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2023-08-28Merge tag 'v6.6-vfs.ctime' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs timestamp updates from Christian Brauner: "This adds VFS support for multi-grain timestamps and converts tmpfs, xfs, ext4, and btrfs to use them. This carries acks from all relevant filesystems. The VFS always uses coarse-grained timestamps when updating the ctime and mtime after a change. This has the benefit of allowing filesystems to optimize away a lot of metadata updates, down to around 1 per jiffy, even when a file is under heavy writes. Unfortunately, this has always been an issue when we're exporting via NFSv3, which relies on timestamps to validate caches. A lot of changes can happen in a jiffy, so timestamps aren't sufficient to help the client decide to invalidate the cache. Even with NFSv4, a lot of exported filesystems don't properly support a change attribute and are subject to the same problems with timestamp granularity. Other applications have similar issues with timestamps (e.g., backup applications). If we were to always use fine-grained timestamps, that would improve the situation, but that becomes rather expensive, as the underlying filesystem would have to log a lot more metadata updates. This introduces fine-grained timestamps that are used when they are actively queried. This uses the 31st bit of the ctime tv_nsec field to indicate that something has queried the inode for the mtime or ctime. When this flag is set, on the next mtime or ctime update, the kernel will fetch a fine-grained timestamp instead of the usual coarse-grained one. As POSIX generally mandates that when the mtime changes, the ctime must also change the kernel always stores normalized ctime values, so only the first 30 bits of the tv_nsec field are ever used. Filesytems can opt into this behavior by setting the FS_MGTIME flag in the fstype. Filesystems that don't set this flag will continue to use coarse-grained timestamps. Various preparatory changes, fixes and cleanups are included: - Fixup all relevant places where POSIX requires updating ctime together with mtime. This is a wide-range of places and all maintainers provided necessary Acks. - Add new accessors for inode->i_ctime directly and change all callers to rely on them. Plain accesses to inode->i_ctime are now gone and it is accordingly rename to inode->__i_ctime and commented as requiring accessors. - Extend generic_fillattr() to pass in a request mask mirroring in a sense the statx() uapi. This allows callers to pass in a request mask to only get a subset of attributes filled in. - Rework timestamp updates so it's possible to drop the @now parameter the update_time() inode operation and associated helpers. - Add inode_update_timestamps() and convert all filesystems to it removing a bunch of open-coding" * tag 'v6.6-vfs.ctime' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (107 commits) btrfs: convert to multigrain timestamps ext4: switch to multigrain timestamps xfs: switch to multigrain timestamps tmpfs: add support for multigrain timestamps fs: add infrastructure for multigrain timestamps fs: drop the timespec64 argument from update_time xfs: have xfs_vn_update_time gets its own timestamp fat: make fat_update_time get its own timestamp fat: remove i_version handling from fat_update_time ubifs: have ubifs_update_time use inode_update_timestamps btrfs: have it use inode_update_timestamps fs: drop the timespec64 arg from generic_update_time fs: pass the request_mask to generic_fillattr fs: remove silly warning from current_time gfs2: fix timestamp handling on quota inodes fs: rename i_ctime field to __i_ctime selinux: convert to ctime accessor functions security: convert to ctime accessor functions apparmor: convert to ctime accessor functions sunrpc: convert to ctime accessor functions ...
2023-08-23Merge tag 'vfs-6.6-merge-2' of ↵Christian Brauner
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>
2023-08-21super: wait until we passed kill superChristian Brauner
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 Brauner
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>
2023-08-21fs: create kiocb_{start,end}_write() helpersAmir Goldstein
aio, io_uring, cachefiles and overlayfs, all open code an ugly variant of file_{start,end}_write() to silence lockdep warnings. Create helpers for this lockdep dance so we can use the helpers in all the callers. Suggested-by: Jan Kara <jack@suse.cz> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Jens Axboe <axboe@kernel.dk> Message-Id: <20230817141337.1025891-4-amir73il@gmail.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-21fs: add kerneldoc to file_{start,end}_write() helpersAmir Goldstein
and use sb_end_write() instead of open coded version. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Jens Axboe <axboe@kernel.dk> Message-Id: <20230817141337.1025891-3-amir73il@gmail.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-21fs: remove get_superChristoph Hellwig
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>
2023-08-18fs/address_space: add alignment padding for i_map and i_mmap_rwsem to ↵Zhu, Lipeng
mitigate a false sharing. When running UnixBench/Shell Scripts, we observed high false sharing for accessing i_mmap against i_mmap_rwsem. UnixBench/Shell Scripts are typical load/execute command test scenarios, which concurrently launch->execute->exit a lot of shell commands. A lot of processes invoke vma_interval_tree_remove which touch "i_mmap", the call stack: ----vma_interval_tree_remove |----unlink_file_vma | free_pgtables | |----exit_mmap | | mmput | | |----begin_new_exec | | | load_elf_binary | | | bprm_execve Meanwhile, there are a lot of processes touch 'i_mmap_rwsem' to acquire the semaphore in order to access 'i_mmap'. In existing 'address_space' layout, 'i_mmap' and 'i_mmap_rwsem' are in the same cacheline. The patch places the i_mmap and i_mmap_rwsem in separate cache lines to avoid this false sharing problem. With this patch, based on kernel v6.4.0, on Intel Sapphire Rapids 112C/224T platform, the score improves by ~5.3%. And perf c2c tool shows the false sharing is resolved as expected, the symbol vma_interval_tree_remove disappeared in cache line 0 after this change. Baseline: ================================================= Shared Cache Line Distribution Pareto ================================================= ------------------------------------------------------------- 0 3729 5791 0 0 0xff19b3818445c740 ------------------------------------------------------------- 3.27% 3.02% 0.00% 0.00% 0x18 0 1 0xffffffffa194403b 604 483 389 692 203 [k] vma_interval_tree_insert [kernel.kallsyms] vma_interval_tree_insert+75 0 1 4.13% 3.63% 0.00% 0.00% 0x20 0 1 0xffffffffa19440a2 553 413 415 962 215 [k] vma_interval_tree_remove [kernel.kallsyms] vma_interval_tree_remove+18 0 1 2.04% 1.35% 0.00% 0.00% 0x28 0 1 0xffffffffa219a1d6 1210 855 460 1229 222 [k] rwsem_down_write_slowpath [kernel.kallsyms] rwsem_down_write_slowpath+678 0 1 0.62% 1.85% 0.00% 0.00% 0x28 0 1 0xffffffffa219a1bf 762 329 577 527 198 [k] rwsem_down_write_slowpath [kernel.kallsyms] rwsem_down_write_slowpath+655 0 1 0.48% 0.31% 0.00% 0.00% 0x28 0 1 0xffffffffa219a58c 1677 1476 733 1544 224 [k] down_write [kernel.kallsyms] down_write+28 0 1 0.05% 0.07% 0.00% 0.00% 0x28 0 1 0xffffffffa219a21d 1040 819 689 33 27 [k] rwsem_down_write_slowpath [kernel.kallsyms] rwsem_down_write_slowpath+749 0 1 0.00% 0.05% 0.00% 0.00% 0x28 0 1 0xffffffffa17707db 0 1005 786 1373 223 [k] up_write [kernel.kallsyms] up_write+27 0 1 0.00% 0.02% 0.00% 0.00% 0x28 0 1 0xffffffffa219a064 0 233 778 32 30 [k] rwsem_down_write_slowpath [kernel.kallsyms] rwsem_down_write_slowpath+308 0 1 33.82% 34.10% 0.00% 0.00% 0x30 0 1 0xffffffffa1770945 779 495 534 6011 224 [k] rwsem_spin_on_owner [kernel.kallsyms] rwsem_spin_on_owner+53 0 1 17.06% 15.28% 0.00% 0.00% 0x30 0 1 0xffffffffa1770915 593 438 468 2715 224 [k] rwsem_spin_on_owner [kernel.kallsyms] rwsem_spin_on_owner+5 0 1 3.54% 3.52% 0.00% 0.00% 0x30 0 1 0xffffffffa2199f84 881 601 583 1421 223 [k] rwsem_down_write_slowpath [kernel.kallsyms] rwsem_down_write_slowpath+84 0 1 With this change: ------------------------------------------------------------- 0 556 838 0 0 0xff2780d7965d2780 ------------------------------------------------------------- 0.18% 0.60% 0.00% 0.00% 0x8 0 1 0xffffffffafff27b8 503 453 569 14 13 [k] do_dentry_open [kernel.kallsyms] do_dentry_open+456 0 1 0.54% 0.12% 0.00% 0.00% 0x8 0 1 0xffffffffaffc51ac 510 199 428 15 12 [k] hugepage_vma_check [kernel.kallsyms] hugepage_vma_check+252 0 1 1.80% 2.15% 0.00% 0.00% 0x18 0 1 0xffffffffb079a1d6 1778 799 343 215 136 [k] rwsem_down_write_slowpath [kernel.kallsyms] rwsem_down_write_slowpath+678 0 1 0.54% 1.31% 0.00% 0.00% 0x18 0 1 0xffffffffb079a1bf 547 296 528 91 71 [k] rwsem_down_write_slowpath [kernel.kallsyms] rwsem_down_write_slowpath+655 0 1 0.72% 0.72% 0.00% 0.00% 0x18 0 1 0xffffffffb079a58c 1479 1534 676 288 163 [k] down_write [kernel.kallsyms] down_write+28 0 1 0.00% 0.12% 0.00% 0.00% 0x18 0 1 0xffffffffafd707db 0 2381 744 282 158 [k] up_write [kernel.kallsyms] up_write+27 0 1 0.00% 0.12% 0.00% 0.00% 0x18 0 1 0xffffffffb079a064 0 239 518 6 6 [k] rwsem_down_write_slowpath [kernel.kallsyms] rwsem_down_write_slowpath+308 0 1 46.58% 47.02% 0.00% 0.00% 0x20 0 1 0xffffffffafd70945 704 403 499 1137 219 [k] rwsem_spin_on_owner [kernel.kallsyms] rwsem_spin_on_owner+53 0 1 23.92% 25.78% 0.00% 0.00% 0x20 0 1 0xffffffffafd70915 558 413 500 542 185 [k] rwsem_spin_on_owner [kernel.kallsyms] rwsem_spin_on_owner+5 0 1 v1->v2: change padding to exchange fields. Link: https://lkml.kernel.org/r/20230716145653.20122-1-lipeng.zhu@intel.com Signed-off-by: Lipeng Zhu <lipeng.zhu@intel.com> Reviewed-by: Tim Chen <tim.c.chen@linux.intel.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: Yu Ma <yu.ma@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-15vfs: fix up the assert in i_readcount_decMateusz Guzik
Drops a race where 2 threads could spot a positive value and both proceed to dec to -1, without reporting anything. Signed-off-by: Mateusz Guzik <mjguzik@gmail.com> Message-Id: <20230811194814.1612336-1-mjguzik@gmail.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-11fs: add infrastructure for multigrain timestampsJeff Layton
The VFS always uses coarse-grained timestamps when updating the ctime and mtime after a change. This has the benefit of allowing filesystems to optimize away a lot metadata updates, down to around 1 per jiffy, even when a file is under heavy writes. Unfortunately, this has always been an issue when we're exporting via NFSv3, which relies on timestamps to validate caches. A lot of changes can happen in a jiffy, so timestamps aren't sufficient to help the client decide to invalidate the cache. Even with NFSv4, a lot of exported filesystems don't properly support a change attribute and are subject to the same problems with timestamp granularity. Other applications have similar issues with timestamps (e.g backup applications). If we were to always use fine-grained timestamps, that would improve the situation, but that becomes rather expensive, as the underlying filesystem would have to log a lot more metadata updates. What we need is a way to only use fine-grained timestamps when they are being actively queried. POSIX generally mandates that when the the mtime changes, the ctime must also change. The kernel always stores normalized ctime values, so only the first 30 bits of the tv_nsec field are ever used. Use the 31st bit of the ctime tv_nsec field to indicate that something has queried the inode for the mtime or ctime. When this flag is set, on the next mtime or ctime update, the kernel will fetch a fine-grained timestamp instead of the usual coarse-grained one. Filesytems can opt into this behavior by setting the FS_MGTIME flag in the fstype. Filesystems that don't set this flag will continue to use coarse-grained timestamps. Later patches will convert individual filesystems to use the new infrastructure. Signed-off-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Message-Id: <20230807-mgctime-v7-9-d1dec143a704@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-11fs: drop the timespec64 argument from update_timeJeff Layton
Now that all of the update_time operations are prepared for it, we can drop the timespec64 argument from the update_time operation. Do that and remove it from some associated functions like inode_update_time and inode_needs_update_time. Signed-off-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Message-Id: <20230807-mgctime-v7-8-d1dec143a704@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-09libfs: Add directory operations for stable offsetsChuck Lever
Create a vector of directory operations in fs/libfs.c that handles directory seeks and readdir via stable offsets instead of the current cursor-based mechanism. For the moment these are unused. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Message-Id: <168814732984.530310.11190772066786107220.stgit@manet.1015granger.net> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-09fs: drop the timespec64 arg from generic_update_timeJeff Layton
In future patches we're going to change how the ctime is updated to keep track of when it has been queried. The way that the update_time operation works (and a lot of its callers) make this difficult, since they grab a timestamp early and then pass it down to eventually be copied into the inode. All of the existing update_time callers pass in the result of current_time() in some fashion. Drop the "time" parameter from generic_update_time, and rework it to fetch its own timestamp. This change means that an update_time could fetch a different timestamp than was seen in inode_needs_update_time. update_time is only ever called with one of two flag combinations: Either S_ATIME is set, or S_MTIME|S_CTIME|S_VERSION are set. With this change we now treat the flags argument as an indicator that some value needed to be updated when last checked, rather than an indication to update specific timestamps. Rework the logic for updating the timestamps and put it in a new inode_update_timestamps helper that other update_time routines can use. S_ATIME is as treated as we always have, but if any of the other three are set, then we attempt to update all three. Also, some callers of generic_update_time need to know what timestamps were actually updated. Change it to return an S_* flag mask to indicate that and rework the callers to expect it. Signed-off-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Message-Id: <20230807-mgctime-v7-3-d1dec143a704@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-09fs: pass the request_mask to generic_fillattrJeff Layton
