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2024-01-31x86/fred: Disallow the swapgs instruction when FRED is enabledH. Peter Anvin (Intel)
SWAPGS is no longer needed thus NOT allowed with FRED because FRED transitions ensure that an operating system can _always_ operate with its own GS base address: - For events that occur in ring 3, FRED event delivery swaps the GS base address with the IA32_KERNEL_GS_BASE MSR. - ERETU (the FRED transition that returns to ring 3) also swaps the GS base address with the IA32_KERNEL_GS_BASE MSR. And the operating system can still setup the GS segment for a user thread without the need of loading a user thread GS with: - Using LKGS, available with FRED, to modify other attributes of the GS segment without compromising its ability always to operate with its own GS base address. - Accessing the GS segment base address for a user thread as before using RDMSR or WRMSR on the IA32_KERNEL_GS_BASE MSR. Note, LKGS loads the GS base address into the IA32_KERNEL_GS_BASE MSR instead of the GS segment's descriptor cache. As such, the operating system never changes its runtime GS base address. Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com> Signed-off-by: Xin Li <xin3.li@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: Shan Kang <shan.kang@intel.com> Link: https://lore.kernel.org/r/20231205105030.8698-19-xin3.li@intel.com
2024-01-31x86/fred: Update MSR_IA32_FRED_RSP0 during task switchH. Peter Anvin (Intel)
MSR_IA32_FRED_RSP0 is used during ring 3 event delivery, and needs to be updated to point to the top of next task stack during task switch. Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com> Signed-off-by: Xin Li <xin3.li@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: Shan Kang <shan.kang@intel.com> Link: https://lore.kernel.org/r/20231205105030.8698-18-xin3.li@intel.com
2024-01-31x86/fred: Reserve space for the FRED stack frameH. Peter Anvin (Intel)
When using FRED, reserve space at the top of the stack frame, just like i386 does. Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com> Signed-off-by: Xin Li <xin3.li@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: Shan Kang <shan.kang@intel.com> Link: https://lore.kernel.org/r/20231205105030.8698-17-xin3.li@intel.com
2024-01-31x86/fred: Add a new header file for FRED definitionsH. Peter Anvin (Intel)
Add a header file for FRED prototypes and definitions. Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com> Signed-off-by: Xin Li <xin3.li@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: Shan Kang <shan.kang@intel.com> Link: https://lore.kernel.org/r/20231205105030.8698-16-xin3.li@intel.com
2024-01-31x86/ptrace: Add FRED additional information to the pt_regs structureXin Li
FRED defines additional information in the upper 48 bits of cs/ss fields. Therefore add the information definitions into the pt_regs structure. Specifically introduce a new structure fred_ss to denote the FRED flags above SS selector, which avoids FRED_SSX_ macros and makes the code simpler and easier to read. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Originally-by: H. Peter Anvin (Intel) <hpa@zytor.com> Signed-off-by: Xin Li <xin3.li@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: Shan Kang <shan.kang@intel.com> Link: https://lore.kernel.org/r/20231205105030.8698-15-xin3.li@intel.com
2024-01-31x86/ptrace: Cleanup the definition of the pt_regs structureXin Li
