing highmem: Rename put_and_unmap_page() to unmap_and_put_page() cachefiles: Allow the cache to be non-root init: remove unused names parameter in split_fs_names() jfs: Use unsigned variable for length calculations fs/sysv: Null check to prevent null-ptr-deref bug fs: use UB-safe check for signed addition overflow in remap_verify_area procfs: consolidate arch_report_meminfo declaration fs: pipe: reveal missing function protoypes ...
2023-06-20fs: Provide helpers for manipulating sb->s_readonly_remountJan Kara1-11/+6
Provide helpers to set and clear sb->s_readonly_remount including appropriate memory barriers. Also use this opportunity to document what the barriers pair with and why they are needed. Suggested-by: Dave Chinner <david@fromorbit.com> Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Dave Chinner <dchinner@redhat.com> Message-Id: <20230620112832.5158-1-jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-06-19Revert "mm: shrinkers: convert shrinker_rwsem to mutex"Qi Zheng1-1/+1
Patch series "revert shrinker_srcu related changes". This patch (of 7): This reverts commit cf2e309ebca7bb0916771839f9b580b06c778530. Kernel test robot reports -88.8% regression in stress-ng.ramfs.ops_per_sec test case [1], which is caused by commit f95bdb700bc6 ("mm: vmscan: make global slab shrink lockless"). The root cause is that SRCU has to be careful to not frequently check for SRCU read-side critical section exits. Therefore, even if no one is currently in the SRCU read-side critical section, synchronize_srcu() cannot return quickly. That's why unregister_shrinker() has become slower. After discussion, we will try to use the refcount+RCU method [2] proposed by Dave Chinner to continue to re-implement the lockless slab shrink. So revert the shrinker_mutex back to shrinker_rwsem first. [1]. https://lore.kernel.org/lkml/202305230837.db2c233f-yujie.liu@intel.com/ [2]. https://lore.kernel.org/lkml/ZIJhou1d55d4H1s0@dread.disaster.area/ Link: https://lkml.kernel.org/r/20230609081518.3039120-1-qi.zheng@linux.dev Link: https://lkml.kernel.org/r/20230609081518.3039120-2-qi.zheng@linux.dev Reported-by: kernel test robot <yujie.liu@intel.com> Closes: https://lore.kernel.org/oe-lkp/202305230837.db2c233f-yujie.liu@intel.com Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Kirill Tkhai <tkhai@ya.ru> Cc: Muchun Song <muchun.song@linux.dev> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yujie Liu <yujie.liu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-15fs: Protect reconfiguration of sb read-write from racing writesJan Kara1-1/+10
The reconfigure / remount code takes a lot of effort to protect filesystem's reconfiguration code from racing writes on remounting read-only. However during remounting read-only filesystem to read-write mode userspace writes can start immediately once we clear SB_RDONLY flag. This is inconvenient for example for ext4 because we need to do some writes to the filesystem (such as preparation of quota files) before we can take userspace writes so we are clearing SB_RDONLY flag before we are fully ready to accept userpace writes and syzbot has found a way to exploit this [1]. Also as far as I'm reading the code the filesystem remount code was protected from racing writes in the legacy mount path by the mount's MNT_READONLY flag so this is relatively new problem. It is actually fairly easy to protect remount read-write from racing writes using sb->s_readonly_remount flag so let's just do that instead of having to workaround these races in the filesystem code. [1] https://lore.kernel.org/all/00000000000006a0df05f6667499@google.com/T/ Signed-off-by: Jan Kara <jack@suse.cz> Message-Id: <20230615113848.8439-1-jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-06-12fs: remove sb->s_modeChristoph Hellwig1-2/+0
There is no real need to store the open mode in the super_block now. It is only used by f2fs, which can easily recalculate it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Acked-by: Christian Brauner <brauner@kernel.org> Link: https://lore.kernel.org/r/20230608110258.189493-18-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-12block: add a sb_open_mode helperChristoph Hellwig1-11/+4
Add a helper to return the open flags for blkdev_get_by* for passed in super block flags instead of open coding the logic in many places. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Acked-by: Christian Brauner <brauner@kernel.org> Link: https://lore.kernel.org/r/20230608110258.189493-17-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-12block: use the holder as indication for exclusive opensChristoph Hellwig1-11/+9
The current interface for exclusive opens is rather confusing as it requires both the FMODE_EXCL flag and a holder. Remove the need to pass FMODE_EXCL and just key off the exclusive open off a non-NULL holder. For blkdev_put this requires adding the holder argument, which provides better debug checking that only the holder actually releases the hold, but at the same time allows removing the now superfluous mode argument. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Acked-by: Christian Brauner <brauner@kernel.org> Acked-by: David Sterba <dsterba@suse.com> [btrfs] Acked-by: Jack Wang <jinpu.wang@ionos.com> [rnbd] Link: https://lore.kernel.org/r/20230608110258.189493-16-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-05fs: add a method to shut down the file systemChristoph Hellwig1-2/+19
Add a new ->shutdown super operation that can be used to tell the file system to shut down, and call it from newly created holder ops when the block device under a file system shuts down. This only covers the main block device for "simple" file systems using get_tree_bdev / mount_bdev. File systems their own get_tree method or opening additional devices will need to set up their own blk_holder_ops. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Christian Brauner <brauner@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Acked-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Link: https://lore.kernel.org/r/20230601094459.1350643-12-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-05block: introduce holder opsChristoph Hellwig1-2/+2