generic_fillattr just fills in the entire stat struct indiscriminately today, copying data from the inode. There is at least one attribute (STATX_CHANGE_COOKIE) that can have side effects when it is reported, and we're looking at adding more with the addition of multigrain timestamps. Add a request_mask argument to generic_fillattr and have most callers just pass in the value that is passed to getattr. Have other callers (e.g. ksmbd) just pass in STATX_BASIC_STATS. Also move the setting of STATX_CHANGE_COOKIE into generic_fillattr. Acked-by: Joseph Qi <joseph.qi@linux.alibaba.com> Reviewed-by: Xiubo Li <xiubli@redhat.com> Reviewed-by: "Paulo Alcantara (SUSE)" <pc@manguebit.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Jeff Layton <jlayton@kernel.org> Message-Id: <20230807-mgctime-v7-2-d1dec143a704@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-06vfs: get rid of old '->iterate' directory operationLinus Torvalds
All users now just use '->iterate_shared()', which only takes the directory inode lock for reading. Filesystems that never got convered to shared mode now instead use a wrapper that drops the lock, re-takes it in write mode, calls the old function, and then downgrades the lock back to read mode. This way the VFS layer and other callers no longer need to care about filesystems that never got converted to the modern era. The filesystems that use the new wrapper are ceph, coda, exfat, jfs, ntfs, ocfs2, overlayfs, and vboxsf. Honestly, several of them look like they really could just iterate their directories in shared mode and skip the wrapper entirely, but the point of this change is to not change semantics or fix filesystems that haven't been fixed in the last 7+ years, but to finally get rid of the dual iterators. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-01fs: add IOCB flags related to passing back dio completionsJens Axboe
Async dio completions generally happen from hard/soft IRQ context, which means that users like iomap may need to defer some of the completion handling to a workqueue. This is less efficient than having the original issuer handle it, like we do for sync IO, and it adds latency to the completions. Add IOCB_DIO_CALLER_COMP, which the issuer can set if it is able to safely punt these completions to a safe context. If the dio handler is aware of this flag, assign a callback handler in kiocb->dio_complete and associated data io kiocb->private. The issuer will then call this handler with that data from task context. No functional changes in this patch. Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-07-24fs: rename i_ctime field to __i_ctimeJeff Layton
Now that everything in-tree is converted to use the accessor functions, rename the i_ctime field in the inode to discourage direct access. Signed-off-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Message-Id: <20230705185812.579118-4-jlayton@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-07-17fs: distinguish between user initiated freeze and kernel initiated freezeDarrick J. Wong
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>
2023-07-10fs: Pass argument to fcntl_setlease as intLuca Vizzarro
The interface for fcntl expects the argument passed for the command F_SETLEASE to be of type int. The current code wrongly treats it as a long. In order to avoid access to undefined bits, we should explicitly cast the argument to int. Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: Jeff Layton <jlayton@kernel.org> Cc: Chuck Lever <chuck.lever@oracle.com> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Anna Schumaker <anna@kernel.org> Cc: Kevin Brodsky <Kevin.Brodsky@arm.com> Cc: Vincenzo Frascino <Vincenzo.Frascino@arm.com> Cc: Szabolcs Nagy <Szabolcs.Nagy@arm.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: David Laight <David.Laight@ACULAB.com> Cc: Mark Rutland <Mark.Rutland@arm.com> Cc: linux-fsdevel@vger.kernel.org Cc: linux-cifs@vger.kernel.org Cc: linux-nfs@vger.kernel.org Cc: linux-morello@op-lists.linaro.org Signed-off-by: Luca Vizzarro <Luca.Vizzarro@arm.com> Message-Id: <20230414152459.816046-3-Luca.Vizzarro@arm.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-07-10fcntl: Cast commands with int args explicitlyLuca Vizzarro
According to the fcntl API specification commands that expect an integer, hence not a pointer, always take an int and not long. In order to avoid access to undefined bits, we should explicitly cast the argument to int. Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: Jeff Layton <jlayton@kernel.org> Cc: Chuck Lever <chuck.lever@oracle.com> Cc: Kevin Brodsky <Kevin.Brodsky@arm.com> Cc: Vincenzo Frascino <Vincenzo.Frascino@arm.com> Cc: Szabolcs Nagy <Szabolcs.Nagy@arm.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: David Laight <David.Laight@ACULAB.com> Cc: Mark Rutland <Mark.Rutland@arm.com> Cc: linux-fsdevel@vger.kernel.org Cc: linux-morello@op-lists.linaro.org Signed-off-by: Luca Vizzarro <Luca.Vizzarro@arm.com> Message-Id: <20230414152459.816046-2-Luca.Vizzarro@arm.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-07-10fs: new helper: simple_rename_timestampJeff Layton
A rename potentially involves updating 4 different inode timestamps. Add a function that handles the details sanely, and convert the libfs.c callers to use it. Signed-off-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Message-Id: <20230705185812.579118-3-jlayton@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-07-10fs: add ctime accessors infrastructureJeff Layton
struct timespec64 has unused bits in the tv_nsec field that can be used for other purposes. In future patches, we're going to change how the inode->i_ctime is accessed in certain inodes in order to make use of them. In order to do that safely though, we'll need to eradicate raw accesses of the inode->i_ctime field from the kernel. Add new accessor functions for the ctime that we use to replace them. Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Message-Id: <20230705185812.579118-2-jlayton@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-06-29Merge tag 'fs_for_v6.5-rc1' of ↵Linus Torvalds
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
2023-06-28Merge tag 'net-next-6.5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next Pull networking changes from Jakub Kicinski: "WiFi 7 and sendpage changes are the biggest pieces of work for this release. The latter will definitely require fixes but I think that we got it to a reasonable point. Core: - Rework the sendpage & splice implementations Instead of feeding data into sockets page by page extend sendmsg handlers to support taking a reference on the data, controlled by a new flag called MSG_SPLICE_PAGES Rework the handling of unexpected-end-of-file to invoke an additional callback instead of trying to predict what the right combination of MORE/NOTLAST flags is Remove the MSG_SENDPAGE_NOTLAST flag completely - Implement SCM_PIDFD, a new type of CMSG type analogous to SCM_CREDENTIALS, but it contains pidfd instead of plain pid - Enable socket busy polling with CONFIG_RT - Improve reliability and efficiency of reporting for ref_tracker - Auto-generate a user space C library for various Netlink families Protocols: - Allow TCP to shrink the advertised window when necessary, prevent sk_rcvbuf auto-tuning from growing the window all the way up to tcp_rmem[2] - Use per-VMA