- Jan 26, 2024
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Baokun Li authored
In [Link] Linus mentions that acquire/release makes it clear which _particular_ memory accesses are the ordered ones, and it's unlikely to make any performance difference, so it's much better to pair up the release->acquire ordering than have a "wmb->rmb" ordering. ========================================================= update pagecache folio_mark_uptodate(folio) smp_wmb() set_bit PG_uptodate === ↑↑↑ STLR ↑↑↑ === smp_store_release(&inode->i_size, i_size) folio_test_uptodate(folio) test_bit PG_uptodate smp_rmb() === ↓↓↓ LDAR ↓↓↓ === smp_load_acquire(&inode->i_size) copy_page_to_iter() ========================================================= Calling smp_store_release() in i_size_write() ensures that the data in the page and the PG_uptodate bit are updated before the isize is updated, and calling smp_load_acquire() in i_size_read ensures that it will not read a newer isize than the data in the page. Therefore, this avoids buffered read-write inconsistencies caused by Load-Load reordering. Link: https://lore.kernel.org/r/CAHk-=wifOnmeJq+sn+2s-P46zw0SFEbw9BSCGgp2c5fYPtRPGw@mail.gmail.com/ Suggested-by:
Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
Baokun Li <libaokun1@huawei.com> Link: https://lore.kernel.org/r/20240124142857.4146716-2-libaokun1@huawei.com Signed-off-by:
Christian Brauner <brauner@kernel.org>
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Jens Axboe authored
Rewrite the alignment checking iterators for iovec and bvec to be easier to read, and also significantly more compact in terms of generated code. This saves 270 bytes of text on x86-64 for me (with clang-18) and 224 bytes on arm64 (with gcc-13). In profiles, also saves a bit of time as well for the same workload: 0.81% -0.18% [kernel.vmlinux] [k] iov_iter_aligned_bvec 0.48% -0.09% [kernel.vmlinux] [k] iov_iter_is_aligned which is a nice side benefit as well. Signed-off-by:Jens Axboe <axboe@kernel.dk> Link: https://lore.kernel.org/r/544b31f7-6d4b-42f5-a544-1420501f081f@kernel.dk Reviewed-by:
Keith Busch <kbusch@kernel.org> Signed-off-by:
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- Jan 24, 2024
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ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/cel/linuxChristian Brauner authored
Merge exportfs fixes from Chuck Lever: * tag 'exportfs-6.9' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/cel/linux: fs: Create a generic is_dot_dotdot() utility exportfs: fix the fallback implementation of the get_name export operation Link: https://lore.kernel.org/r/BDC2AEB4-7085-4A7C-8DE8-A659FE1DBA6A@oracle.com Signed-off-by:
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Wen Yang authored
When printing eventfd->count, interrupts will be disabled and a spinlock will be obtained, competing with eventfd_write(). By moving the "eventfd-count" print out of the spinlock and merging multiple seq_printf() into one, it could improve a bit, just like timerfd_show(). Signed-off-by:
Wen Yang <wenyang.linux@foxmail.com> Link: https://lore.kernel.org/r/tencent_B0B3D2BD9861FD009E03AB18A81783322709@qq.com Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Jens Axboe <axboe@kernel.dk> Cc: Christian Brauner <brauner@kernel.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Dylan Yudaken <dylany@fb.com> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Matthew Wilcox <willy@infradead.org> Cc: Eric Biggers <ebiggers@google.com> Cc: <linux-fsdevel@vger.kernel.org> Cc: <linux-kernel@vger.kernel.org> Signed-off-by:
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- Jan 23, 2024
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Chuck Lever authored
De-duplicate the same functionality in several places by hoisting the is_dot_dotdot() utility function into linux/fs.h. Suggested-by:
Amir Goldstein <amir73il@gmail.com> Reviewed-by:
Jeff Layton <jlayton@kernel.org> Reviewed-by:
Chuck Lever <chuck.lever@oracle.com>
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Trond Myklebust authored
The fallback implementation for the get_name export operation uses readdir() to try to match the inode number to a filename. That filename is then used together with lookup_one() to produce a dentry. A problem arises when we match the '.' or '..' entries, since that causes lookup_one() to fail. This has sometimes been seen to occur for filesystems that violate POSIX requirements around uniqueness of inode numbers, something that is common for snapshot directories. This patch just ensures that we skip '.' and '..' rather than allowing a match. Signed-off-by:
Trond Myklebust <trond.myklebust@hammerspace.com> Reviewed-by:
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- Jan 22, 2024