Add a new blk_holder_ops structure, which is passed to blkdev_get_by_* and installed in the block_device for exclusive claims. It will be used to allow the block layer to call back into the user of the block device for thing like notification of a removed device or a device resize. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Link: https://lore.kernel.org/r/20230601094459.1350643-10-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-05-30fs: Drop wait_unfrozen wait queueJan Kara1-4/+0
wait_unfrozen waitqueue is used only in quota code to wait for filesystem to become unfrozen. In that place we can just use sb_start_write() - sb_end_write() pair to achieve the same. So just remove the waitqueue. Reviewed-by: Christian Brauner <brauner@kernel.org> Message-Id: <20230525141710.7595-1-jack@suse.cz> Signed-off-by: Jan Kara <jack@suse.cz>
2023-05-15vfs: Replace all non-returning strlcpy with strscpyAzeem Shaikh1-2/+2
strlcpy() reads the entire source buffer first. This read may exceed the destination size limit. This is both inefficient and can lead to linear read overflows if a source string is not NUL-terminated [1]. In an effort to remove strlcpy() completely [2], replace strlcpy() here with strscpy(). No return values were used, so direct replacement is safe. [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy [2] https://github.com/KSPP/linux/issues/89 Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com> Reviewed-by: Kees Cook <keescook@chromium.org> Message-Id: <20230510221119.3508930-1-azeemshaikh38@gmail.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-03-28mm: shrinkers: convert shrinker_rwsem to mutexQi Zheng1-1/+1
Now there are no readers of shrinker_rwsem, so we can simply replace it with mutex lock. Link: https://lkml.kernel.org/r/20230313112819.38938-9-zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Kirill Tkhai <tkhai@ya.ru> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Cc: Christian König <christian.koenig@amd.com> Cc: David Hildenbrand <david@redhat.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Sultan Alsawaf <sultan@kerneltoast.com> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-03-14fscrypt: destroy keyring after security_sb_delete()Eric Biggers1-3/+12
fscrypt_destroy_keyring() must be called after all potentially-encrypted inodes were evicted; otherwise it cannot safely destroy the keyring. Since inodes that are in-use by the Landlock LSM don't get evicted until security_sb_delete(), this means that fscrypt_destroy_keyring() must be called *after* security_sb_delete(). This fixes a WARN_ON followed by a NULL dereference, only possible if Landlock was being used on encrypted files. Fixes: d7e7b9af104c ("fscrypt: stop using keyrings subsystem for fscrypt_master_key") Cc: stable@vger.kernel.org Reported-by: syzbot+93e495f6a4f748827c88@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/00000000000044651705f6ca1e30@google.com Reviewed-by: Christian Brauner <brauner@kernel.org> Link: https://lore.kernel.org/r/20230313221231.272498-2-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com>
2023-02-20Merge tag 'for-6.3/dio-2023-02-16' of git://git.kernel.dk/linuxLinus Torvalds1-0/+24
Pull legacy dio update from Jens Axboe: "We only have a few file systems that use the old dio code, make them select it rather than build it unconditionally" * tag 'for-6.3/dio-2023-02-16' of git://git.kernel.dk/linux: fs: build the legacy direct I/O code conditionally fs: move sb_init_dio_done_wq out of direct-io.c
2023-02-20Merge tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/linuxLinus Torvalds1-1/+0
Pull fscrypt updates from Eric Biggers: "Simplify the implementation of the test_dummy_encryption mount option by adding the 'test dummy key' on-demand" * tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/linux: fscrypt: clean up fscrypt_add_test_dummy_key() fs/super.c: stop calling fscrypt_destroy_keyring() from __put_super() f2fs: stop calling fscrypt_add_test_dummy_key() ext4: stop calling fscrypt_add_test_dummy_key() fscrypt: add the test dummy encryption key on-demand
2023-02-07fs/super.c: stop calling fscrypt_destroy_keyring() from __put_super()Eric Biggers1-1/+0
Now that the key associated with the "test_dummy_operation" mount option is added on-demand when it's needed, rather than immediately when the filesystem is mounted, fscrypt_destroy_keyring() no longer needs to be called from __put_super() to avoid a memory leak on mount failure. Remove this call, which was causing confusion because it appeared to be a sleep-in-atomic bug (though it wasn't, for a somewhat-subtle reason). Signed-off-by: Eric Biggers <ebiggers@google.com> Link: https://lore.kernel.org/r/20230208062107.199831-5-ebiggers@kernel.org
2023-01-27fs: Use CHECK_DATA_CORRUPTION() when kernel bugs are detectedJann Horn1-4/+17
Currently, filp_close() and generic_shutdown_super() use printk() to log messages when bugs are detected. This is problematic because infrastructure like syzkaller has no idea that this message indicates a bug. In addition, some people explicitly want their kernels to BUG() when kernel data corruption has been detected (CONFIG_BUG_ON_DATA_CORRUPTION). And finally, when generic_shutdown_super() detects remaining inodes on a system without CONFIG_BUG_ON_DATA_CORRUPTION, it would be nice if later accesses to a busy inode would at least crash somewhat cleanly rather than walking through freed memory. To address all three, use CHECK_DATA_CORRUPTION() when kernel bugs are detected. Signed-off-by: Jann Horn <jannh@google.com> Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>