struct pt_regs is hard to read because the member or section related comments are not aligned with the members. The 'cs' and 'ss' members of pt_regs are type of 'unsigned long' while in reality they are only 16-bit wide. This works so far as the remaining space is unused, but FRED will use the remaining bits for other purposes. To prepare for FRED: - Cleanup the formatting - Convert 'cs' and 'ss' to u16 and embed them into an union with a u64 - Fixup the related printk() format strings Suggested-by: Thomas Gleixner <tglx@linutronix.de> Originally-by: H. Peter Anvin (Intel) <hpa@zytor.com> Signed-off-by: Xin Li <xin3.li@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: Shan Kang <shan.kang@intel.com> Link: https://lore.kernel.org/r/20231205105030.8698-14-xin3.li@intel.com
2024-01-31x86/cpu: Add MSR numbers for FRED configurationH. Peter Anvin (Intel)
Add MSR numbers for the FRED configuration registers per FRED spec 5.0. Originally-by: Megha Dey <megha.dey@intel.com> Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com> Signed-off-by: Xin Li <xin3.li@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: Shan Kang <shan.kang@intel.com> Link: https://lore.kernel.org/r/20231205105030.8698-13-xin3.li@intel.com
2024-01-31x86/cpu: Add X86_CR4_FRED macroH. Peter Anvin (Intel)
Add X86_CR4_FRED macro for the FRED bit in %cr4. This bit must not be changed after initialization, so add it to the pinned CR4 bits. Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com> Signed-off-by: Xin Li <xin3.li@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: Shan Kang <shan.kang@intel.com> Link: https://lore.kernel.org/r/20231205105030.8698-12-xin3.li@intel.com
2024-01-31x86/objtool: Teach objtool about ERET[US]H. Peter Anvin (Intel)
Update the objtool decoder to know about the ERET[US] instructions (type INSN_CONTEXT_SWITCH). Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com> Signed-off-by: Xin Li <xin3.li@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: Shan Kang <shan.kang@intel.com> Link: https://lore.kernel.org/r/20231205105030.8698-11-xin3.li@intel.com
2024-01-31x86/opcode: Add ERET[US] instructions to the x86 opcode mapH. Peter Anvin (Intel)
ERETU returns from an event handler while making a transition to ring 3, and ERETS returns from an event handler while staying in ring 0. Add instruction opcodes used by ERET[US] to the x86 opcode map; opcode numbers are per FRED spec v5.0. Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com> Signed-off-by: Xin Li <xin3.li@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: Shan Kang <shan.kang@intel.com> Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Link: https://lore.kernel.org/r/20231205105030.8698-10-xin3.li@intel.com
2024-01-30x86/fred: Add a fred= cmdline paramXin Li
Let command line option "fred" accept multiple options to make it easier to tweak its behavior. Currently, two options 'on' and 'off' are allowed, and the default behavior is to disable FRED. To enable FRED, append "fred=on" to the kernel command line. [ bp: Use cpu_feature_enabled(), touch ups. ] Signed-off-by: Xin Li <xin3.li@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: Shan Kang <shan.kang@intel.com> Link: https://lore.kernel.org/r/20231205105030.8698-9-xin3.li@intel.com
2024-01-25x86/fred: Disable FRED support if CONFIG_X86_FRED is disabledH. Peter Anvin (Intel)
Add CONFIG_X86_FRED to <asm/disabled-features.h> to make cpu_feature_enabled() work correctly with FRED. Originally-by: Megha Dey <megha.dey@intel.com> Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com> Signed-off-by: Xin Li <xin3.li@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Shan Kang <shan.kang@intel.com> Link: https://lore.kernel.org/r/20231205105030.8698-8-xin3.li@intel.com
2024-01-25x86/cpufeatures: Add the CPU feature bit for FREDH. Peter Anvin (Intel)