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Nikita Zhandarovich authored
syzbot identified a kernel information leak vulnerability in do_sys_name_to_handle() and issued the following report [1]. [1] "BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:114 [inline] BUG: KMSAN: kernel-infoleak in _copy_to_user+0xbc/0x100 lib/usercopy.c:40 instrument_copy_to_user include/linux/instrumented.h:114 [inline] _copy_to_user+0xbc/0x100 lib/usercopy.c:40 copy_to_user include/linux/uaccess.h:191 [inline] do_sys_name_to_handle fs/fhandle.c:73 [inline] __do_sys_name_to_handle_at fs/fhandle.c:112 [inline] __se_sys_name_to_handle_at+0x949/0xb10 fs/fhandle.c:94 __x64_sys_name_to_handle_at+0xe4/0x140 fs/fhandle.c:94 ... Uninit was created at: slab_post_alloc_hook+0x129/0xa70 mm/slab.h:768 slab_alloc_node mm/slub.c:3478 [inline] __kmem_cache_alloc_node+0x5c9/0x970 mm/slub.c:3517 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc+0x121/0x3c0 mm/slab_common.c:1020 kmalloc include/linux/slab.h:604 [inline] do_sys_name_to_handle fs/fhandle.c:39 [inline] __do_sys_name_to_handle_at fs/fhandle.c:112 [inline] __se_sys_name_to_handle_at+0x441/0xb10 fs/fhandle.c:94 __x64_sys_name_to_handle_at+0xe4/0x140 fs/fhandle.c:94 ... Bytes 18-19 of 20 are uninitialized Memory access of size 20 starts at ffff888128a46380 Data copied to user address 0000000020000240" Per Chuck Lever's suggestion, use kzalloc() instead of kmalloc() to solve the problem. Fixes: 990d6c2d ("vfs: Add name to file handle conversion support") Suggested-by:
<syzbot+09b349b3066c2e0b1e96@syzkaller.appspotmail.com> Signed-off-by:
Nikita Zhandarovich <n.zhandarovich@fintech.ru> Link: https://lore.kernel.org/r/20240119153906.4367-1-n.zhandarovich@fintech.ru Reviewed-by:
Jan Kara <jack@suse.cz> Signed-off-by:
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Kemeng Shi authored
The wb_wakeup_delayed is only used in fs-writeback.c. Move it to fs-writeback.c after defination of wb_wakeup and make it static. Signed-off-by:
Kemeng Shi <shikemeng@huaweicloud.com> Link: https://lore.kernel.org/r/20240118203339.764093-1-shikemeng@huaweicloud.com Reviewed-by:
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Rich Felker authored
The pwrite function, originally defined by POSIX (thus the "p"), is defined to ignore O_APPEND and write at the offset passed as its argument. However, historically Linux honored O_APPEND if set and ignored the offset. This cannot be changed due to stability policy, but is documented in the man page as a bug. Now that there's a pwritev2 syscall providing a superset of the pwrite functionality that has a flags argument, the conforming behavior can be offered to userspace via a new flag. Since pwritev2 checks flag validity (in kiocb_set_rw_flags) and reports unknown ones with EOPNOTSUPP, callers will not get wrong behavior on old kernels that don't support the new flag; the error is reported and the caller can decide how to handle it. Signed-off-by:
Rich Felker <dalias@libc.org> Link: https://lore.kernel.org/r/20200831153207.GO3265@brightrain.aerifal.cx Reviewed-by:
Jann Horn <jannh@google.com> Signed-off-by:
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Hu.Yadi authored
Replace SYS_<syscall> with __NR_<syscall>. Using the __NR_<syscall> notation, provided by UAPI, is useful to build tests on systems without the SYS_<syscall> definitions. Replace SYS_move_mount with __NR_move_mount Similar changes: commit 87129ef1 ("selftests/landlock: Make tests build with old libc") Acked-by:
Mickaël Salaün <mic@digikod.net> Signed-off-by:
Hu.Yadi <hu.yadi@h3c.com> Link: https://lore.kernel.org/r/20240111113229.10820-1-hu.yadi@h3c.com Reviewed-by:
Berlin <berlin@h3c.com> Suggested-by:
Jiao <jiaoxupo@h3c.com> Signed-off-by:
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Hu Yadi authored
One build issue comes up due to both mount.h included dev_in_maps.c In file included from dev_in_maps.c:10: /usr/include/sys/mount.h:35:3: error: expected identifier before numeric constant 35 | MS_RDONLY = 1, /* Mount read-only. */ | ^~~~~~~~~ In file included from dev_in_maps.c:13: Remove one of them to solve conflict, another error comes up: dev_in_maps.c:170:6: error: implicit declaration of function ‘mount’ [-Werror=implicit-function-declaration] 170 | if (mount(NULL, "/", NULL, MS_SLAVE | MS_REC, NULL) == -1) { | ^~~~~ cc1: all warnings being treated as errors and then , add sys_mount definition to solve it After both above, dev_in_maps.c can be built correctly on my mache(gcc 10.2,glibc-2.32,kernel-5.10) Signed-off-by:Andrei Vagin <avagin@google.com> Signed-off-by:
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Baolin Wang authored