locking for "page-flipping" TCP receive zerocopy - Prepare TCP for device-to-device data transfers, by making sure that payloads are always attached to skbs as page frags - Make the backoff time for the first N TCP SYN retransmissions linear. Exponential backoff is unnecessarily conservative - Create a new MPTCP getsockopt to retrieve all info (MPTCP_FULL_INFO) - Avoid waking up applications using TLS sockets until we have a full record - Allow using kernel memory for protocol ioctl callbacks, paving the way to issuing ioctls over io_uring - Add nolocalbypass option to VxLAN, forcing packets to be fully encapsulated even if they are destined for a local IP address - Make TCPv4 use consistent hash in TIME_WAIT and SYN_RECV. Ensure in-kernel ECMP implementation (e.g. Open vSwitch) select the same link for all packets. Support L4 symmetric hashing in Open vSwitch - PPPoE: make number of hash bits configurable - Allow DNS to be overwritten by DHCPACK in the in-kernel DHCP client (ipconfig) - Add layer 2 miss indication and filtering, allowing higher layers (e.g. ACL filters) to make forwarding decisions based on whether packet matched forwarding state in lower devices (bridge) - Support matching on Connectivity Fault Management (CFM) packets - Hide the "link becomes ready" IPv6 messages by demoting their printk level to debug - HSR: don't enable promiscuous mode if device offloads the proto - Support active scanning in IEEE 802.15.4 - Continue work on Multi-Link Operation for WiFi 7 BPF: - Add precision propagation for subprogs and callbacks. This allows maintaining verification efficiency when subprograms are used, or in fact passing the verifier at all for complex programs, especially those using open-coded iterators - Improve BPF's {g,s}setsockopt() length handling. Previously BPF assumed the length is always equal to the amount of written data. But some protos allow passing a NULL buffer to discover what the output buffer *should* be, without writing anything - Accept dynptr memory as memory arguments passed to helpers - Add routing table ID to bpf_fib_lookup BPF helper - Support O_PATH FDs in BPF_OBJ_PIN and BPF_OBJ_GET commands - Drop bpf_capable() check in BPF_MAP_FREEZE command (used to mark maps as read-only) - Show target_{obj,btf}_id in tracing link fdinfo - Addition of several new kfuncs (most of the names are self-explanatory): - Add a set of new dynptr kfuncs: bpf_dynptr_adjust(), bpf_dynptr_is_null(), bpf_dynptr_is_rdonly(), bpf_dynptr_size() and bpf_dynptr_clone(). - bpf_task_under_cgroup() - bpf_sock_destroy() - force closing sockets - bpf_cpumask_first_and(), rework bpf_cpumask_any*() kfuncs Netfilter: - Relax set/map validation checks in nf_tables. Allow checking presence of an entry in a map without using the value - Increase ip_vs_conn_tab_bits range for 64BIT builds - Allow updating size of a set - Improve NAT tuple selection when connection is closing Driver API: - Integrate netdev with LED subsystem, to allow configuring HW "offloaded" blinking of LEDs based on link state and activity (i.e. packets coming in and out) - Support configuring rate selection pins of SFP modules - Factor Clause 73 auto-negotiation code out of the drivers, provide common helper routines - Add more fool-proof helpers for managing lifetime of MDIO devices associated with the PCS layer - Allow drivers to report advanced statistics related to Time Aware scheduler offload (taprio) - Allow opting out of VF statistics in link dump, to allow more VFs to fit into the message - Split devlink instance and devlink port operations New hardware / drivers: - Ethernet: - Synopsys EMAC4 IP support (stmmac) - Marvell 88E6361 8 port (5x1GE + 3x2.5GE) switches - Marvell 88E6250 7 port switches - Microchip LAN8650/1 Rev.B0 PHYs - MediaTek MT7981/MT7988 built-in 1GE PHY driver - WiFi: - Realtek RTL8192FU, 2.4 GHz, b/g/n mode, 2T2R, 300 Mbps - Realtek RTL8723DS (SDIO variant) - Realtek RTL8851BE - CAN: - Fintek F81604 Drivers: - Ethernet NICs: - Intel (100G, ice): - support dynamic interrupt allocation - use meta data match instead of VF MAC addr on slow-path - nVidia/Mellanox: - extend link aggregation to handle 4, rather than just 2 ports - spawn sub-functions without any features by default - OcteonTX2: - support HTB (Tx scheduling/QoS) offload - make RSS hash generation configurable - support selecting Rx queue using TC filters - Wangxun (ngbe/txgbe): - add basic Tx/Rx packet offloads - add phylink support (SFP/PCS control) - Freescale/NXP (enetc): - report TAPRIO packet statistics - Solarflare/AMD: - support matching on IP ToS and UDP source port of outer header - VxLAN and GENEVE tunnel encapsulation over IPv4 or IPv6 - add devlink dev info support for EF10 - Virtual NICs: - Microsoft vNIC: - size the Rx indirection table based on requested configuration - support VLAN tagging - Amazon vNIC: - try to reuse Rx buffers if not fully consumed, useful for ARM servers running with 16kB pages - Google vNIC: - support TCP segmentation of >64kB frames - Ethernet embedded switches: - Marvell (mv88e6xxx): - enable USXGMII (88E6191X) - Microchip: - lan966x: add support for Egress Stage 0 ACL engine - lan966x: support mapping packet priority to internal switch priority (based on PCP or DSCP) - Ethernet PHYs: - Broadcom PHYs: - support for Wake-on-LAN for BCM54210E/B50212E - report LPI counter - Microsemi PHYs: support RGMII delay configuration (VSC85xx) - Micrel PHYs: receive timestamp in the frame (LAN8841) - Realtek PHYs: support optional external PHY clock - Altera TSE PCS: merge the driver into Lynx PCS which it is a variant of - CAN: Kvaser PCIEcan: - support packet timestamping - WiFi: - Intel (iwlwifi): - major update for new firmware and Multi-Link Operation (MLO) - configuration rework to drop test devices and split the different families - support for segmented PNVM images and power tables - new vendor entries for PPAG (platform antenna gain) feature - Qualcomm 802.11ax (ath11k): - Multiple Basic Service Set Identifier (MBSSID) and Enhanced MBSSID Advertisement (EMA) support in AP mode - support factory test mode - RealTek (rtw89): - add RSSI based antenna diversity - support U-NII-4 channels on 5 GHz band - RealTek (rtl8xxxu): - AP mode support for 8188f - support USB RX aggregation for the newer chips" * tag 'net-next-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1602 commits) net: scm: introduce and use scm_recv_unix helper af_unix: Skip SCM_PIDFD if scm->pid is NULL. net: lan743x: Simplify comparison netlink: Add __sock_i_ino() for __netlink_diag_dump(). net: dsa: avoid suspicious RCU usage for synced VLAN-aware MAC addresses Revert "af_unix: Call scm_recv() only after scm_set_cred()." phylink: ReST-ify the phylink_pcs_neg_mode() kdoc libceph: Partially revert changes to support MSG_SPLICE_PAGES net: phy: mscc: fix packet loss due to RGMII delays net: mana: use vmalloc_array and vcalloc net: enetc: use vmalloc_array and vcalloc ionic: use vmalloc_array and vcalloc pds_core: use vmalloc_array and vcalloc gve: use vmalloc_array and vcalloc octeon_ep: use vmalloc_array and vcalloc net: usb: qmi_wwan: add u-blox 0x1312 composition perf trace: fix MSG_SPLICE_PAGES build error ipvlan: Fix return value of ipvlan_queue_xmit() netfilter: nf_tables: fix underflow in chain reference counter netfilter: nf_tables: unbind non-anonymous set if rule construction fails ...