Any FRED enabled CPU will always have the following features as its baseline: 1) LKGS, load attributes of the GS segment but the base address into the IA32_KERNEL_GS_BASE MSR instead of the GS segment’s descriptor cache. 2) WRMSRNS, non-serializing WRMSR for faster MSR writes. Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com> Signed-off-by: Xin Li <xin3.li@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Shan Kang <shan.kang@intel.com> Link: https://lore.kernel.org/r/20231205105030.8698-7-xin3.li@intel.com
2024-01-25x86/fred: Add Kconfig option for FRED (CONFIG_X86_FRED)H. Peter Anvin (Intel)
Add the configuration option CONFIG_X86_FRED to enable FRED. Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com> Signed-off-by: Xin Li <xin3.li@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Shan Kang <shan.kang@intel.com> Link: https://lore.kernel.org/r/20231205105030.8698-6-xin3.li@intel.com
2024-01-25Documentation/x86/64: Add documentation for FREDXin Li
Briefly introduce FRED, and its advantages compared to IDT. Signed-off-by: Xin Li <xin3.li@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com> Link: https://lore.kernel.org/r/20231205105030.8698-5-xin3.li@intel.com
2024-01-25x86/trapnr: Add event type macros to <asm/trapnr.h>Xin Li
Intel VT-x classifies events into eight different types, which is inherited by FRED for event identification. As such, event types becomes a common x86 concept, and should be defined in a common x86 header. Add event type macros to <asm/trapnr.h>, and use them in <asm/vmx.h>. Suggested-by: H. Peter Anvin (Intel) <hpa@zytor.com> Signed-off-by: Xin Li <xin3.li@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Shan Kang <shan.kang@intel.com> Link: https://lore.kernel.org/r/20231205105030.8698-4-xin3.li@intel.com
2024-01-25x86/entry: Remove idtentry_sysvec from entry_{32,64}.SXin Li
idtentry_sysvec is really just DECLARE_IDTENTRY defined in <asm/idtentry.h>, no need to define it separately. Signed-off-by: Xin Li <xin3.li@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Shan Kang <shan.kang@intel.com> Link: https://lore.kernel.org/r/20231205105030.8698-3-xin3.li@intel.com
2024-01-25x86/cpufeatures,opcode,msr: Add the WRMSRNS instruction supportXin Li
WRMSRNS is an instruction that behaves exactly like WRMSR, with the only difference being that it is not a serializing instruction by default. Under certain conditions, WRMSRNS may replace WRMSR to improve performance. Add its CPU feature bit, opcode to the x86 opcode map, and an always inline API __wrmsrns() to embed WRMSRNS into the code. Signed-off-by: Xin Li <xin3.li@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Shan Kang <shan.kang@intel.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Acked-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20231205105030.8698-2-xin3.li@intel.com
2024-01-21Linux 6.8-rc1v6.8-rc1Linus Torvalds
2024-01-21Merge tag 'bcachefs-2024-01-21' of https://evilpiepirate.org/git/bcachefsLinus Torvalds
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 ...
2024-01-21Merge tag 'timers-core-2024-01-21' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 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
2024-01-21Merge tag 'powerpc-6.8-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux 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
2024-01-21bcachefs: Improve inode_to_text()Kent Overstreet
Add line breaks - inode_to_text() is now much easier to read. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21bcachefs: logged_ops_format.hKent Overstreet
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21bcachefs: reflink_format.hKent Overstreet
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21bcachefs; extents_format.hKent Overstreet
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21bcachefs: ec_format.hKent Overstreet
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21bcachefs: subvolume_format.hKent Overstreet
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21bcachefs: snapshot_format.hKent Overstreet