We met a kernel crash issue when running stress-ng testing, and the system crashes when printing the dentry name in dump_mapping(). Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 pc : dentry_name+0xd8/0x224 lr : pointer+0x22c/0x370 sp : ffff800025f134c0 ...... Call trace: dentry_name+0xd8/0x224 pointer+0x22c/0x370 vsnprintf+0x1ec/0x730 vscnprintf+0x2c/0x60 vprintk_store+0x70/0x234 vprintk_emit+0xe0/0x24c vprintk_default+0x3c/0x44 vprintk_func+0x84/0x2d0 printk+0x64/0x88 __dump_page+0x52c/0x530 dump_page+0x14/0x20 set_migratetype_isolate+0x110/0x224 start_isolate_page_range+0xc4/0x20c offline_pages+0x124/0x474 memory_block_offline+0x44/0xf4 memory_subsys_offline+0x3c/0x70 device_offline+0xf0/0x120 ...... The root cause is that, one thread is doing page migration, and we will use the target page's ->mapping field to save 'anon_vma' pointer between page unmap and page move, and now the target page is locked and refcount is 1. Currently, there is another stress-ng thread performing memory hotplug, attempting to offline the target page that is being migrated. It discovers that the refcount of this target page is 1, preventing the offline operation, thus proceeding to dump the page. However, page_mapping() of the target page may return an incorrect file mapping to crash the system in dump_mapping(), since the target page->mapping only saves 'anon_vma' pointer without setting PAGE_MAPPING_ANON flag. The page migration issue has been fixed by commit d1adb25d ("mm: migrate: fix getting incorrect page mapping during page migration"). In addition, Matthew suggested we should also improve dump_mapping()'s robustness to resilient against the kernel crash [1]. With checking the 'dentry.parent' and 'dentry.d_name.name' used by dentry_name(), I can see dump_mapping() will output the invalid dentry instead of crashing the system when this issue is reproduced again. [12211.189128] page:fffff7de047741c0 refcount:1 mapcount:0 mapping:ffff989117f55ea0 index:0x1 pfn:0x211dd07 [12211.189144] aops:0x0 ino:1 invalid dentry:74786574206e6870 [12211.189148] flags: 0x57ffffc0000001(locked|node=1|zone=2|lastcpupid=0x1fffff) [12211.189150] page_type: 0xffffffff() [12211.189153] raw: 0057ffffc0000001 0000000000000000 dead000000000122 ffff989117f55ea0 [12211.189154] raw: 0000000000000001 0000000000000001 00000001ffffffff 0000000000000000 [12211.189155] page dumped because: unmovable page [1] https://lore.kernel.org/all/ZXxn%2F0oixJxxAnpF@casper.infradead.org/ Suggested-by:
Matthew Wilcox <willy@infradead.org> Signed-off-by:
Baolin Wang <baolin.wang@linux.alibaba.com> Link: https://lore.kernel.org/r/937ab1f87328516821d39be672b6bc18861d9d3e.1705391420.git.baolin.wang@linux.alibaba.com Signed-off-by:
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Kunwu Chan authored
Use the new KMEM_CACHE() macro instead of direct kmem_cache_create to simplify the creation of SLAB caches. Signed-off-by:
Kunwu Chan <chentao@kylinos.cn> Link: https://lore.kernel.org/r/20240116091137.92375-1-chentao@kylinos.cn Reviewed-by:
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Wen Yang authored
introduce a BUILD_BUG_ON to check that the EFD_SEMAPHORE is equal to its definition in the uapi file, just like EFD_CLOEXEC and EFD_NONBLOCK. Signed-off-by:
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David Disseldorp authored
If initrd_start cpio extraction fails, CONFIG_BLK_DEV_RAM triggers fallback to initrd.image handling via populate_initrd_image(). The populate_initrd_image() call follows successful extraction of any built-in cpio archive at __initramfs_start, but currently performs built-in archive extraction a second time. Prior to commit b2a74d5f ("initramfs: remove clean_rootfs"), the second built-in initramfs unpack call was used to repopulate entries removed by clean_rootfs(), but it's no longer necessary now the contents of the previous extraction are retained. Signed-off-by:
David Disseldorp <ddiss@suse.de> Link: https://lore.kernel.org/r/20240111062240.9362-1-ddiss@suse.de Reviewed-by:
Christoph Hellwig <hch@lst.de> Signed-off-by:
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Andreas Gruenbacher authored
This comment refers to function mark_buffer_inode_dirty(), but the function is actually called mark_buffer_dirty_inode(), so fix the comment. Signed-off-by:
Andreas Gruenbacher <agruenba@redhat.com> Link: https://lore.kernel.org/r/20240108172040.178173-1-agruenba@redhat.com Reviewed-by:
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Jay authored
The word "filesytem" should be "filesystem" Signed-off-by:
Jay <merqqcury@gmail.com> Link: https://lore.kernel.org/r/20240109072927.29626-1-merqqcury@gmail.com Signed-off-by:
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Linus Torvalds authored
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https://evilpiepirate.org/git/bcachefsLinus Torvalds authored