2023-06-28Merge tag 'mm-stable-2023-06-24-19-15' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull mm updates from Andrew Morton: - Yosry Ahmed brought back some cgroup v1 stats in OOM logs - Yosry has also eliminated cgroup's atomic rstat flushing - Nhat Pham adds the new cachestat() syscall. It provides userspace with the ability to query pagecache status - a similar concept to mincore() but more powerful and with improved usability - Mel Gorman provides more optimizations for compaction, reducing the prevalence of page rescanning - Lorenzo Stoakes has done some maintanance work on the get_user_pages() interface - Liam Howlett continues with cleanups and maintenance work to the maple tree code. Peng Zhang also does some work on maple tree - Johannes Weiner has done some cleanup work on the compaction code - David Hildenbrand has contributed additional selftests for get_user_pages() - Thomas Gleixner has contributed some maintenance and optimization work for the vmalloc code - Baolin Wang has provided some compaction cleanups, - SeongJae Park continues maintenance work on the DAMON code - Huang Ying has done some maintenance on the swap code's usage of device refcounting - Christoph Hellwig has some cleanups for the filemap/directio code - Ryan Roberts provides two patch series which yield some rationalization of the kernel's access to pte entries - use the provided APIs rather than open-coding accesses - Lorenzo Stoakes has some fixes to the interaction between pagecache and directio access to file mappings - John Hubbard has a series of fixes to the MM selftesting code - ZhangPeng continues the folio conversion campaign - Hugh Dickins has been working on the pagetable handling code, mainly with a view to reducing the load on the mmap_lock - Catalin Marinas has reduced the arm64 kmalloc() minimum alignment from 128 to 8 - Domenico Cerasuolo has improved the zswap reclaim mechanism by reorganizing the LRU management - Matthew Wilcox provides some fixups to make gfs2 work better with the buffer_head code - Vishal Moola also has done some folio conversion work - Matthew Wilcox has removed the remnants of the pagevec code - their functionality is migrated over to struct folio_batch * tag 'mm-stable-2023-06-24-19-15' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (380 commits) mm/hugetlb: remove hugetlb_set_page_subpool() mm: nommu: correct the range of mmap_sem_read_lock in task_mem() hugetlb: revert use of page_cache_next_miss() Revert "page cache: fix page_cache_next/prev_miss off by one" mm/vmscan: fix root proactive reclaim unthrottling unbalanced node mm: memcg: rename and document global_reclaim() mm: kill [add|del]_page_to_lru_list() mm: compaction: convert to use a folio in isolate_migratepages_block() mm: zswap: fix double invalidate with exclusive loads mm: remove unnecessary pagevec includes mm: remove references to pagevec mm: rename invalidate_mapping_pagevec to mapping_try_invalidate mm: remove struct pagevec net: convert sunrpc from pagevec to folio_batch i915: convert i915_gpu_error to use a folio_batch pagevec: rename fbatch_count() mm: remove check_move_unevictable_pages() drm: convert drm_gem_put_pages() to use a folio_batch i915: convert shmem_sg_free_table() to use a folio_batch scatterlist: add sg_set_folio() ...
2023-06-26Merge tag 'for-6.5/block-2023-06-23' of git://git.kernel.dk/linuxLinus Torvalds
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 'for-6.5/splice-2023-06-23' of git://git.kernel.dk/linuxLinus Torvalds
Pull splice updates from Jens Axboe: "This kills off ITER_PIPE to avoid a race between truncate, iov_iter_revert() on the pipe and an as-yet incomplete DMA to a bio with unpinned/unref'ed pages from an O_DIRECT splice read. This causes memory corruption. Instead, we either use (a) filemap_splice_read(), which invokes the buffered file reading code and splices from the pagecache into the pipe; (b) copy_splice_read(), which bulk-allocates a buffer, reads into it and then pushes the filled pages into the pipe; or (c) handle it in filesystem-specific code. Summary: - Rename direct_splice_read() to copy_splice_read() - Simplify the calculations for the number of pages to be reclaimed in copy_splice_read() - Turn do_splice_to() into a helper, vfs_splice_read(), so that it can be used by overlayfs and coda to perform the checks on the lower fs - Make vfs_splice_read() jump to copy_splice_read() to handle direct-I/O and DAX - Provide shmem with its own splice_read to handle non-existent pages in the pagecache. We don't want a ->read_folio() as we don't want to populate holes, but filemap_get_pages() requires it - Provide overlayfs with its own splice_read to call down to a lower layer as overlayfs doesn't provide ->read_folio() - Provide coda with its own splice_read to call down to a lower layer as coda doesn't provide ->read_folio() - Direct ->splice_read to copy_splice_read() in tty, procfs, kernfs and random files as they just copy to the output buffer and don't splice pages - Provide wrappers for afs, ceph, ecryptfs, ext4, f2fs, nfs, ntfs3, ocfs2, orangefs, xfs and zonefs to do locking and/or revalidation - Make cifs use filemap_splice_read() - Replace pointers to generic_file_splice_read() with pointers to filemap_splice_read() as DIO and DAX are handled in the caller; filesystems can still provide their own alternate ->splice_read() op - Remove generic_file_splice_read() - Remove ITER_PIPE and its paraphernalia as generic_file_splice_read was the only user" * tag 'for-6.5/splice-2023-06-23' of git://git.kernel.dk/linux: (31 commits) splice: kdoc for filemap_splice_read() and copy_splice_read() iov_iter: Kill ITER_PIPE splice: Remove generic_file_splice_read() splice: Use filemap_splice_read() instead of generic_file_splice_read() cifs: Use filemap_splice_read() trace: Convert trace/seq to use copy_splice_read() zonefs: Provide a splice-read wrapper xfs: Provide a splice-read wrapper orangefs: Provide a splice-read wrapper ocfs2: Provide a splice-read wrapper ntfs3: Provide a splice-read wrapper nfs: Provide a splice-read wrapper f2fs: Provide a splice-read wrapper ext4: Provide a splice-read wrapper ecryptfs: Provide a splice-read wrapper ceph: Provide a splice-read wrapper afs: Provide a splice-read wrapper 9p: Add splice_read wrapper net: Make sock_splice_read() use copy_splice_read() by default tty, proc, kernfs, random: Use copy_splice_read() ...