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21bcachefs: alloc_background_format.hKent Overstreet
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21bcachefs: xattr_format.hKent Overstreet
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21bcachefs: dirent_format.hKent Overstreet
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21bcachefs: inode_format.hKent Overstreet
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21bcachefs; quota_format.hKent Overstreet
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21bcachefs: sb-counters_format.hKent Overstreet
bcachefs_format.h has gotten too big; let's do some organizing. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21bcachefs: counters.c -> sb-counters.cKent Overstreet
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21bcachefs: comment bch_subvolumeKent Overstreet
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21bcachefs: bch_snapshot::btimeKent Overstreet
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 <kent.overstreet@linux.dev>
2024-01-21bcachefs: add missing __GFP_NOWARNKent Overstreet
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21bcachefs: opts->compression can now also be applied in the backgroundKent Overstreet
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 <kent.overstreet@linux.dev>
2024-01-21bcachefs: Prep work for variable size btree node buffersKent Overstreet
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: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21bcachefs: grab s_umount only if snapshottingSu Yue
When I was testing mongodb over bcachefs with compression, there is a lockdep warning when snapshotting mongodb data volume. $ cat test.sh prog=bcachefs $prog subvolume create /mnt/data $prog subvolume create /mnt/data/snapshots while true;do $prog subvolume snapshot /mnt/data /mnt/data/snapshots/$(date +%s) sleep 1s done $ cat /etc/mongodb.conf systemLog: destination: file logAppend: true path: /mnt/data/mongod.log storage: dbPath: /mnt/data/ lockdep reports: [ 3437.452330] ====================================================== [ 3437.452750] WARNING: possible circular locking dependency detected [ 3437.453168] 6.7.0-rc7-custom+ #85 Tainted: G E [ 3437.453562] ------------------------------------------------------ [ 3437.453981] bcachefs/35533 is trying to acquire lock: [ 3437.454325] ffffa0a02b2b1418 (sb_writers#10){.+.+}-{0:0}, at: filename_create+0x62/0x190 [ 3437.454875] but task is already holding lock: [ 3437.455268] ffffa0a02b2b10e0 (&type->s_umount_key#48){.+.+}-{3:3}, at: bch2_fs_file_ioctl+0x232/0xc90 [bcachefs] [ 3437.456009] which lock already depends on the new lock. [ 3437.456553] the existing dependency chain (in reverse order) is: [ 3437.457054] -> #3 (&type->s_umount_key#48){.+.+}-{3:3}: [ 3437.457507] down_read+0x3e/0x170 [ 3437.457772] bch2_fs_file_ioctl+0x232/0xc90 [bcachefs] [ 3437.458206] __x64_sys_ioctl+0x93/0xd0 [ 3437.458498] do_syscall_64+0x42/0xf0 [ 3437.458779] entry_SYSCALL_64_after_hwframe+0x6e/0x76 [ 3437.459155] -> #2 (&c->snapshot_create_lock){++++}-{3:3}: [ 3437.459615] down_read+0x3e/0x170 [ 3437.459878] bch2_truncate+0x82/0x110 [bcachefs] [ 3437.460276] bchfs_truncate+0x254/0x3c0 [bcachefs] [ 3437.460686] notify_change+0x1f1/0x4a0 [ 3437.461283] do_truncate+0x7f/0xd0 [ 3437.461555] path_openat+0xa57/0xce0 [ 3437.461836] do_filp_open+0xb4/0x160 [ 3437.462116] do_sys_openat2+0x91/0xc0 [ 3437.462402] __x64_sys_openat+0x53/0xa0 [ 3437.462701] do_syscall_64+0x42/0xf0 [ 3437.462982] entry_SYSCALL_64_after_hwframe+0x6e/0x76 [ 3437.463359] -> #1 (&sb->s_type->i_mutex_key#15){+.+.