Pull more bcachefs updates from Kent Overstreet: "Some fixes, Some refactoring, some minor features: - Assorted prep work for disk space accounting rewrite - BTREE_TRIGGER_ATOMIC: after combining our trigger callbacks, this makes our trigger context more explicit - A few fixes to avoid excessive transaction restarts on multithreaded workloads: fstests (in addition to ktest tests) are now checking slowpath counters, and that's shaking out a few bugs - Assorted tracepoint improvements - Starting to break up bcachefs_format.h and move on disk types so they're with the code they belong to; this will make room to start documenting the on disk format better. - A few minor fixes" * tag 'bcachefs-2024-01-21' of https://evilpiepirate.org/git/bcachefs: (46 commits) bcachefs: Improve inode_to_text() bcachefs: logged_ops_format.h bcachefs: reflink_format.h bcachefs; extents_format.h bcachefs: ec_format.h bcachefs: subvolume_format.h bcachefs: snapshot_format.h bcachefs: alloc_background_format.h bcachefs: xattr_format.h bcachefs: dirent_format.h bcachefs: inode_format.h bcachefs; quota_format.h bcachefs: sb-counters_format.h bcachefs: counters.c -> sb-counters.c bcachefs: comment bch_subvolume bcachefs: bch_snapshot::btime bcachefs: add missing __GFP_NOWARN bcachefs: opts->compression can now also be applied in the background bcachefs: Prep work for variable size btree node buffers bcachefs: grab s_umount only if snapshotting ... -
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull timer updates from Thomas Gleixner: "Updates for time and clocksources: - A fix for the idle and iowait time accounting vs CPU hotplug. The time is reset on CPU hotplug which makes the accumulated systemwide time jump backwards. - Assorted fixes and improvements for clocksource/event drivers" * tag 'timers-core-2024-01-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: tick-sched: Fix idle and iowait sleeptime accounting vs CPU hotplug clocksource/drivers/ep93xx: Fix error handling during probe clocksource/drivers/cadence-ttc: Fix some kernel-doc warnings clocksource/drivers/timer-ti-dm: Fix make W=n kerneldoc warnings clocksource/timer-riscv: Add riscv_clock_shutdown callback dt-bindings: timer: Add StarFive JH8100 clint dt-bindings: timer: thead,c900-aclint-mtimer: separate mtime and mtimecmp regs -
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linuxLinus Torvalds authored
Pull powerpc fixes from Aneesh Kumar: - Increase default stack size to 32KB for Book3S Thanks to Michael Ellerman. * tag 'powerpc-6.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/64s: Increase default stack size to 32KB
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Kent Overstreet authored
Add line breaks - inode_to_text() is now much easier to read. Signed-off-by:Kent Overstreet <kent.overstreet@linux.dev>
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Kent Overstreet authored
Signed-off-by: -
Kent Overstreet authored
Signed-off-by: -
Kent Overstreet authored
Signed-off-by: -
Kent Overstreet authored
Signed-off-by: -
Kent Overstreet authored
Signed-off-by: -
Kent Overstreet authored
Signed-off-by: -
Kent Overstreet authored
Signed-off-by: -
Kent Overstreet authored
Signed-off-by: -
Kent Overstreet authored
Signed-off-by: -
Kent Overstreet authored
Signed-off-by: -
Kent Overstreet authored
Signed-off-by: -
Kent Overstreet authored
bcachefs_format.h has gotten too big; let's do some organizing. Signed-off-by: -
Kent Overstreet authored
Signed-off-by: -
Kent Overstreet authored
Signed-off-by: -
Kent Overstreet authored
Add a field to bch_snapshot for creation time; this will be important when we start exposing the snapshot tree to userspace. Signed-off-by: -
Kent Overstreet authored
Signed-off-by: -
Kent Overstreet authored
The "apply this compression method in the background" paths now use the compression option if background_compression is not set; this means that setting or changing the compression option will cause existing data to be compressed accordingly in the background. Signed-off-by: -
Kent Overstreet authored
bcachefs btree nodes are big - typically 256k - and btree roots are pinned in memory. As we're now up to 18 btrees, we now have significant memory overhead in mostly empty btree roots. And in the future we're going to start enforcing that certain btree node boundaries exist, to solve lock contention issues - analagous to XFS's AGIs. Thus, we need to start allocating smaller btree node buffers when we can. This patch changes code that refers to the filesystem constant c->opts.btree_node_size to refer to the btree node buffer size - btree_buf_bytes() - where appropriate. Signed-off-by:
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