2023-06-26Merge tag 'v6.5/vfs.file' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs file handling updates from Christian Brauner: "This contains Amir's work to fix a long-standing problem where an unprivileged overlayfs mount can be used to avoid fanotify permission events that were requested for an inode or superblock on the underlying filesystem. Some background about files opened in overlayfs. If a file is opened in overlayfs @file->f_path will refer to a "fake" path. What this means is that while @file->f_inode will refer to inode of the underlying layer, @file->f_path refers to an overlayfs {dentry,vfsmount} pair. The reasons for doing this are out of scope here but it is the reason why the vfs has been providing the open_with_fake_path() helper for overlayfs for very long time now. So nothing new here. This is for sure not very elegant and everyone including the overlayfs maintainers agree. Improving this significantly would involve more fragile and potentially rather invasive changes. In various codepaths access to the path of the underlying filesystem is needed for such hybrid file. The best example is fsnotify where this becomes security relevant. Passing the overlayfs @file->f_path->dentry will cause fsnotify to skip generating fsnotify events registered on the underlying inode or superblock. To fix this we extend the vfs provided open_with_fake_path() concept for overlayfs to create a backing file container that holds the real path and to expose a helper that can be used by relevant callers to get access to the path of the underlying filesystem through the new file_real_path() helper. This pattern is similar to what we do in d_real() and d_real_inode(). The first beneficiary is fsnotify and fixes the security sensitive problem mentioned above. There's a couple of nice cleanups included as well. Over time, the old open_with_fake_path() helper added specifically for overlayfs a long time ago started to get used in other places such as cachefiles. Even though cachefiles have nothing to do with hybrid files. The only reason cachefiles used that concept was that files opened with open_with_fake_path() aren't charged against the caller's open file limit by raising FMODE_NOACCOUNT. It's just mere coincidence that both overlayfs and cachefiles need to ensure to not overcharge the caller for their internal open calls. So this work disentangles FMODE_NOACCOUNT use cases and backing file use-cases by adding the FMODE_BACKING flag which indicates that the file can be used to retrieve the backing file of another filesystem. (Fyi, Jens will be sending you a really nice cleanup from Christoph that gets rid of 3 FMODE_* flags otherwise this would be the last fmode_t bit we'd be using.) So now overlayfs becomes the sole user of the renamed open_with_fake_path() helper which is now named backing_file_open(). For internal kernel users such as cachefiles that are only interested in FMODE_NOACCOUNT but not in FMODE_BACKING we add a new kernel_file_open() helper which opens a file without being charged against the caller's open file limit. All new helpers are properly documented and clearly annotated to mention their special uses. We also rename vfs_tmpfile_open() to kernel_tmpfile_open() to clearly distinguish it from vfs_tmpfile() and align it the other kernel_*() internal helpers" * tag 'v6.5/vfs.file' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: ovl: enable fsnotify events on underlying real files fs: use backing_file container for internal files with "fake" f_path fs: move kmem_cache_zalloc() into alloc_empty_file*() helpers fs: use a helper for opening kernel internal files fs: rename {vfs,kernel}_tmpfile_open()
2023-06-26Merge tag 'v6.5/vfs.misc' of ↵Linus Torvalds
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 ...
2023-06-23Merge mm-hotfixes-stable into mm-stable to pick up depended-upon changes.Andrew Morton
2023-06-20fs: Provide helpers for manipulating sb->s_readonly_remountJan Kara
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>
2023-06-19fs: use backing_file container for internal files with "fake" f_pathAmir Goldstein
Overlayfs uses open_with_fake_path() to allocate internal kernel files, with a "fake" path - whose f_path is not on the same fs as f_inode. Allocate a container struct backing_file for those internal files, that is used to hold the "fake" ovl path along with the real path. backing_file_real_path() can be used to access the stored real path. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Message-Id: <20230615112229.2143178-5-amir73il@gmail.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-06-19fs: use a helper for opening kernel internal filesAmir Goldstein
cachefiles uses kernel_open_tmpfile() to open kernel internal tmpfile without accounting for nr_files. cachefiles uses open_with_fake_path() for the same reason without the need for a fake path. Fork open_with_fake_path() to kernel_file_open() which only does the noaccount part and use it in cachefiles. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Message-Id: <20230615112229.2143178-3-amir73il@gmail.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-06-19fs: rename {vfs,kernel}_tmpfile_open()Amir Goldstein
Overlayfs and cachefiles use vfs_open_tmpfile() to open a tmpfile without accounting for nr_files. Rename this helper to kernel_tmpfile_open() to better reflect this helper is used for kernel internal users. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Message-Id: <20230615112229.2143178-2-amir73il@gmail.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-06-12Remove file->f_op->sendpageDavid Howells
Remove file->f_op->sendpage as splicing to a socket now calls sendmsg rather than sendpage. Signed-off-by: David Howells <dhowells@redhat.com> cc: Jens Axboe <axboe@kernel.dk> cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-12fs: remove the now unused FMODE_* flagsChristoph Hellwig
FMODE_NDELAY, FMODE_EXCL and FMODE_WRITE_IOCTL were only used for block internal purposed and are now entirely unused, so remove them. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Christian Brauner <brauner@kernel.org> Link: https://lore.kernel.org/r/20230608110258.189493-31-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-12fs: remove sb->s_modeChristoph Hellwig
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>
2023-06-12fs: Fix comment typoMao Zhu
Delete duplicated word in comment. Signed-off-by: Mao Zhu <zhumao001@208suo.com> Message-Id: <20230611123314.5282-1-dengshaomin@cdjrlc.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-06-09fs: factor out a direct_write_fallback helperChristoph Hellwig
Add a helper dealing with handling the syncing of a buffered write fallback for direct I/O. Link: https://lkml.kernel.org/r/20230601145904.1385409-10-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andreas Gruenbacher <agruenba@redhat.com> Cc: Anna Schumaker <anna@kernel.org> Cc: Chao Yu <chao@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Hannes Reinecke <hare@suse.de> Cc: Ilya Dryomov <idryomov@gmail.com> Cc: Jaegeuk Kim <jaegeuk@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Xiubo Li <xiubli@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09filemap: add a kiocb_invalidate_post_direct_write helperChristoph Hellwig
Add a helper to invalidate page cache after a dio write. Link: https://lkml.kernel.org/r/20230601145904.1385409-7-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Hannes Reinecke <hare@suse.de> Acked-by: Darrick J. Wong <djwong@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andreas Gruenbacher <agruenba@redhat.com> Cc: Anna Schumaker <anna@kernel.org> Cc: Chao Yu <chao@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Ilya Dryomov <idryomov@gmail.com> Cc: Jaegeuk Kim <jaegeuk@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Miklos Szeredi <mszeredi@redhat.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Xiubo Li <xiubli@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-08splice, net: Add a splice_eof op to file-ops and socket-opsDavid Howells