}-{3:3}: [ 3437.463843] down_write+0x3b/0xc0 [ 3437.464223] bch2_write_iter+0x5b/0xcc0 [bcachefs] [ 3437.464493] vfs_write+0x21b/0x4c0 [ 3437.464653] ksys_write+0x69/0xf0 [ 3437.464839] do_syscall_64+0x42/0xf0 [ 3437.465009] entry_SYSCALL_64_after_hwframe+0x6e/0x76 [ 3437.465231] -> #0 (sb_writers#10){.+.+}-{0:0}: [ 3437.465471] __lock_acquire+0x1455/0x21b0 [ 3437.465656] lock_acquire+0xc6/0x2b0 [ 3437.465822] mnt_want_write+0x46/0x1a0 [ 3437.465996] filename_create+0x62/0x190 [ 3437.466175] user_path_create+0x2d/0x50 [ 3437.466352] bch2_fs_file_ioctl+0x2ec/0xc90 [bcachefs] [ 3437.466617] __x64_sys_ioctl+0x93/0xd0 [ 3437.466791] do_syscall_64+0x42/0xf0 [ 3437.466957] entry_SYSCALL_64_after_hwframe+0x6e/0x76 [ 3437.467180] other info that might help us debug this: [ 3437.469670] 2 locks held by bcachefs/35533: other info that might help us debug this: [ 3437.467507] Chain exists of: sb_writers#10 --> &c->snapshot_create_lock --> &type->s_umount_key#48 [ 3437.467979] Possible unsafe locking scenario: [ 3437.468223] CPU0 CPU1 [ 3437.468405] ---- ---- [ 3437.468585] rlock(&type->s_umount_key#48); [ 3437.468758] lock(&c->snapshot_create_lock); [ 3437.469030] lock(&type->s_umount_key#48); [ 3437.469291] rlock(sb_writers#10); [ 3437.469434] *** DEADLOCK *** [ 3437.469670] 2 locks held by bcachefs/35533: [ 3437.469838] #0: ffffa0a02ce00a88 (&c->snapshot_create_lock){++++}-{3:3}, at: bch2_fs_file_ioctl+0x1e3/0xc90 [bcachefs] [ 3437.470294] #1: ffffa0a02b2b10e0 (&type->s_umount_key#48){.+.+}-{3:3}, at: bch2_fs_file_ioctl+0x232/0xc90 [bcachefs] [ 3437.470744] stack backtrace: [ 3437.470922] CPU: 7 PID: 35533 Comm: bcachefs Kdump: loaded Tainted: G E 6.7.0-rc7-custom+ #85 [ 3437.471313] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014 [ 3437.471694] Call Trace: [ 3437.471795] <TASK> [ 3437.471884] dump_stack_lvl+0x57/0x90 [ 3437.472035] check_noncircular+0x132/0x150 [ 3437.472202] __lock_acquire+0x1455/0x21b0 [ 3437.472369] lock_acquire+0xc6/0x2b0 [ 3437.472518] ? filename_create+0x62/0x190 [ 3437.472683] ? lock_is_held_type+0x97/0x110 [ 3437.472856] mnt_want_write+0x46/0x1a0 [ 3437.473025] ? filename_create+0x62/0x190 [ 3437.473204] filename_create+0x62/0x190 [ 3437.473380] user_path_create+0x2d/0x50 [ 3437.473555] bch2_fs_file_ioctl+0x2ec/0xc90 [bcachefs] [ 3437.473819] ? lock_acquire+0xc6/0x2b0 [ 3437.474002] ? __fget_files+0x2a/0x190 [ 3437.474195] ? __fget_files+0xbc/0x190 [ 3437.474380] ? lock_release+0xc5/0x270 [ 3437.474567] ? __x64_sys_ioctl+0x93/0xd0 [ 3437.474764] ? __pfx_bch2_fs_file_ioctl+0x10/0x10 [bcachefs] [ 3437.475090] __x64_sys_ioctl+0x93/0xd0 [ 3437.475277] do_syscall_64+0x42/0xf0 [ 3437.475454] entry_SYSCALL_64_after_hwframe+0x6e/0x76 [ 3437.475691] RIP: 0033:0x7f2743c313af ====================================================== In __bch2_ioctl_subvolume_create(), we grab s_umount unconditionally and unlock it at the end of the function. There is a comment "why do we need this lock?" about the lock coming from commit 42d237320e98 ("bcachefs: Snapshot creation, deletion") The reason is that __bch2_ioctl_subvolume_create() calls sync_inodes_sb() which enforce locked s_umount to writeback all dirty nodes before doing snapshot works. Fix it by read locking s_umount for snapshotting only and unlocking s_umount after sync_inodes_sb(). Signed-off-by: Su Yue <glass.su@suse.com> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21bcachefs: kvfree bch_fs::snapshots in bch2_fs_snapshots_exitSu Yue