Add an optional method, ->splice_eof(), to allow splice to indicate the premature termination of a splice to struct file_operations and struct proto_ops. This is called if sendfile() or splice() encounters all of the following conditions inside splice_direct_to_actor(): (1) the user did not set SPLICE_F_MORE (splice only), and (2) an EOF condition occurred (->splice_read() returned 0), and (3) we haven't read enough to fulfill the request (ie. len > 0 still), and (4) we have already spliced at least one byte. A further patch will modify the behaviour of SPLICE_F_MORE to always be passed to the actor if either the user set it or we haven't yet read sufficient data to fulfill the request. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/CAHk-=wh=V579PDYvkpnTobCLGczbgxpMgGmmhqiTyE34Cpi5Gg@mail.gmail.com/ Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jakub Kicinski <kuba@kernel.org> cc: Jens Axboe <axboe@kernel.dk> cc: Christoph Hellwig <hch@lst.de> cc: Al Viro <viro@zeniv.linux.org.uk> cc: Matthew Wilcox <willy@infradead.org> cc: Jan Kara <jack@suse.cz> cc: Jeff Layton <jlayton@kernel.org> cc: David Hildenbrand <david@redhat.com> cc: Christian Brauner <brauner@kernel.org> cc: Chuck Lever <chuck.lever@oracle.com> cc: Boris Pismenny <borisp@nvidia.com> cc: John Fastabend <john.fastabend@gmail.com> cc: linux-mm@kvack.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-08splice, net: Use sendmsg(MSG_SPLICE_PAGES) rather than ->sendpage()David Howells
Replace generic_splice_sendpage() + splice_from_pipe + pipe_to_sendpage() with a net-specific handler, splice_to_socket(), that calls sendmsg() with MSG_SPLICE_PAGES set instead of calling ->sendpage(). MSG_MORE is used to indicate if the sendmsg() is expected to be followed with more data. This allows multiple pipe-buffer pages to be passed in a single call in a BVEC iterator, allowing the processing to be pushed down to a loop in the protocol driver. This helps pave the way for passing multipage folios down too. Protocols that haven't been converted to handle MSG_SPLICE_PAGES yet should just ignore it and do a normal sendmsg() for now - although that may be a bit slower as it may copy everything. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jakub Kicinski <kuba@kernel.org> cc: Jens Axboe <axboe@kernel.dk> cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-05fs: add a method to shut down the file systemChristoph Hellwig
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>
2023-06-05fs.h: Optimize file struct to prevent false sharingchenzhiyin
In the syscall test of UnixBench, performance regression occurred due to false sharing. The lock and atomic members, including file::f_lock, file::f_count and file::f_pos_lock are highly contended and frequently updated in the high-concurrency test scenarios. perf c2c indentified one affected read access, file::f_op. To prevent false sharing, the layout of file struct is changed as following (A) f_lock, f_count and f_pos_lock are put together to share the same cache line. (B) The read mostly members, including f_path, f_inode, f_op are put into a separate cache line. (C) f_mode is put together with f_count, since they are used frequently at the same time. Due to '__randomize_layout' attribute of file struct, the updated layout only can be effective when CONFIG_RANDSTRUCT_NONE is 'y'. The optimization has been validated in the syscall test of UnixBench. performance gain is 30~50%. Furthermore, to confirm the optimization effectiveness on the other codes path, the results of fsdisk, fsbuffer and fstime are also shown. Here are the detailed test results of unixbench. Command: numactl -C 3-18 ./Run -c 16 syscall fsbuffer fstime fsdisk Without Patch ------------------------------------------------------------------------ File Copy 1024 bufsize 2000 maxblocks 875052.1 KBps (30.0 s, 2 samples) File Copy 256 bufsize 500 maxblocks 235484.0 KBps (30.0 s, 2 samples) File Copy 4096 bufsize 8000 maxblocks 2815153.5 KBps (30.0 s, 2 samples) System Call Overhead 5772268.3 lps (10.0 s, 7 samples) System Benchmarks Partial Index BASELINE RESULT INDEX File Copy 1024 bufsize 2000 maxblocks 3960.0 875052.1 2209.7 File Copy 256 bufsize 500 maxblocks 1655.0 235484.0 1422.9 File Copy 4096 bufsize 8000 maxblocks 5800.0 2815153.5 4853.7 System Call Overhead 15000.0 5772268.3 3848.2 ======== System Benchmarks Index Score (Partial Only) 2768.3 With Patch ------------------------------------------------------------------------ File Copy 1024 bufsize 2000 maxblocks 1009977.2 KBps (30.0 s, 2 samples) File Copy 256 bufsize 500 maxblocks 264765.9 KBps (30.0 s, 2 samples) File Copy 4096 bufsize 8000 maxblocks 3052236.0 KBps (30.0 s, 2 samples) System Call Overhead 8237404.4 lps (10.0 s, 7 samples) System Benchmarks Partial Index BASELINE RESULT INDEX File Copy 1024 bufsize 2000 maxblocks 3960.0 1009977.2 2550.4 File Copy 256 bufsize 500 maxblocks 1655.0 264765.9 1599.8 File Copy 4096 bufsize 8000 maxblocks 5800.0 3052236.0 5262.5 System Call Overhead 15000.0 8237404.4 5491.6 ======== System Benchmarks Index Score (Partial Only) 3295.3 Signed-off-by: chenzhiyin <zhiyin.chen@intel.com> Message-Id: <20230601092400.27162-1-zhiyin.chen@intel.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-05-30fs: Drop wait_unfrozen wait queueJan Kara
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>
2023-05-29Revert "module: error out early on concurrent load of the same module file"Linus Torvalds
This reverts commit 9828ed3f695a138f7add89fa2a186ababceb8006. Sadly, it does seem to cause failures to load modules. Johan Hovold reports: "This change breaks module loading during boot on the Lenovo Thinkpad X13s (aarch64). Specifically it results in indefinite probe deferral of the display and USB (ethernet) which makes it a pain to debug. Typing in the dark to acquire some logs reveals that other modules are missing as well" Since this was applied late as a "let's try this", I'm reverting it asap, and we can try to figure out what goes wrong later. The excessive parallel module loading problem is annoying, but not noticeable in normal situations, and this was only meant as an optimistic workaround for a user-space bug. One possible solution may be to do the optimistic exclusive open first, and then use a lock to serialize loading if that fails. Reported-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/lkml/ZHRpH-JXAxA6DnzR@hovoldconsulting.com/ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-05-25module: error out early on concurrent load of the same module fileLinus Torvalds
It turns out that udev under certain circumstances will concurrently try to load the same modules over-and-over excessively. This isn't a kernel bug, but it ends up affecting the kernel, to the point that under certain circumstances we can fail to boot, because the kernel uses a lot of memory to read all the module data all at once. Note that it isn't a memory leak, it's just basically a thundering herd problem happening at bootup with a lot of CPUs, with the worst cases then being pretty bad. Admittedly the worst situations are somewhat contrived: lots and lots of CPUs, not a lot of memory, and KASAN enabled to make it all slower and as such (unintentionally) exacerbate the problem. Luis explains: [1] "My best assessment of the situation is that each CPU in udev ends up triggering a load of duplicate set of modules, not just one, but *a lot*. Not sure what heuristics udev uses to load a set of modules per CPU." Petr Pavlu chimes in: [2] "My understanding is that udev workers are forked. An initial kmod context is created by the main udevd process but no sharing happens after the fork. It means that the mentioned memory pool logic doesn't really kick in. Multiple parallel load requests come from multiple udev workers, for instance, each handling an udev event for one CPU device and making the exactly same requests as all others are doing at the same time. The optimization idea would be to recognize these duplicate requests at the udevd/kmod level and converge them" Note that module loading has tried to mitigate this issue before, see for example commit 064f4536d139 ("module: avoid allocation if module is already present and ready"), which has a few ASCII graphs on memory use due to this same issue. However, while that noticed that the module was already loaded, and exited with an error early before spending any more time on setting up the module, it didn't handle the case of multiple concurrent module loads all being