bch_fs::snapshots is allocated by kvzalloc in __snapshot_t_mut. It should be freed by kvfree not kfree. Or umount will triger: [ 406.829178 ] BUG: unable to handle page fault for address: ffffe7b487148008 [ 406.830676 ] #PF: supervisor read access in kernel mode [ 406.831643 ] #PF: error_code(0x0000) - not-present page [ 406.832487 ] PGD 0 P4D 0 [ 406.832898 ] Oops: 0000 [#1] PREEMPT SMP PTI [ 406.833512 ] CPU: 2 PID: 1754 Comm: umount Kdump: loaded Tainted: G OE 6.7.0-rc7-custom+ #90 [ 406.834746 ] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014 [ 406.835796 ] RIP: 0010:kfree+0x62/0x140 [ 406.836197 ] Code: 80 48 01 d8 0f 82 e9 00 00 00 48 c7 c2 00 00 00 80 48 2b 15 78 9f 1f 01 48 01 d0 48 c1 e8 0c 48 c1 e0 06 48 03 05 56 9f 1f 01 <48> 8b 50 08 48 89 c7 f6 c2 01 0f 85 b0 00 00 00 66 90 48 8b 07 f6 [ 406.837810 ] RSP: 0018:ffffb9d641607e48 EFLAGS: 00010286 [ 406.838213 ] RAX: ffffe7b487148000 RBX: ffffb9d645200000 RCX: ffffb9d641607dc4 [ 406.838738 ] RDX: 000065bb00000000 RSI: ffffffffc0d88b84 RDI: ffffb9d645200000 [ 406.839217 ] RBP: ffff9a4625d00068 R08: 0000000000000001 R09: 0000000000000001 [ 406.839650 ] R10: 0000000000000001 R11: 000000000000001f R12: ffff9a4625d4da80 [ 406.840055 ] R13: ffff9a4625d00000 R14: ffffffffc0e2eb20 R15: 0000000000000000 [ 406.840451 ] FS: 00007f0a264ffb80(0000) GS:ffff9a4e2d500000(0000) knlGS:0000000000000000 [ 406.840851 ] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 406.841125 ] CR2: ffffe7b487148008 CR3: 000000018c4d2000 CR4: 00000000000006f0 [ 406.841464 ] Call Trace: [ 406.841583 ] <TASK> [ 406.841682 ] ? __die+0x1f/0x70 [ 406.841828 ] ? page_fault_oops+0x159/0x470 [ 406.842014 ] ? fixup_exception+0x22/0x310 [ 406.842198 ] ? exc_page_fault+0x1ed/0x200 [ 406.842382 ] ? asm_exc_page_fault+0x22/0x30 [ 406.842574 ] ? bch2_fs_release+0x54/0x280 [bcachefs] [ 406.842842 ] ? kfree+0x62/0x140 [ 406.842988 ] ? kfree+0x104/0x140 [ 406.843138 ] bch2_fs_release+0x54/0x280 [bcachefs] [ 406.843390 ] kobject_put+0xb7/0x170 [ 406.843552 ] deactivate_locked_super+0x2f/0xa0 [ 406.843756 ] cleanup_mnt+0xba/0x150 [ 406.843917 ] task_work_run+0x59/0xa0 [ 406.844083 ] exit_to_user_mode_prepare+0x197/0x1a0 [ 406.844302 ] syscall_exit_to_user_mode+0x16/0x40 [ 406.844510 ] do_syscall_64+0x4e/0xf0 [ 406.844675 ] entry_SYSCALL_64_after_hwframe+0x6e/0x76 [ 406.844907 ] RIP: 0033:0x7f0a2664e4fb Signed-off-by: Su Yue <glass.su@suse.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21bcachefs: bios must be 512 byte alginedKent Overstreet
Fixes: 023f9ac9f70f bcachefs: Delete dio read alignment check Reported-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21bcachefs: remove redundant variable tmpColin Ian King
The variable tmp is being assigned a value but it isn't being read afterwards. The assignment is redundant and so tmp can be removed. Cleans up clang scan build warning: warning: Although the value stored to 'ret' is used in the enclosing expression, the value is never actually read from 'ret' [deadcode.DeadStores] Signed-off-by: Colin Ian King <colin.i.king@gmail.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21bcachefs: Improve trace_trans_restart_relockKent Overstreet
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21bcachefs: Fix excess transaction restarts in __bchfs_fallocate()Kent Overstreet
drop_locks_do() should not be used in a fastpath without first trying the do in nonblocking mode - the unlock and relock will cause excessive transaction restarts and potentially livelocking with other threads that are contending for the same locks. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21bcachefs: extents_to_bp_stateKent Overstreet
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21bcachefs: bkey_and_val_eq()Kent Overstreet
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21bcachefs: Better journal tracepointsKent Overstreet
Factor out bch2_journal_bufs_to_text(), and use it in the journal_entry_full() tracepoint; when we can't get a journal reservation we need to know the outstanding journal entry sizes to know if the problem is due to excessive flushing. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>