active - but not complete - at the same time. Yes, one of them will eventually win the race and finalize its copy, and the others will then notice that the module already exists and error out, but while this all happens, we have tons of unnecessary concurrent work being done. Again, the real fix is for udev to not do that (maybe it should use threads instead of fork, and have actual shared data structures and not cause duplicate work). That real fix is apparently not trivial. But it turns out that the kernel already has a pretty good model for dealing with concurrent access to the same file: the i_writecount of the inode. In fact, the module loading already indirectly uses 'i_writecount' , because 'kernel_file_read()' will in fact do ret = deny_write_access(file); if (ret) return ret; ... allow_write_access(file); around the read of the file data. We do not allow concurrent writes to the file, and return -ETXTBUSY if the file was open for writing at the same time as the module data is loaded from it. And the solution to the reader concurrency problem is to simply extend this "no concurrent writers" logic to simply be "exclusive access". Note that "exclusive" in this context isn't really some absolute thing: it's only exclusion from writers and from other "special readers" that do this writer denial. So we simply introduce a variation of that "deny_write_access()" logic that not only denies write access, but also requires that this is the _only_ such access that denies write access. Which means that you can't start loading a module that is already being loaded as a module by somebody else, or you will get the same -ETXTBSY error that you would get if there were writers around. [ It also means that you can't try to load a currently executing executable as a module, for the same reason: executables do that same "deny_write_access()" thing, and that's obviously where the whole ETXTBSY logic traditionally came from. This is not a problem for kernel modules, since the set of normal executable files and kernel module files is entirely disjoint. ] This new function is called "exclusive_deny_write_access()", and the implementation is trivial, in that it's just an atomic decrement of i_writecount if it was 0 before. To use that new exclusivity check, all we then do is wrap the module loading with that exclusive_deny_write_access()() / allow_write_access() pair. The actual patch is a bit bigger than that, because we want to surround not just the "load file data" part, but the whole module setup, to get maximum exclusion. So this ends up splitting up "finit_module()" into a few helper functions to make it all very clear and legible. In Luis' test-case (bringing up 255 vcpu's in a virtual machine [3]), the "wasted vmalloc" space (ie module data read into a vmalloc'ed area in order to be loaded as a module, but then discarded because somebody else loaded the same module instead) dropped from 1.8GiB to 474kB. Yes, that's gigabytes to kilobytes. It doesn't drop completely to zero, because even with this change, you can still end up having completely serial pointless module loads, where one udev process has loaded a module fully (and thus the kernel has released that exclusive lock on the module file), and then another udev process tries to load the same module again. So while we cannot fully get rid of the fundamental bug in user space, we _can_ get rid of the excessive concurrent thundering herd effect. A couple of final side notes on this all: - This tweak only affects the "finit_module()" system call, which gives the kernel a file descriptor with the module data. You can also just feed the module data as raw data from user space with "init_module()" (note the lack of 'f' at the beginning), and obviously for that case we do _not_ have any "exclusive read" logic. So if you absolutely want to do things wrong in user space, and try to load the same module multiple times, and error out only later when the kernel ends up saying "you can't load the same module name twice", you can still do that. And in fact, some distros will do exactly that, because they will uncompress the kernel module data in user space before feeding it to the kernel (mainly because they haven't started using the new kernel side decompression yet). So this is not some absolute "you can't do concurrent loads of the same module". It's literally just a very simple heuristic that will catch it early in case you try to load the exact same module file at the same time, and in that case avoid a potentially nasty situation. - There is another user of "deny_write_access()": the verity code that enables fs-verity on a file (the FS_IOC_ENABLE_VERITY ioctl). If you use fs-verity and you care about verifying the kernel modules (which does make sense), you should do it *before* loading said kernel module. That may sound obvious, but now the implementation basically requires it. Because if you try to do it concurrently, the kernel may refuse to load the module file that is being set up by the fs-verity code. - This all will obviously mean that if you insist on loading the same module in parallel, only one module load will succeed, and the others will return with an error. That was true before too, but what is different is that the -ETXTBSY error can be returned *before* the success case of another process fully loading and instantiating the module. Again, that might sound obvious, and it is indeed the whole point of the whole change: we are much quicker to notice the whole "you're already in the process of loading this module". So it's very much intentional, but it does mean that if you just spray the kernel with "finit_module()", and expect that the module is immediately loaded afterwards without checking the return value, you are doing something horribly horribly wrong. I'd like to say that that would never happen, but the whole _reason_ for this commit is that udev is currently doing something horribly horribly wrong, so ... Link: https://lore.kernel.org/all/ZEGopJ8VAYnE7LQ2@bombadil.infradead.org/ [1] Link: https://lore.kernel.org/all/23bd0ce6-ef78-1cd8-1f21-0e706a00424a@suse.com/ [2] Link: https://lore.kernel.org/lkml/ZG%2Fa+nrt4%2FAAUi5z@bombadil.infradead.org/ [3] Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Lucas De Marchi <lucas.demarchi@intel.com> Cc: Petr Pavlu <petr.pavlu@suse.com> Tested-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-05-24splice: Remove generic_file_splice_read()David Howells
Remove generic_file_splice_read() as it has been replaced with calls to filemap_splice_read() and copy_splice_read(). With this, ITER_PIPE is no longer used. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Christian Brauner <brauner@kernel.org> cc: Jens Axboe <axboe@kernel.dk> cc: Steve French <smfrench@gmail.com> cc: Al Viro <viro@zeniv.linux.org.uk> cc: David Hildenbrand <david@redhat.com> cc: John Hubbard <jhubbard@nvidia.com> cc: linux-mm@kvack.org cc: linux-block@vger.kernel.org cc: linux-cifs@vger.kernel.org cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/20230522135018.2742245-30-dhowells@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-05-24splice: Rename direct_splice_read() to copy_splice_read()David Howells
Rename direct_splice_read() to copy_splice_read() to better reflect as to what it does. Suggested-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Christian Brauner <brauner@kernel.org> cc: Steve French <sfrench@samba.org> cc: Jens Axboe <axboe@kernel.dk> cc: Al Viro <viro@zeniv.linux.org.uk> cc: linux-cifs@vger.kernel.org cc: linux-mm@kvack.org cc: linux-block@vger.kernel.org cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/20230522135018.2742245-4-dhowells@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-05-17fs: fix undefined behavior in bit shift for SB_NOUSERHao Ge
Shifting signed 32-bit value by 31 bits is undefined, so changing significant bit to unsigned. It was spotted by UBSAN. So let's just fix this by using the BIT() helper for all SB_* flags. Fixes: e462ec50cb5f ("VFS: Differentiate mount flags (MS_*) from internal superblock flags") Signed-off-by: Hao Ge <gehao@kylinos.cn> Message-Id: <20230424051835.374204-1-gehao@kylinos.cn> [brauner@kernel.org: use BIT() for all SB_* flags] Signed-off-by: Christian Brauner <brauner@kernel.org>